The effect of air temperature on hospital admission of adults with community acquired pneumonia in Baotou, China

The relationship between air temperature and the hospital admission of adult patients with community-acquired pneumonia (CAP) was analyzed. The hospitalization data pertaining to adult CAP patients (age ≥ 18 years) in two tertiary comprehensive hospitals in Baotou, Inner Mongolia Autonomous Region, China from 2014 to 2018 and meteorological data there in the corresponding period were collected. The exposure–response relationship between the daily average temperature and the hospital admission of adult CAP patients was quantified by using a distributed lag non-linear model. A total of 4466 cases of adult patients with CAP were admitted. After eliminating some confounding factors such as relative humidity, wind speed, air pressure, long-term trend, and seasonal trend, a lower temperature was found to be associated with a higher risk of adult CAP. Compared to 21 °C, lower temperature range of 4 to –12 °C was associated with a greater number of CAP hospitalizations among those aged ≥ 65 years, and the highest relative risk (RR) was 2.80 (95% CI 1.15–6.80) at a temperature of − 10 °C. For those < 65 years, lower temperature was not related to CAP hospitalizations. Cumulative lag RRs of low temperature with CAP hospitalizations indicate that the risk associated with colder temperatures appeared at a lag of 0–7 days. For those ≥ 65 years, the cumulative RR of CAP hospitalizations over lagging days 0–5 was 1.89 (95% CI 1.01–3. 56). In brief, the lower temperature had age-specific effects on CAP hospitalizations in Baotou, China, especially among those aged ≥ 65 years.

Mathematical Modelling and Performance Analysis of Flat Plate Solar Dryer- CFD Simulation Approach

This study focuses on the investigation of enhancing convective heat transfer between the absorber and the air inside a channel. The investigation approaches modeling different absorber through CFD simulation and validating the result with experimental data. Supplying air to both sides of the top and the bottom surfaces of the absorber increase the air mass flow rate and therefore increases the thermal efficiency of the dryer. The studies in a V-grooved absorber attain high hot air velocity; high thermal efficiency resulted from high turbulence created in the duct. For the sample taken with a flow range, 0.01kg/s to 0.06 kg/s, the high output temperature was observed in a lower temperature range and increases as the flow rate increases. At a flow rate 0.01 kg/s, the velocity of hot air passing over the V-grooved absorber attain 0.28 m/s and increased to 1.4 m/s as the mass flow rate increased to 0.06 kg/s. For the rectangular absorber, the velocity of hot air attains 0.15 m/s at a flow rate of 0.01 kg/s and increased to 1.46 m/s as the mass flow rate increases to 0.06 kg/s. The double-sided V-grooved absorber contributes 8 – 12.40% value more efficiency compared to the rectangular plate with the same flow orientation. Further investigation is recommended taking the quantitative analysis obtained in this study and generating qualitative data.

The effect of flame straightening on the microstructure and mechanical properties of different strength steels

In many cases, flame straightening is unavoidable after welding for the reduction of deformation. Due to the not very concentrated heat source, the process can cause significant changes in the microstructure, especially in high strength and wear-resistant steels. Due to their different physical properties, the effects vary depending on the flammable gases (acetylene, propane). The situation is complicated by the fact that the manual technology carries a risk of overheating, which can have detrimental effects on the mechanical properties. During our experiments, three steels are investigated (S355J2 + N, XAR400, S960QL). The thermal cycles for the physical simulations were determined by thermocouple measurement during real experimental conditions. Three peak temperatures (1000 °C, 800 °C and 675 °C) and two types of industrial cooling conditions (air and water cooling) were studied. The samples were examined by optical microscopy tests, hardness testing and Charpy V-notch impact tests. During straightening the XAR400 showed high sensitivity to softening even in the lower temperature range, while hardening occurred in the S960QL steel at a higher peak temperature values during water cooling. The inter- and supercritical temperature should be avoided in all steels; however, the subcritical temperature can be beneficial to the toughness properties of the S960QL and XAR400.

Catalytic Abatement of VOCs: Aerobic Combustion of Methane or Ethane over Alumina-Supported Metal Oxides Recovered from Spent Catalysts

&gamma;-Al2O3 supported Cu, Cu-Zn and Cu-Ni-Fe-Zn oxide catalysts were prepared using leachate transition metal nitrate and sulfate aqueous solutions from commercial spent catalysts. A bench-scale rig was used to investigate the combustion activity of these catalysts toward methane or ethane in the air stream (1000 ppmv) at a space velocity of 20,000 h-1. The Cu-Ni-Fe-Zn oxides/&gamma;-Al2O3 catalyst proved to be the most active catalyst for the combustion of methane in the temperature range 290-575&deg;C and of ethane in the lower temperature range of 275-525oC as compared to Cu and Cu-Zn oxide loaded catalysts. X-ray powder diffractograms indicated that the metal oxide species were highly dispersed or amorphous on the alumina surface in all the catalysts except for the detection of a minority phase of monoclinic CuO on the Cu-containing mono-metallic catalysts. The co-existence of ZnO in the CuO catalysts suppresses the activity of the copper oxide species and, therefore, the conversion of methane or ethane was reduced. The present research endeavor provides proof-of-concept that relatively inexpensive metal oxide-based heterogeneous catalysts for VOCs abatement can be recovered from spent catalysts. Hence, environmental and health threats of improper handling of VOCs or spent catalysts may be alleviated.

Simulation of the Carbon Diffusion Saturation Gear from 15Cr2 Steel in the Cementation Process

The studies on cementation focus exclusively on the carbon’s movement. It is described by diffusion equations, often with constant coefficients and without regard to the liaising with temperature. It does not allow to have regard to the further carbon diffusion into the workpiece with the lower temperature range. The most accurate prediction of carbon concentration profiles depending on the parameters of the carburization regime and the chemical composition of steel is possible with the mathematical models using. However, most models show good results for Fe-C austenite without affecting the effect of alloying substitution elements. Taking into account the influence of alloying elements leads to complex empirical dependencies with difficult selected coefficients. It makes their use difficult. The study describes the simulation using the finite element method for the process of austenite’s diffusion saturation Fe-C-Cr system with carbon during cementation. Here is an example of a steel gear 15Cr2 with the temperature influence. The COMSOL Multiphysics program is used to solve the problem numerically. It is found that the model of carbon diffusion in unalloyed austenite for the single-stage cementation regime is in good contact with the experimental data for the Fe-C-Cr austenite of 15Cr2 steel. For a two-stage process, the calculation of the carbon concentration in the surface layer has a slightly greater deviation from the experimental data than it is at a greater depth.

Theoretical Investigation of the CO2 Capture Properties of γ-LiAlO2 and α-Li5AlO4

: Lithium aluminate has attracted researchers’ interests due to its wide applications. By combining electronic structural and lattice phonon thermodynamic calculations, the CO2 capture properties of γ-LiAlO2 and α-Li5AlO4 are investigated. Both γ-LiAlO2 and α-Li5AlO4 are insulators with wide band gaps of 4.70 and 4.76 eV respectively. Their 1st valence bands just below the Fermi level are mainly formed by p orbitals of Li, O and Al as well as s orbital of Li. By increasing the temperature from 0 K up to 1500 K, their phonon free energies are decreased while their entropies are increased. Targeting on developing post- and pre-combustion CO2 capture technologies, the obtained results indicated that γ-LiAlO2 is thermodynamically favorable to capture CO2 at lower temperature range (500-800 K) while α-Li5AlO4 could capture CO2 at higher temperature (800-1000 K) range in comparison with other solid sorbents, such as pure Li2O, Li4SiO4 and Li2ZrO3.

INFLUENCE OF SURFACE CHEMISTRY OF THE FILLER AND THERMAL MODIFICATION OF BNKS-40 / PVC COMPOSITIONS ON THE VIBRO-ABSORBING PROPERTIES OF THE MATERIAL

The study looks into the effect of a silicic acid filler's (SAF) surface chemistry and thermal modification of BNKS-40/PVC-based (80:20) compounds upon material's vibration-absorbing properties. The thermal analysis (TGA and DTA, Shimadzu analyzer, the temperature rise rate - 10 ° С/min), IR spectroscopy (Infralume FT-08, MFTIR) demonstrated, that adsorption of organosilane bis(3triethoxysilylpropyl)disulfide (TESPD) and the following silanization of Newsil 1165МР (145 ° С, 5 min) occur more readily on the surface of the SAF, dried in mild conditions (70 ° С) in advance. Dehydration of the SAF surface contributes to an increase in the proportion of organosilane physically associated with its surface (2.4 times), rather than chemically (1.1 times). SAF silanization results in the decrease in the compounds' Mooney viscosity (MB 1+4, 100 ° С, CU) and the higher content of free TESPD, the more pronounced the decrease is. The dynamic mechanical analysis (Netzsch DMA 242, in the temperature range from -60 to +60 °С and the frequency range from 0.1 to 10 Hz) demonstrated that, free TESPD plasticized the polymer matrix, increasing TanD as well as shifting the peak of mechanical losses into the lower temperature range. In this case, the effective temperature range of vibration absorption (ETRVA, where TanD ≥ 0.3) is somewhat narrowed in comparison with the compound containing the initial SAF. Thermal modification of BNKS-40/PVC compounds (120 ° С, 4 h) is accompanied by ETRVA expansion in the elastomer glass transition range, as well as in the glass transition temperature of the elastomer-thermoplast transition range. This fact is due to the diffusion of polymers in the filler-elastomer/thermoplast- and the elastomer-thermoplast inter-phase zones. Thermal modification is effective with compounds containing silanized filler with the least amount of free TESPD.

Effect of Temperature, Pressure, and Chemical Composition on the Electrical Conductivity of Schist: Implications for Electrical Structures under the Tibetan Plateau

The experimental study on the electrical conductivities of schists with various contents of alkali ions (CA = K2O + Na2O = 3.94, 5.17, and 5.78 wt.%) were performed at high temperatures (623–1073 K) and high pressures (0.5–2.5 GPa). Experimental results indicated that the conductivities of schist markedly increased with the rise of temperature. Pressure influence on the conductivities of schist was extremely weak at the entire range of experimental temperatures. Alkali ion content has a significant influence on the conductivities of the schist samples in a lower temperature range (623–773 K), and the influence gradually decreases with increasing temperature in a higher temperature range (823–1073 K). In addition, the activation enthalpies for the conductivities of three schist samples were fitted as being 44.16–61.44 kJ/mol. Based on the activation enthalpies and previous studies, impurity alkaline ions (K+ and Na+) were proposed as the charge carriers of schist. Furthermore, electrical conductivities of schist (10−3.5–10−1.5 S/m) were lower than those of high-conductivity layers under the Tibetan Plateau (10−1–100 S/m). It was implied that the presence of schist cannot cause the high-conductivity anomalies in the middle to lower crust beneath the Tibetan Plateau.

Characteristics of Coherent Optical Phonons in a Hexagonal YMnO3 Thin Film

This paper reviews our recent study on a coherent optical phonon in a hexagonal YMnO3 thin film together with related optical studies in hexagonal RMnO3 (R = Y, Lu, Ho) compounds. Coherent phonons have been observed in RMnO3 compounds by pump-probe spectroscopy with subpicosecond laser pulses, whereas the observation of coherent optical phonons was reported only in LuMnO3. Recently, we succeeded in the observation of the coherent optical phonon in a YMnO3 thin film. The generation process of the coherent optical phonon is assigned to a displacive mechanism, which is identical to that in LuMnO3. The coherent optical phonon is observed in the temperature range from 10 K to room temperature, while the oscillation intensity strongly decreases as the temperature increases to the Néel temperature of ~70 K from a lower temperature range. It is interesting that the temperature dependence is largely different from that in LuMnO3. We describe that the result can be qualitatively explained by the property of an isostructural transition around the Néel temperature in RMnO3 compounds. In addition, we briefly discuss ultrafast incoherent responses of excited electronic states from the viewpoint of the excitation photon energy of laser pulses.