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This paper reports on the findings of first of its kind to examine motorbike’s chain transmission, focusing on chain lubrication and its effect on the temperature, efficiency and vibrations of the transmission. The novelty of the paper is to investigate holistically the lubrication effect on the transmission by comparing its dynamic performances under three different lubrication conditions: chain not lubricated at all, chain lubricated with a spray polytetrafluoroethylene (PTFE) addicted lube and chain lubricated with a mineral oil at every minute of the test.

A novel mechatronic test rig has been designed and manufactured using a thermocamera, a dynamometer and an accelerometer respectively. The rig enables a multi-parameter dynamic and real-time sensing investigation of any motorbike chain system by recording temperature, transmission's efficiency and vibrations for any tests by. An experimental investigation has been conducted by running a chain under three aforementioned lube conditions at different speeds with the purposes of: (A) measuring the effect that each lube condition has on three critical parameters: temperature, vibrations and the efficiency of the transmission, and (B) identify the best conditions for practical use.

Results showed that proper use of lubricant can increase the efficiency of the system, by an estimated average of 4.1% is desirable. Additionally, using a continuous lubrication with a mineral oil lubricant leads to better transmission compared to the use of the spray PTFE from the efficiency and thermal points of view.

This work presents an experimental investigation on the effect of two different kinds of lubrication form motorbike chain on transmission’s efficiency. The findings are still valid for different applications of chain transmission in dirty environments. Novelty of the paper is highlighted as follows: this is the first work scientifically investigating the importance of lubrication on chain in harsh environments, particularly of motorbike chain. The work reports a comprehensive lete set experiments and analysis of thermal and mechanical effect because of the presence of lubricant has never been shown. Three kinds of lubricants have been used, and show their distinctive effects which are separately highlighted.

The aim of this paper is to investigate hydraulic system performance using vegetable‐based palm oil as hydraulic fluid.

The hydraulic system performance test at different operating conditions, such as pressure, speed and oil ageing, was performed using a Yuken vane pump test rig. The endurance system performance test was also conducted for 200 and 400 h. The effect of speed on flow slip coefficient in discrete and continuous tests was studied. In discrete testing, pressure of 35 and 200 bar and speed of 750 and 1,439 rpm were used in determining flow slip coefficient. The instantaneous data were recorded in a computer using an analog‐to‐digital data acquisition system with respect to time and the parameters stored were reservoir temperature, return line temperature, suction and delivery pressures, instantaneous flow rate, total flow, total running time and torque. The obtained results were interpolated for future prediction of the system performance.

The experimental and interpolated results showed that slip coefficient decreases with increasing pump speed. The effect of aging condition on volumetric efficiency showed that the efficiency increases with aging period due to increase in oil viscosity.

This vegetable‐based palm oil could be a potentially useful substitute for mineral‐based energy transport media such as hydraulic fluid.

The investigation of hydraulic system performance using palm oil as hydraulic fluid is scarce in the literature. Therefore, the current study is quite new for the hydraulic system performance and it is hoped that it will provide a high value to researchers for further research before it can be used as hydraulic fluid.

The purpose of this paper is to identify the energy losses factors during the hydro-mechanical conversion process at high pressure via a novel reduced order dynamic model.

A novel reduced order dynamic model of the axial piston motor was proposed, which provides an explicit insight to the compression flow losses and the Coulomb friction losses. A fully coupled dynamic model of the piston motor was obtained based on the array bond graph method. And then, a reduced order model was obtained by the composition analysis of flow and torque of the axial piston motor. After that, the energy losses estimation model was presented to predict the energy loss of the piston motor under a wide range of working conditions. The model was verified by comparing the experimental and simulation results.

The simulation result indicates that the flow loss caused by oil compression accounts for 59 per cent of the total flow loss, and the Coulomb friction torque accounts for 40 per cent of the total torque loss under a specific working condition. The compression flow loss and Coulomb friction torque are the major factors that lead to the aggravation of energy loss under extreme working conditions of the piston motor.

At high-pressure condition, the compression flow losses due to fluid compressibility cannot be neglected, and the hydro-mechanical losses in varies friction pairs should involve Coulomb friction losses. Flow and torque loss analytical expression in the model involve the design and control parameters of the piston equipment, which can realize the parameter optimization of the piston equipment for the purpose of energy-saving.

Diesel engine can produce power more efficiently with lower exhaust emissions when operated at optimum input parameter settings. To achieve this goal, the purpose of this paper is to optimize the input parameters of diesel engine which will lead to optimum performance and exhaust emissions.

To achieve the goal of improving diesel engine performance and exhaust emissions, four input parameters were considered in the study. Five different levels of each input parameter were taken. Four response variables under no load, half load and full load conditions were recorded. Experiments were performed in random manner according to selected Taguchi L25 orthogonal array. The data were analyzed using grey relational analysis coupled with principal component analysis. Analysis of S/N ratio was performed to obtain the optimum combination of input parameters. The grey relational grade at optimum setting of the input parameters was obtained by regression analysis.

Results of the current research work give the optimum input parameter settings for no load, half load and full load conditions of diesel engine. Engine produces power more efficiently with low exhaust emissions when operated at these optimum settings.

In view of the compliance to the stringent air pollution norms of the nations and fast depleting fossil fuels, it is of the utmost importance to design and operate the engine in the optimum range of its input parameters so that it produces more power with low exhaust emissions. This paper aims at optimizing input parameters of diesel engine to improve performance and exhaust emissions. Results of the study presented in this paper are significantly useful for diesel engine-related researchers and professionals.

From the literature review, it appears that only few researchers have conducted studies pertaining to the optimization of the input parameters of diesel engine to improve performance or exhaust emissions. Although few studies related to the optimization of compression ratio, fuel injection timing, fuel injection pressure and air pressure have been reported, no work related to optimization of temperature and pressure of turbocharged air has been reported. Therefore, the main focus of the current research work is on optimizing the charge air temperature and pressure with respect to performance and exhaust emissions.

This study aims to investigate the aviation, energetic, exergetic, environmental, sustainability and exergoeconomic performances of a micro turbojet engine used in unmanned aerial vehicles at four different modes.

The engine data were collected from engine test cell. The engine performance calculations were performed for four different operation modes.

According to the results, maximum energy and exergy efficiency were acquired as 19.19% and 18.079% at Mode 4. Total cost rate was calculated as 6.757 $/h at Mode-1, which varied to 10.131 $/h at Mode-4. Exergy cost of engine power was observed as 0.249 $/MJ at Mode-1, which decreased to 0.088 $/MJ at Mode-4 after a careful exergoeconomic analysis.

The novelty of this work is the capability to serve as a guide for similar systems with a detailed approach in the thermodynamic, thermoeconomic and environmental assessments by prioritizing efficiency, fuel consumption and cost formation. This investigation intends to establish a design of the opportunities and benefits that the thermodynamic approach provides to turbojet engine systems.

The aim of the research is the development of a small-scale ground mobile robot for surveillance and inspection; the main design goals are mobility in indoor environments with step climbing ability, pivoting around a vertical axis and without oscillations for stable vision, mobility in unstructured environments, low mechanical and control complexity.

The proposed hybrid leg-wheel robot is characterized by a main body equipped with two actuated wheels and two praying Mantis rotating legs; a rear frame with two idle wheels is connected to the main body by a vertical revolute joint for steering; a second revolute joint allows the rear axle to roll. The geometrical synthesis of the robot has been performed using a nondimensional approach for generality's sake.

The experimental campaign on the first prototype confirms the fulfilment of the design objectives; the robot can efficiently walk in unstructured environments realizing a mixed wheeled-legged locomotion.

Thanks to the operative flexibility of Mantis in indoor and outdoor environments, the range of potential applications is wide: surveillance, inspection, monitoring of dangerous locations, intervention in case of terroristic attacks, military tasks.

Different from other robots of similar size, Mantis combines high speed and energetic efficiency, stable vision, capability of climbing over high steps, obstacles and unevenness.

The rotor in screw motor is driven to rotate by highly pressure difference of drilling fluid (DF), while rotor drives drill bit to break rocks. DF works in the volume cavity (VC) which exists between the stator and rotor (SAR), these process realizes the conversion from hydraulic energy to mechanical energy finally. In order to assure seal performance and output power reliability of VC in common hypocycloid screw motor (CHSM), it’s essential to survey SAR end-face profile.

In this article, based on the internal and external cycloid method given for SAR end-face of φ172 7/8-head LZ type CHSM, the interference among SAR is established based on the meshing model through theoretical equilibrium method (TEM). Last, the reasonable design value of SAR interference in TEM is verified with the hydraulic parameters test results.

The profile optimization that top-root part of rotor end-face profiles is replaced by elliptical-circular arcs (ECA) makes the transition area of tooth-top and tooth-root connect smoother than before. The reasonable interference of SAR in TEM is almost 0.16mm~0.22mm to ensure better sealing performance. Through the hydraulic test, the interference positive fluctuation or the number of SAR head reduces increase (starting-pressure-drop) SPD while negative fluctuations by contraries. Meanwhile, DF penetration also decreases the revolution speed with the SAR interference decreases. The less SAR head revolution speed is always below the more with the constant driving power and DF hydraulic drop. Ultimately, decreasing in overall-efficiency occurs for larger fluctuation of interference or or less interference among SAR.

The line type optimization and analysis in TEM for CHSM improves the motor seal and output performance, also has important application values simultaneously.

The purpose of this paper is to analyze the performance of the gas turbine cycle integrated with solid oxide fuel cell technology. In the present work, intermediate temperature solid oxide fuel cell has been considered, as it is economical, can attain an activation temperature in a quick time, and also have a longer life compared to a high-temperature solid oxide fuel cell, which helps in the commercialization and can generate two ways of electricity as a hybrid configuration.

The conceptualized cycle has been analyzed with the help of computer code developed in MATLAB with the help of governing equations. In this work, the focus is on the performance investigation of a Gas turbine intermediate temperature solid oxide fuel cell hybrid cycle. The work also analyzes the performance behavior of the proposed cycle with various design and operating parameters.

It is found that the power generation efficiency of the IT-SOFC-GT hybrid system reaches up to 60% (LHV) for specific design and operating conditions. The cycle calculations of an IT-SOFC-GT hybrid system and its conceptual design have been presented in this work.

The unique feature of this work is that IT-SOFC has been adopted for integration instead of HT-SOFC, and this work also provides the performance behavior of the hybrid system with varying design and operating parameters, which is the novelty of this work. This work has significant scientific merit, as the cost involved for the commercialization of IT-SOFC is comparatively lower than HT-SOFC and provides a good option to energy manufacturers for generating clean energy at a low cost.

THERE is already in existence a vast amount of detailed data appertaining to cooling systems, but there appears to be a serious lack of general works on the whole subject. This paper is an attempt to formulate a general picture of the whole operation of engine cooling, and to provide a complete skeleton on which the various detail works can be hung together.

The purpose of this paper is to analyse pro-anorexia from a discursive, metaphorical standpoint in order to enable an understanding of how pro-anorexia functions as political resistance through technological bodies.

Techno-metaphor is used to reveal how pro-anorexic communities online function through technology.

Six techno-metaphors work to construct pro-anorexic cyborg embodiment through technology. This pro-anorexic cyborg embodiment offers relief from the tensions of patriarchal femininity and provides control over troublesome embodiment. Technology enables women experiencing anorexia to resist the dominant interpretations of their lived experience that subjugate them.

This research offers an understanding of pro-anorexia as resistance to intolerable femininity and reconstructed female bodies through technology. By exploiting technological political space, pro-anorexics are claiming positions and forms of embodiment previously off-limits to women and their biological bodies.