Encapsulation of Submicron-sized Silica Particles by Stimuli-responsive Copolymer Shell Layer

M. Abdur Rahman,M. Rabiul Karim,M. A. Jalil Miah,Hasan Ahmad,Tsuyoshi Yamashita 한국고분자학회 2010 Macromolecular Research Vol.18 No.3

This study examined the encapsulation of submicron-sized silica particles by stimuli-responsive copolymer shell layer. Silica/poly(2-dimethylaminoethyl methacrylate-N-isopropylacrylamide-ethyleneglycol dimethacrylate),abbreviated as silica/P(DM-NIPAM-EGDM) core-shell composite polymer particles, were prepared by the seeded copolymerization of DM, NIPAM and EGDM in the presence of silica particles. The morphology and size distribution were analyzed by scanning electron microscopy. The surface composition showed silica particles covered with a copolymer shell layer consisting of P(DM-NIPAM-EGDM). The temperature and pH dependent adsorption behavior of the low molecular weight surfactants and biomolecules on the silica/P(DM-NIPAM-EGDM) composite polymer particles indicated a stimuli-responsive phase transition. The activity of the adsorbed trypsin (TR) on the composite particles remained high compared to the free TR and adsorbed TR on silica particles.

파키스탄에서의 폐기물관리 - 과제와 해결책

( Abdur Rahman ),( M. Ashraf Moten ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.2

폐기물 관리의 개념은 삶의 질을 향상시키는 것이다. 그러나 이러한 개념은 개발도상국에 있어서는 존재하지 않는 개념이다. 폐기물의 관리는 사회구성원의 참여를 통해서 가장 잘 이루어질 수 있다. 파키스탄에서는 건강을 증진시키고, 환경의 질을 향상시키며, 경제적 여건을 향상시키기 위하여 사회구성원들은 자원을 관리하는 법을 배우기 위한 교육을 받을 필요가 있다. 사회구성원의 파키스탄의 도시지역에서는 매일 55,000톤, 연간 2,000만톤의 폐기물이 발생된다. 폐기물 관리 비용은 톤당 10.5 달러로 산정되며, 이는 폐기물관리비로서 연간 2억 1천만 달러가 소요된다. 각 지방자치체는 예산의 40%를 사용함에도 불구하고 폐기물관리의 기준을 달성하지 못하고 있다. 본 논문은 파키스탄의 8개 도시에서 행한 조사결과에 기초를 두고 있다. 부적절하고 비효율적인 시스템에 의해 폐기물의 절반가량이 수거되지 못하고 있는 것으로 추정되고 있다. 적절한 폐기물 관리는 지자체의 예산을 증가시키고, 생산율을 높이며, 공중위생기준을 향상시키며, 보건상태를 향상시킬 수 있다. 현재 파키스탄에서는 어떤 도시도 폐기물 관리를 위해 잘 계획되고 효율적인 시스템을 갖추고 있지 않다. 이러한 이유로 대도시의 많은 부분, 어떤 경우에는 도시 전체가 환경의 암흑지대로 변해버렸다. 개인 또는 비공식적인 개체를 개입시켜서 효율성을 도모함으로써 각 지자체는 적은 비용으로 폐기물관리 기준을 달성할 수 있다. 청소부와 수거원은 폐기물에서 나온 유가물을 모아서 판매함으로써 이익을 취하면서 폐기물을 사업활동의 매개체로 만들고 있다. 그러므로 이러한 비공식적인 개체는 폐기물 수거, 선별, 재활용품의 판매를 통하여 자원순환을 유도하고 있다. 이러한 활동은 지자체로 하여금 폐기물의 최종처분에 앞선 선별의 부담을 덜어준다. 그러므로 다음과 같은 목적을 갖고 폐기물을 적절히 관리하기 위하여 정책의 개선이 필요하다. ㆍ 폐기물 발생 저감 ㆍ 원료로서 폐기물의 재활용 및 재사용 ㆍ 환경적으로 적합한 방법을 통한 최종폐기물의 처분 The concept of waste management in the world is to improve life. However, this concept is missing in developing nations. Management of solid waste can best be achieved through community participation. In Pakistan, the communities need education to learn how to manage resources to improve their health, enhance the quality of environment and raise their economic situation. It is estimated that the urban areas of Pakistan generates about 55000 tons of solid waste everyday or about 20 million tons per annum. The cost of solid waste management has been estimated at US$ 10.5 per ton requiring an annual allocation of US$ 210 million for solid waste management (SWM). The respective municipalities, despite spending 40% of their budget, have not been able to achieve the desirable standards of SWM. This paper is based on the survey conducted in 8 cities of Pakistan. According to estimates, about half of waste is left uncollected owing to inadequacy and inefficiency of the system. Proper solid waste management can lead to increased revenues for the municipal bodies, higher productivity rate, improved sanitation standard and better health condition. Presently there is not a single city in Pakistan with properly planned and efficient system of SWM. For this reason many parts of large urban areas and in some cases entire cities have turned into environmental black spots. The involvement of private/informal sector enables the respective municipalities to achieve the adequate standards of SWM with reduced cost due to their efficiency and determination. The scavengers/collectors are involved with collection of valuables from solid waste to sell them for economic returns, making solid waste a business activity. Hence this informal sector is busy with resource mobilization through waste collection, sorting and sale of recyclable. This activity reduces the burden of municipalities for sorting of some of the components of solid waste before its final disposal. Thus a strategy needs to be evolved for proper management of solid waste with the objectives to: ㆍ avoid creation of waste ㆍ recycle and reuse waste as raw materials ㆍ dispose off the remaining MSW in an environmentally sound way.

A simple process based on NH2- and CH3-terminated monolayers for low contact resistance and adherent Au electrode in bottom-contact OTFTs

Abdur, R.,Lim, J.,Jeong, K.,Rahman, M. A.,Kim, J.,Lee, J. Springer Science + Business Media 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

<P>An efficient process for the low contact resistance and adherent source/drain Au electrode in bottom-contact organic thin film transistors (OTFTs) was developed. This was achieved by using two different surface-functional groups of self-assembled monolayers, 3-aminopropyltriethoxysilane (APS), and octadecyltrichlorosilane (OTS), combined with atmospheric-pressure (AP) plasma treatment. Prior to the deposition of Au electrode, the amino-terminated monolayer self-assembles on SiO2 dielectrics, enhancing the adhesion of Au electrode as a result of the acid-base interaction of Au with the amino-terminal groups. AP plasma treatment of the patterned Au electrode on the APS-coated surface activates the entire surface to form an OTS monolayer, allowing the formation of a high quality pentacene layer on both the electrode and active region by evaporation. In addition, negligible damage by AP plasma was observed for the device performance. The fabricated OTFTs based on the two monolayers by AP plasma treatment showed the mobility of 0.23 cm(2)/Vs, contact resistance of 29 k Omega-cm, threshold voltage of -1.63 V, and on/off ratio of 9.8 x 10(5), demonstrating the application of the simple process for robust and high-performance OTFTs.</P>

SOLID WASTE MANAGEMENT IN PAKISTAN- CHALLENGES AND OPPORTUNITIES

( Abdur Rahman ),( M. Ashraf Moten ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

The concept of waste management in the world is to improve life. However, this concept is missing in developing nations. Management of solid waste can best be achieved through community participation. In Pakistan, the communities need education to learn how to manage resources to improve their health, enhance the quality of environment and raise their economic situation. It is estimated that the urban areas of Pakistan generates about 55000 tons of solid waste everyday or about 20 million tons per annum. The cost of solid waste management has been estimated at USS 10.5 per ton requiring an annual allocation of US$ 210 million for solid waste management (SWM). The respective municipalities, despite spending 40% of their budget, have not been able to achieve the desirable standards of SWM. This paper is based on the survey conducted in 8 cities of Pakistan. According to estimates, about half of waste is left uncollected owing to inadequacy and inefficiency of the system. Proper solid waste management can lead to increased revenues for the municipal bodies, higher productivity rate, improved sanitation standard and better health condition. Presently there is not a single city in Pakistan with properly planned and efficient system of SWM. For this reason many parts of large urban areas and in some cases entire cities have turned into environmental black spots. The involvement of private/informal sector enables the respective municipalities to achieve the adequate standards of SWM with reduced cost due to their efficiency and determination. The scavengers/collectors are involved with collection of valuables from solid waste to sell them for economic returns, making solid waste a business activity. Hence this informal sector is busy with resource mobilization through waste collection, sorting and sale of recyclable. This activity reduces the burden of municipalities for sorting of some of the components of solid waste before its filial disposal. Thus a strategy needs to be evolved for proper management of solid waste with the objectives to: ㆍ avoid creation of waste ㆍ recycle and reuse waste as raw materials ㆍ dispose off the remaining MSW in an environmentally sound way.

Social behavior practices for child protection and well-being among low-income urban households in Bangladesh

Islam M. Rezaul,Al Gharaibeh Fakir,Azman Azlinda,Hashim Intan H. M.,Islam Md. Robiul,Rahman Abdur 한국사회복지학회 2023 Asian Social Work and Policy Review Vol.17 No.1

The main objective of this study was to explore the status of social behavior practices for child protection and well-being among low-income urban households in Bangladesh. This study used a survey method, and data were collected through a face-to- face structured interview from 378 low-income household heads from 12 wards (Konabari and Kashimpur) of Zone 5 of the Gazipur City Corporation. Results found that the current status of the presence of child protection services is very low (in many cases, this number is zero except children having birth registered). A significant number (55%) of them were married between 15 and 19 years. The study found a low level of access on the components of social behaviors where around 50% to 60% caregivers stated 4 benefits of key behaviors, necessity of hand washing after defecation and before and after taking a meal, the age of boys and girls to get married off, and know the effect and consequences of child marriage. The chi-squared tests confirmed extremely high significance in almost all of the components. Findings will be an important guideline for the policymakers, child service practitioners, and human rights workers.

Magnetic and Temperature-Sensitive Composite Polymer Particles and Adsorption Behavior of Emulsifiers and Trypsin

Ahmad, Hasan,Rahman, M.Abdur,Miah, M.A. Jalil,Tauer, Klaus The Polymer Society of Korea 2008 Macromolecular Research Vol.16 No.7

A combination of magnetic and temperature-responsive properties in the same polymer composites is expected to increase their potential applications in the biomedical field. Accordingly, micron-sized magnetite/polystyrene/poly(2-dimethylaminoethyl methacrylate-ethyleneglycol dimethacrylate), which are abbreviated as $Fe_3O_4$/PS/P (DM-EGDM) composite polymer particles, were prepared by the seeded copolymerization of DM and EGDM in the presence of magnetite/polystyrene ($Fe_3O_4$/PS) particles. $Fe_3O_4$/PS/P(DM-EGDM) composite particles with magnetic properties showed a temperature-sensitive phase transition at approximately $31^{\circ}C$. The adsorption behavior of the low molecular weight emulsifiers and trypsin (TR) as biomolecules were examined on $Fe_3O_4$/PS/P(DM-EGDM) composite polymer particles at different temperatures. The native conformation of TR was followed by measuring the specific activity under various adsorption conditions. The activity of the adsorbed TR on composite polymer particles was higher than those of the tree TR and TR adsorbed on $Fe_3O_4$/PS particles.

Magnetic and Temperature-Sensitive Composite Polymer Particles and Adsorption Behavior of Emulsifiers and Trypsin

Hasan Ahmad,M. Abdur Rahman,M. A. Jalil Miah,Klaus Tauer 한국고분자학회 2008 Macromolecular Research Vol.16 No.7

ITO-free organic solar cell with an PEDOT:PTS/Au/TiO₂ grid hybrid electrode as a transparent anode

Yang, K.,Maniruzzaman, M.,Rahman, M.A.,Abdur, R.,Jeong, K.,Nam, H.S.,Kim, M.J.,Lee, J. Elsevier 2015 CURRENT APPLIED PHYSICS Vol.15 No.suppl1

Poly (3, 4-ethylenedioxythophene): p-toluenesulfonate (PEDOT:PTS)/Au/TiO<SUB>2</SUB> grid hybrid structures were investigated to replace indium tin oxide (ITO) electrodes. The effects of TiO<SUB>2</SUB> on the optical properties of PEDOT:PTS/Au and on the critical thickness of Au films at which point the films become electrically continuous were discussed. The multilayer grids were optimized to provide an average transmission of 81% and a sheet resistance of ~17 @?/@?. In addition, the TiO<SUB>2</SUB> underlayers allowed for the excellent adhesion of the Au grid to a glass substrate. Organic solar cells (OSCs) were fabricated based on PEDOT:PTS(~70 nm)/Au(12.5 nm)/TiO<SUB>2</SUB> (25 nm) grid hybrid anodes and exhibited an open-circuit voltage of 0.62 V, short-circuit current density of 12.27 mA cm<SUP>-2</SUP>, fill factor of 0.51, and power conversion efficiency of 3.88%. These values are comparable to those of ITO-based OSCs. Therefore, PEDOT:PTS/Au/TiO<SUB>2</SUB> grid hybrid structures would be a viable alternative to ITO electrodes for high efficiency organic solar cells.

Effect of Phosphorus, Calcium and Boron on the Growth and Yield of Groundnut (Arachis hypogea L.)

Rezaul Kabir,Sabina Yeasmin,A K M Mominul Islam,Md Abdur Rahman Sarkar 보안공학연구지원센터 2013 International Journal of Bio-Science and Bio-Techn Vol.5 No.3