Reduced air resistance

Various polymer-modified mortars using recycled artificial marble waste fine aggregate (AMWFA) were prepared and investigated for the purpose of feasibility of recycling. Styrene–butadiene rubber (SBR) latex and polyacrylic ester (PAE) emulsion were employed as polymer modifier, and compared each other. The replacement ratio of AMWFA was also changed to investigate the effect of it on physical properties. Adding polymer cement modifier into mortar reduced water–cement ratio, and PAE was the more effective polymer cement modifier to reduce water–cement ratio than SBR.

7p christian2605 11-10-2019 13 0   Download

The CFD results of aero-dynamic performances of the ship as pressure distribution, velocity flow around hull and air resistance acting on hull are investigated by the CFD. By analysing air resistance acting on a conventional cargo river ship which is widely used in Vietnam, a new concept of cargo river ships with drastically reduced air resistance hull form has been developed.

7p trangcham1896 10-12-2018 46 1   Download

The method of skin frictional resistant reduction is injecting air flows to creating small bubbles into the turbulent boundary layer developing on the ship skin. Research found that this method may reduce ship energy consumption. This method could be applied to large ships with not high speed movement. A model ship that is scaled 1/33 of a 20000 ton cargo ship had been created for carrying out experiment in calm water and in regular wave conditions.

11p thienthanquydu 19-10-2018 27 0   Download

Because of improvements in air quality, such deadly air pollution episodes are rare in U.S. cities. Modern research methods have shown, however, that deaths and serious illnesses from common air pollutants still occur at levels well below regulatory standards, and at current levels in New York and most large cities. Local actions to further reduce air pollution will mean changes in policies and behaviors, and will require significant investments in new vehicles and other equipment.

160p saimatkhauroi 01-02-2013 53 8   Download

Noise is a key concern for people living near transport infrastructure, and can be damaging to both health and general well-being. Although train noise is already much less intrusive than noise from air and road traffi c (see Figure 5), the railway sector wants to reduce noise even further, especially that caused by freight trains. Many of these trains still use loud cast-iron brake blocks, unlike passenger trains, most of which use disc brakes.

68p yeutinh98 26-09-2012 72 3   Download

The duty and performance of the vacuum mixing and reacting technology for the preparation of lead/acid battery paste is reported. The production results achieved under vacuum are compared with those of conventional, air-cooled plants. Due to the more effective cooling and the use of a closed system, improvements such as reduced burned-lead portion, control of paste composition and formulation accuracy, and independence of climatic conditions are achieved.

3p congdat261 19-11-2010 106 6   Download