In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation conditions was examined. The variation of angles of attack and wind velocity leads to different values of vortex loading coefficients and shedding frequencies. The relation between the dynamic characteristics and solar collector performance was evaluated. The finite element method was used to estimate the dynamic characteristic of the solar collector in addition to experimental work to evaluate the relation between the dynamic behavior of the collector and its performance.
Statistics indicate criminal in most countries of the world that the suicide rate continues to increase, as it prevalence manufacturing and complexity of life and the intensification of conflicts and escalating problems of rising suicide rates. And suicide is death intentional, that is, the intentional act that leads to ending the life of the individual and self-on purpose. The current research aims to identify the suicide in terms of its causes and its factors and come up with recommendations for the prevention of suicide. Because suicide is a life-threatening problem has tried several theories of interpretation and stand on its grounds. Considering the theories of psychoanalysis (Freud) that suicide is the result of the individ
... Show MoreThe first chapter the importance of research and need for education scientists see that the roots of the use of a specimen Wheatley in learning and teaching back to Grayson Wheatley, one of the largest supporters of a modern construction, which lay the groundwork for the specimen stage and the form in which it is. That was attributed to him, often called his name called while some educators based learning strategy on the issue. He sees the learner in this model make him a meaningful understanding of problems during his progress, thereby acting with his colleagues to find solutions to them in small groups. He
Borders Search: Search by students is determined by th
... Show MoreThe fast evolution of cyberattacks in the Internet of Things (IoT) area, presents new security challenges concerning Zero Day (ZD) attacks, due to the growth of both numbers and the diversity of new cyberattacks. Furthermore, Intrusion Detection System (IDSs) relying on a dataset of historical or signature‐based datasets often perform poorly in ZD detection. A new technique for detecting zero‐day (ZD) attacks in IoT‐based Conventional Spiking Neural Networks (CSNN), termed ZD‐CSNN, is proposed. The model comprises three key levels: (1) Data Pre‐processing, in this level a thorough cleaning process is applied to the CIC IoT Dataset 2023, which contains both malicious and t
A field experiment was carried out in one of the orchards of Al-Qassim district in Babel Governorate to find out the ability of a locally manufactured platform to serve palm trees by working in flat and uneven orchard land, palm tree heights of 4, 8, and 12 meters, and it performs pollination, pruning and harvesting services. The time of ascent and descent, the palm service, and the palm/hour productivity were measured. A randomized complete block design with three replications used a split split-plot arrangement. The nature of the land (flat or uneven) represented the main plots, the height of the palm trees (4, 8, 12) meters, the sub-plots, and the palm service operations (pollinati
Background: The demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwires were introduced. Among them, Teflon and Epoxy coated stainless steel archwires. The amount of force available from the archwire depends on the structural properties and susceptibility to corrosion. All metallic alloys are changed during immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one type to another. They corrode at different rates, which lead to decrease the amount of force applied to the teeth. This in vitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with Teflon and with Epoxy in dry and after immersion in artificial saliva, chl
... Show MoreCryptographic applications demand much more of a pseudo-random-sequence
generator than do most other applications. Cryptographic randomness does not mean just
statistical randomness, although that is part of it. For a sequence to be cryptographically
secure pseudo-random, it must be unpredictable.
The random sequences should satisfy the basic randomness postulates; one of them is
the run postulate (sequences of the same bit). These sequences should have about the same
number of ones and zeros, about half the runs should be of length one, one quarter of length
two, one eighth of length three, and so on.The distribution of run lengths for zeros and ones
should be the same. These properties can be measured determinis
In this paper , some of lexical stylistic , syntactical stylistic devices , and one phonetic stylistic device are going to be illustrated in the study of the aphorisms of “life and death” . These stylistic devices are parallelism , hyperbole , alliteration , meiosis , irony , oxymoron , cliché , litotes , metalepsis , and loose sentences. This paper aims at identifying the functions and the frequencies of these devices. These stylistic devices make one speech and writing more interesting and help to get the attention of readers/ listeners
This research sought to present a concept of cross-sectional data models, A crucial double data to take the impact of the change in time and obtained from the measured phenomenon of repeated observations in different time periods, Where the models of the panel data were defined by different types of fixed , random and mixed, and Comparing them by studying and analyzing the mathematical relationship between the influence of time with a set of basic variables Which are the main axes on which the research is based and is represented by the monthly revenue of the working individual and the profits it generates, which represents the variable response And its relationship to a set of explanatory variables represented by the
... Show MoreThe websites over time have become one of the important tools for communication between individuals among themselves and between individuals and economic units, and they have emerged as one of the important intangible assets to achieve income, as they have become a competitive tool and a marketing outlet for these units and a main means of communication that it uses to exercise its various major activities and achieve potential economic benefits. Therefore, there was a need to measure and display the value of these sites in the financial statements as intangible assets. Accordingly, the purpose of the research was to determine the costs of the websites owned by the economic unit by way purchase and sites that were created i
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