نتایج جستجو برای: air freezing index

تعداد نتایج: 610968  

2014
Yiwen Bu Jason Weiss

Air entrainment is commonly used to improve the durability of concrete materials exposed to freezing and thawing. While the influence of air voids on freeze/thaw damage and salt scaling is frequently studied, the influence of entrained air voids on ionic transport has been studied less frequently. Since ionic transport in concrete materials relies on pore fluid as the medium of conduction, only...

مصباح, اشرف السادات, شریعت, محمود , ندافی, کاظم , کرمانی, مجید ,

Apparently, breathing clean air is of significant importance to human beings and thus attention to what enters our body through inhalation is on the increase. Tehran’s air pollution has received considerable media coverage in recent years: Since particulate matter (TSP and PM10) is one of the important pollutants in this city, an attempt was made to study TSP and PM10 concentrations and to make...

2015
Majken Pagter Uffe Brandt Andersen Lillie Andersen

Global climate models predict an increase in the mean surface air temperature, with a disproportionate increase during winter. Since temperature is a major driver of phenological events in temperate woody perennials, warming is likely to induce changes in a range of these events. We investigated the impact of slightly elevated temperatures (+0.76 °C in the air, +1.35 °C in the soil) during the ...

ژورنال: طب کار 2018

Introduction: Continuous exposure to cold air is considered to be a hazardous agent in the workplace in cold seasons. This study aimed to determine the level of cold strain and relation with physiological responses in auto mechanic employees in cold seasons. Method: This cross-sectional study was conducted in the winter of 2017 on auto mechanic employees in Hamadan city. Physiological response...

Journal: :Environmental science. Processes & impacts 2016
Yevgen Nazarenko Uday Kurien Oleg Nepotchatykh Rodrigo B Rangel-Alvarado Parisa A Ariya

Exposure to vehicle exhaust can drive up to 70 % of excess lifetime cancer incidences due to air pollution in urban environments. Little is known about how exhaust-derived particles and organic pollutants, implicated in adverse health effects, are affected by freezing ambient temperatures and the presence of snow. Airborne particles and (semi)volatile organic constituents in dilute exhaust were...

2013
J. D. Hader T. P. Wright

Recent studies have suggested that the icenucleating ability of some types of pollen is derived from non-proteinaceous macromolecules. These macromolecules may become dispersed by the rupturing of the pollen grain during wetting and drying cycles in the atmosphere. If true, this mechanism might prove to be a significant source of ice nuclei (IN) concentrations when pollen is present. Here we te...

2008
Genxu Wang Yuanshou Li Hongchang Hu Yibo Wang

Seasonal changes over 2 years (2004–2006) in soil moisture content ( v) of frozen alpine frost meadow soils of the QinghaiTibet plateau permafrost region under three different levels of vegetation cover were investigated. Vegetation cover and air temperature changes had significant effects (synergistic effect) on v and its distribution in the soil profile. During periods of soil freezing or tha...

Journal: :American journal of botany 2002
Jordi Martínez-Vilalta William T Pockman

The temperature dependence of freezing-induced xylem cavitation was studied in a Chihuahuan desert population of Larrea tridentata (Zygophyllaceae). Field measurements of wood temperature and xylem embolism were combined with anatomical studies and laboratory measurements of embolism in stem and root samples frozen under controlled conditions. Our laboratory experiments corroborated the previou...

Journal: :Sustainability 2022

Under the trend of climate warming, high-latitude permafrost in Heilongjiang Province is becoming seriously degraded. The question how to quantitatively analyze spatial and temporal trends multi-year has become fundamental for current research. In this study, variations annual mean air temperature (MAAT), ground (MAGST) freezing/thawing index based on surface data from 34 meteorological station...

Journal: :Environmental Health Perspectives 2002
Amy D Kyle Tracey J Woodruff Patricia A Buffler Devra L Davis

Air pollution control in the United States for five common pollutants--particulate matter, ground-level ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide--is based partly on the attainment of ambient air quality standards that represent a level of air pollution regarded as safe. Regulatory and health agencies often focus on whether standards for short periods are attained; the number...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید