scholarly journals Effects of City Size on Thunderstorm Evolution Revealed through a Multiradar Climatology of the Central United States

2018 ◽  
Vol 57 (2) ◽  
pp. 295-317 ◽  
Author(s):  
Darrel M. Kingfield ◽  
Kristin M. Calhoun ◽  
Kirsten M. de Beurs ◽  
Geoffrey M. Henebry

AbstractFive years of 0.01° latitude × 0.01° longitude multiradar multisensor grids of composite reflectivity and vertically integrated signals from the maximum expected size of hail (MESH) and vertically integrated liquid (VIL) were created to examine the role of city size on thunderstorm occurrence and strength around four cities: Dallas–Fort Worth, Texas; Minneapolis–St. Paul, Minnesota; Oklahoma City, Oklahoma; and Omaha, Nebraska. A storm-tracking algorithm identified thunderstorm areas every minute and connected them together to form tracks. These tracks defined the upwind and downwind regions around each city on a storm-by-storm basis and were analyzed in two ways: 1) by sampling the maximum value every 10 min and 2) by accumulating the spatial footprint over its lifetime. Beyond examining all events, a subset of events corresponding to favorable conditions for urban modification was explored. This urban favorable (UF) subset consisted of nonsupercells occurring in the late afternoon/evening in the meteorological summer on weak synoptically forced days. When examining all thunderstorm events, regions at variable ranges upwind of all four cities generally had higher areal mean values of reflectivity, MESH, and VIL relative to downwind areas. In the UF subset, the larger cities (Dallas–Fort Worth and Minneapolis–St. Paul) had a 24%–50% increase in the number of downwind thunderstorms, resulting in a higher areal mean reflectivity, MESH, and VIL in this region. The smaller cities (Oklahoma City and Omaha) did not show such a downwind enhancement in thunderstorm occurrence and strength for the radar variables examined. This pattern suggests that larger cities could increase thunderstorm occurrence and intensity downwind of the prevailing flow under unique environmental conditions.

2020 ◽  
pp. 75-79
Author(s):  
R. M. Gambarova

Relevance. Grain is the key to strategic products to ensure food security. From this point of view, the creation of large grain farms is a matter for the country's selfsufficiency and it leading to a decrease in financial expense for import. Creation of such farms creates an abundance of productivity from the area and leads to obtaining increased reproductive seeds. The main policy of the government is to minimize dependency from import, create abundance of food and create favorable conditions for export potential.The purpose of the study: the development of grain production in order to ensure food security of the country and strengthen government support for this industry.Methods: comparative analysis, systems approach.Results. As shown in the research, if we pay attention to the activities of private entrepreneurship in the country, we can see result of the implementation of agrarian reforms after which various types of farms have been created in republic.The role of privateentrepreneurshipinthedevelopmentofproduction is great. Тhe article outlines the sowing area, production, productivity, import, export of grain and the level of selfsufficiency in this country from 2015 till 2017.


2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.


2021 ◽  
Vol 4 (2) ◽  
pp. 24-31
Author(s):  
Nargiz Sattarova ◽  

This article presents the definitions of the concept of trade services by various scientists, the place and role of trade services in all spheres and sectors of society, as well as a new definition of trade services given by the author.If the main goal of the current stage of economic transformation is to create favorable conditions for the effective operation of trade enterprises, then the main goal of the article is an in-depth study of the essence and content of the concept of trade services as an independent economic entity.


Author(s):  
KU Ahamed ◽  
B Akhter ◽  
MR Islam ◽  
MR Humaun ◽  
MJ Alam

Genetic divergence of 110 lentil germplasm with checks was assessed based on morphological traits using multivariate analysis. Mahalanobis generalized distance (D2) analysis was used to group the lentil genotypes. Significant variations among lentil genotypes were observed in respect of days to 1st flowering, days to 50% flowering, days to maturity, plant height, and number of pods per peduncle, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant. Considering the mean values, the germplasm were grouped into ten clusters. The highest number of genotypes (17) was in cluster X and lowest (5) both in cluster II and IV. Cluster IV had the highest cluster mean for number of pods per plant (297.08), number of seeds per plant (594.16), 100 seed weight (1.44 g) and yield per plant (8.53 g). Among them, the highest inter-cluster distance was obtained between the cluster IV and I (24.61) followed by IV and III (22.33), while the lowest was between IX and II (1.63). The maximum value of inter-cluster distance indicated that genotypes belonging to cluster IV were far diverged from those of cluster I. The first female flower initiation was earlier in BD-3812 (49 days) in cluster I and cluster IV had highest grain yield per plant (8.53). BD-3807 produced significant maximum number of pods per plant (298.40) in cluster IV. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21095 Int. J. Agril. Res. Innov. & Tech. 4 (1): 70-76, June, 2014


2017 ◽  
Vol 50 (2) ◽  
pp. 327-349 ◽  
Author(s):  
Eric Sarmiento

This paper draws on assemblage thinking—especially Deleuze and Guattari’s conception of territorialization—to analyze urban redevelopment processes in Oklahoma City, a mid-sized city in the central United States that has pursued a culturally led, “entrepreneurial” approach to redevelopment. Focusing on the linkages between architecture, sport, and local food in the city, I demonstrate some of the ways in which these realms were woven together in support of the territorial expansion of redevelopment. Following recent research on affect in human geography, I argue that the interweaving of these realms involved careful attention to the material capacities of buildings, athletic bodies, and foods to generate a sense of excitement, pride in place, self-worth, and above all movement in the city. The paper concludes with a discussion of some of the implications of this analysis for the politics of redevelopment and some suggestions for future research.


2002 ◽  
Vol 282 (6) ◽  
pp. H2427-H2440 ◽  
Author(s):  
Christian A. J. Schulze-Bauer ◽  
Peter Regitnig ◽  
Gerhard A. Holzapfel

Adventitial mechanics were studied on the basis of adventitial tube tests and associated stress analyses utilizing a thin-walled model. Inflation tests of 11 nonstenotic human femoral arteries (79.3 ± 8.2 yr, means ± SD) were performed during autopsy. Adventitial tubes were separated anatomically and underwent cyclic, quasistatic extension-inflation tests using physiological pressures and high pressures up to 100 kPa. Associated circumferential and axial stretches were typically <20%, indicating “adventitiosclerosis.” Adventitias behaved nearly elastically for both loading domains, demonstrating high tensile strengths (>1 MPa). The anisotropic and strongly nonlinear mechanical responses were represented appropriately by two-dimensional Fung-type stored-energy functions. At physiological pressure (13.3 kPa), adventitias carry ∼25% of the pressure load in situ, whereas their circumferential and axial stresses were similar to the total wall stresses (∼50 kPa in both directions), supporting a “uniform stress hypothesis.” At higher pressures, they became the mechanically predominant layer, carrying >50% of the pressure load. These significant load-carrying capabilities depended strongly on circumferential and axial in-vessel prestretches (mean values: 0.95 and 1.08). On the basis of these results, the mechanical role of the adventitia at physiological and hypertensive states and during balloon angioplasty was characterized.


2020 ◽  
Author(s):  
Mingzi Chen ◽  
Yanmin Jia ◽  
Huamei Li ◽  
Zheng Wu

Abstract The BiFeO3/g-C3N4 heterostructure, which is fabricated via a simple mixing-calcining method, benefits the significant enhancement of the pyrocatalytic performance. With the growth of the g-C3N4 content in the heterostructure pyrocatalysts from 0 to 25 %, the decomposition ratio of Rhodamine B (RhB) dye after 18 cold-hot temperature fluctuation (25 oC - 65 oC) cycles increases at first and then decreases, reaching a maximum value of ~ 94.2 % at 10% while that of the pure BiFeO 3 is ~ 67.7 %. The enhanced dye decomposition may be due to the fabrication of the heterostructure which strengthens the separation of the positive and negative carriers and further accelerates their migration. The intermediate products in the pyrocatalytic reaction also have been detected and confirmed, which proves the key role of the pyroelectric effect in realizing the dye decomposition using BiFeO3/g-C3N4 heterostructure catalyst. The pyroelectric BiFeO3/g-C3N4 heterostructure shows the potential application in pyrocatalytically degrading dye wastewater.


1990 ◽  
Vol 259 (3) ◽  
pp. H843-H848 ◽  
Author(s):  
H. E. Cingolani ◽  
Y. Koretsune ◽  
E. Marban

During acute respiratory acidosis, cardiac contractile pressure first drops but then recovers substantially. We investigated the mechanism of this response in isovolumic perfused ferret hearts. Developed pressure (DP) and its first derivative (dP/dt) were measured before, during, and after hypercapnia induced by equilibrating the perfusate with 15% CO2, rather than the 5% CO2 used in control. Intramyocardial pH (pHi) was measured by phosphorus nuclear magnetic resonance (NMR) spectroscopy. After the onset of hypercapnia (1-2 min), DP and +dP/dt reached minimal mean values of 37 +/- 2 and 39 +/- 3% of control, respectively. This early decline in myocardial contactility was followed by a partial recovery such that DP and +dP/dt had returned to 66 +/- 6 and 62 +/- 4% of control, respectively, by 14 min of hypercapnia. pHi fell from 7.17 +/- 0.01 in control to 6.88 +/- 0.11 after approximately 2 min of hypercapnia. Thereafter, pHi recovered linearly with a mean slope of 0.011 +/- 0.003 pH U/min. Ethylisopropylamiloride (10(-6) M), a blocker of Na(+)-H+ exchange, prevented the recovery of pHi during hypercapnia and attenuated the recovery of contractility by 40%. We conclude that the recovery of contractility during respiratory acidosis at least partially reflects an underlying recovery of pHi mediated by Na(+)-H+ exchange.


2019 ◽  
Vol 11 (12) ◽  
pp. 1257-1260 ◽  
Author(s):  
Girish Bathla ◽  
Kaustubh Limaye ◽  
Bruno Policeni ◽  
Ernst Klotz ◽  
Markus Juergens ◽  
...  

BackgroundThe role of mechanical thrombectomy in acute ischemic stroke (AIS) has been further expanded by recent trials which relied on the results of CT perfusion (CTP) imaging. However, CTP parameters for ischemia and infarct can vary significantly across different vendors.MethodsWe compared the outcomes of the Siemens CTP software against the clinically validated RAPID software in 45 consecutive patients with suspected AIS. Both perfusion softwares initially processed images using vendor defined parameters for hypoperfusion and non-viable tissue. The software thresholds on the Siemens software were decrementally altered to see if concordant results between softwares could be attained.ResultsAt baseline settings, the mean values for core infarct and hypoperfusion were different (mean of 30/69 mL, respectively, for RAPID and 49/77 mL for Siemens). However, reducing the threshold values for the later software showed a concordance of values at a relative cerebral blood flow <20%, with resulting core infarct and hypoperfusion volumes at 31/69 mL, respectively, for the Siemens software. A Wilcoxon paired test showed no significant difference between the calculated core infarct and hypoperfusion values, both for the entire population as well as for the subgroup of patients with large vessel occlusion.ConclusionEquivalent CTP results between vendor softwares may be attainable by altering the thresholds for hypoperfused and non-viable tissue, despite differences in acquisition techniques, post-processing, and scanners.


Cephalalgia ◽  
1991 ◽  
Vol 11 (6) ◽  
pp. 263-268 ◽  
Author(s):  
Volker Pfaffenrath ◽  
Josef Hummelsberger ◽  
Walter Pöllmann ◽  
Holger Kaube ◽  
Michael Rath

The role of psychological factors in the course of primary headache syndromes is still controversial. Using the Minnesota Multiphasic Personality Inventory (MMPI) we investigated the personality profiles of 434 headache patients (160 migraineurs, 95 with tension type headache, 30 with cluster headache and 149 with combination headache) in accordance with the IHS criteria. In the first three MMPI scales (hypochondria, depression, hysteria) there was a slight increase in T mean values to over 60, but still in the range of two standard deviations of the normal population. There were no statistically significant differences between the four headache groups and between patients with and without analgesic abuse. It was impossible to distinguish headache groups on the basis of their personality profiles by means of reclassification with discriminant analysis. In a cluster analysis, patients with cluster headache showed the highest number (20%) of abnormalities, but also the highest percentage (13%) of completely normal results. Our findings- a cross section analysis of personality profiles-contradict many other MMPI-based studies.


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