China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualitie...China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.展开更多
Soil liquefaction is one of the complex research topics in geotechnical engineering and engineering geology. Especially after the 1964 Niigata earthquake (Japan) induced many soil liquefaction incidents, a variety of ...Soil liquefaction is one of the complex research topics in geotechnical engineering and engineering geology. Especially after the 1964 Niigata earthquake (Japan) induced many soil liquefaction incidents, a variety of soil liquefaction studies were conducted and reported, including the liquefaction potential assessment methods utilizing the shear wave velocity (V<sub>s</sub>) or SPT-N profiles (SPT: standard penetration test). This study used the V<sub>s</sub> and SPT methods recommended by the National Center for Earthquake Engineering Research (NCEER) to examine which is more conservative according to the assessment results on 41 liquefiable soil layers at sites in two major cities in Taiwan. Statistical hypothesis testing was used to make the analysis more quantitative and objective. Based on three sets of hypothesis tests, it shows that the hypothesis—the SPT method is more conservative than the V<sub>s</sub> method—was not rejected on a 5% level of significance.展开更多
A comprehensive overview of standardized testing system for ESL (English as a Second Language) students in U.S kindergarten thru grade 12 public school system is reviewed within the context of basis on federal and s...A comprehensive overview of standardized testing system for ESL (English as a Second Language) students in U.S kindergarten thru grade 12 public school system is reviewed within the context of basis on federal and state laws, as well as instructional basis. Identification process of LEP (Limited English Proficient) students via nomination, testing and testing criteria to be identified as LEP, hence ESL if placed in the program is defined in detail Standardized testing process of these students based on the federal AYP (Adequate Yearly Progress) measures through regular state standardized tests depending on three types of instructional program that LEP student is placed in the school that are Bilingual Education Program, ESL Program, and Two-Way Immersion Dual Language Programs are described. Standardized testing process of these students based on the federal AYP measures through other means if exempted from regular state standardized tests such as LAT (Linguistically Accommodated Testing) and the conditions to be exempted are discussed in detail. Holistically rated English Language Proficiency Assessments that are implemented to fulfill federal AMAOs (Annual Measurable Achievement Objectives) measures are defined briefly. Physical features of LAT test as well as direct and indirect accommodations for LAT reading, mathematics and science tests are defined via the accommodation needed and the type of assistance provided. Lastly, testing criteria to exit LEP status and other issues concerning exiting LEP status are reviewed展开更多
In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occ...In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.展开更多
The methodology of predicting pile shaft skin ultimate friction has been studied in a systematic way. In the light of that, the analysis of the pile shaft resistance for bored and cast in situ piles in cohesive soil...The methodology of predicting pile shaft skin ultimate friction has been studied in a systematic way. In the light of that, the analysis of the pile shaft resistance for bored and cast in situ piles in cohesive soils was carried out thoroughly in the basis of field performance data of 10 fully instrumented large diameter bored piles (LDBPs) used as the bridge foundation. The undrained strength index μ in term of cohesive soils was brought forward in allusion to the cohesive soils in the consistence plastic state, and can effectively combine the friction angle and the cohesion of cohesive soils in undrained condition. And that the classical ' α method' was modified much in effect to predict the pile shaft skin friction of LDBPs in cohesive soils. Furthermore, the approach of standard penetration test (SPT) N value used to estimate the pile shaft skin ultimate friction was analyzed, and the calculating formulae were established for LDBPs in clay and silt clay respectively.展开更多
Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platin...Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platinum group metal(PGM)catalysts creates a barrier for the large-scale application of PEMFC.Tremendous efforts have been devoted to the development of low-cost PGM-free catalysts,especially the Fe-N-C catalysts,to replace the expensive PGM catalysts.However,the characterization methods and evaluation standards of the catalysts varies,which is not conducive to the comparison of PGM-free catalysts.U.S.Department of energy(DOE)is the only authority that specifies the testing standards and activity targets for PGM-free catalysts.In this review,the major breakthroughs of Fe-N-C catalysts are outlined with the reference of DOE standards and targets.The preparation and characteristics of these highly active Fe-N-C catalysts are briefly introduced.Moreover,the efforts on improving the mass transfer and the durability issue of Fe-N-C fuel cell are discussed.Finally,the prospective directions concerning the comprehensive evaluation of the Fe-N-C catalysts are proposed.展开更多
Optical coherence tomography(OCT)has been widely applied to the diagnosis of eye diseasesduring the past two decades.However,valid evaluation methods are stil not available for theclinical OCT devices.In order to asse...Optical coherence tomography(OCT)has been widely applied to the diagnosis of eye diseasesduring the past two decades.However,valid evaluation methods are stil not available for theclinical OCT devices.In order to assess the axial resolution of the OCT system,standard modeleyes with micro-scale multilayer structure have been designed and manufactured in this study.Mimicking a natural human eye,proper Titanium dioxide(TiO_(2))materials of particles withdifferent concentrations were selected by testing the scattering coefficient of PDMS phantoms.The artificial retinas with multilayer films were fabricated with the thicknesses from 9.5 to 30 micrometers using spin coating technology,Subsequently,standard OCT model eyes were ac-complished by embedding the retina phantoms into the artificial frames of eyes.For ease ofmeasurement processing,a series of model eyes were prepared,and each contained flms withthree kinds of thicknesses.Considering the traceability and accuracy of the key parameters of the standard model eyes,the thicknesses of multilayer structures were verfed using ThicknessMonitoring System.Through the experiment with three different OCT devices,it demonstratedthe model eyes fabricated in this study can provide an effective evaluation method for the axialresolution of an ophthalmic OCT device.展开更多
Objective:The paper discusses recent evidence on the assessment of language outcomes in children with hearing loss acquiring oral language. Methods: Research emphasizes that language tests must be specific enough to c...Objective:The paper discusses recent evidence on the assessment of language outcomes in children with hearing loss acquiring oral language. Methods: Research emphasizes that language tests must be specific enough to capture subtle deficits in vocabulary and grammar learning at different developmental ages. The Diagnostic Receptive and Expressive Assessment of Mandarin (DREAM) was carefully designed to be a comprehensive standardized Mandarin assessment normed in China's Mainland. Results:This paper summarizes the evidence-based item design process and validity and reliability results of DREAM. A pilot study reported here shows that DREAM provided detailed information about hearing impaired children's language abilities and can be used to aid intervention planning to maximize progress. Conclusion: DREAM represents an example of translational science, transferring methods from empirical studies of language acquisition in research environments into applied domains such as assessment and intervention. Research on outcomes in China will advance significantly with the availability of evidence-based comprehensive language tests that measure a sufficient age range of skills, are normed on Mandarin speaking children in China's Mainland, and are designed to capture features central to Mandarin language acquisition.展开更多
Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase b...Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).展开更多
Guwahati, the major city in the North Eastern region of India is growing rapidly in every aspect with major infrastructures like sports complex, educational institutions, hospitals, flyovers, multiplex halls, etc. Kno...Guwahati, the major city in the North Eastern region of India is growing rapidly in every aspect with major infrastructures like sports complex, educational institutions, hospitals, flyovers, multiplex halls, etc. Knowledge of the subsurface soil condition is necessary to ensure the structural safety and serviceability of the above mentioned structures before any construction. Therefore, contour maps of Standard penetration test N value, ground water table and shear wave velocity map using Geographical Information System (GIS) platform will be of great help to the foundation designers at the initial stage for site selection and preliminary foundation design under static and seismic condition. Contour maps of Standard penetration test N value at different depth and average contour map of N value of Guwahati city have been prepared. Standard penetration Test N values and depth of water table were taken from a data base of 200 boreholes up to 30 meter depth to prepare N value contour map of Guwahati city. A regression equation between shear wave velocity V<sub>s</sub> and Standard penetration test N value based on twenty seven previous similar correlations was also developed. This regression equation was used to determine shear wave velocity of Guwahati city. The average shear wave velocities for 30 m depth for all locations had been determined and used to generate map on (GIS) platform. Other subsurface geotechnical information of Guwahati city like soil classification and depth to water level from ground surface is also presented in the form of GIS based maps in order to form a data base.展开更多
This paper describes the resisting ability of gunning material for blast furnace to carbon monoxide corrosion under the mixed gas condition through inletting hydrogen into pure CO . A standard for testing ike resistin...This paper describes the resisting ability of gunning material for blast furnace to carbon monoxide corrosion under the mixed gas condition through inletting hydrogen into pure CO . A standard for testing ike resisting ability of refractory to CO corrosion with mixed gas instead of pure CO has also been discussed. The results show : the addition of hydrogen accelerates the CO corrosion on gunning material ; the same results has been reached with the CO , 200 hours and CO 95 % + H2 5 % , 24 hours. It is reasonable to use CO 95% + H25% , 24 hours instead of pure CO, 200 hours to lest the resisting ability of refractory to carbon monoxide corrosion.展开更多
A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place so...A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place soils.Firstly,the liquefaction potential of the soil at the project site is analysed according to the code of seismic design.Then the in-situ single point impact tests are performed on the liquefiable soil.Settlement of crater,excess pore pressure,ground heave and lateral deformation under DC impact are measured and analyzed.Subsequently, the standard penetration test(SPT)and cone penetration test(CPT)are used for investigating the compaction effectiveness.At last,the improvement effect of DC is discussed according to the technical specification of dynamic consolidation to ground treatment.The investigation results indicate that the DC technique is an effective way for remediating liquefiable soil in highway engineering practice.展开更多
The paper presents conclusions related to the design of shallow foundations,at the site where the Substation at Kashari,in Tirana is foreseen to be constructed.The project includes buildings with small to medium struc...The paper presents conclusions related to the design of shallow foundations,at the site where the Substation at Kashari,in Tirana is foreseen to be constructed.The project includes buildings with small to medium structures with 1-3 stories.The geological survey works include 6 boreholes of a depth 20.0 m,90 SPT(Standard Penetration Tests)tests,and laboratory works include 13 direct shear tests,27 unconfined and compressive strength tests,7 CU(consolidated undrained)tests and 9 UU(unconsolidated undrained)tests,etc.The foundation design must fulfill both,bearing and settlement criteria,but in this case the settlements of foundations are not possible to be calculated,since the laboratory works do not include any consolidation test.So,the local bearing capacity is expected to control the design in terms of bearing capacity and settlements.The local bearing capacity of shallow square foundations is evaluated by using Terzaghi’s formula,based on reduced shear strength parameters of soils below the bottom of foundations.The results are compared with the bearing capacity values calculated by using Burland and Burbdige(1984)method,based on the data of SPT tests.This method is used for checking the settlement(serviceability)criterion in the foundation design,when the direct settlement calculation is missing.The paper presents some conclusions related to local bearing capacity foundation-based design.展开更多
Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects ...Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators.In this study,a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards,and implementation of the WBV test in the official testing station was also suggested.A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds.The vector sum A(8)exposures on the rough tracks(earthen and grassland roads)exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road.The vector sum of VDV(8)exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road.The vector sum Sed(8)exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt,concrete,and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards.The WBV evaluation procedure should be considered for implementation at the official tractor test station,which would response to domestic and international tractor test regulations and improve the market competitiveness.展开更多
Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platfor...Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platform,insulation tests on epoxy casting resins are carried out using high-frequency square wave signals.Subsequently,the variations of discharge inception and flashover voltages with frequency were analyzed based on the Secondary Electron Emission Avalanche(SEEA)model.The breakdown characteristics of epoxy casting resins are studied based on the Weibull distribution analysis and inverse power function model.Finally,an insulation test standard is proposed based on the breakdown characteristics of epoxy casting resins for dry-type HV-HF transformers.The results show that,the flashover voltages are noticeably reduced with the increase of frequency while the discharge inception is hardly affected by frequency.Moreover,the drop in breakdown voltages and insulation lifetime shortening are caused by high-frequency thermal effects.Also,the applied voltages of epoxy resin cast dry-type HV-HF transformers are recommended to be 3.27 to 3.49 times their maximum operating voltages in 1min applied withstand tests.The applied voltages of the induced withstand tests should be 2.20 to 2.52 times their maximum operating voltages.展开更多
Due to the increasingly stringent standards, it is important to assess whether the proposed emission reduction will result in ambient concentrations that meet the standards. The Software for Model Attainment Test-Comm...Due to the increasingly stringent standards, it is important to assess whether the proposed emission reduction will result in ambient concentrations that meet the standards. The Software for Model Attainment Test-Community Edition (SMAT-CE) is developed for demonstrating attainment of air quality standards of O3 and PM2.5. SMAT-CE improves computational efficiency and provides a number of advanced visualization and analytical functionalities on an integrated GIS platform. SMAT-CE incorporates historical measurements of air quality parameters and simulated air pollutant concentrations under a number of emission inventory scenarios to project the level of compliance to air quality standards in a targeted future year. An application case study of the software based on the U.S. National Ambient Air Quality Standards (NAAQS) shows that SMAT-CE is capable of demonstrating the air quality attainment of annual PM2.5 and 8-hour O3 for a proposed emission control policy.展开更多
Ceiling fans are used all over the world as a mean of enhancing indoor thermal comfort. A number of grading programs have been initiated for assessing energy performance of ceiling fans, such as ANSI/AMCA 230, Energy ...Ceiling fans are used all over the world as a mean of enhancing indoor thermal comfort. A number of grading programs have been initiated for assessing energy performance of ceiling fans, such as ANSI/AMCA 230, Energy Star, IEC 60879, IS 374 and SLS 1600. The configurations of test setups used for performance evaluations in these standards have significant differences to each other. In this study, the influence of such differences on the calculated performance grade of ceiling fans were investigated and the suitability of each dimension of the test set-up is discussed. Particular emphasis was placed on quantifying the effect of the cylindrical drum used in Energy Star and SLS test methods. For this assessment, extensive three-dimensional numerical simulations and experimental measurements were used. Accordingly, the effect of cylinder height, gap between the fan rotation plane and the cylinder, cylinder diameter and the dimensions of the test chamber were investigated. Results show that, the test cylinder, has no significant impact on the calculated performance grade of the tested ceiling fan (variation is less than 2%), and may be eliminated from the test setup. This justifies the recent decision of AMCA on the removal of test cylinder from the fan test set-up. Further, it was also found that the set up dimensions considered herein is large enough so that the calculated start rating is uneffaced by the surrounding solid walls.展开更多
The present paper examines the evaluation of liquefaction potential of an earth dam foundation in Tunisia. The assessment of soil liquefaction was made using deterministic and probabilistic simplified procedures devel...The present paper examines the evaluation of liquefaction potential of an earth dam foundation in Tunisia. The assessment of soil liquefaction was made using deterministic and probabilistic simplified procedures developed from several case histories. The data collected from the field investigation performed before and after the vibrocompaction are analyzed and the results are reported. The obtained results show that after vibrocompaction, a significant improvement of the soil resistance reduces the liquefaction potential of the sandy foundation. Indeed, in the untreated layers, the factor of safety FS drops below 1 which means that the soil is susceptible for liquefaction. However, in the compacted horizons, the values of FS exceed the unit which justifies the absence of liquefaction hazard of the foundation.展开更多
A hardware platform using broadband antenna,oscilloscope,and spectrum analyzer is designed to receive radio frequency(RF)signals from electromagnetic radiation leakage of computers in the office environment.The proces...A hardware platform using broadband antenna,oscilloscope,and spectrum analyzer is designed to receive radio frequency(RF)signals from electromagnetic radiation leakage of computers in the office environment.The process of receiving and the processing techniques have also been given.Then,the software radio-based computing models and software algorithms are proposed to demodulate and decode the RF signals.An experimental result shows that the text information can be recovered from electromagnetic(EM)leakage wave of computer by this interception system.This architecture not only reduces the cost of the system’s hardware but also makes interception more flexible.The innovation points of this paper are recovering the video information in EM leakage wave of computers in an ordinary office environment based on public equipments and proposing the process of receiving processing techniques that only use the software radiobased computing models and software algorithms.展开更多
This paper presents a fast pseudorandom generation algorithm,which is based on the BLAKE hash function and can pass the random test of the NIST(National Institute of Standards and Technology) Statistical Test Suite....This paper presents a fast pseudorandom generation algorithm,which is based on the BLAKE hash function and can pass the random test of the NIST(National Institute of Standards and Technology) Statistical Test Suite.Through theoretical analysis and experimental imitation,our new algorithm is proven to be more secure and efficient than G-SHA1.Simultaneously,we introduce and discuss the BLAKE in detail.Its security shows that can be utilized to generate pseudorandom bit sequences,which the experimental results show the BLAKE hash function has excellent pseudorandomness.Therefore,we believe the BLAKE is one of the most potential candidate algorithms of SHA-3 program.展开更多
文摘China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.
文摘Soil liquefaction is one of the complex research topics in geotechnical engineering and engineering geology. Especially after the 1964 Niigata earthquake (Japan) induced many soil liquefaction incidents, a variety of soil liquefaction studies were conducted and reported, including the liquefaction potential assessment methods utilizing the shear wave velocity (V<sub>s</sub>) or SPT-N profiles (SPT: standard penetration test). This study used the V<sub>s</sub> and SPT methods recommended by the National Center for Earthquake Engineering Research (NCEER) to examine which is more conservative according to the assessment results on 41 liquefiable soil layers at sites in two major cities in Taiwan. Statistical hypothesis testing was used to make the analysis more quantitative and objective. Based on three sets of hypothesis tests, it shows that the hypothesis—the SPT method is more conservative than the V<sub>s</sub> method—was not rejected on a 5% level of significance.
文摘A comprehensive overview of standardized testing system for ESL (English as a Second Language) students in U.S kindergarten thru grade 12 public school system is reviewed within the context of basis on federal and state laws, as well as instructional basis. Identification process of LEP (Limited English Proficient) students via nomination, testing and testing criteria to be identified as LEP, hence ESL if placed in the program is defined in detail Standardized testing process of these students based on the federal AYP (Adequate Yearly Progress) measures through regular state standardized tests depending on three types of instructional program that LEP student is placed in the school that are Bilingual Education Program, ESL Program, and Two-Way Immersion Dual Language Programs are described. Standardized testing process of these students based on the federal AYP measures through other means if exempted from regular state standardized tests such as LAT (Linguistically Accommodated Testing) and the conditions to be exempted are discussed in detail. Holistically rated English Language Proficiency Assessments that are implemented to fulfill federal AMAOs (Annual Measurable Achievement Objectives) measures are defined briefly. Physical features of LAT test as well as direct and indirect accommodations for LAT reading, mathematics and science tests are defined via the accommodation needed and the type of assistance provided. Lastly, testing criteria to exit LEP status and other issues concerning exiting LEP status are reviewed
文摘In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.
文摘The methodology of predicting pile shaft skin ultimate friction has been studied in a systematic way. In the light of that, the analysis of the pile shaft resistance for bored and cast in situ piles in cohesive soils was carried out thoroughly in the basis of field performance data of 10 fully instrumented large diameter bored piles (LDBPs) used as the bridge foundation. The undrained strength index μ in term of cohesive soils was brought forward in allusion to the cohesive soils in the consistence plastic state, and can effectively combine the friction angle and the cohesion of cohesive soils in undrained condition. And that the classical ' α method' was modified much in effect to predict the pile shaft skin friction of LDBPs in cohesive soils. Furthermore, the approach of standard penetration test (SPT) N value used to estimate the pile shaft skin ultimate friction was analyzed, and the calculating formulae were established for LDBPs in clay and silt clay respectively.
基金supported by the National Thousand Talents Plan of Chinathe National Natural Science Foundation of China(Grant Nos.21673014 and U1766216)+1 种基金the 111 project(B17002)funded by the Ministry of Education of Chinathe Fundamental Research Funds for the Central Universities of China
文摘Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platinum group metal(PGM)catalysts creates a barrier for the large-scale application of PEMFC.Tremendous efforts have been devoted to the development of low-cost PGM-free catalysts,especially the Fe-N-C catalysts,to replace the expensive PGM catalysts.However,the characterization methods and evaluation standards of the catalysts varies,which is not conducive to the comparison of PGM-free catalysts.U.S.Department of energy(DOE)is the only authority that specifies the testing standards and activity targets for PGM-free catalysts.In this review,the major breakthroughs of Fe-N-C catalysts are outlined with the reference of DOE standards and targets.The preparation and characteristics of these highly active Fe-N-C catalysts are briefly introduced.Moreover,the efforts on improving the mass transfer and the durability issue of Fe-N-C fuel cell are discussed.Finally,the prospective directions concerning the comprehensive evaluation of the Fe-N-C catalysts are proposed.
基金supported by the National Key Research and Development Program of China(2016YFF0201005).
文摘Optical coherence tomography(OCT)has been widely applied to the diagnosis of eye diseasesduring the past two decades.However,valid evaluation methods are stil not available for theclinical OCT devices.In order to assess the axial resolution of the OCT system,standard modeleyes with micro-scale multilayer structure have been designed and manufactured in this study.Mimicking a natural human eye,proper Titanium dioxide(TiO_(2))materials of particles withdifferent concentrations were selected by testing the scattering coefficient of PDMS phantoms.The artificial retinas with multilayer films were fabricated with the thicknesses from 9.5 to 30 micrometers using spin coating technology,Subsequently,standard OCT model eyes were ac-complished by embedding the retina phantoms into the artificial frames of eyes.For ease ofmeasurement processing,a series of model eyes were prepared,and each contained flms withthree kinds of thicknesses.Considering the traceability and accuracy of the key parameters of the standard model eyes,the thicknesses of multilayer structures were verfed using ThicknessMonitoring System.Through the experiment with three different OCT devices,it demonstratedthe model eyes fabricated in this study can provide an effective evaluation method for the axialresolution of an ophthalmic OCT device.
基金the financial support of Bethel Hearing and Speaking Training Center Inc. for all research studies in this paper
文摘Objective:The paper discusses recent evidence on the assessment of language outcomes in children with hearing loss acquiring oral language. Methods: Research emphasizes that language tests must be specific enough to capture subtle deficits in vocabulary and grammar learning at different developmental ages. The Diagnostic Receptive and Expressive Assessment of Mandarin (DREAM) was carefully designed to be a comprehensive standardized Mandarin assessment normed in China's Mainland. Results:This paper summarizes the evidence-based item design process and validity and reliability results of DREAM. A pilot study reported here shows that DREAM provided detailed information about hearing impaired children's language abilities and can be used to aid intervention planning to maximize progress. Conclusion: DREAM represents an example of translational science, transferring methods from empirical studies of language acquisition in research environments into applied domains such as assessment and intervention. Research on outcomes in China will advance significantly with the availability of evidence-based comprehensive language tests that measure a sufficient age range of skills, are normed on Mandarin speaking children in China's Mainland, and are designed to capture features central to Mandarin language acquisition.
基金the sponsorship from the Brazilian government agencies CNPqFAPES
文摘Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).
文摘Guwahati, the major city in the North Eastern region of India is growing rapidly in every aspect with major infrastructures like sports complex, educational institutions, hospitals, flyovers, multiplex halls, etc. Knowledge of the subsurface soil condition is necessary to ensure the structural safety and serviceability of the above mentioned structures before any construction. Therefore, contour maps of Standard penetration test N value, ground water table and shear wave velocity map using Geographical Information System (GIS) platform will be of great help to the foundation designers at the initial stage for site selection and preliminary foundation design under static and seismic condition. Contour maps of Standard penetration test N value at different depth and average contour map of N value of Guwahati city have been prepared. Standard penetration Test N values and depth of water table were taken from a data base of 200 boreholes up to 30 meter depth to prepare N value contour map of Guwahati city. A regression equation between shear wave velocity V<sub>s</sub> and Standard penetration test N value based on twenty seven previous similar correlations was also developed. This regression equation was used to determine shear wave velocity of Guwahati city. The average shear wave velocities for 30 m depth for all locations had been determined and used to generate map on (GIS) platform. Other subsurface geotechnical information of Guwahati city like soil classification and depth to water level from ground surface is also presented in the form of GIS based maps in order to form a data base.
文摘This paper describes the resisting ability of gunning material for blast furnace to carbon monoxide corrosion under the mixed gas condition through inletting hydrogen into pure CO . A standard for testing ike resisting ability of refractory to CO corrosion with mixed gas instead of pure CO has also been discussed. The results show : the addition of hydrogen accelerates the CO corrosion on gunning material ; the same results has been reached with the CO , 200 hours and CO 95 % + H2 5 % , 24 hours. It is reasonable to use CO 95% + H25% , 24 hours instead of pure CO, 200 hours to lest the resisting ability of refractory to carbon monoxide corrosion.
基金Supported by the National Youth Science Foundation of China(40802065)the Jiangsu Province Ed-ucation Science Foundation(08KJD580004)the Innovation Research Foundation of Nanjing Institute of Technology(CKJ2011010)
文摘A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place soils.Firstly,the liquefaction potential of the soil at the project site is analysed according to the code of seismic design.Then the in-situ single point impact tests are performed on the liquefiable soil.Settlement of crater,excess pore pressure,ground heave and lateral deformation under DC impact are measured and analyzed.Subsequently, the standard penetration test(SPT)and cone penetration test(CPT)are used for investigating the compaction effectiveness.At last,the improvement effect of DC is discussed according to the technical specification of dynamic consolidation to ground treatment.The investigation results indicate that the DC technique is an effective way for remediating liquefiable soil in highway engineering practice.
文摘The paper presents conclusions related to the design of shallow foundations,at the site where the Substation at Kashari,in Tirana is foreseen to be constructed.The project includes buildings with small to medium structures with 1-3 stories.The geological survey works include 6 boreholes of a depth 20.0 m,90 SPT(Standard Penetration Tests)tests,and laboratory works include 13 direct shear tests,27 unconfined and compressive strength tests,7 CU(consolidated undrained)tests and 9 UU(unconsolidated undrained)tests,etc.The foundation design must fulfill both,bearing and settlement criteria,but in this case the settlements of foundations are not possible to be calculated,since the laboratory works do not include any consolidation test.So,the local bearing capacity is expected to control the design in terms of bearing capacity and settlements.The local bearing capacity of shallow square foundations is evaluated by using Terzaghi’s formula,based on reduced shear strength parameters of soils below the bottom of foundations.The results are compared with the bearing capacity values calculated by using Burland and Burbdige(1984)method,based on the data of SPT tests.This method is used for checking the settlement(serviceability)criterion in the foundation design,when the direct settlement calculation is missing.The paper presents some conclusions related to local bearing capacity foundation-based design.
文摘Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators.In this study,a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards,and implementation of the WBV test in the official testing station was also suggested.A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds.The vector sum A(8)exposures on the rough tracks(earthen and grassland roads)exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road.The vector sum of VDV(8)exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road.The vector sum Sed(8)exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt,concrete,and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards.The WBV evaluation procedure should be considered for implementation at the official tractor test station,which would response to domestic and international tractor test regulations and improve the market competitiveness.
基金supported by the National Key R&D Program of China(2017YFB0903902)。
文摘Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platform,insulation tests on epoxy casting resins are carried out using high-frequency square wave signals.Subsequently,the variations of discharge inception and flashover voltages with frequency were analyzed based on the Secondary Electron Emission Avalanche(SEEA)model.The breakdown characteristics of epoxy casting resins are studied based on the Weibull distribution analysis and inverse power function model.Finally,an insulation test standard is proposed based on the breakdown characteristics of epoxy casting resins for dry-type HV-HF transformers.The results show that,the flashover voltages are noticeably reduced with the increase of frequency while the discharge inception is hardly affected by frequency.Moreover,the drop in breakdown voltages and insulation lifetime shortening are caused by high-frequency thermal effects.Also,the applied voltages of epoxy resin cast dry-type HV-HF transformers are recommended to be 3.27 to 3.49 times their maximum operating voltages in 1min applied withstand tests.The applied voltages of the induced withstand tests should be 2.20 to 2.52 times their maximum operating voltages.
基金provided by the U.S. Environmental Protection Agency (Subcontract Number OR13810-001.04 A10-0223-S001-A04)partly supported by the funding of Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control (No. 2011A060901011)+1 种基金the funding of State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex (No. SCAPC201308)the project of Atmospheric Haze Collaborative Control System Design (No. XDB05030400) from Chinese Academy of Sciences
文摘Due to the increasingly stringent standards, it is important to assess whether the proposed emission reduction will result in ambient concentrations that meet the standards. The Software for Model Attainment Test-Community Edition (SMAT-CE) is developed for demonstrating attainment of air quality standards of O3 and PM2.5. SMAT-CE improves computational efficiency and provides a number of advanced visualization and analytical functionalities on an integrated GIS platform. SMAT-CE incorporates historical measurements of air quality parameters and simulated air pollutant concentrations under a number of emission inventory scenarios to project the level of compliance to air quality standards in a targeted future year. An application case study of the software based on the U.S. National Ambient Air Quality Standards (NAAQS) shows that SMAT-CE is capable of demonstrating the air quality attainment of annual PM2.5 and 8-hour O3 for a proposed emission control policy.
基金This work was financially supported by University of Moratuwa senate research committee grant no CAP/16/02The support provided by Sri Lanka Standards Institution(SLSI)is also gratefully acknowledged.
文摘Ceiling fans are used all over the world as a mean of enhancing indoor thermal comfort. A number of grading programs have been initiated for assessing energy performance of ceiling fans, such as ANSI/AMCA 230, Energy Star, IEC 60879, IS 374 and SLS 1600. The configurations of test setups used for performance evaluations in these standards have significant differences to each other. In this study, the influence of such differences on the calculated performance grade of ceiling fans were investigated and the suitability of each dimension of the test set-up is discussed. Particular emphasis was placed on quantifying the effect of the cylindrical drum used in Energy Star and SLS test methods. For this assessment, extensive three-dimensional numerical simulations and experimental measurements were used. Accordingly, the effect of cylinder height, gap between the fan rotation plane and the cylinder, cylinder diameter and the dimensions of the test chamber were investigated. Results show that, the test cylinder, has no significant impact on the calculated performance grade of the tested ceiling fan (variation is less than 2%), and may be eliminated from the test setup. This justifies the recent decision of AMCA on the removal of test cylinder from the fan test set-up. Further, it was also found that the set up dimensions considered herein is large enough so that the calculated start rating is uneffaced by the surrounding solid walls.
文摘The present paper examines the evaluation of liquefaction potential of an earth dam foundation in Tunisia. The assessment of soil liquefaction was made using deterministic and probabilistic simplified procedures developed from several case histories. The data collected from the field investigation performed before and after the vibrocompaction are analyzed and the results are reported. The obtained results show that after vibrocompaction, a significant improvement of the soil resistance reduces the liquefaction potential of the sandy foundation. Indeed, in the untreated layers, the factor of safety FS drops below 1 which means that the soil is susceptible for liquefaction. However, in the compacted horizons, the values of FS exceed the unit which justifies the absence of liquefaction hazard of the foundation.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.60871081,60671055,and 60771060)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Nos.20070013002 and 20070013004).
文摘A hardware platform using broadband antenna,oscilloscope,and spectrum analyzer is designed to receive radio frequency(RF)signals from electromagnetic radiation leakage of computers in the office environment.The process of receiving and the processing techniques have also been given.Then,the software radio-based computing models and software algorithms are proposed to demodulate and decode the RF signals.An experimental result shows that the text information can be recovered from electromagnetic(EM)leakage wave of computer by this interception system.This architecture not only reduces the cost of the system’s hardware but also makes interception more flexible.The innovation points of this paper are recovering the video information in EM leakage wave of computers in an ordinary office environment based on public equipments and proposing the process of receiving processing techniques that only use the software radiobased computing models and software algorithms.
基金Supported by the National High Technology Research and Development Program of China (863 Program) ( 2007AA01Z411)the National Natural Science Foundation of China ( 60673071, 60970115 )
文摘This paper presents a fast pseudorandom generation algorithm,which is based on the BLAKE hash function and can pass the random test of the NIST(National Institute of Standards and Technology) Statistical Test Suite.Through theoretical analysis and experimental imitation,our new algorithm is proven to be more secure and efficient than G-SHA1.Simultaneously,we introduce and discuss the BLAKE in detail.Its security shows that can be utilized to generate pseudorandom bit sequences,which the experimental results show the BLAKE hash function has excellent pseudorandomness.Therefore,we believe the BLAKE is one of the most potential candidate algorithms of SHA-3 program.