52 research outputs found
Studies on Stable Crack Growth
The goal of this work is to experimentally investigate the stable crack growth (SCG) fracture behavior of AISI 4340 alloy steel. A series of mode I and mixed mode SCG fracture tests were carried out on 8 mm thick compact tension (CT) specimens subjected to quasistatic loading. The wire cutting technique was used to introduce a pre-notch/ pre-crack of 0.05 mm root radius to the specimen. Five different loading angles Ψ between the loading axis and the crack surface were employed; 90° (mode I), 75°, 65°, 60° and 50°. Five different ratios of original crack length to specimen width ao/w were also employed, 0.41, 0.42, 0.43, 0.44 and 0.45. Different combinations of Ψ and ao/w were used. Data concerned with direction of initial crack extension load-load line displacement (L-LLD) diagrams, initiation and maximum loads, range of stable crack growth, crack blunting, crack front geometry, fracture surfaces, and scanning electron microscope fracto graphs were obtained. A noticeable blunting was observed prior the crack initiation. Although the crack commences its growth from a pre-notch / pre-crack of a straight front it has a considerable tunneling at each stage of stable crack growth. In mixed mode, the crack takes place along a straight-line path initially, inclined with the main crack at an angle equal to the direction of crack extension. The loading angle Ψ and the initial crack length to the specimen width ao/w ratio affect the SCG fracture behavior significantly. The direction of initial stable crack extension was determined through an elastic finite element analysis. There was reasonably good agreement between the experimental and the predicted results
Behavior Analysis and Modeling of Stakeholders in Integrated Water Resource Management with a Focus on Irrigated Agriculture
The scarcity of freshwater resources in the Sultanate of Oman, makes it essential that both surface and groundwater resources are carefully managed. Introducing new water demand management tools is important, especially for the coastal agricultural areas (e. g. Al Batinah coastal region) which are affected by sea water intrusion. Based on a social survey performed during this work, the existing situation generates conflicts between different stakeholders (SHs) which have different interests regarding water availability, sustainable aquifer management, and profitable agricultural production. The current aim is to evaluate the implementation potential of several management interventions and their combinations by analysing opinions and responses of the relevant stakeholders in the region. Influencing the behavior and drivers affecting farmers’ decision-making manner, can be a valuable tool to improve water demand management. The work also introduces the use of a participatory process within the frame of an integrated water resources management (IWRM) to support decision makers in taking better informed decisions. Data were collected by questionnaires from different groups of stakeholders. These data were analysed statistically for each group separately as well as relations amongst groups by using the SPSS (Statistical Package for Social Science) software package. Differences were examined between opinions of farmers and decision makers (DM’s) regarding potential interventions. Farmers’ frequency curves showed differences in opinions in some interventions, while differences in opinions were not so high within the group of DM’s. Therefore, Cross Tabulation and Discriminant Analysis (DA) were performed to identify the drivers influencing farmers’ opinions regarding the intervention measures. As an advanced step, a Bayesian Networks (BNs) approach is used for mapping stakeholders’ behaviors and to show the strength of a relationship between dependent and predictor variables. By using BNs it is possible to analyse future scenarios for implementation and acceptance of interventions
Efficiency of the Applied Theory in the Achievement of the Second Intermediate School Students in the Geography Class
يهدف البحث الحالي الى معرفة: فاعلية النظرية التطبيقية في تحصيل طلاب الصف الثاني المتوسط في مادة الجغرافية.
اجراءات البحث:اعتمد الباحث تصميما تجريبيا ذا الضبط الجزئي بين المجموعتين التجريبية والضابطة. وبلغ المجموع الكلي للمجموعتين (42) طالب،وأعد الباحث أهدافاً سلوكية بلغ عددها (100) هدف سلوكي موزعة على المستويات الأربعة من تصنيف بلوم للأهداف السلوكية وهي: (التذكر،الفهم، التطبيق، التحليل)، وأعد الخطة الدراسية لتدريس المجموعتين،استعمل الباحث أداة قياس واحدة وهي:(الاختبار التحصيلي)مكون من (50) فقرة لكلا المجموعتين لقياس التغير الحاصل في مستوى تحصيل الطلاب في مادة الجغرافية واستخرج له الصدق والثبات،وطبق الباحث الاختبار التحصيلي النهائي على طلاب مجموعتي البحث (التجريبية والضابطة) عقب انتهائه من تدريس الموضوعات المحددة في البحث الحالي، وذلك يوم 5/5/2019. واستخدم الباحث الوسائل الإحصائية الآتية:اختبار (t-test) لعينتين مستقلتين ومربع كاي ومعادلة قوة تمييز الفقرة.
تفسير النتائج: ظهر تفوق المجموعة التجريبية التي درست على وفق النظرية التطبيقية على المجموعة الضابطة التي درست المادة مدونها، وذلك بفارق نتائج الاختبار.
- في ضوء النتائج التي أسفر عنها البحث الحالي استنتج الباحث:
- التدريس وفق النظرية التطبيقية ساعد في رفع التحصيل العلمي للطلاب بالتعاون فيما بينهم وتحديد معوقات الدراسة والعمل على حلها.
- في ضوء نتائج هذا البحث أوصي الباحث:
- اعتماد التدريس وفق النظرية التطبيقية في التدريس في المرحلة المتوسطة.
- استكمالا لجوانب هذا البحث أقترح الباحث:
- إجراء دراسة مماثلة للدراسة الحالية في المواد الاجتماعية الأخرى (التاريخ، والتربية الوطنية).- The current research aims to know: the effect of applied theory in the achievement of intermediate school students in the second subject in geography.
- Research Procedures: The researcher adopted an experimental design with partial control between the experimental and control groups. The total of the two groups reached (42) students، and the researcher prepared behavioral goals amounting to (100) behavioral goals distributed at the four levels of Bloom's classification of behavioral goals، namely (remembering، understanding، applying، and analyzing)، and preparing the study plan to teach the two groups،The researcher used one measurement tool which is (the achievement test) consisting of (50) items for both groups to measure the change in the level of students ’achievement in the geography subject and extracted for him honesty and consistency. The researcher applied the final achievement test to the students of the two research groups (experimental and control) after completing his teaching the topics specified in the current research، on: 5/5/2019. The researcher used the following statistical methods: - (t-test) for two independent samples، and Chi-square، and the paragraph strength differentiation equation.
- Interpretation of the results: - The superiority of the experimental group that was studied according to the applied theory was superior to that of the control group without which the subject was studied، through the difference of the test results.
In light of the results of the current research، the researcher concluded:
Teaching according to the applied theory helpedin raising the educational attainment of students through cooperation among them، identifying obstacles to study and working to solve them.
In light of the results of this research، the researcher recommends:
Approval of teaching according to the applied theory of teaching in the intermediate stage.
To complement the aspects of this research، the researcher suggested:
Carrying out a similar study to the current study in other social subjects (history and national education).
 
EFFECT OF MOST COMMON ANTIBIOTICS AGAINST BACTERIA ISOLATED FROM SURGICAL WOUNDS IN ADEN GOVERNORATE HOSPITALS, YEMEN
Objective: The increased antibiotics resistance of pathogenic bacteria isolated from surgical wound is the major health threats challenge the patients especially in developing countries like Yemen. This work was aimed to determine and identify the bacteria associated with surgical wound infections and their resistance to commonly used antibiotics. Methods: One hundred and twenty swabs were sampled from surgical wound patients at Aden City, Yemen. The pathogenic bacteria were isolated and identified according to standard microbiological methods. Also, antibiotic susceptibility tests were determining by using Kirby-Bauer disc diffusion technique. Results: The results showed that out of 120 samples, 68 (56.67%) showed bacterial growth. It was found that the most isolated bacteria was Sylococcus aureus 27 (39.70%) followed by Escherichia coli 19(27.94%), Pseudomonas aeruginosa 13 (19.12%), and Proteus mirabilis 9 (13.24%). All isolated bacteria were recorded to be extremely resistant to the most tested antibiotics. S. aureus was reported to be susceptible to cefotaxime, vancomycin, and ciprofloxacin and highly resistant to ceftazidime, nalidixic acid, erythromycin, and tetracycline. The E. coli isolates showed resistance (100%) to vancomycin and tetracycline and moderately sensitive to ceftazidime and gentamycin. P. aeruginosa showed from high to moderate resistance to most tested antibiotics except gentamycin and cefotaxime. Most of P. mirabilis isolates were sensitive to ceftazidime, cefotaxime, ciprofloxacin, and gentamycin and highly resistant to amoxicillin, erythromycin, and vancomycin. Conclusion: The current study findings that the reduced sensitivity of isolated bacteria to commonly used antibiotics is an alarming and threat upsurge of infections caused by antibiotic-resistant bacteria.
Peer Review History:
Received 27 January 2020; Revised 15 February; Accepted 1 March, Available online 15 March 2020
Academic Editor: Dr. Amany Mohamed Alboghdadly, Princess Nourah bint abdulrahman university, Riyadh, [email protected]
UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.
Received file: Reviewer's Comments:
Average Peer review marks at initial stage: 6.0/10
Average Peer review marks at publication stage: 7.5/10
Reviewer(s) detail:
Dr. Mujde Eryilmaz, Ankara University,Turkey, [email protected]
Rola Jadallah, Arab American University, Palestine, [email protected]
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THE EFFECTS OF WORK STRESS ON JOB SATISFACTION OF HEALTHCARE WORKERS IN A PUBLIC SECTOR HOSPITAL IN ALDAKHLIYA, OMAN
The role of healthcare workers is central to the modern healthcare system and was further highlighted during the COVID-19 pandemic situation. However, the healthcare workers did face a lot of work pressure during the pandemic which also had some negative consequences. In the present study, we investigated the effects of work stress and its five dimensions including the availability of resources, work environment, reward and incentive, functional relationship, and fear of catching COVID-19 on employee job satisfaction in the context of the public healthcare system in Oman. The sample is selected from a selected healthcare unit and data is collected using the survey-based method. The findings show that there are significant effects of two dimensions including functional relationships and work environments on healthcare job satisfaction. Based on the findings, it can be concluded that healthcare workers facing a lot of stress and this issue need greater managerial attention.
Keywords: Work Stress, Job Satisfaction, Healthcare Workers, COVID-19 Pandemic
Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study
Background
Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave.
Methods
This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs.
Results
Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates.
Conclusions
Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility.
Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Image-based object detection and identification
Object detection is a process of identifying and locating objects in image scene. It is a process of combining digital image processing and computer vision. There are two main approaches for object detection, namely contour-based and region-based detection for both approaches. Segmentation plays an important role in object-detection. Detection and extraction of the spatial and spectral responses of different targets of interest could only be carried out with different approaches. In this study, object-based detection is carried out to identify and recognize typical military targets (Plane1, Plane2, Tank) located on natural background using spectral and spatial approaches. This is useful in military intelligence or strategic planning where it assists in identifying the aforementioned targets. In the spectral-based object detection, the spectroradiometer readings of the targets are individually observed on different backgrounds (white platform used as calibration plane, sand and camouflage). These spectroradiometer observations are reduced and examined for forming the unique spectral signatures of the targets. Spatial-characteristics of the targets are also examined using object-based detection where multi-resolution segmentation were employed for this purpose. Results of the study obtained that all the three targets can be extracted with more than 20% differentiation, while the spectral characteristics of the targets are also good indications for object detection with overall accuracy of RMSE = ± 0.6
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Collaborative cyber security situational awareness
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonSituational awareness is often understood as the perception of environmental elements and comprehension of their meaning, and the projection of future status. The advancements in cyberspace technology have fuelled new business and opportunities, but also brought an element of risk to valued assets. Today, the growing gap between different types of cyber-attacks threatens governments and organisations, from individuals to highly organized sponsored teams capable of breaching the most sophisticated systems and the inability to cope with these emerging threats. There is a strong case to be made for effective Collaborative Cyber-Security Situational Awareness (CCSA) that is designed to protect valuable assets, making them more resilient to cybersecurity threats. Cybersecurity experts today must rethink the nature of security, and shift from a conventional approach that stresses protecting vulnerable assets to a larger, more effective framework with the aim of strengthening cyber assets, making them more resilient and part of a cybersecurity process that delivers greater value against cyber threats. This study introduces a new approach to understanding situational awareness of information sharing and collaboration using knowledge from existing situational awareness models. However, current situational awareness models lack resilience in supporting information systems infrastructure, addressing various vulnerabilities, identifying high priority threats and selecting mitigation techniques for cyber threats. The use of exploratory and explanatory analysis techniques executed by Structure Equation Modelling (SEM) allowed the examination of CCSA, in this study. Data from 377 cyber security practitioners affiliated to cybersecurity expert groups including computer emergency response team (CERT) and computer security incident response team (CSIRT) was gathered in the form of an electronic survey and analysed to discover insights and understand the mental model of those cybersecurity experts. Also, a finding from the SEM was the CSSA model aligned perfectly with the second-order Cybernetics model to test the theory in practice, confirming the possibility of using the proposed model in a practical application for this research. Furthermore, the SEM informed the design of the CCSA Environment where an empirical study was employed to verify and validate the CCSA theory in practice. In addition, the SEM informed the design of a behavioural anchor rating scale to measure participant situational awareness performance.
The experiment results proved that when using the CCSA model and replicating real-world cyber-attack scenarios that the outcome of situational awareness performance was 61% more than those who did not employ the use of the CCSA model and associated dashboard tool. Further, it was found that both timeliness and accuracy are important in influencing the outcome of information sharing and collaboration in enhancing cyber situational awareness and decision-making. This thesis for the first time presents a novel CCSA theory which has been confirmed in practice. Firstly, this research work improves the outcome of effectiveness in cyber SA by identifying important variables related with the CCSA model. Second, it provides a new technique to measure operators’ cyber SA performance. Secondly, it provides the necessary steps to employ information sharing in order to improve cyber security incorporated in the CCSA model. Finally, cybersecurity experts should collaborate to identify and close the gap between cybersecurity threats and execution capacity. The novel CCSA model validated in this research can be considered an effective solution in fighting and preventing cyber-attacks. Attainment of cyber security is driven by how information is both secured and presented between members to encourage the use of information sharing and collaboration to resolve cyber security threats in a timely and accurate manner. This research helps researchers and practitioners alike gain an understanding of key aspects of information sharing and collaboration in CSSA which is informed by the CCSA theory and new capability that the implementation of this theory has shown to deliver in practice.Abu Dhabi Police General Head Quarter
Factors Influencing Users’ Intention To Adopt Artificial Intelligence Cybersecurity Systems At Government And Semi-government Organizations In The United Arab Emirates
The revolutionising impacts of artificial intelligence (AI) on other fields have led to the realisation that the technology can improve cybersecurity and mitigate cybercrimes in both private and government organisations. However, this realisation has not contributed to the rapid adoption of cybersecurity systems in the UAE, despite the country being ranked as one of the nations that are quick to embrace emerging technologies. Against this background, this study investigated the factors that influence users' intention to adopt (ITA) AI cybersecurity systems at workplaces in the UAE. It drew upon a theoretical framework derived from the Protection Motivation Theory (PMT) and the Unified Theory of Acceptance and Use of Technology (UTAUT). This framework was extended by introducing new relationships and variables (AI knowledge, resistance to change, and job insecurity) to enhance its predictive power. A quantitative research approach and a correlational research design was adopted, whereby 340 questionnaires were administered to respondents chosen using the purposive sampling technique. These respondents comprised persons working in the IT department and/ or responsible for the cybersecurity of government and semi-government organisations in the UAE
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