TY - CONF TI - Advanced Energy Packaging Techniques AU - Hopkins, Douglas C. T2 - 23rd Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC) C2 - 2008/2/24/ C3 - 23rd Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC) CY - Austin, TX DA - 2008/2/24/ PY - 2008/2/24/ ER - TY - CONF TI - Advanced Power Packaging for Higher Temperatures and Harsh Environments AU - Hopkins, Douglas C. T2 - 41st International Symposium on Microelectronics C2 - 2008/11/2/ C3 - 41st International Symposium on Microelectronics CY - Rhode Island Convention Center, Providence, R.I. DA - 2008/11/2/ PY - 2008/11/2/ ER - TY - CONF TI - Timberland ownership shifts and forest management intensity in Southern U.S AU - Gonzalez, R. AU - Dasmohapatra, S. AU - Saloni, D. AU - Cubbage, F. T2 - Southern Forest Resource Assessment Consortium (SOFAC) C2 - 2008/// DA - 2008/// PY - 2008/// ER - TY - CONF TI - South America: Industrial roundwood supply potential AU - Gonzalez, R. AU - Dasmohapatra, S. AU - Saloni, D. AU - Cubbage, F. T2 - Forest Product Society, 62nd International Convention C2 - 2008/// CY - St. Louis, Missouri DA - 2008/// PY - 2008/// ER - TY - CONF TI - Implementation of lean manufacturing in the secondary wood industry AU - Saloni, D. AU - Pirraglia, A. T2 - Operational Excellence Conference, Institute of Industrial Engineers C2 - 2008/// CY - Minneapolis, MN DA - 2008/// PY - 2008/// ER - TY - CONF TI - Designing and testing of a quantitative methodology capable of forecast the behavior of experimental data sanding and cleaning of the sanding belts for abrasive machining AU - Pirraglia, A. AU - Saloni, D. AU - Lemaster, R. AU - Gasparin, H. T2 - Forest Product Society, 62nd International Convention C2 - 2008/// CY - St. Louis, Missouri DA - 2008/// PY - 2008/// ER - TY - CONF TI - Designing and implementing a quantitative methodology able to forecast the behavior of experimental data for abrasive machining AU - Pirraglia, A. AU - Saloni, D. AU - Lemaster, R. AU - Gasparin, H. T2 - SHPE Conference C2 - 2008/// DA - 2008/// PY - 2008/// ER - TY - MGZN TI - The market of pulp and paper in Venezuela AU - Gonzalez, R. AU - Dasmohapatra, S. AU - Carrero, O. AU - Saloni, D. T2 - TAPPI Paper 360 magazine DA - 2008/// PY - 2008/// ER - TY - CONF TI - An Integrated Production Planning Model with Load-Dependent Lead Times and Safety Stocks AU - Orcun, S. AU - Kempf, K.G. AU - Uzsoy, R. T2 - Foundations of Computer-Aided Process Operations C2 - 2008/6// CY - Cambridge, MA DA - 2008/6// PY - 2008/6// ER - TY - CONF TI - Using a Mathematical Programming Model to Examine the Marginal Prices of Capacitated Resources AU - Kefeli, A. AU - Uzsoy, R. AU - Fathi, Y. AU - Kay, M. T2 - 13th International Working Seminar on Production Economics C2 - 2008/3/3/ CY - Innsbruck, Austria DA - 2008/3/3/ PY - 2008/3/3/ ER - TY - SOUND TI - New Directions in Production Planning: A Tutorial AU - Uzsoy, R. DA - 2008/10// PY - 2008/10// ER - TY - CONF TI - Combining System Dynamics and Factory Physics to Study the Effects of Continuous Improvement on the Operating Curve AU - Godinho Filho, M. AU - Uzsoy, R. T2 - Industrial Engineering Research Conference C2 - 2008/5// CY - Vancouver, BC DA - 2008/5// ER - TY - CONF TI - Stress Management in a High Temperature Multilayered Composite Structure AU - Hopkins, D.C. AU - Kellerman, D.W. T2 - High Temperature Electronics Conference (HiTEC 2008) C2 - 2008/// CY - Albuquerque, New Mexico DA - 2008/// PY - 2008/5/12/ ER - TY - CONF TI - Low Temperature Electromigration and Thermomigration in Lead-Free Solder Joints AU - Abdulhamid, M. AU - Hopkins, D.C. AU - Basaran, C. T2 - International Electronics Packaging Symposium C2 - 2008/// CY - Niskayuna, NY DA - 2008/// PY - 2008/7/29/ ER - TY - JOUR TI - A resource-oriented tolerance representation scheme for the planning of robotic machine tending operations in automated manufacturing systems AU - Steele, Jay W. AU - Wysk, Richard A. AU - Ferreira, Joao C. E. T2 - The International Journal of Advanced Manufacturing Technology DA - 2008/9// PY - 2008/9// DO - 10.1007/S00170-007-1118-5 VL - 38 IS - 7-8 SP - 741–756 SN - 0268-3768 1433-3015 UR - http://dx.doi.org/10.1007/S00170-007-1118-5 KW - robotic machine tending KW - process planning KW - tolerances KW - resource model KW - automated manufacturing systems KW - fixtures ER - TY - CHAP TI - Supply chain management AU - Warsing, D.P. T2 - Operations Research Applications PY - 2008/// SP - 8-1-8-64 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85056984750&partnerID=MN8TOARS ER - TY - JOUR TI - High barrier sustainable co-polymerized coatings AU - Pal, Lokendra AU - Joyce, Margaret K. AU - Fleming, Paul D. AU - Cretté, Stéphanie A. AU - Ruffner, Charles T2 - Journal of Coatings Technology and Research DA - 2008/6/12/ PY - 2008/6/12/ DO - 10.1007/S11998-008-9101-0 VL - 5 IS - 4 SP - 479-489 J2 - J Coat Technol Res LA - en OP - SN - 1547-0091 1935-3804 UR - http://dx.doi.org/10.1007/S11998-008-9101-0 DB - Crossref KW - Barrier coatings KW - Co-polymerization KW - Shape engineered pigments KW - High shape factor engineered clays KW - SBS paperboard KW - Water vapor and gas transmission KW - WVTR KW - Permeability ER - TY - JOUR TI - Inside Cover: Light-Powered Electrical Switch Based on Cargo-Lifting Azobenzene Monolayers (Angew. Chem. Int. Ed. 18/2008) AU - Ferri, Violetta AU - Elbing, Mark AU - Pace, Giuseppina AU - Dickey, Michael D. AU - Zharnikov, Michael AU - Samorì, Paolo AU - Mayor, Marcel AU - Rampi, Maria Anita T2 - Angewandte Chemie International Edition AB - A molecular cargo lifter based on tightly packed monolayers (SAMs) of rigid azobenzene rods is described by M. A. Rampi et al. in their Communication on page 3407 ff. The monolayer, sandwiched between Hg and Au electrodes, is irradiated in situ through a transparent gold surface. The current flowing through the electrodes increases and decreases reversibly under alternating irradiation at 370 and 450 nm. The azobenzene SAM exerts a mechanical force and lifts the Hg drop electrode, and thus the system operates as a photoswitch. DA - 2008/4/21/ PY - 2008/4/21/ DO - 10.1002/anie.200890080 VL - 47 IS - 18 SP - 3290-3290 J2 - Angew. Chem. Int. Ed. LA - en OP - SN - 1433-7851 1521-3773 UR - http://dx.doi.org/10.1002/anie.200890080 DB - Crossref ER - TY - CONF TI - Waiting time approximation in public logistics network AU - Ling, X. AU - Kay, M.G. AU - Telford, J. C2 - 2008/// C3 - IIE Annual Conference and Expo 2008 DA - 2008/// SP - 543-548 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-63849088736&partnerID=MN8TOARS ER - TY - JOUR TI - Integrating a decomposition procedure with problem reduction for factory scheduling with disruptions: a simulation study AU - Upasani, A. AU - Uzsoy, R. T2 - International Journal of Production Research AB - Dispatching rules are widely used in industry because schedules obtained from optimization procedures can be difficult to implement in the face of executional uncertainties. Barua et al. (Barua, A., Narasimhan, R., Upasani, A. and Uzsoy, R., Implementing global factory schedules in the face of stochastic disruptions. Int. J. Prod. Res., 2005, 43(4), 793–818) implement global schedules obtained from an optimization-based heuristic using a dispatching rule, and outperform myopic dispatching rules in the face of disruptions. However, the computation of the global schedules is still time-consuming for realistic instances. Upasani et al. (Upasani, A., Uzsoy, R. and Sourirajan, K., A problem reduction approach for scheduling semiconductor wafer fabrication facilities. IEEE Trans. Semicon. Manuf., 2006, 19, 216–225) develop a problem reduction scheme based on load disparity between work centres, and report significant reduction in CPU times with minimal loss of solution quality in deterministic experiments. In this paper we integrate the problem-reduction scheme to obtain global schedules with the dispatching approach of Barua et al. (Barua, A., Narasimhan, R., Upasani, A. and Uzsoy, R., Implementing global factory schedules in the face of stochastic disruptions. Int. J. Prod. Res., 2005, 43(4), 793–818) in a multi-product environment with stochastic machine breakdowns and job arrivals. A simulation model of a scaled-down wafer fabrication facility is used to evaluate the performance of the proposed procedures. Results show that the integrated procedure outperforms the benchmark dispatching rules while significantly reducing computation times. DA - 2008/11// PY - 2008/11// DO - 10.1080/00207540601156215 VL - 46 IS - 21 SP - 5883-5905 J2 - International Journal of Production Research LA - en OP - SN - 0020-7543 1366-588X UR - http://dx.doi.org/10.1080/00207540601156215 DB - Crossref KW - decomposition heuristics KW - job-shop scheduling KW - global schedules KW - rescheduling KW - semiconductor wafer fab scheduling KW - simulation ER - TY - JOUR TI - Learning effective dispatching rules for batch processor scheduling AU - Geiger, Christopher D. AU - Uzsoy, Reha T2 - International Journal of Production Research AB - Batch processor scheduling, where machines can process multiple jobs simultaneously, is frequently harder than its unit-capacity counterpart because an effective scheduling procedure must not only decide how to group the individual jobs into batches, but also determine the sequence in which the batches are to be processed. We extend a previously developed genetic learning approach to automatically discover effective dispatching policies for several batch scheduling environments, and show that these rules yield good system performance. Computational results show the competitiveness of the learned rules with existing rules for different performance measures. The autonomous learning approach addresses a growing practical need for rapidly developing effective dispatching rules for these environments by automating the discovery of effective job dispatching procedures. DA - 2008/3/15/ PY - 2008/3/15/ DO - 10.1080/00207540600993360 VL - 46 IS - 6 SP - 1431-1454 J2 - International Journal of Production Research LA - en OP - SN - 0020-7543 1366-588X UR - http://dx.doi.org/10.1080/00207540600993360 DB - Crossref KW - dispatching rules KW - AI in manufacturing systems KW - batch scheduling KW - genetic algorithms ER - TY - JOUR TI - Heuristics for minimizing maximum lateness on a single machine with family-dependent set-up times AU - Uzsoy, Reha AU - Velásquez, Juan Diego T2 - Computers & Operations Research AB - We address the problem of scheduling a single machine subject to family-dependent set-up times in order to minimize maximum lateness. We present a number of local improvement heuristics based on the work of previous researchers, a rolling horizon heuristic, and an incomplete dynamic programming heuristic. Extensive computational experiments on randomly generated test problems compare the performance of these heuristics. The rolling horizon procedures perform particularly well but require their parameters to be set based on problem characteristics to obtain their best performance. DA - 2008/6// PY - 2008/6// DO - 10.1016/j.cor.2006.10.003 VL - 35 IS - 6 SP - 2018-2033 J2 - Computers & Operations Research LA - en OP - SN - 0305-0548 UR - http://dx.doi.org/10.1016/j.cor.2006.10.003 DB - Crossref KW - scheduling KW - single machine KW - setup times KW - heuristics KW - dynamic programming ER - TY - JOUR TI - Triz and axiomatic design: A review of case-studies and a proposed synergistic use AU - Shirwaiker, R.A. AU - Okudan, G.E. T2 - Journal of Intelligent Manufacturing DA - 2008/// PY - 2008/// DO - 10.1007/s10845-007-0044-6 VL - 19 IS - 1 SP - 33-47 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-39449128294&partnerID=MN8TOARS KW - TRIZ KW - Axiomatic Design ER - TY - JOUR TI - A Technique to Transfer Metallic Nanoscale Patterns to Small and Non-Planar Surfaces AU - Smythe, Elizabeth J. AU - Dickey, Michael D. AU - Whitesides, George M. AU - Capasso, Federico T2 - ACS Nano AB - Conventional lithographic methods (e.g., electron-beam lithography, photolithography) are capable of producing high-resolution structures over large areas but are generally limited to large (>1 cm(2)) planar substrates. Incorporation of these features on unconventional substrates (i.e., small (<1 mm(2)) and/or non-planar substrates) would open possibilities for many applications, including remote fiber-based sensing, nanoscale optical lithography, three-dimensional fabrication, and integration of compact optical elements on fiber and semiconductor lasers. Here we introduce a simple method in which a thin thiol-ene film strips arbitrary nanoscale metallic features from one substrate and is then transferred, along with the attached features, to a substrate that would be difficult or impossible to pattern with conventional lithographic techniques. An oxygen plasma removes the sacrificial film, leaving behind the metallic features. The transfer of dense and sparse patterns of isolated and connected gold features ranging from 30 nm to 1 mum, to both an optical fiber facet and a silica microsphere, demonstrates the versatility of the method. A distinguishing feature of this technique is the use of a thin, sacrificial film to strip and transfer metallic nanopatterns and its ability to directly transfer metallic structures produced by conventional lithography. DA - 2008/// PY - 2008/// DO - 10.1021/nn800720r VL - 3 IS - 1 SP - 59-65 KW - pattern transfer KW - soft lithography KW - metal nanoparticles KW - nanofabrication KW - nanopatterning ER - TY - JOUR TI - Light-Powered Electrical Switch Based on Cargo-Lifting Azobenzene Monolayers AU - Ferri, Violetta AU - Elbing, Mark AU - Pace, Giuseppina AU - Dickey, Michael D. AU - Zharnikov, Michael AU - Samorì, Paolo AU - Mayor, Marcel AU - Rampi, Maria Anita T2 - Angewandte Chemie AB - Hebebühne: Dicht gepackte selbstorganisierte Monoschichten (SAMs) aus starren konjugierten Azobenzolderivaten zwischen zwei Elektroden gehen eine reversible Photoisomerisierung ein (siehe Bild). Die Strom-Spannungs-Kurven identifizieren die Anordnung als Stromphotoschalter, in dem die SAM wie eine lichtgetriebene Hebebühne wirkt. DA - 2008/4// PY - 2008/4// DO - 10.1002/ange.200705339 VL - 120 IS - 18 SP - 3455-3457 ER - TY - JOUR TI - Unconventional Nanofabrication AU - Dickey, M.D. AU - Whitesides, G.M. T2 - Pharma Focus Asia DA - 2008/5// PY - 2008/5// VL - 5 N1 - Invited RN - Invited ER - TY - JOUR TI - Fabrication of conjugated polymer nanowires by edge lithography AU - Lipomi, Darren J. AU - Chiechi, Ryan C. AU - Dickey, Michael D. AU - Whitesides, George M. T2 - NANO LETTERS AB - This paper describes the fabrication of conjugated polymer nanowires by a three stage process: (i) spin-coating a composite film comprising alternating layers of a conjugated polymer and a sacrificial material, (ii) embedding the film in an epoxy matrix and sectioning it with an ultramicrotome (nanoskiving), and (iii) etching the sacrificial material to reveal nanowires of the conjugated polymer. A free-standing, 100-layer film of two conjugated polymers was spin-coated from orthogonal solvents: poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) from chloroform and poly(benzimidazobenzophenanthroline ladder) (BBL) from methanesulfonic acid. After sectioning the multilayer film, dissolution of the BBL with methanesulfonic acid yielded uniaxially aligned MEH-PPV nanowires with rectangular cross sections, and etching MEH-PPV with an oxygen plasma yielded BBL nanowires. The conductivity of MEH-PPV nanowires changed rapidly and reversibly by >103 upon exposure to I2 vapor. The result suggests that this technique could be used to fabricate high-surface-area structures of conducting organic nanowires for possible applications in sensing and in other fields where a high surface area in a small volume is desirable. DA - 2008/7// PY - 2008/7// DO - 10.1021/nl8009318 VL - 8 IS - 7 SP - 2100-2105 SN - 1530-6984 ER - TY - JOUR TI - Eutectic gallium-indium (EGaIn): A liquid metal alloy for the formation of stable structures in microchannels at room temperature AU - Dickey, Michael D. AU - Chiechi, Ryan C. AU - Larsen, Ryan J. AU - Weiss, Emily A. AU - Weitz, David A. AU - Whitesides, George M. T2 - ADVANCED FUNCTIONAL MATERIALS AB - Abstract This paper describes the rheological behavior of the liquid metal eutectic gallium‐indium (EGaIn) as it is injected into microfluidic channels to form stable microstructures of liquid metal. EGaIn is well‐ ;suited for this application because of its rheological properties at room temperature: it behaves like an elastic material until it experiences a critical surface stress, at which point it yields and flows readily. These properties allow EGaIn to fill microchannels rapidly when sufficient pressure is applied to the inlet of the channels, yet maintain structural stability within the channels once ambient pressure is restored. Experiments conducted in microfluidic channels, and in a parallel‐plate rheometer, suggest that EGaIn's behavior is dictated by the properties of its surface (predominantly gallium oxide, as determined by Auger measurement s); these two experiments both yield approximately the same number for the critical surface stress required to induce EGaIn to flow (∼0 .5 N/m). This analysis–which shows that the pressure that must be exceeded for EGaIn to flow through a microchannel is inversely proportional to the critical (i.e., smallest) dimension of the channel–is useful to guide future fabrication of microfluidic channels to mold EGaIn into functional microstructures. DA - 2008/4/11/ PY - 2008/4/11/ DO - 10.1002/adfm.200701216 VL - 18 IS - 7 SP - 1097-1104 SN - 1616-301X ER - TY - JOUR TI - Electrically Addressable Parallel Nanowires with 30 nm Spacing from Micromolding and Nanoskiving AU - Dickey, Michael D. AU - Lipomi, Darren J. AU - Bracher, Paul J. AU - Whitesides, George M. T2 - NANO LETTERS AB - This paper describes the fabrication of arrays of parallel, electrically addressable metallic nanowires by depositing alternating layers of thin films of metal and polymer—both planar and topographically patterned—and sectioning the laminated structures with an ultramicrotome (nanoskiving). The structures that resulted from this process had two distinct regions: one in which parallel Au nanowires were separated by a minimum distance of 30 nm, and one in which the nanowires diverged such that the distal ends were individually addressable by low-resolution (≥10 μm) photolithography. Conductive polyaniline (PANI) was electrochemically deposited across the nanowire electrodes to demonstrate their electrical addressability, continuity, and physical separation. Before deposition, the wires were electrically isolated; with the PANI, they were electrically connected. After dry etching to remove the polymer, the gap between the nanowire electrodes returned to an insulating state. This procedure provides a method for making wires with dimensions and separations of <50 nm without the use of e-beam or focused-ion-beam “writing” and opens applications in organic and molecular electronics, chemical and biological sensing, and other fields where nanoscale distances between parallel conductive electrodes are desirable. DA - 2008/12// PY - 2008/12// DO - 10.1021/nl8028174 VL - 8 IS - 12 SP - 4568-4573 SN - 1530-6992 ER - TY - JOUR TI - Nanoskiving: A New Method To Produce Arrays of Nanostructures AU - Xu, Qiaobing AU - Rioux, Robert M. AU - Dickey, Michael D. AU - Whitesides, George M. T2 - ACCOUNTS OF CHEMICAL RESEARCH AB - This Account reviews nanoskiving−a new technique that combines thin-film deposition of metal on a topographically contoured substrate with sectioning using an ultramicrotome−as a method of fabricating nanostructures that could replace conventional top-down techniques in selected applications. Photolithography and scanning beam lithography, conventional top-down techniques to generate nanoscale structures and nanostructured materials, are useful, versatile, and highly developed, but they also have limitations: high capital and operating costs, limited availability of the facilities required to use them, an inability to fabricate structures on nonplanar surfaces, and restrictions on certain classes of materials. Nanoscience and nanotechnology would benefit from new, low-cost techniques to fabricate electrically and optically functional structures with dimensions of tens of nanometers, even if (or perhaps especially if) these techniques have a different range of application than does photolithography or scanning beam lithography. Nanoskiving provides a simple and convenient procedure to produce arrays of structures with cross-sectional dimensions in the 30-nm regime. The dimensions of the structures are determined by (i) the thickness of the deposited thin film (tens of nanometers), (ii) the topography (submicrometer, using soft lithography) of the surface onto which the thin film is deposited, and (iii) the thickness of the section cut by the microtome (≥30 nm by ultramicrotomy). The ability to control the dimensions of nanostructures, combined with the ability to manipulate and position them, enables the fabrication of nanostructures with geometries that are difficult to prepare by other methods. The nanostructures produced by nanoskiving are embedded in a thin epoxy matrix. These epoxy slabs, although fragile, have sufficient mechanical strength to be manipulated and positioned; this mechanical integrity allows the nanostructures to be stacked in layers, draped over curved surfaces, and suspended across gaps, while retaining the in-plane geometry of the nanostructures embedded in the epoxy. After removal of the polymer matrix by plasma oxidation, these structures generate suspended and draped nanostructures and nanostructures on curved surfaces. Two classes of applications, in optics and in electronics, demonstrate the utility of nanostructures fabricated by nanoskiving. This technique will be of primary interest to researchers who wish to generate simple nanostructures, singly or in arrays, more simply and quickly than can be accomplished in the clean-room. It is easily accessible to those not trained in top-down procedures for fabrication and those with limited or no access to the equipment and facilities needed for photolithography or scanning-beam fabrication. This Account discusses a new fabrication method (nanoskiving) that produces arrays of metal nanostructures. The defining process in nanoskiving is cutting slabs from a polymeric matrix containing embedded, more extended metal structures. DA - 2008/12// PY - 2008/12// DO - 10.1021/ar700194y VL - 41 IS - 12 SP - 1566-1577 SN - 1520-4898 ER - TY - JOUR TI - Light-powered electrical switch based on cargo-lifting azobenzene monolayers AU - Ferri, Violetta AU - Elbing, Mark AU - Pace, Giuseppina AU - Dickey, Michael D. AU - Zharnikov, Michael AU - Samori, Paolo AU - Mayor, Marcel AU - Rampi, Maria Anita T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - We have liftoff! Tightly packed self-assembled monolayers (SAMs) of ultrarigid conjugated azobenzenes incorporated into a Hg-based junction undergo reversible photoisomerization (see picture). The current–voltage curves indicate that the junction operates as a current photoswitch as result of the forces expressed by the SAMs, which act as a light-powered cargo lifter. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z705339_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. DA - 2008/// PY - 2008/// DO - 10.1002/anie.200705339 VL - 47 IS - 18 SP - 3407-3409 SN - 1521-3773 KW - azo compounds KW - isomerization KW - molecular devices KW - molecular electronics KW - monolayers ER - TY - JOUR TI - High-aspect ratio polymeric pillar arrays formed via electrohydrodynamic patterning AU - Dickey, Michael D. AU - Raines, Allen AU - Collister, Elizabeth AU - Bonnecaze, Roger T. AU - Sreenivasan, S. V. AU - Willson, C. Grant T2 - JOURNAL OF MATERIALS SCIENCE DA - 2008/1// PY - 2008/1// DO - 10.1007/s10853-007-2086-8 VL - 43 IS - 1 SP - 117-122 SN - 0022-2461 ER - TY - JOUR TI - Fabrication of arrays of metal and metal oxide nanotubes by shadow evaporation AU - Dickey, Michael D. AU - Weiss, Emily A. AU - Smythe, Elizabeth J. AU - Chiechi, Ryan C. AU - Capasso, Federico AU - Whitesides, George M. T2 - ACS NANO AB - This paper describes a simple technique for fabricating uniform arrays of metal and metal oxide nanotubes with controlled heights and diameters. The technique involves depositing material onto an anodized aluminum oxide (AAO) membrane template using a collimated electron beam evaporation source. The evaporating material enters the porous openings of the AAO membrane and deposits onto the walls of the pores. The membrane is tilted with respect to the column of evaporating material, so the shadows cast by the openings of the pores onto the inside walls of the pores define the geometry of the tubes. Rotation of the membrane during evaporation ensures uniform deposition inside the pores. After evaporation, dissolution of the AAO in base easily removes the template to yield an array of nanotubes connected by a thin backing of the same metal or metal oxide. The diameter of the pores dictates the diameter of the tubes, and the incident angle of evaporation determines the height of the tubes. Tubes up to approximately 1.5 mum in height and 20-200 nm in diameter were fabricated. This method is adaptable to any material that can be vapor-deposited, including indium-tin oxide (ITO), a conductive, transparent material that is useful for many opto-electronic applications. An array of gold nanotubes produced by this technique served as a substrate for surface-enhanced Raman spectroscopy: the Raman signal (per molecule) from a monolayer of benzenethiolate was a factor of approximately 5 x 10(5) greater than that obtained using bulk liquid benzenethiol. DA - 2008/4// PY - 2008/4// DO - 10.1021/nn800036r VL - 2 IS - 4 SP - 800-808 SN - 1936-086X KW - shadow evaporation KW - nanotube arrays KW - SERS (surface-enhanced Raman spectroscopy) KW - templated fabrication KW - ITO (indium-tin oxide) KW - AAO (anodized aluminum oxide) KW - nanofabrication KW - line-of-sight deposition ER - TY - JOUR TI - Eutectic gallium-indium (EGaIn): A moldable liquid metal for electrical characterization of self-assembled monolayers AU - Chiechi, Ryan C. AU - Weiss, Emily A. AU - Dickey, Michael D. AU - Whitesides, George M. T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - A great GaIn: Micrometer-sized conformal electrodes formed from the title compound are shown to be ideal for measuring the electrical properties of self-assembled monolayers. The image shows the bifurcation of the EGaIn between a metal needle and an Ag surface (not shown) at the point indicated by the two white arrows. The portion above the arrows will form the EGaIn electrode. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z703642_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. DA - 2008/// PY - 2008/// DO - 10.1002/anie.200703642 VL - 47 IS - 1 SP - 142-144 SN - 1521-3773 KW - electrodes KW - gallium KW - indium KW - monolayers KW - tunnel junctions ER - TY - JOUR TI - HEURISTICS FOR BALANCING OPERATING ROOM AND POST-ANESTHESIA RESOURCES UNDER UNCERTAINTY AU - Iser, Jill H. AU - Denton, Brian T. AU - King, Russell E. T2 - 2008 WINTER SIMULATION CONFERENCE, VOLS 1-5 AB - The post-anesthesia care unit (PACU) is a shared resource in the hospital where patients recover from surgery. It is fed by a set of operating rooms (OR's) often spanning several surgical services. It is insufficient to determine the best surgery schedule for any single OR without considering available PACU capacity. We model this as a two-stage process where the first stage is surgery and the second, post-anesthesia recovery. An interesting aspect of the second-stage process is that it begins as soon as the first stage has concluded even if a PACU bed is not available. In this case, the OR continues to house the recovering patient until a PACU bed is available. We analyze the structure of the problem, evaluate several heuristics based on competing performance measures for surgical suite efficiency, and present results of numerical experiments and insights that can be derived from them. DA - 2008/// PY - 2008/// DO - 10.1109/wsc.2008.4736243 SP - 1601-1608 ER - TY - CONF TI - An Experimental study of an iterative simulation-optimization algorithm for production planning AU - Irdem, D. F. AU - Kacar, N. B. AU - Uzsoy, R. C2 - 2008/// C3 - 2008 Winter Simulation Conference, vols 1-5 DA - 2008/// SP - 2176-2184 ER - TY - JOUR TI - A SIMULATION-BASED APPROACH FOR INVENTORY MODELING OF PERISHABLE PHARMACEUTICALS AU - Vila-Parrish, Ana R. AU - Ivy, Julie Simmons AU - King, Russell E. T2 - 2008 WINTER SIMULATION CONFERENCE, VOLS 1-5 AB - Pharmaceutical expenditures are increasing for hospital systems nationwide. We model the inventory and ordering policies for perishable drugs in the setting of an inpatient hospital pharmacy. We consider two stages of inventory: raw material and finished good (e.g. intravenous). We use a two-phased approach to explore policy structures that could be implemented in the hospital pharmacy. We develop a policy which is based on the idea that hospitals can improve both costs and patient demand fulfillment by using knowledge of patient mix to guide their drug inventory and preparation decisions. We compare this policy to a simpler stationary base stock policy. The policies are evaluated on the basis of (1) shortage cost, (2) outdating cost (expirations), and (3) holding cost through a range of cost scenarios. DA - 2008/// PY - 2008/// DO - 10.1109/wsc.2008.4736234 SP - 1532-1538 ER - TY - JOUR TI - South America: Industrial roundwood supply potential AU - Gonzalez, R. W. AU - Saloni, D. AU - Dasmohapatra, S. AU - Cubbage, F. T2 - BioResources DA - 2008/// PY - 2008/// VL - 3 IS - 1 SP - 255-269 ER - TY - JOUR TI - Focused ion beam irradiation effects on nanoscale freestanding thin films AU - Samayoa, M. J. AU - Haque, M. A. AU - Cohen, P. H. T2 - JOURNAL OF MICROMECHANICS AND MICROENGINEERING AB - The focused ion beam (FIB) technique is a versatile tool for nanoscale manipulation, deposition and etching. However, degradation mechanisms which lead to residual stresses in materials exposed to high-energy ion beams are not well understood. In this study, we examine the evolution of residual stresses in 100 nm thick freestanding aluminum films subjected to typical ion beam exposures within a commercial FIB tool. Experimental results show that the magnitude of the residual stresses increase with cumulative ion beam exposure and that upper limits are attainable. Further investigation demonstrates that a decrease in ion beam current at constant acceleration-voltage augments the upper limits, which manifests itself in greater residual stresses. The stress gradients in thin films develop from surface modifications in the form of amorphous top layers, which are modeled as bilayer approximations. Experimental observations and analysis indicate that ion beam exposure effects on the mechanical properties of nanoscale thin films and nanostructures cannot be ignored. DA - 2008/9// PY - 2008/9// DO - 10.1088/0960-1317/18/9/095005 VL - 18 IS - 9 SP - SN - 1361-6439 ER - TY - JOUR TI - Exact and heuristic procedures for capacity expansion problems with congestion AU - Kim, Sukgon AU - Uzsoy, Reha T2 - IIE TRANSACTIONS AB - The problem of determining an optimal capacity expansion and contraction schedule over time for production resources subject to congestion is addressed. Previous to this work non-linear constraints based on expected queue length have been used to represent congestion, whereas concave clearing functions that capture the relationship between expected throughput and expected work in process inventory in a planning period are used in this paper. A column generation procedure that uses a previously developed pseudo-polynomial-time algorithm for the single-workcenter problem to generate new columns is proposed. The fractional solution obtained by column generation is then used to construct a feasible solution. Computational experiments on randomly generated test problems show that the procedure consistently produces near-optimal solutions in modest CPU times. The column generation formulation is also used to obtain lower bounds in an exact branch-and-bound algorithm, and it is shown that this new procedure is able to solve problems that are significantly larger than those possible with previous methods. DA - 2008/// PY - 2008/// DO - 10.1080/07408170802322978 VL - 40 IS - 12 SP - 1185-1197 SN - 0740-817X KW - Capacity expansion KW - clearing functions KW - column generation KW - heuristics KW - branch and price ER - TY - JOUR TI - Properties of Ti-6Al-4V non-stochastic lattice structures fabricated via electron beam melting AU - Cansizoglu, O. AU - Harrysson, O. AU - Cormier, D. AU - West, H. AU - Mahale, T. T2 - MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING AB - This paper addresses foams which are known as non-stochastic foams, lattice structures, or repeating open cell structure foams. The paper reports on preliminary research involving the design and fabrication of non-stochastic Ti–6Al–4V alloy structures using the electron beam melting (EBM) process. Non-stochastic structures of different cell sizes and densities were investigated. The structures were tested in compression and bending, and the results were compared to results from finite element analysis simulations. It was shown that the build angle and the build orientation affect the properties of the lattice structures. The average compressive strength of the lattice structures with a 10% relative density was 10 MPa, the flexural modulus was 200 MPa and the strength to density ration was 17. All the specimens were fabricated on the EBM A2 machine using a melt speed of 180 mm/s and a beam current of 2 mA. Future applications and FEA modeling were discussed in the paper. DA - 2008/9/25/ PY - 2008/9/25/ DO - 10.1016/j.msea.2008.04.002 VL - 492 IS - 1-2 SP - 468-474 SN - 0921-5093 KW - non-stochastic foams KW - repeating open cell structures KW - Ti-6Al-4V KW - direct metal fabrication KW - layered manufacturing KW - rapid prototyping ER - TY - JOUR TI - Integrated planning of production and engineering process improvement AU - Kim, Sukgon AU - Uzsoy, Reha M. T2 - IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING AB - The authors present a planning model to allocate equipment capacity between production that generates immediate revenue and engineering process improvement activity that results in increased future output. The benefit of engineering activity is modeled as a concave function of the total number of engineering lots processed to date, while the production facility is represented by a nonlinear clearing function capturing the nonlinear relationship between resource utilization and cycle time. We analyze the model to develop structural results and illustrate its behavior with numerical examples. DA - 2008/8// PY - 2008/8// DO - 10.1109/TSM.2008.2001215 VL - 21 IS - 3 SP - 390-398 SN - 0894-6507 KW - capacity modeling KW - clearing functions KW - process improvement KW - production planning ER - TY - JOUR TI - In vitro evaluation of a custom cutting jig and custom plate for canine tibial plateau leveling AU - Marcellin-Little, Denis J. AU - Harrysson, Ola L. A. AU - Cansizoglu, Omer T2 - AMERICAN JOURNAL OF VETERINARY RESEARCH AB - To design and manufacture custom titanium bone plates and a custom cutting and drill guide by use of free-form fabrication methods and to compare variables and mechanical properties of 2 canine tibial plateau leveling methods with each other and with historical control values.10 canine tibial replicas created by rapid prototyping methods.Application time, accuracy of correction of the tibial plateau slope (TPS), presence and magnitude of rotational and angular deformation, and replica axial stiffness for 2 chevron wedge osteotomy (CWO) methods were assessed. One involved use of freehand CWO (FHCWO) and screw hole drilling, whereas the other used jig-guided CWO (JGCWO) and screw hole drilling.Replicas used for FHCWO and JGCWO methods had similar stiffness. Although JGCWO and FHCWO did not weaken the replicas, mean axial stiffness of replicas after JGCWO was higher than after FHCWO. The JGCWO method was faster than the FHCWO method. Mean +/- SD TPS after osteotomy was lower for FHCWO (4.4 +/- 1.1 degrees ) than for JGCWO (9.5 +/- 0.4 degrees ), and JGCWO was more accurate (target TPS, 8.9 degrees ). Slight varus was evident after FHCWO but not after JGCWO. Mean postoperative rotation after JGCWO and FHCWO did not differ from the target value or between methods.The JGCWO method was more accurate and more rapid and resulted in more stability than the FHCWO method. Use of custom drill guides could enhance the speed, accuracy, and stability of corrective osteotomies in dogs. DA - 2008/7// PY - 2008/7// DO - 10.2460/ajvr.69.7.961 VL - 69 IS - 7 SP - 961-966 SN - 1943-5681 ER - TY - JOUR TI - Direct metal fabrication of titanium implants with tailored materials and mechanical properties using electron beam melting technology AU - Harrysson, Ola L. A. AU - CansiZoglu, Omer AU - Marcellin-Little, Denis J. AU - Cormier, Denis R. AU - West, Harvey A., II T2 - MATERIALS SCIENCE & ENGINEERING C-BIOMIMETIC AND SUPRAMOLECULAR SYSTEMS AB - The design of custom or tailored implant components has been the subject of research and development for decades. However, the economic feasibility of fabricating such components has proven to be a challenge. New direct metal fabrication technologies such as Electron Beam Melting (EBM) have opened up new possibilities. This paper discusses the design and fabrication of titanium implant components having tailored mechanical properties that mimic the stiffness of bone to reduce stress shielding and bone remodeling. Finite Element Analysis was used to design the tailored structures, and results were verified using mechanical testing. DA - 2008/4/1/ PY - 2008/4/1/ DO - 10.1016/j.msec.2007.04.022 VL - 28 IS - 3 SP - 366-373 SN - 0928-4931 KW - orthopedic implants KW - electron beam melting KW - theoretical modeling KW - materials KW - experimentation ER - TY - JOUR TI - An evaluation of loose tenon joint strength AU - Aman, R. L. AU - West, H. A. AU - Cormier, D. R. T2 - Forest Products Journal DA - 2008/// PY - 2008/// VL - 58 IS - 3 SP - 61-64 ER - TY - JOUR TI - Applications of structural optimization in direct metal fabrication AU - Cansizoglu, Omer AU - Harrysson, Ola L. A. AU - West, Harvey A., II AU - Cormier, Denis R. AU - Mahale, Tushar T2 - RAPID PROTOTYPING JOURNAL AB - Purpose Optimization techniques can be used to design geometrically complex components with a wide variety of optimization criteria. However, such components have been very difficult and costly to produce. Layered fabrication technologies such as electron beam melting (EBM) open up new possibilities though. This paper seeks to investigate the integration of structural optimization and direct metal fabrication process. Design/methodology/approach Mesh structures were designed, and optimization problems were defined to improve structural performance. Finite element analysis code in conjunction with nonlinear optimization routines were used in MATLAB. Element data were extracted from an STL‐file, and output structures from the optimization routine were manufactured using an EBM machine. Original and optimized structures were tested and compared. Findings There were discrepancies between the performance of the theoretical structures and the physical EBM structures due to the layered fabrication approach. A scaling factor was developed to account for the effect of layering on the material properties. Practical implications Structural optimization can be used to improve the performance of a design, and direct fabrication technologies can be used to realise these structures. However, designers must realize that fabricated structures are not identical to idealized CAD structures, hence material properties much be adjusted accordingly. Originality/value Integration of structural optimization and direct metal fabrication was reported in the paper. It shows the process from design through manufacturing with integrated analysis. DA - 2008/// PY - 2008/// DO - 10.1108/13552540810862082 VL - 14 IS - 2 SP - 114-122 SN - 1355-2546 KW - rapid prototypes KW - optimization techniques ER -