The portable generators are the main means of compensating the shortage of national electricity power as in Iraq. However, their noise causes a huge disturbance, uncomforting and loss of concentration of the nearby resident. This problem requires a solution because most shops and residential houses use generators. Covering method is a simple and relatively low cost one for reduction of generato...

Three enclosures (10 x 10 x 1.5-1.3 m in depth) were set beside Dianch Lake, Kunming, People's Republic of China, for the period from July 28 to August 26, 2002. The enclosures were filled with cyanobacterial (Microcystis aeruginosa) water bloom-containing lake water. Lake sediment that contained macrophytes and water chestnut seeds was spread over the entire bottom of each enclosure. Initially...

livestock grazing is one of the most important kinds of land usage that has a high potential to decrease or increase carbon storage in rangeland ecosystem. this research was investigated the effects of enclosure on soil carbon storage in a rangeland with dominant plants of artemisia aucheri. hence, two rangelands of enclosure (shahtappeh-chah mahmood) and no enclosure (chiro) were chosen in sem...

Based on the necessity for enclosure protection of temperature and relative humidity sensors installed in a hostile environment, a wind tunnel was used to quantify the time that the sensors take to reach equilibrium in the environmental conditions to which they are exposed. Two treatments were used: (1) sensors with polyvinyl chloride (PVC) enclosure protection, and (2) sensors with no enclosur...

At present advanced projects of the early XXI century are beginning to develop. These projects include lunar base development and manned missions to Mars. The space suit is one of the basic requirements for successful implementation of future programs. The space suit enclosure enables mobility of crewmembers wearing pressurized space suits which will be required to complete these missions. Requ...

The epiboly of the Caenorhabditis elegans hypodermis involves the bilateral spreading of a thin epithelial sheet from the dorsal side around the embryo to meet at the ventral midline in a process known as ventral enclosure. We present evidence that ventral enclosure occurs in two major steps. The initial migration of the hypodermis is led by a quartet of cells, which exhibit protrusive activity...

The earliest food producers in Africa were mobile pastoralists who left limited archaeological traces. As a result archaeologists studying the spread of food production in the region have difficulty distinguishing early pastoralists from hunter-gatherers with whom they interacted. This geo-ethnoarchaeological study contributes to the resolution of the problem through identification of sediments...

A kind of noise is dominated by broadband noise with low frequency tonal components. To achieve noise control on whole frequency band, it is necessary to implement hybrid control technique combining passive control and active control. There are three methods to combine passive control and active control, including active control in passive enclosures, active control outside passive enclosure an...

background: the adverse effects of noise are well known and noise problems due to industrialization of communities are increasing over the time. oil industries due to the process and nature of production; contain many noise sources such as compressors, turbines, and pumps, which cause excessive noise exposure. the objective of this study was to evaluate the noise characteristics of compressors ...

a numerical investigation of laminar mixed convection heat transfer in a shallow two-sided lid driven rectangular enclosure of aspect ratio 5, (ar=5) is executed. the natural convection effect is sustained by subjecting the bottom wall to a higher temperature than its top counterpart. in addition, the two horizontal walls of the enclosure are moving in different directions and the two vertical ...