Search

Lithium-ion (Li-ion) batteries are extensively utilized in electric vehicles and solar energy storage systems owing to their remarkable energy and power density, capacity, and performance The main problems faced in these systems are the errors that occurred in estimating the battery's state of charge (SOC). For that reason, the current study introduces a novel approach based on a fitting polynomial algorithm for state of charge (FPSOC) estimation. The proposed FPSOC method enhances the accuracy and efficiency of SOC estimation by mitigating temperature-induced inaccuracies. Unlike other methods, this technique eliminates the need for a thermal model, offering a solution to rectify temperature-related errors and overcome limitations found in existing battery SOC estimation methods. Through the utilization of this approach, these challenges can be effectively addressed. Simulation results utilizing the MATLAB/Simulink tool demonstrate that the proposed FPSOC method achieves highly precise SOC determination with significantly lower RMSE errors of 0.72 and 0.84, compared to 7.98 and 7.81 for the CC method, respectively, under real and simulated temperature profiles (from -20 °C to 80 °C). Contrasting with established techniques such as TBCC-APF, TBCC-AEKF, APF, AEKF, HMM, TBCC, Multi-Time, Scale DEKF, FF-LSTM, EKF-CCD, EKF-FUDS, OCV-SOC, and ASVDUKF, the proposed FPSOC method showcases exceptional performance, yielding a remarkably low average error of 0.72 in battery SOC estimation. This demonstrates its reliability and accuracy, positioning it as a highly promising algorithm for battery management systems (BMS).

Lithium-ion batteries are essential to modern technology, requiring accurate estimation of the state of charge (SOC) for optimal performance. Traditional methods such as Coulomb Counting (CC) are ineffective in the face of temperature variations, leading to inaccuracies in SOC estimation, which in turn cause obvious deformation of hysteresis curves. To address this, this paper introduces a novel method called Polynomial Fit State of Charge (FPSOC), for effective SOC estimation. This method incorporates a fifth-degree polynomial fitting that accounts for a wide range of temperature variations (from -10 °°C to +80 °°C), a feature that, according to the authors, has not been offered by all previously published methods. A series of simulation tests using the MATLAB/Simulink tool are conducted under various temperature profiles to evaluate the effectiveness of the FPSOC method. The results demonstrate the notable superiority of the FPSOC model compared to the CC method, with a significantly reduced RMSE of only 0.93 % compared to 6.77 % of the CC model. Particularly effective at low SOC levels (30 %), the FPSOC model demonstrates precision up to six times higher compared to the CC model. Additionally, when evaluated against other recent SOC estimation techniques such as CM, RLSF, EKF, DST, BBDST, ASMO, LPM_H, LSTM-SA Group A and B, and baseline ECM-ID, The FPSOC method proves extremely accurate, with the lowest average error under different temperature conditions.

Childhood asthma is increasingly prevalent globally, leading to a significant disease burden with rising incidence and greater healthcare demands. However, previous research has primarily focused on the impact of temperature variation on hospital visits of childhood asthma, with limited evidence on the effects of lung function parameters. In this continuous eight-year study, we investigated the impact of temperature variation on obstructive pulmonary dysfunction and small airway dysfunction in asthmatic children during summer and winter in Jinan, China. The temperature variation was defined as temperature change between two neighboring days (TCN). Generalized linear models (GLM) were employed to explore associations between temperature variation and obstructive pulmonary ventilation dysfunction, small airway dysfunction and pulmonary function parameters. Results indicated a heightened risk of obstructive pulmonary dysfunction associated with temperature variation, with ORs of 1.103 (95% CI: 1.002, 1.212) for per 1 °C increase in TCN in summer and 1.109 (95% CI: 1.000, 1.221) for per 1 °C decrease in winter. Similar results were found for small airway dysfunctions, indicating a consistent pattern of risk associated with temperature variation. Additionally, TCN was associated with a statistically significant decline in several lung function parameters, including FEV 1 /VCmax, FEV 1 /FVC, MEF 25 , MEF 50 and MMEF in winter. The subgroup analysis by gender revealed that the harmful effects of temperature variation were more pronounced in females during summer and in males during winter. In conclusion, this study found that temperature variation posed significant impacts on the lung function of asthmatic children, which highlighted the need for adaptation strategies to mitigate adverse effects of climate change on children's respiratory health, such as avoiding outdoor activities during significant temperature fluctuations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Mounting evidence supports an association between nonoptimal ambient temperatures (i.e., heat or cold) and risk of low birthweight (LBW) (

An engineered barrier system (EBS) for the deep geological disposal of high-level radioactive waste (HLW) is composed of a disposal canister, buffer material, gap-filling material, and backfill material. As the buffer fills the empty space between the disposal canisters and the near-field rock mass, heat energy from the canisters is released to the surrounding buffer material. It is vital that this heat energy is rapidly dissipated to the near-field rock mass, and thus the thermal conductivity of the buffer is a key parameter to consider when evaluating the safety of the overall disposal system. Therefore, to take into consideration the sizeable amount of heat being released from such canisters, this study investigated the thermal conductivity of Korean compacted bentonites and its variation within a temperature range of 25 °C to 80–90 °C. As a result, thermal conductivity increased by 5–20% as the temperature increased. Furthermore, temperature had a greater effect under higher degrees of saturation and a lower impact under higher dry densities. This study also conducted a regression analysis with 147 sets of data to estimate the thermal conductivity of the compacted bentonite considering the initial dry density, water content, and variations in temperature. Furthermore, the Kriging method was adopted to establish an uncertainty metamodel of thermal conductivity to verify the regression model. The R2 value of the regression model was 0.925, and the regression model and metamodel showed similar results.

Temperature variation and flame pulsation behavior of diesel-wetted wood powder fire were experimentally studied. Fuel component ratios (the mass ratio of diesel to wood powder) and burner diameters were considered. The results show that due to the difference between flash/pyrolysis point of diesel and wood powder, the fuel component that mainly combusts transits from diesel to wood powder gradually. So after ignition, the temperature rises rapidly to 600 °C–800 °C, before getting stable within 200 °C–400 °C. The combustion were divided into three stages: rapid burning, transition stage and steady burning. In steady stage, cases with higher fuel component ratio and larger burner sizes have higher temperature. Transition of fuel component that mainly combusts also caused mass loss rate to decrease, which induced the flame shape to change. Generally, flame pulsation frequency is inversely proportional to burner diameter. However, with the reduction of mass loss rate, flame pulsation frequency decreases slightly. For smaller burner size (D ≤ 7 cm) and lower fuel component ratio (φ = 0.5), flame without pulsation could be observed. A dimensionless correlation regarding flame pulsation frequency for this kind of fire was proposed.

The perovskite solar cells (PSCs) have become the fastest-growing photovoltaic (PV) cells to date. Despite its numerous merits, these cells face issues, such as poor stability, toxicity, etc. The issue of toxicity is dealt by using less-toxic substitutes of lead (Pb), such as Tin (Sn). However, the performance attained by Sn-based PSCs still lags behind Pb based PSCs to a great extent. In this work, we discuss some of the desirable electron transport layers (ETLs) and hole transport layers (HTLs) that can be used to fabricate an efficient Sn-based PSC, and report their performance. HTLs, such as “Spiro-OMeTAD”, Graphene, PEDOT:PSS, Cu2O, CuI, CuSCN and ETLs, such as ZnO, TiO2, PCBM are used in this study. We also simulate three different Sn perovskite materials based PSCs, (i) MASnI3 (ii) FASnI3 and (iii) CsSn0.5Ge0.5I3. We study theoretically the performance of the PSCs with various transport layers and absorber layers by varying the temperature from 300 K to 400 K.

Evidence is still limited for the role of long-term PM2.5 exposure in cerebrovascular diseases among residents in high pollution regions. The study is aimed to investigate the long-term effects of PM2.5 exposure on stroke mortality, and further explore the effect modification of temperature variation on the PM2.5-mortality association in northern China. Based on a cohort data with an average follow-up of 9.8 years among 38,435 urban adults, high-resolution estimates of PM2.5 derived from a satellite-based model were assigned to each participant. A Cox regression model with time-varying exposures and strata of geographic regions was employed to assess the risks of stroke mortality associated with PM2.5, after adjusting for individual risk factors. The cross-product term of PM2.5 exposure and annual temperature range was further added into the regression model to test whether the long-term temperature variation would modify the association of PM2.5 with stroke mortality. Among the study participants, the annual mean level of PM2.5 concentration was 66.3 μg/m3 ranging from 39.0 μg/m3 to 100.6 μg/m3. For each 10 μg/m3 increment in PM2.5, the hazard ratio (HR) was 1.31 (95% CI: 1.04–1.65) for stroke mortality after multivariable adjustment. In addition, the HRs of PM2.5 decreased gradually as the increase of annual temperature range with the HRs of 1.95 (95% CI: 1.36–2.81), 1.53 (95% CI: 1.06–2.22), and 1.11 (95% CI: 0.75–1.63) in the low, middle, and high group of annual temperature range, respectively. The findings provided further evidence of long-term PM2.5 exposure on stroke mortality in high-exposure settings such as northern China, and also highlighted the view that assessing the adverse health effects of air pollution might not ignore the role of temperature variations in the context of climate change.

In this paper, combustion process for iron particles burning in the gaseous oxidizing medium due to radiation is investigated by three weighted residual methods (WRMs) called Galerkin method (GM), least square method (LSM) and collocation method (CM). The effect of thermal radiation from the external surface of burning particle and variations of density of iron particle with temperature are considered. The solutions obtained by WRMs techniques are compared with those of the fourth order Runge–Kutta numerical method. Results show that LSM has the most accurate results among other WRMs. Also, results show that by increasing the heat realized parameter (Ψ), combustion temperature increased and it faster reaches to its constant value.

Backgrounds: Abnormal sperm quality in men is one of the common causes of infertility. Both ambient temperature and extreme heat exposure have been shown to be associated with sperm quality, but there is no epidemiological evidence for the effect of ambient temperature variability. Our aim was to investigate the association between ambient temperature variability exposure and a decline in sperm quality at different stages of sperm development., Methods: A total of 4912 semen samples collected from the Guangdong Human Sperm Bank between 1 January 2019 and 31 December 2019 were analyzed. We selected three exposure periods: the full-stage (0-90 lag days), early-stage (34-77 lag days) and late-stage (0-37 lag days) of sperm development, and then calculated the standard deviation of daily temperature (TVSD), the maximum day-to-day temperature difference (TVD max ) and the mean day-to-day temperature difference (TVD mean ) for the three exposure periods. A linear mixed model was used to explore the exposure response relationship between temperature variability exposure and sperm quality indicators (including sperm concentration, sperm count and sperm motility)., Results: There was a significant negative association of decreased sperm count with the exposure to temperature variability during 0-90 days prior to sperm collection. (TVD max : -0.041; -0.063, -0.019; TVD mean : -0.237; -0.386, -0.088; TVSD: -0.103; -0.196, -0.011). We observed a significant association between the decline in sperm concentration, sperm count and per 1 °C increase in TVD mean during early spermatogenesis. No significant association of temperature variability with sperm motility was found., Conclusions: The results indicate that exposure to temperature variability during the entire period of sperm development is significantly associated with a decline in sperm counts. We found that mean day-to-day temperature differences had a detrimental effect on sperm counts in the early-stage. Our findings provide a scientific basis for public health policy and further mechanistic studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Effect of temperature on antibiotic resistance genes (ARGs) during vermicomposting of domestic excess sludge remains poorly understood. Vermicomposting experiment with excess sludge was conducted at three different temperatures (15 °C, 20 °C, and 25 °C) to investigate the fate of ARGs, bacterial community and their relationship in the process. The vermicomposting at 25 °C did not significantly attenuate the targeted ARGs relative to that at 15 °C and 20 °C. The dynamics of qnrA, qnrS, and tetM genes during vermicomposting at 15 °C and 20 °C followed the first-order kinetic model. Temperature remarkably impacted bacterial diversity of the final products with the lowest Shannon index at 25 °C. The presence of the genus (Aeromonas and Chitinophagaceae) at 25 °C may contribute to the rebound of the genes (qnrA, qnrS and tetM). The study indicates that 20 °C is a suitable vermicomposting temperature to simultaneously reach the highest removal efficiency of the ARGs and the good biostability of the final product., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Ambient temperature extremes due to heat exposure was an established risk factor for preterm birth (<37 gestational weeks). However, there is insufficient epidemiological evidence on the effects of temperature variation(TV), although TV is also associated with heat exposure and can influence human health risk. This study aimed to investigate the relationship between inter- and intraday TV and preterm birth (PTB)., Method: A total of 1,388,994 live singleton births were collected from January 2003 to December 2012, from the Shenzhen Birth registry system. Daily temperature range (DTR) was defined as the difference between the highest and lowest recorded daily temperature. Intraday TV was defined as the maximum daily diurnal temperature range in a given week (Max-DTR). Inter-day TV was defined as the maximum increase or decrease in daily mean temperature between days t and t-1in a given week; either an increase (Temp-inc) or a decrease (Temp-dec). We used Cox proportional hazards models to estimate TV-related PTB risks during the first trimester, the second trimester, and in late pregnancy., Results: The maximum values for DTR, Temp-inc, and Temp-dec were 17 °C, 8 °C and 11 °C, respectively. The greatest TV-related PTB risk occurred in the second trimester, with 5.8% (95%CI: 3.3%, 8.3%), 23.7% (95%CI: 19.6%, 27.9%), and 4.4% (95%CI: 1.8%, 7.1%) differences per 1 °C increase in Max-DTR, Temp-inc, and Temp-dec, respectively. Greater TV was associated with elevated PTB risk during the warm season. The association between TV and PTB was modified by seasons, maternal education and chronic conditions., Conclusions: Sharp TV is a likely risk factor for PTB. Policy makers and clinicians should recognize the potential role of TV in the etiology of PTB so that interventions can be designed to protect pregnant women and their fetuses against extreme temperatures., (Copyright © 2021. Published by Elsevier Inc.)

Phase ratio Φ for an high performance liquid chromatography (HPLC) column is a parameter defined as the ratio between the volume of the stationary phase V s and the void volume of the column V m . Together with the equilibrium constant K of the separation process, phase ratio is part of the retention factor k (k = KΦ). Although a considerable number of studies have been dedicated to the evaluation of V s and V m with the goal of obtaining the value for Φ, there are still debatable results regarding the true value of Φ, which for a column with a specific stationary phase may vary with the composition of the mobile phase. One route for the evaluation of the value of Φ uses the measurements of retention factors k on a specific column and mobile phase for two or more hydrocarbons for which the octanol/water partition coefficients log K ow are known. This procedure has been applied in the present study for the evaluation of Φ for three commercially available C18 columns and two mobile phase compositions water/acetonitrile, in the temperature range 20 °C to 50 °C. It was found that phase ratio does change depending on the temperature, its "effective value" decreasing as the temperature increases which is in accordance with the decrease of retention times in reversed phase HPLC when the temperature increases. Besides other factors that may affect the correct calculation of thermodynamic functions, the change of phase ratio with temperature has implications regarding the possibility to calculate the enthalpy and entropy values from van't Hoff plots of the variation of log k as a function of 1/T, even when the retention process is dominated by unique hydrophobic type interactions., Competing Interests: Declaration of Competing Interest The authors of this work declare that they have no conflict of interest., (Copyright © 2020. Published by Elsevier B.V.)

Background: Stroke is the second leading cause of death in the world. It has multiple risk factors of which some, such as ambient temperature, are less well documented., Objective: We aimed to examine the association between diurnal temperature range (DTR) and stroke mortality, and to test the possible effect modification of this association according to gender, age and educational level., Methods: Daily data on weather and stroke mortality from 16 provincial capital cities in China for the years 2007-2013 were obtained, with a total of 788,783 deaths from stroke. A quasi-Poisson generalized linear regression combined with a distributed lag non-linear model was used to examine the city-specific DTR effect on stroke mortality. The pooled effects of DTR on stroke mortality were then obtained using a meta-analysis, which was based on restricted maximum likelihood estimation., Results: The DTR impacts were generally limited to a period of eight days, while significant effects during lag 0-8 days were only found in the cities of Beijing, Zhengzhou, Nanjing, Hefei, Chongqing and Changsha. The DTR effects were significantly and negatively associated with latitudes at lag 0-10 days (r s = - 0.640, P = 0.008). An increase of 1 °C in DTR was associated with pooled estimate of 0.66% (95%CI: 0.28-1.05%), 0.12% (- 0.26% to 0.51%) and 0.67% (0.26-1.07%) increases in stroke mortality at lag 0-10 days during the total, hot and cold days, respectively. The impact of DTR was much higher in southern China than in northern China [1.02% (0.62% to 1.43%) versus 0.10% (-0.27% to 0.47%) ]. For the individual characteristics, only females, the elderly aged ≥ 65 years, and those with lower educational attainment were vulnerable to DTR., Conclusions: DTR has considerable effects on risk of mortality from stroke in various cities in China, especially among the elderly, females, those with low educational level, and people living in southern China. The results can inform decisions on developing programs to protect vulnerable subpopulations from adverse impacts of DTR., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Compared with cold- and heat-related health impacts, the evidence was very limited in assessing the mortality effects of temperature variation (TV) accounting for both intra-day and inter-day changes in temperature., Objective: We used a newly proposed composite indicator of intra-day and inter-day TV and evaluated TV-mortality associations in Hubei, China at the provincial level., Methods: Daily mortality and meteorological data during 2009-2012 were obtained from 12 urban and rural counties across Hubei Province in China. TV was calculated using the standard deviation of the minimum and maximum temperatures during the exposure days. A quasi-Poisson generalized linear regression combined with distributed lag non-linear model was first applied to estimate county-specific relationship between mortality and TV, adjusting for long-term trend and seasonality, mean temperature, relative humidity, public holiday, and day of the week. A meta-analysis was then conducted to pool the county-specific estimates of TV-related mortality effects., Results: A significant positive association was observed between TV and cause-specific mortality (except for respiratory mortality and ischemic heart disease mortality). The effect estimates varied by exposure days, with the highest at 0-7days. Season-stratified analyses showed similar results, while stronger TV-mortality associations were found in warm season than in cold season. The elderly were more susceptible to TV-related mortality effects than younger groups. Some slight differences in effect estimates were also observed in subgroups stratified by gender, education attainment, place of death, and urban/rural areas., Conclusion: Our study strengthened the evidence that temperature variation was an independent risk factor for non-accidental mortality. Some preventive and intervention strategies should be efficiently developed in response to global climate change, so as to minimize public health burden due to unstable weather patterns., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The life cycle assessment of several zinc oxide (ZnO) nanostructures, fabricated by a facile microwave technique, is presented. Key synthesis parameters such as annealing temperature, varied from 90°C to 220°C, and microwave power, varied from 110W to 710W, are assessed. The effect of these parameters on both the structural characteristics and the environmental sustainability of the nanostructures is examined. The nanostructures were characterized by means of X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), ultraviolet-visible spectroscopy (UV-Vis), Photoluminescence (PL) and Brunauer-Emmett-Teller (BET) analysis. Crystalline size was found to be 22.40nm at 110W microwave power, 24.83nm at 310W, and 24.01nm at 710W. Microwave power and synthesis temperature were both directly proportional to the surface area. At 110W the surface area was 10.44m 2 /g, at 310W 12.88m 2 /g, and at 710W 14.60m 2 /g; while it was found to be 11.64m 2 /g at 150°C and 18.09m 2 /g at 220°C. Based on these, a life cycle analysis (LCA) of the produced ZnO nanoparticles was carried out, using the ZnO surface area (1m 2 /g) as the functional unit. It was found that the main environmental weaknesses identified during the production process were; (a) the use of ethanol for purifying the produced nanomaterials and (b) the electricity consumption for the ZnO calcination, provided by South Africa's fossil-fuel dependent electricity source. When the effect of the key synthesis parameters on environmental sustainability was examined it was found that an increase of either microwave power (from 110 to 710W) or synthesis temperatures (from 90 to 220°C), results in higher sustainability, with the environmental footprint reduced by 27% and 41%, respectively. Through a sensitivity analysis, it was observed that an electricity mix based on renewable energy could improve the environmental sustainability of the nanoparticles by 25%., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: To identify the relationship between temperature variation between neighbouring days (TVN) and hospital visits for childhood asthma in age- and sex-specific groups., Study Design: An ecological design was used to explore the effect of TVN on hospital visits for childhood asthma., Methods: A Poisson generalised linear regression model combined with a distributed lag non-linear model was used to analyse the association between TVN and hospital visits for childhood asthma. All hospital visits for childhood asthma from June 2010 to July 2013 were included (n = 17,022). Daily climate data were obtained from Hefei Meteorological Bureau., Results: A significant correlation was found between TVN and hospital visits for childhood asthma in age- and sex-specific groups. For different gender groups, the effect of TVN on childhood asthma was the greatest at 3 and 5 days lag for males and females. For different age groups, the effect of TVN on childhood asthma was the greatest at 1 and 5 days lag for 0-4 years and 5-14 years children, respectively. A 1 °C increase in TVN was associated with a 4.2% (95% confidence interval 0.9-7.6%) increase in hospital visits for childhood asthma., Conclusions: TVN is associated with hospital visits for childhood asthma. Once the temperature change rapidly, guardians will be urged to pay more attention to their children's health, which may reduce the morbidity of childhood asthma., (Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

An adverse association between diurnal temperature range (DTR) and mortality has been suggested, but with variable relationships in different cities. Comprehensive approaches to understanding the health effects of DTR using multinational data are required. We investigated the association between DTR and cause-specific mortality in an age-specific population and assessed the dependency of the health effects of DTR on geographic and climatic factors. Poisson generalized linear regression analyses with allowances for over-dispersion were applied to daily DTR and cause-specific mortality data from 30 cities in China, Japan, Korea, and Taiwan between 1979 and 2010, adjusted for various climatic and environmental factors. City-specific effects of DTR were estimated and summarized for the overall effects using geographic and climatic determinants in a meta-analysis. For all-cause, circulatory, and respiratory mortality, the greatest city-specific effects per 1°C DTR were found in Tianjin, China (1.80%; 95% confidence interval [CI]: 0.48, 3.14); Tangshan, China (2.25%; 95% CI: 0.65, 3.87); and Incheon, Korea (2.84%; 95% CI: 0.04, 5.73), respectively, and overall effects across 30 cities were 0.58% (95% CI: 0.44, 0.72), 0.81% (95% CI: 0.60, 1.03), and 0.90% (95% CI: 0.63, 1.18), respectively. Using quartile cutoff values for climatic (DTR, and mean temperature) and geographic (latitude, and longitude) characteristics, we divided the 30 cities into 4 different groups and conducted a meta-analysis within the groups using either a random or fixed effects model. Adverse effects of DTR were more pronounced for those aged ≥65years and varied according to geographic, longitudinal (0.07%; 95% CI: 0.05, 0.10), and climatic characteristics and the scale of DTR (0.33%; 95% CI: 0.12, 0.55) for overall all-cause mortality. The DTR is a risk factor affecting human health, depending on geographic location and the temperature variation, with particular vulnerability in aged populations., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Multiple pulse sequences are widely used for signal enhancement in NQR detection applications. Since the various (14)N NQR relaxation times, signal decay times and frequency of each NQR line have a major influence on detection sequence performance, it is important to characterise these parameters and their temperature variation, as fully as possible. In this paper we discuss such measurements for a number of the ν+ and ν- NQR lines of monoclinic and orthorhombic TNT and relate the temperature variation results to molecular dynamics. The temperature variation of the (14)N spin-lattice relaxation times T1 is interpreted as due to hindered rotation of the NO2 group about the C-NO2 bond with an activation energy of 89 kJ mol(-1) for the ortho and para groups of monoclinic TNT and 70 kJ mol(-1) for the para group of orthorhombic TNT., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Asthma is one of the most common chronic conditions affecting both children and adults. Examining the health effects of environmental triggers such as temperature variation may have implications for maintenance of asthma control and prevention. We hypothesized that large diurnal temperature range (DTR) might be a source of additional environmental stress and therefore a risk factor for asthma exacerbation. Daily meteorological data, air pollution concentrations and emergency hospital admissions for asthma from 2004 to 2011 in Hong Kong were collected. Poisson regression models were used to fit the relationship between daily DTR and asthma, after adjusting for the time trend, seasonality, mean temperature, humidity, and levels of outdoor air pollution. Acute adverse effect of DTR on asthma was observed. An increment of 1 °C in DTR over lag0 to lag4 days was associated with a 2.49% (95% CI: 1.86%, 3.14%) increase in daily emergency asthma hospitalizations. The association between DTR and asthma was robust on the adjustment for daily absolute temperature and air pollution. DTR exhibited significantly greater effect in cool season. Males and female children appeared to be more vulnerable to DTR. Results supported that greater temperature variation within a day was an environmental risk factor for asthma exacerbation., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We propose to use constant enthalpy or isenthalpic diagrams as a tool to estimate the extent of the temperature variations caused by the mobile phase pressure drop along a chromatographic column, e.g. of its cooling in supercritical fluid and its heating in ultra-performance liquid chromatography. Temperature strongly affects chromatographic phenomena. Any of its variations inside the column, whether intended or not, can lead to significant changes in separation performance. Although instruments use column ovens in order to keep constant the column temperature, operating conditions leading to a high pressure drop may cause significant variations of the column temperature, both in the axial and the radial directions, from the set value. Different ways of measuring these temperature variations are available but they are too inconvenient to be employed in many practical situations. In contrast, the thermodynamic plot-based method that we describe here can easily be used with only a ruler and a pencil. They should be helpful in developing methods or in analyzing results in analytical laboratories. Although the most effective application area for this approach should be SFC (supercritical fluid chromatography), it can be applied to any chromatographic conditions in which temperature variations take place along the column due to the pressure drop, e.g. in ultra-high pressure liquid chromatography (UHPLC). The method proposed here is applicable to isocractic conditions only., (Copyright © 2014 Elsevier B.V. All rights reserved.)