Integration of renewable energy sources in the distribution network

Tato práce uvádí obecné informace o obnovitelných zdrojích energie, typech elektráren a jejich pracovních principech. Práce je zaměřena na větrné elektrárny (principy, typy, komponenty, výhody a nevýhody). Obsahuje také pravidla pro připojování rozptýlených zdrojů energie k distribuční soustavě. V praktické části je řešena případová studie, která demonstruje napěťové charakteristiky pro síť vysokého napětí před a po připojení větrné elektrárny do distribuční sítě se dvěma různými hodnotami účiníku.This thesis will provide general information about renewable energy sources, types of power plants and their working principles. The thesis is focused on wind power plants (principles, types, components, advantages and disadvantages). It also includes the rules for connecting dispersed energy sources to the distribution system. In practical part, a case study demonstrates voltage characteristics before and after connection of a wind power plant to a distribution network with two different values of power factor

A mixed-methods study of examining the concerns of Saudi Arabian middle and secondary school teachers in adopting the Future Gate Learning Management System: a transformation to digital learning

Doctor of PhilosophyCurriculum and Instruction ProgramsKay Ann TaylorThe purpose of this mixed-method study was to examine the concerns of teachers in middle and secondary schools as they began to implement the Future Gate LMS in Saudi Arabia. A sample of 1045 teachers participated in this study, who represent teachers from schools selected by the Ministry of Education to implement the transformation to digital learning through the Future Gate LMS project. The study examined teachers’ concerns through the lens of the Concern Based Adoption Model (CBAM) framework. The data in this sequential mixed-method study were obtained through two phases. The first phase was quantitative data through the Stage of Concern Questionnaire (SoCQ) and the second phase was qualitative data through an open-ended question on the SoCQ as well as semi-structured interviews. The results from the SoCQ indicated that teachers in the middle and secondary schools who were selected to implement the Future Gate LMS were in the early concern stages. The highest percentile score was Stage 0 Unconcern 87% followed by Stage 1 Personal 84%, Stage 2 Informational 83%, and Stage 3 Management 73%. The lowest percentile score was in Stage 4 Consequences 54% followed by Stage 5 Collaboration 59% and Stage 6 Refocusing 69%. A one-way MANOVA test revealed a statistically significant difference between teachers’ stages of concerns and their gender and type of degree. It also revealed statistically significant differences between teachers’ stages of concerns and their technographic characteristics (prior experience in educational technology use, type of professional development in educational technology, duration of professional development in educational technology, type of professional development in Future Gate LMS, and duration of professional development in Future Gate LMS). One-way MANOVA also revealed statistically significant differences between teachers’ stages of concerns and technology availability in the classroom (technology in the classroom and Internet access in the classroom). The qualitative data analysis indicated that the top three concerns of teachers were centered around technology and Internet in the school, Future Gate LMS activation, and how students deal with Future Gate LMS. This study contributes to the literature to understand teachers’ needs for successfully implementing innovations. Results obtained from this study are important for all stakeholders so that they can understand teachers’ concerns regarding adopting the transformation to digital learning in Saudi Arabia as it is an important project for the Saudi Arabia 2030 vision

Assessment of Knowledge Regarding Osteoporosis Among Female Medical Students at King Faisal University, Saudi Arabia

Introduction: Osteoporosis is a worldwide public health problem that affects both male and females. It is a silent progressive disorder that affects the skeletal system and leads to diminished bone density and fracture. Therefore, awareness, attitude, and practices of people about osteoporosis contribute significantly to primary prevention and early detection of disease. Objective: the present study conducted to assess the knowledge of the female medical students at King Faisal University about osteoporosis in Saudi Arabia. Study design: A cross-sectional study conducted at the medical college of King Faisal University at Al-Ahsa region, Saudi Arabia. The study included all female medical students at King Faisal University, through an online self-administered questionnaire using the Osteoporosis Knowledge Assessment Tool (OKAT) questionnaire. Results: The total number of participants was 176 female medical students, with 58.7% response rate. The age of participants ranged between 17 and 27 years, with a mean and standard deviation of 21.46±1.54 years. The participant's knowledge score about osteoporosis was as follow: 65.1% had satisfactory knowledge, 32.2% had poor knowledge, and only 2.3% of the participant had good knowledge. Conclusion: Most of the participants had a satisfactory knowledge score on osteoporosis. However, there was a significant gap in knowledge regarding the risk factors such as high salt intake. The good knowledge score was significantly low in the present study compared to worldwide. Therefore, an educational effort is needed to improve knowledge and the quality and reliability of information about osteoporosis targeted undergraduates and young females in Saudi Arabia

Calibrating and modelling of statistical delay for signalized intersections at al-Nasiriyah City in Iraq

In this paper develops an empirical delay model for delay prediction by taking lane group parameters to make delay model in the field where delay have considered very important measure that effects at signalized intersection because of relation of delay with performance of signalized intersection, lost travel time, fuel consumption, feasible of movement, discomfortable of drivers also, it is considered the primary measure to determine the level of service at signalized intersection. The main aim of this study is to make a field delay model at signalized intersection by using microsimulation software to calibrate data and using statistical software (SPSS) to create model. The methodology of the study is made by using video recording and manual collected data by taken three biggest signalized intersections where the collection data was very challenged specifically speed forward and uncontrollable drivers and others factors. Sidra Intersection 6.0 is described as an advanced micro-analytical model with a lane-by-lane method and a vehicle drive-cycle model that is used to estimate capacity and performance measures through an iterative method. Calibration of the software is very necessary to find accurate model that can be described the field delay. Multiple Linear Regression analysis (MuLRa) has been generally statistical method to create a model. It has been taken into consideration in the modelling of delay at signalized intersection and adjusted R² is 80% with multi factors that effect on field delay. Vehicle speed has been improved very significance level and impact factor on delay at signalized intersection by lane group experimental method and this finding very important for all simulation software should be taken that in the accounts

Knowledge, Attitudes, and Practices Regarding Diabetic Retinopathy Among Primary Health Care Physicians in Al-Hasa, Saudi Arabia

Background: Diabetic retinopathy (DR) has been shown to be the third most observed cause of visual loss in Saudi Arabia. In the Al-Hasa region in particular, the prevalence of DR has been shown to be 30%. Primary health centre (PHC) physicians play a central role in the early detection and prevention of DR. The aim of this study was to evaluate the knowledge, attitudes, and practices regarding DR of PHC physicians in Al-Hasa, Saudi Arabia.Methods: A cross-sectional descriptive study was conducted at PHCs in Al-Hasa, Saudi Arabia. A self-administered questionnaire was provided to every participant along with a consent form. Out of 71 centres in the region, 63 were included in this study. The questionnaire consisted of three sections and a total of 18 questions. Statistical analysis was carried out using the Statistical Package for the Social Sciences version 21 software program (IBM Corp., Armonk, NY, USA).Results: One hundred forty-one of 209 physicians completed the questionnaire for a response rate of 67%. The mean of overall knowledge score for all participants was 2.6 ± 1.16 points out of four points. Only 34 (24.1%) of the participants correctly referred their diabetic patients according to the guidelines of the American Academy of Ophthalmology. Additionally, only 52 (36.9%) physicians educated their patients regarding the early detection of diabetic complications.Conclusion:  The present study concluded that there exist gaps in applying the correct guidelines. Physicians' attitudes toward patient education were overall satisfactory. Further medical symposiums and workshops are warranted to teach physicians about diabetic complications and screening schedules, including DR

Graded cellular structures for enhanced performance of additively manufactured orthopaedic implants

Hip implants face a significant challenge due to their limited lifespan, a concern amplified by the rising human life expectancy. Lattice structures have demonstrated the ability to provide precise control over geometry, thereby significantly enhancing implant performance. This paper introduces the development of graded additively manufactured Ti6Al4V lattice structures for orthopaedic implants. The objective focuses on developing a graded lattice unit cell design mirroring human bone properties, emphasising high surface curvature and design versatility to improve mechanical and biomedical properties, specifically osseointegration and stress shielding. The study involves modelling and grading simple cubic (SC) and body-centred cubic (BCC) lattice structures with various geometries and graded conditions and conducting compressive tests to identify the optimal configuration. The results showed that filleting was found to be the mechanical strength. On the other hand, BCC lattice structures demonstrated superior performance compared to SC structures. The optimised structure with a pore size of 400 µm provided an elastic modulus of 15.7 GPa, yield strength of 296 MPa and compressive strength of 530 MPa. This graded lattice design approach provides a promising technique for enhancing hip implant performance, offering potential improvements

Development of roundabout delay models using traffic simulation programs: a case study at Al-Mansour City, Iraq

Due to the increased number of vehicles, shopping centers and rapid growth population of Al-Mansour city, daily trips have been increasing besides generating traffic congestion in major roundabouts in the city. Those will make developing an imperial delay model in roundabouts important due to the traffic and geometric influences. Therefore, two major roundabouts have been selected in the city to be taken as a case study. Geometric features for the selected roundabouts have been measured accurately by satellite images via ArcGIS. Traffic and geometric data analysis indicate that both are significantly important on delay models. The delay time produced by SIDRA and SYNCHRO has been compared with the delay time measured from the field. A significant difference in delay for roundabouts is noticed. This difference could be attributed to the difference in driver behaviour. Ideal saturation flow is the main factor related to driver behaviour, so it adjusted to be the average of the saturation flow measured from the field (2200 vphgpl)

Impact of tobacco smoking on oral microbiota – a case-control study.

Oral microbiota is a vital part of human microbiota, including bacterial, protozoa, viral and fungal species. Beneficial microbes form biofilms to form a first-line defense against harmful microorganisms. Tobacco smoking is considered a major environmental factor affecting the orodental microbiota. Smokers harbor more pathogenic microbes than non-smokers. In fact, cigarette smoking exposes the oral cavity to a large number of toxicants, perturbing the oral microbial ecology through various mechanisms. In Saudi Arabia, research on the impact of tobacco smoking on oral microbiota is still lacking. Therefore, this case-control study is an important addition to the literature in terms of tobacco use and its effects on oral microbiota and oral hygiene. 130 men were recruited for this study, including 65 smokers and 65 non-smokers. The following parameters were recorded for all 130 participants – age, weight, height and education. The aim of this study was to investigate and compare the effect of tobacco smoking on the oral microbiome of smokers and non-smokers. The majority of the smokers were young adults between the ages of 21 and 30 inclusive (n=27). The results show that excessive microorganism growth was seen in smokers to a greater degree than non-smokers (38.5% of smokers vs. 8.8% of non-smokers). Not surprisingly, a significant majority (85.3%) of non-smokers had moderate microorganism growth compared to only 53.8% of smokers. cigarette smoking facilitates excessive growth of oral microorganisms, predisposing smokers to various periodontal diseases. In fact, smoking perturbs the balance of oral microbiota, producing a viable environment for microbes to cause diseases. Further large scale prospective studies are required to determine the exact mechanism that causes tobacco to affect oral microbiota

A community-based prediabetes knowledge assessment among Saudi adults in Al-Ahsa region, 2018

Background: Prediabetes has been considered to be a reversible condition; a modification of lifestyle and other intervention can be successfully applied during the prediabetes period to prevent the development of type 2 diabetes. The purpose of the present study was to assess knowledge of prediabetes and its risk factors for the community in the Al-Ahsa region.Design and method: A cross-sectional community-based study was conducted in the Al-Ahsa region from mid-to-late December 2018. A sample size of 812 was determined using a single-proportion formula.Results: Of the 812 respondents who gave consent to participate in the interview; the male to female ratio was 1.1:1. 13.2% of the respondents reported that they had diabetes. Among the respondents, 87.1% had a high level of knowledge of prediabetes, while 12.9% had low-to-moderate knowledge. 84% of males 40 years of age or older, 88.7% (384) of people with university or higher education, and 95.1% (78) of people who worked as health practitioners had high knowledge of prediabetes.Overall, there was a statistically significant association between age and prediabetes knowledge (2 =5.006, p=0.025). Occupation also showed a significant statistical association with prediabetes knowledge (2 =9.85, p=0.02). Conclusion: Knowledge is considered an important factor in the prevention of prediabetes and diabetes. People in Al-Ahsa demonstrated a high level of knowledge regarding some risk factors for prediabetes. However, there were a number of deficiencies in the knowledge of prediabetes risk factors and preventive measures as well as in general knowledge of prediabetes, which may lead to a high prevalence of prediabetes and diabetes