SCUBA diving equipment is the most commonly used compressed gas system in civilian diving and illustrates the important features and function relevant to diving physiology. Basic SCUBA equipment consists of a cylinder of air at high pressure, a demand valve regulator, and a device for holding this equipment on the diver's back. In the modern context the latter is usually an inflatable jacket ca...

Lakes and marshes are valuable water resources and natural environments for the human beings, it is necessary to preserve and improve their water quality. Since experiencing severe pollution problems during the 1950s and 1960s, Japan has been strengthening its environmental policy. Regulations over the quality of water were enforced under the Water Pollution Control Law, resulting in the succes...

Aquatic environmental deterioration is becoming a serious problem due to rapid urbanization and economic development, particularly in developing countries. As two important components of the aquatic environment, water quality and sediment pollution are widely considered to be concerns; however, they are considered separately in most cases. The relationship between water quality and sediment pol...

there are 3700 wells in tehran city, of which 850 are deep wells. to determine tehran ground water quality, as a pretest we selected 102 wells by simple random sampling; water analyses were made according to the latest edition (1985) of the standard methods. comparisons of the obtained results with who standards show that only 0.98% of the samples go beyond the maximum desirable concentration o...

Introduction Pollution can be defined in several ways. Water pollution occurs when energy and other materials are released into water. It includes all of the waste materials that cannot be naturally broken down by water. In other words, anything that is added to the water, above and beyond its capacity to break it down, is pollution. In certain circumstances pollution can be caused by nature it...

Recent air pollution incidents in Chinese cities prompted this study, which makes use of air particulate monitoring information being submitted by volunteer-owned equipment to a public website. As an indicator of severe air pollution spikes, such as those seen in February 2014, the daily average readings for all monitoring locations were mapped and animated as a time series. Figure 1: China air...

Since the present researches on pollution control for textile printing & dyeing industry are mainly focused on qualitative description up to now, instead of special quantitative analysis, based on the census data of pollution sources, this paper adopts literature collection method and single-factor variance components method for continuous variables to identify the factors influencing cost for ...

background: due to the increasing pollution of water resources, this study was carried out for evaluation of water quality pollution indices for monitoring of heavy metals (as, zn, pb and cu) contamination in ghahavand plain, hamadan province, western iran during spring and summer 2012. methods: totally, 20 ground water wells were chosen randomly. the samples were filtered (0.45 μm) and maintai...