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排序方式: 共有807条查询结果,搜索用时 15 毫秒
61.
S. Rajendraboopathy T. Sasikumar K. M. Usha E. S. Vasudev 《The International Journal of Advanced Manufacturing Technology》2009,44(3-4):399-404
A series of 18 tensile coupons were monitored with an acoustic emission (AE) system, while loading them up to failure. AE signals emitted due to different failure modes in tensile coupons were recorded. Amplitude, duration, energy, counts, etc., are the effective parameters to classify the different failure modes in composites, viz., matrix crazing, fiber cut, and delamination, with several subcategories such as matrix splitting, fiber/matrix debonding, fiber pullout, etc. Back propagation neural network was generated to predict the failure load of tensile specimens. Three different networks were developed with the amplitude distribution data of AE collected up to 30%, 40%, and 50% of the failure loads, respectively. Amplitude frequencies of 12 specimens in the training set and the corresponding failure loads were used to train the network. Only amplitude frequencies of six remaining specimens were given as input to get the output failure load from the trained network. The results of three independent networks were compared, and we found that the network trained with more data was having better prediction performance. 相似文献
62.
Howe Alexandra; Pit-ten Cate Ineke M.; Brown Antony; Hadwin Julie A. 《Canadian Metallurgical Quarterly》2008,20(3):305
In this study, we investigated a new instrument: the Southampton Test of Empathy for Preschoolers (STEP). The test incorporated 8 video vignettes of children in emotional scenarios, assessing a child's ability to understand (STEP-UND) and share (STEP-SHA) in the emotional experience of a story protagonist. Each vignette included 4 emotions (angry, happy, fearful, sad) that reflected emotion judgments based on the protagonist's facial expression, situation, verbal cues, and desire. The STEP was administered to 39 preschool children, and internal reliability, concurrent validity, and construct validity were addressed. The results showed good internal consistency. They also highlighted moderate concurrent validity with parent-rated empathy, a measure of facial indices, and construct validity with teacher-rated prosocial behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
Surfactant‐mediated synthesis of polyhydroxybutyrate (PHB) nanoparticles for sustained drug delivery
Senthilkumar Pachiyappan Dawn Shanmuganatham Selvanantham Sree Samanvitha Kuppa Saipriya Chandrasekaran Antony Vincent Samrot 《IET nanobiotechnology / IET》2019,13(4):416
In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC50 values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.Inspec keywords: encapsulation, cancer, scanning electron microscopy, nanoparticles, surfactants, drugs, nanofabrication, antibacterial activity, biomedical materials, drug delivery systems, polymers, nanomedicine, Fourier transform infrared spectra, precipitation (physical chemistry), atomic force microscopy, particle sizeOther keywords: surfactant‐mediated synthesis, polyhydroxybutyrate nanoparticles, sustained drug delivery, surfactant concentrations, PHB nanoparticles, sustained curcumin delivery, drug encapsulation efficiency, anticancer activity, in vitro drug release, nanoprecipitation method, Tween 80, FTIR spectra, SEM, AFM, particle sizes, antibacterial activity, AO‐PI staining, mitochondrial depolarisation assay 相似文献
64.
Water is a basic necessity of man. Economical and efficient production or recycling of water is very much needed in today's world. Solar still has emerged as a life-saving technology to distil brackish water and produce drinkable water using solar energy. The aim of this project was to improve the performance of solar still by adding an air blower which creates a bubbling effect in the still due to which the evaporation rate increases. The bubbling effect using the blower makes the raw water to circulate and to distribute heat energy equally. The evaporated raw water was collected in the glass plate as drop particles. The drop condenses due to ambient air and finally distillate output is collected in the jar, which is placed outside the still. The solar still with air blower arrangement gave higher difference in efficiency and higher distilled output when compared with solar still without an air blower. 相似文献
65.
B. M. Krishna Usha N. Murthy B. Manoj Kumar K. S. Lokesh 《Journal of Applied Electrochemistry》2010,40(3):663-673
Electrochemical (EC) oxidation of distillery wastewater with low (BOD5/COD) ratio was investigated using aluminum plates as electrodes. The effects of operating parameters such as pH, electrolysis
duration, and current density on COD removal were studied. At a current density of 0.03 A cm−2 and at pH 3, the COD removal was found to be 72.3%. The BOD5/COD ratio increased from 0.15 to 0.68 for an optimum of 120-min electrolysis duration indicating improvement of biodegradability
of wastewater. The maximum anodic efficiency observed was 21.58 kg COD h−1 A−1 m−2, and the minimum energy consumption observed was 0.084 kWh kg−1 COD. The kinetic study results revealed that reaction rate (k) decreased from 0.011 to 0.0063 min−1 with increase in pH from 3 to 9 while the k value increased from 0.0035 to 0.0102 min−1 with increase in current density from 0.01 to 0.03 A cm−2. This study showed that the COD reduction is more influenced by the current density. The linear and the nonlinear regression
models reveal that the COD reduction is influenced by the applied current density. 相似文献
66.
Van Driessche B Tafforeau L Hentges P Carr AM Vandenhaute J 《Yeast (Chichester, England)》2005,22(13):1061-1068
The one-step PCR-mediated technique used for modification of chromosomal loci is a powerful tool for functional analysis in yeast. Both Saccharomyces cerevisiae and Schizosaccharomyces pombe are amenable to this technique. However, the scarce availability of selectable markers for Sz. pombe hampers the easy use of this technique in this species. Here, we describe the construction of new vectors deriving from the pFA6a family, which are suitable for tagging in both yeasts owing to the presence of a nourseothricin-resistance cassette. These plasmids allow various gene manipulations at chromosomal loci, viz. N- and C-terminal tagging with 3HA (haemagglutinin) or 13Myc epitopes, GST (glutathione S-transferase), 4TAP (tandem affinity purification) and several GFP (green fluorescent protein) isoforms. For N-terminal modifications, the use of different promoters allows constitutive (PADH1) or regulatable (PGAL1) promoters for S. cerevisiae and derivatives of Pnmt1 for Sz. pombe expression. 相似文献
67.
Cameron P. Brown Jennifer L. Boyd Antony J. Palmer Mick Phillips Charles‐Andre Couture Maxime Rivard Philippa A. Hulley Andrew J. Price Andreas Ruediger Francois Légaré Andrew J. Carr 《Advanced functional materials》2016,26(42):7662-7667
Piezoelectricity is a well‐established property of biological materials, yet its functional role has remained unclear. Here, a mechanical effect of piezoelectric domains resulting from collagen fibril organisation is demonstrated, and its role in tissue function and application to material design is described. Using a combination of scanning probe and nonlinear optical microscopy, a hierarchical structuring of piezoelectric domains in collagen‐rich tissues is observed, and their mechanical effects are explored in silico. Local electrostatic attraction and repulsion due to shear piezoelectricity in these domains modulate fibril interactions from the tens of nanometre (single fibril interactions) to the tens of micron (fibre interactions) level, analogous to modulated friction effects. The manipulation of domain size and organisation thus provides a capacity to tune energy storage, dissipation, stiffness, and damage resistance. 相似文献
68.
Wireless Personal Communications - Chronic kidney disease (CKD) is a gradual loss of kidney function over the period of time and it is irrevocable once functionality reaches the critical state.... 相似文献
69.
Antony Butcher Anna L. Stork James P. Verdon J-Michael Kendall Katrin Plenkers Finlay Booth Marcus Boneham Adrian Koe 《岩石力学与岩土工程学报(英文版)》2021,13(3):500-512
Understanding rock strength is essential when undertaking major excavation projects,as accurate assessments ensure both safe and cost-effective engineered slopes.Balancing the cost-safety trade-off becomes more imperative during the construction of critical infrastructure such as nuclear power stations,where key components are built within relatively deep excavations.Designing these engineered slopes is reliant on rock strength models,which are generally parameterised using estimates of rock properties(e.g.unconfined compressive strength,rock disturbance) measured prior to the commencement of works.However,the physical process of excavation weakens the remaining rock mass.Therefore,the model also requires an adjustment for the anticipated rock disturbance.In practice,this parameter is difficult to quantify and as a result it is often poorly constrained.This can have a significant impact on the final design and cost of excavation.We present results from passive and active seismic surveys,which image the extent and degree of disturbance within recently excavated slopes at the construction site of Hinkley Point C nuclear power station.Results from active seismic surveys indicate that the disturbance is primarily confined to 0.5 m from the excavated face.In conjunction,passive monitoring is used to detected seismic events corresponding to fracturing on the cm-scale and event locations are in agreement with 0.5 m of disturbance into the rock face.This suggests rock disturbance at this site is relatively low and occurred during and immediately after the excavation.A ratio of seismic velocities recorded before and after excavations are used to determine the disturbance parameter required for the Hoek-Brown rock failure criterion,and we assess that rock disturbance is low with the magnitude of the disturbance diminishing more quickly than expected into the excavated slope.Seismic methods provide a low-cost and quick method to assess excavation related rock mass disturbance,which can lead to cost reductions in large excavation projects. 相似文献
70.
Joseph Antony Eapen Merin K. Mampilly Maryann Ephraim Sajith V. 《Metallurgical and Materials Transactions A》2021,52(9):3689-3693
Metallurgical and Materials Transactions A - The present work compares the corrosion resistance properties of electrophoretically deposited MoS2 and WS2 nanosheets coatings on mild steel.... 相似文献