Papers by Keyword: Ratio

Abstract: The 2 stroke single cylinder (63 cc) engine of 750 watt electric generator is very popular in the application because providing enough amount of electricity for small house hold with compact size, light weight with reasonable price. Usually this type of electric generator is fuelled with gasoline that mixed with oil as lubricant. The cylinder volume of the engine is usually around 63 cc. This type of engine can be fuelled with biogas with addition component to mix biogas together with air and lubricant, and set the compression pressure at 10 bar. Biogas mainly contain methane (CH4), carbon dioxide (CO2), moisture (H2O), and hydrogen sulfide (H2S). The CH4 is combustible gas and can be used as a fuel for internal combustion engine. Moisture and H2S are easily removed from biogas. To remove CO2 from biogas is about difficult and costly, therefore acceptable content of CO2 in the biogas should be investigate related with the fuel consumption. This research is conducted to understand the influent of ratio CH4 and CO2 in the biogas to fuel consumption of the 2 stroke single cylinder engine of 750 watt electric generator. The variations ratio of CH4 and CO2 were obtained from anaerobic digester with batch system. The results indicate that the CH4 and CO2 ration in the range 1.667-1.967 will yield optimum efficiency that reach biogas consumption in the range of 9.1-9.8 liter/minute.

Abstract: In order to reveal the impact of reservoir heterogeneity on its recovery and by taking the interlayer heterogeneous and inner layer sand superimposition model (two forms of complexity situation) into account, water flooding experiments have been conducted on parallel connected rock cores, which are selected and artificially casted cores with different permeability, at different injection rates. Experimental results suggested that water displacement recovery is kept decreasing with the increasing of interlayer heterogeneity. when the interlayer permeability ratio (ratio of high permeability versus low permeability) is at about 6.5 and water displacement rate is set at 0.5ml/min, 1ml/min, 1.5ml/min, 2ml/min, respectively, the water flooding experiments indicated that the low permeability recovery increased significantly and low permeability layer became main producer with the increasing of water displacement rate, on the opposite, the high permeability recovery showed no little big change. Laboratory experiments on the model of layer sand body superimposition revealed that the recovery rate of FTRLPTPL model is about 5%~10% higher than that of FTPLPTRL model.(FTRLPTPL is briefed from that flooding from the thick and rich in oil layer and produced from the thin and poor in oil layer. FTPLPTRL is briefed from that flooding from the thin and poor in oil layer and produced from the thick and rich in oil layer.) Analysis on the experiments in different reservoir inner situation told us that recovery enhancement of low permeability layer can play a significant role in increasing the overall recovery rate.

Abstract: This paper has studied the influence of the different ratio on combustion process and emissions of air premixed methanol/diesel dual fuel engine. The research was based on 4B26 diesel engine, and the 3-D numerical simulation on combustion process and emissions of the diesel engine with intake premixed methanol was carried out using AVL FIRE software. The study showed that,with the compression ratio reducing,the ignition delay period prolonged, and the ignition timing delayed, the maximum firing pressure, the peak of pressure rise rate and the maximum combustion temperature in cylinder decreased, the crank angle postponed, the NOX emission decreased and the Soot emission increased obviously.

Abstract: The turbidity of water is one of primary indexes for water quality measurement. Existing main methods for measuring turbidity include scattering method and transmission method. The scattering method is effective for the measurement of low turbidity. Conversely, the transmission method is only suitable for the measurement of high turbidity. In this work, scattering method, transmission method and ratio method are integrated, an on-line turbidity sensor is presented. According to ISO7027 international standards, the sensor’s layout of optical path structure is realized. The detectors are laid in the direction of light source 0 degrees and 90 degrees respectively. Furthermore, the influences of temperature and light on the sensor precision are considered. Least squares support vector machine is introduced to model the turbidity sensor. The experimental results show that this method has much higher precision than the classic methods.

Abstract: Nowadays, the demands of plastics materials are increasing rapidly. Nevertheless, most of these products are non-environmentally friendly and non–biodegradable. Polyvinyl alcohol (PVA) is one of the polymers that have been investigated widely for the potential for use as biodegradable plastics. However, the applications of PVA materials are limited due to their high cost and slow degradation process especially under anaerobic condition. Therefore, this study was conducted to investigate the effect of varying the PVA and starch content on the composite properties. A series of blend films with different ratio of PVA and starch were prepared by solution casting method. The results of this study have revealed that the polyvinyl alcohol and starch at a weight ratio of 70:30 was selected as the best blending composition, whereby the 70:30 blend film have the best elongation at break at about 334.69%, with a tolerable tensile strength value and water absorption capacity of 3.830 MPa and 49.59%, respectively.

Abstract: This article mainly research on different replacement rate of recycled concrete at home and abroad are summarized , and expounds the various researchers in the research of recycled concrete. Outlines the basic properties of recycled concrete, and explain the effects of replacement ratio of recycled concrete, for the development and application of recycled concrete are proposed.

Abstract: Anthropometric measurements are critical dimensions when considering human interface design. This is especially true in vehicle package design where the interaction of the drive with the vehicle interior components need to be precisely determine as a mismatch between them would not only be detrimental to the drives comfort but driving performance and safety as well. In the past car makers often depends on standard databases derived from population that are not necessarily suited to the local population. Among the key concerns are the anthropometric measurements values and body ratio which would drive the design requirements of the vehicle package. Thus this paper describes the study which has been done to understand Malaysian Anthropometry in comparison of current available databases. The results shows significant differences in body proportion which may lead to the necessity to further study the effect of this differences.

Abstract: Fly ash geopolymer coating material potential used to protect surface used in exposure conditions. Ratio of fly ash/alkaline activator and Na₂SiO₃/NaOH play important parameter on determining the best flexural strength of geopolymer coating material. Fly ash and alkali activator (Al₂O₃/Na₂SiO₃) were mixed with the solids-to-liquid ratios in range of 1.0-3.0 and different ratios of Na₂SiO₃/NaOH (1.0-3.0) to prepare geopolymer coating material at constant NaOH concentration of 10 M. Effect of fly ash/alkaline activator ratio and Na₂SiO₃/NaOH on geopolymer coating was determined with respect to the highest flexural strength of the 1200oC sintering temperature of geopolymer coating substrates. The results concluded that the highest strength for fly ash geopolymer coating material is achieved 42 MPa when the solid/liquid ratio is 2.0 and the Na2SiO3/NaOH ratio is 2.5.

Abstract: In order to achieve green building materials, energy conservation, waste reuse purposes. Use city sewage sludge as part of the raw materials for production of shale brick is studied by experiments adopted the different mixing ratio, find matching and the relationship between the compressive strength. Experimental results show that the shale powder to add quality percentage is 40% of dry sludge, formed a burning brick, brick of various performance accord with national standards, not only can save coal and mineral resources, improve the heat insulation brick, but also a lot of recycling of utilization of sludge.

Abstract: The inductive voltage divider is usually used and calibrated at no-load situation, but it also used at taking load situation. For example in the situation of measuring voltage dependence of low voltage capacitors and detecting high voltage bridge, the inductive voltage divider need to take two specific capacitors. This paper have researched the influence of specific capacitive load on its ratio and deduced the analytical formula through related experiments and circuit model analysis when it takes capacitor. And use the method of connecting resistor in series to compensate its ratio accuracy to 1×10^-6 degree.