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.
n this research, some thermophysical properties of ethylene glycol with water (H2O) and two solvent mixtures dimethylformamide/ water (DMF + H2O) were studied. The densities (ρ) and viscosities (η) of ethylene glycol in water and a mixed solvent dimethylformamide (DMF + H2O) were determined at 298.15 K, t and a range of concentrations from 0.1 to1.0 molar. The ρ and η values were subsequently used to calculate the thermodynamics of mixing including the apparent molar volume (ϕv), partial molar volume (ϕvo) at infinite dilution. The solute-solute interaction is presented by Sv results from the equation ∅_v=ϕ_v^o+S_v √m. The values of viscosity (B) coefficients and Falkenhagen coefficient(A) of the Jone-Dole equation and Gibbs free
... Show MoreInvestment drives the wheel of the development of different developed and developing countries. Sudan is a model for a developing country facing a lot of difficulties in the field of both local and foreign investment. The present study was focused on the problem of poor diversification and efficiency of both local and foreign investment in Sudan. Also, it clarified the important role of administrative supervision to strengthen the efficiency of investment, taking the experience of the Sudan as a model. The researchers used the well-known descriptive and analytical tools (questionnaire, interview, observation) to complete this study. A well designed questionnaire was used. It included all questions that could cover all aspects of
... Show MoreObjective: To compare the radiological and functional outcomes of patients of Comminuted intraarticular distal radius fractures treated with or without bone marrow injection along with external fixator ligamentotaxis. Methodology: This prospective comparative study on 41 patients with comminuted intra-articular lower end radius fractures distributed patients randomly into two groups depending on whether an aspirate of bone marrow was injected at the fracture site two weeks after fracture management with external fixation ligamentotaxis. Results: The mean age was 35.8 years, with male predominance. The radiological parameters (radial height, radial inclination, and volar tilt) at the 6th month follow up were lower in the group who did not re
... Show MoreAccording to the measuring the relationship between organizational loyalty and job satisfaction among staff members at one college in the higher education ministry in Iraq by using exploratory factor analysis methods to extraction the components which have the major effects on the variables related to organizational loyalty and job satisfaction .
The research contains four basic topics، the first section related to methodology and regarding the conceptual framework it is discussed in the second section، and the third section concentrated at the presentation and the analysis Scientific results and practical results are section presented in the fourth.
Irrigation has significant role in endodontic treatment, many types of antimicrobial irrigation solutions have been used, but due to the ineffectiveness, safety concerns and side effects of this irrigation, the herbal alternatives for endodontic irrigants might be beneficial. Objectives This study compared the in vitro effectiveness of tea tree oil and clove oil as possible irrigants in endodontics against Enterococcus faecalis in comparison with 3% Sodium hypochlorite. Materials and Methods E. faecalis was isolated from patients in need for endodontic treatment; VITEK was employed for E. faecalis isolate conformation. Muller Hinton agar was prepared with 100μl of freshly prepared suspension of E.faecalis. Wells of 6mm diameter and 4mm dep
... Show MoreThe current study is descriptive; it focuses on studying the contemporary geopolitical problem, and sectarian differences in Caucasus. Nagorno-Karabakh is considered an important disputed region nowadays. Many parties and states participated in this dispute, especially after the conflict had developed into an open war between Armenia and Azerbaijan. Thus, the study aims to examine the causes of the conflict in this region, analyze the international positions on this conflict, and find if Armenia was able to occupy this region. The methodology adopted by the researchers is the functional approach, and the theory of power analysis that Cohen created for analyzing all strengths that drove each of the parties t
... Show MoreWe have provided in this research model multi assignment with fuzzy function goal has been to build programming model is correct Integer Programming fogging after removing the case from the objective function data and convert it to real data .Pascal triangular graded mean using Pascal way to the center of the triangular.
The data processing to get rid of the case fogging which is surrounded by using an Excel 2007 either model multi assignment has been used program LNDO to reach the optimal solution, which represents less than what can be from time to accomplish a number of tasks by the number of employees on the specific amount of the Internet, also included a search on some of the
... Show MoreThe aim of the research is to explain the nature of the relationship between the dimensions of the strategic recovery of the service represented by (compensation, speed of response, apology, initiative (defining the problem) and the strategic goals of the company represented in (profitability, growth, community service, employee satisfaction) in the National Insurance Company, it has been approved The questionnaire as a tool to collect data and information from the sample of (58) who are in (department manager, M. department director, division official, unit official) and the statistical program (spss) was used in calculating (arithmetic mean, standard deviation, coefficient of variation, coefficient of Correlation, t-test, varia
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