2,157 research outputs found

    Study of the damping characteristics of general aviation aircraft panels and development of computer programs to calculate the effectiveness of interior noise control treatment, part 1

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    Tests were carried out on 20 inch x 20 inch panels at different test conditions using free-free panels, clamped panels, and panels as installed in the KU-FRL acoustic test facility. Tests with free-free panels verified the basic equipment set-up and test procedure. They also provided a basis for comparison. The results indicate that the effect of installed panels is to increase the damping ratio at the same frequency. However, a direct comparison is not possible, as the fundamental frequency of a free-free panel differs from the resonance frequency of the panel when installed. The damping values of panels installed in the test facility are closer to the damping values obtained with fixed-fixed panels. Effects of damping tape, stiffeners, and bonded and riveted edged conditions were also investigated. Progress in the development of a simple interior noise level control program is reported

    California Mastitis Test Scores of Individual Quarters Compared With Composite Milk Samples and With Milk Leucocyte Counts

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    Udder inflammation, whether caused by bacterial, physical, or neurological means, usually results in the secretion of milk that is abnormal in character

    Study of noise reduction characteristics of double-wall panels

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    The noise reduction characteristics of general aviation type, flat, double-wall structures were investigated. The experimental study was carried out on 20-by-20 inch panels with an exposed area of 18 by 18 inches. A frequency range from 20 to 5000 Hz was covered. The experimental results, in general, follow the expected trends. At low frequencies the double-wall structures are no better than the single-wall structures. However, for depths normally used in the general aviation industry, the double-wall panels are very attractive. The graphite-spoxy skin panels have higher noise reduction at very low frequencies ( 100 Hz) than the Kevlar skin panels. But the aluminum panels have higher noise reduction in the high frequency region, due to their greater mass. Use of fiberglass insulation is not effective in the low frequency region, and at times it is even negative. But the insulation is effective in the high-frequency region. The theoretical model for predicting the transmission loss of these multilayered panels is also discussed

    Digital Signal Processing Education: Technology and Tradition

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    In this paper we discuss a DSP course presented to both University students and to participants on industrial short courses. The "traditional" DSP course will typically run over one to two semesters and usually cover the fundamental mathematics of z-, Laplace and Fourier transforms, followed by the algorithm and application detail. In the course we will discuss, the use of advanced DSP software and integrated support software allow the presentation time to be greatly shortened and more focussed algorithm and application learning to be introduced. By combining the traditional lecture with the use of advanced DSP software, all harnessed by the web, we report on the objectives, syllabus, and mode of teaching

    Fuel economy and exhaust emissions characteristics of diesel vehicles: Test results of a prototype Fiat 131 NA 2.4 liter automobile

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    The vehicle was tested on a chassis dynamometer over selected drive cycles and steady-state conditions. Two fuels were used, a U.S. no. 2 diesel and a European diesel fuel. The vehicle was tested with retarded timing and with and without an oxidation catalyst. Particulate emission rates were calculated from dilution tunnel measurements and large volume particulate samples were collected for biological and chemical analysis. It was determined that while the catalyst was generally effective in reducing hydrocarbon and carbon monoxide levels, it was also a factor in increasing particulate emissions. Increased particulate emission rates were particularly evident when the vehicle was operated on the European fuel which has a high sulfur content

    Frequency and risk factors of acute kidney injury during diabetic ketoacidosis in children and association with neurocognitive outcomes

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    Importance: Acute kidney injury (AKI) occurs commonly during diabetic ketoacidosis (DKA) in children, but the underlying mechanisms and associations are unclear. Objective: To investigate risk factors for AKI and its association with neurocognitive outcomes in pediatric DKA. Design, Setting, and Participants: This cohort study was a secondary analysis of data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in DKA Study, a prospective, multicenter, randomized clinical trial comparing fluid protocols for pediatric DKA in 13 US hospitals. Included DKA episodes occurred among children age younger than 18 years with blood glucose 300 mg/dL or greater and venous pH less than 7.25 or serum bicarbonate level less than 15 mEq/L. Exposures: DKA requiring intravenous insulin therapy. Main Outcomes and Measures: AKI occurrence and stage were assessed using serum creatinine measurements using Kidney Disease: Improving Global Outcomes criteria. DKA episodes with and without AKI were compared using univariable and multivariable methods, exploring associated factors. Results: Among 1359 DKA episodes (mean [SD] patient age, 11.6 [4.1] years; 727 [53.5%] girls; 651 patients [47.9%] with new-onset diabetes), AKI occurred in 584 episodes (43%; 95% CI, 40%-46%). A total of 252 AKI events (43%; 95% CI, 39%-47%) were stage 2 or 3. Multivariable analyses identified older age (adjusted odds ratio [AOR] per 1 year, 1.05; 95% CI, 1.00-1.09; P = .03), higher initial serum urea nitrogen (AOR per 1 mg/dL increase, 1.14; 95% CI, 1.11-1.18; P \u3c .001), higher heart rate (AOR for 1-SD increase in z-score, 1.20; 95% CI, 1.09-1.32; P \u3c .001), higher glucose-corrected sodium (AOR per 1 mEq/L increase, 1.03; 95% CI, 1.00-1.06; P = .001) and glucose concentrations (AOR per 100 mg/dL increase, 1.19; 95% CI, 1.07-1.32; P = .001), and lower pH (AOR per 0.1 increase, 0.63; 95% CI, 0.51-0.78; P \u3c .001) as variables associated with AKI. Children with AKI, compared with those without, had lower scores on tests of short-term memory during DKA (mean [SD] digit span recall: 6.8 [2.4] vs 7.6 [2.2]; P = .02) and lower mean (SD) IQ scores 3 to 6 months after recovery from DKA (100.0 [12.2] vs 103.5 [13.2]; P = .005). Differences persisted after adjusting for DKA severity and demographic factors, including socioeconomic status. Conclusions and Relevance: These findings suggest that AKI may occur more frequently in children with greater acidosis and circulatory volume depletion during DKA and may be part of a pattern of multiple organ injury involving the kidneys and brain

    The Status of Women Leaders in Utah Business: A 2018 Update

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    In 2014, the Utah Women & Leadership Project (UWLP) released a research and policy brief titled “The Status of Women Leaders in Utah Business.” The document was one of four released in 2014 that focused on understanding the status of women’s leadership in politics, education, nonprofits, and business. This brief provides a four-year update to determine what, if any, progress has been made in women’s leadership within Utah’s business sector. The brief compares Utah data with national data and reviews the applicable literature dealing specifically with women in the highest levels of business leadership, including C-level positions and presence on executive boards

    An interactive three dimensional approach to anatomical description—the jaw musculature of the Australian laughing kookaburra (Dacelo novaeguineae)

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    The investigation of form-function relationships requires a detailed understanding of anatomical systems. Here we document the 3-dimensional morphology of the cranial musculoskeletal anatomy in the Australian Laughing Kookaburra Dacelo novaeguineae, with a focus upon the geometry and attachments of the jaw muscles in this species. The head of a deceased specimen was CT scanned, and an accurate 3D representation of the skull and jaw muscles was generated through manual segmentation of the CT scan images, and augmented by dissection of the specimen. We identified 14 major jaw muscles: 6 in the temporal group (M. adductor mandibulae and M. pseudotemporalis), 7 in the pterygoid group (M. pterygoideus dorsalis and M. pterygoideus ventralis), and the single jaw abductor M. depressor mandibulae. Previous descriptions of avian jaw musculature are hindered by limited visual representation and inconsistency in the nomenclature. To address these issues, we: (1) present the 3D model produced from the segmentation process as a digital, fully interactive model in the form of an embedded 3D image, which can be viewed from any angle, and within which major components can be set as opaque, transparent, or hidden, allowing the anatomy to be visualised as required to provide a detailed understanding of the jaw anatomy; (2) provide a summary of the nomenclature used throughout the avian jaw muscle literature. The approach presented here provides considerable advantages for the documentation and communication of detailed anatomical structures in a wide range of taxa

    Industrial relations in West Germany: The operation of a works council in a predominantly white-collar small organisation in West Germany

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    This thesis describes the operation of a Works Council after initially reviewing the concept of co-determination and existing literature. It details the Company in which the study took place over a thirty month period and is written by a former Works Councillor employed by that Company. It is not, therefore, a pure academic study of a controlled experiment written by an academic; the great expansion of research into West German industrial relations particularly after the 1972 Labour Management Relations Act and 1976 Co-determination Act appears to have missed out the operation of Works Councils and concentrated on worker directors and the subsequent effect on them caused by the legislation. This study aims to fill the gap. Chapters 4, 5 and 6 respectively concentrate on problems encountered by the Works Council and employer in the areas of unequal treatment, grievances and job evaluation/performance appraisal. Each area encompasses the relevant articles of the legislation and their interrelated difficulties; emphasis is placed not only on the facts and the problems but on eventual solutions - if any - and how the system was, or was not, able to cope with them. In addition to describing issues and how they were handled by both Works Council and Management, I have tried to emphasise how Management tries to keep all activity within a largely inflexible legislative framework. Few, if any, studies exist that have been carried out or written by participants in the Works Council system (see Chapter 2). In particular there is a distinct lack of material written by Works Councillors in the white collar sector of smaller organisations with a multi-national background. Using for reference the International Labour Organisation translation of the 1972 L. M. R. A. under which the Works Council operation was governed, this thesis is the unique experience of an Englishman elected to two successive terms of office as a Works Councillor the second as Deputy Chairman of the Works Council. The results of the study may lead to a revision of the general conclusions about the Works Council system, particularly as a system of management accountability, a basis of employee involvement and participation as well as a major influence on co-operation and low levels of conflict; it may also provide realistic guidance as to whether the system is initiating or simply reactive, and whether a Works Council can be a stand alone body rather than simply part of a complex system. The reader is, therefore, invited to approach this study as the author has done - a new product
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