bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding Temperature Profiles Experienced by Biological Samples During a Hybrid Vitrification Technique
Authors: Li Rongheng , Chakraborty Nilay , Li Ben Q.
Published: April 2014

From thermodynamic point of view, vitrification is considered as a superior preservation technique in comparison with the traditional slow-cooling cryopreservation techniques, due to formation of the glassy state in both intra and extracellular environment. While vitrification of biological samples are difficult to achieve, recently a hybrid technique involving partial desiccation of the cell samples prior to cryogenic exposure has been successfully employed to achieve vitrification. In this technique cells in monolayer attached to a substrate was suspended in a trehalose solution and then rapidly and uniformly desiccated to a low moisture content (<0.12 g of water per g of dry weight) using a spin-drying technique. The spin-dried samples were stored in liquid nitrogen (LN2) at a vitrified state (Fig. 1). It was shown that following re-warming to room temperature and re-hydration with a fully complemented cell culture medium, 51% of the spin-dried and vitrified cells survived and demonstrated normal growth characteristics. The current study further investigates the temperature profiles experienced by the cell samples during partial desiccation and cryogenic exposure to identify possible ways to improve this novel vitrification strategy. Physical Vapor Deposition technique was employed to develop glass substrate having thermocouples (2×2×2 μm) at four radial positions across the substrate to record the thermal history of the cell samples during the entire process. Efforts are undertaken to understand the uncertainties related temperature measurement spatially and with respect to time. These temperature characterization studies are important to optimize the newly developed hybrid vitrification technique for vitrification of cellular samples.
Simulation of Gas-Liquid Free Surface Flows in a Refrigerant Distributor and a Nozzle of Continuous-Inkjet
Authors: Ishikawa Masanori , Ishii Eiji , Ikegawa Masato
Published: April 2014

A gas-liquid flow in the mm-μm scale is often used in industrial equipment, and it is necessary to develop prediction technology to determine the complicated behavior of a free surface transform. Open source CFD software, such as OpenFOAM, has recently attracted attention for use in industrial applications. We investigated the possibility of using OpenFOAM in the development process of fluid machinery products. We started out by conducting a continuous-inkjet simulation. We compared the simulation results for the breakup length of a liquid column with theoretical results, and then, we evaluated the effect of nozzle length on the breakup length of the liquid column. Next, we evaluated a refrigerant distributor by conducting another simulation. The simulated distribution ratio of the refrigerants was compared with the experimental results, and we checked the efficiency of a parallel simulation. The simulation results for each model qualitatively agreed well with the theoretical or experimental results. Therefore, we found that the simulation using OpenFOAM was effective for large scale simulation of gas-liquid free surface flows.
Biologically Inspired Closed Loop Manufacturing Networks
Authors: Layton Astrid , Bras Bert , Reap John , Weissburg Marc
Published: April 2014

In this paper we use ecology metrics to analyze closed loop manufacturing networks, specifically eco-industrial parks. Eco-industrial parks (EIP) have become a popular manifestation of sustainable initiatives around the world. EIP examples and proposals have met with varying success. We create here three groupings of industrial networks based on the values of cyclicity, a metric used by ecologists to classify the presence and strength of the structural cycling of materials and energy in a system. Ecological food web structures are naturally evolved closed-loop systems and as such exhibit relatively high cyclicity values. Comparing average biological values for cyclicity, among other metrics, to average values for industrial systems we may begin to reach conclusions on the success of the biological inspiration of these structures. The industrial networks have been grouped into industrial systems with cyclicity values of zero, industrial systems with very high cyclicity values which have not moved beyond the proposal stage, and cyclicity values for those industrial networks which have been successful. The results of these comparisons give insight into what structural properties eco-industrial parks should possibly focus on to better imitate the efficient and sustainable cycling representative of biological networks.
A New Anchorage Device for Orthodontic Applications
Authors: Najari Mohamad , El-Rich Marwan , Adeeb Samer , Taha Bachar
Published: April 2014

In orthodontic treatment, anchorage is the most important element that affects the treatment’s success. To improve the load bearing capacity of the anchorage there are several devices developed in recent decades such as midpalatal implants and onplants but they also have limitation on directions of applied load and their support position adjustability.

The purpose of this study was to investigate the efficiency of a new anchorage device by analyzing the load-bearing and stress distribution among the cortical and cancellous bones of the mandible as well as the anchorage system components using nonlinear 3D Finite Element (FE) method. The new device is composed of an adjustable stainless steel plate equipped with bracket and mounted with two titanium mini-screws into the mandible. The response of this new system was compared to an isolated mini-screw system under different loading scenarios.

A maximum of 500gr force was applied in different directions on the bracket and the isolated mini-screw head to simulate the orthodontic loading. Using the new anchorage device reduced von-Mises stress in the whole structure approximately by 50% comparing to the isolated mini-screw. In the cortical bone and depending on the direction of the applied force, von-Mises stress decreased from 6 to 3MPa under vertical shear force and from 6 to 1.5MPa under horizontal and inclined shear forces. In the cancellous bone the stress decreased similarly as in the cortical bone from 0.6 to ≈0.3MPa under horizontal and inclined shear. Under vertical shear force the decrease was less significant from 0.57MPa to 0.5MPa.

This new device while offering wide fields of orthodontic forces applications thanks to its bracket provides the same resistive force (500gr) as the isolated mini-screw with much lower stresses in the bone and anchorage implant as well. The next step is to investigate the efficiency of this new device in the teeth movement.
Experimental Study of the Cooling Performance of the PAFS (Passive Auxiliary Feedwater System) During Transient Operation
Authors: Bae Byoung-Uhn , Kim Seok , Park Yu-Sun , Kang Kyoung-Ho
Published: April 2014

PAFS (Passive Auxiliary Feedwater System) is one of the advanced passive safety systems adopted in the APR+ (Advanced Power Reactor plus) being developed in Korea. The PAFS aims at completely replacing the conventional active auxiliary feedwater system by cooling down the steam generator’s secondary side with a natural driving force mechanism; i.e., it can remove the core decay heat by condensing steam in a passive condensation heat exchanger (PCHX) submerged inside the passive condensation cooling tank (PCCT). With an aim of validating the cooling and operational performance of the PAFS, the separate effect test facility named as PASCAL (PAFS Condensing Heat Removal Assessment Loop) has been constructed. In this study, postulated transient scenarios occurring in the PAFS were simulated to evaluate the performance of the condensation heat transfer and investigate the thermal hydraulic phenomena of the two-phase natural convection flow. The transient test matrix is composed of inadvertent MSSV (Main Steam Safety Valve) opening test (MO), PAFS start-up actuation test (SU), and non-condensable gas effect test (NC). In the MSSV opening test, MSSV was intentionally opened and closed several times and the characteristics of the natural convection flow were investigated. The experimental results showed that the cooling performance of the PAFS could be recovered after inadvertent opening and closing the MSSV. Start-up actuation test simulated the initial transient when the PAFS actuation signal was generated and the natural convection flow was initiated in the loop, and any significant two-phase flow instability was not observed in the test. The purpose of the non-condensable gas effect test is to study the characteristics of the condensation heat transfer in the heat exchanger when the nitrogen gas was injected. The test results proved that the existence of the non-condensable gas up to 1% of the steam did not produce a meaningful decrease of the cooling capability in the PAFS. From the experimental results described above, the cooling and operating performance of the PAFS was validated with respect to occurrence of the various transient scenarios and it was proved that the function of the PAFS can be effectively performed during the transient situation. The result will be also utilized in validation of the thermal hydraulic system code in the future.
Heat Transfer in Cone Calorimeter Tests of Generic Wall Assemblies
Authors: Aire Charles T. , Torvi David A. , Weckman Elizabeth J.
Published: April 2014

It is critical for the construction industry to ensure that new building designs and materials, including wall and floor assemblies (e.g., a studded wall with insulation and drywall) provide an acceptable level of fire safety. A key fire safety requirement that is specified in building codes is the minimum fire resistance rating, which is a measure of the ability of an assembly to limit fire spread within a building. A manufacturer of building materials (e.g., insulation or drywall) is required to perform full-scale fire resistance furnace tests to determine the fire resistance ratings of assemblies that use their products. Fire resistance test facilities are very limited and these tests are very expensive to perform. Therefore, it can be difficult to properly assess the impact of changes to individual components on the overall fire performance of an assembly during the design process.

As part of a project to develop methods of using small-scale fire test data to predict full-scale fire resistance test results, the heat transfer through scale models of common wall assembly designs was measured during cone calorimeter tests using an incident heat flux of 75 kW/m2. Wall assemblies consisting of single and double layers of 12.7 mm (1/2 in.) regular and lightweight gypsum board, and 15.9 mm (5/8 in.) type X gypsum board, along with mineral wool insulation and wood studs were tested. Temperature measurements made at various points within these assemblies are presented in this paper, and are discussed using results from thermal gravimetric analysis tests of the three types of gypsum board. Implications of this research to the development of heat transfer models and scaling relationships are also briefly discussed.
Water Consumption due to Electricity Generation Versus Manufacturing Processes in an Automotive Life-Cycle
Authors: Semmens John , Bras Bert , Guldberg Tina
Published: April 2014

In this paper, we investigate and compare the amounts and impacts of water consumption due to manufacturing processes versus the water consumption due to the electricity used in those manufacturing processes. As is shown using automotive manufacturing as a case study, the “indirect” water consumption in manufacturing due to electricity generation is significant. Reduction of electricity consumption, in particular from thermo-electric power plants, can lead to substantial water consumption reductions, and thus win-win situations. We also show the amounts of variability that occur dependent on how water consumption of hydro-electric power generation is calculated. In terms of an automotive life-cycle, the amount of water consumed in the production of gasoline dominates the life-cycle, but is itself subject to significant variations dependent on the source of the petroleum used.
An Investigation of Heat Transfer Characteristics of Cool Coating for Building Roofs in the Tropical Climate
Authors: Zingre Kishor T. , Wan Man Pun
Published: April 2014

Heat transfer characteristics of cool coating for building roofs in the tropical climate have been investigated by formulating a cool roof heat transfer (CRHT) model for transient heat flux through a cool-coated multi-layered roof (MLR). Furthermore, the impact of the cool coating on heat flux through roof was quantified by extending the CRHT model to estimate the equivalent thickness of uncoated roof required and the equivalent thermal insulation material thickness to be added over uncoated roof to achieve the same daily heat gain as for a cool-coated roof. It was observed that the impact of cool coating is much more significant for low R-value (5–15 cm2-K/W) roof materials, such as metal roofs, as compared to high R-value (>800 cm2-K/W) roof materials such as concrete, asphalt shingle, wood shingle, etc.
Modeling Wheelchair-Users Undergoing Vibrations
Authors: Brown Korkut , Flashner Henryk , McNitt-Gray Jill , Requejo Philip
Published: April 2014

Experimental data of wheelchair-users with varying levels of spinal-cord injury undergoing impact disturbances while seated in a wheelchair, was used to develop one degree-of-freedom rotational-link models of the wheelchair-users. A procedure based on the Maximum Likelihood estimation method was used to identify the parameters of the proposed models such as stiffness and damping coefficients. A good agreement between experimental and identified models responses was achieved. The proposed approach can be used to categorize the difference in response to vibration of patients with different levels of spinal-cord injury (SCI) and will eventually lead to the development of patient specific design criteria for wheelchair suspension.
Neuromodulation Based Control of Autonomous Robots
Authors: Prince Akimul , Samanta Biswanath
Published: April 2014

The paper presents a control approach based on neuromodulation in vertebrate brains and its implementation on an autonomous robotic platform. The neuromodulatory function is modeled through a neural network for generating context based behavioral responses to sensory input signals from the environment. Three types of neurons are incorporated in the neural network model. The neurons are — cholinergic and noradrenergic (ACh/NE) for attention focusing and action selection, dopaminergic (DA) for curiosity-seeking, and serotonergic (5-HT) for risk aversion behaviors. The neuronal model was implemented on a relatively simple autonomous robot that demonstrated its interesting behavior adapting to changes in the environment.
Three Dimensional CFD Simulation of Thermosyphon Flow in an Unglazed Solar Flat Plate Collector
Authors: Sharma Yagnesh N. , Shivamallaiah Manjunath M. , Karanth Vasudeva K.
Published: April 2014

Thermosyphon unglazed solar flat plate collectors have been widely used all over the world to harness solar energy for generating hot water for various applications. This is mainly due to the passive nature of the system besides being simple in design. However, flat plate collectors are associated with higher heat losses from the surface leading to lower thermal performance. Hence, there is a dire need to optimize the thermal design aspects of the flat plate collector in order to achieve higher thermal performance. In this paper, the results of a full three dimensional CFD simulation of thermosyphon flow in an unglazed solar flat plate collector are presented. It is observed from the parametric study that there are interesting trends for the temperature distribution of the absorber plate and loop water for various simulated solar heat flux inputs. This analysis also brings out the effect of various simulated heat fluxes on the mass flow rates in the collector loop. The results of this CFD simulation study provide an insight into the behavior of the thermosyphon solar flat plate collector under various operating conditions and hence will be further helpful to undertake optimization for enhanced thermal performance of the collector.
Combustion Analysis of Twisting-Blade Piston Diesel Engine Fuelled With Karanja Bio-Diesel
Authors: Rajashekar Chandrashekarapur Ramachandraih , Chandrasekhar Tumkur Krishnamurthy , Prasad Tejendra , Kemparaju Chelur Rangalppa , Shankar Chebiyyam Uma
Published: April 2014

Bio-diesels have very poor atomization characteristics, due to decreased cone angle because of high viscosity and low volatility. Innovativeness is required to use the bio-diesel as efficient vehicular fuel.

This paper presents the effect of piston geometry on combustion and emission characteristics of Karanja bio-diesel fuelled C.I.Engine. The piston crown has been modified into twisting blade combustion chamber. Three blades are made to twist through an angle of 60o in the piston crown at the end of compression stroke to induce turbulence to improve the combustibility of combustible mixture. In the present work the combustion and emission characteristics of twisting blade piston fuelled with Karanja bio-diesel have been studied and compared with standard piston engine.
Mach Number on Outlet Plane of a Straight Micro-Tube
Authors: Asako Y. , Kawashima D. , Yamada T. , Hong C.
Published: April 2014

The Mach number and pressure on the outlet plane of a straight micro-tube were investigated numerically for both laminar and turbulent flow cases. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The LB1 turbulence model was used for the turbulent flow case. The compressible momentum and energy equations with the assumption of the ideal gas were solved. The computational domain is extended to the downstream region from the micro-tube outlet. The back pressure was given to the outside of the downstream region. The computations were performed for a tube whose diameter ranges from 50 to 500 μm. The average Mach number on the outlet plane of the fully under-expanded flow depends on the tube diameter and ranges from 1.16 to 1.25. The flow characteristics of the under-expanded gas flow in a straight micro-tube were revealed.
Kinematic Modeling and Kinesiology Study of a Human Index Finger Based on a Tendon-Driven Articulated Manipulator With Disc-Cam Pulleys
Authors: Shieh Win-Bin , Lin Jian Sheng
Published: April 2014

A tendon-driven articulated manipulator with disc-cam pulleys is presented for the kinematic modeling and the motion analysis of a human index finger. Using the proposed model as a foundation, the driving forces of the tendons of human finger could be further evaluated and compared with the estimation from the EMG signals. The motivation of using such a tendon-driven articulated manipulator model to emulate the structure and functionality of a human finger is initiated by the similarities between these two systems, where the joint motions of the systems are both activated by the force transmission of tendons either by the base-driven actuators or the contraction of human muscles. However, the distinction between these two systems is that the extension/flexion motion of a human finger is coupled with the abduction/adduction motion due to the anatomical complexity of the expansion hood of a human finger, while the motion of a general articulated manipulator is not coupled. Moreover, since the shapes of the base and head of phalanges are irregular, the joints of a human finger cannot be simply treated as a perfect revolute joint. Hence, for the motion compatibility between the human finger and the articulated manipulator, the functionality of the expansion hood and the tendon system of a human index finger are identified and the joints are treated as revolute joints with non-circular pulleys. Based on the kinematic model and motion simulation of the finger-alike tendon-driven articulated manipulator is accomplished, and the prototyping model of the manipulator is constructed. Motion comparison between the models with the constant and non-constant moment arms is also implemented.
On the Behavior of an Oblate Spheroidal Hematite Particle in a Simple Shear Flow Under a Uniform Magnetic Field Applied in the Flow Direction
Authors: Yokoyama Haruka , Satoh Akira
Published: April 2014

We discuss the orientational properties of an oblate spheroidal hematite particle and also its influence on the rheological characteristics of a dilute suspension of these magnetic particles, by means of an analytical approach based on the orientational distribution function. An oblate spheroidal hematite particle has an important characteristic that it is magnetized in a direction normal to the particle axis. This particle is assumed to conduct the rotational Brownian motion including both the usual and spin Brownian motion in a simple shear flow under a uniform magnetic field applied in the shear flow direction. In the present analysis, we have taken into account only the friction force (torque) with neglecting the hydrodynamic interactions among particles. From the balance of the torques acting on a particle, we have developed the basic equation of the orientational distribution function. This basic equation has been numerically solved in order to investigate the dependence of the orientational distribution on the magnetic field strength, shear rate and rotational Brownian motion, and also the relationship between the orientational distribution and the transport coefficients such as viscosity and diffusion coefficient. The results obtained here are summarized as follows. If both the magnetic field and the shear flow are weak, the particle does not exhibit specific directional characteristics under the influence of rotational Brownian motion. If the magnetic field is more dominant, the particle inclines such that the oblate surface is parallel to the magnetic field direction. If the Peclet number increases and the shear flow becomes more dominant, the particle shows a sharper peak of the orientational distribution in the shear flow direction. The viscosity due to the magnetic torque increases and finally converges to a constant value as the magnetic field increases. The viscosity curve has an overshoot profile and this overshoot appears at a larger value of the magnetic field strength for the case of a larger Peclet number. Moreover, the viscosity increases more significantly for a larger aspect ratio or for a more oblate hematite particle. In a sedimentation process under the gravitational field, the translational diffusion coefficient decreases with increasing magnetic field strength in the present case of the magnetic field direction.
General Systems Theory in a Horizontal and Vertical Action Process for Cross-Disciplinary Knowledge Transfer
Authors: Vagts Steffen , Schlattmann Josef
Published: April 2014

Biomimetic product development builds a bridge between the scientific disciplines engineering and biology and represents a cross-disciplinary knowledge circulation, which can produce highly innovative advancements in technology. The methodological support for such projects was initiated by the VDI guideline 6220 by 2012 [1] and still requires further research. The method presented in this abstract tries to provide a significant contribution to the successful transfer of knowledge across disciplines, to convey innovative solutions from biology to technology. The central idea of the method called Heli-Act (an acronym of Helix and Action) described here is based on the system-theoretical analysis of the action and the action carrier, the action circle and the action line under the relevant aspects of the socio-technical integration of methods and tools that will support the action carrier in the biomimetic development process. As a cross-common “language” general systems theory is used, which also includes the mathematical modeling system for both action as well as for object systems, which allows a computer-assisted method implementation. For the association of specialized terminology of the disciplines involved in the cross-disciplinary communication a semantic network is used to derive a translation tool in the Ontology World Language (OWL). Practical application experiences from a current project are presented, which describes the tribological optimization of a technical joint by awareness from the analysis of insects joints.
Improved Energy Efficiency and Controllability of Mobile Work Machines by Reduced Engine Rotational Speed
Authors: Ahopelto Miika , Backas Joni , Ghabcheloo Reza , Huhtala Kalevi
Published: April 2014

The usage and control of combustion engines has a significant effect in the fuel consumption and controllability of mobile work machines. In general, the best efficiency region of engine is at high partial loads. In this area, the challenge is the reduced reaction speed of engine. In this paper, we present an approach to gain high fuel efficiency and good drivability by reducing the rotational speed of the engine. This is possible due the fact that hydrostatic power transmission provides variable gear ratio between the engine and the actuators. At reduced rotational speed, engine operates with higher partial loads and improved fuel efficiency for a given required power. The experimental drive cycle tests are presented and show over 25% reduction in fuel consumption compared to conventional control where engine rotational speed is kept constant.
An Experimental Investigation on the Fabrication of Microlens Array Using Meniscus of Photoresist
Authors: Yoon Jae Sung , Kim Jeong Hwan , Yoo Yeong-Eun , Choi Doo-Sun
Published: April 2014

This study investigates a fabrication process for microlens and its array. This process is based on the capillary attraction of liquid photoresist, which is trapped within the round holes on the silicon substrate. When the photoresist is spin-coated on the surface of silicon wafer, where round holes or pits have been made in advance, concave meniscuses are made in the holes or pits. Therefore, microlens array can be made by replication of the surface of the photoresist after it is solidified. The geometry of the microlens depends on the spin speed, viscosity of the photoresist and the size of the holes. In this study, the variation of the geometry of the microlens is investigated with various diameters of the holes for different spin speed.
Design of a New Knee Orthosis Locking System
Authors: Moreira Pedro , Ramôa Pedro , Flores Paulo
Published: April 2014

The main goal of this work is to present the design of a new locking system for a Stance Control Knee Ankle Foot Orthosis (SCKAFO). The purpose of this solution is to support patients with gait disorders, namely patients with muscular weakness and dystrophy in quadriceps femoris muscle group.

The proposed system is able to perform two distinct functions. The first one deals with the locking situation of the orthosis during the stance phase of human gait, in which contact between the foot and the ground occurs. The second function is associated with unlocking situation of the orthosis during the swing phase, in order to allow for the flexion motion of the knee. Thus, in the context of the present work sensors, are used to detect the key phases that characterize the human gait, allowing for the correct system performance. These sensors are placed into anatomical relevant locations and allow the evaluation of the joint angles and accelerations during human gait. Subsequently, the information collected by these sensors is interpreted by a microcontroller that controls the actuation system in order to lock or unlock the knee orthosis locking mechanism.

Finally, a physical prototype was built and tested in a traditional knee orthosis, which will allow for its validation. From the preliminary results, it can be stated that the model proposed here differs from the available commercial solutions in the measure that it is dynamic and does not require foot sensors to determine the human gait phases to define the lock/unlock.
Effect of Rotation and Magnetic Field on Thermal Stability of Ferromagnetic Fluid
Authors: Aggarwal Amrish K. , Verma Anushri
Published: April 2014

In this paper, the effect of rotation and magnetic field on thermal stability of a layer of ferromagnetic fluid heated from below has been investigated. For a fluid layer between two free boundaries, an exact solution is obtained using a linearized stability theory and normal mode analysis. For the case of stationary convection, it is found that magnetic field and rotation have stabilizing effect on the thermal stability of the system. The principle of exchange of stability is not valid for the problem under consideration, whereas in the absence of rotation and magnetic field, it is valid.
Dynamic Simulation of Dependability of Nickel Reduction Plant
Authors: Penttilä Juha , Ikonen Veijo
Published: April 2014

This paper presents a dynamic simulation model of complex production lines. The model has been used to improve reliability of production line and also for planning and scheduling of maintenance and production. The model presented here is based on stochastic simulation in time domain. Random failures, finite buffers, feedback loops, variable production speeds and scheduled preventive maintenance are taken into account. Collected production data from process automation system has been extensively used in modeling. The approach presented is valuable for the industrial practitioners in the maintenance business and may also be adapted to other areas where operational experience exists. A prototype model has also been merged into production management system. Model can be continuously updated by new data and implications can be observed. Improvements in knowledge of production effectiveness and reliability have been achieved.
Finite Element Analysis and Study of Tool Wear in Machining With Coated Tools
Authors: Reddy Paturi Uma Maheshwera , Reddy Narala Suresh Kumar
Published: April 2014

Accurately predicting the tool wear in any machining process play an important role in enhancing the manufacturing process performance. In all machining operations, cutting tool wear is strongly influenced by contact temperatures, stresses, and relative sliding velocity at the machining interface. Based on cutting temperatures and stresses on the tool face predicted by the finite element simulations, tool wear can be estimated. This paper features a specific study of the application of solid lubricant coatings in machining operations and presents its influence on tool-workpiece contact temperature and tool wear resistance. In the present work, finite element modeling approach concerning orthogonal cutting was carried out in order to understand the machining process performance in terms of tool wear during turning of selected workmaterial with and without solid lubricant (molybdenum disulphide, MoS2) coated tools produced by electrostatic micro-solid lubricant coating technique. Finite element code, DEFORM-3D is utilized to predict the tool wear during machining of workmaterial under two machining environments. The results under similar tested machining conditions show that flank wear resistance was improved remarkably during machining with MoS2 coated tools when compared to machining with uncoated tools. This could be mainly due to the presence of MoS2 film on tool face, which can reduce the cutting temperatures effectively owing to its excellent lubricity action and result in lower specific cutting energy given into the contact. For experimental validation, series of turning tests were carried out under selected conditions. It has been observed from the simulation studies that the tool wear results are in reasonable agreement with the experimental results.
Effect of Swelling Behavior on Elastomeric Materials: Experimental and Numerical Investigation
Authors: Qamar Sayyad Zahid , Akhtar Maaz , Al-Kharusi Moosa S. M.
Published: April 2014

In the last ten years, a new type of advanced polymer known as swelling elastomer has been extensively used as sealing element in the oil and gas industry. These elastomers have been instrumental in various new applications such as water shutoff, zonal isolation, sidetracking, etc. Though swell packers can significantly reduce costs and increase productivity, their failure can lead to serious losses. Integrity and reliability of swelling-elastomer seals under different field conditions is therefore a major concern. Investigation of changes in material behavior over a specified swelling period is a necessary first step for performance evaluation of elastomer seals. Current study is based on experimental and numerical analysis of changes in compressive and bulk behavior of an elastomeric material due to swelling. Tests and simulations were carried out before and after various stages of swelling. Specimens were placed in saline water (0.6% and 12% concentration) at a temperature of 50°C, total swelling period being one month. Both compression and bulk tests were conducted using disc samples. A small test rig had to be designed and constructed for determination of bulk modulus. Young’s modulus (under compression) and bulk modulus were determined for specimens subjected to different swelling periods. Shear modulus and Poisson’s ratio were calculated using isotropic relations. Experiments were also simulated using the commercial finite element software ABAQUS. Different hyperelastic material models were examined. As Ogden model with second strain energy potential gave the closest results, it has been used for all simulations.

The elastomer was a fast-swell type. There were drastic changes in material properties within one day of swelling, under both low and high salinity water. Values of elastic and shear modulus dropped by more than 90% in the first few days, and then remained almost constant during the rest of the one-month period. Poisson’s ratio, as expected, showed a mirror behavior of a sharp increase in the first few days. Bulk modulus exhibited a fluctuating pattern; rapid initial decrease, then a slightly slower increase, followed by a much slower decrease. Salinity shows some notable effect in the first 5 or 6 days, but has almost no influence in the later days. Very interestingly, Poisson’s ratio approaches the limiting value of 0.5 within the first 10 days of swelling, justifying the assumption of incompressibility used in most analytical and numerical models. In general, simulations results are in good agreement with experimental ones.
Heat Transfer and Thermal Balance Analysis of an Aluminum Electrolysis Cell Side Lines: A Heat Recovery Capability and Feasibility Study
Authors: Mollaei Barzi Yaser , Assadi Mohsen
Published: April 2014

In this study, a preliminary investigation is carried out concerning the possibility and feasibility of recovering part of the side walls heat loss to use it in an energy utilization system. For this purpose, a simple smart heat transfer model is developed for the aluminum smelter side lines accounting for the dynamic ledge profile variations and phase change. Using the model, the total side wall heat loss is estimated and evaluated in different operating conditions of the cell. The system flexibility and self-adjustment ability are taken in to account to find the appropriate solution for the heat extraction system. Using the above-mentioned analysis, the heat recovery strategy and also the possible and applicable alternatives for the side walls heat collection and utilization system are investigated.
Hydrothermal Aging and Mechanical Property of Injection Molded Jute/Glass/Polypropylene Hybrid Composites
Authors: Wang Jian , Uawongsuwan Putinun , Yang Yuqiu , Inoya Hiroyuki , Hojo Toshihiko , Hamada Hiroyuki
Published: April 2014

As well known, the durability of the material is always considered in the safety design of the materials. Therefore in this study, the property of injection molded hybrid jute/glass reinforced polypropylene (PP) composites was firstly investigated after the hot water immersion experiment. The hydrothermal aging performance was investigated in the 80 °C hot water immersion experiment with a series of immersion time and different fraction of jute fiber and the effects of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test. Water absorption and weight loss of the reinforced PP composites were recorded and discussed. It is found that with the increase of jute fiber content, the tensile modulus is increased. However, the increasing of jute fiber content decreased the tensile strength of hybrid composites. For the effect of hydrothermal aging, the weight by water absorption was significantly affected by the jute fiber content. The specimens with higher jute fiber content absorbed water easier and significant materials loss by aging was also occurred. Tensile properties of hybrid composites which contain jute fiber showed the lower tensile strength than the monotonic glass/PP composite. It is considered that the hydrophilic property of jute fiber decreases the resistance of the hybrid composite in high humidity environment.
Flow Boiling Enhancement in Microtubes With Crosslinked pHEMA Coatings
Authors: Çıkım Taha , Armağan Efe , Özaydın İnce Gözde , Koşar Ali
Published: April 2014

In this experimental study, flow boiling in mini/microtubes was investigated with surface enhancements provided by crosslinked polyhydroxyethylmethacrylate (pHEMA coatings), which is used as a crosslinker coating with different thicknesses (50 nm, 100 nm and 150 nm) on inner microtube walls. Flow boiling heat transfer experiments were conducted on microtubes (with inner diameters of 249 μm and 507 μm) with enhanced inner surfaces with crosslinked pHEMA coatings. pHEMA nanofilms were coated with initiated chemical vapor deposition (iCVD) technique. De-ionized water was utilized as the working fluid in this study. Experimental results obtained from coated microtubes were compared to their plain surface counterparts at two different mass fluxes, (5,000 kg/m2s and 30,000 kg/m2s) and significant enhancements in Critical Heat Flux and boiling heat transfer were attained. These promising results support the use of crosslinked pHEMA coated microtubes/channels as a surface enhancement technique for micro scale cooling applications.
Dimensional Analysis of the Generated Design Solutions for Reconfigurable Manufacturing System
Authors: Baqai Aamer , Shafiq Arsalan
Published: April 2014

Reconfigurable Manufacturing Systems (RMS) is the recent addition in the series of different of types manufacturing systems. Various approaches deal with generation of design solutions for such systems. In this paper two and three dimensional tolerance analysis of the generated design solutions using algorithmic approach for reconfigurable manufacturing systems is carried out. In this analysis quality is considered as the key performance indicator. Among the existing techniques and methods used for tolerance evaluation, the approach of representing the tolerances as Small Displacement Torsors (SDT) is used. The modified method of graphs is selected for representing the machining process plans among the existing methods. Heuristics for the said graphs are defined. For each geometric variation the torsors are written. 2D or 3D dimensional simulation is performed and solutions are classified according to their tolerance values. The proposed methodology has wide application in the generative approach of process plan generation for reconfigurable manufacturing systems.
Thermogravimetric Analysis and Characterisation of Yard Waste as a Feedstock to Gasification Process
Authors: Bhavanam Anjireddy , Sastry R. C.
Published: April 2014

Gasification has great potential to make use of the biomass and wastes as a source for energy among various thermochemical conversion processes. The aim of this work is to study the suitability of yard waste for energy conversion using gasification process by Thermo gravimetric analysis. Yard waste (consisting of leaves, twigs and grass clippings) is collected from the National Institute of Technology Warangal. It is then dried and ground to a particle size of less than 250μm for thermo gravimetric study. Before going to thermo gravimetric analysis; the sample is analyzed to measure the main properties that affect thermal conversion. Moisture content present in the sample is determined by the oven drying method. Proximate is done according to standard ASTM test methods and ultimate analysis is conducted using elemental analyzer. Finally thermo gravimetric analyses is performed at various heating rates of 10, 30, and 50°Cmin−1 in nitrogen (inert) and air (oxidizing) atmospheres. The weight losses of yard waste in inert atmosphere occur in three stages and in air it occurs in four stages.
Removal Mechanisms of Suspended Particulate Matter in Humidity Swing Air Cleaning Method
Authors: Onoda Nagisa , Nakabeppu Osamu
Published: April 2014

We are studying the removal of the SPM by a humidity swing method, in which sample air is consecutively humidified with heating and dehumidified with cooling. First, the removal effect of this method was experimentally demonstrated. The sample air was humidified to saturated moist air up to 66°C and then cooled to 13°C. The results showed the decrease of the SPM concentration. The SPM survival ratio is plotted against the drop of absolute humidity through the dehumidification; and the survival ratio exponentially decreased to ∼0.2. Also, the dependence of removal characteristic on SPM concentration was not shown for 10 ∼ 10000 particles/cc. Also, growth of SPM due to nuclear condensation was observed in the experiments. However, the number of SPM grown to several micrometers where SPM significantly decreases with gravity was very small. Therefore gravitational sedimentation would not be enhanced. Next, SPM transfer in the dehumidifier was calculated. The heat and mass transfer through the dehumidifier was calculated; and then, variation of SPM concentration by suction flow and themophpresis were obtained. The analysis of SPM transfer showed that the dominant phenomenon for SPM transport in the dehumidifier is suction flow. However, the calculation considering thermophoresis and suction flow predicted the removal effects several times lower than the experiments. Thus, the removal mechanism of the humidity swing method should be explained by unidentified phenomena.
Power Plant Heat Rejection System Modeling and Comparison
Authors: Carter Thomas P. , Furlong James W. , Bushart Sean P. , Shi Jessica
Published: April 2014

As noted in a Summer 2007 EPRI Journal article entitled Running Dry At The Power Plant, “Securing sufficient supplies of fresh water for societal, industrial, and agricultural uses while protecting the natural environment is becoming increasingly difficult in many parts of the United States. Climate variability and change may exacerbate the situation through hotter weather and disrupted precipitation patterns that promote regional drought.” [1] Currently, in the United States, thermoelectric power production accounts for approximately 41% of freshwater withdrawals [2] and 3% of overall fresh water consumption. [3]

The Electric Power Research Institute, EPRI, as part of its Technology Innovation (TI) program, is collaborating with Johnson Controls to conduct a feasibility study comparing the performance of a water saving Thermosyphon Cooling Hybrid System (TCHS) with other heat rejection systems for power plant applications. The TCHS employs a sensible heat rejection device, a thermosyphon cooler (TSC) in conjunction with an evaporative heat rejection device, an open cooling tower, to satisfy the annual cooling requirements of a given power plant. By reducing the evaporative heat load, the TCHS can significantly reduce the annual water consumed for cooling while still maintaining peak power plant output on the hottest summer days.

Details of the interactive simulation program developed to compare various power plant heat rejection systems on an annual 8,760 hourly basis are discussed. Examples of the types of results and comparisons that can be made from the data obtained from the simulation program are presented.
Preliminary Results of Pressure Drop Modeling During Flow Boiling in Open Microchannels With Uniform and Tapered Manifolds (OMM)
Authors: Kalani Ankit , Kandlikar Satish G.
Published: April 2014

Flow boiling with microchannel can dissipate high heat fluxes at low surface temperature difference. A number of issues, such as instabilities, low critical heat flux (CHF) and low heat transfer coefficients, have prevented it from reaching its full potential. A new design incorporating open microchannels with uniform and tapered manifold (OMM) was shown to mitigate these issues successfully. Distilled, degassed water at 80 mL/min is used as the working fluid. Plain and open microchannel surfaces are used as the test sections. Heat transfer and pressure drop performance for uniform and tapered manifold with both the surfaces are discussed. A low pressure drop of 7.5 kPa is obtained with tapered manifold and microchannel chip at a heat flux of 263 W/cm2 without reaching CHF. The pressure drop data is further compared with the homogenous model and the initial results are presented.
Vehicle Sideslip Angle Estimation and Experimental Validation
Authors: Ryu Jihan , Nardi Flavio , Moshchuk Nikolai
Published: April 2014

This paper presents a comparison study of three different methods for the estimation of vehicle’s lateral velocity: one based on algebraic relationships, a second based on a dynamic observer, and lastly one based on kinematic equations. All methods are based on the implementation of an experimental nonlinear model that relates the front and rear axles’ lateral forces to their respective side slip angles. These nonlinear models include the effects of different surface coefficients of friction, and all three methods include a real time estimation of the surface coefficient of friction based on standard production sensors. Real time estimation performance of the proposed observers is compared and evaluated based on experimental implementation on a series production vehicle. Vehicle dynamic tests include highly dynamic maneuvers such as slaloms, single and double lane changes, fishhooks on test surfaces such as ice, snow, gravel, and wet/dry asphalt.