Mechanical

With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking nonpetroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer-Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NO x , SO x , and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

This paper is based on a review of the technical literature on alternative fuel vehicles (AFVs) and discussions with experts in vehicle technology and energy analysis. It is derived from analysis provided to the bipartisan National Commission on Energy Policy.

The transport properties and the swelling behaviour of NAFION and different sulfonated polyetherketones are explained in terms of distinct differences on the microstructures and in the pK a of the acidic functional groups. The less pronounced hydrophobic/hydrophilic separation of sulfonated polyetherketones compared to NAFION corresponds to narrower, less connected hydrophilic channels and to larger separations between less acidic sulfonic acid functional groups. At high water contents, this is shown to significantly reduce electroosmotic drag and water permeation whilst maintaining high proton conductivity. Blending of sulfonated polyetherketones with other polyaryls even further reduces the solvent permeation (a factor of 20 compared to NAFION), increases the membrane flexibility in the dry state and leads to an improved swelling behaviour. Therefore, polymers based on sulfonated polyetherketones are not only interesting low-cost alternative membrane material for hydrogen fuel cell applications, they may also help to reduce the problems associated with high water drag and high methanol cross-over in direct liquid methanol fuel cells (DMFC). The relatively high conductivities observed for oligomers containing imidazole as functional groups may be exploited in fully polymeric proton conducting systems with no volatile proton solvent operating at temperatures significantly beyond 100 • C, where methanol vapour may be used as a fuel in DMFCs.

The technological development of buses with new alternative fuels is considered in this paper. Several types of fuels are considered as alternative-fuel modes, i.e., electricity, fuel cell (hydrogen), and methanol. Electric vehicles may be considered the alternative-fuel vehicles with the lowest air pollution. Hybrid electric vehicles provide an alternate mode, at least for the period of improving the technology of electric vehicles. A hybrid electric vehicle is defined as a vehicle with the conventional internal combustion engine and an electric motor as its major sources of power. Experts from different decision-making groups performed the multiple attribute evaluation of alternative vehicles. AHP is applied to determine the relative weights of evaluation criteria. TOPSIS and VIKOR are compared and applied to determine the best compromise alternative fuel mode. The result shows that the hybrid electric bus is the most suitable substitute bus for Taiwan urban areas in the short and median term. But, if the cruising distance of the electric bus extends to an acceptable range, the pure electric bus could be the best alternative. r

This paper examines the flank and crater wear characteristics of coated carbide tool inserts during dry turning of steel workpieces. A brief review of tool wear mechanisms is presented together with new evidence showing that wear of the TiC layer on both flank and rake faces is dominated by discrete plastic deformation, which causes the coating to be worn through to the underlying carbide substrate when machining at high cutting speeds and feed rates. Wear also occurs as a result of abrasion, as well as cracking and attrition, with the latter leading to the wearing through the coating on the rake face under low speed conditions. When moderate speeds and feeds are used, the coating remains intact throughout the duration of testing. Wear mechanism maps linking the observed wear mechanisms to machining conditions are presented for the first time. These maps demonstrate clearly that transitions from one dominant wear mechanism to another may be related to variations in measured tool wear rates. Comparisons of the present wear maps with similar maps for uncoated carbide tools show that TiC coatings dramatically expand the range of machining conditions under which acceptable rates of tool wear might be experienced. However, the extent of improvement brought about by the coatings depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates. Among these methods, tool condition monitoring using Acoustic Techniques (AET) is an emerging one. Hence, the present work was carried out to study the stability, applicability and relative sensitivity of AET in tool condition monitoring in turning.

This paper examines the flank and crater wear characteristics of coated carbide tool inserts during dry turning of steel workpieces. A brief review of tool wear mechanisms is presented together with new evidence showing that wear of the TiC layer on both flank and rake faces is dominated by discrete plastic deformation, which causes the coating to be worn through to the underlying carbide substrate when machining at high cutting speeds and feed rates. Wear also occurs as a result of abrasion, as well as cracking and attrition, with the latter leading to the wearing through the coating on the rake face under low speed conditions. When moderate speeds and feeds are used, the coating remains intact throughout the duration of testing. Wear mechanism maps linking the observed wear mechanisms to machining conditions are presented for the first time. These maps demonstrate clearly that transitions from one dominant wear mechanism to another may be related to variations in measured tool wear rates. Comparisons of the present wear maps with similar maps for uncoated carbide tools show that TiC coatings dramatically expand the range of machining conditions under which acceptable rates of tool wear might be experienced. However, the extent of improvement brought about by the coatings depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates. Among these methods, tool condition monitoring using Acoustic Techniques (AET) is an emerging one. Hence, the present work was carried out to study the stability, applicability and relative sensitivity of AET in tool condition monitoring in turning.

This study aims to see the effectiveness of High Intensity Interval Training (HIIT) and skill training on cardiovascular endurance and speed among Bukit Jalil Sports School under 16 hockey players. The sample consisted of 40 male players aged 14 to 16 years old. This study was a quantitative research by using quasi experimental method. The respondents were divided into two groups, treatment group (HIIT training) and control group (skill training). The training program was conducted for eight weeks. "Bleep Test" (BT) and "30meter Speed Test" (30ST) were used during pre-test and post-test to see the effectiveness of the training in enhancing physical fitness capabilities. The paired sample t-test analysis between pre and post tests showed significant differences after performing HIIT training in cardiovascular endurance (t = (19) =-5.448, p = 0.000, (p <0.05) in speed (t = (19) = 3.313, p = 0.004, (p <0.05). While the independent t-test of post-test after the intervention program showed no significant differences in the score among HIIT training and skill training on cardiovascular endurance (t = (38) = 1.431, p = 0.161, (p>0.05) but showed significant differences on speed (t = (38) =-3.303, p = 0.002, (p<0.05). The findings of this study clearly showed that HIIT workouts have a positive effect on speed compared to skill training among under 16 years old hockey players in Bukit Jalil Sports School. There was no significant difference between the two groups in cardiovascular endurance. This means that the skill training also enhances cardiovascular endurance. Further research needs to identify a better and holistic intervention program to enhance not only the hockey players' fitness level but the other sports players too.

3Chennai Institute of Technology, Kundratur, Chennai – 69. Tamil Nadu 600119,India E-mail: brrbapu.aero@gmail.com Abstract An investigation of various factors which affect the lead time in spinning mills which produce 14.76 tex (40 Ne) carded yarns linear density is reported. For this study, data were collected from 27 mills producing 14.76 tex carded yarns of linear density. The important parameters which affect the lead time were obtained by principal component analysis of the data. Correlation matrix and multiple regression analysis were carried out taking into account the lead time as the dependent variable and HOK (the number of Operative Hours required to produce 100 kg of yarn), FQI (Fibre Quality Index), YQI (Yarn Quality Index) and spindle production as independent variables. The reliability of the data was checked by Cronbach’s alpha, which indicated 0.839. Other tests such as the Kruskal-Wallis test, Durbin Watson test, KMO (Kaiser – Meyer Olkin) and Bartlett’s test were ...

This paper aims to provide a convenient measure of evaluating the performance of spinning mills using the overall Key Performance Index. Although many authors have advocated the concept of the key performance index, their studies were confined to departments other than spinning. The methodology followed in this paper is based on providing weightages to machine utilisation, spindle production, end breaks, HOK (number of operative hours required to produce 100 kg of yarn), roving production, yarn realisation, CSP (count strength product), units/kg of Yarn and to compute the overall Key Performance Index in a logical manner. It has come to light that some mills have achieved an overall Key Performance Index (OKPI) of more than 100 and less than 100 in certain other mills. Also the important factors which are significant for supply chain management have been highlighted. A very useful source of information and advice for various spinning mills to develop their own supply chain strategie...

Recently, reinforced polymeric composites prepared from natural fibers have received a significant interest among the researchers because of its appreciable sustainability, environmentally friendly, and low cost. However, one particular issue, that is, hydrophilic property, still needs to be addressed for its successful applications. Since the hydrophilic tendency of natural fibers is extremely undesirable, it leads to the quick degradation of fiber-based polymer composites. Hence, the fiber property, hydrophilic nature, is influenced by the presence of noncrystalline and voids part of these fibers that significantly influences the polymer matrix adhesion. Hence, it is very important to understand the water absorption behavior of reinforced fiber composites. In this study, a crop residual material specific to Ethiopia, teff straw (Eragrostis tef), was used as fiber material. The fiber was treated with 1% NaOH followed by 1% CH2=CHCOOH at room temperature for improving the bonding st...

Carbonate reservoirs account for 60% share in global oil reserves, and CO 2-EOR process is employed in these carbonate fields for effective oil recovery and retention as well. Recent research reports that fines migration may lead to reservoir formation damage in oil bearing limestone and dolomite rocks. Although carbonate reservoirs are poor in clay minerals, some mass of clay fines existence in certain carbonate formations will cause severe damage to permeability and well productivity. This paper reports the single-phase flow of subcritical CO 2 in porous limestone rock core containing kaolinite clay fines. Fines are natural reservoir minerals (example, quartz) and clay particles such as kaolinite, illite, feldspar, smectite, and montmorillonite. But, this paper explores this CO 2-clay fines behavior in limestone rock as a function of kaolinite. So, two sets of core flood experiments were performed in the rock temperatures 120 °C and 160 °C. Initially, kaolinite clay has been injected into the limestone core in the form of suspension and then dried for hours in order to retain the solid fines in the internal pore chambers of the core. After that, the CO 2 under subcritical condition has been injected into the porous limestone core for fines mobilization and injected gas recovery. The major observations that are reported from the experimental tests are there is an increase in gas saturation for increasing injection time. Steady rise of heat transfer coefficient and enthalpy was noted for increasing gas saturation and time. Concentration of fines linearly soars with respect to elevating PVI and permeability declines for rising time. Pressure in the limestone core shows abnormal and nonlinear variation. Finally, gas discharge rate declines for increasing injection time. Experimental data are tested against the statistical model (regression), and the outcome indicated good agreement. Overall, this paper has successfully established the CO 2 effects on kaolinite clay fines behavior and its impact on oil recovery in carbonate fields.

Kaolinite clay fines are prevalent in sandstone porous media and it has great impacts on permeability and well productivity decline. High temperature sandstone formations detach the fines from the pore surface and migrate along with the permeating fluid. At some point the fine particles are strained in the pore throats, which leading to permeability damage and well productivity decline. To the best of our knowledge this phenomenon is not well explored in the high temperature carbonate media. Since most of the world's oil reserves are held in carbonate media and its worth to explore the formation damage, especially due to fines migration during higher reservoir temperature at these formations composed of carbonate minerals. Hence, this paper presents laboratory modeling of kaolinite fines colloidal flow in high temperature porous carbonate media during saline water injection. In this paper, we have conducted three sets of coreflood experiments in the temperature ranges of 100°C 150°C, and 200°C. Kaolinite suspension water has been injected into the porous limestone core at these temperature regimes to investigate the possibility of permeability and injectivity deterioration. The main experimental results showed there is an increase in water saturation and heat transfer rates. Concentration of fines surges with increasing PVI and permeability declines with increasing time. Pressure elevates with enhancing PVI, but it plummets after some time. Significantly, the water discharge rate declines for increasing suspension injection and on the other side, for fresh water injection, the rate of water discharge rises steadily. Furthermore, the electrical and thermal conductivities of effluent kaolinite colloid were higher. Moreover, experimental model were tested against statistical based optimizational model, response surface methodology (RSM). These results revealed good agreement and, hence, this paper has explicated the importance of kaolinite clay fines suspension transport in high temperature carbonate reservoirs.

In a nuclear reactor power plant, massive amount of heat generated in the reactor core causes the Reactor vault (RV) temperature to rise, which should be maintained at a permissible temperature range of 65°C-80°C. In order to address this issue we propose to incorporate thermal insulation, which consists of thin stainless steel (SS) sheets of 0.1 mm-thick stacked with uniform gap between them, introduced between the core and RV. The SS sheets (emissivity = 0.05) are of highly polished, reflective type (mirror finish conforming to No. 8 as per ASTM A480/480M), which are made in the form of panels of suitable size and shape covering the entire outer contour. These types of insulations work on the principle of thermal radiation shielding Heat radiations from the reactor core falling on these reflective plates are reflected back thereby restricting the heat flux into the RV concrete. In order to estimate the effectiveness, 10 such plates are arranged over a length of 150 mm inside a casing made of an insulating material. A plate heater attached at the one end produces the desired heat transfer to analyse the thermal behaviour of the reflective plates. Thermocouples are attached to each plate to understand the temperature distribution in the system. Solidworks simulation and numerical calculations will be carried out.

The use of Different types of storage system using phase change materials (PCMs) is an effective way of storing energy and also to make advantages ofheating and cooling systems are installed to maintain temperatures within the well-being zone. PCMs have been extensively used in various storage systems for heat pumps, solar engineering, and thermal control applications. The use of PCM's for heating and cooling applications have been investigated during the past decade. There are large numbers of PCM's, which melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also outline the investigation and analysis of Phase Change materials used in Different Types of storage systems with different applications.

Nuclear reactor produces electricity by fission reaction of uranium and neutron. Due to this reaction, a lot of heat energy is produced. Hence, this must be kept under control or else the components of reactor core may get damaged which in turn leads to radiation leakage which affect the surrounding environment. Ever since nuclear plants came into operation, dissipation of heat is done by water. But some inert gases that have good heat transfer coefficient and good thermal conductivity for heat dissipation process. The ultimate aim of this project is to find out how efficiently a nanofluid and argon gas can dissipate heat from the reactor vault as a coolant in a circuit. The most commonly used nanofluid is Al 2 O 3 nanoparticle with water or ethylene as base fluid. Al 2 O 3 has good thermal properties and it is easily available. In addition, it can be stabilized at various pH levels. The various temperature distribution leads to different characteristic curves and the characteristic curves give detailed report to enhance heat transfer rate from main vessel to safety vessel. The nanofluid used for the heat transfer process is a combination of Al 2 O 3 (nanoparticle) and therminol 55 (base fluid). The alumina nanoparticle is mixed with therminol 55 at 0.01 vol% concentration. Formerly, the experiments have been conducted by using water and nitrogen gas this leads to poor heat transfer rate. We alternatively conducted this experiment by using nanofluid and argon gas for nurturing the heat transfer rate.

This paper describes about the lean and rich gas condensate effects on fines migration in porous rocks. Fines detachment from rock surface and pore throat entrapment are frequent causes of formation damage and well productivity loss. In condensate reservoirs, there is a large volume of liquid formation during reservoir pressure depletion. This will result in liquid loading and production decline. In this work, we critically discuss the fines migration and the permeability decrease mechanism in the gas condensate reservoir. For this purpose, we numerically simulated a condensate reservoir, which is capable of undergoing a phase transition from gas to liquid as a function of pressure depletion, temperature, and time. We have implemented CFD modeling to simulate this retrograde condensation process. The major results revealed that there is a high amount of heat release during phase transition. This heat release and condensed liquid flow detached the fines from the rock surface and finally, get trapped in the pore-throat. Our models have been validated against the experiments and showed good agreement. Overall, this work may serve as a base to reexamine the gas condensate reservoir behavior with fines transport in porous rocks.

The objective of the work is to improve the thermal efficiency of the system by energy conversion processes from the solar collector to the working fluid. The experiment consists of solar collector with porous medium such as pebble stones as packed with the agitator. The collector having the riser tube, the basic purpose of agitator in the riser tube is to improve the heat transfer rate in the system. Here the pebble stones are used to absorb the heat energy and stored in the materials, then it will be gradually transmitted to the working fluids for long duration. The experiment has conducted with porous medium and without the porous medium. The temperature have noted for certain period of time interval and also noted the solar radiation. With respect to these available data and designed value of collector capacity, heat absorption and efficiency have been calculated. In which both factor is being considered and placing of agitator with pebble stones can increase convective heat transfer and reduce thermal loss thereby efficiency is increased gradually.

In this work, an Performance study was investigated on the nano-refrigerant. CuO/AL 2 O 3-R22 a nano-refrigerants were used in a refrigerator without any remodelling of a System. The refrigerator performance was then investigated using energy consumption test and Enhancing Heat transfer rate. The heat transfer enhancement was investigated on the surface of a refrigerator by using Al 2 O 3 /CuO nano-refrigerants The results indicate that CuO-R22 a nano-refrigerants work normally and safely in the refrigerator and has better power consumption and heat transfer rate. Thus, using CuO-R22 a nano-refrigerant in domestic refrigerators is feasible for better heat transfer rate.

This paper summaries the investigation and analysis of thermal energy storage extracted from solar heater and use for domestic purpose. Choosing a suitable phase change materials paraffin wax and sodium acetate try hydrate are used for storing thermal energy in two different insulation tanks. Each tank carries minimum of 15 liters capacity of water. These two different phase change materials are encapsulated in balls and planted in two tanks. Inside the tank phase change materials are receiving hot water from solar panel. This solar energy is stored in encapsulated balls as latent heat energy. Latent heat is absorbed and stored in encapsulated PCM balls. Large quantity of solar energy can be stored in a day time and same heat can be retrieved for later use. PCM are kept in encapsulated balls and planted in the insulation container. Temperature of the water is measured in a definite interval of time. The heat storage system is to be applied to store solar energy and the stored heat i...

In dry-lands across the world, more than two million people are facing difficulty accessing hygienic potable water. The poor people in the remote location of these areas cause a lot of worries to govern bodies to provide drinking water. It is difficult from an economic point to build and operate a water treatment plant, due to less requirement of water as population in these areas is sparse. In such a situation, a solar desalination device can be cost-effective, to produce distilled from brackish groundwater. The thermal efficiency of conventional solar stills is very low along with less productivity. This experimental work is an attempt to increase the efficiency and productivity of solar still. The increased productivity will make solar distillation economically feasible for poor people. A naturally available phase change material like honey-bee wax has been packed inside a hollow aluminum plate and used as an absorber surface within a solar still. The wax maintains the temperature within 60oC and stores the excess heat for utilization after sunshine hours. The experimental study was done by comparing it with a conventional still under the same operating conditions. The still with inclined absorber surface shows a 45% increase in productivity. This is attributed due to extended hours of working of solar still beyond sunshine hours because of latent heat storage and the active model of water flow due to inclined absorber surface.