Browsing by Author "Rahman, Farzana"

Now showing 1 - 19 of 19

Adsorption Mechanism of Methylene Blue by Graphene Oxide-Shielded Mg-Al-Layered Double Hydroxide from Synthetic Wastewater
(ACS Publications, 2021-01-22) Dhar, Loknath; Hossain, Saddam; Rahman, Md Sajjadur; Quraishi, Shamshad B.; Saha, Koushik; Rahman, Farzana; Rahman, Mir Tamzid
Pollution of water resources by various pollutants is a global environmental issue, particularly, dye pollution has a major contribution to it. From various studies, it is confirmed that adsorption is an excellent remediation technique compared to others. Mg–Al-layered double hydroxides (LDHs) intercalated with NO3– ions act as an effective adsorbent-removing ionic species like heavy metal and dyes. Another popular nanomaterial is graphene oxide (GO), which is successfully used as an adsorbent for different pollutants like dye and heavy metal ions. It is prepared based on the modified Hummers method. In this study, GO was introduced on the surface of LDH to improve its adsorption capacity. The adsorption process is well described by the Freundlich model. The maximum adsorption capacity was obtained at around 0.5 and 0.85 mmol of methylene blue (MB) per gram of Mg–Al LDH and modified Mg–Al LDH with GO, respectively. The reaction kinetics of MB with both adsorbents is determined to be the pseudo-second-order. To get more insights of the mechanism, molecular dynamics (MD) simulation was conducted among the modified Mg–Al LDH with GO and MB molecules at both low- and high-concentration environments, which demonstrated that the developed composite adsorbs MB molecules predominantly onto its GO surface and then the MB molecules are adsorbed by the LDH surface. C–H···O (2.49–3.04 Å) and pi-donor···H–O (2.45–3.05 Å) are the major driving forces behind the strong adsorbability. Besides, S···H–O, S···O,N···O–H, pi···lone pair, pi···sigma, pi···cation, and alkyl···hydrophobic interactions play important roles in stabilizing the MB molecules onto the surface of the composite.
Adsorption Mechanism of Methylene Blue by Graphene Oxide-shielded Mg-al-layered Double Hydroxide from Synthetic Wastewater
(The Journal of Physical Chemistry, 2021) Dhar, Loknath; Rahman, Md Sajjadur; Hossain, Saddam; Quraishi, Shamshad B.; Saha, Koushik; Rahman, Farzana; Sarker, Uttam Kumar; Rahman, Mir Tamzid
Pollution of water resources by various pollutants is a global environmental issue, particularly, dye pollution has a major contribution to it. From various studies, it is confirmed that adsorption is an excellent remediation technique compared to others. Mg–Al-layered double hydroxides (LDHs) intercalated with NO3– ions act as an effective adsorbent-removing ionic species like heavy metal and dyes. Another popular nanomaterial is graphene oxide (GO), which is successfully used as an adsorbent for different pollutants like dye and heavy metal ions. It is prepared based on the modified Hummers method. In this study, GO was introduced on the surface of LDH to improve its adsorption capacity. The adsorption process is well described by the Freundlich model. The maximum adsorption capacity was obtained at around 0.5 and 0.85 mmol of methylene blue (MB) per gram of Mg–Al LDH and modified Mg–Al LDH with GO, respectively. The reaction kinetics of MB with both adsorbents is determined to be the pseudo-second-order. To get more insights of the mechanism, molecular dynamics (MD) simulation was conducted among the modified Mg–Al LDH with GO and MB molecules at both low- and high-concentration environments, which demonstrated that the developed composite adsorbs MB molecules predominantly onto its GO surface and then the MB molecules are adsorbed by the LDH surface. C–H•••O (2.49–3.04 Å) and pi-donor•••H–O (2.45–3.05 Å) are the major driving forces behind the strong adsorbability. Besides, S•••H–O, S•••O,N•••O–H, pi•••lone pair, pi•••sigma, pi•••cation, and alkyl•••hydrophobic interactions play important roles in stabilizing the MB molecules onto the surface of the composite.
Diagnosed hematological malignancies in Bangladesh - a retrospective analysis of over 5000 cases from 10 specialized hospitals
(© 2014 BioMed Central Ltd., 2014) Sorowar Hossain, Mohammad; Iqbal, Mohd S; Ahmed Khan, Mohiuddin; Golam Rabbani, Mohammad; Khatun, Hazera; Munira, Sirajam; Miah, M Morshed Zaman; Kabir, Amin Lutful; Islam, Naima; Farhana Dipta, Tashmim; Rahman, Farzana; Mottalib, Abdul; Afrose, Salma; Ara, Tasneem; Biswas, Akhil Ranjan; Rahman, Mizanur; Abedin, AKM Mustafa; Rahman, Mahbubur; Yunus, ABM; Niessen, Louis W; Sultana, Tanvira Afroze
Background: The global burden from cancer is rising, especially as low-income countries like Bangladesh observe rapid aging. So far, there are no comprehensive descriptions reporting diagnosed cancer group that include hematological malignancies in Bangladesh.Methods: This was a multi-center hospital-based retrospective descriptive study of over 5000 confirmed hematological cancer cases in between January 2008 to December 2012. Morphological typing was carried out using the " French American British" classification system.Results: A total of 5013 patients aged between 2 to 90 years had been diagnosed with malignant hematological disorders. A 69.2% were males (n = 3468) and 30.8% females (n = 1545), with a male to female ratio of 2.2:1. The overall median age at diagnosis was 42 years. Acute myeloid leukemia was most frequent (28.3%) with a median age of 35 years, followed by chronic myeloid leukemia with 18.2% (median age 40 years), non-Hodgkin lymphoma (16.9%; median age 48 years), acute lymphoblastic leukemia (14.1%; median age 27 years), multiple myeloma (10.5%; median age 55 years), myelodysplastic syndromes (4.5%; median age 57 years) and Hodgkin's lymphoma (3.9%; median age 36 years). The least common was chronic lymphocytic leukemia (3.7%; median age 60 years). Below the age of 20 years, acute lymphoblastic leukemia was predominant (37.3%), followed by acute myeloid leukemia (34%). Chronic lymphocytic leukemia and multiple myeloma had mostly occurred among older patients, aged 50-over.Conclusions: For the first time, our study presents the pattern and distribution of diagnosed hematological cancers in Bangladesh. It shows differences in population distributions as compared to other settings with possibly a lower presence of non-Hodgkin lymphoma. There might be under-reporting of affected women. Further studies are necessary on the epidemiology, genetics and potential environmental risk factors within this rapidly aging country.
Diagnosed hematological malignancies in Bangladesh - a retrospective analysis of over 5000 cases from 10 specialized hospitals
(© 2014 BioMed Central Ltd., 2014) Sorowar Hossain, Mohammad; Iqbal, Mohd S; Ahmed Khan, Mohiuddin; Golam Rabbani, Mohammad; Khatun, Hazera; Munira, Sirajam; Miah, M Morshed Zaman; Kabir, Amin Lutful; Islam, Naima; Farhana Dipta, Tashmim; Rahman, Farzana; Mottalib, Abdul; Afrose, Salma; Ara, Tasneem; Biswas, Akhil Ranjan; Rahman, Mizanur; Abedin, AKM Mustafa; Rahman, Mahbubur; Yunus, ABM; Niessen, Louis W; Sultana, Tanvira Afroze
Background: The global burden from cancer is rising, especially as low-income countries like Bangladesh observe rapid aging. So far, there are no comprehensive descriptions reporting diagnosed cancer group that include hematological malignancies in Bangladesh.Methods: This was a multi-center hospital-based retrospective descriptive study of over 5000 confirmed hematological cancer cases in between January 2008 to December 2012. Morphological typing was carried out using the " French American British" classification system.Results: A total of 5013 patients aged between 2 to 90 years had been diagnosed with malignant hematological disorders. A 69.2% were males (n = 3468) and 30.8% females (n = 1545), with a male to female ratio of 2.2:1. The overall median age at diagnosis was 42 years. Acute myeloid leukemia was most frequent (28.3%) with a median age of 35 years, followed by chronic myeloid leukemia with 18.2% (median age 40 years), non-Hodgkin lymphoma (16.9%; median age 48 years), acute lymphoblastic leukemia (14.1%; median age 27 years), multiple myeloma (10.5%; median age 55 years), myelodysplastic syndromes (4.5%; median age 57 years) and Hodgkin's lymphoma (3.9%; median age 36 years). The least common was chronic lymphocytic leukemia (3.7%; median age 60 years). Below the age of 20 years, acute lymphoblastic leukemia was predominant (37.3%), followed by acute myeloid leukemia (34%). Chronic lymphocytic leukemia and multiple myeloma had mostly occurred among older patients, aged 50-over.Conclusions: For the first time, our study presents the pattern and distribution of diagnosed hematological cancers in Bangladesh. It shows differences in population distributions as compared to other settings with possibly a lower presence of non-Hodgkin lymphoma. There might be under-reporting of affected women. Further studies are necessary on the epidemiology, genetics and potential environmental risk factors within this rapidly aging country.
Effective synthesis of ethylene urea from CO2 adsorbed cerium doped Mg–Al layered double hydroxide
(Scopus, 2024-01) Rahman, Farzana; Yang, Xinyi; Motswaiso, Fiona; Takanashi, Itsuki; Kameda, Tomohito; Rahman, Mir Tamzid; Saito, Yuko; Kumagai, Shogo; Yoshioka, Toshiaki
The steady increase in CO2 levels in the atmosphere is the leading cause of climate change and global warming and is now a global concern. To reduce the impact of CO2, various novel routes have been proposed to capture, utilize, and convert it into valuable chemicals. In this study, a noble Ce-doped Mg–Al layered double hydroxide (Mg–Al LDH) [Mg/Al molar ratio = 3 and Ce/Al molar ratio = 0.1, 0.5, 1.0] were synthesized using co-precipitation and sol–gel method and used as an adsorbent for CO2 gas and later on efficient source of CO2 in the synthesis of ethylene urea (EU). The specific surface area of the Ce-doped Mg–Al LDHs prepared by sol-gel method (96.1–333 m2/g) were higher than co-precipitation method (0.5–10.6 m2/g). Each Ce-doped Mg–Al LDHs were successfully adsorbed CO2, where first desorption occurred at around 50–250 °C temperature. The comparative adsorption of CO2 was observed increase with decreasing the Ce/Al molar ratio. Adsorption of CO2 was found to be 0.05, 0.04, 0.04 mmol/g for co-precipitation method and 0.62, 0.42, 0.37 mmol/g for sol-gel method, where Ce/Al molar ratio was 0.1, 0.5, 1.0 respectively. The EU produced from the reaction between ethylenediamine (EDA) and CO2 adsorbed Ce-doped Mg–Al LDHs, where a comparative amount of EU was observed in the order of Ce/Al molar ratio = 1.0 > 0.5 > 0.1. According to the temperature effect, EU production was increased with an increase in temperature from 120 °C to 160 °C. At 160 °C, the production of EU by co-precipitation method was found to be 0.03, 0.04, 0.07 mmol/g and by sol-gel method was found to be 0.06, 0.07, 0.16 mmol/g, where Ce/Al molar ratio was 0.1, 0.5, 1.0 respectively. A much higher production was found in all the Ce-doped Mg–Al LDHs compared to pristine Mg–Al LDH at all the temperatures. The performance of Ce-doped Mg–Al LDHs synthesized by the sol-gel method was observed to be better than that of the co-precipitation method in terms of both adsorption of CO2 and production of EU. In this study, Ce-doped Mg–Al LDH introduced as a successful CO2 adsorbent, a source of CO2 and an effective promoter in the ethylene urea production.
Effects of temperature on plant growth and arsenic removal efficiency of Pteris vittata in purifying arsenic-contaminated water in winter: A two-year year-round field study
(Scopus, 2024) Kohda, Yi Huang-Takeshi; Miyauchi, Keisuke; Rahman, Farzana; Naruse, Haruki; Mito, Mitsuaki; Kitajima, Nobuyuki; Chien, Mei-Fang; Endo, Ginro; Inoue, Chihiro
Phytoremediation is a cost-effective and eco-friendly alternative method for arsenic (As) contaminated water treatment. This study conducted a two-year year-round field study (cycle1 and cycle2) in a temperate area (Sendai, Japan) using small As-hyperaccumulator Pteris vittata seedlings to reduce pre-cultivation time and associated costs. The number of seedlings was changed from 256 in the cycle1 period to 165 in the cycle2 period to evaluate the As removal efficiency of P. vittata for As-contaminated water in field conditions with different plant densities. Before the winter season, with continuously increasing fronds, rhizomes, and roots growth, this reduction did not affect the plant's As removal efficiency for As-contaminated water to decrease the As concentration from 30 μg/L to the environmental quality standard for As in water, set at 10 μg/L in Japan. During the winter season, we found that cold weather caused P. vittata to wither and release the accumulated As into water without a greenhouse (cycle1). In the meantime, the bioaccumulation factor (BAF) and the translocation factor (TF) values for fronds of P. vittata decreased (BAF for fronds: from 66,089 to 8,460; TF for fronds: from 13.4 to 3.4). On the other hand, with greenhouse protection (cycle2), P. vittata did not severely wither and kept accumulating As. Moreover, BAF and TF values for fronds of P. vittata increased (BAF for fronds: from 24,372 to 36,740; TF for fronds: from 5.2 to 17.2). Maintaining the air temperature inside the greenhouse, particularly around the rhizomes, above 0 °C may be the reason why P. vittata remained alive and functional during the cold winter. These results indicate that a single-layer polyethylene greenhouse was sufficient for the tropical-subtropical As-hyperaccumulator fern P. vittata to survive the cold winter and snow in the temperate area, enabling year-round phytoremediation treatment of As-contaminated water in the open field.
Effects of temperature on plant growth and arsenic removal efficiency of Pteris vittata in purifying arsenic-contaminated water in winter: A two-year year-round field study
(Scopus, 2024-08) Kohda, Yi Huang-Takeshi; Miyauchi, Keisuke; Rahman, Farzana; Naruse, Haruki; Mito, Mitsuaki; Kitajima, Nobuyuki; Chien, , Mei-Fang; Endo, Ginro; Inoue, Chihiro
Phytoremediation is a cost-effective and eco-friendly alternative method for arsenic (As) contaminated water treatment. This study conducted a two-year year-round field study (cycle1 and cycle2) in a temperate area (Sendai, Japan) using small As-hyperaccumulator Pteris vittata seedlings to reduce pre-cultivation time and associated costs. The number of seedlings was changed from 256 in the cycle1 period to 165 in the cycle2 period to evaluate the As removal efficiency of P. vittata for As-contaminated water in field conditions with different plant densities. Before the winter season, with continuously increasing fronds, rhizomes, and roots growth, this reduction did not affect the plant's As removal efficiency for As-contaminated water to decrease the As concentration from 30 μg/L to the environmental quality standard for As in water, set at 10 μg/L in Japan. During the winter season, we found that cold weather caused P. vittata to wither and release the accumulated As into water without a greenhouse (cycle1). In the meantime, the bioaccumulation factor (BAF) and the translocation factor (TF) values for fronds of P. vittata decreased (BAF for fronds: from 66,089 to 8,460; TF for fronds: from 13.4 to 3.4). On the other hand, with greenhouse protection (cycle2), P. vittata did not severely wither and kept accumulating As. Moreover, BAF and TF values for fronds of P. vittata increased (BAF for fronds: from 24,372 to 36,740; TF for fronds: from 5.2 to 17.2). Maintaining the air temperature inside the greenhouse, particularly around the rhizomes, above 0 °C may be the reason why P. vittata remained alive and functional during the cold winter. These results indicate that a single-layer polyethylene greenhouse was sufficient for the tropical-subtropical As-hyperaccumulator fern P. vittata to survive the cold winter and snow in the temperate area, enabling year-round phytoremediation treatment of As-contaminated water in the open field.
Hydrogel synthesis: Incorporating hydrophobically modified graphite oxide with Mg2Al LDH and alginate coating for evaluating multifarious adsorption utility
(2024-06-15) Rahman, Mir Tamzid; Kameda, Tomohito; Rahman, Farzana; Saito, Yuko; Kumagai, Shogo; Yoshioka, Toshiaki
Addressing diverse water pollutants exposes limitations in specialized methods, requiring costly multi-approach solutions and facing broad acceptance challenges. This study confronts challenges through an in-depth exploration of synthesizing and characterizing the novel Alg[hGO/LDH] hydrogel. This hydrogel, composed of hydrophobically modified graphite oxide (hGO) and Mg2Al layered double hydroxide (LDH), coated with alginate, is meticulously designed using a unique approach to incorporate diverse active sites for adsorbing contaminants within a single material. XRD analysis verifies the effective bonding of hGO to LDH, as indicated by the stepwise formation of the product. FTIR spectra underscore the incremental modification from graphite to Alg[hGO/LDH], revealing various exposed functional groups capable of binding through distinct attractive forces. N2 adsorption/desorption isotherm indicates microporous characteristics, with a BET specific surface area 38.61 m2 g−1 and an average pore diameter 22.57 nm. At a temperature of 25 °C, Alg[hGO/LDH] showcases versatile pH-dependent adsorption behavior towards pollutants, including methylene blue, ibuprofen, naphthalene, arsenic, and lead with removal rates measured at 22.2 %, 20.6 %, 0.7 %, 19.1 %, and 99.9 %, respectively. Mechanistic insights into its sequential formation and adsorption processes highlight electrostatic, π-π interactions, and anion exchange processes. Alg[hGO/LDH] exhibits versatility, promising effectiveness in diverse component adsorption for environmental remediation applications.
Increasing the Potentiality of Graphene Oxide by Chloroacetic Acid for the Adsorption of Lead with Molecular Dynamic Interpretation
(Scopus, 2021) Hossain, Saddam; Rahman, Md Sajjadur; Dhar, Loknath; Quraishi, Shamshad B.; Abser, Md Nurul; Rahman, Farzana; Rahman, Mir Tamzid
The recent progress of graphene oxide (GO), it is considered as the most promising nano adsorbents for water purification. In this study, the adsorption potentiality of this nano material was increased by functionalization of graphene with chloroacetic acid (GO/CAA). The potentiality was evaluated by applying GO and GO/CAA in the removal of lead (Pb) from synthetic waste water. The analyses of FTIR spectroscopy, X-ray diffraction patterns, and scanning electron microscope supported to the successful preparation of GO/CAA from GO. In case of adsorption of Pb (II) by GO and GO/CAA, Langmuir adsorption isotherm indicated more fit for describing the Pb (II) adsorption. According to the Langmuir adsorption isotherm, the maximum adsorption capacities (qe) of GO and GO/CAA were found 0.25 and 0.52 mol/g, respectively. The pseudo second order model displayed higher correlation and hence elucidates the reaction kinetics well with both GO and GO/CAA. Molecular level insights obtained from the molecular dynamics study proved that the studied GO shows excellent adsorption efficiency to the Pb2+ ions by the intermolecular interactions among the Pb cations and oxygen atoms of the GO surface, where anions of the lead compounds could help Pb2+ ions to form clusters around GO layers. Overall, this study suggests that the modification of GO exposed higher potentiality in the purification of Pb (II).
Influence of Low Temperature on Comparative Arsenic Accumulation and Release by Three Pteris Hyper accumulators
(Scopus, 2021) Rahman, Farzana; Sugawara, Kazuki; Wei, Shujun; Kohda, Yi Huang-Takeshi; Chien, Mei-Fang; Inoue, Chihiro
Arsenic (As) hyperaccumulator Pteris ferns are renowned for their capacity to accumulate as and have been used to remediate as-contaminated environment. However, there is less information on how they perform under low temperature though it is important for practical phytoremediation. The purpose of this study was to identify the effect of temperature on as accumulation by three as hyperaccumulators, Pteris multifida, Pteris cretica and Pteris vittata. Ferns were cultured with 5 mg/L as addition under 25 °C to 5 °C for 15 days. The results showed that dropping of temperatures reduced as accumulation by P. vittata moderately but not P. multifida and P. cretica until 10 °C. At 5 °C, all ferns discontinued as accumulation, and the morphology showed necrosis in P. vittata, wherein P. multifida and P. cretica kept healthy. The as distribution showed that as was mainly accumulated in fronds, while P. multifida stored partial as in its root. Both translocation factor and as efflux showed that temperate zone ferns manage as more strictly as compared to P. vittata. Our findings demonstrated that temperature should be considered when applying Pteris ferns for as phytoremediation, and P. multifida could be the most suitable fern for treating As-contaminated water in temperate zone area.
International standard hotel at Mujgunni, Khulna
(BRAC University, 2022-09) Rahman, Farzana; Ahmed, Iftekhar; Faruk, Mohammad
Hotel is the place where tourism and hospitality hold a very significant position by providing the guests their best experience with proper comfort and accommodations. An important tourist attraction area like Khulna division needs more accommodation opportunities for the tourists from all over the world. Mujgunni is located at the heart of Khulna division, making it more convenient for the users to access all the nearby tourist attractions within the district including historical places, heritage sites, amusement park and other recreational zones. Moreover, Sheikh Abu Naser stadium, the only stadium of Khulna division is located at the district of Mujgunni which is a great potential for the tourists to come over. So, BPC decided to take in a project of five star hotel with international standard facilities for the users, right beside the stadium. The main goal of this project would be to provide proper facilities with comfort and luxury to all kind of tourists and also this project would provide all kind of commercial, business and recreational facilities according to the demands of the local people of that area. Lastly, this project has great potential to invite the significant natural ambience of Mujgunni to provide the guests an amazing experience with appropriate privacy and comfort.
Mechanistic Insights of the Adsorption of Eriochrome Black T by the Formulated Mg–Al LDH-Graphene Oxide Composite
(Scopus, 2021) Dhal, Loknath; Rahman, Md Sajjadur; Hossain, Saddam; Quraishi, Shamshad B.; Saha, Koushik; Rahman, Farzana; Sarker, Uttam Kumar; Rahman, Mir Tamzid
Adsorption is one of the best techniques to mitigate industrial dye pollution. In this study, surface of the Mg–Al layered double hydroxide (LDH) was modified with graphene oxide (GO) to improve its adsorption efficacy of Eriochrome Black T (EBT) dye molecules. A higher correlation coefficient value of the Langmuir adsorption model indicated monolayer adsorption of EBT at the active sites of Mg–Al LDH. The optimum adsorption potential was obtained around 0.4 and 1.4 mmol of EBT per g of the LDH and the modified LDH, respectively, and both adsorbents followed pseudo-second-order kinetics. Molecular dynamics study revealed that both GO and LDH contribute to adsorb EBT. Hydrogen bonds, such as C-H…O, O–H…N, O–H…O = S, O–H…N, and N = O…H–O-Al are the major contributing forces behind the adsorption. Besides, π…alkyl, Mg…O = S, π…cation, π…anion, π…donor, π…sigma, and π…lone pair of interactions are the additional contributing forces behind the enhancement of the efficacy of the modified composite.
Mechanistic Insights of the Adsorption of Eriochrome Black T by the Formulated Mg–Al LDH-Graphene Oxide Composite
(Daffodil International University, 2022-04-02) Dhar, Loknath; Rahman, Md Sajjadur; Hossain, Saddam; Quraishi, Shamshad B.; Saha, Koushik; Rahman, Farzana; Sarker, Uttam Kumar; Rahman, Mir Tamzid
Adsorption is one of the best techniques to mitigate industrial dye pollution. In this study, surface of the Mg–Al layered double hydroxide (LDH) was modified with graphene oxide (GO) to improve its adsorption efficacy of Eriochrome Black T (EBT) dye molecules. A higher correlation coefficient value of the Langmuir adsorption model indicated monolayer adsorption of EBT at the active sites of Mg–Al LDH. The optimum adsorption potential was obtained around 0.4 and 1.4 mmol of EBT per g of the LDH and the modified LDH, respectively, and both adsorbents followed pseudo-second-order kinetics. Molecular dynamics study revealed that both GO and LDH contribute to adsorb EBT. Hydrogen bonds, such as C-H…O, O–H…N, O–H…O = S, O–H…N, and N = O…H–O-Al are the major contributing forces behind the adsorption. Besides, π…alkyl, Mg…O = S, π…cation, π…anion, π…donor, π…sigma, and π…lone pair of interactions are the additional contributing forces behind the enhancement of the efficacy of the modified composite.
Structural Equation Approach to Investigate Trip-chaining and Mode Choice Relationships in the Context of Developing Countries
(Transportation Planning and Technology, 2019-04-03) Hadiuzzaman, Md; Farazi, Nahid Parvez; Hossain, Sanjana; Barua, Saurav; Rahman, Farzana
This paper investigates empirical relationships between trip chain type and mode class choice for developing countries. To formulate these two sets of decisions, four empirical models are developed using structural equation modeling (SEM). Those models are calibrated using one-month travel diary data collected in Dhaka city. SEM correlates the observed variables and identifies their relationship with trip-chaining type utility and mode class choice utility. The fitted models are selected based on statistical results and similarity with the real-life situation. Direct relationships between trip-chaining and mode choice utilities are found insignificant. However, several socio-demographic factors influence both simultaneously. Consequently, it is essential to consider mode class choice concurrently for modeling trip chains. This study also investigates the influencing factors for work-based and non-work-based trip chains separately and effects of road users’ heterogeneity. The research results can be utilized to perceive trip chain-mode choice patterns for developing countries.
Synthesis of ethylene urea using carbon-dioxide-adsorbed titanium–zirconium mixed oxides
(Scopus, 2024-08) Motswaiso, Fiona; Suzuki, Ukyo; Sawaguchi, Kyosuke; Rahman, Farzana; Kameda, Tomohito; Kumagai, Shogo; Saito, Yuko; Yoshioka, Toshiaki
To address the increasing global levels of CO2 emissions, it is necessary to develop efficient strategies that can convert CO2 into useful chemicals such as carbonates, ureas, and carbamates. Hybrid systems that combine direct capture and subsequent utilization of CO2 offer a unique emission-controlling pathway for achieving a carbon-neutral society. Ti-Zr mixed oxides could be ideal candidates for CO2 adsorption owing to the high specific surface areas pore sizes. Therefore, in this study, metal oxides with desirable acid-base sites that is, TixZr(1−x)O2 with different Ti/Zr ratios were synthesized using combined sol-gel and solvothermal methods and then utilized to adsorb and synthesize ethylene urea (EU), an important precursor of pharmaceuticals and agricultural products. The results indicated that the CO2 adsorption capacity of TiO2-ZrO2 mixed oxides were higher than that of TiO2 alone at 100 kPa and 25 °C, corresponding to their higher specific surface areas and pore volumes compared to their individual oxide counterparts. CO2-adsorbed TixZr(1−x)O2 was subsequently used as a CO2 source to generate EU through a reaction with ethylenediamine (EDA) and 2-propanol. Notably, samples containing higher proportions of Zr-Ti0.3Zr0.7O2 and ZrO2 produced EU in significant amounts, owing to their acid-base bifunctionality. Overall, EU was synthesized using CO2-adsorbed TixZr(1−x)O2 as a CO2 source and as an accelerator for reacting with EDA, without requiring high-pressure or high-purity CO2.
Synthesis of Ethylene Urea Using Carbon-dioxide-adsorbed Titanium–zirconium Mixed Oxides
(Elsevier, 2024-06-26) Motswaiso, Fiona; Suzuki, Ukyo; Sawaguchi, Kyosuke; Rahman, Farzana; Kameda, Tomohito; Kumagai, Shogo; Saito, Yuko; Yoshioka, Toshiaki
To address the increasing global levels of CO2 emissions, it is necessary to develop efficient strategies that can convert CO2 into useful chemicals such as carbonates, ureas, and carbamates. Hybrid systems that combine direct capture and subsequent utilization of CO2 offer a unique emission-controlling pathway for achieving a carbon-neutral society. Ti-Zr mixed oxides could be ideal candidates for CO2 adsorption owing to the high specific surface areas pore sizes. Therefore, in this study, metal oxides with desirable acid-base sites that is, TixZr(1−x)O2 with different Ti/Zr ratios were synthesized using combined sol-gel and solvothermal methods and then utilized to adsorb and synthesize ethylene urea (EU), an important precursor of pharmaceuticals and agricultural products. The results indicated that the CO2 adsorption capacity of TiO2-ZrO2 mixed oxides were higher than that of TiO2 alone at 100 kPa and 25 °C, corresponding to their higher specific surface areas and pore volumes compared to their individual oxide counterparts. CO2-adsorbed TixZr(1−x)O2 was subsequently used as a CO2 source to generate EU through a reaction with ethylenediamine (EDA) and 2-propanol. Notably, samples containing higher proportions of Zr-Ti0.3Zr0.7O2 and ZrO2 produced EU in significant amounts, owing to their acid-base bifunctionality. Overall, EU was synthesized using CO2-adsorbed TixZr(1−x)O2 as a CO2 source and as an accelerator for reacting with EDA, without requiring high-pressure or high-purity CO2.
Synthesis of Ethylene Urea Using Carbon-dioxide-adsorbed Titanium–zirconium Mixed Oxides
(Elsevier, 2024-06-27) Motswaiso, Fiona; Suzuki, Ukyo; Sawaguchi, Kyosuke; Rahman, Farzana; Kameda, Tomohito; Kumagai, Shogo; Saito, Yuko; Yoshioka, Toshiaki
To address the increasing global levels of CO2 emissions, it is necessary to develop efficient strategies that can convert CO2 into useful chemicals such as carbonates, ureas, and carbamates. Hybrid systems that combine direct capture and subsequent utilization of CO2 offer a unique emission-controlling pathway for achieving a carbon-neutral society. Ti-Zr mixed oxides could be ideal candidates for CO2 adsorption owing to the high specific surface areas pore sizes. Therefore, in this study, metal oxides with desirable acid-base sites that is, TixZr(1−x)O2 with different Ti/Zr ratios were synthesized using combined sol-gel and solvothermal methods and then utilized to adsorb and synthesize ethylene urea (EU), an important precursor of pharmaceuticals and agricultural products. The results indicated that the CO2 adsorption capacity of TiO2-ZrO2 mixed oxides were higher than that of TiO2 alone at 100 kPa and 25 °C, corresponding to their higher specific surface areas and pore volumes compared to their individual oxide counterparts. CO2-adsorbed TixZr(1−x)O2 was subsequently used as a CO2 source to generate EU through a reaction with ethylenediamine (EDA) and 2-propanol. Notably, samples containing higher proportions of Zr-Ti0.3Zr0.7O2 and ZrO2 produced EU in significant amounts, owing to their acid-base bifunctionality. Overall, EU was synthesized using CO2-adsorbed TixZr(1−x)O2 as a CO2 source and as an accelerator for reacting with EDA, without requiring high-pressure or high-purity CO2.
Trapped in desire: Feminine desire and interracial complexities
(BRAC University, 2008-12) Rahman, Farzana; Azim, Firdous
This paper seeks to look at the complexities related to feminine desire as racial issues get combined with it. I will focus on how white female sexuality copes with race issues by looking into two novels and a play. I hope the study of these texts will bring out the predicaments which white female sexuality had to go through due to colonization.
Women and stream of consciousness in Virginia Woolf’s novel: “Mrs. Dalloway” and “To the Lighthouse”
(BRAC University, 2017-04) Rahman, Farzana; Chowdhury, Rukhsana Rahim
Virginia Woolf is best known for her novels, especially “Mrs. Dalloway” (1925) and “To the Lighthouse” (1927), Woolf also wrote pioneering essays on artistic theory, literary history, women’s writing, and the politics of power. Two of Virginia Woolf’s most notable novels, “To the Lighthouse” and “Mrs. Dalloway”, are good examples of the narrative device Stream of Consciousness. At the time, the use of this device was highly experimental. Virginia Woolf applies what is called indirect interior monologue to her writing, which allows her to explore her characters’ stream of consciousness in the third person. For all intents and purposes, this is stream of consciousness as we know and discuss it. Before Woolf, writers had used this stream of consciousness, but their application of it was chaotic and difficult to follow, and it was not very well received by readers. Woolf wrote “Mrs. Dalloway” by exploring the thoughts, feelings, and emotions of her characters, which was very experimental for the time. Woolf’s work exploring the thought, feelings, moods, and expectations of characters in a seamless way changed the structure of writing in a significant way. In this thesis paper, I will discuss and explain the women characterization in these two novel of Virginia Woolf’s “Mrs. Dalloway” and “To the Lighthouse” and will discuss how the term Stream of Consciousness has been applied in these two novel. This thesis divided into four chapters, where several aspects have been discussed from different perspective. The novel “Mrs. Dalloway” and “To the Lighthouse” is the primary source and I have used different articles and several writers’ thoughts for writing this paper.