Search for: biotechnology
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    A system-oriented strategy to enhance electron production of Synechocystis sp. PCC6803 in bio-photovoltaic devices: experimental and modeling insights

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Firoozabadi, H ; Mardanpour, M. M ; Motamedian, E ; Sharif University of Technology
    Nature Research  2021
    Bio-photovoltaic devices (BPVs) harness photosynthetic organisms to produce bioelectricity in an eco-friendly way. However, their low energy efficiency is still a challenge. A comprehension of metabolic constraints can result in finding strategies for efficiency enhancement. This study presents a systemic approach based on metabolic modeling to design a regulatory defined medium, reducing the intracellular constraints in bioelectricity generation of Synechocystis sp. PCC6803 through the cellular metabolism alteration. The approach identified key reactions that played a critical role in improving electricity generation in Synechocystis sp. PCC6803 by comparing multiple optimal solutions of... 

    Contested framings and policy controversies: Analysing biosafety policy-making in Iran

    , Article Science and Public Policy ; Volume 40, Issue 5 , 2013 , Pages 616-627 ; 03023427 (ISSN) Kashani, E. S ; Millstone, E ; Sharif University of Technology
    Vigorous debates have taken place within and between many countries about regulatory policy regimes covering the assessment and approval of genetically modified (GM) crops. In Iran, a very vigorous and hotly contested policy debate concerning legislation covering GM crops occurred between 2004 and 2009, but it was confined within government circles with almost no public discussion. This paper analyses the Iranian policy-making process in the period 2006-9. It explains how and why a stalemate arose in disputes between ministries and departments. The chosen analytical framework draws mainly on the regulation of technological risks and the analysis of public policy-making. It deploys the... 

    Biodegradation of phenol from a synthetic aqueous system using acclimatized activated sludge

    , Article Arabian Journal of Geosciences ; Volume 6, Issue 10 , 2013 , Pages 3847-3852 ; 18667511 (ISSN) Jalayeri, H ; Doulati Ardejani, F ; Marandi, R ; Rafiee pur, S ; Sharif University of Technology
    Phenol is one of the aromatic hydrocarbons. Phenol and its derivatives are highly toxic. These pollutants can be observed in the effluents of many industries. This research investigates the removal of phenol by the use of activated sludge in a batch system. The effects of influencing factors on biodegradation efficiency have been evaluated. The main factors considered in this study were the volume of acclimatized activated sludge inoculation, pH, temperature, and initial concentration of phenol. The inoculation volumes of 1, 3, and 5 mL of acclimatized activated sludge were taken into account. Different pH values of 3, 5, 7, 9, and 11 were examined. The experiments were conducted for... 

    Pore-scale investigation of selective plugging mechanism in immiscible two-phase flow using phase-field method

    , Article Oil and Gas Science and Technology ; Volume 74 , 2019 ; 12944475 (ISSN) Sabooniha, E ; Rokhforouz, M. R ; Ayatollahi, S ; Sharif University of Technology
    Editions Technip  2019
    The selective plugging effect of hydrophobic bacteria cell on secondary oil recovery performance was investigated. Water and aqua solution of purified Acinetobacter strain RAG-1 were injected into an oil-saturated heterogeneous micromodel porous media. Pure water injection expelled oil by 41%, while bacterial solution injection resulted in higher oil recovery efficiency (59%). In the simulation section, a smaller part of the heterogeneous geometry was applied as a computational domain. A numerical model was developed using coupled Cahn-Hilliard phase-field method and Navier-Stokes equations, solved by a finite element solver. In the non-plugging model, approximately 50% of the matrix oil was... 

    Effect of C/N ratio on the phytoremediation of crude oil contaminated soils by puccinellia distance

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 27, Issue 3 , September and October , 2008 , Pages 77-85 ; 10219986 (ISSN) Ezzatian, R ; Voussoughi, M ; Yaghmaei, S ; Abedi Koupai, J ; Borghaei, M ; Gholam Reza, P ; Sharif University of Technology
    Petroleum contamination of soil is a serious problem throughout the oil producer countries. Vegetation may play an important role in the biodegradation of toxic organic chemicals in soil. For petroleum compounds, the presence of rhizosphere micro flora may accelerate biodegradation of the contaminants. In a greenhouse study, petroleum contaminated soil were treated using phytoremediation . The C/N ratios and microbial populations were assessed in the beginning and the end of trials. The results showed that Puccinellia distance could tolerate the harsh condition of the soils. As MPN increases, C/N ratios decrease among trials. N, as a nutrient, had effects on both microbial populations and... 

    Deep analysis of Growth’s Pattern of Technological Capabilities in Knowledge-based Companies: Case Studies in Four Different Sectors

    , M.Sc. Thesis Sharif University of Technology Ghorbanian, Mohammad (Author) ; Souzanchi, Ebrahim (Supervisor)
    Technological capabilities as one of the growth’s aspects in developing countries have gained focus for research in last years. This study attempt to analyze the pattern of technological capabilities in four different sectors including Optic, Aerospace, Pharmaceutical and Biotechnology. In each sectors four Iranian companies as the case studies are selected. After deep interviews with key people in each company, required data is gathered. Data in each company is analyzed. The results of analysis for companies in one sector are gathered for analyzing each sector. In order to evaluate technological capabilities, the time required to improve, lead-lag relationship for gaining higher levels of... 

    Ranking of technology transfer barriers in developing countries; case study of Iran's biotechnology industry

    , Article IEEE International Conference on Industrial Engineering and Engineering Management, 6 December 2011 through 9 December 2011, Singapore ; 2011 , Pages 1602-1606 ; 21573611 (ISSN) ; 9781457707391 (ISBN) Yazdani, K ; Rashvanlouei, K. Y ; Ismail, K ; Sharif University of Technology
    In this paper, first we shall define a list of technology transfer barriers in the biotechnology field through interviews and literature reviews. Next, we shall categorize them into four major categories of technology, and at last introduce all of the hypotheses on the existence of relationship between each part of technology and failure in the technology transfer process. Questionnaires consisting of two parts were created and handed out to all of the specialists and biotechnology idea-holders in the Iranian National Research center of Biotechnology, Lidco Co, Iran Pastor Institute, Biotechnology Department of University of Tehran, etc. Going on, we've evaluated the factors' validity... 

    Investigation on penetration of saffron components through lipid bilayer bound to spike protein of SARS-CoV-2 using steered molecular dynamics simulation

    , Article Heliyon ; Volume 6, Issue 12 , December , 2020 Kordzadeh, A ; Ramazani Saadatabadi, A ; Hadi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    A coronavirus identified as COVID-19 is the reason for an infection outbreak which is started in December 2019. NO completely effective drugs and treatments are not recognized for this virus. Recently, saffron and its compounds were used to treat different viral diseases. Saffron extract and its major ingredients have shown antiviral effects. In this study, the steered molecular dynamics simulation was used for investigating the effect of four main components of saffron that include: crocin, crocetin, safranal, and picrocrocin as candidate for drug molecules, on COVID-19. The binding energies between drug molecules and spike protein and the main protease of the virus were evaluated. The... 

    Strategic Studies on Bioproducts Supply at the Present Situation of Local and Global Markets

    , M.Sc. Thesis Sharif University of Technology Hosseini, Hamid Reza (Author) ; Roostaazad, Reza (Supervisor) ; Maleki, Ali (Co-Advisor)
    in the present situation most of the bioproducts are supplied at the global markets. hence newcomers and also existing suppliers should study the economic and social trends to make strategic decisions in order to enter new markets. analysis of the effect of different parameters on the market entrance strategy is the main focus of this thesis. the pivotal subject of this thesis is the analysis of Enzyme industry value chain in Iran and the role of each actor and their interactions with each other. after visualizing the Enzyme industry value chain, we want to answer this question: what are the main obstacles for entering the Enzyme industry due to the interactions between the industry... 

    Development of a Multi Generation Energy System Based on Biotechnologies

    , M.Sc. Thesis Sharif University of Technology Taheri, Neda (Author) ; Roshandel, Ramin (Supervisor)
    In recent years, the issue of sustainability in the energy systems has attracted the attention of energy researchers. Using fossil fuels in common energy conversion systems cause environmental pollution, declining reserves of fossil resources and increase their prices because of the scarcity of fossil resources. Therefore, achieving the goals of sustainability necessitate using high efficiency energy conversion technology. Bio-inspired energy systems are one of the main candidates to improve energy conversion systems. The main target of this study is developing an optimal multi-generation energy system model, dynamically. MFC, Septic tank and Algae culture are integrated and produced power,... 

    Investigation of Constructing a Biosensor for Endotoxin Detection in Biological Products and Comparison of the Results with Conventional Endotoxin Detection Methods

    , M.Sc. Thesis Sharif University of Technology Zandieh, Mohammad (Author) ; Vosoughi, Manouchehr (Supervisor) ; Hosseini, Nezameddin (Supervisor)
    Lipopolysaccharide (LPS), also known as endotoxin, is a highly toxic component exists in the outer membrane of gram negative bacteria. It releases into the environment during every phase of bacterial growth cycle, so it causes contamination of a wide range of biopharmaceutical products. Even small quantities of endotoxin injected to human body can result in fever, septic shock, and death. Therefore, it is highly important to detect and also quantify endotoxin of biopharmaceutical products in quality control laboratories. The most validated method used for endotoxin detection is Limulus Amebocyte Lysate (LAL). Although this method is sensitive, it has some unavoidable drawbacks such as highly... 

    Biodegradation of polychlorinated biphenyls by lysinibacillus macrolides and bacillus firmus isolated from contaminated soil

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 32, Issue 5 , 2019 , Pages 628-633 ; 1728144X (ISSN) Samadi, A ; Sharifi, H ; Ghobadi Nejad, Z ; Yaghmaei, S ; Sharif University of Technology
    Materials and Energy Research Center  2019
    Polychlorinated biphenyls (PCBs) cause many significant ecological problems because of their low degradability, high harmfulness, and solid bioaccumulation.Two bacterial strains were isolated from soil that had been polluted with electrical transformer liquid for more than 40 years. The isolates were distinguished as Lysinibacillus macrolides DSM54Tand Bacillus firmus NBRC15306Tthrough 16S rRNA sequencing analysis.This is the primary report of an agent of the genus Bacillus firmus equipped for the removal of PCBs. The strains could develop broadly on 2-Chlorobiphenyl and 2,4-dichlorobiphenyl. GC/MS analysis of individual congeners revealed up to 80% degradation of the xenobiotics in 96h,... 

    Introducing a new definition towards clinical detection of microvascular changes using diffusion and perfusion MRI

    , Article Scientia Iranica ; Volume 12, Issue 1 , 2005 , Pages 109-115 ; 10263098 (ISSN) Ashoor, M ; Jiang, Q ; Chopp, M ; Jahed, M ; Sharif University of Technology
    Sharif University of Technology  2005
    Based on MRI diffusion and perfusion, a new criterion for detection and the healing progress of damaged tissue is suggested. The study is based on the ratio of capillary radii in symmetrical damaged and normal tissue neighboring spaces. The Apparent Diffusion Coefficient (ADC) and Cerebral Blood Flow (CBF) were measured in the brain tissues of six male Wistar rats utilizing suggested MRI measurement techniques. The ADC values of damaged and normal regions were (392 ± 34.1) × 10-6 mm2s-1 and (659 ± 40.7) × 10-6 mm2s-1, respectively. The CBF values of damaged and normal regions were 14.5 ± 10.13 ml/min/ 100 g and 125 ± 41.03 ml/min/100 g, respectively. The geometrical parameters of the... 

    Use of second-order calibration for residue screening of some triazines in the presence of coeluting interferences by gas chromatography-selected ion mass spectrometry

    , Article Analytica Chimica Acta ; Volume 537, Issue 1-2 , 2005 , Pages 89-100 ; 00032670 (ISSN) Jalali Heravi, M ; Vosough, M ; Sharif University of Technology
    Elsevier  2005
    The quantities of residues of some triazines such as prometon, propazine, atrazine and simazine in complex matrices of apple samples were determined, using gas chromatography-selected ion mass (GC-SIM) spectrometry. Generalized rank annihilation method (GRAM) as a second-order calibration technique was used for screening, resolving and finally determining the amounts of the residues. Before the GRAM analysis, different steps of data preprocessing such as background correction, de-skewing and standardization for rank alignment was used for every target analyte. The de-skewing and rank alignment algorithms were used for bilinearity and trilinearity corrections, respectively. The two data... 

    Immobilization of penicillin G acylase on non-porous ultrafine silica particles

    , Article Scientia Iranica ; Volume 12, Issue 3 , 2005 , Pages 295-299 ; 10263098 (ISSN) Fazelinia, H ; Kheirolomoom, A ; Sharif University of Technology
    Sharif University of Technology  2005
    In this paper, immobilization of penicillin G aclylase onto non-porous ultrafine silica particles has been studied. The amount of penicillin G acylase immobilized was increased by increasing the free enzyme concentration and, at 0.45 mg/ml concentration of the free enzyme, 80% of the enzyme was immobilized. The optimum pH for immobilization was found to be 7.0, close to the pl of the enzyme. Although immobilization of the enzyme on ultrafine silica particles with and without glutaraldehyde showed almost the same activities, the enzyme immobilized with glutaraldehyde retained its initial activity much longer during 40 cycle-repeated batches with a half life of 163.2 h. © Sharif University of... 

    Pumping effect of bubble growth and collapse in microchannels: Thermo-hydraulic modeling

    , Article Scientia Iranica ; Volume 19, Issue 3 , June , 2012 , Pages 431-436 ; 10263098 (ISSN) Sajadi, B ; Saidi, M. H ; Sharif University of Technology
    In the past two decades, microfluidic systems have become more appealing due to their wide applications in many areas, such as electronics, biotechnology, medicine, etc. Recently, the advantages of using the bubble growth phenomenon as a robust actuator in microfluidic devices have directed research interests towards the investigation of various applications. In this research, a new transient thermo-hydraulic model has been developed for bubble growth in confined volumes. The present model has been used to describe the pumping effect produced by the bubble growth and collapse phenomenon in microchannels. The results show relatively good agreement with experimental data. This study is useful... 

    Performances evaluation of Photo-Fenton process and Sonolysis for the treatment of Penicillin G formulation effluent

    , Article 1st 2011 International Conference on Environment Science and Biotechnology, ICESB 2011, Male, 25 November 2011 through 26 November 2011 ; Volume 8 , 2011 , Pages 202-208 ; 18780296 (ISSN) Saghafinia, M. S ; Emadian, S. M ; Vossoughi, M ; Sharif University of Technology
    Penicillin G is an active pharmaceutical ingredient of great importance in health sectors. Meanwhile, because of its huge quantity production and resistance to biodegradability, this antibiotic is ubiquitously presented in aquatic environment. In this study, the degradation of effluent wastewater from Penicillin G production plant by Photo- Fenton process and Ultrasound process (Sonolysis) was investigated, the effects of different process variables in both methods were evaluated and at last the degradation of Pen-G by these two processes in the optimum conditions was compared. Pen-G concentration and Chemical Oxygen Demand (COD) were selected as the environmental parameters to follow the... 

    Effect of pH on aerobic granulation and treatment performance in sequencing batch reactors

    , Article Chemical Engineering and Technology ; Volume 38, Issue 5 , 2015 , Pages 851-858 ; 09307516 (ISSN) Rezasoltani, S ; Shayegan, J ; Jalali, S ; Sharif University of Technology
    Wiley-VCH Verlag  2015
    Two sequencing batch reactors were operated to investigate the effect of influent alkalinity and reactor pH on aerobic granulation. In the first reactor R1 with high influent alkalinity the pH was adjusted in the neutral range, and in the second reactor R2 with low alkalinity the pH was held within the acidic range. The R1-dominating species were bacteria and the appearance time of granules was three weeks after reactor start-up. On the other hand, the acidic environment of R2 provided favorable conditions for fungal growth, and rapid granule formation occurred within the first week of operation. The varying microbial structure of granules resulted in different reactor performance in terms... 

    Experimental study and thermodynamic modeling for determining the effect of non-polar solvent (hexane)/polar solvent (methanol) ratio and moisture content on the lipid extraction efficiency from Chlorella vulgaris

    , Article Bioresource Technology ; Volume 201 , 2016 , Pages 304-311 ; 09608524 (ISSN) Malekzadeh, M ; Abedini Najafabadi, H ; Hakim, M ; Feilizadeh, M ; Vossoughi, M ; Rashtchian, D ; Sharif University of Technology
    Elsevier Ltd 
    In this research, organic solvent composed of hexane and methanol was used for lipid extraction from dry and wet biomass of Chlorella vulgaris. The results indicated that lipid and fatty acid extraction yield was decreased by increasing the moisture content of biomass. However, the maximum extraction efficiency was attained by applying equivolume mixture of hexane and methanol for both dry and wet biomass. Thermodynamic modeling was employed to estimate the effect of hexane/methanol ratio and moisture content on fatty acid extraction yield. Hansen solubility parameter was used in adjusting the interaction parameters of the model, which led to decrease the number of tuning parameters from 6... 

    Application of nano-structured materials in anaerobic digestion: Current status and perspectives

    , Article Chemosphere ; Volume 229 , 2019 , Pages 188-199 ; 00456535 (ISSN) Baniamerian, H ; Ghofrani Isfahani, P ; Tsapekos, P ; Alvarado Morales, M ; Shahrokhi, M ; Vossoughi, M ; Angelidaki, I ; Sharif University of Technology
    Elsevier Ltd  2019
    Nanotechnology is gaining more attention in biotechnological applications as a research area with a huge potential. Nanoparticles (NPs)can influence the rate of anaerobic digestion (AD)as the nano-sized structures, with specific physicochemical properties, interact with substrate and microorganisms. The present work has classified the various types of additives used to improve the AD processes. Nanomaterials as new additives in AD process are classified into four categories: Zero-valent metallic NPs, Metal oxide NPs, Carbon based nanomaterials, and Multi-compound NPs. In the following, application of nanomaterials in AD process is reviewed and negative and positive effects of these materials...