Investigation of fatigue life characteristics of micropatterned freestanding NiTi thin films

NiTi shape memory alloys present themselves as high potential candidate in several applications. This fact arises from their superior attributes such as large stress output, recoverable strain and outstanding biocompatibility. Fatigue life prediction of bulk shape memory alloys have been extensively investigated in the literature. Yet so far, information about the fatigue life prediction on NiTi thin films is rarely discussed or missing which might limit the window of future applications. In this thesis, NiTi freestanding films with nearly equiatomic composition were fabricated by means of magnetron sputtering, UV lithography, and wet etching. The films were subsequently annealed in vacuum. The fatigue properties of the films were characterized by a self-developed fatigue testing device under tension-tension loading mode. Fatigue life diagrams were conducted and investigated at various testing variables such as different cyclic frequencies and different mean strains. In addition, the influences of the chemical composition, the film thickness, and the annealing conditions on the fatigue characteristics were investigated. The fatigue endurance limit (FEL) in this work was taken at 10 million cycles. A significantly improved FEL of more than 350 % was attained by using different surface finishing. The FEL in this work is the highest among all published literature data on NiTi films. Moreover, the biocompatibilities of NiTi films were examined by investigating the cell growth on films’ surface after different surface finishing. The result showed insignificant dependence of cell growth and adhesion on the film surface. The freestanding films showed a great biocompatibility levels. In addition, the measurements of the Ni ion release on NiTi films modified with the different surface finishing were performed in a balanced salt solution used to mimic human body fluids. The results show that the Ni concentration in the tested solution is below the maximum limit of the international biocombatibitly standards and that the Ni ion release can be modified through different surface finishings. Finally, the factors governing the fatigue characteristics and the biocompatibility aspects of NiTi films were identified and optimized to enhance the overall performance of the NiTi films and increase the design and the integration possibilities in different applications

Survival Rate of Patients with Cardiothoracic Injuries in Road Traffic Accidents, and their Relationship with ISS, GCS and blood transfusions.

Severe thoracic trauma is one of the major causes of injury-related mortality. In the United States, thoracic trauma results in one-fourth of all trauma deaths. Globally, cardiothoracic trauma is also a major contributor to mortality. The most common cardiothoracic injuries include rib fractures, thoracic vertebral fractures, haemothorax, pneumothorax, flail chest, and lung contusions. The purpose of the present study was to determine the survival rate of patients with cardiovascular injuries in road traffic accidents and its relationship with ISS, GCS and blood transfusions at King Khalid Hospital. This study is a useful addition to the literature, as research in this topic is lacking. A total of 189 patients were transported to the hospital with cardiothoracic injuries during the study period. Data was gathered regarding age, gender, nationality, vehicle user type, anatomical region injured, Intensive Care Unit (ICU) admission, Glasgow Coma Scale (GCS), Injury Severity Score (ISS), blood transfusion, treatment and mortality rate. The neurological status was assessed using the GCS score. Injury Severity Scores were calculated to categorize the injury severity. The mean patient age was 31.81 years, with a peak age of between 21–30 years. Males predominated (93.7%) with a male to female ratio of 15:1. Most of the patients were Saudi nationals (61.3%). Overall mortality was 7.9%. Factors that were significantly associated with mortality were head and neck involvement, ICU admission, age (above 60), treatment delivered, and blood transfusions. Cardiothoracic trauma is associated with a high mortality rate, which may depend on the clinical presentation such as GCS, ISS, degree of shock, pattern of injuries, and associated injuries. Immediate management is vital for patients with life-threatening cardiothoracic trauma, as mortality is high if the diagnosis is missed, wrong or left untreated

Factors associated with hospital service satisfaction in a sample of Arab subjects with schizophrenia

<p>Abstract</p> <p>Background</p> <p>Assessment of patients' satisfaction with health care services could help to identify the strengths and weaknesses of the system and provide guidance for further development. The study's objectives were to: (i) assess the pattern of satisfaction with hospital care for a sample of people with schizophrenia in Kuwait, using the Verona Service Satisfaction Scale (VSSS-EU); ii) compare the pattern of satisfaction with those of similar studies; and iii) assess the association of VSSS seven domains with a number of variables representing met and unmet needs for care, family caregiver burden, severity of psychopathology, level of psychosocial functioning, socio-demographic characteristics, psychological well-being and objective quality of life.</p> <p>Methods</p> <p>Consecutive outpatients in stable condition and their family caregivers were interviewed with the VSSS-EU and measures of needs for care, caregiver burden, quality of life and psychopathology.</p> <p>Results</p> <p>There were 130 patients (66.1%m, mean age 36.8). While over two-thirds expressed satisfaction with the domains of "overall satisfaction", "professionals' skills", "access", "efficacy", and "relatives' involvement", only about one-third were satisfied with the domains of "information" and "types of intervention". The later two domains were the areas in which European patients had better satisfaction than our patients, while our patients expressed better satisfaction than the Europeans in the domain of "relatives' involvement". In multiple regression analyses, self-esteem, positive and negative affect were the most important correlates of the domains of service satisfaction, while clinical severity, caregiver burden and health unmet needs for care played relatively minor roles.</p> <p>Conclusion</p> <p>The noted differences and similarities with the international data, as well as the predictive power of self-esteem and affective state, support the impression that patients' attitudes towards psychiatric care involve a complex relationship between clinical, personal and socio-cultural characteristics; and that many of the factors that impact on satisfaction with service relate to individual psychological characteristics. The weaknesses in the system, highlighted by the pattern of responses of the participants, indicate possible gaps in the provision of comprehensive psychiatric care in the country and obviate the need for public mental health education and development of services to enhance the quality of care.</p

Toward an organizational learning model for bureaucratic organizations: A strategic management perspective

This dissertation explores the development of organizational learning activities in bureaucratic organizations. Its central question is How do bureaucracies learn? In order to answer this question, three phases seem to be necessary. The first phase provides an extensive review of the organizational learning literature. Eight learning models are examined, articulated, and used to suggest a preliminary model for learning in bureaucracies. The model postulates three interrelated processes that reflect on-going dilemmas for bureaucracies. These dilemmas can be summarized in terms of bureaucracies\u27 ability: to manage their relations with their environments; to establish and maintain their interpretation systems; and to manipulate their internal structures for learning purposes. The combination of these variables allows us to consider and synthesize a wide range of variables that together can explain a great portion of learning in bureaucracies. In the second phase the proposed model is used as a conceptual framework to evaluate learning activities as they actually occur in the United States Postal Service (USPS). Most of the learning activities that the USPS has engaged in since the passage of the Postal Reorganizational Act (PRA) of 1970 are analyzed. The third phase is a synthesis of both the theoretical and empirical findings that is intended to provide an integrated schema of organizational learning in bureaucracies. The study utilizes an exploratory method of a single organization. The chosen methodology provides the researcher with an opportunity to give a first exposition of a wide range of variables that might have positive or negative impacts on the development of learning processes in bureaucracies. Finally, it is suggested that future research focus should be shifted toward the development of an understanding of how bureaucracies can stimulate, rather than impede, learning. Such an understanding should be grounded in specific assumptions about a bureaucracy\u27s meanings, designs, and functions

Group size, composition, cohesiveness and leadership: A Proposed group Performance Model

The main objective of this study is to investigate the potential effect of group size, composition, cohesiveness and leadership style on groups' performance. Hackman and Morris' model (1983) was used as a frame of reference. The proposed variables were embedded into that model to end up with a modified one. The choice of the above mentioned variables was based on a comprehensive literature review. The researcher used "The ABVInformation Data Base" to complete such a review that covers articles from 1978 through 1993. Most of the recent articles related to the subject matter were thoroughly reviewed and integrated to the body of this research. The study contains three parts. The first part was devoted to the examination of the underlying assumptions of (H&M) model. A new variable was introduced to the proposed model. The second part was devoted to study how each of the proposed variables would affect group performance. Finally, the third part was designed to incorporate the proposed variables into the (H&M) model. Four hypotheses were introduced to explain the expected impact of the proposed variables on group performance. Our major assumption here is that the impact on group performance is a product of the interaction of the proposed variables. In other words, although each individual variable is expected to have its own impact on the group performance, all variables are expected to have a unique impact on group performance

Toward an organizational learning model for bureaucratic organizations: A strategic management perspective

This dissertation explores the development of organizational learning activities in bureaucratic organizations. Its central question is How do bureaucracies learn? In order to answer this question, three phases seem to be necessary. The first phase provides an extensive review of the organizational learning literature. Eight learning models are examined, articulated, and used to suggest a preliminary model for learning in bureaucracies. The model postulates three interrelated processes that reflect on-going dilemmas for bureaucracies. These dilemmas can be summarized in terms of bureaucracies\u27 ability: to manage their relations with their environments; to establish and maintain their interpretation systems; and to manipulate their internal structures for learning purposes. The combination of these variables allows us to consider and synthesize a wide range of variables that together can explain a great portion of learning in bureaucracies. In the second phase the proposed model is used as a conceptual framework to evaluate learning activities as they actually occur in the United States Postal Service (USPS). Most of the learning activities that the USPS has engaged in since the passage of the Postal Reorganizational Act (PRA) of 1970 are analyzed. The third phase is a synthesis of both the theoretical and empirical findings that is intended to provide an integrated schema of organizational learning in bureaucracies. The study utilizes an exploratory method of a single organization. The chosen methodology provides the researcher with an opportunity to give a first exposition of a wide range of variables that might have positive or negative impacts on the development of learning processes in bureaucracies. Finally, it is suggested that future research focus should be shifted toward the development of an understanding of how bureaucracies can stimulate, rather than impede, learning. Such an understanding should be grounded in specific assumptions about a bureaucracy\u27s meanings, designs, and functions

Selenium Removal by Constructed Wetlands: Role of Biological Volatilization

Selenium-laden effiuents from oil refineries are polluting San Francisco Bay, California. One environmentally-friendly way of cleaning up selenium (Se) from effiuents is by plant and microbial Se volatilization using constructed wetlands. Using mesocosms, we investigated the role of biological Se volatilization in a 36-hectare constructed wetland located adjacent to San Francisco Bay. The constructed wetland was highly effective in removing Se from selenite-contaminated oil refinery wastewater: 89% of the Se was removed. Inflow Se concentrations of 20-30 ug L-1 decreased to &lt; 5 ug L-l in the outflow. Most of the Se was removed by immobilization into sediments and plant tissues where Se concentrations reached ~5 and ~15 mg kg-1, respectively. Biological volatilization may have accounted for as much as 10 to 30% of the Se removed. The highest mean rates of Se volatilization for vegetated sites were 190, 180 and 150 p.1gSe m-2 day-1 (rabbitfoot grass, cattail and saltmarsh bulrush, respectively). Rates for the most dominant species, saltmarsh bulrush, varied during the year: the mean rates were 150, 70 and 25 ug Se m-2 day-1 in February, June and October, respectively. We conclude that biological Se volatilization is a significant pathway of Se removal in wetlands

The use of multi-detector computed tomography and ultrasonography for evaluation of pleural lesions

Background and objective: Multidetector CT (MDCT) and ultrasonography (US) are of increasing importance for assessment of many pulmonary disorders. Our aim was to evaluate their role in diagnosis of pleural diseases. Methods: Patients from Tanta University Hospital who were suspected to have pleural lesions (symptoms, signs and/or suggestive chest X-ray) during one year period were enrolled in the study. US and MDCT were done for all of them, then data were reported and analyzed. Results: Seventy-one patients were included, sixty of them had evident pleural lesions. Chest pain was the commonest presenting symptom. Malignancy represented 36.7% of pleural lesions, a percentage similar to lesions due to infection etiology. Free pleural effusions were the most common pleural lesions followed by pleural thickening. US was diagnostic in 72% of pleural lesions detectable by MDCT. Multiplanar reconstruction (MPR) images had an additional value than axial images in 39% of pleural lesions, mostly in cases of pleural thickening, free pleural effusion, pleural masses, encysted pleural effusions and pleural plaques. On the other hand, the MPR images had the same value as axial images in empyema and pneumothorax cases. Conclusion: MDCT is an important noninvasive imaging tool in accurate detection and characterization of pleural lesions with complementary MPR images that solve many diagnostic problems. Ultrasonography is a safer alternative but with less diagnostic value