Investigation the effect of adding graphene oxide into diesel/higher alcohols blends on a diesel engine performance

ABSTRACT

This article aims to study the influence of the addition of graphene oxide nanoparticles (GO) to diesel/higher alcohols blends on the combustion, emission, and exergy parameters of a CI engine under various engine loads. The higher alcohols mainly n-butanol, n-heptanol, and n-octanol are blended with diesel at a volume fraction of 50%. Then, the 25 and 50 mg/L concentrations of GO are dispersed into diesel/higher alcohols blends using an ultrasonicator. The GO structures are examined using TEM, TGA, XRD and FTIR. The findings show that there is a reduction in p_max. and HRR when adding higher alcohols with diesel fuel. Regarding engine emission, there is a significant improvement in emissions formation with adding higher alcohols. The addition of GO into diesel/higher alcohols blends improves the brake thermal efficiency by 15%. Moreover, the p_max. and HRR are both enhanced by 4%. The CO, UHC and smoke formation are reduced considerably by 40%, 50 and 20%, respectively, while NO_x level is increased by 30% with adding GO. Finally, adding high percentages of n-butanol, n-heptanol, and n-octanol with diesel fuel with the presence of GO has the potential to achieve ultra-low CO, UHC, and smoke formation meanwhile keeping high thermal efficiency level.     

Natural gas engine driven heat pump system – a case study of an office building

ABSTRACT

An eQUEST model was developed to conduct a simulation study of a natural gas engine-driven heat pump (GEHP) for an office building in Woodstock, Ontario, Canada. Prior to the installation of the GEHP, the heating and cooling demands of the office building were provided by rooftop units (RTUs), comprising of natural gas heater and electric air conditioner. Energy consumption for both GEHP and RTUs were monitored for operation in alternating months. These recorded energy consumptions along with weather data were used in the regression analysis. The developed eQUEST models were validated and calibrated with the regression analysis results with respect to the ASHRAE Guideline 14–2014. The eventual models were then applied to investigate the potential annual energy consumption, greenhouse gas (GHG) emission and energy cost savings achieved by using the GEHP in Woodstock, and other cities in Canada, particularly in Ontario.     

Radiation Effects on Blends of Poly(ε-Caprolactone) and Diatomites

Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower.     

Watershed scale assessment of nitrogen and phosphorus loadings in the Indian River Lagoon basin,Florida

There is a growing evidence that the ecological and biological integrity of the lagoon has declined during the last 50 years, probably due to the decline in water quality. Establishment of a watershed scale seagrass-based nutrient load assessment is the major aim of water quality management in the Indian River Lagoon (IRL). Best estimate loadings incorporate wet and dry deposition, surface water, groundwater, sediment nutrient flux, and point source effluent discharge data. On the average, the IRL is receiving annual external loadings of 832, 645 and 94,476kg of total nitrogen (TN) and total phosphorus (TP), respectively, from stormwater discharges and agricultural runoff. The average internal cycling of TN and TP from sediment deposits in the IRL was about 42,640kg TN and 1050kg TPyr(-1). Indirect evidence suggests that atmospheric deposition has played a role in the ongoing nutrient enrichment in the IRL. The estimated total atmospheric deposition of TN and TP was about 32,940 and 824kgyr(-1), while groundwater contribution was about 84,920 and 24,275kgyr(-1), respectively, to the surface waters of the IRL. The estimated annual contribution of point effluent discharge was about 60,408kg TN and 7248kg TP. In total, the IRL basin is receiving an annual loading of about 1,053,553kg TN and 127,873kg TP. With these results, it is clear that the current rate of nutrient loadings is causing a shift in the primary producers of the IRL from macrophyte to phytoplankton- or algal-based system. The goal is to reverse that shift, to attain and maintain a macrophyte-based estuarine system in the IRL.     

Nitrogen Budget of a Spruce Forest Ecosystem After Six-year Addition of Ammonium Sulphate in Southwest Sweden

A nitrogen (N) budget was constructed for a period of 6 years (1988–1993) in a Norway spruce stand with current deposition of 19 kg N and 22 kg S ha⁻¹ year⁻¹. The stand was fertilized annually by addition of 100 kg N and 114 kg S ha⁻¹ (NS). Above and below ground biomass, litterfall, fine- root litter production, soil solution and net mineralization were measured to estimate pools, fluxes and accumulation of nitrogen. The average needle litterfall in control (C) and NS plots in 1993 was 2.2 and 2.5 ton ha⁻¹ year⁻¹, respectively. The fine root litter production prior to treatment (1987) was 4.4 ton ha⁻¹ year⁻¹ and after treatment (1993) it was 4.5 and 3.9 ton ha⁻¹ year⁻¹ in C and NS plots, respectively. Net N mineralization in the soil profile down to 50 cm was estimated to be 86 and 115 kg ha⁻¹ year⁻¹ in C and NS plots, respectively in 1992. During the treatment period the uptake of N in the needle biomass in C and NS plots was 29 and 77 kg ha⁻¹ year⁻¹, respectively. No N was accumulated in needles of C plot where the NS plots accumulated 34 kg ha⁻¹ year⁻¹. Of the annually added inorganic N to NS plots 47% was accumulated in the above and below ground biomass and 37% in the soil. N fluxes via fine-root litter production in the C plots were much higher (54 kg ha⁻¹ year⁻¹) than that via litterfall (29 kg ha⁻¹ year⁻¹). The corresponding values in the NS plots were 65 and 43 kg ha⁻¹ year⁻¹, respectively. Most of the net N mineralization occurred in the FH layer and upper mineral soil. It is concluded that fine root litter and litterfall play an important role in the cycling of N. Despite a high N uptake the losses of N in litterfall and fine root litter resulted in an incorporation of N in soil organic matter.     

热电联产发展中存在的环保问题及对策

结合我国热电联产项目发展现状,对其存在的主要问题进行了系统分析,从优化布局、清洁生产、节能降耗、推广热电冷联供、强化运行和管理等方面,提出了促进热电联产项目健康发展的对策建议.     

潮湿巷道风流温度与湿度变化规律分析

通过对矿井风流与围岩热湿交换理论的研究,提出理论上更可靠的风流温、湿度计算方法,编制了模拟解算矿井风流与围岩热湿交换的计算机程序,解算出潮湿巷道风流温度及湿度的变化规律,并分析通风时间、湿度系数等参数对风流温度及湿度变化规律的影响;沿风流流动方向,风流温度及湿度不断增加;巷道风流温度及湿度随着通风时间的增加而不断减小,通风时间越长减小的幅度越小;围岩壁面湿度系数对风流温度及湿度的影响较大,其他参数不变时,壁面湿度系数越大,风流温度越小,风流湿度越大。     

FACTORS AFFECTING SALINITY REDUCTION IN LAKE TARPON,PINELLAS COUNTY,FLORIDA1

ABSTRACT: Following an enclosure of a sink-hole connecting Lake Tarpon to the Gulf of Mexico, the chloride concentration of lake waters decreased. Water and chloride budgets for the lake in 1975 were prepared, and predictions using the model of Lerman and Brunskill (1971) were made as to the time required for the lake to achieve fresh water status. Model verification indicated good agreement with predictions in 1976; however, data on [C1^-] for 1977 and 1978 are not as supportive of the model used. The information concerning the Lake Tarpon watershed provided by this latter fact is discussed.     

AN EXAMINATION OF LAND USE - NUTRIENT EXPORT RELATIONSHIPS1

ABSTRACT: Lake and watershed management strategies and recent environmental legislation dictate that nonpoht nutrient sources associated with storm water runoff must be assessed. Accordingly, a nutrient flu assessment for phosphorus and nitrogen is conducted through an extensive literature review of nutrient export studies. These studies are reevaluated. The nutrient export coefficients are screened according to sampling design criteria and compiled according to land use. The ecological mechanisms within each land use influencing the magnitude of nutrient flux are also discussed     

管道中烟道气流动传热及酸凝结规律

针对注烟道气稠油热采中管道输送烟道气酸凝结问题,以连续性方程、能量方程和动量方程为基础建立了烟道气沿管道流动与传热计算模型,计算了烟道气沿管道的压力分布、温度分布和酸凝结点距离,分析了不同入口参数和烟道气成分对管道中烟道气的压力、温度、酸凝结点的影响。结果表明:SO3或水蒸汽含量增加时,烟道气酸凝结点温度提高,凝结点距离减小;入口烟道气压力提高,烟道气压降变小,温降不变,酸凝结点距离减小;入口烟温升高,压降和温降都增大,酸凝结点距离增大;保温层厚度增加,温降减小,酸凝结点距离增大。计算和分析结果表明:减少烟道气中SO3或水蒸汽含量可以有效地增大酸凝结点距离,减轻管道腐蚀问题。