Use of Gray Water in Cooling Air Conditioning Condenser

Arid and semi-arid countries experience challenges especially in the use of air conditioning units which tend to consume more electricity in the summer due to the effect of the heat on the compressor. The solution to this problem is the use of spray cooling with the spray targeting the compressor to cool it through evaporation as a result of the absorption of the latent heat of vaporization. However, a problem still exists in these countries mainly because they lack adequate water and have to resort to the use of gray water. This paper, therefore, investigates the use of gray water as a spray coolant and its effects on nozzles of various sizes.Gray water contains minerals and chemicals which are bound to accumulate at the tip of the nozzle in a process called scaling. Scaling results in the narrowing of the nozzle affecting the spread diameter, nozzle diameter and the cone angle of the resultant spray. The experiment highlighted in this paper will use tap water and gray water both of which are tested using two nozzles. The diameter of the nozzles is measured with the utilization of a microscope while the cone angle of the resultant spray is measured with the use of images taken from a high-resolution camera.It is observed that both tap water and gray water produce a certain amount of scaling at the tip of the nozzles. The scaling affects the cone angles and the spread diameters. While tap water has a small reduction in the cone angle, the gray water results in a larger reduction. The tap water also results in an increase in the effective spread diameter while the gray water results in its decrease. However, because water is scarce in the arid countries, gray water is the most suitable with the solution to the problem being the constant replacement of the nozzles after a particular period

A systemic approach for construction contract claims settlement in the Kingdom of Saudi Arabia

The Kingdom of Saudi Arabia (KSA) construction sector is an important part of the country’s Vision 2030 programme that is focused upon increasing non-oil economic growth. The structure of the KSA construction sector is different to many countries because of the reliance upon foreign workers and international companies to deliver projects. Culture also plays an important role, together with the use of Sharia law for dispute settlement. The KSA government is a key client of the sector commissioning projects to develop and improve housing, infrastructure, and social projects. Construction claims are endemic on KSA public sector projects. Cases of disputes, conflicts, and claims are on the rise over the past two decades which impact the time, cost, and quality of the work. In the worst-case scenario, they may even result in project abandonment. Making claims and resolving disputes takes a long time, costs money and resources, and can affect the professional relationship of the parties involved. The costs of disputes and contractual claims is rising and becoming more difficult. The claims settlement procedure is a complex process of interdependent and interrelated activities, which takes time and can delay the project. This research considers the efficiency of claim settlement procedures in KSA construction projects with the aim of developing a code of best practice. To develop the code, data and information was collected through mixed methods, including qualitative and quantitative methods. Interviews were conducted with 15 professionals involved in KSA construction projects. A survey questionnaire was designed and distributed to the professionals to collect quantitative data to frame measures for the code of best practice. The primary causes of claims have been identified. The most important feature is the lack of design development at the tender stage, with projects being started on site with incomplete and inaccurate information, which ultimately leads to claims. Contingency allowances are included in tenders for risks that are poorly specified. The two most critical areas in the pre-construction phase are the design process and the contract awarding procedure. There are five contributions. Firstly, the research explored the underlying causes of disputes and claims through qualitative and quantitative data raised from interviews and survey questionnaires from 15 respondents

SARS-CoV-2 and Coronavirus Ancestors under a Molecular Scope

The Pandemic of COVID-19 has been thoroughly followed and discussed on many levels due to the high level of attention that it has brought by its effect on the world. While this disease might seem like to arise out of the blue, we will shed light on COVID-19 disease which is caused by the virus SARS-CoV2 and belong to family of coronaviruses. We will discuss current knowledge about SARS-CoV2 emergence, diagnosis, its mode of action, and genomic information, For an antiviral treatment to be used, it should be preceded by a foundation of information about the virus genome and its family as discussed in this review

Enhancing hydrogen generation through advanced power conditioning in renewable energy integration

Producing hydrogen using renewable energy is a pivotal move towards cleaner and eco-friendlier energy generation, playing a vital role in safeguarding the environment. This method merges power electronic tools with electrolysers, which are key in enhancing hydrogen creation efficiency. Given that electrolysis operate on direct current (DC) voltage, there's a need for DC-DC or AC-DC converters to guarantee the right voltage and current for optimal electrolysis. This study aims to present a power regulation system tailored for hydrogen production powered by renewable resources. This system consists of two main stages: the matrix converter and the 12-pulse diode rectifier. The matrix converter ensures a controlled intake of current from the alternating current (AC) side, leading to a sinusoidal output with limited harmonic disruption. Additionally, it produces an AC voltage with a controlled magnitude and frequency, designed to suit the 12-pulse diode rectifier that follows. This meticulous voltage control is fundamental, granting enhanced operational adaptability and producing a high-quality waveform to support the electrolysis. Finally, the 12-pulse diode rectifier's task is to transform the AC from the matrix converter into a consistent DC voltage, crucial for effective hydrogen production

An artificial gorilla troops optimizer for stochastic unit commitment problem solution incorporating solar, wind, and load uncertainties

The unit commitment (UC) optimization issue is a vital issue in the operation and management of power systems. In recent years, the significant inroads of renewable energy (RE) resources, especially wind power and solar energy generation systems, into power systems have led to a huge increment in levels of uncertainty in power systems. Consequently, solution the UC is being more complicated. In this work, the UC problem solution is addressed using the Artificial Gorilla Troops Optimizer (GTO) for three cases including solving the UC at deterministic state, solving the UC under uncertainties of system and sources with and without RE sources. The uncertainty modelling of the load and RE sources (wind power and solar energy) are made through representing each uncertain variable with a suitable probability density function (PDF) and then the Monte Carlo Simulation (MCS) method is employed to generate a large number of scenarios then a scenario reduction technique known as backward reduction algorithm (BRA) is applied to establish a meaningful overall interpretation of the results. The results show that the overall cost per day is reduced from 0.2181% to 3.7528% at the deterministic state. In addition to that the overall cost reduction per day is 19.23% with integration of the RE resources. According to the results analysis, the main findings from this work are that the GTO is a powerful optimizer in addressing the deterministic UC problem with better cost and faster convergence curve and that RE resources help greatly in running cost saving. Also uncertainty consideration makes the system more reliable and realistic