Search Options

Sort by:

Sort search results by

Publication Type:

Publication Type filter

Open access:

Publication Date:

Periodicals:

Periodicals filter

Search results

Online since: August 2015
Authors: Pais Saedin, Mohamad Adha Mohamad Idin, Ahmad Asri Abd Samat, Aimi Idzwan Tajudin
The complete data of the bus system was taken from [8].
The real power losses after reconfiguration showed a significant reduction in a rate of 31.077 % from 0.2024 MW to 0.1395 MW.
The complete data of the bus system was taken from [6].
For the proposed technique, the real power losses after reconfiguration showed a significant reduction in a rate of 31.077 % from 0.2024 MW to 0.1395 MW.
All the distribution system experienced reduction in real power loss when the network is reconfigured using this algorithm.
Online since: October 2011
Authors: Wen Bin Ma, Chao Ma, Gui Xing Zheng, Rui Zhao
The method of MAS technology for grid-based fault location has the following issues: the need to do based on a large number of electrical data, transmission volume upload is not timely; position calculation amount of information to determine a long time; when appearing DG and the IDT putting in use or out of use , the algorithm is not easy to change, affecting the flexibility of MAS.
According to the relevant network data, establish the topological relationship between nodes.
The Grid Fault Location Method Base on MAS of Rough Sets Decision table and the reduction.4 Tuple is a knowledge representation system, Of which: isfinite set of objects, Called the domain; A non-empty finite set, Called the set of attributes, and, and are called condition attributes set and decision attribute set; V is the range of attribute A: is an information function, Take properties offrom any elementof u, find uniquely determinedin the v, make G become Family of equivalence relations, the intersection of all equivalence relations in the G were Called indiscernibility relation on G, use I(G) show, if there,,is independent, Satisfy, is called a reduction of G, use R(G) show, Full reduction of G is defined as the intersection of nuclear, denoted as: .
Discernibility matrix of decision tableis a Matrix, The row i column j element of the decision table of the i-th row and j-line comparisons of: (1) After a reduction of more than one property after the reduction has been combined, Re-use twenty-two property obtained between the minimum information entropy as the best combination of attribute reduction combinations.
Composed of seven samples of the decision table are: Table 2 Fault diagnosis decision table Of the decision table attribute reduction, 3 properties available for the reduction were {CO1,CB1,CO2,CO3}, {RR1,CB1,CO2,CO3},{CO1,RR1,CO2,CO3}。
Online since: August 2015
Authors: Mouleeswaran Senthilkumar, M. Yuvaraja, M. Kok
The defects such as unbalance of impeller, bent shaft in pump, misalignment of shaft, hydraulic pulsation, cavitation and bearing defects are diagnosed using vibration data.
Thus by diagnosing centrifugal pump using vibration data reduces cost and time for periodical maintenance.
This data is of absolutely no value to the vibration analyst unless some specific details about the machine are known.
By changing the accelerometer orientation, data was recorded in other two axes at the same bearing location.
From the data collected, the defects are identified through vibration analysis by finding the difference in amplitudes.
Online since: September 2013
Authors: Zhi Wu Yu, Peng Liu, Yi Wan
Study on chloride ion penetration for concrete structures in zhunhai area Yi Wan1,a,Zhiwu Yu1,b,Peng Liu1,c 1School of Civil Engineering,Central South University,Hunan Changsha,410004,China a276353876@qq.com,bzhwyu@mail.csu.edu.cn,c23671871@qq.com Keywords: chloride;concrete samples;diffusion coefficient;alternate wetting-dry Abstract.The chloride concentration distribution is an efficient method of evaluating corrosion characteristics of concrete structures.A number of concrete samples at various positions were drilled in Zhuhai area and the free chloride concentration of concrete were determinated.Besides,the influences of elevations,distances from the sea and the local environment on chloride were analyzed.The value of chloride diffusion coefficient and surface chloride ion concentration along various elevation at the sea were calculated according to Fick’s second law.The results show that chloride’s erosive action tends to reduction with elevation and it is the most serious
Introduction The chloride erosion is one mainly reason of durability reduction for concrete structures in coastal areas,which is achieved by causing corrosion of reinforcing bar of concrete.The complex invasion mechanism of chloride ion is under the combined aciton including diffusion,capillary and permeability[1], and it is influenced by the physics and chemical actions between chloride ions and component materials of concrete.The deterioration of concrete relates to chloride penetration depth and permeability primarily,therefore,The determination of chloride concentration at different depths on the basis of natural environment is a reliable and practical method [2].
In addition,chloride concentration are between 0.14% and 0.4% within depth of 25mm.The convection plays a leading role in alternate wetting-dry area.And the depth of convection are 12.5mm,17.5mm,16.5mm,which is within the range of water transport(about 30mm) as previously demonstrated[6,7].At the elevations of +0.5m and +1m,there are convection and diffusion zone,where the convection depth is between 3.5mm and 6.5mm with about 0.72% at its peak.It turns out that chloride’s erosive action tends to reduction with elevation, the chloride concentration at the elevations of +0.5m and +1m is higher than others,it is related to humiture and soaking time of chloride.Furthermore,the relatively large convection depth is caused by the serious alternant wetting-dry at the elevations of +1.5m,+2.0m and +2.5m.
The diffusion zone of concrete samples at the elevations of +0.5 m, +1 m, +1.5 m were fitted based on equation(2).The picture of curve-fitting parameters is drawn in Fig.6,and the fitting data is shown in Tab.1.
elevation T/s Dcl/m2/s Cs/% R2 +0.5m 473040000 0.605E-13 0.904 0.954 +1.5m 473040000 1.468E-13 1.064 0.977 +2.5m 473040000 1.397E-13 0.823 0.947 Tab.1 Fitted datas of chloride diffusion Tab.1 indicates that the fitting surface chloride ion concentration is about 1% with a slight fluctuation.The calcuated chloride diffusion coefficient is in the order of 10-13m2 / s, and the previous literatures shows that it is in the order of 10-12m2/s,which may result from that there were hydration reactions of the magnesium ion,sulfate ion with the cement hydration products to form magnesium hydroxide and other substances.The pores of the concrete surface were filled with the formation of a barrier to prevent chloride invasion.
Online since: September 2013
Authors: Hong Liang Pan, Jian Jun Chen, Quan Sun, Yu Xi Yan
The elastic and plastic parameters, which determine the curve in elastic and strain hardening stages, were obtained from the experimental data.
Fig. 4 Crack length versus reduction for different tension A comparison of the crack length of simulated and experimental results is shown in Fig. 3.
It is shown that the crack length increases with the increasing of total reduction.
The variation of crack length versus total reduction for different tension level is shown in Fig. 4.
The two results agree well with each other and indicate that crack length increases with an increasing of total reduction and unit tension.
Online since: July 2011
Authors: Dan Li Zhou, Yu Qin Zhu
In the work, nano-sized MoO3 and unsupported MoS2 hydro desulfurization catalysts were synthesized using a novel hydrothermal reduction method.
Experimental materials and preparation methods Experimental materials By analysis and comparison,the hydrothermal reduction is used to prepare MoO3, the former body of MoS2 catalyst, and the MoS2 catalyst is synthesized by the hydrothermal deoxidization which is compared with the method of high temperature hydrogen sulphurization.
Materials of hydrothermal reduction to prepare MoO3(MoO3-Hy), of high temperature hydrogen sulphurization to produce MoS2(MoS2-D),and of hydrothermal deoxidization to prepare MoS2 have been shown in table1, table2, and table 3 respectively.
Table1 Materials of hydrothermal reduction using for the preparation of MoO3 Materials Specification hydrochloric acid 37% sodium molybdate ≥99.5% Table2 Materials of hydrogen sulphurization using for the preparation of MoS2 Materials Specification hydrochloric acid 37% sodium hydroxide 98% hydrogen 99.99% sodium sulfide nonahydrate ≥ 98% nitrogen 99.99% sodium molybdate ≥99.5% Table3 Materials of hydrothermal deoxidization using for the preparation of MoS2 Materials Specification hydrochloric acid 37% nitrogen 99.99% alcohol 95% MoO3 ≥99.5% sodium sulfide nonahydrate ≥98% Preparation methods Hydrothermal reduction for the preparation of MoO3 :The mixture of sodium molybdate and hydrochloric acid in certain proportion was put into the inner of reactor and heated from the ambient temperature at a certain speed to 150˚C.
Handbook of thermochemical data for compounds & aqueous species.
Online since: October 2011
Authors: Zhen Hong Yuan, Chang Hua Shang, Shun Ni Zhu, Zhong Ming Wang
For the biosynthesis of monovinyl chlorophyll, the reduction of the 8-vinyl group which is located on the B-ring of the macrocycle is essential. 3,8-Divinyl protochlorophyllide a 8-vinyl reductase (DVR) catalyzes the reduction of 8-vinyl group on the tetrapyrrole to an ethyl group, which is necessary for monovinyl chlorophyll (Chl) synthesis.
Among the variety of chlorophyll species, monovinyl chlorophyll a are most commonly utilized for the photochemistry in photosynthetic organisms. 3,8-Divinyl protochlorophyllide a 8-vinyl reductase (DVR) catalyzes the reduction of 8-vinyl group on the tetrapyrrole to an ethyl group, which is necessary for monovinyl chlorophyll (Chl) synthesis.
Conclusions In conclusion, our data show full-length DVR cDNA was cloned from Dunaliella parva, which includes 1326 bp coding region, 22 bp 5'-untranslated regions and 383 bp 3'-untranslated regions.
Online since: July 2008
Authors: Emad A. Badawi, N.A. Kamel, M. Abdel-Rahman, Yahia A. Lotfy, M.A. Abdel-Rahman
The advantages of this method are in the obtaining of both qualitative and quantitative data on defect behavior in materials.
The dominant change in values of S-parameter as a function of thickness reduction is shown in figure (3).
In such figure, the S- parameter increases with increasing of thickness reduction of the sample.
The defect density is increasing exponentially with increasing of thickness reduction.
Above 4% of thickness reduction, the Sparameter values kept approximately constant.
Online since: May 2014
Authors: Evgueni I. Poliak, Debanshu Bhattacharya
The production of advanced high strength steels (AHSS) has been rapidly expanding in recent years as these steels allow for considerable reduction in weight and enhancement of car safety due to the unique combination of high strength, toughness and formability.
Only the data pertinent to typical HSM finishing rolling temperatures are shown.
In Fig. 2, the data for typical X80 grade and 0.16 % C – 0.8 % Mn steel are also shown; the former grade is traditionally CR processed.
Rolling temperatures, speeds and pass reductions have to be adjusted to ensure full recrystallization between the passes but at the same time to prevent grain coarsening after the rolling passes.
Then in DRCR, to avoid this situation, DRX should be completed in each rolling pass that would in turn require large pass reductions practically unachievable because specifics of rolling geometry and high deformation resistance.
Online since: November 2011
Authors: R. Arumugam, R. Karthikeyan, K. Vijayakumar
The static and transient electromagnetic characteristics have been obtained through the electromagnetic finite element analysis software MagNet6.22.1 while the thermal and vibration aspects have been studied through coupled field Finite Element Analysis employing the multi physics software ANSYS10 while the Impulse hammers excitation - free vibration test using RT Pro Photon data acquisition system facilitated the experimental determination of vibration characteristics.
The study concludes that the advantages of less weight , low torque ripple, low eddy current losses, reduction in vibration level of stator structure coupled with the ability to maintain precise mechanical dimensional tolerance may present SMC-SRG a viable candidate in standalone wind energy conversion systems meant for rural and remote area electrification scheme.
Fig.9.Nodal temperature distribution Fig.10 Circumferential mode shapes The experimental setup for the impulse hammers excitation - free vibration test [5] of the SMC-SRG using RT Pro Photon data acquisition system is shown in Fig.11.
Conclusion This paper delineated the fabrication and testing of Switched reluctance generator structure with SOMOLOY1000, a soft magnetic composite material and the investigation led to the conclusion that the advantages of less weight , low torque ripple, low eddy current losses, reduction in vibration level of stator structure coupled with the ability to maintain precise mechanical dimensional tolerance may present SMC-SRG a viable candidate in standalone wind energy conversion systems meant for rural and remote area electrification scheme.
Showing 5091 to 5100 of 40699 items