scholarly journals Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator

2019 ◽  
Author(s):  
samir touzani

The seawater desalination technique presented in this article is based on a new technique for the production of water vapor which has the advantage of using solar energy with maximum evaporation efficiency. This innovation is limited to the production of steam and can be combined with a known technique of condensation of the steam in order to complete the desalination cycle of seawater. This technique is based on the simple principle that the heat transferred from the hot source to the cold source is maximum if the difference between their respective temperatures is kept at its maximum. Thus, by carrying out successive operations of heating thin layers of water, the technique makes it possible to maximize the efficiency of the evaporation by bringing the temperature of the fluid to its initial value at each iteration, thus enabling, according to the Newton's law, to favor the transfer of heat to water.Then, in this paper, we present the theoretical demonstration of the soundness of this technique by using the analogy with electricity using the equivalent resistance for circuits in parallel. Next, an application of the technique which is the subject of a patent of invention is presented in the detal. It is a desalination engine for seawater using solar radiation from a Fresnel concentrator. The presented invention makes it possible to produce steam continuously by heating thin layers of sea water by the Fresnel concentrator. The development prospects of the invention are also presented using the techniques of Nanotechnology.

2021 ◽  
Author(s):  
samir touzani

The purpose of this paper is to formulate the heat transfer needed to generate continuously the steam from the “Linear Fresnel concentrator Steam Generator” according to its dimensions. For more detail information refer to the article "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[1], the preprint "Detail Design - Linear Fresnel concentrator Steam Generator"[2] and the preprint Steam Flow formulation of the Linear Fresnel concentrator Steam Generator[3]. The heat transfer flow assessment depending of many dimensions is the key point out put of this paper. At the glance, these dimensions are the geometry of the Linear Fresnel Concentrator, the tilt to the sun's rays, the length , the radius of the tangled cylinders, the thickness of the annulus spaces and the cavity between the composed device absorber and mirror. The device absorber is composed of the tangled cylinders and the steam collector. Note that the known LFR applications for both industrial and power sectors requires medium temperatures ranging from 100°C to 250°C. The flat plate solar collectors are suitable for low temperature applications maximum up to 80°C and parabolic concentrators are suitable for high temperatures applications above 300°C. Hence, the present work will focus on LFR with parabolic concentrator because sea water desalination requires reaching the boiling point under pressure near atmospheric pressure which is 100 °C. Furthermore, the diameter of absorber device for parabolic concentrator may vary from 5 in to 10 in which is much greater than tubes dimensions for trapezoidal cavity. Then, this dimension fact allows efficient flow water circulation and meaningful steam flow generation.[1] touzani, s. (2019, March 28). Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator. https://doi.org/10.31219/osf.io/dvr9y[2] touzani, s. (2020, September 12). Detail Design - Linear Fresnel concentrator Steam Generator. https://doi.org/10.31219/osf.io/wuq92[3] touzani, s. (2020, September 21). Steam Flow formulation of the Linear Fresnel concentrator Steam Generator. https://doi.org/10.31219/osf.io/ske5c


2020 ◽  
Author(s):  
samir touzani

The purpose of this paper is to formulate the steam flow that will be generated by the “Linear Fresnel concentrator Steam Generator” according to its dimensions. For mor detail information refer to the article "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[https://doi.org/10.31219/osf.io/dvr9y] and the preprint "Detail Design - Linear Fresnel concentrator Steam Generator"[https://doi.org/10.31219/osf.io/wuq92] . The steam Flow is the key point out put of this paper. It will allow to figure out the impact of the sea water desalination engine, its cost and its benefits.


2017 ◽  
Vol 1 (2) ◽  
pp. 137
Author(s):  
Noorlela Binti Noordin ◽  
Abdul Razaq Ahmad ◽  
Anuar Ahmad

This study was aimed to evaluate the Malay proficiency among students in Form Two especially non-Malay students and its relationship to academic achievement History. To achieve the purpose of the study there are two objectives, the first is to look at the difference between mean of Malay Language test influences min of academic achievement of History subject among non-Malay students in Form Two and the second is the relationship between the level of Malay proficiency and their academic achievement for History. This study used quantitative methods, which involved 100 people of Form Two non-Malay students in one of the schools in Klang, Selangor. This study used quantitative data were analyzed using descriptive statistics and statistical inference with IBM SPSS Statistics v22 software. This study found that there was a relationship between the proficiency of Malay language among non-Malay students with achievements in the subject of History. The implications of this study are discussed in this article.


2019 ◽  
pp. 74-98
Author(s):  
A.B. Lyubinin

Review of the monograph indicated in the subtitle V.T. Ryazanov. The reviewer is critical of the position of the author of the book, believing that it is possible and even necessary (to increase the effectiveness of General economic theory and bring it closer to practice) substantial (and not just formal-conventional) synthesis of the Marxist system of political economy with its non-Marxist systems. The article emphasizes the difference between the subject and the method of the classical, including Marxist, school of political economy with its characteristic objective perception of the subject from the neoclassical school with its reduction of objective reality to subjective assessments; this excludes their meaningful synthesis as part of a single «modern political economy». V.T. Ryazanov’s interpretation of commodity production in the economic system of «Capital» of K. Marx as a purely mental abstraction, in fact — a fiction, myth is also counter-argued. On the issue of identification of the discipline «national economy», the reviewer, unlike the author of the book, takes the position that it is a concrete economic science that does not have a political economic status.


Author(s):  
Lexi Eikelboom

This book argues that, as a pervasive dimension of human existence with theological implications, rhythm ought to be considered a category of theological significance. Philosophers and theologians have drawn on rhythm—patterned movements of repetition and variation—to describe reality, however, the ways in which rhythm is used and understood differ based on a variety of metaphysical commitments with varying theological implications. This book brings those implications into the open, using resources from phenomenology, prosody, and the social sciences to analyse and evaluate uses of rhythm in metaphysical and theological accounts of reality. The analysis relies on a distinction from prosody between a synchronic approach to rhythm—observing the whole at once and considering how various dimensions of a rhythm hold together harmoniously—and a diachronic approach—focusing on the ways in which time unfolds as the subject experiences it. The text engages with the twentieth-century Jesuit theologian Erich Przywara alongside thinkers as diverse as Augustine and the contemporary philosopher Giorgio Agamben, and proposes an approach to rhythm that serves the concerns of theological conversation. It demonstrates the difference that including rhythm in theological conversation makes to how we think about questions such as “what is creation?” and “what is the nature of the God–creature relationship?” from the perspective of rhythm. As a theoretical category, capable of expressing metaphysical commitments, yet shaped by the cultural rhythms in which those expressing such commitments are embedded, rhythm is particularly significant for theology as a phenomenon through which culture and embodied experience influence doctrine.


Plant Disease ◽  
1997 ◽  
Vol 81 (9) ◽  
pp. 1053-1056 ◽  
Author(s):  
R. S. Hunt ◽  
F. G. Peet

The spread rate of tomentosus root disease, caused by Inonotus tomentosus, was investigated by a new technique employing temporal differences in the initiation of the reduced annual radial increment between pairs of diseased trees. Pairs of infected trees (stumps) located on the periphery of disease centers were selected in each of six widely separated spruce (Picea spp.) stands in British Columbia. Distances between 12 pairs of stumps were measured, and disks were collected from each stump. Similarly, disks from four additional pairs were collected from trees in a younger stand. Uninfected control disks were collected for all sites. Tree-ring measurements were determined for all disk samples and the year in which the reduction of the annual increment attributable to I. tomentosus began was determined for infected trees. The difference between initiation years for pairs of infected trees divided into the distance between them produced an average annual spread rate of 20 cm/yr. This rate will be used in developing a model for the disease.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Maged Baher Naguib ◽  
Mohamed Rifaat Ahmed ◽  
Yasser Taha Madian ◽  
Tarek Mohamady Elnahriry ◽  
Wael Elshahat Eldeeb

Abstract Background Following the reduction of the nasal hump to a desired level, spreader grafts are usually positioned to prevent the complication of nasal valve collapse. Auto-spreader flap is a new technique that gained more popularity recently and can be used as an alternative to spreader graft. This RCCT compared between both techniques aesthetically and functionally as well as the operative time. Results Forty patients, 17 males (42.5%) and 23 females (57.5%), were included. The mean duration of operation in auto-spreader flap was 11.8 ± 3.4 min, while it was 19.2 ± 3.2 min in spreader graft. The difference between the two procedures was statistically significant (P < 0.05). Functional assessment of nasal obstruction was done for all patients in both groups preoperative that was (75.6 ± 19.9) which showed marked improvement when re-evaluated 3 moths postoperatively (18.9 ± 14.7), and after 6 months NOSE scale was (29.1 ± 20.2). The overall aesthetic satisfaction was 62.5% (25 of 40) irrespective of the surgery done. Sixteen out of 20 patients in spreader group and 9 out of 20 in auto-spreader flap group. Conclusion Auto-spreader flap and spreader graft are very effective surgical procedure for treatment of nasal obstruction due to internal nasal valve dysfunction, but the auto-spreader flap had shorter operative time. However, spreader graft has a superior aesthetic outcome.


In the present communications the effect of oxygen upon the fermentation of glucose and upon the growth of the bacteria, in so far as this affects fermentation, is considered. To this end the organisms have been grown both aerobically and anaerobically, and subsequently made to ferment glucose, both aerobically and anaerobically, with the object of comparing the products of decomposition in the two cases. There are clearly two problems : firstly, the effect of exposure to oxygen during growth upon the subsequent fermentation, whether aerobic or anaerobic, and, secondly, the effect of oxygen admitted during the fermentation. The first question relates to the part played by oxygen in the formation of enzymes, the second to the part played by oxygen in their action on carbohydrates. The first question is considered, though in but a preliminary way, in Section A, the second, more fully, in Section B. Section A. Object of the Experiments . Two results were aimed at in these experiments. Firstly, to compare the products of fermentation of glucose anaerobically, after anaerobic growth, with the products of fermentation anaerobically after previous growth aerobically. And, secondly, to obtain information as to the effect of introducing oxygen during the fermentation itself. This latter consideration, however, though brought to notice by these experiments, is considered only incidentally here because it forms the subject of Section B. In the present section we wish to direct attention particularly to those differences which exist between the fermentation after anaerobic and aerobic growth, not upon the effect of aeration during the fermentation. To point out the difference which previous growth aerobically or anaerobically has made, several analyses from previous experiments are included in Table IV side by side with the completely anaerobic experiments of Tables I, II, and III.


Litera ◽  
2021 ◽  
pp. 38-55
Author(s):  
Rivaa Mukhammad Salem Alsalibi

The subject of this research is the specifics, forms and functions of interaction in social media groups between the representatives of ethnic communities. The goal consists in determination of the role of social networks in adaptation of ethnocultural communities of St. Petersburg. The research is based on the polling technique for acquisition of information on the cognitive, emotional, and behavioral state of a person. The survey was conducted via distribution of questionnaires among the representatives of ethnic groups. The article also employs the method of systematic scientific observation over the social media groups, topic raised therein, as well as reading and analysis of the comments. The scientific novelty of this work consists in outlining of the nature, trends and development prospects of cross-cultural communications as the channel for ethnocultural interaction. &nbsp;The main conclusions, which touch upon users from various ethnic communities who do not have enough experience in organization of activity of social media groups, demonstrate that it causes the loss of the sense of security, accumulation of prejudices and escalation of interethnic conflicts, as well as preference of the with restricted access, which contributes to lock down of the group and impedes adaptation in the accepting society. Stabilization of situation can be achieved by improvement of the quality of content posted in the social media, as well as level of their administration.


2016 ◽  
Vol 5 (09) ◽  
pp. 83-97
Author(s):  
Claudio Reyes Lozano

Los estudios críticos de género sustancialistas desconocen su posición teórico-política en el momento de explayar algunas de sus hipótesis fundamentales. El presente estudio intenta dar cuenta de las consecuencias éticas que asume llevar hasta el final algunas de estas posiciones teóricas. Advertimos así que obras fundamentales de estos estudios se apropian con claridad, y sin saberlo, de una lógica aristotélica para tratar la asunción material del cuerpo, el sujeto y el género ¿Qué encontramos específicamente en esta lógica? Esta última se caracteriza por tener su raíz en una ontología inamovible, en donde cualquier intento de desbaratar el “ser” tiene como respuesta inmediata la exclusión violenta de la diferencia: concretamente observamos esto, dialogando tanto con colegas como legos, en la “violencia académica” pero también en la “violencia cotidiana” ¿Cómo salir del cierre metafísico que ha mantenido durante décadas la violencia y exclusión de aquello que se generó en primera instancia, paradójicamente, como argumentación de tolerancia y emancipación? Pensamos que deconstruyendo el discurso de género aristotélico podremos vislumbrar nuevas hipótesis y posiciones ético-políticas que no recurran, para validarse, a la exclusión violenta de nuevos cuerpos-sujetos-géneros. Some critical gender studies do not know their theoretical and political position at the time to developing some of their basic assumptions. This study attempts to explain the ethical consequences that lead to the end some of these theoretical positions. We realize that fundamental works of these studies clearly appropriating, and without knowing it, an aristotelian logic to justify the assumption of material body, the subject and gender. What specifically found in this logic? It is characterized to found on an immovable ontology, where any attempt to disrupt the “being” has as an immediate violent response to exclude the difference: specifically we observe this, dialoguing with colleagues and laymen, in the “academic violence” but also “everyday violence”. How to get out of the metaphysical closure that maintained for decades the violence and exclusion of what is generated in the first place, paradoxically, as argument of tolerance and emancipation? We think deconstructing the aristotelian discourse of gender can warn new hypotheses and ethical positions that not based, to validate, on a violent exclusion of new bodies-subject-genres positions.


Sign in / Sign up

Export Citation Format

Share Document