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Microencapsulation of microbial cells 总被引：2，自引：0，他引：2
Sweta Rathore Parind Mahendrakumar DesaiCeline Valeria Liew Lai Wah ChanPaul Wan Sia Heng 《Journal of food engineering》2013
Microencapsulation involves coating or entrapping of a core material with a polymeric material to generate microspheres in the size range of 1–1000 μm. This versatile technology has been used to encapsulate a wide array of products such as pharmaceuticals, flavors, volatile oils, plant extracts, enzymes and others. In the recent decades, this technology has also been applied to the area of microbial cell immobilization owing to its numerous advantages over other cell immobilization techniques such as higher cell loading capacity, enhanced cell survival and increased production rate of the desired microbial products. The confinement of microbial cells within a semipermeable polymeric matrix enables the physical isolation of cells from the external environment while maintaining a hospitable internal micro-environment. It has found application in various biotechnological processes such as probiotic encapsulation in food industries, in biotransformation and fermentation processes producing antibiotics, organic acids, enzymes, and alcohols as well as environmental decontamination such as waste water treatment. The judicious selection of materials and methods for the production of microspheres is critical for ensuring minimum damage to the viability of the encapsulated microbial cells. The conventional methods used for microencapsulation of microbial cells are reviewed along with the recent advances in the respective methods. The effect of microencapsulation on the microbial cells, the stability of the microspheres as well as the techniques for enumeration of the encapsulated cells are also discussed, followed by a summary of recent applications of microencapsulation in different biotechnological processes. 相似文献
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Catalytic oxidation of cyclohexane was investigated over polymer‐anchored Co(II) catalyst prepared by modification of polymer surface by NOx and subsequent functinalization by amination. The catalyst characterized by various techniques, such as elemental analysis, atomic absorption spectroscopy, Fourier transform infrared spectroscopy (FT‐IR), thermo‐gravimetric analysis, and scanning electron microscopy confirmed the modification of polymer surface and bond formation between functionalized resin and metal ion. The oxidation of cyclohexane using molecular oxygen (O2) as an oxidant was studied in the temperature and pressure range of 373–413 K and 1.0–1.4 MPa, respectively. The maximum cyclohexane conversion of 18.4% was obtained at 413 K and 1.2 MPa pressure. Cyclohexanone and cyclohexanol were found as the main reaction products with 93.0% selectivity. No appreciable change in catalytic activity and on product selectivity was observed after the catalyst recycled three times. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2127–2135, 2013 相似文献
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生产商飞速地建造更大的生产设备,但利润总是不可能超越成本和风险。TFT-LCD生产线的规模有实际限制吗? 相似文献
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Ch. Mangamma P. Pramod Kumar Bala Siddulu Malga Lakshmi Appidi Sweta Matta 《亚洲传热研究》2024,53(4):1689-1708
The aim of the study is to measure the Dufour number effects on the flow patterns and heat transfer in an exponentially accelerated infinite vertical plate embedded in a porous medium in the presence of heat source and chemical reaction. Time-dependent variations in temperature, velocity, and other factors should be taken into consideration due to the flow's unsteadiness. The fluid considered is a gray, absorbing/emitting radiation but nonscattering medium. Using the finite element method, a set of nondimensionless equations is solved analytically. Results are discussed graphically for concentration, temperature, and velocity profiles. Skin friction, Sherwood number, and Nusselt number are also explained for flow parameters through graphs. 相似文献
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Sweta Jain Meenu Chawla Vasco N. G. J. Soares Joel J. Rodrigues 《International Journal of Communication Systems》2016,29(12):1820-1843
Delay tolerant networks are a class of ad hoc networks that enable data delivery even in the absence of end‐to‐end connectivity between nodes, which is the basic assumption for routing in ad hoc networks. Nodes in these networks work on store‐carry and forward paradigm. In addition, such networks make use of message replication as a strategy to increase the possibility of messages reaching their destination. As contact opportunities are usually of short duration, it is important to prioritize scheduling of messages. Message replication may also lead to buffer congestion. Hence, buffer management is an important issue that greatly affects the performance of routing protocols in delay tolerant networks. In this paper, Spray and Wait routing protocol, which is a popular controlled replication‐based protocol for delay tolerant networks, has been enhanced using a new fuzzy‐based buffer management strategy Enhanced Fuzzy Spray and Wait Routing, with the aim to achieve increased delivery ratio and reduced overhead ratio. It aggregates three important message properties namely number of replicas of a message, its size, and remaining time‐to‐live, using fuzzy logic to determine the message priority, which denotes its importance with respect to other messages stored in a node's buffer. It then intelligently selects messages to schedule when a contact opportunity occurs. Because determination of number of replicas of a message in the network is a difficult task, a new method for estimation of the same has been proposed. Simulation results show improved performance of enhanced fuzzy spray and wait routing in terms of delivery ratio and resource consumption. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This article discusses the impact of chemical reaction and radiation on an unstable two-dimensional laminar flow around a viscous fluid over a semi-infinite, vertical absorbent surface that moves progressively. The governing classification of partial differentiation was converted into an ordinary differentiation system in this case. To get numerical solutions, the Galerkin finite element technique is applied to nondimensional velocity, micro-rotation, temperature, and concentration profiles. The consequences of skin friction, the combined pressure quantity, the mass, and heat assignments at the boundary are formed using different fluid properties and flow conditions. Physical quantities and their effects Graphs depict the radiation parameter R, thermal conductivity k, Eckert number Ec, and other velocities, micro-rotation, temperature, and concentration factors. The main findings of this current problem is showing the chemical reaction effects on velocity and concentration. It is observed that both the velocity and concentration of the fluid decrease when Kr increases. 相似文献
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Debasish Roy;Ananta Vashisth;Prameela Krishnan;Joydeep Mukherjee;Mahesh Chand Meena;Niraj Biswakarma;Pooja Rathore;Koushik Bag;Sweta Kumari; 《Journal of the science of food and agriculture》2024,104(11):6831-6843
The continuous cultivation of rice–wheat in the same field is a key element of double-cropping systems in the Indo-Gangetic plains. Yields of such cropping systems are increasingly challenged as climate change drives increases in temperature, terminal stress and uneven rainfall, delaying rice harvesting and subsequently delaying sowing of wheat. In this paper, we evaluate the optimum sowing dates to achieve high grain yield and quality of wheat cultivars in northwest India. Three cultivars of wheat, HD-2967, HD-3086 and PBW-723, were sown on three different dates at the research farm of ICAR-IARI, New Delhi, to generate different weather conditions at different phenological stages. Different biophysical attributes, photosynthetic rate, stomatal conductance and transpiration rate, were measured at different phenological stages. Yield and grain quality parameters such as protein, starch, amylopectin, amylose and gluten were measured in different cultivars sown on different dates. 相似文献
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Mahesh Gour Sweta Jain T. Sunil Kumar 《International journal of imaging systems and technology》2020,30(3):621-635
Biopsy is one of the most commonly used modality to identify breast cancer in women, where tissue is removed and studied by the pathologist under the microscope to look for abnormalities in tissue. This technique can be time-consuming, error-prone, and provides variable results depending on the expertise level of the pathologist. An automated and efficient approach not only aids in the diagnosis of breast cancer but also reduces human effort. In this paper, we develop an automated approach for the diagnosis of breast cancer tumors using histopathological images. In the proposed approach, we design a residual learning-based 152-layered convolutional neural network, named as ResHist for breast cancer histopathological image classification. ResHist model learns rich and discriminative features from the histopathological images and classifies histopathological images into benign and malignant classes. In addition, to enhance the performance of the developed model, we design a data augmentation technique, which is based on stain normalization, image patches generation, and affine transformation. The performance of the proposed approach is evaluated on publicly available BreaKHis dataset. The proposed ResHist model achieves an accuracy of 84.34% and an F1-score of 90.49% for the classification of histopathological images. Also, this approach achieves an accuracy of 92.52% and F1-score of 93.45% when data augmentation is employed. The proposed approach outperforms the existing methodologies in the classification of benign and malignant histopathological images. Furthermore, our experimental results demonstrate the superiority of our approach over the pre-trained networks, namely AlexNet, VGG16, VGG19, GoogleNet, Inception-v3, ResNet50, and ResNet152 for the classification of histopathological images. 相似文献
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Highly efficient and low-cost Pt-Co/CAB bimetallic cathode electrocatalysts were synthesized for hydrogen-based proton exchange membrane fuel cell (PEMFC) using three different types of solvent, namely, dimethyl sulphoxide (DMSO), dimethylformamide (DMF), and ethylene glycol (EG). The physical characterization of synthesized cathode electrocatalysts Pt-Co/CAB-DMSO, Pt-Co/CAB-DMF and Pt-Co/CAB-EG was performed by scanning electron microscope–energy-dispersive X-ray (SEM–EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques, whereas the electrochemical investigation of all three Pt-Co/CAB electrocatalysts was performed by CV and EIS studies. The synthesized Pt-Co/C-EG electrocatalyst produced the highest power density of 19.61 mW/cm2 at a room temperature of 33°C. The power density increased to 26.11 mW/cm2, that is, 133%, when the cell operating temperature was raised from 33 to 70°C. The excellent performance of the Pt-Co/CAB-EG cathode electrode proves that it can be recommended as a commercial electrocatalyst for PEMFC cathode. In addition, the EG/EG was identified as the best solvent for the synthesis of Pt-Co/CAB cathode electrocatalysts. 相似文献