Increased Temperature Levels Research Articles

Experimental Study of Parylene Based Capacitive Humidity Sensor for Integrated Thermal Comfort Sensing Application

In this letter, we report the temperature effect and noise characterization of the Parylene-based capacitive humidity sensor which can be used for integrated CMOS compatible thermal comfort sensing. The sensor is comprised of a pair of interdigitated Pt electrodes deposited on a silicon substrate and a parylene hygroscopic layer coated on the electrodes using room temperature chemical vapor deposition process. The sensor was characterized at different relative humidity (RH) values and working temperatures in a testing setup. The capacitance of the sensor increases with the RH due to the absorption of water molecules on the surface of the sensing film. The capacitance of the sensor also increases with temperature, which is due to the stronger thermal movement of the molecules that helps increase the polarization at increased temperature levels. Besides, a readout circuit was done on a printed circuit board using capacitance to voltage converter for the sensor. The sensor achieved a maximum sensitivity of 76.2 mV/%RH and response and recovery times of about 31.5 and 29.2 s, respectively. Besides, the sensor shows a noise level of 1.399 mV rms within 25 Hz bandwidth in the output voltage response. The experimental results also indicated a resolution of about 0.072-2% within the ASHRAE standard approved RH range (25-95%) for the fabricated sensor.

Comparison of kinetic models for boron adsorption in major soil groups of India

The aim of present study was to understand the boron (B) adsorption kinetics in soils. Three soils belonging to Alfisol, Vertisol and Inceptisol orders were selected. The soils were widely differed in their properties. Externally applied B content was allowed to equilibrate with intermittent shaking at different temperature levels (25 and 35°C) for different intervals ranging from 0.5 to 72 h. Boron retention by soils followed decreasing order of: Vertisol > Inceptisol > Alfisol. Five different kinetic models viz. zero-order, firstorder, parabolic, Elovich and power function were used for describing B adsorption kinetics in soils. The Elovich equation was proved to be the best among the various kinetic equations studied to describe B adsorption kinetics. The equilibrium concentration was achieved at 16 h at 35°C whereas it takes more time at 25°C. Adsorption of B decreased with a subsequent increase in temperature level.

In vitro activity of hyperthermia on swarming motility and antimicrobial susceptibility profiles of Proteus mirabilis isolates

Aim Swarming motility is a virulence factor for Proteus mirabilis and is a coordinated multicellular movement of bacteria. In this study, we investigated the inhibitory effect of hyperthermia on bacterial swarming motility and antimicrobial resistance. Methods Thirty-one P. mirabilis isolates were included in the study. Seven inoculated agar plates were incubated inside incubators with increasing temperature levels: at 36 °C (control) and 40–45 °C. On the next day, inhibition of swarming was evaluated and minimum paralyzing temperature (MPT) values were determined. An antimicrobial susceptibility test (antibiogram) is performed by exposing bacteria to increasing concentrations of antibiotics, in vitro. Thus, we used the Kirby-Bauer disk diffusion test as a screening method to analyze the antibiogram profiles of the isolates at 36 °C and 42 °C. Finally, a time-kill assay was performed to analyze the killing effect of hyperthermia (42 °C) on planktonic bacteria, in combination with the antibiotic meropenem at the first and third hours. A Wilcoxon signed-rank test was used to compare the killing effects of meropenem, hyperthermia and their combinations. Results The median MPT value was determined as 44 °C. In the disk diffusion assay, susceptibility development was observed in 94% of isolates for at least one antibiotic. In the time-kill assay, we observed a significant killing effect of hyperthermia in combination with meropenem. Under the microscope, we observed the formation of spherical cells by the effect of heat. Conclusion We conclude that these findings might be useful when employing the hyperthermia method to treat infectious diseases caused by P. mirabilis in the future.

Drying characteristics of Turkish ravioli, mantı

Manti is a type of ravioli with a unique taste, which has been appreciated by many people in Turkey for years. In this study, two common types of manti samples (traditional Kayseri manti produced by wrapping dough sheets into small bags and triangular manti) were dried to make them microbiologically safe by lowering their water activities to a desired level of less than 0.6. Drying process was carried out in a conventional dryer at 60, 70 and 80 °C and the drying kinetics of manti samples was determined by the Page, Henderson and Pabis, Modified Page, Logarithmic and Newton models. The best-fit model for the drying characteristics of triangular manti was the Newton model at 60 and 70 °C while the Page and Modified Page models were the best at 80 °C. Moreover, Page/Modified Page, Newton and Page/Modified Page models were the best-fit models for traditional Kayseri manti at 60 °C, 70 °C and 80 °C, respectively. Faster drying rates were obtained for triangular manti, and the desired water activity value for this manti was reached at drying temperatures of 70 °C and 80 °C, and only at 80 °C for the traditional Kayseri manti. Drying rates increased by increasing temperature levels.

Economic Growth and Negative Externalities in India

Of late the world has realized that the growth models that believed in growth- environment tradeoff are not sustainable. In the pursuit of increasing their GDP, countries have ignored the negative externalities of growth, which would seriously threaten the survival of the future generation. Two kinds of damage are caused by unsustainable growth. Firstly, productive base, particularly, natural capital, like forest, minerals, energy, is depleting. Secondly, environmental pollution and climate change caused by excessive CO2 emissions are threatening human lives in terms of deteriorating health conditions and increasing temperature level (OECD, 2012). In the light of these concerns, sustainable development has become an important goal of nations. This study attempts to assess the extent of negative externalities in India and analyze the relationship between negative externalities and growth of GNI. The study finds that the economic growth of India is more sustainable as compared to all income categories countries. Further, the analysis detected a bidirectional relationship between negative externalities and GNI growth in the post-1990s.
 Keywords: Negative Externalities, Sustainable Development, and Genuine Saving Rate.
 JEL Classification: Q560

Copper Anode Furnace: Chemical, Mineralogical and Thermo-Chemical Considerations of Refractory Wear Mechanisms

In copper anode furnaces, the installed refractory lining is exposed to chemical attack caused by slag and copper oxide. This results in infiltration of the brick microstructure and corrosion of the bricks’ inherent components. Increased temperature level changes the temperature and partial pressure during the furnace operation, as well as the copper infiltration into the brick microstructure, leading to further degeneration of the microstructure and decreased lining life. The mechanical load includes the erosion caused by primary movement of the metal bath, slag and charging material, as well as stresses in the brickwork due to improper lining procedures. Thus, chemical and mineralogical investigation carried out on “post-mortem samples”, together with thermochemical calculations by FactSage™ software, enables better understanding of refractory wear in the copper anode furnace.

Effects of Dust Storms and Climatological Factors on Mortality and Morbidity of Cardiovascular Diseases Admitted to ED.

Objective This study was designed to investigate the effects of Desert Dust Storms and Climatological Factors on Mortality and Morbidity of Cardiovascular Diseases admitted to emergency department in Gaziantep. Method Hospital records, obtained between September 01, 2009 and January 31, 2014, from four state hospitals in Gaziantep, Turkey, were compared to meteorological and climatological data. Statistical analysis was performed by Statistical Package for the Social Science (SPSS) for windows version 24.0. Results 168,467 patients were included in this study. 83% of the patients had chest pain and 17% of patients had cardiac failure (CF). An increase in inpatient hospitalization due to CF was observed and corresponded to the duration of dust storms measured by number of days. However, there was no significant increase in emergency department (ED) presentations. There was no significant association of cardiac related mortality and coinciding presence of a dust storm or higher recorded temperature. The association of increases in temperature levels and the presence of dust storms with “acute coronary syndrome- (ACS-) related emergency service presentations, inpatient hospitalization, and mortality” were statistically significant. The relationship between the increase in PM10 levels due to causes unrelated to dust storms and the outpatient application, admission, and mortality due to heart failure was not significant. The increase in particle matter 10 (PM) levels due to causes outside the dust storm caused a significant increase in outpatient application, hospitalization, and mortality originated from ACS. Conclusion Increased number of dust storms resulted in a higher prevalence of mortality due to ACS while mortality due to heart failure remained unchanged. Admission, hospitalization, and mortality due to chest pain both dependent and independent of ACS were increased by the presence of dust storms, PM10 elevation, and maximum temperature.

Perceptions of climate change impacts and adaptation measures used by crop smallholder farmers in Amathole district municipality, Eastern Cape province, South Africa

The climate is changing, with imminent threats. Projections for increased inconsistencies in climatic elements such as rainfall and temperature have continued to raise concerns, particularly amongst crop producers. Globally, about eighty-two per cent of crop production activities are rain fed; crop yields are thus considered under threat. The majority of South African smallholder and resource-poor crop production farmers rely heavily on rain-fed agriculture, making them vulnerable to the vagaries of climate change risks. As sustainability is crucial to the continuous survival of this population, this study assessed their perceptions of climate change impacts on crop production activities and their adaptation responses. A multistage sampling procedure was used to select a total of 130 crop smallholder farmers from 18 villages in the Mbahashe Local Municipality, from the Amathole District, Eastern Cape Province, South Africa. Simple descriptive statistical tools, principal component analysis and Ward’s linkage cluster analysis were used for the study’s data analysis. Findings revealed a perceived increase in temperature levels and a drastic decline in rainfall. Harsh and aggressive climatic conditions, with attendant problems of drought, heat waves and wind speed, were also indicated. There is a perceived increased difficulty in production activities as a result of water scarcity, poor soil conditions, pest infestations and disease infections, amongst many other challenges. There is a growing threat of unsustainable agricultural production, which may in due course increase poverty levels among the smallholder farmers. In order to sustain production activities, immediate government interventions are required for appropriate extension service delivery, particularly in the area of climate change coping and adaptation responses.

Thermodynamic analysis of engineering solutions aimed at raising the efficiency of integrated gasification combined cycle

Raising the efficiency and environmental friendliness of electric power generation from coal is the aim of numerous research groups today. The traditional approach based on the steam power cycle has reached its efficiency limit, prompted by materials development and maneuverability performance. The rival approach based on the combined cycle is also drawing nearer to its efficiency limit. However, there is a reserve for efficiency increase of the integrated gasification combined cycle, which has the energy efficiency at the level of modern steam-turbine power units. The limit of increase in efficiency is the efficiency of NGCC. One of the main problems of the IGCC is higher costs of receiving and preparing fuel gas for GTU. It would be reasonable to decrease the necessary amount of fuel gas in the power unit to minimize the costs. The effect can be reached by raising of the heat value of fuel gas, its heat content and the heat content of cycle air. On the example of the process flowsheet of the IGCC with a power of 500 MW, running on Kuznetsk bituminous coal, by means of software Thermoflex, the influence of the developed technical solutions on the efficiency of the power plant is considered. It is received that rise in steam-air blast temperature to 900°C leads to an increase in conversion efficiency up to 84.2%. An increase in temperature levels of fuel gas clean-up to 900°C leads to an increase in the IGCC efficiency gross/net by 3.42%. Cycle air heating reduces the need for fuel gas by 40% and raises the IGCC efficiency gross/net by 0.85-1.22%. The offered solutions for IGCC allow to exceed net efficiency of analogous plants by 1.8-2.3%.

Simulation research on a variable-lift absorption cycle and its application in waste heat recovery of combined heat and power system

To solve the dilemma between temperature lift capability and coefficient of performance (COP) when absorption heat pump is applied in low grade heat utilization, a variable-lift absorption cycle and an improved one based on it are introduced here. The variable-lift absorption cycles have relatively simple systems and contains enough number of absorbers and condensers to develop plenty of gradually increasing temperature levels to match heating process. For a given heating demand and waste heat temperature level, the results of application of variable-lift absorption cycles in waste heat recovery of combined heat and power(CHP) system show that, the variable-lift cycles can always work efficiently when return water temperature of primary heating network (PHN) varies from 30 °C to 50 °C. The needed heat source temperatures of variable-lift cycles are always over 12 °C lower than single effect cycle. The higher return water temperature of PHN yields more obvious advantage of the improved cycle. When the return water temperature of PHN is 50 °C, variable lift-2C cycle and variable lift-3C cycle can reduce the equivalent power consumption for space heating by 8.5% and 15% respectively when comparing to single effect cycle. The essence of the variable-lift cycles is further clarified from the heat transfer analysis in T-Q diagram.

The perils of climate change: In utero exposure to temperature variability and birth outcomes in the Andean region

The discussion on the effects of climate change on human activity has primarily focused on how increasing temperature levels can impair human health. However, less attention has been paid to the effect of increased climate variability on health. We investigate how in utero exposure to temperature variability, measured as the fluctuations relative to the historical local temperature mean, affects birth outcomes in the Andean region. Our results suggest that exposure to a temperate one standard deviation relative to the municipality’s long-term temperature mean during pregnancy reduces birth weight by 20g. and increases the probability a child is born with low birth weight by a 0.7 percentage point. We also explore potential channels driving our results and find some evidence that increased temperature variability can lead to a decrease in health care and increased food insecurity during pregnancy.

Understanding the effect of temperature on the interfacial behavior of CFRP-wood composite via molecular dynamics simulations

Abstract Carbon fiber-reinforced polymer (CFRP) bonding technique can provide an adequate enhancement to wood structures. Varying temperature levels can affect the strengthening by CFRP, particularly the interfacial behavior of CFRP-wood composite, while the fundamental mechanism is still not clear. This research aims to evaluate the temperature effect on interfacial bonding of CFRP-wood composite, and to explore the fundamental mechanism by using molecular dynamics (MD) simulations. After the specimens are conditioned at various temperature levels, the interfacial bonding performance of CFRP-wood composites is evaluated by acoustic-laser technique and shear test. The results indicate that the bonding is strong at low temperature and deteriorates at high temperature. Meanwhile, the fracture energy measured from the shear test and the MD simulation shows a similar trend, which decreases as the temperature level increases. It is found that the constituent materials deteriorate with increasing temperature, as evidenced by the conformational changes of the modeled epoxy-wood interface, which significantly weakens the interfacial bonding. The finding unveiled from our study demonstrates that the long-term exposure to high temperature can significantly deteriorate the CFRP-wood composite and consequently lead to a structural failure ahead of its service life, which should be considered particularly in tropical and subtropical regions.

Nonlinear Ultrasonic Damage Characterization of Limestone

ABSTRACTCharacterization of dolomitic limestone rock samples with increasing levels of damage is presented using a nonlinear ultrasonic approach. Limestone test samples with increasing levels of damage were created artificially by exposing virgin samples to increasing temperature levels of 100, 200, 300, 400, 500, 600, and 700°C for a ninety minute period of time. These samples were first characterized using ultrasonic dilatational and shear phase velocity measurements and corresponding attenuations. Then, a nonlinear approach based upon noncollinear wave mixing of two dilatational waves was used. Criteria were used to assure that the detected scattered wave originated via wave interaction in the limestone and not from nonlinearities in the testing equipment. It was observed that both the dilatational velocity and the noncollinear wave mixing approach are able to characterize the level of damage in limestone rock. However, the nonlinear approach is more sensitive to damage accumulation by about two orders of magnitude.

Climate change impacts and potential benefits of heat-tolerant maize in South Asia

Maize is grown by millions of smallholder farmers in South Asia (SA) under diverse environments. The crop is grown in different seasons in a year with varying exposure to weather extremes, including high temperatures at critical growth stages which are expected to increase with climate change. This study assesses the impact of current and future heat stress on maize and the benefit of heat-tolerant varieties in SA. Annual mean maximum temperatures may increase by 1.4–1.8 °C in 2030 and 2.1–2.6 °C in 2050, with large monthly, seasonal, and spatial variations across SA. The extent of heat stressed areas in SA could increase by up to 12 % in 2030 and 21 % in 2050 relative to the baseline. The impact of heat stress and the benefit from heat-tolerant varieties vary with the level of temperature increase and planting season. At a regional scale, climate change would reduce rainfed maize yield by an average of 3.3–6.4 % in 2030 and 5.2–12.2 % in 2050 and irrigated yield by 3–8 % in 2030 and 5–14 % in 2050 if current varieties were grown under the future climate. Under projected climate, heat-tolerant varieties could minimize yield loss (relative to current maize varieties) by up to 36 and 93 % in 2030 and 33 and 86 % in 2050 under rainfed and irrigated conditions, respectively. Heat-tolerant maize varieties, therefore, have the potential to shield maize farmers from severe yield loss due to heat stress and help them adapt to climate change impacts.

Fracture Properties of Polystyrene Aggregate Concrete after Exposure to High Temperatures.

This paper mainly reports an experimental investigation on the residual mechanical and fracture properties of polystyrene aggregate concrete (PAC) after exposure to high temperatures up to 800 degrees Celsius. The fracture properties namely, the critical stress intensity factor (), the critical crack tip opening displacement (CTODC) for the Two-Parameter Model, and the fracture energy (GF) for the Fictitious Crack Model were examined using the three-point bending notched beam test, according to the RILEM recommendations. The effects of polystyrene aggregate (PA) content and temperature levels on the fracture and mechanical properties of concrete were investigated. The results showed that the mechanical properties of PAC significantly decreased with increase in temperature level and the extent of which depended on the PA content in the mixture. However, at a very high temperature of 800 °C, all samples showed 80 percent reduction in modulus of elasticity compared to room temperature, regardless of the level of PA content. Fracture properties of control concrete (C) and PAC were influenced by temperature in a similar manner. Increasing temperature from 25 °C to 500 °C caused almost 50% reduction of the fracture energy for all samples while 30% increase in fracture energy was occurred when the temperature increased from 500 °C to 800 °C. It was found that adding more PA content in the mixture lead to a more ductile behaviour of concrete.

Restructuring of Epibacterial Communities on Fucus vesiculosus forma mytili in Response to Elevated pCO2 and Increased Temperature Levels.

Marine multicellular organisms in composition with their associated microbiota—representing metaorganisms—are confronted with constantly changing environmental conditions. In 2110, the seawater temperature is predicted to be increased by ~5°C, and the atmospheric carbon dioxide partial pressure (pCO2) is expected to reach approximately 1000 ppm. In order to assess the response of marine metaorganisms to global changes, e.g., by effects on host-microbe interactions, we evaluated the response of epibacterial communities associated with Fucus vesiculosus forma mytili (F. mytili) to future climate conditions. During an 11-week lasting mesocosm experiment on the island of Sylt (Germany) in spring 2014, North Sea F. mytili individuals were exposed to elevated pCO2 (1000 ppm) and increased temperature levels (Δ+5°C). Both abiotic factors were tested for single and combined effects on the epibacterial community composition over time, with three replicates per treatment. The respective community structures of bacterial consortia associated to the surface of F. mytili were analyzed by Illumina MiSeq 16S rDNA amplicon sequencing after 0, 4, 8, and 11 weeks of treatment (in total 96 samples). The results demonstrated that the epibacterial community structure was strongly affected by temperature, but only weakly by elevated pCO2. No interaction effect of both factors was observed in the combined treatment. We identified several indicator operational taxonomic units (iOTUs) that were strongly influenced by the respective experimental factors. An OTU association network analysis revealed that relationships between OTUs were mainly governed by habitat. Overall, this study contributes to a better understanding of how epibacterial communities associated with F. mytili may adapt to future changes in seawater acidity and temperature, ultimately with potential consequences for host-microbe interactions.

Induced thermal stress on serotonin levels in the blue swimmer crab, Portunus pelagicus

The temperature of habitat water has a drastic influence on the behavioral, physiological and biochemical mechanisms of crustaceans. Hyperglycemia is a typical response of many aquatic animals to harmful physical and chemical environmental changes. In crustaceans increased circulating crustacean hyperglycemic hormone (CHH) and hyperglycemia are reported to occur following exposure to several environmental stress. The biogenic amine, serotonin has been found to modulate the CHH levels and oxidation of serotonin into its metabolites is catalysed by monoamine oxidase. The blue swimmer crab, Portunus pelagicus is a dominant intertidal species utilized throughout the indo-pacific region and is a particularly important species of Palk bay. It has high nutritional value and delicious taste and hence their requirements of capture and cultivation of this species are constantly increasing. This species experiences varying and increasing temperature levels as it resides in an higher intertidal zone of Thondi coast. The present study examines the effect of thermal stress on the levels of serotonin and crustacean hyperglycemic hormone in the hemolymph of P. pelagicus and analyzes the effect of the monoamine oxidase inhibitor, pargyline on serotonin and CHH level after thermal stress. The results showed increased levels of glucose, CHH and serotonin on exposure to 26°C in control animals. Pargyline injected crabs showed highly significant increase in the levels of CHH and serotonin on every 2°C increase or decrease in temperature. A greater CHH level of 268.86±2.87fmol/ml and a greater serotonin level of 177.69±10.10ng/ml was observed at 24°C. This could be due to the effect of in maintaining the level of serotonin in the hemolymph and preventing its oxidation, which in turn induces hyperglycemia by releasing CHH into hemolymph. Thus, the study demonstrates the effect of thermal stress on the hemolymph metabolites studied and the role of pargyline in elevating the levels of serotonin and CHH on thermal stress in the blue swimmer crab, P. pelagicus.

Damage characterization in dimension limestone cladding using noncollinear ultrasonic wave mixing

A method capable of characterizing artificial weathering damage in dimension stone cladding using access to one side only is presented. Dolomitic limestone test samples with increasing levels of damage were created artificially by exposing undamaged samples to increasing temperature levels of 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, and 700°C for a 90 min period of time. Using access to one side only, these test samples were nondestructively evaluated using a nonlinear approach based upon noncollinear wave mixing, which involves mixing two critically refracted dilatational ultrasonic waves. Criteria were used to assure that the detected scattered wave originated via wave interaction in the limestone and not from nonlinearities in the testing equipment. Bending tests were used to evaluate the flexure strength of beam samples extracted from the artificially weathered samples. It was observed that the percentage of strength reduction is linearly correlated ( R 2 = 98 ) with the temperature to which the specimens were exposed; it was noted that samples exposed to 400°C and 600°C had a strength reduction of 60% and 90%, respectively. It was also observed that results from the noncollinear wave mixing approach correlated well ( R 2 = 0.98 ) with the destructively obtained percentage of strength reduction.

Effects of elevated temperature on pumice based geopolymer composites

Aluminosilicate type materials can be activated in alkaline environment and can produce geopolymer cements with low environmental impacts. Geopolymers are believed to provide good fire resistance so the effects of elevated temperatures on mechanical and microstructural properties of pumice based geopolymer were investigated in this study. Pumice based geopolymer was exposed to elevated temperatures of 100, 200, 300, 400, 500, 600, 700 and 800°C for 3 h. The residual strength of these specimens were determined after cooling at room temperature as well as ultrasonic pulse velocity, and the density of pumice based geopolymer pastes before and after exposing to high temperature was determined. Microstructures of these samples were investigated by Fourier transform infrared for all temperatures and SEM analyses for samples that were exposed to 200, 400, 600 and 800°C. Specimens, which were initially grey, turned whitish accompanied by the appearance of cracks as temperatures increased to 600 and 800°C. Consequently, compressive strength losses in geopolymer paste were increased with increasing temperature level. On the other hand, compressive strength of geopolymer paste was less affected by high temperature in comparison with the ordinary Portland cement. As a result of this study, it is concluded that pumice based geopolymer is useful in compressive strength losses exposed to elevated temperatures.

Bioactive and rheological properties of rose hip marmalade.

In this study, bioactive (total phenolic, antioxidant and antiradical activity) and rheological properties (steady and dynamic) of rose hip marmalade were investigated. Bioactive properties were determined in rose hip marmalade and extract. Extract had higher total phenolic content (38.5mg GAE/g dry extract), antioxidant activity (124mg AAE/g dry extract) and antiradical activity (49.98%) than marmalade. Steady and dynamic rheological properties of the marmalade were determined at different temperature levels (5, 25 and 45°C). Rose hip marmalade exhibited shear thinning behavior and Ostwald de Waele model best described flow behavior of the sample (R (2) ≥0.9880) at different temperature levels. Consistency index and apparent viscosity values (η 50 ) at shear rate 50s(-1) decreased with increase in temperature level. Viscoelastic properties were determined by oscillatory shear measurements and G' (storage modulus) values were found to be higher than G'' (loss modulus) values, indicating that the rose hip marmalade had a weak gel-like structure with solid-like behavior. G', G'', G (*) (complex modulus) and η* (complex viscosity) values decreased with increase in temperature level. Modified Cox-Merz rule was satisfactorily applied to correlate apparent and complex viscosity values of the rose hip marmalade at all temperatures studied.