1,319 research outputs found
On variable hydrostatic transmission for road vehicles, powered by supply of fluid at constant pressure
Various hydrostatic power transmission systems for automotive applications with power supply at constant pressure and unrestricted flow and with a Volvo Flygmotor variable displacement motor as the principal unit were investigated. Two most promising concepts were analyzed in detail and their main components optimized for minimum power loss at the EPA Urban Driving Cycle. The best fuel consumption is less than 10 lit. per 100 kM for a 1542 kG vehicle with a hydrostatic motor and a two speed gear box in series (braking power not recovered). Realistic system pressure affects the fuel consumption just slightly, but the package volume/weight drastically. Back pressure increases losses significantly. Special attention was paid to description of the behavior and modeling of the losses of variable displacement hydrostatic machines
自記式「健康チェック票THI」による健康に及ぼす喫煙の影響評価-地方都市と大都市の学生間の比較-
キャンパスが群馬県内(Iキャンパス)、東京都内(Tキャンパス)および愛知県内(Nキャンパス)にあるA私立大学の学生347人(男子121人、女子226人)を対象に、喫煙が健康に及ぼす影響について、自記式「健康チェック票THI」によって評価した。対象学生の喫煙率は全国平均と比較して、Iキャンパスの男子学生がやや高かったことを除くと、ほぼ同程度であった。健康状態は1.2万人の標準グループから得られた尺度得点の分布をもとに、パーセンタイル値で評価した。喫煙者の健康状態は非喫煙者と比較して、身体面およびメンタル面の両方において劣る傾向がみられ、特に、女子学生の方が男子学生より顕著であった。さらに、Iキャンパスの学生より、TキャンパスやNキャンパスの学生の方が、メンタル面の症状レベルが高い傾向が認められた。これらの結果は、喫煙が身体面の健康状態に悪影響を及ぼすことを確認するとともに、その影響は地方都市より大都会で学ぶ学生に強く出やすい可能性を示している
Ready to Use Detector Modules for the NEAT Spectrometer Concept, Design, First Results
The paper presents the detector system developed by Datalist Systems, Ltd. previously ANTE Innovative Technologies for the NEAT II spectrometer at HZB. We present initial concept, design and implementation highlights as well as the first results of measurements such as position resolution. The initial concept called for modular architecture with 416 3He detector tubes organized into thirteen 32 tube modules that can be independently installed and removed to and from the detector vacuum chamber for ease of maintenance. The unalloyed aluminum mechanical support modules for four 8 tube units each also house the air boxes that contain the front end electronics preamplifiers that need to be on atmospheric pressure. The modules have been manufactured and partly assembled in Hungary and then fully assembled and installed on site by Datalist Systems crew. The signal processing and data acquisition solution is based on low time constant 60 ns preamplifier electronics and sampling ADC s running at 50 MS s i.e. a sample every 20 ns for all 832 data channels. The preamplifiers are proprietary, developed specifically for the NEAT spectrometer, while the ADC s and the FPGA s that further process the data are based on National Instruments products. The data acquisition system comprises 26 FPGA modules each serving 16 tubes providing for up to 50 kHz count rate per individual tube and it is organized into two PXI chassis and two data acquisition computers that perform post processing, event classification and provide appropriate preview of the collected data. The data acquisition software based on Event Recording principles provides a single point of contact for the scientific software with an Event Record List with absolute timestamps of 100ns resolution, timing data of 100 ns resolution for the seven discs chopper system as well as classification data that can be used for flexible data filtering in off line analysis of the gathered data. A unique 3 tier system of filtering criteria of events is in operation a hard threshold in the FPGA s to reduce the effect of noise, a pulse shape based classification to eliminate gamma sensitivity and an additional flexible feature based classification to filter out pileup and other unwanted phenomena. This ensures high count rates 50kHz per tube, 1MHz overall while maintaining good quality of measurements e.g. position resolution .The first measurement results show that the delivered detector system meets the initial requirements of 20 mm position resolution along the 2000mm long detector tubes. This is partly due to the innovative event classification system that provides vital pulse shape data that can be used for sophisticated position resolution algorithms implemented on the DAQ computer
High link performance of Brillouin-loss based microwave bandpass photonic filters
We present a high link-performance multi-band microwave photonic filter based on stimulated Brillouin scattering (SBS) loss responses. The bandpass filter response is formed by suppressing the out-of-band signal using multiple broadened SBS loss responses, which avoids introducing additional noise in the passband. The low-noise SBS bandpass filter is implemented in an optimized high-performance MWP link, which enabled the demonstration of filter functionalities with a low noise figure, reconfigurability, and high resolution. A noise figure of 18.9 dB is achieved in the passband with a filter bandwidth of 0.3 GHz at a central frequency of 14 GHz, with a link gain of −13.9 dB and a spurious free dynamic range of 106 dB.Hz2/3. Bandwidth reconfiguration from 0.1 GHz to 1 GHz and multi-bandpass responses are also demonstrated
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Estimating and managing the changing methodological parameters of self-report surveys of addictive behavior - based on the waves of the National Survey on Addiction Problems in Hungary
The standard nature of the procedures and tools of sampling and data collection cannot guarantee the stability of data reliability and validity because non-sampling errors are highly sensitive to social conditions. The present study provides a post-hoc attempt to estimate and manage the changing methodological parameters of self-report surveys of addictive behaviours (being highly subjected to changes in social conditions) to make data interpretation easier. The analysis is based on the data of two national Hungarian representative surveys assessing addiction problems in 2007 and 2015 (National Survey on Addiction Problems in Hungary [NSAPH]). Both surveys were conducted using a Hungarian nationwide representative sample aged 18-64 years applying similar procedures in data collection and-processing. Regarding data concerning substance use, both surveys included variables to estimate non-sampling errors in line with current international practices. The methodological parameters of NSAPH2015 showed an increase in non-sampling errors regarding substance use behaviour compared to NSAPH2007. The present paper elaborates an estimation procedure based on the assumption that when following a population, the proportion of people who have ever engaged in a specific type of addictive behaviour cannot be reduced in the given population over time. This also applies to cohorts followed by cross-sectional surveys among national representative samples, as far as lifetime prevalence and data on the age of first use/activity is available. To identify valid trends in different behaviours in epidemiological research assessing addictive behaviours or other sensitive data, researchers should provide the required conditions for controlling or correcting data by cohort analysis
Molecular Profiling of Lymphatic Endothelial Cell Activation In Vitro
The lymphatic vascular system plays a key role in cancer progression. Indeed, the activation of lymphatic endothelial cells (LECs) through the lymphangiogenic process allows for the formation of new lymphatic vessels (LVs) that represent the major route for the dissemination of solid tumors. This process is governed by a plethora of cancer-derived and microevironmental mediators that strictly activate and control specific molecular pathways in LECs. In this work we used an in vitro model of LEC activation to trigger lymphangiogenesis using a mix of recombinant pro-lymphangiogenic factors (VFS) and a co-culture system with human melanoma cells. Both systems efficiently activated LECs, and under these experimental conditions, RNA sequencing was exploited to unveil the transcriptional profile of activated LECs. Our data demonstrate that both recombinant and tumor cell-mediated activation trigger significant molecular pathways associated with endothelial activation, morphogenesis, and cytokine-mediated signaling. In addition, this system provides information on new genes to be further investigated in the lymphangiogenesis process and open the possibility for further exploitation in other tumor contexts where lymphatic dissemination plays a relevant role
Dynamics and heterogeneity of brain damage in multiple sclerosis
Multiple Sclerosis (MS) is an autoimmune disease driving inflammatory and
degenerative processes that damage the central nervous system (CNS). However,
it is not well understood how these events interact and evolve to evoke such a
highly dynamic and heterogeneous disease. We established a hypothesis whereby
the variability in the course of MS is driven by the very same pathogenic
mechanisms responsible for the disease, the autoimmune attack on the CNS that
leads to chronic inflammation, neuroaxonal degeneration and remyelination. We
propose that each of these processes acts more or less severely and at
different times in each of the clinical subgroups. To test this hypothesis, we
developed a mathematical model that was constrained by experimental data (the
expanded disability status scale [EDSS] time series) obtained from a
retrospective longitudinal cohort of 66 MS patients with a long-term follow-up
(up to 20 years). Moreover, we validated this model in a second prospective
cohort of 120 MS patients with a three-year follow-up, for which EDSS data and
brain volume time series were available. The clinical heterogeneity in the
datasets was reduced by grouping the EDSS time series using an unsupervised
clustering analysis. We found that by adjusting certain parameters, albeit
within their biological range, the mathematical model reproduced the different
disease courses, supporting the dynamic CNS damage hypothesis to explain MS
heterogeneity. Our analysis suggests that the irreversible axon degeneration
produced in the early stages of progressive MS is mainly due to the higher
rate of myelinated axon degeneration, coupled to the lower capacity for
remyelination. However, and in agreement with recent pathological studies,
degeneration of chronically demyelinated axons is not a key feature that
distinguishes this phenotype. Moreover, the model reveals that lower rates of
axon degeneration and more rapid remyelination make relapsing MS more
resilient than the progressive subtype. Therefore, our results support the
hypothesis of a common pathogenesis for the different MS subtypes, even in the
presence of genetic and environmental heterogeneity. Hence, MS can be
considered as a single disease in which specific dynamics can provoke a
variety of clinical outcomes in different patient groups. These results have
important implications for the design of therapeutic interventions for MS at
different stages of the disease
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