Testing of two different types of photovoltaic–thermal (PVT) modules with heat flow pattern under tropical climatic conditions

2013 ◽  
Vol 17 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Swapnil Dubey ◽  
Andrew A.O. Tay
Keyword(s):  
Heat Flow ◽  
Flow Pattern ◽  
Climatic Conditions ◽  
Different Types

scholarly journals Epidermis structure in Mesembryanthemaceae

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 937-937
Author(s):  
H. -D. Ihlenfeldt
Keyword(s):  
Cell Walls ◽  
Climatic Conditions ◽  
Radiation Balance ◽  
Outer Cell ◽  
Extreme Conditions ◽  
Prominent Feature ◽  
Oxalate Crystals ◽  
Different Types ◽  
Bladder Cells ◽  
Epidermis Structure

The Mesembryanthemaceae, which inhabit the deserts and semi-deserts of Southern Africa, exhibit two very different types of epidermis. The first is characterized by thick outer cell walls encrusted by oxalate crystals, a thick cuticle and thick wax layers. In the second type, the epidermal cells exhibit only very thin outer cell walls, not encrusted by oxalate crystals, a very thin cuticle, and wax layers are poorly developed; the most prominent feature of this type is the occurrence of huge idioblasts often protruding as ‘bladder cells’. With regard to the climatic conditions in the native habitats this type of epidermis must be called ‘abnormal’. Both types of epidermis may form sculptures of three distinct size classes, which are not necessarily homologous. The function of these sculptures is still poorly understood. There is evidence that the sculptures influence the optical properties of the surfaces and thereby the radiation balance (and heat stress) of the leaves.From recent research, it has become evident that the two different types of epidermis are the anatomical expression of two different strategies for survival under extreme conditions. Species with the idioblast type of epidermis exhibit a strategy that might be called ‘opportunistic’. These species have developed a mechanism of gaining water from the atmosphere during the night under favourable conditions. There are indications that the idioblasts are involved in this mechanism.

scholarly journals Geothermal field and geology of the Caspian Sea region

2019 ◽  
pp. 104-118 ◽  
Author(s):  
Vladimir I. Zui ◽  
Siamak Mansouri Far Far
Keyword(s):  
Heat Flow ◽  
Flow Pattern ◽  
Caspian Sea ◽  
Sedimentary Basins ◽  
Geothermal Field ◽  
Flow Density ◽  
General Tendency ◽  
The Caspian Sea ◽  
Northern Iran ◽  
The North

The Caspian Sea and adjacent areas form the vast oil and gas-bearing megabasin. It consists of North Caspian, Middle Caspian, and South Caspian sedimentary basins. The granite-metamorphic basement of the basins becomes from north to south younger in the direction from Early Precambrian to Early Cimmerian age. It represents a transitional zone from the southern edge of the East European Craton to Alpine folding. Geothermal investigations have been carried out both in hundreds of deep boreholes and within the Caspian Sea and a few preliminary heat flow maps were published for the Caspian Sea region. All they excluded from consideration the southern part of the region within Iranian national borders. We prepared a new heat flow map including the northern Iran. The purpose of the article is to consider heat flow pattern within the whole Caspian Sea region including its southern part. Two vast high heat flow anomalies above 100 mW/m2 distinguished in the map: within the southwestern Iran and in waters of the Caspian Sea to the North of the Apsheron Ridge, separated by elongated strip of heat flow below 50 –55 mW/m 2 . A general tendency of heat flow from growing was distinguished from the Precambrian crustal blocks of the North Caspian Depression to the Alpine folding within the territory of Iran. Analysis of the heat flow pattern is discussed and two heat flow density profiles were compiled.

scholarly journals Movement Studies on a Hanging Glacier in Relation with an Ice Avalanche

1977 ◽  
Vol 19 (81) ◽  
pp. 671-672 ◽  
Author(s):  
André Flotron
Keyword(s):  
Flow Pattern ◽  
The State ◽  
Least Square ◽  
Velocity Versus ◽  
Surface Part ◽  
Different Types ◽  
Best Fit ◽  
Ice Avalanche

AbstractIn 1972 the state of a hanging glacier on the Weisshorn gave cause for alarm, as part of it seemed to be accelerating and a repetition of an earlier avalanche of ice seemed possible (see Röthlisberger, previous abstract). For this reason movement surveys were undertaken. The various surveying methods applied on the Weisshorn are outlined and the accuracy of the measurements is given. By least-square analysis different types of curves have been fitted to the data for velocity versus time. The best fit obtained so-far has been with hyperbolae. The confidence of extrapolations from such curves is discussed in relation to forecasts. By evaluating repeated photographs taken by an automatic camera from a single position, using a stereo plotter, the flow pattern has been established at the surface, part of the front, and one of the lateral faces of the ice mass. Changes with time caused by the deformation of the ice mass, the formation of crevasses and the crumbling away of the ice at the edge have been observed.

scholarly journals Flat Glass or Crystal Dome Aperture? A Year-Long Comparative Analysis of the Performance of Light Pipes in Real Residential Settings and Climatic Conditions

2020 ◽  
Vol 12 (9) ◽  
pp. 3858 ◽  
Author(s):  
Magda Sibley ◽  
Antonio Peña-García
Keyword(s):  
Comparative Analysis ◽  
Flat Glass ◽  
Climatic Conditions ◽  
Long Term Effect ◽  
Different Types ◽  
The Difference ◽  
The Aesthetic ◽  
One Year ◽  
The One

This paper presents the first comparative study of its type of the performance of light pipes with different types of apertures: a flat glass versus a bohemian crystal dome. Measurements were taken at 20-minute intervals over a period of one year in the bathrooms of two newly built identical houses of the same orientation located in Manchester, UK. The comparative analysis of the data collected for both light pipes types reveals that the crystal domed aperture consistently outperforms the flat glass one. Furthermore, the difference in the recorded horizontal illuminance is most marked during the winter months and at the end of the one-year experiment, indicating that the crystal dome has better performance for low incident winter light and higher resistance for the long term effect of weathering and pollution. This study provides strong evidence based on long term real measurements. Such evidence informs architects’ decisions when weighing up the aesthetic considerations of a flat glass aperture versus the higher illumination levels afforded by a crystal dome aperture with higher resistance to weathering and pollution.

Effective R-value of enclosed reflective space for different building applications

2019 ◽  
Vol 43 (5) ◽  
pp. 398-427 ◽  
Author(s):  
Hamed H Saber ◽  
Wahid Maref ◽  
Ali E Hajiah
Keyword(s):  
Heat Flow ◽  
Thermal Performance ◽  
Accurate Determination ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Building Envelopes ◽  
Inclination Angles ◽  
R Value ◽  
Enclosed Space

Many parts of the building envelopes contain enclosed airspaces. Also, the insulating glass units in fenestration systems, such as curtain walls, windows, and skylight devices, contain enclosed spaces that are normally filled with air or heavy gas such as argon, xenon, or krypton. The thermal resistance (R-value) of an enclosed space depends mainly on the type of the filling gas, emissivity of all surfaces that bound the space, the size and orientation of the space, the direction of heat flow through the space, and the respective temperatures of all surfaces that define the space. Assessing the energy performance of building envelopes and fenestration systems, subjected to different climatic conditions, requires accurate determination of the R-values of the enclosed spaces. In this study, a comprehensive review is conducted on the thermal performance of enclosed airspaces for different building applications. This review includes the computational and experimental methods for determining the effective R-value of enclosed reflective airspaces. Also, the different parameters that affect the thermal performance of enclosed airspaces are discussed. These parameters include the following: (a) dimensions, (b) inclination angles, (c) directions of heat flow, (d) emissivity of all surfaces that bound the space, and (e) operating conditions. Moreover, numerical simulations are conducted using a previously developed and validated model to investigate the effect of the inclination angle, direction of heat transfer, and the coating emissivity on the R-values of enclosed spaces when they are filled with different types of gases.

RADIAL-AXIAL HEAT FLOW IN REGIONS BOUNDED INTERNALLY BY CIRCULAR CYLINDERS

1953 ◽  
Vol 31 (4) ◽  
pp. 472-479 ◽  
Author(s):  
J. H. Blackwell
Keyword(s):  
Heat Flow ◽  
Integral Transform ◽  
Circular Cylinders ◽  
Flow Problems ◽  
Solution Type ◽  
Transient Heat Flow ◽  
Different Types ◽  
Axial Heat ◽  
Simple Product ◽  
Product Solution

Two radial–axial transient heat flow problems have been solved for regions bounded internally by circular cylinders. They are not of the simple "product-solution" type and it is considered that they may have application in other fields of physics where the Diffusion Equation applies. The problems arose during investigation into "end-effect" in cylindrical thermal-conductivity probes. The solutions are obtained by integral-transform methods, two different types of transform being used in each solution.

Heat flow pattern at the Chicxulub impact crater, northern Yucatan, Mexico

2016 ◽  
Vol 311 ◽  
pp. 135-149 ◽  
Author(s):  
J.M. Espinosa-Cardeña ◽  
J.O. Campos-Enríquez ◽  
M. Unsworth
Keyword(s):  
Heat Flow ◽  
Flow Pattern ◽  
Impact Crater ◽  
Chicxulub Impact Crater ◽  
Chicxulub Impact

scholarly journals Prioritization of olive breeding objectives in Spain: Analysis of a producers and researchers survey

2021 ◽  
pp. e0701-e0701
Author(s):  
Lorenzo León ◽  
Keyword(s):  
Oil Content ◽  
Fruit Size ◽  
Calcareous Soils ◽  
Climatic Conditions ◽  
Olive Cultivar ◽  
Breeding Programs ◽  
Different Types ◽  
Breeding Objectives ◽  
Olive Cultivars ◽  
Survey Results

Aim of study: Trait prioritization of potential olive (Olea europaea L.) breeding objectives has been evaluated in this work from two surveys to researchers working on olive and olive producers / orchard managers. Area of study: Olive growing area in Andalusia (South of Spain) Material and methods: Twenty-five breeding objectives were associated to plant growth, fructification, oil content and composition, resistance to pest and disease and tolerance to soil and climatic conditions. Two assessment methods were applied (ranking and rating), showing similar results in both the researchers and producers surveys. Main results: Higher productivity was the objective with the highest score, followed by Verticillium wilt resistance and higher oil content. After them, tolerance to water stress and resistance to Xylella fastidiosa were among the preferred objectives. Conversely, the least preferred objectives were late harvesting, high fruit size and tolerance to water lodging and calcareous soils. In the producers’ survey, results have been consistent among the different types of orchards and farmers’ characteristics. It is also interesting to notice that more than 50% of the producers expressed their willingness to orchard enlargement or renewal in the three coming years and 25% of them would change the olive cultivar. They would be willing to pay an average 43% overprice for new cultivar fulfilling their requirements and 75% would support the use of genetic modified olives. Research highlights: These results should be considered to analyze the scope of current breeding programs and define the main criteria to be considered for future works aiming at developing new olive cultivars.

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