Permeability plays an important role in the field of geotechnical engineering. Under high temperature and high pressure condition, the physical-chemical and structure properties (such as decomposition, oxidation, dehydration, evaporation, phase transition etc.) of rock have obviously changing, which are significant affected the rock permeability. In order to analyze the influence of temperature and confining pressure on the permeability of rock (sandstones, siltstones and conglomerates) data for permeability was obtained from the literature. The results indicate that temperature and confining pressure have great influence on the permeability of rock, especially for sandstone. There is a threshold temperature and when the heating temperature is lower than the threshold temperature, the permeability of sandstone gradually increases with an increase in temperature. When the heating temperature is higher than 300 ºC (especially 400 ºC), the permeability rapidly increases. The permeability of sandstone decreases gradually with the confining pressure increases. This study of the relationship between rock permeability and temperature and confining pressure lays a foundation for investigations of multi-disciplinary issues regarding high temperatures and high pressures and it can be used for the study of petroleum storage and safe nuclear waste disposal., Zhenlong Ge, Qiang Sun and Wenping Li., and Obsahuje bibliografii
In the frame of advanced studies of coal structure the temperature conditions of coal origin were investigated through thermal stability of aluminum complexes in coal substance. These compounds were discovered by solid-state nuclear magnetic resonance measurements of 27Al as a part of coal substance closely bonded to organic mass of coal. In obtained spectra, Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes were identified. These complexes were further prepared and their thermal stability tested by thermal analysis method. It was found that a) they can originate under room temperature and atmospheric pressure and b) they are thermally stable only up to approximately 85 or 95 °C. As both Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes are the integrated constituents of coal substance it can be deduced that, in the beginning, coal was formed under very mild thermal conditions. As investigated materials, coals and clays from the Czech basins and gagatite from Poland were measured., Pavel Straka and Jana Náhunková., and Obsahuje bibliografii
Whole blood surface tension of 15 healthy subjects recorded by the ring method was investigated in the temperature range from 20 to 40 °C. The surface tension σ as a function of temperature t (°C) is described by an equation of linear regression as σ(t) = (-0.473 t + 70.105) × 10-3 N/m. Blood serum surface tension in the range from 20 to 40 °C is described by linear regression equation σ(t) = (-0.368 t + 66.072) × 10-3 N/m and linear regression function of blood sediment surface tension is σ(t) = (-0.423 t + 67.223) ×10-3 N/m., J. Rosina, E. Kvašňák, D. Šuta, H. Kolářová, J. Málek, L. Krajči., and Obsahuje bibliografii
When exposing the leaf fragments of wheat (cv. Grana) to decreasing temperature, measurements of delayed luminescence allow to conclude lhát the photosynthetic apparatus in the few-days-old leaves is more low temperature sensitive than that in the leaves several days old.
nclusion of natural (glycerol, proline) or synthetic (polyethylene glycol) compatible solutes in the assay medium for phosphoenolpyruvate carboxylase (EC 4.1.1.31) activity at low substrate (phosphoenolpyruvate) levels enhanced the enzymic activity throughout the temperature range tested (11-42 °C). This effect was much more pronounced above 30 °C and, therefore, the optimum for activity was shifted from 27-29 °C to 37-39 °C, a temperature more consistent with the prevailing leaf temperatures during the growing season for C4-plants; there was also a better correlation between activity/temperature profile and the net photosynthetic rate of intact leaves of Cynodon dactylon (L.) Pers., at the temperature range tested.
This paper focuses on the impact of changes in temperature on one bay of St Vitus’ Cathedral in Prague Castle. The objective of the study is to simulate as correctly as possible the distribution of temperatures in the structure, and then to compute the thermal dilatation movements. Theoretical simulation of dilatation movements involves simulating the temperatures in the structure and then computing the displacements. Insolation and changes in air temperature around the structure are included in the temperature simulation. The computed temperature fields are used as a loading for computing the forces and deformations of one bay of St Vitus’ Cathedral. The theoretical deformation values obtained by means of the 3-D finite element model were compared with the measurements. The computed surface temperatures were also confronted with the surface temperatures measured in the interior and on the exterior of the cathedral. The results obtained from the simulations correspond well with the measured surface temperatures and deformations., Pavel Beran, Jiří Máca and Petr Fajman., and Obsahuje bibliografii
In order to manage the risks posed to domestic crop production by quarantine pests such as Thrips palmi, their potential to establish in a new environment must be assessed. The thermal requirements for development of T. palmi were determined and compared with UK temperatures, to estimate its potential for development under UK conditions. Temperature and rate of development of T. palmi from egg to adult were linearly related between 15 and 30°C, allowing calculation of an overall threshold of 10.1°C, and a sum of effective temperatures of 194 degree-days. In the UK, development of T. palmi would be possible outdoors during the summer when a maximum of up to four or five generations could occur. Comparison of these data with those of the recently established and biologically similar pest, Frankliniella occidentalis, shows that establishment of T. palmi in the UK is unlikely to be limited by an inability to complete the life cycle during the favourable season., Jamie R. McDonald, Jeffrey S. Bale, Keith F.A. Walters, and Lit
The functional response of Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) to different population densities of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) was investigated under laboratory conditions of 65 ± 5% R.H., a photoperiod of 14L : 10D and at temperatures of 25, 30 and 35 ± 1°C. Two, 4, 6, 8, 16, 32 and 64 third instar nymphs of P. solenopsis were exposed to newly emerged mated female parasitoids for 24 h. The parasitoid exhibited a type II functional response at all temperatures. The searching efficiencies (a) and handling times (Th) were 0.1818 h-1 and 5.0012 h at 25°C, 0.1382 h-1 and 3.2807 h at 30°C, and 0.2097 h-1 and 2.3635 h at 35°C, respectively. The maximum attack rates (T/Th) were 4.8, 7.3 and 10.2 nymphs at 25, 30 and 35°C, respectively. This indicates that A. bambawalei is more likely to be an effective biological control agent of P. solenopsis in warm seasons., Razieh Joodaki, Nooshin Zandi-Sohani, Sara Zarghami, Fatemeh Yarahmadi., and Obsahuje bibliografii
The first trimester of pregnancy is characterized by continuous proliferation, invasion and differentiation of cytotrophoblasts. These processes are precisely controlled both, in space and time by molecules such as endothelin-1 (ET-1). ET-1 is expressed in human first trimester trophoblast and is known to stimulate cytotrophoblast proliferation through endothelin A and B receptor subtypes (ETA and ETB), and cytotrophoblast invasion through ETB. However, temporal changes of the ET system during the first trimester of pregnancy have not been previously studied. This study tested the hypothesis that ET-1 release, ETA and ETB expression are increased towards the end of the first trimester of pregnancy (weeks 10-12 vs. weeks 6-9), resulting in increased cytotrophoblast proliferation and invasion. Tissue samples were obtained from 17 surgical pregnancy interruptions (week 6-9: n=9; week 10-12: n=8). After cytotrophoblast isolation, the invasive and proliferative phenotypes were immune-separated by an α6-integrin antibody. Both proliferative and invasive cytotrophoblasts were cultured separately on plastic or Matrigel for 24 h. ET-1 release into the culture medium of both cytotrophoblast subtypes was measured by radioimmunoassay. ETA and ETB mRNA expression was measured by RT-PCR, and the ET-1 effect on cytotrophoblast proliferation and invasion was determined using proliferation and invasion assays, respectively. ET-1 release increased from early to late first trimester of pregnancy in both proliferative (1.8-4.5 fold) and invasive cytotrophoblasts (9.3-28 fold), especially when cultured on Matrigel. This was paralleled by less ETB mRNA on invasive cytotrophoblasts independent of the time period in first trimester, whereas ETA expression was similar on proliferative an invasive cytotrophoblasts. Proliferation and invasion of cytotrophoblasts under control conditions decreased from early to late first trimester. The ET-1/ET-receptor system changes between weeks 6-9 and 10-12 in pregnancy. Our data suggest an autocrine and endocrine ET-1 effect, which is stronger in late than in early first trimester of pregnancy paralleled by different stimulatory effects on trophoblast invasion and proliferation. In general, this suggests time as an additional effector of the critical processes governing placental development in the first trimester of human pregnancy., A. Majali-Martinez, S. Barth, U. Lang, G. Desoye, M. Cervar-Zivkovic., and Seznam literatury