Differences In Temperature Range Research Articles

First isoflavone-based hexacatenar derivatives with columnar liquid crystalline self-assembly and binding selectivity behavior

ABSTRACT The incorporation of different functional groups into organic molecules is a common method to construct soft liquid crystalline materials with multiple properties and adjust mesophases from one-dimensional to three-dimensional structures. This article reports the synthesis, characterization, self-assembly, and binding selectivity behaviors of the first isoflavone-based hexacatenar liquid crystalline materials with an isoflavone as central rigid core and two 1,2,3-triazole dendritic wings as terminal functional units. Polarized optical microscopy, differential scanning calorimetry, and small-angle X-ray scattering (SAXS) investigations indicated that all the compounds could self-assemble into rectangular columnar mesophase. The differences in temperature range of mesophase and sequence of mesophase compared with previously reported coumarin-based polycatenars were attributed to the change of position of carbonyl. The optical spectra indicated that these compounds display selectivity for Fe2+ among the different and cations. FT-IR and density functional theory calculations before and after interaction with Fe2+ were employed to demonstrate the recognition sites. The design strategy here provides a simple method to construct supramolecular self-assembly materials with wide properties and potentials.

Experimental Investigation and Performance Optimization during Machining of Hastelloy C-276 Using Green Lubricants.

Smart manufacturing is the demand of industry 4.0, in which the mass production of difficult-to-cut materials is of great concern to fulfil the goal of sustainable machining. Presently, the machining of superalloy is of upmost interest because of its wide application. However, the limited data on the turning of Hastelloy C-276 highlights its challenges during processing. Hence, the machining performance of superalloy considering surface quality, thermal aspects and chip reduction coefficient was examined with minimum quantity lubrication of several oils to address the sustainable development goal (SDG-12). The output responses were optimized through response surface methodology along with analysis of variance. The research exhibited that the output responses were dominated by cutting speed and feed rate having a percentage benefaction of 24.26% and 60%, respectively, whilst the depth of cut and lubricant type have an influence of 10–12%. No major difference in temperature range was reported during the different lubrication conditions. However, a substantial variation in surface roughness and the chip reduction coefficient was revealed. The percentage error evaluated in surface roughness, temperature and chip reduction coefficient was less than 5%, along with an overall desirability of 0.88, describing the usefulness of the model used. The SEM micrograph indicated a loss of coating, nose and flank wear during all lubrication conditions. Lastly, incorporating a circular economy has reduced the economic, ecological and environmental burden.

Engineering of continuous bienzymatic cascade process using monolithic microreactors – In flow synthesis of trehalose

Here, we present a two-step continuous flow enzymatic synthesis process in monolithic microreactors using basic sugars as substrates. In the first step UDP-glucose pyrophosphorylase (TaGalU) catalyses the synthesis of uridine-diphosphate-glucose (UDP-Glc) using uridine triphosphate (UTP) and glucose-1-phosphate (Glc-1-P). This is followed by the trehalose transferase (mCherry-TuTreT) catalysed reaction of UDP-Glc and Glc, to obtain trehalose. First, procedures for immobilisation of both enzymes on functionalised silica supports were studied and it was found that covalent bonding by amino groups using a glutaraldehyde linker gives highly active biocatalysts. Due to a drastic difference in temperature range of activity and stability of the immobilised enzymes a bi-reactor cascade was rationally the best solution. Depending on the applied flow rate and hence reaction (residence) time (1.5–10 min) the space-time-yield values varied, respectively, from 1.9 to 14.4 and 8.3 to 49.6 gproduct·L-1·h−1·mgprotein-1, for UDP-glucose pyrophosphorylase and trehalose transferase catalysed reactions. Prolonged (100 h) continuous flow operation showed that the system is operationally stable, but owing to neutral pH, it is prone to microbiological infections. They can be eliminated applying an antibacterial/antifungal therapy or preventive actions by storing and washing the reactors with a NaN3 solution. The presented process paves the way for the continuous in flow synthesis of natural and non-natural trehalose analogues and disaccharides.

Local topography effects on the surface temperatures on Mars – Application to the case of Recurring Slope Lineae (RSL)

Recurring Slope Lineae (RSL) are dark linear recurrent features which incrementally lengthen and fade each year on Martian slopes. Their activity during warmest seasons rises the question of modern martian water related process. To investigate this question, this study focuses on the thermal context of slopes hosting RSL. The paper presents a numerical study of surface and subsurface temperatures at high spatial resolution (1 m/pix) of three well-described RSL sites: Palikir Crater, Coprates Chasma and Rauna Crater. We then compare our local thermal simulations to quantitative measurements of the length and timing of RSL lengthening and fading in these three sites. We underline that RSL sites surface temperatures are poorly correlated with RSL morphology's changes. Indeed, lineae lengthening occurs while surface temperature are under the melting point of pure water (273 K) for at least two sites: Coprates Chasma and Rauna Crater, for two different sets of surface physical properties. We also highlight the significant differences in temperature range while lengthening occurs for all the sites, from ~220 K in Coprates Chasma site to a maximum of ~300 K in Palikir Crater. RSL are sometimes associated with signals in topography, involving significant heating variations of the surface, which can yield to the formation of local winds. Facing the thermal inconsistency between wet triggering processes and RSL reported activity, we suggest that RSL are more probably dry processes.

The Microbiome of the Worldwide Invasive Ascidian Didemnum vexillum

All multicellular organisms, including ascidians, host diverse microbial communities that are essential for their evolution. The global invader Didemnum vexillum is a colonial species native to Japan with two main genetic clades, A (the only invasive) and B, which provides a unique opportunity to assess if the microbiome remains stable in the colonization process or shifts according to local environment. We have analysed, using 16S amplicon sequencing, the microbiome of 65 D. vexillum colonies from 13 populations worldwide including the two clades in the native area, plus samples from a congeneric species and seawater from one of the localities. We found 3,525 zero-radius OTUs (ZOTUs) in D. vexillum, belonging to 36 bacterial and 3 archaeal phyla. The microbiome of this species had a markedly different composition from surrounding seawater and from the congeneric species. For the globally invasive clade A, we found 3,154 ZOTUs, and 8 of them were present in all colonies, constituting a core microbiome with high-abundance (69.57% of the total reads) but low diversity (0.25% of the total number of ZOTUs). The variable component was quantitatively much less important but comprised a highly diverse assemblage. In a multiple regression model, global microbiome structure correlated with differences in temperature range across localities, and also with geographic distances, pointing to horizontal acquisition of the symbionts. However, the ascidian may have a strong capacity to select and enrich its microbiome, as we found that the most abundant ZOTUs from tunic samples had low abundance in seawater samples from the same locality. The microbiome structure also correlated with the genetic distances between colonies obtained in a previous genome-wide analysis, suggesting some potential for vertical transmission. In geographically restricted comparisons, temperature and genetic makeup but not geography explained microbiome structure. The combination of a quantitatively dominant core component and a highly diverse variable fraction in the microbiome of D. vexillum can contribute to the success of this global invader in different environments.

Environment in poultry production covered with thermal and aluminum roofing tiles

Brazil is a country of tropical climate, a fact that hinders the poultry production in the aspect of thermal comfort. Thus, we aimed to evaluate the thermal environment in commercial poultry houses with different covers during the months of December 2012 to May 2013, in the municipality of Rio Verde, Goiás. The experimental design was completely randomized in split plots with factorial arrangement of treatments 2x3, being two shed models (thermal and aluminum roof tiles) and three sections within each shed (initial, central and final) for 182 days, having the days as replicates. The thermal environment was assessed through thermal comfort indices: Temperature and Humidity Index, Black Globe Temperature and Humidity Index, Radiant Heat Load and Enthalpy. The data was analyzed by SISVAR 5.1., through the analysis of variance, the Scott Knott test used to compare the means, considering a significance level of 1%. The results showed a significant statistical difference between the sheds and the points assessed (P < 0.05). The thermal shed had the lowest values for the environmental variables (Dbt and Bgt) and thermal indices studied, but larger values for the RH compared to the shed with aluminum covering. The use of thermal covers minimizes the difference in temperature range throughout various times of the day, being at 14:00 o'clock the prominence time to others.

Padrões de cobertura e uso da terra e sua influência na temperatura do ar em Rio Claro, SP

A modificação dos padrões de cobertura e uso da terra de um determinado lugar resulta em alterações na temperatura do ar. A partir desta premissa, este trabalho teve como objetivo analisar os gradientes de temperatura do ar entre cinco locais com diferentes padrões de cobertura e uso da terra, situados na Floresta Estadual Edmundo Navarro de Andrade (FEENA), Rio Claro (SP), e na área urbana do mesmo município. A temperatura do ar foi amostrada a cada 30 min por meio de registradores digitais autônomos, entre setembro de 2010 e agosto de 2011 em cinco padrões de ocupação da terra: 1) floresta de árvores nativas, 2) reflorestamento de eucalipto com sub-bosque de árvores nativas, 3) reflorestamento de eucalipto, 4) áreaurbana mista industrial, comercial e residencial, 5) área urbana residencial e comercial. Com os dados consistidos foram realizadas análises estatísticas de posição, dispersão, regressão/correlação e de séries temporais. Estes resultados foram organizados em tabelas, gráficos e diagramas temporo-espaciais para revelar a estrutura térmica e suas relações com os padrões de cobertura e uso da terra. Os padrões de ocupação com características urbanas apresentam maior diferença térmica em relação à floresta de árvores nativas, com desvios médios de 1,7 ºC no outono e primavera, e de 2,0 ºC no verão e inverno. A baixa variação altimétrica entre os postos da FEENA foi suficiente para mascarar em vários casos a influência das diferenças de vegetação, indicando que o efeito topoclimático se sobrepôs ao microclimático sob determinados tipos de tempo. Na área urbana o efeito topoclimático não foi suficientemente forte para atenuar a influência da mudança da cobertura e uso da terra e da energia dissipada pela dinâmica urbana. Essa influência pôde ser percebida pelas diferenças nas amplitudes térmicas, desvios em relação à temperatura da floresta de árvores nativas e pela modificação do ritmo térmico relacionada à dissipação de calor proveniente das atividades humanas (ciclo de sete dias).

Effect of particle size on phase transitions in metastable alumina nanoparticles: A view from high-resolution solid-state 27Al NMR study

Nanoparticles are known to have physical properties different from their bulk analogs, a characteristic that bears wide technological potential. Detailed knowledge of the atomic structures of diverse metastable/stable polymorphs in alumina nanoparticles with varying particle size is essential to understand their macroscopic properties and the behavior of their phase transitions. In this study, we report high-resolution solid-state 27 Al 2D triple-quantum (3Q) magic-angle spinning (MAS) and 1D MAS nuclear magnetic resonance (NMR) spectra for alumina nanoparticles with varying temperature and particle size with an aim to explore the nature of phase transitions in alumina nanoparticles. Although the 27 Al MAS NMR spectra of alumina nanoparticles cannot fully resolve all the crystallographically distinct Al sites for metastable aluminas such as γ-, δ-, and θ-Al 2 O 3 , the simulation of 27 Al MAS NMR spectra collected at different magnetic fields following the Czjzek model allows us to obtain the quantitative fractions of alumina polymorphs in nanoparticles and the NMR characteristics of their Al sites. The 27 Al 3QMAS NMR spectra resolved crystallographically distinct [6] Al and [4] Al sites in (γ,δ)- and θ-Al 2 O 3 in the isotropic dimension for the first time. The fraction of θ-Al 2 O 3 gradually increases up to ~1473 K at the expense of a decrease in (γ,δ)-Al 2 O 3 . The onset of formation of α-Al 2 O 3 from metastable aluminas is observed above ~1493 K. Several phase transitions in alumina nanoparticles observed in the current study include, γ,δ → θ-Al 2 O 3 , γ,δ → α-Al 2 O 3 , and θ → α-Al 2 O 3 . Although the phase transition γ,δ → θ-Al 2 O 3 occurs gradually with increasing annealing temperature from 873 to 1473 K, the phase transitions γ,δ → α-Al 2 O 3 and θ → α-Al 2 O 3 occur dramatically within a narrow temperature range between 1473 and 1573 K. The observed difference in temperature range (gradual vs. dramatic) for phase transition γ,δ → θ-Al 2 O 3 and γ,δ,θ → α-Al 2 O 3 originates from the different structural disorder in the metastable aluminas (i.e., γ-, δ-, θ-) and α-Al 2 O 3 . The effect of particle size on the phase transition (γ,δ) → θ-Al 2 O 3 between 298 and ~1473 K is not observed significantly. On the other hand, the transition temperature for γ,δ,θ → α-Al 2 O 3 , where the 50% for alumina is α-Al 2 O 3 , apparently increases as the particle size increases (as evidenced by TEM observation), indicating a larger energy penalty for phase transitions into α-Al 2 O 3 in larger alumina nanoparticles. This could be due to higher surface energy of θ-Al 2 O 3 than that of α-Al 2 O 3 and/or the fact that the transition from θ-Al 2 O 3 to α-Al 2 O 3 is kinetically favored for smaller nanoparticles. The mechanistic details of phase transitions among alumina polymorphs provided in the current study yield insights into the nature of the phase transition mechanisms for other oxide nanoparticles ubiquitous in the Earth’s surface environment.

冷凍マグロ肉の肉色保持に関する研究-IV

It was reported that the freezing storage at comparatively high freezing temperatures, such as -2 ?? -5°C accelerated discoloration of tuna meat rather more than unfrozen storage about at 0°C1). In order to seek a clue for the solution of the mechanism of this phenomenon, the relation between the discoloration of tuna meat and storage temperatures was examined in detail. The meat samples frozen at -80°C in polyethylene bags were stored at intervals of 1°C between -3 and -10°C, and after 4 days' storage the rate of discoloration was measured in terms of relative amount of metmyoglobin to total myoglgbin. The experiments were repeated three times, using different individuals of tuna. The results showed similar patterns in the color change with one another. As shown in Figs. 1-3, the discoloration in the inner part of meat was more considerable than in the surface at the freezing temperatures examined here. It is of interest that the temperature range causing the maximum discoloration was found about at -3 to -4°C in the surface, while it was found about at -6 to -7°C in the inner part. These results were discussed in connection with different factors affecting the meat color, and it was postulated that the difference in temperature range of the maximum discoloration between in the surface and in the inner part of meat, might be caused by the difference of partial pressure of oxygen between each portion of meat. The discoloration in question was also discussed in comparison with the similar phenomenons of acceleration of biochemical reaction in frozen meat, such as denaturation of protein, ATP degradation, and lipid hydrolysis, etc., pointing out that the temperature range of maximum discoloration in the surface of meat is comparable to those of maximum acceleration of different reactions as above cited. As to the effect of the nature of packaging materials on the discoloration, polyethylene pack and vacuum pack with aluminum foil laminated by polyethylene were examined, and the latter was found superior in the color retention of the interior meat (Fig. 5). The results suggest that the control of partial pressure of oxygen at the inner part of tuna meat will be very important to prevent the discoloration during freezing storage.

The Formation of Nitrate from Ammonium Nitrogen in Soils: I. Effect of Temperature

AbstractThe quantitative relationship between temperature and nitrification rates was determined in four different soils under laboratory conditions. The formation of nitrates took place at all temperatures studied between 2 and 35° C. when other factors were favorable. The rate of nitrification increased with temperature with the greatest increase between 7 and 15° C.In Genesee silt loam (pH 7.7) nitrate nitrogen was formed at rates of 2, 10, 45, 60, 90, and 120 ppm. per week at 2, 7, 15.5, 21, 27, and 35° C., respectively, until the 200 ppm. ammonium nitrogen (NH4 ‐N) added was oxidized. The maximum rate in the Mellott C horizon (pH 7.8) was nearly equal to that achieved in the Genesee; the rate in the Chalmers silty clay loam (pH 6.2) was intermediate; the slowest rates found occurred in the Clermont silt loam (pH 5.0) which had maximum rates of 0, 0, 25, 30, 30, and 15 ppm. per week at the temperatures from 2 to 35° C. given above. The initial rate in the Mellott C and Clermont was much slower than the maximum rate. After 4 weeks the rate decreased in the Chalmers and Clermont, probably due to increased acidity.A marked decrease in the rate of nitrification occurred as the pH dropped below neutrality. Change of pH by adding calcium carbonate did not change the temperature range of nitrification in Clermont silt loam. Differences in temperature range existed between the soils as well as differences in the rate of nitrification.Temperatures fluctuating in a 24‐hour cycle generally resulted in an increased rate of nitrification at temperatures below 15.5° C. and a decreased rate above 15.5° C. in Genesee silt loam.

Six Standard Seasons of the Year

Scientific advance in the systematic branches of geography is an essential prerequisite for any studies in comparative regional geography. Notable advance has been made in this respect in the development of scientific measurements of climates. We have been given terms, concepts, and types which can be quantitatively defined and which therefore enable us to express briefly the climatic characteristics of any place, and thereby compare them with those of another place. Most of these terms-precipitation efficiency, temperature efficiency, length of growing season and the like-as well as the types based upon them, have been developed largely in consideration of the effects on vegetation, whether natural or cultivated. Granted that these effects are fundamental in respect to land use and therefore to our economic life, other aspects of climate likewise have geographic importance. The temperature conditions of different times of the year have marked effects upon our comfort, the clothing we must wear, our outdoor activities, and the heat requirements of our houses and of our automobiles. The student of landscape phenomena can observe these effects in the character of houses and barns and more directly in the appearance at different times of the year, of roads and streets, rivers and lakes-in general of the visible landscape. These temperature differences in different parts of the year, which vary in character and length in different parts of the world, are not described in terms of temperature efficiency nor even of length of growing season. Differences in temperature range in different parts of the growing season, roughly expressed in terms of moderately warm temperature and hot temperature, have important effects on our way of life which are reflected in the structure of our homes. Likewise in the opposite time of the year a period of severe cold, associated with icy pavements and snow-covered sidewalks is very different from moderately cold periods in which snow and ice are less common, even though frosts are sufficiently frequent to prevent vegetative growth. This concept of seasons based on differences in temperature range is recognized in ordinary usage of the names of seasons: winter, spring, summer, and fall. Throughout most of the important populated areas of the 165