Differences In Temperature Changes Research Articles

Can Current AGCMs Reproduce Historical Changes in the Atmospheric Diabatic Heating over the Tibetan Plateau

AbstractRecent studies have demonstrated a persistent decreasing trend in the spring sensible heat (SH) source over the Tibetan Plateau (TP) during the past three decades. By comparing simulations from nine state-of-the-art atmospheric general circulation models (AGCMs) driven by historical forcing fields with both observational data and five reanalysis datasets, the authors found that the AGCMs are unable to reproduce the change in the SH flux over the TP. This deficiency arises because the observed decreasing trend in SH flux depends primarily on the change in surface wind speed according to the bulk formula, whereas in the models it is also influenced largely by changes in the land-air temperature difference related to the systematic cold bias. In addition, an obvious discrepancy exists in other aspects of the diabatic heating simulated by the models, suggesting that a significant improvement is required in the physical schemes associated with land surface processes and diabatic heating over the compli...

The Effect of Tub Bathing on Body Temperature in Preterm Infants: Randomized Clinical Trial

Background: Bathing of a premature newborn is important in care giving, but due to inadequate evidences, infant caregivers are not sure about bathing being safe in terms of not causing hypothermia and are not systematically considered in the infants’ care giving programs. Aim: To determine the effect of tub bathing on body temperature of preterm infants”. Methods: This study is a randomized controlled clinical trial which was conducted in 1392 in neonatal unit of Al-zahra hospital. 118 preterm infants were randomly divided into intervention and control groups. The infants in the control group received routine skin care only. The intervention group was bathed three times every other day inside the bathtub. In both group, the infants’ body temperature was measured at the same times by the researcher. Data were analyzed with SPSS software version 14 using independent T-test, Chi-square and repeated measurements tests. Results: In both groups, boys outnumbered girls. At the time of inclusion, the infants' age was 5.8 ± 8.6 days and their weight was 320.6 ± 1660.0 grams. In both groups, the mean temperature of premature infants after bath was dropped in all three times. Which was statistically significant in the first and second baths (P<0.001). There was no statistically significant differences in temperature changes between two groups in differnet times of measurement (P=0.31). Conclusion: The results of this study showed that bathing in bathtub does not cause improper body temperature changes in preterm infants. It is recommended that this correct bathing method should be used in the care giving program of the infants hospitalized in neonates' wards and Neonatal Intensive Care Units.

Assessment of Asphalt Concrete Pavement Quality by Using Infrared Thermal Imaging Technology

Manholes cause uneven pavements, which affect the quality of pavement services, leading to public criticism in Taiwan. Many manholes are buried beneath pavements to ensure evenness and enhance the usability of pavements for pedestrians. The presence of manholes affects the quality of the asphalt concrete underneath the pavement because then conducting excavations using road construction equipment becomes difficult, ultimately leading to early deterioration of the pavement surfaces. Temperatures can also differ considerably between the manhole and non-manhole locations on asphalt concrete pavement. This study used infrared thermal imaging technology and an analysis of variances statistical method to investigate the differences in temperature changes at manhole locations. This technology can obtain accurate and detailed information on surface temperatures. The results reveal that the asphalt concrete in manhole and non-manhole areas will exhibit temperature differences of approximately 24-58℃, thus allowing for more accurate positioning of manholes during construction. In addition, this infrared thermal imaging technology can be used to determine pavement construction quality base on temperature uniformity of the asphalt concrete. Thus, infrared thermal imaging technology provides an optimal and cost-effective solution for constructing and maintaining pavements.

Body temperature increases during pediatric full mouth rehabilitation surgery under general anesthesia

Background/purposeGeneral anesthesia is necessary for full mouth rehabilitation surgery in children. Pediatric patients are susceptible to developing hypothermia during surgery under general anesthesia. This study reports gradually increased body temperature in pediatric patients receiving full mouth rehabilitation surgery. Materials and methodsFollowing institutional review board approval, the medical records of pediatric patients who received full mouth rehabilitation surgery from 2011 through 2012 were collected. The body temperatures (preoperative, periodic during operation, and postoperative 5 hours and 12 hours) and the maximum differences in temperature change during operation were recorded. ResultsA total of 34 patients were enrolled in this study. An increase in body temperature was found. The mean ± standard deviation of the difference in temperature change was found to be 2.50 ± 1.17°C. A significant positive correlation was noted (r = 0.464, P = 0.006) between the maximum temperature changes and the operation duration. At 12 hours after operation, no patients were reported to have a tympanic temperature >37.5°C. ConclusionBody temperature transiently increased during pediatric full mouth rehabilitation surgery. The increase in body temperature was associated with operation duration. The etiology is uncertain. Continuous body temperature monitoring and the application of both heating and cooling devices during pediatric full mouth rehabilitation surgery should be mandatory.

Monitoring tumor state from thermal images in animal and human models.

Thermography is a potentially useful method for tumor progress monitoring since it is noninvasive, nonradiative, low-cost, and rapid. Perfusion and metabolism are dominant factors for determining tumor temperature difference and are also correlated to the tumor's growth rate. Therefore, estimating them from the tumor thermal image can be a very useful tumor monitoring method, since thermal changes occur before physical changes. The goal of this work was to study the effect of tumor state on the thermal image in different tumor types, using simulations and measurements. Simulated tumor models, representing flat and extruding tumors, typical to transplantable and natural tumors, respectively, were simulated and the effects of tumor metabolism and perfusion on the temperature difference were analyzed. Data regarding tumor size and measured temperature differences were obtained from the literature, discussing five types of transplantable tumors in mice and rats. The growth rates of all tumors were calculated by fitting tumor size measurements to a tumor growth model and were used as an indicator to tumor aggressiveness. Tumor temperature difference was calculated by taking the effect of its extruding shape into account, according to a previously published method. Tumor state was estimated from the normalized temperature differences using simulations and compared to the calculated aggressiveness rates. Computational models of human breast cancers, both in round and flat breast models, were recreated using a finite-element-method heat transfer simulation. Tumor size and state were simulated according to the results obtained from the animal tumor analysis, representing two different tumor aggressiveness levels. The calculated temperature difference as a function of tumor size was calculated for each test case. Perfusion was shown to be highly dominant in determining the tumor's temperature difference. Since both metabolism and perfusion were shown to have a linear effect on the temperature difference, a conversion value was defined between them. The analysis of the animal experimental results showed correlations between tumor aggressiveness and the following factors: the normalized temperature difference, the estimated tumor state, and the temperature difference change rate. The simulated human breast cancer models analysis showed highly varying temperature differences between the simulated models. Although for each model there is a clear difference between the temperature differences of the test cases simulated, the large differences between the results might make tumor state estimation difficult. However, reviewing the gradient of the tumor temperature change as a function of tumor size showed that the ratio between the gradients of both test cases was similar for all models. Therefore, the effect of model errors and differences in the simulated tissue structure and properties and the environmental conditions between the different models, can be mitigated. This pattern may be used to estimate tumor state in in vivo experiments. Continuous monitoring of tumor temperature difference produces valuable information on tumor state and aggressiveness that can be used both in the clinic and in the laboratory. Monitoring can be either performed on a single image, or continuous on multiple images, revealing changes in tumor state.

Effects of Decorative Veneer and Structure on the Thermal Conductivity of Engineered Wood Flooring

This paper explores the thermal conductivity of engineered wood flooring, which is widely used in world market. The effects of decorative veneer type and structure on the thermal conductivity of engineered wood flooring were studied. Four decorative veneer types and three different structures of engineered wood flooring served as test specimens. All samples were placed in a laboratory simulating a heating system environment, of which the temperature should be measured three times every five minutes. The temperature differences between the upper and lower surfaces were as follows: cherry > maple > birch > eastern black walnut. Three types of structures also showed differences in temperature changes, based on five-minute observations. The larger the decorative veneer’s density, the higher the thermal conductivity, and the faster the heat transferred, meaning less heat was lost. The thermal conductivity of three-layer engineered wood flooring, with decorative veneer made of sawn wood, exhibited the best properties. The second best of the three samples was the three-layer engineered wood flooring with decorative veneer made of thick veneer and plywood. Finally, a multilayered engineered wood flooring performed the worst. The engineered wood flooring for use in heating systems should be chosen for its larger density of decorative veneer made of sawn wood.

Effects of GSICS correction on estimation of sea surface temperature using COMS data

A main objective of the Global Space-Based Inter-Calibration System (GSICS) is to ensure consistent accuracy of thermal infrared (IR) channels of satellite measurements. In this article, IR channels observed by the Communication, Ocean, and Meteorological Satellite (COMS) were corrected using observations by the Infrared Atmospheric Sounding Interferometer (IASI) on board Meteorological Operation (MetOp) satellites as a reference. We then produced sea surface temperature (SST) products using GSICS-corrected COMS/Meteorological Imager (MI) IR data and evaluated the accuracies of the SST data by comparing with buoy data. Our results showed that SST produced from GSICS-corrected IR data was more accurate than that from original IR data, with a difference of 0.01–0.2ºC. Differences in SST between the original and GSICS-corrected IR showed a linear proportional relationship around IR2 (12.0 μm) during the day and IR1 (10.8 μm) at night. In the IR1 analysis, accuracies of daytime SST were improved significantly when the GSICS correction was applied to COMS IR data; also, the mean and median values of SST discrepancies (between the original and GSICS-corrected IR) according to changes in brightness temperature difference (BTD) were close to 0ºC. We found that the accuracies of SST estimation from satellite IR bands were greatly improved by applying the GSICS correction.

Влияние эффективности исходных материалов на показатели надежности термоэлектрических охлаждающих устройств. Часть І: Однокаскадные ТЭУ

Increase of the reliability of information systems depends on the reliability improvement of their component elements, including cooling devices, providing efficiency of thermally loaded components. Thermoelectric devices based on the Peltier effect have significant advantages compared with air and liquid systems for thermal modes of the radio-electronic equipment. This happens due to the absence of moving parts, which account for the failure rate. The article presents research results on how thermoelectric efficiency modules affect the failure rate and the probability of non-failure operation in the range of working temperature of thermoelectric coolers. The authors investigate a model of relative failure rate and the probability of failure-free operation single-stage thermoelectric devices depending on the main relevant parameters: the operating current flowing through the thermocouple and resistance, temperature changes, the magnitude of the heat load and the number of elements in the module. It is shown that the increase in the thermoelectric efficiency of the primary material for a variety of thermocouple temperature changes causes the following: maximum temperature difference increases by 18%; the number of elements in the module decreases; cooling coefficient increases; failure rate reduces and the probability of non-failure operation of thermoelectric cooling device increases. Material efficiency increase by 1% allows reducing failure rate by 2,6—4,3% in maximum refrigeration capacity mode and by 4,2—5,0% in minimal failure rate mode when temperature difference changes in the range of 40—60 K. Thus, the increase in the thermoelectric efficiency of initial materials of thermocouples can significantly reduce the failure rate and increase the probability of failure of thermoelectric coolers depending on the temperature difference and the current operating mode.

Influence of the implant drill design and sequence on temperature changes during site preparation.

The purpose of this study was to compare bone temperature changes during implant drilling with two drill designs employed in three different drilling sequences. Two implant drill designs and three drilling sequences were evaluated in vitro using artificial bone cylinders. The evaluated drills were different only in the cutting-surface length (control, 16 mm; test, 4 mm). Three drilling sequences (control A, test B1, and test B2) were evaluated with and without irrigation. Temperatures were measured with thermocouple technology. The temperature changes generated by the final drill of each sequence were recorded as the experimental results and were subjected to the Student t test. There were statistically significant differences in temperature changes when comparing the control group A with the test groups B1 (P = .001) and B2 (P = .01) during drilling without coolant. The mean temperature changes were 12.4°C, 6.5°C, and 13.7°C for groups A, B1, and B2, respectively. The Student t test showed statistically significant differences between temperature changes of the control group A and the test groups B1 (P < .01) and B2 (P < .05) during drilling with coolant. The mean temperature changes were 0.9°C, 0.7°C, and 1.9°C for groups A, B1, and B2, respectively. Reduction in length of the cutting surface of the drill may limit frictional heat. Drills with the same length of cutting surface may induce lower bone temperature changes, when considering a preliminary drilling step with a pilot drill.

Thermal Characteristic Analysis of Rectangular and Large-Capacity Lithium-Ion Power Batteries

Operating temperature and thermal uniformity have great effect on the performance, cycle life and safety of lithium-ion power batteries. In order to investigate the surface temperature change and distribution of a large-capacity and rectangular LiFePO4/C power battery, this paper conducts experiments on charging and discharging a battery module and cell at different current rates and various ambient temperatures. Results of thermalcouple-measurement show that temperature rising rates at different temperatures during charge and discharge change in accordance with the variation tendency of the resistance at different state of charge (SOC) and oprating temperatures. Under elevated ambient temperatures, the temperature excurtion and maximum temperature difference of the module are all smaller. Under the same ambient temperature, battery temperature at the end moment of discharge increases and the temperature uniformity of the module deteriorate at higher discharging rate. Temperature excurtion over the same time period is in a relationship of a standard quadratic function with the discharge current. Results of the thermal infrared imaging tests show that the maximum surface temperature differences at different discharging currents of 20A, 40A, and 80A are all above 5°C under natral convection heat transfer. The temperature of the lower part is higher than that of the upper part, while that of the central area is the highest. In a comprehensive charging and discharging scheme, the tendency of maximum surface temperature difference changes in accordance with that of the average surface temperature.

Effect of low intensity pulsed ultrasound on repairing the periodontal bone of Beagle canines

ObjectiveTo investigate the repairing effect of low intensity pulsed ultrasound (LIPUS) on the Beagle canines periodontal bone defect. MethodsA total of 12 Beagle dogs with periodontal bone defect model were randomly divided into control group, LIPUS group, guided tissue regeneration (GTR) group and LIPUS+GTR group, with three in each. After completion of the models, no other proceeding was performed in control group; LIPUS group adopt direct exposure to radiation line LIPUS processing 1 week after modeling; GTR group adopted treatment with GTR, following the CTR standard operation reference; LIPUS+GTR group was treated with LIPUS joint GTR. Temperature change before treatment and histopathological change of periodontal tissue after repair was observed. ResultsThere was no significant difference in temperature changes of periodontal tissue between groups (P>0.05). The amount and maturity of LIPUS+GTR group were superior to other groups; new cementum, dental periodontal bones of GTR group were superior to the control group but less than LIPUS group; new collagen and maturity of the control group is not high relatively. ConclusionsLIPUS can accelerate the calcium salt deposition and new bone maturation, thus it can serve as promoting periodontal tissue repair, and shortening the periodontal tissue repair time.

贵州百花湖夏季浮游植物昼夜垂直分布特征研究

PDF HTML阅读 XML下载 导出引用 引用提醒 贵州百花湖夏季浮游植物昼夜垂直分布特征 DOI: 10.5846/stxb201301070054 作者: 作者单位: 贵州师范大学生命科学学院,贵州师范大学生命科学学院,贵州师范大学生命科学学院,贵阳市环境监测中心站 作者简介: 通讯作者: 中图分类号: S932.7 基金项目: 贵州省科学技术基金项目[黔科合SY（2010）3012]；国家重点基础研究发展计划973前期（2012CB426506）；贵阳市社会发展公关项目（2008筑科农合同字第5-3号）；贵阳市社会发展攻关项目（2011筑科农合同字第59号） Diel vertical distribution patterns of phytoplanktion in Baihua Reservoir, Guizhou Province Author: Affiliation: School of Life Sciences,Guizhou Normal University,School of Life Sciences,Guizhou Normal University,,Environmental Monitoring Centre of Guiyang City Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了探讨浮游植物在水体中的昼夜垂直分布格局，于2012年7月31日至8月1日对百花湖（水库）浮游植物进行昼夜24 h定点分层研究。研究结果表明：蓝藻、绿藻、硅藻种类数在水体中具有明显的分层现象，蓝藻种类数在0.5-2 m居多，绿藻种类数在0.5-6 m明显多于7-14 m，硅藻种类数主要分布在6 m及以深的水层中。湖泊假鱼腥藻（Pseudanabaena limnetica）为绝对优势种，相对丰度为82.69%。8：00时湖泊假鱼腥藻在2-3 m处聚集程度最高，10：00时聚集程度最高的水层上升至0.5 m，10：00-12：00湖泊假鱼腥藻的细胞丰度由0.5 m向2 m扩增，12：00时在2 m处达到全天峰值，此时0.5 m处的细胞丰度是除6：00外的最小值，12：00-14：00湖泊假鱼腥藻的细胞丰度由2 m向0.5 m扩增，16：00时又大量聚集于1 m处，说明湖泊假鱼腥藻在白天具有明显的垂直迁移现象；湖泊假鱼腥藻丰度的MI指数白天在1.45-2.07之间，夜间在1.40-1.46之间，变化趋势与时间深度等值图结果相符，说明湖泊假鱼腥藻在水体中昼夜均呈聚集分布，且白天的聚集程度及变化幅度大于夜间；百花湖浮游植物总丰度的昼夜垂直分布格局与湖泊假鱼腥藻一致；水体中浮游植物总丰度和湖泊假鱼腥藻丰度夜间低于白天。光照的昼夜交替和水柱温差的昼夜变化是影响浮游植物总丰度和湖泊假鱼腥藻垂直分布格局昼夜变化的重要环境因素。 Abstract:The mechanism of causing the migration and accumulation of bloom-forming species is important content for the bloom occurred by cyanobacteria. In recent years, the structure of phytoplankton community has changed in Baihua Reservoir. However, there was no such information in previous literatures. This paper was based on the research of Baihua Reservoir to elaborate diel vertical migrations of the phytoplankton. It may be important to understand the mechanism of bloom and explain the regularities of the vertical migrations. The study on diel vertical distribution of phytoplankton in Baihua Reservoir was carried out from July 31 to August 1, 2012. The sampling sites was located at the center of the Baihua Reservoir. All the samples of phytoplankton were carried on qualitative and quantitative analysis in laboratory. Meanwhile, photosynthetically available radiation and water temperature were measured. Patterns of diel vertical distribution were elucidated quantitatively using two different analysis methods. Firstly, mapping method was used to describe the time-depth distribution of phytoplankton individuals and abiotic factors. Secondly, the significant differences of vertical distribution from a state of randomness were tested with Morisita's index. The correlations between Morisita's index of biological indicators and environmental factors were analyzed by Statistical Product and Service Solutions. The results showed that the number of phytoplankton species about cyanobacteria, chlorophyta and bacillariophyta was discriminable at different depths. Cyanobacteria mainly distributed from 0.5 m to 2 m, chlorophyta from 0.5 m to 6 m and bacillariophyta mainly distributed from 6 m to 14 m. Pseudanabaena limnetica was the predominant species, accounted for 82.69％of total abundance. The Pseudanabaena limnetica stratified in the 2-3 m at 8:00a.m.. The cells were tent to migrate to the surface during after 2 hours. The Pseudanabaena limnetica above the layer sink down from 10:00a.m. to 12:00a.m., appearing the maximum in 2 m. They floated up again from 12:00a.m. to 14:00, and aggregated in 1 m at 16:00. It showed that Pseudanabaena limnetica presented the vertical migration in the day. The morisita's index of Pseudanabaena limnetica was between 1.45 and 2.07 in the day, and between 1.40 and 1.46 in the night. Combined with the depth-time distribution, it showed that Pseudanabaena limnetica aggregated in water layers. And the aggregation degree was lower in the night than that in the day. Pseudanabaena limnetica could reflected the total of phytoplankton abundance. Densities of phytoplankton and Pseudanabaena limnetica were higher in the day than that in the night. The distribution patterns of phytoplankton and Pseudanabaena limnetica were coincident with the photosynthetically available radiation and water column temperature difference. Carbohydrate ballasting and gas vesicle burst might be the main mechanisms for buoyancy changes in Pseudanabaena limnetica during the period. At the same time, it was probable that the change of water column temperature difference caused passive migration of Pseudanabaena limnetica. 参考文献 相似文献 引证文献

An Early-Warning Method for Agglomeration Detection in Gas-Solid Fluidized Bed Based on Hydromechanics

The occurrence of agglomeration in gas-solid fluidized bed can have a very negative impact on the efficiency of reactor operation. In order to overcome the agglomeration problem, an Agglomeration Early-Warning System (AEWS) is proposed. AEWS is able to detect the event of such undesired behavior and make it possible to operate more efficiently. The sensitivity and selectivity of AEWS is illustrated with experimental results. In order to minimize the false alarm, both moving time window method and minimizing value method were analyzed. The experimental results have shown that agglomeration can be recognized 30-60min earlier with AEWS than that with conventional methods based on changes in pressure drop or temperature difference over the bed.

Heat transfer in an industrial directional solidification furnace with multi-heaters for silicon ingots

We carried out transient global simulations of melting, growing and annealing processes in an industrial directional solidification furnace with a top and side heater. The power distribution between the two heaters was set to 3:7, 5:5 and 7:3 to investigate its effect on global heat transfer and silicon crystal growth. Quantitative comparisons of temperature distributions are presented. Increasing the top heating power slightly increases the melting time and changes the melting sequence. In the crystal growth process, adjusting the power distribution from 3:7 to 7:3 can lead to an 8–12K change in axial temperature difference in the silicon domain. Both the intensity and pattern of the silicon melt flow are influenced by the change in power distribution. The melt-crystal interface is less convex to the melt with an increase in top heating power, especially at the final stage of solidification. In the annealing process, the ingot temperature decreases to approximately 1600K to reduce the thermal stress and dislocation density. Isotherm shapes are different at this stage and may lead to different thermal stress and dislocation density distributions in the silicon ingot. The numerical results provide a basic understanding of the heat transfer characteristics due to power distribution in an industrial multi-heater directional solidification furnace.

Thermos Ability in Maintaining Crystalloid Liquid Temperature (Ringer’s Lactate and Normal Saline 0,9%): an Alternative in Maintaining Resuscitation Fluid Temperature

Haemorrhagic shock should be treated with fluid therapy at 390°C to avoid hypothermia. Storage of infusion fluid in a rice thermos is one method to maintain the temperature of the infusion fluid. This study aimed to determine the effect of using a thermos to maintain a temperature of 390C crystalloid liquid (ringer lactate and normal saline 0,9%) at a room temperature of 250C. This research method uses experimental quantitative (pre-experimental) with a one-shot case study design. Six bottles of Ringer's lactate and six bottles of normal saline 0,9% were warmed to 390C, then stored in a rice thermos at 250C and the temperature changes were measured for 6 hours. A digital thermometer was used to take measurements. The Mann-Whitney test was used to analyze the data. The results show that the temperature of Ringer's lactate fluid was reduced by an average of 4,60C, and normal saline was reduced by an average of 4,30C. There was a significant difference in temperature changes in the ringer's lactate fluid and normal saline 0,9% (p=0,000;α=0,05). The results of the study were that the rice thermos was able to maintain the temperature of ringer's lactate fluid at 390C for 96 minutes and normal saline 0,9% for 78 minutes, while to prevent hypothermia (360C) ringer's lactate fluid for 4 hours 59 minutes and normal saline 0,9 % for 4 hours 55 minutes.

Energy spectrum and phase diagrams of two-sublattice hard-core boson model

The energy spectrum, spectral density and phase diagrams have been obtained for two-sublattice hard-core boson model in frames of random phase approximation approach. Reconstruction of boson spectrum at the change of temperature, chemical potential and energy difference between local positions in sublattices is studied. The phase diagrams illustrating the regions of existence of a normal phase which can be close to Mott-insulator (MI) or charge-density (CDW) phases as well as the phase with the Bose-Einstein condensate (SF phase) are built.

Experimental study of friction and heat transfer characteristics in narrow rectangular channel

This work presents an experimental investigation of the friction and heat transfer characteristics in a narrow rectangular channel. Nine groups of experiments are conducted and the fluid temperature difference between the inlet and outlet of the test section is kept constant in each experimental run. The results show that the friction factors in isothermal condition can be well correlated by the Leon correlation for the developed laminar and turbulent flow, and the Bhatti and Shah correlation for the laminar to turbulent transition region. In addition, the friction factors prediction correlations in non-isothermal condition are proposed based on the viscosity ratio method.The heat transfer characteristic is not affected by the change of temperature difference in laminar flow. However, as in the fully developed turbulent flow, the Prandtl number significantly influences the heat transfer characteristic. The heat transfer temperature difference between the wall and fluid increases with the increase of Reynolds number in the laminar flow, and decreases sharply as the flow enters the transition region. However, it does not present a significant variation in the fully developed turbulent flow regime. Based on the analysis of heat transfer temperature difference, a new correlation for calculating the Nusselt number in the turbulent flow regime of a rectangular channel is introduced and the agreement between experimental data and predicted values is satisfactory.

Mapping Soil Texture of a Plain Area Using Fuzzy-c-Means Clustering Method Based on Land Surface Diurnal Temperature Difference

The use of landscape covariates to estimate soil properties is not suitable for the areas of low relief due to the high variability of soil properties in similar topographic and vegetation conditions. A new method was implemented to map regional soil texture (in terms of sand, silt and clay contents) by hypothesizing that the change in the land surface diurnal temperature difference (DTD) is related to soil texture in case of a relatively homogeneous rainfall input. To examine this hypothesis, the DTDs from moderate resolution imagine spectroradiometer (MODIS) during a selected time period, i.e., after a heavy rainfall between autumn harvest and autumn sowing, were classified using fuzzy-c-means (FCM) clustering. Six classes were generated, and for each class, the sand (> 0.05 mm), silt (0.002–0.05 mm) and clay (< 0.002 mm) contents at the location of maximum membership value were considered as the typical values of that class. A weighted average model was then used to digitally map soil texture. The results showed that the predicted map quite accurately reflected the regional soil variation. A validation dataset produced estimates of error for the predicted maps of sand, silt and clay contents at root mean of squared error values of 8.4%, 7.8% and 2.3%, respectively, which is satisfactory in a practical context. This study thus provided a methodology that can help improve the accuracy and efficiency of soil texture mapping in plain areas using easily available data sources.

Heat generation during implant placement in low‐density bone: effect of surgical technique, insertion torque and implant macro design

The study aimed to investigate the effect of surgical technique, implant macrodesign and insertion torque on bone temperature changes during implant placement. In the in vitro study, 144 self-tapping (blueSKY(®) 4×10mm; Bredent) and 144 non-self-tapping (Standard implant(®) 4.1×10mm; Straumann) were placed in osteotomies prepared in pig ribs by lateral bone condensing or bone drilling techniques. The maximum insertion torque values of 30, 35 and 40Ncm were used. Real-time bone temperature measurement during implant placement was performed by three thermocouples positioned vertically, in tripod configuration around every osteotomy, at a distance of 5mm from it and at depths of 1, 5 and 10mm. Data were analysed using Kruskal-Wallis, Mann-Whitney U-tests and Regression analysis. Significant predictor of bone temperature at the osteotomy depth of 1mm was insertion torque (P=0.003) and at the depth of 10-mm implant macrodesign (P=0.029), while no significant predictor at depth of 5mm was identified (P>0.05). Higher insertion torque values as well as non-self-tapping implant macrodesign were related to higher temperatures. Implant placement in sites prepared by bone drilling induced significantly higher temperature increase (P=0.021) compared with bone condensing sites at the depth of 5mm, while no significant difference was recorded at other depths. Compared with 30Ncm, insertion torque values of 35 and 40Ncm produced significantly higher temperature increase (P=0.005; P=0.003, respectively) at the depth of 1mm. There was no significant difference in temperature change induced by 35 and 40Ncm, neither by implant macrodesign at all investigated depths (P>0.05). Placement of self-tapping implants with low insertion torque into sites prepared by lateral bone condensing technique might be advantageous in terms of thermal effect on bone.

Spectroscopic and Physical Properties of --ZnO- Glasses

Bismuth glasses containing ZnO and Li2O were prepared by conventional melt-quench technique. ZnO is gradually substituted by Li2O, and its effect on various physical, thermal, and electrical conduction properties was studied and analyzed. Raman studies revealed that these glasses are mainly made up of [BiO3] and [BiO6] units. The density decreases and molar volume increases with the incorporation of Li2O into these glasses. MDSC studies have been performed on these glasses to determine the glass transition temperature and other related thermal parameters such as change in the glass transition temperature () and specific heat capacity difference (). These studies revealed that the glasses possess high values, and decreases with Li2O content. The trend of these properties is attributed to the changes in the glass network structure. Dc electrical conductivity revealed that the conductivity increases and activation energy decreases with Li2O content.