TO THE PROBLEM OF APPLICABILITY OF THE TAMMAN TEMPERATURE CONCEPT TO NANOSIZED OBJECTS: TO THE 160TH ANNIVERSARY OF GUSTAV TAMMAN

Во введении представлен краткий критический обзор имеющихся интерпретаций температуры Таммана, обычно определяемой как T = 0,5T, и температуры Хюттига T = 0,3T, где T - макроскопическое значение температуры плавления материала. Для наночастиц предложено в указанных выше определяющих соотношениях заменить T на температуру плавления малого объекта T, т.е. определить T как 0,5T, а T как 0,3T. В молекулярно-динамических экспериментах на наночастицах Au, осуществленных с помощью LAMMPS, было установлено, что при температуре T=T как в центральной части ГЦК-наночастицы, так и в её поверхностном слое возникают локальные очаги квазикристаллической структуры, которые попеременно идентифицируются программой OVITO то как имеющие кристаллическую структуру, то как не имеющие кристаллической упорядоченности. Однако, вопреки мнению Э. Рукенштейна (1984), при T=T жидкий слой на поверхности кристаллической наночастицы еще не образуется. Вместе с тем в наших молекулярно-динамических экспериментах не обнаружено какое-либо проявление температуры Хюттига T в структуре кристаллических наночастиц Au. The introduction provides a brief critical review of the available definitions and interpretations of the Tamman temperature, usually defined as T = 0,5T, and of the Hüttig temperature T = 0,3T where T is the macroscopic value of the melting point of the material. For a nanoparticle we propose to replace in the above relations T by the melting temperature of the small object T , i.e. to define T as 0,5T and T as 0,3T . In our molecular dynamics experiments on Au nanoparticles, carried out using the LAMMPS program, we found that at the temperature T = T , in both the central part of the fcc nanoparticle (the core) and in its surface layer (the shell), some local species of a quasicrystalline structure appear which are alternately identified either as crystalline or as non-crystalline by the OVITO program. However, contrary to opinion of E. Rukenstein (1984), at T = T , a liquid layer on the surface of the crystalline nanoparticle is not formed yet. However, a liquid-like layer was gradually developed in the course of the further temperature elevation. At the same time, in our molecular dynamics experiments we did not reveal any manifestation of the Huttig temperature T in the structure of crystalline Au nanoparticles reproduced in our molecular dynamics experiments. It is also of interest that in our molecular dynamics experiments the nanoparticle sintering took place not only above the Tammann temperature but below it as well.

Study of temperature logs of linseed, corn and chia seeds for the treatment of joint pain and inflammation

Thermal energy storage in the form of heat provides transient relief in inflammatory and traumatic, subacute and chronic disorders such as: sprains, muscle strains, muscle spasms, low back pain, cervical injuries, various forms of arthritis, arthralgia, neuralgia. Heat increases blood flow and connective tissue extensibility; it also decreases joint stiffness, pain and muscle spasm and helps relieve inflammation. The application of heat can be superficial and the intensity or duration of the physiological effects depends mainly on the temperature of the tissue, the rate of temperature elevation and the area treated. In this work a comparison of the capacity to absorb and contain sensible heat using a combination of linseed, corn and chia seeds in water is made in order to identify which combination is able to retain heat longer and to take advantage of this characteristic in the treatment of pain and inflammation.

Temperature measurement methods in an experimental setup during bone drilling: A brief review on the comparison of thermocouple and infrared thermography

Predicting thermal response in orthopedic surgery or dental implantation remains a significant challenge. This study aims to find an effective approach for measuring temperature elevation during a bone drilling experiment by analyzing the existing methods. Traditionally thermocouple has frequently been used to predict the bone temperature in the drilling process. However, several experimental studies demonstrate that the invasive method using thermocouple is impractical in medical conditions and preferred the thermal infrared (IR) camera as a non-invasive method. This work proposes a simplified experimental model that uses the thermocouple to determine temperature rise coupled with the thermal image source approach. Furthermore, our new method provides a significant opportunity to calibrate the thermal IR camera by finding out the undetected heat elevation in a workpiece depth.

Elevated CO2 ameliorate the negative effects of high temperature on groundnut (Arachis hypogaea)- Studies under free-air temperature elevation

Four groundnut (Arachis hypogaea L.) genotypes- Narayani, Dharani, K-6 and K-9 were assessed for growth and yield responses at elevated temperature of 3.0 ± 0.5°C above ambient canopy temperature (eT) and its interaction with elevated CO of 550 ± 50ppm (eT+eCO ) under Free Air 2 2 Temperature Elevation (FATE) facility. The study revealed that eT significantly decreased photosynthetic rate (A ) of all groundnut genotypes whereas eT+eCO condition ameliorated the ill effects of eT. The net 2 impact of eT on A was higher than transpiration rate (Tr) and this reflected in decreased WUE with all net genotypes. WUE improved significantly at eT+eCO with increased A and decreased Tr. Increase in 2 net canopy temperature (eT) resulted decreased relative water content (RWC), cell membrane stability and increased osmotic potential, Malondialdehyde (MDA) content and accumulation of proline. Elevated CO 2 along with eT (eT+eCO ) facilitated these parameters to recover to that of ambient controls, revealing the 2 ameliorative effect of eCO . Similar responses were recorded for biomass and yield parameters. Among 2 the selected groundnut genotypes, superior performance for seed yield at high temperature of >40°C by K-9 was due to ability to maintain better reproductive capacity and Dharani was responsive to elevated CO even at high temperature, indicating the genotypic variability.

Epidural fever

Epidural analgesia (EPA) is the most eff ective method of intrapartum pain relief and is considered to be very safe. Recently, it has been used in up to 34% of parturients with EPA and is also associated with maternal temperature elevations during labor. The mechanism of this epidural-associated fever remains incompletely understood. The most likely etiology seems to be non-infectious infl ammation caused by an epidural catheter. However, some authors deny this association. They theorize it is caused by selection bias only, as EPA is more often required by women with more painful and prolonged or more complicated labor, where temperature elevation is due to other causes. They point out that in some studies, fever was correlated to EPA only with concurrent placental infl ammation. Maternal fever, despite the cause, either infectious or non-infectious origin, carries important clinical and public health implications. Further research that evaluates maternal epidural status and its infl uence on maternal or neonatal fever could improve sepsis evaluation and lead to worldwide decrease of unnecessary antibio tic exposure. Key words: epidural fever – epidural analgesia – thermoregulation

Fabrication of Planar Heating Chuck Using Nichrome Thin Film as Heating Element for PECVD Equipment

Improving semiconductor equipment and components is an important goal of semiconductor manufacture. Especially during the deposition process, the temperature of the wafer must be precisely controlled to form a uniform thin film. In the conventional plasma-enhanced chemical vapor deposition (PECVD) chuck, heating rate, and temperature uniformity are limited by the spiral pattern and volume of the heating element. To overcome the structural limitation of the heating element of conventional chuck, we tried to develop the planar heating chuck (PHC), a 6-inch PECVD chuck with a planar heating element based on NiCr thin film that would be a good candidate for rapidly and uniformly heating. The time for the temperature elevation from room temperature to 330 °C was 398 s. In a performance evaluation, the fabricated PHC successfully completed a SiO2 PECVD process.

Modeling of Interstitial Microwave Hyperthermia for Hepatic Tumors Using Floating Sleeve Antenna

Background: Liver tumor, also known as hepatic tumor is one of the most common cancers with 80% of cases occurs in developing countries. Microwave hyperthermia is one of the promising treatment modalities that use microwaves to destroy the cancer cells by rising their temperature to 41- 45°C. This temperature elevation is achieved by using an applicator such as antennas. This study aims to design a microwave sleeve antenna capable of heating hepatic tumors (with different sizes and locations) to the therapeutic range of temperature for hyperthermia. Method: The sleeve antenna was designed to be resonate at 2.45 GHz and tested in a free space. Then; the antenna was tested in 6 different 3D liver models: Model A: without a tumor or blood vessels, Model B: with a tumor (2B3cm) and without blood vessels, Model C: created by adding blood vessels to model B, then a small tumor (1.5a1.5cm) was created and its location (Model D) and size (Model E) were changed. Finally, a model with a spherical tumor of 1.5 cm diameter (Model F) was tested. Results: The return loss (S-parameters) of the antenna was varied from -45 dB to -25 dB in the different liver models. The Specific Absorption Rate (SAR) reached 30W/kg in the tumor and less than 24 W/kg in the surrounding tissues, while the tumor temperature elevated to the therapeutic ranges of hyperthermia in the all models and the surrounding tissues remain at a safe temperature range. Conclusions: The obtained results showed the capability of the designed antenna to raise the temperature of hepatic tumors to the therapeutic ranges of hyperthermia.