Chloride Ion Penetration Resistance of Reactive Powder Concrete with Mineral Admixtures

This study employed the rapid chloride ion penetration test and the salt spray erosion method to examine electric flux changes in mineral-admixed reactive powder concrete (RPC). Variations in the chloride ion content and diffusion coefficient under different erosion durations and depths were also investigated. The impact of mineral admixtures on the chloride penetration resistance was explored. Notably, after mixing fly ash (FA) and granulated blast furnace slag (GGBS), the electric flux values of RPC of each group were significantly reduced, and the electric flux values of RPC of the mixed group were significantly lower than those of the single mixed group and the reference group, in which the electric flux of FA10G10 was reduced by 85.2% compared to the control group; at the same erosion cycle and depth, the chloride ion content and diffusion coefficient of the mixed group were significantly lower than the control group. It shows that the reasonable compounding of mineral admixtures can better exert the "superposition effect", improve the compactness inside the matrix, and effectively reduce the chloride ion penetration rate. Considering comprehensively, the FA10G10 group has the best chloride penetration ion resistance effect

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Spatial Patterns and Influence Factors of Conversion Coefficients between Two Typical Pan Evaporimeters in China

Pan measurement is a reliable and efficient method for indicating the evaporative demand of the atmosphere. There are several types of pan evaporimeters worldwide, and the estimation of the conversion coefficients (Kp) between them is necessary in hydrologic research. In China, E601B pans were installed at all meteorological stations beginning in 1998. They replaced the 20 cm pans (φ20). To fully use the records from the two pans and obtain long-term pan evaporation, the spatial patterns of Kp between φ20 and E601B and the factors that influence Kp are investigated based on records from 573 national meteorological stations from 1998 to 2001. In this study, The results show that higher Kp values are found in southwestern regions and lower values are found in northeastern regions during the warm seasons (from May to September), while Kp values are lower during warm seasons than during cold seasons (from October to April the following year). In addition, net radiation was found to be the dominant climate factor that affects variations in Kp, followed by relative humidity and the vapor pressure deficit. This study can improve the benefit of not only the selection of appropriate evaporimeters by meteorological departments, but also of the study of temporal variability and trends in the evaporative demand

Numerical Investigation of Thermal Distribution and Pressurization Behavior in Helium Pressurized Cryogenic Tank by Introducing a Multi-component Model

AbstractAn improved CFD model involving a multi-component gas mixturein the ullage is constructed to predict the pressurization behavior of a cryogenic tank considering the existence of pressurizing helium.A temperature difference between the local fluid and its saturation temperature corresponding to the vapor partial pressure is taken as the phase change driving force. As practical application of the model, hydrogen and oxygen tanks with helium pressurization arenumerically simulated by using themulti-component gas model. The results presentthat the improved model produce higher ullage temperature and pressure and lower wall temperaturethan those without multi-component consideration. The phase change has a slight influence on thepressurization performance due to the small quantities involved

Reduced Runoff Due to Anthropogenic Intervention in the Loess Plateau, China

To maintain the sustainable utilization of water resources and reduce soil erosion in the Loess Plateau, the Chinese government has adopted a number of environmental restoration strategies since 1999, including the Grain for Green Project (GFGP) and the Natural Forest Conservation Program; these large projects greatly alter the regional water cycle. Detecting runoff changes and quantitatively assessing the contribution of anthropogenic activities (including land use/cover change (LUCC) and water diversion) and climate change (including potential evaporation and precipitation) are imperative for implementing sustainable management strategies. Using observed records from 15 hydrological stations and 85 national meteorological stations from 1980 to 2013, the decomposition method, based on the Budyko hypothesis, is used to quantify the impact of climate variation and anthropogenic interference on annual runoff for the 12 catchments in the Loess Plateau. The results show the following: (1) the observed annual runoff exhibited a negative trend in all 12 catchments (significant in eight catchments) with a range of −1.94 to −0.16 mm·year−1 and exhibited a substantial difference before and after 1999; (2) the sensitivity of runoff to vegetation change, precipitation, and potential evapotranspiration increased in most catchments after 1999, indicating that great challenges and uncertainties might be introduced to regional water resource availability; and (3) the anthropogenic interference, particularly LUCC caused by forest strategies, has become the main contribution to runoff change. We suggest that more attention should be given to water resource availability and that the hydrologic consequences of revegetation should be taken into account in future management