1,432 research outputs found

    The Orthogonal 2D Planes Split of Quaternions and Steerable Quaternion Fourier Transformations

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    The two-sided quaternionic Fourier transformation (QFT) was introduced in \cite{Ell:1993} for the analysis of 2D linear time-invariant partial-differential systems. In further theoretical investigations \cite{10.1007/s00006-007-0037-8, EH:DirUP_QFT} a special split of quaternions was introduced, then called ±\pmsplit. In the current \change{chapter} we analyze this split further, interpret it geometrically as \change{an} \emph{orthogonal 2D planes split} (OPS), and generalize it to a freely steerable split of \H into two orthogonal 2D analysis planes. The new general form of the OPS split allows us to find new geometric interpretations for the action of the QFT on the signal. The second major result of this work is a variety of \emph{new steerable forms} of the QFT, their geometric interpretation, and for each form\change{,} OPS split theorems, which allow fast and efficient numerical implementation with standard FFT software.Comment: 25 pages, 5 figure

    Locating Star-Forming Regions in Quasar Host Galaxies

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    We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band [O II] λ\lambda3727, Hβ\beta, [O III] λ\lambda5007 and Paα\alpha images, taken with the WFPC2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically around the nucleus, powered primarily by star formation. We determine star-formation rates of order a few tens of M⊙_\odot/yr. The host galaxies of our target quasars have stellar masses of order 101110^{11} M⊙_\odot and specific star formation rates on a par with those of M82 and luminous infrared galaxies. As such they fall at the upper envelope or just above the star-formation mass sequence in the specific star formation vs stellar mass diagram. We see a clear trend of increasing star formation rate with quasar luminosity, reinforcing the link between the growth of the stellar mass of the host and the black hole mass found by other authors.Comment: Accepted for publication in M.N.R.A.

    Representação em XML da Floresta Sintáctica

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    A Floresta Sintáctica é um recurso linguístico mantido e distribuído livremente ao público pela Linguateca. Face à necessidade de abranger uma maior comunidade de linguistas e de programadores na área do processamento da linguagem natural, procura-se distribuir este recurso em outros formatos alem do existente, tais como formatos baseados em XML. Pretende-se neste documento descrever o processo de equipar a Floresta Sintáctica com mecanismos que facilitem a sua utilização. Para isso pretende-se converter o seu formato actual para formatos baseados em XML. Serão analisados os problemas e questões da definição XML deste tipo de recurso. Apresenta-se ainda um módulo experimental construído especificamente para facilitar a construção de processadores da Floresta

    Barriers to Accessing Medicines among Syrian Asylum Seekers and Refugees in a German Federal State

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    In Germany, asylum seekers and refugees (AS&Rs) face challenges when accessing healthcare services including medicines. The aim of this study was to explore the barriers to accessing medicines among Syrian AS&Rs in the state of North Rheine-Westphalia, and to provide an understanding of their perspectives towards taking medicines that contain alcohol or pork products. This study is based on a cross-sectional survey using a combination of sampling methods. We used descriptive statistics to analyze quantitative data. Participants’ answers to an open-ended question yielded qualitative data that were categorized based on the thematic areas they discussed or addressed. Among the 1641 respondents, language barriers had more of an effect on the access to medicines than any other factor studied. The effect of language barriers on access to medicines was more pronounced for female participants, those who were older than 50 years, and participants who had chronic diseases in comparison to the other groups of participants. Male participants and those younger than 50 years of age showed more acceptance towards taking medicines that contain alcohol or pork products. Based on our results, we recommend providing more support for AS&Rs to learn the German language, particularly for female refugees, older refugees, and those with chronic diseases or disabilities. We also recommend providing translated medical leaflets for patients who wish to receive them in their native language. Healthcare providers should try to consider the special conditions of AS&Rs patients and take into account their perspectives about treatments and diseases

    Outpatient cardiovascular diseases and diabetes medicines dispensing in the population with government health insurance in Syria between 2018 and 2019 : a retrospective analysis

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    Abstract Background Low- and middle-income countries bear the highest burden of non-communicable diseases (NCDs) mortality and morbidity. Syria has undergone an epidemiological transition from infectious diseases to NCDs in the past decades. Despite the high prevalence of cardiovascular diseases (CVDs) and diabetes in Syria, little is known about medicines utilization or prescriptions for these diseases. The aims of this study are to present the patterns and rates of dispensing medicines used for CVDs and diabetes among patients with government health insurance in Syria and examine age, sex, and regional variation in the dispensing of these medicines. Methods Outpatient data from June 2018 to May 2019 on dispensed medicines for 81,314 adults with government health insurance were obtained. The dispensing rate was expressed as the number of defined daily doses (DDDs) per 1000 beneficiaries per day (DID). The DID is a measurement that is used in drug utilization research to control for differences or changes in population size between or within countries. The number of DIDs was adjusted according to beneficiaries’ sex, age, and governorate. Results Beneficiaries received 302.09 DIDs of CVDs medicines and 35.66 DIDs of diabetes medicines, including 0.96 DID of insulin (2.99% of the total of diabetes medicines). CVDs and diabetes medicine dispensing rates were low during the study period and included very low rates of insulin dispensing compared to the dispensing rates of these medicines in other countries in East Mediterranean Region or in Europe. We found lower dispensing rates of CVDs medicines among female beneficiaries (249.59 DIDs) than male beneficiaries (388.80 DIDs). Similarly, the dispensing rates of diabetes medicines among female beneficiaries (29.42 DIDs) were lower than those among male beneficiaries (45.98 DIDs). In addition, there were lower rates of CVDs and diabetes medicines and very low to no dispensing of insulin in some governorates that were partly controlled by the Syrian government compared to other governorates that were completely or mostly controlled by the Syrian government. Conclusions Additional efforts are needed to raise awareness about the prevention and management of CVDs and diabetes especially among females in Syria and consider cultural issues that might influence access to healthcare services. There is a crucial need to address the political and geographical challenges caused by the conflict which have limited access to CVDs and diabetes medicines in some regions in Syria

    Modeling of S-RAM Energy Recover Compressor Integration in a Transcritical Carbon Dioxide Cycle for Application in Electronics Cooling in Varying Gravity

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    As electronics in military aircraft become increasingly complicated, additional cooling is necessary to enable efficient and high computing performance. Additionally, the varying forces that a military aircraft endure during maneuvering and inverted flight introduce unique design constraints to the electronics cooling systems. Because this cooling system will be in an aircraft, the capacity and unique design constraints must all be met with a design that is as lightweight as possible. This paper presents a study comparing the coefficient of performance (COP) of several cycle architectures with both R134a and carbon dioxide ( ). Cycles with single-stage and two-stage compression with intercooling are compared, and both are modeled with suction-to-liquid line heat exchangers. The cycles utilizing are transcritical in order to reach the required temperatures for heat rejection from the gas cooler. Additionally, cycles with expansion work recovery and an ejector are compared. The cooling requirements are up to 150 kW with a heat source temperature as low as and a heat sink temperature of up to . The purpose of this analysis is to understand which of the above cycles performs with the highest efficiency for the given electronics cooling application

    Against Bureaucracy. Why Flexibility and Decentralisation Cannot Solve Organisational Problems

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    Kühl S, Dittrich EJ. Against Bureaucracy. Why Flexibility and Decentralisation Cannot Solve Organisational Problems. In: Makó C, Warhurst C, eds. The Management and Organisation of Firms in the Global Context. Budapest: University of Gödöllo; 1999: 119-125

    Recovery of Waste Thermal Energy in U.S. Residential Appliances

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    With the United States being the world’s second largest consumer of primary energy, research into areas of significant consumption can provide large impacts in terms of the global energy consumption. Buildings account for 41% of US total energy consumption with the residential sector making up a majority. Household appliances account for the second largest site energy consumption at 27%, after the HVAC system for the U.S. residential sector. By quantifying the expected energy available in the waste stream for five major appliances; household refrigerator, clothes dryer and washer, dishwasher, and cooking oven, a potential energy source is presented. A cold water cooling stream is applied to the waste stream of each appliance and an estimated amount of energy can be recovered. The household refrigerator is modeled having an increase in cooling capacity of about 12% and a reduction on compressor power consumption of about 26%. A sample operation of the clothes dryer has the exhaust air stream being cooled down to 30.5°C (86.9°F) or on the other side, is able to heat 19 liter (5 gal) of water up to about 54.5°C (130.1°F). Large volumes of water are available by the clothes washer, but due to typical operation characteristics, low wash and rinse temperatures, the waste stream was not high in temperature. While the dishwasher provided higher heat source temperatures, 40°C (104°F), than the clothes washer, 36°C (97°F), the opposite was true. The volume of waste water drained is very low compared to the clothes washer 11.7 liter (3.1 gal) to 155 liter (41 gal). Thus water temperatures in the storage tank did not reach above 30°C (86°F) even with low storage volumes. The cooking oven can generate very high water temperatures depending how small of a storage tank is connected. Further work in this area is recommended due to the potential of high water temperatures generated from residential waste energy streams not currently being captured, and thus can offset some site-energy usage
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