373 research outputs found
A statistical approach for estimating mean maximum urban temperature excess.
Munkánkban a városi hősziget (UHI) maximális napi kifejlődését vizsgáltuk Szegeden, a beépítettségi paraméterek függvényében. A hőmérsékleti adatok valamint a beépítettségi arány, a vízfelszín-arány, az égbolt láthatósági index és az épületmagasság, valamint ezek területi kiterjesztései közötti kapcsolatot statisztikus modellezéssel határoztuk meg. A kapott modell-egyenleteket mindkét félévre (fűtési és nem-fűtési) többváltozós lineáris regresszió segítségével állapítottuk meg. Az eredményekből világosan látszik, hogy szignifikáns kapcsolat mutatható ki a maximális UHI területi eloszlása és a beépítettségi paraméterek között, ami azt jelenti, hogy e tényezők fontos szerepet jatszanak a városi hőmérsékleti többlet területi eloszlásának kialakításában. A városi paraméterek közül az égbolt láthatósági index és az épületmagasság a leginkább meghatározó tényező, ami összhangban van a városi felszín energia-egyenlegével.
| Investigations concentrated on the urban heat island (UHI) in its strongest development during the diurnal cycle in Szeged, Hungary. Task includes development of statistical models in the heating and non-heating seasons using urban surface parameters (built-up and water surface ratios, sky view factor, building height) and their areal extensions. Model equations were determined by means of stepwise multiple linear regression analysis. As the results show, there is a clear connection between the spatial distribution of the UHI and the examined parameters, so these parameters play an important role in the evolution of the UHI intensity field. Among them the sky view factor and the building height are the most determining factors, which are in line with the urban surface energy balance
A statistical approach for estimating mean maximum urban temperature excess
Investigations concentrated on the urban heat island (UHI) in its strongest development during the
diurnal cycle in Szeged, Hungary. Task includes development of statistical models in the heating and non-heating
seasons using urban surface parameters (built-up and water surface ratios, sky view factor, building height) and
their areal extensions. Model equations were determined by means of stepwise multiple linear regression analysis.
As the results show, there is a clear connection between the spatial distribution of the UHI and the examined
parameters, so these parameters play an important role in the evolution of the UHI intensity field. Among them the
sky view factor and the building height are the most determining factors, which are in line with the urban surface
energy balance
Integrated Process of Arabinose Biopurification and Xylitol Fermentation Based on the Diverse Action of Candida boidinii
Hemicellulosic hydrolysates of agro-residues are promising raw materials for xylitol and arabinose production through biotechnological methods.
Two-step acidic fractionation of corn fibre was developed to produce a glucose- and arabinose-rich hydrolysate and a xylose-rich hydrolysate. An integrated process of arabinose biopurification on the glucose- and arabinose-rich hydrolysate and xylitol fermentation on the xylose-rich hydrolysate using Candida boidinii NCAIM Y.01308 was introduced, in which cell mass produced in arabinose biopurification was used as inoculum in the xylitol fermentation. Aerobic biopurification resulted in an arabinose solution containing 9.2 g L–1 of arabinose with a purity of 90 %, based on total sugars. Xylitol fermentation under microaerobic conditions resulted in a xylitol yield of 53 % of theoretical and a xylitol concentration of 10.4 g L–1 in three days.
Hence, an integrated biorefinery process of hemicellulosic hydrolysates was developed based on the diverse action of C. boidinii to purify arabinose and produce xylitol
Neural mechanisms for voice recognition
We investigated neural mechanisms that support voice recognition in a training paradigm with fMRI. The same listeners were trained on different weeks to categorize the mid-regions of voice-morph continua as an individual's voice. Stimuli implicitly defined a voice-acoustics space, and training explicitly defined a voice-identity space. The predefined centre of the voice category was shifted from the acoustic centre each week in opposite directions, so the same stimuli had different training histories on different tests. Cortical sensitivity to voice similarity appeared over different time-scales and at different representational stages. First, there were short-term adaptation effects: Increasing acoustic similarity to the directly preceding stimulus led to haemodynamic response reduction in the middle/posterior STS and in right ventrolateral prefrontal regions. Second, there were longer-term effects: Response reduction was found in the orbital/insular cortex for stimuli that were most versus least similar to the acoustic mean of all preceding stimuli, and, in the anterior temporal pole, the deep posterior STS and the amygdala, for stimuli that were most versus least similar to the trained voice-identity category mean. These findings are interpreted as effects of neural sharpening of long-term stored typical acoustic and category-internal values. The analyses also reveal anatomically separable voice representations: one in a voice-acoustics space and one in a voice-identity space. Voice-identity representations flexibly followed the trained identity shift, and listeners with a greater identity effect were more accurate at recognizing familiar voices. Voice recognition is thus supported by neural voice spaces that are organized around flexible ‘mean voice’ representations
Evaluation of a WRF-LCZ system in simulating urban effects under non-ideal synoptic patterns
The modelling of meteorological variables under non-ideal (e.g. characterized by cyclonal activity) synoptic patterns is always challenging. It is particularly true, when the simulations are performed on local or neighborhood scale. In this study, the spatio-temporal distribution of urban heat island of Szeged was predicted by the Weather Research and Forecasting (WRF) model during two period with different meteorological background. During the first, a thick and permanent fog layer was located over the Carpathian Basin. The second one was dominated by a Mediterranean low that has caused high sums of precipitation. The comparison of modelled and observed variables suggested that the computed outputs showed robust consistency with the observations during the rainfall event. On the foggy days, however, WRF had difficulties to capture the daily variability of urban heat island intensity. It was due to the large underestimations of moisture circumstances
Low Temperature Precursor Route for Highly Efficient Spherically Shaped LED-Phosphors M2Si5N8:Eu2+ (M = Eu, Sr, Ba)
The highly efficient nitridosilicate phosphors M2Si5N8 (M = Sr, Ba, Eu) for phosphor-converted pc-LEDs were synthesized at low temperatures using a novel precursor route involving metal amides M(NH2)2. These precursors have been synthesized by dissolution of the respective metals in supercritical ammonia at 150°C and 300 bar. The thermal behavior and decomposition process of the amides were investigated with temperature programmed powder X-ray diffractometry and thermoanalytical measurements (DTA/TG). These investigations rendered the amides as suitable intermediates for reaction with silicon diimide (Si(NH)2). Thus, the desired nitridosilicate phosphors were obtained at relatively low temperatures around 1150−1400°C which is approximately 300°C lower compared to common synthetic approaches starting from metals or oxides. The influence of the thermal treatment on the phosphor morphology has been studied extensively. The accessibility of spherical phosphor particles represents another striking feature of this route since it improves light extraction from the crystallites due to decreasing light guiding and decreasing re-absorption inside the phosphor particle. The synthesized luminescent materials M2Si5N8:Eu2+ (M = Sr, Ba) exhibit quantum efficiencies and emission band widths (FWHM 70−90 nm) comparable to standard phosphor powders. Employment of Eu(NH2)2 as dopant reagent for synthesis of Ba2Si5N8:Eu2+ proved favorable for the formation of spherical crystallites compared to doping with Eu metal, halides, or oxide
Receptive field atlas and related CNN models
In this paper we demonstrate the potential of the cellular nonlinear/neural network paradigm (CNN) that of the analogic cellular computer architecture (called CNN Universal Machine | CNN-UM) in modeling different parts and aspects of the nervous system. The structure of the living sensory systems and the CNN share a lot of features in common: local interconnections ("receptive field architecture"), nonlinear and delayed synapses for the processing tasks, the
potentiality of feedback and using the advantages of both the analog and logic signal-processing mode. The results of more than ten years of cooperative work of many engineers and neurobiologists have been collected in an atlas: what we present here is a kind of selection from these studies emphasizing the exibility of the CNN computing: visual, tactile and auditory modalities
are concerned
Exclusive neuronal expression of SUCLA2 in the human brain
SUCLA2 encodes the ATP-forming subunit (A-SUCL-) of succinyl-CoA ligase, an enzyme of the citric acid cycle. Mutations in SUCLA2 lead to a mitochondrial disorder manifesting as encephalomyopathy with dystonia, deafness and lesions in the basal ganglia. Despite the distinct brain pathology associated with SUCLA2 mutations, the precise localization of SUCLA2 protein has never been investigated. Here we show that immunoreactivity of A-SUCL- in surgical human cortical tissue samples was present exclusively in neurons, identified by their morphology and visualized by double labeling with a fluorescent Nissl dye. A-SUCL- immunoreactivity co-localized >99% with that of the d subunit of the mitochondrial F0-F1 ATP synthase. Specificity of the anti-A-SUCL- antiserum was verified by the absence of labeling in fibroblasts from a patient with a complete deletion of SUCLA2. A-SUCL- immunoreactivity was absent in glial cells, identified by antibodies directed against the glial markers GFAP and S100. Furthermore, in situ hybridization histochemistry demonstrated that SUCLA2 mRNA was present in Nissl-labeled neurons but not glial cells labeled with S100. Immunoreactivity of the GTP-forming subunit (G-SUCL-) encoded by SUCLG2, or in situ hybridization histochemistry for SUCLG2 mRNA could not be demonstrated in either neurons or astrocytes. Western blotting of post mortem brain samples revealed minor G-SUCL- immunoreactivity that was however, not upregulated in samples obtained from diabetic versus non-diabetic patients, as has been described for murine brain. Our work establishes that SUCLA2 is expressed exclusively in neurons in the human cerebral cortex
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