Lead-acid batteries have been used increasingly in recent years in solar power systems, especially in homes and small businesses, due to their cheapness and advanced development in manufacturing them. However, these batteries have low voltages and low capacities, to increase voltage and capacities, they need to be connected in series and parallel. Whether they are connected in series or parallel, their voltages and capacities must be equal otherwise the quality of service will be degraded. The fact that these different voltages are inherent in their manufacturing, but these unbalanced voltages can be controlled. Using a switched capacitor is a method that was used in many methods for balancing voltages, but their responses are slow. To increase the response and control of the balancing process, this research proposes a novel technique that consists of a dynamic capacitor for controlling the unbalanced voltages of series-connected lead-acid batteries. The proposed technique uses a main capacitor and an inductor with two switches their on/off states are controlled through a pulse width modulation. The technique is designed and validated using MATLAB/Simulink and the results for different cases are compared with other techniques such as switched capacitor technique. Results show that the proposed method promised the balancing control in a shorter time and better performance than other techniques which are crucial in the battery’s voltage balancing.
Biodiesel is an environmentally friendly fuel and a good substitution for the fossil fuel. However, the purity of this fuel is a major concern that challenges researchers. In this study, a calcium oxide based catalyst has been prepared from local waste eggshells by the calcination method and tested in production biodiesel. The eggshells were powdered and calcined at different temperatures (700, 750, 800, 850 and 900 °C) and periods of time (1, 2, 3, 4 and 5 hr.). The effect of calcination temperature and calcination time on the structure and activity of the solid catalyst were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunaure-Emmett-Teller (BET). The optimum catalyst performance was obtained at 900 °C
... Show MoreNanotechnology is a continually expanding field for its uses and applications in multiple areas i.e. medicine, science, and engineering. Biosynthesis is straightforward, less-toxicity, and cost-effective technology. TiO2 NPs biosynthesis has attained consideration in recent decades. In this study, probiotic bacteria were isolated from cow’s raw milk samples, and then were identified by using the Vitek2 system; as Leuconostoc spp. included Leuconostoc mesenteroides subsp. mesenteroides (Leu.1), Leuconostoc mesenteroides subsp. cremoris (Leu.4), and Leuconostoc pseudomesenteroides (Leu.14). All Leuconostoc spp. isolates showed an ability for TiO2 NPs bio-production, after being incubated at anaerobic conditions (30 o C/ 24 h) in DeM
... Show MoreThe research problem is that most of the construction projects exceed the planned value, due to the failure to implement the plans on time. The current study aims to monitor the implementation of the project and for each of the executed tasks of the table of quantities in order to detect deviations at the time they occur, evaluate the time and cost performance, and then identify the areas of waste and analyze the implementation of each task in order to diagnose the underlying problems and find possible and applicable solutions in the environment Iraqi. The research was applied in one of the companies specialized in the field of construction projects, and one of the most important conclusions reached is the possibility of applying
... Show MoreAbstract
This research deals with the technical of opening text during the critical
study about the poem of Al- ssiyab which is named ( city with out rain)
We chose this poem also to make connection with the western critical
theories.
Our study aims to explain the act of opening texts and critics and its
methods and directions in modern Arabic poetry.
It also aims to show the differences in the point of view between critics
and poetries.
The research depends on dimension vision of selective, and descriptive.
Information security in data storage and transmission is increasingly important. On the other hand, images are used in many procedures. Therefore, preventing unauthorized access to image data is crucial by encrypting images to protect sensitive data or privacy. The methods and algorithms for masking or encoding images vary from simple spatial-domain methods to frequency-domain methods, which are the most complex and reliable. In this paper, a new cryptographic system based on the random key generator hybridization methodology by taking advantage of the properties of Discrete Cosine Transform (DCT) to generate an indefinite set of random keys and taking advantage of the low-frequency region coefficients after the DCT stage to pass them to
... Show MoreThe 1500m race event is part of the athletics system, and the continuous competition to break records and achieve the highest levels of achievement in athletics events, especially the 1500m race event, is one of the topics that occupies the minds of many people interested in achieving digital development for this event, given the distance of the race and the time it takes to complete it. Because it is unique from other events, it has characteristics that distinguish it from other events, despite it being a middle-distance event, which shares with them that its speed is measured by the step, which consists of the length of the step and its frequency. Increasing any of these two factors while keeping one of them constant or increasing
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Abstract
What the research come to:
1- The presentation of the image of the proud person in this
mortal life appeared in several styles such as (conversation)
arousing the insert once and convincing in other time,
(confirmation) in all its types، (argument) scolding with the
gradual progress of time of the discourse .Interview and
parallelism are two of these styles with the presences of the
repetition style especially in the topics that has a reference to
the theme of (pride) being implied not directly stated. The
Koran discourse varied in its reference to the theme of pride
according to the context which is mentioned directly
(eighteen times) which formed one third of the number of
Praise be to God, who has seen uniting the wonders of manufactures, and pronounced Pthamidh oddity Alambdoat, and swam his creation in different languages, Glory is not equal to one in the earth and the heavens, praise Him, and I bear witness that there is no god but Allah alone with no partner certificate towering branches, and I bear witness that Muhammad is His slave and Messenger sent swage Arab government balance, and clearest statement, and the highest residence and Ohllagha words, and Oovaha Zmama, he pointed the way and advised the creation, and the month of Islam, breaking idols, and showed provisions, uncle Balanaam, God separated blessings and peace upon our Prophet Muhammad and the God of the good and virtuous and his compani
... Show MoreTime affects all elements of the intellectual scene or the theatrical scene. It came along with the theatrical doctrines according to the conditions of those doctrines and their conceptual ideas or the method of their mechanisms in the application. While it is classically or realistically integrated, we see it in the expressionist doctrine inconsistent and its inconsistency makes it responsive for the deconstruction strategy. Hence the researcher entitled his study (deconstruction the theatrical time in the expressionist doctrine) so that deconstruction would be a field for his study. The study starts with an introduction presenting the research problem, importance and objective. The theoretical framework consisted of three s
... Show Morethis research seeks to shed light on the study of the impact of Putinism on the Russian-Ukrainian war that broke out in early 2022, by studying the contents of the speeches of Russian President Vladimir Putin before the start of the war. This research uses the structural approach in analyzing the components of the Russian political regime. The research tools used in this research include case studies, content analysis of Russian speeches, and personal meetings of researchers and specialists in Russian affairs. It sums up a number of important conclusions, most notably are : 1) Putinism is a totalitarian regime that includes the political doctrine during the era of Russian President Vladimir Putin. 2) Duginism represents the totality of t
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