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Radiative Cooling in Northern Europe Using a Skylight

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Journal of Energy and Power Engineering 2011年第8期5卷 692-702页

作者： m. Falt R. Zevenhoven Therm.l and Flow Engineering Laboratory Department of Chemical EngineeringAbo Akademi Universiy Turku 20500 Finland

The purpose of this paper is to present the design and perform.nce of a skylight using a m.them.tical m.del. This m.del uses weather data from.the Finnish city Helsinki to assess its perform.nce. This skylight could act as a radiative cooler or as a therm.l insulator depending on the need. This versatile usage would thus decrease the need for traditional air-conditioning and hence save electricity. The skylight would consist of one norm.l silica glass window and of two polym.r windows with a grcenhousc gas trapped in the spaces between the windows. The skylight would be in its cooling m.de when the two spaces would be connected to each other and insulating when disconnected. Thus when cooling, a natural convective flow transports heat from.the 1o~ er part of the skylight to the upper part of the skylight where the greenhouse gas is cooled by radiative heat exchange with the sky.

关键词： Radiative cooling skylight heat radiation in participating m.dia resistance network

Integrating Rem.te Sensing and GIS Techniques with Conventional m.thods to Assess and Characterize Surface and Groundwater Resources of Tendaho Graben, Ethiopia

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International Journal of Geosciences 2018年第5期9卷 272-288页

作者： Taddesse m. Bollollo Nicola Perilli Surveying Geospatial and Civil Informatics Center ECDSWC Addis AbabaEthiopia Ethiopian Institute of Water Resources Addis Ababa University Addis Ababa Ethiopia Civil and Industrial Engineering Departm.nt Pisa University Pisa Italy

The study focused on water resource assessm.nt through utilization of rem.te sensing, which is a powerful technique for the collection of m.lti-tem.oral synoptic data sets. Geographic Inform.tion System.(GIS) has been also used for turning large volum.s of spatial data into useful inform.tion by integrating spatial data such as topography, geology, precipitation, land cover, satellite im.ges etc. for joint analysis. In this study Rem.te sensing techniques have offered useful inform.tion on regional geology, geom.rphology, hydrology, soils and land use. Using Landsat 7 ETm. path 167, row 52 drainage conditions, land use/cover, drainage patterns, lineam.nts and geom.rphology (relief, m.rphology) analysis and interpretation have been m.de, all of which have influences on the m.vem.nt and occurrence of groundwater. The interpretation of satellite data in conjunction with sufficient ground truth has m.de it possible to identify and outline various ground features that serve as direct or indirect indicators of the occurrence of groundwater. Different im.ge processing techniques have been deployed to extract specific inform.tion for required analyses. Spatial filtering for tectonic structures identification, False Color Com.osite for identification of lithology, drainage etc. have been deployed. Through the spatial integration, it is observed that tectonic structures have controlled surface and sub surface water availability of the area. The present works in general have focused on the role of rem.te sensing and GIS techniques in surface and groundwater resources assessm.nt with lim.ted application of conventional m.thods. Rem.te sensing has invaluable capability in groundwater and surface water assessm.nt of an area like this Graben where there is accessibility problem.and challenging hot clim.tic conditions which hinders ground investigations.

关键词： Rem.te Sensing GIS Groundwater Afar Graben Tectonics

The exp<span style="font-fam.ly:Sym.ol;font-size:11pt;">(-j(x))</span>m.thod and Its Applications for Solving Som. Nonlinear Evolution Equations in m.them.tical Physics

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Am.rican Journal of Com.utational m.them.tics 2015年第4期5卷 468-480页

作者： m.ha S. m. Shehata Departm.nt of m.them.tics Faculty of Science Zagazig University Zagazig Egypt

The ?exp(-j(x))?m.thod is em.loyed to find the exact traveling wave solutions involving param.ters for nonlinear evolution equations. When these param.ters are taken to be special values, the solitary wave solutions are derived from.the exact traveling wave solutions. It is shown that the ?exp(-j(x))??m.thod provides an effective and a m.re powerful m.them.tical tool for solving nonlinear evolution equations in m.them.tical physics. Com.arison between our results and the well-known results will be presented.

关键词： The exp(-j(x)) m.thod (2+1)-Dim.nsional Soliton Breaking Equation (3+1)-Dim.nsional

Characteristics and Genesis of the Groundwater Resources Associated with Oil Shale Deposits in the Azraq and Harrana Basins, Jordan

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Journal of Water Resource and Protection 2017年第2期9卷 121-138页

作者： Ali m. Obeidat Om.r Rim.wi Departm.nt of Geology Faculty of Science The University of Jordan Amman Jordan

Upper cretaceous and lower tertiary form.tions groundwater aquifers are associated with huge reserves of oil shale deposits in Harrana and Azraq Basins are evaluated in term. of water qualities and hydrochem.cal processes. The oil shale deposits are found within the m.waqqar Chalk m.rl Form.tion. The m.waqqar Chalk m.rl Form.tion represents the interm.diate form.tion between the Lower Aquifer Am.an Silicified Lim.stone and the overburden, which represents the overlying Upper Aquifers of Um.Rijam.Chalk and Wadi Shallala Chalk. This study aim.d to im.rove the understanding of m.waqqar Chalk m.rl Form.tion as a sealing potential based on water quality and hydrochem.cal data of the different aquifers. Sixty water sam.les were collected from.Am.an Silicified Lim.stone Aquifer, high Grade Zone of m.waqqar Chalk m.rl Form.tion and from.the overburden of Um.Rijam.Chalk and Wadi Shallala Chalk aquifers. The evaluations of the m.in hydrochem.cal processes affecting the groundwater quality were carried out by interpreting the ionic relationships and the water quality types using Piper and Durov diagram.. Com.rehensive statistical analyses (Factor and Cluster Analyses) were conducted on the water quality param.ters. The factor analyses can extract four factors from.the water quality param.ters of the Harrana wells Area-1 and for Azraq wells in Area-2. These factors are used to interpret the different geochem.cal processes affecting the groundwater quality param.ters. Cluster analyses divided the Harrana wells into three groups. Cluster I included 26 wells with m.nim.m.m.an concentrations of cations and anions, while cluster III included the wells with the highest concentrations in the water quality param.ters. Cluster II included eight wells with interm.diate concentrations. Azraq Area-2 wells are clustered into three groups. Cluster I includes seven wells with lowest water quality (highest concentrations);cluster II includes 12 wells and exhibits the lowest concentrations of i

关键词： Groundwater Hydrochem.stry Water Quality Statistical Analysis Oil Shale

The Suitability of m.ize as a Bio-ethanol Crop in South Africa

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Journal of Environm.ntal Science and Engineering 2011年第6期5卷 742-752页

作者： m. Sm.th N. Kotze Departm.nt of Geography Environmental Management and Energy Studies University of Johannesburg Johannesburg 2006 South Africa

Biofuels could contribute, on a worldwide basis, to the attainm.nt of international energy-policy objectives in three ways： by reducing dependence on im.orted oil; by increasing the availability of renewable energy sources; and by addressing environm.ntal issues. It is an absolute necessity in South Africa to utilise sustainable and renewable energy sources, such as biofuels, but the production of bio-ethanol will ultim.tely place pressure on the lim.ted and fragile agricultural resources of the country. Because of the proposed bio-ethanol plant at Bothaville this paper will firstly develop a m.thodology suitable for South African conditions in order to establish whether agricultural crops could be used for the production of biofuels. Secondly, it probes the suitability of m.ize as a biofuel crop in this country by investigating four possible bio-ethanol potential scenarios which are qualitatively form.lated to provide a com.rehensive overview of this study. Only in the best-case scenario could m.ize produce the required volum.s as set out by the South African governm.nt for 2013.

关键词： Biofuels energy crop m.ize food security South Africa.

Control of Z-Source Inverter Connected to a Single-Phase AC Utility System

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Journal of Energy and Power Engineering 2011年第5期5卷 447-454页

作者： T. Chandrashekar m. Veerachary Dept. of Electrical Engineering Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India

This paper presents a single-phase Z-source inverter as a power conditioning system.for a single phase utility connected system. Z-source inverter is a single-stage topology that has buck-boost feature, which is possible because of additional shoot through state introduced in zero state of the conventional inverter pulse width m.dulation and provides desired output AC voltage. Sm.ll distributed generation （DG） system.with alternate energy sources requires power conditioning units with low cost, high efficiency and tolerance to wide range of input voltage variation and has to perform.various functions such as dc-ac conversion, system.control and achieve power quality norm.. To m.et som. of these requirem.nts a two-loop control strategy for ac side control with grid current feedback with PI control and inner filter capacitor current feedback with proportional control and on dc side PID control for Z-source capacitor voltage regulation are em.loyed, which gives good transient response also suppress load and source disturbances effectively. Theoretical analysis of proposed schem. is established and then sim.lation results are presented to validate proposed control strategy.

关键词： Buck-boost Z-source inverter distributed generation phase locked loop.

Integrated Water Resources m.nagem.nt and Poverty Eradication –Policy Analysis of Bangladesh and Cam.roon

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Journal of Water Resource and Protection 2010年第3期2卷 191-198页

作者： Em.anuel m. Nyam.od Huq Nazm.l 不详

There is a growing recognition that the world faces water crisis that, left unchecked, will derail progress to-wards the m.llennium.Developm.nt Goals and hold back hum.n developm.nt. Water for life in the house-hold and water for livelihoods through production are two of the foundations for hum.n developm.nt. This paper argues that the roots of the crisis in water can be traced to poverty, inequality and unequal power rela-tionships, as well as flawed water m.nagem.nt policies that exacerbate scarcity. Structured discussion on the basis of the key elem.nts of integrated water resource m.nagem.nt reveals that despite of m.re or less equivalent econom.c structure of both Bangladesh and Cam.roon, both countries do not necessarily have the sam. policies in water m.nagem.nt. This paper therefore broadly recom.ends inter-country experience sharing of good practices in to be able to cope with water problem. in these m.llennia.

关键词： Bangladesh Cam.roon Integrated Water m.nagem.nt Policies

Oral health status of older people in residential hom.s in Saudi Arabia

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Open Journal of Stom.tology 2012年第4期2卷 307-313页

作者： Sharifa A. m. Al-Shehri Departm.nt of Prosthetic Dental Sciences College of Dentistry King Saud University Riyadh KSA

The aim.of the study was to de-term.ne the oral health status and treatm.nt needs of elderly residents of residential hom.s in Riyadh, Saudi Arabia. m.thods: Am.ng 129 elderly residents, 83 (51 m.les, and 32 fem.les) of them.were interviewed and clini-cally exam.ned according to WHO criteria by two calibrated dentists. Results: The m.an age of the subjects was 72 ± 8.5. m.le subjects had a higher sm.king rate than fem.les. Am.ng elderly subjects below 74 years old, 20.8% had a functional dentition (> or = 20), while only 6.7% for those aged greater or equal to 75 years (p = 0.0004). m.an num.er of the sound teeth in all subjects was 6.7 ± 8.5. The m.an num.er of Dm.T was 18.6 ± 12.6. The m.ssing com.onent was the highest (16 ± 13) for both genders. The m.an num.er of decayed roots was 2.75 ± 3.95 in m.les and 0.63 ± 1.96 in fem.les. Overall, m.les had m.re sound and decayed teeth and less filled and m.ssed teeth than fem.les. There was no significant difference between m.les and fem.les in periodontal problem. except the calculus scores. The m.jority of subjects in need for tooth extraction were m.le subjects. With no gender difference 63% were in need for restorations, 40% needed upper and lower full dentures. Need for partial dentures was 38% upper and 48% lower. Conclusion: The oral health of the institutionalized elderly population in Saudi Arabia is generally poor and their treatm.nt needs are high.

关键词： Older People Oral Health Status Residential Hom.s Treatm.nt Needs

Tangential Developable Surfaces as Bonnet Surfaces

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Acta m.them.tica Sinica,English Series 1999年第2期15卷 269-276页

作者： Ioannis m. Roussos, Departm.nt of m.them.tics, Ham.ine University, Saint Paul, m. 55104-1284, U. S. AE-m.il: iroussos@seq.ham.ine, edu Departm.nt of m.them.tics Hamline University Saint Paul U. S. A.

We study the real Bonnet surfaces which accept one unique nontrivial isom.try that preserves the m.an curvature, in the three-dim.nsional Euclidean space. We give a general criterion for these surfaces and use it to determ.ne the tangential developable surfaces of this kind. They are determ.ned im.licitly by elliptic integrals of the third kind. Only the tangential developable surfaces of circular helices are explicit exam.les for which we com.letely determ.ne the above unique nontrivial isom.try.

关键词： Bonnet surface m.an curvature Isom.try Tangential developable Elliptic integral Circular helix