Development of Modules With Different Types of Concentrators and Receivers of Solar Radiation

2021 ◽  
pp. 74-103
Keyword(s):  
Solar Radiation ◽  
Service Life ◽  
Thermal Efficiency ◽  
Radiation Detector ◽  
Solar Concentrator ◽  
Two Component ◽  
Different Types ◽  
Polysiloxane Gel

Optical schemes and designs of four types of solar modules with louvered heliostats and concentrators with zero shading losses and blocking of solar radiation have been developed. The design of a compact thermal photovoltaic solar radiation detector for a non-tracking parabolic-cylindrical solar concentrator provides the thermal efficiency of the module in the range of 0,6–0,7, the service life of at least 25 years due to the sealing of the photoelectric elements using a two-component polysiloxane gel.

scholarly journals The Effects of Roadside Woody Vegetation on the Surface Temperature of Cycle Paths

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 483
Author(s):  
Nikola Žižlavská ◽  
Tomáš Mikita ◽  
Zdeněk Patočka
Keyword(s):  
Solar Radiation ◽  
Surface Temperature ◽  
Well Being ◽  
Road Surface ◽  
Woody Vegetation ◽  
Surface Model ◽  
Main Hypothesis ◽  
Roadside Vegetation ◽  
Different Types ◽  
Aerial Vehicle

The article is on the effects of woody vegetation growing on the roadside on the temperature of the surface of cycle paths. The main hypothesis of the study is that vegetation has the effect of lowering the temperature of the surroundings in its shadow and thus improves the comfort of users of cycle paths in the summer months. The second hypothesis is to find out which type of road surface is most suitable for the thermal well-being of users. This goal was achieved by measuring the temperature of selected locations on cycle paths with different types of construction surfaces with nearby woody vegetation using a contactless thermometer over several days at regular intervals. The positions of the selected locations were measured using GNSS and the whole locality of interest was photographed using an unmanned aerial vehicle (UAV), or drone, and subsequently a digital surface model (DSM) of the area was created using a Structure from Motion (SfM) algorithm. This model served for the calculation of incident solar radiation during the selected days using the Solar Area Graphics tool with ArcGIS software. Subsequently, the effect of the shade of the surrounding vegetation on the temperature during the day was analysed and statistically evaluated. The results are presented in many graphs and their interpretation used to evaluate the effects of nearby woody vegetation and the type of road surface on the surrounding air temperature and the comfort of users of these routes. The results demonstrate the benefits of using UAVs for the purpose of modelling the course of solar radiation during the day, showing the effect of roadside vegetation on reducing the surface temperature of the earth’s surface and thus confirming the need for planting and maintaining such vegetation.

Lexical-Grammatical Status and Lexicographic Presentation of Two-Component Stable Prepositional Combinations

2021 ◽  
pp. 32-51
Author(s):  
Elena V. Generalova ◽  
Keyword(s):  
Summary Table ◽  
Complex Issue ◽  
Dictionary Entry ◽  
Figurative Meaning ◽  
Advantages And Disadvantages ◽  
Unresolved Question ◽  
Two Component ◽  
Different Types ◽  
Syntactic Properties ◽  
Theoretical Issues

The aim of the article is to review the ways of dictionary presentation of stable prepositional combinations and the factors essential for their lexical-grammatical status and the type of optimal lexicographic description. The object of the study is twocomponent prepositional combinations with stable meanings and the “preposition+noun” structure. The material of the article is data of different dictionaries of Russian presenting stable prepositional combinations. In the course of the study, the following questions were answered: why the definition and interpretation of the lexical-grammatical nature of stable prepositional combinations are so difficult and ambiguous; what lexicographic interpretation these units have in dictionaries of different types; what the advantages and disadvantages of different ways of dictionary interpretation of such language material are. The following methods were used: introspective (observation, generalization, classification), systematic lexicographic description according to dictionary parameters, dictionary definition analysis. The summary table of the lexicographic presentation of stable combinations allows seeing both the unresolved question of dictionary interpretation of such units and the patterns of their interpretation depending on the type of a dictionary. As a result of the analysis the following conclusions were drawn. 1) In modern Russian there is a rather large (about 2,000 units) class of language units (prepositional combinations), the lexical-grammatical status of which is not defined, and there is no term for their definition; this class is historically formed and continues to replenish. 2) The type of dictionary presentation of stable prepositional combinations is determined by the dictionary concept, grammatical and syntactic properties, presence of figurative meaning and possibility of component variation of such combinations. 3) The unresolved theoretical issues have as a result the lexicographic discrepancy in the presentation of these language units. Extreme lexicographic solutions are a separate dictionary entry for each combination and the presentation of such units only as stable combinations in the entry of a noun (presented in academic explanatory dictionaries). 4) Taking into account only the factor of presence/absence of a gap seems to formalize the dictionary presentation of adverbs with both conjoined and split spelling, really existing in Russian, and the position of recognition of these units with independent words and their isolate presentation is not impeccable for dictionary users. 5) In the author’s opinion, the presentation of stable prepositional combinations exclusively as independent vocabules is inferior to the traditional lexicographic approach because the isolated presentation of this material breaks the semantic connections of these complex lexical units; the most complex issue is the differentiation of adverbs with split spelling and stable combinations.

scholarly journals Early-Age Cracking in Concrete: Causes, Consequences, Remedial Measures, and Recommendations

2018 ◽  
Vol 8 (10) ◽  
pp. 1730 ◽  
Author(s):  
Md. Safiuddin ◽  
A. Kaish ◽  
Chin-Ong Woon ◽  
Sudharshan Raman
Keyword(s):  
Service Life ◽  
Concrete Structures ◽  
Real Life ◽  
Early Age ◽  
Structural Elements ◽  
Remedial Measures ◽  
Curing Conditions ◽  
Factors Affecting ◽  
Different Types ◽  
Service Conditions

Cracking is a common problem in concrete structures in real-life service conditions. In fact, crack-free concrete structures are very rare to find in real world. Concrete can undergo early-age cracking depending on the mix composition, exposure environment, hydration rate, and curing conditions. Understanding the causes and consequences of cracking thoroughly is essential for selecting proper measures to resolve the early-age cracking problem in concrete. This paper will help to identify the major causes and consequences of the early-age cracking in concrete. Also, this paper will be useful to adopt effective remedial measures for reducing or eliminating the early-age cracking problem in concrete. Different types of early-age crack, the factors affecting the initiation and growth of early-age cracks, the causes of early-age cracking, and the modeling of early-age cracking are discussed in this paper. A number of examples for various early-age cracking problems of concrete found in different structural elements are also shown. Above all, some recommendations are given for minimizing the early-age cracking in concrete. It is hoped that the information conveyed in this paper will be beneficial to improve the service life of concrete structures. Concrete researchers and practitioners may benefit from the contents of this paper.

scholarly journals The use of paraffin wax in a new solar cooker with inner and outer reflectors

2015 ◽  
Vol 19 (5) ◽  
pp. 1663-1671 ◽  
Author(s):  
Bihter Arabacigil ◽  
Numan Yuksel ◽  
Atakan Avci
Keyword(s):  
Solar Radiation ◽  
Thermal Efficiency ◽  
Heating Time ◽  
Peak Temperature ◽  
Paraffin Wax ◽  
Optimum Angle ◽  
Surface Temperatures ◽  
Late Evening ◽  
Reflecting Surface ◽  
Potential Use

In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30?. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 ?C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30? receives also reflected radiation from the inner reflectors. Besides, the heating time is decreased to approximately 1 hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.

scholarly journals Effects of Aerosols and Clouds on the Levels of Surface Solar Radiation and Solar Energy in Cyprus

2021 ◽  
Author(s):  
Ilias Fountoulakis ◽  
Panagiotis Kosmopoulos ◽  
Kyriakoula Papachristopoulou ◽  
Panagiotis-Ioannis Raptis ◽  
Rodanthi-Elisavet Mamouri ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Renewable Energy Sources ◽  
Financial Loss ◽  
Low Latitude ◽  
High Quality ◽  
Surface Solar Radiation ◽  
Satellite Retrievals ◽  
Different Types ◽  
Fine Resolution

Cyprus plans to drastically increase the share of renewable energy sources from 13.9% in 2020 to 22.9% in 2030. Solar energy can play a key role in the effort to fulfil this goal. The potential for production of solar energy over the island is much higher than most of European territory because of the low latitude of the island and the nearly cloudless summers. In this study, high quality and fine resolution satellite retrievals of aerosols and dust, from the newly developed MIDAS climatology, as well as information for clouds from CMSAF are used in order to quantify the effects of aerosols, dust, and clouds on the levels of surface solar radiation (SSR) and the corresponding financial loss for different types of installations for production of solar energy. An SSR climatology has been also developed based on the above information. Ground-based measurements were also incorporated to study the contribution of different species to the aerosol mixture and the effects of day-to-day variability of aerosols on SSR. Aerosols attenuate 5 – 10% of annual GHI and 15 – 35% of annual DNI, while clouds attenuate ~25 – 30% and 35 – 50% respectively. Dust is responsible for 30 – 50% of the overall attenuation by aerosols.

scholarly journals Monte Carlo simulations of two-component drop growth by stochastic coalescence

2008 ◽  
Vol 8 (2) ◽  
pp. 7289-7313 ◽  
Author(s):  
L. Alfonso ◽  
G. B. Raga ◽  
D. Baumgardner
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Stochastic Algorithm ◽  
Aerosol Composition ◽  
Particle Charging ◽  
Two Component ◽  
Different Types ◽  
Framework Species ◽  
Stochastic Coalescence ◽  
Good Agreement

Abstract. The evolution of two-dimensional drop distributions is simulated in this study using a Monte Carlo method.~The stochastic algorithm of Gillespie (1976) for chemical reactions in the formulation proposed by Laurenzi et al. (2002) was used to simulate the kinetic behavior of the drop population. Within this framework species are defined as droplets of specific size and aerosol composition. The performance of the algorithm was checked by comparing the numerical with the analytical solutions found by Lushnikov (1975). Very good agreement was observed between the Monte Carlo simulations and the analytical solution. Simulation results are presented for bi-variate constant and hydrodynamic kernels. The algorithm can be easily extended to incorporate various properties of clouds such as including several crystal habits, different types of soluble CCN, particle charging and drop breakup.

Contribution for the Study of New Pathogenic Indicators Removal from W.S.P. in Portugal

1991 ◽  
Vol 24 (2) ◽  
pp. 381-386 ◽  
Author(s):  
M. J. Nascimento ◽  
J. S. Oliveira ◽  
L. Oliveira ◽  
J. T. Mexia
Keyword(s):  
Solar Radiation ◽  
Climatic Factor ◽  
Climatic Parameters ◽  
Faecal Coliforms ◽  
Different Types ◽  
Microbial Removal ◽  
Pathogens Removal ◽  
Faecal Streptococci

In the control of pathogens removal in W.S.P. in Portugal, other indicators than the classic ones were used to quantify die-off kinetics (Faecal coliforms, Faecal Streptococci, Clostridiumperfringens, Pseudomonasaeruginosa and Heterotrophies). The influence of climatic parameters (temperature, precipitation, solar radiation) in that kinetics was studied, different equations being tested to express relationships existing among climatic parameters and microbial removal in different types of ponds. The existence of significant correlations among these factors and parameters was concluded, as well as the dominance of certain models to quantify these relationships, differing according to the microorganisms considered, the type of lagoon and the climatic factor (θ) studied.

scholarly journals Identifying building obsolescence: towards increasing buildings' service life

2020 ◽  
Vol 38 (5) ◽  
pp. 635-652
Author(s):  
Mohammad Pourebrahimi ◽  
Seyed Rahman Eghbali ◽  
Ana Pereira Roders
Keyword(s):  
Service Life ◽  
Research Question ◽  
Effective Prevention ◽  
Content Type ◽  
Environmental Consequences ◽  
Different Types ◽  
The Relationship ◽  
Effective Prevention Strategies ◽  
Relevant Factors ◽  
New Framework

PurposeObsolescence is a decline or loss of utility of an object, building or product. Different types of building obsolescence decrease buildings’ utility and shorten their service life. The purpose of this paper is identification of building obsolescence types and the relevant factors that affect buildings to become obsolete. It is also intended to categorise building obsolescence types to provide a contribution towards increasing building service life and delivering sustainability.Design/methodology/approachA systematic literature review is applied to conduct this research. It follows five steps: (1) formulating the research question; (2) locating studies; (3) selecting and evaluating relevant studies; (4) analysing the findings; (5) reporting and making use of the results.FindingsVia this study, it is revealed that there are 33 types of building obsolescence. They are clustered in 10 categories regarding their conceptual and causing aspects and are presented based on their recurrence in the literature. According to the findings, economic obsolescence (including economic, financial and market obsolescence types) and functional obsolescence (including functional, use and utility obsolescence types) are the most remarkable categories.Originality/valueInvestigating the literature makes it clear that building obsolescence types have been studied intermittently with infrequent profound exploration of the relationship between them. This paper presents a comprehensive identification of building obsolescence types and introduces obsolescence categories that classify connected obsolescence types. It is a new framework for further studies on building obsolescence to find more effective prevention strategies to mitigate social, economic and environmental consequences of building obsolescence.

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