Moderate Temperature Range Research Articles

Biofuel potential of liquid products from protein- and lipid-rich biomass hydrothermal liquefaction

Hydrothermal liquefaction (HTL) of oleaginous microorganisms is an economical method with which to transform all compounds of wet biomass into competitive biofuels without the need for pretreatments such as feedstock drying and lipid extraction. In the present work, liquefaction of microalgae or yeasts in subcritical water is investigated in a self-built HTL system. Fractional yield distribution of the end-products and characterization of biocrudes from algae HTL are studied by considering the effects of the reaction temperature and residence time. The identified compounds in the biocrudes are compared to those in yeast-derived HTL biocrudes and the reaction scheme is reported. The present work reveals that no significant quality change of algae-derived HTL biocrudes is observed in a moderate temperature range thus the N-containing compounds vary complicatedly at different residence times. Compared to the pyrolysis biocrudes of algae and yeast, the collected HTL biocrudes do not perform the advantage, in terms of biofuel potential of a high portion of N-containing compounds, especially heterocyclic compounds. It should be noted that the low protein content in the feedstocks cannot definitely be proven to have led to the reduced heterocyclic compounds in HTL biocrudes. If lipids had been present, this would have enhanced the formation of N-containing heterocyclic compounds. Instead, amino acid degradation was accelerated by the high level of carbohydrates, forming amides. This paper presents a promising effort to develop an efficient route to transform oleaginous microorganisms into biofuels.

Temperature impacts on hate speech online: evidence from 4 billion geolocated tweets from the USA

A link between weather and aggression in the offline world has been established across a variety of societal settings. Simultaneously, the rapid digitalisation of nearly every aspect of everyday life has led to a high frequency of interpersonal conflicts online. Hate speech online has become a prevalent problem that has been shown to aggravate mental health conditions, especially among young people and marginalised groups. We examine the effect of temperature on the occurrence of hate speech on the social media platform Twitter and interpret the results in the context of the interlinkage between climate change, human behaviour, and mental health. In this quantitative empirical study, we used a supervised machine learning approach to identify hate speech in a dataset containing around 4 billion geolocated tweets from 773 cities across the USA between May 1, 2014 and May 1, 2020. We statistically evaluated the changes in daily hate tweets against changes in local temperature, isolating the temperature influence from confounding factors using binned panel-regression models. The prevalence of hate tweets was lowest at moderate temperatures (12 to 21°C) and marked increases in the number of hate tweets were observed at hotter and colder temperatures, reaching up to 12·5% (95% CI 8·0-16·5) for cold temperature extremes (-6 to -3°C) and up to 22·0% (95% CI 20·5-23·5) for hot temperature extremes (42 to 45°C). Outside of the moderate temperature range, the hate tweets also increased as a proportion of total tweeting activity. The quasi-quadratic shape of the temperature-hate tweet curve was robust across varying climate zones, income quartiles, religious and political beliefs, and both city-level and state-level aggregations. However, temperature ranges with the lowest prevalence of hate tweets were centred around the local temperature mean and the magnitude of the increases in hate tweets for hot and cold temperatures varied across the climate zones. Our results highlight hate speech online as a potential channel through which temperature alters interpersonal conflict and societal aggression. We provide empirical evidence that hot and cold temperatures can aggravate aggressive tendencies online. The prevalence of the results across climatic and socioeconomic subgroups points to limitations in the ability of humans to adapt to temperature extremes. Volkswagen Foundation.

Experimental Investigation of Thermal Strengthening in Sichuan Marble

It is well documented that temperatures higher than 400 ℃ can significantly lower rock strength due to thermally induced decomposition and microcracks. However, rock strength increase under temperatures 25–400 ℃ has also been reported. It remains elusive whether thermal strengthening does exist or it is just an illusion caused by rock heterogeneity. To uncover such a mystery, we carried out triaxial compression tests on Sichuan marble under 25–200 ℃. Rock heterogeneity was at a low level and data dispersion was limited in our experiment. We managed to observe a clear trend of strength increase with temperature, justifying the existence of thermal strengthening in Sichuan marble. To unveil the mechanism of thermal strengthening, five factors, as predominant and comprehensive as we could concern, were investigated. After careful examination and analysis, thermal expansion was inferred to be the main reason leading to the thermal strengthening in Sichuan marble. The mechanism may lie in tighter compaction between mineral grains due to thermal expansion. Since thermal expansion is a physical process that can occur in all crystalline rocks upon heating, thermal strengthening holds a high potential to be a general property of crystalline rocks in the moderate temperature range. To our best knowledge, this study is the first to explicitly confirm the existence of thermal strengthening and comprehensively investigate the underlying mechanisms. The findings provide a new understanding of the thermal effect on rock strength, which may aid rock engineering design under a thermo-mechanical coupling working condition.

Evaluation of CO2 adsorption capacity with a nano-CaO synthesized by chemical combustion/ball milling

Abstract The adsorption of CO2 on a nano-calcium oxide (nano-CaO) adsorbent was investigated under different conditions of temperature and supply pressure, considering kinetic, isotherm, and thermodynamic parameters. CaO is a crystalline material with a high surface area and nanosized particles with high porosity, which showed rapid initial CO2 adsorption rates in the moderate temperature range studied. The adsorption was well described by the pseudo-second-order and the intraparticle diffusion kinetic models. The Langmuir isotherm model fitted the experimental data well, indicating a monolayer-type process. The thermodynamic parameters revealed that the CO2/nano-CaO adsorption was endothermic, not spontaneous, and proceeded via physical and chemical processes. The activation energy value confirmed that the mechanism involved is a chemical process. In addition, the nano-CaO adsorbent could be regenerated five times without any significant loss of performance or properties. All the obtained results reveal that this porous nanoadsorbent has huge potential to be applied for CO2-capture technologies on a large scale.

Tribological properties of bismuth sulfide (Bi[formula omitted]S[formula omitted]) particles as grease additive for aluminum forming operations

In the present work, the friction and galling-prevention properties of a lubricating grease with the addition of Bi2S3 particles have been investigated. To achieve this, commercial lithium greases containing Bi2S3, hexagonal boron nitride, and graphite were employed to lubricate steel–aluminum contacts under different tribological configurations, namely reciprocating sliding tests with varying normal loads and sliding speeds and load scanner tests at 25, 200 and 300 °C. The addition of Bi2S3 enhanced the tribological response of the grease in reciprocating tests and provided protection against galling up to temperatures of 200 °C. However, its performance severely deteriorated at 300 °C. Thus, Bi2S3 showed promising properties as an additive for lubricating greases operating under a wide range of normal loads, sliding speeds, and moderate temperatures.

Protocol Optimization of DNA Extraction from Banana Fruits

Background: DNA extraction is the process by which the DNA is extracted and purified from the living or dead cells or tissues. There are many different kits commercially available for DNA extraction, with varying protocols. This study aimed at determining the optimal conditions for the extraction of high yield DNA from banana fruits.
 Methodology: DNA was extracted from banana fruits by precipitation method. The DNA yield was determined using the Nanodrop DNA quantification technique.
 Results: The optimal sodium chloride salt concentration for DNA extraction from banana fruits was 4mM and the amount of DNA extracted increased as the temperature decreased. The highest yield was obtained between 4 0C to 0 0C.
 Conclusion: We report for the first time a protocol with an optimal salt concentration (NaCl, 4mM) for quality DNA yield from banana fruits. A critical consideration is required to establish an optimal range of moderate temperatures and DNA concentrations for better quality and desired yields. There may not be a universal protocol for DNA extraction from all plant materials.

Association between ambient temperature and cardiovascular disease hospitalisations among farmers in suburban northwest China

Cardiovascular disease (CVD) has become a severe public health and social issue in China. However, in northwest China, evidence on the association between ambient temperature and CVD hospitalisations in suburban farmers is somewhat limited. We collected CVD hospitalisations and meteorological data (2012-2015) in Zhangye suburbs and assessed the temperature-related risk and burden of admission by fitting a distributed lag nonlinear model to probe the relationship between ambient temperature and CVD hospitalisations among farmers in suburban northwest China. The results show that 23,921 cases of CVD admissions were recorded from 2012 to 2015. There was a "U-shaped" association between temperature and hospitalisations. Compared with the minimum admissions temperature (MAT) at 15.3°C, the cumulative relative risk (RR) over lag 0-21days was 1.369 (95% CI 0.980-1.911) for extreme cold temperature (1st percentile, -15°C), 1.353 (95% CI 1.063-1.720) for moderate cold (5th percentile, -11°C), 1.415 (95% CI 1.117-1.792) for extreme heat (99th percentile, 26°C), and 1.241 (95% CI 1.053-1.464) for moderate heat (95th percentile, 24°C). Female farmers were more susceptible to low and high temperatures than male farmers. Farmers aged ≥ 65years old were more sensitive to low temperatures, while farmers aged < 65years old were more sensitive to high temperatures. A total of 13.4% (3,208 cases) of the hospitalisation burden for CVD were attributed to temperature exposure, with the moderate range of temperatures accounting for the most significant proportion (12.2%). Ambient temperature, primarily moderate temperatures, might be an essential factor for cardiovascular-related hospitalisations among farmers in suburban northwest China.

Prediction of a high-ZT and strong anisotropic thermoelectric material: Monolayer InClSe

In this work, thermoelectric (TE) properties of monolayer InClSe are investigated by using the first-principles calculations combined with Boltzmann transport theory, which is a novel member of FeOCl-type 2D materials . We find that the electronic and thermal transport parameters along x and y axis are quite different, resulting in a strong anisotropic thermoelectric performance of monolayer InClSe, which provides a possibility to design anisotropic thermoelectric device. For n-type doping, monolayer InClSe has high electrical conductivity along x-axis. Detailed calculations reveal that the high electrical conductivity is originate from the long electron relaxation time and high connectivity of electron conduction channels. The high electrical conductivity and satisfactory Seebeck coefficient result in the excellent power factor ( PF ) for monolayer InClSe . For n-type doping, the optimal PF along x-axis can reach 47.8 mW m −1 K −2 at 700 K, which is much higher than most typical thermoelectric materials . Combining excellent PF and suppressed lattice thermal conductivity , the n-type doping monolayer InClSe has high ZT values in wide temperature range (300 K–700 K) along x-axis and the maximal ZT value reaches 2.82 at 700 K. Our results demonstrate that monolayer InClSe is a promising thermoelectric candidate for energy harvesting in moderate-temperature range. The calculated figure of merit ZT of n-type monolayer InClSe at three different temperature 300 K, 500 K, and 700 K, respectively. • We demonstrate that monolayer InClSe is a promising anisotropic thermoelectric candidate. • For n-type doping, ultra-high electrical conductivity along x-axis reaches 1.82 × 10 5 S/m (300 K) at carrier concentration 1 × 10 12 cm −2 . • For n-type doping, the optimal PF along x-axis can reach 47.8 mW m −1 K −2 at 700 K, and the maximal ZT value is 2.82.

Cloning, expression, and characterization of a recombinant xylanase from Bacillus sonorensis T6.

Xylanase is one of industrial enzymes with diverse applications including the paper-bleaching industry and feed additives. Here, a strain having xylanolytic activity and identified as Bacillus sonorensis T6 was isolated from soil. A secretory enzyme was identified by mass-spectrometry as a xylanase of glycosyl hydrolase family 11, with a molecular weight of 23.3 kDa. The xylanase gene of Bacillus sonorensis T6 was cloned and expressed in Escherichia coli (yielding an enzyme designated as rXynT6-E) and in Pichia pastoris (yielding rXynT6-P). The recombinant xylanases were found to have optimal activity at 47–55°C and pH 6.0–7.0. The recombinant xylanase expressed in P. pastoris has 40% higher thermal stability than that expressed in E. coli. The recombinant xylanases retained 100% of activity after 10 h incubation in the pH range 3–11 and 68% of activity after 1 h at pH 2.0. The xylanase activities of rXynT6-E and rXynT6-P under optimal conditions were 1030.2 and 873.8 U/mg, respectively. The good stability in a wide range of pH and moderate temperatures may make the xylanase from Bacillus sonorensis T6 useful for various biotechnological applications, e.g., as an enzyme additive in the feed industry.

Characterization of spray dried diosgenin from fenugreek using binary blend of carrier agents

The utilization of nutraceutical products is enhancing widely due to upcoming diseases. Consumption of bitter food is remarkably less irrespective of their health benefits. From ancient times fenugreek and its bioactive compound diosgenin is quite popular. Diosgenin is providing health benefits by controlling cellular mechanisms in view of different metabolic diseases. This article rivets over the encapsulation of fenugreek diosgenin with a binary blend of maltodextrin (MD) and whey protein concentrate (WPC) by spray drying. While drying, core material diosgenin concentration was varied. The produced powder was analyzed for bulk density, tapped density, flowability, powder yield, encapsulation efficiency, color, and analytical properties. The yield and encapsulation efficiency were observed to be higher as the amount of core material was increased in feed. Among the selected diosgenin concentration, 4DGP with MD and WPC yield better results in comparison with other selected concentrations from 1DGP to 5DGP. 4DGP produced 87.77% encapsulation efficiency that depicted good interaction of diosgenin with MD and WPC. The diosgenin powder properties like bulk density, tapped density, Carr's index, Hausner ratio, hygroscopicity, and degree of caking were observed. The analytical properties of powder revealed the presence of functional groups (aromatic ester C-O; nitro compounds N-O; and alkene C=C), moderate glass transition temperature range (113.77 to 137.28°C), and 77.6% amorphous nature of spray dried diosgenin powder. The color of powder varied from off cream to pale yellow as the amount of core material varied. These properties of diosgenin powder could be utilized in the development of functional food products which could benefit mankind.

Effect of Sb/Bi atom substitution site on electronic transport properties of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; alloy

Mg&lt;sub&gt;2&lt;/sub&gt;(Si,Sn)-based thermoelectric materials, which are environmentally friendly and low-cost, have great development potential in a moderate temperature range. Electronic transport properties of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;1-&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Sn&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; alloys can be optimized by doping elements. Doping is still one of the most effective methods of optimizing electronic transport performance, such as carrier concentration, mobility, and effective mass. The most effective doping elements are Sb and Bi. Much attention has been paid to the influence of element type and doping content. Different substitution sites will also greatly affect the electronic transport parameters. In this work, the defect formation energy value of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; alloy for substituting Sb atoms and Bi atoms for Sn sties and Si sites, respectively, are calculated by first-principles calculations. The influence on electronic transport parameters is systematically analyzed by combining the calculated results of band structures and density of states. Corresponding component Sb and Bi atoms doped Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; alloys are prepared by rapid solidification method, and microstructures, Seebeck coefficients, and electrical conductivities of the alloys are measured. Combined with the predicted results by solving the Boltzmann transport equation, electronic transport performances are compared and analyzed. The results indicate that both Sn and Si sites are equally susceptible to Sb and Bi doping, but the Si sites are preferentially substituted due to their lower ∆&lt;i&gt;E&lt;/i&gt;&lt;sub&gt;f&lt;/sub&gt; values. Doped Bi atoms provide a higher electron concentration, and Sb atoms offer higher carrier effective mass. Thus, the maximum &lt;i&gt;σ&lt;/i&gt; value of the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.615&lt;/sub&gt;Bi&lt;sub&gt;0.01&lt;/sub&gt; alloy is 1620 S/cm. The maximum &lt;i&gt;S&lt;/i&gt; value of the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.365&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt;Sb&lt;sub&gt;0.01&lt;/sub&gt; alloy is –228 μV/K. Correspondingly, the highest &lt;i&gt;PF&lt;/i&gt; value for this alloy is 4.49 mW/(m·K) at &lt;i&gt;T&lt;/i&gt; = 800 K because of the dominant role of &lt;i&gt;S&lt;/i&gt; values. Although its power factor is slightly lower, the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.615&lt;/sub&gt;Sb&lt;sub&gt;0.01&lt;/sub&gt; alloy is expected to exhibit lower lattice thermal conductivity due to the lattice shrinkage caused by substituting Sb sites for Sn sites. The optimal doping concentration of the Bi-doped alloy is lower than that of the Sb-doped alloy. These results are expected to provide a significant reference for optimizing the experimental performance of Mg&lt;sub&gt;2&lt;/sub&gt;(Si, Sn)-based alloys.

Effect of Different Sb/Bi Substituted Sites on Electronic Transport Properties of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; Alloy

Mg&lt;sub&gt;2&lt;/sub&gt;(Si, Sn)-based thermoelectric materials, which are environmentally friendly and low-cost, have great development potential at moderate temperature range. Electronic transport properties of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;1-&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Sn&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt; alloys can be optimized by doping elements. Doping is still one of the most effective methods for optimizing electronic transport performance, such as carrier concentration, mobility, and effective mass. The most effective doping elements are Sb and Bi. A significant amount of attention has been focused on the influence of element type and doping content. Different substituted sites will also have a great impact on the electronic transport parameters. In this work, the defect formation energy values of Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; alloys for Sb/Bi atoms substituting Sn/Si sites were calculated by first-principles calculations. The influence on electronic transport parameters was systematically analyzed combined with the calculated results of band structures and density of states. Corresponding component Sb/Bi doped Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt; alloys were prepared by rapid solidification method, and microstructures, Seebeck coefficients, and electrical conductivities of the alloys were measured. Combined with the predicted results by solving the Boltzmann transport equation, electronic transport performance was compared and analyzed. The results indicate that, both Sn and Si sites were equally susceptible to Sb and Bi doping, but the Si sites were preferentially substituted due to their lower ∆&lt;i&gt;E&lt;/i&gt;&lt;sub&gt;f&lt;/sub&gt; values. Doped Bi atoms provided a higher electron concentration, and Sb atoms provided a higher carrier effective mass. Thus, the maximum &lt;i&gt;σ&lt;/i&gt; value of the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.615&lt;/sub&gt;Bi&lt;sub&gt;0.01&lt;/sub&gt; alloy was 1620 Scm&lt;sup&gt;-1&lt;/sup&gt;. The maximum &lt;i&gt;S&lt;/i&gt; value of the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.365&lt;/sub&gt;Sn&lt;sub&gt;0.625&lt;/sub&gt;Sb&lt;sub&gt;0.01&lt;/sub&gt; alloy was -228 μVK&lt;sup&gt;-1&lt;/sup&gt;. Correspondingly, the highest &lt;i&gt;PF&lt;/i&gt; value for this alloy was 4.49 mWm&lt;sup&gt;-1&lt;/sup&gt;K&lt;sup&gt;-1&lt;/sup&gt; at &lt;i&gt;T&lt;/i&gt;=800 K because the dominant role of &lt;i&gt;S&lt;/i&gt; values. Although its power factor was slightly lower, the Mg&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;0.375&lt;/sub&gt;Sn&lt;sub&gt;0.615&lt;/sub&gt;Sb&lt;sub&gt;0.01&lt;/sub&gt; alloy was expected to exhibit lower lattice thermal conductivity due to the lattice shrinkage caused by Sb substituting Sn sites. The optimal doping concentration of the Bi-doped alloys was lower than that of the Sb-doped alloys. These results are expected to provide a significant reference for the experimental performance optimization of Mg&lt;sub&gt;2&lt;/sub&gt;(Si, Sn)-based alloys.

Effects of coexisting oxoanions on SO&lt;sub&gt;3&lt;/sub&gt; decomposition activity of molten-phase potassium metavanadate catalysts

Molten-state potassium metavanadate (KVO3) supported on mesoporous SiO2 materials have emerged as active catalysts for SO3 decomposition over a moderate temperature range (≤650 °C), which is a potential O2 evolution reaction useful for solar thermochemical water splitting. The molten phase formed at ≥520 °C contained tetrahedral VO42−, which plays a vital role in accelerating the SO3 uptake and conversion to SO2/O2. The present study aimed to reveal how the SO3 decomposition activity is affected by adding other oxoanions such as borate (BO33−), carbonate (CO32−), and phosphate (PO43−) into the melt. Although borate showed a deteriorating effect, phosphate tended to improve the catalytic activity when the P/V molar ratio was equal to or less than 0.5. The addition of phosphate produced a mixed phosphate vanadate with a composition of KV2PO8, which consists of infinite tetrahedral PO4 and pyramidal VO5 linked by vertex sharing. Because of the congruent melting at temperature as low as ∼530 °C, KV2PO8 may be expected as another candidate of active molten phase catalyst for SO3 decomposition.

Weak Singularities of the Isothermal Entropy Change as the Smoking Gun Evidence of Phase Transitions of Mixed-Spin Ising Model on a Decorated Square Lattice in Transverse Field.

The magnetocaloric response of the mixed spin-1/2 and spin-S () Ising model on a decorated square lattice is thoroughly examined in presence of the transverse magnetic field within the generalized decoration-iteration transformation, which provides an exact mapping relation with an effective spin-1/2 Ising model on a square lattice in a zero magnetic field. Temperature dependencies of the entropy and isothermal entropy change exhibit an outstanding singular behavior in a close neighborhood of temperature-driven continuous phase transitions, which can be additionally tuned by the applied transverse magnetic field. While temperature variations of the entropy display in proximity of the critical temperature a striking energy-type singularity , two analogous weak singularities can be encountered in the temperature dependence of the isothermal entropy change. The basic magnetocaloric measurement of the isothermal entropy change may accordingly afford the smoking gun evidence of continuous phase transitions. It is shown that the investigated model predominantly displays the conventional magnetocaloric effect with exception of a small range of moderate temperatures, which contrarily promotes the inverse magnetocaloric effect. It turns out that the temperature range inherent to the inverse magnetocaloric effect is gradually suppressed upon increasing of the spin magnitude S.

Enhanced hydrogen production by the catalytic alkaline thermal gasification of cellulose with Ni/Fe dual-functional CaO based catalysts

A two-stage system involving alkaline thermal gasification of cellulose with Ca(OH)2 sorbent and catalytic reforming with Ni/Fe dual-functional CaO based catalysts is proposed and applied to enhance H2 production and in-situ CO2 capture. The results show that the H2 concentration is maximized at a considerably lower temperature (500 °C) than commercialized biomass gasification processes, reducing energy consumption. Sol-gel method is deemed better than impregnation method for its lower cost and higher-concentration H2 production. Among the prepared catalysts, sol-NiCa catalyst exhibits the best performance in CO2 absorption, resistance to carbon deposition, and cyclic stability, creating maximum H2 concentration (79.22 vol%), H2 yield (27.36 mmol g−1 cellulose), and H2 conversion (57.61%). Introduction of Ni rather than Fe on the CaO based catalyst promotes steam methane reforming at moderate temperature range of 400–600 °C, generating low contents of CH4 (5.38 vol%), CO2 (4.82 vol%), and CO (10.58 vol%).

A Study of the Flexural Behavior of Fiber-Reinforced Concretes Exposed to Moderate Temperatures.

The use of synthetic fibers in fiber-reinforced concretes (FRCs) is often avoided due to the mistrust of lower performance at changing temperatures. This work examines the effect of moderate temperatures on the flexural strengths of FRCs. Two types of polypropylene fibers were tested, and one steel fiber was employed as a reference. Three-point bending tests were carried out following an adapted methodology based on the standard EN 14651. This adapted procedure included an insulation system that allowed the assessment of FRC flexural behavior after being exposed for two months at temperatures of 5, 20, 35 and 50 °C. In addition, the interaction of temperature with a pre-cracked state was also analyzed. To do this, several specimens were pre-cracked to 0.5 mm after 28 days and conditioned in their respective temperature until testing. The findings suggest that this range of moderate temperatures did not degrade the behavior of FRCs to a great extent since the analysis of variances showed that temperature is not always a significant factor; however, it did have an influence on the pre-cracked specimens at 35 and 50 °C.

Thermodynamic Performance Analysis of Solar Based Organic Rankine Cycle Coupled with Thermal Storage for a Semi-Arid Climate

This study focuses on the thermodynamic performance analysis of the solar organic Rankine cycle (SORC) that uses solar radiation over a moderate temperature range. A compound parabolic collector (CPC) was adjusted to collect solar radiation because of its long-lasting nature and featured low concentration ratios, which are favorable for moderate temperature applications. A thermal storage tank was fixed to preserve the solar energy and ensure the system’s continuous performance during unfavorable weather. However, water was used as the heat transfer fluid and R245fa was used as the working fluid in this system. The performance in both the hottest and coldest months was analyzed using the average hourly profile in MATLAB using weather data from Riyadh, Saudi Arabia. Variations in the tank temperature during the charging and discharging modes were found. The hourly based thermal efficiency and net power output for both configurations were also compared. The results show that at 17:00, when the cycle was about to shut down, the thermal efficiency was 12.79% and the network output was 16 kW in July, whereas in January, the efficiency was ~12.80% and the net power output was 15.54 kW.

ISOLATION, PRODUCTION AND OPTIMIZATION OF CELLULASE BY BACILLUS PUMILUS UNDER SUBMERGED FERMENTATION USING LABORATORY MEDIUM BY SMF METHOD

Cellulolytic waste is superfluous in lithosphere and its conversion is one of the basic necessities. In current research, we have screen out potential bacterial isolates that were found capable for degradation of cellulose material. They can easily convert it into simple usable form of sugar. All isolates were capable to use cellulose in natural environmental condition such as pH, humidity and moderate temperature range. Isolation was done using to carboxymethycellulose agar medium. While, the isolates were cultivated by submerged fermentation method (Smf). Among all isolates Bacullis pumilus was found most potent strain for cellulose degradation and for production of cellulase at large scale

Modelling the inactivation of Staphylococcus aureus at moderate heating temperatures

The survival of bacterial contaminants at moderate processing temperatures is of interest to many food producers, especially in terms of the safety and quality of the final products. That is why the heat resistance of Staphylococcus aureus 2064, an isolate from artisanal Slovakian cheese, was studied in the moderate temperature range (57–61 °C) by the capillary method. The fourth decimal reduction time t&lt;sub&gt;4D&lt;/sub&gt;- and z-values were estimated in two steps by traditional log-linear Bigelow and non-linear Weibull models. In addition, a one-step fitting procedure using the Weibull model was also applied. All the approaches provided comparable t&lt;sub&gt;4D&lt;/sub&gt;-values resulting in the following z-values of 11.8 °C, 12.3 °C and 11.3 °C, respectively. Moreover, the one-step approach takes all the primary data into z-value calculation at once, thus providing a more representative output at the reasonable high coefficient of determination R&lt;sub&gt;2&lt;/sub&gt; = 0.961

Upgrade and present limitations of solar thermionic-thermoelectric technology up to 1000 K

The thermal and electrical performance of the innovative solar thermionic-thermoelectric generator (ST2G) has been carefully analyzed by using a high-flux solar simulator. Specific technological solutions have been integrated with respect to the first prototype for the operational testing at the moderate temperature range of 700–1000 K. The influence of spacers with different thickness has been studied to quantify the reduction of output current due to space-charge effect, whereas a BaF2-based coating has been deposited on the anode to make its work function (~2.1 eV) approach the cathode one, on which a hydrogen-terminated nitrogen doped nano-diamond film acts as emitter (work function of ~2.0 eV). The engineered ceramic absorber has demonstrated to be a reliable selective solar absorber with a high solar-to-thermal efficiency of 84% for solar concentration ratio of 200 suns, extrapolated to 83% at 500 suns. As expected, the thermionic energy converter still provides a small converted power. However, the minimum inter-electrode spacing used (50 μm) and the engineered anode allow to better figure out the present limitations in the electrical power generation and how to surpass them in the near future.