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Search Results: 1 - 10 of 90 matches for " Luqman Buchori "
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The Influence of Casting Machine Speed in Cellulose Acetate Membrane Preparation
Luqman Buchori
International Journal of Science and Engineering , 2010, DOI: 10.12777/ijse.v1i2.1231
Abstract: Membranes are being increasingly used as a valuable separation tool in laboratory as well as in industrial processes. Continual development of new membrane materials is crucial to sustain and expand the growing interest in this technology and modern polymer chemistry is highly proficient in tailoring polymers with desired properties such as increased mechanical, thermal and chemical stability. Cellulose acetate (CA) is one of the membrane polymers that has been used for aqueous based separation and used as both reverses osmosis (RO) and ultrafiltration (UF) membranes. This paper presents investigation of influence of casting machine speed in membrane preparation. CA is used in this study. That was CA-398-30 with average acetyl content 39.8 wt %. Non solvent used is water and the solvent is 99.7 % organic Dimethyl Sulfoxide (DMSO). The homogenous CA/DMSO solutions were prepared by dissolving CA in DMSO solvent. The CA concentration were varied 13 and 16 % while casting solution speed were varied from 20 to 80 mm/sec with distance cutting machine were fixed at 14 cm. In addition, non solvent in coagulation bath also were varied by 100 % water and 10 % DMSO in water. The results of this experiment describe effect of casting machine speed to water permeability. The effect of CA concentration to water permeability shows the adversative result between 13 and 16 % CA in 100 non solvent water. The similar result also observed in 10 % DMSO in water.
Optimization of Reactor Temperature and Catalyst Weight for Plastic Cracking to Fuels Using Response Surface Methodology
I. Istadi,S. Suherman,Luqman Buchori
Bulletin of Chemical Reaction Engineering & Catalysis , 2010, DOI: 10.9767/bcrec.5.2.797.103-111
Abstract: The present study deals with effect of reactor temperature and catalyst weight on performance of plasticwaste cracking to fuels over modified catalyst waste as well as their optimization. From optimization study,the most operating parameters affected the performance of the catalytic cracking process is reactortemperature followed by catalyst weight. Increasing the reactor temperature improves significantly thecracking performance due to the increasing catalyst activity. The optimal operating conditions of reactortemperature about 550 oC and catalyst weight about 1.25 gram were produced with respect to maximumliquid fuel product yield of 29.67 %. The liquid fuel product consists of gasoline range hydrocarbons (C4-C13)with favorable heating value (44,768 kJ/kg). 2010 BCREC UNDIP. All rights reserved(Received: 10th July 2010, Revised: 18th September 2010, Accepted: 19th September 2010)[How to Cite: I. Istadi, S. Suherman, L. Buchori. (2010). Optimization of Reactor Temperature and Catalyst Weight for Plastic Cracking to Fuels Using Response Surface Methodology. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2): 103-111. doi:10.9767/bcrec.5.2.797.103-111]
Utilizing Shear Factor Model and Adding Viscosity Term in Improving a Two-Dimensional Model of Fluid Flow in Non Uniform Porous Media
Yazid Bindar,,IGBN Makertihartha,,M. Dani Supardan,Luqman Buchori
ITB Journal of Engineering Science , 2007,
Abstract: In a packed bed catalytic reactor, the fluid flow phenomena are very complicated because the fluid and solid particle interactions dissipate the energy. The governing equations were developed in the forms of specific models. The shear factor model was introduced in the momentum equation for covering the effect of flow and solid interactions in porous media. A two dimensional numerical solution for this kind of flow has been constructed using the finite volume method. The porous media porosity was treated as non-uniform distribution in the radial direction. Experimentally, the axial velocity profiles produce the trend of having global maximum and minimum peaks at distance very close to the wall. This trend is also accurately picked up by the numerical result. A more comprehensive shear factor formulation results a better velocity prediction than other correlations do. Our derivation on the presence of porous media leads to an additional viscosity term. The effect of this additional viscosity term was investigated numerically. It is found that the additional viscosity term improves the velocity prediction for the case of higher ratio between tube and particle diameters.
Process Parameters Optimization of Potential SO42-/ZnO Acid Catalyst for Heterogeneous Transesterification of Vegetable Oil to Biodiesel
Istadi Istadi,Didi D. Anggoro,Luqman Buchori,Inshani Utami
Bulletin of Chemical Reaction Engineering & Catalysis , 2012, DOI: 10.9767/bcrec.7.2.4064.150-157
Abstract: Among the possible renewable energy resources, diesel fuels derived from triglycerides of vegetable oils and animal fats have shown potential as substitutes for petroleum-based diesel fuels. The biodiesel could be produced from vegetable oils over homogeneous catalyst, heterogeneous catalyst, or enzymatic catalyst. In this study, the synthesized SO42-/ZnO catalyst was explored to be used in the heterogeneous biodiesel production by using the vegetable oils and methanol. The study began with the preparation of SO42-/ZnO catalyst followed by the transesterification reaction between vegetable oil with methanol. The independent variables (reaction time and the weight ratio of catalyst/oil) were optimized to obtain the optimum biodiesel (fatty acid methyl ester) yield. The results of this study showed that the acid catalyst SO42-/ZnO was potential to be used as catalyst for biodiesel production through heterogeneous transesterification of vegetable oils. Optimum operating condition for this catalytic reaction was the weight ratio of catalyst/oil of 8:1 and reaction time of 2.6 h with respect to 75.5% yield of methyl ester products. The biodiesel product was also characterized to identify the respected fatty acid methyl ester components. Copyright 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME) 2012) Received: 23rd October 2012, Revised: 25th November 2012, Accepted: 25th November 2012 [How to Cite: I. Istadi, Didi D. Anggoro, Luqman Buchori, Inshani Utami, Roikhatus Solikhah, (2012). Process Parameters Optimization of Potential SO42-/ZnO Acid Catalyst for Heterogeneous Transesterification of Vegetable Oil to Biodiesel. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2): 150-157. (doi:10.9767/bcrec.7.2.4064.150-157)] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4064.150-157 ] | View in
Conservation of Agroecosystem through Utilization of Parasitoid Diversity: Lesson for Promoting Sustainable Agriculture and Ecosystem Health
DAMAYANTI BUCHORI,BANDUNG SAHARI,NURINDAH
HAYATI Journal of Biosciences , 2008,
Abstract: For many years, agricultural intensification and exploitation has resulted in biodiversity loss and threaten ecosystem functioning. Developing strategies to bridge human needs and ecosystem health for harmonization of ecosystem is a major concern for ecologist and agriculturist. The lack of information on species diversity of natural enemies and how to utilize them with integration of habitat management that can renovate ecological process was the main obstacle. Parasitoids, a group of natural enemies, play a very important role in regulating insect pest population. During the last ten years, we have been working on exploration of parasitoid species richness, how to use it to restore ecosystem functions, and identifying key factors influencing host-parasitoid interaction. Here, we propose a model of habitat management that is capable of maintaining agricultural biodiversity and ecosystem functions. We present data on parasitoid species richness and distribution in Java and Sumatera, their population structure and its impact toward biological control, relationship between habitat complexes and parasitoid community, spatial and temporal dynamic of parasitoid diversity, and food web in agricultural landscape. Implications of our findings toward conservation of agroecosystem are discussed.
REINCARNATION: RE-APPRAISING THE BELIEF OF YORUBA MUSLIMS WITHIN THE CONTEXT OF ISLAMIC ORTHODOXY
Shaykh Luqman Jimoh
Ilorin Journal of Religious Studies , 2012,
Abstract: Reincarnation is one phenomenon that has always generated great controversies. While some people, based on personal experiences, are convinced of its possibility, some others outrightly denounce it. The Yoruba Muslims with regards to belief in reincarnation are divided into two; a section among them believes in the phenomenon, another section, however, opposes it and denies its occurrence. This study, contextualising the phenomenon within the framework of Islamic orthodoxy, attempts reconciliation between the two opposing views of Yoruba Muslims on reincarnation.
VISCERAL LEISHMANIASIS IN AFGHANISTAN
Muhammad Luqman Butt
The Professional Medical Journal , 2001,
Abstract: Visceral Leishmaniasis also known as Kala-azar is a severe chronic infection of thereticuloendothelial system characterized by fever, chills, weight loss, splenomegaly, anemia,leucopenia, thrombocytopenia and a natural mortality. It is caused by Leishmania donovani. Thisstudy was conducted at Quetta and all the patients were Afghani who came to Quetta fromAfghanistan for the diagnosis and treatment. Our study population consisted of 15 patients, 12 were maleand 3 female. The age ranged from 3 years to 10 years. All patients were presented with massivesplenomegaly. The liver was also enlarged. Thirteen out of fifteen patient presented with pancytopenia, onlytwo patients have leukocyte count within normal range. Reticulocyte response was variable, it was from 0.6to 4.5%. Slight hypercellularity of bone marrow was found in 70% of cases. In most cases histiocytes containlarge number of Leishmania Donovani(LD) bodies, but free L.D. bodies which were released from thehistiocytes were found in all cases.
Encapsulation and Hemocyte Numbers in Crocidolomia pavonana and Spodoptera litura Fabricius (Lepidoptera) Attacked by Parasitoid Eriborus argenteopilosus Cameron (Hymenoptera)
DAMAYANTI BUCHORI,BANDUNG SAHARI,ENDANG SRI RATNA
HAYATI Journal of Biosciences , 2009,
Abstract: Eriborus argenteopilosus is the most important parasitoid attacking cabbage pest Crocidolomia pavonana in Indonesia. Previous studies proved that parasitoid encapsulation was found to be an important factor limiting the effectiveness of the parasitoid in controlling pest population in the field. Since 1998, we have conducted series studies to investigate encapsulation mechanism developed by hosts against parasitoid, responses of parasitoid toward encapsulation ability and to determine factors that may help parasitoid avoid encapsulation. Parasitoid responses were examined on two different hosts C. pavonana and Spodoptera litura. Our findings showed that parasitization level was found to be high both on C. pavonana and S. litura. Encapsulation occurred to be high in all larva stages of C. pavonana, in contrast encapsulation was recorded very low in all larvae stages of S. litura. We recorded that encapsulation in the larval body of C. pavonana was completed in 72 hours and mostly occurred in higher larval stage. Melanization was only recorded in encapsulated parasitoid inside larva body of C. pavonana, not in S. litura. We recorded that encapsulation increased blood cell number of both larvae C. pavonana and S. litura. Encapsulation may affect development of immature parasitoid. Weight of S. litura’s pupae containing encapsulated parasitoid was found to be lower in S. litura, but not in C. pavonana. Our investigation also proved that superparasitism may help parasitoid avoid encapsulation.
Spatial Analysis of Agricultural Landscape and Hymenoptera Biodiversity at Cianjur Watershed
YAHERWANDI,SYAFRIDA MANUWOTO,DAMAYANTI BUCHORI,PURNAMA HIDAYAT
HAYATI Journal of Biosciences , 2006,
Abstract: Hymenoptera is one of the four largest insect order (the other three are Coleoptera, Diptera, and Lepidoptera). There are curerently over 115 000 described Hymenoptera species. It is clear that Hymenoptera is one of the major components of insect biodiversity. However, Hymenoptera biodiversity is affected by ecology, environment, and ecosystem management. In an agricultural areas, the spatial structure, habitat diversity, and habitat composition may vary from cleared landscapes to structurally rich landscape. Thus, it is very likely that such large-scale spatial patterns (landscape effects) may influence local biodiversity and ecological functions. Therefore, the objective of this research were to study diversity and configuration elements of agricultural landscapes at Cianjur Watershed with geographical information sytems (GIS) and its influence on Hymenoptera biodiversity. The structural differences between agricultural landscapes of Nyalindung, Gasol, and Selajambe were characterized by patch analyst with ArcView 3.2 of digital land use data. Results indicated that class of land uses of Cianjur Watershed landscape were housing, mixed gardens, talun and rice, vegetable, and corn fields. Landscape structure influenced the biodiversity of Hymenoptera. Species richness and the species diversity were higher in Nyalindung landscape compare to Gasol and Selajambe landscape.
Polydnavirus Symbiont Detected from Calyx TissuesWasps of Three Lepidopteran Cabbage Pests
ENDANG SRI RATNA,DAMAYANTI BUCHORI,TEGUH SANTOSO
Microbiology Indonesia , 2011, DOI: 10.5454/mi.5.3.3
Abstract: Parasitoid wasps are a potent biological control agent in the field. The successful of parasitism are determined by several factors, among them by the presence of polydnavirus (PDV) symbiont that could break down the immunity mechanism of its host.We explored the existence of PDV on wasps , Snellenius manilae, Cotesia sp., and Diadegma semiclausum a group of parasitoid on cabbage pests in Indonesia. Morphological study of PDV was done by preparing ultrasectioned calyx tissues and negative stained of extracted calyx fluid of adult parasitoids. Virogenic stroma resulted from differentiated calyxepithelial cells appeared on all three wasps. Bracovirus and ichnovirus were detected from the calyx tissues of S. manila and D. semiclausum . The electron dense materials of PDV were distributed within nucleus and vacuolated cytoplasm of calyx cells, calyx lumen and on the surface of eggs wasps. PDVs particles were also shown in the extracted calyx fluid of Cotesia sp.
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