Bond-orientationally-ordered phases that scatter light strongly

We test several approximate theories of thermal rate constants against accurate quantal equilibrium rate constants for collinear bimolecular reactions governed by given potential energy surfaces. The systems considered are F+H2 and F+D2 for the Muckerman potential energy surface no. 5 at 200–1200 K and H+F2, D+F2, and T+F2 for potential surface II of Jonathan, Okuda, and Timlin at 233–1260 K. For F+H2, conventional transition state theory overestimates the accurate rate constant by factors of 2.9–3.4, with the largest errors at the lowest and highest temperatures. Vibrationally adiabatic transmission coefficients or variational transition state theory decrease the error to factors of 1.2–1.3 at the lowest temperature and to a factor of 3.2 at the highest temperature. The unified statistical model reduces the errors to a factor of 1.1 at the lowest temperature and a factor of 2.7 at the highest temperature. For F+D2 the trends are similar but the errors in all the methods are smaller at all temperatures. For H+F2 conventional transition state theory underestimates the rate constants by a factor of 0.56 at the lowest temperature with the error decreasing to 2% at the highest temperature. Various formulations of vibrationally adiabatic transmission coefficients, in conjunction with either conventional or variational transition state theory, reduce the error to factors of 0.84–0.96 at the lowest temperature while not destroying the good agreement at the highest temperature. The unified statistical theory seems to overestimate the recrossing correction for this reaction, though only by about 10%. The results are similar for D+F2 and T+F2 except that the low-temperature underestimates of the calculations without tunneling are not as severe. The best theory, improved canonical variational theory with the Marcus–Coltrin path semiclassical adiabatic ground-state transmission coefficient, reproduces the accurate quantal results for H+F2, D+F2, and T+F2 within 5% or better in every case for the whole temperature range.

To improve the creep strength of Ni-base superalloys, Re and Ru additions were investigated with using 2nd generation single crystal superalloy TMS-82+ which contains 2.4 mass%Re, as the base alloy. When Re and Ru were added at the same time, creep strength was improved at lower and higher temperature. We suppose that these were caused by the solution strengthening due to Re at lower temperature, and the stabilization of γ/γ′ structure at higher temperature by Ru addition. Further more, in the case of Re addition, creep strength at lower temperature was improved, and creep strength at higher temperature became worse due to the TCP phase formation. Also, in the case of Ru addition, creep strength at lower and higher temperature became worse, although TCP phase formation was completely suppressed. This is because Ru is not an effective element for the solution strengthening at high temperature.

The rate of light-saturated photosynthesis in 3 marine algae [Phaeodactylum tricornutum Bohlin, Nitzschia closterium (Ehrenberg) Smith and Dunaliella tertiolecta Butcher] varies during growth in batch culture. The photosynthetic rare declines most rapidly during growth at the higher temperatures. Because of these changes in photosynthesis rate, the previously reported enhanced photosynthetic abilities caused by growth at lower temperatures (generally interpreted as evidence for higher enzyme levels) can only be observed when measurements are made late in the exponential phase or after the onset of the stationary phase of growth. When allowance is made for the earlier peak of photosynthetic ability in cultures growing at higher temperatures, there is no evidence for adaptation to lower temperatures being caused by increased levels of the enzymes required for carbon-dioxide fixation. When the changes due to growth in batch culture are taken into account, certain effects of temperature can be recognized. the dry weight: chlorophyll ratio of all 3 algae increases with decreasing growth temperatures. For P. tricornutum and N. closterium, growth at lower temperatures reduces the cellular content of chlorophyll a, but has little effect on the chlorophyll content of D. tertiolecta. The dry weight: cell-number ratio of D. tertiolecta and P. tricornutum increases with lower growth temperatures, but growth temperature has little effect on the cell mass of N. closterium. Growth of the 3 algae at lower temperatures does not increase their ability to photosynthesize at these lower temperatures. Rather, it reduces their ability to assimilate carbon dioxide at the higher temperatures.

We study the formulation of bond-orientational order in an arbitrary two dimensional geometry. We find that bond-orientational order is properly formulated within the framework of differential geometry with torsion. The torsion reflects the intrinsic frustration for two-dimensional crystals with arbitrary geometry. Within a Debye-Huckel approximation, torsion may be identified as the density of dislocations. Changes in the geometry of the system cause a reorganization of the torsion density that preserves bond-orientational order. As a byproduct, we are able to derive several identities involving the topology, defect density and geometric invariants such as Gaussian curvature. The formalism is used to derive the general free energy for a 2D sample of arbitrary geometry, both in the crystalline and hexatic phases. Applications to conical and spherical geometries are briefly addressed.

The rainy and rainless years, and the higher and lower temperature years in arid central Asia were divided by using the gridded monthly air temperature and precipitation data from the Climate Research Unit (CRU) and the Tyndall Center, University of East Anglia, UK. And the mechanisms of temperature and precipitation change in these typical years were analyzed by using the NCEP/NCAR data from the National Centers for Environmental Prediction and the National Center for Atmospheric Research of USA. The results show that in the rainy years, the ascending motion areas are located in the west part of arid central Asia in winter and in the east part in summer. No matter in the rainy or rainless years, the sinking motion areas are located in the east part of arid central Asia in winter and in the west part in summer. For precipitation, in winter, the dynamical structure of rainy years presents decreasing of the Ural pressure ridge and East Asian trough in association with the deepening of East European trough. In opposite, the Ural pressure ridge and East Asian trough has a stiffness condition and the meridional airflow strengthening in the rainless years. In summer, the dynamical structure of rainy years presents the strengthening of East European high pressure ridge and the western Pacific subtropical high ridge in association with the western-spread of subtropical ridge. For temperature, in winter, the west part of arid central Asia is affected by south-west warm airflow and the east part is affected by north-west airflow in higher temperature years. However, the whole arid central Asia is controlled by north-west airflow in lower temperature years. In summer, the intensity and location of the west Pacific subtropical high pressure play an important role in determining the higher or lower temperature years. It should be higher temperature years when the subtropical high pressure strengthens and western-spreads. It should be lower temperature years when the subtropical high pressure decreases and withdraws eastward.

New universal indicator

The mixing of field-induced and current-induced degradation mechanisms can result in TDDB data showing a strong non-Arrhenius temperature dependence. Generally, at higher fields and lower temperatures, the current-induced mechanism dominates and a small activation energy is observed. At lower fields and higher temperatures, the field induced degradation mechanism tends to dominate and a strong temperature dependence is produced. The mixing of the current-induced and field-induced mechanisms can result in an activation energy associated with TDDB which is not unique but strongly dependent on test conditions and oxide thickness. The mixing is validated over various voltage, field, thickness and temperature regimes.

Climate change and the subsequent increase of global temperature are the most current and important threats to biodiversity. Despite the importance of temperature, our knowledge about the level of behavioural and physiological adaptations of ant species from temperate regions to cope with high temperatures is limited compared to the broad knowledge of typical thermal specialists from warmer regions. In the current study, we investigated the temperature-related foraging risk of xerothermic ant species from the temperate climate in Europe, Formica cinerea. Our aims were to check how an increase in external soil temperature affects the foraging activity of workers and how the temperature during development and worker age affects foraging activity in high temperatures. Based on our results, we can draw the following conclusions: (1) the majority of workers utilize a risk-aversive strategy in relation to foraging in high surface temperatures; (2) pupal development temperature affects the risk taken by adult workers: workers that developed in a higher temperature forage more often but for shorter intervals compared to workers that developed in a lower temperature; (3) age is an important factor in temperature-related foraging activity, as with increasing age, workers forage significantly longer at the highest temperatures. Our study is one of the first to assess the potential factors that can affect the foraging risk of ants from a temperate climate in high ambient temperatures.Significance statementOur study is the first direct test of workers' age and the development temperature of pupae on the thermal-related foraging strategy of adult F. cinerea workers. It shows that worker age and the development temperature of pupae interact to promote tolerance of thermal stress. We found that with increasing age, workers are prone to forage significantly longer at the highest and riskiest temperatures. Workers that developed in the high temperature (28°C) foraged more often but for shorter intervals compared to workers that developed in the lower temperature (20°C). Interestingly, the factor of age is more significant for ants that developed in the higher temperature of 28°C; the foraging time of these ants significantly increased with their age.

We present an x-ray study of liquid crystal membranes in the vicinity of the hexatic-smectic phase transition by means of angular x-ray cross-correlation analysis. By applying two-point angular-intensity cross-correlation functions to the measured series of diffraction patterns the parameters of bond-orientational (BO) order in hexatic phase were directly determined. The temperature dependence of the positional correlation lengths was analyzed as well. The obtained correlation lengths show larger values for the higher-order Fourier components of BO order. These findings indicate a strong coupling between BO and positional order.

Infinite dilution activity coefficients for benzene and toluene in water and in aqueous solutions of the protein denaturants urea and guanidine hydrochloride

Thermally-enhanced bioremediation is a promising treatment approach for petroleum contamination; however, studies examining temperature effects on anaerobic biodegradation in zones containing light non-aqueous phase liquids (LNAPLs) are lacking. Herein, laboratory microcosm studies were conducted for a former refinery to evaluate LNAPL transformation, sulfate reduction, and methane generation over a one-year period for temperatures ranging from 4 to 40 °C, and microbial community shifts were characterized. Temperatures of 22 and 30 °C significantly increased total biogas generation compared to lower (4 and 9 °C) and higher temperatures (35 and 40 °C; p < 0.1). Additionally, at 22 and 30 °C methane generation commenced ~6 months earlier than for 35 and 40 °C. Statistically significant biodegradation of benzene, toluene and xylenes was observed at elevated temperatures but not at lower temperatures (p < 0.1). Additionally, a novel differential chromatogram approach was developed to overcome challenges associated with resolving losses in complex mixtures of hydrocarbons, and application of this method revealed greater losses of hydrocarbons at 22 and 30 °C as compared to lower and higher temperatures. Finally, molecular biology assays revealed that the composition and activity of microbial communities shifted in a temperature-dependent manner. Collectively, results demonstrated that anaerobic biodegradation processes can be enhanced by increasing the temperature of LNAPL-containing soils, but biodegradation does not simply increase as temperature increases likely due to a lack of microorganisms that thrive at temperatures well above the historical high temperatures for a site. Rather, optimal degradation is achieved by holding soils at the high end of, or slightly higher than, their natural range.

To examine the varietal difference of swelling behaviour and total solids content in residual cooking liquid, milled white rice sampled of 58 varieties were treated with excess water fqr 30 minutes at temperatures ranging from 60° to 96°C. Swelling behaviour was experssed as the water-uptake ratio (weight of cooked rice)/(weight of raw rice), because the water-uptake ratio was colosely related to the swelling in the volume as shown in fig. 1. The total solid content was experssed as percent of raw rice, (dry weight of total solids) × 100/(dry weight of raw rice). The results are summarized. as follows: 1) In general, Japonica varieties began to swell at the lower temperatures than did Indica varieties, and among Indicas many of the semi-hard varieties (medium-grain), swelled at the lower temperatures than did the hard varieties (long-grain). Therefore, at the lower temperatures than 75°C, Japonicas and many of semi-hard varieties had higher water-uptake ratios than had Indicas and the hard varieties respectively, wereas at the temperature of 96°C, the hard varieties had the higher water-uptake ratios than any of the other varieties tested. (fig. 2) The varietal differences of water-uptake ratio were most distinct in the range from 65° to 75°C. 2) Among Japonicas, the varieties matured under lower temperatures began to swell at the lower cooking temperature than did those matured under higher temperatures. This relation was observed among the different samples of the same varieties matured under different temperatures.(table 1. fig. 3) Therefore, a highly significant negative correlation existed between the water-uptake ratios at cooking temperatures from 65° to 75°C and the mean temperatures during ripening.(r-0.956 at 70°C) 3) Microscopic observations of cooked rice revealed that swelling of rice grains was closely connected with swelling of starch granules and disruption of cells. In Towada and Fujisaka-5, swelling of starch granules and disruption of cells were observed on the outer layers of rice cooked at 70°C and on the fairly inner layers of rice cooked at 80°C. On the other hand, in Blue-bonnet, these changes were not observed when cooked at 70°C, but existed at 80°C. (photo. 1, 2). 4) The swelling of rice grain at the low cooking temperatures (60-75°C) will be attributed to the low geratinization temperature of starch and the fragility of cell membrane, and the swelling at the high temperatures (85-96°C) may be affected by the structure of starch and density of starch in endosperm (hardness distribution in endosperm18)). The rice which has high water-uptake ratio at low cooking temperature is considered to have a tendency to be cooked more easily and to become tender boiled rice. 5) Figure 4 shows that the maxima of total solids contents were at 65°C in glutinous varieties, 70°C or 75°C in Japonicas and 90° or 96°C in Indicas. Then the total solids contents at temperatures from 65° to 75°C were markedly higher in Japonicas than in Indicas and among Indicas some of the semi-hard varieties had fairly high total solids contents. (table 1) 6) Among Japonicas, highly significant negative correlation existed between total solids contents at cooking temperature from 65° to 75°C and mean temperature during ripening (r-0.789 at 65°C). This correlation was not recognized among Indicas in fig. 5 and 6, but according to the previous report19), when ripening temperatures were artificially coctrolled to 23° and 30°C, the rice matured at 23°C had higher total solids contents than had those matured at 30°C in all Indicas examined. Accordingly, swelling behaviour and amounts of total solids in residual liquids depend to a great extent on varieties and to some extent on climatic conditions. [the rest omitted]

The interplay between bystander cardiopulmonary resuscitation and ambient temperature on neurological outcome after cardiac arrest: A nationwide observational cohort study

Hydrogen production by water splitting with Mn3-xCoxO4 mixed oxides thermochemical cycles: A thermodynamic analysis

Dynamic light scattering, or DLS, is commonly used to determine the lower critical transition temperature (LCST) of a temperature induced stimuli-responsive polymer. By applying a temperature sweep, the coacervation or agglomeration of stimuli-responsive polymers can be observed. For materials, such as Poly(N-isopropylacrylamide), or pNIPAM, which have a reverse LCST, the polymers are soluble at lower temperatures and condense or precipitate out of solution at higher temperatures. The transition temperature is the transition between this soluble and condensed state.Our lab has developed a protocol to look at changes in the LCST behavior in the presence of an applied potential. By lining the DLS cuvette with a conductive tape, we can apply the potential across the 1 cm light path. After a certain voltage threshold, changes in the observed LCST behavior is found with pNIPAM. To the best of our knowledge, this result has never been recorded. Typically, the LCST of pNIPAM is not adjustable, but using this technique, we can observe the effect with an applied potential. We share this protocol for other groups to use to investigate the effect of applied potential on the coacervation of stimuli-responsive polymers. We intend to report details of our protocol and initially observed results of the observed behavior in the presence of an applied potential. Acknowledgements: The authors would like to acknowledge the financial support from NIH (P20 GM113131), NSF (CBET 1638896), the Collaborative Research Excellence Initiative Pilot Research Program at the University of New Hampshire, and the Hamel Center of Undergraduate Research at the University of New Hampshire. The authors also would like to acknowledge the assistance of Dr. Balog’s laboratory and Dr. Halpern’s laboratory.