WorldWideScience

Sample records for alternative fabrication techniques

  1. Displacement Talbot lithography: an alternative technique to fabricate nanostructured metamaterials

    Science.gov (United States)

    Le Boulbar, E. D.; Chausse, P. J. P.; Lis, S.; Shields, P. A.

    2017-06-01

    Nanostructured materials are essential for many recent electronic, magnetic and optical devices. Lithography is the most common step used to fabricate organized and well calibrated nanostructures. However, feature sizes less than 200 nm usually require access to deep ultraviolet photolithography, e-beam lithography or soft lithography (nanoimprinting), which are either expensive, have low-throughput or are sensitive to defects. Low-cost, high-throughput and low-defect-density techniques are therefore of interest for the fabrication of nanostructures. In this study, we investigate the potential of displacement Talbot lithography for the fabrication of specific structures of interest within plasmonic and metamaterial research fields. We demonstrate that nanodash arrays and `fishnet'-like structures can be fabricated by using a double exposure of two different linear grating phase masks. Feature sizes can be tuned by varying the exposure doses. Such lithography has been used to fabricate metallic `fishnet'-like structures using a lift-off technique. This proof of principle paves the way to a low-cost, high-throughput, defect-free and large-scale technique for the fabrication of structures that could be useful for metamaterial and plasmonic metasurfaces. With the development of deep ultraviolet displacement Talbot lithography, the feature dimensions could be pushed lower and used for the fabrication of optical metamaterials in the visible range.

  2. The Metal-Zirconia Implant Fixed Hybrid Full-Arch Prosthesis: An Alternative Technique for Fabrication.

    Science.gov (United States)

    Stumpel, Lambert J; Haechler, Walter

    2018-03-01

    The metal-resin hybrid full-arch prosthesis has been a traditionally used type of restoration for full-arch implant fixed dentures. A newer development has centered around the use of monolithic zirconia or zirconia veneered with porcelain. Being a ceramic, zirconia has the potential for fracture. This article describes a technique that utilizes a metal substructure to support a chemically and mechanically resinbonded shell of zirconia. The workflow is discussed, ranging from in-office master cast fabrication to the CAD/ CAM production of the provisional and the definitive metal-zirconia prosthesis. The article also highlights the advantages and disadvantages of various materials used for hybrid prostheses.

  3. Alternative Assessment Techniques.

    Science.gov (United States)

    Lowenthal, Barbara

    1988-01-01

    Maintaining the precision necessary for administering norm referenced tests can be a problem for the special education teacher who is trained to assist the student. Criterion-referenced tests, observations, and interviews are presented as effective alternative assessment techniques. (JDD)

  4. Different techniques in fabrication of ocular prosthesis.

    Science.gov (United States)

    Cevik, Pinar; Dilber, Erhan; Eraslan, Oguz

    2012-11-01

    Loss of an eye caused by cancer, trauma, or congenital defect creates a deep psychological impact on an individual's life especially social and professional life. Custom-made prosthesis, compared to stock prosthesis, provides a better fit to the eye socket, better cosmetic results, and less discomfort to the patient in the long term. The main objective of this article was to describe 3 different alternative and practical techniques of fabricating custom-made ocular prosthesis. An impression of anophthalmic socket was made with the addition of cured silicone-based precision impression material in all techniques. A master cast was prepared and duplicated with condensation silicone. A self-cure acrylic resin was polymerized in the silicone model and was fitted into the patient's eye socket. A digital photograph of the patient's iris was made using a digital camera and printed on good-quality photo paper in various shades and sizes in the first and the second techniques. Then the photo paper was coated with PVC so as not to allow any color flowing. The proper iris was then inserted to the acrylic base. The prosthesis was final processed using orthodontic heat polymerizing clear acrylic resin.In the other technique, after the trying-in process with wax pattern, an acrylic base was fabricated using heat polymerizing scleral acrylic resin. The prosthetic iris was fabricated from a transparent contact lens by painting the lens with watercolor paints and attaching it to an acrylic resin with tissue conditioner. The final process was made with heat polymerizing transparent acrylic resin. Custom-made prosthesis allows better esthetic and functional results to the patient in comparison to stock prosthesis. Further follow-up is necessary to check the condition and fit of the ocular prosthesis in such patients.

  5. Nanowire and microwire fabrication technique and product

    Energy Technology Data Exchange (ETDEWEB)

    Sumant, Anirudha V.; Zach, Michael; Marten, Alan David

    2018-02-27

    A continuous or semi-continuous process for fabricating nanowires or microwires makes use of the substantially planar template that may be moved through electrochemical solution to grow nanowires or microwires on exposed conductive edges on the surface of that template. The planar template allows fabrication of the template using standard equipment and techniques. Adhesive transfer may be used to remove the wires from the template and in one embodiment to draw a continuous wire from the template to be wound around the drum.

  6. Antenna Fabrication using 3D printing techniques

    OpenAIRE

    Elibiary, Ahmed

    2017-01-01

    This thesis focuses to explore the use of additive manufacturing (AM) techniques to fabricate various radio frequency (RF) devices. 3D printing, a term used for AM has evolved to the point where it is being introduced into various industries, one of these, discussed in this thesis is the fabrication of antennas for the aim to reduce manufacturing costs and time.\\ud The aim is to investigate the performance and reliability of a modified low-cost 3D printer to print plastic and metal simultaneo...

  7. Alternative Fabrication of Recycling Fast Reactor Metal Fuel

    International Nuclear Information System (INIS)

    Kim, Ki-Hwan; Kim, Jong Hwan; Song, Hoon; Kim, Hyung-Tae; Lee, Chan-Bock

    2015-01-01

    Metal fuels such as U-Zr/U-Pu-Zr alloys have been considered as a nuclear fuel for a sodium-cooled fast reactor (SFR) related to the closed fuel cycle for managing minor actinides and reducing a high radioactivity levels since the 1980s. In order to develop innovative fabrication method of metal fuel for preventing the evaporation of volatile elements such as Am, modified casting under inert atmosphere has been applied for metal fuel slugs for SFR. Alternative fabrication method of fuel slugs has been introduced to develop an improved fabrication process of metal fuel for preventing the evaporation of volatile elements. In this study, metal fuel slugs for SFR have been fabricated by modified casting method, and characterized to evaluate the feasibility of the alternative fabrication method. In order to prevent evaporation of volatile elements such as Am and improve quality of fuel slugs, alternative fabrication methods of metal fuel slugs have been studied in KAERI. U-10Zr-5Mn fuel slug containing volatile surrogate element Mn was soundly cast by modified injection casting under modest pressure. Evaporation of Mn during alternative casting could not be detected by chemical analysis. Mn element was most recovered with prevention of evaporation by alternative casting. Modified injection casting has been selected as an alternative fabrication method in KAERI, considering evaporation prevention, and proven benefits of high productivity, high yield, and good remote control

  8. A Technique: Generating Alternative Thoughts

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-04-01

    Conclusion: Generating alternative explanations and balanced thoughts are the end point and important part of therapy work on automatic thoughts. When applied properly and rehearsed as homework between sessions, these methods may lead to improvement in many mental disorders. [JCBPR 2013; 2(1.000: 53-59

  9. Fabrication of SERS Substrate by Multilayered Nanosphere Deposition Technique

    International Nuclear Information System (INIS)

    Fu, Chit Yaw; Dinish, U. S.; Praveen, Thoniyot; Koh, Zhen Yu; Kho, Khiang Wei; Malini, Olivo

    2010-01-01

    Metal film over nanosphere (MFON) has been employed as a reproducible and predictable SERS-active device in biosensing applications. In addition to its economic fabrication process, such substrate can be further processed to a prism-structure with increased SERS enhancement and wider Plasmon tunability. In this work, we investigate an alternative coating method to deposit a larger area of well-ordered PS beads with different sizes (oe = 100nm and 400 nm) onto a glass. The result suggests that the proposed well-coating technique can be suitably used to form closely-packed PS beads with diameter less than 100 nm for developing MFON substrates.

  10. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    Energy Technology Data Exchange (ETDEWEB)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  11. Inferior alveolar nerve block: Alternative technique

    OpenAIRE

    Thangavelu, K.; Kannan, R.; Kumar, N. Senthil

    2012-01-01

    Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple techni...

  12. Fabrication of a wettability-gradient surface on copper by screen-printing techniques

    International Nuclear Information System (INIS)

    Huang, Ding-Jun; Leu, Tzong-Shyng

    2015-01-01

    In this study, a screen-printing technique is utilized to fabricate a wettability-gradient surface on a copper substrate. The pattern definitions on the copper surface were freely fabricated to define the regions with different wettabilities, for which the printing definition technique was developed as an alternative to the existing costly photolithography techniques. This fabrication process using screen printing in tandem with chemical modification methods can easily realize an excellent wettability-gradient surface with superhydrophobicity and superhydrophilicity. Surface analyses were performed to characterize conditions in some fabrication steps. A water droplet movement sequence is provided to clearly demonstrate the droplet-driving effectiveness of the fabricated gradient surface. The droplet-driving efficiency offers a promising solution for condensation heat transfer applications in the foreseeable future. (paper)

  13. Inferior alveolar nerve block: Alternative technique.

    Science.gov (United States)

    Thangavelu, K; Kannan, R; Kumar, N Senthil

    2012-01-01

    Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages.

  14. A new RFQ linac fabrication technique

    International Nuclear Information System (INIS)

    Schrage, D.; Roybal, P.; Young, L.; Clark, W.; DePaula, R.; Martinez, F.

    1994-01-01

    The use of hydrogen furnace brazing has been applied as a joining technology to the fabrication of a Radio-Frequency-Quadrupole (RFQ) linac for the Los Alamos Accelerator Performance Demonstration Facility (APDF). The design concept provides a monolithic cavity with no longitudinal rf, vacuum, or mechanical joints. A 530 MHz, 0.46 meter long engineering model RFQ has been fabricated and tested at the Los Alamos National Laboratory as a technical demonstration of this concept. It is planned that two funneled RFQ's for the APDF (7 MeV, 350 MHz, 100 mAmp CW, each eight meters in length) will be manufactured by this method

  15. Evaluation of miniature tension specimen fabrication techniques and performance

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Blotter, M.A.; Edwards, D.J.

    1993-01-01

    The confident application of miniature tensile specimens requires adequate control over their fabrication and is facilitated by automated test and analysis techniques. Three fabrication processes -- punching, chemical milling, and electrical discharge machining (EDM) -- were recently evaluated, leading to the replacement of the previously used punching technique with a wire EDM technique. The automated data acquisition system was upgraded, and an interactive data analysis program was developed

  16. Evaluation of miniature tensile specimen fabrication techniques and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, M.L. (Pacific Northwest Lab., Richland, WA (United States)); Blotter, M.A.; Edwards, D.J. (Missouri Univ., Rolla, MO (United States))

    1992-01-01

    The confident application of miniature tensile specimens requires adequate control over their fabrication and is facilitated by automated test and analysis techniques. Three fabrication processes -- punching, chemical, milling, and electrical discharge machining (EDM) -- were recently evaluated, leading to the replacement of the previously used punching technique with a wire EDM technique. The automated data acquisition system was upgraded, and an interactive data analysis program was developed.

  17. Evaluation of miniature tensile specimen fabrication techniques and performance

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Blotter, M.A.; Edwards, D.J.

    1992-01-01

    The confident application of miniature tensile specimens requires adequate control over their fabrication and is facilitated by automated test and analysis techniques. Three fabrication processes -- punching, chemical, milling, and electrical discharge machining (EDM) -- were recently evaluated, leading to the replacement of the previously used punching technique with a wire EDM technique. The automated data acquisition system was upgraded, and an interactive data analysis program was developed

  18. Improved fabrication techniques for infrared bolometers

    Science.gov (United States)

    Lange, A. E.; Mcbride, S. E.; Richards, P. L.; Haller, E. E.; Kreysa, E.

    1983-01-01

    Ion implantation and sputter metallization are used to produce ohmic electrical contacts to Ge:Ga chips. The method is shown to give a high yield of small monolithic bolometers with very little low-frequency noise. It is noted that when one of the chips is used as the thermometric element of a composite bolometer it must be bonded to a dielectric substrate. The thermal resistance of the conventional epoxy bond is measured and found to be undesirably large. A procedure for soldering the chip to a metallized portion of the substrate in such a way as to reduce this resistance is outlined. An evaluation is made of the contribution of the metal film absorber to the heat capacity of a composite bolometer. It is found that the heat capacity of a NiCr absorber at 1.3 K can dominate the bolometer performance. A Bi absorber possesses significantly lower heat capacity. A low-temperature blackbody calibrator is built to measure the optical responsivity of bolometers. A composite bolometer system with a throughput of approximately 0.1 sr sq cm is constructed using the new techniques. The noise in this bolometer is white above 2.5 Hz and is slightly below the value predicted by thermodynamic equilibrium theory.

  19. Fabrication techniques to eliminate postweld heat treatment

    International Nuclear Information System (INIS)

    Lochhead, J.C.

    1978-01-01

    Postweld heat treatments to reduce residual stresses (stress relief operations) have been a common practice in the pressure vessel industry for a large number of years. A suitable heat treatment operation can, in particular for low alloy steels, have additional beneficial effects, i.e. a reduction in peak hardness values in the heat-affected zone, an improvement in weld metal properties, and a lowering of the adverse effects of the welding process on the mechanical properties of the parent material adjacent to the weld metal. However, continuing studies in the field of brittle fracture, improved parent materials, and more sophisticated nondestructive testing techniques have led to the elimination of such a practice in ever-increasing thickness ranges and types of material. For instance, the recently issued BS 5500 compared with BS 1113 (1969) lifts the thickness limit requiring stress relief in certain circumstances from 19 to 35mm for C steels. With respect to materials the CEGB has stated that as a result of successful operational experience it will no longer be necessary to postweld heat treat butt welds in 2 1/4 Cr-1Mo tubes of certain dimensions. Despite this trend, over a period of years a number of instances have arisen where, because of some factor, postweld heat treatment, although perhaps desirable, is not possible. This Paper describes several such examples. It must be noted that the examples quoted consist of relatively important and major items. It has been necessary within the confines of this Paper to condense the reports. It is hoped that no significant factors have been omitted. (author)

  20. Fabrication techniques of X-ray spiral zone plates

    International Nuclear Information System (INIS)

    Gao Nan; Zhu Xiaoli; Li Hailiang; Xie Changqing

    2010-01-01

    The techniques to make X-ray spiral zone plates using electron beam and X-ray lithography were studied. A master mask was fabricated on polyimide membrane by E-beam lithography and micro-electroplating. Spiral zone plates were efficiently replicated by X-ray lithography and micro-electroplating. By combining the techniques, spiral zone plates at 1 keV were successfully fabricate. With an outermost zone width of the 200 nm, and the gold absorbers thickness of 700 nm, the high quality zone plates can be used for X-ray phase contrast microscopy.(authors)

  1. New fabrication techniques for the nuclear fuels of tomorrow

    International Nuclear Information System (INIS)

    Babelot, J.F.; Bokelund, H.; Gerontopoulos, P.; Gueugnon, J.F.; Richter, K.

    1995-01-01

    The shift of the emphasis of the work at the Institute for Transuranium Elements (ITU) from the development of fuels based on uranium and plutonium to safety aspects concerning the use of plutonium and other of actinides, necessitates the production of targets containing appreciable amounts of minor actinides for irradiation experiments. The handling of minor actinides requires additional protective measures, combined with improved fuel fabrication techniques. The boundary conditions for a suitable process are flexibility, adaptability to remote control, and minimization of dust formation. A method based on the sol-gel fabrication technique meets these criteria, and was selected for the present developments at ITU. (author)

  2. Neural engineering from advanced biomaterials to 3D fabrication techniques

    CERN Document Server

    Kaplan, David

    2016-01-01

    This book covers the principles of advanced 3D fabrication techniques, stem cells and biomaterials for neural engineering. Renowned contributors cover topics such as neural tissue regeneration, peripheral and central nervous system repair, brain-machine interfaces and in vitro nervous system modeling. Within these areas, focus remains on exciting and emerging technologies such as highly developed neuroprostheses and the communication channels between the brain and prostheses, enabling technologies that are beneficial for development of therapeutic interventions, advanced fabrication techniques such as 3D bioprinting, photolithography, microfluidics, and subtractive fabrication, and the engineering of implantable neural grafts. There is a strong focus on stem cells and 3D bioprinting technologies throughout the book, including working with embryonic, fetal, neonatal, and adult stem cells and a variety of sophisticated 3D bioprinting methods for neural engineering applications. There is also a strong focus on b...

  3. Development of fabrication technique of bulk high superconductor

    International Nuclear Information System (INIS)

    Hong, Gye Won; Kim, Chang Joong; Kim, Ki Baik; Lee, Ho Jin; Lee, Hee Gyoun; Kwon, Sun Chil.

    1997-05-01

    In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBCO bulk superconductor with high mechanical strength and critical current density. In this project, plastic extrusion and melt process techniques were studied. The components materials for the current lead and the flywheel application were fabricated and their characteristics were investigated from the view point of microstructure and phase formation during heat treatment process. (author). 64 refs., 59 figs

  4. The fabrication techniques of Z-pinch targets. Techniques of fabricating self-adapted Z-pinch wire-arrays

    International Nuclear Information System (INIS)

    Qiu Longhui; Wei Yun; Liu Debin; Sun Zuoke; Yuan Yuping

    2002-01-01

    In order to fabricate wire arrays for use in the Z-pinch physical experiments, the fabrication techniques are investigated as follow: Thickness of about 1-1.5 μm of gold is electroplated on the surface of ultra-fine tungsten wires. Fibers of deuterated-polystyrene (DPS) with diameters from 30 to 100 microns are made from molten DPS. And two kinds of planar wire-arrays and four types of annular wire-arrays are designed, which are able to adapt to the variation of the distance between the cathode and anode inside the target chamber. Furthermore, wire-arrays with diameters form 5-24 μm are fabricated with tungsten wires, respectively. The on-site test shows that the wire-arrays can self-adapt to the distance changes perfectly

  5. Titanium. Properties, raw datum surface, physicochemical basis and fabrication technique

    International Nuclear Information System (INIS)

    Garmata, V.A.; Petrun'ko, A.N.; Galitskij, N.V.; Olesov, Yu.G.; Sandler, R.A.

    1983-01-01

    On the nowadays science and technology achievements the complex of titanium metallurgy problems comprising raw material base, physico-chemical basis and fabrication technique, properties and titanium usage fields is considered for the first time. A particular attention is given to raw material base, manufacturing titanium concentrates and titanium tetrachloride, metallothermal reduction, improvement of metal quality. Data on titanium properties are given, processes of titanium powder metallurgy, scrap and waste processing, problems of economics and complex raw material use are considered

  6. Techniques of Fabrication of Provisional Restoration: An Overview

    Directory of Open Access Journals (Sweden)

    K. M. Regish

    2011-01-01

    Full Text Available A properly fabricated provisional restoration is important in achieving a successful indirect restoration. The importance of provisional restorations as an integral part of fixed prosthodontic treatment is evident from the abundance of the literature pertaining to their importance regarding margin fidelity, function, occlusion, and esthetics. There are a variety of techniques available to suit the individual needs of the clinician and of the clinical situation, from a single unit to a complete-arch provisional fixed prostheses.

  7. High volume fabrication of laser targets using MEMS techniques

    International Nuclear Information System (INIS)

    Spindloe, C; Tomlinson, S; Green, J; Booth, N.; Tolley, M K; Arthur, G; Hall, F; Potter, R; Kar, S; Higginbotham, A

    2016-01-01

    The latest techniques for the fabrication of high power laser targets, using processes developed for the manufacture of Micro-Electro-Mechanical System (MEMS) devices are discussed. These laser targets are designed to meet the needs of the increased shot numbers that are available in the latest design of laser facilities. Traditionally laser targets have been fabricated using conventional machining or coarse etching processes and have been produced in quantities of 10s to low 100s. Such targets can be used for high complexity experiments such as Inertial Fusion Energy (IFE) studies and can have many complex components that need assembling and characterisation with high precision. Using the techniques that are common to MEMS devices and integrating these with an existing target fabrication capability we are able to manufacture and deliver targets to these systems. It also enables us to manufacture novel targets that have not been possible using other techniques. In addition, developments in the positioning systems that are required to deliver these targets to the laser focus are also required and a system to deliver the target to a focus of an F2 beam at 0.1Hz is discussed. (paper)

  8. Optical fiber sensors fabricated by the focused ion beam technique

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Wang, Fei; Bang, Ole

    2012-01-01

    crystal fiber (PCF). Using this technique we fabricate a highly compact fiber-optic Fabry-Pérot (FP) refractive index sensor near the tip of fiber taper, and a highly sensitive in-line temperature sensor in PCF. We also demonstrate the potential of using FIB to selectively fill functional fluid......Focused ion beam (FIB) is a highly versatile technique which helps to enable next generation of lab-on-fiber sensor technologies. In this paper, we demonstrate the use application of FIB to precisely mill the fiber taper and end facet of both conventional single mode fiber (SMF) and photonic...

  9. An efficient enzyme-powered micromotor device fabricated by cyclic alternate hybridization assembly for DNA detection.

    Science.gov (United States)

    Fu, Shizhe; Zhang, Xueqing; Xie, Yuzhe; Wu, Jie; Ju, Huangxian

    2017-07-06

    An efficient enzyme-powered micromotor device was fabricated by assembling multiple layers of catalase on the inner surface of a poly(3,4-ethylenedioxythiophene and sodium 4-styrenesulfonate)/Au microtube (PEDOT-PSS/Au). The catalase assembly was achieved by programmed DNA hybridization, which was performed by immobilizing a designed sandwich DNA structure as the sensing unit on the PEDOT-PSS/Au, and then alternately hybridizing with two assisting DNA to bind the enzyme for efficient motor motion. The micromotor device showed unique features of good reproducibility, stability and motion performance. Under optimal conditions, it showed a speed of 420 μm s -1 in 2% H 2 O 2 and even 51 μm s -1 in 0.25% H 2 O 2 . In the presence of target DNA, the sensing unit hybridized with target DNA to release the multi-layer DNA as well as the multi-catalase, resulting in a decrease of the motion speed. By using the speed as a signal, the micromotor device could detect DNA from 10 nM to 1 μM. The proposed micromotor device along with the cyclic alternate DNA hybridization assembly technique provided a new path to fabricate efficient and versatile micromotors, which would be an exceptional tool for rapid and simple detection of biomolecules.

  10. 48 CFR 852.273-71 - Alternative negotiation techniques.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Alternative negotiation techniques. 852.273-71 Section 852.273-71 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 852.273-71 Alternative negotiation technique...

  11. Fabrication of piezoresistive microcantilever using surface micromachining technique for biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Na, Kwang-Ho [Department of Electrical Engineering and Nano-Bio Research Center, Myongji University, Yongin, Gyeonggido 449-728 (Korea, Republic of); Kim, Yong-Sang [Department of Electrical Engineering and Nano-Bio Research Center, Myongji University, Yongin, Gyeonggido 449-728 (Korea, Republic of); Kang, C.J. [Department of Physics and Nano-Bio Research Center, Myongji University, San38-2 Namdong, Yongin, Gyeonggido 449-728 (Korea, Republic of)]. E-mail: cjkang@mju.ac.kr

    2005-11-15

    A microcantilever-based biosensor with piezoresistor has been fabricated using surface micromachining technique, which is cost effective and simplifies a fabrication procedure. In order to evaluate the characteristics of the cantilever, the cystamine terminated with thiol was covalently immobilized on the gold-coated side of the cantilever and glutaraldehyde that would be bonded with amine group in the cystamine was injected subsequently. This process was characterized by measuring the deflection of the cantilever in real time monitoring. Using a piezoresistive read-out and a well-known optical beam deflection method as well, the measurement of deflection was carried out. The sensitivity of piezoresistive method is good enough compared with that of optical beam deflection method.

  12. FY-87 packing fabrication techniques (commercial waste form) results

    International Nuclear Information System (INIS)

    Werry, E.V.; Gates, T.E.; Cabbage, K.S.; Eklund, J.D.

    1988-04-01

    This report covers the investigation of fabrication techniques associated with the development of suitable materials and methods to provide a prefabricated packing for waste packages for the Basalt Waste Isolation Project (BWIP). The principal functions of the packing are to minimize container corrosion during the 300 to 1000 years following repository closure and provide long-term control of the release of radionuclides from the waste package. The investigative work, discussed in this report, was specifically conceived to develop the design criteria for production of full-scale prototypical packing rings. The investigative work included the preparation of procedures, the preparation of fabrication materials, physical properties, and the determination of the engineering properties. The principal activities were the preparation of the materials and the determination of the physical properties. 21 refs., 20 figs., 14 tabs

  13. Estimates of Canadian fuel fabrication costs for alternative fuel cycles and systems

    International Nuclear Information System (INIS)

    Blahnik, C.

    1979-04-01

    Unit fuel fabrication costs are estimated for alternate fuel cycles and systems that may be of interest in Ontario Hydro's strategy analyses. A method is proposed for deriving the unit fuel fabrication price to be paid by a Canadian utility as a function of time (i.e. the price that reflects the changing demand/supply situation in the particular scenario considered). (auth)

  14. Advanced accounting techniques in automated fuel fabrication facilities

    International Nuclear Information System (INIS)

    Carlson, R.L.; DeMerschman, A.W.; Engel, D.W.

    1977-01-01

    The accountability system being designed for automated fuel fabrication facilities will provide real-time information on all Special Nuclear Material (SNM) located in the facility. It will utilize a distributed network of microprocessors and minicomputers to monitor material movement and obtain nuclear materials measurements directly from remote, in-line Nondestructive Assay instrumentation. As SNM crosses an accounting boundary, the accountability computer will update the master files and generate audit trail records. Mass balance accounting techniques will be used around each unit process step, while item control will be used to account for encapsulated material, and SNM in transit

  15. Alternative diagnostic technique for carpal tunnel syndrome

    International Nuclear Information System (INIS)

    Hayakawa, Katsuhiko; Nakane, Takashi; Kobayashi, Shigeru; Shibata, Kunio

    2002-01-01

    Compressive and entrapment neuropathies are common clinical syndromes characterized by neurologic deficits due to mechanical or dynamic compression of peripheral nerves. However, the definitive diagnosis based on clinical symptoms alone is difficult in many cases, and the electrophysiological diagnostic method is solely used as a supplementary diagnostic method at present. As a new diagnostic method for entrapment neuropathy, the present study investigated the usefulness of gadolinium-enhanced MRI in carpal tunnel syndrome. On enhanced MRI of idiopathic carpal tunnel syndrome, contrast-enhancement in the median nerve was found in 30 of 34 hands (88.2%). Enhanced MRI allows to visualize intraneural edema in the nerve easily on the naked eye. Therefore, this technique supplied useful information for making definitive diagnosis and is promising as a non-invasive diagnostic method for entrapment neuropathy. (author)

  16. Alternative diagnostic technique for carpal tunnel syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Katsuhiko; Nakane, Takashi [Aiko Orthopaedic Hospital, Nagoya (Japan); Kobayashi, Shigeru; Shibata, Kunio [Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine

    2002-10-01

    Compressive and entrapment neuropathies are common clinical syndromes characterized by neurologic deficits due to mechanical or dynamic compression of peripheral nerves. However, the definitive diagnosis based on clinical symptoms alone is difficult in many cases, and the electrophysiological diagnostic method is solely used as a supplementary diagnostic method at present. As a new diagnostic method for entrapment neuropathy, the present study investigated the usefulness of gadolinium-enhanced MRI in carpal tunnel syndrome. On enhanced MRI of idiopathic carpal tunnel syndrome, contrast-enhancement in the median nerve was found in 30 of 34 hands (88.2%). Enhanced MRI allows to visualize intraneural edema in the nerve easily on the naked eye. Therefore, this technique supplied useful information for making definitive diagnosis and is promising as a non-invasive diagnostic method for entrapment neuropathy. (author)

  17. Development of techniques for fabrication of film probe sensor assembly

    International Nuclear Information System (INIS)

    Moorhead, A.J.

    1982-10-01

    Pulsed laser welding and brazing techniques were developed for fabrication of sensors designed to measure liquid film properties in out-of-reactor safety tests that simulate a loss-of-coolant accident in a pressurized-water nuclear reactor. These sensors were made possible by a unique ceramic-to-metal seal system based on a cermet insulator and a brazing filler metal, both developed at ORNL. This seal system was shown to resist steam to an exposure of at least 100 h at 700 0 C (1292 0 F) and to resist repetitive thermal transients of 300 0 C/s (540 0 F). Procedures were also developed for induction brazing the instrumentation cables to a stainless steel end cap and for laser welding this component to the brazed sensor body itself. Cable end seals and sensor bodies fabricated with these designs and techniques maintained excellent helium leaktightness ( -6 cm 3 /s) after 20 severe thermal shock tests from 500 0 C air into water at 80 0 C

  18. Photoelectrode Fabrication of Dye-Sensitized Nanosolar Cells Using Multiple Spray Coating Technique

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2013-01-01

    Full Text Available This paper presents a spray coating technique for fabricating nanoporous film of photoelectrode in dye-sensitized nanosolar cells (DSSCs. Spray coating can quickly fabricate nanoporous film of the photoelectrode with lower cost, which can further help the DSSCs to be commercialized in the future. This paper analyzed photoelectric conversion efficiency of the DSSCs using spray coated photoelectrode in comparison with the photoelectrode made with the doctor blade method. Spray coating can easily control transmittance of the photoelectrode through the multiple spray coating process. This work mainly used a dispersant with help of ultrasonic oscillation to prepare the required nano-TiO2 solution and then sprayed it on the ITO glasses. In this work, a motor-operated conveyor belt was built to transport the ITO glasses automatically for multiple spray coating and drying alternately. Experiments used transmittance of the photoelectrode as a fabrication parameter to analyze photoelectric conversion efficiency of the DSSCs. The influencing factors of the photoelectrode transmittance during fabrication are the spray flow rate, the spray distance, and the moving speed of the conveyor belt. The results show that DSSC with the photoelectrode transmittance of ca. 68.0 ± 1.5% and coated by the spray coating technique has the best photoelectric conversion efficiency in this work.

  19. COGNITIVE RESTRUCTURING: ALTERNATIVE COUNSELING TECHNIQUES TO REDUCTION ACADEMIC PROCRASTINATION

    Directory of Open Access Journals (Sweden)

    Annisa Sofiana

    2016-12-01

    Full Text Available Procrastination is often experienced by almost everyone, including students who often delay to resolve any responsibility in the academic process that would decrease the individual academic achievement. cognitive restructuring is one of the cognitive techniques used in counseling in addition to cognitive behavioral techniques (behavioral and didaktif techniques. This technique has several procedures by focusing on identifying an effort and changing dysfunctional thoughts or negative self-statements into a new belief that is more rational and adaptive, which will affect more rational behavior anyway. Cognitive restructuring techniques assessed to be an alternative counseling techniques in reducing academic procrastination.

  20. System study of alternative waste management techniques: Final report

    International Nuclear Information System (INIS)

    1986-01-01

    This report summarizes the important results achieved in conjunction with the Research and Development Priority ''Alternative Waste Management Techniques'' sponsored by the Federal Ministry of Research and Technology from 1981 to 1984. The subject of these studies was solely ''direct disposal'' of spent fuel elements. For this purpose a reference concept was selected from a variety of possible processes and engineered in detailed form by firms in the nuclear industry. Those who worked on the engineering concepts consider this waste management method technically feasible. Several disposal casks have been fabricated. The basic licensability of direct disposal can be evaluated on the basis of the documentation developed by the companies. The direct disposal method was compared with the ''integrated waste management concept'' using reference fuel cycles with respect to the following criteria: radiological safety and nuclear material safeguards and, in addition, economic and energy-policy aspects. It was found that with respect to radiological safety, including the long-term safety of the final repository, there are no significant differences between the two fuel cycles with and without reprocessing. With respect to the nuclear material safeguards of a final repository containing spent fuel elements, there are still a number of unanswered questions. From an economic standpoint, direct disposal will be more economical in the foreseeable future than integrated waste management. Quantification of the effects of one or the other waste management method on the national economy is not necessarily possible. Reprocessing is supported primarily by technological and energy-policy considerations. On the basis of the results, the conclusion is reached that reprocessing should be pursued further, but that at the same time direct disposal should be developed to the point of practical maturity

  1. A microelectromechanical accelerometer fabricated using printed circuit processing techniques

    Science.gov (United States)

    Rogers, J. E.; Ramadoss, R.; Ozmun, P. M.; Dean, R. N.

    2008-01-01

    A microelectromechanical systems (MEMS) capacitive-type accelerometer fabricated using printed circuit processing techniques is presented. A Kapton polymide film is used as the structural layer for fabricating the MEMS accelerometer. The accelerometer proof mass along with four suspension beams is defined in the Kapton polyimide film. The proof mass is suspended above a Teflon substrate using a spacer. The deflection of the proof mass is detected using a pair of capacitive sensing electrodes. The top electrode of the accelerometer is defined on the top surface of the Kapton film. The bottom electrode is defined in the metallization on the Teflon substrate. The initial gap height is determined by the distance between the bottom electrode and the Kapton film. For an applied external acceleration (normal to the proof mass), the proof mass deflects toward or away from the fixed bottom electrode due to inertial force. This deflection causes either a decrease or increase in the air-gap height thereby either increasing or decreasing the capacitance between the top and the bottom electrodes. An example PCB MEMS accelerometer with a square proof mass of membrane area 6.4 mm × 6.4 mm is reported. The measured resonant frequency is 375 Hz and the Q-factor in air is 0.52.

  2. A microelectromechanical accelerometer fabricated using printed circuit processing techniques

    International Nuclear Information System (INIS)

    Rogers, J E; Ramadoss, R; Ozmun, P M; Dean, R N

    2008-01-01

    A microelectromechanical systems (MEMS) capacitive-type accelerometer fabricated using printed circuit processing techniques is presented. A Kapton polymide film is used as the structural layer for fabricating the MEMS accelerometer. The accelerometer proof mass along with four suspension beams is defined in the Kapton polyimide film. The proof mass is suspended above a Teflon substrate using a spacer. The deflection of the proof mass is detected using a pair of capacitive sensing electrodes. The top electrode of the accelerometer is defined on the top surface of the Kapton film. The bottom electrode is defined in the metallization on the Teflon substrate. The initial gap height is determined by the distance between the bottom electrode and the Kapton film. For an applied external acceleration (normal to the proof mass), the proof mass deflects toward or away from the fixed bottom electrode due to inertial force. This deflection causes either a decrease or increase in the air-gap height thereby either increasing or decreasing the capacitance between the top and the bottom electrodes. An example PCB MEMS accelerometer with a square proof mass of membrane area 6.4 mm × 6.4 mm is reported. The measured resonant frequency is 375 Hz and the Q-factor in air is 0.52

  3. OLED Fabrication by Using a Novel Planar Evaporation Technique

    Directory of Open Access Journals (Sweden)

    Fu-Ching Tung

    2014-01-01

    Full Text Available Organic light-emitting diode fabrication is suffering from extremely high material wasting during deposition especially using a typical point or even line source. Moreover, the need of depositing a high number of emitters and host(s with a precise composition control in a single layer makes traditional vapor codeposition systems nearly impossible, unless otherwise with a very low yield. To improve, we have developed a novel thin-film deposition system with a planar source loadable with any premetered solvent-mixed organic compounds, plausibly with no component number limitation. We hence demonstrate experimentally, along with a Monte Carlo simulation, in the report the feasibility of using the technique to deposit on a large area-size substrate various organic materials with a relatively high material utilization rate coupling with high film uniformity. Specifically, nonuniformity of less than ±5% and material utilization rate of greater than 70% have been obtained for the studied films.

  4. Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: an in vitro study.

    Science.gov (United States)

    Reddy, S Srikanth; Revathi, Kakkirala; Reddy, S Kranthikumar

    2013-01-01

    Conventional casting technique is time consuming when compared to accelerated casting technique. In this study, marginal accuracy of castings fabricated using accelerated and conventional casting technique was compared. 20 wax patterns were fabricated and the marginal discrepancy between the die and patterns were measured using Optical stereomicroscope. Ten wax patterns were used for Conventional casting and the rest for Accelerated casting. A Nickel-Chromium alloy was used for the casting. The castings were measured for marginal discrepancies and compared. Castings fabricated using Conventional casting technique showed less vertical marginal discrepancy than the castings fabricated by Accelerated casting technique. The values were statistically highly significant. Conventional casting technique produced better marginal accuracy when compared to Accelerated casting. The vertical marginal discrepancy produced by the Accelerated casting technique was well within the maximum clinical tolerance limits. Accelerated casting technique can be used to save lab time to fabricate clinical crowns with acceptable vertical marginal discrepancy.

  5. Predicting the Mechanical Properties of Viscose/Lycra Knitted Fabrics Using Fuzzy Technique

    Directory of Open Access Journals (Sweden)

    Ismail Hossain

    2016-01-01

    Full Text Available The main objective of this research is to predict the mechanical properties of viscose/lycra plain knitted fabrics by using fuzzy expert system. In this study, a fuzzy prediction model has been built based on knitting stitch length, yarn count, and yarn tenacity as input variables and fabric mechanical properties specially bursting strength as an output variable. The factors affecting the bursting strength of viscose knitted fabrics are very nonlinear. Hence, it is very challenging for scientists and engineers to create an exact model efficiently by mathematical or statistical model. Alternatively, developing a prediction model via ANN and ANFIS techniques is also difficult and time consuming process due to a large volume of trial data. In this context, fuzzy expert system (FES is the promising modeling tool in a quality modeling as FES can map effectively in nonlinear domain with minimum experimental data. The model derived in the present study has been validated by experimental data. The mean absolute error and coefficient of determination between the actual bursting strength and that predicted by the fuzzy model were found to be 2.60% and 0.961, respectively. The results showed that the developed fuzzy model can be applied effectively for the prediction of fabric mechanical properties.

  6. Characterization of a Viking Blade Fabricated by Traditional Forging Techniques

    Science.gov (United States)

    Vo, H.; Frazer, D.; Bailey, N.; Traylor, R.; Austin, J.; Pringle, J.; Bickel, J.; Connick, R.; Connick, W.; Hosemann, P.

    2016-12-01

    A team of students from the University of California, Berkeley, participated in a blade-smithing competition hosted by the Minerals, Metals, and Materials Society at the TMS 2015 144th annual meeting and exhibition. Motivated by ancient forging methods, the UC Berkeley team chose to fabricate our blade from historical smithing techniques utilizing naturally-occurring deposits of iron ore. This approach resulted in receiving the "Best Example of a Traditional Blade Process/Ore Smelting Technique" award for our blade named "Berkelium." First, iron-enriched sand was collected from local beaches. Magnetite (Fe3O4) was then extracted from the sand and smelted into individual high- and low-carbon steel ingots. Layers of high- and low-carbon steels were forge-welded together, predominantly by hand, to form a composite material. Optical microscopy, energy dispersive spectroscopy, and Vickers hardness mechanical testing were conducted at different stages throughout the blade-making process to evaluate the microstructure and hardness evolution during formation. It was found that the pre-heat-treated blade microstructure was composed of ferrite and pearlite, and contained many nonmetallic inclusions. A final heat treatment was performed, which caused the average hardness of the blade edge to increase by more than a factor of two, indicating a martensitic transformation.

  7. Fabrication of channeled scaffolds with ordered array of micro-pores through microsphere leaching and indirect Rapid Prototyping technique.

    Science.gov (United States)

    Tan, J Y; Chua, C K; Leong, K F

    2013-02-01

    Advanced scaffold fabrication techniques such as Rapid Prototyping (RP) are generally recognized to be advantageous over conventional fabrication methods in terms architectural control and reproducibility. Yet, most RP techniques tend to suffer from resolution limitations which result in scaffolds with uncontrollable, random-size pores and low porosity, albeit having interconnected channels which is characteristically present in most RP scaffolds. With the increasing number of studies demonstrating the profound influences of scaffold pore architecture on cell behavior and overall tissue growth, a scaffold fabrication method with sufficient architectural control becomes imperative. The present study demonstrates the use of RP fabrication techniques to create scaffolds having interconnected channels as well as controllable micro-size pores. Adopted from the concepts of porogen leaching and indirect RP techniques, the proposed fabrication method uses monodisperse microspheres to create an ordered, hexagonal closed packed (HCP) array of micro-pores that surrounds the existing channels of the RP scaffold. The pore structure of the scaffold is shaped using a single sacrificial construct which comprises the microspheres and a dissolvable RP mold that were sintered together. As such, the size of pores as well as the channel configuration of the scaffold can be tailored based on the design of the RP mold and the size of microspheres used. The fabrication method developed in this work can be a promising alternative way of preparing scaffolds with customized pore structures that may be required for specific studies concerning cell-scaffold interactions.

  8. Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor

    Science.gov (United States)

    Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy

    2013-01-01

    Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited

  9. Helium-cooled pebble bed test blanket module alternative design and fabrication routes

    International Nuclear Information System (INIS)

    Lux, M.

    2007-01-01

    According to first results of the recently started European DEMO study, a new blanket integration philosophy was developed applying so-called multi-module segments. These consist of a number of blanket modules flexibly mounted onto a common vertical manifold structure that can be used for replacing all modules in one segment at one time through vertical remote-handling ports. This principle gives new freedom in the design choices applied to the blanket modules itself. Based on the alternative design options considered for DEMO also the ITER test blanket module was newly analyzed. As a result of these activities it was decided to keep the major principles of the reference design like stiffening grid, breeder unit concept and perpendicular arrangement of pebble beds related to the First Wall because of the very positive results of thermo-mechanical and neutronics studies. The present paper gives an overview on possible further design optimization and alternative fabrication routes. One of the most significant improvements in terms of the hydraulic performance of the Helium cooled reactor can be reached with a new First Wall concept. That concept is based on an internal heat transfer enhancement technique and allows drastically reducing the flow velocity in the FW cooling channels. Small ribs perpendicular to the flow direction (transverse-rib roughness) are arranged on the inner surface of the First Wall cooling channels at the plasma side. In the breeder units cooling plates which are mostly parallel but bent into U-shape at the plasma-side are considered. In this design all flow channels are parallel and straight with the flow entering on one side of the parallel plate sections and exiting on the other side. The ceramic pebble beds are embedded between two pairs of such type of cooling plates. Different modifications could possibly be combined, whereby the most relevant discussed in this paper are (i) rib-cooled First Wall channels, (ii) U-bent cooling plates for

  10. Advanced accountability techniques for breeder fuel fabrication facilities

    International Nuclear Information System (INIS)

    Bennion, S.I.; Carlson, R.L.; DeMerschman, A.W.; Sheely, W.F.

    1978-01-01

    The United States Department of Energy (DOE) has assigned the Hanford Engineering Development Laboratory (HEDL), operated by the Westinghouse Hanford Company, the project lead in developing a uniform nuclear materials reporting system for all contractors on the Hanford Reservation. The Hanford Nuclear Inventory System (HANISY) is based upon HEDL's real-time accountability system, originally developed in 1968. The HANISY system will receive accountability data either from entry by process operators at remote terminals or from nondestructive assay instruments connected to the computer network. Nuclear materials will be traced from entry, through processing to final shipment through the use of minicomputer technology. Reports to DOE will be formed directly from the realtime files. In addition, HEDL has established a measurement program that will complement the HANISY system, providing direct interface to the computer files with a minimum of operator intervention. This technology is being developed to support the High Performance Fuels Laboratory (HPFL) which is being designed to assess fuel fabrication techniques for proliferation-resistant fuels

  11. Alternate gram staining technique using a fluorescent lectin.

    Science.gov (United States)

    Sizemore, R K; Caldwell, J J; Kendrick, A S

    1990-01-01

    Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

  12. An Evaluation of Pinhole Castration as an Alternative Technique for ...

    African Journals Online (AJOL)

    We evaluated pinhole castration as an alternative technique for dog population control in resource poor rural communities of Gulu, Northern Uganda. Through a campaign dubbed 'Big Fix Gulu', households in selected communities were mobilized using radio announcements, posters and school visits, to present dogs for ...

  13. An Alternative Technique in the Control of Massive Presacral Rectal ...

    African Journals Online (AJOL)

    Bleeding control was provided by GORE‑TEX® graft. We conclude that fıxatıon of GORE‑TEX® aortic patch should be kept in mind for uncontrolled massive presacral bleeding. KEYWORDS: GORE‑TEX® graft, presacral bleeding, rectal cancer. An Alternative Technique in the Control of Massive Presacral Rectal. Bleeding: ...

  14. Improved ceramic slip casting technique. [application to aircraft model fabrication

    Science.gov (United States)

    Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)

    1993-01-01

    A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, slip casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous slip casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the slip material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell

  15. Study on the Filament Yarns Spreading Techniques and Assessment Methods of the Electronic Fiberglass Fabric

    Science.gov (United States)

    Wang, Xi; Chen, Shouhui; Zheng, Tianyong; Ning, Xiangchun; Dai, Yifei

    2018-03-01

    The filament yarns spreading techniques of electronic fiberglass fabric were developed in the past few years in order to meet the requirements of the development of electronic industry. Copper clad laminate (CCL) requires that the warp and weft yarns of the fabric could be spread out of apart and formed flat. The penetration performance of resin could be improved due to the filament yarns spreading techniques of electronic fiberglass fabric, the same as peeling strength of CCL and drilling performance of printed circuit board (PCB). This paper shows the filament yarns spreading techniques of electronic fiberglass fabric from several aspects, such as methods and functions, also with the assessment methods of their effects.

  16. Technique for fabrication of gradual standards of radiographic image blachening density

    International Nuclear Information System (INIS)

    Borovin, I.V.; Kondina, M.A.

    1987-01-01

    The technique of fabrication of gradual standards of blackening density for industrial radiography by contact printing from a negative is described. The technique is designed for possibilities of industrial laboratoriesof radiation defectoscopy possessing no special-purpose sensitometric equipment

  17. Alternative containment integrity test methods, an overview of possible techniques

    International Nuclear Information System (INIS)

    Spletzer, B.L.

    1986-01-01

    A study is being conducted to develop and analyze alternative methods for testing of containment integrity. The study is focused on techniques for continuously monitoring containment integrity to provide rapid detection of existing leaks, thus providing greater certainty of the integrity of the containment at any time. The study is also intended to develop techniques applicable to the currently required Type A integrated leakage rate tests. A brief discussion of the range of alternative methods currently being considered is presented. The methods include applicability to all major containment types, operating and shutdown plant conditions, and quantitative and qualitative leakage measurements. The techniques are analyzed in accordance with the current state of knowledge of each method. The bulk of the techniques discussed are in the conceptual stage, have not been tested in actual plant conditions, and are presented here as a possible future direction for evaluating containment integrity. Of the methods considered, no single method provides optimum performance for all containment types. Several methods are limited in the types of containment for which they are applicable. The results of the study to date indicate that techniques for continuous monitoring of containment integrity exist for many plants and may be implemented at modest cost

  18. Structural design and fabrication techniques of composite unmanned aerial vehicles

    Science.gov (United States)

    Hunt, Daniel Stephen

    Popularity of unmanned aerial vehicles has grown substantially in recent years both in the private sector, as well as for government functions. This growth can be attributed largely to the increased performance of the technology that controls these vehicles, as well as decreasing cost and size of this technology. What is sometimes forgotten though, is that the research and advancement of the airframes themselves are equally as important as what is done with them. With current computer-aided design programs, the limits of design optimization can be pushed further than ever before, resulting in lighter and faster airframes that can achieve longer endurances, higher altitudes, and more complex missions. However, realization of a paper design is still limited by the physical restrictions of the real world and the structural constraints associated with it. The purpose of this paper is to not only step through current design and manufacturing processes of composite UAVs at Oklahoma State University, but to also focus on composite spars, utilizing and relating both calculated and empirical data. Most of the experience gained for this thesis was from the Cessna Longitude project. The Longitude is a 1/8 scale, flying demonstrator Oklahoma State University constructed for Cessna. For the project, Cessna required dynamic flight data for their design process in order to make their 2017 release date. Oklahoma State University was privileged enough to assist Cessna with the mission of supporting the validation of design of their largest business jet to date. This paper will detail the steps of the fabrication process used in construction of the Longitude, as well as several other projects, beginning with structural design, machining, molding, skin layup, and ending with final assembly. Also, attention will be paid specifically towards spar design and testing in effort to ease the design phase. This document is intended to act not only as a further development of current

  19. Material control in nuclear fuel fabrication facilities. Part II. Accountability, instrumentation and measurement techniques in fuel fabrication facilities

    International Nuclear Information System (INIS)

    Borgonovi, G.M.; McCartin, T.J.; McDaniel, T.; Miller, C.L.; Nguyen, T.

    1978-01-01

    This report describes the measurement techniques, the instrumentation, and the procedures used in accountability and control of nuclear materials, as they apply to fuel fabrication facilities. A general discussion is given of instrumentation and measurement techniques which are presently used being considered for fuel fabrication facilities. Those aspects which are most significant from the point of view of satisfying regulatory constraints have been emphasized. Sensors and measurement devices have been discussed, together with their interfacing into a computerized system designed to permit real-time data collection and analysis. Estimates of accuracy and precision of measurement techniques have been given, and, where applicable, estimates of associated costs have been presented. A general description of material control and accounting is also included. In this section, the general principles of nuclear material accounting have been reviewed first (closure of material balance). After a discussion of the most current techniques used to calculate the limit of error on inventory difference, a number of advanced statistical techniques are reviewed. The rest of the section deals with some regulatory aspects of data collection and analysis, for accountability purposes, and with the overall effectiveness of accountability in detecting diversion attempts in fuel fabrication facilities. A specific example of application of the accountability methods to a model fuel fabrication facility is given. The effect of random and systematic errors on the total material uncertainty has been discussed, together with the effect on uncertainty of the length of the accounting period

  20. Material control in nuclear fuel fabrication facilities. Part II. Accountability, instrumentation and measurement techniques in fuel fabrication facilities

    Energy Technology Data Exchange (ETDEWEB)

    Borgonovi, G.M.; McCartin, T.J.; McDaniel, T.; Miller, C.L.; Nguyen, T.

    1978-01-01

    This report describes the measurement techniques, the instrumentation, and the procedures used in accountability and control of nuclear materials, as they apply to fuel fabrication facilities. A general discussion is given of instrumentation and measurement techniques which are presently used being considered for fuel fabrication facilities. Those aspects which are most significant from the point of view of satisfying regulatory constraints have been emphasized. Sensors and measurement devices have been discussed, together with their interfacing into a computerized system designed to permit real-time data collection and analysis. Estimates of accuracy and precision of measurement techniques have been given, and, where applicable, estimates of associated costs have been presented. A general description of material control and accounting is also included. In this section, the general principles of nuclear material accounting have been reviewed first (closure of material balance). After a discussion of the most current techniques used to calculate the limit of error on inventory difference, a number of advanced statistical techniques are reviewed. The rest of the section deals with some regulatory aspects of data collection and analysis, for accountability purposes, and with the overall effectiveness of accountability in detecting diversion attempts in fuel fabrication facilities. A specific example of application of the accountability methods to a model fuel fabrication facility is given. The effect of random and systematic errors on the total material uncertainty has been discussed, together with the effect on uncertainty of the length of the accounting period.

  1. Detailed design, fabrication and testing of an engineering prototype compensated pulsed alternator. Final report

    International Nuclear Information System (INIS)

    Bird, W.L. Jr.; Woodson, H.H.

    1980-03-01

    The design, fabrication, and test results of a prototype compensated pulsed alternator are discussed. The prototype compulsator is a vertical shaft single phase alternator with a rotating armature and salient pole stator. The machine is designed for low rep rate pulsed duty and is sized to drive a modified 10 cm Beta amplifier. The load consists of sixteen 15 mm x 20 mm x 112 cm long xenon flashlamps connected in parallel. The prototype compulsator generates an open circuit voltage of 6 kV, 180 Hz, at a maximum design speed of 5400 rpm. At maximum speed, the inertial energy stored in the compulsator rotor is 3.4 megajoules

  2. Wire electric-discharge machining and other fabrication techniques

    Science.gov (United States)

    Morgan, W. H.

    1983-01-01

    Wire electric discharge machining and extrude honing were used to fabricate a two dimensional wing for cryogenic wind tunnel testing. Electric-discharge cutting is done with a moving wire electrode. The cut track is controlled by means of a punched-tape program and the cutting feed is regulated according to the progress of the work. Electric-discharge machining involves no contact with the work piece, and no mechanical force is exerted. Extrude hone is a process for honing finish-machined surfaces by the extrusion of an abrasive material (silly putty), which is forced through a restrictive fixture. The fabrication steps are described and production times are given.

  3. Novel in-situ lamella fabrication technique for in-situ TEM.

    Science.gov (United States)

    Canavan, Megan; Daly, Dermot; Rummel, Andreas; McCarthy, Eoin K; McAuley, Cathal; Nicolosi, Valeria

    2018-03-29

    In-situ transmission electron microscopy is rapidly emerging as the premier technique for characterising materials in a dynamic state on the atomic scale. The most important aspect of in-situ studies is specimen preparation. Specimens must be electron transparent and representative of the material in its operational state, amongst others. Here, a novel fabrication technique for the facile preparation of lamellae for in-situ transmission electron microscopy experimentation using focused ion beam milling is developed. This method involves the use of rotating microgrippers during the lift-out procedure, as opposed to the traditional micromanipulator needle and platinum weld. Using rotating grippers, and a unique adhesive substance, lamellae are mounted onto a MEMS device for in-situ TEM annealing experiments. We demonstrate how this technique can be used to avoid platinum deposition as well as minimising damage to the MEMS device during the thinning process. Our technique is both a cost effective and readily implementable alternative to the current generation of preparation methods for in-situ liquid, electrical, mechanical and thermal experimentation within the TEM as well as traditional cross-sectional lamella preparation. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. A novel fabrication technique for free-hanging homogeneous polymeric cantilever waveguides

    International Nuclear Information System (INIS)

    Nordström, Maria; Hübner, Jörg; Boisen, Anja; Calleja, Montserrat

    2008-01-01

    We present a novel bonding technique developed for the fabrication of a cantilever-based biosensing system with integrated optical read-out. The read-out mechanism is based on single-mode waveguides fabricated monolithically in SU-8. For optimal operation of the read-out mode, the cantilever waveguides should be homogenous and this bonding technique ensures free-hanging cantilevers that are surrounded by the same material for bottom and top claddings. The bonding step is necessary because SU-8 is a negative resist where free-hanging structures cannot be fabricated directly. This paper gives details on the processing aspects and the parameters of the fabrication steps

  5. Review on recent Developments on Fabrication Techniques of Distributed Feedback (DFB) Based Organic Lasers

    Science.gov (United States)

    Azrina Talik, Noor; Boon Kar, Yap; Noradhlia Mohamad Tukijan, Siti; Wong, Chuan Ling

    2017-10-01

    To date, the state of art organic semiconductor distributed feedback (DFB) lasers gains tremendous interest in the organic device industry. This paper presents a short reviews on the fabrication techniques of DFB based laser by focusing on the fabrication method of DFB corrugated structure and the deposition of organic gain on the nano-patterned DFB resonator. The fabrication techniques such as Laser Direct Writing (LDW), ultrafast photo excitation dynamics, Laser Interference Lithography (LIL) and Nanoimprint Lithography (NIL) for DFB patterning are presented. In addition to that, the method for gain medium deposition method is also discussed. The technical procedures of the stated fabrication techniques are summarized together with their benefits and comparisons to the traditional fabrication techniques.

  6. Fabrication technique of U-siliscide solution crucible

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chull Koo; Kim, Joon Soo; Ha, Ho Gwan; Kang, Hwan Gui; Kim, Jung Goo; Yun, Jong Yong [Dongsuh Ceramic Institute, Seoul (Korea, Republic of)

    1997-07-01

    The objective of this study is to establish ZrO{sub 2} crucibel fabrication technology preventing the infiltration by foreign substances. This study was established and practiced technology of formation and sintering of dense zirconia crucible was established at the second year. 21 refs., 10 tabs., 21 figs. (author)

  7. Paediatric sutureless circumcision-an alternative to the standard technique.

    LENUS (Irish Health Repository)

    2012-01-31

    INTRODUCTION: Circumcision is one of the most commonly performed surgical procedures in male children. A range of surgical techniques exist for this commonly performed procedure. The aim of this study is to assess the safety, functional outcome and cosmetic appearance of a sutureless circumcision technique. METHODS: Over a 9-year period, 502 consecutive primary sutureless circumcisions were performed by a single surgeon. All 502 cases were entered prospectively into a database including all relevant clinical details and a review was performed. The technique used to perform the sutureless circumcision is a modification of the standard sleeve technique with the use of a bipolar diathermy and the application of 2-octyl cyanoacrylate (2-OCA) to approximate the tissue edges. RESULTS: All boys in this study were pre-pubescent and the ages ranged from 6 months to 12 years (mean age 3.5 years). All patients had this procedure performed as a day case and under general anaesthetic. Complications included: haemorrhage (2.2%), haematoma (1.4%), wound infection (4%), allergic reaction (0.2%) and wound dehiscence (0.8%). Only 9 (1.8%) parents or patients were dissatisfied with the cosmetic appearance. CONCLUSION: The use of 2-OCA as a tissue adhesive for sutureless circumcisions is an alternative to the standard suture technique. The use of this tissue adhesive, 2-OCA, results in comparable complication rates to the standard circumcision technique and results in excellent post-operative cosmetic satisfaction.

  8. Top-quark mass measurements: Alternative techniques (LHC + Tevatron)

    CERN Document Server

    Adomeit, Stefanie; The ATLAS collaboration

    2014-01-01

    Measurements of the top-quark mass employing alternative techniques are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at the LHC. The alternative methods presented include measurements using the lifetime of $B$-hadrons, the transverse momentum of charged leptons and the endpoints of kinematic distributions in top quark anti-quark pair ($t\\bar{t}$) final states. The extraction of the top-quark pole mass from the $t\\bar{t}$ production cross-section and the normalized differential $t\\bar{t}$ + 1-jet cross-section are discussed as well as the top-quark mass extraction using fixed-order QCD predictions at detector level. Finally, a measurement of the top-quark mass using events enhanced in single top t-channel production is presented.

  9. Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array.

    Science.gov (United States)

    Chen, Yu-Liang; Jiang, Hong-Ren

    2017-06-23

    This article provides a simple method to prepare partially or fully coated metallic particles and to perform the rapid fabrication of electrode arrays, which can facilitate electrical experiments in microfluidic devices. Janus particles are asymmetric particles that contain two different surface properties on their two sides. To prepare Janus particles, a monolayer of silica particles is prepared by a drying process. Gold (Au) is deposited on one side of each particle using a sputtering device. The fully coated metallic particles are completed after the second coating process. To analyze the electrical surface properties of Janus particles, alternating current (AC) electrokinetic measurements, such as dielectrophoresis (DEP) and electrorotation (EROT)- which require specifically designed electrode arrays in the experimental device- are performed. However, traditional methods to fabricate electrode arrays, such as the photolithographic technique, require a series of complicated procedures. Here, we introduce a flexible method to fabricate a designed electrode array. An indium tin oxide (ITO) glass is patterned by a fiber laser marking machine (1,064 nm, 20 W, 90 to 120 ns pulse-width, and 20 to 80 kHz pulse repetition frequency) to create a four-phase electrode array. To generate the four-phase electric field, the electrodes are connected to a 2-channel function generator and to two invertors. The phase shift between the adjacent electrodes is set at either 90° (for EROT) or 180° (for DEP). Representative results of AC electrokinetic measurements with a four-phase ITO electrode array are presented.

  10. Digital radiography: study of an alternative technique to conventional radiography

    International Nuclear Information System (INIS)

    Banchet, J.; Tisseur, D.; Thomas, A.

    2009-01-01

    Digital radiography, already in use in many industrial applications, appears as a potential alternative technique to conventional radiography in the nuclear field (and more especially to the inspection of welded joints). The advantages of digital radiography are a reduced explosion risk (due to the use of lower energy and activity sources), a lower installation time, a reduced exclusion zone, and the absence of effluents. However, to the contrary of the US case, this technique may not be used in France as it is not referenced in the regulating codes (RCCM, etc.). Areva has launched a R and D study in order to characterize the equivalencies between digital and conventional radiography. First results of this study are given

  11. A novel fabrication technique for free-hanging homogeneous polymeric cantilever waveguides

    DEFF Research Database (Denmark)

    Nordström, M.; Calleja, M.; Hübner, Jörg

    2008-01-01

    We present a novel bonding technique developed for the fabrication of a cantilever-based biosensing system with integrated optical read-out. The read-out mechanism is based on single-mode waveguides fabricated monolithically in SU-8. For optimal operation of the read-out mode, the cantilever...

  12. Two-beam laser fabrication technique and the application for fabricating conductive silver nanowire on flexible substrate

    Directory of Open Access Journals (Sweden)

    Gui-Cang He

    2017-03-01

    Full Text Available In this study, a two-beam laser fabrication technique is proposed to fabricate silver nanowire (AgNW on the polyethylene terephthalate (PET substrate. The femtosecond pulse laser in the technique plays a role in generating Ag nanoparticles from the silver aqueous solution by multiphoton photoreduction. The continuous wave (CW laser of the technique works as optical tweezers, and make the Ag nanoparticles gather to a continuous AgNW by the optical trapping force. The optical trapping force of the CW laser was calculated under our experimental condition. The flexibility and the resistance stability of the AgNW that fabricated by this technique are very excellent. Compared to the resistance of the AgNW without bending, the decreasing rate of the AgNW resistance is about 16% under compressed bending condition at the radius of 1 mm, and the increasing rate of the AgNW resistance is only 1.3% after the AgNW bended about 3500 times at the bending radius of 1 mm. The study indicates that the AgNW is promising for achieving flexible device and would promote the development of the flexible electronics.

  13. A comparison of enhancement techniques for footwear impressions on dark and patterned fabrics.

    Science.gov (United States)

    Farrugia, Kevin J; Bandey, Helen; Dawson, Lorna; Daéid, Niamh Nic

    2013-11-01

    The use of chemical enhancement techniques on porous substrates, such as fabrics, poses several challenges predominantly due to the occurrence of background staining and diffusion as well as visualization difficulties. A range of readily available chemical and lighting techniques were utilized to enhance footwear impressions made in blood, soil, and urine on dark and patterned fabrics. Footwear impressions were all prepared at a set force using a specifically built footwear rig. In most cases, results demonstrated that fluorescent chemical techniques were required for visualization as nonfluorescent techniques provided little or no contrast with the background. Occasionally, this contrast was improved by oblique lighting. Successful results were obtained for the enhancement of footwear impressions in blood; however, the enhancement of footwear impressions in urine and soil on dark and patterned fabrics was much more limited. The results demonstrate that visualization and fluorescent enhancement on porous substrates such as fabrics is possible. © 2013 American Academy of Forensic Sciences.

  14. Fabrication Techniques of Stretchable and Cloth Electroadhesion Samples for Implementation on Devices with Space Application

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this study is to determine materials and fabrication techniques for efficient space-rated electroadhesion (EA) samples. Liquid metals, including...

  15. Development of a Direct Fabrication Technique for Full-Shell X-Ray Optics

    Science.gov (United States)

    Gubarev, M.; Kolodziejczak, J. K.; Griffith, C.; Roche, J.; Smith, W. S.; Kester, T.; Atkins, C.; Arnold, W.; Ramsey, B.

    2016-01-01

    Future astrophysical missions will require fabrication technology capable of producing high angular resolution x-ray optics. A full-shell direct fabrication approach using modern robotic polishing machines has the potential for producing high resolution, light-weight and affordable x-ray mirrors that can be nested to produce large collecting area. This approach to mirror fabrication, based on the use of the metal substrates coated with nickel phosphorous alloy, is being pursued at MSFC. The design of the polishing fixtures for the direct fabrication, the surface figure metrology techniques used and the results of the polishing experiments are presented.

  16. Characteristics of a single-channel superconducting flux flow transistor fabricated by an AFM modification technique

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seokcheol [Jeonnam Regional Innovation Agency, 1000 Namak-Ri, Samhyang-Myun, Muan-Gun, Jeollanam-Do 534-700 (Korea, Republic of)], E-mail: suntrac@jina.re.kr; Kim, Seong-Jong [Mokpo Maritime University, Chukkyo-Dong, Mokpo City, Cheonnam 530-729 (Korea, Republic of)

    2007-11-01

    The demand for high performance, integrity, and miniaturization in the area of electronic and mechanic devices has drawn interest in the fabrication of nanostructures. However, it is difficult to fabricate the channel with nano-scale using a conventional photography techniques. AFM anodization technique is a maskless process and effective method to overcome the difficulty in fabricating a nano-scale channel. In this paper, we first present a new fabrication of a single-channel SFFT using a selective oxidation process induced by an AFM probe. The modified channel was investigated by electron probe microanalyzer (EPMA) to find the compositional variation of the transformed region. In order to confirm the operation of a single-channel SFFT, we measured the voltage-current characteristics at the temperature of liquid nitrogen by an I-V automatic measurement system. Our results indicate that the single-channel SFFT having effect as a weak link is effectively fabricated by an AFM lithography process.

  17. Characteristics of a single-channel superconducting flux flow transistor fabricated by an AFM modification technique

    International Nuclear Information System (INIS)

    Ko, Seokcheol; Kim, Seong-Jong

    2007-01-01

    The demand for high performance, integrity, and miniaturization in the area of electronic and mechanic devices has drawn interest in the fabrication of nanostructures. However, it is difficult to fabricate the channel with nano-scale using a conventional photography techniques. AFM anodization technique is a maskless process and effective method to overcome the difficulty in fabricating a nano-scale channel. In this paper, we first present a new fabrication of a single-channel SFFT using a selective oxidation process induced by an AFM probe. The modified channel was investigated by electron probe microanalyzer (EPMA) to find the compositional variation of the transformed region. In order to confirm the operation of a single-channel SFFT, we measured the voltage-current characteristics at the temperature of liquid nitrogen by an I-V automatic measurement system. Our results indicate that the single-channel SFFT having effect as a weak link is effectively fabricated by an AFM lithography process

  18. A preferential coating technique for fabricating large, high quality optics

    International Nuclear Information System (INIS)

    Alcock, S.G.; Cockerton, S.

    2010-01-01

    A major challenge facing optic manufacturers is the fabrication of large mirrors (>1 m) with minimal residual slope errors (<0.5 μrad rms). We present a differential coating method with the potential to satisfy such exacting technical demands. Iterative cycles of measurement using the Diamond-NOM, followed by preferential deposition, were performed on a 1200 mm long, silicon mirror. The applied coatings were observed to reduce the optical slope and figure errors from 1.62 to 0.44 μrad rms, and from 208 to 13 nm rms, respectively. It is hoped that this research will lead to commercially available products, of direct benefit to the Synchrotron, Free Electron Laser, Astronomy, Space, and Laser communities, who all require state-of-the-art optics.

  19. Low dose monitoring by double implant technique in IC fabrication

    International Nuclear Information System (INIS)

    Ahmad, I.B.; Weidemann, J.

    1995-01-01

    The utilisation of low dose implant monitoring (using Boron) in a manufacturing line has been discussed. The utilisation of phosphorus ions as the second implant dose were also studied as comparison. The technique relies on the fact that the sheet resistant of doped layer will increase significantly when damaged by relatively low implant dose. The technique is very sensitive and applicable for adjusting the channel dose so that an accurate threshold voltage in MOS device could be achieved

  20. Facile fabrication of controllable zinc oxide nanorod clusters on polyacrylonitrile nanofibers via repeatedly alternating immersion method

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ying; Li, Xia; Yu, Hou-Yong, E-mail: phdyu@zstu.edu.cn [Zhejiang Sci-Tech University, The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles (China); Hu, Guo-Liang; Yao, Ju-Ming, E-mail: yaoj@zstu.edu.cn [Zhejiang Sci-Tech University, National Engineering Lab for Textile Fiber Materials and Processing Technology (China)

    2016-12-15

    Polyacrylonitrile/zinc oxide (PAN/ZnO) composite nanofiber membranes with different ZnO morphologies were fabricated by repeatedly alternating hot–cold immersion and single alternating hot–cold immersion methods. The influence of the PAN/ZnCl{sub 2} ratio and different immersion methods on the morphology, microstructure, and properties of the nanofiber membranes was investigated by using field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), and ultraviolet–visible (UV–Vis) spectroscopy. A possible mechanism for different morphologies of PAN/ZnO nanofiber membranes with different PAN/ZnCl{sub 2} ratio through different immersion processes was presented, and well-dispersed ZnO nanorod clusters with smallest average dimeter of 115 nm and hexagonal wurtzite structure were successfully anchored onto the PAN nanofiber surface for R-7/1 nanofiber membrane. Compared to S-5/1 prepared by single alternating hot–cold immersion method, the PAN/ZnO nanofiber membrane fabricated by repeatedly alternating hot–cold immersion method (especially for R-7/1) showed improved thermal stability and high photocatalytic activity for methylene blue (MB). Compared to S-5/1, decomposition temperature at 5% weight loss (T{sub 5%}) was increased by 43 °C from 282 to 325 °C for R-7/1; meanwhile, R-7/1 showed higher photocatalytic degradation ratio of approximately 100% (after UV light irradiation for 8 h) than 65% for S-5/1 even after irradiation for 14 h. Moreover, the degradation efficiency of R-7/1 with good reuse stability remained above 94% after 3 cycles.

  1. Current status on detail design and fabrication techniques development of ITER blanket shield block in Korea

    International Nuclear Information System (INIS)

    Kim, Duck Hoi; Cho, Seungyon; Ahn, Mu-Young; Lee, Eun-Seok; Jung, Ki Jung

    2007-01-01

    The allocation of components and systems to be delivered to ITER on an in-kind basis, was agreed between the ITER Parties. Among parties, Korea agreed to procure inboard blanket modules 1, 2 and 6, which consists of FW and shield block. Regarding shield block the detail design and Fabrication techniques development have been undertaken in Korea. Especially manufacturing feasibility study on shield block had been performed and some technical issues for the fabrication were selected. Based on these results, fabrication techniques using EB welding are being developed. Meanwhile, the detail design of inboard standard module has been carried out. The optimization of flow driver design to improve the cooling performance was executed. And, thermo-hydraulic analysis on half block of inboard standard module was performed. In this study, current status and some results from Fabrication techniques development on ITER blanket shield block are described. The detail design activity and results on shield block are also introduced herein. (orig.)

  2. Alternative technique to neutron probe calibration in situ

    International Nuclear Information System (INIS)

    Encarnacao, F.; Carneiro, C.; Dall'Olio, A.

    1990-01-01

    An alternative technique of neutron probe calibration in situ was applied for Podzolic soil. Under field condition, the neutron probe calibration was performed using a special arrangement that prevented the lateral movement of water around the access tube of the neutron probe. During the experiments, successive amounts of water were uniformly infiltrated through the soil profile. Two plots were set to study the effect of the plot dimension on the slope of the calibration curve. The results obtained shown that the amounts of water transferred to the soil profile were significantly correlated to the integrals of count ratio along the soil profile on both plots. In consequence, the slope of calibration curve in field condition was determined. (author)

  3. ALTERNATIVE TECHNIQUE FOR CHOLECYSTECTOMY COMPARABLE TO SINGLE PORT.

    Science.gov (United States)

    Sabbag, Carlos; Blitzckow, Ana

    2017-01-01

    With the advancement of laparoscopic surgery, new techniques have been proposed and disseminated in order to reduce the surgical aggression and get better cosmetic results. To present alternative technique for videocholecystectomy comparable to single port technique using conventional material for laparoscopic surgery. Introduction of laparoscopic devices using two incisions; gallbladder traction with thread, exposition of Calot triangle, and ligature of cystic pedicle with polymer clips. Nine operations were carried out with this method, without complications and no increase in operative time, being compared to conventional videocholecistectomy, however vastly superior in aesthetic results. The technique is feasible, reproducible, showing benefits to patient´s safety. Com o avanço da cirurgia laparoscópica, novas técnicas têm sido propostas e difundidas com o objetivo de diminuir a agressão cirúrgica e obter melhores resultados estéticos. Apresentar técnica alternativa para videocolecistectomia similar à técnica de single port, contudo utilizando material convencional para cirurgia laparoscópica. Procedimento de videocolecistectomia com uso de duas incisões, exposição do trígono de Calot por tração da vesícula biliar com fio e ligadura dos elementos do hilo cístico com clipes de polímero. Foram realizadas nove operações com esse método, não se observando complicações e nem aumento do tempo operatório em relação à videocolecistectomia convencional, contudo com resultado estético grandemente superior. A técnica é factível, reprodutível e mostra benefícios e segurança ao paciente.

  4. Zero Kelvin Big Bang, an Alternative Paradigm: I. Logic and the Cosmic Fabric

    Science.gov (United States)

    Haynes, Royce

    2011-11-01

    This is the first of three papers describing an alternative paradigm of cosmogony, the beginning and evolution of the universe. The Zero Kelvin Big Bang (ZKBB) theory is compared to the prevailing Standard Big Bang (SBB) paradigm, and challenges the notion that our universe is "all there is." Logic suggests that the Big Bang was not a creation event, but that the universe did have a beginning: a "cosmic fabric" of pre- existing matter, in pre-existing space. Instead, the Zero Kelvin Big Bang was a transitional event between that "beginning" and what would become our universe. Extrapolating entropy back in time (as SBB does for matter and energy), and applying simple logic, suggests a "cosmic fabric" of the simplest, stable particles of matter, at the lowest energy state possible: singlet state, spin-oriented atomic hydrogen at zero kelvin, at a density of, at most, only a few atoms per cubic meter of space, infinite and (almost) eternal. Papers II and III describe the condensation of part of the cosmic fabric into a Bose-Einstein condensate (BEC) as Lemaître's primeval atom, followed by an implosion- explosion Big Bang.

  5. Comparison of marginal and internal adaptation of copings fabricated from three different fabrication techniques: An in vitro study.

    Science.gov (United States)

    Arora, Aman; Yadav, Avneet; Upadhyaya, Viram; Jain, Prachi; Verma, Mrinalini

    2018-01-01

    The purpose of this study was to compare the marginal and internal adaptation of cobalt-chromium (Co-Cr) copings fabricated from conventional wax pattern, three-dimensional (3D)-printed resin pattern, and laser sintering technique. A total of thirty copings were made, out of which ten copings were made from 3D-printed resin pattern (Group A), ten from inlay wax pattern (Group B), and ten copings were obtained from direct metal laser sintering (DMLS) technique (Group C). All the thirty samples were seated on their respective dies and sectioned carefully using a laser jet cutter and were evaluated for marginal and internal gaps at the predetermined areas using a stereomicroscope. The values were then analyzed using one-way ANOVA test and post hoc Bonferroni test. One-way ANOVA showed lowest mean marginal discrepancy for DMLS and highest value for copings fabricated from inlay wax. The values for internal discrepancy were highest for DMLS (169.38) and lowest for 3D-printed resin pattern fabricated copings (133.87). Post hoc Bonferroni test for both marginal and internal discrepancies showed nonsignificant difference when Group A was compared to Group B ( P > 0.05) and significant when Group A was compared with Group C ( P < 0.05). Group B showed significant difference ( P < 0.05) when compared with Group C. Marginal and internal discrepancies of all the three casting techniques were within clinically acceptable values. Marginal fit of DMLS was superior as compared to other two techniques, whereas when internal fit was evaluated, conventional technique showed the best internal fit.

  6. Environmental control aspects for fabrication, reprocessing and waste disposal of alternative LWR and LMFBR fuels

    International Nuclear Information System (INIS)

    Nolan, A.M.; Lewallen, M.A.; McNair, G.W.

    1979-11-01

    Environmental control aspects of alternative fuel cycles have been analyzed by evaluating fabrication, reprocessing, and waste disposal operations. Various indices have been used to assess potential environmental control requirements. For the fabrication and reprocessing operations, 50-year dose commitments were used. Waste disposal was evaluated by comparing projected nuclide concentrations in ground water at various time periods with maximum permissible concentrations (MPCs). Three different fabrication plants were analyzed: a fuel fabrication plant (FFP) to produce low-activity uranium and uranium-thorium fuel rods; a plutonium fuel refabrication plant (PFRFP) to produce plutonium-uranium and plutonium-thorium fuel rods; and a uranium fuel refabrication plant (UFRFP) to produce fuel rods containing the high-activity isotopes 232 U and 233 U. Each plant's dose commitments are discussed separately. Source terms for the analysis of effluents from the fuel reprocessing plant (FRP) were calculated using the fuel burnup codes LEOPARD, CINDER and ORIGEN. Effluent quantities are estimated for each fuel type. Bedded salt was chosen for the waste repository analysis. The repository site is modeled on the Waste Isolation Pilot Program site in New Mexico. Wastes assumed to be stored in the repository include high-level vitrified waste from the FRP, packaged fuel residue from the FRP, and transuranic (TRU) contaminated wastes from the FFP, PFRFP, and UFRFP. The potential environmental significance was determined by estimating the ground-water concentrations of the various nuclides over a time span of a million years. The MPC for each nuclide was used along with the estimated ground-water concentration to generate a biohazard index for the comparison among fuel compositions

  7. COCONUT WATER VINEGAR: NEW ALTERNATIVE WITH IMPROVED PROCESSING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ANAS OTHAMAN

    2014-06-01

    Full Text Available Vinegar is a condiment made from various sugary and starchy materials by alcoholic and subsequent acetic fermentation. Vinegar can be produced via different methods and from various types of raw material. A new alternative substrate for vinegar production namely mature coconut water has been tested and was compared with 2 common substrates which were coconut sap and pineapple juice. Substrates such as sap and juices have been found to have high amount of total soluble solids which corresponding to high sugar content in the substrates which is more than 14oBrix. Therefore, both substrates could be directly used for vinegar production without requirement of other carbon sources. However, coconut water which showed low Brix value need to be adjusted to 14oBrix by adding sucrose prior to the fermentation process. Substrates fermented with Saccharomyces cerevisiae have yielded 7-8% of alcohol within 7-10 days aerobic incubation at room temperature. The alcoholic medium were then used as a seed broth for acetic fermentation with Acetobactor aceti as inoculums and fermented for approximately 2 months to obtain at least 4% of acetic acid. Investigation on the effect of inoculum sizes and implementation of back-slopping technique were performed to improve the processing method for coconut water vinegar production. The results show that 10% of inoculum size was the best for acetic acid fermentation and the back-slopping technique has helped to reduce the process time of coconut water vinegar production.

  8. A Fabrication Technique for Nano-gap Electrodes by Atomic Force Microscopy Nano lithography

    International Nuclear Information System (INIS)

    Jalal Rouhi; Shahrom Mahmud; Hutagalung, S.D.; Kakooei, S.

    2011-01-01

    A simple technique is introduced for fabrication of nano-gap electrodes by using nano-oxidation atomic force microscopy (AFM) lithography with a Cr/ Pt coated silicon tip. AFM local anodic oxidation was performed on silicon-on-insulator (SOI) surfaces by optimization of desired conditions to control process in contact mode. Silicon electrodes with gaps of sub 31 nm were fabricated by nano-oxidation method. This technique which is simple, controllable, inexpensive and fast is capable of fabricating nano-gap structures. The current-voltage measurements (I-V) of the electrodes demonstrated very good insulating characteristics. The results show that silicon electrodes have a great potential for fabrication of single molecule transistors (SMT), single electron transistors (SET) and the other nano electronic devices. (author)

  9. Evaluation of a radioisotope labelling technique for measuring bacterial adherence on fabrics

    International Nuclear Information System (INIS)

    Youlo Hsieh; Timm, Debra; Merry, Joanne

    1986-01-01

    A technique utilizing tritiated thymidine labelled bacteria to quantify bacteria on fabrics has been evaluated. Quenching or self-absorption of isotope solution and labelled bacteria suspension by some of the fabrics has been observed. The extents of self-absorption of both isotope and labelled bacteria solutions on various fabrics was found to be dependent upon the fiber contents, i.e. the chemical compositions, of the substrata. This observation confirms that reduction of scintillation efficiency or self-absorption does occur when radio-labelled substances in suspensions were measured with the presence of some fabrics. Cautions should be taken when radio-labelling techniques are applied to detect isotope-labelled micro-organisms or other substances which are in contact with fabrics in the form of solutions. However, when there is no excess and nonattached labelled bacteria in the aqueous surrounding of the fabric, scintillation counting efficiency of the labelled bacteria on all fabrics studied remained constant over a period of 8 h. This indicates that the application of the described isotope labelling procedure is appropriate for quantifying adherent bacteria on fibrous substrate. (author)

  10. Development of joining techniques for fabrication of fuel rod simulators

    International Nuclear Information System (INIS)

    Moorhead, A.J.; McCulloch, R.W.; Reed, R.W.; Woodhouse, J.J.

    1980-10-01

    Much of the safety-related thermal-hydraulic tests on nuclear reactors are conducted not in the reactor itself, but in mockup segments of a core that uses resistance-heated fuel rod simulators (FRS) in place of the radioactive fuel rods. Laser welding and furnace brazing techniques are described for joining subassemblies for FRS that have survived up to 1000 h steady-state operation at 700 to 1100 0 C cladding temperatures and over 5000 thermal transients, ranging from 10 to 100 0 C/s. A pulsed-laser welding procedure that includes use of small-diameter filler wire is used to join one end of a resistance heating element of Pt-8 W, Fe-22 Cr-5.5 Al-0.5 Co, or 80 Ni-20 Cr (wt %) to a tubular conductor of an appropriate intermediate material. The other end of the heating element is laser welded to an end plug, which in turn is welded to a central conductor rod

  11. The development of an alternative thermoplastic powder prepregging technique

    Science.gov (United States)

    Ogden, A. L.; Hyer, M. W.; Wilkes, G. L.; Loos, A. C.

    1992-01-01

    An alternative powder prepregging technique is discussed that is based on the deposition of powder onto carbon fibers that have been moistened using an ultrasonic humidifier. The dry fiber tow is initially spread to allow a greater amount of the fiber surface to be exposed to the powder, thus ensuring a significant amount of intimate contact between the fiber and the matrix. Moisture in the form of ultrafine water droplets is then deposited onto the spread fiber tow. The moisture promotes adhesion to the fiber until the powder can be tacked to the fibers by melting. Powdered resin is then sieved onto the fibers and then tacked onto the fibers by quick heating in a convective oven. This study focuses on the production of prepregs and laminates made with LaRC-TPI (thermoplastic polyimide) using this process. Although the process appears to be successful, early evaluation was hampered by poor interfacial adhesion. The adhesion problem, however, seems to be the result of a material system incompatibility, rather than being influenced by the process.

  12. Magnetic domain observation of FeCo thin films fabricated by alternate monoatomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, T., E-mail: ohtsuki@spring8.or.jp; Kotsugi, M.; Ohkochi, T. [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kojima, T.; Mizuguchi, M.; Takanashi, K. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-01-28

    FeCo thin films are fabricated by alternate monoatomic layer deposition method on a Cu{sub 3}Au buffer layer, which in-plane lattice constant is very close to the predicted value to obtain a large magnetic anisotropy constant. The variation of the in-plane lattice constant during the deposition process is investigated by reflection high-energy electron diffraction. The magnetic domain images are also observed by a photoelectron emission microscope in order to microscopically understand the magnetic structure. As a result, element-specific magnetic domain images show that Fe and Co magnetic moments align parallel. A series of images obtained with various azimuth reveal that the FeCo thin films show fourfold in-plane magnetic anisotropy along 〈110〉 direction, and that the magnetic domain structure is composed only of 90∘ wall.

  13. In vitro evaluation of marginal adaptation in five ceramic restoration fabricating techniques.

    Science.gov (United States)

    Ural, Cağri; Burgaz, Yavuz; Saraç, Duygu

    2010-01-01

    To compare in vitro the marginal adaptation of crowns manufactured using ceramic restoration fabricating techniques. Fifty standardized master steel dies simulating molars were produced and divided into five groups, each containing 10 specimens. Test specimens were fabricated with CAD/CAM, heat-press, glass-infiltration, and conventional lost-wax techniques according to manufacturer instructions. Marginal adaptation of the test specimens was measured vertically before and after cementation using SEM. Data were statistically analyzed by one-way ANOVA with Tukey HSD tests (a = .05). Marginal adaptation of ceramic crowns was affected by fabrication technique and cementation process (P cementation (P cementation. Marginal adaptation values obtained in the compared systems were within clinically acceptable limits. Cementation causes a significant increase in the vertical marginal discrepancies of the test specimens.

  14. New technique for fabrication of high frequency piezoelectric Micromachined Ultrasound Transducers

    DEFF Research Database (Denmark)

    Pedersen, T; Thomsen, Erik Vilain; Zawada, T

    2008-01-01

    A novel technique for fabrication of linear arrays of high frequency piezoelectric Micromachined Ultrasound Transducers (pMUT) on silicon substrates is presented. Piezoelectric elements are formed by deposition of PZT ((PbZrxTi1-x)O3) into etched features of the silicon substrate such that the de......A novel technique for fabrication of linear arrays of high frequency piezoelectric Micromachined Ultrasound Transducers (pMUT) on silicon substrates is presented. Piezoelectric elements are formed by deposition of PZT ((PbZrxTi1-x)O3) into etched features of the silicon substrate...

  15. Putting it to the test : alternative exploration techniques seek recognition

    Energy Technology Data Exchange (ETDEWEB)

    Cope, G.

    2005-06-01

    In the past, remote sensing techniques such as magnetic surveying, geochemical sampling and radiometric surveys, were efficient in hard rock mining exploration but were limited in hydrocarbon detection due to problems such as diurnal and weather variations. This article discussed some of the recent advances in technology that have been developed to overcome many of the drawbacks of older systems. Two Calgary-based companies are currently offering innovative and viable exploration alternatives. The Gore-Sorber module is the most accurate and comprehensive surface geochemical sampling technology currently available to the oil and gas industry. The testing module consists of 2 portions of expanded polytetrafluoroethylene polymer material sealed into a GORE-TEX sheath to prevent water and particle contamination. The module is then inserted into a shallow hole to a depth of 50 centimetres and left there for up to 2 weeks. The sample position is marked and surveyed. Over the course of the 2 weeks, volatile and semi-volatile soil gases in the C2-C15 range are absorbed into the material. The modules are analysed in mass spectrometers and gas chromatographs to determine zone and phase information. Advantages of the system include a reduction in soil contamination; the elimination of day-to-day fluctuations; and the fact that lab analysis allows for higher sensitivity. Costs are approximately $60,000 to $70,000 for an area of 16 square kilometres. Disadvantages include the inability to define the amount of hydrocarbons in place or their depth and the fact that proper field operation and collection of data by trained personnel is critical to the analysis process. The technique has been gaining in popularity in Canada as more exploration is directed towards environmentally sensitive frontier areas. Radiometric surveys record the gamma ray emissions of potassium, uranium and thorium as they decay radioactively. As hydrocarbons leak to the surface, they cause geochemical changes

  16. Preparation and Characterization of Some Nanometal Oxides Using Microwave Technique and Their Application to Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    M. Gouda

    2015-01-01

    Full Text Available The objective of this paper is the synthesis of some nanometal oxides via microwave irradiation technique and their application to augment multifunctional properties of cotton fabric. Cotton fabrics containing nanometal oxides were prepared via a thiol-modification of cotton fabric samples and then dipped into the metal salt solutions precursors and transferred to the microwave oven. The surface morphology and quantitative analysis of the obtained modified cotton fabrics containing nanometal oxides were studied by scanning electron microscopy coupled with high energy dispersive X-ray (SEM-EDX. The shape and distribution of nanometal oxide inside the fabric samples were analyzed by transmission electron microscopy of cross-section fabric samples. The iron oxide nanoparticles had a nanosphere with particle size diameter 15–20 nm, copper oxide nanoparticles had a nanosphere with particle size diameter 25–30 nm, and cobalt oxide nanoparticles had a nanotube-like shape with a length of 100–150 nanometer and a diameter of ~58 nanometer, whereas the manganese oxide nanoparticles had a linear structure forming nanorods with a diameter of 50–55 nanometer and a length of 70–80 nanometers. Antibacterial activity was evaluated quantitatively against gram-positive bacteria such as Staphylococcus aureus and gram-negative bacteria such as Escherichia coli, UV-protection activity was analyzed using UV-DRS spectroscopy, and flame retardation of prepared fabric samples was evaluated according to the limiting oxygen index (LOI. Results revealed that the prepared fabric sample containing nanometal oxide possesses improved antibacterial, LOI, and UV-absorbing efficiency. Moreover, the metal oxide nanoparticles did not leach out the fabrics by washing even after 30 laundering washing cycles.

  17. Electrohydrodynamic bubbling: an alternative route to fabricate porous structures of silk fibroin based materials.

    Science.gov (United States)

    Ekemen, Zeynep; Ahmad, Zeeshan; Stride, Eleanor; Kaplan, David; Edirisinghe, Mohan

    2013-05-13

    Conventional fabrication techniques and structures employed in the design of silk fibroin (SF) based porous materials provide only limited control over pore size and require several processing stages. In this study, it is shown that, by utilizing electrohydrodynamic bubbling, not only can new hollow spherical structures of SF be formed in a single step by means of bubbles, but the resulting bubbles can serve as pore generators when dehydrated. The bubble characteristics can be controlled through simple adjustments to the processing parameters. Bubbles with diameters in the range of 240-1000 μm were fabricated in controlled fashion. FT-IR characterization confirmed that the rate of air infused during processing enhanced β-sheet packing in SF at higher flow rates. Dynamic mechanical analysis also demonstrated a correlation between air flow rate and film tensile strength. Results indicate that electrohydrodynamically generated SF and their composite bubbles can be employed as new tools to generate porous structures in a controlled manner with a range of potential applications in biocoatings and tissue engineering scaffolds.

  18. A new fabrication technique for back-to-back varactor diodes

    Science.gov (United States)

    Smith, R. Peter; Choudhury, Debabani; Martin, Suzanne; Frerking, Margaret A.; Liu, John K.; Grunthaner, Frank A.

    1992-01-01

    A new varactor diode process has been developed in which much of the processing is done from the back of an extremely thin semiconductor wafer laminated to a low-dielectric substrate. Back-to-back BNN diodes were fabricated with this technique; excellent DC and low-frequency capacitance measurements were obtained. Advantages of the new technique relative to other techniques include greatly reduced frontside wafer damage from exposure to process chemicals, improved capability to integrate devices (e.g. for antenna patterns, transmission lines, or wafer-scale grids), and higher line yield. BNN diodes fabricated with this technique exhibit approximately the expected capacitance-voltage characteristics while showing leakage currents under 10 mA at voltages three times that needed to deplete the varactor. This leakage is many orders of magnitude better than comparable Schottky diodes.

  19. Fit Analysis of Different Framework Fabrication Techniques for Implant-Supported Partial Prostheses.

    Science.gov (United States)

    Spazzin, Aloísio Oro; Bacchi, Atais; Trevisani, Alexandre; Farina, Ana Paula; Dos Santos, Mateus Bertolini

    2016-01-01

    This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the frameworks and the abutments was evaluated with an optical microscope using the single-screw test. Data were analyzed using one-way analysis of variance and Tukey test (α = .05). The one-piece casted frameworks presented significantly higher vertical misfit values than those found for framework cemented on prepared abutments and laser welding techniques (P Laser welding and framework cemented on prepared abutments are effective techniques to improve the adaptation of three-unit implant-supported prostheses. These techniques presented similar fit.

  20. Selection of micro-fabrication techniques on stainless steel sheet for skin friction

    NARCIS (Netherlands)

    Zhang, Sheng; Zeng, Xiangqiong; Matthews, David Thomas Allan; Igartua, A.; Rodriguez Vidal, E.; Contreras Fortes, J.; Saenz de Viteri, V.; Pagano, F.; Wadman, B.; Wiklund, E.D.; van der Heide, Emile

    2016-01-01

    This review gives a concise introduction to the state-of-art techniques used for surface texturing, e.g., wet etching, plasma etching, laser surface texturing (LST), 3D printing, etc. In order to fabricate deterministic textures with the desired geometric structures and scales, the innovative

  1. Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes

    Science.gov (United States)

    Ruiz-Trejo, Enrique; Atkinson, Alan; Brandon, Nigel P.

    2015-04-01

    A combination of electroless and electrolytic techniques is used to incorporate nickel into a porous Ce0.9Gd0.1O1.90 scaffold. First a porous backbone was screen printed into a YSZ electrolyte using an ink that contains sacrificial pore formers. Once sintered, the scaffold was coated with silver using Tollens' reaction followed by electrodeposition of nickel in a Watts bath. At high temperatures the silver forms droplets enabling direct contact between the gadolinia-doped ceria and nickel. Using impedance spectroscopy analysis in a symmetrical cell a total area specific resistance of 1 Ωcm2 at 700 °C in 97% H2 with 3% H2O was found, indicating the potential of this fabrication method for scaling up.

  2. Mass production compatible fabrication techniques of single-crystalline silver metamaterials and plasmonics devices

    Science.gov (United States)

    Rodionov, Ilya A.; Baburin, Alexander S.; Zverev, Alexander V.; Philippov, Ivan A.; Gabidulin, Aidar R.; Dobronosova, Alina A.; Ryzhova, Elena V.; Vinogradov, Alexey P.; Ivanov, Anton I.; Maklakov, Sergey S.; Baryshev, Alexander V.; Trofimov, Igor V.; Merzlikin, Alexander M.; Orlikovsky, Nikolay A.; Rizhikov, Ilya A.

    2017-08-01

    During last 20 years, great results in metamaterials and plasmonic nanostructures fabrication were obtained. However, large ohmic losses in metals and mass production compatibility still represent the most serious challenge that obstruct progress in the fields of metamaterials and plasmonics. Many recent research are primarily focused on developing low-loss alternative materials, such as nitrides, II-VI semiconductor oxides, high-doped semiconductors, or two-dimensional materials. In this work, we demonstrate that our perfectly fabricated silver films can be an effective low-loss material system, as theoretically well-known. We present a fabrication technology of plasmonic and metamaterial nanodevices on transparent (quartz, mica) and non-transparent (silicon) substrates by means of e-beam lithography and ICP dry etch instead of a commonly-used focused ion beam (FIB) technology. We eliminate negative influence of litho-etch steps on silver films quality and fabricate square millimeter area devices with different topologies and perfect sub-100 nm dimensions reproducibility. Our silver non-damage fabrication scheme is tested on trial manufacture of spasers, plasmonic sensors and waveguides, metasurfaces, etc. These results can be used as a flexible device manufacture platform for a broad range of practical applications in optoelectronics, communications, photovoltaics and biotechnology.

  3. A simple approach to hollow maxillary complete denture fabrication: An innovative technique

    Directory of Open Access Journals (Sweden)

    Kathleen Manuela D'souza

    2017-01-01

    Full Text Available A severely atrophic maxillary arch exhibits reduced denture bearing area and increased inter-ridge distance, thus, affecting retention of the complete denture. Such clinical situations necessitate the fabrication of a hollow complete denture to reduce the weight of the prosthesis and increase retention. This article describes a simple technique to fabricate a hollow maxillary complete denture using salt and thermoplastic poly (methyl methacrylate sheet. The vacuum-formed thermoplastic matrix regulates the quantity of salt and determines its placement in the unpolymerized denture base material during the denture packing stage. The matrix lining the hollow cavity also aids to reinforce the hollow denture base.

  4. 3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication.

    Directory of Open Access Journals (Sweden)

    Gabriel N Meloni

    Full Text Available A simple and cost effective alternative for fabricating custom Scanning Electron Microscope (SEM sample holders using 3D printers and conductive polylactic acid filament is presented. The flexibility of the 3D printing process allowed for the fabrication of sample holders with specific features that enable the high-resolution imaging of nanoelectrodes and nanopipettes. The precise value of the inner semi cone angle of the nanopipettes taper was extracted from the acquired images and used for calculating their radius using electrochemical methods. Because of the low electrical resistivity presented by the 3D printed holder, the imaging of non-conductive nanomaterials, such as alumina powder, was found to be possible. The fabrication time for each sample holder was under 30 minutes and the average cost was less than $0.50 per piece. Despite being quick and economical to fabricate, the sample holders were found to be sufficiently resistant, allowing for multiple uses of the same holder.

  5. The Sine Method: An Alternative Height Measurement Technique

    Science.gov (United States)

    Don C. Bragg; Lee E. Frelich; Robert T. Leverett; Will Blozan; Dale J. Luthringer

    2011-01-01

    Height is one of the most important dimensions of trees, but few observers are fully aware of the consequences of the misapplication of conventional height measurement techniques. A new approach, the sine method, can improve height measurement by being less sensitive to the requirements of conventional techniques (similar triangles and the tangent method). We studied...

  6. Comparative Accuracy of Facial Models Fabricated Using Traditional and 3D Imaging Techniques.

    Science.gov (United States)

    Lincoln, Ketu P; Sun, Albert Y T; Prihoda, Thomas J; Sutton, Alan J

    2016-04-01

    The purpose of this investigation was to compare the accuracy of facial models fabricated using facial moulage impression methods to the three-dimensional printed (3DP) fabrication methods using soft tissue images obtained from cone beam computed tomography (CBCT) and 3D stereophotogrammetry (3D-SPG) scans. A reference phantom model was fabricated using a 3D-SPG image of a human control form with ten fiducial markers placed on common anthropometric landmarks. This image was converted into the investigation control phantom model (CPM) using 3DP methods. The CPM was attached to a camera tripod for ease of image capture. Three CBCT and three 3D-SPG images of the CPM were captured. The DICOM and STL files from the three 3dMD and three CBCT were imported to the 3DP, and six testing models were made. Reversible hydrocolloid and dental stone were used to make three facial moulages of the CPM, and the impressions/casts were poured in type IV gypsum dental stone. A coordinate measuring machine (CMM) was used to measure the distances between each of the ten fiducial markers. Each measurement was made using one point as a static reference to the other nine points. The same measuring procedures were accomplished on all specimens. All measurements were compared between specimens and the control. The data were analyzed using ANOVA and Tukey pairwise comparison of the raters, methods, and fiducial markers. The ANOVA multiple comparisons showed significant difference among the three methods (p 3D-SPG showed statistical difference in comparison to the models fabricated using the traditional method of facial moulage and 3DP models fabricated from CBCT imaging. 3DP models fabricated using 3D-SPG were less accurate than the CPM and models fabricated using facial moulage and CBCT imaging techniques. © 2015 by the American College of Prosthodontists.

  7. Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

    Energy Technology Data Exchange (ETDEWEB)

    Cai Kaiyong, E-mail: Kaiyong_cai@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Sui Xiaojing; Hu Yan [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Zhao Li [China National Centre for Biotechnology Development, No. 16, Xi Si Huan Zhong Lu, Haidian District, Beijing 100036 (China); Lai Min; Luo Zhong; Liu Peng; Yang Weihu [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2011-12-01

    To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: {yields} Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. {yields} The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. {yields} The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

  8. Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

    International Nuclear Information System (INIS)

    Cai Kaiyong; Sui Xiaojing; Hu Yan; Zhao Li; Lai Min; Luo Zhong; Liu Peng; Yang Weihu

    2011-01-01

    To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: → Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. → The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. → The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

  9. Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

    Directory of Open Access Journals (Sweden)

    Yeonhee Lee

    2013-05-01

    Full Text Available Time-of-flight secondary ion mass spectrometry (TOF-SIMS and X-ray photoelectron spectroscopy (XPS are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric.

  10. Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

    Science.gov (United States)

    Lee, Jihye; Kang, Min Hwa; Lee, Kang-Bong; Lee, Yeonhee

    2013-01-01

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric. PMID:28809257

  11. Aversive Techniques and the Doctrine of Least Restrictive Alternative.

    Science.gov (United States)

    Barton, Lyle E.; And Others

    1983-01-01

    Litigation and the issues surrounding the use of behavioral procedures to handicapped persons are reviewed. Attention is directed to the use of aversive techniques, e.g., corporal punishment, electric shock, timeout, and restraint. (SEW)

  12. COCONUT WATER VINEGAR: NEW ALTERNATIVE WITH IMPROVED PROCESSING TECHNIQUE

    OpenAIRE

    MUHAMMAD ANAS OTHAMAN; SHAIFUL ADZNI SHARIFUDIN; AZLINA MANSOR; AINAA ABD KAHAR; KAMARIAH LONG

    2014-01-01

    Vinegar is a condiment made from various sugary and starchy materials by alcoholic and subsequent acetic fermentation. Vinegar can be produced via different methods and from various types of raw material. A new alternative substrate for vinegar production namely mature coconut water has been tested and was compared with 2 common substrates which were coconut sap and pineapple juice. Substrates such as sap and juices have been found to have high amount of total soluble solids which correspo...

  13. An alternative gallbladder extraction technique in laparoscopic cholecystectomy.

    Science.gov (United States)

    Tang, C N; Wong, D C T

    2006-05-01

    In this era of minimally invasive surgery, the challenge remains in finding techniques to reduce access trauma in terms of fewer and smaller size trocar ports. Our new described technique will allow a smaller subxiphoid port to be used to achieve extraction of the gallbladder without the need to change to a 5 mm laparoscope. We believe this method is easy to learn, safe and with no observable complications from our experience.

  14. Evaluation of metal-ceramic bond characteristics of three dental Co-Cr alloys prepared with different fabrication techniques.

    Science.gov (United States)

    Wang, Hongmei; Feng, Qing; Li, Ning; Xu, Sheng

    2016-12-01

    fabricated with the SLM techniques could be a promising alternative for metal ceramic restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Fabrication of a metal-free ceramic restoration utilizing the monobloc technique.

    Science.gov (United States)

    Pissis, P

    1995-01-01

    This article presents a new technique which utilizes a porcelain core/crown unit, fabricated in the laboratory as a single component. The monobloc technique was developed by the author to replace the traditional metal post and core which prevents the transmission of light through porcelain crowns, creating a dark color effect. Between 1989 and 1992, a number of cases were successfully treated with several variations of the monobloc technique. Approximately 50 cases were completed with vitro-ceramic and followed up. The learning objective of this article is to introduce this novel technique. The article discusses the development of the technique, its advantages, disadvantages, and the potential failures. The clinical procedure is illustrated with several case presentations.

  16. Fabrication and Characterization of Surrogate Glasses Aimed to Validate Nuclear Forensic Techniques

    Science.gov (United States)

    2017-12-01

    the glass formed during a nuclear event, trinitite [14]. The SiO2 composition is generally greater than 50% for trinitite and can vary appreciably...CHARACTERIZATION OF SURROGATE GLASSES AIMED TO VALIDATE NUCLEAR FORENSIC TECHNIQUES by Ken G. Foos December 2017 Thesis Advisor: Claudia...December 2017 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE FABRICATION AND CHARACTERIZATION OF SURROGATE GLASSES AIMED TO

  17. MFM observation of spin structures in nano-magnetic-dot arrays fabricated by damascene technique

    International Nuclear Information System (INIS)

    Sato, K.; Yamamoto, T.; Tezuka, T.; Ishibashi, T.; Morishita, Y.; Koukitu, A.; Machida, K.; Yamaoka, T.

    2006-01-01

    Regularly aligned arrays of magnetic nano dots buried in silicon wafers have been fabricated using damascene technique with the help of electron beam lithography. Arrays of square, rectangular, cross-shaped and Y-shaped structures of submicron size have been obtained. Spin distributions have been observed by means of magnetic force microscopy and analyzed by a micromagnetic simulation with Landau-Lifshitz-Gilbert equations. Importance of magnetostatic interactions working between adjacent dots has been elucidated

  18. A Flexible Ascorbic Acid Fuel Cell with a Microchannel Fabricated using MEMS Techniques

    Science.gov (United States)

    Mogi, Hiroshi; Fukushi, Yudai; Koide, Syohei; Sano, Ryohei; Sasaki, Tsubasa; Nishioka, Yasushiro

    2013-12-01

    We fabricated a miniature ascorbic acid fuel cells equipped with a microchannel for the circulation of ascorbic acid (AA) solution using micro electronic mechanical system techniques. The fuel cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminium (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen-printing techniques. The porous carbon was deposited by screen-printing of carbon-black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the cathode surface. The microchannel with a depth of 200 μm was fabricated using a hot-embossing technique. A maximum power of 0.60 μW at 0.58 V that corresponds to a power density of 1.83 μW/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature.

  19. Prosthetic Rehabilitation in Children: An Alternative Clinical Technique

    Directory of Open Access Journals (Sweden)

    Nádia Carolina Teixeira Marques

    2013-01-01

    Full Text Available Complete and partial removable dentures have been used successfully in numerous patients with oligodontia and/or anodontia. However, there is little information in the literature regarding the principles and guidelines to prosthetic rehabilitation for growing children. This case report describes the management of a young child with oligodontia as well as the treatment planning and the prosthetic rehabilitation technique.

  20. Evaluation of alternative drying techniques for the earthworm flour processing

    Directory of Open Access Journals (Sweden)

    Laura Suárez Hernández

    2016-01-01

    Full Text Available Production of earthworm flour includes several steps, among which the most critical is the drying process due to factors such as time and energ y requirements. In addition, the information available about this process is relquite limited. Thus, this work evaluated four drying techniques likely to be implemented by lombricultores: sun drying, oven drying, drying tunnel and microwave assisted drying. Drying kinetics values were obtained for all drying techniques, and specific parameters as the following were evaluated: drying tray material (stainless and ceramic steel for sun drying, microwave power (30 %, 50 % and 80 % and amount of material to be dried (72 and 100 g for microwave assisted drying, temperature (50, 65, 90 and 100 °C for oven drying, and temperature (50 and 63 °C and air speed (2.9 to 3.6 m/s for tunnel drying. It was determined that the most efficient technique is the drying tunnel, because this allows the combination of heat transfer by conduction and convection, and enables controlling the operating parameters. Finally, nutritional analyzes were performed in samples obtained by each drying technique evaluated. The crude protein content for sun drying, microwave assisted drying, oven drying and tunnel drying were 66.36 %, 67.91 %, 60.35 % and 62.33 % respectively, indicating that the drying method and operating parameters do not significantly affect the crude protein content.

  1. Precision Learning Assessment: An Alternative to Traditional Assessment Techniques.

    Science.gov (United States)

    Caltagirone, Paul J.; Glover, Christopher E.

    1985-01-01

    A continuous and curriculum-based assessment method, Precision Learning Assessment (PLA), which integrates precision teaching and norm-referenced techniques, was applied to a math computation curriculum for 214 third graders. The resulting districtwide learning curves defining average annual progress through the computation curriculum provided…

  2. Marginal adaptation and CAD-CAM technology: A systematic review of restorative material and fabrication techniques.

    Science.gov (United States)

    Papadiochou, Sofia; Pissiotis, Argirios L

    2018-04-01

    The comparative assessment of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and other fabrication techniques pertaining to marginal adaptation should be documented. Limited evidence exists on the effect of restorative material on the performance of a CAD-CAM system relative to marginal adaptation. The purpose of this systematic review was to investigate whether the marginal adaptation of CAD-CAM single crowns, fixed dental prostheses, and implant-retained fixed dental prostheses or their infrastructures differs from that obtained by other fabrication techniques using a similar restorative material and whether it depends on the type of restorative material. An electronic search of English-language literature published between January 1, 2000, and June 30, 2016, was conducted of the Medline/PubMed database. Of the 55 included comparative studies, 28 compared CAD-CAM technology with conventional fabrication techniques, 12 contrasted CAD-CAM technology and copy milling, 4 compared CAD-CAM milling with direct metal laser sintering (DMLS), and 22 investigated the performance of a CAD-CAM system regarding marginal adaptation in restorations/infrastructures produced with different restorative materials. Most of the CAD-CAM restorations/infrastructures were within the clinically acceptable marginal discrepancy (MD) range. The performance of a CAD-CAM system relative to marginal adaptation is influenced by the restorative material. Compared with CAD-CAM, most of the heat-pressed lithium disilicate crowns displayed equal or smaller MD values. Slip-casting crowns exhibited similar or better marginal accuracy than those fabricated with CAD-CAM. Cobalt-chromium and titanium implant infrastructures produced using a CAD-CAM system elicited smaller MD values than zirconia. The majority of cobalt-chromium restorations/infrastructures produced by DMLS displayed better marginal accuracy than those fabricated with the casting technique. Compared with copy

  3. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

    Science.gov (United States)

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  4. UAS Mapping as an alternative for land surveying techniques?

    Directory of Open Access Journals (Sweden)

    L. Devriendt

    2014-03-01

    Full Text Available Can a UAS mapping technique compete with standard surveying techniques? Since the boom in different RPAS (remotely piloted air system, UAV (unmanned aerial vehicle, or UAS (unmanned aerial system, this is one of the crucial questions when it comes to UAS mappings. Not the looks and feels are important but the reliability, ease-to-use, and accuracy that you get with a system based on hardware and corresponding software. This was also one of the issues that the Dutch Land Registry asked a few months ago aimed at achieving an effective and usable system for updating property boundaries in new-build districts. Orbit GT gave them a ready-made answer: a definitive outcome based on years of research and development in UAS mapping technology and software.

  5. Slot technique - an alternative method of scatter reduction in radiography

    International Nuclear Information System (INIS)

    Panzer, W.; Widenmann, L.

    1983-01-01

    The most common method of scatter reduction in radiography is the use of an antiscatter grid. Its disadvantage is the absorption of a certain percentage of primary radiation in the lead strips of the grid and the fact that due to the limited thickness of the lead strips their scatter absorption is also limited. A possibility for avoiding this disadvantage is offered by the so-called slot technique, ie, the successive exposure of the subject with a narrow fan beam provided by slots in rather thick lead plates. The results of a comparison between grid and slot technique regarding dose to the patient, scatter reduction, image quality and the effect of automatic exposure control are reported. (author)

  6. Novel fabrication techniques for low-mass composite structures in silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, Neal, E-mail: neal.hartman@cern.ch; Silber, Joseph; Anderssen, Eric; Garcia-Sciveres, Maurice; Gilchriese, Murdock; Johnson, Thomas; Cepeda, Mario

    2013-12-21

    The structural design of silicon-based particle detectors is governed by competing demands of reducing mass while maximizing stability and accuracy. These demands can only be met by fiber reinforced composite laminates (CFRP). As detecting sensors and electronics become lower mass, the motivation to reduce structure as a proportion of overall mass pushes modern detector structures to the lower limits of composite ply thickness, while demanding maximum stiffness. However, classical approaches to composite laminate design require symmetric laminates and flat structures, in order to minimize warping during fabrication. This constraint of symmetry in laminate design, and a “flat plate” approach to fabrication, results in more massive structures. This study presents an approach to fabricating stable and accurate, geometrically complex composite structures by bonding warped, asymmetric, but ultra-thin component laminates together in an accurate tool, achieving final overall precision normally associated with planar structures. This technique has been used to fabricate a prototype “I-beam” that supports two layers of detecting elements, while being up to 20 times stiffer and up to 30% lower mass than comparable, independent planar structures (typically known as “staves”)

  7. Material control in nuclear fuel fabrication facilities. Part II. Accountability, instrumntation, and measurement techniques in fuel fabrication facilities, P.O.1236909. Final report

    International Nuclear Information System (INIS)

    Borgonovi, G.M.; McCartin, T.J.; McDaniel, T.; Miller, C.L.; Nguyen, T.

    1978-12-01

    This report describes the measurement techniques, the instrumentation, and the procedures used in accountability and control of nuclear materials, as they apply to fuel fabrication facilities. Some of the material included has appeared elswhere and it has been summarized. An extensive bibliography is included. A spcific example of application of the accountability methods to a model fuel fabrication facility which is based on the Westinghouse Anderson design

  8. Material control in nuclear fuel fabrication facilities. Part II. Accountability, instrumntation, and measurement techniques in fuel fabrication facilities, P. O. 1236909. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Borgonovi, G.M.; McCartin, T.J.; McDaniel, T.; Miller, C.L.; Nguyen, T.

    1978-12-01

    This report describes the measurement techniques, the instrumentation, and the procedures used in accountability and control of nuclear materials, as they apply to fuel fabrication facilities. Some of the material included has appeared elswhere and it has been summarized. An extensive bibliography is included. A spcific example of application of the accountability methods to a model fuel fabrication facility which is based on the Westinghouse Anderson design.

  9. Pump failure leads to alternative vertical pump condition monitoring technique

    International Nuclear Information System (INIS)

    DeVilliers, Adriaan; Glandon, Kevin

    2011-01-01

    Condition monitoring and detecting early signs of potential failure mechanisms present particular problems in vertical pumps. Most often, the majority of the pump assembly is not readily accessible for visual or audible inspection or conventional vibration monitoring techniques using accelerometers and/or proximity sensors. The root cause failure analysis of a 2-stage vertical centrifugal service-water pump at a nuclear power generating facility in the USA is presented, highlighting this long standing challenge in condition monitoring of vertical pumps. This paper will summarize the major findings of the root cause analysis (RCA), highlight the limitations of traditional monitoring techniques, and present an expanded application of motor current monitoring as a means to gain insight into the mechanical performance and condition of a pump. The 'real-world' example of failure, monitoring and correlation of the monitoring technique to a detailed pump disassembly inspection is also presented. This paper will explain some of the reasons behind well known design principles requiring natural frequency separation from known forcing frequencies, as well as explore an unexpected submerged brittle fracture failure mechanism, and how such issues may be avoided. (author)

  10. Comparison of denture tooth movement between CAD-CAM and conventional fabrication techniques.

    Science.gov (United States)

    Goodacre, Brian J; Goodacre, Charles J; Baba, Nadim Z; Kattadiyil, Mathew T

    2018-01-01

    Data comparing the denture tooth movement of computer-aided design and computer-aided manufacturing (CAD-CAM) and conventional denture processing techniques are lacking. The purpose of this in vitro study was to compare the denture tooth movement of pack-and-press, fluid resin, injection, CAD-CAM-bonded, and CAD-CAM monolithic techniques for fabricating dentures to determine which process produces the most accurate and reproducible prosthesis. A total of 50 dentures were evaluated, 10 for each of the 5 groups. A master denture was fabricated and milled from prepolymerized poly(methyl methacrylate). For the conventional processing techniques (pack-and-press, fluid resin, and injection) a polyvinyl siloxane putty mold of the master denture was made in which denture teeth were placed and molten wax injected. The cameo surface of each wax-festooned denture was laser scanned, resulting in a standard tessellation language (STL) format file. The CAD-CAM dentures included 2 subgroups: CAD-CAM-bonded teeth in which the denture teeth were bonded into the milled denture base and CAD-CAM monolithic teeth in which the denture teeth were milled as part of the denture base. After all specimens had been fabricated, they were hydrated for 24 hours, and the cameo surface laser scanned. The preprocessing and postprocessing scan files of each denture were superimposed using surface-matching software. Measurements were made at 64 locations, allowing evaluation of denture tooth movement in a buccal, lingual, mesial-distal, and occlusal direction. The use of median and interquartile range values was used to assess accuracy and reproducibility. Levene and Kruskal-Wallis analyses of variance were used to evaluate differences between processing techniques (α=.05). The CAD-CAM monolithic technique was the most accurate, followed by fluid resin, CAD-CAM-bonded, pack-and-press, and injection. CAD-CAM monolithic technique was the most reproducible, followed by pack-and-press, CAD

  11. Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 2: Production techniques

    Science.gov (United States)

    Berry, J.; Nesbit, M.; Saberi, S.; Petridis, H.

    2014-01-01

    Aim The aim of this study was to identify the communication methods and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians' perspective. This second paper reports on the production techniques utilised. Materials and methods Seven hundred and eighty-two online questionnaires were distributed to the Dental Laboratories Association membership and included a broad range of topics, such as demographics, impression disinfection and suitability, and various production techniques. Settings were managed in order to ensure anonymity of respondents. Statistical analysis was undertaken to test the influence of various demographic variables such as the source of information, the location, and the size of the dental laboratory. Results The number of completed responses totalled 248 (32% response rate). Ninety percent of the respondents were based in England and the majority of dental laboratories were categorised as small sized (working with up to 25 dentists). Concerns were raised regarding inadequate disinfection protocols between dentists and dental laboratories and the poor quality of master impressions. Full arch plastic trays were the most popular impression tray used by dentists in the fabrication of crowns (61%) and bridgework (68%). The majority (89%) of jaw registration records were considered inaccurate. Forty-four percent of dental laboratories preferred using semi-adjustable articulators. Axial and occlusal under-preparation of abutment teeth was reported as an issue in about 25% of cases. Base metal alloy was the most (52%) commonly used alloy material. Metal-ceramic crowns were the most popular choice for anterior (69%) and posterior (70%) cases. The various factors considered did not have any statistically significant effect on the answers provided. The only notable exception was the fact that more methods of communicating the size and shape of crowns were utilised for

  12. Fabrication of superconducting MgB2 nanostructures by an electron beam lithography-based technique

    Science.gov (United States)

    Portesi, C.; Borini, S.; Amato, G.; Monticone, E.

    2006-03-01

    In this work, we present the results obtained in fabrication and characterization of magnesium diboride nanowires realized by an electron beam lithography (EBL)-based method. For fabricating MgB2 thin films, an all in situ technique has been used, based on the coevaporation of B and Mg by means of an e-gun and a resistive heater, respectively. Since the high temperatures required for the fabrication of good quality MgB2 thin films do not allow the nanostructuring approach based on the lift-off technique, we structured the samples combining EBL, optical lithography, and Ar milling. In this way, reproducible nanowires 1 μm long have been obtained. To illustrate the impact of the MgB2 film processing on its superconducting properties, we measured the temperature dependence of the resistance on a nanowire and compared it to the original magnesium diboride film. The electrical properties of the films are not degraded as a consequence of the nanostructuring process, so that superconducting nanodevices may be obtained by this method.

  13. Fabrication of dielectrophoretic microfluidic chips using a facile screen-printing technique for microparticle trapping

    International Nuclear Information System (INIS)

    Wee, Wei Hong; Kadri, Nahrizul Adib; Pingguan-Murphy, Belinda; Li, Zedong; Hu, Jie; Xu, Feng; Li, Fei

    2015-01-01

    Trapping of microparticles finds wide applications in numerous fields. Microfluidic chips based on a dielectrophoresis (DEP) technique hold several advantages for trapping microparticles, such as fast result processing, a small amount of sample required, high spatial resolution, and high accuracy of target selection. There is an unmet need to develop DEP microfluidic chips on different substrates for different applications in a low cost, facile, and rapid way. This study develops a new facile method based on a screen-printing technique for fabrication of electrodes of DEP chips on three types of substrates (i.e. polymethyl-methacrylate (PMMA), poly(ethylene terephthalate) and A4 paper). The fabricated PMMA-based DEP microfluidic chip was selected as an example and successfully used to trap and align polystyrene microparticles in a suspension and cardiac fibroblasts in a cell culture solution. The developed electrode fabrication method is compatible with different kinds of DEP substrates, which could expand the future application field of DEP microfluidic chips, including new forms of point-of care diagnostics and trapping circulating tumor cells. (paper)

  14. Fabrication of flex sensors through direct ink write technique and its electrical characterization

    Science.gov (United States)

    Abas, Muhammad; Rahman, Khalid

    2016-11-01

    The present work is intended to fabricate low-cost flex sensor from conductive carbon paste using direct ink write (DIW) technique. DIW method is one of the additive manufacturing processes, which is capable to deposit a variety of material on a variety of substrates by a different mechanism to feature resolution at a microns level. It is widely used in the electronic industry for fabrication of PCBS and electrodes for different electronic devices. The DIW system in present study extrudes material stored in the syringe barrel through nozzle using compressed air. This mechanism will assist in creating patterns on a variety of substrates. Pneumatic controller is employed to control deposition of material, while computer-controlled X-Y stage is employed to control pattern generation. For effective and control patterning, printing parameters were optimized using Taguchi design optimization technique. The conductive carbon paste is used as ink for pattern generation on flexible PET substrate. Samples of flex sensor having different dimensions are prepared through DIW. The fabricated sensors were used as flexion sensor, and its electrical characteristic was evaluated. The obtained sensors are stable and reliable in performance.

  15. A Novel Bio-carrier Fabricated Using 3D Printing Technique for Wastewater Treatment

    Science.gov (United States)

    Dong, Yang; Fan, Shu-Qian; Shen, Yu; Yang, Ji-Xiang; Yan, Peng; Chen, You-Peng; Li, Jing; Guo, Jin-Song; Duan, Xuan-Ming; Fang, Fang; Liu, Shao-Yang

    2015-01-01

    The structure of bio-carriers is one of the key operational characteristics of a biofilm reactor. The goal of this study is to develop a series of novel fullerene-type bio-carriers using the three-dimensional printing (3DP) technique. 3DP can fabricate bio-carriers with more specialized structures compared with traditional fabrication processes. In this research, three types of fullerene-type bio-carriers were fabricated using the 3DP technique and then compared with bio-carrier K3 (from AnoxKaldnes) in the areas of physicochemical properties and biofilm growth. Images acquired by 3D profiling and SEM indicated that the surface roughness of the 3DP bio-carrier was greater than that of K3. Furthermore, contact angle data indicated that the 3DP bio-carriers were more hydrophilic than K3. The biofilm on the 3DP bio-carriers exhibited higher microbial activity and stronger adhesion ability. These findings were attributed to excellent mass transfer of the substrate (and oxygen) between the vapour-liquid-solid tri-phase system and to the surface characteristics. It is concluded that the novel 3DP fullerene-type bio-carriers are ideal carriers for biofilm adherence and growth. PMID:26202477

  16. Surface properties and corrosion behavior of Co-Cr alloy fabricated with selective laser melting technique.

    Science.gov (United States)

    Xin, Xian-zhen; Chen, Jie; Xiang, Nan; Wei, Bin

    2013-01-01

    We sought to study the corrosion behavior and surface properties of a commercial cobalt-chromium (Co-Cr) alloy which was fabricated with selective laser melting (SLM) technique. For this purpose, specimens were fabricated using different techniques, such as SLM system and casting methods. Surface hardness testing, microstructure observation, surface analysis using X-ray photoelectron spectroscopy (XPS) and electrochemical corrosion test were carried out to evaluate the corrosion properties and surface properties of the specimens. We found that microstructure of SLM specimens was more homogeneous than that of cast specimens. The mean surface hardness values of SLM and cast specimens were 458.3 and 384.8, respectively; SLM specimens showed higher values than cast ones in hardness. Both specimens exhibited no differences in their electrochemical corrosion properties in the artificial saliva through potentiodynamic curves and EIS, and no significant difference via XPS. Therefore, we concluded that within the scope of this study, SLM-fabricated restorations revealed good surface properties, such as proper hardness, homogeneous microstructure, and also showed sufficient corrosion resistance which could meet the needs of dental clinics.

  17. Fabrication of three-dimensional polymer quadratic nonlinear grating structures by layer-by-layer direct laser writing technique

    Science.gov (United States)

    Bich Do, Danh; Lin, Jian Hung; Diep Lai, Ngoc; Kan, Hung-Chih; Hsu, Chia Chen

    2011-08-01

    We demonstrate the fabrication of a three-dimensional (3D) polymer quadratic nonlinear (χ(2)) grating structure. By performing layer-by-layer direct laser writing (DLW) and spin-coating approaches, desired photobleached grating patterns were embedded in the guest--host dispersed-red-1/poly(methylmethacrylate) (DR1/PMMA) active layers of an active-passive alternative multilayer structure through photobleaching of DR1 molecules. Polyvinyl-alcohol and SU8 thin films were deposited between DR1/PMMA layers serving as a passive layer to separate DR1/PMMA active layers. After applying the corona electric field poling to the multilayer structure, nonbleached DR1 molecules in the active layers formed polar distribution, and a 3D χ(2) grating structure was obtained. The χ(2) grating structures at different DR1/PMMA nonlinear layers were mapped by laser scanning second harmonic (SH) microscopy, and no cross talk was observed between SH images obtained from neighboring nonlinear layers. The layer-by-layer DLW technique is favorable to fabricating hierarchical 3D polymer nonlinear structures for optoelectronic applications with flexible structural design.

  18. Periodontal ligament and intraosseous anesthetic injection techniques: alternatives to mandibular nerve blocks.

    Science.gov (United States)

    Moore, Paul A; Cuddy, Michael A; Cooke, Matthew R; Sokolowski, Chester J

    2011-09-01

    and Overview. The provision of mandibular anesthesia traditionally has relied on nerve block anesthetic techniques such as the Halsted, the Gow-Gates and the Akinosi-Vazirani methods. The authors present two alternative techniques to provide local anesthesia in mandibular teeth: the periodontal ligament (PDL) injection and the intraosseous (IO) injection. The authors also present indications for and complications associated with these techniques. The PDL injection and the IO injection are effective anesthetic techniques for managing nerve block failures and for providing localized anesthesia in the mandible. Dentists may find these techniques to be useful alternatives to nerve block anesthesia.

  19. Alternating current techniques for corrosion monitoring in water reactor systems

    International Nuclear Information System (INIS)

    Isaacs, H.S.; Weeks, J.R.

    1977-01-01

    Corrosion in both nuclear and fossil fueled steam generators is generally a consequence of the presence of aggressive impurities introduced into the coolant system through condenser leakage. The impurities concentrate in regions of the steam generator protected from coolant flow, in crevices or under deposited corrosion products and adjacent to heat transfer surfaces. These three factors, the aggressive impurity, crevice type areas and heat transfer surfaces appear to be the requirements for the onset of rapid corrosion. Under conditions where coolant impurities do not concentrate the corrosion rates are low, easily measured and can be accounted for by allowances in the design of the steam generator. Rapid corrosion conditions cannot be designed for and must be suppressed. The condition of the surfaces when rapid corrosion develops must be markedly different from those during normal operation and these changes should be observable using electrochemical techniques. This background formed the basis of a design of a corrosion monitoring device, work on which was initiated at BNL. The basic principles of the technique are described. The object of the work is to develop a corrosion monitoring device which can be operated with PWR steam generator secondary coolant feed water

  20. Study and fabrication of tunnel diodes made on germanium using a collective planar technique

    International Nuclear Information System (INIS)

    Vrahides, Michel

    1973-01-01

    The main results of the theory on tunnel diodes are presented in the first chapter. From these results are deduced the technological requirements that any fabrication process should meet to make tunnel diodes. These requirements show up that, among the three techniques for junction making (thermal diffusion of impurities, epitaxy, alloying), the last one is presently the best fitted to the fabrication of tunnel junctions. By analyzing the defects created by various alloying technologies presently used, together with a study of the benefits due to a use of chemical photolithography, evaporation under vacuum and masking by deposited oxide, it is possible to design a tentative scheme of a 0.5 ns tunnel diode. Then, in a second chapter, is presented the collective process for fabrication that has been used on monocrystalline, P-type, germanium wafers. 8 000 tunnel diodes may be positioned on a 1.5 inch diameter wafer by using that process. A description of the various apparatus used is also given. The experimental results are described in the third chapter. The influence of the various fabrication parameters on the electrical characteristics of the diodes are discussed. It is shown, by studying the fabrication yields and parameter spreading, that 80 per cent of the diodes exhibit a standard tunnel diode behaviour and that 90 per cent of these present a peak current dispersion less than ± 25 per cent. When measuring at the peak current drifts under temperature stresses, a good analogy with conventional tunnel diode is found. Some measurements of switching times have led to values as low as 0.6 nanoseconds. (author) [fr

  1. AlGaInAs EML having high extinction ratios fabricated by identical epitaxial layer technique

    Science.gov (United States)

    Deng, Qiufang; Guo, Lu; Liang, Song; Sun, Siwei; Xie, Xiao; Zhu, Hongliang; Wang, Wei

    2018-04-01

    AlGaInAs electroabsorption-modulated lasers (EMLs) fabricated by identical epitaxial layer technique are demonstrated. The EML device shows an infinite characteristic temperature when the temperature ranges from 20 oC to 30 oC. The integrated modulator has static extinction ratios of larger than 20 dB at a reverse bias voltage of - 2 V. The small signal modulation bandwidth of the modulator is larger than 11 GHz. At 10 Gb/s data modulation, the dynamic extinction ratio is about 9.5 dB in a back to back test configuration. Because only a simple fabrication procedure is needed, our EMLs are promising low cost light sources for optical fiber transmission applications.

  2. Recent advances in fuel fabrication techniques and prospects for the nineties

    International Nuclear Information System (INIS)

    Frain, R.G.; Caudill, H.L.; Faulhaber, R.

    1987-01-01

    Advanced Nuclear Fuels Corporation's approach and experience with the application of a flexible, just-in-time manufacturing philosophy to the production of customized nuclear fuel is described. Automation approaches to improve productivity are described. The transfer of technology across product lines is discussed as well as the challenges presented by a multiple product fabrication facility which produces a wide variety of BWR and PWR designs. This paper also describes the method of managing vendor quality control programs in support of standardization and clarity of documentation. Process simplification and the ensuing experience are discussed. Prospects for fabrication process advancements in the nineties are given with emphasis on the benefits of dry conversion of UF 6 to UO 2 powder, and increased use of automated and computerized inspection techniques. (author)

  3. Transparent optically vanadium dioxide thermochromic smart film fabricated via electrospinning technique

    Science.gov (United States)

    Lu, Yuan; Xiao, Xiudi; Cao, Ziyi; Zhan, Yongjun; Cheng, Haoliang; Xu, Gang

    2017-12-01

    The monoclinic phase vanadium dioxide VO2 (M) based transparent thermochromic smart films were firstly fabricated through heat treatment of opaque VO2-based composite nanofibrous mats, which were deposited on the glass substrate via electrospinning technique. Noteworthily, the anti-oxidation property of VO2 smart film was improved due to inner distribution of VO2 in the polymethylmethacrylate (PMMA) nanofibers, and the composite mats having water contact angle of 165° determined itself good superhydrophobic property. Besides, PMMA nanofibrous mats with different polymer concentrations demonstrated changeable morphology and fiber diameter. The VO2 nanoparticles having diameter of 30-50 nm gathered and exhibited ellipse-like or belt-like structure. Additionally, the solar modulation ability of PMMA-VO2 composite smart film was 6.88% according to UV-Vis-NIR spectra. The research offered a new notion for fabricating transparent VO2 thermochromic material.

  4. Fabrication of BN/Al(-Mg) metal matrix composite (MMC) by pressureless infiltration technique

    Energy Technology Data Exchange (ETDEWEB)

    Jung, W.G.; Kwon, H. [School of Advanced Materials Eng., Kookmin Univ., Seoul (Korea)

    2004-07-01

    BN/Al(-Mg) metal matrix composite (MMC) was fabricated by the pressureless infiltration technique. The phase characterizations of the composites were analyzed using the SEM, TEM, EDS and EPMA on reaction products after the electrochemical dissolution of the matrix. It is confirmed that aluminum nitride (AlN) was formed by the reaction of Mg{sub 3}N{sub 2} and Al alloy melt. Plate type AlN and polyhedral type Mg(-Al) boride were formed by the reaction between Mg{sub 3}N{sub 2}, BN and molten Al in the composite. The reaction mechanism in the fabrication of BN/Al(-Mg) MMC was derived from the phase analysis results and the thermodynamic investigation. (orig.)

  5. Fatigue Life of Titanium Alloys Fabricated by Additive Layer Manufacturing Techniques for Dental Implants

    Science.gov (United States)

    Chan, Kwai S.; Koike, Marie; Mason, Robert L.; Okabe, Toru

    2013-02-01

    Additive layer deposition techniques such as electron beam melting (EBM) and laser beam melting (LBM) have been utilized to fabricate rectangular plates of Ti-6Al-4V with extra low interstitial (ELI) contents. The layer-by-layer deposition techniques resulted in plates that have different surface finishes which can impact significantly on the fatigue life by providing potential sites for fatigue cracks to initiate. The fatigue life of Ti-6Al-4V ELI alloys fabricated by EBM and LBM deposition techniques was investigated by three-point testing of rectangular beams of as-fabricated and electro-discharge machined surfaces under stress-controlled conditions at 10 Hz until complete fracture. Fatigue life tests were also performed on rolled plates of Ti-6Al-4V ELI, regular Ti-6Al-4V, and CP Ti as controls. Fatigue surfaces were characterized by scanning electron microscopy to identify the crack initiation site in the various types of specimen surfaces. The fatigue life data were analyzed statistically using both analysis of variance techniques and the Kaplan-Meier survival analysis method with the Gehan-Breslow test. The results indicate that the LBM Ti-6Al-4V ELI material exhibits a longer fatigue life than the EBM counterpart and CP Ti, but a shorter fatigue life compared to rolled Ti-6Al-4V ELI. The difference in the fatigue life behavior may be largely attributed to the presence of rough surface features that act as fatigue crack initiation sites in the EBM material.

  6. Aqueous phase oxidation techniques as an alternative to incineration

    International Nuclear Information System (INIS)

    Gray, L.W.; Adamson, M.G.; Hickman, R.G.; Farmer, J.C.; Chiba, Z.; Gregg, D.W.; Wang, F.T.

    1992-03-01

    The Lawrence Livermore National Laboratory (LLNL) has three aqueous phase techniques under development for oxidation of high value or high risk waste steams. One is direct electrochemical oxidation and one is mediated electrochemical oxidation utilizing regenerable, strongly oxidizing cations such as Ag(II), Co (III), Ce(IV), etc. These cations can either attack oxidizable materials directly and/or indirectly via first reacting with water to generate OH radicals which then attack the oxidizable materials. The third system utilizes H 2 O 2 and UV light to generate OH radicals directly which in turn attack the oxidizable materials. All systems have the advantage of a chemical off-switch in that when the power is turned off, the reaction quickly subsides. All systems operate with low concentrations (typically <5 wt %) of oxidizable materials, therefore, the stored energy for possible run-away reactions is very low. 15 figures, 22 references

  7. The Kock pouch reconsidered: an alternative surgical technique.

    Science.gov (United States)

    Crawshaw, Alison; Williams, Julia; Woodhouse, Fran

    The psychological impact stoma surgery can have on an individual is well documented within the literature (White and Hunt, 1997; Borwell, 2009; Williams, 2005; Brown, 2005). For many years, surgeons have explored and developed innovations in surgical techniques, in particular restorative procedures with a view of preventing permanent stoma formation; ileal anal pouch (IAP) now being the surgical procedure of choice for treatment of ulcerative colitis (UC) and familial adenomatous polyposis (FAP). However, high morbidity rates are associated with pouch longevity (Castillo et al 2005; Nessar and Wu, 2012) and once removed can lead to a high-output ileostomy with risks of electrolyte imbalance and malabsorption. This then creates the dilemma of whether the Kock pouch (KP) should be offered as a surgical option. This article offers a historical perspective of the KP and its place in the surgical management of UC and FAP. This article also presents results from a recent audit funded by the Ileostomy Association (IA), highlighting how patients manage their KP and the importance of maintaining bowel control and being free of an incontinent stoma as a means of coming to terms with their condition.

  8. Characterization of fabricated three dimensional scaffolds of bio ceramic-polymer composite via microstereolithography technique

    International Nuclear Information System (INIS)

    Marina Talib; Covington, J.A.; Bolarinwa, A.

    2013-01-01

    Full-text: Microstereolithography is a method used for rapid proto typing of polymeric and ceramic components. This technique converts a computer-aided design (CAD) to a three dimensional (3D) model, and enables layer per layer fabrication curing a liquid resin with UV-light or laser source. The aim of this project was to formulate photo curable polymer reinforced with synthesized calcium pyrophosphate (CPP), and to fabricate a 3D scaffolds with optimum mechanical properties for specific tissue engineering applications. The photo curable ceramic suspension was prepared with acrylate polyester, multifunctional acrylate monomer with the addition of 50-70 wt % of CPP, photo initiators and photo inhibitors. The 3D structure of disc (5 mm height x 4 mm diameter) was successfully fabricated using Envisiontec Perfactory3. They were then sintered at high temperature for polymer removal, to obtain a ceramic of the desired porosity. The density increased to more than 35 % and the dimensional shrinkage after sintering were 33 %. The discs were then subjected compressive measurement, biodegradation and bioactivity test. Morphology and CPP content of the sintered polymer was investigated with SEM and XRD, respectively. The addition of CPP coupled with high temperature sintering, had a significant effect on the compressive strength exhibited by the bio ceramic. The values are in the range of cancellous bone (2-4 MPa). In biodegradation and bioactivity test, the synthesized CPP induced the formation of apatite layer and its nucleation onto the composite surface. (author)

  9. A novel fabrication method of silicon nano-needles using MEMS TMAH etching techniques

    International Nuclear Information System (INIS)

    Yan Sheping; Xu Yang; Yang Junyi; Wang Huiquan; Jin Zhonghe; Wang Yuelin

    2011-01-01

    Nano-needles play important roles in nanoscale operations. However, current nano-needle fabrication is usually expensive and controling the sizes and angles is complicated. We have developed a simple and low cost silicon nano-needle fabrication method using traditional microelectromechanical system (MEMS) tetramethyl ammonium hydroxide (TMAH) etching techniques. We take advantage of the fact that the decrease of the silicon etch rate in TMAH solutions exhibits an inverse fourth power dependence on the boron doping concentration in our nano-needle fabrication. Silicon nano-needles, with high aspect ratio and sharp angles θ as small as 2.9 deg., are obtained, which could be used for bio-sensors and nano-handling procedures, such as penetrating living cells. An analytic model is proposed to explain the etching evolution of the experimental results, which is used to predict the needle angle, length, and etching time. Based on our method, nano-needles with small acute angle θ can be obtained.

  10. An alternative technique for simulating volumetric cylindrical sources in the Morse code utilization

    International Nuclear Information System (INIS)

    Vieira, W.J.; Mendonca, A.G.

    1985-01-01

    In the solution of deep-penetration problems using the Monte Carlo method, calculation techniques and strategies are used in order to increase the particle population in the regions of interest. A common procedure is the coupling of bidimensional calculations, with (r,z) discrete ordinates transformed into source data, and tridimensional Monte Carlo calculations. An alternative technique for this procedure is presented. This alternative proved effective when applied to a sample problem. (F.E.) [pt

  11. Fabrication of Polymeric Coatings with Controlled Microtopographies Using an Electrospraying Technique.

    Directory of Open Access Journals (Sweden)

    Qiongyu Guo

    Full Text Available Surface topography of medical implants provides an important biophysical cue on guiding cellular functions at the cell-implant interface. However, few techniques are available to produce polymeric coatings with controlled microtopographies onto surgical implants, especially onto implant devices of small dimension and with complex structures such as drug-eluting stents. Therefore, the main objective of this study was to develop a new strategy to fabricate polymeric coatings using an electrospraying technique based on the uniqueness of this technique in that it can be used to produce a mist of charged droplets with a precise control of their shape and dimension. We hypothesized that this technique would allow facile manipulation of coating morphology by controlling the shape and dimension of electrosprayed droplets. More specifically, we employed the electrospraying technique to coat a layer of biodegradable polyurethane with tailored microtopographies onto commercial coronary stents. The topography of such stent coatings was modulated by controlling the ratio of round to stretched droplets or the ratio of round to crumped droplets under high electric field before deposition. The shape of electrosprayed droplets was governed by the stability of these charged droplets right after ejection or during their flight in the air. Using the electrospraying technique, we achieved conformal polymeric coatings with tailored microtopographies onto conductive surgical implants. The approach offers potential for controlling the surface topography of surgical implant devices to modulate their integration with surrounding tissues.

  12. Evaluation of the marginal fit of metal copings fabricated on three different marginal designs using conventional and accelerated casting techniques: an in vitro study.

    Science.gov (United States)

    Vaidya, Sharad; Parkash, Hari; Bhargava, Akshay; Gupta, Sharad

    2014-01-01

    Abundant resources and techniques have been used for complete coverage crown fabrication. Conventional investing and casting procedures for phosphate-bonded investments require a 2- to 4-h procedure before completion. Accelerated casting techniques have been used, but may not result in castings with matching marginal accuracy. The study measured the marginal gap and determined the clinical acceptability of single cast copings invested in a phosphate-bonded investment with the use of conventional and accelerated methods. One hundred and twenty cast coping samples were fabricated using conventional and accelerated methods, with three finish lines: Chamfer, shoulder and shoulder with bevel. Sixty copings were prepared with each technique. Each coping was examined with a stereomicroscope at four predetermined sites and measurements of marginal gaps were documented for each. A master chart was prepared for all the data and was analyzed using Statistical Package for the Social Sciences version. Evidence of marginal gap was then evaluated by t-test. Analysis of variance and Post-hoc analysis were used to compare two groups as well as to make comparisons between three subgroups . Measurements recorded showed no statistically significant difference between conventional and accelerated groups. Among the three marginal designs studied, shoulder with bevel showed the best marginal fit with conventional as well as accelerated casting techniques. Accelerated casting technique could be a vital alternative to the time-consuming conventional casting technique. The marginal fit between the two casting techniques showed no statistical difference.

  13. A hollow definitive obturator fabrication technique for management of partial maxillectomy.

    Science.gov (United States)

    Patil, Pravinkumar Gajanan; Patil, Smita Pravinkumar

    2012-11-01

    Maxillary obturator prosthesis is the most frequent treatment option for management of partial or total maxillectomy. Heavy weight of the obturators is often a dislocating factor. Hollowing the prosthesis to reduce its weight is the well established fact. The alternate technique to hollow-out the prosthesis has been described in this article which is a variation of previously described processing techniques. A pre-shaped wax-bolus was incorporated inside the flasks during packing of the heat-polymerized acrylic resin to automatically create the hollow space. The processing technique described is a single step flasking procedure to construct a closed-hollow-obturator prosthesis as a single unit. To best understand the technique, this article describes management of a patient who had undergone partial maxillectomy secondary to squamous cell carcinoma rehabilitated with a hollow-obturator prosthesis.

  14. Development and fabrication of patient-specific knee implant using additive manufacturing techniques

    Science.gov (United States)

    Zammit, Robert; Rochman, Arif

    2017-10-01

    Total knee replacement is the most effective treatment to relief pain and restore normal function in a diseased knee joint. The aim of this research was to develop a patient-specific knee implant which can be fabricated using additive manufacturing techniques and has reduced wear rates using a highly wear resistant materials. The proposed design was chosen based on implant requirements, such as reduction in wear rates as well as strong fixation. The patient-specific knee implant improves on conventional knee implants by modifying the articulating surfaces and bone-implant interfaces. Moreover, tribological tests of different polymeric wear couples were carried out to determine the optimal materials to use for the articulating surfaces. Finite element analysis was utilized to evaluate the stresses sustained by the proposed design. Finally, the patient-specific knee implant was successfully built using additive manufacturing techniques.

  15. Fabrication and Characterization of three dimensional Scaffolds for tissue engineering application via microstereolithography technique

    International Nuclear Information System (INIS)

    Marina Talib; Covington, J.A.; Dove, A.; Bolarinwa, A.; Grover, L.

    2012-01-01

    Microstereolithography is a method used for rapid proto typing of polymeric and ceramic components. This technique converts a computer-aided design (CAD) to a three dimensional (3D) model, and enables layer-per-layer fabrication curing a liquid resin with UV-light or laser source. However, the use of stereo lithography in tissue engineering has not been significantly explored possibly due to the lack of commercially available implantable or biocompatible materials from the SL industry. This study seeks to develop a range of new bio-compatible/degradable materials that are compatible with a commercial 3D direct manufacture system (envisionTEC Desktop). Firstly, a selection of multifunctional polymer and calcium phosphate were studied in order to formulate biodegradable photo polymer resin for specific tissue engineering applications. A 3D structure was successfully fabricated from the formulated photo curable resins. The photo polymer of ceramic suspension was prepared with the addition of 50-70 wt % of calcium pyrophosphate (CPP) and hydroxyapatite (HA). They were then sintered at high temperature for polymer removal, to obtain a ceramic of the desired porosity. Mechanical properties, morphology and calcium phosphate content of the sintered polymers were characterised and investigated with SEM and XRD, respectively. The addition of calcium phosphate coupled with high temperature sintering, had a significant effect on the mechanical properties exhibited by the bio ceramic. The successful fabrication of novel bio ceramic polymer composite with MSL technique offers the possibility of designing complex tissue scaffolds with optimum mechanical properties for specific tissue engineering applications. (author)

  16. Fabrication of Capacitive Acoustic Resonators Combining 3D Printing and 2D Inkjet Printing Techniques

    Directory of Open Access Journals (Sweden)

    Rubaiyet Iftekharul Haque

    2015-10-01

    Full Text Available A capacitive acoustic resonator developed by combining three-dimensional (3D printing and two-dimensional (2D printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency.

  17. Fabrication of high-transmission microporous membranes by proton beam writing-based molding technique

    Science.gov (United States)

    Wang, Liping; Meyer, Clemens; Guibert, Edouard; Homsy, Alexandra; Whitlow, Harry J.

    2017-08-01

    Porous membranes are widely used as filters in a broad range of micro and nanofluidic applications, e.g. organelle sorters, permeable cell growth substrates, and plasma filtration. Conventional silicon fabrication approaches are not suitable for microporous membranes due to the low mechanical stability of thin film substrates. Other techniques like ion track etching are limited to the production of randomly distributed and randomly orientated pores with non-uniform pore sizes. In this project, we developed a procedure for fabricating high-transmission microporous membranes by proton beam writing (PBW) with a combination of spin-casting and soft lithography. In this approach, focused 2 MeV protons were used to lithographically write patterns consisting of hexagonal arrays of high-density pillars of few μm size in a SU-8 layer coated on a silicon wafer. After development, the pillars were conformably coated with a thin film of poly-para-xylylene (Parylene)-C release agent and spin-coated with polydimethylsiloxane (PDMS). To facilitate demolding, a special technique based on the use of a laser-cut sealing tape ring was developed. This method facilitated the successful delamination of 20-μm thick PDMS membrane with high-density micropores from the mold without rupture or damage.

  18. Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

    Science.gov (United States)

    Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

    2008-09-01

    One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

  19. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    International Nuclear Information System (INIS)

    Lee, Ho Jin; Lee, B. S.; Kim, K. B.

    2003-09-01

    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si 3 N 4 . Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation

  20. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Lee, B. S.; Kim, K. B

    2003-09-01

    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si{sub 3}N{sub 4}. Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation.

  1. A new method of fabricating a blend scaffold using an indirect three-dimensional printing technique

    International Nuclear Information System (INIS)

    Jung, Jin Woo; Lee, Hyungseok; Hong, Jung Min; Park, Jeong Hun; Cho, Dong-Woo; Shim, Jung Hee; Choi, Tae Hyun

    2015-01-01

    Due to its simplicity and effectiveness, the physical blending of polymers is considered to be a practical strategy for developing a versatile scaffold having desirable mechanical and biochemical properties. In the present work, an indirect three-dimensional (i3D) printing technique was proposed to fabricate a 3D free-form scaffold using a blend of immiscible materials, such as polycaprolactone (PCL) and gelatin. The i3D printing technique includes 3D printing of a mold and a sacrificial molding process. PCL/chloroform and gelatin/water were physically mixed to prepare the blend solution, which was subsequently injected into the cavity of a 3D printed mold. After solvent removal and gelatin cross-linking, the mold was dissolved to obtain a PCL–gelatin (PG) scaffold, with a specific 3D structure. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that PCL masses and gelatin fibers in the PG scaffold homogenously coexisted without chemical bonding. Compression tests confirmed that gelatin incorporation into the PCL enhanced its mechanical flexibility and softness, to the point of being suitable for soft-tissue engineering, as opposed to pure PCL. Human adipose-derived stem cells, cultured on a PG scaffold, exhibited enhanced in vitro chondrogenic differentiation and tissue formation, compared with those on a PCL scaffold. The i3D printing technique can be used to blend a variety of materials, facilitating 3D scaffold fabrication for specific tissue regeneration. Furthermore, this convenient and versatile technique may lead to wider application of 3D printing in tissue engineering. (paper)

  2. A new method of fabricating a blend scaffold using an indirect three-dimensional printing technique.

    Science.gov (United States)

    Jung, Jin Woo; Lee, Hyungseok; Hong, Jung Min; Park, Jeong Hun; Shim, Jung Hee; Choi, Tae Hyun; Cho, Dong-Woo

    2015-11-03

    Due to its simplicity and effectiveness, the physical blending of polymers is considered to be a practical strategy for developing a versatile scaffold having desirable mechanical and biochemical properties. In the present work, an indirect three-dimensional (i3D) printing technique was proposed to fabricate a 3D free-form scaffold using a blend of immiscible materials, such as polycaprolactone (PCL) and gelatin. The i3D printing technique includes 3D printing of a mold and a sacrificial molding process. PCL/chloroform and gelatin/water were physically mixed to prepare the blend solution, which was subsequently injected into the cavity of a 3D printed mold. After solvent removal and gelatin cross-linking, the mold was dissolved to obtain a PCL-gelatin (PG) scaffold, with a specific 3D structure. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that PCL masses and gelatin fibers in the PG scaffold homogenously coexisted without chemical bonding. Compression tests confirmed that gelatin incorporation into the PCL enhanced its mechanical flexibility and softness, to the point of being suitable for soft-tissue engineering, as opposed to pure PCL. Human adipose-derived stem cells, cultured on a PG scaffold, exhibited enhanced in vitro chondrogenic differentiation and tissue formation, compared with those on a PCL scaffold. The i3D printing technique can be used to blend a variety of materials, facilitating 3D scaffold fabrication for specific tissue regeneration. Furthermore, this convenient and versatile technique may lead to wider application of 3D printing in tissue engineering.

  3. The Usability of Boric Acid as an Alternative Foaming Agent on the Fabrication of Al/Al2O3 Composite Foams

    Science.gov (United States)

    Yaman, Bilge; Onuklu, Eren; Korpe, Nese O.

    2017-09-01

    Pure Al and alumina (2, 5, 10 wt.% Al2O3)-added Al composite foams were fabricated through powder metallurgy technique, where boric acid (H3BO3) is employed as a new alternative foaming agent. It is aimed to determine the effects of boric acid on the foaming behavior and cellular structure and also purposed to develop the mechanical properties of Al foams by addition of Al2O3. Al and Al composite foams with porosity fraction in the range of 46-53% were achieved by sintering at 620 °C for 2 h. Cell morphology was characterized using a combination of stereomicroscope equipped with image analyzer and scanning electron microscopy. Microhardness values were measured via using Vickers indentation technique. Quasi-static compression tests were performed at strain rate of 10-3 s-1. Compressive strength and energy absorption of the composite foams enhanced not only by the increasing weight fraction of alumina, but also by the usage of boric acid which leads to formation of boron oxide (B2O3) acting as a binder in obtaining dense cell walls. The results revealed that the boric acid has outstanding potential as foaming agent in the fabrication of Al and Al composite foams by providing improved mechanical properties.

  4. The longitudinal offset technique for apodization of coupled resonator optical waveguide devices: concept and fabrication tolerance analysis.

    Science.gov (United States)

    Doménech, José David; Muñoz, Pascual; Capmany, José

    2009-11-09

    In this paper, a novel technique to set the coupling constant between cells of a coupled resonator optical waveguide (CROW) device, in order to tailor the filter response, is presented. The technique is demonstrated by simulation assuming a racetrack ring resonator geometry. It consists on changing the effective length of the coupling section by applying a longitudinal offset between the resonators. On the contrary, the conventional techniques are based in the transversal change of the distance between the ring resonators, in steps that are commonly below the current fabrication resolution step (nm scale), leading to strong restrictions in the designs. The proposed longitudinal offset technique allows a more precise control of the coupling and presents an increased robustness against the fabrication limitations, since the needed resolution step is two orders of magnitude higher. Both techniques are compared in terms of the transmission esponse of CROW devices, under finite fabrication resolution steps.

  5. A novel porous scaffold fabrication technique for epithelial and endothelial tissue engineering.

    Science.gov (United States)

    McHugh, Kevin J; Tao, Sarah L; Saint-Geniez, Magali

    2013-07-01

    Porous scaffolds have the ability to minimize transport barriers for both two- (2D) and three-dimensional tissue engineering. However, current porous scaffolds may be non-ideal for 2D tissues such as epithelium due to inherent fabrication-based characteristics. While 2D tissues require porosity to support molecular transport, pores must be small enough to prevent cell migration into the scaffold in order to avoid non-epithelial tissue architecture and compromised function. Though electrospun meshes are the most popular porous scaffolds used today, their heterogeneous pore size and intense topography may be poorly-suited for epithelium. Porous scaffolds produced using other methods have similar unavoidable limitations, frequently involving insufficient pore resolution and control, which make them incompatible with 2D tissues. In addition, many of these techniques require an entirely new round of process development in order to change material or pore size. Herein we describe "pore casting," a fabrication method that produces flat scaffolds with deterministic pore shape, size, and location that can be easily altered to accommodate new materials or pore dimensions. As proof-of-concept, pore-cast poly(ε-caprolactone) (PCL) scaffolds were fabricated and compared to electrospun PCL in vitro using canine kidney epithelium, human colon epithelium, and human umbilical vein endothelium. All cell types demonstrated improved morphology and function on pore-cast scaffolds, likely due to reduced topography and universally small pore size. These results suggest that pore casting is an attractive option for creating 2D tissue engineering scaffolds, especially when the application may benefit from well-controlled pore size or architecture.

  6. Magnetic properties of nickel nanowires decorated with cobalt nanoparticles fabricated by two step electrochemical deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Maaz, K., E-mail: maaz@impcas.ac.cn [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore, 45650, Islamabad (Pakistan); Duan, J.L. [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Karim, S. [Nanomaterials Research Group, Physics Division, PINSTECH, Nilore, 45650, Islamabad (Pakistan); Chen, Y.H.; Yao, H.J.; Mo, D.; Sun, Y.M. [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Liu, J., E-mail: j.liu@impcas.ac.cn [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2016-10-01

    We demonstrate fabrication and magnetic characterization of novel nanostructures composed of Ni nanowires decorated with Co nanoparticles by two step etching and electrochemical deposition in polycarbonate template. Structural analysis confirmed the formation of nickel nanowires with diameter of 62 nm which are surrounded by cobalt nanoparticles of about 15 nm in diameter. By electron microscopy analyses it is evident that the nanoparticles are distributed on the surface of the nanowires. Analysis of magnetization data indicates that ferromagnetic Ni nanowires exhibit an easy axis of magnetization parallel to the wire long-axis while the angular dependence of coercivity indicates that magnetization reversal occurs through the curling process in these nanowires. An exchange bias accompanied by vertical shift in magnetization was observed below ∼20 K, measured under a cooling field of 1 kOe, which is attributed to the spin interactions between the spin-glass like surface layer and ferromagnetic core of the nanowires and nanoparticles. - Highlights: • Co-decorated Ni nanowires were fabricated by two-step electrodeposition technique. • The nanoparticles are distributed on the surface of nanowires. • Magnetization reversal occurs through the curling process in the nanowires. • Temperature dependent coercivity follows thermal activation model.

  7. Hemoglobin protein hollow shells fabricated through covalent layer-by-layer technique

    International Nuclear Information System (INIS)

    Duan Li; He Qiang; Yan Xuehai; Cui Yue; Wang Kewei; Li Junbai

    2007-01-01

    Hemoglobin (Hb) protein microcapsules held together by cross-linker, glutaraldehyde (GA), were successfully fabricated by covalent layer-by-layer (LbL) technique. The Schiff base reaction occurred on the colloid templates between the aldehyde groups of GA and free amino sites of Hb results in the formation of GA/Hb microcapsules after the removal of the templates. The structure of obtained monodisperse protein microcapsule was characterized by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The UV-Vis spectra measurements demonstrate the existence of Hb in the assembled capsules. Cyclic voltammetry (CV) and potential-controlled amperometric measurements (I-t curve) confirm that hemoglobin microcapsules after fabrication remain their heme electroactivity. Moreover, direct electron transfer process from protein to electrode surface was performed to detect the heme electrochemistry without using any mediator or promoter. The experiments of fluorescence recovery after photobleaching (FRAP) by CLSM demonstrate that the hemoglobin protein microcapsules have an improved permeability comparing to the conventional polyelectrolyte microcapsules

  8. Comparison of marginal and internal adaptation of copings fabricated from three different fabrication techniques: An in vitro study

    Directory of Open Access Journals (Sweden)

    Aman Arora

    2018-01-01

    Conclusion: Marginal and internal discrepancies of all the three casting techniques were within clinically acceptable values. Marginal fit of DMLS was superior as compared to other two techniques, whereas when internal fit was evaluated, conventional technique showed the best internal fit.

  9. Fabrication of Nanohydroxyapatite/Poly(caprolactone Composite Microfibers Using Electrospinning Technique for Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Mohd Izzat Hassan

    2014-01-01

    Full Text Available Tissue engineering fibrous scaffolds serve as three-dimensional (3D environmental framework by mimicking the extracellular matrix (ECM for cells to grow. Biodegradable polycaprolactone (PCL microfibers were fabricated to mimic the ECM as a scaffold with 7.5% (w/v and 12.5% (w/v concentrations. Lower PCL concentration of 7.5% (w/v resulted in microfibers with bead defects. The average diameter of fibers increased at higher voltage and the distance of tip to collector. Further investigation was performed by the incorporation of nanosized hydroxyapatite (nHA into microfibers. The incorporation of 10% (w/w nHA with 7.5% (w/v PCL solution produced submicron sized beadless fibers. The microfibrous scaffolds were evaluated using various techniques. Biodegradable PCL and nHA/PCL could be promising for tissue engineering scaffold application.

  10. Roles of Ag in fabricating Si nanowires by the electroless chemical etching technique

    International Nuclear Information System (INIS)

    Wan, X.; Wang, Q. K.; Wangyang, P. H.; Tao, H.

    2012-01-01

    Silicon wafers coated with a film of Ag pattern are used for investigating roles of Ag in the fabrication of silicon nanowire arrays (SiNWs) by the electroless chemical etching technique. The diameter of SiNWs grown in the mixed AgNO 3 /HF solution ranges from 20 to 250 nm. A growth mechanism for such obtained SiNWs is proposed and further experimentally verified. As a comparison as well as to better understand this chemical process, another popular topic on growing SiNWs in the H 2 O 2 /HF solution is also studied. Originating from different chemical reaction mechanisms, Ag film could protect the underneath Si in the AgNO 3 /HF solution and it could, on the contrary, accelerate etching of the underneath Si in the H 2 O 2 /HF solution.

  11. Recent Progress of Fabrication of Cell Scaffold by Electrospinning Technique for Articular Cartilage Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Yingge Zhou

    2018-01-01

    Full Text Available As a versatile nanofiber manufacturing technique, electrospinning has been widely employed for the fabrication of tissue engineering scaffolds. Since the structure of natural extracellular matrices varies substantially in different tissues, there has been growing awareness of the fact that the hierarchical 3D structure of scaffolds may affect intercellular interactions, material transportation, fluid flow, environmental stimulation, and so forth. Physical blending of the synthetic and natural polymers to form composite materials better mimics the composition and mechanical properties of natural tissues. Scaffolds with element gradient, such as growth factor gradient, have demonstrated good potentials to promote heterogeneous cell growth and differentiation. Compared to 2D scaffolds with limited thicknesses, 3D scaffolds have superior cell differentiation and development rate. The objective of this review paper is to review and discuss the recent trends of electrospinning strategies for cartilage tissue engineering, particularly the biomimetic, gradient, and 3D scaffolds, along with future prospects of potential clinical applications.

  12. New Technique for Fabrication of Scanning Single-Electron Transistor Microscopy Tips

    Science.gov (United States)

    Goodwin, Eric; Tessmer, Stuart

    Fabrication of glass tips for Scanning Single-Electron Transistor Microscopy (SSETM) can be expensive, time consuming, and inconsistent. Various techniques have been tried, with varying levels of success in regards to cost and reproducibility. The main requirement for SSETM tips is to have a sharp tip ending in a micron-scale flat face to allow for deposition of a quantum dot. Drawing inspiration from methods used to create tips from optical fibers for Near-Field Scanning Optical Microscopes, our group has come up with a quick and cost effective process for creating SSETM tips. By utilizing hydrofluoric acid to etch the tips and oleic acid to guide the etch profile, optical fiber tips with appropriate shaping can be rapidly prepared. Once etched, electric leads are thermally evaporated onto each side of the tip, while an aluminum quantum dot is evaporated onto the face. Preliminary results using various metals, oxide layers, and lead thicknesses have proven promising.

  13. Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

    Directory of Open Access Journals (Sweden)

    Sakuma Y

    2006-01-01

    Full Text Available AbstractAn atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs. Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

  14. Applications of ultrasonic phased array technique during fabrication of nuclear tubing and other components for the Indian nuclear power program

    International Nuclear Information System (INIS)

    Kapoor, K.

    2015-01-01

    Ultrasonic phased array technique has been applied in fabrication of nuclear fuel and structural at NFC. The integrity of the nuclear fuel and structural components is most crucial as they are exposed to severe environment during operation leading to rapid degradation of its properties during its lifecycle. Nuclear Fuel Complex has mandate for the fabrication of the nuclear fuel and core structurals for Indian PHWRs/BWR, sub-assemblies for the PFBR and steam generator tubing for PFBR and PHWRs which are the most critical materials for the Indian Nuclear Power program. NDE during fabrication of these materials is thus most crucial as it provides the confidence to the designer for safe operation during its lifetime. Many of these techniques have to be developed in-house to meet unique requirements of high sensitivity, resolution and shape of the components. Some of the advancements in the NDE during the fabrication include use of ultrasonic phased array which is detailed in this paper

  15. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Ruixin [Institute of Medical Equipment, Academy of Military and Medical Sciences, No. 106, Wandong Street, Hedong District, Tianjin 300000 (China); Jiang, Wenxue, E-mail: jiangortholivea@sina.cn [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Sun, Yufu [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Hui [Tianjin Medical University General Hospital, No. 154 Anshan Road, Tianjin, TJ 300052 (China)

    2016-09-02

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  16. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    International Nuclear Information System (INIS)

    Sun, Kai; Li, Ruixin; Jiang, Wenxue; Sun, Yufu; Li, Hui

    2016-01-01

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  17. Development of Ultraviolet (UV) Radiation Protective Fabric Using Combined Electrospinning and Electrospraying Technique

    Science.gov (United States)

    Sinha, Mukesh Kumar; Das, B. R.; Kumar, Kamal; Kishore, Brij; Prasad, N. Eswara

    2017-06-01

    The article reports a novel technique for functionization of nanoweb to develop ultraviolet (UV) radiation protective fabric. UV radiation protection effect is produced by combination of electrospinning and electrospraying technique. A nanofibrous web of polyvinylidene difluoride (PVDF) coated on polypropylene nonwoven fabric is produced by latest nanospider technology. Subsequently, web is functionalized by titanium dioxide (TiO2). The developed web is characterized for evaluation of surface morphology and other functional properties; mechanical, chemical, crystalline and thermal. An optimal (judicious) nanofibre spinning condition is achieved and established. The produced web is uniformly coated by defect free functional nanofibres in a continuous form of useable textile structural membrane for ultraviolet (UV) protective clothing. This research initiative succeeds in preparation and optimization of various nanowebs for UV protection. Field Emission Scanning Electron Microscope (FESEM) result reveals that PVDF webs photo-degradative behavior is non-accelerated, as compared to normal polymeric grade fibres. Functionalization with TiO2 has enhanced the photo-stability of webs. The ultraviolet protection factor of functionalized and non-functionalized nanowebs empirically evaluated to be 65 and 24 respectively. The developed coated layer could be exploited for developing various defence, para-military and civilian UV protective light weight clothing (tent, covers and shelter segments, combat suit, snow bound camouflaging nets). This research therefore, is conducted in an attempt to develop a scientific understanding of PVDF fibre coated webs for photo-degradation and applications for defence protective textiles. This technological research in laboratory scale could be translated into bulk productionization.

  18. Fabrication technique for a custom face mask for the treatment of obstructive sleep apnea.

    Science.gov (United States)

    Prehn, Ronald S; Colquitt, Tom

    2016-05-01

    The development of the positive airway pressure custom mask (TAP-PAP CM) has changed the treatment of obstructive sleep apnea. The TAP-PAP CM is used in continuous positive airway pressure therapy (CPAP) and is fabricated from the impression of the face. This mask is then connected to a post screwed into the mechanism of the TAP3 (Thornton Anterior Positioner) oral appliance. This strapless CPAP face mask features an efficient and stable CPAP interface with mandibular stabilization (Hybrid Therapy). A technique with a 2-stage polyvinyl siloxane face impression is described that offers improvements over the established single-stage face impression. This 2-stage impression technique eliminates problems inherent in the single-stage face impression, including voids, compressed tissue, inadequate borders, and a rushed experience due to the setting time of the single stage. The result is a custom mask with an improved seal to the CPAP device. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  19. Performance evaluation of WDXRF as a process control technique for MOX fuel fabrication

    International Nuclear Information System (INIS)

    Pandey, A.; Khan, F.A.; Das, D.K.; Behere, P.G.; Afzal, Mohd

    2015-01-01

    This paper presents studies on Wavelength Dispersive X-Ray Fluorescence (WDXRF), as a powerful non destructive technique (NDT) for the compositional analysis of various types of MOX fuels. The sample has come after mixing and milling of UO 2 and PuO 2 powder for the estimation of plutonium, as a process control step of fabrication of (U, Pu)O 2 mixed oxide (MOX) fuel. For the characterization for heavy metal in various MOX fuel, a WDXRF method was established as a process control technique. The attractiveness of our system is that it can analyze the samples in solid form as well as in liquid form. The system is adapted in a glove box for handling of plutonium based fuels. The glove box adapted system was optimized with Uranium and Thorium based MOX sample before introduction of Pu. Uranium oxide and thorium oxide have been estimated in uranium thorium MOX samples. Standard deviation for the analysis of U 3 O 8 and ThO 2 were found to be 0.14 and 0.15 respectively. The results are validated against the conventional wet chemical methods of analysis. (author)

  20. Advanced single-wafer sequential multiprocessing techniques for semiconductor device fabrication

    International Nuclear Information System (INIS)

    Moslehi, M.M.; Davis, C.

    1989-01-01

    Single-wafer integrated in-situ multiprocessing (SWIM) is recognized as the future trend for advanced microelectronics production in flexible fast turn- around computer-integrated semiconductor manufacturing environments. The SWIM equipment technology and processing methodology offer enhanced equipment utilization, improved process reproducibility and yield, and reduced chip manufacturing cost. They also provide significant capabilities for fabrication of new and improved device structures. This paper describes the SWIM techniques and presents a novel single-wafer advanced vacuum multiprocessing technology developed based on the use of multiple process energy/activation sources (lamp heating and remote microwave plasma) for multilayer epitaxial and polycrystalline semiconductor as well as dielectric film processing. Based on this technology, multilayer in-situ-doped homoepitaxial silicon and heteroepitaxial strained layer Si/Ge x Si 1 - x /Si structures have been grown and characterized. The process control and the ultimate interfacial abruptness of the layer-to-layer transition widths in the device structures prepared by this technology will challenge the MBE techniques in multilayer epitaxial growth applications

  1. Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

    Science.gov (United States)

    Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

    2018-01-01

    Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

  2. Photothermal and thermoelastic microscopies: two alternative techniques for the non-destructive testing of materials; Microscopies photothermiques et thermoelastiques: deux techniques alternatives pour le CND des materiaux

    Energy Technology Data Exchange (ETDEWEB)

    Fouaidy, M. [Institut de Physique Nucleaire, IN2P3/CNRS 91 - Orsay (France); Ridouane, H. [Faculte des Sciences Ben M' sik, LPPPC, Casablanca (Morocco)

    2002-07-01

    This work aims at evaluating the possibility of application of photothermal and thermoelastic microscopies to the non-destructive testing of materials, such as niobium used in the fabrication of superconductive RF cavities. The theoretical results obtained in this study show the diagnostic potentialities of these techniques when applied to niobium sheets or directly to cavities. The microscopes that use an intensity modulated laser as excitation source have a lateral resolution comprised between 1 {mu}m for f{sub mod} = 10 MHz and 30 to 50 {mu}m for f{sub mod} = 10 kHz with a 1 {mu}m diameter beam. These techniques allow the detection, localization, and sometimes the characterization, of subsurface and deep defects and inclusions. In far field regime the resolution of the method depends on the thermal diffusion depth. Thanks to the strong dependence between the laser induced stress and the thickness of the target, the photothermal and thermoelastic microscopes can be used also for the measurement of cavities thickness and internal profile. (J.S.)

  3. Development of nano-fabrication technique utilizing self-organizational behavior of point defects induced by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Noriko [Department of Environmental Systems Engineering, Kochi University of Technology, Tosayamada-Cho, Kochi-Prefecture 782-8502 (Japan); Taniwaki, Masafumi [Department of Environmental Systems Engineering, Kochi University of Technology, Tosayamada-Cho, Kochi-Prefecture 782-8502 (Japan)]. E-mail: taniwaki.masafumi@kochi-tech.ac.jp

    2006-04-01

    The present authors proposed a novel nano-fabrication technique that is able to arrange the fine cells orderly, based on their finding in GaSb implanted at a low temperature. In this article, first the experimental results that anomalous cellular structure was formed in GaSb by ion implantation is introduced and the self-organizational formation mechanism of the structure is described. Next a nano-fabrication technique that utilizes focused ion beam is described. This technique consists of two procedures, i.e. the formation process of the voids array and the development of the initial array to ordered cellular structure. Finally, the nano-fabrication is actually performed by this technique and their results are reported. Fabrication succeeded in structures where the dot (cell) interval was 100 nm or larger. The minimum ion dose for initial voids which develops to the ordered cellular structure is evaluated. It is also shown that the substrate temperature during implantation is an essential parameter for this technique.

  4. Development of nano-fabrication technique utilizing self-organizational behavior of point defects induced by ion irradiation

    International Nuclear Information System (INIS)

    Nitta, Noriko; Taniwaki, Masafumi

    2006-01-01

    The present authors proposed a novel nano-fabrication technique that is able to arrange the fine cells orderly, based on their finding in GaSb implanted at a low temperature. In this article, first the experimental results that anomalous cellular structure was formed in GaSb by ion implantation is introduced and the self-organizational formation mechanism of the structure is described. Next a nano-fabrication technique that utilizes focused ion beam is described. This technique consists of two procedures, i.e. the formation process of the voids array and the development of the initial array to ordered cellular structure. Finally, the nano-fabrication is actually performed by this technique and their results are reported. Fabrication succeeded in structures where the dot (cell) interval was 100 nm or larger. The minimum ion dose for initial voids which develops to the ordered cellular structure is evaluated. It is also shown that the substrate temperature during implantation is an essential parameter for this technique

  5. Advanced analysis technique for the evaluation of linear alternators and linear motors

    Science.gov (United States)

    Holliday, Jeffrey C.

    1995-01-01

    A method for the mathematical analysis of linear alternator and linear motor devices and designs is described, and an example of its use is included. The technique seeks to surpass other methods of analysis by including more rigorous treatment of phenomena normally omitted or coarsely approximated such as eddy braking, non-linear material properties, and power losses generated within structures surrounding the device. The technique is broadly applicable to linear alternators and linear motors involving iron yoke structures and moving permanent magnets. The technique involves the application of Amperian current equivalents to the modeling of the moving permanent magnet components within a finite element formulation. The resulting steady state and transient mode field solutions can simultaneously account for the moving and static field sources within and around the device.

  6. High-Quality Large-Magnification Polymer Lens from Needle Moving Technique and Thermal Assisted Moldless Fabrication Process.

    Directory of Open Access Journals (Sweden)

    Ratthasart Amarit

    Full Text Available The need of mobile microscope is escalating as well as the demand of high quality optical components in low price. We report here a novel needle moving technique to fabricate milli-size lens together with thermal assist moldless method. Our proposed protocol is able to create a high tensile strength structure of the lens and its base which is beneficial for exploiting in convertinga smart phone to be a digital microscope. We observe that no bubble trapped in a lens when this technique is performed which can overcome a challenge problem found in a typical dropping technique. We demonstrate the symmetry, smoothness and micron-scale resolution of the fabricated structure. This proposed technique is promising to serve as high quality control mass production without any expensive equipment required.

  7. Characterization and analysis of surface notches on Ti-alloy plates fabricated by additive manufacturing techniques

    International Nuclear Information System (INIS)

    Chan, Kwai S.

    2015-01-01

    Rectangular plates of Ti–6Al–4V with extra low interstitial (ELI) were fabricated by layer-by-layer deposition techniques that included electron beam melting (EBM) and laser beam melting (LBM). The surface conditions of these plates were characterized using x-ray micro-computed tomography. The depth and radius of surface notch-like features on the LBM and EBM plates were measured from sectional images of individual virtual slices of the rectangular plates. The stress concentration factors of individual surface notches were computed and analyzed statistically to determine the appropriate distributions for the notch depth, notch radius, and stress concentration factor. These results were correlated with the fatigue life of the Ti–6Al–4V ELI alloys from an earlier investigation. A surface notch analysis was performed to assess the debit in the fatigue strength due to the surface notches. The assessment revealed that the fatigue lives of the additively manufactured plates with rough surface topographies and notch-like features are dominated by the fatigue crack growth of large cracks for both the LBM and EBM materials. The fatigue strength reduction due to the surface notches can be as large as 60%–75%. It is concluded that for better fatigue performance, the surface notches on EBM and LBM materials need to be removed by machining and the surface roughness be improved to a surface finish of about 1 μm. (paper)

  8. Characterization and analysis of surface notches on Ti-alloy plates fabricated by additive manufacturing techniques

    Science.gov (United States)

    Chan, Kwai S.

    2015-12-01

    Rectangular plates of Ti-6Al-4V with extra low interstitial (ELI) were fabricated by layer-by-layer deposition techniques that included electron beam melting (EBM) and laser beam melting (LBM). The surface conditions of these plates were characterized using x-ray micro-computed tomography. The depth and radius of surface notch-like features on the LBM and EBM plates were measured from sectional images of individual virtual slices of the rectangular plates. The stress concentration factors of individual surface notches were computed and analyzed statistically to determine the appropriate distributions for the notch depth, notch radius, and stress concentration factor. These results were correlated with the fatigue life of the Ti-6Al-4V ELI alloys from an earlier investigation. A surface notch analysis was performed to assess the debit in the fatigue strength due to the surface notches. The assessment revealed that the fatigue lives of the additively manufactured plates with rough surface topographies and notch-like features are dominated by the fatigue crack growth of large cracks for both the LBM and EBM materials. The fatigue strength reduction due to the surface notches can be as large as 60%-75%. It is concluded that for better fatigue performance, the surface notches on EBM and LBM materials need to be removed by machining and the surface roughness be improved to a surface finish of about 1 μm.

  9. Characterization of clays used in the fabrication of traditional brazilian ceramic pans: culture and technique

    International Nuclear Information System (INIS)

    Borlini, Monica Castoldi; Aguiar, Mariane Costalonga de; Vieira, Carlos Mauricio Fontes; Monteiro, Sergio Neves

    2009-01-01

    The fabrication process of clay pans in the state of Espirito Santo, southeast of Brazil, is a recognized part of the country's popular culture. In Goiabeiras, a district of the state capital Vitoria, the traditional production of these pans is the source of income for many families. The technique used in these ceramic pans is of indigenous origin, characterized by manual molding, outdoor burning and application of tannin dye. The clay pans are distributed to several Brazilian states and are nowadays conquering the external market. In producing these pans, two types of, yellow and gray, clays are used. The actual source of raw material comes from the deposit of the Mulemba valley, where a concern on the possibility of exhaustion exists. The objective of this study was then to characterize these two types of clays and so contribute to the continuity of traditional clay pan production by knowing the characteristics of the local clays in case of an eventual need for their replacement. Chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analysis of the clays were performed. The results showed that the clays are high plasticity kaolinite with considerable amounts of SiO 2 and Al 2 O 3 as well as of alkaline oxides, earth alkaline oxides and Fe 2 O 3 . (author)

  10. Fabrication and characterization of CuAlO2 transparent thin films prepared by spray technique

    International Nuclear Information System (INIS)

    Bouzidi, C.; Bouzouita, H.; Timoumi, A.; Rezig, B.

    2005-01-01

    CuAlO 2 thin films have been grown on glass substrates using spray technique; a low-cost method of thin films depositing. The deposition was carried out in a 450-525 deg. C range of substrate temperature. The solution and gas flow rates were kept constant at 5 cm 3 min -1 and 6.10 -3 m 3 min -1 , respectively. Compressed air was used as a carrier gas. The structural, morphological and optical properties of these thin films have been studied. These properties are strongly related to the substrate temperature and to the [Cu]/[Al] molar ratio r. X-ray diffraction analysis confirmed the initial amorphous nature of as-deposited films and phase transition into crystalline CuAlO 2 with the preferential orientation (1 0 1) upon annealing at 570 deg. C. The optical transmission of 80% has been achieved in the visible spectrum. CuAlO 2 band gap energy in the range of 3.34-3.87 eV has been found by optical measurement depending on fabrication parameters

  11. Fabrication of a two-level tumor bone repair biomaterial based on a rapid prototyping technique

    Energy Technology Data Exchange (ETDEWEB)

    Kai He; Yan Yongnian; Zhang Renji; Wang Xiaohong [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education and Center of Organ Manufacturing, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang Xinluan; Madhukar, Kumta Shekhar; Qin Ling [Department of Orthoapedics and Traumatology, The Chinese University of Hong Kong. Shatin, NT (Hong Kong)], E-mail: wangxiaohong@tsinghua.edu.cn, E-mail: kumta@cuhk.edu.hk, E-mail: qin@ort.cuhk.edu.hk

    2009-06-01

    After the removal of the giant cell tumor (GCT) of bone, it is necessary to fill the defects with adequate biomaterials. A new functional bone repair material with both stimulating osteoblast growth and inhibiting osteoclast activity has been developed with phosphorylated chitosan (P-chitosan) and disodium (1 {yields} 4)-2-deoxy-2-sulfoamino-{beta}-D-glucopyranuronan (S-chitosan) as the additives of poly(lactic acid-co-glycolic acid) (PLGA)/calcium phosphate (TCP) scaffolds based on a double-nozzle low-temperature deposition manufacturing technique. A computer-assisted design model was used and the optimal fabrication parameters were determined through the manipulation of a pure PLGA/TCP system. The microscopic structures, water absorbability and mechanical properties of the samples with different P-chitosan and S-chitosan concentrations were characterized correspondingly. The results suggested that this unique composite porous scaffold material is a potential candidate for the repair of large bone defects after a surgical removal of GCT.

  12. Fabrication and thermal oxidation of ZnO nano fibers prepared via electro spinning technique

    International Nuclear Information System (INIS)

    Baek, Jeongha; Park, Juyun; Kim, Don; Kang, Yongcheol; Koh, Sungwi; Kang, Jisoo

    2012-01-01

    Materials on the scale of nano scale have widely been used as research topics because of their interesting characteristics and aspects they bring into the field. Out of the many metal oxides, zinc oxide (ZnO) was chosen to be fabricated as nano fibers using the electro spinning method for potential uses of solar cells and sensors. After ZnO nano fibers were obtained, calcination temperature effects on the ZnO nano fibers were studied and reported here. The results of scanning electron microscopy (SEM) revealed that the aggregation of the ZnO nano fibers progressed by calcination. X-ray diffraction (XRD) study showed the hcp ZnO structure was enhanced by calcination at 873 and 1173 K. Transmission electron microscopy (TEM) confirmed the crystallinity of the calcined ZnO nano fibers. X-ray photoelectron spectroscopy (XPS) verified the thermal oxidation of Zn species by calcination in the nano fibers. These techniques have helped US deduce the facts that the diameter of ZnO increases as the calcination temperature was raised; the process of calcination affects the crystallinity of ZnO nano fibers, and the thermal oxidation of Zn species was observed as the calcination temperature was raised

  13. A practical technique for the fabrication of highly ordered macroporous structures of inorganic oxides

    International Nuclear Information System (INIS)

    Tang Fengqiu; Uchikoshi, Tetsuo; Sakka, Yoshio

    2006-01-01

    Well-defined macroporous ceramics consisting of SiO 2 , TiO 2 and ZrO 2 have been fabricated via a template-assisted colloidal processing technique. Close-packed polymer spheres were first prepared as a template using centrifugation or gravitational sedimentation, followed by infiltration with alkoxide precursors. The centrifugation should be preferred because it is a less time-consuming process and the materials are better ordered. The removal of the template beads was achieved by calcination of the organic-inorganic hybrids at appropriate temperatures, yielding well-ordered macroporous ceramics. The arrangement of the porous structures could be changing the preparation of the packed polymer templates. Some novel arrangements of macropores were obtained in these macroporous ceramics: a simple square-packed arrangement for SiO 2 , the coexistence of hexagonal close-packed and simple close-packed arrangements for TiO 2 , and face-centered cubic packed arrangement for ZrO 2 . The resulting highly structured ceramics could have applications in areas ranging from quantum electronics to photocatalysis and battery materials

  14. Replacement of a hopeless maxillary central incisor: a technique for the fabrication of an immediate implant-supported interim restoration.

    Science.gov (United States)

    Graiff, Lorenzo; Vigolo, Paolo

    2012-04-01

    Placement of a dental implant and an interim restoration in the esthetic zone immediately following tooth extraction is now a common procedure. However, in such clinical situations, the fabrication of an appropriate interim restoration may be challenging. The aim of this article is to present a technique for modifying the extracted tooth so it can be used as an implant-supported interim restoration.

  15. Fabrication and formation of bioactive anodic zirconium oxide nanotubes containing presynthesized hydroxyapatite via alternative immersion method

    International Nuclear Information System (INIS)

    Wang Luning; Luo Jingli

    2011-01-01

    Hydroxyapatite (HA) coating has been widely applied on metallic biomedical implants to enhance their biocompatibility. It has been reported that HA coating can be formed on annealed zirconium with anodic zirconium oxide nanotubular arrays after immersion in simulated biological fluid (SBF) for about 14 days. In the present study, we apply an alternative immersion method (AIM) to form presynthesized HA on ZrO 2 nanotubes. The AIM-treated specimen was then moved to the SBF to evaluate the capability for the formation of HA on it. The HA coating formed after only 2 days immersion and thickened after 5 days in the SBF. The HA coating is the carbonated HA with a ratio of Ca to P of about 1.4, similar to the physiological HA containing other minor elements such as Mg and Na. The results demonstrate that the AIM treatment is indeed suitable for the zirconium oxide nanotubes and highly accelerates the formation of HA coating in comparison with the existing methods, i.e. the annealing of the as-formed zirconium oxide nanotubular arrays.

  16. Investigations on microstructural and optical properties of CdS films fabricated by a low-cost, simplified spray technique using perfume atomizer for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K.; Philominathan, P. [PG and Research Department of Physics, AVVM, Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu (India)

    2008-11-15

    Good quality CdS films were fabricated by employing a simplified spray pyrolysis technique using perfume atomizer. CdS films have been deposited from aqueous solutions of sulphur and cadmium, keeping the molar concentrations of S:Cd = 0.01:0.01, 0.02:0.02, 0.04:0.04 and 0.06:0.06 in the starting solutions. The structural studies reveal that the S:Cd concentration has a strong influence on the microstructural characteristics of the sprayed CdS films. It was found that there is a transition in the preferred orientation from (0 0 2) plane to (1 0 1) plane when S:Cd molar concentration increases. The SEM images depict that the films are uniform and homogeneous. All the films have high optical transmittance (>80%) in the visible range. The optical band gap values are found to be in the range of 2.46-2.52 eV. CdS films fabricated by this simple and economic spray technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Hence, this simplified version of spray technique can be considered as an economic alternative to conventional spray pyrolysis (using carrier gas), for the mass production of low-cost, large area CdS coatings for solar cell applications. (author)

  17. Comparison the Marginal and Internal Fit of Metal Copings Cast from Wax Patterns Fabricated by CAD/CAM and Conventional Wax up Techniques

    Science.gov (United States)

    Vojdani, M; Torabi, K; Farjood, E; Khaledi, AAR

    2013-01-01

    Statement of Problem: Metal-ceramic crowns are most commonly used as the complete coverage restorations in clinical daily use. Disadvantages of conventional hand-made wax-patterns introduce some alternative ways by means of CAD/CAM technologies. Purpose: This study compares the marginal and internal fit of copings cast from CAD/CAM and conventional fabricated wax-patterns. Materials and Method: Twenty-four standardized brass dies were prepared and randomly divided into 2 groups according to the wax-patterns fabrication method (CAD/CAM technique and conventional method) (n=12). All the wax-patterns were fabricated in a standard fashion by means of contour, thickness and internal relief (M1-M12: representative of CAD/CAM group, C1-C12: representative of conventional group). CAD/CAM milling machine (Cori TEC 340i; imes-icore GmbH, Eiterfeld, Germany) was used to fabricate the CAD/CAM group wax-patterns. The copings cast from 24 wax-patterns were cemented to the corresponding dies. For all the coping-die assemblies cross-sectional technique was used to evaluate the marginal and internal fit at 15 points. The Student’s t- test was used for statistical analysis (α=0.05). Results: The overall mean (SD) for absolute marginal discrepancy (AMD) was 254.46 (25.10) um for CAD/CAM group and 88.08(10.67) um for conventional group (control). The overall mean of internal gap total (IGT) was 110.77(5.92) um for CAD/CAM group and 76.90 (10.17) um for conventional group. The Student’s t-test revealed significant differences between 2 groups. Marginal and internal gaps were found to be significantly higher at all measured areas in CAD/CAM group than conventional group (pmarginal and internal fit than CAD/CAM (machine-milled) technique. All the factors for 2 groups were standardized except wax pattern fabrication technique, therefore, only the conventional group results in copings with clinically acceptable margins of less than 120um. PMID:24724133

  18. The fission-track analysis: An alternative technique for provenance studies of prehistoric obsidian artefacts

    CERN Document Server

    Bellot-Gurlet, L; Dorighel, O; Oddone, M; Poupeau, G; Yegingil, Z

    1999-01-01

    Comparison of fission-track parameters - age and track densities - is an alternative tool for correlating obsidian artefacts with their potential natural sources. This method was applied by different fission-track groups in various regions and results were compared with those obtained using the more popular provenance identification techniques based on chemical composition studies. Hundreds of analyses prove that fission-track dating is a complementary technique which turns out to be very useful, specially when the chemical composition does not fully discriminate different sources. Archaeologically significant results were obtained applying the fission-track analysis in various regions of earth.

  19. Overview of Alternative Bunching and Current-shaping Techniques for Low-Energy Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Piot, Philippe [Northern Illinois U.

    2015-12-01

    Techniques to bunch or shape an electron beam at low energies (E <15 MeV) have important implications toward the realization of table-top radiation sources [1] or to the design of compact multi-user free-electron lasers[2]. This paper provides an overview of alternative methods recently developed including techniques such as wakefield-based bunching, space-charge-driven microbunching via wave-breaking [3], ab-initio shaping of the electron-emission process [4], and phase space exchangers. Practical applications of some of these methods to foreseen free-electron-laser configurations are also briefly discussed [5].

  20. The fission-track analysis: An alternative technique for provenance studies of prehistoric obsidian artefacts

    International Nuclear Information System (INIS)

    Bellot-Gurlet, L.; Bigazzi, G.; Dorighel, O.; Oddone, M.; Poupeau, G.; Yegingil, Z.

    1999-01-01

    Comparison of fission-track parameters - age and track densities - is an alternative tool for correlating obsidian artefacts with their potential natural sources. This method was applied by different fission-track groups in various regions and results were compared with those obtained using the more popular provenance identification techniques based on chemical composition studies. Hundreds of analyses prove that fission-track dating is a complementary technique which turns out to be very useful, specially when the chemical composition does not fully discriminate different sources. Archaeologically significant results were obtained applying the fission-track analysis in various regions of earth

  1. A Conservative Method for Treating Severely Displaced Pediatric Mandibular Fractures: An Effective Alternative Technique

    OpenAIRE

    Sahand Samieirad; Saeedeh khajehahmadi; Elahe Tohidi; Meysam Pakravan

    2016-01-01

    Pediatric mandibular fractures have been successfully managed in various ways. The use of a lingual splint is an option. This article presents a 4-year old boy who was treated by an alternative conservative method with a combination of an arch bar plus a lingual splint, circum-mandibular wiring and IMF for the reduction, stabilization and fixation of a severely displaced bilateral man‌dibular body fracture. This technique is a reliable, noninvasive procedure; it also limits the discomfort and...

  2. Fabrication of microlens arrays using a CO2-assisted embossing technique

    International Nuclear Information System (INIS)

    Huang, Tzu-Chien; Chan, Bin-Da; Ciou, Jyun-Kai; Yang, Sen-Yeu

    2009-01-01

    This paper reports a method to fabricate microlens arrays with a low processing temperature and a low pressure. The method is based on embossing a softened polymeric substrate over a mold with micro-hole arrays. Due to the effect of capillary and surface tension, microlens arrays can be formed. The embossing medium is CO 2 gas, which supplies a uniform pressing pressure so that large-area microlens arrays can be fabricated. CO 2 gas also acts as a solvent to plasticize the polymer substrates. With the special dissolving ability and isotropic pressing capacity of CO 2 gas, microlens arrays can be fabricated at a low temperature (lower than T g ) and free of thermal-induced residual stress. Such a combined mechanism of dissolving and embossing with CO 2 gas makes the fabrication of microlens arrays direct with complex processes, and is more compatible for optical usage. In the study, it is also found that the sag height of microlens changes when different CO 2 dissolving pressure and time are used. This makes it easy to fabricate microlens arrays of different geometries without using different molds. The quality, uniformity and optical property of the fabricated microlens arrays have been verified with measurements of the dimensions, surface smoothness, focal length, transmittance and light intensity through the fabricated microlens arrays

  3. Design and Fabrication Technique of the Key Components for Very High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Song, Ki Nam; Kim, Yong Wan

    2006-12-15

    The gas outlet temperature of Very High Temperature Reactor (VHTR) may be beyond the capability of conventional metallic materials. The requirement of the gas outlet temperature of 950 .deg. C will result in operating temperatures for metallic core components that will approach very high temperature on some cases. The materials that are capable of withstanding this temperature should be prepared, or nonmetallic materials will be required for limited components. The Ni-base alloys such as Alloy 617, Hastelloy X, XR, Incoloy 800H, and Haynes 230 are being investigated to apply them on components operated in high temperature. Currently available national and international codes and procedures are needed reviewed to design the components for HTGR/VHTR. Seven codes and procedures, including five ASME Codes and Code cases, one French code (RCC-MR), and on British Procedure (R5) were reviewed. The scope of the code and code cases needs to be expanded to include the materials with allowable temperatures of 950 .deg. C and higher. The selection of compact heat exchangers technology depends on the operating conditions such as pressure, flow rates, temperature, but also on other parameters such as fouling, corrosion, compactness, weight, maintenance and reliability. Welding, brazing, and diffusion bonding are considered proper joining processes for the heat exchanger operating in the high temperature and high pressure conditions without leakage. Because VHTRs require high temperature operations, various controlled materials, thick vessels, dissimilar metal joints, and precise controls of microstructure in weldment, the more advanced joining processes are needed than PWRs. The improved solid joining techniques are considered for the IHX fabrication. The weldability for Alloy 617 and Haynes 230 using GTAW and SMAW processes was investigated by CEA.

  4. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique

    Directory of Open Access Journals (Sweden)

    Phaechamud T

    2016-06-01

    Full Text Available Thawatchai Phaechamud,1 Sarun Tuntarawongsa2 1Department of Pharmaceutical Technology, 2Pharmaceutical Intelligence Unit Prachote Plengwittaya, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand Abstract: Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (Tg of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and -31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully. Keywords

  5. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique

    Science.gov (United States)

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (Tg) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and −31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully. PMID:27366064

  6. Design and Fabrication Technique of the Key Components for Very High Temperature Reactor

    International Nuclear Information System (INIS)

    Lee, Ho Jin; Song, Ki Nam; Kim, Yong Wan

    2006-12-01

    The gas outlet temperature of Very High Temperature Reactor (VHTR) may be beyond the capability of conventional metallic materials. The requirement of the gas outlet temperature of 950 .deg. C will result in operating temperatures for metallic core components that will approach very high temperature on some cases. The materials that are capable of withstanding this temperature should be prepared, or nonmetallic materials will be required for limited components. The Ni-base alloys such as Alloy 617, Hastelloy X, XR, Incoloy 800H, and Haynes 230 are being investigated to apply them on components operated in high temperature. Currently available national and international codes and procedures are needed reviewed to design the components for HTGR/VHTR. Seven codes and procedures, including five ASME Codes and Code cases, one French code (RCC-MR), and on British Procedure (R5) were reviewed. The scope of the code and code cases needs to be expanded to include the materials with allowable temperatures of 950 .deg. C and higher. The selection of compact heat exchangers technology depends on the operating conditions such as pressure, flow rates, temperature, but also on other parameters such as fouling, corrosion, compactness, weight, maintenance and reliability. Welding, brazing, and diffusion bonding are considered proper joining processes for the heat exchanger operating in the high temperature and high pressure conditions without leakage. Because VHTRs require high temperature operations, various controlled materials, thick vessels, dissimilar metal joints, and precise controls of microstructure in weldment, the more advanced joining processes are needed than PWRs. The improved solid joining techniques are considered for the IHX fabrication. The weldability for Alloy 617 and Haynes 230 using GTAW and SMAW processes was investigated by CEA

  7. Low-Cost, Silicon Carbide Replication Technique for LWIR Mirror Fabrication, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SSG proposes an innovative optical manufacturing approach that will enable the low-cost fabrication of lightweighted, Long Wave Infrared (LWIR) Silicon Carbide (SiC)...

  8. Novel Nano-Materials and Nano-Fabrication Techniques for Flexible Electronic Systems

    Directory of Open Access Journals (Sweden)

    Kyowon Kang

    2018-05-01

    Full Text Available Recent progress in fabricating flexible electronics has been significantly developed because of the increased interest in flexible electronics, which can be applied to enormous fields, not only conventional in electronic devices, but also in bio/eco-electronic devices. Flexible electronics can be applied to a wide range of fields, such as flexible displays, flexible power storages, flexible solar cells, wearable electronics, and healthcare monitoring devices. Recently, flexible electronics have been attached to the skin and have even been implanted into the human body for monitoring biosignals and for treatment purposes. To improve the electrical and mechanical properties of flexible electronics, nanoscale fabrications using novel nanomaterials are required. Advancements in nanoscale fabrication methods allow the construction of active materials that can be combined with ultrathin soft substrates to form flexible electronics with high performances and reliability. In this review, a wide range of flexible electronic applications via nanoscale fabrication methods, classified as either top-down or bottom-up approaches, including conventional photolithography, soft lithography, nanoimprint lithography, growth, assembly, and chemical vapor deposition (CVD, are introduced, with specific fabrication processes and results. Here, our aim is to introduce recent progress on the various fabrication methods for flexible electronics, based on novel nanomaterials, using application examples of fundamental device components for electronics and applications in healthcare systems.

  9. A blanket design, apparatus, and fabrication techniques for the mass production of multilayer insulation blankets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.; Otavka, J.G.; Ruschman, M.K.; Schoo, C.J.

    1989-09-01

    The multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) consists of full cryostat length assemblies of aluminized polyester film fabricated in the form of blankets and installed as blankets to the 4.5K cold mass and the 20K and 80K thermal radiation shields. Approximately 40,000 MLI blankets will be required in the 10,000 cryogenic devices comprising the SSC accelerator. Each blanket is nearly 17 meters long and 1.8 meters wide. This paper reports the blanket design, an apparatus, and the fabrication method used to mass produce pre-fabricated MLI blankets. Incorporated in the blanket design are techniques which automate quality control during installation of the MLI blankets in the SSC cryostat. The apparatus and blanket fabrication method insure consistency in the mass produced blankets by providing positive control of the dimensional parameters which contribute to the thermal performance of the MLI blanket. By virtue of the fabrication process, the MLI blankets have inherent features of dimensional stability three-dimensional uniformity, controlled layer density, layer-to-layer registration, interlayer cleanliness, and interlayer material to accommodate thermal contraction differences. 11 refs., 6 figs., 1 tab

  10. CT digital radiography: Alternative technique for airway evaluation in physically disabled patients

    International Nuclear Information System (INIS)

    Mandell, G.A.; Harcke, H.T.; Brunson, G.; Delengowski, R.; Padman, R.

    1987-01-01

    Evaluation of the airway for the presence of granulation tissue prior to removal of a tracheostomy is essential to prevent sudden respiratory decompensation secondary to obstruction. Airway examination in a brain and/or spinal cord injured patient is especially difficult under fluoroscopy. The patient's lack of mobility results in poor visualization of the trachea, secondary to the overlying dense osseous components of the shoulders and thoracic cage. A CT localization view (digital view), which allows manipulation and magnification of the digital data in order to see the hidden airway and detect associated obstructing lesions, is proffered as an alternative technique to high KV, magnification technique. Thirteen examinations were performed satisfactorily in eleven patients examined by this technique with little expenditure of time, physical exertion, and irradiation. The sensitivity, specificity and accuracy of digital airway examination were 100%, 67% and 92% respectively with bronchoscopy used as the standard. (orig.)

  11. Transmural coil embolization—alternative technique for management of arterial perforation during subintimal angioplasty

    Directory of Open Access Journals (Sweden)

    Karthikeyan Damodharan

    2016-01-01

    Full Text Available Subintimal angioplasty of lower limb arterial occlusion carries a relatively higher risk of vessel perforation compared to transluminal angioplasty. Vessel perforation is a potentially life threatening complication which requires prompt recognition and management. They are usually managed by endovascular techniques such as low-pressure balloon tamponade, covered stents, and coil embolization of the ruptured artery. We describe a technique of treating vessel perforation following balloon angioplasty. Patient developed a large perforation of the proximal superficial femoral artery (SFA after balloon inflation during subintimal angioplasty of complete SFA occlusion. Following failure of balloon tamponade in sealing the perforation, we successfully treated it by deploying an embolization coil at the site of perforation through the vessel wall followed by balloon tamponade. Our technique could be a useful relatively inexpensive alternative treatment option in the management of vessel perforation compared to covered stents.

  12. A novel 2D silicon nano-mold fabrication technique for linear nanochannels over a 4 inch diameter substrate

    Science.gov (United States)

    Yin, Zhifu; Qi, Liping; Zou, Helin; Sun, Lei

    2016-01-01

    A novel low-cost 2D silicon nano-mold fabrication technique was developed based on Cu inclined-deposition and Ar+ (argon ion) etching. With this technique, sub-100 nm 2D (two dimensional) nano-channels can be etched economically over the whole area of a 4 inch n-type  silicon wafer. The fabricating process consists of only 4 steps, UV (Ultraviolet) lithography, inclined Cu deposition, Ar+ sputter etching, and photoresist & Cu removing. During this nano-mold fabrication process, we investigated the influence of the deposition angle on the width of the nano-channels and the effect of Ar+ etching time on their depth. Post-etching measurements showed the accuracy of the nanochannels over the whole area: the variation in width is 10%, in depth it is 11%. However, post-etching measurements also showed the accuracy of the nanochannels between chips: the variation in width is 2%, in depth it is 5%. With this newly developed technology, low-cost and large scale 2D nano-molds can be fabricated, which allows commercial manufacturing of nano-components over large areas. PMID:26752559

  13. Fabrication of different pore shapes by multi-step etching technique in ion-irradiated PET membranes

    Science.gov (United States)

    Mo, D.; Liu, J. D.; Duan, J. L.; Yao, H. J.; Latif, H.; Cao, D. L.; Chen, Y. H.; Zhang, S. X.; Zhai, P. F.; Liu, J.

    2014-08-01

    A method for the fabrication of different pore shapes in polyethylene terephthalate (PET)-based track etched membranes (TEMs) is reported. A multi-step etching technique involving etchant variation and track annealing was applied to fabricate different pore shapes in PET membranes. PET foils of 12-μm thickness were irradiated with Bi ions (kinetic energy 9.5 MeV/u, fluence 106 ions/cm2) at the Heavy Ion Research Facility (HIRFL, Lanzhou). The cross-sections of fundamental pore shapes (cylinder, cone, and double cone) were analyzed. Funnel-shaped and pencil-shaped pores were obtained using a two-step etching process. Track annealing was carried out in air at 180 °C for 120 min. After track annealing, the selectivity of the etching process decreased, which resulted in isotropic etching in subsequent etching steps. Rounded cylinder and rounded cone shapes were obtained by introducing a track-annealing step in the etching process. Cup and spherical funnel-shaped pores were fabricated using a three- and four-step etching process, respectively. The described multi-step etching technique provides a controllable method to fabricate new pore shapes in TEMs. Introduction of a variety of pore shapes may improve the separation properties of TEMs and enrich the series of TEM products.

  14. RANGELAND DEGRADATION: EXTENT, IMPACTS, AND ALTERNATIVE RESTORATION TECHNIQUES IN THE RANGELANDS OF ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available Rangeland degradation remains a serious impediment to improve pastoral livelihoods in the lowlands of Ethiopia. This review paper presents an overview of the extent of rangeland degradation, explores its drivers, discusses the potential impacts of rangeland degradation and also suggests alternative rangeland restoration techniques. It is intended to serve as an exploratory tool for ensuing more detailed quantitative analyses to support policy and investment programs to address rangeland degradation in Ethiopia. The extent of rangeland degradation increases with time, and the productivity of rangelands are losing if not given due attention. The major drivers leading to rangeland degradation includes climate change, overgrazing, bush encroachment, population pressure, drought, and government policy, encroachment of rain fed agriculture and decline of traditional resource management institution. Degradation of rangeland has resulted in substantial declines in rangeland condition, water potential, soil status, and animal performance, livestock holding at the household level and community become destitute. Another consequence of rangeland degradation is linked to food insecurity, poverty to the extent of food aid, expansion of aridity and the need for alternative livelihood and income diversification. Moreover, it has increasingly become a threat to the pastoral production systems, and has contributed towards increases in poverty and tribal conflicts over grazing land and water resources. In spite of these impacts, the adoption of alternative restoration techniques in the country is highly insufficient. To address rangeland degradation problems, there is a strong need to substantially increase the investments and strengthen the policy support for sustainable land management.

  15. Antitumor activity of docetaxel-loaded polymeric nanoparticles fabricated by Shirasu porous glass membrane-emulsification technique

    Directory of Open Access Journals (Sweden)

    Yu YN

    2013-07-01

    Full Text Available Yunni Yu,1,* Songwei Tan,1,2,* Shuang Zhao,1 Xiangting Zhuang,1 Qingle Song,1 Yuliang Wang,1 Qin Zhou,2,3 Zhiping Zhang1,2 1Tongji School of Pharmacy, 2National Engineering Research Center for Nanomedicine, 3College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Docetaxel (DTX has excellent efficiency against a wide spectrum of cancers. However, the current clinical formulation has limited its usage, as it causes some severe side effects. Various polymeric nanoparticles have thus been developed as alternative formulations of DTX, but they have been mostly fabricated on a laboratory scale. Previously, we synthesized a novel copolymer, poly(lactide-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS, and found that it exhibited great potential in drug delivery with improved properties. In this study, we applied the Shirasu porous glass (SPG membrane-emulsification technique to prepare the DTX-loaded PLA-TPGS nanoparticles on a pilot scale. The effect of several formulation variables on the DTX-loaded nanoparticle properties, including particle size, zeta potential, and drug-encapsulation efficiency, were investigated based on surfactant type and concentration in the aqueous phase, organic/aqueous phase volumetric ratio, membrane-pore size, transmembrane cycles, and operation pressure. The DTX-loaded nanoparticles were obtained with sizes of 306.8 ± 5.5 nm and 334.1 ± 2.7 nm (mean value ± standard deviation, and drug-encapsulation efficiency of 81.8% ± 4.5% and 64.5% ± 2.7% for PLA-TPGS and poly(lactic-co-glycolic acid (PLGA nanoparticles, respectively. In vivo pharmacokinetic study exhibited a significant advantage of PLA-TPGS nanoparticles over PLGA nanoparticles and Taxotere. Drug-loaded PLA-TPGS nanoparticles exhibited 1.78-, 6.34- and 3.35-fold higher values for area under the curve, half-life, and mean

  16. Comparative study on structural and optical properties of CdS films fabricated by three different low-cost techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K. [P.G. and Research Department of Physics, AVVM. Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu 613503 (India)], E-mail: kkr1365@yahoo.com; Philominathan, P. [P.G. and Research Department of Physics, AVVM. Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu 613503 (India)

    2009-03-15

    Highly crystalline and transparent cadmium sulphide films were fabricated at relatively low temperature by employing an inexpensive, simplified spray technique using perfume atomizer (generally used for cosmetics). The structural, surface morphological and optical properties of the films were studied and compared with that prepared by conventional spray pyrolysis using air as carrier gas and chemical bath deposition. The films deposited by the simplified spray have preferred orientation along (1 0 1) plane. The lattice parameters were calculated as a = 4.138 A and c = 6.718 A which are well agreed with that obtained from the other two techniques and also with the standard data. The optical transmittance in the visible range and the optical band gap were found as 85% and 2.43 eV, respectively. The structural and optical properties of the films fabricated by the simplified spray are found to be desirable for opto-electronic applications.

  17. Growth characteristics of Dayak Borneo yam (Dioscorea hispida and detoxification techniques as alternative food

    Directory of Open Access Journals (Sweden)

    RUDITO

    2017-03-01

    Full Text Available Abstract. Rudito, Suwarto, Azkiyah L, Witono Y, Saragih B, Arung ET. 2017. Growth characteristics of Dayak Borneo yam (Dioscorea hispida and detoxification techniques as alternative food. Pros Sem Nas Masy Biodiv Indon 3: 99-103. Finding of local food sources to enhance food security areas. This study focuses on the characteristics of growth Dayak Borneo yam observation, toxic substances and detoxification techniques development of non nutritional. The objective of the research was to find out a more concrete picture, as well as comparing it with Java yam non nutritional components as a basis for further exploration of alternative food. Observations indicate that the plant growth of Dayak Borneo yam had specific characteristics, and can be grown in intercropping with other crops. Yam tubers have negative image due to the toxins contained by this commodity, as well as technology management (detoxification and processing of yam products that have not been controlled by the community. But based on the results of physical and chemical detoxification, indicates that the Dayak Borneo yam can be exploited further as food. Dayak Borneo yam need to be developed modification process in raw materials of Dayak Borneo yam as modified starch through fermentation techniques which also intended to obtain intermediate product from which Dayak Borneo yam has a larger functionality as a food ingredient.

  18. Development, Characterization and Cell Cultural Response of 3D Biocompatible Micro-Patterned Poly-ε-Caprolactone Scaffolds Designed and Fabricated Integrating Lithography and Micromolding Fabrication Techniques

    KAUST Repository

    Limongi, Tania; Miele, Ermanno; Shalabaeva, Victoria; Rocca, Rosanna La; Schipani, Rossana; Malara, Natalia; Angelis, Francesco de; Giugni, Andrea; Di Fabrizio, Enzo M.

    2014-01-01

    Scaffold design and fabrication are very important subjects for biomaterial, tissue engineering and regenerative medicine research playing a unique role in tissue regeneration and repair. Among synthetic biomaterials Poly-ε- Caprolactone (PCL) is very attractive bioresorbable polyester due to its high permeability, biodegradability and capacity to be blended with other biopolymers. Thanks to its ability to naturally degrade in tissues, PCL has a great potential as a new material for implantable biomedical micro devices. This work focuses on the establishment of a micro fabrication process, by integrating lithography and micromolding fabrication techniques, for the realization of 3D microstructure PCL devices. Scaffold surface exhibits a combination in the patterned length scale; cylindrical pillars of 10 μm height and 10 μm diameter are arranged in a hexagonal lattice with periodicity of 30 μm and their sidewalls are nano-sculptured, with a regular pattern of grooves leading to a spatial modulation in the z direction. In order to demonstrate that these biocompatible pillared PCL substrates are suitable for a proper cell growth, NIH/3T3 mouse embryonic fibroblasts were seeded on them and cells key adhesion parameters were evaluated. Scanning Electron Microscopy and immunofluorescence analysis were carried out to check cell survival, proliferation and adhesion; cells growing on the PCL substrates appeared healthy and formed a well-developed network in close contact with the micro and nano features of the pillared surface. Those 3D scaffolds could be a promising solution for a wide range of applications within tissue engineering and regenerative medicine applications.

  19. Development, Characterization and Cell Cultural Response of 3D Biocompatible Micro-Patterned Poly-ε-Caprolactone Scaffolds Designed and Fabricated Integrating Lithography and Micromolding Fabrication Techniques

    KAUST Repository

    Limongi, Tania

    2014-12-12

    Scaffold design and fabrication are very important subjects for biomaterial, tissue engineering and regenerative medicine research playing a unique role in tissue regeneration and repair. Among synthetic biomaterials Poly-ε- Caprolactone (PCL) is very attractive bioresorbable polyester due to its high permeability, biodegradability and capacity to be blended with other biopolymers. Thanks to its ability to naturally degrade in tissues, PCL has a great potential as a new material for implantable biomedical micro devices. This work focuses on the establishment of a micro fabrication process, by integrating lithography and micromolding fabrication techniques, for the realization of 3D microstructure PCL devices. Scaffold surface exhibits a combination in the patterned length scale; cylindrical pillars of 10 μm height and 10 μm diameter are arranged in a hexagonal lattice with periodicity of 30 μm and their sidewalls are nano-sculptured, with a regular pattern of grooves leading to a spatial modulation in the z direction. In order to demonstrate that these biocompatible pillared PCL substrates are suitable for a proper cell growth, NIH/3T3 mouse embryonic fibroblasts were seeded on them and cells key adhesion parameters were evaluated. Scanning Electron Microscopy and immunofluorescence analysis were carried out to check cell survival, proliferation and adhesion; cells growing on the PCL substrates appeared healthy and formed a well-developed network in close contact with the micro and nano features of the pillared surface. Those 3D scaffolds could be a promising solution for a wide range of applications within tissue engineering and regenerative medicine applications.

  20. A miniature rigid/flex salinity measurement device fabricated using printed circuit processing techniques

    International Nuclear Information System (INIS)

    Broadbent, H A; Ketterl, T P; Reid, C S

    2010-01-01

    The design, fabrication and initial performance of a single substrate, miniature, low-cost conductivity, temperature, depth (CTD) sensor board with interconnects are presented. In combination these sensors measure ocean salinity. The miniature CTD device board was designed and fabricated as the main component of a 50 mm × 25 mm × 25 mm animal-attached biologger. The board was fabricated using printed circuit processes and consists of two distinct regions on a continuous single liquid crystal polymer substrate: an 18 mm × 28 mm rigid multi-metal sensor section and a 72 mm long flexible interconnect section. The 95% confidence intervals for the conductivity, temperature and pressure sensors were demonstrated to be ±0.083 mS cm −1 , 0.01 °C, and ±0.135 dbar, respectively.

  1. MAG4 versus alternative techniques for forecasting active region flare productivity

    Science.gov (United States)

    Falconer, David A; Moore, Ronald L; Barghouty, Abdulnasser F; Khazanov, Igor

    2014-01-01

    MAG4 is a technique of forecasting an active region's rate of production of major flares in the coming few days from a free magnetic energy proxy. We present a statistical method of measuring the difference in performance between MAG4 and comparable alternative techniques that forecast an active region's major-flare productivity from alternative observed aspects of the active region. We demonstrate the method by measuring the difference in performance between the “Present MAG4” technique and each of three alternative techniques, called “McIntosh Active-Region Class,” “Total Magnetic Flux,” and “Next MAG4.” We do this by using (1) the MAG4 database of magnetograms and major flare histories of sunspot active regions, (2) the NOAA table of the major-flare productivity of each of 60 McIntosh active-region classes of sunspot active regions, and (3) five technique performance metrics (Heidke Skill Score, True Skill Score, Percent Correct, Probability of Detection, and False Alarm Rate) evaluated from 2000 random two-by-two contingency tables obtained from the databases. We find that (1) Present MAG4 far outperforms both McIntosh Active-Region Class and Total Magnetic Flux, (2) Next MAG4 significantly outperforms Present MAG4, (3) the performance of Next MAG4 is insensitive to the forward and backward temporal windows used, in the range of one to a few days, and (4) forecasting from the free-energy proxy in combination with either any broad category of McIntosh active-region classes or any Mount Wilson active-region class gives no significant performance improvement over forecasting from the free-energy proxy alone (Present MAG4). Key Points Quantitative comparison of performance of pairs of forecasting techniques Next MAG4 forecasts major flares more accurately than Present MAG4 Present MAG4 forecast outperforms McIntosh AR Class and total magnetic flux PMID:26213517

  2. Fabrication of Ultrasensitive Field-Effect Transistor DNA Biosensors by a Directional Transfer Technique Based on CVD-Grown Graphene.

    Science.gov (United States)

    Zheng, Chao; Huang, Le; Zhang, Hong; Sun, Zhongyue; Zhang, Zhiyong; Zhang, Guo-Jun

    2015-08-12

    Most graphene field-effect transistor (G-FET) biosensors are fabricated through a routine process, in which graphene is transferred onto a Si/SiO2 substrate and then devices are subsequently produced by micromanufacture processes. However, such a fabrication approach can introduce contamination onto the graphene surface during the lithographic process, resulting in interference for the subsequent biosensing. In this work, we have developed a novel directional transfer technique to fabricate G-FET biosensors based on chemical-vapor-deposition- (CVD-) grown single-layer graphene (SLG) and applied this biosensor for the sensitive detection of DNA. A FET device with six individual array sensors was first fabricated, and SLG obtained by the CVD-growth method was transferred onto the sensor surface in a directional manner. Afterward, peptide nucleic acid (PNA) was covalently immobilized on the graphene surface, and DNA detection was realized by applying specific target DNA to the PNA-functionalized G-FET biosensor. The developed G-FET biosensor was able to detect target DNA at concentrations as low as 10 fM, which is 1 order of magnitude lower than those reported in a previous work. In addition, the biosensor was capable of distinguishing the complementary DNA from one-base-mismatched DNA and noncomplementary DNA. The directional transfer technique for the fabrication of G-FET biosensors is simple, and the as-constructed G-FET DNA biosensor shows ultrasensitivity and high specificity, indicating its potential application in disease diagnostics as a point-of-care tool.

  3. Cleaning capacity of hybrid instrumentation technique using reamer with alternating cutting edges system files: Histological analysis

    Directory of Open Access Journals (Sweden)

    Emilio Carlos Sponchiado Junior

    2014-01-01

    Full Text Available Aim: The aim of the following study is to evaluate the cleaning capacity of a hybrid instrumentation technique using Reamer with Alternating Cutting Edges (RaCe system files in the apical third of mesial roots of mandibular molars. Materials and Methods: Twenty teeth were selected and separated into two groups (n = 20 according to instrumentation technique as follows: BioRaCe - chemomechanical preparation with K-type files #10 and #15; and files BioRaCe BR0, BR1, BR2, BR3, and BR4; HybTec - hybrid instrumentation technique with K-type files #10 and #15 in the working length, #20 at 2 mm, #25 at 3 mm, cervical preparation with Largo burs #1 and #2; apical preparation with K-type files #15, #20, and #25 and RaCe files #25.04 and #30.04. The root canals were irrigated with 1 ml of 2.5% sodium hypochlorite at each change of instrument. The specimens were histologically processed and photographed under light optical microscope. The images were inserted onto an integration grid to count the amount of debris present in the root canal. Results: BioRaCe presented the highest percentage of debris in the apical third, however, with no statistically significant difference for HybTec (P > 0.05. Conclusions: The hybrid technique presented similar cleaning capacity as the technique recommended by the manufacturer.

  4. Electrochemical performances of proton-conducting SOFC with La-Sr-Fe-O cathode fabricated by electrophoretic deposition techniques

    International Nuclear Information System (INIS)

    Asamoto, Makiko; Miyake, Shinji; Yonei, Yuka; Yamaura, Hiroyuki; Yahiro, Hidenori

    2009-01-01

    The electrochemical performances of Proton-conducting SOFC with La 0.7 Sr 0.3 FeO 3 (LSF) cathode fabricated by the electrophoretic deposition (EPD) technique were investigated. The EPD technique provided the uniform layer of LSF cathode with constant thickness and can easily control the thickness by changing an applied voltage. The power density of the SOFC cell was dependent on the thickness of LSF cathode. The activation energy was measured to elucidate the rate-determining step for LSF cathode reaction. (author)

  5. A Conservative Method for Treating Severely Displaced Pediatric Mandibular Fractures: An Effective Alternative Technique

    Directory of Open Access Journals (Sweden)

    Sahand Samieirad

    2016-06-01

    Full Text Available Pediatric mandibular fractures have been successfully managed in various ways. The use of a lingual splint is an option. This article presents a 4-year old boy who was treated by an alternative conservative method with a combination of an arch bar plus a lingual splint, circum-mandibular wiring and IMF for the reduction, stabilization and fixation of a severely displaced bilateral man‌dibular body fracture. This technique is a reliable, noninvasive procedure; it also limits the discomfort and morbidity associated with maxillomandibular fixation or open reduction and internal fixation in pediatric patients

  6. Remote fabrication of breeder reactor fuel

    International Nuclear Information System (INIS)

    Gerber, E.W.; Hoitink, N.C.; Graham, R.A.

    1984-06-01

    The Secure Automated Fabrication (SAF) Line, a remotely operable plutonium fuel fabrication facility, incorporates advanced automation techniques. Included in the plant are 24 robots used to perform complex operations, and to enhance equipment standardization and ease of maintenance. Automated equipment is controlled remotely from centrally located supervisory computer control consoles or alternatively from control consoles dedicated to individual systems

  7. Low cost batch fabrication of microdevices using ultraviolet light-emitting diode photolithography technique

    Science.gov (United States)

    Lee, Neam Heng; Swamy, Varghese; Ramakrishnan, Narayanan

    2016-01-01

    Solid-state technology has enabled the use of light-emitting diodes (LEDs) in lithography systems due to their low cost, low power requirement, and higher efficiency relative to the traditional mercury lamp. Uniform irradiance distribution is essential for photolithography to ensure the critical dimension (CD) of the feature fabricated. However, light illuminated from arrays of LEDs can have nonuniform irradiance distribution, which can be a problem when using LED arrays as a source to batch-fabricate multiple devices on a large wafer piece. In this study, the irradiance distribution of an UV LED array was analyzed, and the separation distance between light source and mask optimized to obtain maximum irradiance uniformity without the use of a complex lens. Further, employing a diffuser glass enhanced the fabrication process and the CD loss was minimized to an average of 300 nm. To assess the performance of the proposed technology, batch fabrication of surface acoustic wave devices on lithium niobate substrate was carried out, and all the devices exhibited identical insertion loss of -18 dB at a resonance frequency of 39.33 MHz. The proposed low-cost UV lithography setup can be adapted in academic laboratories for research and teaching on microdevices.

  8. Characterization techniques to predict mechanical behaviour of green ceramic bodies fabricated by ceramic microstereolithography

    Science.gov (United States)

    Adake, Chandrashekhar V.; Bhargava, Parag; Gandhi, Prasanna

    2018-02-01

    Ceramic microstereolithography (CMSL) has emerged as solid free form (SFF) fabrication technology in which complex ceramic parts are fabricated from ceramic suspensions which are formulated by dispersing ceramic particles in UV curable resins. Ceramic parts are fabricated by exposing ceramic suspension to computer controlled UV light which polymerizes resin to polymer and this polymer forms rigid network around ceramic particles. A 3-dimensional part is created by piling cured layers one over the other. These ceramic parts are used to build microelectromechanical (MEMS) devices after thermal treatment. In many cases green ceramic parts can be directly utilized to build MEMS devices. Hence characterization of these parts is essential in terms of their mechanical behaviour prior to their use in MEMS devices. Mechanical behaviour of these green ceramic parts depends on cross link density which in turn depends on chemical structure of monomer, concentrations of photoinitiator and UV energy dose. Mechanical behaviour can be determined with the aid of nanoindentation. And extent of crosslinking can be verified with the aid of DSC. FTIR characterization is used to analyse (-C=C-) double bond conversion. This paper explains characterization tools to predict the mechanical behaviour of green ceramic bodies fabricated in CMSL

  9. Fabrication of silk fibroin film using centrifugal casting technique for corneal tissue engineering.

    Science.gov (United States)

    Lee, Min Chae; Kim, Dong-Kyu; Lee, Ok Joo; Kim, Jung-Ho; Ju, Hyung Woo; Lee, Jung Min; Moon, Bo Mi; Park, Hyun Jung; Kim, Dong Wook; Kim, Su Hyeon; Park, Chan Hum

    2016-04-01

    Films prepared from silk fibroin have shown potential as biomaterials in tissue engineering applications for the eye. Here, we present a novel process for fabrication of silk fibroin films for corneal application. In this work, fabrication of silk fibroin films was simply achieved by centrifugal force. In contrast to the conventional dry casting method, we carried out the new process in a centrifuge with a rotating speed of 4000 rpm, where centrifugal force was imposed on an aluminum tube containing silk fibroin solution. In the present study, we also compared the surface roughness, mechanical properties, transparency, and cell proliferation between centrifugal and dry casting method. In terms of surface morphology, films fabricated by the centrifugal casting have less surface roughness than those by the dry casting. For elasticity and transparency, silk fibroin films obtained from the centrifugal casting had favorable results compared with those prepared by dry casting. Furthermore, primary human corneal keratocytes grew better in films prepared by the centrifugal casting. Therefore, our results suggest that this new fabrication process for silk fibroin films offers important potential benefits for corneal tissue regeneration. © 2015 Wiley Periodicals, Inc.

  10. Diagnostics of glass fiber reinforced polymers and comparative analysis of their fabrication techniques with the use of acoustic emission

    Science.gov (United States)

    Bashkov, O. V.; Bryansky, A. A.; Panin, S. V.; Zaikov, V. I.

    2016-11-01

    Strength properties of the glass fiber reinforced polymers (GFRP) fabricated by vacuum and vacuum autoclave molding techniques were analyzed. Measurements of porosity of the GFRP parts manufactured by various molding techniques were conducted with the help of optical microscopy. On the basis of experimental data obtained by means of acoustic emission hardware/software setup, the technique for running diagnostics and forecasting the bearing capacity of polymeric composite materials based on the result of three-point bending tests has been developed. The operation principle of the technique is underlined by the evaluation of the power function index change which takes place on the dependence of the total acoustic emission counts versus the loading stress.

  11. Fabrication of ITO particles using a combination of a homogeneous precipitation method and a seeding technique and their electrical conductivity

    Directory of Open Access Journals (Sweden)

    Yoshio Kobayashi

    2015-09-01

    Full Text Available The present work proposes a method to fabricate indium tin oxide (ITO particles using precursor particles synthesized with a combination of a homogeneous precipitation method and a seeding technique, and it also describes their electronic conductivity properties. Seed nanoparticles were produced using a co-precipitation method with aqueous solutions of indium (III chloride, tin (IV chloride aqueous solution and sodium hydroxide. Three types of ITO nanoparticles were fabricated. The first type was fabricated using the co-precipitation method (c-ITO. The second and third types were fabricated using a homogeneous precipitation method with the seed nanoparticles (s-ITO and without seeds (n-ITO. The as-prepared precursor particles were annealed in air at 500 °C, and their crystal structures were cubic ITO. The c-ITO nanoparticles formed irregular-shaped agglomerates of nanoparticles. The n-ITO nanoparticles had a rectangular-parallelepiped or quasi-cubic structure. Most s-ITO nanoparticles had a quasi-cubic structure, and their size was larger than the n-ITO particles. The volume resistivities of the c-ITO, n-ITO and s-ITO powders decreased in that order because the regular-shaped particles were made to strongly contact with each other.

  12. Alternative method of highway traffic safety analysis for developing countries using delphi technique and Bayesian network.

    Science.gov (United States)

    Mbakwe, Anthony C; Saka, Anthony A; Choi, Keechoo; Lee, Young-Jae

    2016-08-01

    Highway traffic accidents all over the world result in more than 1.3 million fatalities annually. An alarming number of these fatalities occurs in developing countries. There are many risk factors that are associated with frequent accidents, heavy loss of lives, and property damage in developing countries. Unfortunately, poor record keeping practices are very difficult obstacle to overcome in striving to obtain a near accurate casualty and safety data. In light of the fact that there are numerous accident causes, any attempts to curb the escalating death and injury rates in developing countries must include the identification of the primary accident causes. This paper, therefore, seeks to show that the Delphi Technique is a suitable alternative method that can be exploited in generating highway traffic accident data through which the major accident causes can be identified. In order to authenticate the technique used, Korea, a country that underwent similar problems when it was in its early stages of development in addition to the availability of excellent highway safety records in its database, is chosen and utilized for this purpose. Validation of the methodology confirms the technique is suitable for application in developing countries. Furthermore, the Delphi Technique, in combination with the Bayesian Network Model, is utilized in modeling highway traffic accidents and forecasting accident rates in the countries of research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. A high aspect ratio SU-8 fabrication technique for hollow microneedles for transdermal drug delivery and blood extraction

    Science.gov (United States)

    Chaudhri, Buddhadev Paul; Ceyssens, Frederik; De Moor, Piet; Van Hoof, Chris; Puers, Robert

    2010-06-01

    Protein drugs, e.g. hormonal drugs, cannot be delivered orally to a patient as they get digested in the gastro-intestinal (GI) tract. Thus, it is imperative that these kinds of drugs are delivered transdermally through the skin. To provide for real-time feedback as well as to test independently for various substances in the blood, we also need a blood sampling system. Microneedles can perform both these functions. Further, microneedles made of silicon or metal have the risk of breaking inside the skin thereby leading to complications. SU-8, being approved of as being biocompatible by the Food and Drug Agency (FDA) of the United States, is an attractive alternative because firstly it is a polymer material, thereby reducing the chances of breakages inside the skin, and secondly it is a negative photoresist, thereby leading to ease of fabrication. Thus, here we present very tall (around 1600 µm) SU-8 polymer-based hollow microneedles fabricated by a simple and repeatable process, which are a very good candidate for transdermal drug delivery as well as blood extraction. The paper elaborates on the details that allow the fabrication of such extreme aspect ratios (>100).

  14. A high aspect ratio SU-8 fabrication technique for hollow microneedles for transdermal drug delivery and blood extraction

    International Nuclear Information System (INIS)

    Chaudhri, Buddhadev Paul; Ceyssens, Frederik; Van Hoof, Chris; Puers, Robert; De Moor, Piet

    2010-01-01

    Protein drugs, e.g. hormonal drugs, cannot be delivered orally to a patient as they get digested in the gastro-intestinal (GI) tract. Thus, it is imperative that these kinds of drugs are delivered transdermally through the skin. To provide for real-time feedback as well as to test independently for various substances in the blood, we also need a blood sampling system. Microneedles can perform both these functions. Further, microneedles made of silicon or metal have the risk of breaking inside the skin thereby leading to complications. SU-8, being approved of as being biocompatible by the Food and Drug Agency (FDA) of the United States, is an attractive alternative because firstly it is a polymer material, thereby reducing the chances of breakages inside the skin, and secondly it is a negative photoresist, thereby leading to ease of fabrication. Thus, here we present very tall (around 1600 µm) SU-8 polymer-based hollow microneedles fabricated by a simple and repeatable process, which are a very good candidate for transdermal drug delivery as well as blood extraction. The paper elaborates on the details that allow the fabrication of such extreme aspect ratios (>100).

  15. Plasmonic nanoparticle lithography: Fast resist-free laser technique for large-scale sub-50 nm hole array fabrication

    Science.gov (United States)

    Pan, Zhenying; Yu, Ye Feng; Valuckas, Vytautas; Yap, Sherry L. K.; Vienne, Guillaume G.; Kuznetsov, Arseniy I.

    2018-05-01

    Cheap large-scale fabrication of ordered nanostructures is important for multiple applications in photonics and biomedicine including optical filters, solar cells, plasmonic biosensors, and DNA sequencing. Existing methods are either expensive or have strict limitations on the feature size and fabrication complexity. Here, we present a laser-based technique, plasmonic nanoparticle lithography, which is capable of rapid fabrication of large-scale arrays of sub-50 nm holes on various substrates. It is based on near-field enhancement and melting induced under ordered arrays of plasmonic nanoparticles, which are brought into contact or in close proximity to a desired material and acting as optical near-field lenses. The nanoparticles are arranged in ordered patterns on a flexible substrate and can be attached and removed from the patterned sample surface. At optimized laser fluence, the nanohole patterning process does not create any observable changes to the nanoparticles and they have been applied multiple times as reusable near-field masks. This resist-free nanolithography technique provides a simple and cheap solution for large-scale nanofabrication.

  16. Fabrication Of Atomic-scale Gold Junctions By Electrochemical Plating Technique Using A Common Medical Disinfectant

    Science.gov (United States)

    Umeno, Akinori; Hirakawa, Kazuhiko

    2005-06-01

    Iodine tincture, a medical liquid familiar as a disinfectant, was introduced as an etching/deposition electrolyte for the fabrication of nanometer-separated gold electrodes. In the gold dissolved iodine tincture, the gold electrodes were grown or eroded slowly in atomic scale, enough to form quantum point contacts. The resistance evolution during the electrochemical deposition showed plateaus at integer multiples of the resistance quantum, (2e2/h)-1, at the room temperature. The iodine tincture is a commercially available common material, which makes the fabrication process to be the simple and cost effective. Moreover, in contrast to the conventional electrochemical approaches, this method is free from highly toxic cyanide compounds or extraordinary strong acid. We expect this method to be a useful interface between single-molecular-scale structures and macroscopic opto-electronic devices.

  17. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-01-01

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA. PMID:27023546

  18. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Directory of Open Access Journals (Sweden)

    Chin-Guo Kuo

    2016-03-01

    Full Text Available In this investigation, anodic aluminum oxide (AAO with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  19. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties.

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-03-24

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  20. FABRICATION OF TISSUE-SIMULATIVE PHANTOMS AND CAPILLARIES AND THEIR INVESTIGATION BY OPTICAL COHERENCE TOMOGRAPHY TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. V. Bykov

    2013-03-01

    Full Text Available Methods of tissue-simulative phantoms and capillaries fabrication from PVC-plastisol and silicone for application as test-objects in optical coherence tomography (OCT and skin and capillary emulation are considered. Comparison characteristics of these materials and recommendations for their application are given. Examples of phantoms visualization by optical coherence tomography method are given. Possibility of information using from B-scans for refractive index evaluation is shown.

  1. Overview of advanced techniques for fabrication and testing of ITER multilayer plasma facing walls

    Energy Technology Data Exchange (ETDEWEB)

    Tavassoli, A.-A.F. [Commissariat a l`Energie Atomique, Saclay, Gif-sur-Yvette (France)

    1998-09-01

    The design of the ITER primary first wall incorporates a multi-layered structure consisting of a layer of beryllium bonded to a layer of copper alloy with embedded stainless steel tubes which in turn is bonded to a stainless steel structure. In this configuration, the stainless steel provides structural support, the copper alloy improved resistance to high heat loads, and the beryllium layer a low Z metal interface with plasma. Fabrication, testing and control of this multi-layered structure, and indeed the entire blanket shield module, calls for advanced methods. Several associations in the four home teams and their industrial partners have been involved in various fabrication and joining tasks now grouped under L4 blanket project. In this paper, an overview of the work done so far for joining stainless steel to stainless steel, stainless steel to copper alloy, copper alloy to copper alloy, and copper alloy to beryllium is presented. Specialised papers dealing with most of the topics treated here are scheduled in this symposium. The fabrication and joining methods presented here, other than the conventional welding and brazing, follow four main routes. Two of them make extensive use of hot-isostatic pressing (HIP); (a) solid to solid; (b) solid or powder to powder, with or without a prior cold or hot isostatic pressing of one of the products. The third combines advantages of casting and HIPping for fabricating large and complex parts. The fourth investigates the possibility of using explosive welding for joining copper alloys to stainless steel. Other methods, including friction welding, are investigated for specific parts. (orig.) 34 refs.

  2. Novel materials, fabrication techniques and algorithms for microwave and THz components, systems and applications

    Science.gov (United States)

    Liang, Min

    This dissertation presents the investigation of several additive manufactured components in RF and THz frequency, as well as the applications of gradient index lens based direction of arrival (DOA) estimation system and broadband electronically beam scanning system. Also, a polymer matrix composite method to achieve artificially controlled effective dielectric properties for 3D printing material is studied. Moreover, the characterization of carbon based nano-materials at microwave and THz frequency, photoconductive antenna array based Terahertz time-domain spectroscopy (THz-TDS) near field imaging system, and a compressive sensing based microwave imaging system is discussed in this dissertation. First, the design, fabrication and characterization of several 3D printed components in microwave and THz frequency are presented. These components include 3D printed broadband Luneburg lens, 3D printed patch antenna, 3D printed multilayer microstrip line structure with vertical transition, THz all-dielectric EMXT waveguide to planar microstrip transition structure and 3D printed dielectric reflectarrays. Second, the additive manufactured 3D Luneburg Lens is employed for DOA estimation application. Using the special property of a Luneburg lens that every point on the surface of the Lens is the focal point of a plane wave incident from the opposite side, 36 detectors are mounted around the surface of the lens to estimate the direction of arrival (DOA) of a microwave signal. The direction finding results using a correlation algorithm show that the averaged error is smaller than 1º for all 360 degree incident angles. Third, a novel broadband electronic scanning system based on Luneburg lens phased array structure is reported. The radiation elements of the phased array are mounted around the surface of a Luneburg lens. By controlling the phase and amplitude of only a few adjacent elements, electronic beam scanning with various radiation patterns can be easily achieved

  3. Comparison of Fit of Dentures Fabricated by Traditional Techniques Versus CAD/CAM Technology.

    Science.gov (United States)

    McLaughlin, J Bryan; Ramos, Van; Dickinson, Douglas P

    2017-11-14

    To compare the shrinkage of denture bases fabricated by three methods: CAD/CAM, compression molding, and injection molding. The effect of arch form and palate depth was also tested. Nine titanium casts, representing combinations of tapered, ovoid, and square arch forms and shallow, medium, and deep palate depths, were fabricated using electron beam melting (EBM) technology. For each base fabrication method, three poly(vinyl siloxane) impressions were made from each cast, 27 dentures for each method. Compression-molded dentures were fabricated using Lucitone 199 poly methyl methacrylate (PMMA), and injection molded dentures with Ivobase's Hybrid Pink PMMA. For CAD/CAM, denture bases were designed and milled by Avadent using their Light PMMA. To quantify the space between the denture and the master cast, silicone duplicating material was placed in the intaglio of the dentures, the titanium master cast was seated under pressure, and the silicone was then trimmed and recovered. Three silicone measurements per denture were recorded, for a total of 243 measurements. Each silicone measurement was weighed and adjusted to the surface area of the respective arch, giving an average and standard deviation for each denture. Comparison of manufacturing methods showed a statistically significant difference (p = 0.0001). Using a ratio of the means, compression molding had on average 41% to 47% more space than injection molding and CAD/CAM. Comparison of arch/palate forms showed a statistically significant difference (p = 0.023), with shallow palate forms having more space with compression molding. The ovoid shallow form showed CAD/CAM and compression molding had more space than injection molding. Overall, injection molding and CAD/CAM fabrication methods produced equally well-fitting dentures, with both having a better fit than compression molding. Shallow palates appear to be more affected by shrinkage than medium or deep palates. Shallow ovoid arch forms appear to benefit from

  4. An interlaboratory study to find an alternative to the MPN technique for enumerating Escherichia coli in shellfish

    DEFF Research Database (Denmark)

    Ogden, I.D.; Brown, G.C.; Gallacher, S.

    1998-01-01

    Nine laboratories in eight countries tested 16 batches of common mussels (Mytilus edulis) over a 32 week period in order to find an alternative to the Most Probable Number (MPN) technique to enumerate E. coli. The alternatives investigated included the 3M Petrifilm system, the Merck Chromocult agar...

  5. Mycoplasma testing of cell substrates and biologics: Review of alternative non-microbiological techniques.

    Science.gov (United States)

    Volokhov, Dmitriy V; Graham, Laurie J; Brorson, Kurt A; Chizhikov, Vladimir E

    2011-01-01

    methods for detection of mycoplasmas remains whether these alternative methods can provide a limit of detection comparable or superior to those of the culture methods. An additional challenge is that nucleic acid amplification technique (NAT) methods do not allow for accurate discrimination between viable and non-viable mycoplasma contaminants, which might lead to false-positive results (e.g. from inactivated raw materials, etc.). Our review provides an overview of these alternative methods and discusses the pros and cons of their application for the testing of mycoplasmas in biologics and cell substrates. Published by Elsevier Ltd.

  6. Simple and cost-effective fabrication of size-tunable zinc oxide architectures by multiple size reduction technique

    Directory of Open Access Journals (Sweden)

    Hyeong-Ho Park, Xin Zhang, Seon-Yong Hwang, Sang Hyun Jung, Semin Kang, Hyun-Beom Shin, Ho Kwan Kang, Hyung-Ho Park, Ross H Hill and Chul Ki Ko

    2012-01-01

    Full Text Available We present a simple size reduction technique for fabricating 400 nm zinc oxide (ZnO architectures using a silicon master containing only microscale architectures. In this approach, the overall fabrication, from the master to the molds and the final ZnO architectures, features cost-effective UV photolithography, instead of electron beam lithography or deep-UV photolithography. A photosensitive Zn-containing sol–gel precursor was used to imprint architectures by direct UV-assisted nanoimprint lithography (UV-NIL. The resulting Zn-containing architectures were then converted to ZnO architectures with reduced feature sizes by thermal annealing at 400 °C for 1 h. The imprinted and annealed ZnO architectures were also used as new masters for the size reduction technique. ZnO pillars of 400 nm diameter were obtained from a silicon master with pillars of 1000 nm diameter by simply repeating the size reduction technique. The photosensitivity and contrast of the Zn-containing precursor were measured as 6.5 J cm−2 and 16.5, respectively. Interesting complex ZnO patterns, with both microscale pillars and nanoscale holes, were demonstrated by the combination of dose-controlled UV exposure and a two-step UV-NIL.

  7. Simple and cost-effective fabrication of size-tunable zinc oxide architectures by multiple size reduction technique

    International Nuclear Information System (INIS)

    Park, Hyeong-Ho; Hwang, Seon-Yong; Jung, Sang Hyun; Kang, Semin; Shin, Hyun-Beom; Kang, Ho Kwan; Ko, Chul Ki; Zhang Xin; Hill, Ross H; Park, Hyung-Ho

    2012-01-01

    We present a simple size reduction technique for fabricating 400 nm zinc oxide (ZnO) architectures using a silicon master containing only microscale architectures. In this approach, the overall fabrication, from the master to the molds and the final ZnO architectures, features cost-effective UV photolithography, instead of electron beam lithography or deep-UV photolithography. A photosensitive Zn-containing sol–gel precursor was used to imprint architectures by direct UV-assisted nanoimprint lithography (UV-NIL). The resulting Zn-containing architectures were then converted to ZnO architectures with reduced feature sizes by thermal annealing at 400 °C for 1 h. The imprinted and annealed ZnO architectures were also used as new masters for the size reduction technique. ZnO pillars of 400 nm diameter were obtained from a silicon master with pillars of 1000 nm diameter by simply repeating the size reduction technique. The photosensitivity and contrast of the Zn-containing precursor were measured as 6.5 J cm −2 and 16.5, respectively. Interesting complex ZnO patterns, with both microscale pillars and nanoscale holes, were demonstrated by the combination of dose-controlled UV exposure and a two-step UV-NIL.

  8. Outcomes of Orbital Floor Reconstruction After Extensive Maxillectomy Using the Computer-Assisted Fabricated Individual Titanium Mesh Technique.

    Science.gov (United States)

    Zhang, Wen-Bo; Mao, Chi; Liu, Xiao-Jing; Guo, Chuan-Bin; Yu, Guang-Yan; Peng, Xin

    2015-10-01

    Orbital floor defects after extensive maxillectomy can cause severe esthetic and functional deformities. Orbital floor reconstruction using the computer-assisted fabricated individual titanium mesh technique is a promising method. This study evaluated the application and clinical outcomes of this technique. This retrospective study included 10 patients with orbital floor defects after maxillectomy performed from 2012 through 2014. A 3-dimensional individual stereo model based on mirror images of the unaffected orbit was obtained to fabricate an anatomically adapted titanium mesh using computer-assisted design and manufacturing. The titanium mesh was inserted into the defect using computer navigation. The postoperative globe projection and orbital volume were measured and the incidence of postoperative complications was evaluated. The average postoperative globe projection was 15.91 ± 1.80 mm on the affected side and 16.24 ± 2.24 mm on the unaffected side (P = .505), and the average postoperative orbital volume was 26.01 ± 1.28 and 25.57 ± 1.89 mL, respectively (P = .312). The mean mesh depth was 25.11 ± 2.13 mm. The mean follow-up period was 23.4 ± 7.7 months (12 to 34 months). Of the 10 patients, 9 did not develop diplopia or a decrease in visual acuity and ocular motility. Titanium mesh exposure was not observed in any patient. All patients were satisfied with their postoperative facial symmetry. Orbital floor reconstruction after extensive maxillectomy with an individual titanium mesh fabricated using computer-assisted techniques can preserve globe projection and orbital volume, resulting in successful clinical outcomes. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Immobilization techniques in the fabrication of nanomaterial-based electrochemical biosensors: a review.

    Science.gov (United States)

    Putzbach, William; Ronkainen, Niina J

    2013-04-11

    The evolution of 1st to 3rd generation electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. However, in recent years, modification of the transducer with nanomaterials has become increasingly studied and imparts many advantages. The sensitivity and overall performance of enzymatic biosensors has improved tremendously as a result of incorporating nanomaterials in their fabrication. Given the unique and favorable qualities of gold nanoparticles, graphene and carbon nanotubes as applied to electrochemical biosensors, a consolidated survey of the different methods of nanomaterial immobilization on transducer surfaces and enzyme immobilization on these species is beneficial and timely. This review encompasses modification of enzymatic biosensors with gold nanoparticles, carbon nanotubes, and graphene.

  10. Feasibility study of applying an advanced composite structure technique to the fabrication of helicopter rotor blades

    Science.gov (United States)

    Gleich, D.

    1972-01-01

    The fabrication of helicopter rotary wings from composite materials is discussed. Two composite spar specimens consisting of compressively prestressed stainless steel liner over-wrapped with pretensioned fiberglass were constructed. High liner strength and toughness together with the prescribed prestresses and final sizing of the part are achieved by means of cryogenic stretch forming of the fiber wrapped composite spar at minus 320 F, followed by release of the forming pressure and warm up to room temperature. The prestresses are chosen to provide residual compression in the metal liner under operating loads.

  11. Hemispherical cavities on silicon substrates: an overview of micro fabrication techniques

    Science.gov (United States)

    Poncelet, O.; Rasson, J.; Tuyaerts, R.; Coulombier, M.; Kotipalli, R.; Raskin, J.-P.; Francis, L. A.

    2018-04-01

    Hemispherical photonic crystals found in species like Papilio blumei and Cicendella chinensis have inspired new applications like anti-counterfeiting devices and gas sensors. In this work, we investigate and compare four different ways to micro fabricate such hemispherical cavities: using colloids as template, by wet (HNA) or dry (XeF2) isotropic etching of silicon and by electrochemical etching of silicon. The shape and the roughness of the obtained cavities have been discussed and the pros/cons for each method are highlighted.

  12. Utilization of the Rutherford backscattering technique for precise measurements of thickness by an alternative procedure

    International Nuclear Information System (INIS)

    Chagas, E.F.

    1985-01-01

    This technique was used to determine the thickness of targets on very thick substrates as this type of target is used a lot in nuclear physics, and especially in γ spectroscpy. The difficulties introduced in this case, occur because of the appearance of a small peak on a very high continuous background, due to the fact that the atomic number of the substrate is bigger than that of the targets. These difficulties are overcome using an alternative procedure to determine precisely the loss of energy of the beam whilst crossing the refered target. Targets of 59 Co, 46-48-50 Ti and 10 B on substrate of Pd and Ta, with thicknesses betwnn 30μg/cm 2 and 500μg/cm 2 were measured with a precision of 5%. The biggest sources of imprecision are the amounts of dE/dX. (Author) [pt

  13. Square Wave Voltammetry: An Alternative Technique to Determinate Piroxicam Release Profiles from Nanostructured Lipid Carriers.

    Science.gov (United States)

    Otarola, Jessica; Garrido, Mariano; Correa, N Mariano; Molina, Patricia G

    2016-08-04

    A new, simple, and fast electrochemical (EC) method has been developed to determine the release profile of piroxicam, a nonsteroidal anti-inflammatory drug, loaded in a drug delivery system based on nanostructured lipid carriers (NLCs). For the first time, the samples were analyzed by using square wave voltammetry, a sensitive EC technique. The piroxicam EC responses allow us to propose a model that explains the experimental results and to subsequently determine the amount of drug loaded into the NLCs formulation as a function of time. In vitro drug release studies showed prolonged drug release (up to 5 days), releasing 60 % of the incorporated drug. The proposed method is a promising and stable alternative for the study of different drug delivery systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Fabrication of cryogenic inertial-confinement-fusion targets using target free-fall technique. Report No. 2-82

    International Nuclear Information System (INIS)

    Kim, K.; Murphy, M.J.

    1982-04-01

    Techniques for fabricating cryogenic inertial confinement fusion targets (i.e., spherical shells containing a uniform layer of DT ice) are investigated using target free-fall concept. Detection and characterization of the moving targets are effected by optoelectronic means, of which the principal is an RF ac-interferometer. This interferometer system demonstrates, for the first time, the speed capabilities of the phase-modulation ac-interferometry. New techiques developed for handling, holding, launching, and transporting targets are also described. Results obtained at both room and cryogenic temperatures are presented

  15. Study of the standard direct costs of various techniques of advanced endoscopy. Comparison with surgical alternatives.

    Science.gov (United States)

    Loras, Carme; Mayor, Vicenç; Fernández-Bañares, Fernando; Esteve, Maria

    2018-03-12

    The complexity of endoscopy has carried out an increase in cost that has a direct effect on the healthcare systems. However, few studies have analyzed the cost of advanced endoscopic procedures (AEP). To carry out a calculation of the standard direct costs of AEP, and to make a financial comparison with their surgical alternatives. Calculation of the standard direct cost in carrying out each procedure. An endoscopist detailed the time, personnel, materials, consumables, recovery room time, stents, pathology and medication used. The cost of surgical procedures was the average cost recorded in the hospital. Thirty-eight AEP were analyzed. The technique showing lowest cost was gastroscopy + APC (€116.57), while that with greatest cost was ERCP with cholangioscopy + stent placement (€5083.65). Some 34.2% of the procedures registered average costs of €1000-2000. In 57% of cases, the endoscopic alternative was 2-5 times more cost-efficient than surgery, in 31% of cases indistinguishable or up to 1.4 times more costly. Standard direct cost of the majority of AEP is reported using a methodology that enables easy application in other centers. For the most part, endoscopic procedures are more cost-efficient than the corresponding surgical procedure. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  16. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks.

    Science.gov (United States)

    Gholami, Mohammad; Brennan, Robert W

    2016-01-06

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  17. Comparative evaluation of marginal fit and axial wall adaptability of copings fabricated by metal laser sintering and lost-wax technique: An in vitro study.

    Science.gov (United States)

    Gaikwad, Bhushan Satish; Nazirkar, Girish; Dable, Rajani; Singh, Shailendra

    2018-01-01

    The present study aims to compare and evaluate the marginal fit and axial wall adaptability of Co-Cr copings fabricated by metal laser sintering (MLS) and lost-wax (LW) techniques using a stereomicroscope. A stainless steel master die assembly was fabricated simulating a prepared crown; 40 replicas of master die were fabricated in gypsum type IV and randomly divided in two equal groups. Group A coping was fabrication by LW technique and the Group B coping fabrication by MLS technique. The copings were seated on their respective gypsum dies and marginal fit was measured using stereomicroscope and image analysis software. For evaluation of axial wall adaptability, the coping and die assembly were embedded in autopolymerizing acrylic resin and sectioned vertically. The discrepancies between the dies and copings were measured along the axial wall on each halves. The data were subjected to statistical analysis using unpaired t -test. The mean values of marginal fit for copings in Group B (MLS) were lower (24.6 μm) than the copings in Group A (LW) (39.53 μm), and the difference was statistically significant ( P adaptability in comparison with copings fabricated by the LW technique. However, the values of marginal fit of copings fabricated that the two techniques were within the clinically acceptable limit (<50 μm).

  18. Alternative Techniques for Cannulation of Biliary Strictures Resistant to the 0.035 System Following Living Donor Liver Transplantation

    International Nuclear Information System (INIS)

    Yoon, Hee Mang; Kim, Jin Hyoung; Ko, Gi Young; Song, Ho Young; Gwon, Dong Il; Sung, Kyu Bo

    2012-01-01

    To assess the clinical efficacy of alternative techniques for biliary stricture cannulation in patients undergoing living donor liver transplantation (LDLT), after cannulation failure with a conventional (0.035-inch guidewire) technique. Of 293 patients with biliary strictures after LDLT, 19 (6%) patients, 11 men and 8 women of mean age 48.5 years, had the failed cannulation of the stricture by conventional techniques. Recannulation was attempted by using two alternative methods, namely a micro-catheter set via percutaneous access and a snare (rendezvous) technique using percutaneous and endoscopic approaches. Strictures were successfully cannulated in 16 (84%) of the 19 patients. A microcatheter set was used in 12 and a snare technique in four patients. Stricture cannulation failed in the remaining three patients, who finally underwent surgical revision. Most technical failures using a conventional technique for biliary stricture cannulation after LDLT can be overcome by using a microcatheter set or a snare (rendezvous) technique.

  19. Alternative Techniques for Cannulation of Biliary Strictures Resistant to the 0.035 System Following Living Donor Liver Transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hee Mang; Kim, Jin Hyoung; Ko, Gi Young; Song, Ho Young; Gwon, Dong Il; Sung, Kyu Bo [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    To assess the clinical efficacy of alternative techniques for biliary stricture cannulation in patients undergoing living donor liver transplantation (LDLT), after cannulation failure with a conventional (0.035-inch guidewire) technique. Of 293 patients with biliary strictures after LDLT, 19 (6%) patients, 11 men and 8 women of mean age 48.5 years, had the failed cannulation of the stricture by conventional techniques. Recannulation was attempted by using two alternative methods, namely a micro-catheter set via percutaneous access and a snare (rendezvous) technique using percutaneous and endoscopic approaches. Strictures were successfully cannulated in 16 (84%) of the 19 patients. A microcatheter set was used in 12 and a snare technique in four patients. Stricture cannulation failed in the remaining three patients, who finally underwent surgical revision. Most technical failures using a conventional technique for biliary stricture cannulation after LDLT can be overcome by using a microcatheter set or a snare (rendezvous) technique.

  20. Examination of the ion-implantation route to fabrication of the Kane quantum computer using advanced imaging techniques

    International Nuclear Information System (INIS)

    Pakes, C.; Millar, V.; Peng, J.; Cimmino, A.; Prawer, S.; Jamieson, D.; Yang, C.; McKinnon, R.; Stanley, F.; Clark, R.; University of New South Wales, NSW; Dzurak, A.

    2002-01-01

    Full text: The Kane solid-state quantum computer employs as qubits an array of 31 P atoms embedded with nanoscale precision in a silicon matrix. One proposal for the fabrication of such an array is by phosphorous-ion implantation. We present an overview of a program of research aiming to develop advanced imaging techniques to address key issues relating to the fabrication of the Kane device by ion implantation, focusing particularly on the development of surface-resist technology to allow the registration of single implanted ions and an examination of the extent of damage imposed on the silicon matrix. Our surface resists take the form of a polymethylmethacrylate (PMMA) thin-films, which have been exposed both to MeV and keV ions. Registration of ion implantation is based on the development of localised chemical modification arising from latent damage caused within the PMMA layer by the passage of an implanted ion. On development of the resist, atomic force microscopy imaging demonstrates the formation of clearly defined etched holes, of typical diameter 30 nm, which are ascribed to single-ion impacts. The use of novel scanning probes, such as carbon nanotubes, for imaging complex PMMA resist structures will be illustrated. Potential applications to the fabrication of self-aligned gate structures will be discussed

  1. Fabrication and processing of polymer solar cells: A review of printing and coating techniques

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    Polymer solar cells are reviewed in the context of the processing techniques leading to complete devices. A distinction is made between the film-forming techniques that are used currently such as spincoating, doctor blading and casting and the, from a processing point of view, more desirable film...... are described with focus on the particular advantages and disadvantages associated with each case....

  2. Fabrication techniques of metal liner used for pressure vessels made by composite material

    International Nuclear Information System (INIS)

    Takahashi, W.K.; Al-Qureshi, H.A.

    1982-01-01

    Different viable techniques for the manufacturing of metal liner used for pressure vessels are presented. The aim of these metal liner is to avoid the fluid leakage from the pressurized vessel and to serve as a mandreal to be wound by composite material. The studied techniques are described and the practical results are illustrated. Finally a comparative study of the manufacturing techniques is made in order to define the process that furnishes the metal liner with the best characteristics. The advantages offered by these type of pressure vessels when compared with the conventional metallic vessels, are also presented. (Author) [pt

  3. Investigation of Non-Vacuum Deposition Techniques in Fabrication of Chalcogenide-Based Solar Cell Absorbers

    KAUST Repository

    Alsaggaf, Ahmed

    2015-07-01

    The environmental challenges are increasing, and so is the need for renewable energy. For photovoltaic applications, thin film Cu(In,Ga)(S,Se)2 (CIGS) and CuIn(S,Se)2 (CIS) solar cells are attractive with conversion efficiencies of more than 20%. However, the high-efficiency cells are fabricated using vacuum technologies such as sputtering or thermal co-evaporation, which are very costly and unfeasible at industrial level. The fabrication involves the uses of highly toxic gases such as H2Se, adding complexity to the fabrication process. The work described here focused on non-vacuum deposition methods such as printing. Special attention has been given to printing designed in a moving Roll-to-Roll (R2R) fashion. The results show potential of such technology to replace the vacuum processes. Conversion efficiencies for such non-vacuum deposition of Cu(In,Ga)(S,Se)2 solar cells have exceeded 15% using hazardous chemicals such as hydrazine, which is unsuitable for industrial scale up. In an effort to simplify the process, non-toxic suspensions of Cu(In,Ga)S2 molecular-based precursors achieved efficiencies of ~7-15%. Attempts to further simplify the selenization step, deposition of CuIn(S,Se)2 particulate solutions without the Ga doping and non-toxic suspensions of Cu(In,Ga)Se2 quaternary precursors achieved efficiencies (~1-8%). The contribution of this research was to provide a new method to monitor printed structures through spectral-domain optical coherence tomography SD-OCT in a moving fashion simulating R2R process design at speeds up to 1.05 m/min. The research clarified morphological and compositional impacts of Nd:YAG laser heat-treatment on Cu(In,Ga)Se2 absorber layer to simplify the annealing step in non-vacuum environment compatible to R2R. Finally, the research further simplified development methods for CIGS solar cells based on suspensions of quaternary Cu(In,Ga)Se2 precursors and ternary CuInS2 precursors. The methods consisted of post deposition reactive

  4. Alternative oil extraction methods from Echium plantagineum L. seeds using advanced techniques and green solvents.

    Science.gov (United States)

    Castejón, Natalia; Luna, Pilar; Señoráns, Francisco J

    2018-04-01

    The edible oil processing industry involves large losses of organic solvent into the atmosphere and long extraction times. In this work, fast and environmentally friendly alternatives for the production of echium oil using green solvents are proposed. Advanced extraction techniques such as Pressurized Liquid Extraction (PLE), Microwave Assisted Extraction (MAE) and Ultrasound Assisted Extraction (UAE) were evaluated to efficiently extract omega-3 rich oil from Echium plantagineum seeds. Extractions were performed with ethyl acetate, ethanol, water and ethanol:water to develop a hexane-free processing method. Optimal PLE conditions with ethanol at 150 °C during 10 min produced a very similar oil yield (31.2%) to Soxhlet using hexane for 8 h (31.3%). UAE optimized method with ethanol at mild conditions (55 °C) produced a high oil yield (29.1%). Consequently, advanced extraction techniques showed good lipid yields and furthermore, the produced echium oil had the same omega-3 fatty acid composition than traditionally extracted oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Alternative fabrication scheme to study effects of rework of nonconforming products and delayed differentiation on a multiproduct supply-chain system

    Directory of Open Access Journals (Sweden)

    Yuan-Shyi Peter Chiu

    2017-07-01

    Full Text Available This study uses an alternative fabrication scheme to study the effect of rework of nonconforming items and delayed differentiation on a multiproduct supply-chain system. Traditional economic production quantity model focuses on a single-product inventory system where all products made are assumed to be perfect quality and finished products are issued continuously. To increase machine utilization, lower quality costs in production, and reflect the real-world vendor-buyer integrated systems Chiu et al. (2016a [Chiu, Y-S.P., Kuo, J-S., Chiu, S. W., Hsieh, Y-T. (2016a. Effect of delayed differentiation on a multiproduct vendor–buyer integrated inventory system with rework. Advances in Production Engineering & Management, 11(4, 333-344.] employed a single-machine two-stage production scheme to study the effects of rework and delayed differentiation on a multi-product supply-chain system. With the intention of further reducing fabrication cycle time, this study considers an alternative two-machine two-stage fabrication scheme to re-explore the problem in Chiu et al. (2016a. Machine one solely produces all common parts for multiple end products. Then, machine two fabricates the customized multiproduct using a common cycle time strategy. Through the use of mathematical modeling and analyses, the optimal production cycle length and distribution policy are derived. Numerical examples are provided to demonstrate practical usage of the research results, and show its significant benefit in reducing fabrication cycle time compared to that obtained from prior studies that used different schemes.

  6. Digital evaluation of absolute marginal discrepancy: A comparison of ceramic crowns fabricated with conventional and digital techniques.

    Science.gov (United States)

    Liang, Shanshan; Yuan, Fusong; Luo, Xu; Yu, Zhuoren; Tang, Zhihui

    2018-04-05

    Marginal discrepancy is key to evaluating the accuracy of fixed dental prostheses. An improved method of evaluating marginal discrepancy is needed. The purpose of this in vitro study was to evaluate the absolute marginal discrepancy of ceramic crowns fabricated using conventional and digital methods with a digital method for the quantitative evaluation of absolute marginal discrepancy. The novel method was based on 3-dimensional scanning, iterative closest point registration techniques, and reverse engineering theory. Six standard tooth preparations for the right maxillary central incisor, right maxillary second premolar, right maxillary second molar, left mandibular lateral incisor, left mandibular first premolar, and left mandibular first molar were selected. Ten conventional ceramic crowns and 10 CEREC crowns were fabricated for each tooth preparation. A dental cast scanner was used to obtain 3-dimensional data of the preparations and ceramic crowns, and the data were compared with the "virtual seating" iterative closest point technique. Reverse engineering software used edge sharpening and other functional modules to extract the margins of the preparations and crowns. Finally, quantitative evaluation of the absolute marginal discrepancy of the ceramic crowns was obtained from the 2-dimensional cross-sectional straight-line distance between points on the margin of the ceramic crowns and the standard preparations based on the circumferential function module along the long axis. The absolute marginal discrepancy of the ceramic crowns fabricated using conventional methods was 115 ±15.2 μm, and 110 ±14.3 μm for those fabricated using the digital technique was. ANOVA showed no statistical difference between the 2 methods or among ceramic crowns for different teeth (P>.05). The digital quantitative evaluation method for the absolute marginal discrepancy of ceramic crowns was established. The evaluations determined that the absolute marginal discrepancies were

  7. CIS-Type PV Device Fabrication by Novel Techniques; Phase I Annual Technical Report, 1 July 1998 - 30 June 1999

    International Nuclear Information System (INIS)

    Basol, B.M.; Halani, A.; Kapur, V.K.; Leidholm, C.R.; Norsworthy, G.; Roe, R.

    1999-01-01

    This report describes work performed by International Solar Electric Technology, Inc. (ISET) during phase I of the R and D partnership subcontract titled ''CIS-Type PV Device Fabrication by Novel Techniques.'' The objective of this program is to bring ISET's novel non-vacuum CIS technology closer to commercialization by concentrating on issues such as device-efficiency improvement, larger-bandgap absorber growth, and module fabrication. Advances made in CIS and related compound solar cell fabrication processes have clearly shown that these materials and device structures can yield power conversion efficiencies in the 15%-20% range. However, many of the laboratory results on CIS-type devices have been obtained using relatively high-cost vacuum-based deposition techniques. The present project was specifically geared toward developing a low-cost, non-vacuum ''particle deposition'' method for CIS-type absorber growth. There are four major processing steps in this technique: i) preparation of a starting powder containing all or some of the chemical species constituting CIS, ii) preparation of an ink using the starting powder, iii) deposition of the ink on a substrate in the form of a thin precursor layer, and iv) conversion of the precursor layer into a fused photovoltaic absorber through annealing steps. During this Phase I program, ISET worked on tasks that were geared toward the following goals: i) elimination of back-contact problems, ii) growth of large-bandgap absorbers, and iii) fabrication of mini-modules. As a result of the Phase I research, a Mo back-contact structure was developed that eliminated problems that resulted in poor mechanical integrity of the absorber layers. Sulfur inclusion into CIS films through high-temperature sulfurization in H2S gas was also studied. It was determined that S diffusion was a strong function of the stoichiometry of the CIS layer. Sulfur was found to diffuse rapidly through the Cu-rich films, whereas the diffusion constant was

  8. High-quality vertical light emitting diodes fabrication by mechanical lift-off technique

    Science.gov (United States)

    Tu, Po-Min; Hsu, Shih-Chieh; Chang, Chun-Yen

    2011-10-01

    We report the fabrication of mechanical lift-off high quality thin GaN with Hexagonal Inversed Pyramid (HIP) structures for vertical light emitting diodes (V-LEDs). The HIP structures were formed at the GaN/sapphire substrate interface under high temperature during KOH wet etching process. The average threading dislocation density (TDD) was estimated by transmission electron microscopy (TEM) and found the reduction from 2×109 to 1×108 cm-2. Raman spectroscopy analysis revealed that the compressive stress of GaN epilayer was effectively relieved in the thin-GaN LED with HIP structures. Finally, the mechanical lift-off process is claimed to be successful by using the HIP structures as a sacrificial layer during wafer bonding process.

  9. Immobilization Techniques in the Fabrication of Nanomaterial-Based Electrochemical Biosensors: A Review

    Directory of Open Access Journals (Sweden)

    Niina J. Ronkainen

    2013-04-01

    Full Text Available The evolution of 1st to 3rd generation electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. However, in recent years, modification of the transducer with nanomaterials has become increasingly studied and imparts many advantages. The sensitivity and overall performance of enzymatic biosensors has improved tremendously as a result of incorporating nanomaterials in their fabrication. Given the unique and favorable qualities of gold nanoparticles, graphene and carbon nanotubes as applied to electrochemical biosensors, a consolidated survey of the different methods of nanomaterial immobilization on transducer surfaces and enzyme immobilization on these species is beneficial and timely. This review encompasses modification of enzymatic biosensors with gold nanoparticles, carbon nanotubes, and graphene.

  10. Optimized Shielding and Fabrication Techniques for TiN and Al Microwave Resonators

    Science.gov (United States)

    Kreikebaum, John Mark; Kim, Eunseong; Livingston, William; Dove, Allison; Calusine, Gregory; Hover, David; Rosenberg, Danna; Oliver, William; Siddiqi, Irfan

    We present a systematic study of the effects of shielding and packaging on the internal quality factor (Qi) of Al and TiN microwave resonators designed for use in qubit readout. Surprisingly, Qi =1.3x106 TiN samples investigated at 100 mK exhibited no significant changes in linewidth when operated without magnetic shielding and in an open cryo-package. In contrast, Al resonators showed systematic improvement in Qi with each successive shield. Measurements were performed in an adiabatic demagnetization refrigerator, where typical ambient fields of 0.2 mT are present at the sample stage. We discuss the effect of 100 mK and 500 mK Cu radiation shields and cryoperm magnetic shielding on resonator Q as a function of temperature and input power in samples prepared with a variety of surface treatments, fabrication recipes, and embedding circuits. This research was supported by the ARO and IARPA.

  11. POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

    2017-01-01

    Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

  12. Review of Commercially Available Microfluidic Materials and Fabricating Techniques for Point of Care Testing

    Directory of Open Access Journals (Sweden)

    Luck EREKU

    2016-07-01

    Full Text Available During the last two decades silicon and MEMs technology had been the mainstay of early microfluidic devices. However, recent times have brought into focus the need for low cost and readily available materials capable of achieving the expected microfluidics physical and chemical requirements. Also what mentioning is the rapid improvement in microfabrication technology over the years, which has significantly aided new and cheaper ways to produce microfluidic Point-Of-Care-Testing devices commercially or for research purposes. This review article discusses the usefulness of a wide range of available materials and their unique properties suitability in microfluidic applications. Likewise, advantages and drawbacks of manufacturing procedures and outputs of different fabrication methods are also brought into focus.

  13. Techniques for fabricating an infrared optical pyrometry system for pulsed electron beam diagnostics

    International Nuclear Information System (INIS)

    Ouellette, A.L.

    1976-01-01

    A description is given of an infrared optical pyrometry system which was designed to make fast time resolved temperature measurements. The purpose of this equipment is to determine the amount of energy from an electron beam or some other type of pulsed energy deposition that is absorbed in a target. The system is capable of measuring energy deposition levels up to 4000 J/g in carbon, which corresponds to a graphite target temperature of 2200 0 C. Methods of fabrication, alignment, and calibration are presented. The measurement of absorbed energy in a target as a function of position and depth is discussed as a possible application, and several measurements are described which permit a comparison of results from this system with those taken by other methods

  14. Cermet based solar selective absorbers : further selectivity improvement and developing new fabrication technique

    OpenAIRE

    Nejati, Mohammadreza

    2008-01-01

    Spectral selectivity of cermet based selective absorbers were increased by inducing surface roughness on the surface of the cermet layer using a roughening technique (deposition on hot substrates) or by micro-structuring the metallic substrates before deposition of the absorber coating using laser and imprint structuring techniques. Cu-Al2O3 cermet absorbers with very rough surfaces and excellent selectivity were obtained by employing a roughness template layer under the infrared reflective l...

  15. Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

    Science.gov (United States)

    Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

    2015-11-01

    In this work, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ˜600 kA with ˜200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. This technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

  16. Effect of Coil Current on the Properties of Hydrogenated DLC Coatings Fabricated by Filtered Cathodic Vacuum Arc Technique

    Science.gov (United States)

    Liao, Bin; Ouyang, Xiaoping; Zhang, Xu; Wu, Xianying; Bian, Baoan; Ying, Minju; Jianwu, Liu

    2018-01-01

    We successfully prepared hydrogenated DLC (a-C:H) with a thickness higher than 25 μm on stainless steel using a filtered cathode vacuum arc (FCVA) technique. The structural and mechanical properties of DLC were systematically analyzed using different methods such as x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, Vickers hardness, nanohardness, and friction and wear tests. The effect of coil current on the arc voltage, ion current, and mechanical properties of resultant films was systematically investigated. The novelty of this study is the fabrication of DLC with Vickers hardness higher than 1500 HV, in the meanwhile with the thickness higher than 30 μm through varying the coil current with FCVA technique. The results indicated that the ion current, deposition rate, friction coefficient, and Vickers hardness of DLC were significantly affected by the magnetic field inside the filtered duct.

  17. Electrospraying technique for the fabrication of metronidazole contained PLGA particles and their release profile

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Molamma P., E-mail: nnimpp@nus.edu.sg [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Zamani, Maedeh [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Felice, Betiana [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Laboratorio de Medios e Interfases, Departamento de Bioingeniería, Universidad Nacional de Tucumán, Av. Independencia 1800, Tucumán (Argentina); Ramakrishna, Seeram [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore)

    2015-11-01

    Advanced engineering of materials for the development of drug delivery devices provides scope for novel and versatile strategies for treatment of various diseases. ‘Electrospraying’ was used to prepare PLGA microparticles and further encapsulate the drug, metronidazole (Met) within the particles to function as a drug delivery system. Two different solvents were utilized for the preparation of drug loaded PLGA particles, whereby the polymeric solution in dichloromethane (DCM) produced particles of bigger sizes than using trifluoroethanol (TFE). Scanning electron microscopy showed the spherical morphology of the particles, with sizes of 3946 ± 407 nm and 1774 ± 167 nm, respectively for PLGA-Met(DCM) and PLGA-Met(TFE). The FTIR spectroscopy proved the incorporation of metronidazole in the polymer, but without any specific drug–polymer interaction. The release of the drug from the particles was studied in phosphate buffered saline, where a sustained drug release was obtained for at least 41 days. Cytotoxicity evaluation of the drug extract using mesenchymal stem cells (MSCs) showed not hindering the proliferation of MSCs, and the cell phenotype was retained after incubation in the drug containing media. Electrospraying is suggested as a cost-effective and single step process for the preparation of polymeric microparticles for prolonged and controlled release of drug. - Highlights: • Electrospraying as a novel method for the fabrication of drug delivery device • Metronidazole encapsulated PLGA particles were fabricated by electrospraying. • Solvent DCM produced particles of double the size than using TFE. • Sustained release of metronidazole studied for a period of 41 days • Drug release pattern from particles followed Fickian diffusion. • PLGA-metronidazole particles can function as a substrate for periodontal regeneration.

  18. Fabrication of assembled ZnO/TiO2 heterojunction thin film transistors using solution processing technique

    Science.gov (United States)

    Liau, Leo Chau-Kuang; Lin, Yun-Guo

    2015-01-01

    Ceramic-based metal-oxide-semiconductor (MOS) field-effect thin film transistors (TFTs), which were assembled by ZnO and TiO2 heterojunction films coated using solution processing technique, were fabricated and characterized. The fabrication of the device began with the preparation of ZnO and TiO2 films by spin coating. The ZnO and TiO2 films that were stacked together and annealed at 450 °C were characterized as a p-n junction diode. Two types of the devices, p-channel and n-channel TFTs, were produced using different assemblies of ZnO and TiO2 films. Results show that the p-channel TFTs (p-TFTs) and n-channel TFTs (n-TFTs) using the assemblies of ZnO and TiO2 films were demonstrated by source-drain current vs. drain voltage (IDS-VDS) measurements. Several electronic properties of the p- and n- TFTs, such as threshold voltage (Vth), on-off ratio, channel mobility, and subthreshold swing (SS), were determined by current-voltage (I-V) data analysis. The ZnO/TiO2-based TFTs can be produced using solution processing technique and an assembly approach.

  19. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    International Nuclear Information System (INIS)

    Liu, Yang; Ren, Li; Wang, Yingjun

    2014-01-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair

  20. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China)

    2014-05-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

  1. One-step fabrication of submicrostructures by low one-photon absorption direct laser writing technique with local thermal effect

    Science.gov (United States)

    Nguyen, Dam Thuy Trang; Tong, Quang Cong; Ledoux-Rak, Isabelle; Lai, Ngoc Diep

    2016-01-01

    In this work, local thermal effect induced by a continuous-wave laser has been investigated and exploited to optimize the low one-photon absorption (LOPA) direct laser writing (DLW) technique for fabrication of polymer-based microstructures. It was demonstrated that the temperature of excited SU8 photoresist at the focusing area increases to above 100 °C due to high excitation intensity and becomes stable at that temperature thanks to the use of a continuous-wave laser at 532 nm-wavelength. This optically induced thermal effect immediately completes the crosslinking process at the photopolymerized region, allowing obtain desired structures without using the conventional post-exposure bake (PEB) step, which is usually realized after the exposure. Theoretical calculation of the temperature distribution induced by local optical excitation using finite element method confirmed the experimental results. LOPA-based DLW technique combined with optically induced thermal effect (local PEB) shows great advantages over the traditional PEB, such as simple, short fabrication time, high resolution. In particular, it allowed the overcoming of the accumulation effect inherently existed in optical lithography by one-photon absorption process, resulting in small and uniform structures with very short lattice constant.

  2. Nanocrystalline transparent SnO{sub 2}-ZnO films fabricated at lower substrate temperature using a low-cost and simplified spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K.; Sakthivel, B.; Philominathan, P. [P. G. and Research Department of Physics, AVVM. Sri Pushpam College, Poondi, Thanjavur, Tamilnadu 613503 (India)

    2010-03-15

    Nanocrystalline and transparent conducting SnO{sub 2}- ZnO films were fabricated by employing an inexpensive, simplified spray technique using a perfume atomizer at relatively low substrate temperature (360{+-}5 C) compared with conventional spray method. The structural studies reveal that the SnO{sub 2}-ZnO films are polycrystalline in nature with preferential orientation along the (101) plane. The dislocation density is very low (1.48 x 10{sup 15}lines/m{sup 2}), indicating the good crystallinity of the films. The crystallite size of the films was found to be in the range of 26-34 nm. The optical transmittance in the visible range and the optical band gap are 85% and 3.6 eV respectively. The sheet resistance increases from 8.74 k{omega}/{open_square} to 32.4 k{omega}/{open_square} as the zinc concentration increases from 0 to 40 at.%. The films were found to have desirable figure of merit (1.63 x 10{sup -2} ({omega}/{open_square}){sup -1}), low temperature coefficient of resistance (-1.191/K) and good thermal stability. This simplified spray technique may be considered as a promising alternative to conventional spray for the massive production of economic SnO{sub 2} - ZnO films for solar cells, sensors and opto-electronic applications. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. The role of alternative (advanced) conscious sedation techniques in dentistry for adult patients: a series of cases.

    Science.gov (United States)

    Robb, N

    2014-03-01

    The basic techniques of conscious sedation have been found to be safe and effective for the management of anxiety in adult dental patients requiring sedation to allow them to undergo dental treatment. There remains great debate within the profession as to the role of the so called advanced sedation techniques. This paper presents a series of nine patients who were managed with advanced sedation techniques where the basic techniques were either inappropriate or had previously failed to provide adequate relief of anxiety. In these cases, had there not been the availability of advanced sedation techniques, the most likely recourse would have been general anaesthesia--a treatment modality that current guidance indicates should not be used where there is an appropriate alternative. The sedation techniques used have provided that appropriate alternative management strategy.

  4. Non-platinum nanocatalyst on porous nitrogen-doped carbon fabricated by cathodic vacuum arc plasma technique

    Energy Technology Data Exchange (ETDEWEB)

    Sirirak, Reungruthai [Material Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sarakonsri, Thapanee, E-mail: tsarakonsri@gmail.com [Material Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Medhesuwakul, Min [Plasma & Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-11-30

    Highlights: • High surface area porous coral-like nitrogen-doped carbon (NC) and non-platinum nanocatalysts were fabricated on proton exchange membrane using the cathodic vacuum arc plasma (CVAP) technique. • It is a one-step catalysts preparation directly on nafion proton exchange membrane. This CVAP technique is the first new method that was applied in a polymer electrolyte membrane fuel cells (PEMFCs) catalysts preparation. • Due to these excellent characteristics of nitrogen-doped carbon, it is expected to exhibit a good catalyst supporter for PEMFC. • In addition, the Fe–NC catalysts fabricated via this CVAP technique are sphere-like nanoparticle and well disperse on coral-like NC film, which particularity exhibits that these prepared catalysts ought to be a good oxygen reduction reaction (ORR) catalyst for PEMFC. • This approach can be extended to the synthesis of other non-platinum ORR catalyst for broad range applications in energy conversion. - Abstract: Polymer electrolyte membrane fuel cells (PEMFCs) convert chemical energy directly into electrical energy where catalysts composing of non-noble transition metals, nitrogen, and carbon compounds are the most promising materials to replace the expensive platinum catalysts for oxygen reduction reaction (ORR). In this research, cathodic vacuum arc plasma (CVAP) technique was used to fabricate porous nitrogen doped carbon (NC) and non-platinum catalyst on porous NC (Fe–NC) directly on ion exchange membrane for being used as an ORR catalyst at the cathode. The porous NC layer was fabricated on silicon wafer at 0.05 mTorr, 0.1 mTorr, 0.5 mTorr, 1 mTorr, and 5 mTorr of nitrogen gas inlet. The AFM, and SEM images are observed to be regularly big with quite high hillocks and thin NC layers; these results indicate that the optimum process pressure of nitrogen gas inlet is 5 mTorr for porous NC fabrication. The SEM–EDS detects Fe, N, and C elements in the prepared catalysts, and the XRD pattern reviews

  5. Non-platinum nanocatalyst on porous nitrogen-doped carbon fabricated by cathodic vacuum arc plasma technique

    International Nuclear Information System (INIS)

    Sirirak, Reungruthai; Sarakonsri, Thapanee; Medhesuwakul, Min

    2015-01-01

    Highlights: • High surface area porous coral-like nitrogen-doped carbon (NC) and non-platinum nanocatalysts were fabricated on proton exchange membrane using the cathodic vacuum arc plasma (CVAP) technique. • It is a one-step catalysts preparation directly on nafion proton exchange membrane. This CVAP technique is the first new method that was applied in a polymer electrolyte membrane fuel cells (PEMFCs) catalysts preparation. • Due to these excellent characteristics of nitrogen-doped carbon, it is expected to exhibit a good catalyst supporter for PEMFC. • In addition, the Fe–NC catalysts fabricated via this CVAP technique are sphere-like nanoparticle and well disperse on coral-like NC film, which particularity exhibits that these prepared catalysts ought to be a good oxygen reduction reaction (ORR) catalyst for PEMFC. • This approach can be extended to the synthesis of other non-platinum ORR catalyst for broad range applications in energy conversion. - Abstract: Polymer electrolyte membrane fuel cells (PEMFCs) convert chemical energy directly into electrical energy where catalysts composing of non-noble transition metals, nitrogen, and carbon compounds are the most promising materials to replace the expensive platinum catalysts for oxygen reduction reaction (ORR). In this research, cathodic vacuum arc plasma (CVAP) technique was used to fabricate porous nitrogen doped carbon (NC) and non-platinum catalyst on porous NC (Fe–NC) directly on ion exchange membrane for being used as an ORR catalyst at the cathode. The porous NC layer was fabricated on silicon wafer at 0.05 mTorr, 0.1 mTorr, 0.5 mTorr, 1 mTorr, and 5 mTorr of nitrogen gas inlet. The AFM, and SEM images are observed to be regularly big with quite high hillocks and thin NC layers; these results indicate that the optimum process pressure of nitrogen gas inlet is 5 mTorr for porous NC fabrication. The SEM–EDS detects Fe, N, and C elements in the prepared catalysts, and the XRD pattern reviews

  6. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    OpenAIRE

    Li Yuting; Gan Fangji; Wan Zhengjun; Liao Junbi; Li Wenqiang

    2015-01-01

    Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of s...

  7. Comparison of some coating techniques to fabricate barrier layers on packaging materials

    Energy Technology Data Exchange (ETDEWEB)

    Hirvikorpi, Terhi, E-mail: terhi.hirvikorpi@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Vaehae-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Harlin, Ali, E-mail: ali.harlin@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Karppinen, Maarit, E-mail: maarit.karppinen@tkk.f [Laboratory of Inorganic Chemistry, Department of Chemistry, Aalto University School of Science and Technology, Kemistintie 1, P.O. Box 16100, FI-00076 AALTO (Finland)

    2010-07-30

    Atomic layer deposition (ALD), electron beam evaporation, magnetron sputtering and a sol-gel method were used to deposit thin aluminum oxide coatings onto two different fiber-based packaging materials of commercial board grades coated with synthetic and biodegradable polymers. Significant decreases in both the water vapor and oxygen permeation rates were observed. With each technique the barrier performance was improved. However, among the techniques tested ALD was found to be most suitable. Our results moreover revealed that biodegradable polylactic acid-coated paperboard with a 25-nm thick layer of aluminum oxide grown by ALD on top of it showed promising barrier characteristics against water vapor and oxygen.

  8. Comparison of some coating techniques to fabricate barrier layers on packaging materials

    International Nuclear Information System (INIS)

    Hirvikorpi, Terhi; Vaehae-Nissi, Mika; Harlin, Ali; Karppinen, Maarit

    2010-01-01

    Atomic layer deposition (ALD), electron beam evaporation, magnetron sputtering and a sol-gel method were used to deposit thin aluminum oxide coatings onto two different fiber-based packaging materials of commercial board grades coated with synthetic and biodegradable polymers. Significant decreases in both the water vapor and oxygen permeation rates were observed. With each technique the barrier performance was improved. However, among the techniques tested ALD was found to be most suitable. Our results moreover revealed that biodegradable polylactic acid-coated paperboard with a 25-nm thick layer of aluminum oxide grown by ALD on top of it showed promising barrier characteristics against water vapor and oxygen.

  9. Fabrication of Thermoelectric Devices Using Additive-Subtractive Manufacturing Techniques: Application to Waste-Heat Energy Harvesting

    Science.gov (United States)

    Tewolde, Mahder

    Thermoelectric generators (TEGs) are solid-state devices that convert heat directly into electricity. They are well suited for waste-heat energy harvesting applications as opposed to primary energy generation. Commercially available thermoelectric modules are flat, inflexible and have limited sizes available. State-of-art manufacturing of TEG devices relies on assembling prefabricated parts with soldering, epoxy bonding, and mechanical clamping. Furthermore, efforts to incorporate them onto curved surfaces such as exhaust pipes, pump housings, steam lines, mixing containers, reaction chambers, etc. require custom-built heat exchangers. This is costly and labor-intensive, in addition to presenting challenges in terms of space, thermal coupling, added weight and long-term reliability. Additive manufacturing technologies are beginning to address many of these issues by reducing part count in complex designs and the elimination of sub-assembly requirements. This work investigates the feasibility of utilizing such novel manufacturing routes for improving the manufacturing process of thermoelectric devices. Much of the research in thermoelectricity is primarily focused on improving thermoelectric material properties by developing of novel materials or finding ways to improve existing ones. Secondary to material development is improving the manufacturing process of TEGs to provide significant cost benefits. To improve the device fabrication process, this work explores additive manufacturing technologies to provide an integrated and scalable approach for TE device manufacturing directly onto engineering component surfaces. Additive manufacturing techniques like thermal spray and ink-dispenser printing are developed with the aim of improving the manufacturing process of TEGs. Subtractive manufacturing techniques like laser micromachining are also studied in detail. This includes the laser processing parameters for cutting the thermal spray materials efficiently by

  10. Fabrication of three-dimensional platinum microstructures with laser irradiation and electrochemical technique

    International Nuclear Information System (INIS)

    Kikuchi, T.; Takahashi, H.; Maruko, T.

    2007-01-01

    Three-dimensional (3D) platinum microstructures were fabricated by successive procedures: aluminum anodizing, laser irradiation, nickel/platinum electroplating, and removal of the aluminum substrate, the oxide films, and the nickel metal layer. Aluminum plates and rods were anodized in an oxalic acid solution to form porous type oxide films. The anodized specimens were immersed in a nickel electroplating solution, and then irradiated with a pulsed Nd-yttrium aluminum garnet (YAG) laser beam to remove the anodic oxide film with a three-dimensional XYZθ stage. The specimens were cathodically polarized in the nickel and a platinum electroplating solution to form the metal micropattern at the laser-irradiated area. The electroplated specimens were immersed in NaOH solution to dissolve the aluminum substrate and the oxide films, and then immersed in HCl solution to dissolve the nickel deposits. A platinum grid-shaped microstructure, a microspring, and a cylindrical network microstructure with 50-100 μm line width were obtained successfully

  11. Fabrication of three-dimensional platinum microstructures with laser irradiation and electrochemical technique

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T. [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-Ku, Sapporo (Japan)]. E-mail: kiku@elechem1-mc.eng.hokudai.ac.jp; Takahashi, H. [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-Ku, Sapporo (Japan); Maruko, T. [Furuya Metal Co. Ltd., R and D Group, Shimodate Daiichi Kogyodanchi 1915, Morisoejima, Chikusei, Ibaraki (Japan)

    2007-02-01

    Three-dimensional (3D) platinum microstructures were fabricated by successive procedures: aluminum anodizing, laser irradiation, nickel/platinum electroplating, and removal of the aluminum substrate, the oxide films, and the nickel metal layer. Aluminum plates and rods were anodized in an oxalic acid solution to form porous type oxide films. The anodized specimens were immersed in a nickel electroplating solution, and then irradiated with a pulsed Nd-yttrium aluminum garnet (YAG) laser beam to remove the anodic oxide film with a three-dimensional XYZ{theta} stage. The specimens were cathodically polarized in the nickel and a platinum electroplating solution to form the metal micropattern at the laser-irradiated area. The electroplated specimens were immersed in NaOH solution to dissolve the aluminum substrate and the oxide films, and then immersed in HCl solution to dissolve the nickel deposits. A platinum grid-shaped microstructure, a microspring, and a cylindrical network microstructure with 50-100 {mu}m line width were obtained successfully.

  12. Fabrication and characterization of YVO4:Eu3+ nanomaterials by the microwave technique

    Institute of Scientific and Technical Information of China (English)

    Tran Thu Huong; Vu Duc Tu; Tran Kim Anh; Le Thi Vinh; Le Quoc Minh

    2011-01-01

    Fabrication and characterization of YVO4:Eu3+ nanophosphors prepared by microwave (MW) irradiation assisted soft template synthesis were reported.The effects of synthesis conditions such as different powers of MW irradiation,pH values and concentration of reaction materials on properties of nanophosphor were also investigated to obtain the controllable size,morphology and high luminescence efficiency.Morphology,crystalline structure,and optical properties were characterized by field emission scanning electron microscopy (FE-SEM),X-ray diffraction (XRD) and fluorescence spectroscopy,respectively.The results showed that YVO4:Eu3+ nanophosphors were obtained by using diethyleneglycol (DEG) as soft template,with pH values in the range of 4 to 12,upon microwave irradiation from 300 to 900 W,at temperature of 80 ℃.The high fluorescent YVO4:Eu3+ nanocrystals obtained with size from 15 nm down to 8 nm are more effective to develop an ultrahigh sensitive fluorescent label for biomolecule,cell and tissue.

  13. Fabrication of Antireflection Nanodiamond Particle Film by the Spin Coating Deposition Technique

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2014-01-01

    Full Text Available Diamond-based antireflective (AR coatings were fabricated using a spin coating of diamond suspension at room temperature as nucleation enhancement procedure and microwave plasma enhanced chemical vapour deposition. Various working pressures were used to investigate their effect on the optical characterization of the as-deposited diamond films. Scanning electron microscopy (SEM and atomic forced microscopy (AFM were employed to analyze the surface properties of the diamond films. Raman spectra and transmission electron microscopy (TEM also were used for analysis of the microstructure of the films. The results showed that working pressure had a significant effect on thickness, surface roughness, and wettability of the as-deposited diamond films. Deposited under 35 Torr or working pressure, the film possessed a low surface roughness of 13.8 nm and fine diamond grain sizes of 35 nm. Reflectance measurements of the films also were carried out using UV-Vis spectrometer and revealed a low reflectance value of the diamond films. The achievement demonstrated feasibility of the proposed spin-coating procedure for large scale production and thus opens up a prospect application of diamond film as an AR coating in industrial optoelectronic device.

  14. Physical and degradation properties of PLGA scaffolds fabricated by salt fusion technique.

    Science.gov (United States)

    Mekala, Naveen Kumar; Baadhe, Rama Raju; Parcha, Sreenivasa Rao; Yalavarthy, Prameela Devi

    2013-07-01

    Tissue engineering scaffolds require a controlled pore size and interconnected pore structures to support the host tissue growth. In the present study, three dimensional (3D) hybrid scaffolds of poly lactic acid (PLA) and poly glycolic acid (PGA) were fabricated using solvent casting/particulate leaching. In this case, partially fused NaCl particles were used as porogen (200-300µ) to improve the overall porosity (≥90%) and internal texture of scaffolds. Differential scanning calorimeter (DSC) analysis of these porous scaffolds revealed a gradual reduction in glass transition temperature (Tg) (from 48°C to 42.5°C) with increase in hydrophilic PGA content. The potential applications of these scaffolds as implants were further tested for their biocompatibility and biodegradability in four simulated body fluid (SBF) types in vitro. Whereas, simulated body fluid (SBF) Type1 with the optimal amount of HCO3 (-) ions was found to be more appropriate and sensible for testing the bioactivity of scaffolds. Among three combinations of polymer scaffolds, sample B with a ratio of 75:25 of PLA: PGA showed greater stability in body fluids (pH 7.2) with an optimum degradation rate (9% to 12% approx). X-ray diffractogram also confirmed a thin layer of hydroxyapatite deposition over sample B with all SBF types in vitro.

  15. Micromechanical Structures Fabrication; FINAL

    International Nuclear Information System (INIS)

    Rajic, S

    2001-01-01

    Work in materials other than silicon for MEMS applications has typically been restricted to metals and metal oxides instead of more ''exotic'' semiconductors. However, group III-V and II-VI semiconductors form a very important and versatile collection of material and electronic parameters available to the MEMS and MOEMS designer. With these materials, not only are the traditional mechanical material variables (thermal conductivity, thermal expansion, Young's modulus, etc.) available, but also chemical constituents can be varied in ternary and quaternary materials. This flexibility can be extremely important for both friction and chemical compatibility issues for MEMS. In addition, the ability to continually vary the bandgap energy can be particularly useful for many electronics and infrared detection applications. However, there are two major obstacles associated with alternate semiconductor material MEMS. The first issue is the actual fabrication of non-silicon micro-devices and the second impediment is communicating with these novel devices. We have implemented an essentially material independent fabrication method that is amenable to most group III-V and II-VI semiconductors. This technique uses a combination of non-traditional direct write precision fabrication processes such as diamond turning, ion milling, laser ablation, etc. This type of deterministic fabrication approach lends itself to an almost trivial assembly process. We also implemented a mechanical, electrical, and optical self-aligning hybridization technique for these alternate-material MEMS substrates

  16. Transfer printing techniques for materials assembly and micro/nanodevice fabrication.

    Science.gov (United States)

    Carlson, Andrew; Bowen, Audrey M; Huang, Yonggang; Nuzzo, Ralph G; Rogers, John A

    2012-10-09

    Transfer printing represents a set of techniques for deterministic assembly of micro-and nanomaterials into spatially organized, functional arrangements with two and three-dimensional layouts. Such processes provide versatile routes not only to test structures and vehicles for scientific studies but also to high-performance, heterogeneously integrated functional systems, including those in flexible electronics, three-dimensional and/or curvilinear optoelectronics, and bio-integrated sensing and therapeutic devices. This article summarizes recent advances in a variety of transfer printing techniques, ranging from the mechanics and materials aspects that govern their operation to engineering features of their use in systems with varying levels of complexity. A concluding section presents perspectives on opportunities for basic and applied research, and on emerging use of these methods in high throughput, industrial-scale manufacturing. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Structures and Techniques For Implementing and Packaging Complex, Large Scale Microelectromechanical Systems Using Foundry Fabrication Processes.

    Science.gov (United States)

    1996-06-01

    switches 5-43 Figure 5-27. Mechanical interference between ’Pull Spring’ devices 5-45 Figure 5-28. Array of LIGA mechanical relay switches 5-49...like coating DM Direct metal interconnect technique DMD ™ Digital Micromirror Device EDP Ethylene, diamine, pyrocatechol and water; silicon anisotropic...mechanical systems MOSIS MOS Implementation Service PGA Pin grid array, an electronic die package PZT Lead-zirconate-titanate LIGA Lithographie

  18. Influence of crack length on crack depth measurement by an alternating current potential drop technique

    International Nuclear Information System (INIS)

    Raja, Manoj K; Mahadevan, S; Rao, B P C; Behera, S P; Jayakumar, T; Raj, Baldev

    2010-01-01

    An alternating current potential drop (ACPD) technique is used for sizing depth of surface cracks in metallic components. Crack depth estimations are prone to large deviations when ACPD measurements are made on very shallow and finite length cracks, especially in low conducting materials such as austenitic stainless steel (SS). Detailed studies have been carried out to investigate the influence of crack length and aspect ratio (length to depth) on depth estimation by performing measurements on electric discharge machined notches with the aspect ratio in the range of 1 to 40 in SS plates. In notches with finite length, an additional path for current to flow through the surface along the length is available causing the notch depths to be underestimated. The experimentally observed deviation in notch depth estimates is explained from a simple mathematical approach using the equivalent resistive circuit model based on the additional path available for the current to flow. A scheme is proposed to accurately measure the depth of cracks with finite lengths in SS components

  19. Distal fascia lata lengthening: an alternative surgical technique for recalcitrant trochanteric bursitis

    Science.gov (United States)

    Ortega, Javier; García-Rayo, Ramón; Resines, Carlos

    2009-01-01

    This article presents a simple technique for fascia lata lengthening that is less aggressive, can be performed under local anaesthetic with little morbidity and disability, and has excellent results. Eleven patients (13 hips) were enrolled in this study. Mean age was 54.6 years, there was one man and ten women. Outcomes were assessed by using a visual analog pain scale, Harris hip score and Lickert scale (satisfaction). There was a mean follow-up time of 43 months (range 15–84). All patients were scored by the Harris hip scale with a mean improvement from 61 (range 48–77) to 91 (range 76–95) after surgery. The mean visual analogue scale (VAS) score improved from 83 (range 60–99) to 13 (range 0–70). We had 12 of 13 patients reporting a good result. Mean surgical time was 15 min, and only one seroma was reported as a complication. No inpatient management was needed. In conclusion, distal “Z” lengthening of the fascia lata appears to be a good alternative for treatment of this condition. PMID:19214507

  20. Perineal colostomy: an alternative to avoid permanent abdominal colostomy: operative technique, results and reflection.

    Science.gov (United States)

    da Silva, Alcino Lázaro; Hayck, Johnny; Deoti, Beatriz

    2014-01-01

    The most common injury to indicate definitive stoma is rectal cancer. Despite advances in surgical treatment, the abdominoperineal resection is still the most effective operation in radical treatment of malignancies of the distal rectum invading the sphincter and anal canal. Even with all the effort that surgeons have to preserve anal sphincters, abdominoperineal amputation is still indicated, and a definitive abdominal colostomy is necessary. This surgery requires patients to live with a definitive abdominal colostomy, which is a condition that modify body image, is not without morbidity and has great impact on the quality of life. To evaluate the technique of abdominoperineal amputation with perineal colostomy with irrigation as an alternative to permanent abdominal colostomy. Retrospective analysis of medical records of 55 patients underwent abdominoperineal resection of the rectum with perineal colostomy in the period 1989-2010. The mean age was 58 years, 40 % men and 60 % women. In 94.5% of patients the indication for surgery was for cancer of the rectum. In some patients were made three valves, other two valves and in the remaining no valve at all. Complications were: mucosal prolapse, necrosis of the lowered segment and stenosis. The abdominoperineal amputation with perineal colostomy is a good therapeutic option in the armamentarium of the surgical treatment of rectal cancer.

  1. A novel selenization technique for fabrication of superconducting FeSex thin film

    International Nuclear Information System (INIS)

    Chai Qinglin; Tu Hailing; Hua Zhiqiang; Wang Lei; Qu Fei

    2011-01-01

    A novel selenization technique was applied to prepare superconducting FeSe x films with pre-set FeS films. The combination of reactive sputtering deposition with elemental diffusion technique would extend to prepare films of other iron-based superconductors. The results of transport measurement got close or greater than that of previous reports. T c,onset and T c,0 got to 10.2 K and 4 K respectively. We believe that increase of the content of Fe 7 Se 8 could not only reduce T c but also slow down the decline of resistivity. A combinative method with reactive sputtering deposition and selenization technique was applied to prepare superconducting FeSe x films on LaAlO 3 substrates successfully. The influence of selenizing temperature on film components was studied. FeSe 0.96 and FeSe films had similar and good performances in transport measurement but little difference in magnetic property. The critical onset temperature got to 11.2 K and T c,0 got to 4 K approximately. X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy were used to analyze the ratio of constituents and morphology of several selenized films. FeSe x film had a porous structure on surface and no well preferred orientation, which were confirmed to have little influence on superconducting properties.

  2. Evaluation of the marginal fit of metal copings fabricated on three different marginal designs using conventional and accelerated casting techniques: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sharad Vaidya

    2014-01-01

    Conclusion: Among the three marginal designs studied, shoulder with bevel showed the best marginal fit with conventional as well as accelerated casting techniques. Accelerated casting technique could be a vital alternative to the time-consuming conventional casting technique. The marginal fit between the two casting techniques showed no statistical difference.

  3. Electrical Investigation of Nanostructured Fe2O3/p-Si Heterojunction Diode Fabricated Using the Sol-Gel Technique

    Science.gov (United States)

    Mansour, Shehab A.; Ibrahim, Mervat M.

    2017-11-01

    Iron oxide (α-Fe2O3) nanocrystals have been synthesized via the sol-gel technique. The structural and morphological features of these nanocrystals were studied using x-ray diffraction, Fourier transform-infrared spectroscopy and transmission electron microscopy. Colloidal solution of synthesized α-Fe2O3 (hematite) was spin-coated onto a single-crystal p-type silicon (p-Si) wafer to fabricate a heterojunction diode with Mansourconfiguration Ag/Fe2O3/p-Si/Al. This diode was electrically characterized at room temperature using current-voltage (I-V) characteristics in the voltage range from -9 V to +9 V. The fabricated diode showed a good rectification behavior with a rectification factor 1.115 × 102 at 6 V. The junction parameters such as ideality factor, barrier height, series resistance and shunt resistance are determined using conventional I-V characteristics. For low forward voltage, the conduction mechanism is dominated by the defect-assisted tunneling process with conventional electron-hole recombination. However, at higher voltage, I-V ohmic and space charge-limited current conduction was became less effective with the contribution of the trapped-charge-limited current at the highest voltage range.

  4. Fabrication of gas diffusion layer based on x-y robotic spraying technique for proton exchange membrane fuel cell application

    International Nuclear Information System (INIS)

    Sitanggang, Ramli; Mohamad, Abu Bakar; Daud, Wan Ramli Wan; Kadhum, Abdul Amir H.; Iyuke, S.E.

    2009-01-01

    The x-y robotic spraying technique developed in the Universiti Kebangsaan Malaysia is capable of fabricating various sizes of thickness and porosity of gas diffusion layer (GDL) used in the proton exchange membrane fuel cell (PEMFC). These parameters are obtained by varying the characteristic spray numbers of the robotic spraying machine. This investigation results were adequately represented with mathematical equations for hydrogen gas distribution in GDL. Volumetric modulus (M) parameter is used to determine the value of current density produced on the electrode of a single cell PEMFC. Thus the M parameter can be employed as indicator for a successful GDL fabrication. GDL type 4 has three variables of layer design that can be optimized to function as gas distributor, gas storage, flooding preventer on GDL surface, to evacuate water from the electrode and to control the electrical conductivity. The gas distribution in GDL was mathematically represented with average error of 15.5%. The M value of GDL type 4 according to the model was 0.22 cm 3 /s and yielded a current density of 750 A/m 2 .

  5. Investigate the electrical and thermal properties of the low temperature resistant silver nanowire fabricated by two-beam laser technique

    Science.gov (United States)

    He, Gui-Cang; Dong, Xian-Zi; Liu, Jie; Lu, Heng; Zhao, Zhen-Sheng

    2018-05-01

    A two-beam laser fabrication technique is introduced to fabricate the single silver nanowire (AgNW) on polyethylene terephthalate (PET) substrate. The resistivity of the AgNW is (1.31 ± 0.05) × 10-7 Ω·m, which is about 8 times of the bulk silver resistivity (1.65 × 10-8 Ω·m). The AgNW electrical resistance is measured in temperature range of 10-300 K and fitted with the Bloch-Grüneisen formula. The fitting results show that the residue resistance is 153 Ω, the Debye temperature is 210 K and the electron-phonon coupling constant is (5.72 ± 0.24) × 10-8 Ω·m. Due to the surface scattering, the Debye temperature and the electron-phonon coupling constant are lower than those of bulk silver, and the residue resistance is bigger than that of bulk silver. Thermal conductivity of the single AgNW is calculated in the corresponding temperature range, which is the biggest at the temperature approaching the Debye temperature. The AgNW on PET substrate is the low temperature resistance material and is able to be operated stably at such a low temperature of 10 K.

  6. Design and fabrication of ZnO/TiO2-based thin-film inverter circuits using solution processing techniques

    International Nuclear Information System (INIS)

    Liau, Leo Chau-Kuang; Kuo, Juo-Wei; Chiang, Hsin-Ni

    2012-01-01

    Novel and cost-effective ceramic-based thin-film inverter circuits, based on two layers of TiO 2 and ZnO films to construct junction field-effect transistors (FETs), were designed and fabricated by solution coating techniques. The double layers of the sol–gel ZnO and TiO 2 films were coated and characterized as a diode according to the current–voltage performance. Two types of FETs, the p-channel (p-FET) and the n-channel (n-FET) devices, were produced using different coating sequences of ZnO and TiO 2 layers. Both of the transistor performances were evaluated by analyzing the source–drain current versus voltage (I ds –V ds ) data with the control of the gate voltage (V g ). The ZnO/TiO 2 -based inverter circuits, such as the complementary-FET device, were further fabricated using the integration of the p-FET and the n-FET. The voltage transfer characteristics of the inverters were estimated by the tests of the input voltage (V in ) versus the output voltage (V out ) for the thin-film inverter circuits. (paper)

  7. Design and fabrication of Sn-Nb-Cu-Ta-C composites for multifilamentary superconducting Nb/sub 3/Sn wires by using the modified tube technique

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A; Kosek, Z M

    1987-10-01

    The factors determining the design and fabrication of Nb/sub 3/Sn multifilamentary wires by the tube technique are discussed. New improved methods of obtaining multifilamentary Nb/sub 3/Sn wires on the basis of both external diffusion and internal diffusion processes, by using the tube technique in a simpler and less expensive way, are presented.

  8. Poly(methyl methacrylate) Composites with Size-selected Silver Nanoparticles Fabricated Using Cluster Beam Technique

    DEFF Research Database (Denmark)

    Muhammad, Hanif; Juluri, Raghavendra R.; Chirumamilla, Manohar

    2016-01-01

    based on cluster beam technique allowing the formation of monocrystalline size-selected silver nanoparticles with a ±5–7% precision of diameter and controllable embedment into poly (methyl methacrylate). It is shown that the soft-landed silver clusters preserve almost spherical shape with a slight...... tendency to flattening upon impact. By controlling the polymer hardness (from viscous to soft state) prior the cluster deposition and annealing conditions after the deposition the degree of immersion of the nanoparticles into polymer can be tuned, thus, making it possible to create composites with either...

  9. The development of fabrication techniques for europia/iron cermet tips for coarse-control arms in DIDO and PLUTO

    International Nuclear Information System (INIS)

    Moore, D.A.; Tarrant, E.A.

    1980-11-01

    The applicability of cermet-fabrication techniques to the production of europia/iron cermets for use as coarse-control arm tips in the materials test reactors DIDO and PLUTO has been investigated. Spheroids of europia were prepared by a dry agglomeration process. These were sintered, dispersed in iron powder and pressed into plates; the plates were then sintered to densify the iron matrix. These stages were optimised to produce a strong cermet with a europia density of >= 2.75 g/cm 3 . The uniformity of distribution of the absorber particles was confirmed by radiography, and adequate neutron-absorption worth by measurements carried out in the GLEEP reactor. An outline flow sheet has been prepared for the manufacture of europia/iron cermet plates suitable for use in the tips of DIDO and PLUTO coarse-control arms. (author)

  10. Reflectance spectra characteristics from an SPR grating fabricated by nano-imprint lithography technique for biochemical nanosensor applications

    Science.gov (United States)

    Setiya Pradana, Jalu; Hidayat, Rahmat

    2018-04-01

    In this paper, we report our research work on developing a Surface Plasmon Resonance (SPR) element with sub-micron (hundreds of nanometers) periodicity grating structure. This grating structure was fabricated by using a simple nano-imprint lithography technique from an organically siloxane polymers, which was then covered by nanometer thin gold layer. The formed grating structure was a very well defined square-shaped periodic structure. The measured reflectance spectra indicate the SPR wave excitation on this grating structure. For comparison, the simulations of reflectance spectra have been also carried out by using Rigorous Coupled-Wave Analysis (RCWA) method. The experimental results are in very good agreement with the simulation results.

  11. Solid-state ZnS quantum dot-sensitized solar cell fabricated by the Dip-SILAR technique

    International Nuclear Information System (INIS)

    Mehrabian, M; Mirabbaszadeh, K; Afarideh, H

    2014-01-01

    Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfide quantum dots (ZnS QDs), which served as the light absorber and the recombination blocking layer simultaneously. ZnS QDs were prepared successfully by a novel successive ionic layer adsorption and reaction technique based on dip-coating (Dip-SILAR). The dependences of the photovoltaic parameters on the number of SILAR cycles (n) were investigated. The cell with n = 6 (particle average size ∼9 nm) showed an energy conversion efficiency of 2.72% under the illumination of one sun (AM 1.5, 100 mW cm −2 ). Here we investigate also the cohesion between ZnS QDs and ZnO film to obtain a well-covering QD layer. (paper)

  12. Low temperature fabrication of conductive silver lines and dots via transfer-printing and nanoimprinting lithography techniques

    International Nuclear Information System (INIS)

    Wu, Chun-Chang; Hsu, Steve Lien-Chung; Chiu, Ching-Wei; Wu, Jung-Tang

    2013-01-01

    In this work, we have developed novel methods to fabricate conductive silver tracks and dots directly from silver nitrate solution by transfer-printing and nanoimprinting lithography techniques, which are inexpensive and can be scaled down to the nanometer scale. The silver nitrate precursor can be reduced in ethylene glycol vapor to form silver at low temperatures. Energy dispersive spectrometric analysis results indicate that the silver nitrate has been converted to silver completely. In order to obtain smooth and continuous conductive patterned silver features with high resolution, the silver lines with widths of a few tens of micrometers to nanometers were patterned by using a spin-coating approach. Using a 14 M silver nitrate solution, continuous silver conductive lines with a resistivity of 8.45 × 10 −5 Ω cm has been produced. (paper)

  13. Fabrication and characterization of In2S3 thin films deposited by thermal evaporation technique

    International Nuclear Information System (INIS)

    Timoumi, A.; Bouzouita, H.; Kanzari, M.; Rezig, B.

    2005-01-01

    Indium sulphide, In 2 S 3 , thin films present an alternative to conventional CdS films as buffer layer for CIS-based thin film solar cells. The objective is to eliminate toxic cadmium for environmental reasons. Indium sulphide is synthesized and deposited by single source vacuum thermal evaporation method on glass substrates. The films are analyzed by X-ray diffraction (XRD) and spectrophotometric measurements. They have a good crystallinity, homogeneity and adhesion. The X-ray diffraction analysis confirmed the initial amorphous nature of the deposited InS film and phase transition into crystalline In 2 S 3 formed upon annealing at free air for 250 deg. C substrate temperature for 2 h. The optical constants of the deposited films were obtained from the analysis of the experimental recorded transmission and reflectance spectral data over the wavelength range of 300-1800 nm. We note that the films annealed at 250 deg. C for 2 h show a good homogeneity with 80% transmission. An analysis of the optical absorption data of the deposited films revealed an optical direct band gap energy in the range of 2.0-2.2 eV

  14. Microstructure quantification of ultrafine grained pure copper fabricated by simple shear extrusion (SSE) technique

    International Nuclear Information System (INIS)

    Bagherpour, E.; Qods, F.; Ebrahimi, R.; Miyamoto, H.

    2016-01-01

    In the present paper commercially pure copper was processed by simple shear extrusion (SSE) technique up to 12 passes using the so-called route C. For SSE processing an appropriate die with a linear die profile was designed and constructed. Effect of SSE passes on isotropy and uniformity of microstructures are focused. Electron back-scattering diffraction (EBSD) was used to evaluate the microstructure of the deformed samples in three orthogonal planes. To investigate the microstructural uniformity EBSD maps were taken from center to periphery of the extrusion direction plane (ED-plane) samples. Significant evolution in grain refinement was achieved down to sub-micron grain size in all planes. Hardness measurements show a considerable increase in hardness of the material after the processing, which confirms the microstructural evolutions. EBSD scans revealed a homogeneous ultrafine grained microstructure after 12 passes. Micro-shear bands were found as potential sites for accelerating the formation of new grains by fragmentation of the initial grains. The total frequency of coincidence site lattice (CSL) boundaries including Σ3 boundaries increased by the increasing of SSE passes. The higher fraction of low to high angle grain boundaries of SSE compared to equal channel angular pressing is an evidence for the cyclic behavior of SSE technique.

  15. 10-channel fiber array fabrication technique for parallel optical coherence tomography system

    Science.gov (United States)

    Arauz, Lina J.; Luo, Yuan; Castillo, Jose E.; Kostuk, Raymond K.; Barton, Jennifer

    2007-02-01

    Optical Coherence Tomography (OCT) shows great promise for low intrusive biomedical imaging applications. A parallel OCT system is a novel technique that replaces mechanical transverse scanning with electronic scanning. This will reduce the time required to acquire image data. In this system an array of small diameter fibers is required to obtain an image in the transverse direction. Each fiber in the array is configured in an interferometer and is used to image one pixel in the transverse direction. In this paper we describe a technique to package 15μm diameter fibers on a siliconsilica substrate to be used in a 2mm endoscopic probe tip. Single mode fibers are etched to reduce the cladding diameter from 125μm to 15μm. Etched fibers are placed into a 4mm by 150μm trench in a silicon-silica substrate and secured with UV glue. Active alignment was used to simplify the lay out of the fibers and minimize unwanted horizontal displacement of the fibers. A 10-channel fiber array was built, tested and later incorporated into a parallel optical coherence system. This paper describes the packaging, testing, and operation of the array in a parallel OCT system.

  16. Microstructure quantification of ultrafine grained pure copper fabricated by simple shear extrusion (SSE) technique

    Energy Technology Data Exchange (ETDEWEB)

    Bagherpour, E., E-mail: e.bagherpour@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan); Qods, F., E-mail: qods@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Ebrahimi, R., E-mail: ebrahimy@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Miyamoto, H., E-mail: hmiyamot@mail.doshisha.ac.jp [Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan)

    2016-09-30

    In the present paper commercially pure copper was processed by simple shear extrusion (SSE) technique up to 12 passes using the so-called route C. For SSE processing an appropriate die with a linear die profile was designed and constructed. Effect of SSE passes on isotropy and uniformity of microstructures are focused. Electron back-scattering diffraction (EBSD) was used to evaluate the microstructure of the deformed samples in three orthogonal planes. To investigate the microstructural uniformity EBSD maps were taken from center to periphery of the extrusion direction plane (ED-plane) samples. Significant evolution in grain refinement was achieved down to sub-micron grain size in all planes. Hardness measurements show a considerable increase in hardness of the material after the processing, which confirms the microstructural evolutions. EBSD scans revealed a homogeneous ultrafine grained microstructure after 12 passes. Micro-shear bands were found as potential sites for accelerating the formation of new grains by fragmentation of the initial grains. The total frequency of coincidence site lattice (CSL) boundaries including Σ3 boundaries increased by the increasing of SSE passes. The higher fraction of low to high angle grain boundaries of SSE compared to equal channel angular pressing is an evidence for the cyclic behavior of SSE technique.

  17. Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques

    Directory of Open Access Journals (Sweden)

    Hae Ri Kim

    2016-07-01

    Full Text Available The microstructures and mechanical properties of cobalt-chromium (Co-Cr alloys produced by three CAD/CAM-based processing techniques were investigated in comparison with those produced by the traditional casting technique. Four groups of disc- (microstructures or dumbbell- (mechanical properties specimens made of Co-Cr alloys were prepared using casting (CS, milling (ML, selective laser melting (SLM, and milling/post-sintering (ML/PS. For each technique, the corresponding commercial alloy material was used. The microstructures of the specimens were evaluated via X-ray diffractometry, optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy, and electron backscattered diffraction pattern analysis. The mechanical properties were evaluated using a tensile test according to ISO 22674 (n = 6. The microstructure of the alloys was strongly influenced by the manufacturing processes. Overall, the SLM group showed superior mechanical properties, the ML/PS group being nearly comparable. The mechanical properties of the ML group were inferior to those of the CS group. The microstructures and mechanical properties of Co-Cr alloys were greatly dependent on the manufacturing technique as well as the chemical composition. The SLM and ML/PS techniques may be considered promising alternatives to the Co-Cr alloy casting process.

  18. Fabrication of Al–TiC composites by hot consolidation technique: its microstructure and mechanical properties

    Directory of Open Access Journals (Sweden)

    Sangita Mohapatra

    2016-04-01

    Full Text Available Al-based metal matrix composites reinforced with different volume fraction of TiC particles as reinforcement was synthesized by the hot consolidation process. The titanium carbide used in this study was synthesized directly from the titanium ore (ilmenite, FeTiO3 by carbothermic reduction process through thermal plasma technique. The field emission scanning electron micrographs (FESEM reveals the homogeneous distribution of TiC particles in the Al-matrix. Enhanced Young's modulus and mechanical properties with appreciable ductility were observed in the composite samples. The significant increases in the mechanical properties of the composites demonstrate the effectiveness of the low-density TiC reinforcement.

  19. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Baier, S.; Rochet, A.; Hofmann, G. [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Kraut, M. [Institute for Micro Process Engineering, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany); Grunwaldt, J.-D., E-mail: grunwaldt@kit.edu [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany)

    2015-06-15

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  20. Fabrication and Characterization of a Micro Methanol Sensor Using the CMOS-MEMS Technique

    Directory of Open Access Journals (Sweden)

    Chien-Fu Fong

    2015-10-01

    Full Text Available A methanol microsensor integrated with a micro heater manufactured using the complementary metal oxide semiconductor (CMOS-microelectromechanical system (MEMS technique was presented. The sensor has a capability of detecting low concentration methanol gas. Structure of the sensor is composed of interdigitated electrodes, a sensitive film and a heater. The heater located under the interdigitated electrodes is utilized to provide a working temperature to the sensitive film. The sensitive film prepared by the sol-gel method is tin dioxide doped cadmium sulfide, which is deposited on the interdigitated electrodes. To obtain the suspended structure and deposit the sensitive film, the sensor needs a post-CMOS process to etch the sacrificial silicon dioxide layer and silicon substrate. The methanol senor is a resistive type. A readout circuit converts the resistance variation of the sensor into the output voltage. The experimental results show that the methanol sensor has a sensitivity of 0.18 V/ppm.

  1. Low background materials and fabrication techniques for cables and connectors in the Majorana Demonstrator

    Science.gov (United States)

    Busch, M.; Abgrall, N.; Alvis, S. I.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Barton, C. J.; Bertrand, F. E.; Bode, T.; Bradley, A. W.; Brudanin, V.; Buuck, M.; Caldwell, T. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Gilliss, T.; Giovanetti, G. K.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Haufe, C. R.; Hehn, L.; Henning, R.; Hoppe, E. W.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; Lopez, A. M.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Myslik, J.; O'Shaughnessy, C.; Othman, G.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Reine, A. L.; Rielage, K.; Robertson, R. G. H.; Rouf, N. W.; Shanks, B.; Shirchenko, M.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.; Zhu, B. X.

    2018-01-01

    The Majorana Collaboration is searching for the neutrinoless double-beta decay of the nucleus 76Ge. The Majorana Demonstrator is an array of germanium detectors deployed with the aim of implementing background reduction techniques suitable for a tonne scale 76Ge-based search (the LEGEND collaboration). In the Demonstrator, germanium detectors operate in an ultra-pure vacuum cryostat at 80 K. One special challenge of an ultra-pure environment is to develop reliable cables, connectors, and electronics that do not significantly contribute to the radioactive background of the experiment. This paper highlights the experimental requirements and how these requirements were met for the Majorana Demonstrator, including plans to upgrade the wiring for higher reliability in the summer of 2018. Also described are requirements for LEGEND R&D efforts underway to meet these additional requirements

  2. Fabrication and Characterization of a Micro Methanol Sensor Using the CMOS-MEMS Technique.

    Science.gov (United States)

    Fong, Chien-Fu; Dai, Ching-Liang; Wu, Chyan-Chyi

    2015-10-23

    A methanol microsensor integrated with a micro heater manufactured using the complementary metal oxide semiconductor (CMOS)-microelectromechanical system (MEMS) technique was presented. The sensor has a capability of detecting low concentration methanol gas. Structure of the sensor is composed of interdigitated electrodes, a sensitive film and a heater. The heater located under the interdigitated electrodes is utilized to provide a working temperature to the sensitive film. The sensitive film prepared by the sol-gel method is tin dioxide doped cadmium sulfide, which is deposited on the interdigitated electrodes. To obtain the suspended structure and deposit the sensitive film, the sensor needs a post-CMOS process to etch the sacrificial silicon dioxide layer and silicon substrate. The methanol senor is a resistive type. A readout circuit converts the resistance variation of the sensor into the output voltage. The experimental results show that the methanol sensor has a sensitivity of 0.18 V/ppm.

  3. Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, K., E-mail: kazuhide.ozeki.365@vc.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Aoki, H. [International Apatite Institute Co., Ltd., 2-12-9, Misaki-cho, Chiyoda-ku, Tokyo 101-0061 (Japan)

    2017-03-01

    Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

  4. Growth Assisted by Glancing Angle Deposition: A New Technique to Fabricate Highly Porous Anisotropic Thin Films.

    Science.gov (United States)

    Sanchez-Valencia, Juan Ramon; Longtin, Remi; Rossell, Marta D; Gröning, Pierangelo

    2016-04-06

    We report a new methodology based on glancing angle deposition (GLAD) of an organic molecule in combination with perpendicular growth of a second inorganic material. The resulting thin films retain a very well-defined tilted columnar microstructure characteristic of GLAD with the inorganic material embedded inside the columns. We refer to this new methodology as growth assisted by glancing angle deposition or GAGLAD, since the material of interest (here, the inorganic) grows in the form of tilted columns, though it is deposited under a nonglancing configuration. As a "proof of concept", we have used silver and zinc oxide as the perpendicularly deposited material since they usually form ill-defined columnar microstructures at room temperature by GLAD. By means of our GAGLAD methodology, the typical tilted columnar microstructure can be developed for materials that otherwise do not form ordered structures under conventional GLAD. This simple methodology broadens significantly the range of materials where control of the microstructure can be achieved by tuning the geometrical deposition parameters. The two examples presented here, Ag/Alq3 and ZnO/Alq3, have been deposited by physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD), respectively: two different vacuum techniques that illustrate the generality of the proposed technique. The two type of hybrid samples present very interesting properties that demonstrate the potentiality of GAGLAD. On one hand, the Ag/Alq3 samples present highly optical anisotropic properties when they are analyzed with linearly polarized light. To our knowledge, these Ag/Alq3 samples present the highest angular selectivity reported in the visible range. On the other hand, ZnO/Alq3 samples are used to develop highly porous ZnO thin films by using Alq3 as sacrificial material. In this way, antireflective ZnO samples with very low refractive index and extinction coefficient have been obtained.

  5. Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

    International Nuclear Information System (INIS)

    Ozeki, K.; Masuzawa, T.; Aoki, H.

    2017-01-01

    Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

  6. SU-E-T-31: Alternative VMAT Technique Reduces Total Monitor Units for Lung SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Happersett, L; Mechalakos, J; Kuo, L; Zhang, P; Rimner, A [Memorial Sloan-Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: To investigate an alternative approach to VMAT optimization for hypofractionation lung treatment which increases average aperture opening and results in lower total Monitor Units (MU) without significantly sacrificing plan quality. Methods: Benchmark Volumetric Modulated Arc Therapy (bVMAT) plans were generated for 10 lung Stereotactic Body radiotherapy (SBRT) cases using Eclipse Version 11.0.42 (Varian Medical Systems) without a maximum MU constraint. Prescriptions ranged from 40 to 54Gy in 3 to 5 fractions. AAA dose calculation and PRO fluence based optimization was utilized. Two comparison VMAT plans were generated for each case, one that forced an initial “open” mlc aperture conformal to the tumor as a starting condition (oVMAT) with similar optimization parameters and arc geometries, and one that repeated the bVMAT optimization but added a maximum MU constraint (muVMAT). All plans used two arcs with lengths between 168 to 230 degrees. PTV D 95% and Dmean, lung V20 Gy, chest wall V30 Gy, average aperture opening and MU's were compared. Statistical significance was evaluated using Wilcoxon signed rank test. Results: Average PTV D(95), PTV mean and lung V20Gy over all plans was 99.2 ± 1.7%, 103.3 ± 0.6% and 7.8 ± 2.4% respectively. The average chest wall V30Gy was 61 ± 61 cc and ranged between 0 to 166 cc. There were no significant differences between the three techniques for the dosimetric quantities. MUs were reduced by 11 ±11% (p<0.01) and 25 ± 5% (p<0.01) and the average aperture size was increased by 13.7 ± 14% (p=0.02) and 35.8 ± 10% (p<0.01) with muVMAT and oVMAT, respectively, compared to bVMAT. Conclusion: oVMAT and muVMAT techniques were both able to increase average aperture size and reduce total MU compared to the benchmark VMAT plan, but the magnitude of the changes observed for oVMAT was larger.

  7. Tsunakawa-Shaw method - an absolute paleointensity technique using alternating field demagnetization

    Science.gov (United States)

    Yamamoto, Y.; Mochizuki, N.; Shibuya, H.; Tsunakawa, H.

    2015-12-01

    Among geologic materials volcanic rocks have been typically used to deduce an absolute paleointensity. In the last decade, however, there seems a becoming consensus that volcanic rocks are not so ideal materials due to such as magnetic grains other than non-interacting single domain particles. One approach to obtain a good paleointensity estimate from the rocks is to reduce and correct the non-ideality, suppress alterations in laboratory and screen out suspicious results. We have been working on a development and an application of the Tsunakawa-Shaw method, which has been previously called the LTD-DHT Shaw method. This method is an AF(alternating field)-based technique and thus a paleointensity is estimated using coercivity spectra. To reduce the non-ideality, all remanences undergo low-temperature demagnetization (LTD) before any AF demagnetizations to remove multi-domain like component. To correct the non-ideality, anhysteretic remanent magnetizations (ARMs) are imparted with their directions parallel to natural remanent magnetizations and laboratory-imparted thermoremanent magnetizations (TRMs) and measured before and after laboratory heating. These ARMs are used to correct remanence anisotropies, possible interaction effects originated from the non-ideal grains and TRM changes caused by laboratory alterations. TRMs are imparted by heating specimens above their Curie temperatures and then cooling to room temperature at once to simulate nature conditions. These cycles are done in vacuum to suppress alterations in laboratory. Obtained results are judged by selection criteria, including a check for validity of the ARM corrections.It has been demonstrated that successful paleointensities are obtained from historical lavas in Japan and Hawaii, and from baked clay samples from a reconstructed ancient kiln, with the flow-mean precision of 5-10%. In case of old volcanic rocks, however, the method does not necessarily seem to be perfect. We will summarize these points in

  8. A clinical evaluation of alternative fixation techniques for medial malleolus fractures.

    Science.gov (United States)

    Barnes, Hayley; Cannada, Lisa K; Watson, J Tracy

    2014-09-01

    Medial malleolus fractures have traditionally been managed using partially threaded screws and/or Kirschner wire fixation. Using these conventional techniques, a non-union rate of as high as 20% has been reported. In addition too many patients complaining of prominent hardware as a source of pain post-fixation. This study was designed to assess the outcomes of medial malleolar fixation using a headless compression screw in terms of union rate, the need for hardware removal, and pain over the hardware site. Saint Louis University and Mercy Medical Center, Level 1 Trauma Centers, St. Louis, MO. After IRB approval, we used billing records to identify all patients with ankle fractures involving the medial malleolus. Medical records and radiographs were reviewed to identify patients with medial malleolar fractures treated with headless compression screw fixation. Our inclusion criteria included follow-up until full weight bearing and a healed fracture. Follow-up clinical records and radiographs were reviewed to determine union, complication rate and perception of pain over the site of medial malleolus fixation. Sixty-four ankles were fixed via headless compression screws and 44 had adequate follow-up for additional evaluation. Seven patients had isolated medial malleolar fractures, 23 patients had bimalleolar fractures, and 14 patients had trimalleolar fractures. One patient (2%) required hardware removal due to cellulitis. One patient (2%) had a delayed union, which healed without additional intervention. Ten patients (23%) reported mild discomfort to palpation over the medial malleolus. The median follow-up was 35 weeks (range: 12-208 weeks). There were no screw removals for painful hardware and no cases of non-union. Headless compression screws provide effective compression of medial malleolus fractures and result in good clinical outcomes. The headless compression screw is a beneficial alternative to the conventional methods of medial malleolus fixation. Copyright

  9. Post-Heat Treatment and Mechanical Assessment of Polyvinyl Alcohol Nanofiber Sheet Fabricated by Electrospinning Technique

    Directory of Open Access Journals (Sweden)

    Mahir Es-saheb

    2014-01-01

    Full Text Available Polyvinyl alcohol (PVA sheets based nanofibers were produced by electrospinning technique. Postheat treatment of the produced PVA sheets with temperatures both below and above Tg to improve the mechanical properties of this material is conducted. The morphology, microstructures, and thermal degradation of the nanofibers sheets produced were investigated using scanning electron microscopy (SEM, transmission electron microscope (TEM, and thermal gravimetric analysis (TGA. Produced nanofibers are compact, and entangled with each other, with diameters from around 150 to 210. Some mechanical characteristics of the successfully produced PVA sheets, and heat-treated, are then conducted and assessed employing uniaxial tensile tests at different speeds ranging from 1 mm/min to 100 mm/min. The tensile test results obtained show that the PVA sheets are strain rate sensitive with increasing strength as the speed (i.e., strain rate increases. The yield tensile stress ranges from 2.411 to 6.981 MPa, the ductility (i.e., elongation percent from ∼21 to 60%, and Young modulus ranges from 103 to 0.137 KPa. However, for heat-treated samples, it is found that the yield strength increases almost by ∼35–40% more than the values of untreated cases with values reaching up to about 3.627–9.63 MPa.

  10. Fabrication of a dual-planar-coil dynamic microphone by MEMS techniques

    International Nuclear Information System (INIS)

    Horng, Ray-Hua; Chen, Kuo-Feng; Tsai, Yao-Cheng; Suen, Cheng-You; Chang, Chao-Chih

    2010-01-01

    A dual-planar-coil miniature dynamic microphone, one of the electro-acoustic transducers working with the principle of the electromagnetic induction, has been realized by semiconductor micro-processing and micro-electro-mechanical system (MEMS) techniques. This MEMS microphone mainly consists of a 1 µm thick diaphragm sandwiched by two spiral coils and vibrating in the region with the highest magnetic flux density generated by a double magnetic system. In comparison with the traditional dynamic microphone, besides the miniaturized dimension, the MEMS microphone also provides 325 times the vibration velocity of the diaphragm faster than the traditional microphone. Measured by an audio analyzer, the frequency response of the MEMS microphone is only 4.5 dBV Pa −1 lower than that of the traditional microphone in the range between 50 Hz and 20 kHz. The responsivity of −54.8 dB Pa −1 (at 1 kHz) of the MEMS device is competitive to that of a traditional commercial dynamic microphone which typically ranges from −50 to −60 dBV Pa −1 (at 1 kHz).

  11. Fabrication and properties of samarium doped calcium sulphate thin films using spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Reghima, Meriem [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia); Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Faculté des Sciences de Bizerte, Université de Carthage, Zarzouna 7021 (Tunisia); Guasch, Cathy [Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Azzaza, Sonia; Alleg, Safia [Laboratoire de Magnétisme et Spectroscopie des Solides (LM2S), Département de Physique, Faculté des Sciences, Université Badji Mokhtar Annaba, B.P. 12, 23000 Annaba (Algeria); Kamoun-Turki, Najoua [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia)

    2016-10-01

    Using low cost spray pyrolysis technique, polycrystalline CaSO{sub 4} thin films were successfully grown on a glass substrate with a thickness of about 1 μm. Samarium doping has been performed on CaSO{sub 4} thin films to explore luminescence properties. The characterizations of these films were carried out using X-ray diffraction, Scanning Electron Microscopy and optical measurements. The structural analyses reveal the existence of hexagonal CaSO{sub 4} phase with a (200) preferred orientation belonging to CaS compound for substrate temperatures below 350 °C. It is shown that the crystallinity of the sprayed thin films can be improved by increasing substrate temperature up to 250 °C. Warren-Averbach analysis has been applied on X-ray diffractogram to determine structural parameters involving the phase with its amount, the grain size and the lattice parameters using Maud software. The surface topography shows a rough surface covered by densely packed agglomerated clusters having faceted and hexagonal shapes. Energy dispersive microscopy measurements confirm the presence of calcium and sulfur in equal proportions as well as high percentage of oxygen. Photoluminescence at room temperature revealed that luminescence peaks are attributed to the intrinsic emission of pure CaSO{sub 4} phase. - Highlights: • Warren Averbach analysis reveal the presence of hcp structure of CaSO{sub 4} phase. • A mixture of CaSO{sub 4} and CaHO{sub 4.5}S phases has been detected for lower T{sub s}. • For increasing T{sub s}, the CaHO{sub 4.5}S phase has been disappeared. • The origin of PL peaks has been identified.

  12. Fabrication and characterization of powder metallurgy tantalum components prepared by high compaction pressure technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youngmoo [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Agency for Defense Development, Yuseong, P.O. Box 35, Yuseong-gu, Daejeon 34186, Republic of Korea. (Korea, Republic of); Lee, Dongju [Korea Atomic Energy Research Institute, 111 Daedeok-daero, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Hwang, Jaewon [Samsung Electronics, 129 Samsung-ro, Youngtong-gu, Suwon 16677 (Korea, Republic of); Ryu, Ho Jin, E-mail: hojinryu@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Hong, Soon Hyung, E-mail: shhong@kaist.ac.kr [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of)

    2016-04-15

    The present study has investigated the consolidation behaviors of tantalum powders during compaction and sintering, and the characteristics of sintered components. For die compaction, the densification behaviors of the powders are simulated by finite element analyses based on the yield function proposed by Shima and Oyane. Accordingly, the green density distribution for coarser particles is predicted to be more uniform because they exhibits higher initial relative tap density owing to lower interparticle friction. It is also found that cold isostatic pressing is capable of producing higher dense compacts compared to the die pressing. However, unlike the compaction behavior, the sintered density of smaller particles is found to be higher than those of coarser ones owing to their higher specific surface area. The maximum sintered density was found to be 0.96 of theoretical density where smaller particles were pressed isostatically at 400 MPa followed by sintering at 2000 °C. Moreover, the effects of processing conditions on grain size and texture were also investigated. The average grain size of the sintered specimen is 30.29 μm and its texture is less than 2 times random intensity. Consequently, it is concluded that the higher pressure compaction technique is beneficial to produce high dense and texture-free tantalum components compared to hot pressing and spark plasma sintering. - Highlights: • Higher Ta density is obtained from higher pressure and sintering temperature. • High compaction method enables P/M Ta to achieve the density of 16.00 g·cm{sup −3}. • A P/M Ta component with fine microstructure and random orientation is developed.

  13. Fabrication of CdS/CdTe-Based Thin Film Solar Cells Using an Electrochemical Technique

    Directory of Open Access Journals (Sweden)

    I. M. Dharmadasa

    2014-06-01

    Full Text Available Thin film solar cells based on cadmium telluride (CdTe are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n → p or p → n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV effect as well as making use of IR photons from the surroundings when fully optimised.

  14. Rapid fabricating technique for multi-layered human hepatic cell sheets by forceful contraction of the fibroblast monolayer.

    Directory of Open Access Journals (Sweden)

    Yusuke Sakai

    Full Text Available Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions.

  15. Alternative Constraint Handling Technique for Four-Bar Linkage Path Generation

    Science.gov (United States)

    Sleesongsom, S.; Bureerat, S.

    2018-03-01

    This paper proposes an extension of a new concept for path generation from our previous work by adding a new constraint handling technique. The propose technique was initially designed for problems without prescribed timing by avoiding the timing constraint, while remain constraints are solving with a new constraint handling technique. The technique is one kind of penalty technique. The comparative study is optimisation of path generation problems are solved using self-adaptive population size teaching-learning based optimization (SAP-TLBO) and original TLBO. In this study, two traditional path generation test problem are used to test the proposed technique. The results show that the new technique can be applied with the path generation problem without prescribed timing and gives better results than the previous technique. Furthermore, SAP-TLBO outperforms the original one.

  16. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

    OpenAIRE

    Isabel Eleanor Moore; Kevin Joseph Murphy

    2015-01-01

    Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS) river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that...

  17. Alternative technique of cervical spinal stabilization employing lateral mass plate and screw and intra-articular spacer fixation

    Directory of Open Access Journals (Sweden)

    Atul Goel

    2013-01-01

    Full Text Available Aim: The author discusses an alternative technique of segmental cervical spinal fixation. Material and Methods: The subtleties of the technique are discussed on the basis of experience with 3 cases with a follow-up of between 30 and 36 months. Technique: The technique involves debridement of facetal articular cartilage, distraction of facets, jamming of ′Goel spacer′ into the articular cavity and fortification of the fixation by lateral mass plate and screw fixation. The ′double-insurance′ method of fixation is safe for vertebral artery, nerve roots and spinal neural structures and the fixation is strong. Conclusions: The discussed technique is safe and provides a strong fixation and a ground for ultimate arthrodesis.

  18. Comparison of Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor thin films fabricated by the spin coating and radio frequency magnetron techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jafer, R.M.; Yousif, A. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, Postal Code 11115 Omdurman (Sudan); Kumar, Vinod [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Photovoltaic Laboratory, Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India); Pathak, Trilok Kumar [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Semiconductor Physics Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Purohit, L.P. [Semiconductor Physics Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Coetsee, E., E-mail: CoetseeE@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa)

    2016-09-15

    The reactive radio-frequency (RF) magnetron sputtering and spin coating fabrication techniques were used to fabricate Y{sub 2−x}O{sub 3}:Bi{sub x=0.5%} phosphor thin films. The two techniques were analysed and compared as part of investigations being done on the application of down-conversion materials for a Si solar cell. The morphology, structural and optical properties of these thin films were investigated. The X-ray diffraction results of the thin films fabricated by both techniques showed cubic structures with different space groups. The optical properties showed different results because the Bi{sup 3+} ion is very sensitive towards its environment. The luminescence results for the thin film fabricated by the spin coating technique is very similar to the luminescence observed in the powder form. It showed three obvious emission bands in the blue and green regions centered at about 360, 410 and 495 nm. These emissions were related to the {sup 3}P{sub 1}–{sup 1}S{sub 0} transition of the Bi{sup 3+} ion situated in the two different sites of the Y{sub 2}O{sub 3} matrix with I a-3(206) space group. Whereas the thin film fabricated by the radio frequency magnetron technique showed a broad single emission band in the blue region centered at about 416 nm. This was assigned to the {sup 3}P{sub 1}–{sup 1}S{sub 0} transition of the Bi{sup 3+} ion situated in one of the Y{sub 2}O{sub 3} matrix's sites with a Fm-3 (225) space group. The spin coating fabrication technique is suggested to be the best technique to fabricate the Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor thin films. - Highlights: • RF sputtering and spin coating were used to fabricate Y{sub 2−x}O{sub 3}:Bi{sub x=0.5%} phosphor thin films. • XRD results of the two films showed cubic structures with different space groups. • PL showed different emission for the Bi{sup 3+} ions in the two films. • Three emission bands in the blue and green regions centered at about 360, 410 and 495 nm. • RF

  19. Facing the rain after the phase out: Performance evaluation of alternative fluorinated and non-fluorinated durable water repellents for outdoor fabrics.

    Science.gov (United States)

    Schellenberger, S; Gillgard, P; Stare, A; Hanning, A; Levenstam, O; Roos, S; Cousins, I T

    2018-02-01

    Fluorinated durable water repellent (DWR) agents are used to obtain water and stain repellent textiles. Due to the on-going phase-out of DWRs based on side-chain fluorinated polymers (SFP) with "long" perfluoroalkyl chains, the textile industry lacks suitable alternatives with comparable material characteristics. The constant development and optimization of SFPs for textile applications initiated more than half a century ago has resulted in a robust and very efficient DWR-technology and textiles with exceptional hydro- and oleo-phobic properties. The industry is now in the predicament that the long-chain SFPs with the best technical performance have undesirable toxicological and environmental behaviour. This study provides a comprehensive overview of the technical performance of presently available fluorinated and non-fluorinated DWRs as part of a chemical alternatives assessment (CAA). The results are based on a study with synthetic outdoor fabrics treated with alternative DWRs and tested for repellency using industrial standard and complementary methods. Using this approach, the complex structure-property relationships of DWR-polymers could be explained on a molecular level. Both short-chain SFPs and non-fluorinated DWRs showed excellent water repellency and durability in some cases while short-chain SFPs were the more robust of the alternatives to long-chain SFPs. A strong decline in oil repellency and durability with perfluoroalkyl chain length was shown for SFP DWRs. Non-fluorinated alternatives were unable to repel oil, which might limit their potential for substitution in textile application that require repellency towards non-polar liquids. Copyright © 2017. Published by Elsevier Ltd.

  20. An economic analysis of alternative fertility control and associated management techniques for three BLM wild horse herds

    Science.gov (United States)

    Bartholow, John M.

    2004-01-01

    Contemporary cost projections were computed for several alternative strategies that could be used by BLM to manage three wild horse populations. The alternatives included existing gather and selective removal methods, combined with potential contraceptive applications of varying duration and other potentially useful management techniques. Costs were projected for a 20-year economic life using the Jenkins wild horse population model and cost estimates from BLM that reflect state-by-state per horse removal, adoption, long-term holding, and contraceptive application expenses. Important findings include: Application of currently available 2-year contraceptives appears capable of reducing variable operating costs for wild horse populations by about 21% on average.

  1. Polymer Waveguide Fabrication Techniques

    Science.gov (United States)

    Ramey, Delvan A.

    1985-01-01

    The ability of integrated optic systems to compete in signal processing aplications with more traditional analog and digital electronic systems is discussed. The Acousto-Optic Spectrum Analyzer is an example which motivated the particular work discussed herein. Provided real time processing is more critical than absolute accuracy, such integrated optic systems fulfill a design need. Fan-out waveguide arrays allow crosstalk in system detector arrays to be controlled without directly limiting system resolution. A polyurethane pattern definition process was developed in order to demonstrate fan-out arrays. This novel process is discussed, along with further research needs. Integrated optic system market penetration would be enhanced by development of commercial processes of this type.

  2. Biodegradable Poly(Lactic Acid/Multiwalled Carbon Nanotube Nanocomposite Fabrication Using Casting And Hot Press Techniques

    Directory of Open Access Journals (Sweden)

    Park S.G.

    2015-06-01

    Full Text Available Biodegradable advanced polymer composites have recently received a large amount of attention. The present study aimed to design poly(lactic acid multiwalled carbon nanotube nanocomposites (PLA/MWCNTs using a simple fabrication technique. A PLA sheet was first dissolved in dichloromethane, and MWCNTs were subsequently added at various concentrations (0.5, 1.5 and 5% while applying shear strain stirring to achieve dispersion of carbon nanotubes (CNTs. These solutions were then molded and a hot press was used to generate sheets free of voids with entrapped solvent. The prepared samples were characterized using field emission scanning electron microscopy (FE-SEM, x-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and thermogravimetric analysis (TGA. Our data showed composite samples free of defects and voids, indicating that the hot press is capable of generating sufficiently compact polymer matrices. Additionally, TGA and FTIR showed significant bonding interactions between the PLA matrix and the nano-fillers. Collectively, our results suggest that incorporation of CNTs as nano-fillers into biodegradable polymers may have multiple applications in many different sectors.

  3. A novel approach to fabricate dye-encapsulated polymeric micro- and nanoparticles by thin film dewetting technique.

    Science.gov (United States)

    Chatterjee, Manosree; Hens, Abhiram; Mahato, Kuldeep; Jaiswal, Namita; Mahato, Nivedita; Nagahanumaiah; Chanda, Nripen

    2017-11-15

    A new method is reported for fabrication of polymeric micro- and nanoparticles from an intermediate patterned surface originated by dewetting of a polymeric thin film. Poly (d, l-lactide-co-glycolide) or PLGA, a biocompatible polymer is used to develop a thin film over a clean glass substrate which dewets spontaneously in the micro-/nano-patterned surface of size range 50nm to 3.5µm. Since another water-soluble polymer, poly vinyl alcohol (PVA) is coated on the same glass substrate before PLGA thin film formation, developed micro-/nano-patterns are easily extracted in water in the form of micro- and nanoparticle mixture of size range 50nm to 3.0µm. This simplified method is also used to effectively encapsulate a dye molecule, rhodamine B inside the PLGA micro-/nanoparticles. The developed dye-encapsulated nanoparticles, PLGA-rhodamine are separated from the mixture and tested for in-vitro delivery application of external molecules inside human lung cancer cells. For the first time, the use of thin film dewetting technique is reported as a potential route for the synthesis of polymeric micro-/nanoparticles and effective encapsulation of external species therein. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Modified two-step emulsion solvent evaporation technique for fabricating biodegradable rod-shaped particles in the submicron size range.

    Science.gov (United States)

    Safari, Hanieh; Adili, Reheman; Holinstat, Michael; Eniola-Adefeso, Omolola

    2018-05-15

    Though the emulsion solvent evaporation (ESE) technique has been previously modified to produce rod-shaped particles, it cannot generate small-sized rods for drug delivery applications due to the inherent coupling and contradicting requirements for the formation versus stretching of droplets. The separation of the droplet formation from the stretching step should enable the creation of submicron droplets that are then stretched in the second stage by manipulation of the system viscosity along with the surface-active molecule and oil-phase solvent. A two-step ESE protocol is evaluated where oil droplets are formed at low viscosity followed by a step increase in the aqueous phase viscosity to stretch droplets. Different surface-active molecules and oil phase solvents were evaluated to optimize the yield of biodegradable PLGA rods. Rods were assessed for drug loading via an imaging agent and vascular-targeted delivery application via blood flow adhesion assays. The two-step ESE method generated PLGA rods with major and minor axis down to 3.2 µm and 700 nm, respectively. Chloroform and sodium metaphosphate was the optimal solvent and surface-active molecule, respectively, for submicron rod fabrication. Rods demonstrated faster release of Nile Red compared to spheres and successfully targeted an inflamed endothelium under shear flow in vitro and in vivo. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Fabrication and characterisation of ligand-functionalised ultrapure monodispersed metal nanoparticle nanoassemblies employing advanced gas deposition technique

    Science.gov (United States)

    Geremariam Welearegay, Tesfalem; Cindemir, Umut; Österlund, Lars; Ionescu, Radu

    2018-02-01

    Here, we report for the first time the fabrication of ligand-functionalised ultrapure monodispersed metal nanoparticles (Au, Cu, and Pt) from their pure metal precursors using the advanced gas deposition technique. The experimental conditions during nanoparticle formation were adjusted in order to obtain ultrafine isolated nanoparticles on different substrates. The morphology and surface analysis of the as-deposited metal nanoparticles were investigated using scanning electron microscopy, x-ray diffraction and Fourier transform infra-red spectroscopy, which demonstrated the formation of highly ordered pure crystalline nanoparticles with a relatively uniform size distribution of ∼10 nm (Au), ∼4 nm (Cu) and ∼3 nm (Pt), respectively. A broad range of organic ligands containing thiol or amine functional groups were attached to the nanoparticles to form continuous networks of nanoparticle-ligand nanoassemblies, which were characterised by scanning electron microscopy and x-ray photoelectron spectroscopy. The electrical resistance of the functional nanoassemblies deposited in the gap spacing of two microfabricated parallel Au electrodes patterned on silicon substrates ranged between tens of kΩ and tens of MΩ, which is suitable for use in many applications including (bio)chemical sensors, surface-enhanced Raman spectroscopy and molecular electronic rectifiers.

  6. Highly conducting and crystalline doubly doped tin oxide films fabricated using a low-cost and simplified spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K., E-mail: kkr1365@yahoo.co [P.G. and Research Department of Physics, AVVM. Sri Pushpum College, Poondi, Thanjavur District, Tamil Nadu 613503 (India); Muruganantham, G.; Sakthivel, B. [P.G. and Research Department of Physics, AVVM. Sri Pushpum College, Poondi, Thanjavur District, Tamil Nadu 613503 (India)

    2009-11-15

    Doubly doped (simultaneous doping of antimony and fluorine) tin oxide films (SnO{sub 2}:Sb:F) have been fabricated by employing an inexpensive and simplified spray technique using perfume atomizer from aqueous solution of SnCl{sub 2} precursor. The structural studies revealed that the films are highly crystalline in nature with preferential orientation along the (2 0 0) plane. It is found that the size of the crystallites of the doubly doped tin oxide films is larger (69 nm) than that (27 nm) of their undoped counterparts. The dislocation density of the doubly doped film is lesser (2.08x10{sup 14} lines/m{sup 2}) when compared with that of the undoped film (13.2x10{sup 14} lines/m{sup 2}), indicating the higher degree of crystallinity of the doubly doped films. The SEM images depict that the films are homogeneous and uniform. The optical transmittance in the visible range and the optical band gap of the doubly doped films are 71% and 3.56 eV respectively. The sheet resistance (4.13 OMEGA/square) attained for the doubly doped film in this study is lower than the values reported for spray deposited fluorine or antimony doped tin oxide films prepared from aqueous solution of SnCl{sub 2} precursor (without using methanol or ethanol).

  7. Colour Fastness and Tensile Strength of Cotton Fabric Dyed with Natural Extracts of Alkanna tinctoria by Continuous Dyeing Technique

    International Nuclear Information System (INIS)

    Khattak, S. P.; Rafique, S.; Inayat, F.; Ahmad, B.

    2015-01-01

    A natural dye extracted from the roots of alkanet (Alkanna tinctoria) was applied on cotton fabric by pad-steam dyeing technique. The study was designed to evaluate the colour fastness and tensile properties of dyed cotton after using various mordants, cationizing agents, UV absorbers and crosslinkers with this natural dye. Metallic mordants included aluminium sulphate, copper sulphate, ferric chloride, potassium dichromate and hydrated potassium aluminum sulphate or alum. Alkanet root extract produced variety of green shades with different dyeing auxiliaries. Better wash, light, crocking fastness; good colour coordinates such as chroma, hue, colour strength and increase in tensile strength was accomplished with post-mordanting of CuSO/sub 4/. Cationization of cotton with quaternary ammonium compound (both pre-treatment and post-treatment) and post-finishing with soft polyurethane emulsion has enhanced the fastness properties, tensile strength as well as relative colour strength (K/S) , whereas, reactive UV absorber based on oxalanilide and heterocyclic compound as UV absorber greatly increased the light fastness of alkanet dyed cotton. Crosslinkers applied with alkanet dye on cotton (methylolation product based on glyoxalmonourein, modified dimethyloldihydroxyethylene urea, modified dihydroxy ethylene urea) also improved the fastness but could not bring further development in the shade and K/S value of the dyed sample. (author)

  8. The electrocatalytic oxidation of carbohydrates at a nickel/carbon paper electrode fabricated by the filtered cathodic vacuum arc technique

    International Nuclear Information System (INIS)

    Fu, Yingyi; Wang, Tong; Su, Wen; Yu, Yanan; Hu, Jingbo

    2015-01-01

    The direct electrochemical behaviour of carbohydrates at a nickel/carbon paper electrode with a novel fabrication method is investigated. The investigation is used for verification the feasibility of using monosaccharides and disaccharides in the application of fuel cell. The selected monosaccharides are glucose, fructose and galactose; the disaccharides are sucrose, maltose and lactose. The modified nickel/carbon paper electrode was prepared using a filtered cathodic vacuum arc technique. The morphology image of the nickel thin film on the carbon paper surface was characterized by scanning electron microscopy (SEM). The existence of nickel was verified by X-ray photoelectron spectroscopy (XPS). The contact angle measurement was also used to characterize the modified electrode. Cyclic voltammetry (CV) was employed to evaluate the electrochemical behaviour of monosaccharides and disaccharides in an alkaline aqueous solution. The modified electrode exhibits good electrocatalytic activities towards carbohydrates. In addition, the stability of the nickel/carbon paper electrode with six sugars was also investigated. The good catalytic effects of the nickel/carbon paper electrode allow for the use of carbohydrates as fuels in fuel cell applications

  9. Review on the Photocatalyst Coatings of TiO2: Fabrication by Mechanical Coating Technique and Its Application

    Directory of Open Access Journals (Sweden)

    Yun Lu

    2015-07-01

    Full Text Available This review presents the latest results of studies directed at photocatalyst coatings of titanium dioxide (TiO2 prepared by mechanical coating technique (MCT and its application. Compared with traditional coating techniques, MCT is a simple, low cost and useful coating formation process, which is proposed and developed based on mechanical frictional wear and impacts between substrate materials and metal powder particles in the bowl of planetary ball mill. The formation process of the metal coatings in MCT includes four stages: The nucleation by adhesion, the formation and coalescence of discrete islands, formation and thickening of continuous coatings, exfoliation of continuous coatings. Further, two-step MCT was developed based on the MCT concept for preparing composite coatings on alumina (Al2O3 balls. This review also discusses the influence on the fabrication of photocatalyst coatings after MCT and improvement of its photocatalytic activity: oxidation conditions, coating materials, melt salt treatment. In this review, the oxidation conditions had been studied on the oxidation temperature of 573 K, 673 K, 773 K, 873 K, 973 K, 1173 K and 1273 K, the oxidation time of 0.5 h, 1 h, 3 h, 10 h, 15 h, 20 h, 30 h, 40 h, and 50 h. The photocatalyst coatings showed the highest photocatalytic activity with the oxidation condition of 1073 K for 15 h. The metal powder of Ti, Ni and Cr had been used as the coating materials. The composite metal powder could affect the surface structure and photocatalytic activity. On the other hand, the melt salt treatment with KNO3 is an effective method to form the nano-size structure and enhance photocatalytic activity, especially under visible light.

  10. Fabrication of divertor mock-up with ODS-Cu and W by the improved brazing technique

    Science.gov (United States)

    Tokitani, M.; Hamaji, Y.; Hiraoka, Y.; Masuzaki, S.; Tamura, H.; Noto, H.; Tanaka, T.; Muroga, T.; Sagara, A.; FFHR Design Group

    2017-07-01

    Copper alloy has been considered as a divertor cooling tube or heat sink not only in the helical reactor FFHR-d1 but also in the tokamak DEMO reactor, because it has a high thermal conductivity. This work focused on applying an oxide dispersion strengthened copper alloy (ODS-Cu), GlidCop® (Cu-0.3 wt%Al2O3) as the divertor heat sink material of FFHR-d1. This alloy has superior high temperature yield strength exceeding 300 MPa at room temperature even after annealing up to ~1000 °C. The change in material properties of Pure-Cu, GlidCop® and CuCrZr by neutron irradiation are summarized in this paper. A primary dose limit is the radiation-induced hardening/softening (~0.2 dpa/1-2 dpa) which has a temperature dependence. According to such an evaluation, the GlidCop® can be selected as the current best candidate material in the commercial base of the divertor heat sink, and its temperature should be maintained as close as possible to 300 °C during operation. Bonding between the W armour and the GlidCop® heat sink was successfully performed by using an improved brazing technique with BNi-6 (Ni-11%P) filler material. The bonding strength was measured by a three-point bending test and reached up to approximately 200 MPa. Surprisingly, several specimens showed an obvious yield point. This means that the BNi-6 brazing (bonding) layer caused relaxation of the applied stress. The small-scale divertor mock-up of the W/BNi-6/GlidCop® was successfully fabricated by using the improved brazing technique. The heat loading test was carried out by the electron beam device ACT2 in NIFS. The mock-up showed an excellent heat removal capability for use in the FFHR-d1 divertor.

  11. Marginal and internal fit of cobalt-chromium copings fabricated using the conventional and the direct metal laser sintering techniques: A comparative in vitro study

    Directory of Open Access Journals (Sweden)

    Sujana Ullattuthodi

    2017-01-01

    Conclusions: Within the limitations of this in vitro study, it was concluded that the internal fit of conventional copings was superior to that of the DMLS copings. Marginal fit of the copings fabricated by two different techniques had no significant difference.

  12. Using Alternative Teaching Techniques To Enhance Student Performance in the Traditional Introductory Public Relations Course.

    Science.gov (United States)

    Lubbers, Charles A.

    2002-01-01

    Examines the value of two alternative tools as supplements for the traditional introduction to public relations course. Considers the usage of a study manual, usage of televised review sessions, year in school and major status. Indicates that all four variables are significantly correlated with class performance, but that the study manual explains…

  13. Selected Alternative Training Techniques in HRD. [and] Invited Reaction. [and] Final Word: A Rejoinder.

    Science.gov (United States)

    Von Bergen, C. W.; Soper, Barlow; Rosenthal, Gary T.; Wilkinson, Lamar V.; Watkins, Karen E.

    1997-01-01

    Von Bergen, Soper, Rosenthal, and Wilkinson examine four alternative training methods (subliminal self-help, meditation, mental imagery/practice, and neurolinguistic programming), concluding that only mental practice is supported by scientific evidence. Watkins takes issue with their dismissal of qualitative evidence. Their rejoinder asserts the…

  14. Two-step impression/ injection, an alternative putty/ wash impression technique: case report.

    Science.gov (United States)

    Caputi, S; Murmura, G; Sinjari, B; Varvara, G

    2012-01-01

    We here describe a new technique for making a definitive impression that we refer to as the two-step impression/injection technique. This technique initially follows the classical one-step putty/ light-body impression technique with the polymerization of the putty and the light-body compound. This is then followed by the second step: injection of extra-light-body compound into the preparation through a hole in the metal stock tray. The aim of this additional step is to control the wash bulk and minimize the changes that can produce unfavorable impression results. This new two-step impression/injection technique allows displacement of soft tissues, such as the tongue, during the first seating of the putty and wash materials, while in the second step, the extra-light-body compound records all of the finer details without being compressed.

  15. High luminescent fibers with hybrid SiO2-coated CdTe nanocrystals fabricated by electrospinning technique

    International Nuclear Information System (INIS)

    Cao, Yongqiang; Liu, Ning; Yang, Ping; Shi, Ruixia; Ma, Qian; Zhang, Aiyu; Zhu, Yuanna; Wang, Junpeng; Wang, Jianrong

    2015-01-01

    The polyvinylpyrrolidone (PVP) hybrid luminescent micro-/nanofibers doped with the novel hybrid SiO 2 -coated CdTe nanocrystals (HS-CdTe NCs) have been fabricated for the first time via the electrospinning technique. The morphologies and photoluminescence (PL) emissions of HS-CdTe/PVP micro-/nanofibers prepared by doping the HS-CdTe NCs with the different PL peak wavelength (571, 616, and 643 nm) in PVP fibers were investigated by optical and PL microscope. The results revealed that all the HS-CdTe/PVP hybrid fibers showed an ultralong length for several hundreds of micrometers and a relatively uniform diameter of 1000 ∼ 1200 nm. The hybrid fibers displayed a wavelength-tunable PL emission, determining by the PL of doped HS-CdTe NCs. Moreover, similar to the original PL properties of HS-CdTe NCs before the electrospinning, the HS-CdTe/PVP fibers also showed a series of superior PL properties, such as narrow and symmetry PL spectrum, high, and uniform brightness. For comparison purpose, we also prepared three CdTe/PVP hybrid fibers by doping the 553 nm, 600 nm, and 633 nm PL-emitting CdTe NCs respectively in PVP electrospinning fibers. The characterization results showed that, the obtained three CdTe/PVP hybrid fibers had a basically satisfactory micro-/nanofiber morphology with a long length and relatively uniform diameter, but all the fibers exhibited very weak PL emissions. The enormous contrast in PL properties between HS-CdTe/PVP and CdTe/PVP fibers should mainly be ascribed to the different connection modes of ligands with the NCs and the passivation effect of inert hybrid silica shell on HS-CdTe. It is hopeful that the high luminescent HS-CdTe/PVP micro-/nanofibers with the tunable PL peak wavelength would be a good candidate in the optical sensor, light-emitting devices (LEDs), nanometer-scale waveguides, and the other related photonic materials. - Highlights: • The HS-CdTe/PVP electrospun hybrid fibers were fabricated for the first time. • The

  16. Metal-ceramic bond strength between a feldspathic porcelain and a Co-Cr alloy fabricated with Direct Metal Laser Sintering technique.

    Science.gov (United States)

    Dimitriadis, Konstantinos; Spyropoulos, Konstantinos; Papadopoulos, Triantafillos

    2018-02-01

    The aim of the present study was to record the metal-ceramic bond strength of a feldspathic dental porcelain and a Co-Cr alloy, using the Direct Metal Laser Sintering technique (DMLS) for the fabrication of metal substrates. Ten metal substrates were fabricated with powder of a dental Co-Cr alloy using DMLS technique (test group) in dimensions according to ISO 9693. Another ten substrates were fabricated with a casing dental Co-Cr alloy using classic casting technique (control group) for comparison. Another three substrates were fabricated using each technique to record the Modulus of Elasticity ( E ) of the used alloys. All substrates were examined to record external and internal porosity. Feldspathic porcelain was applied on the substrates. Specimens were tested using the three-point bending test. The failure mode was determined using optical and scanning electron microscopy. The statistical analysis was performed using t-test. Substrates prepared using DMLS technique did not show internal porosity as compared to those produced using the casting technique. The E of control and test group was 222 ± 5.13 GPa and 227 ± 3 GPa, respectively. The bond strength was 51.87 ± 7.50 MPa for test group and 54.60 ± 6.20 MPa for control group. No statistically significant differences between the two groups were recorded. The mode of failure was mainly cohesive for all specimens. Specimens produced by the DMLS technique cover the lowest acceptable metal-ceramic bond strength of 25 MPa specified in ISO 9693 and present satisfactory bond strength for clinical use.

  17. Towards ABET accreditation for a SWE program: alternative student assessment techniques

    International Nuclear Information System (INIS)

    Alghamdi, A.; Nasir, M.; Alnafjan, K.

    2011-01-01

    This paper describes assessment techniques utilized for assessing undergraduate students studying in a software engineering program. The purpose behind this work is to get the program accredited by the Accreditation Board of Engineering and Technology (ABET). Therefore, a number of applied direct and indirect assessment techniques are described. These techniques are implemented towards the end of the semester to assess the extent to which the student and course outcomes are satisfied. Consequently, results are obtained and analyzed and various learning issues are eventually identified. Finally, the paper provides suggestions for improvement in course delivery as well as learning mechanism. (author)

  18. Clinical acceptability of metal-ceramic fixed partial dental prosthesis fabricated with direct metal laser sintering technique-5 year follow-up.

    Science.gov (United States)

    Prabhu, Radhakrishnan; Prabhu, Geetha; Baskaran, Eswaran; Arumugam, Eswaran M

    2016-01-01

    In recent years, direct metal laser sintered (DMLS) metal-ceramic-based fixed partial denture prostheses have been used as an alternative to conventional metal-ceramic fixed partial denture prostheses. However, clinical studies for evaluating their long-term clinical survivability and acceptability are limited. The aim of this study was to assess the efficacy of metal-ceramic fixed dental prosthesis fabricated with DMLS technique, and its clinical acceptance on long-term clinical use. The study group consisted of 45 patients who were restored with posterior three-unit fixed partial denture prosthesis made using direct laser sintered metal-ceramic restorations. Patient recall and clinical examination of the restorations were done after 6months and every 12 months thereafter for the period of 60 months. Clinical examination for evaluation of longevity of restorations was done using modified Ryge criteria which included chipping of the veneered ceramic, connector failure occurring in the fixed partial denture prosthesis, discoloration at the marginal areas of the veneered ceramic, and marginal adaptation of the metal and ceramic of the fixed denture prosthesis. Periapical status was assessed using periodical radiographs during the study period. Survival analysis was made using the Kaplan-Meier method. None of the patients had failure of the connector of the fixed partial denture prostheses during the study period. Two exhibited biological changes which included periapical changes and proximal caries adjacent to the abutments. DMLS metal-ceramic fixed partial denture prosthesis had a survival rate of 95.5% and yielded promising results during the 5-year clinical study.

  19. Investigation of the effects of particle size on the mechanical properties of porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique

    International Nuclear Information System (INIS)

    Noman, A.

    1978-12-01

    An investigation was made of the influence of particle size on the properties of both porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique. The residual porosity, extrusion pressure, tensile strength, and ductility were found to be dependent on the particle size distribution. All of these parameters were found to increase with increasing particle size. The influence of sintering time at a temperature of 2250 0 C was also studied. With increasing sintering time, the residual porosity and tensile strength decreased, whereas the ductility increased. The procedures for fabricating infiltrated niobium rods and the various tests employed to determine their properties are described

  20. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    Science.gov (United States)

    Li, Yuting; Gan, Fangji; Wan, Zhengjun; Liao, Junbi; Li, Wenqiang

    2015-10-01

    Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  1. Surgical closure of persistent arterial duct with minimal invasive anterior thoracotomy: an alternative technique.

    Science.gov (United States)

    Fouilloux, Virginie; Gran, Célia; Kreitmann, Bernard

    2014-10-01

    Surgical approach for persistent ductus arteriosus ligation is typically a left lateral thoracotomy opening the pleural-space with left lung retraction. We describe an alternative approach, with a minimally invasive anterior parasternal incision. This is particularly adapted to preterm infants weighing less than 1.5 kg. This approach ensures a good exposure of vessels. We believe that it is safe, reliable and reproducible. The learning curve should not be an issue for surgeons used to manage low weight patients. Georg Thieme Verlag KG Stuttgart · New York.

  2. LCA of pork products & evaluation of alternative super-chilling techniques

    DEFF Research Database (Denmark)

    Bonou, Alexandra; Birkved, Morten

    after cooling technologies, which affect the products’ shelf life: The purpose is to identify the technology leading to least environmental impacts in a life cycle perspective; also to facilitate a benchmarking of these technologies relative to existing after-cooling approaches i.e. freezing.......This LCA study has two aims: 1) The environmental assessment of Danish pork products (Danish Landrace breed): The purpose is to put the pork production system into perspective and to identify the relative contribution of different life cycle stages; 2) The comparative assessment of alternative...

  3. An Alternative Technique for Cementation of Cast Post and Core Restoration

    Directory of Open Access Journals (Sweden)

    Bhushan Satish Gaikwad

    2015-01-01

    Full Text Available Cementation of cast post and core restoration involves the application of luting cement in the prepared post space which is intra radicular. Commonly an endodontic instrument, lentulo spiral, and rotary hand piece at slow speed is used. Occasionally, the luting cement does not reach the base or is not uniformly spread on to the walls of the prepared post space. The inefficiency of the luting cement to cover all the surfaces of the prepared post space results in a compromised post and core treatment. An alternate procedure using a disposable syringe and needle has been described to achieve better results.

  4. The fabrication of well-interconnected polycaprolactone/hydroxyapatite composite scaffolds, enhancing the exposure of hydroxyapatite using the wire-network molding technique.

    Science.gov (United States)

    Cho, Yong Sang; Hong, Myoung Wha; Jeong, Hoon-Jin; Lee, Seung-Jae; Kim, Young Yul; Cho, Young-Sam

    2017-11-01

    In this study, the fabrication method was proposed for the well-interconnected polycaprolactone/hydroxyapatite composite scaffold with exposed hydroxyapatite using modified WNM technique. To characterize well-interconnected scaffolds in terms of hydroxyapatite exposure, several assessments were performed as follows: morphology, mechanical property, wettability, calcium ion release, and cell response assessments. The results of these assessments were compared with those of control scaffolds which were fabricated by precision extruding deposition (PED) apparatus. The control PED scaffolds have interconnected pores with nonexposed hydroxyapatite. Consequently, cell attachment of proposed WNM scaffold was improved by increased hydrophilicity and surface roughness of scaffold surface resulting from the exposure of hydroxyapatite particles and fabrication process using powders. Moreover, cell proliferation and differentiation of WNM scaffold were increased, because the exposure of hydroxyapatite particles may enhance cell adhesion and calcium ion release. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2315-2325, 2017. © 2016 Wiley Periodicals, Inc.

  5. The Suprameatal Approach: A Safe Alternative Surgical Technique for Cochlear Implantation

    NARCIS (Netherlands)

    Postelmans, Job T. F.; Tange, Rinze A.; Stokroos, Robert J.; Grolman, Wilko

    2010-01-01

    Objective: To report on surgical complications arising post-operatively in 104 patients undergoing cochlear implantation surgery using the suprameatal approach (SMA). Second, to examine the advantages and disadvantages of the SMA technique compared with the classic mastoidectomy using the posterior

  6. Propensity Score Estimation with Data Mining Techniques: Alternatives to Logistic Regression

    Science.gov (United States)

    Keller, Bryan S. B.; Kim, Jee-Seon; Steiner, Peter M.

    2013-01-01

    Propensity score analysis (PSA) is a methodological technique which may correct for selection bias in a quasi-experiment by modeling the selection process using observed covariates. Because logistic regression is well understood by researchers in a variety of fields and easy to implement in a number of popular software packages, it has…

  7. Alternative Food Preservation Techniques, New Technology in Food Preparation and Appropriateness of Food Supply for the Permanently Manned Space Station

    Science.gov (United States)

    Whelan, R. H.

    1985-01-01

    Alternative food preservation techniques are defined as unique processes and combinations of currently used processes for food preservation. Food preservation is the extension of the useful shelf-life of normally perishable foods (from harvest to final consumption) by controlling micro-organisms, enzymes, chemical changes, changes in sensory characteristics and the prevention of subsequent recontamination. The resulting products must comply with all applicable food manufacturing practice regulations and be safe. Most of the foods currently used in both space and military feeding are stabilized either by dehydration or the use of a terminal sterilization process. Other available options would be formulation to reduce water activity, the refrigeration and freezing of perishable foods, chemical addition, and physical treatment (ionizing or nonionizing radiation or mechanical action). These alternatives are considered and proposals made.

  8. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

    Directory of Open Access Journals (Sweden)

    Isabel Eleanor Moore

    2015-06-01

    Full Text Available Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that produces similar results is necessary in order to collect data from a wide variety of habitats.MethodsBoth kick and dredge nets were used to collect macroinvertebrate samples at 16 riverine sites in Zambia, ranging from backwaters and floodplain lagoons to fast flowing streams and rivers. The data were used to calculate ZISS, diversity (S: number of taxa present, and Average Score Per Taxon (ASPT scores per site, using the two sampling methods to compare their sampling effectiveness. Environmental parameters, namely pH, conductivity, underwater photosynthetically active radiation (PAR, temperature, alkalinity, flow, and altitude, were also recorded and used in statistical analysis. Invertebrate communities present at the sample sites were determined using multivariate procedures.ResultsAnalysis of the invertebrate community and environmental data suggested that the testing exercise was undertaken in four distinct macroinvertebrate community types, supporting at least two quite different macroinvertebrate assemblages, and showing significant differences in habitat conditions. Significant correlations were found for all three bioassessment score variables between results acquired using the two methods, with dredge-sampling normally producing lower scores than did the kick net procedures. Linear regression models were produced in order to correct each biological variable score collected by a dredge net to a score similar to that of one collected by kick net

  9. Alternative management techniques for the uranium mill tailings site at Salt Lake City, UT

    International Nuclear Information System (INIS)

    Rogers, V.C.; Goldsmith, W.A.; Haywood, F.F.; Gantner, G.K.

    1976-01-01

    The concentrations of 226 Ra and other uranium-chain radionuclides present in tailings piles at uranium-milling sites are on the order of 10 3 times higher than those usually found in soil-surface minerals. The public radiation exposure attributable to these sites is primarily due to inhalation of 222 Rn progeny. This paper presents the radiological assessment of the uranium-milling site at Salt Lake City, Utah. Adverse health effects are estimated from present and projected public radiation exposures. Three alternative remedial action measures can be used to reduce radiation exposures: (1) decontamination of offsite areas contaminated by tailings materials; (2) covering the tailings with contamination-free material; and (3) removal of the tailings to a more remote location. These three measures are examined in terms of costs incurred and serious health effects avoided

  10. Standard practice for examination of welds using the alternating current field measurement technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes procedures to be followed during alternating current field measurement examination of welds for baseline and service-induced surface breaking discontinuities. 1.2 This practice is intended for use on welds in any metallic material. 1.3 This practice does not establish weld acceptance criteria. 1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system might not be exact equivalents; therefore, each system shall be used independently of the other. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  11. Laser ablation inductively coupled plasma mass spectrometry. An alternative technique for monitoring 90Sr

    International Nuclear Information System (INIS)

    TsingHai Wang; Yan-Chen Lai; Yi-Kong Hsieh; Chu-Fang Wang

    2017-01-01

    Developing a rapid detection method for monitoring released 90 Sr remains a challenge to analytical chemists, particularly considering its low concentration and significant interferences in environmental samples. We proposed a concept as an alternative to detect 90 Sr on the surface of fish scales using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The high affinity of fish scales to Sr is capable of preconcentrating 90 Sr that minimizes isobaric interferences from 90 Zr + or 89 YH + , while tailing effect by abundant 88 Sr can be effectively reduced by adjusting the forward power of ICP-MS component. Adopting dried droplets of internal standards further allows a semiquantification of 90 Sr content on the surface of fish scales, which also arises an opportunity to monitoring the bioaccumulation of 90 Sr after Fukushima Daiichi nuclear disaster. (author)

  12. Subcuticular Suture Technique: Alternative to Frost Suture to Prevent Ectropion After Transcutaneous Incision of Lower Eyelid.

    Science.gov (United States)

    Kudva, Adarsh; Kamath, Abhay; Cariappa, K M; Gadicherla, Srikanth; Dhara, B Vasantha

    2017-12-01

    An ectropion is a complication that can arise from reconstruction in the infraorbital region. Often, this complication occurs despite proper positioning of the lower lid at the time of closure. Various transcutaneous approaches to orbit skeleton have investigated in view of complication arising from them. A subtarsal approach with a postoperative Frost suture gives an advantage to reduce the occurrence of ectropion especially after treatment of orbital floor fractures. This case describes a method of subcuticular suturing technique for subtarsal incision of lower lid which can be used to support the lid during healing period, thus decreasing the rate of ectropion. The technique described here is an alterative method for frost suturing with certain advantages.

  13. Alternation Frequency Thresholds for Stereopsis as a Technique for Exploring Stereoscopic Difficulties

    Directory of Open Access Journals (Sweden)

    Svetlana Rychkova

    2011-01-01

    Full Text Available When stereoscopic images are presented alternately to the two eyes, stereopsis occurs at F ⩾ 1 Hz full-cycle frequencies for very simple stimuli, and F ⩾ 3 Hz full-cycle frequencies for random-dot stereograms (eg Ludwig I, Pieper W, Lachnit H, 2007 “Temporal integration of monocular images separated in time: stereopsis, stereoacuity, and binocular luster” Perception & Psychophysics 69 92–102. Using twenty different stereograms presented through liquid crystal shutters, we studied the transition to stereopsis with fifteen subjects. The onset of stereopsis was observed during a stepwise increase of the alternation frequency, and its disappearance was observed during a stepwise decrease in frequency. The lowest F values (around 2.5 Hz were observed with stimuli involving two to four simple disjoint elements (circles, arcs, rectangles. Higher F values were needed for stimuli containing slanted elements or curved surfaces (about 1 Hz increment, overlapping elements at two different depths (about 2.5 Hz increment, or camouflaged overlapping surfaces (> 7 Hz increment. A textured cylindrical surface with a horizontal axis appeared easier to interpret (5.7 Hz than a pair of slanted segments separated in depth but forming a cross in projection (8 Hz. Training effects were minimal, and F usually increased as disparities were reduced. The hierarchy of difficulties revealed in the study may shed light on various problems that the brain needs to solve during stereoscopic interpretation. During the construction of the three-dimensional percept, the loss of information due to natural decay of the stimuli traces must be compensated by refreshes of visual input. In the discussion an attempt is made to link our results with recent advances in the comprehension of visual scene memory.

  14. Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis

    International Nuclear Information System (INIS)

    Kuo, William T.; Cupp, John S.; Louie, John D.; Kothary, Nishita; Hofmann, Lawrence V.; Sze, Daniel Y.; Hovsepian, David M.

    2012-01-01

    Purpose: We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation. Methods: We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis. Results: Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Günther-Tulip (GTF; mean 606 days, range 154–1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196–529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens. Conclusion: Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.

  15. Alternative technique in atypical spinal decompression: the use of the ultrasonic scalpel in paediatric achondroplasia

    Science.gov (United States)

    Woodacre, Timothy; Sewell, Matthew; Clarke, Andrew J; Hutton, Mike

    2016-01-01

    Spinal stenosis can be a very disabling condition. Surgical decompression carries a risk of dural tear and neural injury, which is increased in patients with severe stenosis or an atypical anatomy. We present an unusual case of symptomatic stenosis secondary to achondroplasia presenting in a paediatric patient, and highlight a new surgical technique used to minimise the risk of dural and neural injury during decompression. PMID:27288205

  16. A rapid alternative technique for obtaining silver-positive patterns in chromosomes

    OpenAIRE

    Kavalco,Karine Frehner; Pazza,Rubens

    2004-01-01

    Silver nitrate chromosome staining to evidence nucleolar organizer regions (NORs) is a widely adopted methodology. The aim of the present work was to improve this technique, reducing the preparation time without decreasing the quality of the results. Microwave irradiation proved to be quite efficient and reliable for this purpose, as it allowed to identify Ag-NORs equivalent to those obtained by the conventional procedure and also to reduce the concentration of the employed reagents, as well ...

  17. Application of Freeman Chain Codes: An Alternative Recognition Technique for Malaysian Car Plates

    OpenAIRE

    Jusoh, Nor Amizam; Zain, Jasni Mohamad

    2011-01-01

    Various applications of car plate recognition systems have been developed using various kinds of methods and techniques by researchers all over the world. The applications developed were only suitable for specific country due to its standard specification endorsed by the transport department of particular countries. The Road Transport Department of Malaysia also has endorsed a specification for car plates that includes the font and size of characters that must be followed by car owners. Howev...

  18. On Alternative Approaches to 3D Image Perception: Monoscopic 3D Techniques

    Science.gov (United States)

    Blundell, Barry G.

    2015-06-01

    In the eighteenth century, techniques that enabled a strong sense of 3D perception to be experienced without recourse to binocular disparities (arising from the spatial separation of the eyes) underpinned the first significant commercial sales of 3D viewing devices and associated content. However following the advent of stereoscopic techniques in the nineteenth century, 3D image depiction has become inextricably linked to binocular parallax and outside the vision science and arts communities relatively little attention has been directed towards earlier approaches. Here we introduce relevant concepts and terminology and consider a number of techniques and optical devices that enable 3D perception to be experienced on the basis of planar images rendered from a single vantage point. Subsequently we allude to possible mechanisms for non-binocular parallax based 3D perception. Particular attention is given to reviewing areas likely to be thought-provoking to those involved in 3D display development, spatial visualization, HCI, and other related areas of interdisciplinary research.

  19. A novel and alternative approach to controlled release drug delivery system based on solid dispersion technique

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Giri

    2012-12-01

    Full Text Available The solid dispersion method was originally used to improve the dissolution properties and the bioavailability of poorly water soluble drugs by dispersing them into water soluble carriers. In addition to the above, dissolution retardation through solid dispersion technique using water insoluble and water swellable polymer for the development of controlled release dosage forms has become a field of interest in recent years. Development of controlled release solid dispersion has a great advantage for bypassing the risk of a burst release of drug; since the structure of the solid dispersion is monolithic where drug molecules homogeneously disperse. Despite the remarkable potential and extensive research being conducted on controlled release solid dispersion system, commercialization and large scale production are limited. The author expects that recent technological advances may overcome the existing limitations and facilitate the commercial utilization of the techniques for manufacture of controlled release solid dispersions. This article begins with an overview of the different carriers being used for the preparation of controlled release solid dispersion and also different techniques being used for the purpose. Kinetics of drug release from these controlled release solid dispersions and the relevant mathematical modeling have also been reviewed in this manuscript.

  20. An alternative noninvasive technique for the treatment of iatrogenic femoral pseudoaneurysms: stethoscope-guided compression.

    Science.gov (United States)

    Korkmaz, Ahmet; Duyuler, Serkan; Kalayci, Süleyman; Türker, Pinar; Sahan, Ekrem; Maden, Orhan; Selçuk, Mehmet Timur

    2013-06-01

    latrogenic femoral pseudoaneurysm is a well-known vascular access site complication. Many invasive and noninvasive techniques have been proposed for the management of this relatively common complication. In this study, we aimed to evaluate efficiency and safety of stethoscope-guided compression as a novel noninvasive technique in the femoral pseudoaneurysm treatment. We prospectively included 29 consecutive patients with the diagnosis of femoral pseudoaneurysm who underwent coronary angiography. Patients with a clinical suspicion of femoral pseudoaneurysm were referred to colour Doppler ultrasound evaluation. The adult (large) side of the stethoscope was used to determine the location where the bruit was best heard. Then compression with the paediatric (small) side of the stethoscope was applied until the bruit could no longer be heard and compression was maintained for at least two sessions. Once the bruit disappeared, a 12-hour bed rest with external elastic compression was advised to the patients, in order to prevent disintegration of newly formed thrombosis. Mean pseudoaneurysm size was 1.7 +/- 0.4 cmx 3.0 +/- 0.9 cm and the mean duration of compression was 36.2 +/- 8.5 minutes.Twenty-six (89.6%) of these 29 patients were successfully treated with stethoscope-guided compression. In 18 patients (62%), the pseuodoaneurysms were successfully closed after 2 sessions of 15-minute compression. No severe complication was observed. Stethoscope-guided compression of femoral pseudoaneurysms is a safe and effective novel technique which requires less equipment and expertise than other contemporary methods.

  1. A facile alternative technique for large-area graphene transfer via sacrificial polymer

    Directory of Open Access Journals (Sweden)

    Eric Auchter

    2017-12-01

    Full Text Available A novel method of transferring large-area graphene sheets onto a variety of substrates using Formvar (polyvinyl formal is presented. Due to the ease at which formvar can be dissolved in chloroform this method allows for a consistent, a clean, and a more rapid transfer than other techniques including the PMMA assisted one. This novel transfer method is demonstrated by transferring large-area graphene onto a range of substrates including commercial TEM grids, silicon dioxide and glass. Raman spectroscopy was used to confirm the presence of graphene and characterize the morphological properties of the large-area sheets. SEM and AFM analyses demonstrated the effectiveness of our rapid transfer technique for clean crystalline large-area graphene sheets. The removal of the sacrificial polymer was found to be one to two orders of magnitude faster than PMMA methods. Ultimately this facile transfer technique offers new opportunities for a wide range of applications for large-area graphene through the utilization of a new sacrificial polymer.

  2. Spontaneous emergence, imitation and spread of alternative foraging techniques among groups of vervet monkeys.

    Directory of Open Access Journals (Sweden)

    Erica van de Waal

    Full Text Available Animal social learning has become a subject of broad interest, but demonstrations of bodily imitation in animals remain rare. Based on Voelkl and Huber's study of imitation by marmosets, we tested four groups of semi-captive vervet monkeys presented with food in modified film canisters ("aethipops'. One individual was trained to take the tops off canisters in each group and demonstrated five openings to them. In three groups these models used their mouth to remove the lid, but in one of the groups the model also spontaneously pulled ropes on a canister to open it. In the last group the model preferred to remove the lid with her hands. Following these spontaneous differentiations of foraging techniques in the models, we observed the techniques used by the other group members to open the canisters. We found that mouth opening was the most common technique overall, but the rope and hands methods were used significantly more in groups they were demonstrated in than in groups where they were not. Our results show bodily matching that is conventionally described as imitation. We discuss the relevance of these findings to discoveries about mirror neurons, and implications of the identity of the model for social transmission.

  3. A home-based intervention using augmentative and alternative communication (AAC) techniques in rural Kenya: what are the caregivers' experiences?

    Science.gov (United States)

    Gona, J K; Newton, C R; Hartley, S; Bunning, K

    2014-01-01

    Caring for a child with complex communication needs associated with a developmental condition frequently adds stress to the caregiver. Furthermore, professional assistance is scarce in low-income rural settings. For such children speech is frequently unachievable. Augmentative and alternative communication provides options for supplementing or replacing speech with other techniques. The current study aimed to examine the experiences of caregivers in Kenya before and after a home-based intervention using augmentative and alternative communication techniques with children with complex communication needs. Caregivers were interviewed pre- and post-intervention. The interviews were digitally recorded, transcribed and translated into English. Content analysis was applied through the stages of text familiarization and topic organization. Emergent themes and their sub-themes were identified and labelled. Connections between themes were established and interpretations made. The procedure was completed by a second researcher independently. Conflicting ideas were jointly discussed until consensus was achieved. Four themes emerged from the data: communication process; struggle; normality; and supernatural power. Before intervention, the caregivers acknowledged their expertise in communications with the child, while also revealing their sense of isolation, burden and pain. Normality was present as a source of comparison and also an aspirational goal. Post-intervention more positive language was used to describe the child. There was an 'opening up' of communication that recognized the child's strengths and some social support systems were re-established. The power of the supernatural was recognized before and after intervention. Caring of a child with complex communication needs presents many challenges. A home-based intervention using augmentative and alternative communication techniques appears to have been a catalyst for some positive transformations in the caregivers

  4. A Novel Hybrid Axial-Radial Atmospheric Plasma Spraying Technique for the Fabrication of Solid Oxide Fuel Cell Anodes Containing Cu, Co, Ni, and Samaria-Doped Ceria

    Science.gov (United States)

    Cuglietta, Mark; Kuhn, Joel; Kesler, Olivera

    2013-06-01

    Composite coatings containing Cu, Co, Ni, and samaria-doped ceria (SDC) have been fabricated using a novel hybrid atmospheric plasma spraying technique, in which a multi-component aqueous suspension of CuO, Co3O4, and NiO was injected axially simultaneously with SDC injected radially in a dry powder form. Coatings were characterized for their microstructure, permeability, porosity, and composition over a range of plasma spray conditions. Deposition efficiency of the metal oxides and SDC was also estimated. Depending on the conditions, coatings displayed either layering or high levels of mixing between the SDC and metal phases. The deposition efficiencies of both feedstock types were strongly dependent on the nozzle diameter. Plasma-sprayed metal-supported solid oxide fuel cells utilizing anodes fabricated with this technique demonstrated power densities at 0.7 V as high as 366 and 113 mW/cm2 in humidified hydrogen and methane, respectively, at 800 °C.

  5. Advanced Fabrication Techniques for Precisely Controlled Micro and Nano Scale Environments for Complex Tissue Regeneration and Biomedical Applications

    Science.gov (United States)

    Holmes, Benjamin

    As modern medicine advances, it is still very challenging to cure joint defects due to their poor inherent regenerative capacity, complex stratified architecture, and disparate biomechanical properties. The current clinical standard for catastrophic or late stage joint degradation is a total joint implant, where the damaged joint is completely excised and replaced with a metallic or artificial joint. However, these procedures still only lasts for 10-15 years, and there are hosts of recovery complications which can occur. Thus, these studies have sought to employ advanced biomaterials and scaffold fabricated techniques to effectively regrow joint tissue, instead of merely replacing it with artificial materials. We can hypothesize here that the inclusion of biomimetic and bioactive nanomaterials with highly functional electrospun and 3D printed scaffold can improve physical characteristics (mechanical strength, surface interactions and nanotexture) enhance cellular growth and direct stem cell differentiation for bone, cartilage and vascular growth as well as cancer metastasis modeling. Nanomaterial inclusion and controlled 3D printed features effectively increased nano surface roughness, Young's Modulus and provided effective flow paths for simulated arterial blood. All of the approaches explored proved highly effective for increasing cell growth, as a result of increasing micro-complexity and nanomaterial incorporation. Additionally, chondrogenic and osteogenic differentiation, cell migration, cell to cell interaction and vascular formation were enhanced. Finally, growth-factor(gf)-loaded polymer nanospheres greatly improved vascular cell behavior, and provided a highly bioactive scaffold for mesenchymal stem cell (MSC) and human umbilical vein endothelial cell (HUVEC) co-culture and bone formation. In conclusion, electrospinning and 3D printing when combined effectively with biomimetic and bioactive nanomaterials (i.e. carbon nanomaterials, collagen, nHA, polymer

  6. Techniques for Continuous Monitoring of Airborne Plutonium Activity and Experience of their Use in a Fuel-Element Fabrication Plant

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, D. C.; Perry, K. E.G. [Atomic Energy Establishment. Winfrith, Dorset (United Kingdom); Loosemore, W. R.; Sparke, W. G. [Atomic Energy Research Establishment, Harwell, Berks (United Kingdom)

    1967-12-15

    The development of installed plutonium-in-air monitoring techniques in the U.K.A.E.A. is described together with operational experience in a fuel-element fabrication facility at Winfrith where mixed PuO{sub 2}/UO{sub 2} fuels are manufactured on a tonne scale in freestanding glove boxes for use in reactor physics experiments. Transportable single-point sampling instruments have been designed in which alpha activity collected on a fixed filter paper of area 20 cm{sup 2} is continuously viewed by scintillation or silicon surface barrier detectors. Discrimination against natural alpha activity, typically 10{sup -4}{mu}Ci/m{sup 3}, is achieved by energy analysis: preset alarms operate if an exposure exceeds 5 to 80 maximum permissible concentration hours for plutonium. Evidence is presented which shows that there is no significant chronic exposure to plutonium: inhalation exposure of the workers in this facility results from highly localized releases of airborne activity caused by occasional, minor, often unnoticed damage to box gloves or posting bags. Personal air samplers have been used which show that, in a particular incident, the exposure of an individual may be several orders of magnitude greater than that shown by a continuous monitor only a few metres away, even when many radioactive particles are released. Undesirably large exposures to individuals can occur therefore without an alarm being given by one of the indicating air samplers. In this situation reliance has had to be placed on the early detection of glove damage by frequent surface contamination monitoring. A new monitoring system is now being used to detect localized exposures. Air is monitored at up to 20 positions each near die face of a glove box. Alpha activity on each fixed-filter paper is viewed continuously by silicon surface barrier detectors. An immediate local alarm operates at a count rate equivalent to 80 mpc hours of plutonium. Additionally, each detector is scanned in sequence by a

  7. Monti’s procedure as an alternative technique in complex urethral distraction defect

    Directory of Open Access Journals (Sweden)

    Jalil Hosseini

    2010-06-01

    Full Text Available PURPOSE: Pelvic fracture urethral distraction defect is usually managed by the end to end anastomotic urethroplasty. Surgical repair of those patients with post-traumatic complex posterior urethral defects, who have undergone failed previous surgical treatments, remains one of the most challenging problems in urology. Appendix urinary diversion could be used in such cases. However, the appendix tissue is not always usable. We report our experience on management of patients with long urethral defect with history of one or more failed urethroplasties by Monti channel urinary diversion. MATERIALS AND METHODS: From 2001 to 2007, we evaluated data from 8 male patients aged 28 to 76 years (mean age 42.5 in whom the Monti technique was performed. All cases had history of posterior urethral defect with one or more failed procedures for urethral reconstruction including urethroplasty. A 2 to 2.5 cm segment of ileum, which had a suitable blood supply, was cut. After the re-anastomosis of the ileum, we closed the opened ileum transversely surrounding a 14-16 Fr urethral catheter using running Vicryl sutures. The newly built tube was used as an appendix during diversion. RESULTS: All patients performed catheterization through the conduit without difficulty and stomal stenosis. Mild stomal incontinence occurred in one patient in the supine position who became continent after adjustment of the catheterization intervals. There was no dehiscence, necrosis or perforation of the tube. CONCLUSION: Based on our data, Monti’s procedure seems to be a valuable technique in patients with very long complicated urethral defect who cannot be managed with routine urethroplastic techniques.

  8. Alternative technique for biodiesel quality control using an optical fiber long-period grating sensor

    International Nuclear Information System (INIS)

    Falate, Rosane; Nike, Karen; Costa Neto, Pedro Ramos da; Cacao Junior, Eduardo; Muller, Marcia; Kalinowski, Hypolito Jose; Fabris, Jose Luis

    2007-01-01

    We report the use of an optical fiber sensor to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device is based on the long-period grating sensitivity to the surrounding medium refractive index, which leads to measurable modifications in the grating transmission spectrum. The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques of total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the proposed method. (author)

  9. A rapid alternative technique for obtaining silver-positive patterns in chromosomes

    Directory of Open Access Journals (Sweden)

    Karine Frehner Kavalco

    2004-01-01

    Full Text Available Silver nitrate chromosome staining to evidence nucleolar organizer regions (NORs is a widely adopted methodology. The aim of the present work was to improve this technique, reducing the preparation time without decreasing the quality of the results. Microwave irradiation proved to be quite efficient and reliable for this purpose, as it allowed to identify Ag-NORs equivalent to those obtained by the conventional procedure and also to reduce the concentration of the employed reagents, as well as the precipitation of debris on the preparation.

  10. Alternative technique for biodiesel quality control using an optical fiber long-period grating sensor

    Energy Technology Data Exchange (ETDEWEB)

    Falate, Rosane [Universidade Estadual de Ponta Grossa, PR (Brazil). Dept. de Informatica; Nike, Karen; Costa Neto, Pedro Ramos da [Universidade Tecnologica Federal do Parana, Curitiba (Brazil). Dept. de Quimica; Cacao Junior, Eduardo; Muller, Marcia; Kalinowski, Hypolito Jose; Fabris, Jose Luis [Universidade Tecnologica Federal do Parana, Curitiba (Brazil). Dept. de Fisica]. E-mail: fabris@utfpr.edu.br

    2007-07-01

    We report the use of an optical fiber sensor to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device is based on the long-period grating sensitivity to the surrounding medium refractive index, which leads to measurable modifications in the grating transmission spectrum. The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques of total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the proposed method. (author)

  11. Transforaminal Lumbar Puncture: An Alternative Technique in Patients with Challenging Access.

    Science.gov (United States)

    Nascene, D R; Ozutemiz, C; Estby, H; McKinney, A M; Rykken, J B

    2018-05-01

    Interlaminar lumbar puncture and cervical puncture may not be ideal in all circumstances. Recently, we have used a transforaminal approach in selected situations. Between May 2016 and December 2017, twenty-six transforaminal lumbar punctures were performed in 9 patients (25 CT-guided, 1 fluoroscopy-guided). Seven had spinal muscular atrophy and were referred for intrathecal nusinersen administration. In 2, CT myelography was performed via transforaminal lumbar puncture. The lumbar posterior elements were completely fused in 8, and there was an overlying abscess in 1. The L1-2 level was used in 2; the L2-3 level, in 10; the L3-4 level, in 12; and the L4-5 level, in 2 procedures. Post-lumbar puncture headache was observed on 4 occasions, which resolved without blood patching. One patient felt heat and pain at the injection site that resolved spontaneously within hours. One patient had radicular pain that resolved with conservative treatment. Transforaminal lumbar puncture may become an effective alternative to classic interlaminar lumbar puncture or cervical puncture. © 2018 by American Journal of Neuroradiology.

  12. Waterpipes and e-cigarettes: Impact of alternative smoking techniques on indoor air quality and health

    Science.gov (United States)

    Fromme, Hermann; Schober, Wolfgang

    2015-04-01

    Waterpipe (WP) smoking is growing as an alternative to cigarette smoking, especially in younger age groups. E-cigarette use has also increased in recent years. A majority of smokers mistakenly believe that WP smoking is a social entertainment practice that leads to more social behavior and relaxation and that this type of smoking is safe or less harmful and less addictive than cigarette smoking. In reality, WP smokers are exposed to hundreds of toxic substances that include known carcinogens. High exposures to carbon monoxide and nicotine are major health threats. Persons exposed to secondhand WP smoke are also at risk. There is growing evidence that WP smoke causes adverse effects on the pulmonary and cardiovascular systems and is responsible for cancer. E-cigarettes are marketed as a smokeless and safe way to inhale nicotine without being exposed to the many toxic components of tobacco cigarettes, and as an aid to smoking cessation. In fact, consumers (vapers) and secondhand vapers can be exposed to substantial amounts of VOC, PAH or other potentially harmful substances. Of major health concern is the inhalation of fine and ultrafine particles formed from supersaturated 1,2-propanediol vapor. Such particles can be deposited in the deeper parts of the lung and may harm the respiratory system or increase the risk of acquiring asthma. More research on the safety of e-cigarettes needs to be conducted to ensure a high level of public health protection in the long-term.

  13. Hot radial pressing: An alternative technique for the manufacturing of plasma-facing components

    International Nuclear Information System (INIS)

    Visca, E.; Libera, S.; Mancini, A.; Mazzone, G.; Pizzuto, A.; Testani, C.

    2005-01-01

    The Hot radial pressing (HRP) manufacturing technique is based on the radial diffusion bonding principle performed between the cooling tube and the armour tile. The bonding is achieved by pressurizing the cooling tube while the joining interface is kept at the vacuum and temperature conditions. This technique has been used for the manufacturing of relevant mock-ups of the ITER divertor vertical target. Tungsten monoblock mock-ups were successfully tested to high heat flux thermal fatigue (20 MW/m 2 of absorbed heat flux for 1000 cycles). After these good results the activity is now focused on the developing of a manufacturing process suitable also for the CFC monoblock mock-ups. A FE calculation was performed to investigate the stress involved in the CFC tiles during the process and to avoid the CFC fracture. The results obtained by the FE calculation and by the test performed in air simulating a HRP manufacturing process for a CFC monoblock mock-ups is reported in the paper

  14. PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

    International Nuclear Information System (INIS)

    Sultana, Naznin; Wang Min

    2012-01-01

    Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

  15. An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

    International Nuclear Information System (INIS)

    Palma, Daniel A.P.; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S.

    2009-01-01

    The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)

  16. An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

    Energy Technology Data Exchange (ETDEWEB)

    Palma, Daniel A.P. [Instituto Federal do Rio de Janeiro, Nilopolis, RJ (Brazil)], e-mail: dpalmaster@gmail.com; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear], e-mail: asilva@con.ufrj.br, e-mail: agoncalves@con.ufrj.br, e-mail: aquilino@lmp.ufrj.br

    2009-07-01

    The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)

  17. A Alternative Analog Circuit Design Methodology Employing Integrated Artificial Intelligence Techniques

    Science.gov (United States)

    Tuttle, Jeffery L.

    In consideration of the computer processing power now available to the designer, an alternative analog circuit design methodology is proposed. Computer memory capacities no longer require the reduction of the transistor operational characteristics to an imprecise formulation. Therefore, it is proposed that transistor modelling be abandoned in favor of fully characterized transistor data libraries. Secondly, availability of the transistor libraries would facilitate an automated selection of the most appropriate device(s) for the circuit being designed. More specifically, a preprocessor computer program to a more sophisticated circuit simulator (e.g. SPICE) is developed to assist the designer in developing the basic circuit topology and the selection of the most appropriate transistor. Once this is achieved, the circuit topology and selected transistor data library would be downloaded to the simulator for full circuit operational characterization and subsequent design modifications. It is recognized that the design process is enhanced by the use of heuristics as applied to iterative design results. Accordingly, an artificial intelligence (AI) interface is developed to assist the designer in applying the preprocessor results. To demonstrate the retrofitability of the AI interface to established programs, the interface is specifically designed to be as non-intrusive to the host code as possible. Implementation of the proposed methodology offers the potential to speed the design process, since the preprocessor both minimizes the required number of simulator runs and provides a higher acceptance potential of the initial and subsequent simulator runs. Secondly, part count reductions may be realizable since the circuit topologies are not as strongly driven by transistor limitations. Thirdly, the predicted results should more closely match actual circuit operations since the inadequacies of the transistor models have been virtually eliminated. Finally, the AI interface

  18. Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

    International Nuclear Information System (INIS)

    Olson, R. E.; Leeper, R. J.

    2013-01-01

    The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ∼34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid” (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry

  19. Evaluation and Optimization Study on a Hybrid EOR Technique Named as Chemical-Alternating-Foam Floods

    Directory of Open Access Journals (Sweden)

    Xu Xingguang

    2017-01-01

    Full Text Available This work presents a novel Enhanced Oil Recovery (EOR method called Chemical-Alternating-Foam (CAF floods in order to overcome the drawbacks of the conventional foam flooding such as insufficient amount of in-situ foams, severe foam collapse and surfactant retention. The first part of this research focused on the comparison of conventional foam floods and CAF floods both of which had the same amount of gas and chemicals. It showed that: (1 CAF floods possessed the much greater Residual Resistance Factor (RRF at elevated temperature; (2 the accumulative oil recovery of the CAF floods was 10%-15% higher than that of the conventional foam flooding. After 1.8 Pore Volume (PV injection, the oil recovery reached the plateau for both methods; (3 CAF floods yielded the most amount of incremental oil at the 98% water cut (water content in the effluent, while the continuous foam floods achieved the best performance at 60% water cut. The second part of this work determined the optimal foam quality (gas/liquid ratio or the volume percent gas within foam, chemical/foam slug size ratio, cycle number and injection sequence for the CAF floods. It was found that the CAF was endowed with the peak performance if the foam quality, chemical/foam slug size ratio, cycle number was fixed at 80%, 1:1 and 3 respectively with the chemical slug being introduced ahead of the foam slug. Through systematic and thorough research, the proposed hybrid process has been approved to be a viable and effective method significantly strengthening the conventional foam flooding.

  20. Two novel kinetic techniques for determining relative V/K values for alternate substrates

    International Nuclear Information System (INIS)

    Anderson, V.; Kannan, B.

    1986-01-01

    The equilibrium perturbation method of determining kinetic isotope effects has been extended to permit the accurate measurement of relative V/K values for alternate substrates. In the Enoyl-CoA hydratase reaction at pH 8.0 the V/K for trans-2-pentenoyl-CoA (5:1(2t)-CoA) less than 10% greater than V/K for crotonyl-CoA while at pH 4.6 V/K for 5:1(2t)-CoA is over twice the V/K for crotonyl-CoA. This change in the ratio of V/K values indicates that there must be a pKa in the V/K pH profile for 5:1(2t)-CoA that is not characteristic of the free enzyme, a simple interpretation being 5:1(2t)-CoA is a sticky substrate. The pseudoequilibrium perturbation method is inaccurate when the ratio of V/K values exceeds 3. A companion pseudoequilibrium method is introduced where the initial conditions are constrained to produce an initial velocity of zero, rather than requiring the initial and final concentrations of the chromophoric substrate to be identical. The ratio of V/K values is simply the ratio of the concentration of the perturbant molecule to the equilibrium concentration of the nonperturbing analogue. This method combines the advantages of both the equilibrium perturbation method and of initial steady state measurements. The kinetic mechanism of L-3-hydroxyacyl-CoA dehydrogenase, an enzyme whose severe substrate inhibition and small primary 2 H isotope effect have made routine kinetic studies impractical, has been investigated by this method

  1. Arthroscopic Bankart repair and subscapularis augmentation: an alternative technique treating anterior shoulder instability with bone loss.

    Science.gov (United States)

    Maiotti, Marco; Russo, Raffaele; Zanini, Antonio; Schröter, Steffen; Massoni, Carlo; Bianchedi, Diana

    2016-06-01

    This study presents the preliminary results of a new arthroscopic technique consisting of the association of 2 procedures, capsulolabral repair and subscapularis augmentation tenodesis, in the treatment of traumatic anterior shoulder instability with both glenoid bone loss and a Hill-Sachs lesion. Eighty-nine patients engaged in sports were enrolled in this retrospective case-series study with 2 to 5 years' follow-up. All patients underwent a computed tomography scan to assess the percentage of glenoid bone loss by the Pico method. A prior stabilization procedure had failed in 20 patients, who were then segregated into a different group. Visual analog scale (VAS), Rowe, and American Shoulder and Elbow Surgeons (ASES) scores were used to assess the results. Only 3 of 89 patients had a post-traumatic redislocation. The mean length of follow-up was 31.5 months (range, 25-60 months). The VAS, Rowe, and ASES scores showed significant improvements: The VAS score decreased from a mean of 3.1 to 0.5 (P = .0157), the Rowe score increased from 58.9 to 94.1 (P = .0215), and the ASES score increased from 68.5 to 95.5 (P = .0197). The mean deficit of external rotation was 6° with the arm at the side of the trunk, and the mean deficit was 3° with the arm in 90° of abduction. The described procedure is a reproducible and effective technique used to restore joint stability in patients engaged in sports who have incurred anterior recurrent shoulder dislocation associated with glenoid bone loss (Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  2. Maxillary distraction osteogenesis in cleft lip and palate cases with midface hypoplasia using rigid external distractor: an alternative technique.

    Science.gov (United States)

    Dua, Gaurav; Navin Kumar, Andrews; Roy, Indranil Deb; Roy, Supriyo Kumar

    2014-05-01

    Patients with operated cleft lip and palate present with a problem of midface hypoplasia, and such patients have been traditionally treated with orthognathic surgery. Such a procedure has its own limitations of relapse and hence a newer modality of distraction osteogenesis with histiogenesis can be chosen to overcome such limitations for midfacial advancement. The purpose of this study is to evaluate an alternative technique and its postoperative stability in maxillary distraction osteogenesis in patients of cleft lip and cleft palate using a rigid external device (RED). Nine patients with midface bone stock deficiency were selected for maxillary advancement. At the first surgery under general anesthesia, after Le Fort I osteotomy, RED system was used with the alternative technique. After distraction, evaluation was done for ease of the procedure, stability, and complications. Lateral cephalograms were evaluated at 3 stages: T1, pre-distraction; T2, post-distraction; and T3, 1 year post-distraction. A mean 13.4-mm midface advancement was shown with bone formation at the pterygomaxillary region without losing the vector and having a standby mode in case the wire broke during distraction The results were stable even at 1 year of follow-up. Maxillary position improved in relation to the cranial base. This study showed that the RED was versatile in midface advancement.

  3. The HOPE fixation technique - a promising alternative to common prostate cancer biobanking approaches

    International Nuclear Information System (INIS)

    Braun, Martin; Becker, Karl-Friedrich; Perner, Sven; Menon, Roopika; Nikolov, Pavel; Kirsten, Robert; Petersen, Karen; Schilling, David; Schott, Christina; Gündisch, Sibylle; Fend, Falko

    2011-01-01

    The availability of well-annotated prostate tissue samples through biobanks is key for research. Whereas fresh-frozen tissue is well suited for a broad spectrum of molecular analyses, its storage and handling is complex and cost-intensive. Formalin-fixed paraffin-embedded specimens (FFPE) are easy to handle and economic to store, but their applicability for molecular methods is restricted. The recently introduced Hepes-glutamic acid-buffer mediated Organic solvent Protection Effect (HOPE) is a promising alternative, which might have the potential to unite the benefits of FFPE and fresh-frozen specimen. Aim of the study was to compare HOPE-fixed, FFPE and fresh-frozen bio-specimens for their accessibility for diagnostic and research purposes. 10 prostate cancer samples were each preserved with HOPE, formalin, and liquid nitrogen and studied with in-situ and molecular methods. Samples were H&E stained, and assessed by immunohistochemistry (i.e. PSA, GOLPH2, p63) and FISH (i.e. ERG rearrangement). We assessed DNA integrity by PCR, using control genes ranging from 100 to 600 bp amplicon size. RNA integrity was assessed through qRT-PCR on three housekeeping genes (TBP, GAPDH, β-actin). Protein expression was analysed by performing western blot analysis using GOLPH2 and PSA antibodies. Of the HOPE samples, morphologic quality of H&E sections, immunohistochemical staining, and the FISH assay was at least equal to FFPE tissue, and significantly better than the fresh-frozen specimens. DNA, RNA, and protein analysis of HOPE samples provided similar results as compared to fresh-frozen specimens. As expected, FFPE-samples were inferior for most of the molecular analyses. This is the first study, comparatively assessing the suitability of these fixation methods for diagnostic and research utilization. Overall, HOPE-fixed bio-specimens combine the benefits of FFPE- and fresh-frozen samples. Results of this study have the potential to expand on contemporary prostate tissue

  4. Fabrication of 2 × 8 power splitters in silica-on-silicon by the direct UV writing technique

    DEFF Research Database (Denmark)

    Olivero, Massimo; Svalgaard, Mikael

    2006-01-01

    In this letter, we present the first demonstration of 2 × 8 power splitters made in silica-on-silicon by direct ultraviolet (UV) writing. The fabricated components are compact and exhibit good performance in terms of loss, uniformity, and bandwidth, showing that direct UV writing can become...

  5. Fit accuracy of metal partial removable dental prosthesis frameworks fabricated by traditional or light curing modeling material technique: An in vitro study

    Science.gov (United States)

    Anan, Mohammad Tarek M.; Al-Saadi, Mohannad H.

    2015-01-01

    Objective The aim of this study was to compare the fit accuracies of metal partial removable dental prosthesis (PRDP) frameworks fabricated by the traditional technique (TT) or the light-curing modeling material technique (LCMT). Materials and methods A metal model of a Kennedy class III modification 1 mandibular dental arch with two edentulous spaces of different spans, short and long, was used for the study. Thirty identical working casts were used to produce 15 PRDP frameworks each by TT and by LCMT. Every framework was transferred to a metal master cast to measure the gap between the metal base of the framework and the crest of the alveolar ridge of the cast. Gaps were measured at three points on each side by a USB digital intraoral camera at ×16.5 magnification. Images were transferred to a graphics editing program. A single examiner performed all measurements. The two-tailed t-test was performed at the 5% significance level. Results The mean gap value was significantly smaller in the LCMT group compared to the TT group. The mean value of the short edentulous span was significantly smaller than that of the long edentulous span in the LCMT group, whereas the opposite result was obtained in the TT group. Conclusion Within the limitations of this study, it can be concluded that the fit of the LCMT-fabricated frameworks was better than the fit of the TT-fabricated frameworks. The framework fit can differ according to the span of the edentate ridge and the fabrication technique for the metal framework. PMID:26236129

  6. Adding guarana powder to medfly diets: an alternative for improving the Sterile Insect Technique

    Directory of Open Access Journals (Sweden)

    Jamile Câmara de Aquino

    2016-06-01

    Full Text Available ABSTRACT Ceratitis capitata (medfly is a globally important horticultural pest that can be controlled using the sterile insect technique (SIT, but the success of SIT depends on the sexual performance of mass-reared males when released into the field. We added “guarana” (Paullinia cupana powder (derived from an Amazonian fruit that is considered to be a stimulant with aphrodisiac effects, capable of improving human physical stamina to the diets of adult male medflies to determine whether it increased their sexual performance. The basic diet of a protein extract + sucrose (1:3 was enriched with guarana powder (3 % on a volume basis. Experiments examining sexual competitiveness were performed using lab-reared males fed with the enriched diet vs. lab-reared males fed on the basic diet (and lab-reared females fed on the basic diet, as well as lab-reared males fed with the enriched diet vs. wild males fed on the basic diet (and wild females fed on the basic diet. The results of both experiments indicated that males maintained on diets enriched with guarana powder showed higher copulation successes than males fed only with the basic diet. Guarana powder therefore contributed to the greater mating success of lab-reared males (probably because of its stimulant properties, and may represent a new and viable option for increasing SIT effectiveness.

  7. Alternative solidification techniques for radioactive ion exchange resins and liquid concentrates

    International Nuclear Information System (INIS)

    Thegerstroem, C.

    1980-01-01

    Methods, that are used or are under development for solidification of radioactive ion exchange resins or liquid concentrates, utilize normally cement, bitumen or some polymere as matrix material. This report contains a review and a description of these solidification processes and their products, especially of relatively new techniques that are under development in different countries. It is possible that solidification in thermosetting resins will be more used in the future, especially when product quality requirements are high (for instance when solidifying medium level resins) or when special waste categories has to be solidified. However it is not probable that thermosetting resins will be extensively used in a broad application as matrix material. In that case the methods are to complicated and expensive compared to, for instance, solidification in concrete. Systems for incorporation in polyesteremulsions (Dow-process) have a potential as they are quite simple and can accept a large variation of liquid wastes. Some methods in an early stage of development (for instance Inert Carrier Radwaste Process) will have to be tested in active application before they can be further evaluated. (author)

  8. Marginal and internal fit of cobalt-chromium copings fabricated using the conventional and the direct metal laser sintering techniques: A comparative in vitro study.

    Science.gov (United States)

    Ullattuthodi, Sujana; Cherian, Kandathil Phillip; Anandkumar, R; Nambiar, M Sreedevi

    2017-01-01

    This in vitro study seeks to evaluate and compare the marginal and internal fit of cobalt-chromium copings fabricated using the conventional and direct metal laser sintering (DMLS) techniques. A master model of a prepared molar tooth was made using cobalt-chromium alloy. Silicone impression of the master model was made and thirty standardized working models were then produced; twenty working models for conventional lost-wax technique and ten working models for DMLS technique. A total of twenty metal copings were fabricated using two different production techniques: conventional lost-wax method and DMLS; ten samples in each group. The conventional and DMLS copings were cemented to the working models using glass ionomer cement. Marginal gap of the copings were measured at predetermined four points. The die with the cemented copings are standardized-sectioned with a heavy duty lathe. Then, each sectioned samples were analyzed for the internal gap between the die and the metal coping using a metallurgical microscope. Digital photographs were taken at ×50 magnification and analyzed using measurement software. Statistical analysis was done by unpaired t -test and analysis of variance (ANOVA). The results of this study reveal that no significant difference was present in the marginal gap of conventional and DMLS copings ( P > 0.05) by means of ANOVA. The mean values of internal gap of DMLS copings were significantly greater than that of conventional copings ( P < 0.05). Within the limitations of this in vitro study, it was concluded that the internal fit of conventional copings was superior to that of the DMLS copings. Marginal fit of the copings fabricated by two different techniques had no significant difference.

  9. Assessment of alternative management techniques of tank bottom petroleum sludge in Oman

    International Nuclear Information System (INIS)

    Al-Futaisi, Ahmed; Jamrah, Ahmad; Yaghi, Basma; Taha, Ramzi

    2007-01-01

    This paper investigated several options for environmentally acceptable management techniques of tank bottom oily sludge. In particular, we tested the applicability of managing the sludge by three options: (1) as a fuel supplement; (2) in solidification; (3) as a road material. Environmental testing included determination of heavy metals concentration; toxic organics concentration and radiological properties. The assessment of tank bottom sludge as a fuel supplement included various properties such as proximate analysis, ultimate analysis and energy content. Solidified sludge mixtures and road application sludge mixtures were subjected to leaching using the toxicity characteristic leaching procedure (TCLP). Tank bottom sludge was characterized as having higher concentrations of lead, zinc, and mercury, but lower concentrations of nickel, copper and chromium in comparison with values reported in the literature. Natural occurring radioactive minerals (NORM) activity values obtained on different sludge samples were very low or negligible compared to a NORM standard value of 100 Bq/g. The fuel assessment results indicate that the heating values, the carbon content and the ash content of the sludge samples are comparable with bituminous coal, sewage sludge, meat and bone meal and petroleum coke/coal mixture, but lower than those in car tyres and petroleum coke. The nitrogen content is lower than those fuels mentioned above, while the sulfur content seems comparable with bituminous coal, petroleum coke and a petroleum coke/coal mixture. The apparent lack of leachability of metals from solidification and road material sludge applications suggests that toxic metals and organics introduced to these applications are not readily attacked by weak acid solutions and would not be expected to migrate or dissolved into the water. Thus, in-terms of trace metals and organics, the suggested sludge applications would not be considered hazardous as defined by the TCLP leaching procedure

  10. Fabrication of NdFeB microstructures using a silicon molding technique for NdFeB/Ta multilayered films and NdFeB magnetic powder

    International Nuclear Information System (INIS)

    Jiang Yonggang; Fujita, Takayuki; Uehara, Minoru; Iga, Yuki; Hashimoto, Taichi; Hao, Xiuchun; Higuchi, Kohei; Maenaka, Kazusuke

    2011-01-01

    The silicon molding technique is described for patterning of NdFeB/Ta multilayered magnetic films and NdFeB magnetic powder at the micron scale. Silicon trenches are seamlessly filled by 12-μm-thick NdFeB/Ta multilayered magnetic films with a magnetic retentivity of 1.3 T. The topography image and magnetic field distribution image are measured using an atomic force microscope and a magnetic force microscope, respectively. Using a silicon molding technique complemented by a lift-off process, NdFeB magnetic powder is utilized to fabricate magnetic microstructures. Silicon trenches as narrow as 20 μm are filled by a mixture of magnetic powder and wax powder. The B-H hysteresis loop of the patterned magnetic powder is characterized using a vibrating sample magnetometer, which shows a magnetic retentivity of approximately 0.37 T. - Highlights: → We demonstrate the fabrication of micro-magnets using silicon molding processes. → NdFeB/Ta films are well filled in silicon trenches with a thickness of 12 μm. → The 12-μm-thick NdFeB/Ta magnetic film shows a retentivity of 1.3 T. → Magnetic structures as narrow as 20 μm are fabricated using NdFeB magnetic powder. → VSM measurement shows a retentivity of 0.37 T for patterned NdFeB magnetic powder.

  11. Fabrication of NdFeB microstructures using a silicon molding technique for NdFeB/Ta multilayered films and NdFeB magnetic powder

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Yonggang, E-mail: yonggangj@gmail.com [School of Mechanical Engineering and Automation, Beihang University, Xueyuan Road No. 37, Haidian District, Beijing 100191 (China); Maenaka Human-Sensing Fusion project, Japan Science and Technology Agency, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Fujita, Takayuki [Maenaka Human-Sensing Fusion project, Japan Science and Technology Agency, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Uehara, Minoru [NEOMAX Co. Ltd., 2-15-17, Egawa, Shimamoto-Cho, Mishima-gun, Osaka 618-0013 (Japan); Iga, Yuki [Maenaka Human-Sensing Fusion project, Japan Science and Technology Agency, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Hashimoto, Taichi [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Hao, Xiuchun; Higuchi, Kohei [Maenaka Human-Sensing Fusion project, Japan Science and Technology Agency, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Maenaka, Kazusuke [Maenaka Human-Sensing Fusion project, Japan Science and Technology Agency, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan)

    2011-11-15

    The silicon molding technique is described for patterning of NdFeB/Ta multilayered magnetic films and NdFeB magnetic powder at the micron scale. Silicon trenches are seamlessly filled by 12-{mu}m-thick NdFeB/Ta multilayered magnetic films with a magnetic retentivity of 1.3 T. The topography image and magnetic field distribution image are measured using an atomic force microscope and a magnetic force microscope, respectively. Using a silicon molding technique complemented by a lift-off process, NdFeB magnetic powder is utilized to fabricate magnetic microstructures. Silicon trenches as narrow as 20 {mu}m are filled by a mixture of magnetic powder and wax powder. The B-H hysteresis loop of the patterned magnetic powder is characterized using a vibrating sample magnetometer, which shows a magnetic retentivity of approximately 0.37 T. - Highlights: > We demonstrate the fabrication of micro-magnets using silicon molding processes. > NdFeB/Ta films are well filled in silicon trenches with a thickness of 12 {mu}m. > The 12-{mu}m-thick NdFeB/Ta magnetic film shows a retentivity of 1.3 T. > Magnetic structures as narrow as 20 {mu}m are fabricated using NdFeB magnetic powder. > VSM measurement shows a retentivity of 0.37 T for patterned NdFeB magnetic powder.

  12. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    Directory of Open Access Journals (Sweden)

    Li Yuting

    2015-10-01

    Full Text Available Potential drop techniques are of two types: the direct current potential drop (DCPD technique and alternating current potential drop (ACPD technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  13. A simple gold nanoparticle-mediated immobilization method to fabricate highly homogeneous DNA microarrays having higher capacities than those prepared by using conventional techniques

    International Nuclear Information System (INIS)

    Jung, Cheulhee; Mun, Hyo Young; Li, Taihua; Park, Hyun Gyu

    2009-01-01

    A simple, highly efficient immobilization method to fabricate DNA microarrays, that utilizes gold nanoparticles as the mediator, has been developed. The fabrication method begins with electrostatic attachment of amine-modified DNA to gold nanoparticles. The resulting gold-DNA complexes are immobilized on conventional amine or aldehyde functionalized glass slides. By employing gold nanoparticles as the immobilization mediator, implementation of this procedure yields highly homogeneous microarrays that have higher binding capacities than those produced by conventional methods. This outcome is due to the increased three-dimensional immobilization surface provided by the gold nanoparticles as well as the intrinsic effects of gold on emission properties. This novel immobilization strategy gives microarrays that produce more intense hybridization signals for the complementary DNA. Furthermore, the silver enhancement technique, made possible only in the case of immobilized gold nanoparticles on the microarrays, enables simple monitoring of the integrity of the immobilized DNA probe.

  14. Fabrication of ridge waveguide structure from photosensitive TiO2/ormosil hybrid films by using an ultraviolet soft imprint technique

    International Nuclear Information System (INIS)

    Zhang, Xuehua; Que, Wenxiu; Chen, Jing; Gao, Tianxi; Hu, Jiaxing; Liu, Weiguo

    2013-01-01

    Photosensitive TiO 2 /organically modified silane hybrid films were prepared by combining a low-temperature sol–gel process with a spin-coating technique. Optical properties and photochemical activities of the as-prepared hybrid sol–gel films under different UV irradiation time were characterized and monitored by prism coupling technique, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. Surface morphology of the hybrid films was also observed by an atomic force microscopy. Advantages for fabrication of ridge waveguide structure based on the photosensitive hybrid films were demonstrated by an ultraviolet soft imprint technique. Effects of imprint force, imprint time, and UV irradiation time on high replication fidelity of the ridge waveguide structure were also investigated. An altitude replication fidelity of 99.7% can be obtained when the imprint force of 2 MPa, imprint time of 30 min and UV irradiation time of 45 min were chosen. Scanning electron microscopy and surface profiler were used to characterize the morphological and surface profile properties of the as fabricated ridge waveguide structure. Results indicate that the as-prepared photosensitive hybrid materials have great applicability for the fabrication of micro-optical elements and advantage as the imprint layer under the ultraviolet soft imprint technique. - Highlights: ► Photosensitive TiO 2 /ormosil hybrid film is prepared by a sol–gel process. ► Optical properties of the films change a little with UV exposure time. ► Photo-chemical property of the film changes a lot with UV exposure time. ► The imprint force and time, and the UV exposure time affect the imprint fidelity. ► A fidelity value of 99.7% is obtained under an optimized condition

  15. Fabrication of ridge waveguide structure from photosensitive TiO{sub 2}/ormosil hybrid films by using an ultraviolet soft imprint technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuehua [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Que, Wenxiu, E-mail: wxque@mail.xjtu.edu.cn [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Chen, Jing; Gao, Tianxi; Hu, Jiaxing [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Liu, Weiguo [Micro-optoelectronic Systems Laboratories, Xi' an Technological University, Xi' an 710032, Shaanxi (China)

    2013-03-01

    Photosensitive TiO{sub 2}/organically modified silane hybrid films were prepared by combining a low-temperature sol–gel process with a spin-coating technique. Optical properties and photochemical activities of the as-prepared hybrid sol–gel films under different UV irradiation time were characterized and monitored by prism coupling technique, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. Surface morphology of the hybrid films was also observed by an atomic force microscopy. Advantages for fabrication of ridge waveguide structure based on the photosensitive hybrid films were demonstrated by an ultraviolet soft imprint technique. Effects of imprint force, imprint time, and UV irradiation time on high replication fidelity of the ridge waveguide structure were also investigated. An altitude replication fidelity of 99.7% can be obtained when the imprint force of 2 MPa, imprint time of 30 min and UV irradiation time of 45 min were chosen. Scanning electron microscopy and surface profiler were used to characterize the morphological and surface profile properties of the as fabricated ridge waveguide structure. Results indicate that the as-prepared photosensitive hybrid materials have great applicability for the fabrication of micro-optical elements and advantage as the imprint layer under the ultraviolet soft imprint technique. - Highlights: ► Photosensitive TiO{sub 2}/ormosil hybrid film is prepared by a sol–gel process. ► Optical properties of the films change a little with UV exposure time. ► Photo-chemical property of the film changes a lot with UV exposure time. ► The imprint force and time, and the UV exposure time affect the imprint fidelity. ► A fidelity value of 99.7% is obtained under an optimized condition.

  16. Fabricating a pearl/PLGA composite scaffold by the low-temperature deposition manufacturing technique for bone tissue engineering

    International Nuclear Information System (INIS)

    Xu Mingen; Li Yanlei; Suo Hairui; Wang Qiujun; Ge Yakun; Xu Ying; Yan Yongnian; Liu Li

    2010-01-01

    Here we developed a composite scaffold of pearl/poly(lactic-co-glycolic acid) (pearl/PLGA) utilizing the low-temperature deposition manufacturing (LDM). LDM makes it possible to fabricate scaffolds with designed microstructure and macrostructure, while keeping the bioactivity of biomaterials by working at a low temperature. Process optimization was carried out to fabricate a mixture of pearl powder, PLGA and 1,4-dioxane with the designed hierarchical structures, and freeze-dried at a temperature of -40 deg. C. Scaffolds with square and designated bone shape were fabricated by following the 3D model. Marrow stem cells (MSCs) were seeded on the pearl/PLGA scaffold and then cultured in a rotating cell culture system. The adhesion, proliferation and differentiation of MSCs into osteoblasts were determined using scanning electronic microscopy, WST-1 assay, alkaline phosphatase activity assay, immunofluorescence staining and real-time reverse transcription polymerase chain reaction. The results showed that the composite scaffold had high porosity (81.98 ± 3.75%), proper pore size (micropores: <10 μm; macropore: 495 ± 54 μm) and mechanical property (compressive strength: 0.81 ± 0.04 MPa; elastic modulus: 23.14 ± 0.75 MPa). The pearl/PLGA scaffolds exhibited better biocompatibility and osteoconductivity compared with the tricalcium phosphate/PLGA scaffold. All these results indicate that the pearl/PLGA scaffolds fulfill the basic requirements of bone tissue engineering scaffold.

  17. A study on ultra-precision machining technique for Al6061-T6 to fabricate space infrared optics

    Science.gov (United States)

    Ryu, Geun-man; Lee, Gil-jae; Hyun, Sang-won; Sung, Ha-yeong; Chung, Euisik; Kim, Geon-hee

    2014-08-01

    In this paper, analysis of variance on designed experiments with full factorial design was applied to determine the optimized machining parameters for ultra-precision fabrication of the secondary aspheric mirror, which is one of the key elements of the space cryogenic infrared optics. A single point diamond turning machine (SPDTM, Nanotech 4μpL Moore) was adopted to fabricate the material, AL6061-T6, and the three machining parameters of cutting speed, feed rate and depth of cut were selected. With several randomly assigned experimental conditions, surface roughness of each condition was measured by a non-contact optical profiler (NT2000; Vecco). As a result of analysis using Minitab, the optimum cutting condition was determined as following; cutting speed: 122 m/min, feed rate: 3 mm/min and depth of cut: 1 μm. Finally, a 120 mm diameter aspheric secondary mirror was attached to a particularly designed jig by using mixture of paraffin and wax and successfully fabricated under the optimum machining parameters. The profile of machined surface was measured by a high-accuracy 3-D profilometer(UA3P; Panasonic) and we obtained the geometrical errors of 30.6 nm(RMS) and 262.4 nm(PV), which satisfy the requirements of the space cryogenic infrared optics.

  18. Fabrication of Orientation-Controlled 3D Tissues Using a Layer-by-Layer Technique and 3D Printed a Thermoresponsive Gel Frame.

    Science.gov (United States)

    Tsukamoto, Yoshinari; Akagi, Takami; Shima, Fumiaki; Akashi, Mitsuru

    2017-06-01

    Herein, we report the fabrication of orientation-controlled tissues similar to heart and nerve tissues using a cell accumulation and three-dimensional (3D) printing technique. We first evaluated the 3D shaping ability of hydroxybutyl chitosan (HBC), a thermoresponsive polymer, by using a robotic dispensing 3D printer. HBC polymer could be laminated to a height of 1124 ± 14 μm. Based on this result, we fabricated 3D gel frames of various shapes, such as square, triangular, rectangular, and circular, for shape control of 3D tissue and then normal human cardiac fibroblasts (NHCFs) coated with extracellular matrix nanofilms were seeded in the frames. Observation of shape-controlled tissues after 1 day of cultivation showed that the orientation of fibroblasts was in one direction when a short-sided, thin, rectangular-shaped frame was used. Next, we tried to fabricate orientation-controlled tissue with a vascular network by coculturing NHCF and normal human cardiac microvascular endothelial cells. As a consequence of cultivation for 4 days, observation of cocultured tissue confirmed aligned cells and blood capillaries in orientation-controlled tissue. Our results clearly demonstrated that it would be possible to control the cell orientation by controlling the shape of the tissues by combining a cell accumulation technique and a 3D printing system. The results of this study suggest promising strategies for the fabrication of oriented 3D tissues in vitro. These tissues, mimicking native organ structures, such as muscle and nerve tissue with a cell alignment structure, would be useful for tissue engineering, regenerative medicine, and pharmaceutical applications.

  19. Chemical and Radiochemical Composition of Thermally Stabilized Plutonium Oxide from the Plutonium Finishing Plant Considered as Alternate Feedstock for the Mixed Oxide Fuel Fabrication Facility

    International Nuclear Information System (INIS)

    Tingey, Joel M.; Jones, Susan A.

    2005-01-01

    Eighteen plutonium oxide samples originating from the Plutonium Finishing Plant (PFP) on the Hanford Site were analyzed to provide additional data on the suitability of PFP thermally stabilized plutonium oxides and Rocky Flats oxides as alternate feedstock to the Mixed Oxide Fuel Fabrication Facility (MFFF). Radiochemical and chemical analyses were performed on fusions, acid leaches, and water leaches of these 18 samples. The results from these destructive analyses were compared with nondestructive analyses (NDA) performed at PFP and the acceptance criteria for the alternate feedstock. The plutonium oxide materials considered as alternate feedstock at Hanford originated from several different sources including Rocky Flats oxide, scrap from the Remote Mechanical C-Line (RMC) and the Plutonium Reclamation Facility (PRF), and materials from other plutonium conversion processes at Hanford. These materials were received at PFP as metals, oxides, and solutions. All of the material considered as alternate feedstock was converted to PuO2 and thermally stabilized by heating the PuO2 powder at 950 C in an oxidizing environment. The two samples from solutions were converted to PuO2 by precipitation with Mg(OH)2. The 18 plutonium oxide samples were grouped into four categories based on their origin. The Rocky Flats oxide was divided into two categories, low- and high-chloride Rocky Flats oxides. The other two categories were PRF/RMC scrap oxides, which included scrap from both process lines and oxides produced from solutions. The two solution samples came from samples that were being tested at Pacific Northwest National Laboratory because all of the plutonium oxide from solutions at PFP had already been processed and placed in 3013 containers. These samples originated at the PFP and are from plutonium nitrate product and double-pass filtrate solutions after they had been thermally stabilized. The other 16 samples originated from thermal stabilization batches before canning at

  20. Fabrication of p-CuO/n-ZnO heterojunction diode via sol-gel spin coating technique

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu, Rajeev R., E-mail: rajeevrprabhu@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Saritha, A.C.; Shijeesh, M.R. [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Jayaraj, M.K. [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Centre for Advanced Materials, Cochin University of Science and Technology, Kochi 682 022 (India)

    2017-06-15

    Highlights: • Facile all-solution growth of nanostructured p-CuO and n-ZnO TSO films is reported. • Annealing the films in air affects the structural, electrical and optical properties. • p-n heterojunction using these films was fabricated in ITO/n-ZnO/p-CuO/Au structure. • Transparent heterojunction diode performed well with a V{sub on} of 2.5 V and n of 3.15. • Fabricated p-CuO/n-ZnO heterojunction diode can be used for UV detector application. - Abstract: We report a facile all-solution approach for the growth of nanostructured p-CuO and n-ZnO thin films. The influence of annealing temperature on the physical properties of CuO and ZnO thin films was examined. XRD and Raman spectra depict the structural and phase purity of solution grown CuO and ZnO films. The electrical as well as the optical properties of thin films were also studied. The average optical transmission of CuO and ZnO thin films in the visible spectral region was found to be above 80 and 95% respectively. Band gap energy variations on annealing temperature were investigated for CuO as well as ZnO films. Surface morphology analyzed by FESEM shows that the films are very smooth. All solution grown p-n heterojunction using p-CuO and n-ZnO films was fabricated in the structure ITO/n-ZnO/p-CuO/Au which showed rectification behavior with a turn on voltage of 2.5 V and an ideality factor of 3.15.

  1. The effect of core material, veneering porcelain, and fabrication technique on the biaxial flexural strength and weibull analysis of selected dental ceramics.

    Science.gov (United States)

    Lin, Wei-Shao; Ercoli, Carlo; Feng, Changyong; Morton, Dean

    2012-07-01

    The objective of this study was to compare the effect of veneering porcelain (monolithic or bilayer specimens) and core fabrication technique (heat-pressed or CAD/CAM) on the biaxial flexural strength and Weibull modulus of leucite-reinforced and lithium-disilicate glass ceramics. In addition, the effect of veneering technique (heat-pressed or powder/liquid layering) for zirconia ceramics on the biaxial flexural strength and Weibull modulus was studied. Five ceramic core materials (IPS Empress Esthetic, IPS Empress CAD, IPS e.max Press, IPS e.max CAD, IPS e.max ZirCAD) and three corresponding veneering porcelains (IPS Empress Esthetic Veneer, IPS e.max Ceram, IPS e.max ZirPress) were selected for this study. Each core material group contained three subgroups based on the core material thickness and the presence of corresponding veneering porcelain as follows: 1.5 mm core material only (subgroup 1.5C), 0.8 mm core material only (subgroup 0.8C), and 1.5 mm core/veneer group: 0.8 mm core with 0.7 mm corresponding veneering porcelain with a powder/liquid layering technique (subgroup 0.8C-0.7VL). The ZirCAD group had one additional 1.5 mm core/veneer subgroup with 0.7 mm heat-pressed veneering porcelain (subgroup 0.8C-0.7VP). The biaxial flexural strengths were compared for each subgroup (n = 10) according to ISO standard 6872:2008 with ANOVA and Tukey's post hoc multiple comparison test (p≤ 0.05). The reliability of strength was analyzed with the Weibull distribution. For all core materials, the 1.5 mm core/veneer subgroups (0.8C-0.7VL, 0.8C-0.7VP) had significantly lower mean biaxial flexural strengths (p Empress and e.max groups, regardless of core thickness and fabrication techniques. Comparing fabrication techniques, Empress Esthetic/CAD, e.max Press/CAD had similar biaxial flexural strength (p= 0.28 for Empress pair; p= 0.87 for e.max pair); however, e.max CAD/Press groups had significantly higher flexural strength (p Empress Esthetic/CAD groups. Monolithic core

  2. Proposal to negotiate a collaboration agreement related to the application of novel cavity fabrication techniques and Nb/Cu sputter coating technology in the field of superconducting RF for the Future Circular Collider (FCC) study

    CERN Document Server

    2015-01-01

    Proposal to negotiate a collaboration agreement related to the application of novel cavity fabrication techniques and Nb/Cu sputter coating technology in the field of superconducting RF for the Future Circular Collider (FCC) study

  3. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    Science.gov (United States)

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

    Science.gov (United States)

    Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

    2011-01-01

    Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

  5. Fabrication of Li{sub 4}SiO{sub 4} pebbles by a sol-gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Wu Xiangwei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Wen Zhaoyin [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)], E-mail: zywen@mail.sic.ac.cn; Xu Xiaogang; Liu Yu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

    2010-04-15

    Li{sub 4}SiO{sub 4} pebbles are considered as candidate ceramic breeder materials in many blanket designs. In this work, Li{sub 4}SiO{sub 4} pebbles with adequate sphericity were fabricated by a water-based sol-gel process using LiOH and SiO{sub 2} (aerosil) as the raw materials, which has not been reported for fabrication of Li{sub 4}SiO{sub 4} pebbles previously. Thermal analysis, phase analysis and morphological observations were carried out systematically. The effects of LiOH/C{sub 6}H{sub 8}O{sub 7} molar ratios and sintering temperature on the microstructure and density of the pebbles were discussed. Experimental results showed that when the LiOH/C{sub 6}H{sub 8}O{sub 7} molar ratio was 3, the microstructure of the Li{sub 4}SiO{sub 4} pebbles was the most favorable. While sintered at 900 deg. C for 4 h, Li{sub 4}SiO{sub 4} pebbles with about 1.2 mm in diameter were obtained and the density of the pebbles achieved about 74%.

  6. Optimization of LOPA-based direct laser writing technique for fabrication of submicrometric polymer two- and three-dimensional structures

    Science.gov (United States)

    Do, Mai Trang; Li, Qinggele; Ledoux-Rak, Isabelle; Lai, Ngoc D.

    2013-05-01

    We demonstrate a novel and very simple method allowing very easy flexible fabrication of 2D and 3D submicrometric structures. By using a photosensitive polymer (SU8) possessing an ultralow one-photon absorption (LOPA) coefficient at the excition laser wavelength (532 nm) and a high numerical aperture (NA = 1.3, oil immersion) objective lens, various submicrometric structures with feature size as small as 150 nm have been successfully fabricated. We have further investigated the energy accumulation effect in LOPA direct laser writing when the structure lattice constant approaches the diffraction limit. In this case, a proximity correction, i.e., a compensation of the doses between different voxels, was applied, allowing to create uniform and submicrometric structures with a lattice constant as small as 400 nm. As compared to commonly used two-photon absorption microscopy, the LOPA method allows to simplify the experimental setup and also to minimize the photo-damaging or bleaching effect. The idea of using LOPA also opens a new and inexpensive way to optically address 3D structures, namely 3D fluorescence imaging and 3D data storage.

  7. Fabrication of Nanostructures Using Self-Assembled Peptides as Templates

    DEFF Research Database (Denmark)

    Castillo, Jaime

    2015-01-01

    the advantages of diphenylalanine are explained step by step offering new alternatives to fabricate nanostructures in a simple and rapid way. The chapter is complemented with techniques to manipulate the self-assembled diphenylalanine nanostructures without changing its properties during the manipulation process.......This chapter evaluates the use of a short-aromatic dipeptide, diphenylalanine, as a template in the fabrication of new nanostructures (nanowires, coaxial nanocables, nanochannels) using materials such as silicon, conducting and non-conducting polymers. Diphenylalanine self...

  8. Alternative radiation-free registration technique for image-guided pedicle screw placement in deformed cervico-thoracic segments.

    Science.gov (United States)

    Kantelhardt, Sven R; Neulen, Axel; Keric, Naureen; Gutenberg, Angelika; Conrad, Jens; Giese, Alf

    2017-10-01

    Image-guided pedicle screw placement in the cervico-thoracic region is a commonly applied technique. In some patients with deformed cervico-thoracic segments, conventional or 3D fluoroscopy based registration of image-guidance might be difficult or impossible because of the anatomic/pathological conditions. Landmark based registration has been used as an alternative, mostly using separate registration of each vertebra. We here investigated a routine for landmark based registration of rigid spinal segments as single objects, using cranial image-guidance software. Landmark based registration of image-guidance was performed using cranial navigation software. After surgical exposure of the spinous processes, lamina and facet joints and fixation of a reference marker array, up to 26 predefined landmarks were acquired using a pointer. All pedicle screws were implanted using image guidance alone. Following image-guided screw placement all patients underwent postoperative CT scanning. Screw positions as well as intraoperative and clinical parameters were retrospectively analyzed. Thirteen patients received 73 pedicle screws at levels C6 to Th8. Registration of spinal segments, using the cranial image-guidance succeeded in all cases. Pedicle perforations were observed in 11.0%, severe perforations of >2 mm occurred in 5.4%. One patient developed a transient C8 syndrome and had to be revised for deviation of the C7 pedicle screw. No other pedicle screw-related complications were observed. In selected patients suffering from pathologies of the cervico-thoracic region, which impair intraoperative fluoroscopy or 3D C-arm imaging, landmark based registration of image-guidance using cranial software is a feasible, radiation-saving and a safe alternative.

  9. Fabrication of full high-T sub c superconducting YBa sub 2 Cu sub 3 O sub 7 sub - sub x trilayer junctions using a polishing technique

    CERN Document Server

    Kuroda, K; Takami, T; Ozeki, T

    2003-01-01

    We have successfully fabricated full high-T sub c superconducting YBa sub 2 Cu sub 3 O sub 7 sub - sub x (YBCO)/PrBa sub 2 Cu sub 3 O sub 7 sub - sub x (PBCO)/YBCO trilayer junctions, which have a simple device structure, such as a Pb-alloy-based Josephson tunneling junction. It has been demonstrated that a polishing technique is extremely useful in the fabrication process: it is effective in smoothing a coarse surface and gentling the slopes of the edges, or decreasing the slope angles. Owing to the polishing technique, the PBCO barrier layer and the upper YBCO layer have been notably thinned: the thicknesses of these layers are 10 nm and 250 nm, respectively. Junctions with the dimensions of 5 mu m x 5 mu m showed resistively shunted junction-like current-voltage curves with a typical critical current density of 110 A/cm sup 2 at 4.2 K. Furthermore, the operation of superconducting quantum interference devices has been demonstrated. (author)

  10. Meniscus-force-mediated layer transfer technique using single-crystalline silicon films with midair cavity: Application to fabrication of CMOS transistors on plastic substrates

    Science.gov (United States)

    Sakaike, Kohei; Akazawa, Muneki; Nakagawa, Akitoshi; Higashi, Seiichiro

    2015-04-01

    A novel low-temperature technique for transferring a silicon-on-insulator (SOI) layer with a midair cavity (supported by narrow SiO2 columns) by meniscus force has been proposed, and a single-crystalline Si (c-Si) film with a midair cavity formed in dog-bone shape was successfully transferred to a poly(ethylene terephthalate) (PET) substrate at its heatproof temperature or lower. By applying this proposed transfer technique, high-performance c-Si-based complementary metal-oxide-semiconductor (CMOS) transistors were successfully fabricated on the PET substrate. The key processes are the thermal oxidation and subsequent hydrogen annealing of the SOI layer on the midair cavity. These processes ensure a good MOS interface, and the SiO2 layer works as a “blocking” layer that blocks contamination from PET. The fabricated n- and p-channel c-Si thin-film transistors (TFTs) on the PET substrate showed field-effect mobilities of 568 and 103 cm2 V-1 s-1, respectively.

  11. Electrical characterization of Ni/n-ZnO/p-Si/Al heterostructure fabricated by pulsed laser deposition technique

    International Nuclear Information System (INIS)

    Chand, Subhash; Kumar, Rajender

    2014-01-01

    Highlights: • The Ni/n-ZnO/p-Si/Al heterojunction diodes are fabricated by pulsed laser deposition. • The band gap of the deposit ZnO films was found to be 3.43 eV. • Forward I–V data of Ni/n-ZnO/p-Si/Al hetrojunction are interpreted in terms of thermionic emission–diffusion mechanism. • The C–V characteristics of the Ni/n-ZnO/p-Si/Al hetrojunction diode are measured in the temperature range 80–300 K. • The barrier height of Ni/n-ZnO/p-Si/Al hetrojunction diode is also calculated from C–V measurements. - Abstract: The ZnO thin films are grown on the p-Si for the heterojunction fabrication by pulsed laser deposition method. X-ray diffraction study showed that the texture of the film is hexagonal with a strong (0 0 2) plane as preferred direction. High purity vacuum evaporated nickel and aluminum metals were used to make contacts to the n-ZnO and p-Si, respectively. The current–voltage characteristics of Ni/n-ZnO/p-Si(1 0 0)/Al hetero structure measured over the temperature range 80–300 K have been studied on the basis of thermionic emission diffusion mechanism. The equivalent Schottky barrier height and diode ideality factor are determined by fitting of measured current–voltage data in to thermionic diffusion equation. It is observed that the barrier height decreases and the ideality factor increases with decrease of temperature and the activation energy plot exhibit non-linear behavior. These characteristics are attributed to the Gaussian distribution of barrier heights. The capacitance–voltage characteristics of Ni/n-ZnO/p-Si(1 0 0)/Al heterojunction diode are also studied over wide temperature range. From the measured capacitance–voltage data the built in voltage and impurity concentration in n-type ZnO is estimated

  12. A process to fabricate fused silica nanofluidic devices with embedded electrodes using an optimized room temperature bonding technique

    Science.gov (United States)

    Boden, Seth; Karam, P.; Schmidt, A.; Pennathur, S.

    2017-05-01

    Fused silica is an ideal material for nanofluidic systems due to its extreme purity, chemical inertness, optical transparency, and native hydrophilicity. However, devices requiring embedded electrodes (e.g., for bioanalytical applications) are difficult to realize given the typical high temperature fusion bonding requirements (˜1000 °C). In this work, we optimize a two-step plasma activation process which involves an oxygen plasma treatment followed by a nitrogen plasma treatment to increase the fusion bonding strength of fused silica at room temperature. We conduct a parametric study of this treatment to investigate its effect on bonding strength, surface roughness, and microstructure morphology. We find that by including a nitrogen plasma treatment to the standard oxygen plasma activation process, the room temperature bonding strength increases by 70% (0.342 J/m2 to 0.578 J/m2). Employing this optimized process, we fabricate and characterize a nanofluidic device with an integrated and dielectrically separated electrode. Our results prove that the channels do not leak with over 1 MPa of applied pressure after a 24 h storage time, and the electrode exhibits capacitive behavior with a finite parallel resistance in the upper MΩ range for up to a 6.3Vdc bias. These data thus allow us to overcome the barrier that has barred nanofluidic progress for the last decade, namely, the development of nanometer scale well-defined channels with embedded metallic materials for far-reaching applications such as the exquisite manipulation of biomolecules.

  13. Fabrication of zein nanostructure

    Science.gov (United States)

    Luecha, Jarupat

    The concerns on the increase of polluting plastic wastes as well as the U.S. dependence on imported petrochemical products have driven an attention towards alternative biodegradable polymers from renewable resources. Zein protein, a co-product from ethanol production from corn, is a good candidate. This research project aims to increase zein value by adopting nanotechnology for fabricating advanced zein packaging films and zein microfluidic devices. Two nanotechnology approaches were focused: the polymer nanoclay nanocomposite technique where the nanocomposite structures were created in the zein matrix, and the soft lithography and the microfluidic devices where the micro and nanopatterns were created on the zein film surfaces. The polymer nanoclay nanocomposite technique was adopted in the commonly used zein film fabrication processes which were solvent casting and extrusion blowing methods. The two methods resulted in partially exfoliated nanocomposite structures. The impact of nanoclays on the physical properties of zein films strongly depended on the film preparation techniques. The impact of nanoclay concentration was more pronounced in the films made by extrusion blowing technique than by the solvent casting technique. As the processability limitation for the extrusion blowing technique of the zein sample containing hight nanoclay content, the effect of the nanoclay content on the rheological properties of zein hybrid resins at linear and nonlinear viscoelastic regions were further investigated. A pristine zein resin exhibited soft solid like behavior. On the other hand, the zein hybrid with nanoclay content greater than 5 wt.% showed more liquid like behavior, suggesting that the nanoclays interrupted the entangled zein network. There was good correspondence between the experimental data and the predictions of the Wagner model for the pristine zein resins. However, the model failed to predict the steady shear properties of the zein nanoclay nanocomposite

  14. Adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by selective laser melting technique.

    Science.gov (United States)

    Ye, Ye; Jiao, Ting; Zhu, Jiarui; Sun, Jian

    2018-01-24

    The purpose of the study was to evaluate the adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by the selective laser melting (SLM) technique. Twenty pairs of edentulous casts were randomly and evenly divided into two groups, and manufacturing of the Co-Cr alloy maxillary complete denture base was conducted either by the SLM technique or by the conventional method. The base-cast sets were transversally sectioned into three sections at the distal canines, mesial of the first molars and the posterior palatal zone. The gap between the metal base and cast was measured in these three sections with a stereoscopic microscope, and the data were analysed using t tests. A total of five specimens of 5 mm diameter were fabricated with the Co-Cr alloy by SLM and the traditional casting technology. A scanning electron microscope (SEM) was used to evaluate the differences in microstructure between these specimens. There was no statistical difference between the three sections in all four groups (P > 0.05). At the region of the canines, the clearance value for the SLM Co-Cr alloy group was larger than that of the conventional method group (P  0.05). The SLM Co-Cr alloy has a denser microstructure behaviour and less casting defect than the cast Co-Cr alloy. The SLM technique showed initial feasibility for the manufacture of dental bases of complete dentures, but large sample studies are needed to prove its reliability in clinical applications. The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.

  15. The fit of cobalt-chromium three-unit fixed dental prostheses fabricated with four different techniques: a comparative in vitro study.

    Science.gov (United States)

    Örtorp, Anders; Jönsson, David; Mouhsen, Alaa; Vult von Steyern, Per

    2011-04-01

    This study sought to evaluate and compare the marginal and internal fit in vitro of three-unit FDPs in Co-Cr made using four fabrication techniques, and to conclude in which area the largest misfit is present. An epoxy resin master model was produced. The impression was first made with silicone, and master and working models were then produced. A total of 32 three-unit Co-Cr FDPs were fabricated with four different production techniques: conventional lost-wax method (LW), milled wax with lost-wax method (MW), milled Co-Cr (MC), and direct laser metal sintering (DLMS). Each of the four groups consisted of eight FDPs (test groups). The FDPs were cemented on their cast and standardised-sectioned. The cement film thickness of the marginal and internal gaps was measured in a stereomicroscope, digital photos were taken at 12× magnification and then analyzed using measurement software. Statistical analyses were performed with one-way ANOVA and Tukey's test. Best fit based on the means (SDs) in μm for all measurement points was in the DLMS group 84 (60) followed by MW 117 (89), LW 133 (89) and MC 166 (135). Significant differences were present between MC and DLMS (p<0.05). The regression analyses presented differences within the parameters: production technique, tooth size, position and measurement point (p < 0.05). Best fit was found in the DLMS group followed by MW, LW and MC. In all four groups, best fit in both abutments was along the axial walls and in the deepest part of the chamfer preparation. The greatest misfit was present occlusally in all specimens. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Using virtual ridge augmentation and 3D printing to fabricate a titanium mesh positioning device: A novel technique letter.

    Science.gov (United States)

    Al-Ardah, Aladdin; Alqahtani, Nasser; AlHelal, Abdulaziz; Goodacre, Brian; Swamidass, Rajesh; Garbacea, Antoanela; Lozada, Jaime

    2018-05-02

    This technique describes a novel approach for planning and augmenting a large bony defect using a titanium mesh (TiMe). A 3-dimensional (3D) surgical model was virtually created from a cone beam computed tomography (CBCT) and wax-pattern of the final prosthetic outcome. The required bone volume (horizontally and vertically) was digitally augmented and then 3D printed to create a bone model. The 3D model was then used to contour the TiMe in accordance with the digital augmentation. With the contoured / preformed TiMe on the 3D printed model a positioning jig was made to aid the placement of the TiMe as planned during surgery. Although this technique does not impact the final outcome of the augmentation procedure, it allows the clinician to virtually design the augmentation, preform and contour the TiMe, and create a positioning jig reducing surgical time and error.

  17. Fabrication of a three-dimensional micro-manipulator by laser irradiation and electrochemical techniques and the effect of electrolytes on its performance

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T.; Akiyama, Y.; Ueda, M.; Sakairi, M.; Takahashi, H. [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-Ku, Sapporo (Japan)

    2007-03-20

    Ribbon type and three-dimensional micro-actuators, consisting of three-layer structure of acrylic acid resin/Au/polypyrrole, were fabricated by aluminum anodizing, laser irradiation, and electrochemical techniques, and their performance was examined. Anodized aluminum specimens were irradiated with a pulsed Nd-YAG laser to remove anodic oxide films locally, and then an Au layer was deposited at the area where film had been removed. The subsequent electrophoretic deposition of acrylic acid resin on the Au layer, dissolution of anodic oxide film and the metal substrate, and deposition of polypyrrole on backside of Au layer by electro-polymerization enabled the fabrication of a three-layer actuator. Cyclic voltammetry of the ribbon type actuator in different electrolyte solutions showed that redox reactions of polypyrrole is accompanied with doping and dedoping of hydrated cations, and that the redox reaction strongly depends on the valency of cations in the solutions. The three-dimensional micro-actuator showed good performance as a manipulator, gripping and moving objects of several milligram in solutions. (author)

  18. A Novel Ultraviolet Irradiation Technique for Fabrication of Polyacrylamide-metal (M = Au, Pd) Nanocomposites at Room Temperature

    International Nuclear Information System (INIS)

    Zhou, Y.; Hao, L.Y.; Zhu, Y.R.; Hu, Y.; Chen, Z.Y.

    2001-01-01

    Polyacrylamide (PAM)-metal (M = gold, palladium) nanocomposites with metal nanoparticles homogeneously dispersed in the polymer matrix have been prepared via a novel ultraviolet irradiation technique at room temperature, which is based on the simultaneous occurrence of photo-reduction formation of the colloidal metal particles and photo-polymerization of the acrylamide (AM) monomer. The UV-vis absorption spectra and TEM were employed to characterize the M-PAM nanocomposites by different irradiation times. The average sizes of the colloidal gold and palladium particles dispersed in the nanocomposites were calculated by XRD patterns and TEM images. The present method may be extended to prepare other metal-polymer hybrid nanocomposite materials

  19. Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

    International Nuclear Information System (INIS)

    Wang Yanrong; Yang Hong; Xu Hao; Luo Weichun; Qi Luwei; Zhang Shuxiang; Wang Wenwu; Zhu Huilong; Zhao Chao; Chen Dapeng; Ye Tianchun; Yan Jiang

    2017-01-01

    In the process of high- k films fabrication, a novel multi deposition multi annealing (MDMA) technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing (PDA) times. The equivalent oxide thickness (EOT) decreases when the annealing time(s) change from 1 to 2. Furthermore, the characteristics of SILC (stress-induced leakage current) for an ultra-thin SiO 2 /HfO 2 gate dielectric stack are studied systematically. The increase of the PDA time(s) from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes. (paper)

  20. R&D for a single-layer Nb$_{3}$Sn common coil dipole using the react-and-wind fabrication technique

    CERN Document Server

    Ambrosio, G; Barzi, E; Bauer, P; Chichili, D R; Ewald, K D; Fehér, S; Imbasciati, L; Kashikhin, V V; Limon, P J; Litvinenko, L; Novitski, I; Rey, J M; Scanlan, R M; Yadav, S; Yamada, R; Zlobin, A V

    2002-01-01

    A dipole magnet based on the common coil design, using prereacted Nb /sub 3/Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting in a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrica...

  1. Design and fabrication of light weight current collectors for direct methanol fuel cells using the micro-electro mechanical system technique

    Science.gov (United States)

    Sung, Min-Feng; Kuan, Yean-Der; Chen, Bing-Xian; Lee, Shi-Min

    The direct methanol fuel cell (DMFC) is suitable for portable applications. Therefore, a light weight and small size is desirable. The main objective of this paper is to design and fabricate a light weight current collector for DMFC usage. The light weight current collector mainly consists of a substrate with two thin film metal layers. The substrate of the current collector is an FR4 epoxy plate. The thin film metal layers are accomplished by the thermo coater technique to coat metal powders onto the substrate surfaces. The developed light weight current collectors are further assembled to a single cell DMFC test fixture to measure the cell performance. The results show that the proposed current collectors could even be applied to DMFCs because they are light, thin and low cost and have potential for mass production.

  2. Inkjet Printing as High-Throughput Technique for the Fabrication of NiCo2O4 Films

    Directory of Open Access Journals (Sweden)

    Reyna Dianela Bacelis-Martínez

    2017-01-01

    Full Text Available Owing to its distinctive physicochemical properties, nickel-cobalt mixed oxide (NiCo2O4 has become a promising and innovative material for applications in many technological fields. The design of fast and reliable techniques for the deposition of this material is essential in the development of applications. In this work, NiCo2O4 films were successfully prepared by an inkjet printing technique using a suitable ink obtained from metal nitrates in a glycerol-water mixture. In order to deposit well-defined and uniform film patterns, the instrumental parameters such as drop spacing and inkjet voltage have been explored. The pure crystalline bimetallic nickel cobaltite oxide is obtained at 500°C with a homogeneous compositional distribution along the film. The average thickness observed by scanning electron microscopy is around 490 nm, whereas X-ray photoelectron spectroscopy analysis revealed that the film surface presents mixed oxidation states for both metals: Co2+, Co3+, Ni2+, and Ni3+. The electrocatalytic performance of inkjet-printed NiCo2O4 films for the water oxidation reaction is comparable with earlier reports.

  3. Increasing sensitivity of arc-induced long-period gratings—pushing the fabrication technique toward its limits

    International Nuclear Information System (INIS)

    Smietana, M; Bock, W J; Mikulic, P; Chen, J

    2011-01-01

    This paper presents an investigation of the sensing properties of long-period gratings (LPGs) written with the electric-arc technique in commonly used standard germanium-doped Corning SMF28 and boron co-doped Fibercore PS1250/1500 fibers. In order to increase the sensitivity of the LPGs, we studied and established for each fiber the writing parameters allowing for the coupling of the highest possible order of cladding modes at a resonance wavelength around λ = 1550 nm. The sensitivity of the LPGs to refractive index, to temperature and to hydrostatic pressure was investigated. The experimental results were supported by extensive numerical simulations. Thanks to the well-established and precisely controlled arc-writing process, we were able to reduce the minimum period of the gratings down to 345 and 221 µm, respectively, for LPGs based on the SMF28 and PS1250/1500 fibers. To the best of our knowledge, these are the shortest periods ever achieved for these fibers using the arc-manufacturing technique. The pressure sensitivities of 13 and 220 pm bar −1 are the highest ever measured for LPGs written in the SMF28 and PS1250/1500 fibers, respectively. Moreover, a reduction in the diameters of the SMF28 fiber induced by the arc was found, which significantly affected the distribution of resonances generated by the coupled cladding modes

  4. Biocompatible cephalosporin-hydroxyapatite-poly(lactic-co-glycolic acid)-coatings fabricated by MAPLE technique for the prevention of bone implant associated infections

    Science.gov (United States)

    Rădulescu, Dragoş; Grumezescu, Valentina; Andronescu, Ecaterina; Holban, Alina Maria; Grumezescu, Alexandru Mihai; Socol, Gabriel; Oprea, Alexandra Elena; Rădulescu, Marius; Surdu, Adrian; Trusca, Roxana; Rădulescu, Radu; Chifiriuc, Mariana Carmen; Stan, Miruna S.; Constanda, Sabrina; Dinischiotu, Anca

    2016-06-01

    In this study we aimed to obtain functionalized thin films based on hydroxyapatite/poly(lactic-co-glycolic acid) (HAp/PLGA) containing ceftriaxone/cefuroxime antibiotics (ATBs) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The prepared thin films were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), selected area electron diffraction (SAED), and infra red (IR) analysis. HAp/PLGA/ATBs thin films sustained the growth of human osteoblasts, proving their good biocompatibility. The microscopic evaluation and the culture-based quantitative assay of the E. coli biofilm development showed that the thin films inhibited the initial step of microbial attachment as well as the subsequent colonization and biofilm development on the respective surfaces. This study demonstrates that MAPLE technique could represent an appealing technique for the fabrication of antibiotics-containing polymeric implant coatings. The bioevaluation results recommend this type of surfaces for the prevention of bone implant microbial contamination and for the enhanced stimulation of the implant osseointegration process.

  5. Biocompatible cephalosporin-hydroxyapatite-poly(lactic-co-glycolic acid)-coatings fabricated by MAPLE technique for the prevention of bone implant associated infections

    Energy Technology Data Exchange (ETDEWEB)

    Rădulescu, Dragoş [Bucharest University Hospital, Department of Orthopedics and Traumatology, Bucharest (Romania); Grumezescu, Valentina [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Lasers Department, National Institute for Lasers, Plasma & Radiation Physics, Magurele, Bucharest (Romania); Andronescu, Ecaterina [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Holban, Alina Maria [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1–3 Portocalelor Lane, Sector 5, 77206 Bucharest (Romania); Research Institute of the University of Bucharest –ICUB, 91-95 Splaiul Independentei, 050095 Bucharest (Romania); Grumezescu, Alexandru Mihai, E-mail: grumezescu@yahoo.com [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Socol, Gabriel [Lasers Department, National Institute for Lasers, Plasma & Radiation Physics, Magurele, Bucharest (Romania); Oprea, Alexandra Elena [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Rădulescu, Marius [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); and others

    2016-06-30

    Graphical abstract: - Highlights: • HAp/PLGA thin coatings by Matrix Assisted Pulsed Laser Evaporation. • Anti-adherent coating on medical surfaces against S. aureus and P. aeruginosa colonization. • Coatings with potential applications in implant osseointegration. - Abstract: In this study we aimed to obtain functionalized thin films based on hydroxyapatite/poly(lactic-co-glycolic acid) (HAp/PLGA) containing ceftriaxone/cefuroxime antibiotics (ATBs) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The prepared thin films were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), selected area electron diffraction (SAED), and infra red (IR) analysis. HAp/PLGA/ATBs thin films sustained the growth of human osteoblasts, proving their good biocompatibility. The microscopic evaluation and the culture-based quantitative assay of the E. coli biofilm development showed that the thin films inhibited the initial step of microbial attachment as well as the subsequent colonization and biofilm development on the respective surfaces. This study demonstrates that MAPLE technique could represent an appealing technique for the fabrication of antibiotics-containing polymeric implant coatings. The bioevaluation results recommend this type of surfaces for the prevention of bone implant microbial contamination and for the enhanced stimulation of the implant osseointegration process.

  6. Ultrathin Silicon Sheet in the Management of Unilateral Post-traumatic Temporo-Mandibuar Joint Ankylosis in Children: A Good Alternative to Conventional Techniques.

    Science.gov (United States)

    Aggarwal, Sushil Kumar; Ankur, Bhatnagar; Jain, R K

    2015-09-01

    We have described a new technique of using ultra-thin silicon sheet (0.2 mm) between two transected bony ends for temporo-mandibular joint (TMJ) ankylosis in children with advantages of short operative time, minimal foreign material insertion and faster recovery time post-operatively which makes our technique a good alternative to conventional techniques. Our study is a non-randomized prospective study conducted on 10 children aged between 4 and 15 years who presented to our tertiary care institute with severe trismus after traumatic injury and were willing to undergo this new technique. The main outcome measure taken into consideration was difference between pre-operative, intra-operative (on table) and post-operative mouth opening (minimum 2 years follow-up). The pre-operative mouth opening in our cases varied from 1 to 5 mm. The intra-operative mouth opening achieved ranged from 2.8 to 3.2 cm. The mouth opening was about more than 2.7 cm in all our cases at 2 years of follow-up. Our technique is a good alternative to conventional techniques used for TMJ ankylosis in children but few more randomized controlled trials are required to assess its effectiveness in comparison to conventional techniques and for universal adoption of this technique.

  7. Fabric based supercapacitor

    International Nuclear Information System (INIS)

    Yong, S; Tudor, M J; Beeby, S P; Owen, J R

    2013-01-01

    Flexible supercapacitors with electrodes coated on inexpensive fabrics by the dipping technique. This paper present details of the design, fabrication and characterisation of fabric supercapacitor. The sandwich structured supercapacitors can achieve specific capacitances of 11.1F/g, area capacitance 105 mF.cm −2 and maintain 95% of the initial capacitance after cycling the device for more than 15000 times

  8. Fabrication of hydroxyapatite-baghdadite nanocomposite scaffolds coated by PCL/Bioglass with polyurethane polymeric sponge technique

    Directory of Open Access Journals (Sweden)

    Ebrahim Karamian

    2017-07-01

    Full Text Available Objecttive (s: Silicate bioceramics like Baghdadite with chemical formula Ca3ZrSi2O9, has attracted the attention of researchers in biomedical field due to its remarkable in-vitro and in-vivo bioactivity and mechanical properties.Materials and Methods: Therefore, in the current study the baghdadite powder with Sol-Gel method was synthesized. Then, hydroxyapatite/Baghdadite (HA/Bagh scaffolds were prepared by the replacing the polyurethane polymeric sponge technique. Afterwhile, the ceramic scaffolds were sintered at 1150ºC for 3 h. The prepared scaffold was then coated by polycaprolactone/bioglass (PCL/BG polymer nanocomposite. Results: Bioactivity and biomineralization in the simulated body fluid (SBF revealed that the nanocomposite scaffolds coate with PCL/BG had significant bioactivity properties. The morophology and microstructure investigation of soaked samples in SBF indicate that bone-like apatite formed on the surfaces. Also, ion release in SBF containing the scaffolds was measured by inductively coupled plasma (ICP analysis. The nucleation positions of apatite crystals were areas with high silicon containing, Si+4 ion positions.Conclusion: The study indicates that scaffold containing 30 wt. % baghdadite had proper bioactivity behaviordue to its ability to form bone-like apatite on the surface of specimens.

  9. Surface-enhanced Raman scattering by colloidal CdSe nanocrystal submonolayers fabricated by the Langmuir–Blodgett technique

    Directory of Open Access Journals (Sweden)

    Alexander G. Milekhin

    2015-12-01

    Full Text Available We present the results of an investigation of surface-enhanced Raman scattering (SERS by optical phonons in colloidal CdSe nanocrystals (NCs homogeneously deposited on both arrays of Au nanoclusters and Au dimers using the Langmuir–Blodgett technique. The coverage of the deposited NCs was less than one monolayer, as determined by transmission and scanning electron microscopy. SERS by optical phonons in CdSe nanocrystals showed a significant enhancement that depends resonantly on the Au nanocluster and dimer size, and thus on the localized surface plasmon resonance (LSPR energy. The deposition of CdSe nanocrystals on the Au dimer nanocluster arrays enabled us to study the polarization dependence of SERS. The maximal SERS signal was observed for light polarization parallel to the dimer axis. The polarization ratio of the SERS signal parallel and perpendicular to the dimer axis was 20. The SERS signal intensity was also investigated as a function of the distance between nanoclusters in a dimer. Here the maximal SERS enhancement was observed for the minimal distance studied (about 10 nm, confirming the formation of SERS “hot spots”.

  10. Superhard nanocomposite nc-TiC/a-C:H film fabricated by filtered cathodic vacuum arc technique

    International Nuclear Information System (INIS)

    Wang Yaohui; Zhang Xu; Wu Xianying; Zhang Huixing; Zhang Xiaoji

    2008-01-01

    Superhard nanocomposite nc-TiC/a-C:H films, with an excellent combination of high elastic recovery, low friction coefficient and good H/E ratio, were prepared by filtered cathodic vacuum arc technique using the C 2 H 2 gas as the precursor. The effect of C 2 H 2 flow rate on the microstructure, phase composition, mechanical and tribological properties of nanocomposite nc-TiC/a-C:H films have been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy disperse spectroscopy (EDS), microindentation and tribotester measurements. It was observed that the C 2 H 2 flow rate significantly affected the Ti content and hardness of films. Furthermore, by selecting the proper value for C 2 H 2 flow rate, 20 sccm, one can deposit the nanocomposite film nc-TiC/a-C:H with excellent properties such as superhardness (66.4 GPa), high elastic recovery (83.3%) and high H/E ratio (0.13)

  11. Fabrication and evaluation of pH-modulated solid dispersion for telmisartan by spray-drying technique.

    Science.gov (United States)

    Marasini, Nirmal; Tran, Tuan Hiep; Poudel, Bijay Kumar; Cho, Hyuk Jun; Choi, Young Keun; Chi, Sang-Cheol; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2013-01-30

    The present study was undertaken to overcome the problems associated with solubility, dissolution and oral bioavailability of a poorly water-soluble ionizable drug, telmisartan (TMS). For these purposes, a solubility test was carried to select the appropriate formulation composition from various carriers and alkalizers. Solid dispersions (SDs) of TMS were prepared at different drug-to-carrier ratios by the spray-drying technique, and were characterized by dissolution and aqueous solubility studies. The optimum formulation was investigated by dissolution studies at different pH and water media and its solid state characterisations were performed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. In solubility and dissolution tests, all TMS-loaded pH-modulated SDs (pH(M)-SDs) exhibited marked improvement in the dissolution behavior when compared with crystalline TMS powder. The optimum formulation of pH(M)-SD consisted of TMS/PVP (polyvinylpyrrolidone) K30/Na(2)CO(3) at a weight ratio of 2/0.5/3 and showed significant improvement in the aqueous solubility and dissolution rate by approximately 40,000- and 3-fold, respectively, compared to TMS powder. Solid-state characterization revealed the changed in crystallinity of TMS into amorphous state. Furthermore, area under the drug concentration time-curve (AUC) of TMS from the pH(M)-SD increased by 13.4- and 2.1-fold, compared with TMS powder and commercial product, respectively. According to these observations, taken together with dissolution and pharmacokinetic behaviors, pH-modulated SD in the presence of an alkalizer for a poorly water-soluble ionizable drug, TMS, appeared to be efficacious for enhancing its bioavailability. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Evidence for an impact-induced magnetic fabric in Allende, and exogenous alternatives to the core dynamo theory for Allende magnetization

    Science.gov (United States)

    Muxworthy, Adrian R.; Bland, Phillip A.; Davison, Thomas M.; Moore, James; Collins, Gareth S.; Ciesla, Fred J.

    2017-10-01

    We conducted a paleomagnetic study of the matrix of Allende CV3 chondritic meteorite, isolating the matrix's primary remanent magnetization, measuring its magnetic fabric and estimating the ancient magnetic field intensity. A strong planar magnetic fabric was identified; the remanent magnetization of the matrix was aligned within this plane, suggesting a mechanism relating the magnetic fabric and remanence. The intensity of the matrix's remanent magnetization was found to be consistent and low ( 6 μT). The primary magnetic mineral was found to be pyrrhotite. Given the thermal history of Allende, we conclude that the remanent magnetization was formed during or after an impact event. Recent mesoscale impact modeling, where chondrules and matrix are resolved, has shown that low-velocity collisions can generate significant matrix temperatures, as pore-space compaction attenuates shock energy and dramatically increases the amount of heating. Nonporous chondrules are unaffected, and act as heat-sinks, so matrix temperature excursions are brief. We extend this work to model Allende, and show that a 1 km/s planar impact generates bulk porosity, matrix porosity, and fabric in our target that match the observed values. Bimodal mixtures of a highly porous matrix and nominally zero-porosity chondrules make chondrites uniquely capable of recording transient or unstable fields. Targets that have uniform porosity, e.g., terrestrial impact craters, will not record transient or unstable fields. Rather than a core dynamo, it is therefore possible that the origin of the magnetic field in Allende was the impact itself, or a nebula field recorded during transient impact heating.

  13. Rough order of magnitude cost estimate for immobilization of 18.2 MT of plutonium sharing existing facilities at Hanford with MOX fuel fabrication facility: alternative 4B

    International Nuclear Information System (INIS)

    DiSabatino, A.

    1998-01-01

    The purpose of this Cost Estimate Report is to identify preliminary capital and operating costs for a facility to immobilize 18.2 metric tons (nominal) of plutonium as a ceramic in an existing facility at Hanford, the Fuels and Materials Examination Facility (FMEF). The MOX Fuel Fabrication Facility (MFFF), which is being costed in a separate report, will also be located in the FMEF in this co-location option

  14. Experimental study of PLLA/INH slow release implant fabricated by three dimensional printing technique and drug release characteristics in vitro.

    Science.gov (United States)

    Wu, Gui; Wu, Weigang; Zheng, Qixin; Li, Jingfeng; Zhou, Jianbo; Hu, Zhilei

    2014-07-19

    Local slow release implant provided long term and stable drug release in the lesion. The objective of this study was to fabricate biodegradable slow release INH/PLLA tablet via 3 dimensional printing technique (3DP) and to compare the drug release characteristics of three different structured tablets in vitro. Three different drug delivery systems (columnar-shaped tablet (CST), doughnut-shaped tablet (DST) and multilayer doughnut-shaped tablet (MDST)) were manufactured by the three dimensional printing machine and isoniazid was loaded into the implant. Dynamic soaking method was used to study the drug release characteristics of the three implants. MTT cytotoxicity test and direct contact test were utilized to study the biocompatibility of the implant. The microstructures of the implants' surfaces were observed with electron microscope. The PLLA powder in the tablet could be excellently combined through 3DP without disintegration. Electron microscope observations showed that INH distributed evenly on the surface of the tablet in a "nest-shaped" way, while the surface of the barrier layer in the multilayer doughnut shaped tablet was compact and did not contain INH. The concentration of INH in all of the three tablets were still higher than the effective bacteriostasis concentration (Isoniazid: 0.025 ~ 0.05 μg/ml) after 30 day's release in vitro. All of the tablets showed initial burst release of the INH in the early period. Drug concentration of MDST became stable and had little fluctuation starting from the 6th day of the release. Drug concentration of DST and CST decreased gradually and the rate of decrease in concentration was faster in DST than CST. MTT cytotoxicity test and direct contact test indicated that the INH-PLLA tablet had low cytotoxicity and favorable biocompatibility. Three dimensional printing technique was a reliable technique to fabricate complicated implants. Drug release pattern in MDST was the most stable among the three implants. It was

  15. Film fabrication of Fe or Fe3O4 nanoparticles mixed with palmitic acid for vertically aligned carbon nanotube growth using Langmuir-Blodgett technique

    Science.gov (United States)

    Nakamura, Kentaro; Kuriyama, Naoki; Takagiwa, Shota; Sato, Taiga; Kushida, Masahito

    2016-03-01

    Vertically aligned carbon nanotubes (VA-CNTs) were studied as a new catalyst support for polymer electrolyte fuel cells (PEFCs). Controlling the number density and the diameter of VA-CNTs may be necessary to optimize PEFC performance. As the catalyst for CNT growth, we fabricated Fe or Fe3O4 nanoparticle (NP) films by the Langmuir-Blodgett (LB) technique. The catalyst Fe or Fe3O4 NPs were widely separated by mixing with filler molecules [palmitic acid (C16)]. The number density of VA-CNTs was controlled by varying the ratio of catalyst NPs to C16 filler molecules. The VA-CNTs were synthesized from the catalyst NP-C16 LB films by thermal chemical vapor deposition (CVD) using acetylene gas as the carbon source. The developing solvents used in the LB technique and the hydrogen reduction conditions of CVD were optimized to improve the VA-CNT growth rate. We demonstrate that the proposed method can independently control both the density and the diameter of VA-CNTs.

  16. Accuracy and precision of polyurethane dental arch models fabricated using a three-dimensional subtractive rapid prototyping method with an intraoral scanning technique.

    Science.gov (United States)

    Kim, Jae-Hong; Kim, Ki-Baek; Kim, Woong-Chul; Kim, Ji-Hwan; Kim, Hae-Young

    2014-03-01

    This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of inter-examiner and inter-method variability. The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.

  17. Fabrication of integrated metallic MEMS devices

    DEFF Research Database (Denmark)

    Yalcinkaya, Arda Deniz; Ravnkilde, Jan Tue; Hansen, Ole

    2002-01-01

    A simple and complementary metal oxide semiconductor (CMOS) compatible fabrication technique for microelectromechanical (MEMS) devices is presented. The fabrication technology makes use of electroplated metal layers. Among the fabricated devices, high quality factor microresonators are characteri......A simple and complementary metal oxide semiconductor (CMOS) compatible fabrication technique for microelectromechanical (MEMS) devices is presented. The fabrication technology makes use of electroplated metal layers. Among the fabricated devices, high quality factor microresonators...

  18. In vitro and in vivo performance of bioactive Ti6Al4V/TiC/HA implants fabricated by a rapid microwave sintering technique.

    Science.gov (United States)

    Choy, Man Tik; Tang, Chak Yin; Chen, Ling; Wong, Chi Tak; Tsui, Chi Pong

    2014-09-01

    Failure of the bone-implant interface in a joint prosthesis is a main cause of implant loosening. The introduction of a bioactive substance, hydroxyapatite (HA), to a metallic bone-implant may enhance its fixation on human bone by encouraging direct bone bonding. Ti6Al4V/TiC/HA composites with a reproducible porous structure (porosity of 27% and pore size of 6-89 μm) were successfully fabricated by a rapid microwave sintering technique. This method allows the biocomposites to be fabricated in a short period of time under ambient conditions. Ti6Al4V/TiC/HA composites exhibited a compressive strength of 93 MPa, compressive modulus of 2.9 GPa and microhardness of 556 HV which are close to those of the human cortical bone. The in vitro preosteoblast MC3T3-E1 cells cultured on the Ti6Al4V/TiC/HA composite showed that the composite surface could provide a biocompatible environment for cell adhesion, proliferation and differentiation without any cytotoxic effects. This is among the first attempts to study the in vivo performance of load-bearing Ti6Al4V/TiC and Ti6Al4V/TiC/HA composites in a live rabbit. The results indicated that the Ti6Al4V/TiC/HA composite had a better bone-implant interface compared with the Ti6Al4V/TiC implant. Based on the microstructural features, the mechanical properties, and the in vitro and in vivo test results from this study, the Ti6Al4V/TiC/HA composites have the potential to be employed in load-bearing orthopedic applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. In vitro and in vivo performance of bioactive Ti6Al4V/TiC/HA implants fabricated by a rapid microwave sintering technique

    International Nuclear Information System (INIS)

    Choy, Man Tik; Tang, Chak Yin; Chen, Ling; Wong, Chi Tak; Tsui, Chi Pong

    2014-01-01

    Failure of the bone–implant interface in a joint prosthesis is a main cause of implant loosening. The introduction of a bioactive substance, hydroxyapatite (HA), to a metallic bone–implant may enhance its fixation on human bone by encouraging direct bone bonding. Ti6Al4V/TiC/HA composites with a reproducible porous structure (porosity of 27% and pore size of 6–89 μm) were successfully fabricated by a rapid microwave sintering technique. This method allows the biocomposites to be fabricated in a short period of time under ambient conditions. Ti6Al4V/TiC/HA composites exhibited a compressive strength of 93 MPa, compressive modulus of 2.9 GPa and microhardness of 556 HV which are close to those of the human cortical bone. The in vitro preosteoblast MC3T3-E1 cells cultured on the Ti6Al4V/TiC/HA composite showed that the composite surface could provide a biocompatible environment for cell adhesion, proliferation and differentiation without any cytotoxic effects. This is among the first attempts to study the in vivo performance of load-bearing Ti6Al4V/TiC and Ti6Al4V/TiC/HA composites in a live rabbit. The results indicated that the Ti6Al4V/TiC/HA composite had a better bone–implant interface compared with the Ti6Al4V/TiC implant. Based on the microstructural features, the mechanical properties, and the in vitro and in vivo test results from this study, the Ti6Al4V/TiC/HA composites have the potential to be employed in load-bearing orthopedic applications. - Highlights: • Ti6Al4V/TiC and Ti6Al4V/TiC/HA composites were fabricated by microwave sintering. • Ti6Al4V/TiC/HA exhibited mechanical properties close to human cortical bone. • Ti6Al4V/TiC/HA could provide a biocompatible environment for bone cell growth. • Ti6Al4V/TiC/HA showed a better bone–implant interface than Ti6Al4V/TiC. • Ti6Al4V/TiC/HA could be used for bone replacement under load-bearing conditions

  20. Depleted uranium management alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T.J.; Nishimoto, D.D.

    1994-08-01

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process.

  1. Depleted uranium management alternatives

    International Nuclear Information System (INIS)

    Hertzler, T.J.; Nishimoto, D.D.

    1994-08-01

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process

  2. Resistless Fabrication of Nanoimprint Lithography (NIL Stamps Using Nano-Stencil Lithography

    Directory of Open Access Journals (Sweden)

    Juergen Brugger

    2013-10-01

    Full Text Available In order to keep up with the advances in nano-fabrication, alternative, cost-efficient lithography techniques need to be implemented. Two of the most promising are nanoimprint lithography (NIL and stencil lithography. We explore here the possibility of fabricating the stamp using stencil lithography, which has the potential for a cost reduction in some fabrication facilities. We show that the stamps reproduce the membrane aperture patterns within ±10 nm and we validate such stamps by using them to fabricate metallic nanowires down to 100 nm in size.

  3. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    Science.gov (United States)

    Ebrahimpour, Omid

    second part of the project. Alumina sol was synthesized by the hydrolysis of Aluminum isopropoxide using the Yoldas method. Alumina sol was homogenous and had a needle-like shape with a thickness of 2--3 nm. Crystalline changes during the heating process of alumina sol were studied using XRD. In addition, Fourier transform infrared (FTIR) spectroscopy was performed to identify the functional groups on the alumina sol surface as a function of temperature. In the third part of the project, the feasibility of the in-situ polymerization technique was investigated to fabricate porous SiC ceramics. In this part, the mixture of SiC and calcined alumina powders were coated by polyethylene via in-situ polymerizing referred to as the polymerization compounding process in a slurry phase. The polymerization was conducted under very moderate operational conditions using the Ziegler-Natta catalyst system. Differential scanning calorimetry (DSC) and TGA analysis and morphological studies (SEM and TEM) revealed the presence of a high density of polyethylene on the surface of SiC and alumina powders. The amount of polymer was controlled by the polymerization reaction time. Most parts of particles were coated by a thin layer of polyethylene and polymer. The porous SiC ceramics, which were fabricated by these treated particles showed higher mechanical and physical properties compared to the samples made without any treatment. The relative intensity of mullite was higher compared to the samples prepared by the traditional process. The effects of the sintering temperature, forming pressure and polymer content were also studied on the physical and mechanical properties of the final product. In the last phase of this research work, the focus of the investigation was to take advantage of both the sol-gel processing and in-situ polymerization method to develop a new process to manufacture mullite-bonded porous SiC ceramic with enhanced mechanical and physical properties. Therefore, first the Si

  4. The Validation of an Interactive Videodisc as an Alternative to Traditional Teaching Techniques: Auscultation of the Heart.

    Science.gov (United States)

    Branck, Charles E.; And Others

    1987-01-01

    This study of 87 veterinary medical students at Auburn University tests the effectiveness and student acceptance of interactive videodisc as an alternative to animal experimentation and other traditional teaching methods in analyzing canine cardiovascular sounds. Results of the questionnaire used are presented, and benefits of interactive video…

  5. AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN SCIENCE AND TECHNIQUE. PART 32: ALTERNATIVE ENERGY: STATE AND PROSPECTS OF DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2016-06-01

    Full Text Available Purpose. Implementation of brief analytical review of the state and prospect of development in the modern world of alternative energy, including wind energy, sun energy, geothermal energy, biogas energy, flood-tide water energy, hydrogen energy and small water energy. Methodology. Scientific methods of collection, analysis and analytical treatment of scientific and technical information in area of the present state of world energy and ways of its further development. Results. A brief scientific and technical review is resulted about the state and prospects of world development of basic types of alternative energy. It is shown that, in spite of comparatively small stake (to 10 % of this untraditional energy in general world balance of making of electric power, world association taking into account the necessary changing in the nearest 50 years of present oil-gas «foundation» of energy on other with large raw material, potential and ecological possibilities are forced to invest large financial means in development of the indicated directions of alternative energy. Originality. First on the basis of materials of separate magazine publications, scientific monographs and internet-reports on power problem the brief analytical review of the state and prospects of world development of basic types of alternative energy is executed. Practical value. Deepening and spread of the scientific and technical learnings in area of functioning and ways of development of modern energy. Scientific popularization of arising up before society claimed tasks from global and important for all of humanity of power problem.

  6. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties

    Directory of Open Access Journals (Sweden)

    Mehrabanian M

    2011-08-01

    Full Text Available Mehran Mehrabanian1, Mojtaba Nasr-Esfahani21Member of Young Researchers Club, Najafabad Branch, Islamic Azad University, Isfahan, Iran; 2Department of Materials Science and Engineering, Najafabad Branch, Islamic Azad University, Isfahan, IranAbstract: Nanohydroxyapatite (n-HA/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60% for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 µm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.Keywords: scaffold, nanohydroxyapatite, nylon 6,6, salt-leaching/solvent casting, bioactivity

  7. Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chong [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Chen, Xiaohan; Han, Qiaorong [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhou, Min [Department of Vascular Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Mao, Chun, E-mail: maochun127@yahoo.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhu, Qinshu [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Shen, Jian, E-mail: jshen@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China)

    2013-05-07

    Highlight: •A novel method for detection of glucose in whole blood has been developed. •The method based on antibiofouling and self-assembly technology was investigated. •The antibiofouling technique utilized for sensor is significant for diagnostics. -- Abstract: Acknowledging the benefits of hyperbranched polymers and their nanoparticles, herein we report the design and synthesis of sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO{sub 3}H) nanoparticles and their biomedical application. The H30-SO{sub 3}H nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR). The good hemocompatibility of H30-SO{sub 3}H nanoparticles was also investigated by coagulation tests, complement activation and platelet activation. The novel glucose biosensor was fabricated by immobilizing the positively charged Au nanoparticles, H30-SO{sub 3}H nanoparticles and glucose oxidase (GOx) onto the surface of glassy carbon electrode (GCE). It can be applied in whole blood directly, which was based on the good hemocompatibility and antibiofouling property of H30-SO{sub 3}H nanoparticles. The biosensor had good electrocatalytic activity toward glucose with a wide linear range (0.2–20 mM), a low detection limit 1.2 × 10{sup −5} M in whole blood and good anti-interference property. The development of materials science will offer a novel platform for application to substance detection in whole blood.

  8. Application of a cold spray technique to the fabrication of a copper canister for the geological disposal of CANDU spent fuels

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Heui-Joo, E-mail: hjchoi@kaeri.re.k [Korea Atomic Energy Research Institute, Radioactive Waste Management Technology Development, 150 Dukjin-dong, Yuseong, Daejon, 305-353 (Korea, Republic of); Lee, Minsoo; Lee, Jong Youl [Korea Atomic Energy Research Institute, Radioactive Waste Management Technology Development, 150 Dukjin-dong, Yuseong, Daejon, 305-353 (Korea, Republic of)

    2010-10-15

    A new method was proposed for the manufacture of a copper-cast iron canister for the spent fuel disposal based on the cold spray coating technique. The thickness of a copper shell could be fabricated to be as thin as 10 mm with the new method. Around 6 tons of copper could be saved with a 10 mm thick canister compared with a 50 mm thick canister. The electrochemical properties of the cold sprayed copper layer and forged copper were measured through a polarization test. The two copper layers showed very similar electrochemical properties. The lifetime of a 10 mm copper canister was estimated with a mathematical model based on the mass transport of sulfide ions through the buffer. The results showed that the canister lifetime was more than 140,000 years under the Korean granite groundwater condition. The thermal analysis with a current pre-conceptual design of a CANDU spent fuel canister showed that the maximum temperature between the canister and the saturated buffer was below the thermal criteria, 100 {sup o}C. Finally, the mechanical stability of the copper canister was confirmed with a computer program, ABAQUS, under the rock movement scenario.

  9. Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique

    International Nuclear Information System (INIS)

    Sun, Chong; Chen, Xiaohan; Han, Qiaorong; Zhou, Min; Mao, Chun; Zhu, Qinshu; Shen, Jian

    2013-01-01

    Highlight: •A novel method for detection of glucose in whole blood has been developed. •The method based on antibiofouling and self-assembly technology was investigated. •The antibiofouling technique utilized for sensor is significant for diagnostics. -- Abstract: Acknowledging the benefits of hyperbranched polymers and their nanoparticles, herein we report the design and synthesis of sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO 3 H) nanoparticles and their biomedical application. The H30-SO 3 H nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy ( 1 H NMR). The good hemocompatibility of H30-SO 3 H nanoparticles was also investigated by coagulation tests, complement activation and platelet activation. The novel glucose biosensor was fabricated by immobilizing the positively charged Au nanoparticles, H30-SO 3 H nanoparticles and glucose oxidase (GOx) onto the surface of glassy carbon electrode (GCE). It can be applied in whole blood directly, which was based on the good hemocompatibility and antibiofouling property of H30-SO 3 H nanoparticles. The biosensor had good electrocatalytic activity toward glucose with a wide linear range (0.2–20 mM), a low detection limit 1.2 × 10 −5 M in whole blood and good anti-interference property. The development of materials science will offer a novel platform for application to substance detection in whole blood

  10. Morphological appearances and photo-controllable coloration of dye-doped cholesteric liquid crystal/polymer coaxial microfibers fabricated by coaxial electrospinning technique.

    Science.gov (United States)

    Lin, Jia-De; Chen, Che-Pei; Chen, Lin-Jer; Chuang, Yu-Chou; Huang, Shuan-Yu; Lee, Chia-Rong

    2016-02-08

    This study systematically investigates the morphological appearance of azo-chiral dye-doped cholesteric liquid crystal (DDCLC)/polymer coaxial microfibers obtained through the coaxial electrospinning technique and examines, for the first time, their photocontrollable reflection characteristics. Experimental results show that the quasi-continuous electrospun microfibers can be successfully fabricated at a high polymer concentration of 17.5 wt% and an optimum ratio of 2 for the feeding rates of sheath to core materials at 25 °C and a high humidity of 50% ± 2% in the spinning chamber. Furthermore, the optical controllability of the reflective features for the electrospun fibers is studied in detail by changing the concentration of the azo-chiral dopant in the core material, the UV irradiation intensity, and the core diameter of the fibers. Relevant mechanisms are addressed to explain the optical-control behaviors of the DDCLC coaxial fibers. Considering the results, optically controllable DDCLC coaxial microfibers present potential applications in UV microsensors and wearable smart textiles or swabs.

  11. Fabrication of a large area cathode-supported thin electrolyte film for solid oxide fuel cells via tape casting and co-sintering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chunhua; Liu, Renzhu; Wang, Shaorong; Wen, Tinglian [Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2009-04-15

    A large area cathode-supported electrolyte film, comprising porous (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3} (LSM95) cathode substrate, LSM95/Zr{sub 0.89}Sc{sub 0.1}Ce{sub 0.01}O{sub 2-x} (SSZ) cathode active layer, and SSZ electrolyte, has been successfully fabricated by tape casting and co-sintering techniques. The interface reaction between cathode and electrolyte was inhibited by using A-site deficient LSM. A dense enough SSZ thin film with a thickness of {proportional_to}26 {mu}m was obtained at 1250 C. By using Pt as anode, the obtained single cell reached the maximum power density of 0.54 W cm{sup -2} at 800 C in O{sub 2}/humidified H{sub 2}, with open circuit voltage (OCV) value of 1.08 V. (author)

  12. Microstructure and Mechanical Properties of MWCNTs Reinforced A356 Aluminum Alloys Cast Nanocomposites Fabricated by Using a Combination of Rheocasting and Squeeze Casting Techniques

    Directory of Open Access Journals (Sweden)

    Abou Bakr Elshalakany

    2014-01-01

    Full Text Available A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM and scanning electron microscopy (SEM equipped with an energy dispersive X-ray analysis (EDX. This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt% of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.

  13. An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

    Science.gov (United States)

    Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

    2014-03-01

    Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

  14. Fabrication Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Fabrication Facilities are a direct result of years of testing support. Through years of experience, the three fabrication facilities (Fort Hood, Fort Lewis, and...

  15. Nr 1115 National Assembly, Nr 640 Senate - Stage report on alternate techniques to hydraulic fracturing for the exploration and exploitation of non conventional hydrocarbons

    International Nuclear Information System (INIS)

    Lenoir, Jean-Claude; Bataille, Christian

    2013-01-01

    While noticing that these resources are more supposed that demonstrated, this report first addresses the potential of non conventional hydrocarbon resources: definition, forms and assessment. It presents the status and locations of such resources in France, and discusses how uncertainties can be reduced as far as gas shale and hydrocarbons are concerned (exploration drillings seem necessary). The second part proposes an overview of the various extraction techniques: technologies without fracturing, and hydraulic fracturing (description, recall of previous uses in France, technique management). The third part presents alternate techniques as research topics to be explored: stimulation by another pressurized fluid than water, or by other physical processes (electric arc, thermal process). Proposals are stated. The document also comprised a report of meeting of the scientific committee, a list of heard persons, and a feasibility study

  16. 'Stent in a stent'--an alternative technique for removing partially covered stents following sleeve gastrectomy complications.

    Science.gov (United States)

    Vasilikostas, Georgios; Sanmugalingam, Nimalan; Khan, Omar; Reddy, Marcus; Groves, Chris; Wan, Andrew

    2014-03-01

    Endoscopic stenting is a relatively new technique for the treatment of post sleeve gastrectomy complications. Partially covered stents are used in this method to minimise the risk of migration but they are associated with difficulties with removal. Patients requiring emergency stenting following sleeve gastrectomy underwent insertion of a partially covered metallic stent. One month later, if the stent was not easily removable, a fully covered overlapping stent was inserted and the patient was readmitted 2 weeks later for removal of both stents. Four patients required stenting following sleeve gastrectomy leaks, and one patient required stenting for a stricture. In these cases, a 'stent in a stent' technique was used for removal. This technique allows the safe removal of partially covered stents inserted following sleeve gastrectomy complications.

  17. Special Care Dentistry Association consensus statement on sedation, anesthesia, and alternative techniques for people with special needs.

    Science.gov (United States)

    Glassman, Paul; Caputo, Anthony; Dougherty, Nancy; Lyons, Ray; Messieha, Zakaria; Miller, Christine; Peltier, Bruce; Romer, Maureen

    2009-01-01

    Many people with special needs (PSN) have difficulty having good oral health or accessing oral health services because of a disability or medical condition. The number of people with these conditions living in community settings and needing oral health services is increasing dramatically due to advances in medical care, deinstitutionalization, and changing societal values. Many of these individuals require additional supports beyond local anesthesia in order to receive dental treatment services. The purpose of this consensus statement is to focus on the decision-making process for choosing a method of treatment or a combination of methods for facilitating dental treatment for these individuals. These guidelines are intended to assist oral health professionals and other interested parties in planning and carrying out oral health treatment for PSN. Considerations for planning treatment and considerations for each of several alternative modalities are listed. Also discussed are considerations for the use of combinations of modalities and considerations for the repeated or frequent use of these modalities. Finally, the need to advocate for adequate education and reimbursement for the full range of support alternatives is addressed. The Special Care Dentistry Association (SCDA) is dedicated to improving oral health and well being of PSN. The SCDA hopes that these guidelines can help oral health professionals and other interested individuals and groups to work together to ensure that PSN can achieve a "lifetime of oral health."

  18. An alternative technique in the treatment of anterior cross bite in a case of Nickel allergy: a case report.

    Science.gov (United States)

    Giancotti, A; Mozzicato, P; Mampieri, G

    2011-03-01

    The objective of this paper is to show an alternative use of an Essix based appliance in the treatment of anterior single-tooth crossbite malocclusion in a patient with Nickel allergy. Anterior crossbite malocclusion of one or more teeth, without posterior crossbite association, is a relatively frequent condition both in the mixed and the permanent dentition. This kind of malocclusion is usually treated with either fixed or removable appliances. The use of preformed Essix appliances could be an alternative to traditional removable and fixed orthodontic devices in patients with Nickel allergy as well as in every patient. The treatment was successfully completed in 12 weeks, the anterior single tooth crossbite was corrected using three full arch Essix-based appliances planned on the set-up casting, providing a gradual vestibular movement. Patient compliance was requested in order to provide the planned dental movement. The Essix appliance can be successfully used to correct a single-tooth crossbite even in allergic subjects in a short time with patient cooperation.

  19. Fabrication of Eu doped CdO [Al/Eu-nCdO/p-Si/Al] photodiodes by perfume atomizer based spray technique for opto-electronic applications

    Science.gov (United States)

    Ravikumar, M.; Ganesh, V.; Shkir, Mohd; Chandramohan, R.; Arun Kumar, K. Deva; Valanarasu, S.; Kathalingam, A.; AlFaify, S.

    2018-05-01

    In this study, thin films of cadmium oxide (CdO) with different concentrations (0, 1, 3, and 5 wt%) of Eu doping were deposited onto Si and glass substrates by a novel and facile spray technique using simple perfume atomizer for the first time. Prepared films were characterized for structural, morphological, optical properties and the photo diode studies, using X-ray diffraction, scanning electron microscope, UV-Vis spectrophotometer, Isbnd V characteristics, and fundamental parameters are reported. All the prepared Eu:CdO films exhibit cubic structure. The preferential orientation is along (200) plane. Scanning electron microscopy study indicates the growth of smooth and pin-hole free films with clusters of homogeneous grains. The values of band gap energy are found to be varying from 2.42 to 2.33 eV for various Eu doping concentration from 0 to 5 wt%. EDAX studies revealed the presence of Eu, Cd and O elements without any other impurities. FTIR spectra showed a peak at 575 cm-1 confirming the stretching mode of Cdsbnd O. The resistivity (ρ), high carrier concentration (n) and carrier mobility (μ) for 3 wt% CdO thin film are found to be 0.452 × 10-3(Ω.cm), 17.82 × 1020 cm-3 and 7.757 cm2/V, respectively. Current-voltage measurements on the fabricated nanostructured Al/Eu-nCdO/p-Si/Al heterojunction device showed a non-linear electric characteristics indicating diode like behaviour.

  20. Report on alternative techniques to hydraulic fracturing for the exploration and exploitation of non conventional hydrocarbons - National Assembly No. 1581 / Senate No. 174

    International Nuclear Information System (INIS)

    LENOIR, Jean-Claude; BATAILLE, Christian

    2013-01-01

    Based on several hearings, and on missions in the USA and in Poland, this report addresses the issue of alternative techniques to hydraulic fracturing which appeared to be more advanced than hearings performed for a preliminary report had suggested. A first part outlines the necessity of fracturing the rock, and presents several possible modalities, proposes a detailed overview of alternative techniques to hydraulic fracturing used in the USA and in Poland. The second part outlines that coal gas is already an exploitable resource without rock fracturing; it discusses the possible perspectives thus associated for the old French coal-mining sites, outlines that this resource can be exploited without requiring hydraulic fracturing, and comments the first assessments. The third part addresses the possible management of risks associated with hydraulic fracturing: risks vary from one region to the other and therefore require further studies; the non-conventional hydrocarbon issue is addressed in different ways in the USA; the use of this technique must be controlled by public authorities. The next part outlines the need of an assessment of national resources before any assessment of the economic impact. The last part formulates several proposals for the future

  1. Fabrication of miniaturized electrostatic deflectors using LIGA

    International Nuclear Information System (INIS)

    Jackson, K.H.; Khan-Malek, C.; Muray, L.P.

    1997-01-01

    Miniaturized electron beam columns (open-quotes microcolumnsclose quotes) have been demonstrated to be suitable candidates for scanning electron microscopy (SEM), e-beam lithography and other high resolution, low voltage applications. In the present technology, microcolumns consist of open-quotes selectively scaledclose quotes micro-sized lenses and apertures, fabricated from silicon membranes with e-beam lithography, reactive ion beam etching and other semiconductor thin-film techniques. These miniaturized electron-optical elements provide significant advantages over conventional optics in performance and ease of fabrication. Since lens aberrations scale roughly with size, it is possible to fabricate simple microcolumns with extremely high brightness sources and electrostatic objective lenses, with resolution and beam current comparable to conventional e-beam columns. Moreover since microcolumns typically operate at low voltages (1 KeV), the proximity effects encountered in e-beam lithography become negligible. For high throughput applications, batch fabrication methods may be used to build large parallel arrays of microcolumns. To date, the best reported performance with a 1 keV cold field emission cathode, is 30 nm resolution at a working distance of 2mm in a 3.5mm column. Fabrication of the microcolumn deflector and stigmator, however, have remained beyond the capabilities of conventional machining operations and semiconductor processing technology. This work examines the LIGA process as a superior alternative to fabrication of the deflectors, especially in terms of degree of miniaturization, dimensional control, placement accuracy, run-out, facet smoothness and choice of suitable materials. LIGA is a combination of deep X-ray lithography, electroplating, and injection molding processes which allow the fabrication of microstructures

  2. Property-process relationships in nuclear fuel fabrication

    International Nuclear Information System (INIS)

    Tikare, V.

    2015-01-01

    Nuclear fuels are fabricated using many different techniques as they come in a large variety of shapes and compositions. The design and composition of nuclear fuels are predominantly dictated by the engineering requirements necessary for their function in reactors of various designs. Other engineering properties requirements originate from safety and security concerns, and the easy of handling, storing, transporting and disposing of the radioactive materials. In this chapter, the more common of these fuels will be briefly reviewed and the methods used to fabricate them will be presented. The fuels considered in this paper are oxide fuels used in LWRs and FRs, metal fuels in FRs and particulate fuels used in HTGRs. Fabrication of alternative fuel forms and use of standard fuels in alternative reactors will be discussed briefly. The primary motivation to advance fuel fabrication is to improve performance, reduce cost, reduce waste or enhance safety and security of the fuels. To achieve optimal performance, developing models to advance fuel fabrication has to be done in concert with developing fuel performance models. The specific properties and microstructures necessary for improved fuel performance must be identified using fuel performance models, while fuel fabrication models that can determine processing variables to give the desired microstructure and materials properties must be developed. (author)

  3. Low-temperature oxidizing plasma surface modification and composite polymer thin-film fabrication techniques for tailoring the composition and behavior of polymer surfaces

    Science.gov (United States)

    Tompkins, Brendan D.

    This dissertation examines methods for modifying the composition and behavior of polymer material surfaces. This is accomplished using (1) low-temperature low-density oxidizing plasmas to etch and implant new functionality on polymers, and (2) plasma enhanced chemical vapor deposition (PECVD) techniques to fabricate composite polymer materials. Emphases are placed on the structure of modified polymer surfaces, the evolution of polymer surfaces after treatment, and the species responsible for modifying polymers during plasma processing. H2O vapor plasma modification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and 75A polyurethane (PU) was examined to further our understanding of polymer surface reorganization leading to hydrophobic recovery. Water contact angles (wCA) measurements showed that PP and PS were the most susceptible to hydrophobic recovery, while PC and HDPE were the most stable. X-ray photoelectron spectroscopy (XPS) revealed a significant quantity of polar functional groups on the surface of all treated polymer samples. Shifts in the C1s binding energies (BE) with sample age were measured on PP and PS, revealing that surface reorganization was responsible for hydrophobic recovery on these materials. Differential scanning calorimetry (DSC) was used to rule out the intrinsic thermal properties as the cause of reorganization and hydrophobic recovery on HDPE, LDPE, and PP. The different contributions that polymer cross-linking and chain scission mechanisms make to polymer aging effects are considered. The H2O plasma treatment technique was extended to the modification of 0.2 microm and 3.0 microm track-etched polycarbonate (PC-TE) and track-etched polyethylene terephthalate (PET-TE) membranes with the goal of permanently increasing the hydrophilicity of the membrane surfaces. Contact angle measurements on freshly treated and aged samples confirmed the wettability of the

  4. Quantifying the Error Associated with Alternative GIS-based Techniques to Measure Access to Health Care Services

    Directory of Open Access Journals (Sweden)

    Amy Mizen

    2015-11-01

    Full Text Available The aim of this study was to quantify the error associated with different accessibility methods commonly used by public health researchers. Network distances were calculated from each household to the nearest GP our study area in the UK. Household level network distances were assigned as the gold standard and compared to alternate widely used accessibility methods. Four spatial aggregation units, two centroid types and two distance calculation methods represent commonly used accessibility calculation methods. Spearman's rank coefficients were calculated to show the extent which distance measurements were correlated with the gold standard. We assessed the proportion of households that were incorrectly assigned to GP for each method. The distance method, level of spatial aggregation and centroid type were compared between urban and rural regions. Urban distances were less varied from the gold standard, with smaller errors, compared to rural regions. For urban regions, Euclidean distances are significantly related to network distances. Network distances assigned a larger proportion of households to the correct GP compared to Euclidean distances, for both urban and rural morphologies. Our results, stratified by urban and rural populations, explain why contradicting results have been reported in the literature. The results we present are intended to be used aide-memoire by public health researchers using geographical aggregated data in accessibility research.

  5. Fabrication of Nanoimprint stamps for photonic crystals

    International Nuclear Information System (INIS)

    Kouba, J; Kubenz, M; Mai, A; Ropers, G; Eberhardt, W; Loechel, B

    2006-01-01

    We report on fabrication of nanoimprint stamps for fabrication of two dimensional photonic crystals in visible range of spectra. Nanoimprint stamps made of silicon and/or nickel were successfully fabricated using electron beam lithography and advanced dry etching techniques. The quality of the stamps was evaluated using scanning electron microscopy. The fabricated stamps were also evaluated by imprinting them into suitable polymer materials

  6. Helical Tomotherapy for Whole-Brain Irradiation With Integrated Boost to Multiple Brain Metastases: Evaluation of Dose Distribution Characteristics and Comparison With Alternative Techniques

    International Nuclear Information System (INIS)

    Levegrün, Sabine; Pöttgen, Christoph; Wittig, Andrea; Lübcke, Wolfgang; Abu Jawad, Jehad; Stuschke, Martin

    2013-01-01

    Purpose: To quantitatively evaluate dose distribution characteristics achieved with helical tomotherapy (HT) for whole-brain irradiation (WBRT) with integrated boost (IB) to multiple brain metastases in comparison with alternative techniques. Methods and Materials: Dose distributions for 23 patients with 81 metastases treated with WBRT (30 Gy/10 fractions) and IB (50 Gy) were analyzed. The median number of metastases per patient (N mets ) was 3 (range, 2-8). Mean values of the composite planning target volume of all metastases per patient (PTV mets ) and of the individual metastasis planning target volume (PTV ind met ) were 8.7 ± 8.9 cm 3 (range, 1.3-35.5 cm 3 ) and 2.5 ± 4.5 cm 3 (range, 0.19-24.7 cm 3 ), respectively. Dose distributions in PTV mets and PTV ind met were evaluated with respect to dose conformity (conformation number [CN], RTOG conformity index [PITV]), target coverage (TC), and homogeneity (homogeneity index [HI], ratio of maximum dose to prescription dose [MDPD]). The dependence of dose conformity on target size and N mets was investigated. The dose distribution characteristics were benchmarked against alternative irradiation techniques identified in a systematic literature review. Results: Mean ± standard deviation of dose distribution characteristics derived for PTV mets amounted to CN = 0.790 ± 0.101, PITV = 1.161 ± 0.154, TC = 0.95 ± 0.01, HI = 0.142 ± 0.022, and MDPD = 1.147 ± 0.029, respectively, demonstrating high dose conformity with acceptable homogeneity. Corresponding numbers for PTV ind met were CN = 0.708 ± 0.128, PITV = 1.174 ± 0.237, TC = 0.90 ± 0.10, HI = 0.140 ± 0.027, and MDPD = 1.129 ± 0.030, respectively. The target size had a statistically significant influence on dose conformity to PTV mets (CN = 0.737 for PTV mets ≤4.32 cm 3 vs CN = 0.848 for PTV mets >4.32 cm 3 , P=.006), in contrast to N mets . The achieved dose conformity to PTV mets , assessed by both CN and PITV, was in all investigated volume strata

  7. High resolution diffraction imaging of mercuric iodide: Demonstration of the necessity for alternate crystal processing techniques for highly purified material

    International Nuclear Information System (INIS)

    Steiner, B.; Berg, L. van den; Laor, U.

    1995-01-01

    The overall crystalline lattice uniformity in recently available, highly purified mercuric iodide single crystals has been shown to be impacted by crystal handling techniques that were previously satisfactory. High resolution diffraction imaging of the surface regularity of crystals of various levels of purity and growth orientation shows: (1) that the newer materials have a generally lower level of precipitates, (2) that the incidence of these precipitates is now closely correlated with growth direction, and (3) that the deformation resistance and resulting sensitivity to crystal handling procedures are also closely correlated with these factors in this soft material. As a result, gentler cutting and polishing procedures have been developed and are shown to be effective in preserving overall lattice regularity in the new material. The polishing required to remove residual surface scratches affect the lattice orientation of the softer, precipitate-free regions, while not affecting those regions with detectable levels of precipitates. These results correlate closely with the electrical properties of devices made from these crystals. Mercuric iodide single crystals have proved to be particularly useful for x and γ ray detectors because their room temperature operation allow for simple, efficient, and compact instrumentation

  8. Fractional filling with the microdepot technique as an alternative to bolus hyaluronic acid injections in facial volume restoration.

    Science.gov (United States)

    Lim, Adrian C; Lowe, Patricia M

    2011-05-01

    For volume restoration of the face, hyaluronic acid is conventionally injected through long, large-bore, 18-gauge needles because of the higher viscosity subtypes required. These hyaluronic acids are either more highly cross-linked or larger in particle size than the less-viscous subtypes. The microdepot injection technique involves using the 31-gauge BD insulin syringe (Becton-Dickinson, North Ryde, NSW Australia) to deposit small amounts of filler (0.05-0.1 mL) throughout the area of volume loss. The procedure is extremely well tolerated, requiring only topical and ice anaesthesia. Using this method, volume restoration can be achieved naturally and progressively over a period of time. Fractional filling every 3-4 months is continued until the desired level of volume correction is attained. Patients undergoing fractional filling followed over a 12-month period did not indicate any observable compromise in filler longevity, even when highly viscous hyaluronic acid fillers were injected through small-bore, 31-gauge insulin syringes. © 2011 The Authors. Australasian Journal of Dermatology © 2011 The Australasian College of Dermatologists.

  9. An Alternative to Optimize the Indonesian’s Airport Network Design: An Application of Minimum Spanning Tree (MST Technique

    Directory of Open Access Journals (Sweden)

    Luluk Lusiantoro

    2012-09-01

    Full Text Available Using minimum spanning tree technique (MST, this exploratory research was done to optimize the interrelation and hierarchical network design of Indonesian’s airports. This research also identifies the position of the Indonesian’s airports regionally based on the ASEAN Open Sky Policy 2015. The secondary data containing distance between airports (both in Indonesia and in ASEAN, flight frequency, and correlation of Gross Domestic Regional Product (GDRP for each region in Indonesia are used as inputs to form MST networks. The result analysis is done by comparing the MST networks with the existing network in Indonesia. This research found that the existing airport network in Indonesia does not depict the optimal network connecting all airports with the shortest distance and maximizing the correlation of regional economic potential in the country. This research then suggests the optimal networks and identifies the airports and regions as hubs and spokes formed by the networks. Lastly, this research indicates that the Indonesian airports have no strategic position in the ASEAN Open Sky network, but they have an opportunity to get strategic positions if 33 airports in 33 regions in Indonesia are included in the network.

  10. Localization of proteins in paint cross-sections by scanning electrochemical microscopy as an alternative immunochemical detection technique

    Energy Technology Data Exchange (ETDEWEB)

    Sciutto, Giorgia; Prati, Silvia [Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, Ravenna 48121 (Italy); Department of Chemistry “G. Ciamician”, University of Bologna, Via Selmi, Bologna 2 40126 (Italy); Mazzeo, Rocco, E-mail: rocco.mazzeo@unibo.it [Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, Ravenna 48121 (Italy); Department of Chemistry “G. Ciamician”, University of Bologna, Via Selmi, Bologna 2 40126 (Italy); Zangheri, Martina; Roda, Aldo; Bardini, Luca; Valenti, Giovanni; Rapino, Stefania [Department of Chemistry “G. Ciamician”, University of Bologna, Via Selmi, Bologna 2 40126 (Italy); Marcaccio, Massimo, E-mail: massimo.marcaccio@unibo.it [Department of Chemistry “G. Ciamician”, University of Bologna, Via Selmi, Bologna 2 40126 (Italy)

    2014-06-01

    Highlights: • Advanced immuno-electrochemical detection of proteins in paint samples by SECM. • Analysis performed directly on cross-section with high spatial resolution. • Identification of HRP catalytic activity for a selective location of analyte. • Satisfactory results were obtained for aged real samples. • The way forward for an extensive application of SECM in conservation science is shown. - Abstract: The qualitative identification of proteinaceous substances, as well as their location within a complex paint stratigraphy, is one of the most challenging issues in the characterization of painting materials. Nevertheless, information on paint components represent a crucial task for studies concerning both the ancient painting techniques adopted and the state of conservation, being fundamental investigations for the selection of appropriate conservation actions. The present research was aimed at developing a new detection approach for the immunochemical localization of ovalbumin in paint cross-sections based on the use of scanning electrochemical microscopy (SECM). The immunochemical analyses were performed using an anti-ovalbumin primary antibody and a secondary antibody labelled with horseradish peroxidase (HRP). SECM measurements were performed in feedback mode using benzoquinone (BQ)/hydroquinone (H{sub 2}Q) redox couple. In presence of hydrogen peroxide (H{sub 2}O{sub 2}), HRP catalyzes the re-oxidation of H{sub 2}Q to BQ and the increment of BQ concentration in correspondence of the target protein was detected by SECM through the electrochemical reduction of the regenerated BQ at the microelectrode. Indeed, the localization of ovalbumin was possible thanks to a clear discrimination of SECM currents, achieved by the comparison of the measurements recorded before and after H{sub 2}O{sub 2} administration, based on the HRP on/off approach. The method was evaluated both on samples from standard mocks-up and on a historical sample, collected from a

  11. Junction and circuit fabrication

    International Nuclear Information System (INIS)

    Jackel, L.D.

    1980-01-01

    Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

  12. Antifungal activity of fabrics knitted by metalized Silver/Polyester composite yarn

    Science.gov (United States)

    Özkan, İ.; Duru Baykal, P.

    2017-10-01

    In this study, antifungal properties of fabric knitted from metalized silver/polyester composite yarn were investigated. Intermingling is an alternative technique for yarn blending process. Yarns having different features can be combined by feeding the same intermingling jet. This process is defined as commingling. In the study, intermingling process was used to produce metalized silver/polyester composite yarn. Commingled yarns were knitted to single jersey fabrics by IPM brand sample type circular knitting machine. Antifungal activity test was applied to samples against Aspergillus Niger according to AATCC 30 test procedure. It has been identified that the application provides antifungal activity to fabric.

  13. An application of high vacuum technique: fabrication of Geiger - Mueller counters and measurements of fallout radioactivity in Rio de Janeiro, Brazil, between 1950 and 1960

    International Nuclear Information System (INIS)

    Gross, B.

    1986-01-01

    The initial development of vacuum technology, in Brazil, is described. Special attention is given to the fabrication of Geiger-Mueller counters in the period between 1950-1960, abd the results obtained by its use in measurements of radioactivity produced by hydrogen weapons explosions in the atmosphere. (M.C.K.) [pt

  14. Layerless fabrication with continuous liquid interface production.

    Science.gov (United States)

    Janusziewicz, Rima; Tumbleston, John R; Quintanilla, Adam L; Mecham, Sue J; DeSimone, Joseph M

    2016-10-18

    Despite the increasing popularity of 3D printing, also known as additive manufacturing (AM), the technique has not developed beyond the realm of rapid prototyping. This confinement of the field can be attributed to the inherent flaws of layer-by-layer printing and, in particular, anisotropic mechanical properties that depend on print direction, visible by the staircasing surface finish effect. Continuous liquid interface production (CLIP) is an alternative approach to AM that capitalizes on the fundamental principle of oxygen-inhibited photopolymerization to generate a continual liquid interface of uncured resin between the growing part and the exposure window. This interface eliminates the necessity of an iterative layer-by-layer process, allowing for continuous production. Herein we report the advantages of continuous production, specifically the fabrication of layerless parts. These advantages enable the fabrication of large overhangs without the use of supports, reduction of the staircasing effect without compromising fabrication time, and isotropic mechanical properties. Combined, these advantages result in multiple indicators of layerless and monolithic fabrication using CLIP technology.

  15. Fabrication of superconducting niobium radio frequency structures

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Amato, J.; Brawley, J.

    1983-01-01

    During the last several years a variety of superconducting radio frequency structures have been designed, fabricated and tested. The diverse structures and fabrication techniques are described. This paper is a description of the authors' experiences in this field

  16. The Role of Hand-Assisted Laparoscopic Technique in the Age of Single-Incision Laparoscopy: An Effective Alternative to Avoid Open Conversion in Colorectal Surgery.

    Science.gov (United States)

    Jung, Kyung Uk; Yun, Seong Hyeon; Cho, Yong Beom; Kim, Hee Cheol; Lee, Woo Yong; Chun, Ho-Kyung

    2018-04-01

    Continuous efforts to reduce the numbers and size of incisions led to the emergence of a new technique, single-incision laparoscopic surgery (SILS). It has been rapidly accepted as the preferred surgical approach in the colorectal area. In the age of SILS, what is the role of hand-assisted laparoscopic surgery (HALS)? We introduce the way to take advantage of it, as an effective alternative to avoid open conversion. This is a retrospective review of prospectively collected data of SILS colectomies performed by a single surgeon in Samsung Medical Center between August 2009 and December 2012. Out of 631 cases of SILS colectomy, 47 cases needed some changes from the initial approach. Among these, five cases were converted to HALS. Four of them were completed successfully without the need for open conversion. One patient with rectosigmoid colon cancer invading bladder was finally opened to avoid vesical trigone injury. The mean operation time of the 4 patients was 265.0 minutes. The mean estimated blood loss was 587.5 mL. The postoperative complication rate associated with the operation was 25%. Conversion from SILS to HALS in colorectal surgery was feasible and effective. It seemed to add minimal morbidity while preserving advantages of minimally invasive surgery. It could be considered an alternative to open conversion in cases of SILS, especially when the conversion to conventional laparoscopy does not seem to be helpful.

  17. Digital fabrication

    CERN Document Server

    2012-01-01

    The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...

  18. PIGMI mechanical fabrication

    International Nuclear Information System (INIS)

    Hart, V.E.

    1976-01-01

    A prime goal of the mechanical design effort associated with the PIGMI (Pion Generator for Medical Irradiations) program is to investigate new materials and fabrication techniques in an effort to obtain increased machine efficiency and reliability at a reasonable cost. The following discussion deals with the modeling program that LASL is pursuing for 450-MHz and 1350-MHz PIGMI development. (author)

  19. Fabrication of barium titanate nanoparticles/poly (methylmethacrylate composite films by a combination of deposition process and spin-coating technique

    Directory of Open Access Journals (Sweden)

    Yoshio Kobayashi

    2014-10-01

    Full Text Available The present work proposes a method for fabricating poly(methylmethacrylate (PMMA film containing barium titanate (BT nanoparticles (BT/PMMA film. BT particles with an average size of 77.6 ± 30.5 nm and a crystal size of 28.1 nm were synthesized by adding sodium hydroxide aqueous solution to titanium tetraisopropoxide/acetylacetone/i-propanol solution suspending barium hydroxide. A sodium glass plate, of which surface was modified with polyvinylpyrrolidone, was immersed into water suspending the BT particles, which resulted in deposition of the BT particles on the plate. A BT/PMMA film was fabricated by twice performance of a process composed of spin-coating of N-methyl-2-pyrrolidone (NMP dissolving PMMA on the plate, and then drying the coated plate in the atmosphere at room temperature. Spin-coating of a PMMA/NMP solution with a PMMA concentration of 150 g/L at a rotating speed of 5000 rpm provided fabrication of a BT/PMMA film with a BT volume fraction of 35.5%, a thickness of ca. 300 nm, and a transmittance of ca. 90% in the visible light region.

  20. Three techniques for the fabrication of high precision, mm-sized metal components based on two-photon lithography, applied for manufacturing horn antennas for THz transceivers

    Science.gov (United States)

    Standaert, Alexander; Brancato, Luigi; Lips, Bram; Ceyssens, Frederik; Puers, Robert; Reynaert, Patrick

    2018-03-01

    This paper proposes a novel packaging solution which integrates micro-machined 3D horn antennas with millimeter-wave and THz tranceivers. This packaging solution is shown to be a valid competitor to existing technologies like metallic split-block waveguides and low temperature cofired ceramics. Three different fabrication methods based on two-photon lithography are presented to form the horn antennas. The first uses two-photon lithography to form the bulk of the antenna. This structure is then metalised through physical vapor deposition (PVD) and copper plating. The second fabrication method makes use of a soft polydimethylsiloxane (PDMS) mold to easily replicate structures and the third method forms the horn antenna through electroforming. A prototype is accurately positioned on top of a 400 GHz 28 nm CMOS transmitter and glued in place with epoxy, thus providing a fully packaged solution. Measurement results show a 12 dB increase in the antenna gain when using the packaged solution. The fabrication processes are not limited to horn antennas alone and can be used to form a wide range of mm-sized metal components.