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71.
Morphological specializations of the epidermis of an angler catfish Chaca chaca (Siluriformes,Chacidae) in relation to its ecological niche: A scanning electron microscopic investigation 下载免费PDF全文
Arup Mistri Usha Kumari Swati Mittal Ajay Kumar Mittal 《Microscopy research and technique》2018,81(5):439-448
The present work was undertaken with the aim to deduce morphological adaptations in skin of an angler catfish Chaca chaca by means of scanning electron microscopy. The fish is nocturnal, bottom dwelling, sluggish, ambush predator, lives in sand, mud, or soft substrates often buried and camouflaged for protection and to feed. The surface of the epidermis is covered with polygonal epithelial cells, each having surface relief of microridges forming intricate patterns. In between epithelial cells irregularly distributed mucous cell openings, randomly distributed epidermal specialized structures, taste buds, and neuromasts are discernible. The epidermal specialized structures are keratinized. These are either irregularly the rounded elevated plaque like or the cone shaped structures. The superficial keratinized cells could frequently be discernible exfoliated at the surface. At intervals, characteristic epidermal projections could be observed. Surface of these projections at intervals is differentiated into short stumpy protuberances, each bearing a taste bud at its summit. Further, near the basal portion of these epidermal projections, conical, or rounded plaque like epidermal specialized structures are also discernible. The surface sculpture of the skin of Chaca chaca is associated with the structural and functional significance and physiological adaptations of the epidermis with respect to its ecological niche. 相似文献
72.
In this paper a methodology is proposed to model the stochastic electro-thermal degradation accumulation in cables.The cable life and the reliability are predicted by estimating the accumulated electro-thermal degradation during seasonal load cycles.The degradation is considered,in a novel approach,as stochastic in nature due to variations in the manufacturing process of insulation raw material and in operational and environmental conditions.The methodology is based on estimation of life by using combined electro-thermal life model,simulation of degradation accumulation process under electro-thermal stress in each season of the year based on Miner’s cumulative damage theory and reliability prediction from a probabilistic point of view.A case study is demonstrated on 10 k V XLPE cables which are directly buried in the UK and China.Results show that,the electro-thermal life of the cable is 56 and 69 years in China and the UK,respectively at 50%failure probability,or the life of the cable in the UK would be 13 years longer than in China,when other stresses such as mechanical and environmental are also considered and assumed to be the same. 相似文献
73.
This study deals with the degradation of polyethylene terephthalate (PET) waste through aminolysis with various amines. All of these degradation experiments were carried out at ambient temperature and at normal pressure. Although PET is known to be recycled in many ways, but still there is a need of development of other environment friendly recycling techniques. The amines used to study the degradation of PET waste were namely methylamine, ethylamine, and n‐butyl amine, respectively where the degradation of PET waste completes in 45 days. The aminolyzed products so obtained were characterized by using various conventional techniques such as spectroscopic techniques namely IR, NMR, and simultaneous differential scanning calorimeter (DSC). In the present research work, a useful method of PET recycling by using various amines was successfully established. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
74.
Swati S. PradhanS.K. Pradhan V. BhavanasiSambita Sahoo S.N. SarangiS. Anwar P.K. Barhai 《Thin solid films》2012,520(6):1809-1813
The deposition of rutile phase TiO2 films on unheated substrates by radio frequency magnetron sputtering is elaborated. The effect of total pressure and O2/Ar flow ratio on the growth of rutile film on different substrates has been studied thoroughly. The development of crystalline phase along with film deposition rate, surface morphology, optical transmission and band gap were also investigated for various growth conditions. It was found that the rutile phase crystallinity increased with decrease in total pressure and increase in O2 flow. In addition, the grown rutile films have interesting optical characteristics such as high transmittance (~ 85%) and high refractive index (~ 2.7) with a band gap about 3.2 eV. 相似文献
75.
Sharma S Madou M 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2012,370(1967):2448-2473
Nanosized gas sensor elements are potentially faster, require lower power, come with a lower limit of detection, operate at lower temperatures, obviate the need for expensive catalysts, are more heat shock resistant and might even come at a lower cost than their macro-counterparts. In the last two decades, there have been important developments in two key areas that might make this promise a reality. First is the development of a variety of very good performing nanostructured metal oxide semiconductors (MOSs), the most commonly used materials for gas sensing; and second are advances in very low power loss miniaturized heater elements. Advanced nano- or micro-nanogas sensors have attracted much attention owing to a variety of possible applications. In this article, we first discuss the mechanism underlying MOS-based gas sensor devices, then we describe the advances that have been made towards MOS nanostructured materials and the progress towards low-power nano- and microheaters. Finally, we attempt to design an ideal nanogas sensor by combining the best nanomaterial strategy with the best heater implementation. In this regard, we end with a discussion of a suspended carbon nanowire-based gas sensor design and the advantages it might offer compared with other more conventional gas sensor devices. 相似文献
76.
Girjesh Singh S. B. Shrivastava Deepti Jain Swati Pandya T. Shripathi V. Ganesan 《Bulletin of Materials Science》2010,33(5):581-587
We report the conducting and transparent In doped ZnO films fabricated by a homemade chemical spray pyrolysis system (CSPT).
The effect of In concentration on the structural, morphological, electrical and optical properties have been studied. These
films are found to show (0 0 2) preferential growth at low indium concentrations. An increase in In concentration causes a
decrease in crystalline quality of films as confirmed by X-ray diffraction technique which leads to the introduction of defects
in ZnO. Indium doping also significantly increased the electron concentrations, making the films heavily n type. However, the crystallinity and surface roughness of the films decreases with increase in indium doping content likely
as a result of the formation of smaller grain size, which is clearly displayed in AFM images. Typical optical transmittance
values in the order of (80%) were obtained for all films. The lowest resistivity value of 0.045 Ω-m was obtained for film
with 5% indium doping. 相似文献
77.
L. Subashini K. V. Phani Prabhakar Ravi C. Gundakaram Swati Ghosh 《Materials and Manufacturing Processes》2016,31(16):2186-2198
Maraging steel 250 grade plates of 10 mm thickness were welded in single pass using a laser-arc hybrid welding (LHW) setup comprising 3.5 kW CO2 laser and synergic pulse metal inert gas (MIG) welding power source at a welding speed of 1 m/min. The influence of single-pass welding on the bead characteristics, microstructure, and mechanical properties was investigated. The size and volume fraction of reverted austenite was effectively reduced in the fusion zone. Moreover, the width of the heat-affected zones (HAZ) was reduced and the microhardness results did not show significant softening in the HAZ after post weld aging. Tensile testing of the welds in transverse direction showed 97.3% weld efficiency. The fusion zone exhibited KIc fracture toughness of 77.4 MPa√m which was affected by the distribution pattern of reverted austenite. The study vividly brings out the process advantages of LHW for accomplishing thick section welds of maraging steel in single pass with narrow groove and lesser filler wire consumption. 相似文献
78.
Swati Sharma Arun Gupta Ashok Kumar Chua Gek Kee Hesam Kamyab Syed Mohd Saufi 《Clean Technologies and Environmental Policy》2018,20(10):2157-2167
Feathers biomass from poultry industry is considered as an important waste product, which creates serious environmental problems. In this study, keratin was extracted from waste chicken feathers using sodium sulfide as a reducing agent under optimized conditions. The extracted keratin particles were used to develop a bioploymeric film by adding microcrystalline cellulose as nano-additive agent. The calculated yield of 80.2% was obtained for keratin from feathers dry weight 25 g (w/w). The extracted keratin was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis, differential scanning calorimetry, wide-angle X-ray diffraction. The physiochemical characteristics of the feathers were compared with the keratin powder. The regenerated keratin particles preserved their chemical composition, thermal strength and stability after chemical extraction. The extracted keratin particles showed 10–20-µm spongy porous microparticles in SEM analysis. The keratin powder was used to synthesize a bioplastic film using glycerol (3.5%) and microcrystalline cellulose (0.2%) in NaOH for 48 h at 60 °C. The calculated thickness of bioplastic film was 1.12 × 10?4 mm with tensile strength of 3.62 ± 0.6 MPa. The Young’s modulus and break elongation for synthesized bioplastic film were 1.52 ± 0.34 MPa and 15.8 ± 2.2%, respectively. The feather and keratin showed maximum similarity index of 64.74% (l-alanyl, l-alanyl, l-alanine, p-nitroanilide) and 64.32% with d-pantethine, respectively, using OMNIC Specta software. Overall, the study presented a highly efficient method to convert the waste feather biomass into a bioplastic film which can be used in biopolymer, biomedical and pharmaceutical industries. 相似文献
79.
Tobias Baier Swati Mohanty Klaus S. Drese Federica Rampf Jungtae Kim Friedhelm Schönfeld 《Microfluidics and nanofluidics》2009,7(2):205-216
The separation of cells from a complex sample by immunomagnetic capture has recently obtained increased attention for microfluidic
applications. Here, we present a simulation approach for immunomagnetic separation in a flow-through microfluidic environment
that for the first time takes binding kinetics of beads to target cells as well as binding of multiple beads per cell into
account. The approach is implemented into a computational fluid dynamics code and facilitates the tailored design of microfluidic
magnetophoretic devices with an optimised separation performance. Although the specific computational model under study is
constrained to a 2D geometry, appropriate parameter sets that allow for a continuous separation of cell/bead complexes from
non-magnetic particles could be derived. In addition, based on magnetophoretic mobilities, a critical threshold value of beads
per cell is revealed, where further binding is considerably reduced or the reaction cascade ceases. 相似文献
80.
A conducting polymer-based chemical sensor was fabricated by depositing a film containing polyaniline blended with polyethylene oxide and doped with copper chloride onto interdigitated electrodes in a surface cell configuration. It was found to be very sensitive to alcoholic vapours, especially methanol. Its characteristics such as response time (tr), recovery time (td), sensitivity factor (σmax/σ0), etc. have been studied with respect to film composition, chemical vapour dosage, etc. It was found that the sensitivity was maximum and tr minimum at a certain concentration of polyaniline in the film matrix. Although the response was quite fast (tr < 10 s), the recovery was slow and in many cases followed a two-step process. The two components in the recovery were clearly delineated in log-log plots, from which one could be associated with diffusion and the other with selective residual adsorption of the chemical vapour by the conducting polymer moieties. These results have been discussed in the light of the charge transport mechanism and the formation of interfacial barriers between polyaniline domains. 相似文献