Rotational Piezoelectric Energy Harvesting (RPZTEH) is widely used due to mechanical rotational input power availability in industrial and natural environments. This paper reviews the recent studies and research in RPZTEH based on its excitation elements and design and their influence on performance. It presents different groups for comparison according to their mechanical inputs and applications, such as fluid (air or water) movement, human motion, rotational vehicle tires, and other rotational operational principal including gears. The work emphasises the discussion of different types of excitations elements, such as mass weight, magnetic force, gravity force, centrifugal force, gears teeth, and impact force, to show their effect on enhancing output power. It revealed that a small compact design with the use of magnetic, gravity, and centrifugal forces as excitation elements and a fixed piezoelectric to avoid a slip ring had a good influence on output power optimisation. One of the interesting designs that future works should focus on is using gear for frequency up-conversion to enhance output power density and keep the design simple and compact.
The current study deals with one of the ancient and modern techniques of ceramic art, which has evolved dramatically. This technique is interested in the muddy Body and its coloring, rather than interesting in the coloring of the layer on the surface of the glass port on the ceramic object. It is classified as ceramic techniques of the single heartburn, where use many coloring oxides. As well as, the use of (Pigment), which is often made of metal compounds, or metal oxides such as iron and manganese, copper and cobalt and more others.
The first chapter includes the problem, the importance, the goal, and the boundaries of the study. In addition, focuses on determining the terms such as (Sgrafitto). The second chapter consists of two to
The effect of annealing on the structural and optical properties of Antimony trisulfide (Sb2S3) is investigated. Sb2S3 powder is vaporized on clean glass substrates at room temperature under high vacuum pressure to form thin films. The structural research was done with the aid of X-ray diffraction (XRD) and atomic force microscopy (AFM). The amorphous to the polycrystalline transformation of these thin films was shown by X-ray diffraction analysis after thermal annealing. These films' morphology is explained. The absorption coefficient and optical energy gap of the investigated films are calculated using transmission spectra. Both samples have strong absorption in the visible spectrum, according to UV-visible absorption spectra. The optical
... Show More-convex sets and -convex functions, which are considered as an important class of generalized convex sets and convex functions, have been introduced and studied by Youness [5] and other researchers. This class has recently extended, by Youness, to strongly -convex sets and strongly -convex functions. In these generalized classes, the definitions of the classical convex sets and convex functions are relaxed and introduced with respect to a mapping . In this paper, new properties of strongly -convex sets are presented. We define strongly -convex hull, strongly -convex cone, and strongly -convex cone hull and we proof some of their properties. Some examples to illustrate the aforementioned concepts and to cl
... Show MoreThe Arab-Israeli conflict passed through several stages before reaching the final stage of normalization, namely conflict, conflict and public normalization. Thus, the UAE became the third country to establish official relations with Israel after Egypt in 1979 and Jordan in 1994. With the announcement of the normalization agreement, opinions varied between supporters and opponents of the idea of normalization with Israel, and some countries expressed their acceptance of establishing official relations between the Emirates and Israel, while others warned of the consequences of normalization, which they described as treachery. Although the UAE confirmed that the normalization agreement between the two sides was credited with stopping Israel's
... Show MoreThe research problem can be summarized through focusing on the environment that surrounds students and class congestion, how these factors affect directly or indirectly the academic achievement of students, how these factors affect understanding the scientific material that the student receives in this physical environment, how classroom’s components such as seats, space With which the student can move, the number of students in the same class, the lighting, whether natural or artificial, and is this lighting sufficient or not enough, the nature of the wall paint old or modern, is it comfortable for sight, the blackboard if it is Good or exhausted, In addition to air-conditioning sets in summer and winter, this is on the on
... Show MoreReceipt date: 8/8/2020 acceptance date: 9/11/2020 Publication date: 31/12/2021
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The American-Iranian relations have been characterized by tensions since the arrival of the guardian jurist regime in Iran to leadership in 1979, as it was considered a turning point not only in the cont
... Show MoreThe aim of the current study is to demonstrate the effect of honey on the sperms characteristics (sperm concentration, sperm motility, grade of activity and sperm normal morphology) as well as pregnancy rate in mice. Sperms were obtained from caudal epididymis of male mice and prepared by adding10% of honey to the IVF medium using direct sperms activation technique for 30 minute incubation period before artificial insemination.
The study revealed a significant (P > 0.05) increase in active sperm motility (grade A and grade B) 49% and pregnancy rate 53.3% in female mice artificially inseminated with sperms. On the other hand, there were no significant differences in sperm con
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