A linear engine generator with a compact double-acting free piston mechanism allows for full integration of the combustion engine and generator, which provides an alternative chemical-to-electrical energy converter with a higher volumetric power density for the electrification of automobiles, trains, and ships. This paper aims to analyse the performance of the integrated engine with alternative permanent magnet linear tubular electrical machine topologies using a coupled dynamic model in Siemens Simcenter software. Two types of alternative generator configurations are compared, namely long translator-short stator and short translator-long stator linear machines. The dynamic models of the linear engine and linear generator, validated
... Show MoreThe evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient
In the current study, two sites were selected from the city of Adhamiya, central Baghdad. The first site is the Adhamiya Corniche, which includes a sample of river water and the second includes domestic sewage in the same area. The total density of benthic invertebrates was 775 ind/m2, which is divided into 15 taxa. Biological indices were found, such as the stability index, the abundance index, the biodiversity index (Shannon’s index), the homogeneity index, and the invader’s guide. The result showed an increase in the density of benthic invertebrates, as well as an increase in the diversity of these organisms.
This work aims to find a solution to the problem under investigation and to study non-local boundary-value problems for rectangular domains and two-dimensional thirdorder partial differential equations (PDEs). A finite-difference method combined with the trapezoidal rule is used to solve problems. The numerical results were determined to be steady and accurate.
Secondary trigeminal neuralgia (STN) results from an identifiable underlying pathology, including tumor compression, multiple sclerosis, arteriovenous malformations, hypertension, structural lesions, inflammation, trauma, or familial genetic conditions. This study, through a comprehensive review of the literature in PubMed, Google Scholar, Web of Science, and the Cochrane Library, explores the multifaceted aspects of STN. This study delves into the diverse etiological factors, focusing on the pathophysiological mechanisms that lead to trigeminal nerve dysfunction. The clinical manifestations of STN often overlap with those of primary trigeminal neuralgia, creating diagnostic challenges and necessitating a thorough evaluation that in
... Show MoreClimate change significantly affects photovoltaic (PV) energy potential in arid regions. This study quantifies climate change impacts on both monofacial and bifacial PV energy potential across Iraq using Community Climate System Model (CCSM4) projections under Representative Concentration Pathway (RCP) 4.5 and RCP8.5 scenarios spanning 2020–2100. Specific mathematical frameworks accounting for thermal and irradiance characteristics were applied across 18 representative regions covering Iraq’s diverse climatic zones, with bifacial systems modeled using dual-surface irradiance capture incorporating ground reflection and thermal dynamics. Results reveal distinct northwest–southe
ABSTRACT
This study aimed to choose top stocks through technical analysis tools specially the indicator called (ratio of William index), and test the ability of technical analysis tools in building a portfolio of shares efficient in comparison with the market portfolio. These one technical tools were used for building one portfolios in 21 companies on specific preview conditions and choose 10 companies for the period from (March 2015) to (June 2017). Applied results of the research showed that Portfolio yield for companies selected according to the ratio of William index indicator (0.0406) that
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