Search for: encapsulation
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    Removal of phenols from wastewater with encapsulated horseradish peroxidase in calcium alginate

    , Article Engineering Letters ; Volume 17, Issue 4 , 2009 ; 1816093X (ISSN) Alemzadeh, I ; Nejati, S ; Vossoughi, M ; Sharif University of Technology
    Horseradish peroxidase was encapsulated in calcium alginate for the purpose of phenol removal. Upon immobilization, pH profile of enzyme activity changes as it shows higher value at basic and acidic solution. Investigation into time course of phenol removal for both encapsulated and free enzyme showed that encapsulated enzyme had nearly similar efficiency in comparison with the same concentration of free enzyme; however the capsules were reusable up to four cycles without any changes in their retention activity  

    Removal of phenols with encapsulated horseradish peroxidase in calcium alginate

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 28, Issue 2 , 2009 , Pages 43-49 ; 10219986 (ISSN) Alemzadeh, I ; Nejati, S ; Sharif University of Technology
    Horseradish peroxidase was encapsulated in calcium alginate for the purpose of phenol removal. Considering enzyme encapsulation efficiency, retention activity and enzyme leakage of the capsules, the best gelation condition was found to be 1 % w/v of sodium alginate solution and 5.5 % w/v of calcium chloride hexahydrate. Upon immobilization, pH profile of enzyme activity changes as it shows higher value at basic and acidic solution. Besides, for each phenol concentration there would be an enzyme concentration which going further than this value has no significant effect on phenol removal. Investigation into time course of phenol removal for both encapsulated and free enzyme showed that... 

    Effects of sucrose, skim milk and yeast powder on survival of lactobacillus rhamnosus gg encapsulated with alginate during one-week storage at room conditions

    , Article Applied Food Biotechnology ; Volume 9, Issue 3 , 2022 , Pages 251-259 ; 23455357 (ISSN) Khodadadi, P ; Tabandeh, F ; Alemzadeh, I ; Soltani, M ; Sharif University of Technology
    National Nutrition and Food Technology Research Institute  2022
    Background and Objective: During the manufacture and storage of probiotic products, there are always possibilities that probiotics be exposed to harmful stresses such as high temperature, low pH, various osmotic pressures and high oxygen levels, which can decrease the number of living cells. Encapsulation is one of the methods used to protect living cells such as probiotic bacteria from environmental challenges. Up-to-date, various compounds with abilities to protect bacteria during freeze-drying and to increase viability during storage have been identified. In this study, alginate with calcium chloride was used to encapsulate probiotic bacteria using extrusion method. Then, effects of... 

    Performance evaluation and optimization of encapsulated cascade PCM thermal storage

    , Article Journal of Energy Storage ; Volume 11 , 2017 , Pages 64-75 ; 2352152X (ISSN) Shamsi, H ; Boroushaki, M ; Geraei, H ; Sharif University of Technology
    Elsevier Ltd  2017
    One of the main components of any solar power plant is its thermal heat storage system. Heat storage reduces the cost of power generation by increasing the capacity factor of the system. This paper aims to model and optimize the operation of a consecutive multi-layer Phase Change Material (PCM) thermal heat storage system, named Cascade Latent Heat Storage (CLHS), using the method of characteristics and genetic algorithm. The model is validated through comparison with experimental data available in the literature. The model can predict fluid and PCM temperature, PCM phase and the energy absorbed by PCM. A sensitivity analysis is employed for both the PCM and the fluid parameters. The PCM... 

    Enhanced antibacterial activity of echinacea angustifolia extract against multidrug-resistant klebsiella pneumoniae through niosome encapsulation

    , Article Nanomaterials ; Volume 11, Issue 6 , 2021 ; 20794991 (ISSN) Moghtaderi, M ; Mirzaie, A ; Zabet, N ; Moammeri, A ; Mansoori Kermani, A ; Akbarzadeh, I ; Eshrati Yeganeh, F ; Chitgarzadeh, A ; Bagheri Kashtali, A ; Ren, Q ; Sharif University of Technology
    MDPI AG  2021
    With the increased occurrence of antibiotic-resistant bacteria, alternatives to classical antibiotics are urgently needed for treatment of various infectious diseases. Medicinal plant extracts are among the promising candidates due to their bioactive components. The aim of this study was to prepare niosome-encapsulated Echinacea angustifolia extract and study its efficacy against multidrug-resistant Klebsiella pneumoniae strains. Encapsulation was first optimized by Design of Experiments, followed by the empirical study. The obtained niosomes were further charac-terized for the size and morphology using dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning... 

    Self-encapsulation of single-texture CoSi2 nanolayer by TaSi2

    , Article Thin Solid Films ; Volume 516, Issue 18 , 31 July , 2008 , Pages 6008-6012 ; 00406090 (ISSN) Akhavan, O ; Azimirad, R ; Moshfegh, A. Z ; Sharif University of Technology
    In this work, we have studied single-texture formation of CoSi2 layer in heat-treated Co/Ta0.7W0.3/Si(100) structure. Moreover, self-encapsulation process of the CoSi2 layer and surface roughness of the encapsulated layer, as a contact layer, has been examined. A direct current magnetron co-sputtering technique was employed to deposit a 10 nm Ta0.7W0.3 alloy intermediate layer. After growth of the layer on the Si substrate, a 25 nm Co layer was deposited using thermal evaporation method. Post-annealing process of the films was treated in an N2(80%) + H2(20%) ambient in a temperature range from 400 to 1000 °C for 60 min. X-ray diffraction analysis showed that a single-texture CoSi2 layer with... 

    Development of Extended Release System for Aspirin

    , M.Sc. Thesis Sharif University of Technology Poursadeghian, Arezou (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Hemmati, Ali Asghar ($item.subfieldsMap.e)
    Today, in order to increase the effectiveness of the drug and reduce its side effects, modern drug delivery systems replace the traditional methods of drug production. Some of these systems are designed to allow their drug release to proceed gradually and prolonged, so that its concentration in the blood remains at a relatively constant level and preserves the therapeutic effect of the drug. Aspirin or acetylsalicylic acid is a non-steroidal anti-inflammatory drug (NSAIDs). Aspirin is widely used to prevent secondary heart attacks and stroke and reduce the risk of death in patients with chronic coronary artery disease and stroke. Aspirin is used as an anticoagulant agent for patients with... 

    Development of an ethernet over SDH system for next generation SDH networks

    , Article The Mediterranean Journal of Computers and Networks ; Volume 2, Issue 2 , 2006 , pp. 80-90 Bakhshi, S ; Pakravan, M. R. (Mohammad Reza) ; Darmani, Y. (Yousef) ; Sharif University of Technology
    The demands for carrying data traffic in long distances have been increasing rapidly and Service providers encounter the challenging issue of the best approach for handling the high volumes of Ethernet traffic generated by the proliferation of network access applications. The next generation SONET/SDH solutions offer integration of several functionalities into a single network element, thus reducing the power and space requirements as well as facilitating the configuration and management of the network. They are expected to continuously support TDM services, while enabling carriers to offer new Ethernet-based data services. Therefore Ethernet over SDH standard that enables legacy SDH/SONET... 

    Multi- and Single-cellular Encapsulation within Microchannels for Effective Cell Lysis and DNA Extraction and Purification

    , M.Sc. Thesis Sharif University of Technology Hassani Gangaraj, Mojtaba (Author) ; Shamloo, Amir (Supervisor)
    In this study a droplet-based microfluidic system is desighned and fabricated to effectiverly lyse MCF7 cells and extract and purify their DNAs. The main purpose of this study is to transfer all the steps from macro scale to a microfluidic system containing a fluidic chip. This system is a semi automatic system and every part of the lysis and purification process is performed in one step. The first step is to encapsulate single cells and multi cells inside the droplets. By controlling the concentration of the cell solution, the number of encapsulated cells inside the droplet is efficiently and easily controlled and the cells were encapsulated as single cells and as multi cells inside the... 

    Investigation of the effect of adding nano-encapsulated phase change material to water in natural convection inside a rectangular cavity

    , Article Journal of Energy Storage ; Volume 40 , 2021 ; 2352152X (ISSN) Golab, E ; Goudarzi, S ; Kazemi Varnamkhasti, H ; Amigh, H ; Ghaemi, F ; Baleanu, D ; Karimipour, A ; Sharif University of Technology
    Elsevier Ltd  2021
    The present simulation aims to investigate adding NEPCM nanoparticles to water in the natural convection inside a cavity by using FVM method and SIMPLE algorithm. Nano-encapsulated phase change material (NEPCM) consists of a shell and core with phase change property. The NEPCM particles in base fluid have the ability to transfer heat by absorbing and dissipating heat in the liquid-solid phase change state. In this study, the energy wall phenomenon due to the phase change of NEPCM core has appeared that the whose energy transfer strength is proportional to the latent heat of NEPCM core and the thickness of the energy wall. Moreover, the relationship between the energy wall and the heat... 

    Preparation and Characterization of Self-healing Coatings Using Inhibitor Loaded Polymeric Nanocontainers

    , Ph.D. Dissertation Sharif University of Technology Pirhady Tavandashti, Nahid (Author) ; Ghorbani, Mohammad (Supervisor) ; Shojaei, Akbar (Supervisor)
    The aim of this work was to synthesize hollow polyaniline nanostructures to be used as pH responsive nanoreservoirs for corrosion inhibitors in self-healing cotings. First, homogeneous and fairly monosized microspherers of polyaniline with nanosized shell was synthesized using a simple soft template method with β-naphthalene sulfonic acid (β-NSA) as both the surfactant and dopant, and ammonium persulfate (APS) as the oxidant at 2-5◦C. The morphology of PANI-NSA was successfully controlled from nanotubes to microsphere, by changing the synthesis conditions (i.e. pH, the concentration of surfactant and monomer, temperature, etc). Then, the nanostructured hollow PANI microspheres were applied... 

    Encapsulation of peppermint oil with arabic gum-gelatin by complex coacervation method

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 26, Issue 8 , 2013 , Pages 807-814 ; 10252495 (ISSN) Pakzad, H ; Alemzadeh, I ; Kazemi, A ; Sharif University of Technology
    The gelatin/gum arabic microcapsules encapsulating peppermint oil were prepared by complex coacervationusing tannic acid as hardening agent. The effects of various parameters, including concentration of wall material, core material, tannic acid and Tween 80 were investigated on particle size and encapsulation efficiency. For statistical evaluation of the parameters, Taguchi method was concerned. The size of prepared spherical microcapsules was 19-66 micrometers. The results showed that, particle size increased with increasing the core and the wall concentration and decreased with increasing tannic acid and Tween 80 concentraIfd efficiency increased by increasing the core and wall... 

    An interface–particle interaction approach for evaluation of the co-encapsulation efficiency of cells in a flow-focusing droplet generator

    , Article Sensors (Switzerland) ; Volume 20, Issue 13 , 2020 , Pages 1-17 Yaghoobi, M ; Saidi, M. S ; Ghadami, S ; Kashaninejad, N ; Sharif University of Technology
    MDPI AG  2020
    Droplet-based microfluidics offers significant advantages, such as high throughput and scalability, making platforms based on this technology ideal candidates for point-of-care (POC) testing and clinical diagnosis. However, the efficiency of co-encapsulation in droplets is suboptimal, limiting the applicability of such platforms for the biosensing applications. The homogeneity of the bioanalytes in the droplets is an unsolved problem. While there is extensive literature on the experimental setups and active methods used to increase the efficiency of such platforms, passive techniques have received less attention, and their fundamentals have not been fully explored. Here, we develop a novel... 

    Study of Antimicrobial Properties For Propolis

    , M.Sc. Thesis Sharif University of Technology Gholizade, Tahere (Author) ; Roostaazad, Reza (Supervisor) ; Bayat, Farhad (Co-Advisor)
    Propolis is a resin compound which is collected from different Plant sources by bees. It is processed by salivary enzymes and is combined with wax bee and is used in hives, Specially in entrance door. In this study Propolis is selected as a natural substance. The aim of this study is to change the substance to get use of in industry. For this, first, antimicrobial properties of it was proved and then for industrial use encapsulation was done to keep the capability of it. Since propolis extract was prepared with 70% ethanol, and the encapsulation was done with the polymer-effective material ratio of 5,0,1,2 by a proper polymer with no bad effect on the body. Later an appropriate powder was... 

    Investigation on Insulin Release from Microcapsules Containing Beta Cell

    , M.Sc. Thesis Sharif University of Technology Hosseinzadeh, Zahra (Author) ; Alemzadeh, Iran (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
    Type 1 diabetes, formerly known as insulin-dependent diabetes, may present at any age, but is the most common type of diabetes affecting children and adolescents. People with type 1 diabetes do not produce enough insulin. This type accounts for 5-10% of all types of diabetes. In this type of diabetes, beta cell destruction occurs in the pancreas. In type 1 diabetes, the pancreas does not secrete any insulin; insulin is a hormone that enables the body to convert glucose in food into energy. If sugar in the blood cannot enter the cells, it accumulates in the arteries and results in high blood sugar. High blood sugar over time can have irreversible effects on various parts of the body. Curcumin... 

    Observations on the dynamics of bubble cluster in an ultrasonic field

    , Article Nonlinear Dynamics ; Volume 72, Issue 3 , 2013 , Pages 561-574 ; 0924090X (ISSN) Behnia, S ; Zahir, H ; Yahyavi, M ; Barzegar, A ; Mobadersani, F ; Sharif University of Technology
    The dynamics driven interaction between the bubbles in a cavitation cluster is known to be a complex phenomenon indicative of a highly active nonlinear as well as chaotic behavior in ultrasonic fields. By considering the cluster of encapsulated microbubble with a thin elastic shell in ultrasonic fields, in this paper, the dynamics of microbubbles has been studied via applying the methods of chaos physics. Bifurcation, Lyapunov exponent, and time series are plotted with respect to variables such as amplitude, initial bubble radius, frequency and viscosity. The findings of the study indicate that a bubble cluster undergoes a chaotic unstable region as the amplitude and frequency of ultrasonic... 

    Experimental investigation of paraffin nano-encapsulated phase change material on heat transfer enhancement of pulsating heat pipe

    , Article Journal of Thermal Analysis and Calorimetry ; Volume 137, Issue 5 , 2019 , Pages 1603-1613 ; 13886150 (ISSN) Heydarian, R ; Shafii, M. B ; Rezaee Shirin Abadi, A ; Ghasempour, R ; Alhuyi Nazari, M ; Sharif University of Technology
    Springer Netherlands  2019
    In this study, a mixture of nano-encapsulated phase change materials in water has been used as the working fluid in a pulsating heat pipe in order to investigate its thermal performance. The results of the experiments showed that using the nano-encapsulated paraffin dispersed in water as working fluid improves heat transfer and decreases the thermal resistance of the pulsating heat pipe. On the other hand, among the tested concentrations for nano-encapsulated paraffin, there is an optimal value in which increasing the concentration causes an increase in the thermal resistance of the pulsating heat pipe due to the increased dynamic viscosity of the fluid. Enhancement in the thermal... 

    A review on the applications of micro-/nano-encapsulated phase change material slurry in heat transfer and thermal storage systems

    , Article Journal of Thermal Analysis and Calorimetry ; 2020 Ghoghaei, M. S ; Mahmoudian, A ; Mohammadi, O ; Shafii, M. B ; Jafari Mosleh, H ; Zandieh, M ; Ahmadi, M. H ; Sharif University of Technology
    Springer Netherlands  2020
    In modern heat transfer systems, thermal storage not only causes the balance between demand and supply, but also improves the heat transfer efficiency in these systems. In the present study, a comprehensive review of the applications of micro- or nano-encapsulated phase change slurries (MPCMs/NPCMs), as well as their effects on thermal storage and heat transfer enhancement, has been conducted. MPCMs/NPCMs have a myriad of applications and various usages such as pipe and channel flows, photovoltaic/thermal, solar heaters, air conditioning systems, storage tanks and heat pipes that have been categorized and studied. It was found that there are many advantageous adding MPCM/NPCM to the base... 

    Enzymatic outside-in cross-linking enables single-step microcapsule production for high-throughput three-dimensional cell microaggregate formation

    , Article Materials Today Bio ; Volume 6 , 2020 Van Loo, B ; Salehi, S. S ; Henke, S ; Shamloo, A ; Kamperman, T ; Karperien, M ; Leijten, J ; Sharif University of Technology
    Elsevier B.V  2020
    Cell-laden hydrogel microcapsules enable the high-throughput production of cell aggregates, which are relevant for three-dimensional tissue engineering and drug screening applications. However, current microcapsule production strategies are limited by their throughput, multistep protocols, and limited amount of compatible biomaterials. We here present a single-step process for the controlled microfluidic production of single-core microcapsules using enzymatic outside-in cross-linking of tyramine-conjugated polymers. It was hypothesized that a physically, instead of the conventionally explored biochemically, controlled enzymatic cross-linking process would improve the reproducibility,... 

    Water repellent room temperature vulcanized silicone for enhancing the long-term stability of perovskite solar cells

    , Article Solar Energy ; Volume 218 , 2021 , Pages 28-34 ; 0038092X (ISSN) Samadpour, M ; Heydari, M ; Mohammadi, M ; Parand, P ; Taghavinia, N ; Sharif University of Technology
    Elsevier Ltd  2021
    A key direction toward enhancing the long term and outdoor stability of the perovskite solar cells is encapsulation. As a result, a suitable encapsulation package is required to prevent moisture and oxygen penetration toward the perovskite solar cells. In this work, a low-cost commercially available bilayer structure of poly (methyl methacrylate)/ room-temperature vulcanizing silicone rubber (RTV) encapsulation package for enhancing the long term stability of the perovskite solar cells has been investigated. Encapsulated cells retained more than 80% of the initial efficiency at the environmental condition of 50% moisture, and room temperature after 1000 h, however reference cell efficiency...