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442. A combined CFD-experimental method for abrasive erosion testing of concrete
- Creator:
- Messa, Gianandrea Vittorio, Branco, Renan De Lima, Filho, José Gilberto Dalfré, and Malavasi, Stefano
- Type:
- article, model:article, and TEXT
- Subject:
- abrasive erosion, computational fluid dynamics, concrete, experiments, and two-phase flow
- Language:
- Slovak
- Description:
- Serious damage may occur to concrete hydraulic structures, such as water galleries, spillways, and stilling basins, due to the abrasive erosion caused by the presence of solid particles in the flow. This underlines the importance of being capable in providing characterization of the concrete from the point of view of its vulnerability to abrasive erosion, in order to improve the design of the structure and the material selection. Nevertheless, the existing apparatus for concrete abrasive erosion testing are either far from allowing realistic simulation of the actual environment in which this phenomenon occurs, or show a large degree of complexity and cost. An alternative method has been developed with the aid of Computational Fluid Dynamics (CFD). CFD was first employed to verify the effectiveness of a new laboratory equipment. Afterwards, a parameter has been introduced which, by successful comparison against preliminary experiments, proved suitable to quantify the effect of the fluid dynamic conditions on the concrete abrasive erosion, thereby opening the way to CFD-based customization of the apparatus. In the future, the synergy of numerical and physical modelling will allow developing predictive models for concrete erosion, making it possible to reliably simulate real structures.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
443. A comparative study of reactive hyperemia in human forearm skin and muscle
- Creator:
- Addor, G., Delachaux, A., Dischl, B., Hayoz, D., Liauder, L., Waeber, B., and Feihl, Francois
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, patologická fyziologie, ischemie, physiology, pathological physiology, ischemia, vasodilation, laser Doppler, strain gauge plethysmography, surrogate endpoint, acetylsalicylate, 14, and 612
- Language:
- English
- Description:
- Reactive hyperemia (RH) in forearm muscle or skin microcirculation has been considered as a surrogate endpoint in clinical studies of cardiovascular disea e. We evaluated two potential confounders that might limit such use of RH, namely laterality of measurement and intake of non-steroidal anti-inflammatory drugs (NSAIDS). Twenty-three young non-smoking healthy adults were enrolled. In Experiment 1 (n=16), the RH elicited by 3 min of ischemia was recorded in the muscle (strain gauge plethysmography, hand excluded) and skin (laser Doppler imaging) of both forearms. In Experiment 2 (n=7), RH was determined in the dominant forearm only, one hour following oral acetylsalicylic acid (1 g) or placebo. In Experiment 1, peak RH was identical in both forearms, and so were the corresponding durations of responses. RH lasted significantly less in muscle than in skin (p=0.003), a hitherto unrecognized fact. In the skin, acetylsalicylate reduced duration (43 vs. 57.4 s for placebo, p=0.03), without affecting the peak response. In muscle, duration tended to decrease with acetylsalicylate (21.4 vs. 26.0 s with placebo, p=0.06) and the peak increase in blood flow was blunted (27.2 vs. 32.4 ml/min/100 ml tissue with placebo, p=0.003). We conclude that, when using RH as a surrogate endpoint in studies of cardiovascular disease, a confounding by laterality of measurement need not be feared, but NSAIDS may have an influence, although perhaps not on the peak response in the skin., G. Addor, A. Delachaux, B. Dischl, D. Hayoz, L. Liaudet, B. Waeber, F. Feihl., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
444. A comparative study of the abdominal trichobothria of Trichophora, with emphasis on Lygaeoidea (Hemiptera: Heteroptera)
- Creator:
- Gao, Cuiqing, Rédei, Dávid, Shi, Xueqin, Cai, Bo, Liang, Ke, Gao, Shuo, and Bu, Wenjun
- Type:
- article, model:article, and TEXT
- Subject:
- Heteroptera, Hemiptera, Trichophora, Lygaeoidea, abdominal trichobothria, morphology, and systematics
- Language:
- English
- Description:
- Members of the clade Trichophora (Hemiptera: Heteroptera: Pentatomomorpha) have trichobothria on their abdominal sterna. There is no comparative study of the fine structure of abdominal trichobothria in the group and until now the trichobothria of their immatures were virtually unknown. The fine structure of the abdominal trichobothrial complex (= the trichobothrium and its associated structures) of adults of 98 species belonging to 25 families in 5 superfamilies and larvae of 7 species belonging to 7 families in 2 superfamilies of Trichophora were examined using scanning electron microscopy. This study indicates that the fine structure of the abdominal trichobothria is very variable and useful for determining evolutionary lineages within the clade. Six types of bothria, three of trichomes and three of microtrichia are recognized and their evolutionary transformations discussed. Changes in the size of trichomes, and density and size of the microtrichia during the postembryonic development of selected species are discussed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
445. A comparison of aggression and impulsivity between smokers and non-smokers
- Creator:
- Zaidi, Uzma
- Format:
- electronic, electronic resource, remote, and elektronický zdroj
- Type:
- model:article, article, Text, srovnávací studie, and TEXT
- Subject:
- kouření--epidemiologie--psychologie--škodlivé účinky, agrese--psychologie, impulzivní chování, poruchy vyvolané užíváním tabáku--psychologie, průzkumy a dotazníky, studenti, dospělí, lidé, and mužské pohlaví
- Language:
- English
- Description:
- The study aimed to investigate the role of aggression and impulsivity in smoking among male adult students. It was hypothesized that there would be significant difference between smokers and non- smokers on the traits of aggression and impulsivity. The sample of two hundred male adult students was selected from different universities of Islamabad. Two subscales of Impulsiveness and Aggression were administered to measure the personality traits of aggression and impulsivity. Descriptive statistics and t-test was calculated for analysis of data. Results showed that there is significant differences in aggression and impulsivity between smokers and non-smokers. The result can be helpful for psychologist and other professionals to plan public health therapeutic and social reengineering interventions for youth., Uzma Zaidi, and Literatura
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
446. A comparison of different rubber dam systems on a dental simulator
- Creator:
- Kapitán, Martin, Šustová, Zdeňka, Koberová Ivančaková, Romana, and Suchánek, Jakub
- Format:
- print, text, and regular print
- Type:
- model:article, article, Text, srovnávací studie, časopisecké články, práce podpořená grantem, and TEXT
- Subject:
- design vybavení, lidé, testování materiálů, biologické modely, and gumové blány
- Language:
- English
- Description:
- The purpose of this study was to test the hypothesis that more recently developed rubber dam systems (OptraDam ® Plus and OptiDam™) are faster and easier to handle, and that the quality of isolation is not decreased. The rubber dam systems were applied in standard conditions on a dental simulator in several model clinical situations. The time of preparation, application and removal were measured and the quality of isolation was evaluated. The median time of rubber dam placement was 51 s (Q1 = 38 s; Q3 = 79 s). The shortest median time of application was with OptiDam™ (42 s), followed by a conventional rubber dam (53 s), and finally the longest was with OptraDam® Plus (58 s). The median volume of fluid remaining in the isolated space after 5 minutes was 9.5 mL (Q1 = 8 mL; Q3 = 10 mL). The largest median volume of remaining water was with OptiDam™ (10 mL), followed by a conventional rubber dam (9.5 mL) and the least with OptraDam® Plus (8.5 mL). The afore-stated hypothesis about the advantages of modern rubber dam isolation systems was accepted for OptiDam™, but rejected for OptraDam® Plus. The results could contribute to decision-making concerning the choice of rubber dam system. and Martin Kapitán, Zdeňka Šustová, Romana Ivančaková, Jakub Suchánek
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
447. A comparison of numerical models results with in-situ measurement of ground vibrations caused by sheet pile driving
- Creator:
- Tomáš Petřík, Eva Hrubešová, and Markéta Lednická
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, numerické modelování, numerical modeling, dynamic analysis, Plaxis 2D, sheet pile driving, vibration velocity amplitude, vibration frequency, vibratory hammer, 7, and 551
- Language:
- English
- Description:
- This paper pursues the effect of changes in distance and vibration frequency on the vibration velocity amplitude. As an example, we used the vibrating sheet piles at the cons truction of a new multi-functional FEI building on the premises of VŠB - TU Ostrava, at 17 listopadu street. The effect of these changes is monitored both in in-situ measurements and in a simulated real-life situation. The calculation software Plaxis 2D is used for creation of numer ical models. At the close, the results from in-situ measurements are confronted with those achieved from the models., Tomáš Petřík, Eva Hrubešová and Markéta Lednická., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
448. A comparison of portal vein embolization with poly(2-hydroxyethylmethacrylate) and a histoacryl/lipiodol mixture in patients scheduled for extended right hepatectomy
- Creator:
- Jan H. Peregrin, Radim Janoušek, Dana Kautznerová, Martin Oliverius, Eva Sticová, Martin Přádný, and Michálek, J.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, extended right hepatectomy, portal vein embolization, embolization-induced left liver lobe hypertrophy, 14, and 612
- Language:
- English
- Description:
- To determine whether PHEMA [poly(2-hydroxyethylmethacrylate)] is suitable for portal vein embolization in patients scheduled to right hepatectomy and whether it is as effective as the currently used agent (a histoacryl/lipiodol mixture). Two groups of nine patients each scheduled for extended right hepatectomy for primary or secondary hepatic tumor, had right portal vein embolization in an effort to induce future liver remnant (FLR) hypertrophy. One group had embolization with PHEMA, the other one with the histoacryl/lipiodol mixture. In all patients, embolization was performed using the right retrograde transhepatic access. Embolization was technically successful in all 18 patients, with no complication related to the embolization agent. Eight patients of either group developed FLR hypertrophy allowing extended right hepatectomy. Likewise, one patient in each group had recanalization of a portal vein branch. Hist ology showed that both embolization agents reach the periphery of portal vein branches, with PHEMA penetrating somewhat deeper into the periphery. PHEMA has been shown to be an agent suitable for embolization in the portal venous system comparable with existing embolization agent (histoacryl/lipiodol mixture)., J. H. Peregrin, R. Janoušek, D. Kautznerová, M. Oliverius, E. Sticová, M. Přádný, J. Michálek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
449. A comparison of the amino acid profiles of the pea aphid, Acyrthosiphon pisum, and the social aphid species, Pemphigus spyrothecae (Hemiptera: Aphididae)
- Creator:
- Pike, Nathan
- Type:
- article, model:article, and TEXT
- Subject:
- Hemiptera, Aphididae, Pemphigus spyrothecae, Acyrthosiphon pisum, artificial diet, soldier aphid, lant gall, amino acid profile, and high performance liquid chromatography
- Language:
- English
- Description:
- The relative proportions of free amino acids as well as the amino acid compositions of hydrolysed unprecipitated peptides and hydrolysed whole carcasses were quantified for two aphid species: the gall-dwelling social aphid Pemphigus spyrothecae and the pea aphid Acyrthosiphon pisum. The whole-tissue amino acid profiles of the two taxonomically distant species had a surprisingly high level of correspondence. In contrast, when comparing the A. pisum profiles obtained in the current study to those obtained in an earlier study, major differences were identified. It is concluded that there are good prospects for developing an artificial diet for P. spyrothecae. There may also exist considerable scope for tailoring the existing diets of A. pisum to suit specialised populations which develop poorly on the standard diet. The amino acid profile of P. spyrothecae is the first such profile that has been reported for a gall-forming aphid.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
450. A comparison of the effects of troglitazone and vitamin E on the fatty acid composition of serum phospholipids in an experimental model of insulin resistance
- Creator:
- Chvojková, Š., Ludmila Kazdová, and Jana Divišová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, vitamin E, mastné kyseliny, inzulinová rezistence, fatty acids, insulin resistance, troglitazone, serum phospholipids, 14, and 612
- Language:
- English
- Description:
- The aim of this study was to investigate the effects of troglitazone (TRO) - a new insulin-sensitizing agent - on some metabolic parameters in an experimental model of hypertriglyceridemia and insulin resistance, hereditary hypertriglyceridemic rats, and to compare its effects with those of vitamin E, an antioxidant agent. Three groups of the above rats were fed diets with a high content of sucrose (70 % of energy as sucrose) for four weeks. The first group was supplemented with TRO (120 mg/kg diet), the second one with vitamin E (500 mg/kg diet), and the third group served as the control. Vitamin E supplementation did not lower serum triglycerides (2.42±0.41 vs. 3.39±0.37 mmol/l, N.S.) while TRO did (1.87±0.24 vs. 3.39±0.37 mmol/l, p<0.01). Neither TRO nor vitamin E influenced the serum levels of free fatty acids (FFA). Both drugs influenced the spectrum of fatty acids in serum phospholipids - TRO increased the levels of polyunsaturated fatty acids (PUFA) n-6 (36.04±1.61 vs. 19.65±1.56 mol %, p<0.001), vitamin E increased the levels of PUFA n-3 (13.30±0.87 vs. 6.79±0.87 mol %, p<0.001) and decreased the levels of saturated fatty acids (32.97±0.58 vs. 51.45±4.01 mol %, p<0.01). In conclusion, TRO lowered the level of serum triglycerides but vitamin E did not have this effect in hypertriglyceridemic rats. Compared with TRO, vitamin E had a different effect on the spectrum of fatty acids in serum phospholipids., Š. Chvojková, L. Kazdová, J. Divišová., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public