The role of solar energy in the drying of vine fruit

1962 ◽  
Vol 13 (4) ◽  
pp. 662 ◽  
Author(s):  
BW Wilson

In Australia grapes are dried almost exclusively by natural energy on tiered racks usually sheltered by an iron roof. Under these conditions it was shown that there is a close relationship between direct solar radiation and rate of drying. Wavelengths of 0.7 to 0.9 µ, which are abundant in sunlight, penetrated grape skins, particularly after (cold) dipping treatments, and temperatures within the grapes in excess of 8°C above air temperatures were frequently recorded. The quantity of water evaporated from grapes on a weighed drying rack approximated closely to estimates based on simultaneous measurements of solar radiation. The efficiency of tiered drying racks was superior to that of two types of low cost air driers in which solar energy absorbers were used.

2013 ◽  
Vol 34 (3-4) ◽  
pp. 211-220
Author(s):  
Felix Hermerschmidt ◽  
Panayiotis D. Pouloupatis ◽  
George Partasides ◽  
Andreas Lizides ◽  
Stella Hadjiyiannakou ◽  
...  

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.


2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ulku Ece Ayli ◽  
Ekin Özgirgin ◽  
Maısarh Tareq

Abstract One of the most promising renewable energy sources is solar energy due to low cost and low harmful emissions, and from the 1980s, one of the most beneficial applications of solar energy is the utilization of solar chimney power plants (SCPP). Recently, with the advancement in computer technology, the use of computational fluid dynamics (CFD) methodology for studying SCPP has become an extensive, robust, and powerful technique. In light of the above, in this study, numerical simulations of an SCPP through three-dimensional axisymmetric modeling is performed. A numerical model is created using CFD software, and the results are verified with an experimental study from the literature. The amount of solar radiation and surrounding weather (ambient temperature) were analyzed, and the effects of the irradiance and air temperature on the output power of the SCPP were studied. Ambient temperature is considered as one of the most important factors that influence collector efficiency in a negative or a positive manner. Solar irradiance is considered to be the most important factor that has an impact on SCPP performance. The investigation includes the study of the relationship between solar insolation and ambient temperatures during the daytime since the difference between the minimum and maximum power values and the performance are very important considering seasonal changes. According to the results, power values are dependent on the amount of solar radiation as well as the ambient temperature, and the importance of selection of location thus climate for an SCPP is found to affect the design of the SCPP.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Kacem Gairaa ◽  
Yahia Bakelli

Due to its geographical position in the solar belt, Algeria is blessed with an abundance of solar energy and has the opportunity to utilize this bounty of natural energy effectively, promoting a clean environment and developing renewable energy technologies in the region. This paper assesses and analyses the solar energy potential in Ghardaïa area (south Algeria) to help users for solar energy applications. A database of solar radiation components has been employed for this purpose. The data presented in the paper are compared with other data supplied by renowned regional and international establishments, such as the solar atlas for the Mediterranean and the NASA. The frequency and the hourly distribution of solar radiation components indicate that the region is considered as an economical area and favorable for solar applications, such as the photovoltaic and the concentrating solar power (CSP) technologies. In addition to solar radiation, data of two functions, namely, clearness index and sunshine fraction have been examined; their results specify that the site has a clear sky conditions in most time of the year. In general, the obtained results illustrate that the site under consideration can use solar energy as a promising solution to conventional energy.


2020 ◽  
Vol 16 (4) ◽  
pp. 455-461
Author(s):  
Gabriela M. Baia ◽  
Otniel Freitas-Silva ◽  
Murillo F. Junior

Fruits and vegetables are foods that come into contact with various types of microorganisms from planting to their consumption. A lack or poor sanitation of these products after harvest can cause high losses due to deterioration and/ or pathogenic microorganisms. There are practically no post-harvest fungicides or bactericides with a broad spectrum of action that have no toxic residual effects and are safe. However, to minimize such problems, the use of sanitizers is an efficient device against these microorganisms. Chlorine is the most prevalent sanitizing agent because of its broad spectrum, low cost and well-established practices. However, the inevitable formation of disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), is considered one of the main threats to food safety. Alternative sanitizers, such as chlorine dioxide (ClO2) and ozone, are becoming popular as a substitute for traditional post-harvest treatments. Thus, this review addresses the use of chlorine, chlorine dioxide and ozone emphasizing aspects, such as usage, safe application, spectrum of action and legislation. In order to ensure the quality and safety of final products, the adoption of well-prepared sanitation and sanitation programs for post-harvest fruits and vegetables is essential.


Author(s):  
Ruth Gamble

Chapter 2 examines lineages in Tibetan society and the Buddhist tradition and explains how they influenced the development of Tibet’s reincarnation lineages. It begins by explaining the role of family lineages in thirteenth-century Tibet, describing how lineages helped form identities, created links between people, and served as a mechanism for inheritance. It then examines the three main forms of Buddhist lineages—monastic, Mahāyāna, and Tantric—and shows how these lineages were often intermingled with Tibetan family lineages and inheritance practices. The chapter ends by outlining how lineages associated with manifestation, particularly lineages associated with Avalokiteśvara, underpinned claims by Tibetans to be the manifestation of this bodhisattva and other celestial beings. This chapter also explains how the Karmapas’ reincarnation lineage, traditions, and institutions were presented not as a break from other lineages but as an extension of them, and it highlights the close relationship between lineages and specific places.


Author(s):  
Martin Giraudeau

This chapter is an analysis of the project appraisal procedures in place at American Research and Development Corporation (ARD) between 1946 and 1973, under the management of Georges F. Doriot. It shows the importance of knowledge technologies and administrative procedures in the way the venture capital company dealt with uncertain futures. The origins of these knowledge practices are traced back to Georges F. Doriot’s own views on business and more generally to the pragmatist movement in business administration of which he was a member. The conduct of project appraisal at ARD is then observed directly, and this reveals its reliance on a rich set of knowledge and diagnostic techniques as well as administrative procedures. These observations allow for a specification of the nature and role of imagination in the entrepreneurship and venture capital practices examined here—in particular, its close relationship with organized knowledge.


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