896 research outputs found
High-pressure behavior of superconducting boron-doped diamond
This work investigates the high-pressure structure of freestanding
superconducting ( = 4.3\,K) boron doped diamond (BDD) and how it affects
the electronic and vibrational properties using Raman spectroscopy and x-ray
diffraction in the 0-30\,GPa range. High-pressure Raman scattering experiments
revealed an abrupt change in the linear pressure coefficients and the grain
boundary components undergo an irreversible phase change at 14\,GPa. We show
that the blue shift in the pressure-dependent vibrational modes correlates with
the negative pressure coefficient of in BDD. The analysis of x-ray
diffraction data determines the equation of state of the BDD film, revealing a
high bulk modulus of =51028\,GPa. The comparative analysis of
high-pressure data clarified that the sp carbons in the grain boundaries
transform into hexagonal diamond.Comment: 7 pages, 4 figure
Response of bacterioplankton community structures to hydrological conditions and anthropogenic pollution in contrasting subtropical environments
Bacterioplankton community structures under contrasting subtropical marine environments (Hong Kong waters) were analyzed using 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) and subsequent sequencing of predominant bands for samples collected bimonthly from 2004 to 2006 at five stations. Generally, bacterial abundance was significantly higher in the summer than in the winter. The general seasonal variations of the bacterial community structure, as indicated by cluster analysis of the DGGE pattern, were best correlated with temperature at most stations, except for the station close to a sewage discharge outfall, which was best explained by pollution-indicating parameters (e.g. biochemical oxygen demand). Anthropogenic pollutions appear to have affected the presence and the intensity of DGGE bands at the stations receiving discharge of primarily treated sewage. The relative abundance of major bacterial species, calculated by the relative intensity of DGGE bands after PCR amplification, also indicated the effects of hydrological or seasonal variations and sewage discharges. For the first time, a systematic molecular fingerprinting analysis of the bacterioplankton community composition was carried out along the environmental and pollution gradient in a subtropical marine environment, and it suggests that hydrological conditions and anthropogenic pollutions altered the total bacterial community as well as the dominant bacterial groups. © 2009 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.published_or_final_versio
Ocean acidification impairs vermetid reef recruitment.
Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems
Effect of Zinc on Germination, Seedling Growth and Biochemical Content of Cluster Bean (Cyamopsis tetragonoloba (L.) Taub)
Cluster bean seeds were grown in the presence of 0, 10, 25, 50, 100,150 and 200 mgl-l of zinc sulphate solution in order to asses the effect of metal on germination, growth and biochemical changes. The results indicated that low level of zinc concentration (10 and 25 mgl-l) showed a significant increase in the germination, seedling growth and biochemical content; whereas the higher concentrations (50-200 mgl-l) decreased the same except for proline content
A Perturbed Self-organizing Multiobjective Evolutionary Algorithm to solve Multiobjective TSP
Travelling Salesman Problem (TSP) is a very important NP-Hard problem getting focused more on these days. Having improvement on TSP, right now consider the multi-objective TSP (MOTSP), broadened occurrence of travelling salesman problem. Since TSP is NP-hard issue MOTSP is additionally a NP-hard issue. There are a lot of algorithms and methods to solve the MOTSP among which Multiobjective evolutionary algorithm based on decomposition is appropriate to solve it nowadays. This work presents a new algorithm which combines the Data Perturbation, Self-Organizing Map (SOM) and MOEA/D to solve the problem of MOTSP, named Perturbed Self-Organizing multiobjective Evolutionary Algorithm (P-SMEA). In P-SMEA Self-Organizing Map (SOM) is used extract neighborhood relationship information and with MOEA/D subproblems are generated and solved simultaneously to obtain the optimal solution. Data Perturbation is applied to avoid the local optima. So by using the P-SMEA, MOTSP can be handled efficiently. The experimental results show that P-SMEA outperforms MOEA/D and SMEA on a set of test instances
Pengaruh keadilan organisasi dan kepercayaan terhadap efikasi kendiri dan kepuasan penilaian prestasi guru.
Kajian ini dijalankan untuk mengkaji pengaruh persepsi guru terhadap keadilan organisasi dan kepercayaan guru terhadap organisasi dan pemimpin dengan efikasi kendiri dan persepsi guru terhadap kepuasan penilaian prestasi guru. Kesan moderator kepercayaan guru terhadap organisasi dan pemimpin turut dikaji. Sejumlah 1171 orang guru sekolah menengah dari negeri Perak, Pulau Pinang, Kedah dan Perlis menjadi responden kajian.
This research was carried out to study the influence of teachers’ organizational justice perception and teachers’ trust on organization and leader towards teachers’ self efficacy and teachers’ perception on performance appraisal satisfaction. The moderator effect of teachers’ trust on organization and leader was also studied. A total of 1171 secondary school teachers from the states of Perak, Penang, Kedah and Perlis became the research respondents
Ring opening metathesis polymerisation of a new bio-derived monomer from itaconic anhydride and furfuryl alcohol
A new oxa-norbornene bio-based lactone obtained from the 100% atom economic reaction of furfuryl alcohol and itaconic anhydride via a tandem Diels-Alder addition and lactonisation is presented. Esterification of the resulting acid gives a monomer for the production of a bio-based polymer with low polydispersity and well controlled molecular weight via ring-opening metathesis polymerisation (ROMP)
Data Security Model Employing Hyperelliptic Curve Cryptography (HECC) and Secure Hash Algorithm-3 (Sha-3) in Cloud Computing
Data owners use the huge space offered by ‘Cloud’ Computing for storage of data and also for carrying out
computations. To eliminate the burden of storing file locally, cloud stores
them on remote servers using virtualization concepts. Therein arises one of the
major issues in the field of cloud computing: security. Data owners lack in
having direct control over files stored in the cloud and consequently, the
problem of data security arises. An efficient scheme to provide data security,
while storing data in the cloud has been proposed which makes use of Hyperelliptic
curve cryptography (HECC) for encryption and decryption and Secure Hash
Algorithm-3 (SHA-3) for data integrity verification. Implementation results
clearly illustrate that HECC remains as a good alternative asymmetric key
technique rather than ECC and RSA when securing documents in cloud
Robust sensing suite for measuring temporal dynamics of surface temperature in sewers
© 2018, The Author(s). Sewerage systems are paramount underground infrastructure assets for any nation. In most cities, they are old and have been exposed to significant microbial induced corrosion. It is a serious global problem as they pose threats to public health and economic repercussions to water utilities. For managing sewer assets efficaciously, it is vital to predict the rate of corrosion. Predictive models of sewer corrosion incorporate concrete surface temperature measurements as an observation. However, currently, it has not been fully utilized due to unavailability of a proven sensor. This study reports the feasibility of infrared radiometer for measuring the surface temperature dynamics in the aggressive sewer conditions. The infrared sensor was comprehensively evaluated in the laboratory at different environmental conditions. Then, the sensor suite was deployed in a Sydney based sewer for three months to perform continuous measurements of surface temperature variations. The field study revealed the suitability of the developed sensor suite for non-contact surface temperature measurements in hostile sewer conditions. Further, the accuracy of the sensor measurements was improved by calibrating the sensor with emissivity coefficient of the sewer concrete. Overall, this study will ameliorate the present sewer corrosion monitoring capabilities by providing new data to models predicting sewer corrosion
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