Department of Applied Chemistry and Chemical Engineering
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Item Modification of cotton fabric with Natural antimicrobial agents for Ecofriendly protective textiles(University of Rajshahi, Rajshahi, 221) Saha, Joykrisna; Mondal, Md. Ibrahim H.; Sheikh, Md. Rezaul KarimIn recent time‘s health and hygiene issues have achieved the greatest attention among the awareness people of all over the world. Health and hygiene are the primary obligations for human beings to live comfortably and work with maximum safety. The aim of the present work is to develop environment friendly protective textiles using Aloe vera, chitosan and sericin on bleached cotton woven fabrics for medical and health care apparel against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria. Aloe vera, chitosan and silk sericin are natural biopolymer which exhibited different significant biological property. Aloe vera extract was prepared from Aloe vera leaves through methanol solvent using a rotary evaporator. Chitosan was made from shrimp shell through several steps of alkali and acid treatments and silk sericin powder was obtained from a boiled water solution of silk cocoons through ethanol precipitation. Extracted Aloe vera, chitosan and sericin powder were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Energy dispersive spectroscopy (EDS), UV-visible spectrophotometer, X-ray diffraction (XRD). Solubility, degree of deacetylation, antibacterial activity, antioxidant property and UV protection factor were also analyzed. Both quantitative and qualitative methods were used to assay the antimicrobial activity. The antioxidant activity was evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Chitosan was found to have a 90% degree of deacetylation.-----Item The adsorption of stearic acid and pyridine and determination of specific surface area of powdered solids(University of Rajshahi, 1979) Ghosh, Ashim Kumar; Rahman, M.A.The Bet Gas Adsorption, Flow Micro-Calorimetric And Adsorption From Solution Methods For The Determination Of Surface Areas Of Cupric Oxide, Ferric Oxide And Alumina Pow- Ders Have Been Compared With A View To Examine The Validity Of The Method Of Adsorption From Solution As A Standard. Nitrogen Gas Has Been Chosen For The Bet Method Whereas Stearic Acid, A Commonly Employed Solute, Has Been Used For The Flow Micro-Calorimetric And Adsorption From Solution Measurements. It Has Been Found That Adsorption Of Nitrogen Gas On All The Adsorbents Is Physical In Nature But Stearic Acid Employed In The Flow Micro-Calorimetric And Adsorption From Solution Methods Gives Mostly Chemisorption Of The Mole- Cules On The Adsorbent Powders. Surface Areas Determined By The Flow Micro-Calorimetric And Adsorption From Solutions Have Been Found To Be Identical For The Respective Powders. Despite The Difference In Mechanism Of Adsorption Of Nitro- Gen And Stearic Acid Molecules The Flow Micro-Calorimetric And Adsorption From Solution Surface Areas Agree Fairly Well With The Bet Nitrogen Gas Adsorption Surface Areas Of The Adsorbents If It Is Assumed That The Area Occupied Per Mole- Cule Of Stearic Acid To Be Of The Order Of 60-70 2. The Orientation Of Stearic Acid Molecules On The Solid/Liquid Interface, Therefore, Take Place So That Acid Molecules Lie Neither Completely Perpendicular Nor Completely Parallel To neither completely perpendicular nor completely parallel to the surface. possible orientations of the stearic acid chain on the surface are envisaged. Correspondence of the surface areas of the adsor-bents using nitrogen gas and stearic acid solution reveal that the total sites of the adsorbents are independent of the nature of the solute molecules. To study this hypothesis further pyridine, an orga- nic base, has been chosen as solute and its adsorption on the same adsorbents have been studied. the surface areas obtained by adsorption of pyridine from solution have been found to be identical to the respective areas obtained by bet method and stearic acid adsorption if it is considered that the area occupied by one molecule of pyridine to be around 24.7 2,the molecular area of pyridine. Adsorption of stearic acid on magnesium oxide and silica gel powders gave surface areas to be 90 and 370 m2/g respectively considering area occupied per molecule of stea- ric acid to be 63.3 and 67.5 2. these value agree fairly well with the values quoted in literature. surface areas of these two powders determined by adsorption of pyridine agree fairly well with the above mentioned value if it is consi- dered that one molecule of pyridine occupies 24.8 2. It may, therefore, be concluded that with the appro- priate values of areas occupied per molecule of solute method adsorption of stearic acid and pyridine may be taken as standard for the determination of surface area of the adsor- bents considered.Item Processing of Ilmenite by Various Roasting, Leaching and Solvent Extraction Processes(University of Rajshahi, 1992) Habib, Md. Ahsan; Islam, M.F.; Biswas, R.K.The processing of ilmenite (TiFe03) to produce pigment grade while Ti02 and black Fe2 03 by various thermal, leaching and liquid-liquid extraction with subsequent precipilation treatments has been investigated. Thermal pre-treatment of ilmente with LPG-pyrolysed product at 7oo·c for 75 min- at LPG-flow rat.e 230 cm3 min-1 peoduces a roasted mass which gives ~83.5% titanium and 80% iron dissolutions in 6 g eq dm-3 hydrochloric acid at its boiling point, solid to liquid phase ratio (S/L) of 0.02 kg dm-3 and at pulp agitaLion speed of 350 rpm for 5h. Under similar condition sulphuric acid diss0lves only 66% titanium o.nd 73% iron. X-ray powder diffraction patterns (XRD) of ilmenite and roasted muss suggest the chemicaJ/physical change occurring during roasting. A different method of thermal treatment of ilmenite is to react with the reformed products of the LPG-H20 vapour mixture in presence of nickel catalyst. The optimum conditions for roasting are 700 ° C temperature, 110 cm3 min-1 LPG-flow rate, 0.041 atm. water vapour pressure and 40 min time. XRD shows the changes but the composition of roasted mass can not be identified. Hydrochloric acid gives better leaching results than sulphuric acid of identical concentration. About 93% titanium and 95% iron are dissolv,•d in (i g eq dm-3 hydrochloric acid at its boiling point, S/JJ ratio of 0.02 kg dm-3 and at 350 rpm for 4h. Under simHar condition, only ~46% titanium and ~64% iron are dissolved in sulphuric acid. --------------Item Study of the Cross Sections of Fast Neutron Induced (n,2n), (n,p) and (n, a) Reactions on the Isotopes of Zinc, Germanium, Scandium and Zirconium(University of Rajshahi, 2001) Rakib-uz-Zaman, Md.; Molla, Nurul Islam; Uddin, Md. ShuzaThe fast neutron induced reaction cross sections were studied systematically in the energy range of I3.82 to 14.71 MeV using the neutron generator facility under identical conditions in order to provide real nuclear data required in the fusion reactor design and in developing semiconductor technology. In the present investigation, the activation cross section data for 64Zn(n,2n)63Zn, 64Zn(n,p)64Cu, 70Zn(n,2n)69mzn, 70Ge( n,2n )69Ge, 74Ge(n,a) 71mzn, 76Ge( n,2n) 75m+gGe, 45Sc( n,2n )44mSc and 90Zr( n,2n )89Zr reactions in the energy range of 13.82 to 14.71 MeV were measured in an unified experimental condition. High purity samples of natural isotopic compositions were used. Each sample was irradiated separately by neutrons. Monoenergetic neutrons were produced via 3H(d,n)4I-Ie reaction at J-25 neutron generator facility of the Institute of Nuclear Science and Technology, AERE, Saver, Dhaka by the bombardment of the solid tritium target with deuteron. The different energies of the neutrons were obtained as a function of emission angle to the direction of incoming deuteron beam. The neutron activation technique in combination with high resolution HPGe-detector y-ray spectrometry was used to measure the activities of the reaction products and to identify them. Peak area analysis was done using Multi Channel Analyzer (MCA) system based on personal computer. The effective neutron flux densities at the energies of interest were determined by the irradiation of monitor Al-foil with sample. The neutron flux obtained in the present work was in the range of 7 .366x 105 to l.855x I 06 ncnf2s"1 using known cross section data obtained from llVonach. To determine the cross sections of the desired reactions, the well-known activation equation was used. The total uncertainty in cross section was obtained by considering both the statistical errors and possible major sources of systematic errors. The overall uncertainties observed in our experiment were in the range of7- 15 %...............................Item Synthesis and Characterization of Solid Catalysts(University of Rajshahi, 2004-12) Azad, Md. Abul Kalam; Rahman, M. AnisurAmorphous silica-alumina catalysts having different silicon aluminum ratios were prepared. The Brönsted surface acidity of these catalyst samples was measured by the base exchange method using aqueous CHCOONH solution and the results were compared with those measured by the base exchange method using NH4OH and KOH as adsorbates from aqueous solution. The amount of NH4' in CH3COONH4 and NH4OH and K in KOH adsorbed was determined by spectrophotometrically and titrimetrically respectively by measuring the concentration of NH4 and K in the solution before and after adsorption. Variation of surface acidity of catalyst samples-A (synthesized without pore regulating agent), sample-B (synthesized with tetramethylammonium bromide as a pore regulating agent) and sample-C (synthesized with pore regulating agent and base exchanged with NILCI solution to obtain H' form by calculation) have been studied using different concentrations of ammonium acetate, ammonium hydroxide and potassium hydroxide solutions. It has been observed that the surface acidity of a given size catalyst increases with the increasing of concentration of CH3COONH, NH4OH and KOH but dilute solutions of CHCOONH, NH4OH and KOH are sufficient to saturate the catalyst surface. It has been observed that the surface acidity of the catalyst samples found by using CHCOONI, is greater than that of NH4OH and KOH: Of the two bases NH4OH gives slightly greater surface acidity than that of given by KOH. At a given concentration of CH3COONH, NH4OH and KOH solutions the surface acidity was more pronounced when ammonium acetate solution was used as an adsorbate. A plausible explanation for this discrepancy is that with the use of NH4OH and KOII as bases considerable dealumination takes place with a consequent decrease of surface acidity of the catalyst samples. In all cases, the surface acidity was found to increase with the decrease of sample size. Surface acidity was also found to increase as the Al content of the catalyst was increased. The surface acidity of the catalyst samples-13 and C are greater than that of sample-A. But this increase of surface acidity is more noticeable in case of sample-C. Iron(III) dispersed on silica was prepared by the incipient wetness method and its surface acidity measured by CH3COONH, solutions was found negligibly small and was comparable to that of chromatographic silica and alumina. Finally, the Brönsted surface acidity of the catalyst sample-A measured by the base exchanged method using ammonium acetate has been found to be well correlated with the equilibrium pH of CH3COONH4 solution. This may therefore, be concluded that surface acidity of silica-alumina catalyst depends on its mode of preparation, sample size, ratio of Si:Al and concentration of titrants although very dilute solutions of titrants are sufficient to saturate the catalyst surface. A weak base like CH3COONH4 gives comparatively high values of surface acidity of all the silica-alumina catalyst samples where dealumination from the silica-alumina catalyst samples are supposed to be negligible. The total surface acidity of the silica-alumina catalyst sample was also determined by the Tamele method (Amine titration method). Considering the carcinogenic effect of benzene and toxicity of n-butylamine substitutes of benzene as a solvent and n- butylamine as a titrant have been sought. With this end in view attempts have been made to modify the Amine titration method by replacing benzene with cyclohexane or n-hexane or n-heptane and replacing n-butylamine by di-n-butylamine or di-iso- butylamine or sec-butylamine. For this parameters varied were concentration of di-n- butylamine, di-iso-butylamine, n-butylamine and sec-butylamine solutions, sample size of catalyst and types of catalyst samples. The results in the present investigation show that surface acidity of catalyst samples tends to increase with the decrease of catalyst sample size. Unlike Brönsted acidity for a given size of sample the total surface acidity tends to increase with the silicon content of the catalyst sample. For bases, the total surface acidity of various catalyst samples increase in the order of di-iso- butylamineItem Some Physico-Chemical Properties of Cyanex 272 and Extraction of Some Metal Ions(University of Rajshahi, 2006-05) Singha, Hari Prosad; Biswas, R. K.Using a reported technique for purifying organophosphorous extractants, the as-received Cyanex 272 extractant containing 85% bis-2,4,4-trimethylpentyl- phosphinic acid [BTMPPA] has been purified to a purity of about 99% BTMPPA. The purified reagent has been characterized and compared to the literature values. A technique for the colorimetric estimation of purified Cyanex 272 has been developed. It consists of the digestion of pure sample or its aqueous solution (after evaporating out most of water) with concentrated HNO3 (70%) - HCIO (70%) mixture at 2:1 ratio for 1 h. The oxidizing mixed acid quantitatively converts Cyanex 272 to a clear solution of orthophosphate which can be easily estimated by the molybdenum blue colorimetric method at 830 nm. The method is sensitive with a molar extinction coefficient of 2.6 x 10 and reproducible within ± 2%. Applying this technique of analysis, the dimerization constant (K2), distribution or partition coefficient (K) and the ionization constant (K) of the purified Cyanex 272 ie. BTMPPA have been estimated to be 190, 53 and 5.52 x 10, respectively. Interactions of BTMPPA+ diluent (n-hexane cyclohexane / benzene / toluene / chloroform / carbon tetrachloride / 1,2-dichloroethane (DCE) / 1-heptanol) binary mixtures have been studied in terms of density and viscosity measurements and also in terms of derived properties such as excess molar volumes (V), excess viscosities (n) and excess Gibbs free energy changes of activation of flow (AGE). Variations of these values together with the variations of the Grunberg-Nissan interaction parameter (d) for BTMPPA diluent binary systems show that BTMPPA interacts with the diluents in varying degrees. However, no correlation between d, AGE, nor V and the Cu2+/ Fe3+ - extraction characteristics with BTMPPA could be noticed. - The interfacial adsorption property of Cyanex 272 (purified) at the 0.50 mol/dm3 H2SO4 (pH = 0.8) / BTMPPA - diluent (carbon tetrachloride / cyclohexane/ DCE/ n-hexane / toluene / kerosene / benzene / chloroform / 1-heptanol/ 1-hexanol) interface have been investigated. Applying the Gibbs adsorption isotherm to the y vs. log [BTMPPA] plots for each of the diluent used (y being the interfacial tension, mN/m), the apparent cross-sectional areas (A in A2) of BTMPPA molecules adsorbed at the interfaces have been estimated. A (A3) is found to vary in the order: CCl4 (157 A2)Item Solvent Extraction of Mn(II), Ni(II) and Zn(II) by Cyanex 272: Equilibrium and Kinetic Studies(University of Rajshahi, 2010-06) Rahman, Md. Saidur; Biswas, Ramjit KumarThe solvent extraction systems: Mn(II)-SO, -Ac Cyanex 272-kerosene, Ni(II)- SO4-Ac Cyanex 272-kerosene and Zn(II)-SO4 Cyanex 272-kerosene have been thoroughly investigated from equilibrium and kinetic point of views. From the dependence of extraction ratio (at constant equilibrium values of other parameters) on various parametric concentrations, the equations for extraction ratios have been derived at 303 K as: log Dmn=-6.17+2 pHm) + log [H2Azam)-log (1 + 1.9 [SO"]) log Di-11.16+2 pH)+ log [H2A2)-log (1+ 6.92 [SO."])-log [Ac"]; at [H2A2]) <0.05 kmol/m log DN-11.56+2 pH)+3 log [H2A2km)-log (1+6.92 [SO, D)-log [Ac]; at [H2A2 >0.10 kmol/m log Dzn --3.11+2 pH)+ log [H2A2])-log (1+2 [SO,"]); at [H2A2] (en) <0.05 kmol/m3 log "Dzn -2.08 +2 pH() +2 log [H2A2](o)-log (1+2 [SO"]); at [H2A2]()>0.10 kmol/m where, the first terms on the right hand sides represent the logarithmic values of extraction equilibrium constants (Kex). The equilibrium extraction reactions in low concentration regions of extractant are suggested as M(II) + H2A2(0) [MA2](0) + 2 H; but disolvated and monosolvated species are extracted in the cases of Ni(II) and Zn(II), respectively, at high concentration regions of Cyanex 272 (H2A2). The extraction processes are found to be endothermic. The maximum loading capacities of the extractant are found to be 9.52 g Mn(II), 21.28 g Ni(II) and 11.5 g Zn(II) per 100 g extractant. The extracted species are strippable by dilute H2SO4, HNO3 and HCl solutions. In kinetics of forward extractions of the selected divalent metal ions by Cyanex 272, the rates have been measured the single falling drop technique at various extraction parametric concentrations in order to determine the orders of reaction with respect to various concentration terms and also to evaluate the log kr values. Rates have measured at various temperatures to determine E., AH* and AS* values at various parametric conditions for all systems under consideration. The rates of forward extractions of Mn(II), Ni(II) and Zn(II) at 303 K can be expressed respectively as: log F-3.6+ log [Mn(II)] +0.5 log [H2A2]()-log (1+ 105 [H])-log (1+1.58[SO"]) log Fr=-3.7+ log [Ni(11)] +0.5 log [H2A2](o)-log (1+ 10635 [H])-log (1+6.3[SO, ])-log (1 +0.55 [Ac"] log Fr=-8.4 + log [Zn(II)-log [H])+0.5 log [H2A2])+ log (1+ 1.07 [H2A]()) where, Fr represents flux of metal transfer from one phase to another and defined as rate per unit interfacial area. From the rate equations, the mechanisms of extractions are given. Invariably in all cases under investigation, the attachment of the first monomeric anion of the extractant (A') to the metal ion is the rate controlling (M2++ A slow [MA]'); which has been supported by high activation energy (>48 kJ/mol). However, in certain parametric conditions diffusions rather the chemical reaction stated become rate controlling, which is supported by low activation energy. In case of Ni(II) extraction, at high concentration region of extractant, the reaction: Ni2++ HA2 (int) → [NIHA2] becomes rate controlling. The highly negative AS* values in all cases suggest the chemical rate determining step occurs via SNo2 mechanism. The kinetics of stripping of metal ions from highly metal ion loaded organic phases by sulphuric acid solutions have been investigated by the single falling drop technique to derive respective stripping rate equations at 303 K. The stripping rate equations derived for stripping of Mn(II), Ni(II) and Zn(II), respectively, are: log F1 = -4.88 + log [MnA2])- 0.5 log (1+0.002 [H]') + log (1 +5.129 [SO,")) log F-4.35+ log [Ni-H2A2 complex])-log (1 + 1042 [H])-log ([H2A2])+2.5 [H2A2])+ log (1+6 [SO, ])+ log (1 + 3.2 [Ac']) log F-5.24+ log [Zn-HA, complex]) + log [H]-0.5 log [H2A2]) + log (1 +1.5 log [SO."]) The rate equations have been analyzed to give stripping mechanisms. It is found that the dissociation of second anion ligand from [MA2](o) is rate determining which occurs in the bulk aqueous phase (MA slow M2++ A), which is, supported by high Eq. values. This mechanism is valid for Mn(II) and Zn(II) covering all concentration region of free extractant in the organic phase; and also for Ni(II) in low concentration region of extractant, but at its high concentration region, the dissociation of dimeric anion (HA2) from [Ni(HA2)2. H2A2] (0) appears as rate determining. However, low E, value suggests this step occurs via SN2 mechanism. The extraction equilibrium constants (Ke) for Mn(II) and Zn(II) derived from equilibrium studies are matchable to those from respective kinetic studies (Kex = kr/k). But in the case of Ni(II), a deviation by a factor of 10 is obtained, which may be attributed to the loss buffer action resulting the change of interfacial pH. The possibilities of separations of the metal ions under consideration from their mixtures by Cyanex 272 have been theoretically evaluated and it has been shown that the mutual almost complete separation of this metal ion by single or by at least two stage extractions by Cyanex 272 solution in kerosene is possible.Item Solvent Extraction of Ti(IV) and V(IV) by Cyanex 301 and Cyanex 302 and Application of Yates Experimental Design(University of Rajshahi, 2012) Karmaka, Aneek Krishna; Biswas, Ranjit KumarThe solvent extractions in (i) Ti(IV)-Cyanex 301 {HA), (ii) Ti{IY)-Cyanex 302 (H2A2), (iii) V(IV)-HA and (iv) V(IV) - H2A2 have been investigated from equilibrium and kinetic points of view. Yates Experimental Design has been made to the equilibrium and kinetic data for all systems. In system (i) and (ii), heptanol and hexanol (respectively) have been used as de-emulsifier. The equilibration times are 40, 30, 15 and 20 min, respectively. The extraction equilibria at 303 K can be expressed (respectively) as: Kcx = 101.1 17 = co (1+316.2 [Ti(IV)]) {I+ 0.794 [SO/] ([H+] + 229 [W]2) / [HA)to) K.x = 10°.339 = cD (I+ 141.3 [Ti(JV)]) (I+ 1.86 [SO/°]) ([H+)+58.88 [H+J2) I [H2A2Jtii1 K.x = 10·t.42 = cD [H+J2 / [HA)fo) (1+1.58 [SO/]) Kcx = cD [H+r (I +2.24 [SO/·]) / [H2 A2 lfo) [Kcx depends on 'x' and 'x' varies between 2 - OJ The processes are endothermic with H values of -27, -50, -16 and -25 kJ/mol (at l.t.r and - 90 kJ/mol at h.t.r), respevtively. The loading capacities are 7.11, 5.08, 7.87 and 4.05 g/L respective metal ions/ 100 g respective extractant. Suitable diluents are chlorobenzene, n-heptane, kerosene and toluene (benzene) respectively, for systems (i), (ii), (iii) and (iv). The cited equilibrium expressions have been used to suggest equilibrium reactions. The extracted species are [TiOA2], [TiOA2.HA], [VOA2] and [VO(HA2)2] in respective systems; but the reacting metallic species depends on the aqueous pH and sulphate ion concentration ranges. The kinetics of forward extraction of the systems (i), (ii), (iii) and (iv) have been investigated by measuring initial flux of metal ion transfer in a Lewis cell operated at 3 Hz………………………………………Item Preparation, Characterization and Application of Activated Carbon for Arsenic Separation from Water(University of Rajshahi, 2013) Jahan, Israt; Rahman, Md. Sahedur; Asadullah, Md.; Hassan, A.T.M. KamrulArsenic removal from water in the form of As(III) and As(V) using activated carbon and iron loaded activated carbon has been studied. Activated carbon has been prepared from jute stick using both chemical activation and physical activation methods. In chemical activation, H3P04 was used as an activating agent while in physical activation steam was used. The activated carbons produced were characterized by determining BET surface area, iodine value, methylene blue dye number, reactivity, pore volume and pore size. In addition, the studies on structural feature, surface functionality and morphology were also carried out using Raman spectroscopy, FT-IR spectroscopy and Scanning Electron Microscopy (SEM). The maximum BET surface area, iodine value and methylene blue number were found to be 1664 m2/g, 1440 mg/g and 475 mg/g, respectively. Activated carbon produced at optimum conditions was used for As(III) and As(V) separation from water in different method, such as batch process, continuous column filtration method and commercial filter method. Around 48% of As(l11) separation while complete removal of As(V) was achieved using chemically activated carbon (ACC) in column filtration method. However, the main objective of this work is to remove As(III) to an acceptable range (below 0.01 ppm), which is the predominant species in the most underground water, especially in Bangladesh. To enhance the arsenic adsorption capacity, iron species was loaded onto the ACC as well as physically activated carbon (ACS). The iron loaded activated carbon F ACC exhibited superior performance in As(III) separation in column filtration method. Almost complete removal of As(III) was achieved when 9 cm of bed thickness using 1.5 g of F ACC was used in a glass column. However, in order F ACC to utilize in practical filtration of arsenic contaminated water an investigation in the scale of 24 L/day of water, a minimum requirement of commercial filtration, was perfonned. In this study a commercial house hold filter body was used after removing the ceramic candleand layers of filter cartridge. The F ACC was filled in the blank filter cartridge and used for filtration. To compare the separation capacity ofFACC, ACC and FACS were also used in the commercial filtration method. The F ACC showed the dominant performance and almost 99% arsenic was removed from the water. Based on the characterization data, F ACC poses much higher BET surface area, micropore surface area and micropore volume which mainly contributed in liquid phase adsorption. In addition, surface polarity due to the presence of functional groups on ACC contributed to widely distribute of iron species on the surface which in turn contributed to efficiently adsorb As(III) from water. Finally, this study embarked an efficient way of As(III) and As(V) separation from water which can be recommended to commercially use for drinking water purification, especially in the countries where arsenic contamination in drinking water created a public health problems.Item Microbiological Cytotoxic, Haematological and Histopathological Investigations of Seven Bitter Medicinal Plants of Bangladesh(University of Rajshahi, 2014) Molla, Md. Tamzid Hossain; Alam, Mohammad TaufiqPlants are credited with many medicinal properties. Medicinal plants are alleged to possess therapeutic effects in various diseases. Seven bitter medicinal plants of Bangaldesh, viz, Andrographis paniculata N., Vinca rosea L., Adhatoda vasica N., Vitex vegundo L., Aloe indica W., Flacortia ramontchi and Nyctanthes arbortristis L. have been selected for present investigation owing to their recognised medicinal importance. The extracts of these plants are used in the treatment of bronchitis, stomachic, carminative, anthelmintic, fever, asthma, inflammation, febrifuge, gonorrhoea, antitumor, liver complaints, vomiting, leprosy, jaudice, dyspepsia, piles, antidiabelic, anti-cancer, leucoderma, lumours, gonorrhoea, rheumatism, diarrhoea, and many other diseases. These extracts are anti-asthmatic, antipasmodic, expectorent, antitussive, antifungal, antimalarial, antibacterial and antimutagenic. Our present work deals with the extraction of the above medicinal plants with ethanol and microbiological, cytotoxic, haematological and histopathological investigations of the extracts of the above plants. The leaves of the above medicinal plants were washed separately with tap-water to remove adhering dirt. They were cut into small pieces with a knife. The chopped pieces were dried in the sun for four days. The sun-dried materials were then dried in an electric oven at 40oc for about 72 hours when the leaves became almost dry. These were then removed from the oven and the dried leaves were pulverized into powder and paste with the help of a grinding machine. The whole operations for the leaves of seven medicinal plants were done separately. The powdered and pasty leaves were stored in seven separate air tight containers and kept in a cold, dark place for investigation. The powdered and pasty leaves were taken in seven separate quick-fit glass stoppered bottles. The contents of the bottles were shaken continuously with ethanol in an electric shaker for about nine hours. The bottles were allowed to stand for several days. The contents of the bottles were filtered successively in a tincture press and the filtrates were separately collected in seven glass containers. The ethanol extracts of seven medicinal plants were concentrated under reduced pressure when brownish-yellow semi-solid masses were obtained. Each of the concentrated extracts was preserved in a refrigerator for investigations. In every extraction, 250 g of powered or pasty leaves of the plants were taken in 500 ml ethanol. Antimicrobial activity of the ethanol extracts was evaluated by ‘Disc diffusion method’145. Disc diffusion method is essentially a qualitative or semi quantitative test, which indicates the sensitivity or resistance of microorganism to the test material. The microbiological investigation was done to determine the susceptibility of some pathogenic bacteria to ethanol extracts of the seven medicinal plants under investigation. Dried filter paper discs impregnated separately with the test materials were placed gently on nutrient agar plates inoculated with the test organism. The dried discs absorbed water media and the test materials diffused. As a result, there is a gradual change of test materials concentration in the media surrounding each disc. The plates were then incubated at 37.5°C for 24 hours to allow growth of the organisms. If there is any antimicrobial activity of test materials it will inhibit the growth of microorganisms and a clear zone of inhibition will be visualized surrounding the discs. The antimicrobial activity of the test materials is determined by measuring the diameter of zone of inhibition. The larger zone of inhibition is observed for more susceptible organism. The antibacterial activity of the crude ethanol extracts obtained from the leaves of seven medicinal plants (viz, Andrographis paniculata N., Vinca rosea L., Adhatoda vasica N., Vitex vegundo L., Aloe indica W., Flacortia ramontchi and Nyctanthes arbortristis L.) were tested against nine bacteria at concentration of 300 µg/disc, 400 µg/disc and 500 µg/disc. Standard antibiotic disc kanamycin (30µg/disc) was used for comparison. The diameters of the zones of inhibition derived by ethanol extracts of the leaves of the plants were measured in mm with a transparent scale and the results were recorded. The minimum inhibitory concentration (MIC) of ethanol extracts of the leaves of the above medicinal plants against four gram-positive bacteria and five gram-negative bacteria were determined by serial tube dilution technique. The diameters of the zones of inhibition derived by ethanol extract of the leaves of An. paniculata showed maximum activity against B. megaterium and Shigella dysenteriae. No activity of the extract on Sarcina lutea, Shigella shiga, Shigella sonnei was experienced. The extract of Vinca rosea L. was active against Staphylociccus aureus, B. subtilis, Sarcina lutea, Salmonella typhi, E. coli and Shigella dysenteria. The extract was found to possess the maximum activity on B.subtilis and Salmonella typhi. Activity of the extract against B. megaterium, Shigella shiga and Shigella sonnei was not found. Ad. vasica shows the maximum activity against B. megaterium and Shigella dysenteriae. The extract had no or little activity against Sarcina lutea, Shigella shiga and Salmonella typhi. V. vegundo showed the maximum activity on Staphylociccus aureus and Salmonella typhi. The extract had a little activity on Sarcina lutea, Shigella shiga and Shigella sonnei. A. vera had the maximum activity against B. megaterium and E. coli. The extract showed no activity on Sarcina lutea, Shigella shiga and Shigella sonnei. F. ramontchi showed maximum activity against B. subtilis and Shigella sonnei. The activity of the extract against Sarcina lutea, Shigella shiga and Salmonella typhi was not observed. N. arbortristis was very active against B. subtilis and Salmonella typhi. The activity of the extract against B. megaterium, Sarcina lutea and Shigella shiga was not found. The Minimum Inhibitory Concentration (MIC) of the crude ethanol extract was determined by Serial Tube Dilution Technique against nine test organisms mentioned earlier. Nutrient broth medium and culture media were prepared earlier following the standard methods143,145. Fresh culture of the pathogenic microorganisms, preparation of test samples, placement of the discs and incubation were achieved accordingly. Kanamycin (30 µg/disc) was used as standards disc. Crude ethanol extracts of the leaves of the above medicinal plants were transferred in seven separate vials containing 2% DMSO solution (2ml). This was mixed well to achieve sample solutions having concentration 1024 µg/ml. Nine sterilized test tubes containing 1 µg/ml, 2 µg/ml, 4µg/ml, 8µg/ml, 16µg/ml, 32µg/ml, 64µg/ml, 128µg/ml and 256µg/ml sample solutions were prepared for each of the 7 ethanol extracts by SDT148. Nine test tubes containing ethanol extracts of Andrographis paniculata N. having the above concentrations were considered for determining the MIC against Bacillus megaterium. Three test tubes containing media (CM), media plus sample (CMS) and media plus inoculums (CMI) were also maintained for the experiments. Diluted inoculums (10µl) were added to each of the nine test tubes and mixed well. One ml of the sample was added to CMS and mixed well. 10µl of inoculums of Bacillus megaterium was added to CMI to observe the growth of the organisms in the media. CM containing media was used the check the sterility of the solution. Twelve test tubes were incubated at 37.5oC for 24 hours. After incubation, the test tubes were examined for visible growth of the organisms. The lowest concentration of the test material at which there was no visible growth was recorded as the MIC of the test material for the test organisms. The first sign of inhibition of test organisms by the ethanol extract of Andrographis paniculata N. was visualized in the test tubes and recorded. Similar 8 experiments were performed for the same extract against remaining 8 bacteria and MIC of the particular extract against above nine bacteria were recorded. Same experimental procedures were followed for the determination of MIC of remaining 6 extracts (viz, extracts of Vinca rosea L., Adhatoda vasica N., Vitex vegundo L., Aloe indica W., Flacortia ramontchi and Nyctanthes arbortristis L.) against nine bacteria mentioned above. Thus, the MIC of seven ethanol extracts of the leaves of above seven plants against nine bacterial strains were determined and the results were recorded in 63 tables. Thus, the MIC values of ethanol extracts of the leaves of the above medicinal plants were determined. It was evident from the results that all the extracts had notable antimicrobial activities against most of the test organisms. The extract of the plants had MIC values ranging from 32 to 128 mg/ml. All plant extracts showed no MIC against Shigella Shiga only. These extracts had notable activities on other bacterial strains mentioned above. Appreciable MIC of the extracts has been enunciated in the results. The first sign of inhibition of organisms was seen in the test tube against the respective extracts having lower concentrations than those cited in the results had no inhibitory activities on the organisms. The results revealed that the ethanol extracts of the plants under present investigation possess appreciable antibacterial activities. The MIC values of the extracts have remarkable significance about the therapeutic effects of the active principles associated with the leaves of the plants. Cytotoxic effects of ethanol extracts of the plants were investigated. Brine Shrimp Lethality bioassay150 indicates cytotoxicity and a wide range of pharmacological activities of the compounds as well. It utilizes a large number of organisms for statistical validation and a relatively small amount of sample. Generally the median effective dose (ED50) values for cytotoxicity’s are one tenth of median Lethal Concentration (LC50) values in the Brine Shrimp bioassay.151-155 This can be accompanied by testing in vitro lethality in a simple zoologic organism, viz, Brine Shrimp nauplii, Leach (Artemia Salina). In this method, bioactivity can be found not only for natural product extracts but also for pure compounds. Brine Shrimp Lethality test is a positive correlation between Brine Shrimp toxicity and cytotoxicity. The crude ethanol extracts of seven medicinal plants under present investigation represented positive response to Brine Shrimp Lethality Bioassay. Lethal concentration (LC50) of Brine Shrimp Lethality was determined to evaluate the cytotoxic effect of ethanol extracts. LC50 of Brine Shrimp Lethality was obtained from a plot of percentage of mortality versus concentration of the extracts on the graph. The results, presented in the tables and graphs, established a positive correlation between Brine Shrimp Lethality and cytotoxicity. Brine Shrimp Lethality bioassay resembled that the ethanol extracts the leaves of Andrographis paniculata N. is more cytotoxic (LC50= 30 µg/ml) than those of other extracts. The very low LC50 indicated the high toxic effect of the extract of the leaves of the plant. Low cytotoxic effect of each of Vitex vegundo L. and Nyctanthes arbortristis L. (LC50= 72 µg/ml) was observed. The other ethanol extracts exhibited moderate cytotoxic effects. Thus, it may be concluded that the ethanol extracts of the leaves of seven medicinal plants under present investigation have cytotoxic effects. Haematological investigation deals with the composition, formation, destruction, production and conservation of blood and related substances in blood, blood plasma and tissue fluids. Hence, the dietary effects of ethanol extracts of the medicinal plants under present investigation supplemented separately with formulated cereal at 5% level have been investigated in the present study. A survey of 28 consecutive days on young male albino rats, body weight ranging 52-56 g was performed. The dietary effects of the extracts at 5% level with formulated cereal on the composition of red cells like erythrocytes and white cells, viz, leucocytes and platelets (thrombocytes) were investigated in this experiment. Its effects on the composition of white cells like esnophil, neutrophil, monocytes, basophil and lymphocytes were investigated. Haematological parameters, i,e, haemoglobin, red blood cells (RBC), erythrocyte sedimentation rate (ESR), cholesterol, white blood cells (WBC) and total count of WBC of the rats under experimental and control groups were investigated after feeding the extracts, separately fortified with the formulated cereal at 5% level for a period of 28 consecutive days. Histopathological as well as toxicological effects of the ethanol extracts were investigated on livers, lungs, kidneys, hearts and spleens of the experimental rats. These were achieved by observing the changes in the cellular structures of these organs. The present investigation included the identification and toxicological effects in those organs of the experimental rats. These were achieved by observing any changes in the cellular structures (degradation and regeneration) of organs of the experiment rats after taking fortified cereal for a period of 28 consecutive days. Dietary effects of feeding on the experimental rats during the experimental period were evaluated by careful observation of the depression of central nervous system, excitation, muscular reflexes and behavior of the rats. Haematological and histopathological investigations of the ethanol extracts of the plants supplemented separately with formulated cereal at 5% level on young male albino rats after feeding for 28 consecutive days both for the experimental rats and control group were performed. During this experiment, the effect of feeding the supplemented cereal on gain in body weights of the rats during the experimental period was investigated simultaneously. A control group of the rats for formulated cereal (without having any extracts) was also maintained for gain in body weight. Initial body weight of the rats, gain in body weight during the experiment of feeding and gain in body weight per one gram of food intake by each of the rats were recorded. The results resembled that there was a close similarity of the diets in gain in body weight of the rats. It appeared from the results that the diets had almost equal impact in gain in body weight. The results were computed to show the gain in body weight for one gram of food intake by 16 young male albino rats for feeding eight diets. Analysis of variance table and a difference table for multiple comparison of mean gain in body weight per one gram of food intake were computed to show which of the diets was statistically more significant for gain in body weight and for the normal development of the rats. It was evident from the tables that all the diets had similar impacts for normal development and maintenance of the rats. None of the diets was statistically significant in gain in body weight of the rats. Separate tables were prepared for Dan can’s New Multiple Range Test for protection level α = 0.01 and α = 0.05. The tables failed to identify which of the diets was statistically significant at 1% or 5% levels of significance. The tables also showed that the treatments and errors of the diets had no Least Significance Range (LSR) in comparison with their respective Standard Significance Range (SSR).162 Total count of RBC and WBC, differential count of WBC and percentage of haemoglobin in the blood of the rats were investigated and the results were summarized. Comparing these values with those of reference values for haematological parameters it resembled that the changes in the parameters remained within the normal limit. No abnormalities in haematological investigations were detected. During the experimental period, the rats under investigation were found to restore no signs of muscular numbness of the legs, salivation, excitation, weakness, diarrhoea, etc. and no reflex abnormalities were detected. Thus, it appeared that the dietary effects of feeding the ethanol extracts of the plants fortified at 5% level with formulated cereal for a period of 28 consecutive days had no adverse action on both control and experimental rats. At the end of the feeding experiment for a period of 28 consecutive days, the rats were sacrificed under mild anesthesia with ether-chloroform and their livers, lungs, kidneys, hearts and spleens were preserved, processed, sliced and the tissues were mounted on glass slides and viewed under microscope to find any histopathological change in the organ. Microscopic view of sliced tissues of the organs on glass slides were recorded. On gross necropsy evaluation, all the organs under examination exhibited normal color. No abnormal histopathological change in the cellular structure in the tissues was detected. This implied from microscopic view of those organs that the effect of feeding the ethanol extract at 5% level with the formulated cereal for 28 consecutive days had no adverse effect on cellular structure of those organs of the experiment rats and no morphological changes occurred therein. From the foregoing evidences, it appeared that the ethanol extracts of the above plants, fortified with formulated cereal at 5% level was non-toxic.Item The Effect of Starch Interactions with Soap or Surfactants Studied by the Ternary Phase Diagram(University of Rajshahi, 2014) Hossain, Md. Mohsin; Mondal, Md. Ibrahim H.Starch interactions with various surfactants have been studied for the investigation of ability and cleansing activity of starch-surfactant-water system. The surfactants investigated were sodium dodecyl sulphate (SDS), cetyltrimethyl ammonium bromide (CTAB), Triton-X-100, Brij-30 and tween-20. The Degree of substitution of starch is 0.8 and the concentration of starch was varied from 0.01 to 1% w/v. The effect of mixing on the micellisation of the ternary surfactant solutions can be described to a good approximation by taking into account only the effects of the volume difference between the hydrocarbon chains length. Mixed micelle formation with starch depends on the chain-length difference in the same way as for starch-surfactant micelle…………………………………………….Item Biodegradable Polymers: Drug Release Characteristics(University of Rajshahi, 2014) Mahmud, Abu; Bakr, Md. AbuFour polymers namely: i) maleic acid-butane-1,4-diol polyester (MBP), ii) maleic acid-adipic acid-propane-1,2-diol co-polyester (MAPC), iii) malic acid-adipic acid-butane-1,4-diol co-polyester (MABP) and iv) maleic acid-citric acid-propane-1,2-diol co-polyester (MCPC) from different composition and ratios of their corresponding monomers were synthesized and characterized. Their biodegradation and in-vitro drug release behavior in simulated physiological environments were also investigated. All of these four polymers were synthesized using xylene as the reaction medium in Dean-Stark apparatus. The polycondensation temperature was varied from 130 to 1450C for different polymers. The reaction time was about 5 hours followed by 1 hour post curing and anhydrous FeCl3 (approximately 0.4% of the total weight) was used as catalyst. The synthesized co-polyesters were collected from the reaction vessel by dissolving them in acetone and re-precipitated using water as non-solvent. The purified co-polyesters were characterized by their solubility tests in common organic solvents, molecular weights, IR-spectra, elemental analyses, hydrolytic and soil degradation tests. Probable structures of the co-polyesters were also assigned. Molecular weight determination was carried out by end group analysis and viscosity method. Soil burial tests revealed that, all of these polyesters degraded biologically and normally mixed with soil imparting no natural imbalance. At room temperature, hydrolytic degradation study in solutions of different pH values showed that co-polyesters i), ii) and iii) remained almost intact in solutions of pH 0-3.0, slight degradation was observed in pH range 3.0-6.0 but they gradually degraded in solutions of pH >6.0. Such pH responsive degradation nature of these polyesters led us to investigate their possible application as enteric coating material. Diclofenac sodium and naproxen core (uncoated) tablets were used as model drugs for this purpose. Simulated physiological environments and procedures according to British pharmacopoeia (BP) were followed to monitor the drug release pattern of polymer coated tablets and satisfactory results were obtained. However, hydrolytic degradation study of the co-polyester (iv) reveals that in acid medium the polymer sample swells insignificantly. But in alkaline medium it swells well and the ester linkage is hydrolyzed with respect to time. Because of such time dependent pH responsive nature, this polyester was tried as a drug carrier for extended release drug-polymer matrix tablets and pure dichlofenac sodium was used as the model drug. The drug was incorporated in the polymer matrix by melt granulation process keeping the drug polymer ratio as 1:2. The prepared granules were compressed in a single punch tablet machine to get them in tablet forms. In-vitro drug release from these matrix tablets were studied spectrophotometrically under physiological condition (phosphate buffer of pH 7.4 at 370C). The release pattern has shown a bit higher release in the first hour, then a nearly zero order release for 10-11 hours followed by declining release for the subsequent few hours.Item Antiproliferative Activity of Sword Bean Lectin and Carbonate Apatite Against Ehrlich Ascites Carcinoma Cell(University of Rajshahi, 2016) Waheed, Momtaz Fatima; Alam, M. Taufiq; Molla, Md. Abul Hossain; Kabir, Syed RashelA glucose specific lectin has been purified from the seeds of Canavalia gladiata (sword bean) in a single step by affinity chromatographic technique. For protein extraction, delipidated sword bean meal was homogenized with 100 mM sodium acetate-acetic acid buffer pH 5.5 for 5 hours at 4-6oC. The clear supernatant was separated by centrifugation at 11,000 rpm for 10 minutes at 4-6oC and designated as crude extract. The crude extract was subjected to 90% ammonium sulfate precipitation for overnight at 4-6oC. After centrifuge at 11,000 rpm for 10 minutes 4-6oC, the precipitate was dissolved in 100mM sodium acetate-acetic acid buffer pH 5.5 containing 1mM MnCl2, 1mM CaCl2 and 100mM NaCl. The protein solution was dialyzed against the same buffer to remove remaining ammonium sulfate. After dialysis, the sample was centrifuged and the clear supernatant was injected to the affinity column packed with Sephadex G-200 gel and equilibrated with binding buffer (100mM sodium acetate-acetic acid buffer pH 5.5 containing 1mM MnCl2, 1mM CaCl2 and 100mM NaCl). The column was washed to remove unbound materials. Gel-bound protein was eluted with 100mM sodium acetate-acetic acid buffer pH 5.5 containing 0.4M glucose. Finally, in order to remove salts and glucose from the eluted protein solution, it was dialyzed against deionized distilled water. The purity of the protein was checked by 12.5% SDS-PAGE method. The SDS-PAGE gel shows five bands in the lane of crude extract and single band in the lane of purified protein, which indicates the affinity matrix system was able to purify only one kind of protein in a single step. The molecular weight of the affinity purified sword bean lectin (SBL) was determined and it was found to be 28 KDa. The purified sword bean lectin powerfully agglutinate human blood types A, B, O erythrocytes almost equally. The order of hemagglutination activity with chicken and mice erythrocytes was mice>> chicken> human blood types A, B and O groups but not with the bovine and goat erythrocytes. This SBL was stable upto 60°C and showed maximum hemagglutinating activity at pH 7.5. The sugar inhibition assay exhibited its sugar specificity highly against D(+) glucose at Minimal Inhibition Concentration (MIC) of 25 mM and maltose, D(-) mannose, fructose at MIC of 3.125 mM. But lectins were not inhibited by the presence of D(+) galactose, L(+) arabinose. Antiproliferation activity of purified SBL was tested against Ehrlich Ascites Carcinoma (EAC) cell in the swiss albino mice at a dose of 4 mg/kg/day and it worked as an active inhibitor. The result was compared with a known effective anticancer drug, bleomycin at the dose of 0.3 mg/kg/day (i.p.). The cell growth inhibition was found to be 77% and 90% for SBL and bleomycin respectively. RBC level of EAC cell bearing mice increased to 8.6 which is very close to normal value of 9.4. The hemoglobin level also increased to 10.0 which is near to normal value of 11.4 gm/dl. Carrier of various drugs and bio-active molecules such as peptides, proteins and DNAs etc. through the cell membrane into cells has attracted increasing attention because of its importance in medicine and drug delivery. Therefore, SBL combining with inorganic carbonate apatite as drug carrier in different concentration was also used to treat EAC cell bearing mice to get a better result, but the result was not satisfactory. The combined effect of SBL and carbonate apatite decreased EAC cell growth inhibition from 77% to 47% and 45% to 9% when 5mM carbonate apatite (4 ml/kg/day) was used with SBL at the dose of 4mg/kg/day and 2.5 mg/kg/day respectively whereas 5mM carbonate apatite at the same dose itself gave a very good inhibition of 70%. The RBC and hemoglobin level increased after treating with carbonate apatite to 8.0 and 10.9 which is nearer to normal level of 9.4 and 11.4 respectively. Fluorescence study of SBL and SBL combined with carbonate apatite showed that surface induced denaturation of SBL was occurred when it was administered in combination with carbonate apatite. As a result it prohibit the individual antiproliferation effect of sword bean lectin and carbonate apatite.Item Biochemical and Nutritional Nvestigations of Bangladeshi Fresh Water Fish Puntius Gonionotus(University of Rajshahi, 2016) Dutta, Prodip Kumar; Molla, Md. Abul HossainBangladesh is one of the developing countries of the world. A large number of populations in Bangladesh have been suffering from malnutrition. To over come this problem, it is necessary to increase the production of protein rich food for her peoples. Most of the people of the developing countries are still dependent almost entirely on fish as a source of animal protein. In Bangladesh, fishes are common as well as cheap sources of protein, fat, mineral and some vitamins. It is said “Rice and Fish” is the staple food of the people of Bangladesh. Therefore, optimum utilization of fishes, rich in nutrients, is of paramount importance to minimize micronutrients gap and thereby it is possible to improve nutritional status in the country. Puntiusgonionotus(P. gonionotus, locally known as China punti) fishes are being used as popular sources of fishes in some parts in Bangladesh. This fishes are found in Bangladesh mainly in the district of Pabna, Rajshahi, Bogra and Natore. Fishery of this fishes was carried out in three different ghers (polders). No remarkable change was found in pH, temperature and densities of water bodies used as fish habitat of these study areas. Total dissolve solid (TDS), electrical conductivity (EC), salinity and free CO2 were found maximum (22.3± 1.12 g/L; 33.85±0.82 ms/cm; 22±2.45 ppt, and 5.5±0.04 mg/L respectively) whereas hardness (mg CaCO3/L); Ca2+ (mg/L); Mg (mg/L); dissolve oxygen ((mg/L) and total suspended solid (TSS) (g) were found minimum (630±2.54; 70±2.46; 110.75±4.75; 5.6±0.04 and 0.020±0.01 respectively) CO2 and dissolved oxygen (D.O) are reliable for this fish culture but hardness’s were so high and may be concerned for the fish habitats. Alkalinity and chemical oxygen demand (COD) were found maximum (200±3.56 mgCaCO3/L and 140±1.88 mg/L respectively). Different types of gears and crafts were found for fishing P. gonionotus fishes in these ghers and in the river during full moon. Fishermen handover their catches in different distannce and nearby market through a more or less distinguish channel. In between the fishermen and final consumers there are a few intermediates. The market price and landing of fish varied marginally from market to market. The price of this fish to the consumer varies from season to season. In the fishery, xiv maximum labour force is employed in the traditional sector. They have normally large family members. The fishermen of these areas are mostly poor and illiterate. The proximate composition of flesh of this fish was determined using standard methods of analysis. The grand mean values were moisture 71.51±0.93%; protein 22.21±0.92%; lipid 5.24±0.64%; ash 1.02±0.05%; crude fibre4.655±0.32% and dry matter 28.50±0.65%. The analytical properties of the crude lipid were evaluated. It was observed that lipid was reddish brown colour and density and refractive index of the lipid were 0.9516 g/cc and 1.4612–1.4635 respectively. Studies on the chemical characteristics of this fish lipid indicated that the iodine value (I.V), saponification value (S.V), saponification equivalent (S.Eq.), acid value (A.V), ester value (E.V), peroxide value (P.V), percentage of free fatty acids (as oleic) were found to be 108.72; 186.52; 296.52; 1.96 mg/KOH; 235.29; 1.78 mEq/Kg; 1.78 % respectively. The lipid is found to be edible as its acid value was estimated to be low (1.96 mg/KOH). The chemical indices indicate that the fish is a good source of protein. This fish contained several dietary minerals such as calcium (Ca), magnesium (Mg), sodium (Na), phosphorus (P), potassium (K), iron (Fe), copper (Cu) and zinc (zn). The macro mineral elements calcium (Ca), sodium (Na), potassium (K), magnesium (Mg), and phosphorus (P) were found to be in the range of 276±4.54 mg; 76.01±2.16 mg; 294.4±2.01 mg; 48.1±1.83 mg and 210.0±1.80 mg per 100 g portion respectively. The micro minerals, iron (Fe), copper (Cu) and zinc (Zn), content in this fish were varied from 1.70±0.16 mg; 1.01±0.20 mg; 3.80±0.82 mg per 100 g portion respectively. The observations in dietary minerals suggested that the fish P. gonionotuscould be provided a significant proportion of calcium (Ca), magnesium (Mg), sodium (Na) and also potassium (K). The distribution pattern of fatty acids in fish lipid was separated and identified by Thin Layer Chromatography (TLC). Fish lipid under investigation contained myristic acid (C14: 0), palmitic acid (C16: 0), stearic acid (C18:0), oleic acid (C18: 1), lionoleic acid (C18: 2), lionolenic acid (C18: 3), arachidic acid (C20: 0) and behenic acid (C22: 0). These results revealed that the lipid is pharmacologically active owing to the fact that it is necessary for proper functioning of many metabolic processes. Fatty acids xv composition and chain length of fatty acids in this fish lipid were determined by Gas Liquid Chromatography (GLC). In GLC examination, the mixture of fatty acid methyl esters derived from fish lipid were separated on polar column having stationary phase diethyleneglycosuccinate (DEGS). The identities of the individual fatty acid were achieved by co-chromatography with standard reference compounds. It was established from the GLC examination, the mixture of fatty acid methyl esters derived from fish lipid that the mixture contained fatty acids consisting of carbon C14 to C22. The percentage of each fatty acid methyl ester derived from fish lipid was provided by printed out record of the chromatogram of GLC. The percentages of composition of each fatty acid methyl ester in the fish lipid derived from the chromatogram were 6.33% myristic acid; 24.23% palmitic acid; 8.42% stearic acid; 30.29% oleic acid; 7.35% lionoleic acid; 5.46% lionolenic acid; 2.47% arachidic acid; 4.25% behenic acid and 11.13% unknown acid. Analysis of this fish lipid for fatty acids indicates that the lipid contained 7.35% linoleic acid (ω-6 fatty acid) and 5.46% linolenic acid (ω -3 fatty acid). These fatty acids are an important part of the structural component of cell membranes and are necessary for the formation of eicosanoids which assist in blood pressure regulation, blood clot formation, maintenance of blood lipid levels and assist in the body immune response. The fish lipid contained about 43.1 oleic acid (monounsaturated fatty acids) can able to promote the high level of HDL cholesterol and hence decreasing the risk of heart diseases in human body. The concentrations of saturated fatty acids in this fish lipid were 42.43% of total lipids; monounsaturated fatty acids 43.1% and polyunsaturated fatty acids 14.43%. The fish lipid is suitable for edible purpose as it contained both ω-3 and ω-6 fatty acid especially linoleic and alpha-linolenic acids. The effect of feeding Fish Protein Concentrate (FPC) at different protein levels with formulated cereal have been performed to identified the nutritional significance of fish P. gonionotus by determining the gain in body weights per one gram of food intake, Protein Efficiency Ratio (PER) and Calorie Efficiency Ratio (CER) values in twelve male young male albino rats for 32 consecutive days. For this purpose, five experimental diets were prepared at different protein levels (5% to 25%) with supplied formulated cereal where the control diet was prepared with supplied xvi formulated cereal only. Each mean gain in body weight per one gram of food intake, PER and CER were increased with increasing protein levels supplemented with formulated cereal and showed maximum value of 0.534g, 2.53 and 13.02 respectively at 15% protein level. When protein levels were further increased through FPC, fall in gain in body weights per one gram of food, PER and CER have been observed in diet E (0.457g, 2.11 and 11.15 respectively) and diet-F (0.432g, 1.02 and 10.53 respectively). Locomotive behaviour, central nervous system, excitation, weakness, reflexes, salivation, urination, diarrhoea, etc. of all albino rats are found normal during the experimental period. After consuming the diets containing FPC at different protein levels produces no observable changes in blood constituents like total RBC count (106 /µl), hemoglobin (g/dl), erythrocyte sedimentation rate (ESR)(mm), total WBC Count (103 /µl), differential count of WBC (neutrophil, lymphocytes, monocytes, eosoniphils) with that of control group and the blood cholesterol (mg/dl) levels of the treated rats were increased gradually than control group. Histopathological examination of the heart, liver, lung, kidney and spleen of all treated rats were found normal and no morphological change were found in their microscopic view with respect to the control group. In Brine Shrimp Lethality bioassay, the chloroform-methanol extract of this fish lipid showed negative results indicating that the fish lipid was biologically inactive. From this experiment, it is revealed that the fish lipid has no toxicity against any living organismsItem Chemical and Biological Studies on Antidiabetic Single Plants and Composite Herbal Preparations(University of Rajshahi, 2016) Ahmed, Md Ranzu; Sayeed, Md. Abu; Mosihuzzaman, Mohammed; Rokeya, BegumEleven antidiabetic herbal preparations (ADHPs) were collected from the local herbal drug stores in Dhaka city. Among these ADHPs, four were tablet, three were capsule and rest of the ADHPs were in liquid form. Eleven ADHPs were screened at BIRDEM for their efficacy in reducing blood glucose in type 2 diabetic Long Evans model rats produced at BIRDEM and BUHS. Seven drugs showed positive response in acute tests. These seven drugs were fed to diabetic model rats for 28 days and some of them showed significant hypoglycemic activity. One with the significant activity had only one plant Salvia haematodes Lin in its composition. This plant (roots) was taken for chemical studies. The flowers of the plant Phlogacanthus thyrsiflorus Nees is used for controlling blood glucose in South Eastern Indian people. The flowers were used to study the antidiabetic effect on Type 2 diabetic rats. The powdered root (5 kg) of Salvia haematodes Linn was extracted with n-hexane, DCM, EtOAc and methanol at room temperature, respectively. Dried and powdered flowers (300 g) of P thyrsiflorus was extracted with DCM, EtOAc and methanol at room temperature, respectively. This flower also was extracted with aq 80% ethanol to get 144 g extract. The ethanol extract (144 g) was suspended in water and was partitioned with DCM followed by 1-butanol. The DCM and 1-butanol soluble part was 49.87 g and 54 g, respectively. The extracts of ADHPs and Pthyrsiflorus flowers were directly tested for their antidiabetic effects, alpha-glucosidase inhibitor activity, antioxidant activity, SPF testing, microbial contamination, insulin secratory activity, isolation of active compound (s), toxic metal analysis, OCPs testing, identification & quantification of synthetic drug and antioxidant. ADHP-2, ADHP-4 and ADHP-6 showed significant results of lowering the blood glucose level and lipid profile. The body weight of the treated T2DM rats were unchanged during the experimentation. Ethanol extract of flowers of P thyrsiflorus Nees possesses hypoglycemic and hypolipidemic properties, which reduces the oxidative changes induced by STZ administration. The results of the current study revealed that roots and flower of S haematodes & P thyrsiflorus, respectively, exhibited wide range of α-glucosidase inhibitory activities. For the root of S haematodes, n-haxane part of MeOH extract showed more significant (IC50 = 0.5226 μg/mL) activity which was better than positive control quercetin (IC50 = 1.544 μg/mL). Another fraction, root’s of S haematodes, EtOAc (EA) part of MeOH extract showed significant (IC50 = 1.318 μg/mL value) activity compare to the positive control quercetin (IC50 = 1.544 μg/mL). n-Hexane part of EtOAc extract of the same plant also showed significant (IC50 = 1.184 μg/mL) activity compared to the positive control quercetin (IC50 = 1.544 μg/mL). From the flower of P thyrsiflorus, EtOAc (EA) part showed significant activity (IC50 = 1.539 μg/mL) which is very similar to the positive control quercetin (IC50 = 1.544 μg/mL). Methanol extracts of ADHP-1, ADHP-7, ADSP-8 and ADSP-9 exihibited 94.8 ± 0.0312%, 91.88 ± 0.0534%, 94.76 ± 0.0.0045% and 94.37 ± 0.0466%, respectively, at concentration 400 µg/ml when compared with standard sample (ascorbic acid, 97.15 ± 0.0502%). The IC50 value of the methanol extracts of ADHP-1 (17±0.0243 µg /ml) was significant when compared to that of the standard Ascorbic acid, 2 ± 0.0156, respectively. Methanol extracts of ADHP-1, ADHP-3, ADHP-6, ADHP-7, ADSP-8 and ADSP-9 was found to 98.38 ± 0.0156%, 95.54 ± 0.0321%, 94.34 ± 0.0371%, 95.90 ± 0.0551 % , 96.03 ± 0.0151% and 96.03 ± 0.0212% free radical scavenging activity, respectively at concentration 400 µg/ml when control sample (ascorbic acid) exhibited 99.90 ± 0.0145%. IC50 values for the methanol extract of ADHP-1 (21±0.0251 µg /ml) was significant when compared with control sample (ascorbic acid) exhibited IC50 at 10 ± 0.0156 µg/ml. Methanol extracts of different ADHP’s and ADSP’s sample exhibited good activity for reducing power assay in the present study. Where standard ascorbic acid gives absorbance 1.250 ± 0.0075 at 700 nm. The present study reveals, ADHP-6, ADSP-8 and ADSP-9 extracts exhibited 715.54±0.0485, 830.48±0.0365 & 850.74±0.0854 absorbances, respectively for total antioxidant activity. The plant extract which possess potential antioxidant activity and UV absorption capacity can prevent photo-aging and skin cancer (Ganesan et. al., 2013). The present study showed that the S haematodes Linn has significant UV absorption capacity, especially the chloroform and ethyl acetate fractions with the SPF value 10.18 and 9.63, respectively. On the other hand, another plant’s flower (P thyrsiflorus Nees) showed the SPF value 5.82 for methanol extract. Out of 07 antidiabetic solid and liquid samples, except ADHP-3, Bacillus subtilis (3.5 – 4.0 x 104 cfu/g) was identified from solid ADHPs and Enterococcus spp. (1.0 x104 cfu/ml) was identified from liquid ADHP, but all samples were free from fungi (yeasts and moulds). Bacillus subtillis has been identified 3.5 x 104 cfu/g, 3.7 x 104 cfu/g, 3.2 x 104 cfu/g, 3.8 x 104 cfu/g, 4.0 x 104 cfu/g in the ADHP-1, ADHP-4, ADHP-5, ADHP-6 and ADHP-7, respectively. Enterococcus spp. (1.0 x104 cfu/ml) was identified from liquid ADHP-2. ADHP-3 was free from all kinds of microbial contaminations. Compounds 1 and 4 of P thyrsiflorus showed significant effect on glucose-stimulated insulin secretion from MIN6 cells. Using repeated column and high performance liquid chromatography (HPLC) eight compounds were isolated from the dichloromethane, chloroform and 1-butanol soluble part of methanol extracts of flower and root of the plants. The structures of the isolated compounds were elucidated by extensive spectroscopic studies. Three compounds - sitosterol (1), stigmasterol (2) and 7-hydroxy coumarin (3) were isolated from the DCM and Chloroform part of roots of S haematodes. Morever, five compounds - sitosterol (4), stigmasterol (5), 8(17),13-labdadien-15,16-olide-19-oic acid (6), 19-hydroxy-8(17),13-labdadien-15,16-olide (7) and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-chromenone (luteolin) (8) were isolated from the dichloromethane extract and 1-butanol part of methanol extract of flowers, respectively. Among these eight compounds, compound (4) and (7) showed significant effect on glucose-stimulated insulin secretion from MIN6 cells. Toxic metal content particularly, Nickel (Ni), Copper (Cu), Manganese (Mn), Chromium (Cr), Cadmium (Cd), Lead (Pb), and Arsenic (As) were tested in the thirteen ADHPs. The amount of nickel was below detection level in all the preparations when the detection limit was 0.02 ppm. The copper concentrations varied in a wide range in all ADHPs between 0.48 to 39.58 ppm except ADHP 5 & 6. Cadmium content was detected some of the ADHP samples except ADHP-2, 4, 5, 6 & 7. Unfortunately, ADHP-3, 8, 9 & 10 samples the cadmium level were more than the level of all permissible limit (WHO, US FDA, HAS Singapore and Chinese Pharmacopoeia, Tables 3.3.1 and 3.3.2). Even if we consider a more relax permissible limit for cadmium (WHO and US FDA guidelines; Table 3.3.2), one-third of the total ADHPs (ADHP-3, 8, 9 & 10) failed to comply with the safety limit. The content of lead (Pb) in the analyzed samples ranged from less than 1.0 to 18.44 ppm. All the ADHP’s samples showed the value of Pb metal below detection level (DL=0.00005 ppm) except ADHP-3 and 8. The maximum concentrations of lead in ADHP- 3 and ADHP-8 were 0.08 ppm and 18.44 ppm, respectively. Arsenic (As) content in the analyzed samples ranged from 0.05 to 0.75 ppm. All the ADHP’s samples showed the value of As metal with the highest value in ADHP-7 (0.75 ppm) & ADHP-8 (0.74 ppm) and lowest value in ADHP-6 (0.05 ppm) as shown in Table 3.8.1. The US FDA, WHO, HSA Singapore & Chinese Pharmacopiea maximum permissible limit of As in consumed medicinal herbs is 10 ppm, 10 ppm, 5 ppm and 2 ppm respectively (Table: 3.8.2). The obtained results showed that all the analyzed ADHP samples the As contents were below the permissible limits. Four organochlorine pesticide’s residue analysis of ADHPs standards namely 4,4-DDE; 4,4-DDD; 2,4-DDT & 4,4-DDT were used to quantify the pesticides present in 07 Antidiabetic Herbal Preparations (ADHPs). 4,4-DDE was found in ADHP-1, ADHP-2, ADHP-6 & ADHP-7 amounting to 0.203 ng/g, 0.588 ng/g, 1.413 ng/g & 1.838 ng/g, respectively. 4,4-DDD amounting to 0.373 ng/g was found only in ADHP-2. 2,4-DDT was found in ADHP-2 and ADHP- 6 amounting to 1.937 ng/g and 0.756 ng/g, respectively. And 4,4-DDT was found to be present in ADHP-1, ADHP-2, ADHP-6 and ADHP-7 amounting to 0.971 ng/g, 8.608 ng/g, 3.377 ng/g and 2.917 ng/g, respectively. ADHP-03, 04, 05 were free from organochlorine pesticide residues. Small amount of metformin HCl was found in all samples of ADHP. Metformin HCl was quantified 2.25%, 2.62%, 1.28%, 1.58%, 1.47%, 1.35% & 2.47% in ADHP-1, ADHP-2, ADHP-3, ADHP-4, ADHP-5, ADHP-6 and ADHP-7, respectively. Large amounts of glaclazide (5.74%) and glibenclamide (3.82%) were quantified and isolated from ADHP-6 and ADHP-7, respectively, indicating deliberate addition. A new HPLC method to analyze seventeen antioxidant compounds simultaneously was developed and validated for, linearity, accuracy, stability and precision. All of the ADHPs and ADSPs cotainined good amount of different antioxidants. Especially ADHP-1, ADHP-2, ADHP-4, ADHP-5, ADHP-6, ADHP-7, and ADSP-8, 9 showed significat amount of antioxidants which is known to play benifical role for humans (Table-3.11.11).Item Modification of Cellulosic Fibres with Synthesized Functional Chitosan Derivatives for Ecofriendly Textile Products(University of Rajshahi, 2017) ISLAM, MD. MOFAKKHARUL; Mondal, Md. Ibrahim H.Cellulosic fibres, especially jute and cotton, are the most abundant agriculturalrenewable raw materials. They have the qualities of stiffness, low elasticity,susceptibility toward sunlight and microbial attacks etc. which are hindrances on use of those fibres. Chitinous wastes from different sources and fish processing industries always pollute the environment in different ways. A huge amount of prawn shell wastes is deposited as sea food waste in different areas of fish processing industries which have virtually no demand for its use. These indigenous, cheap and available chitinous wastes can easily be used to produce valuable chitosan (Ch) and its functional derivatives, especially N-octyl chitosan (NOCh), carboxymethyl chitosan (CMCh), carboxymethyl chitosan-grafted-acrylic acid (CMCh-g-AA), N-(2-hydroxy) propyl-3- trimethyl ammonium chitosan chloride (HTAChC) and N-methylolacrylamide-N-(2- hydroxy) propyl-3-trimethyl ammonium chitosan chloride (NMA-HTAChC), which are commercially important and will ultimately reduce pollution problems. The purpose of this research was to develop soluble chitosan and water soluble modifiers, based on that chitosan, which have excellent textile modification properties. These new products can substitute for toxic textile chemical modifiers. In addition, cellulosic fibres like jute and cotton can enhance their effectiveness for intensified textile use through ecofriendly modification. In addition, the dyeability of unmodified and modified jute and cotton fibres, including their tensile strength, moisture absorbance, swelling capacity, chemical resistance, dye-ability and colour fastness properties were investigated. Chitosan was prepared from chitin, which was obtained from prawn shell waste by a series of chemical processes involving demineralization, deproteinization,decolouration, and deacetylation. Chitosan (Ch) and its said derivatives were successfully prepared by deacetylation of chitin, reductive amination of chitosan, carboxymethylation of chitosan, graft copolymerization of CMCh, quarternization of chitosan and acrylamidomethylation of HTAChC, respectively, at ambient condition, which were also optimized. The optimized condition for deacetylation is 50% alkalinesolution, solid to liquor ration 1:50 (w/v), at 800C for 4h, in presence of ethanol withreflux system. Lower yield and substitution to higher yield and substituted products were obtained from single step to multistep reactions. Chitosan and its synthesized derivatives were characterized with their physicochemical properties, degree of deacetylation (DDA), solubility, viscosity, molecular weight, nitrogen content, degree of substitution (DS) and degree of quarternization (DQ) were investigated. The obtained DDA of prepared chitosan was 85% and DS of prepared NOCh and CMCh in different steps of reaction ranges from 0.008 to 0.051 and 0.54 to 1.44 and DS was determined by titrimetric analysis. The moisture absorbency, ash content and molecular weight of prepared chitosan, NOCh, CMCh, CMCh-g-AA, HTAChC and NMA-HTAChC were 9.79%, 8.17%, 13.76%, 6.83%, 18.43%, 17.71% and 1.34%, 0.75%, 14.87%, 8.39%, 0.84%, 0.79%, respectively and 1,39,958.73 Da for chitosan, 1,62,181 Da for NOCh, 2,06,179 Da for CMCh, 3,10,270 Da for CMCh-g-AA. The synthesized chitosan, NOCh, CMCh, CMCh-g-AA, HTAChC and NMA-HTAChC are characterized by Fourier Transform Infrared Spectroscopy (FTIR) which showed prominent peaks at 1659 cm-1 for (-CO) at 1600 cm-1 for (–NH2) groups of chitosan, at 1516 cm-1 for corresponding to C-H stretching into methyl groups of NOCh, at 1384 cm-1 for symmetrical -COO− group and near at 1741 cm-1 for −COOH group of CMCh and at 1319 cm-1 for poly (AA) of CMCh-g-AA, at 1480 cm-1 for C-H bending of trimethylammonium group of HTAChC and at 1670 cm-1 for C=O stretching and 1545 cm-1 for N–H bending of NMA-HTAChC which confirms the synthesized derivatives. The structure of chitosan, NOCh, CMCh, CMCh-g-AA, HTAChC and NMA-HTAChC were investigated by FTIR and 1H NMR. Jute and cotton fibres were modified with prepared chitosan and its functional derivatives. Optimized modification conditions for jute and cotton with chitosan, NOCh, CMCh, CMCh-g-AA, HTAChC and NMA-HTAChC where modifier concentration 20% on the basis of weight of fibre, 5% K2S2O8, 5% FeSO4 based on the weight of monomer, solid liquor ration of 1:50 temperature 550C and time for 60 min. Grafting of chitosan, NOCh, CMCh, CMCh-g-AA, HTAChC and NMA-HTAChC on cellulosic fibre surfaces were confirmed by graft yield percent for jute 6.79%, 6.12%,12.06%, 9.39%, 10.69% and 14.74% and for cotton 11.78%, 10.75%, 16.77%, 12.06%, 14.56% and 18.86% respectively. FTIR at 1600 cm-1 for the NH2 group, at 1516 cm-1 for C-H stretching, at 1740 cm-1 for –COOH group, at 1319 cm-1 for poly (AA), at 1480 cm-1 for C=O stretching and 1545 cm-1 for N–H bending respectively due to incorporation of said modifier on cellulosic fibres. The surface of fibres was investigated by Scanning Electron Microscopy (SEM) and modified fibres surface was smoother than unmodified fibres. X-ray diffraction pattern showed moderate crystallinity and the order is as follows: chitosan modified > NOCh modified > CMCh modified > CMCh-g-AA modified > HTAChC modified > and NMA-HTAChC modified cellulosic jute and cotton. The thermal behavior of modified fibres was also investigated by TGA, DTA and DTG analysis. On the basis of initial decomposition temperature (Ti) thermal stability of those jute and cotton fibres follows the order, chitosan modified > CMCh modified > unmodified > NOCh modified > HTAChC modified > CMCh-g-AA modified, NMA- HTAChC modified and chitosan modified > unmodified > HTAChC modified > NOCh modified > NMA- HTAChC modified > CMCh modified > CMCh-g-AA modified respectively. It was observed that textile modifying properties of NMA-HTAChC is comperatively better than that of other functional chitosan derivatives due to higher fibre affinity of NMA-HTAChC. It was also observed that over all modification showed improved chemical resistance to acid and alkali, moisture absorbency, tensile strength, moderate thermal stability and reduced swelling resistance in different solvent, compared to unmodified jute and cotton fibres. The modified fibres were dyed with reactive dyes (Reactive Orange 14 and Reactive Brown 10) and direct dyes (Direct Orange 31 and Direct Yellow 29). Dyeing of modified and unmodified jute and cotton fibres revealed that dye exhaustions were increased up to 10% due to modification through sorption of prepared chitosan and its functional derivatives causes the increment of reactive sites of the fibres which also enhanced the sunlight, wash, alkali and acid fastness of the dyed fibres. Chitosan and its functional derivatives are safe, biocompatible and ecofriendly substances for human use so those are valuable as textile materials for textile and garment finishing.Item A Study on the Electrochemical Dissolution of Ilmenite, Zircon and Lead Sulphate(University of Rajshahi, 2017) Zakaria, Md. Golam; Biswas, Ranjit Kumar; Ali, M. RostomIlmenite and zircon used in the investigation were collected in a single lot from Bangladesh Atomic Energy Commission's Pilot Plant for separation of heavy minerals from beach sands at Cox's Bazar. The lead sulphate was collected on dismantling of locally available waste lead-acid batteries. The ilmenite, zircon and lead sulphate were characterized by XRD and EDAX analyses. The electrochemical dissolution technique was used to investigate on the dissolutions of ilmenite, zircon and lead sulphate in sulfuric acid solutions, sodium hydroxide solutions and nitric acid solutions, respectively, at various conditions. Cyclic voltammetry was used as a reliable source to determine the dissolution potentials of ilmenite, zircon and lead sulphate. It was seen from the cyclic voltammetric studies that the dissolution of ilmenite was very difficult without the addition of graphite powder in ilmenite. The effects of ilmenite-graphite ratio, acid concentration and temperature on cyclic voltammograms were investigated to understand the dissolution process of ilmenite. The investigated results showed that the dissolution rate of ilmenite (FeTiO3) was low at low applied reduction potentials (˂-0.40 V) and temperatures (˂60 C). However, the dissolution rate was increased at more negative applied reduction potentials and higher temperatures. The dissolution rate was also increased on increasing acid concentration up to 1 mol dm-3; and at more acid concentration and higher reduction potential, it was decreased due to the starting of H2 gas evolution which eventually decreased the active surface area of pellet by adsorption. The activation energy (Ea) was estimated as 50±10 kJ mol-1 in the higher temperature region (htr) and 15±5 kJ mol-1 in the lower temperature region (ltr). The value of activation energy suggested the process to be diffusion controlled at ltr and chemically controlled at htr. The dissolution of zircon fraction could not be obtained in NaOH solution without the addition of graphite in zircon fraction due to low conductivity of zircon fraction. The effects of zircon-graphite ratio, acid concentration and temperature on cyclic voltammograms were investigated to understand the dissolution process of zircon. The dissolution rate of zircon (ZrSiO4) was low at low applied reduction potentials (<-0.30 V) and temperatures (<75 C). At more negative potentials and higher temperatures, the dissolution rate of zircon was increased through increasing rate of the reduction of Zr4+. The dissolution rate was also increased on increasing alkali concentration up to 3 mol dm-3; and at higher alkali concentration and higher reduction potentials, it was decreased due to the starting of H2 gas evolution which eventually decreased the active surface area of zircon pellet by adsorption. The values of Ea in the higher (~ 85 C), intermediate (~70 C) and lower (~30 C) temperature regions are 23±1 kJ mol-1, 45±10 kJ mol-1 and 20±5 kJ mol-1, respectively. The values of Ea, at low temperature region suggested that the process was diffusion controlled; and with the rise of temperature, the diffusion layer/film was anyhow destroyed to convert the process to be chemical controlling at ~70 C. Low value of activation energy at higher temperature was an indicative to two parallel reactions. The dissolution of storage battery waste product (PbSO4) could not be obtained in HNO3 solution without the addition of graphite in battery waste due to low conductivity of battery waste product (PbSO4). The dissolution rate of lead from storage battery waste product (PbSO4) was low at applied reduction potentials up to -0.52 V and temperatures below 60 C. At higher temperatures, the dissolution rate of lead from battery waste product (PbSO4) was increased through increasing rate of the reduction of PbO2 and PbSO4. The dissolution rate of lead was also increased on increasing HNO3 acid concentration up to 1 mol dm-3; and at more higher HNO3 concentration (˃1.0 mol dm-3), the slow increasing rate of the dissolution of lead from storage battery waste was observed due to the starting of H2 gas evolution resulting in the decrease of the active surface area of storage battery waste pellet by adsorption. The values of Ea in the higher (˃60 C)) and lower temperature regions (˂60 C) were estimated to be 45±5 kJ mol-1 and 2±1 kJ mol-1, respectively. The values of Ea suggested the existence of a diffusion film at lower temperature which was believed to be destroyed at higher temperature. At lower temperature region, the process was diffusion controlled and with the rise of temperature, the process became chemically controlling.Item Synthesis and Chracterization of Eco-Friendly Hydrogels from Cellulosic Materials(University of Rajshahi, Rajshahi, 2019) Haque, Md. Obaidul; Mondal, Md. Ibrahim H.; Sayeed, Md. Abu; Yeasmin, Mst. SarminaHydrogels are insoluble, three-dimensional, crosslinked polymeric networks which swell in the presence of water and other fluids. They can imbibe plenty of water without dissolution compared to their own mass. Most of the present superabsorbent hydrogels are petrochemical-based and non-degradable in nature. Cellulose is the most abundant natural biopolymer which possess an intrinsic nature of degradability, biocompatibility and non-toxicity. Some cellulose derivatives show smart behavior. Cellulose-based biodegradable Super Absorbent Hydrogels (SAH) have been synthesized from three cellulosic materials (cotton, sugarcane bagasse and CMC) by simple and energy-efficient graft co-polymerization. Among the materials, cotton is pure cellulosic material. Sugarcane bagasse is a cellulose-enriched agro-waste product. Carboxymethyl cellulose (CMC) is the most-consumed cellulose derivative all over the world. Every year, in Bangladesh, a large amount of agro-waste is produced and becomes a source of environmental pollution. This is one reason that three cellulosic sources (cotton, sugarcane bagasse and carboxymethyl cellulose) have been chosen for this research to synthesize biodegradable hydrogels. Besides synthesis, another objective was to characterize the product, physically and instrumentally, and find the applications which could be beneficial to human welfare. Biocompatible hydrogels were synthesized from base material cellulosic sources (cotton, sugarcane bagasse and carboxymethyl cellulose) and, by varying combinations of monomers [acrylic acid (AA), acrylamide (Am) and methyl methacrylate (MMA) and one polymer-poly vinyl pyrollidone(PVP)], a number of hydrogel samples were synthesized. The prepared hydrogels in this research work are, i) Cot-g-poly(AA-co-Am) hydrogel; ii) Cot-g-poly(Am-co-PVP) hydrogel; iii) Cot-g-poly(Am-co-MMA) hydrogel; iv) Sugarcane bagasse-g- poly(AA-co-Am) hydrogel; v) Sugarcane bagasse-g-poly(Am-co-PVP) hydrogel; vi) Sugarcane bagasse-g- poly(Am-co-MMA) hydrogel; vii) CMC-g- poly(AA-co-Am) hydrogel; viii) CMC-g-poly(Am-co-PVP) hydrogel; ix) CMC-g- poly(Am-co-MMA) hydrogel and x) anti-microbial hydrogel.