Biodiesel production process optimization from Spirulina maxima microalgae and performance investigation in a diesel engine

M. A. Rahman,M. A. Aziz,A. M. Ruhul,M. M. Rashid 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

Biodiesel is a renewable, easily biodegradable, eco-friendly and sustainable alternative energy source. In this investigation, crude oil wasextracted from Spirulina maxima microalgae through biochemical conversion method with the help of soxhlet apparatus. Biodiesel productionprocess parameters were optimized through base transesterification. Maximum biodiesel yield achieved was 87.75 % at optimalreaction condition after transesterification, when methanol to oil ratio was 6:1, catalyst loading was 1 % KOH (wt.%), temperature was65 °C, and stirring speed was 600 rpm for a reaction time of 70 minutes. All the physicochemical properties of the produced biodieselwere determined and compared with the ASTM D6751 specification. Finally, performance and emission of an unmodified diesel enginewas evaluated with 20 % and 40 % (v/v) biodiesel blends and compared the results with ordinary Diesel fuel (DF). Using biodiesel blendsimproves Hydrocarbon (HC) emission by 10-15 % and Carbon monoxide (CO) emission by 9.3-13.9 %. However, Brake specific fuelconsumption (BSFC), Oxides of nitrogen (NOX), Carbon dioxide (CO2) and smoke opacity were found to be slightly higher for biodieselblends, and Brake thermal efficiency (BTE) was found slightly lower than DF. Thus, Spirulina maxima serves as a potential feedstock forbiodiesel production and prospective fuel in diesel engine application.

Evaluating the performance of gamma irradiated okra fiber reinforced polypropylene (PP) composites: comparative study with jute/PP

A. N. M. Masudur Rahman,Shah Alimuzzaman,Ruhul A. Khan,Jamal Hossen 한국의류학회 2018 Fashion and Textiles Vol.5 No.1

In this study, two bast fibers such as okra and jute were selected to manufacture composites taking polypropylene (PP) as matrix material by means of compression molding technique with maintaining 40% fiber content on the total weight of the composites. Investigation was done on tensile properties such as tensile strength (TS), tensile modulus (TM), elongation at break (EB%), bending properties such as bending strength (BS), bending modulus (BM) and impact properties like impact strength (IS) and hardness (Shore-A) of the composites. From analyzed data, it was found that Okra/ PP composites showed very competitive mechanical properties to Jute/PP composites. Non-irradiated okra composite showed the value of TS, TM, BS, BM, IS and hardness to be 32.2 MPa, 602 MPa, 55.6 MPa, 3.6 GPa, 19.54 kJ/m2 and 95 (Shore-A), respectively, whereas that value for non-irradiated jute composite was 35.5 MPa, 629 MPa, 71.5 MPa, 4.5 GPa, 21.48 kJ/m2 and 96 (Shore-A), respectively. The composite samples were exposed to different intensities of gamma radiation (250‒1000 krad) at a dose rate of 330 krad/h and changes in mechanical properties were examined. Both irradiated composites (500 krad) showed significant improvement of mechanical properties compared to that of the non-irradiated composites. Maximum TS, TM, BS, BM and IS value were found to be 41.9 MPa, 685 MPa, 72 MPa, 4.7 GPa and 22.6 kJ/m2, respectively for irradiated okra composite and 45.3 MPa, 717 MPa, 88 MPa, 6.7 GPa and 24.3 kJ/m2, respectively for irradiated jute composite. Fourier transform infrared spectroscopy was used to identify the surface groups of the composites. Water absorption, degradation behavior of the composites under soil and heat medium were also performed. Degradation tests revealed that okra composite retained its original mechanical properties higher than that of jute composite. The morphology of the composites was inspected by scanning electron microscope.

CAUSALITY AND DYNAMICS OF ENERGY CONSUMPTION AND OUTPUT: EVIDENCE FROM NON-OECD ASIAN COUNTRIES

RUHUL A. SALIM,SHUDDHASATTWA RAFIQ,A.F.M. KAMRUL HASSAN 중앙대학교 경제연구소 2008 Journal of Economic Development Vol.33 No.2

This article examines the short-run and long-run causal relationship between energy consumption and output in six non-OECD Asian developing countries. Standard time series econometrics is used for this purpose. Based on cointegration and vector error correction modeling, the empirical result shows a bi-directional causality between energy consumption and income in Malaysia, while a unidirectional causality from output to energy consumption in China and Thailand and energy consumption to output in India and Pakistan. Bangladesh remains as an energy neutral economy confirming the fact that it is one of the lowest energy consuming countries in Asia. Both the generalized variance decompositions and the impulse response functions confirm the direction of causality in these countries. These findings have important policy implications for concerned countries. Countries like China and Thailand may contribute to the fight against global warming directly implementing energy conservation measures whereas India and Pakistan may focus on technological developments and mitigation policies. For Malaysia, a balanced combination of alternative policies seems to be appropriate

Causality and Dynamics of Energy Consumption and Output: Evidence from Non-OECD Asian Countries

RUHUL A. SALIM;SHUDDHASATTWA RAFIQ;A.F.M. KAMRUL HASSAN 경제연구소 2008 Journal of Economic Development Vol.33 No.2

This article examines the short-run and long-run causal relationship between energy consumption and output in six non-OECD Asian developing countries. Standard time series econometrics is used for this purpose. Based on cointegration and vector error correction modeling, the empirical result shows a bi-directional causality between energy consumption and income in Malaysia, while a unidirectional causality from output to energy consumption in China and Thailand and energy consumption to output in India and Pakistan. Bangladesh remains as an energy neutral economy confirming the fact that it is one of the lowest energy consuming countries in Asia. Both the generalized variance decompositions and the impulse response functions confirm the direction of causality in these countries. These findings have important policy implications for concerned countries. Countries like China and Thailand may contribute to the fight against global warming directly implementing energy conservation measures whereas India and Pakistan may focus on technological developments and mitigation policies. For Malaysia, a balanced combination of alternative policies seems to be appropriate.

Spectrum Sensing and Data Transmission in a Cognitive Relay Network Considering Spatial False Alarms

Tishita, Tasnina A.,Akhter, Sumiya,Islam, Md. Imdadul,Amin, M. Ruhul Korea Information Processing Society 2014 Journal of information processing systems Vol.10 No.3

In this paper, the average probability of the symbol error rate (SER) and throughput are studied in the presence of joint spectrum sensing and data transmission in a cognitive relay network, which is in the environment of an optimal power allocation strategy. In this investigation, the main component in calculating the secondary throughput is the inclusion of the spatial false alarms, in addition to the conventional false alarms. It has been shown that there exists an optimal secondary power amplification factor at which the probability of SER has a minimum value, whereas the throughput has a maximum value. We performed a Monte-Carlo simulation to validate the analytical results.

Review : Prevention of Lung Cancer: Future Perspective with Natural Compounds

( Johann C Brandes ),( A. R. M. Ruhul Amin ),( Fadlo Khuri ),( Dong Moon Shin ) 대한결핵 및 호흡기학회 2010 Tuberculosis and Respiratory Diseases Vol.69 No.1

Lung cancer remains the most common cause of cancer death in the United States and worldwide. About 80~90% of cases are smoking-related and smoking cessation programs are of great importance in reducing lung cancer risk. However, the lifetime risk for lung cancer remains elevated even in ex-smokers. Chemoprevention holds the promise to further reduce this risk and thus to decrease lung cancer incidence and mortality. Over the last decades, most chemoprevention trials for lung cancer have yielded negative outcomes. Population-based studies suggest that high intake of certain foods such as soy, red wine or green vegetables may be associated with decreased cancer risk. Because of these observations and their general safety, a plethora of natural compounds is currently being studied for the chemoprevention of cancer. In this review we discuss promising in vitro and in vivo data of novel natural compounds, their interference with molecular mechanisms responsible for lung cancer development and potential implications for their further preclinical and clinical investigation.

Prevention of Lung Cancer: Future Perspective with Natural Compounds

Brandes, Johann C.,Amin, A.R.M. Ruhul,Khuri, Fadlo,Shin, Dong-Moon The Korean Academy of Tuberculosis and Respiratory 2010 Tuberculosis and Respiratory Diseases Vol.69 No.1

Lung cancer remains the most common cause of cancer death in the United States and worldwide. About 80~90% of cases are smoking-related and smoking cessation programs are of great importance in reducing lung cancer risk. However, the lifetime risk for lung cancer remains elevated even in ex-smokers. Chemoprevention holds the promise to further reduce this risk and thus to decrease lung cancer incidence and mortality. Over the last decades, most chemoprevention trials for lung cancer have yielded negative outcomes. Population-based studies suggest that high intake of certain foods such as soy, red wine or green vegetables may be associated with decreased cancer risk. Because of these observations and their general safety, a plethora of natural compounds is currently being studied for the chemoprevention of cancer. In this review we discuss promising in vitro and in vivo data of novel natural compounds, their interference with molecular mechanisms responsible for lung cancer development and potential implications for their further preclinical and clinical investigation.