The Role of Organic Acids in New Particle Formation from Methanesulfonic Acid and Methylamine

Atmospheric organic acids (OAs) are expected to enhance methanesulfonic acid (MSA)-driven new particle formation (NPF). However, the exact role of OAs in MSA-driven NPF remains unclear. Here, we employed a two-step strategy to probe the role of OAs in MSA-methylamine (MA) NPF. Initially, we evaluated the enhancing potential of 12 commonly detected OAs in ternary MA-MSA-OA cluster formation by considering the formation free energies of the (MSA)1(MA)1(OA)1 clusters and the atmospheric concentrations of the OAs. It was found that formic acid (ForA) has the highest potential to stabilize the MA-MSA clusters. The high enhancing potential of ForA results from its acidity, structural factors such as no intramolecular H-bonds and high atmospheric abundance. The second step is to extend the MSA-MA-ForA system to larger cluster sizes. The results indicate that ForA can indeed enhance MSA-MA NPF at atmospheric conditions (the upper limited temperature is 258.15 K), indicating that ForA might have an important role in MSA-driven NPF. The enhancing effect of ForA is mainly caused by an increased formation of the (MSA)2(MA)1 cluster, which is involved in the pathway of binary MSA-MA nucleation. Hence, our results indicate that OAs might be required to facilitate MSA-driven NPF in the atmosphere.

Thermodynamic Hadron-Quark Phase Transition of Chiral Nuclear Matter at High Temperature

Based on the extended Nambu-Jona–Lasinio (NJL) model with the scalar-vector eightpoint interaction [15], we consider what ultimately happens to exact chiral nuclear matter as it is heated. In the realm of very high temperature the fundamental degrees of freedom of the strong interaction, quarks and gluons, come into play and a transition from nuclear matter consisting of confined baryons and mesons to a state with ‘liberated’ quarks and gluons is expected. In this paper, the hadron-quark phase transition occurs above a limited temperature and after the chiral phase transition in the nuclear matter. There is a so-called quarkyonic- like phase, in which the chiral symmetry is restored but the elementary excitation modes are nucleonic at high density, appears just before deconfinement.PACS: 21.65.-f, 21.65.Mn, 11.30.Rd, 12.39.Ba, 25.75.Nq, 68.35.Rh

Perioperative temperature management: a survey of 6 Asia–Pacific countries

Background Anesthesia leads to impairments in central and peripheral thermoregulatory responses. Inadvertent perioperative hypothermia is hence a common perioperative complication, and is associated with coagulopathy, increased surgical site infection, delayed drug metabolism, prolonged recovery, and shivering. However, surveys across the world have shown poor compliance to perioperative temperature management guidelines. Therefore, we evaluated the prevalent practices and attitudes to perioperative temperature management in the Asia–Pacific region, and determined the individual and institutional factors that lead to noncompliance. Methods A 40-question anonymous online questionnaire was distributed to anesthesiologists and anesthesia trainees in six countries in the Asia–Pacific (Singapore, Malaysia, Philippines, Thailand, India and South Korea). Participants were polled about their current practices in patient warming and temperature measurement across the preoperative, intraoperative and postoperative periods. Questions were also asked regarding various individual and environmental barriers to compliance. Results In total, 1154 valid survey responses were obtained and analyzed. 279 (24.2%) of respondents prewarm, 508 (44.0%) perform intraoperative active warming, and 486 (42.1%) perform postoperative active warming in the majority of patients. Additionally, 531 (46.0%) measure temperature preoperatively, 767 (67.5%) measure temperature intraoperatively during general anesthesia, and 953 (82.6%) measure temperature postoperatively in the majority of patients. The availability of active warming devices in the operating room (p < 0.001, OR 10.040), absence of financial restriction (p < 0.001, OR 2.817), presence of hospital training courses (p = 0.011, OR 1.428), and presence of a hospital SOP (p < 0.001, OR 1.926) were significantly associated with compliance to intraoperative active warming. Conclusions Compliance to international perioperative temperature management guidelines in Asia–Pacific remains poor, especially in small hospitals. Barriers to compliance were limited temperature management equipment, lack of locally-relevant standard operating procedures and training. This may inform international guideline committees on the needs of developing countries, or spur local anesthesiology societies to publish their own national guidelines.

Temperature Field Online Reconstruction for In-Service Concrete Arch Dam Based on Limited Temperature Observation Data Using AdaBoost-ANN Algorithm

Temperature is one of the factors affecting the safety operation of concrete arch dams. To accurately reconstruct the temperature field of the concrete arch dam online based on the temperature data of several typical dam sections, this paper proposes the AdaBoost-ANN algorithm. The algorithm uses artificial neural network (ANN) to establish a training set of the measured temperature data and the temperature field of the concrete arch dam obtained by the three-dimensional finite element model; these trained artificial neural networks are used as weak classifiers of the AdaBoost algorithm. Then, the AdaBoost-ANN algorithm is used to establish the mapping relationship between the measured temperature data and the temperature field, and the online reconstruction of the temperature field of the concrete arch dam is realized. The case study shows that the temperature field of the concrete arch dam can be accurately established by AdaBoost-ANN algorithm based on limited temperature observation data. The algorithm is more time-saving and labor-saving than the finite element method and is convenient for online reconstruction of the temperature field and assessment of the safety status of the concrete arch dam.

Experimental Study on Thermal Performance of a Loop Heat Pipe with Different Working Wick Materials

In loop heat pipes (LHPs), wick materials and their structures are important in achieving continuous heat transfer with a favorable distribution of the working fluid. This article introduces the characteristics of loop heat pipes with different wicks: (i) sintered stainless steel and (ii) ceramic. The evaporator has a flat-rectangular assembly under gravity-assisted conditions. Water was used as a working fluid, and the performance of the LHP was analyzed in terms of temperatures at different locations of the LHP and thermal resistance. As to the results, a stable operation can be maintained in the range of 50 to 520 W for the LHP with the stainless-steel wick, matching the desired limited temperature for electronics of 85 °C at the heater surface at 350 W (129.6 kW·m−2). Results using the ceramic wick showed that a heater surface temperature of below 85 °C could be obtained when operating at 54 W (20 kW·m−2).

Strengthening method of wheelset tires

The main ways to strengthen and increase the resourse of wheelset bandage as result of which it is determined that the most economical and quick-to-implement method is the use of tribotechnical materials are considered. The main disadvantage in using of tribotechnical materials is the limited temperature range of rolling stock operation is determined. Qualitative selection of anti-wear and heat-resistant additives, as well as binder is perfomed based on the physical properties required for tribotechnical materials and the range of component content in the lubricant is determined. The wear resistance of wheelset bands is increased by 28 % as result of performance tests.

A CFD thermal analysis and validation of a Li-ion pouch cell under different temperatures conditions

Li-ion cells are one of the core components for the actual and future electric mobility. Differently from other types of applications and due to the high charge/discharge rates, the thermal-related issues in batteries for mobility are drastically relevant and can affect the reliability, the safety and the performance of the system. Indeed, limited temperature differences within a battery pack have a significant impact on its efficiency, thus it is important to predict and control the cell and battery pack temperature distribution. In the proposed study, a CFD analysis has been carried out to quantify the temperature and heat distribution on a single li-ion pouch cell. The main objective of this work is to determine the temperature imbalance on the cell and the required cooling load in order to be able to correctly design the cooling system and the best module architecture. The internal heat generation occurs as a result of electrochemical reactions taking place during charge and discharge of batteries. An electric model of the cell allows to assess the thermal power generation; the model parameters are changed according to the operative conditions to improve the accuracy, specifically to take into account varying temperature conditions and C-rates. The high accuracy of the model with respect to experimental data shows the potentiality of the proposed approach to support the optimization of Li-ion modules cooling systems and architecture design.

A parametric analysis on PEFCs for high-temperature applications

Polymer Electrolyte Fuel Cells (PEFCs) are an increasingly significant facet of modern renewable energy and transportation, providing an electrochemical method of energy generation with high power density, thermal properties, and efficiency. PEFCs tend to increase in efficiency as temperature increases but detrimental effects begin to occur, including membrane degradation and dehydration. These effects are unfavourable in the design of optimised fuel cells as they can result in reduced efficiency and lifetime. Current PEFCs are in a state where they are commercially viable but have a very limited temperature operation region (<80°C). This meta-study analysis presents research around expanding the operational temperatures of PEFCs through a parametric analysis of active cell area, phosphonic acid content, and organic/inorganic fillers. This analysis finds an increase in proton conductivity for PEFCs at higher temperature by using phosphonic acid functionalised membranes with maximised degree of phosphonation (up to 1.5 DP). It was also found that using ionic liquid functionalised carbon materials as fillers was an effective strategy to enhance the proton conductivity of PEFCs in a higher temperature environment while also providing increased thermal stability of the membrane. Additionally, higher thermal efficiency and power density may be achieved by increasing temperature and humidity to maximise proton conductivity towards theoretical maxima dictated by the active cell area, which was found to peak at 36 cm2.

Phase Behavior of a Cell Fluid Model with Modified Morse Potential

The present article gives a theoretical description of a first-order phase transition in the cell fluid model with a modified Morse potential and an additional repulsive interaction. In the framework of the grand canonical ensemble, the equation of state of the system in terms of chemical potential–temperature and terms of density–temperature is calculated for a wide range of the density and temperature. The behavior of the chemical potential as a function of the temperature and density is investigated. The maximum and minimum admissible values of the chemical potential, which approach each other with decreasing the temperature, are exhibited. The existence of a liquid-gas phase transition in a limited temperature range below the critical Tc is established.

The Thermo-Optical Treatment of Cancer by Laser Light with Ag Nanoparticles

In this paper, the photo thermal treatment of cancer with Ag nano- particles is studied. The PTT for tissue under the effect of heat by laser source with injection of silver nano- particles on the affected area. Bio-heat equation is solved by the numerical simulation methods. Results are summarized in the effect on the increasing of temperature at different time durations. These results are looked that the depth penetration of laser that lead to increasing heat raising during the increasing the time duration of exposure. Then, it estimated the peak value of depth on limited temperature.