Modelling fracture of aged graphite bricks under radiation and temperature

The graphite bricks of the UK carbon dioxide gas cooled nuclear reactors are subjected to neutron irradiation and radiolytic oxidation during operation which will affect thermal and mechanical material properties and may lead to structural failure. In this paper, an empirical equation is obtained and used to represent the reduction in the thermal conductivity as a result of temperature and neutron dose. A 2D finite element thermal analysis was carried out using Abaqus to obtain temperature distribution across the graphite brick. Although thermal conductivity could be reduced by up to 75% under certain conditions of dose and temperature, analysis has shown that it has no significant effect on the temperature distribution. It was found that the temperature distribution within the graphite brick is non-radial, different from the steady state temperature distribution used in the previous studies [1, 2]. To investigate the significance of this non-radial temperature distribution on the failure of graphite bricks, a subsequent mechanical analysis was also carried out with the nodal temperature information obtained from the thermal analysis. To predict the formation of cracks within the brick and the subsequent propagation, a linear traction–separation cohesive model in conjunction with the extended finite element method (XFEM) is used. Compared to the analysis with steady state radial temperature distribution, the crack initiation time for the model with non-radial temperature distribution is delayed by almost one year in service, and the maximum crack length is also shorter by around 20%

Synthesis, Characterization, and Antibacterial Studies of Mn (II) , Fe (II) , Co(II) , Ni(II), Cu (II) and Cd(II) Mixed- Ligand Complexes Containing Amino Acid ( L-Valine) And (1,10- phenanthroline)

A new six mixed Ligand complexes of some transition metal ions Mn (II) , Fe (II) , Co(II) , Ni(II), Cu(II)and non transition metal ion Cd(II)) with L-valine (Val H ) as a primary Ligand and 1,10-phenanthroline(phen) as a secondary Ligands have been prepared. All the prepared complexes have been characterized bymolar conductance, magnetic susceptibility infrared ,electronic spectral and AAA . The complexes with theformulas [M(Val)2(phen)] , M= Mn (II) , Fe (II) , Co(II) , Ni(II), Cu (II) ,and Cd(II) , L- Val H=(C5H11NO2) ,(C12H8N2) =(phen)Key words: Amino Acid,( L-valine), 1,10-Phenanthroline, mixed ligand complexes, Antibacterial activities,spectral studie

Adaptive hybrid technique for face recognition

One of the most important biometric features for personal identification is the face. In current paper, a new method of face verification upon on singular value decomposition (SVD) and standard deviation (SD) would be described. Due to many variations in real-life such as pose, illumination, or facial expression, there would be difficulty of face recognition. It should be mentioned that there are many approaches for face recognition, however, there is no one could be considered as the most suitable for many situations. One of the methods used is Singular value vector for an image detecting, but the drawback of this approach is the low rate of recognition, where one scale singular value vector is used for face acknowledgment. There an algorithm has been developed to expand the rate of the recognition. In this paper, an approach has been proposed to associate two feature sets obtained from SVD and SD method. It has noticed a good recognition rate could be obtained from the experimental results, where approximately more that 97.5% recognition rate has obtained on the ORL data base. The results from current proposed method have matched with some techniques and it has shown that this method is better than the existing approaches. An extensive experiment has demonstrated not only better performance, but it offers a great likely to achieve equivalent performance to other categories of state-of-the-art methods

Free Convection of Ag/H2O Nanofluid in Square Cavity with Different Position and Orientation of Egg Shaped Cylinder

A numerical simulation was conducted to study the free convection of Ag/H2O nanofluid between a square cavity with cold walls and an egg shaped cylinder with a hot wall. Utilizing the egg equation, dimensionless governing equations were solved using the Galerkin Finite Element Method (GFEM). In this work, several parameters were studied, i.e. Rayleigh number (103 ≤ Ra ≤ 106), volume fraction (0 ≤ φ ≤ 0.05), position (-0.2 ≤ Y ≤ 0.2), and orientation angle (-90° ≤ γ ≤ 90°). The numerical results are presented as streamline contours, isotherm contours, and local and average Nusselt numbers. Moreover, the results were used to analyze the fluids’ structure, temperature distribution, and heat transfer rate. The numerical results confirmed that the stream intensity value increased with an increase of the Rayleigh number as well as the movement of the cylinder towards the bottom wall for all values of the orientation angle. Variation of the vertical position of the cylinder inside the cavity had a noticeable effect on , which increased by 50% at γ = -90°, and by 58% at γ = -45°. However, at Y = -0.2,  increased by 58% at γ = -45° and decreased by 7% at γ = -90°. The highest heat transfer rate was obtained at high Rayleigh number (Ra = 106), volume fraction (φ = 0.05), negative position (Y = -0.2), and the highest positive orientation angle (γ = 90°)

Natural convection investigation under influence of internal bodies within a nanofluid-filled square cavity

The current article presents a numerical simulation of the nanofluid convection inside a square enclosure with two inner adiabatic circular bodies. Galerkin finite-element analysis was utilized to solve the governing equations under the assumptions of laminar, steady flow conditions considering a homogeneous single-phase approach. The parameters under investigation are Rayleigh number (Ra), solid volume fraction, the horizontal position of the two inner cylinders, and the inclination angle of the enclosure. The results indicate that increasing the Rayleigh number, and the solid volume fraction improves the heat transport rate. It is obtained that at low Ra, there is no significant impact on the enclosure angle, while as the Ra goes up, the heat transfer rate increases gradually. In addition, the best location of the internal bodies is in the middle of the cavity as it exhibits an increase in the flow velocity. To obtain the highest Nusselt number, it is recommended to use an inclination angle of 30 at any value of the Rayleigh number

Enteral Nutrition Prescription in Children and Adults with Inflammatory Bowel Diseases: Gaps in Current Gastroenterology Practice in Saudi Arabia

Background: Evidence for the effectiveness of enteral nutrition (EN) for the management of patients with inflammatory bowel disease (IBD) is well-established. However, there is considerable global variation in EN practices. This study aimed to characterize the practices and perceptions of gastroenterologists regarding the use of EN in patients with IBD in one of the largest countries in the Gulf region. Methods: A cross-sectional study was conducted on pediatric and adult gastroenterologists working in Saudi Arabia who are involved in IBD management. A self-administered web-based survey was distributed via social media platforms and mailing lists of national gastroenterology societies. Results: A total of 80 gastroenterologists completed the survey. However, only 55 reported that they were currently practicing EN in any form. EN was mostly indicated by gastroenterologists who “sometimes” recommend EN for: the prevention and correction of undernutrition (50.9%), preoperative optimization (50.9%), and the induction of remission in patients with active and long-standing CD (36.4%), at initial diagnosis (34.5%), during the management of complications (61.8%), and after failing to respond to pharmacological therapy (58.2%). Exclusive enteral nutrition (EEN) is regularly recommended by 14.5% of gastroenterologists. The prescription of EEN was significantly associated with the pediatric profession (p p p p < 0.01). The most reported barriers to using EN were patients’ lack of acceptance (73.8%) and poor adherence (65%). A lack of dietitian support and a lack of standardized protocols were also reported as barriers by many physicians. Pediatric gastroenterologists were more likely to use at least one assessment method to evaluate EN success. Conclusion: EN practices differ between gastroenterologists working in Saudi Arabia. Future EN protocols should be optimized to support both children and adults with IBD. Gastroenterology training programs should offer nutrition support-focused training to help physicians better utilize EN

Anomaly Detection Using Explainable Random Forest for the Prediction of Undesirable Events in Oil Wells

The worldwide demand for oil has been rising rapidly for many decades, being the first indicator of economic development. Oil is extracted from underneath reservoirs found below land or ocean using oil wells. An offshore oil well is an oil well type where a wellbore is drilled underneath the ocean bed to obtain oil to the surface that demands more stability than other oil wells. The sensors of oil wells generate massive amounts of multivariate time-series data for surveillance engineers to analyze manually and have continuous insight into drilling operations. The manual analysis of data is challenging and time-consuming. Additionally, it can lead to several faulty events that could increase costs and production losses since the engineers tend to focus on the analysis rather than detecting the faulty events. Recently, machine learning (ML) techniques have significantly solved enormous real-time data anomaly problems by decreasing the data engineers’ interaction processes. Accordingly, this study aimed to utilize ML techniques to reduce the time spent manually to establish rules that detect abnormalities in oil wells, leading to rapid and more precise detection. Four ML algorithms were utilized, including random forest (RF), logistic regression (LR), k-nearest neighbor (K-NN), and decision tree (DT). The dataset used in this study suffers from the class imbalance issue; therefore, experiments were conducted using the original and sampled datasets. The empirical results demonstrated promising outcomes, where RF achieved the highest accuracy, recall, precision, F1-score, and AUC of 99.60%, 99.64%, 99.91%, 99.77%, and 1.00, respectively, using the sampled data, and 99.84%, 99.91%, 99.91%, 99.91%, and 1.00, respectively, using the original data. Besides, the study employed Explainable Artificial Intelligence (XAI) to enable surveillance engineers to interpret black box models to understand the causes of abnormalities. The proposed models can be used to successfully identify anomalous events in the oil wells

Prevalence of emergency cases among pilgrims presenting at King Abdulaziz International Airport Health Care Center at Hajj Terminal, Jeddah, Saudi Arabia during Hajj Season, 1440 H – 2019

Introduction: About 2-3 million pilgrims come to Makkah, Saudi Arabia from all countries to perform Hajj. During the Hajj season of 2019 (1440 H), the total number of pilgrims was 2,489,406, of whom 1,855,027 came from foreign countries. This study aims to investigate the prevalence, pattern, and findings of emergency health problems among pilgrims travelling through King Abdul Aziz International Airport Health Care Center (KAIA-HC) at Hajj Terminal in Jeddah during hajj season of 1440-H. Methodology: A cross-sectional study was conducted by reviewing the medical records of pilgrims coming for treatment at KAIA-HC, before and after Hajj between 1 Dhul Qi’dah to 29 Dhul Hijjah 1440 AH (Corresponding to 4 July to 31 August 2019 AD). The collected data included demographics, medical history, diagnoses of the emergency health problems, infections, and their findings. Data were analyzed using Epi Info 7 and SPSS 25. Results: About 296 (3.87%) of 7,643 pilgrims treated at KAIA-HC were emergency cases. Their average age was 43 years (Standard Deviation (SD) ±7.5); 51.3% were females; the highest (45.3%) was between 30 – 59 years age group, both males and females; the highest two nationalities were Indonesian (14.2%) and Egyptian (12.5%). Diagnoses included hypertension 59(19.9%), bronchial asthma 53 (17.9%), and 23 cases (10.5%) were suffering from hypotension. 16 (5.4%) of patients had a myocardial infarction and 10 (3.4%) had cerebrovascular accidents. In 13 cases (4.4%), a chest infection was reported. Diabetes complications (hyperglycemia, hypoglycemia, and diabetic ketoacidosis) were reported in 28 (9.4%) of the cases. There were 28 (9.5%) surgical diagnoses, 13 (4.4%) were cut wounds, 11 (3.7%) were bone fracture and dislocation, and 4 (1.4%) were head trauma. With regard to the findings, 82 (27.7%) were referred to hospitals; 10 (3.3%) cases required Cardio-Pulmonary Resuscitation, seven of whom survived. The most common referral causes were myocardial Infarction amounting 12(4.05%), followed by cerebrovascular accident 10(3.3%) and chest infection in 8 (2.7%). 13 (4.4%) of the total cases died. The most common causes of death were myocardial infarction, asthma, hypertension and hyperglycemia. Conclusion: Our study emphasizes that emergency cases presented at KAIA-HC were few. Cardiovascular diseases represented the main reason for emergency cases, followed by respiratory diseases. 51% of patients were discharged without the need for a higher level of medical care