Search Results

You are looking at 1 - 10 of 4,798 items for :

Clear All

flowers. Soil temperature to a depth of 4 inches was measured with a soil probe thermometer (Taylor® Switchable Digital Thermometer; Taylor Precision Products, Oak Brook, IL). Air temperature was measured with Taylor® Indoor/Outdoor Thermometers (Taylor

Full access

a category of environmental chemicals that are a major contributor to reduced indoor air quality. Humans inhale a diverse array of VOCs from the air in homes and offices. Some VOCs are known to be toxic, thus their prevalence poses a serious health

Free access
Author:

Abstract

Air quality monitoring is carried out in Canada and the United States by air pollution control agencies in order to:

  1. provide information on the quality of the ambient air and determine long-term trends;

  2. identify pollutants and their sources, and determine the effects of emission controls on air quality levels;

  3. control episodes brought on by unique weather conditions by obtaining data on a real time basis and ordering emergency shutdowns of sources of pollution. Air pollution episodes during which hazardous air quality levels are reached may thus be prevented;

  4. determine background levels to assist in determining the transport diffusion and fate of the pollutants emitted, and the chemical reactions which take place in the atmosphere;

  5. research the effects of pollutants on health, property, and vegetation to enable the agencies to set meaningful air quality criteria and standards.

Open Access

retention ( da Silva et al., 1993 ). Container size modifies the ratio of water and air within the substrate, because as column height decreases, there is an increased proportion of water and corresponding reduction in air ( Argo et al., 1996 ; Handreck and

Open Access

This study was funded in part by a grant from the California State Air Resources Board. The statements and conclusions of this report are those of the Univ. of California and not necessarily those of the California State Air Resources Board

Free access

Abstract

The air transport of perishable commodities has increased markedly in recent years. A potential for an even greater volume of business is found in reduced rates and improvements in aircraft and handling facilities.

Open Access

Abstract

Air monitoring has become a complex, expensive, and difficult undertaking. Regardless of the problems involved, however, atmospheric pollutant measurement is essential to properly evaluate the air pollution cause and effect relationship.

Open Access

Indoor air pollution is ranked as one of the world's greatest public health risks ( Wolverton, 1997 ). The United Nations Development Program estimated in 1998 that over 2 million humans die each year due to the persistence of deleterious indoor air

Free access

In many parts of China, greenhouses are often not ventilated during winter and early spring to conserve heat. Hence, crops thus face unventilated conditions with the occlusion of air, resulting high humidity and low CO 2 concentration. As is known

Open Access

greenhouse conditions. In response to this production constraint, the objectives of this study were to evaluate three air stream application modules that apply a controlled and directed air stimulus to plants sustainably cultivated under greenhouse conditions

Open Access