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Incurrent times wire arc additive manufacturing is becoming popular and alternate to conventional machining because of its eco-friendly as wastages. Wire arc additive manufacturing (WAAM) develops the parts by depositing wire material one layer above other because it is based on old technology i.e., welding. It even has ability to generate complex parts. As WAAM requires post processing to obtain the better surface and accuracy of dimensions. To study about the post processing of WAAM specimen, in this work Wire cut EDM is used, which can machine complicated shapes with high accuracy for any conducting material without taking into account the hardness of the material. Selection of input parameters is the key for better surface finish in Wire EDM. Mechanical properties are used for testing of specimen are Tensile test, Compression test, and Izod test. In this study Pulse on time, Wire tension, Servo Voltage with three levels were considered as input parameter and Material removal, Surface roughness are considered as output responses. Response surface Methodology is used for designing the experiment. It is observed that wire tension plays vital role in surface finish, pulse on time is important in material removal but not in surface finish. Servo voltage predominant for surface roughness.

Green hydrogen is one of the new and promising renewable energy sources, and there is a growing recognition that hydrogen will be the fuel of the future. While numerous methods may be used to manufacture hydrogen, only a few of them are ecologically benign. It is argued that solar hydrogen generated from water using solar energy is a leading candidate for renewable energy. Also, one of the most critical challenges facing green hydrogen is its production as an environmentally safe energy source. Moreover, there are several ways to produce it, including through solar panels alone. In this research, a review will be made of the most important research that has studied the production of green hydrogen using solar energy alone or using different sources of renewable energy so that the system becomes a hybrid. The HOMER Pro program makes a technical study of many scenarios and selects the best ones. In this research, the focus was on hydrogen production in the city of NEOM in the Kingdom of Saudi Arabia, because it is one of the most important pillars of Saudi Arabia's vision of 2030, and it will be the largest exporter of green hydrogen in the world. The HOMER Pro program was used to simulate hydrogen production through solar panels distributed over 100 square meters, and the amount of hydrogen produced was measured and compared with other cities in the Kingdom of Saudi Arabia. Through simulation, it was concluded that the city of NEOM has high potential in the production of green hydrogen, due to several reasons, the most important of which is the amount of solar radiation falling on it, in addition to being close to a source of water for the process of hydrogen separation from water.

An experimental study has been carried out to investigate the effects of stainless-steel balls on forced convection flow in pipe under uniform heat flux. Water is used as the working fluid and stainless-steel balls as a porous media. The Reynolds number range from (5000 to 9000) based on the diameter of the pipe. The experiments were conducted on three various numbers of stainless-steel balls (N) with various diameters (dp), which give various porosity (0.33, 0.38 and 0.41). These are (N= 2400, dp=1mm), (N=1600, dp=3mm) and (N= 750, dp=5mm). Results show that, heat transfer coefficient increases with the decrease in the porosity due to the reduction in the space between balls. This led to an increase in turbulence and produced eddies. Furthermore, enhancement in heat transfer coefficient reached its maximum value of (45%) for ball diameter with (dp=1mm) and water flow rate (9 L/min). New Correlation equations for the average heat transfer coefficient were obtained for three different diameters of balls (1, 3 and 5 mm).

The necessity for renewable energy sources is on the increase all around the world because of the negative consequences of burning fossil fuel to produce energy. Recently, Saudi Arabia has decided to become the world’s largest producer of solar energy by the vision of Kingdom of Saudi Arabia in 2030. This study mainly focuses on developing a solar photovoltaic cell based thermoelectric refrigerator (compressor less refrigerator) which can function as the refrigerator system in houses. The design was going to be equipped with the controller and sensors to reach the required minimum temperature which is around 6°C that is almost similar to the commercial refrigerators.

Background information Aspergillosis is an alarming complication in asthma, leading to worsening symptoms and irreversible lung damage. It is underdiagnosed among asthmatics worldwide, especially in our geographical region. Aim This research was aimed to shed some light on the prevalence of Aspergillus sensitization and allergic bronchopulmonary aspergillosis (ABPA) in asthmatic patients in the Kingdom of Bahrain. Importance This project has never been conducted in the region and hopefully will lead to a better care for asthmatics. Methodology Our study population consisted of adult outpatients visiting the pulmonary and chest diseases clinic at Al-Salmaniya Medical Complex (SMC); the main inclusion condition was manifesting respiratory distress symptoms related to one or more respiratory tract diseases. 152 individuals were selected; the study group consisted of 119 asthmatic patients manifesting respiratory distress. The control group consisted of 33 nonasthmatic patients that manifested pulmonary distress symptoms due to respiratory tract diseases other than asthma like chronic obstructive pulmonary disease, bronchitis, among others. Sera samples were collected in SMC and analyzed via Phadia-250 fluoro-enzyme-immunoassay to determine the levels of Aspergillus fumigatus-specific IgE. The rAsp f1 antigen was used against IgE. Results Our results indicated a 16% prevalence of A. fumigatus sensitization in asthmatics; also, 75.6% of asthmatics were sensitized to pollen grains, and 22.3% reported one or many food allergies. Furthermore, details of patients with significant levels of A. fumigatus- specific IgE were analyzed, and ABPA prevalence was estimated to be 10.1% in asthmatics. Conclusion Increasing awareness toward these indolent diseases is required, as well as, more efforts in determining the burden of aspergillosis in other parts of the region.

In wireless networks a set of issues should be considered, one of the most issue sis the security issue especially in wireless Ad hoc networks due to the absence of centralized control. Black Hole attacks are one of the Denial of Service (DoS) attacks that affect the performance of the network by reducing the efficiency of this network. In this paper a new technique is proposed depending on one of the most common classification algorithms called ReiefF to select the most relevant features to detect black hole nodes and prevent the use of these nodes in routes and mark these nodes as a bad node. An experiments are employed using simulation environment and a set of metrics are evaluated giving a result that the proposed technique gave a significant improvement in the network performance starting from 20% up to 40%.

Background: Coronavirus disease 2019 (COVID-19) is a global pandemic, which is associated with venous thromboembolism and pulmonary embolism (PE). This study aimed to estimate the pooled incidence of PE among patients hospitalized with COVID-19 within the published literature. Methods: This systematic review and meta-analysis was performed according to PRISMA guidelines. An electronic search using MEDLINE /PubMed, ScienceDirect, Cochrane, and OpenGray databases was conducted May 19th, 2020. Eligible studies included sufficient data to calculate the incidence of PE diagnosed during hospitalization in patients with COVID-19. Case reports were excluded. Quality was assessed using the Newcastle-Ottawa scale (observational cohort and case-control), AXIS tool (cross-sectional), and quality assessment tool (case series). Demographics and PE incidence data were extracted from the included studies and analyzed with R language. The pooled incidence of PE in patients hospitalized with COVID-19 was calculated. Results: The database search identified 128 records. Ten observational studies were eligible and were included in the meta-analysis with a total of 1722 patients (mean age= 63.36). .The incidence of PE was noted to be higher in males. The D-dimer levels were specified between PE group and non-PE group in only three studies, while the remaining either reported it improperly or had missing data.The pooled PE incidence in patients hospitalized with COVID-19 was 17% (95% CI: 0.1-0.26). There was a high degree of study heterogeneity (I2 = 94%, p Conclusion: The pooled PE incidence in patients hospitalized with COVID-19 is 17%. This increased incidence is greater than that previously reported in the general population of non-COVID-19. Attention and further investigation of this risk is warranted.

Theoretical and experimental study has been conducted on steam condensation process on rotating disk condenser at different rotation speed and power supplied to the evaporation tank. The experimental investigation involved, special test apparatus designed and fabricated to realize the condensation process of the saturated steam on the upper surface of a disk whose base is kept at low temperature. The designed system ensures low temperature for the base of the disk equals to 5°C. The heating element of the steam production sub-system is capable to work at different heating capacities (385, 270, 168 watt). The rotating system is capable to rotate the disc at different rotation speed ranging (103 -150 rpm). Proper slipring is fixed on this shaft to transfer the temperature signals from rotating disc to the read out device. The slip ring is used of 6-way mercury type. The experimental results showed that maximum condensate rate is ensured at rotation speed equals (N=150rpm), steam production power supply (Psteam=385watt) at cooling water temperature (Tcool=5°C). It is observed that there is a gradual increase in condensate rate with increasing rotating speed. It is concluded that rotational speed increase leads to increase in the average heat flux across the disc, while local heat transfer is affected by the condensate layer thickness over the upper disc surface. The disk surface temperature measured values decrease continuously in the radial direction and disc average temperature is proportional with its rotational speed as maximum average temperature is reached when this speed equals 150 rpm. The film thickness gradually increases from center to outer portion of the disk based on both condensate rate and centrifugal force that affects this thickness which in turn depend on the speed, cooling temperature, water evaporation rate. The agreement between the experimental and theoretical overall heat transfer coefficient appears to be reliable with a deviation of about (0.7-22%).

In this paper, a novel image forgery detection method is proposed based on the steerable pyramid transform (SPT) and local binary pattern (LBP). First, given a color image, we transform it in the YCbCr color space and apply the SPT transform on chrominance channels Cb and Cr, yielding a number of multi-scale and multi-oriented subbands. Then, we describe the texture in each SPT subband using LBP histograms. The histograms from each subband are concatenated to produce a feature vector. Finally, a support vector machine uses the feature vector to classify images into forged or authentic. The proposed method has been evaluated on three publicly available image databases. Our experimental results demonstrate the effectiveness of the proposed method and its superiority over some recent other methods.

Stress is the condition where there is undue demand for physical and mental energy due to excessive and aversive environmental factors (stressors) and cause deformations those are identifiable through physiological disequilibrium. Temperature stress imparts physical and economical losses to livestock production in temperate, subtropical and tropical regions of the world. Each species, breed or animal with its physiological state, has a comfort zone, in which the energy expenditure of the animal is minimal, constant and independent of environmental temperature. When environmental temperatures move out of the thermo-neutral zone (or comfort zone) dairy cattle begin to experience heat stress. Thermo-neutral zone depends on the age, breed, feed intake, diet composition, previous state of temperature acclimatization, production, housing and stall conditions, tissue (fat, skin) insulation and external (coat) insulation, and the behaviour of the animal. The ranges of thermo-neutral zone are from lower critical temperature (LCT) to upper critical temperature (UCT). LCT is the environmental temperature at which an animal needs to increase metabolic heat production to maintain body temperature. UCT is the environmental temperature at which the animal increases heat production as a consequence of a rise in body temperature resulting for inadequate evaporative heat loss. Heat stress negatively impacts a variety of dairy parameters including milk yield and reproduction and therefore is a significant financial burden in many dairy-producing areas of the world. Advances in management (i.e. cooling systems) and nutritional strategies have alleviated some of the negative impact of thermal stress on dairy cattle, but production continues to decrease during the summer. In this review an attempt has been made to bring forth the effect of heat stress and to discuss their impact on dairy cows.

Discurs inaugural curs 1859 a 1860

Discurs inaugural curs 1859 a 1860