49 resultados para Head-On Collisions.

em Deakin Research Online - Australia


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This paper uses the H1 tracking ideas in the missile guidance problem. The controller performs as a Precision guidance controller for small desired attack angles although theoretically the formulas are valid (when intercepting a maneuvering target in a precision guidance point of view) only for the case of head on collision. The controller essentially navigates the missile in a unique relative arc that is de ned by the missile and target location and the desired attack angle.

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Background: The functional results associated with nonoperative treatment of severely impacted valgus fractures of the proximal part of the humerus are poor, and these injuries are difficult to treat with minimally invasive percutaneous fixation techniques. The aim of this study was to review the functional and radiographic results and complications of a new operative technique in a series of twenty-five patients.

Methods: Over a two-year period, we treated twenty-nine patients with a severely impacted valgus fracture of the proximal part of the humerus. Three patients were lost to follow-up and one died, leaving twenty-five patients who were available for the study. In all of the fractures, the head-shaft angle had been tilted into =160° of valgus and the greater tuberosity was displaced by >1 cm. All patients were treated with open reduction of the fracture, and the space created behind the humeral head was filled with Norian Skeletal Repair System (SRS) bone substitute. The fractures were stabilized with either screws or buttress plate fixation. Associated rotator cuff tears were repaired. All patients underwent functional outcome assessment with use of the Constant, DASH (Disabilities of the Arm, Shoulder and Hand), and SF-36 (Short Form-36) scores at one year, and twelve patients were followed for two years.

Results: All fractures united within the first year, all reductions were maintained, and no patient had signs of osteonecrosis of the humeral head on the latest follow-up radiographs. At one year, the median Constant score was 80 points and the median DASH score was 22 points. The functional results continued to be satisfactory in the twelve patients who were followed for two years. The results in our series were better than those achieved in studies of nonoperative treatment of similar fracture configurations. There were six clinically relevant complications, although none required a reoperation and all six patients had a satisfactory short-term functional outcome.

Conclusions: Internal fixation of severely impacted valgus fractures of the proximal part of the humerus, supplemented by Norian SRS bone substitute to fill the proximal humeral metaphyseal defect, produces good early functional and radiographic outcomes. Additional follow-up will be required to assess whether these initially satisfactory outcomes are maintained over the longer term.

Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

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Background: The functional results associated with nonoperative treatment of severely impacted valgus fractures of the proximal part of the humerus are poor, and these injuries are difficult to treat with minimally invasive percutaneous fixation techniques. The aim of this study was to review the functional and radiographic results and complications of a new operative technique in a series of twenty-five patients.

Methods: Over a two-year period, we treated twenty-nine patients with a severely impacted valgus fracture of the proximal part of the humerus. Three patients were lost to follow-up and one died, leaving twenty-five patients who were available for the study. In all of the fractures, the head-shaft angle had been tilted into > or = 160 degrees of valgus and the greater tuberosity was displaced by >1 cm. All patients were treated with open reduction of the fracture, and the space created behind the humeral head was filled with Norian Skeletal Repair System (SRS) bone substitute. The fractures were stabilized with either screws or buttress plate fixation. Associated rotator cuff tears were repaired. All patients underwent functional outcome assessment with use of the Constant, DASH (Disabilities of the Arm, Shoulder and Hand), and SF-36 (Short Form-36) scores at one year, and twelve patients were followed for two years.

Results: All fractures united within the first year, all reductions were maintained, and no patient had signs of osteonecrosis of the humeral head on the latest follow-up radiographs. At one year, the median Constant score was 80 points and the median DASH score was 22 points. The functional results continued to be satisfactory in the twelve patients who were followed for two years. The results in our series were better than those achieved in studies of nonoperative treatment of similar fracture configurations. There were six clinically relevant complications, although none required a reoperation and all six patients had a satisfactory short-term functional outcome.

Conclusions: Internal fixation of severely impacted valgus fractures of the proximal part of the humerus, supplemented by Norian SRS bone substitute to fill the proximal humeral metaphyseal defect, produces good early functional and radiographic outcomes. Additional follow-up will be required to assess whether these initially satisfactory outcomes are maintained over the longer term.

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Solo Exhibition, Framed Photograhs and Video installations as part of the 'Head On Photography Festival'

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In this paper, we investigated the Langmuir film and Langmuir–Blodgett (LB) monolayer film of a nonionic amphiphilic molecule, 4-(6-p-pyridyloxyl)hexyloxyl-4′-dodecyloxylazobenzene (C12AzoC6Py) and its mixture with poly(d,l-lactide-co-glycolide) (PLG) at different subphase pH values (2.0, 2.6, 3.3, 4.4, and 6.5, respectively) by surface pressure–area (π–A) isotherms, in situ interface Brewster angle microscopy (BAM), and ex situ atomic force microscopy (AFM). For pure C12AzoC6Py, its π–A isotherms display a plateau when the subphase pH value is lower than 3.0. The pressure of the plateau increases with the decrease of pH until 2.0. Over the plateau, the π–A isotherms become almost identical to the one under neutral conditions. The appearance of such a plateau can be explained as the coexistence of protonation and unprotonation of pyridyl head groups of the employed amphiphile. In contrast to the homogeneous surface morphology of pure C12AzoC6Py near the plateau by BAM observation, the surface in the case of its mixing with PLG exhibits a dendritic crystalline state under low surface pressure at subphase pH lower than 3.0. The crystalline state becomes soft and gradually melts into homogeneous aggregates with surface pressure increasing to a higher value than that of the plateau. Meanwhile, the hydrolysis of PLG in the mixture system at the interface has been affirmed to be restrained to a very large extent. And the PLG was believed to be compelled to the up layer of the LB film due to the phase separation, which is examined by AFM. Based on the experimental results, the corresponding discussion was also performed.

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This research investigates whether club head speed is a valid determinant of golfing performance and the effects of a golf-specific warm-up program on club-head speed in male golfers in the immediate and short term (five-week)

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This article draws on Bourdieu’s theorisation of domination and Gramsci’s notions of hegemony within the context of a larger empirical study of Australian university academic governance, and of academic boards (also known as academic senates or faculty senates) in particular. Reporting data that suggest a continued but radically altered form of collegial governance in which hegemony is exercised by management rather than by the professor, it theorises the domination of academic boards within western democratic universities. However, traditional collegial governance is also dependent upon a community of scholars, a role historically played by the academic board. In view of the suggested transition in collegial governance and the resultant convergence of academic work and management, the article concludes with questions about whether academic boards can continue to serve as communities of scholars in future.

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Immobility plus preexisting chronic disease or acute trauma can activate the coagulation system, thus increasing the risk for thromboembolic events. The effects of long-term bed-rest immobility and microgravity on the coagulation system of healthy persons (e.g., during crewed Mars missions) have not yet been studied. The main objective of the second Berlin BedRest Study (BBR2-2) "Coagulation Part" was to investigate adaptations of the hemostatic system during long-term bed rest (60 days) under simulated microgravity (6° head-down-tilt [6°HDT]) and after mobilization in three different volunteer groups (randomly assigned to CTR= inactive control group; RE= resistive exercise only group; and RVE= resistive exercise with whole-body vibration group). In 24 males (aged 21-45 years), before, during, and after long-term bed rest, key parameters of coagulation were measured from venous blood samples: D-dimer (DD), thrombin-antithrombin III complex (TAT), and prothrombin fragment F1 + 2 (PT-F1 + 2). Additionally, modified rotational thrombelastometry (ROTEM (®) ) analysis was performed. Times of exploratory analyses were as follows: baseline data collection 2 days before bed rest (BDC-2); eight different days of 6°HDT bed rest (HDT1-HDT60), and two different days after reambulation (R + 3 and R + 6). We found significant changes in DD, TAT, and PT-F1 + 2 over the total time course, but no consistent effect of physical interventions (RE, RVE) on these parameters. Notably, no parameter reached levels indicative of intravascular thrombin formation. All ROTEM® parameters remained within the normal range and no pathological traces were found. Sixty days of 6°HDT bed rest are not associated with pronounced activation of the coagulation system indicative of intravascular thrombus formation in healthy volunteers independent of the training type during the bed rest.

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A positive change in the learning environment in schools is visible through ongoing professional development of teachers and administrators. Monitoring the professional development program and providing support to teachers and administrators to transfer their learnings into the school environment ensures some measures of quality. Quality issues led to the launching of the Professional Development Program (PDP) for Primary School Teachers (PSTs) of Sindh by the United Educational Initiative (UEI), a consortium of five Governmental and Non-Governmental Organizations, working under the supervision of Education Sector Reform Assistance (ESRA). Implementation of the UEI-PDP in four districts of Sindh, is ensured by a team of professionals in each district. Recognising that capacity building of district education employees would improve the educational system in the country, 130 Master Trainers were selected, on merit, from the District Education Office for the training of 17,000 teachers and 3000 Head teachers/administrators over a period of two years. This paper developed the design of a Monitoring Process for a Professional Development Program for Primary School Teachers and Administrators. Data was collected through Pre/Post observations, Interviews, Questionnaires and Reports. Such tools make it possible for the monitoring teams to observe, to inquire further, and, along with the Managers, Master Trainers and School Support Team, seek to explain the progress of the program and take corrective action where indicated. Both formative evaluations as well as summative  evaluation techniques are utilized for evaluating the program. The monitoring process that assisted in formative evaluations is described. In order to assist in summative evaluation, data collected through the monitoring process was further developed to categorize the schools where teachers and head teachers are trained. It is hoped that the categorization of the schools may lead to further improvements in those schools which fall in the group for need improvement. It may also initiate further research as to reasons behind why some schools are in the good category and why others fall in the average category.

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Our present research focuses on kinematic and dynamic modeling of a 3-DOF robotic cutting head for the next generation of CNC machines. The robotic cutting head is one kind of parallel manipulator of 3-PUU type, which has a high flexibility of motion in three-dimensional space. The parallel manipulator consists of three linear servomotors, which drive three connecting rods independently according to the cutting strategy. Being a parallel manipulator, the robotic cutting head has higher stiffness and position accuracy; consequently, higher velocities and accelerations can be achieved. A very suitable application of this mechanism is as a cutting head of a precision machine tool for three-dimensional cutting problems.

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On-site collision tests of full-scale concrete barriers are an important method to understand what happens to concrete barriers when vehicles collide with them. However, such tests require both time and money, so modeling and simulation of collisions by computer have been developed as an alternative in this research. First, spring subgrade models were developed to formulate the ground boundary of concrete barriers based on previous experiments. Then, the finite element method models were developed for both heavy trucks and concrete barriers to simulate their dynamic collision performances. Comparison of the results generated from computer simulations and on-site experiments demonstrates that the developed models can be applied to simulate the collision of heavy trucks with concrete barriers, to replicate the movement of the truck at the collision, and to investigate the performance of the concrete barriers. The developed research methodology can be widely used to support the design of new concrete barriers and the safety analysis of existing ones.

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Real vehicle collision experiments on full-scale road safety barriers are important to determine the outcome of a vehicle versus barrier impact accident. However, such experiments require large investment of time and money. Numerical simulation has therefore been imperative as an alternative method for testing concrete barriers. In this research, spring subgrade models were first developed to simulate the ground boundary of concrete barriers. Both heavy trucks and concrete barriers were modeled using finite element methods (FEM) to simulate dynamic collision performances. Comparison of the results generated from computer simulations and on-site full-scale experiments demonstrated that the developed models could be applied to simulate the collision of heavy trucks with concrete barriers to provide the data to design new road safety barriers and analyze existing ones.

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The aims of this study are (1) to establish a reliable and valid quality-of-life (QOL) questionnaire for Chinese patients with head and neck (H&N) cancer who are treated with radiation therapy and (2) to evaluate the impact of the immediate side effects of treatment on the QOL of these patients. The 39-item "Quality of Life Radiation Therapy Instrument with Head and Neck Companion Module" (QOL-RTI/H&N) was translated into Chinese. In the reliability evaluation phase (study module 1), the questionnaire was administered twice to 56 H&N cancer patients, 7 days apart, during the second and third week of radiation therapy. In the validity evaluation phase (study module 2), 138 patients completed the QOL-RTI/H&N before starting and at the end of radiation therapy. Sixty-nine of these 138 patients also completed the QOL-RTI/H&N during the second week of their radiation therapy, at the same time as completing the Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N) questionnaire. Cronbach alpha coefficients were 0.88 for the general-tool QOL-RTI and 0.90 for the H&N subscale. Test-retest reliability was satisfactory with intraclass correlation coefficients of 0.89 for the general-tool QOL-RTI and 0.75 for the H&N subscale. The instrument can discriminate between patients with stage I or II disease and those with stage III or IV disease (P < .05). Concurrent validity was established by the good agreement with the FACT-H&N (r = 0.86, P < .001). A highly significant deterioration was in the QOL from the baseline to the end of treatment (mean difference for general tool = 1.95, P < .001; mean difference for H&N subscale = 4.85, P < .001). The Chinese QOL-RTI/H&N is a reliable and valid tool for determining the QOL in H&N cancer patients receiving radiation therapy. The immediate side effects of treatment had a significantly negative impact on the patients' QOL. The impact was relatively large for the functional and treatment-site aspects.