bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced Electro-Osmotic Flow Pump for Micro-Scale Heat Exchangers
Authors: Al-Rjoub Marwan F. , Roy Ajit K. , Ganguli Sabyasachi , Banerjee Rupak K.
Published: July 2013

Non-uniform heat flux generated by microchips can create “hot spots” in localized areas on the microchip surface. This research presents an improved design of an active cooling electro-osmotic flow (EOF) based micro-pump for hot spots thermal management. The design of the micro-pump was simpler and more practical for the application compared to designs presented in literature.

Most micro-channel heat sink devices presented in literature were silicon based. Though silicon has better thermal conductivity when compared to polymers used in micro-devices fabrication, processes of silicon fabrication are complicated and time consuming. Also, most micro-channel fabrication processes use silicon etching which leads to rough walls within the micro-channel. An improved design, which uses a combination of silicon and Polydimethylsiloxane (PDMS), is being developed and tested. The main idea of this design is to utilize the favorable thermal properties of silicon while achieving both smoother charged surfaces and ease of fabrication of PDMS material.

The EOF micro-pump was tested for four cooling fluid namely, DI water, distilled water, borax buffer, and Al2O3 nano-particles suspended in water solution. A maximum flow rate of 31.2 μL/min was achieved using distilled water at 500 V of EOF voltage. Such micro-pump with this flow rate range can be implemented in a closed loop heat rejection system for hot spot thermal management. Moreover, it can be used in Lap-on-chip and uTAS application for sample transport.
Tunable Negative Refractive Index Metamaterials Based on Thermochromic Oxides
Authors: Xuan Yimin , Huang Jinguo , Li Qiang
Published: July 2013

A tunable metamaterial is proposed by combining a thermochromic oxide with a fishnet structure. The reflection and transmission coefficients are calculated by finite-difference time-domain (FDTD) method. Then the effective electromagnetic parameters of the metamaterial are retrieved on the basis of these data. The results reveal that an effective negative refractive index is obtained by this proposed structure. Furthermore, the wavelength region with negative refractive index can be self-regulated by simply tuning the temperature, which is of importance to extend the applications of negative refractive index materials. The effects of structural sizes on the negative refractive index are discussed in detail. The size-dependence indicates that wavelength region with negative refractive index can be designed to locate at the desired position by dexterously tailoring the structural parameters.
Numerical Study of Nanofluid Transport in Tumors During Nanofluid Infusion for Magnetic Nanoparticle Hyperthermia Treatment
Authors: Su Di , Ma Ronghui , Zhu Liang
Published: July 2013

The application of nanostructures in hyperthermia treatment of cancer has attracted growing research interest due to the fact that magnetic nanoparticles are able to generate impressive levels of heat when excited by an external magnetic field [1–3]. Various types of nanoparticles such as magnetite and superparamagentic iron oxide nanoparticles have demonstrated great potentials in hyperthermia treatment; however many challenges need to be addressed for future applications of this method in clinical studies. One leading issue is the limited knowledge of nanoparticle distribution in tumors. Since the temperature elevation is induced as the result of the heat generation by the nanoparticles, the concentration distributions of the particles in a tumor play a critical role in determining the efficacy of the treatment. The lack of control of the nanoparticle distribution may lead to inadequacy in killing tumor cells and/or damage to the healthy tissue.
A Generalized Landauer Formalism of Nanoscale Thermal Radiative Transfer
Authors: Narayanaswamy Arvind
Published: July 2013

Though the dependence of near-field radiative transfer on the gap between two planar objects is well understood and that between curved objects is becoming clearer, a general theory of micro and nanoscale radiative transfer is still unavailable. Here, I describe a general framework based on Rytov’s theory of fluctuational electrodynamics that can be used to analyze radiative transfer between any two structures, independent of their length scale.
Modeling and Influence Study of Gas Bubbles on Characteristics of a Piezoelectric Valve-Less Micropump
Authors: Li Songjing , Liu Jixiao , Jiang Dan
Published: July 2013

The aim of this paper is to develop a theoretical model of a piezoelectric valve-less micropump for liquid delivery with entrapped gas bubbles and evaluate the influence of gas bubbles on the dynamic characteristics of the micropump by using this model. In the model, we consider the vibration of piezoelectric diaphragm, the pressure loss through the nozzle/diffuser and the compressibility of working liquids with entrapped gas bubbles. In order to validate the developed model and make it useful as a design and prediction tool, experimental studies are carried out to investigate the flow rate and dynamic pressure inside the pump chamber when gas bubbles are absent or present in the micropump. The presence of gas bubbles inside the pump chamber is also observed with a high-speed video camera. The outlet flow rate of the micropump with different size of trapped gas bubbles are calculated and compared.
The Effect of Nanoparticle Size on Margination and Adhesion Propensity in Artificial Micro-Capillaries
Authors: Jurney Patrick , Agarwal Rachit , Singh Vikramjit , Roy Krishnendu , Sreenivasan S. V. , Shi Li
Published: July 2013

Intravenous injection of nanoparticles as drug delivery vehicles is a common practice used in in-vivo and clinical trials of therapeutic agents to target specific cancerous or pathogenic sites. The vascular flow dynamics of nanocarriers in human capillaries play an important role in the ultimate efficacy of this drug delivery method. This article reports an experimental study of the effect of nanoparticle size on their margination and adhesion propensity in micro fabricated microfluidic channels of a half elliptical cross-section. Spherical polystyrene particles ranging in diameter from 60 to 970 nm were flown in the microchannels and individual particles adhered to either the channel’s top or bottom wall were imaged using fluorescence microscopy. The results show a significant increase in adhesion for particles with diameter below 200 nm as well as the emergence of a critical nanoparticle diameter of about 970 nm, where no nanoparticle adherence was observed on the top wall. For the same particle number concentration, the total volume of the nanoparticles adhered to the top and bottom walls was found to increase with decreasing diameter for diameters less than 200 nm. The results are explained by the competition between Brownian motion, gravity and hemodynamic forces on the nanoparticles. These findings on the flow behavior of spherical nanoparticles in artificial micro-capillaries provide further insight for the rational design of nanocarriers for targeted cancer therapeutics.
Study of the Effect of Photonic Crystals on Absorptance and Efficiency of Absorption of Two Organic Photovoltaic Cells by the Finite Element Method
Authors: Velez Maximiliano A. , Guzman Amador M.
Published: July 2013

The present numerical work describes the simulation and analysis of the absorptance and absorption efficiency of a solar cell, where the effect of utilizing photonic crystals as an active material of the cell was studied. The study was performed by numerical simulations using a computational code based on the Finite Element Method [1]. The results were obtained for photonic crystals with periodicity in both one and two dimensions [2]. In the first one, periodicity, thickness of the active material, and distance with respect to the electrode for hole collection were varied, and two organic materials for the active zone were tested, P3HT:PCBM and TDPT:PCBM. In the case of crystals with periodicity in two dimensions, only the period in one of the two dimensions was varied, based on the cell with the highest efficiency of absorption proposed for cells with periodic photonic crystals in one dimension. All simulations were obtained for waves with TM polarization, zero angle of incidence and wavelengths between 400 and 700 nm.
Study of Specific Heat Capacity Enhancement of Molten Salt Nanomaterials for Solar Thermal Energy Storage (TES)
Authors: Yang Hongjoo , Banerjee Debjyoti
Published: July 2013

The overall thermal efficiency of solar power plants is highly sensitive to the operating characteristics of the Thermal Energy Storage (TES) devices. Enhancing the operating temperature of TES is imperative for enhancing the thermal efficacy of solar power plants. However, material property limitations for high temperature operation severely limit the choice of materials for TES. Molten salts and their eutectics are promising candidates for high temperature operation of TES. To enhance the thermal and operational efficiency of TES, the thermo-physical properties such as the specific heat capacity and thermal conductivity of the materials need to be maximized. The specific heat capacity (Cp) of molten salt is relatively smaller than other conventional TES materials. Recent studies have shown that addition of nanoparticles to molten salts can significantly enhance their specific heat capacity. Several transport and energy storage mechanisms have been proposed to account for these enhancements. Primarily, the layering of solvent molecules due to inter-molecular forces (due to competition between adhesive and cohesive forces) is observed at solid-liquid interface, leading to the formation of a more dense or “compressed layer” of solvent molecules on the dispersed nanoparticles. The formation and existence of the compressed layer has been demonstrated experimentally and from numerical predictions (e.g., Molecular Dynamics/ MD models). To verify the enhancement of specific heat capacity of molten salt nanofluids, the influence of compressed layer has been explored in this study. This implies that for the same amount (or concentration) of nanoparticle, the ratio of surface/volume of the individual nanoparticles can change significantly depending on the nanoparticles size and shape — which in turn can affect the mass fraction of the compressed layer formed on the surface of the nanoparticles.

In this study, the specific heat capacity of the molten salt nanomaterials was investigated for: (a) silica nanoparticles in eutectic mixture of alkali chloride salt eutectics, and (b) silica nanoparticles in an eutectic mixture of alkali carbonate salts eutectics. The effect of the particle size distribution was considered in this study and it was observed that smaller nanoparticles contribute a larger proportion to the observed specific heat capacity enhancements. The size of distribution of the nanoparticles in the molten salt mixture/ nanomaterial (nanocomposites and nanofluids) was measured by using Scanning Electron Microscopy (SEM), and subsequently the actual number of nanoparticles (as a function of size) that were dispersed in molten salt fluid was calculated. The specific heat capacity of molten salt nanomaterial was calculated using a classical mixing model and by accounting for the contribution from the compressed layer in the mixture.
Real-Time Error Prediction for High-Precision Operation of Parallel Kinematic Machines
Authors: Bi Z. M. , Wang Guoping
Published: July 2013

Closed-loop parallel kinematic machines (PKMs) have been proposed to improve precision and operation speed over conventional machine tools and robots. However, an embarrassing dilemma is that most of the existing PKMs achieve very lower precision in contrast to equivalent serial machine tools or robots, which are competitive to same tasks. Limited works have been conducted to evaluate errors thus improve precision of machine in real-time control. It becomes necessary to explore the relation of the motion error with the dynamics of a PKM. In this paper, the new model of the error evaluation has been proposed; three major sources of error under consideration are the deformations of the components under dynamic loads, the deformations at joint contacts, and the clearances of passive joints. To illustrate the modeling procedure, the dynamic model of machine is developed to determine internal forces among components and locations of joint contacts. Errors caused by machine dynamics are evaluated analytically in real time; in particular, the errors happened at the contacts of passive joints are estimated based on Hertz theory. The developed error models can be applied to compensate the motion errors of tool tip in real-time. The Exechon parallel kinematic machine is used as a case study, the results from simulation has been compared with the test data.
Ultrasonic-Vibration Assisted Pelleting for Cellulosic Biofuel Manufacturing: Investigation on Power Consumption With Design of Experiment
Authors: Zhang Qi , Zhang Pengfei , Pei Z. J. , Pritchett Graham , Zhang Meng , Song Xiaoxu , Deines T. W.
Published: July 2013

Cellulosic biomass is abundantly available in the nature. It is an attractive feedstock to make alternative fuels to petroleum-based transportation fuels. Because of low bulk density and irregular shape, raw biomass materials are difficult to handle, transport, and store. Pelleting can increase the density of cellulosic biomass. Pellets can be easily handled, resulting in reducing their transportation and storage costs. Ultrasonic vibration-assisted (UV-A) pelleting is a new pelleting method. Moisture content, particle size, pelleting pressure, and ultrasonic power are four important input parameters affecting pellet quality and sugar yield (proportional to biofuel yield). However, their effects on power consumption in UV-A pelleting have not been adequately investigated. Since power consumption directly affects ethanol manufacturing costs, it is desirable to understand how input parameters affect power consumption. This paper reports an experimental investigation of power consumption in UV-A pelleting. A 24 factorial design is employed to evaluate the effects of four input parameters (moisture content, particle size, pelleting pressure, and ultrasonic power) on power consumption in UV-A pelleting. Results show that three input parameters (moisture content, particle size, and ultrasonic power) significantly affect power consumption. Higher moisture content, lower ultrasonic power, and larger particle size result in higher power consumption. Only one interaction of two parameters is significant, i.e. with the increase of pelleting pressure, power consumption will increase at the high level of particle size while decrease at the low level of particle size.
Hook Shaped Residual Stress: The Effect of Tool Ploughing, and the Analysis of the Mechanical and Thermal Effects
Authors: Zhang Xueping , Wu Shenfeng , Liu C. Richard
Published: July 2013

To investigate the unique hook-shaped residual stress profile generated from hard turning process, an improved orthogonal (2-D) Finite Element (FE) model is established to include the ploughing effect of cutting edge. The model is further decomposed into two FE sub-models (sub-model 1 and sub-model 2) to determine the thermal and mechanical effects on the residual stress profiles by saw-tooth chip formation process and honed-edge ploughing process respectively. The two FE sub-models are sequentially adopted to evaluate the compression effect induced by chip formation process and ploughing effect resulted from honed-edge cutting tool on residual stress profile. Their separated and integrated effects on residual stress hook-shape profile are addressed by comparing the predicted residual stresses by sub-model 1, sub-model 2, the two sub-models’ superposition, and the whole improved FE model. The results show that chip formation effect on residual stress profile happens earlier than the ploughing effect. Chip formation effect provides a foundation for the finalized residual stress profile by determining the maximum depth and magnitude of the compressive residual stress. Ploughing process generates much more thermal load to produce the tensile residual stress in hard turned surface and sequentially drives the final resultant residual stress into an obvious hook-shaped by modifying the previous compressive residual stress profile. The location with the maximum compressive residual stress is identified as the critical position to separate the mechanical load and thermal load generated from ploughing effect. The decomposition methodology on mechanical and thermal effects is proposed and thoroughly discussed in the paper.
Tribological Conditioning of Cylinder Running Surfaces
Authors: Karpuschewski B. , Welzel F.
Published: July 2013

In the wake of increasing performance requirements for internal combustion engines, regarding downsizing, and rising mobility, efficient manufacturing processes are gaining significance in Far Eastern markets. Also in consideration of increasing emission limits for these combustion engines, investigations regarding alternative technologies for the efficient manufacturing of performance-optimized cylinder running surfaces were carried out by the Institute of Manufacturing Technology and Quality Management. The microstructure of these surfaces and the subsequent surface integrity are in the focus of considerations. Using tribological analysis of the mechanical running-in behavior of cylinder running surfaces, conclusions will be drawn on the impact of the last honing step of the engine production. These investigations are carried out in terms of a possible conditioning of tribotechnical systems in their production and the concomitant reduction of friction and wear-intensive running-in processes. In this regard alternative finishing operations like burnishing are investigated.
Initial Investigation Into Helical Milling of Laminated Stacks of Electrical Steel
Authors: Liles Howard , Mayor J. Rhett
Published: July 2013

This paper serves to report the findings of an initial study on the holing of laminated stacks of electrical steels. Three different holing methods were considered: plunge milling, helical milling (orbit milling), and drilling. Stack delamination, axial thrust force, and burr formation were measured at various feed rates for each process and utilized as comparison metrics. Results from the initial experimental investigation indicate that drilling produces significant burr and plunge milling, whilst reducing burr formation compared to drilling, led to delamination of the stack. Helical milling minimized thrust forces, avoided delamination and minimized burr formation. An interesting spring back effect was also observed during the cutting of the laminated stacks. It is concluded that helical milling is a viable and effective processing method for making holes in laminated stack of hard electrical steels.
Contour Detection for Robotic Chamfering Based on Optical Measurement Technologies: Fringe Projection vs. Profile Sensor
Authors: Karpuschewski Bernhard , Münder Richard
Published: July 2013

In the present paper, two competing methods for contactless detection of component geometries are compared. In principle, it is important to examine the extent to which automation can succeed by mechanical machining processes by using advanced sensors. As an example of a process here the chamfering of large gearings with an industrial robot is chosen. It will examine to what extent there is a possibility to ensure through selected sensor applications and configurations, a geometry detection. Here ostensibly application-related parameters are presented and referred. This should also be done in regard to their use in industrial environments where metallic gloss and external light sources often present a problem. Finally, it should be a statement made as to whether the methods discussed are suitable for this application due to their technological parameters.
Titanium Oxide Nanotubes Doped for Use in a Visible-Light Biophotofuel Cell
Authors: Clark Evan , Gan Yong X. , Xue Chao
Published: July 2013

Multiple metal and non-metal dopants were added to titanium oxide nanotubes to enhance the photosensitive behavior. Six elements including nitrogen, sulfur, zinc, copper, cobalt, and nickel were incorporated into titanium oxide as the dopants. The doped titanium oxide nanotubes were made into photosensitive anodes and placed in ethanol to form fuel cells. The open circuit voltage measurement results showed that after doping, all the specimens tested were allowed the absorption of visible light. However, the resulted in voltages were slightly less than of those obtained through ultraviolet light absorption tests. Among the transition metal doping elements and the non-metal elements, cobalt, nickel and zinc showed the most promise in improving the visible light absorption.
Nano Finishing of Brass Tubes by Using Mechanically Alloyed Magnetic Abrasives
Authors: Sran Lakhvir Singh , Khangura Sehijpal Singh , Singh Amarjit
Published: July 2013

With advancement of technology, finely finished surface is one of the major requirements of modern industry. Fine machining with conventional edged tools is uneconomical and sometimes impossible. Magnetic Abrasive Finishing (MAF) is one promising process which is able to remove the material at micro/nano from metallic and non metallic surfaces. The magnetic abrasives play vital role in MAF. Literature reveals different techniques such as sintering, plasma, chemical, etc. for manufacturing of bonded magnetic abrasives. In the present paper, the bonded magnetic abrasives prepared by a new technique called mechanical alloying have been successfully used for the internal finishing of the brass tubes. After rough boring operation, the inner surface of the tubes is finely finished by newly developed magnetic abrasives. Best surface finish obtained by using these magnetic abrasives is of the order of 9 nm.
Application of Multiple Regression and Adaptive Neuro-Fuzzy Inference System for Prediction of Surface Roughness in EDM
Authors: Baraskar S. S. , Banwait S. S.
Published: July 2013

A manufacturing system is oriented towards higher production rate, better quality and reduced cost and time to make a product. Surface roughness is an index parameter for determining the quality of a machined product and is influenced by various input process parameters. Surface roughness prediction in Electrical Discharge Machine (EDM) is being attempted with many methodologies, yet there is a need to develop robust, autonomous and accurate predictive system. This work proposes the application of hybrid intelligent technique, multiple regression and adaptive neuro-fuzzy inference system (ANFIS) for prediction of surface roughness in EDM. An experimental data set is obtained with current, pulse-on time and pulse-off time as input parameters and surface roughness as output parameter. Central composite rotatable design was used to plan the experiments. Multiple regression model is developed using the experimental data, to generate additional input-output data set. The input-output data set is used for training and validation of the proposed technique. After validation, data are forwarded for prediction of surface roughness. The proposed hybrid model for the prediction of surface roughness has very good agreement with the experimental results.
A Reliability-Based Approach to Flatness Actuator Effectiveness in 20-High Rolling Mills
Authors: Malik Arif , Wendel John , Zipf Mark , Nelson Andrew
Published: July 2013

20-High rolling mills process high strength and/or very thin non-ferrous and ferrous metals using a complex, cluster arrangement of rolls. The 20-high roll cluster arrangement achieves specific flatness goals in the thin sheet by delivering maximum rolling pressure while minimizing the deflections of the small diameter rolls. 20-high mills also employ flatness control mechanisms with sophisticated actuators, such as those to shift intermediate rolls and deflect backup bearing shafts. The purpose of this is to compensate for variations in strip dimensional and mechanical properties which can cause poor flatness control quality from discrepancies in work-roll gap profile and distribution of rolling force. This suggests that the random property differences in the rolling parameters that substantially affect the flatness must be directly accounted for in flatness control algorithms in order to achieve strict flatness quality. The use of accurate mathematical models that account for the rolling pass target gage reduction can optimize the flatness control actuators and help gain an advantage in the thin gauge strip competitive global market. Based on the expected process parameter variations and nominal mill set-points (speed, tension, gage reduction, etc.), the mill’s process control computer should determine the probability that target flatness control quality will be met for a required length of strip. The process computer should then either modify the number of rolling passes or adjust the thickness reduction schedule before rolling begins to secure an improved flatness probability estimate if the probability of achieving target strip flatness is too low for the required deliverable quality. Therefore, this research integrates 1) 20-high roll-stack mill mathematical modeling, 2) probability distribution data for random important rolling parameters, 3) reliability-based models to predict the probability of achieving desired strip flatness, and 4) optimization examples. The results can be used to reduce wasted rolled metal from poor flatness before rolling.
In Vitro Dental Cutting of Feldspar and Leucite Glass Ceramics Using an Electric Handpiece
Authors: Song Xiao-Fei , Peng Jianhui , Yin Ling , Lin Bin
Published: July 2013

Glass ceramics are important restorative materials in dentistry. They are used as veneer-core bilayer all-ceramic or metal-fused ceramic restorations or monolithic inlays/onlays/crowns to replace missing or damaged tooth structures for aesthetic and functional purposes. However, glass ceramic materials, such as feldspar and leucite glass ceramics, which are subject to this investigation, are brittle and easily induced microfractures in abrasive cutting using dental handpieces and coarse burs. In this paper, we investigated the dental abrasive cutting characteristics of feldspar and leucite glass ceramics using a high-speed electric handpiece and coarse diamond burs. Cutting forces, specific removal energy, surface roughness and morphology were investigated as functions of specific material removal rate and maximum undeformed chip thickness. The results indicate that increasing the specific material removal rate or the maximum undeformed chip thickness resulted in increases in both tangential and normal forces, but a decrease in specific removal energy for both ceramics. Tangential, normal forces and specific removal energy were significantly larger in up cutting than those in down cutting. Surface roughness for the two ceramics was not affected by the specific removal rate or the maximum undeformed chip thickness. Both microfrature and ductile microcutting morphology were observed in the machined surfaces for both ceramics. There existed a brittle to ductile transition trend when decreasing the specific material removal rate or the maximum undeformed chip thickness for the two ceramics. In comparison with feldspar glass ceramic, leucite glass ceramic generated better surfaces due to its more ductile deformation occurring in dental cutting.
Process Stability and Energy Efficiency of the Grinding Process of High Performance Materials
Authors: Uhlmann E. , Sammler F. , Heitmueller F. , Hochschild L. , Sammler C.
Published: July 2013

The application of high performance materials can lead to enhanced product properties. The associated challenging material properties set higher demands on the manufacturing processes. However, the ever-present demand for cost reduction of the manufacturing processes conflicts with the continuously increasing demands on product quality.

In principle, higher surface quality results in higher energy consumption. Higher geometrical demands in combination with difficult to cut materials lead to increasingly complex machine tool and subsystem solutions, which also contribute to the higher energy consumption. However, the full potential of a process is often not utilized in order to ensure that damages to the workpiece at the end of cost intensive and long value chains are avoided. This leads to the situation that complex machine tools equipped with high performance tools operate under significantly reduced productivity. This means that the production process itself must be reliable in particular during high performance machining.

In this paper, various grinding strategies were regarded in terms of possible increase in productivity and process stability. Furthermore a nonconventional option of flexible machining is presented. It will be shown that the process of speed stroke grinding of ceramic materials can be used as a highly productive alternative to reciprocating grinding and external cylindrical grinding with grooved cBN-grinding-wheels for example in the grinding of rolling bearing rings. The machining of high performance materials with simple machine concepts, such as robots, is presented with regards to more flexibility and at the same time machine accuracies comparable to these machine tools.
Experimental Characterization of Vibration-Assisted Reverse Micro Electrical Discharge Machining (EDM) for Surface Texturing
Authors: Mastud Sachin , Garg Mayank , Singh Ramesh , Samuel Johnson , Joshi Suhas
Published: July 2013

There are several examples in nature where the biological surfaces exhibit unique functional response, such as velcro, fish scale and lotus leaves. The texture on lotus leaf exhibits super-hydrophobicity and self cleaning properties. Lotus leaf has hemispherical protrusions of 20–30 μm in diameters which are randomly distributed over the surface. This work is focused on creating similar textured surfaces on Ti6Al4V rods via a vibration assisted reverse micro Electrical Discharge Machining (R-MEDM) process. Textured surfaces containing micropillars of 40–50 μm in diameter spaced at 35 μm have been created during the process. These textured surfaces are expected to exhibit hydrophobicity and hemocompatibility. To experimentally characterize the process, a full factorial design of experiments has been conducted to analyze the effects of voltage, capacitance, amplitude and frequency of the anode (plate electrode) vibrations on the erosion rate and process stability. The process stability is expressed in terms of the percentages of the normal, open circuit and the short circuit durations in the voltage-current (VI) signature obtained during the process. It has been observed that the normal discharge durations increase with an increase in the amplitude and the frequency of the vibrations. Fabricated texture exhibits hydrophobicity and the measured contact angles in a sessile drop test with water varied between 110 and 115°. Also, the textured surface was subjected to hemotoxicity tests which yielded positive results. Based on these results, it can be seen that the machined textured surface are hydrophobic and biocompatible in nature which could potentially find applications in cardiovascular biomedical implants. In addition, this process has been used to create hierarchical structures comprising of primary and a secondary structure over it to mimic the hierarchical structures found on lotus leaves.
Microfracturing Ceramic Abrasive in Grinding
Authors: Badger Jeffrey A.
Published: July 2013

Microfracturing “ceramic” abrasives have been in common use for 20 years. However, their success has been limited because of a lack of understanding of how they function and in choosing grinding parameters that take advantage of their self-sharpening ability. A study was made into how these abrasives function and into which grinding parameters should be used to achieve optimum results.
Real Time Dispatching Control of Multi-Dollies Material Handling Systems in General Assembly Lines
Authors: Pan Chaoye , Chang Qing , Ni Jun
Published: July 2013

Material handling process on assembly lines is important because poor planning and control policies lead to low utilization of workforce and resources, which will cause more inadequate part delivery (part starvation) and reduce the overall system performance. Therefore, the delivery system must be optimized such that minimum number of workforce can be achieved without sacrificing production rate. In real assembly process, for better safety and higher efficiency, dolly trains are widely used to replace traditional forklifts for part delivery, which allows drivers to deliver more than one parts per trip and raises problems: how to choose proper number of parts and the delivery order at the beginning of each trip to achieve optimal dispatching control. Effective algorithms and strategies are addressed and compared in this study to provide practical guidelines for dolly material handling system.
Fabrication of Textured 3D Microstructures Using ‘Bulk Lithography’
Authors: Gandhi Prasanna , Bhole Kiran , Chaudhari Naresh
Published: July 2013

This paper presents the method of fabrication of textured three dimensional (3D) microstructures in single scan of laser beam. The textured 3D microstructures are obtained on one of the free surface (surface opposite to the substrate) of the microstructure. Fabrication of textured 3D microstructure is achieved using newly developed 3D microfabrication process termed as ‘Bulk lithography’. In this process the required depth variation is obtained during fabrication by allowing unconstrained depth photopolymerization and varying laser exposure while scanning. Hence, representative experimental results of dimensionless cured depth against dimensionless energy were obtained. Three different regimes of cured depth namely absorption, transition and scattering were observed under wide energy exposure. A predefined texture can be incorporated in CAD model itself and the structures can be fabricated when restricted to absorption dominant regime. However, the novelty of the proposed method lies in a distinct phenomenon observed in transition and scattering regime based on characteristic multiple scattering leading to textured surfaces in these regimes.. Further, it is observed experimentally that these textures are function of the exposure energy and are hypothyzed because of scattering of light.
Finite Element Modeling of Pad Deformation due to Diamond Disc Conditioning in Chemical Mechanical Polishing (CMP)
Authors: Baisie Emmanuel A. , Li Z. C. , Zhang X. H.
Published: July 2013

Chemical mechanical planarization (CMP) is widely used to planarize and smooth the surface of semiconductor wafers. In CMP, diamond disc conditioning is traditionally employed to restore pad planarity and surface asperity. Pad deformation which occurs during conditioning affects the material removal mechanism of CMP since pad shape, stress and strain are related to cut rate during conditioning, pad wear rate and wafer material removal rate (MRR) during polishing. Available reports concerning the effect of diamond disc conditioning on pad deformation are based on simplified models of the pad and do not consider its microstructure. In this study, a two-dimensional (2-D) finite element analysis (FEA) model is proposed to analyze the interaction between the diamond disc conditioner and the polishing pad. To enhance modeling fidelity, image processing is utilized to characterize the morphological and mechanical properties of the pad. An FEA model of the characterized pad is developed and utilized to study the effects of process parameters (conditioning pressure and pad stiffness) on pad deformation. The study reveals that understanding the morphological and mechanical properties of CMP pads is important to the design of high performance pads.
Effect of Warm Laser Shock Peening on the Tensile Strength and Ductility of Aluminum Alloys
Authors: Ye Chang , Lin Dong , Liao Yiliang , Cheng Gary J.
Published: July 2013

In this study, aluminum alloy 7075 (AA 7075) is processed by WLSP and compared with LSP at room temperature (RT-LSP). The microstructure of AA 7075 after processing is characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Tensile test and hardness test were carried out to investigate the effect of WLSP to material strength and ductility. It has been found that highly dense nanoscale precipitate particles are generated after WLSP. These nanoscale precipitate particles effectively block dislocations and thus increase the material strength.
Classifier Fusion for Acoustic Emission Based Tool Wear Monitoring
Authors: Yum Juil , Kim Tae Hyung , Kannatey-Asibu Elijah
Published: July 2013

It is often difficult for a single classifier to achieve perfect classification during process monitoring. Sensor fusion enables the final decision to be improved, but uses voting methods, which usually do not perform well when there is a tie vote. In this paper, classifier fusion with class-weighted voting is investigated to further enhance the performance of monitoring systems. The overall performances of individual classifiers are used as the weighting factors to classifier fusion based on majority voting. When applied to tool wear monitoring of the coroning process, the classifier that was based on overall performance weighting improved the classification rate to 95.6% and the one based on state performance weighting showed 98.5% classification, compared to 87.7% for classifier fusion with unity weighting. A classifier fusion further increased performance from 98.5% to 99.7% by applying a penalty vote on the weighting factor.
Dynamic Strategies for Preventive Maintenance Scheduling With Throughput Target Variation
Authors: Jin Xiaoning , Ni Jun
Published: July 2013

This paper considers a period-review production and preventive maintenance (PM) scheduling problem for manufacturing systems subject to uncertain demand in a finite-horizon. We consider multiple levels of PM which provide the system with flexibility of choosing various types of PM to be adaptive to the throughput target. A model with PM flexibility is proposed to simultaneously determine optimal production quantity and PM level for a single-product manufacturing system. A real option analysis (ROA) is applied to quantify the benefit of PM flexibility so that it can be considered in a cost function. The optimal strategy for a joint maintenance and production system that maximizes the overall expected profit of the system is obtained by a stochastic dynamic programming approach. Results are supported by numerical examples and show the comparison between the proposed PM-flexible model and the conventional PM planning model with single and fixed PM type. Managerial insights are provided on making adaptive PM and production decisions by trading off revenue and costs of corrective actions in different manufacturing applications.
Micro and Nano Design and Fabrication of a Novel Artificial Photosynthesis Device
Authors: Ren Xiang , Zhang Qingwei , Li Ho-lung , Zhou Jack
Published: July 2013

Artificial photosynthesis is a new method to generate sustainable energy. In order to constrain reaction solution in a solid state structure and increase the reaction efficiency, we designed a novel artificial photosynthesis device with porous chitosan scaffold with interconnected micro-channels. We built 3D interconnected chitosan channels with a home-made heterogeneous 3D rapid prototyping machine, and we used lyophilization method to generate the nano pores inside the chitosan scaffold. Chitosan gel in acetic acid can form different viscosities by different chitosan’s molecular weight and the different concentrations of both chitosan and the acetic acid, so we found a proper material recipe to construct 3D scaffold by our own rapid prototyping machine. Optional support material sodium bicarbonate is used in printing 3D scaffold for holding the printed structure permanently, and the result shows that this method can make the scaffold stronger and harmless to further processes such as adding light reaction units and dark reaction solution into the device.
Twist in Single Point Incremental Forming
Authors: Asghar Javed , Shibin E. , Bhattacharya A. , Reddy N. V.
Published: July 2013

Twist in incremental forming is observed in all configurations including single point incremental forming. In addition to tangential force, other parameters like stiffness seems to play a significant role in the twist phenomenon. Present work makes an attempt to experimentally study the twist in SPIF of conical components and compare the same with numerical predictions. Experimental and numerical results are found to be in good qualitative agreement. Further work is in progress to study the twist behavior in detail.
A Process-Based Approach for Cradle-to-Gate Energy and Carbon Footprint Reduction in Product Design
Authors: Alsaffar Ahmed J. , Haapala Karl R. , Kim Kyoung-Yun , Okudan Kremer Gül E.
Published: July 2013

Interest in accounting for environmental impacts of products, processes, and systems during the design phase is increasing. Numerous studies have undertaken investigations for reducing environmental impacts across the product life cycle. Efforts have also been launched to quantify such impacts more accurately. Energy consumption and carbon footprint are among the most frequently adopted and investigated environmental performance metrics. The purpose of this paper is to serve two objectives — first, it provides a review of recent developments for carbon footprint reduction in manufacturing processes and supply chain operations. Second, a future vision is shared toward developing a method for reducing carbon footprint through simultaneous consideration of manufacturing processes and supply chain activities. The approach is demonstrated by developing analytical models for alternative manufacturing processes and supply chain networks associated in the manufacture of a bicycle pedal plate to realize its potential in assessing energy and GHG (greenhouse gas) emissions. The sustainable design and manufacturing research community should benefit from the review presented. In addition, a point of departure for concurrent consideration of multiple stages of the product life cycle for environmental performance is established for the research community to move current efforts forward in pursuit of environmental, economic, and social sustainability.
Micropatterning of Porous Polymer Structures
Authors: Zhang Wei , Li Min , Wang Chaosheng , Zhou Jack G. , Yao Donggang
Published: July 2013

In contrast to the immense literature in porous material generation, micropatterning of porous devices remains a technical challenge. In this study, a new process for micropatterning of porous structures with a controllable morphology was developed and investigated. This process combines polymer melt blending, hot embossing, and in mold annealing for geometrical pattern transfer and simultaneous morphological control. A special effort was made to generate a microgroove pattern with an open pore structure. Parametric experimental studies were conducted on stamps with different feature sizes under different processing conditions. The results demonstrated the feasibility and the versatility of the proposed technique in fabricating micropatterned porous structures. By varying the geometrical and boundary conditions during in mold annealing, micropatterns with graded porous structures were demonstrated.
Milling Tool of Micro-EDM by Ultrasonic Assisted Multi-Axial Wire Electrical Discharge Grinding Processes
Authors: Hsue Albert Wen-Jeng , Wang Jun-Jie , Chang Chia-Hung
Published: July 2013

Conventional micro EDM milling relies on time-consuming WEDG to achieve acceptable quality of micro tools. In this study, a rotational axis augmented to Wire Electrical Discharge Grinding (WEDG) processes with ultrasonic assistance and its application to EDM micro-milling is reported. On its removing mechanism, a quantitative analysis based upon wire-EDM discharge-angle was proposed to clarify fundamental understanding of such a novel multi-axial machining process. Then, a test on EDM micro-milling with 70 microns of diameter tool is conducted. Its significant effects on improving dressing efficiency and surface integrity of micro tools were verified, and the effectiveness for EDM micro-milling with a screw type of tool was also verified experimentally. Because of its geometric properties, the screw surface contributed to deliver debris from machining region to outsider. Therefore, a better EDM micro-milling configuration may be introduced into the micro-EDM manufacturing field.
American Society of Mechanical Engineers Performance Test Code 34 – ASME PTC 34, Waste Combustors With Energy Recovery: What Is PTC 34 and How Can It Help You?
Authors: Deduck Stephen G. , Xiao Lambert
Published: July 2013

ASME PTC 34 is a test procedure for determining the thermal capacity and thermal efficiency of systems (typically boilers) combusting waste fuels (typically Municipal Solid Waste - MSW) and for determining the higher heating value (HHV) of those waste fuels. The basis of the procedure is more commonly known as the “boiler-as-a-calorimeter” method. The need for PTC 34 arose from the difficulties in obtaining representative samples and accurate fuel analyses using traditional laboratory methods such as a “bomb calorimeter”. Unsuccessful attempts were made to come up with a larger “bomb calorimeter”, so a committee was formed to create PTC 34 which was published in 2007.

ASME PTC 34 is firmly based on the widely accepted boiler test code, ASME PTC 4 – “Fired Steam Generators”, but has several different challenges in having to measure the relatively difficult parameters of flue gas flow and moisture and fuel and ash quantities. As a result, the uncertainty of PTC 34 is higher. However, the philosophy of correcting results to standard, contract or reference fuel analysis is the same in PTC 4 and PTC 34. So, an industry approved Code for acceptance testing is available to the Energy-from-Waste industry.

ASME PTC 34 can be used in several ways depending on the analysis time period. It can be used for typical short-term, i.e. 8-hour, performance or acceptance tests, again with the ability to correct to reference fuel analyses. Alternatively, multiple “samples” of fuel HHV can be obtained using PTC 34. With the test data and HHV results, accurate correlations can then be generated to be able to make adjustments for varying fuel conditions in longer term, i.e. 7-day, throughput capacity testing. The 8-hour HHV determinations can also be used to validate or even calibrate correlations used over the life of a waste combustor as operating parameters stray from their normal ranges. Taken to the extreme, PTC 34 can be used as a basis for near-real-time monitoring of fuel quality or possibly combustion control. Recent developments of laser-based flue gas moisture instruments and the economizer heat balance method for determining flue gas flow make this leap possible.

The goals of this paper are to make the industry more aware of ASME PTC 34 and the guidance it contains on making the difficult measurements, to promote its use as a standard in the industry and to instill confidence in the time-tested and accepted process of making corrections to test results for off-design fuel characteristics.