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A Compact Rhombus Shaped Antenna with Extended Stubs for Ultra-Wideband Applications

Computers, Materials & Continua 2022年第11期73卷 2637-2650页

作者： Syed Misbah un Noor Muhammad Amir Khan Shahid Khan NZ Jhanjhi Mamoona Humayun Hesham A.Alhumyan Department of Electrical Engineering IIC University of TechnologyPhnom PenhCambodia Department of Computer Science COMSATS University IslamabadAbbottabad Campus22060Pakistan Department of Electrical and Computer Engineering COMSATS University IslamabadAbbottabad Campus22060Pakistan School of Computer Science SCSTaylor’s UniversitySubang Jaya47500SelangorMalaysia 5Center for Smart Society 0 CSS5 Faculty of Innovation and TechnologyTaylor’s UniversitySubang Jaya47500Malaysia Department of Information Systems College of Computer and Information SciencesJouf UniversityAl-JoufKSA

Ultra-wideband(UWB)is highly preferred for short distance *** a result of this significance,this project targets the design of a compact UWB *** paper describes a printed UWB rhombusshaped antenna with a partial ground *** achieve wideband response,two stubs and a notch are incorporated at both sides of the rhombus design and ground plane *** excite the antenna,a simple microstrip feed line is *** suggested antenna is built on a 1.6 mm thick FR4 *** proposed design is very compact with overall electrical size of 0.18λ×0.25λ(14×18 mm2).The rhombus shaped antenna covers frequency ranging from 3.5 to 11 GHz with 7.5 GHz impedance *** proposed design simulated and measured bandwidths are 83.33%and 80%,*** pattern in terms of E-field and H-field are discussed at 4,5.5 and 10 GHz *** proposed design has 65%radiation efficiency and 1.5 dBi peak *** proposed design is simulated in CST(Computer Simulation technology)simulator and the simulated design is fabricated for the measured *** simulated and measured findings are in close *** obtained results confirm the application of the proposed design for the ultra-wide band applications.

关键词： Ultra-wideband impedance bandwidth radiation pattern CST electrical size

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Depositional Environment of Sediments in Tonle Sap Sedimentary Basin, Western Part of Cambodia: Insights from Field and Geochemical Studies

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Open Journal of Geology 2023年第7期13卷 651-666页

作者： Sopheap Pech Chandoeun Eng Chanmoly Or Afikah Binti Rahim Ratha Heng Chitra Buth Sreymean Sio Research and Innovation Center Institute of Technology of Cambodia Phnom Penh Cambodia Faculty of Geo-Resources and Geotechnical Engineering Institute of Technology of Cambodia Phnom Penh Cambodia Faculty of Engineering Universiti Teknologi Malaysia Johor Malaysia Faculty of Engineering Chulalongkorn University Bangkok Thailand

Tonle Sap sedimentary basin was considered a favorable geological condition for hydrocarbon accumulation in the onshore Cambodia. Two exposure outcrops in Battambang province, called Somlout and Takream, were selected to represent sediments in this basin. The sedimentology and geochemistry studies provide insights into the depositional environment of sediments using field investigation, lithological, sedimentological, paleontological, and geochemical analysis. The redox condition, water column, and depositional setting were analyzed by plotting the ratio of V vs. Cr, Uauthigenic vs. V/Cr, Sr vs. Ba, Ca vs. (Fe + Ca), and Fe2O3/TiO2 vs. Al2O3/(Al2O3 + Fe2O3) diagram. Moreover, these diagrams can be used to predict depositional conditions as well. Based on the results, Somlout and Takream comprise calcareous shale and limestone facies. The geochemical analysis showed that Somlout calcareous shale samples were deposited in the dysoxic freshwater of the lake setting during the regression, while Somlout limestones and Takream were deposited in high salinity seawater, oxic condition of shallow-marine water. In addition, Somlout limestones consist of fragmental fusulinid foraminifera, bivalve shelve, and bryozoan, which suggest a barrier environment. Meanwhile, Teakream consists of fine-grained calcareous shale, and lime-mudstone, which are presented to form in the quiet marine setting of the lagoon environment. Therefore, the Tonle Sap basin sediments were deposited in the Somlout area’s barrier and lake environment, and the lagoon environment for Takream.

关键词： Depositional Environment Sedimentary Basin Geochemistry Paleontology Tonle Sap

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Evaluation of early-age strains and stresses in roller-compacted concrete pavement

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第1期9卷 93-105页

作者： Tetsya Sok Young Kyu Kim Jun Young Park Seung Woo Lee Public Infrastructure Department Ministry of Public Works and TransportPhnom Penh 12100Cambodia Institute for Disaster Prevention Gangneung-Wonju National UniversityGangneung-si 25457South Korea Korea Expressway Research Institute Korea Expressway CorporationHwaseong-si 18489South Korea Civil Engineering Department Gangneung-Wonju National UniversityGangneung-si 25457South Korea

In the structural design of a roller-compacted concrete pavement(RCCP), it is crucial to estimate strain and stress developments in the RCCP slab realistically. Since the RCCP mix uses less cement and lower amount of water, shrinkage strain and concrete temperature during the hardening stage are expected to be reduced as compared to those of conventional concrete mixture, resulting in a reduction of the concrete early-age deformation and stress developments in the RCCP slab. In this paper, early-age concrete strain and stress developments in RCCP slab subjected to environmental loads were evaluated. A full-scale test section of RCCP under real climatic conditions was monitored. The early-age total strains,stress-independent strains, shrinkage strains, and coefficient of thermal expansion(CTE) of the RCCP were measured and analyzed. Using the results of measured strains, in-situ CTE and shrinkage strain, and temperature, the early-age concrete stress development is computed by incorporating a viscoelastic property of the early-age concrete. The results revealed that the shrinkage strain of the RCCP is quite low as compared to that of conventional concrete. The early-age stress developments in the RCCP slab are strongly governed by the thermal-induced stresses. Shrinkage-induced stresses were quite small and might be negligible in a preliminary estimation of early-age stress developments in the RCCP slab.

关键词： Road engineering Roller-compacted concrete pavement Concrete strain Concrete stress Shrinkage strain Environmental loads

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Effects of Loess Cavity on Soil Moisture Movement: Revealed by Soil Column and HYDRUS Model

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Journal of Water Resource and Protection 2019年第4期11卷 371-394页

作者： Lybun Porn Baowen Yan Sovannaka Soun Sereyrorth Ouk College of Water Resources and Architectural Engineering Northwest A&F University Yangling China Faculty of Hydrology and Water Resources Engineering Institute of Technology of Cambodia Phnom Penh Cambodia

The purpose of this study is to advance our current understanding of soil moisture storage in subsurface and water infiltration rate in loess soil. Therefore, a set of experiments was conducted on two soil columns filled with silty clay loam, with and without applying cavity technical method. For the soil column applied with loess cavity, the ponding infiltration was simulated using HYDRUS-2D/3D, version 2.x and the simulated results were verified by those of observation. The results show that 1) the loess cavity significantly decreased the infiltration rates when the flux permeated through it (varying from 0.358 to 0.208 cm·min-1) as compared with no cavity soil column (varying from 0.408 to 0.241 cm·min-1);2) similarly, the total cumulative infiltration and at the termination of wetting front advancement of soil column with cavity were 66 cm and 69 cm lower than that of no cavity soil column (76 and 78 cm), respectively. Consequently, the soil moisture at the subsurface and surrounding the loess cavity was effectively ameliorated;3) the model was capable of predicting water infiltration processes in the soil column with loess cavity, and the root mean square error of simulated water contents, wetting front advancements, cumulative infiltrations, and infiltration rates were from 0.22 to 3.63 cm3·cm-3, 1.6 to 3.63 cm, 3.44 cm, and 0.026 cm·min-1, respectively. Overall, the findings in this study indicate that loess cavity can effectively increase soil moisture storage at shallow surface and the HYDRUS-2D/3D model is capable of simulating and predicting scenarios to help achieve stable shallow soil surface with loess cavity.

关键词： Loess Cavity HYDRUS-2D/3D Wetting Front Advancement Infiltration Rate Cumulative Infiltration Water Content

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Applicability of TRMM Precipitation Product in Qinba Mountainous Area of Shaanxi Province

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Journal of Water Resource and Protection 2021年第12期13卷 1076-1091页

作者： Chunpanha Khem Baowen Yan Sereyrorth Ouk College of Water Resources and Architectural Engineering Northwest A&F University Xianyang China Faculty of Hydrology and Water Resources Engineering Institute of Technology of Cambodia Phnom Penh Cambodia

The applicability of Tropical Rainfall Measuring Mission (TRMM3B42V7) precipitation data in the region was evaluated using the measured daily precipitation data in 16 hydrological stations in Shaanxi Province from 1998 to 2014. The evaluation process with several statistical error metrics was applied to daily, monthly, and annual timescale. The results show that the satellite and gauge stations show good consistency for monthly and annual timescale, but rather worse accuracy of daily timescale. All timescales produced the overestimated result of average precipitation measurement. The spatially statistical distribution shows a slight correlation between the observation and satellite estimation, especially at the higher elevation area such as Taibai. The TRMM precipitation value is closer to the gauge station precipitation value at a place with lower elevation, whether the timescale is daily, monthly or annual. At the same time, the smaller timescale leads to closer relations between elevation and metrics. The research results are important value of the research study of meteorological process in the Qinba mountain area.

关键词： TRMM Applicability Precipitation Qinba Mountain Area

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The distinct morphological phenotypes of Southeast Asian aborigines are shaped by novel mechanisms for adaptation to tropical rainforests

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National Science Review 2022年第3期9卷 85-95页

作者： Xiaoming Zhang Qi Liu Hui Zhang Shilei Zhao Jiahui Huang Tuot Sovannary Long Bunnath Hong Seang Aun Ham Samnom Bing Su Hua Chen State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences China National Center for Bioinformation School of Future technology and Sino-Danish College University of Chinese Academy of Sciences Kunming College of Life Science University of Chinese Academy of Sciences Department of Geography and Land Management Royal University of Phnom Penh Capacity Development Facilitator for Handicap International Federation and Freelance Research

Southeast Asian aborigines, the hunter-gatherer populations living in tropical rainforests, exhibit distinct morphological phenotypes, including short stature, dark skin, curly hair and a wide and snub nose. The underlying genetic architecture and evolutionary mechanism of these phenotypes remain a long-term mystery. We conducted whole genome deep sequencing of 81 Cambodian aborigines from eight ethnic groups. Through a genome-wide scan of selective sweeps, we discovered key genes harboring Cambodian-enriched mutations that may contribute to their phenotypes, including two hair morphogenesis genes(TCHH and TCHHL1), one nasal morphology gene(PAX3) and a set of genes(such as ENTPD1-AS1) associated with short stature. The identified new genes and novel mutations suggest an independent origin of the distinct phenotypes in Cambodian aborigines through parallel evolution, refuting the long-standing argument on the common ancestry of these phenotypes among the worldwide rainforest hunter-gatherers. Notably, our discovery reveals that various types of molecular mechanisms, including antisense transcription and epigenetic regulation, contribute to human morphogenesis, providing novel insights into the genetics of human environmental adaptation.

关键词： Cambodian aborigines genomic polymorphism positive selection parallel evolution environmental adaptation morphogenesis

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Numerical Study on Hydraulic Characteristics and Discharge Capacity of Modified Piano Key Weir with Various Inlet/Outlet Width Ratio

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World Journal of Engineering and technology 2023年第1期11卷 113-135页

作者： Ilan Ich Genguang Zhang Anbin Li Vinhteang Kaing Ty Sok College of Water Resources and Architectural Engineering Northwest A&F University Yangling China Faculty of Hydrology and Water Resources Engineering Institute of Technology of Cambodia Russian Federation Blvd. Phnom Penh Cambodia Department of Civil and Environmental Engineering School of Environment and Society Tokyo Institute of Technology Tokyo Japan Research and Innovation Center Institute of Technology of Cambodia Russian Federation Blvd. Phnom Penh Cambodia

A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/Wo) on the discharge efficiency of MPKW is still not investigated numerically. The present work utilized the numerical modeling to investigate and analyze the effects of the inlet/outlet key width ratios on the hydraulic characteristics and discharge capacity of the MPKW. To validate the numerical model with the experimental data, the results indicate that the average relative error is 2.96%, which confirms that the numerical model is fairly well to predictthe specifications of flow over on the MPKW. Numerical simulation results indicated that the discharge capacity of the MPKW can be improved up to 8.5% by optimizing the Wi/Wo ratio ranging from 1.53 to 1.67 even if the other parameters of the MPKW keep unchanged. A big Wi/Wo ratio generally leads to an increase in discharge capacity at low heads and a little effect on the discharge efficiency at high heads. The discharge efficiency of the inlet and outlet crests increases up to 9.6% for high heads, while discharge efficiency of the lateral crest decreases up to 23.5% compared with the reference model. The findings of the study revealed that the intrinsic influencing mechanism of the Wi/Wo ratio on the discharge performance of MPKWs.

关键词： Discharge Capacity FLOW-3D Hydraulic Characteristics Numerical Simulation Modified Piano Key Weir Parameter Optimization

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Cloning, characterization and expression analysis of a microsomal glutathione S-transferase gene from the seagrass Zostera marina

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Acta Oceanologica Sinica 2019年第10期38卷 111-115页

作者： Wenjie Yan Jiao Liu Samphal Seng Bin Zhou Kuke Ding Department of Marine Ecology College of Marine Life SciencesOcean University of ChinaQingdao 266003China Institute of Oceanology Chinese Academy of SciencesQingdao 266071China Faculty of Fisheries&Aquaculture Royal University of AgriculturePhnom Penh 12101Cambodia National Institute for Radiological Protection Chinese Center for Disease Control and PreventionBeijing 100088China Key Laboratory of Radiological Protection and Nuclear Emergency Chinese Center for Disease Control and PreventionBeijing 100088China

The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under different *** speaking,express ZmGST in Escherichia coli,then purify the recombinant protein and make the thermal stability ***,the experiments were carried out to provide a theoretical basis for the further elaboration to the population degradation mechanisms of *** conclusion,the thermostability and the response of ZmGST gene to temperature changes can determine its temperature tolerance range,and affect its resilience in turn.

关键词： Zostera marina antioxidant enzyme glutathione S-transferase (GST) temperature enzyme activity

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Lithogeochemistry of Intrusive Rocks in the Halo Porphyry Copper-Molybdenum Prospect, Northeast Cambodia

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Open Journal of Geology 2019年第7期9卷 342-363页

作者： Seang Sirisokha Kotaro Yonezu Thomas Tindell Tetsuya Nakanishi Koichiro Watanabe Jocelyn Pelletier Department of Earth Resources Engineering Kyushu University Fukuoka Japan Department of Geo-Resources and Geotechnical Engineering Institute of Technology of Cambodia Phnom Penh Cambodia Kyushu university Museum Kyushu University Fukuoka Japan Geology Resources Department Geoccop Montreal Canada

The Halo copper-molybdenum prospect is a porphyry system in Ratanakiri province, northeastern part of Cambodia. There is only one research was carried out on this prospect about geological mapping and short wave infrared (SWIR) spectroscopy on alteration mineral identification. The purpose of this research is to confirm the deposit type from previous Angkor Gold’s report and find the centre of porphyry deposit based on characteristic of intrusive rocks at surface and subsurface, characteristics of the intrusive rocks and alteration lithogeochemistry of intrusive and volcanic rocks by using Pearce Element Ratio (PER) analysis. PER analysis was used to examine the nature and extend of the alteration halos in the porphyry Halo copper-molybdenum prospect. The intrusive rocks and volcanic rocks in Halo, range from diorite to granite (quartz feldspar porphyry) in composition as well as dacite to trachyandesite (andesite porphyry) in composition, respectively. They were formed in a subduction-related tectonic setting, likely a volcanic arc. Trace elements spider diagrams were normalized to primitive mantle display strong enrichment in large-ion lithophile elements such as Rb, Ba and K and depletion in some high-field strength elements such as Nb and Ti, suggesting magmas generated in a subduction-related tectonic setting. PER analysis indicates a moderate to high degree of sericite alteration of dacites, quartz feldspar porphyries, andesite porphyries and granodiorite porphyries. Moreover, three alterations in the Halo prospect such as potassic (secondary K-feldspar and biotite), phyllic (sericite) and propylitic (epidote) alteration were identified, which are consistent with petrography analysis. The potassic alteration zone is vectoring center of the hydrothermal system which may represent the locus of mineralization. Therefore the geochemical signature of potassic alteration within the quartz feldspar porphyry, andesite porphyry and granodiorite porphyry with high grad

关键词： Cambodia Hydrothermal Alteration Halo Porphyry Copper-Molybdenite Deposit Pearce Element Ratio Analysis

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Mental Health Literacy of university Students in Vietnam and Cambodia

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International Journal of Mental Health Promotion 2022年第3期24卷 439-456页

作者： Anja Dessauvagie Hoang-Minh Dang Tuyet Truong Thu Nguyen Bich Hong Nguyen Huong Cao Socheata Kim Gunter Groen Hamburg university of Applied Sciences Department of Social WorkHamburgGermany VNU university of Education Center for ResearchInformation and Service in Psychology(CRISP)HanoiVietnam Thai Nguyen university of Agriculture and Forestry Advanced Education Programs OfficeThai Nguyen CityVietnam VNU-HCM university of Social Sciences and Humanities Faculty of EducationHo Chi Minh CityVietnam Thai Nguyen university of Economics and Business Administration Faculty of EconomicsThai Nguyen CityVietnam Vinh university of technology Education Department of Scientific Management and International PartnershipsVinh CityVietnam Paragon International university Department of Business AdministrationPhnom PenhCambodia

Mental health literacy(MHL)refers to knowledge and attitudes that shape the recognition,management,and prevention of mental *** the topic has been exhaustively researched in Western countries,research from Southeast Asia still is *** studies in this field showed a moderate recognition of mental disorders,a high prevalence of stigmatizing attitudes and a low willingness to seek professional help among Southeastern-Asian *** study explored the level of MHL among university students from different parts of Vietnam and *** with influencing factors(gender,age,study year,educational attainment of the parents,urban/rural origin,ethnicity,personal experiences with mental disorders)were also *** online survey,using a 30-item Vietnamese version of the Mental Health Literacy Scale(MHLS),was conducted at six university sites in Vietnam and *** of 1032 students from different study branches were *** MHL of Vietnamese and Cambodian university students was lower,compared to samples from Australia or the *** and students with a personal experience of mental disorders(self or family)showed a significantly higher *** differences in MHL were found between students from different socioeconomic backgrounds(professional attainment of parents,urban/rural origin).Findings on the influence of ethnicity were *** needs to be improved among the university students of Vietnam and *** health promotion should specifically target male students,students from STEM branches,and international students.

关键词： Help-seeking mental disorders mental health literacy Southeastern Asia stigma university students

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