Evaluation of diesel engine performance using diesel–cashew nut shell oil blends

The performance, emission and combustion characteristics of a single-cylinder, direct injection diesel engine was studied at various loads at a constant speed of 1500?rpm with neat diesel and cashew nut shell oil (CNSO) blends. Among all the blends, 20% CNSO blend, showed better performance compared to all the other blends. Also, it has been found that CNSO blends can be used in the available diesel engine without making any modification.     

Impact of partially stabilised zirconia on a single-cylinder diesel engine’s performance,using orange oil methyl ester biodiesel

Exhaustion of crude oil resources, rise in fuel prices and necessity to find less-carbon fuel have encouraged to find an alternative fuel. Biodiesel is characterised by its fuel properties, which may have an adverse effect on performance and emission characteristics of the engine. Thus, it is necessary to trans-esterify the extracted orange oil and make it viable for diesel engine. In the present work, partially stabilised zirconia was used as a thermal barrier coating (TBC) for the combustion chamber components using plasma spray technique. The present study focused on the impact of TBC on performance and emission characteristics of a diesel engine with B1 (20% orange oil methyl ester with 80% diesel) sample and diesel. Increased brake thermal efficiency and reduced brake-specific fuel consumption are observed for B1 in the TBC engine. On comparing with the uncoated engine, the B1 in coated engine exhibited lower carbon monoxide, hydrocarbon, oxides of nitrogen and smoke emissions than diesel.     

Investigation on a diesel engine’s performance with integration of magnetic flux on the fuel line

Application of magnetic flux (MF) on the fuel line of diesel engines is a promising technique to enhance the performance of the engine. In this work, MF was applied by placing neodymium magnet pairs (MP) on the fuel line of a diesel engine test setup. Tests were carried out for different loads in the range of 0–8?kg. In the first stage, performance of the test setup was evaluated without MF for fixed load condition; in the second stage, performance evaluation was done by increasing number of MP on the fuel line – that is, the number of magnetic pairs was increased from 1 to 4. The experimental results confirmed that fuel consumption rate decreases with an increase in magnetic pair from 1 to 3; after employing the fourth magnetic pair, an increase in fuel consumption rate was observed. This clearly gives an idea for the presence of critical magnetic field for fuel savings.     

Development of De-NOx selective catalytic reduction catalyst using V2O5 –TiO2 supported on a ceramic filter candle

This study reports the development of a V₂O₅-TiO₂-based selective catalytic reduction (SCR) catalyst supported on alumina-silicate water filter candles for NO_x abatement. The synthesised catalysts have been characterised by thermogravimetry/differential scanning calorimetry, X-ray diffraction, scanning electron microscope and measurement of NO_x removal performance. The catalyst synthesised under optimal conditions shows NO_x reduction efficiency of >97%. SCR performance has been augmented using O₂ as a carrier gas. This simple, reproducible procedure can have wide applications in NOx abatement.     

Effect of ethanol on the performance,emission and combustion characteristics of a compression ignition engine fuelled with vegetable oil–diesel blend

Experimental work had been carried out to analyse the effect of ethanol on the performance, emission and combustion characteristic of vegetable oil–diesel blend (50% vol. rapeseed oil and 50% vol. diesel fuel). The vegetable oil–diesel–ethanol blended fuels were prepared by using microemulsification technique and the main properties were measured. The results showed that, with the increase in ethanol volume fraction in the blends, the viscosity and density were decreased and close to those of diesel fuel. The combustion started later; the peak cylinder pressure, peak heat release rate varied significantly under different operating conditions and the corresponding crank angles of the peak values were retarded. There were slightly higher brake-specific fuel consumptions. Smoke and nitrogen oxide emissions were observed to reduce, but carbon monoxide and hydrocarbon emissions were found slightly higher with the increase of ethanol volume fraction under all ranges of engine operating conditions.     

Optimisation of performance and emission characteristics of CI engine fuelled with Mahua oil methyl ester–diesel blend using response surface methodology

ABSTRACT

The aim of present study is to optimise the performance and emission characteristics of compression ignition engine fuelled with biodiesel blended diesel fuel using response surface methodology (RSM). During engine trials, two parameters, viz. blend ratio and load torque, were varied and the responses like brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxides (NOx) and smoke opacity were investigated. Statistical tool like RSM was used to design experiments. Optimisation of parameters was performed using the desirability approach of RSM for superior performance and lower emission. The results revealed that at optimal input parameters (40% fuel blend and 15?Nm load torque), the values of performance and emission parameters in optimal solutions: BSFC (kg/kWh): 0.2252, BTE (%): 29.2885, CO (vol. %): 0.00757, HC (ppm): 5.7195, NO_x (ppm): 319.78, smoke (vol. %): 4.50 were found for the Mahua oil methyl esters blended with diesel.     

新型纳米Al2O3/ZrO2抗冲磨面层涂料的研究

采用高速分散和超声空化相结合的手段,在分散剂作用下,将纳米Al<,2>O<,3>/ZrO<,2>均匀分散于环氧树脂中,对其进行增韧增强改性,并配制成适用于高速水流冲磨的新型纳米抗冲磨面层涂料,分析了纳米粒子分散方式、纳米Al<,2.O<,3>ZrO<,2>组成比例、纳米粒子含量及分散剂用量等几种主要因素对其性能的影响,试验表明,该涂料具有优良的耐磨、粘结、耐盐雾和耐老化等性能.     

Performance,emission and combustion characteristics of a single cylinder spark ignition engine using ethanol–petrol-blended fuels

The performance, exhaust emission and combustion analyses of a single cylinder spark ignition engine fuelled with extended range of ethanol–petrol blends were carried out successfully at full load conditions. Ethanol produced from raffia trunks was blended with petrol at different proportions by volume. In order to establish a baseline for comparison, the engine was first run on neat petrol. The engine performance parameters (engine torque, brake power, brake specific fuel consumption, brake mean effective pressure and brake thermal efficiency), exhaust emission parameters (CO, HC, CO₂ and O₂ emissions) and combustion parameters were determined for each blend of fuel at different engine speeds. The test results interestingly revealed that the addition of ethanol to petrol causes an improvement in combustion characteristics and significant reduction in exhaust emissions which in turn improved engine performance. In all, ethanol and its blends with petrol exhibited performance characteristics trends similar to that of petrol thus confirming them as suitable alternative fuels for spark ignition engines.     

Investigation of geotextile–soil interaction under a cyclic vertical load using the discrete element method

Geotextiles are often used in roadway construction as separation, filtration, and reinforcement. Their performance as reinforcement in geotextile-reinforced bases depends on geotextile–soil interaction. This paper investigates the geotextile–soil interaction under a cyclic wheel load using the Discrete Element Method (DEM). In this study, soil was modeled as unbonded particles using the linear contact stiffness model, and the geotextile was modeled as bonded particles. The micro-parameters of the soil and the geotextile were determined using biaxial tests and a tensile test, respectively. The influence of the placement depth and the stiffness of the geotextile on the performance of the reinforced base was investigated. The DEM results show that the depth of the geotextile significantly affected the degree of interaction between the geotextile and the soil. Under the applied cyclic vertical load, the geotextile developed a low tensile strain. The effect of the stiffness of the geotextile on the deformation was more significant when the geotextile was placed at a shallower location than when placed at a deeper location.     

Investigation on combustion of fire retardant board under different N2–O2 mixture gas atmospheres by using thermogravimetric analysis

By thermogravimetric analysis (TGA) and kinetic study, the thermal decomposition and combustion processes of a fire retardant board were investigated under different N₂–O₂ mixture gas atmospheres, with 20%, 15%, 10% and 5% oxygen, respectively. The samples were heated from 373 K to 1223 K with a constant heating rate of 30 K/min. The trend of the thermogravimetry (TG) curves and derivative thermogravimetry (DTG) curves were interpreted regarding the conversion yields and the reactivity of samples. There are nine reaction stages which are discernible easily from DTG curves for samples under different gas atmospheres. Each sample’s top value among maximum mass loss rates of all reaction stages appears during reaction 4 stage. The reaction orders and apparent activation energies of all samples during all reaction stages vary between 1.4 and 4.0 and between 7.358 kJ/mol and 535.555 kJ/mol.     

Effects of soil–pile interaction on the response of bridge pier to barge collision using energy distribution method

Abstract

In this paper, the effects of soil–structure interaction (SSI) on the response of a girder bridge pier is evaluated by assessing the energy distributions in the barge–pier collision system. The finite-element models of two example piers of St. George Island Causeway Bridge, which have different structural and geometrical characteristics, are developed in LS-DYNA software to simulate the barge–pier collision scenarios. By comparing the energy distribution results among the barge and pier components, it is obtained that barge bow component has greater value of the internal energy contribution than pier components in the barge collision with more stiff pier. While, in the barge collision with more flexible pier, the pier components including the pier structure, piles and SSI have more internal energy contributions than the barge component. In addition, From the comparison of energy absorbed by the pier structure between the cases with and without SSI, it is found that the effect of the substructure and its relevant SSI on the response of the more flexible pier affected by the produced large deformations and relative displacements of the pier substructure, is more than that of stiff pier which displaces with semi-rigid and global deflections.     

Excavation-induced hydraulic conductivity reduction around a tunnel – Part 2: Verification of proposed method using numerical modeling

During tunnel excavation in a jointed rock mass, significant joint closure takes place in the immediate vicinity of tunnel due to joint effective normal stress increase, and the equivalent hydraulic conductivity is largely reduced within a zone approximately one tunnel-radius thick around the tunnel. A significant pressure drop takes place across this zone, and the actual raise of pore-water pressure in the surrounding rock mass is steeper than that estimated from the analytical solution that considers the jointed rock mass around the tunnel as a homogeneous, isotropic medium. This paper presents a numerical modeling of the mechanical and hydraulic behavior of a jointed rock mass around a tunnel and provides estimates of the groundwater inflow rate to be compared to those estimated from generally used analytical solutions. The numerical analysis results presented here verify the validity of the analytical method described in the Part 1 paper for estimating groundwater inflow rate into a tunnel considering excavation-induced hydraulic conductivity reduction.     

3D reconstruction–based numerical modeling of irregular-shaped geo-objects using digital images: a novel approach

Bulletin of Engineering Geology and the Environment - Naturally occurring rock mass have rough surface with irregular geometry and highly unpredictable material properties, making them almost...     

An empirical analysis of the influences of corporate social responsibility on organizational performance of Taiwan’s construction industry: using corporate image as a mediator

Corporate social responsibility (CSR) has become a hot issue for modern enterprises recently. The primary purpose of this study was to investigate the relationships of CSR and organizational performance. The secondary purpose was to determine whether the effect of CSR on organizational performance could be mediated by corporate image. To fulfil the primary purpose, a questionnaire-based survey was used to measure CSR, corporate image and overall organizational performance in Taiwan’s construction industry. Two hundred and eighty-one valid samples were collected and statistically analysed using factor analysis, correlation analysis and hierarchical regression analysis. The analysis results suggest that CSR is positively correlated with corporate image and organizational performance. Additionally, levels of corporate image are positively associated with organizational performance levels. The results also indicate that corporate image may serve as a mediator between CSR and organizational performance, meaning that companies benefit from investment in CSR realization, even if they also have a positive corporate image.     

Optimisation of electronic device coupled LiBr–H2O absorption heat pump system working at ambient temperature using Taguchi approach

The study attempts to optimise the parameters of a lithium bromide–water (LiBr–H₂O) miniature absorption refrigeration system using Taguchi approach for electronic cooling working at ambient conditions. Thermodynamic optimisation was performed to obtain the optimum coefficient of performance (COP) for heat removal of 100?W by using the Taguchi approach. Three factors were considered: generator temperature (T_g), condenser temperature (T_c) and absorber temperature (T_a), at three different levels. The result showed that the percentage contribution of generator temperature is more on COP. Optimisation of three significant heat exchangers: evaporator, condenser and absorber, was performed by using the Taguchi approach. The study was carried out individually for all the components by varying the hydraulic diameter and aspect ratio at three different levels. The results showed that the hydraulic diameter contributes more than the aspect ratio.     

Standing on ye shoulders of giants: promoting a social systems engineering education using ICE president addresses (1820–2014)

Given the paucity of engineering history presently taught on civil engineering programmes, the purpose of this paper is to promote the role of historical testimonies for the delivery of an enhanced, contemporary and social system’s educational experience. Drawing on the addresses of the presidents of the Institution of Civil Engineers (ICE) (1820–2014) as a source of inspiration and motivation, civil engineering students (n?=?428) were required to select and read six inaugural addresses of former ICE presidents and use these as a catalyst for writing their own ‘ICE presidential address’ while keeping an eye forwards to the year 2050. The results reveal that the ICE presidential addresses help introduce undergraduates to the real and ‘human’ world of civil engineering and provide the students with a ‘social’, as opposed to a scientific, understanding of their profession. Exploring and exploiting the substantial depository of knowledge, values, wisdom and social context of ICE presidential addresses are both innovative and novel and worthy of adoption and adaptation by other academies seeking to prepare civil engineering undergraduates as global citizens.     

Continuous monitoring of sand–cement stiffness starting from layer compaction with a resonant frequency-based method: Issues on mould geometry and sampling

The application of a vibration-based methodology for the continuous measurement of the stiffness of sand–cement has recently been proposed by the authors of this work. Such methodology consists of placing the sand–cement sample into a mould, then placing the mould in simply supported conditions, and finally monitoring it over time to assess the evolution of its resonant frequency. This evolving resonant frequency of the system can be analytically correlated to the stiffness of the tested material. Based on the success of the pilot application, this work has been extended to the methodology of in situ sampling. Such an extension involves the use of new geometries and materials for the moulds. The performance of the adapted technique is verified by comparing its results to those obtained through uniaxial compression cyclic tests up to the age of 28 days. This work also encompasses the characterisation of the hydration kinetics of a cement paste, made with the same cement as that used for cementing sand, and draws conclusions about the relationship of stiffness evolution in both materials.     

An introduction to the karst geomorphology of the Bisetun–Taqe Bostan historical region (northeast Kermanshah,Iran) with special emphasis on karst development as a serious threat for the UNESCO World Heritage Site

The Bisetun–Taqe Bostan crushed carbonate massif (northeast of Kermanshah City) is a historical region that includes several famous monuments. Several types of karst features, the surface kind especially, have been developed in the area because of high rainfall in the area, tectonic crushing and high purity of the rocks. The field survey showed that the major karst features are karren, including rillenkarren, trittkarren, and solution runnels. Some of the monument stones by it have been deteriorating. Cavities and caves, solution dolines, and karstic springs are other observed karstic features in the area. Cavities and caves present mostly at intersections of shear faults or joint sets, which are considered the main location of water seepage throughout the limestone mass. Dolines in the region can be divided into two groups including solution and collapse dolines. The first group involves deep and large dolines without surface deposit cover, whereas the second group includes shallow dolines with smaller sizes covered by soil layers. Dolines are not problematic for the monuments because of their relatively high distance from them. There are a number of karstic springs in the study area; the Bisetun and Taq-e Bostan springs are the most important among them. Both springs discharge at a fault surface in vicinity of the monuments. As a part of the present study, deterioration occurring in the monuments due to the karst development was investigated. Moreover, some physical and chemical preservation methods were proposed to protect the monuments.