Higher Temperature Values Research Articles

Investigating karst aquifers in tectonically complex alpine areas coupling geological and hydrogeological methods

In this work, a reliable understanding of the storage patterns and flow dynamics of a tectonically complex karst system is attained by means of the combined analysis of results derived from geological and karst-specific -i.e. hydrogeological- approaches (hydrodynamic, hydrochemical, hydrothermal and isotopic). The pilot site comprises rocks belonging to six different complexes within the Betic Cordillera: External Zone (1), Flysch Complex (1) and the Internal Zone (4). Quick and sharp variations in natural responses after rainfall were recorded in the overflow springs located in the External Zone. In contrast, groundwater drained by permanent springs placed in the Internal Zone present high mineralization and temperature values, as well as lagged and buffered responses to precipitation events. At a first glance, one could assume that two independent systems with different behaviors are at work, following a classical interpretation: conduit flow-type functioning for Jurassic limestones (External Zone) and diffuse-flow behavior for the Triassic calcareous rocks (Internal Zone). However, integration of results with those derived from the water budget and geological observations leads us to propose a sole aquifer, formed by rocks belonging to several geological domains, but hydrogeologically connected, where shorter and longer water–rock interactions along flow paths coexist. Overthrust surfaces and the subsequent normal faults involve diverse low permeable formations imbricated within a tectonic suture, inducing strong heterogeneities in groundwater flow patterns. The geological complexity and the inner geometry at the southeast border of the aquifer jointly modulate the global signal coming from the External Zone, which is attenuated before arriving at the permanent springs found in the Internal Zone. We conclude by emphasizing that a continuous transfer of feedback from geological to hydrogeological approaches, and vice versa, enhances knowledge in both directions, helping us to avoid misinterpretations about the hydrogeological behaviors of aquifers and, ultimately, to better evaluate and manage water resources.

Green to Grey: An Urban Heat Assessment of Kumasi, Ghana

The current study assessed the city of Kumasi, Ghana to find out the extent of urban heat and the views of the populace about their climate. Both the subjective and objective approaches were utilized in the study. Secondary data from the Meteorological Survey Department in Kumasi covering temperature and relative humidity values for a 42- year period (1976 - 2018) was retrieved and used in the analysis to find the trend of urban heat phenomenon. Alongside, a developed questionnaire had a response from 2,083 people. The findings reveal among other things that there’s a 2ºC rise in mean annual temperature from 1976 to 2018. Additionally, the data shows that the past 4 years have had high mean temperature values. Subjectively, 1, 271 residence representing 61% voted in the “slightly warm-hot” range on the thermal sensation scale. Majority of the respondents across all the ages indicated how uncomfortable their outdoor spaces have become in recent times. 36% of the respondents attributed this discomfort to the lack of greenery with over 95% across all ages indicating that Kumasi city has lost its greenery and green spaces to buildings and other infrastructural activities. Whiles climate change and global warming have both become a global menace, the onus lies on individual countries and for that matter, various city authorities to make a conscious effort in planning our cities with greenery to alleviate the menace we already find ourselves. A conscious effort to retrieve and restore encroached green spaces must be undertaken by the city authorities while the parks and gardens division ought to be efficiently resourced to manage our green spaces.

New cardo silylated poly(azomethine)s containing 9,9′‐diphenylfluorene units as materials with Brønsted acid‐dependent fluorescence

AbstractAromatic poly(azomethine)s have been studied due to their attractive properties such as high thermal stability, semiconducting behavior and the ability to coordinate species with their imine units (CN). In this paper, the synthesis and characterization of two novel silylated poly(azomethine)s containing cardo units are reported. These materials were highly soluble in organic solvents such as chloroform and m‐cresol and were thermally stable, and PAzMC1 exhibited a high glass transition temperature value (287 °C), while that for PAzMC2 was not observed. UV–visible spectrophotometry revealed absorption bands related to the aromatic backbone of both PAzMCs, 300–285 nm in tetrahydrofuran and 310–301 nm in dimethylsulfoxide, and bands attributed to the conjugated imine unit at around 350 nm. In order to investigate the phenomenon of the emission of fluorescence promoted by dopant agents with regard to potential optoelectronic applications, the materials were doped with H2SO4 and their optical and electrochemical properties investigated. Thus, the absorption band of the imine group was suppressed due to the nitrogen atoms being protonated. Fluorescence spectroscopy analysis developed in dilute solutions of polymers showed no emission from the undoped polymers, whereas the acid‐doped species emitted fluorescence in the UV and violet regions (322 nm). Cyclic voltammetry measurements were carried out and HOMO–LUMO energies were estimated. This study provides a starting point for the development of new poly(azomethine)s with doping‐dependent emission. © 2019 Society of Chemical Industry

Temperature regime of Fibrist Histosols of the Bakchar Mire (West Siberia)

Temperature regime of Fibrist Histosols of the Bakchar Mire (West Siberia)

Plasticity of fruit and oil traits in olive among different environments

Olive is a long-living perennial species with a wide geographical distribution, showing a large genetic and phenotypic variation in its growing area. There is an urgent need to uncover how olive phenotypic traits and plasticity can change regardless of the genetic background. A two-year study was conducted, based on the analysis of fruit and oil traits of 113 cultivars from five germplasm collections established in Mediterranean Basin countries and Argentina. Fruit and oil traits plasticity, broad‐sense heritability and genotype by environment interaction were estimated. From variance and heritability analyses, it was shown that fruit fresh weight was mainly under genetic control, whereas oleic/(palmitic + linoleic) acids ratio was regulated by the environment and genotype by environment interaction had the major effect on oil content. Among the studied cultivars, different level of stability was observed, which allowed ranking the cultivars based on their plasticity for oil traits. High thermal amplitude, the difference of low and high year values of temperature, negatively affected the oil content and the oleic acid percentage. Information derived from this work will help to direct the selection of cultivars with the highest global fitness averaged over the environments rather than the highest fitness in each environment separately.

Analysis effects of oil viscosity and temperature on orbit of ring gear in internal gear motor and pump

Effect of oil temperature and viscosity on the ring gear orbit in the internal gear motor and pump is analyzed in this study. The mobility method is used to calculate the ring gear orbit. The mathematical model of oil viscosity and temperature is then integrated into the mobility method. The simulation results point out that the oil temperature and viscosity have great effect on the eccentricity, position angle and minimum oil film thickness. The metal - to - metal contact phenomenon occurs if internal gear motor and pump operates under high values of oil temperature or low values of oil viscosity conditions.

Analysis effects of oil viscosity and temperature on orbit of ring gear in internal gear motor and pump

Effect of oil temperature and viscosity on the ring gear orbit in the internal gear motor and pump is analyzed in this study. The mobility method is used to calculate the ring gear orbit. The mathematical model of oil viscosity and temperature is then integrated into the mobility method. The simulation results point out that the oil temperature and viscosity have great effect on the eccentricity, position angle and minimum oil film thickness. The metal - to - metal contact phenomenon occurs if internal gear motor and pump operates under high values of oil temperature or low values of oil viscosity conditions.

Evaluation and minimisation of energy consumption in a medium-scale reverse osmosis brackish water desalination plant

The Reverse Osmosis (RO) process has been expansively used in water treatment as a result of its low energy consumption compared to thermal distillation processes, leading to reduced overall water production cost. Evaluation and minimisation of energy consumption (expressed in kWh/m3 of fresh water production) in a medium-scale spiral wound brackish water RO (BWRO) desalination plant of the Arab Potash Company (APC) are the main aims of this research. The model developed earlier by the authors has been integrated to simulate the process and achieve the main aims. Energy consumption calculations of low salinity BWRO desalination plant, with and without an energy recovery device, have been carried out using the gPROMS software suite. In other words, this research evaluated the impact of adding an energy recovery device on the RO process energy consumption of the APC, which is introduced for the first time. Also, the effects of several operating conditions of BWRO process include the feed flow rate, pressure and temperature on the performance indicators, which include the energy consumption and total plant recovery at different energy recovery device efficiencies, were studied. The simulation results showed that the total energy consumption could be reduced at low values of feed flow rates and pressures and high values of temperatures. More importantly, there is an opportunity to reduce the total energy consumption between 47% and 53.8% compared to the one calculated for the original design without an energy recovery device.

SENSOR EFFECTIVENESS FOR SOIL WATER CONTENT MEASUREMENTS UNDER NORMAL AND EXTREME CONDITIONS

AbstractAn environmental sensor (the Decagon 5TE sensor with an EM50 data logger) is a soil salinity, temperature and water content (SWC) sensor that can be used by researchers and farmers around the world. Herein, 22 sensors were tested under different conditions of soil salinity, temperature, organic matter, texture, clay content, bulk density and water content, ranging from normal to extreme. The results indicated that the main issue with this device is that its SWC determinations are only accurate within a limited soil salinity and temperature range. Conversely, the organic matter, texture, clay content and bulk density have no direct impact on the sensors' accuracy. The sensors work best when the soil salinity and temperature are 2.5 dS m−1 and 25 °C, respectively. This sensor can be used appropriately after calibration when the soil salinity and temperatures are within the 1.9–4.0 dS m−1 and 16–30 °C ranges, respectively. When the soil salinity and temperature values are higher or lower than these ranges, the sensors do not work accurately. More investigation is needed to study the effectiveness of the sensors under high values of soil salinity and temperature. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.

Preparation of photo-crosslinkable cinnamate modified hyaluronic acid for immobilization of horseradish peroxidase

Abstract In this work, a photo-responsive hydrogel membrane based on cinnamate-modified hyaluronic acid (HA-CM) was developed and safely cross-linked under UV light curing. The obtained material was effectively utilized for immobilization of horseradish peroxidase (HRP) enzyme via encapsulation and entrapment strategy with efficiency above 95%. The prepared HA-CM biopolymer was investigated before the UV curing using instrumental and spectral techniques including Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). During the UV irradiation, the progress of the cross-linking reaction was monitored by the UV–vis light spectroscopy. In addition, when the photo-induced cross-linking had accomplished, the morphological appearance of the hydrogel membrane was recorded using a scanning electron microscope (SEM). The HRP immobilized in HA-CM membranes displayed remarkable stability against the environmental pH changes especially under alkaline media and shift the optimum pH to 8 compared to the free HRP, which exhibited the highest activity at pH 7. Also, the entrapped enzyme was able to preserve above 85% of its catalytic activity at higher temperature values where the free enzyme had deactivated by approximately 50%. Moreover, HA-CM-HRP maintained 87% of its activity after 10 sequential reuse cycles, which indicate the economic value of the employed immobilization strategy.

Quantum scrambling and state dependence of the butterfly velocity

Operator growth in spatially local quantum many-body systems defines a scrambling velocity. We prove that this scrambling velocity bounds the state dependence of the out-of-time-ordered correlator in local lattice models. We verify this bound in simulations of the thermal mixed-field Ising spin chain. For scrambling operators, the butterfly velocity shows a crossover from a microscopic high temperature value to a distinct value at temperatures below the energy gap.

The Evaluation of Impact of Cable Power Lines on the Environment

The thermal impact of cable power lines and structural materials of cables on the environment has been considered. A quantitative evaluation of the thermal impact of electrical cables with cross-linked polyethylene insulation on the environment was carried out using the Elcut program. Analysis of the temperature field near the loaded cable line of 10 kV demonstrated high values of soil temperature that negatively affects its redox potential and living organisms. To evaluate the environmental impact of electrical cable materials, an approach has been developed that takes into account not only the toxicity of the materials but also their volumetric content in the cable. Cable lines with cables with traditional paper-oil insulation cause more damage to the environment than cable lines with cables, insulated with crosslinked polyethylene. The environment, in turn, also has an impact on the electrical cables: the values of long-term permissible load currents depend on the ambient temperature (when laying cables in the open air, in an earthen trench or in cable rooms). The impact of solar radiation on the thermal conditions of the electric cable is estimated. A comparative analysis of the complex environmental impact of electric cables with traditional insulation and insulation of crosslinked polyethylene demonstrated that unarmored cable with crosslinked polyethylene insulation at a voltage of 10 kV (regardless of the type of its shell) causes less damage to the environment than the same traditional cable throughout the considered temperature range on their surfaces.

Surface temperature distribution on a spherical ice particle growing by accretion in wet growth regime

AbstractExperimental evidence has demonstrated that temperature on the surface of an ice particle growing by accretion is not uniform. This non‐uniformity is relevant because the ice particle surface temperature is an important microphysical parameter that influences the sign and magnitude of the charge transfer during ice particles collisions. In particular, when high values of ambient temperature and liquid water content are reached, the ice particle surface temperature is expected to reach 0 °C, which is known as wet growth regime. Previous experimental results have shown that wet growth is not uniformly reached on the ice particle surface and a surface temperature distribution is developed. In order to know the surface temperature distribution of a fixed ice particle growing by accretion of supercooled water, numerical calculations were carried out. It was found that the surface temperature distribution has a strong dependence on liquid water content, ambient temperature, airflow velocity and water droplet size. The stagnation point always reaches higher temperatures and, in many cases, its temperature is near 0 °C. For some values of the liquid water content, ambient temperature and airflow velocity, it was possible to determine temperature differences up to 7 °C between the stagnation point and the equator. This variation in the surface temperature implies that the region near the stagnation point would experience wet growth, while the rest of the ice particle surface would remain in dry growth regime, supporting the partial wet growth hypothesis. This could also explain the charge transfer reported during ice particles collisions under wet growth conditions.

Analysis of the correlation between the extreme temperature of incision surface and non-union of incision in internal fixation of calcaneal fracture

Objective To explore the correlation between the extreme temperature of incision surface and non-union of incision in internal fixation of calcaneal fracture. Methods From January 2016 to December 2017, 142 patients with closed unilateral calcaneal fracture treated with open reduction and internal fixation in the Integrated Chinese and Western Medicine Hospital of Wenzhou were enrolled.The incision temperature was collected by infrared radiation thermometers intermittently for 4-5 times, and the extreme values were used for further analysis.The primary endpoint of the study was the incision healing 14 days after surgeries.The patients′ age, gender, inflammatory indicators and body mass index (BMI) were evaluated, as well as related factors such as diabetes and arteriosclerosis. Results All patients completed the follow-up observation 14 days after operation, and finally achieved the wound healing in 105 cases, and the wound non-healing in 37 cases.The average extreme value of low temperature was (34.91±0.47)℃ in the union group and (34.13±0.60)℃ in the disunion group, and the average extreme value of high temperature was (36.61±0.55)℃ in the union group and (36.90±0.52)℃ in the disunion group, there were statistically significant differences between the two groups(t=7.152, -2.762, P=0.000, 0.007). Logistic regression analysis results showed that age[β(regression coefficient)=-0.111], extreme high(β=2.728) or very low (β=-3.854), arteriosclerosis(β=4.597), history of diabetes(β=2.234) were risk factors for incision nonunion(P=0.046, 0.003, 0.001, 0.002, 0.024). Conclusion Extreme incision temperature is observed to be associated with an increased risk of operative incision disunion after open reduction and internal fixation for calcaneal fractures. Key words: Fractures, bone; Calcaneus; Fracture fixation, internal; Body temperature; Wound healing; Postoperative complications; Logistic models

Thermal expansivity and degradation properties of PLA/HA and PLA/βTCP in vitro conditioned composites

The objective of this study was to investigate the thermal expansivities and degradation properties for several in vitro conditioned biodegradable poly(lactic acid)/hydroxyapatite (PLA/HA) and poly(lactic acid)/β-tricalcium phosphate (PLA/βTCP) composites with different mass% of the particle reinforcements (i.e. 10, 20 and 30). The samples were prepared by extrusion followed by injection moulding and incubated in a customized simulated body fluid at 37 °C over 60, 90, 120, 150 and 180 days, respectively. Thermal expansion and degradation properties of in vitro conditioned samples, along with dynamic mechanical properties of unconditioned ones, were systematically investigated through coefficients of linear thermal expansion and thermal strain changes, decomposition temperatures, mass changes and per cent residues. The results indicated that PLA/βTCP composites performed better than PLA/HA composites, irrespective of their filler mass%, revealing high values of glass transition temperatures, around a mean value of 65 °C, both on dynamic mechanical analysis and on dilatation measurements but lower values on their degradation temperatures, such as 360 °C. The results suggest the feasibility of tailoring high-loaded osteoconductive fillers-reinforced PLA composites for various medical and engineering applications.

A Dual Black Hole Associated with Obscured and Unobscured AGNs: CXO J101527.2+625911

Abstract We report the results of an investigation to determine the nature of the offset active galactic nucleus (AGN) found in the source CXO J101527.2+625911. Hubble Space Telescope and Chandra X-ray observatory data have suggested that the offset AGN, which has an angular separation of only 0.″26 from the center of the host galaxy, is a recoiled supermassive black hole (rSMBH). We carried out high angular resolution observations with both the Very Long Baseline Array (1.54 GHz) and the Very Large Array (10.0 GHz and 33.0 GHz) and detected a single compact radio source in the center of the host galaxy, with no radio continuum emission associated with the offset AGN. The detected radio source has a high brightness temperature value of T b = 7.2 × 107 K, indicating that the radio emission is associated with an AGN. Furthermore, we present the decomposition of high-resolution KECK spectra of the [O iii] 5007 Å line into two narrow emission line components, which is a characteristic sign of a dual black hole system. These new radio and optical wavelength results suggest that CXO J101527.2+625911 is the host of a dual black hole system rather than an rSMBH.

Effect of Sc addition on the microstructure, mechanical properties, and damping capacity of Al–20Zn alloy

In this study, hot rolling (HR), solid solution treatment (ST), and friction stir processing (FSP) were applied to Al–20Zn and Al–20Zn–0.5Sc alloys to obtain their elongated, coarsened, and fine-equiaxed grain structures. Sc addition refined the grains of Al–20Zn alloys in any state. The dynamic precipitation during deformation, such as HR and FSP, was promoted by the Al3Sc phase in the alloy containing Sc. The strength of Al–20Zn alloy was improved by Sc addition. Furthermore, a reasonable ductility was obtained in the ST sample when added with Sc. The fine grains and high density of Al3Sc particles with grain boundary pinning effect resulted in increased high-temperature internal friction value and excellent damping stability of the HR and FSP Al–20Zn–0.5Sc samples.

Simple fiber-optic sensor for simultaneous and sensitive measurement of high pressure and high temperature based on the silica capillary tube.

A simple fiber-optic sensor for simultaneous measurement of high pressure and high temperature was proposed. The sensor was simply fabricated by splicing two sections of silica capillary tubes (SCTs) with different inner diameters to the single-mode fiber. The thick core SCT functions as a Fabry-Perot (FP) micro-cavity and an anti-resonant reflecting waveguide at the same time. The two different sensing mechanisms lead to the high contrast sensitivity values of pressure and temperature (‒3.76 nm/MPa, 27.7 pm/°C and 4.24 nm/MPa, 0.82 pm/°C). We also proposed a simple and effective method to evaluate the actual sensitivities of two-parameter sensors by using linear programming, which shows that our sensor is more sensitive than others in high pressure and high temperature simultaneous detection. Besides, low cost, good mechanical property and convenient reflective probe make the sensor more competitive in actual application.

Investigation of the Temperature Effect on the Electrical Parameters of a Photovoltaic Module at Ouargla City

Abstract To predict the I-V characteristics of the photovoltaic module, five parameters photovoltaic model Abstract: To predict the I-V characteristics of the photovoltaic module, five parameters photovoltaic model was utilized. The most influential parameters in the photovoltaic module are the solar irradiance level (E) and the temperature (T). The present research was conducted due to the high-temperature values in Ouargla city (can reach 60 °C in the hot season), which will affect remarkably the installed PV installations in this region. The experimental was done in several days cause the investigation need a constant irradiance values with different temperature. The temperature of a photovoltaic module varies according to other conditions, the temperature measurements made on the rear face of the PV module may not be indicative due to a temperature gradient in the material of the rear face of the module. Unfortunately, photovoltaic systems manufacturers do not take into consideration these environmental circumstances which negatively influence the module parameters and yielded deterioration in the system efficiency. The aim of this paper is to investigate the effect of the temperature term on the electrical performances such as the open circuit voltage (Voc), short circuit current (Isc), optimal power (Pm) and Fill Factor. The temperature distribution is non-uniform temperature on the surface of PV modules joined to that of the quality of temperature measurements affects the values of temperature coefficients found. To validate a model allows the researcher to get approximately the I-V characteristic similar to the experiment values. It use the conventional technique (Newton Raphson method) and it was compared by an artificial intelligent method which is the PSO technique, the five parameters estimated (Iph, Is, Rs, Rp, n). This proposed approach can be utilized to model any marketable PV module based on given datasheet parameters only. Statistical indicators were adopted to evaluate the performance of the proposed models; where the relative error of the PSO method comes more less the conventional method.

Space-temporal evaluation of changes in temperature and soil use and cover in the metropolitan region of baixada santista

The Metropolitan Region of Baixada Santista (MRBS) harbors one of the main port areas of Brazil: the Port of Santos. Due to the accelerated urban development in this region, the monitoring of biophysical parameters is fundamental. Therefore, this paper aims to i) estimate the soil surface temperature (Ts) and identify the Urban Heat Islands (UHI) formation; and ii) compare the Ts and the normalized difference vegetation index (NDVI) for MRBS from 1986 to 2016 using Landsat 5 and 8 images. Remote sensing tools are essential to meet the objectives of this work for providing both the spatial and temporal evaluation of a region. The spatial analysis was based on the NDVI to evaluate the vegetation density and size from five previously established classes (i.e., water bodies, urban grid, exposed soil and road corridors, shrub, and dense vegetation). The NDVI mapping showed a significant reduction in the cover area referred to the dense vegetation class (91.7%), while the urban grid category increased by 29.4%, resulting from the urban expansion and green cover reduction over the region during this period. Surface temperature thematic maps showed high-temperature values related to increased urbanization and decreased rainfall. Moreover, an 8°C rise in surface temperature over the last 30 years was registered due to the regional development, which has replaced natural soils by anthropic materials and reduced dense vegetation. This phenomenon has resulted in the formation and intensification of UHI, especially after the 2000s.