The Influence of a 3D Model of a Radio Electronic Component on Thermal Simulation

Very often, when designing and developing radio electronic devices, engineers are regularly faced with the need to solve various kinds of problems to ensure the operation of a product under the required mechanical loads or thermal conditions during operation. One of the main issues that arise when conducting thermal modeling of radio electronics is the correct assessment of the results. There are a number of electronic components that need to be cooled, mainly through a printed circuit board: power supply transistors, power diodes, microcircuits, etc. For such elements, 90% (or more) of the heat flux from the component is diverted through the printed circuit board, and then to the radiator. Therefore, when carrying out the simulation, it is necessary to have previously obtained reliable temperature results on the power elements. The use of a detailed 3D model for modeling is most often unjustified and can introduce certain errors in the calculations. This article compares different 3D transistor models and the effect of detailing on the modeling process in CAD SolidWorks.

Advances and Challenges in Palaeoenvironmental Studies Based on Oxygen Isotope Composition of Skeletal Carbonates and Phosphates

Oxygen isotopes are widely used in palaeoenvironmental and palaeoclimatic studies as they record variations in the precipitation temperature of biogenic carbonates and phosphates. Problems associated with the preservation state of fossils, selection of the proper temperature equation, vital effects occurring during biomineralization, habitat effects of organisms as well as salinity, bathymetry and water circulation changes limit, however, the applicability of oxygen isotopes to reconstruction of ancient environmental settings. The progress of oxygen isotope studies, temperature calculations and ambiguities of the isotope record are discussed in this paper. The same applies to the methods of retrieving reliable temperature signals and the record of water chemistry changes based on well-preserved calcareous and phosphatic fossils. Sometimes neglected importance of sedimentological and faunistic data associated with sea-level changes and salinity variations is emphasised as an important tool for refinement of the temperature trends of epeiric sedimentary basins. In addition, published case datasets and new laboratory techniques, including micro-area and clumped isotope analyses, are presented to demonstrate examples and prospective ways of extension of the scope of palaeoenvironmental research. The provided information may be used in discussion and a critical review of published oxygen isotope data and their palaeoenvironmental interpretations.

The Potential of a Smartphone as an Urban Weather Station—An Exploratory Analysis

The ongoing urbanization requires enhanced understanding of the local meteorological and climatological conditions within the urban environment for multiple applications, concerning energy demand, human health, and spatial planning. Identifying areas with harmful meteorological conditions enables citizens and local authorities to take actions to optimize quality of life for urban dwellers. At the moment cities have (in general) limited networks of meteorological monitoring stations. To overcome this lack of observations, the use of non-traditional data sources is rapidly increasing. However, the use of such data sources without enough prior verification has become a controversial topic in the scientific community. This study aims to verify and assess one of the main non-traditional data sources, i.e. smartphones. The goal is to research the potential of smartphones (using the Samsung Galaxy S4 as an example phone model) to correctly sense air temperature, relative humidity, and solar radiation, and to determine to what extent environmental conditions negatively affect their performance. The smartphone readings were evaluated against observations from reference instrumentation at a weather station and a mobile measurement platform. We test the response time of the smartphone thermometer and hygrometer, and the light sensor’s cosine response. In a lab setting, we find that a smartphone can provide reliable temperature information when it is not exposed to direct solar radiation. The smartphone’s hygrometer performs better at low relative humidity levels while it can over-saturate at higher levels. The light sensor records show substantial correlation with global radiation observations, and short response times. Measurements along an urban transect of 10 km show the smartphone’s ability to react to fast changes of temperature in the field, both in time and space. However, a bias correction (dependent on wind speed and radiation) is required to represent the reference temperature. Finally we show that after such a bias correction, a smartphone record can successfully capture spatial variability over a transect as well.

Metamorphic pressure-temperature conditions of the Lützow-Holm Complex of East Antarctica deduced from Zr-in-rutile geothermometer and Al2SiO5 minerals enclosed in garnet

<p>The Zr content of rutile coexisting with zircon and quartz is mainly a function of the temperature condition and is calibrated as Zr-in-rutile geothermometers. Because of their robustness under high-temperature conditions, they have been applied to granulite facies rocks instead of the conventional Fe-Mg exchange type geothermometers to estimate more reliable temperature conditions. However, it is recently pointed out that in order for rutile to retain the primary Zr content, rutile must be chemically isolated from zircon and quartz during cooling. In this context, inclusion rutile separately enclosed in garnet can be considered to retain the primary Zr content at the time of entrapment, only if rutile, zircon, and quartz are all enclosed in a contemporaneous domain of the garnet.</p><p>In this study, we re-examined the pressure-temperature (<em>P-T</em>) conditions of high-grade pelitic gneisses from selected regions (Akarui Point, Skarvsnes, Skallen, and Rundvågshetta) of the Lützow-Holm Complex (LHC), East Antarctica. The LHC has been divided into the upper-amphibolite facies zone, the transitional zone, and the granulite facies zone, based on matrix mineral assemblages of mafic- to intermediate gneisses. Akarui Point is located in the transitional zone and others in the granulite facies zone.</p><p>While previous studies commonly applied the conventional Fe-Mg exchange type geothermometers, we applied the Zr-in-rutile geothermometer of Tomkins et al. (2007) to rutile grains enclosed in garnet that also encloses zircon, quartz, and Al<sub>2</sub>SiO<sub>5</sub> minerals. By utilizing the phosphorus zoning in garnet, we defined contemporaneous domains of the garnet and identified coexisting inclusion minerals in each domain. In this way, coexisting Al<sub>2</sub>SiO<sub>5</sub> minerals and rutile grains were utilized to constrain the <em>P-T</em> condition of each domain of the garnet.</p><p>As a result, samples from Akarui Point, Skarvsnes, and Skallen were shown to have experienced almost the same <em>P-T</em> conditions around the kyanite/sillimanite transition boundary (~ 830-850 °C/~ 11 kbar). This is significantly higher than the previously estimated peak condition of 770-790 °C/7.7-9.8 kbar based on the conventional garnet-biotite geothermometer in the case of Akarui Point. From Rundvågshetta, where ultrahigh-<em>T</em> metamorphism is reported by previous studies, higher-<em>T</em> condition (850 ± 15 °C/0.1 kbar to 927 ± 16 °C/12.5 kbar) than those of other three regions was confirmed from inclusion rutile in garnet enclosing sillimanite. Therefore, the traditional metamorphic zone mapping, which classified Akarui Point as belonging to the transitional zone, does not reflect the highest metamorphic grade attained. It should be noted that the regional <em>P-T</em> conditions estimated from inclusion minerals in this study is that of earlier higher-<em>P</em> metamorphic stage than the regional <em>P-T</em> conditions determined by the metamorphic zone mapping utilizing matrix mineral assemblages. This result indicates that the Zr-in-rutile geothermometer is a powerful tool to reveal the <em>P-T</em> evolution of high-grade metamorphic terrains, when combined with detailed microstructural observations focusing on the relationship between rutile, zircon, and quartz.</p>

Effect of fuzzy-controlled slow freezing on pumpkin (Cucurbita Moschata Duch) cell disintegration and phenolics

Freezing has been widely used to preserve vegetables including seasonal pumpkins. This work aimed to investigate the effects of freezing on pumpkin cell disintegration and phenolics. A fuzzy logic control (FLC) system was built to obtain better temperature control of the freezing system. Changes in cellular disintegration, electrical conductivity and phenolics content were evaluated. The angle measure technique and principal component analysis were used to delineate the surface texture changes of the frozen pumpkin cells. The results showed that FLC offered reliable temperature control performance. Freezing at -18 °C for 7 h caused the highest cell degradation of 0.467 on the disintegration scale. Decomposition was also indicated by an almost double increase in electrical conductivity. The changes in texture were accurately reflected in the mean angle spectra and 81.3% and 7.4% of the variability due to treatments could be explained by two principal components respectively. Freezing pumpkin at -18 °C for 6 h correlated to the maximum increase in total phenolics of 70.44%. The increased phenolics were dominated by caffeic acid, chlorogenic acid and p-coumaric acid. In conclusion, as the freezing system exhibits positive effects on the phenolics content of pumpkin, it may be employed to process seasonal pumpkin to obtain higher value from the produce.

MR Thermometry Data Correlate with Pathological Response for Soft Tissue Sarcoma of the Lower Extremity in a Single Center Analysis of Prospectively Registered Patients

Background: There is a strong biologic rationale for using locoregional hyperthermia in soft tissue sarcoma and a randomized trial reported significant improvements with hyperthermia. The aim of this study was to describe the opportunities of magnetic resonance (MR)-based thermometry in a cohort of soft tissue sarcoma patients undergoing combined radiotherapy and locoregional hyperthermia. Patients and Methods: For eleven evaluable patients, tumor volume (VTu) and a separate volume for temperature analysis with reliable temperature distribution (Vtherm) were contoured for every hyperthermia treatment (103 therapies). Temperature data were recorded for all tumors and were correlated with clinical features and pathologic response data. Results: Of 48 patients with high-risk soft tissue sarcomas treated with radio(chemo)therapy and locoregional hyperthermia, MR thermometry was possible in 11 (23%) patients. For all patients, the temperature superseded by 90% of VTu (T90(VTu)) and T90 (Vtherm) were in the range of 37–43 °C and 40–45 °C, respectively. Larger tumors tended to reach higher temperatures. For tumors showing a pathologic response in the resection specimen after preoperative treatment, temperature (T90 (Vtherm)) was significantly higher than in tumors without pathologic response. Conclusion: Lower extremity sarcomas undergoing preoperative treatment with locoregional hyperthermia are especially suitable for MR thermometry. MR thermometry is a promising non-invasive way for temperature measurement during locoregional hyperthermia, showing a positive dose-response relationship.

Non-Invasive Method of Diabetes Measurement using Teg Sensor via Foot Skin Temperature

Diabetes is a type of metabolic dieses identified by unstable blood glucose level due to the defect in body to generate or use of insulin. Diabetes is created due to the defect in metabolism of converting the glucose to energy in blood. Hyperglycaemia is a stage were glucose value in the body is greater than 140 mg/dl which leads to type 1 diabetes for the patient. Type 1 diabetes is caused due to lack of generation of insulin in human blood and type 2 diabetes is caused due to resistance to insulin action which leads to several other diseases like foot ulcer and sever wounds in human foot or other parts of the body. Early diagnosing of diabetes disease plays an important task in improving the standard of healthy living. Traditional methods of identifying diabetes does not provides effective results and the results are not more reliable. Temperature based diabetes diagnosing model is defined using TEG sensor to analyse the heat changes in human foot. Imbalanced glucose level affects the performance of nerves system which leads to slower response for temperature change in the foot surface. TEG sensor is used to measure the heat transfer in foot by applying cold water over foot. The rate of temperature changes in foot represents the level of diabetes caused in the patient body. The signals from TEG sensor was collected and processed using signal analysis algorithm using MATLAB software.