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Sample records for gold-tipped elastomeric pillars

  1. Pillarization

    NARCIS (Netherlands)

    Maussen, M.; Stone, J.; Dennis, R.M.; Rizova, P.S.; Smith, A.D.; Hou, X.

    2016-01-01

    Pillarization describes a society as divided into a number of "pillars," being compartments standing for the networks of organizations belonging to religious and ideological subcultures. Typically the associations cover a broad range of societal domains (education, media, political parties). The

  2. DC-pulsed voltage electrochemical method based on duty cycle self-control for producing TERS gold tips

    International Nuclear Information System (INIS)

    Vasilchenko, V E; Kharintsev, S S; Salakhov, M Kh

    2013-01-01

    This paper presents a modified dc-pulsed low voltage electrochemical method in which a duty cycle is self tuned while etching. A higher yield of gold tips suitable for performing tip-enhanced Raman scattering (TERS) measurements is demonstrated. The improvement is caused by the self-control of the etching rate along the full surface of the tip. A capability of the gold tips to enhance a Raman signal is exemplified by TERS spectroscopy of single walled carbon nanotubes bundle, sulfur and vanadium oxide

  3. An elastomeric grating coupler

    NARCIS (Netherlands)

    Kocabas, A.; Ay, F.; Dana, A.; Aydinli, A.

    We report on a novel nondestructive and reversible method for coupling free space light to planar optical waveguides. In this method, an elastomeric grating is used to produce an effective refractive index modulation on the surface of the optical waveguide. The external elastomeric grating binds to

  4. pillared and un-pillared bentonite clays

    African Journals Online (AJOL)

    BARTH EKWUEME

    2011-07-29

    Jul 29, 2011 ... A pseudo-second order kinetic model was used to characterize the metal ion transport ... may endanger human health through consumption of sea food and ... widely reported. The pillared clays are two – dimensional zeolite.

  5. Capabilities: Science Pillars

    Science.gov (United States)

    Alamos National Laboratory Delivering science and technology to protect our nation and promote world stability Science & Innovation Collaboration Careers Community Environment Science & Innovation Facilities Science Pillars Research Library Science Briefs Science News Science Highlights Lab Organizations

  6. Coal pillar design procedures

    CSIR Research Space (South Africa)

    York, G

    2000-03-01

    Full Text Available Final Project Report Coal pillar design procedures G. York, I. Canbulat, B.W. Jack Research agency: CSIR Mining Technology Project number: COL 337 Date: March 2000 2 Executive Summary Examination of collapsed pillar cases outside of the empirical... in strength occurs with increasing specimen size. 45 40 35 30 25 20 15 10 5 0 20 40 60 80 100 120 140 160 UNIAX IA L COMPR EHEN SIV E S TR ENG TH (M Pa ) CUBE SIZE (cm) Figure 1...

  7. Pillar-type acoustic metasurface

    DEFF Research Database (Denmark)

    Jin, Yabin; Bonello, Bernard; Moiseyenko, Rayisa

    2017-01-01

    We theoretically investigate acoustic metasurfaces consisting of either a single pillar or a line of identical pillars on a thin plate, and we report on the dependence on the geometrical parameters of both the monopolar compressional and dipolar bending modes. We show that for specific dimensions...

  8. Three Philosophical Pillars That Support Collaborative Learning.

    Science.gov (United States)

    Maltese, Ralph

    1991-01-01

    Discusses three philosophical pillars that support collaborative learning: "spaces of appearance," active engagement, and ownership. Describes classroom experiences with collaborative learning supported by these pillars. (PRA)

  9. High-aspect-ratio, silicon oxide-enclosed pillar structures in microfluidic liquid chromatography.

    Science.gov (United States)

    Taylor, Lisa C; Lavrik, Nickolay V; Sepaniak, Michael J

    2010-11-15

    The present paper discusses the ability to separate chemical species using high-aspect-ratio, silicon oxide-enclosed pillar arrays. These miniaturized chromatographic systems require smaller sample volumes, experience less flow resistance, and generate superior separation efficiency over traditional packed bed liquid chromatographic columns, improvements controlled by the increased order and decreased pore size of the systems. In our distinctive fabrication sequence, plasma-enhanced chemical vapor deposition (PECVD) of silicon oxide is used to alter the surface and structural properties of the pillars for facile surface modification while improving the pillar mechanical stability and increasing surface area. The separation behavior of model compounds within our pillar systems indicated an unexpected hydrophobic-like separation mechanism. The effects of organic modifier, ionic concentration, and pressure-driven flow rate were studied. A decrease in the organic content of the mobile phase increased peak resolution while detrimentally effecting peak shape. A resolution of 4.7 (RSD = 3.7%) was obtained for nearly perfect Gaussian shaped peaks, exhibiting plate heights as low as 1.1 and 1.8 μm for fluorescein and sulforhodamine B, respectively. Contact angle measurements and DART mass spectrometry analysis indicate that our employed elastomeric soft bonding technique modifies pillar properties, creating a fortuitous stationary phase. This discovery provides evidence supporting the ability to easily functionalize PECVD oxide surfaces by gas-phase reactions.

  10. Fabrication of elastomeric silk fibers.

    Science.gov (United States)

    Bradner, Sarah A; Partlow, Benjamin P; Cebe, Peggy; Omenetto, Fiorenzo G; Kaplan, David L

    2017-09-01

    Methods to generate fibers from hydrogels, with control over mechanical properties, fiber diameter, and crystallinity, while retaining cytocompatibility and degradability, would expand options for biomaterials. Here, we exploited features of silk fibroin protein for the formation of tunable silk hydrogel fibers. The biological, chemical, and morphological features inherent to silk were combined with elastomeric properties gained through enzymatic crosslinking of the protein. Postprocessing via methanol and autoclaving provided tunable control of fiber features. Mechanical, optical, and chemical analyses demonstrated control of fiber properties by exploiting the physical cross-links, and generating double network hydrogels consisting of chemical and physical cross-links. Structure and chemical analyses revealed crystallinity from 30 to 50%, modulus from 0.5 to 4 MPa, and ultimate strength 1-5 MPa depending on the processing method. Fabrication and postprocessing combined provided fibers with extensibility from 100 to 400% ultimate strain. Fibers strained to 100% exhibited fourth order birefringence, revealing macroscopic orientation driven by chain mobility. The physical cross-links were influenced in part by the drying rate of fabricated materials, where bound water, packing density, and microstructural homogeneity influenced cross-linking efficiency. The ability to generate robust and versatile hydrogel microfibers is desirable for bottom-up assembly of biological tissues and for broader biomaterial applications. © 2017 Wiley Periodicals, Inc.

  11. Stress reduction for pillar filled structures

    Science.gov (United States)

    Nikolic, Rebecca J.; Conway, Adam; Shao, Qinghui; Voss, Lars; Cheung, Chin Li; Dar, Mushtaq A.

    2015-09-01

    According to one embodiment, an apparatus for detecting neutrons includes an array of pillars, wherein each of the pillars comprises a rounded cross sectional shape where the cross section is taken perpendicular to a longitudinal axis of the respective pillar, a cavity region between each of the pillars, and a neutron sensitive material located in each cavity region.

  12. Evaluation of Force Degradation Pattern of Elastomeric Ligatures and Elastomeric Separators in Active Tieback State

    Directory of Open Access Journals (Sweden)

    Amir Mohammadi

    2015-12-01

    Full Text Available Background and aims. The purpose of this study was to evaluate initial force and force decay of commercially available elastomeric ligatures and elastomeric separators in active tieback state in a simulated oral environment. Materials and methods. A total of 288 elastomeric ligatures and elastomeric separators from three manufacturers (Dentaurum, RMO, 3M Unitek were stretched to 100% and 150% of their original inner diameter. Force levels were measured initially and at 3-minute, 24-hour, and 1-, 2-, 3- and 4-week intervals. Data were analyzed by univariate analysis of variance and a post hoc Tukey test. Results. The means of initial forces of elastomeric ligatures and separators from three above-mentioned companies, when stretched to 100% of their inner diameters, were 199, 305 and 284 g, and 330, 416, 330 g; when they were stretched to 150% of their inner diameters the values were 286, 422 and 375 g, and 433, 540 and 504 g, respectively. In active tieback state, 11‒18% of the initial force of the specimens was lost within the first 3 minutes and 29‒63% of the force decay occurred in the first 24 hours; then force decay rate decreased. 62‒81% of the initial force was lost in 4 weeks. Although force decay pattern was identical in all the products, the initial force and force decay of Dentaurum elastomeric products were less than the similar products of other companies (P<0.05. Under the same conditions, the force of elastomeric separators was greater than elastomeric ligatures of the same company. Conclusion. Regarding the force pattern of elastomeric ligatures and separators and optimal force for tooth movement, many of these products can be selected for applying orthodontic forces in active tieback state.

  13. Chemical Stability of Telavancin in Elastomeric Pumps

    Directory of Open Access Journals (Sweden)

    Patrick Sand, MSc

    2015-12-01

    Conclusions: The results of this study indicate that telavancin remains chemically stable when diluted in the Intermate Infusion System and the Homepump Eclipse elastomeric pumps and stored at 2°C to 8°C for up to 8 days protected from light at the concentration range and dilution schemes evaluated.

  14. Tribologically modified surfaces on elastomeric materials

    NARCIS (Netherlands)

    Rodriguez, N.V.; Masen, Marc Arthur; Schipper, Dirk J.

    2013-01-01

    As the result of tribological loading, the properties of the surface of elastomeric materials will alter. This effect has been observed using SEM and EDS analysis of the tread of a used car tyre, where differences in structure between the substrate and the area near the surface were found. To study

  15. Biodegradable elastomeric scaffolds for soft tissue engineering

    NARCIS (Netherlands)

    Pêgo, A.P.; Poot, Andreas A.; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Elastomeric copolymers of 1,3-trimethylene carbonate (TMC) and ε-caprolactone (CL) and copolymers of TMC and D,L-lactide (DLLA) have been evaluated as candidate materials for the preparation of biodegradable scaffolds for soft tissue engineering. TMC-DLLA copolymers are amorphous and degrade more

  16. A microfluidic device with pillars

    DEFF Research Database (Denmark)

    2014-01-01

    The invention provides a microfluidic device for mixing liquid reagents, the device comprises, a chip forming at least one reaction chamber between a bottom and a top and extending between an inlet and an outlet. To enable manufacturing from less rigid materials, the device comprises pillars...

  17. Further validation of bracket pillar design methodology

    CSIR Research Space (South Africa)

    Vieira, F

    1998-07-01

    Full Text Available Design charts for bracket pillar design were developed under a previous SIMRAC project GAP 223 to provide rock mechanics engineers with an initial estimate of bracket pillar sizes for clearly identified geological discontinuities, based on mining...

  18. 30 CFR 75.207 - Pillar recovery.

    Science.gov (United States)

    2010-07-01

    ... SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.207 Pillar recovery. Pillar recovery shall be... be left in place. (b) Before mining is started in a pillar split or lift— (1) At least two rows of breaker posts or equivalent support shall be installed— (i) As close to the initial intended breakline as...

  19. Tensile properties of orthodontic elastomeric ligatures.

    Science.gov (United States)

    Ahrari, F; Jalaly, T; Zebarjad, M

    2010-01-01

    Tensile properties of elastomeric ligatures become important when efficiency of orthodontic appliances is considered. The aim of this study was to compare tensile strength, extension to tensile strength, toughness and modulus of elasticity of elastomeric ligatures in both the as--received condition and after 28 days of immersion in the simulated oral environment. Furthermore, the changes that occurred in tensile properties of each brand of ligatures after 28 days were evaluated. Experimental-laboratory based. Elastomeric ligatures were obtained from different companies and their tensile properties were measured using Zwick testing machine in both the as-received condition and after 28 days of immersion in the simulated oral environment. The data were analyzed using independent sample t-tests, analysis of variance and Tukey tests. After 28 days, all the ligatures experienced a significant decrease in tensile strength, extension to tensile strength and toughness ( P tensile properties of different brands of ligatures in both conditions ( P tensile properties of different brands of ligatures, which should be considered during selection of these products.

  20. Hydrogen isotope permeation in elastomeric materials

    International Nuclear Information System (INIS)

    Steinmeyer, R.H.; Braun, J.D.

    1976-01-01

    The permeabilities of elastomeric and polymeric materials to hydrogen isotopes were measured at room temperature. The technique for measuring permeation rates is based on the following constant-volume method: a fixed pressure of gas is applied to one side of the specimen to be studied and the permeability constant is determined from the observed rate of pressure increase in an initially evacuated volume on the other side of the specimen. Permeability constants for hydrogen, deuterium, and tritium were measured for Mylar, Teflon, Kapton, Saran, Buna-N, and latex rubber. Results were compared with literature values for hydrogen and deuterium where available and showed excellent agreement

  1. Organically pillared layered zinc hydroxides

    International Nuclear Information System (INIS)

    Kongshaug, K.O.; Fjellvaag, Helmer

    2004-01-01

    The two organically pillared layered zinc hydroxides [Zn 2 (OH) 2 (ndc)], CPO-6, and [Zn 3 (OH) 4 (bpdc)], CPO-7, were obtained in hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc) and zinc nitrate (CPO-6) and 4,4'biphenyldicarboxylate (bpdc) and zinc nitrate (CPO-7), respectively. In CPO-6, the tetrahedral zinc atoms are connected by two μ 2 -OH groups and two carboxylate oxygen atoms, forming infinite layers extending parallel to the bc-plane. These layers are pillared by ndc to form a three-dimensional structure. In CPO-7, the zinc hydroxide layers are containing four-, five- and six coordinated zinc atoms, and the layers are built like stairways running along the [001] direction. Each step is composed of three infinite chains running in the [010] direction. Both crystal structures were solved from conventional single crystal data. Crystal data for CPO-6: Monoclinic space group P2 1 /c (No. 14), a=11.9703(7), b=7.8154(5), c=6.2428(4) A, β=90.816(2) deg., V=583.97(6) A 3 and Z=4. Crystal data for CPO-7: Monoclinic space group C2/c (No. 15), a=35.220(4), b=6.2658(8), c=14.8888(17) A, β=112.580(4) deg., V=3033.8(6) A 3 and Z=8. The compounds were further characterized by thermogravimetric- and chemical analysis

  2. Evaluation of shear mounted elastomeric damper

    Science.gov (United States)

    Zorzi, E.; Walton, J.

    1982-01-01

    Viton-70 elastomeric shear mounted damper was built and tested on a T-55 power turbine spool in the rotor's high speed balancing rig. This application of a shear mounted elastomeric damper demonstrated for the first time, the feasibility of using elastomers as the primary rotor damping source in production turbine engine hardware. The shear damper design was selected because it was compatible with actual gas turbine engine radial space constraints, could accommodate both the radial and axial thrust loads present in gas turbine engines, and was capable of controlled axial preload. The shear damper was interchangeable with the production T-55 power turbine roller bearing support so that a direct comparison between the shear damper and the production support structure could be made. Test results show that the Viton-70 elastomer damper operated successfully and provided excellent control of both synchronous and nonsynchronous vibrations through all phases of testing up to the maximum rotor speed of 16,000 rpm. Excellent correlation between the predicted and experienced critical speeds, mode shapes and log decrements for the power turbine rotor and elastomer damper assembly was also achieved.

  3. Suspension of Water Droplets on Individual Pillars

    DEFF Research Database (Denmark)

    Tóth, T.; Ferraro, D.; Chiarello, E.

    2011-01-01

    We report results of extensive experimental and numerical studies on the suspension of water drops deposited on cylindrical pillars having circular and square cross sections and different wettabilities. In the case of circular pillars, the drop contact line is pinned to the whole edge contour unt...

  4. Reassessment of coal pillar design procedure

    CSIR Research Space (South Africa)

    Madden, BJ

    1995-12-01

    Full Text Available The SIMRAC project COL 021A entitled “a reassessment of coal pillar design procedures” set out to achieve a coal pillar design procedure that takes cognisance of different geological and structural factors as well as the influence...

  5. Thermoelectric properties of silicon nano pillars

    Energy Technology Data Exchange (ETDEWEB)

    Stranz, Andrej; Soekmen, Uensal; Waag, Andreas; Peiner, Erwin [Institute of Semiconductor Technology, Braunschweig (Germany)

    2010-07-01

    In order to establish silicon as a efficient thermoelectric material, its high thermal conductivity has to be reduced which is feasible, e.g., by nano structuring. Therefore, in this study Si-based sub-micron pillars of various dimensions were investigated. Using anisotropic etching followed by thermal oxidation we could fabricate pillars of diameters <500 nm, about 25 {mu}m in height with aspect ratios of more than 50. The distance between the pillars was varied from 500 nm to 10 micron. Besides the fabrication and structural characterization of sub-micron silicon pillars, and adequate metrology for measuring their thermoelectric properties was implemented. Commercial tungsten probes and self-made gold probes, as well as Wollaston wire probes were used for electrical and thermal conductivity, as well as Seebeck voltage measurements on single pillars in a scanning electron microscope equipped with nano manipulators.

  6. Long-Term Stability Evaluation and Pillar Design Criterion for Room-and-Pillar Mines

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2017-10-01

    Full Text Available The collapse of abandoned room-and-pillar mines is often violent and unpredictable. Safety concerns often resulted in mine closures with no post-mining stability evaluations. As a result, large amounts of land resources over room-and-pillar mines are wasted. This paper attempts to establish an understanding of the long-term stability issues of goafs (abandoned mines. Considering progressive pillar failures and the effect of single pillar failure on surrounding pillars, this paper proposes a pillar peeling model to evaluate the long-term stability of coal mines and the associated criteria for evaluating the long-term stability of room-and-pillar mines. The validity of the peeling model was verified by numerical simulation, and field data from 500 pillar cases from China, South Africa, and India. It is found that the damage level of pillar peeling is affected by the peel angle and pillar height and is controlled by the pillar width–height ratio.

  7. Pillar support for a wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, A

    1978-08-24

    The invention concerns a stationary pillar for a wind power plant with vertical rotors in the outside walls of individual parts of the structure, which are arranged above one antoher and which can turn together freely as a pillar facade. There are problems in such a stationary pillar because of storm forces on the one hand, which try to buckle the pillar, and, on the other hand, the pillar should be easy to mount without difficult fishplates or screwed connections. In order to solve this problem, the invention provides that tension elements run from the top ring of the pillar to the foundation through all the spars and through the connecting rings inside the spars, whose tension forces not only counteract buckling of the pillar, but also pull the intersections of the spars together in tension and independently of the screwed connections also provided. The connecting rings at the connections to the spars have half sleeves, which are pushed into a sleeve of the spar coming from below. The tension elements can consist of bundles of steel wires or a wire rope.

  8. Contact angle of unset elastomeric impression materials.

    Science.gov (United States)

    Menees, Timothy S; Radhakrishnan, Rashmi; Ramp, Lance C; Burgess, John O; Lawson, Nathaniel C

    2015-10-01

    Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed. The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing. Two traditional polyvinyl siloxane (PVS) (Aquasil, Take 1), 2 modified PVS (Imprint 4, Panasil), a polyether (Impregum), and 2 hybrid (Identium, EXA'lence) materials were compared. Each material was flattened to 2 mm and a 5 μL drop of distilled water or saliva was dropped on the surface at 25 seconds (t0) after the start of mix. Contact angle measurements were made with a digital microscope at initial contact (t0), t1=2 seconds, t2=5 seconds, t3=50% working time, and t4=95% working time. Data were analyzed with a generalized linear mixed model analysis, and individual 1-way ANOVA and Tukey HSD post hoc tests (α=.05). For water, materials grouped into 3 categories at all time-points: the modified PVS and one hybrid material (Identium) produced the lowest contact angles, the polyether material was intermediate, and the traditional PVS materials and the other hybrid (EXA'lence) produced the highest contact angles. For saliva, Identium, Impregum, and Imprint 4 were in the group with the lowest contact angle at most time points. Modified PVS materials and one of the hybrid materials are more hydrophilic than traditional PVS materials when measured with water. Saliva behaves differently than water in contact angle measurement on unset impression material and produces a lower contact angle on polyether based materials. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Kinetic analysis of elastomeric lag damper for helicopter rotors

    Science.gov (United States)

    Liu, Yafang; Wang, Jidong; Tong, Yan

    2018-02-01

    The elastomeric lag dampers suppress the ground resonance and air resonance that play a significant role in the stability of the helicopter. In this paper, elastomeric lag damper which is made from silicone rubber is built. And a series of experiments are conducted on this elastomeric lag damper. The stress-strain curves of elastomeric lag dampers employed shear forces at different frequency are obtained. And a finite element model is established based on Burgers model. The result of simulation and tests shows that the simple, linear model will yield good predictions of damper energy dissipation and it is adequate for predicting the stress-strain hysteresis loop within the operating frequency and a small-amplitude oscillation.

  10. Design of Merensky Reef crush pillars

    CSIR Research Space (South Africa)

    Watson, BP

    2010-10-01

    Full Text Available appear stiff enough. However, evidence from the pillar bursts suggests that unfailed pillars located at 10 m or more from the face are in a dangerous, soft-loading situation and may burst if failure takes place. From the evidence of the few collapses... reached a deformation of 32 mm during the initial failure and all failed in a reasonably stable manner. The unacceptable stiffness of the surrounding strata is about 5.0 mm/GN. Most of the measured pillars failed under loading conditions where...

  11. PEDOT pillar fabrication using DOD inkjet system

    Science.gov (United States)

    Cui, Wei; Chang, Cheng-Ling; Wang, Wei-Chih

    2012-04-01

    In this paper, we present our preliminary results of high aspect ratio 3D PEDOT pillar study by drop-on demand (DOD) direct printing system. Design of the experimental setup and the fabrication of the DOD PEDOT pillar are introduced. Currently, the system can achieve a PEDOT pillar with a height of 300 μm and 80 μm in diameter. The proposed PEDOT 3D printing process has a wide range of potential applications in the eletronics and display industry.

  12. The Three Pillars of Machine Programming

    OpenAIRE

    Gottschlich, Justin; Solar-Lezama, Armando; Tatbul, Nesime; Carbin, Michael; Rinard, Martin; Barzilay, Regina; Amarasinghe, Saman; Tenenbaum, Joshua B; Mattson, Tim

    2018-01-01

    In this position paper, we describe our vision of the future of machine programming through a categorical examination of three pillars of research. Those pillars are: (i) intention, (ii) invention, and(iii) adaptation. Intention emphasizes advancements in the human-to-computer and computer-to-machine-learning interfaces. Invention emphasizes the creation or refinement of algorithms or core hardware and software building blocks through machine learning (ML). Adaptation emphasizes advances in t...

  13. Discussing three pillars of corporate governance

    OpenAIRE

    Andrei STĂNCULESCU; Eugen MITRICĂ

    2015-01-01

    This paper is a meaningful attempt to critically analyze the cohesion and relationship between three fundamental pillars of the corporate governance system: the shareholders, the board of directors and the employees. We present the characteristics of each pillar and discuss its relevance in corporate governance. A couple of world-renowned corporate governance models are considered. A synthetic conclusion is drawn based on information presented.

  14. Imaging of the cervical articular pillar

    Energy Technology Data Exchange (ETDEWEB)

    Yeomans, E. [Orange Base Hospital, Orange, NSW (Australia)

    1998-12-01

    The cervical articular pillar, due to the complex anatomical structure of the cervical spine, is not well demonstrated in routine plain radiographic views. Dedicated views have been devised to demonstrate the pillar, yet their performance has abated considerably since the inception of Computed Tomography (CT) in the 1970`s. It is the consideration that CT does not image the articular pillar with a 10 per cent accuracy that poses the question: Is there still a need for plain radiography of the cervical articular pillar? This paper studies the anatomy, plain radiography, and incidence of injury to the cervical articular pillar. It discusses (with reference to current and historic literature) the efficacy of current imaging protocols in depicting this injury. It deals with plain radiography, CT, complex tomography, and Magnetic Resonance Imaging (MRI) of the cervical spine to conclude there may still be a position in current imaging protocols for plain radiography of the cervical articular pillar. Copyright (1998) Australian Institute of Radiography 43 refs., 5 figs.

  15. Chemical Stability of Telavancin in Elastomeric Pumps☆

    Science.gov (United States)

    Sand, Patrick; Aladeen, Traci; Kirkegaard, Paul; LaChance, Dennis; Slover, Christine

    2015-01-01

    Background VIBATIV is a once-daily, injectable lipoglycopeptide antibiotic approved in the U.S. for the treatment of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by susceptible isolates of Staphylococcus aureus when alternative treatments are not suitable. In addition, VIBATIV is approved in the U.S. for the treatment of adult patients with complicated skin & skin structure infections (cSSSI) caused by susceptible isolates of Gram-positive bacteria, including Staphylococcus aureus, both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains. Objective To evaluate the chemical stability of telavancin (Vibativ; Theravance Biopharma US, Inc, Northbrook, Illinois), a lipoglycopeptide antibiotic with activity against methicillin-resistant Staphylococcus aureus, in 2 types of elastomeric pumps, the Intermate Infusion System (Baxter International Inc) and the Homepump Eclipse (I-Flow Corporation). Methods Different sizes of the Baxter (Ontario, Canada) (105 mL and 275 mL) and I-Flow (Stoughton, Massachusetts) (100 mL and 250 mL) pumps were compared with glass controls. The telavancin drug product was reconstituted and diluted to concentrations of 0.6 mg/mL and 8.0 mg/mL using either 0.9% saline, 5% dextrose in water, or sterilized water for injection (0.6 mg/mL telavancin) or saline (8.0 mg/mL telavancin) followed by Ringer’s Lactate solution. Pumps were filled and stored at 2°C to 8°C, protected from light. Aliquots from both pump types and for all telavancin reconstitution/dilution schemes and concentrations were taken over a period of 8 days and analyzed for appearance, pH, telavancin concentration and purity, and degradation products. Results The pH of all pump solutions remained consistent throughout the 8-day analysis period, within a range of 4.6 to 5.7 for the 0.6 mg/mL and 4.4 to 4.9 for the 8.0 mg/mL telavancin solutions. There was no significant change in the chromatographic purity for any of the pump

  16. Chemical Stability of Telavancin in Elastomeric Pumps.

    Science.gov (United States)

    Sand, Patrick; Aladeen, Traci; Kirkegaard, Paul; LaChance, Dennis; Slover, Christine

    2015-12-01

    VIBATIV is a once-daily, injectable lipoglycopeptide antibiotic approved in the U.S. for the treatment of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by susceptible isolates of Staphylococcus aureus when alternative treatments are not suitable. In addition, VIBATIV is approved in the U.S. for the treatment of adult patients with complicated skin & skin structure infections (cSSSI) caused by susceptible isolates of Gram-positive bacteria, including Staphylococcus aureus, both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains. To evaluate the chemical stability of telavancin (Vibativ; Theravance Biopharma US, Inc, Northbrook, Illinois), a lipoglycopeptide antibiotic with activity against methicillin-resistant Staphylococcus aureus, in 2 types of elastomeric pumps, the Intermate Infusion System (Baxter International Inc) and the Homepump Eclipse (I-Flow Corporation). Different sizes of the Baxter (Ontario, Canada) (105 mL and 275 mL) and I-Flow (Stoughton, Massachusetts) (100 mL and 250 mL) pumps were compared with glass controls. The telavancin drug product was reconstituted and diluted to concentrations of 0.6 mg/mL and 8.0 mg/mL using either 0.9% saline, 5% dextrose in water, or sterilized water for injection (0.6 mg/mL telavancin) or saline (8.0 mg/mL telavancin) followed by Ringer's Lactate solution. Pumps were filled and stored at 2°C to 8°C, protected from light. Aliquots from both pump types and for all telavancin reconstitution/dilution schemes and concentrations were taken over a period of 8 days and analyzed for appearance, pH, telavancin concentration and purity, and degradation products. The pH of all pump solutions remained consistent throughout the 8-day analysis period, within a range of 4.6 to 5.7 for the 0.6 mg/mL and 4.4 to 4.9 for the 8.0 mg/mL telavancin solutions. There was no significant change in the chromatographic purity for any of the pump solutions examined. All decreases in

  17. Development of a flameproof elastic elastomeric fiber

    Science.gov (United States)

    Howarth, J. T.; Nilgrom, J.; Massucco, A.; Sheth, S. G.; Dawn, F. S.

    1971-01-01

    Various flexible polyurethane structures containing halogen were synthesized from polyesters derived from aliphatic or aromatic polyols and dibasic acids. Aliphatic halide structures could not be used because they are unstable at the required reaction temperatures, giving of hydrogen halide which hydrolyzes the ester linkages. In contract, halogen-containing aromatic polyols were stable and satisfactory products were made. The most promising composition, a brominated neopentyl glycol capped with toluene disocyanate, was used as a conventional diisocyanate, in conjunction with hydroxy-terminated polyethers or polyesters to form elastomeric urethanes containing about 10% bromine with weight. Products made in this manner will not burn in air, have an oxygen index value of about 25, and have tensile strength values of about 5,000 psi at 450% elongation. The most efficient additives for imparting flame retardancy to Spandex urethanes are aromatic halides and the most effective of these are the bromide compounds. Various levels of flame retardancy have been achieved depending on the levels of additives used.

  18. Unvulcanized elastomeric waterproofing materials for construction application

    Directory of Open Access Journals (Sweden)

    O. V. Karmanova

    2016-01-01

    Full Text Available In the construction was widespread elastomer profiles, which have the ability to swell in water. Such products should have a high capacity for swelling, elasticity, resistance to weathering. At the present time for these purposes are used materials, mostly of foreign origin. With the increasing pace of construction in Russia the problem of replacement of imported materials is particularly relevant. The work was dedicated to the creation of water-swellable elastomer materials using bentonite powders and study of their properties. Сomparative testing of imported and domestic hydrophilic sealants were held. Rationale and choice of components for the cords of bentonite was conducted. Polymer base is saturated ethylene-propylene rubber. Bentonite from different manufacturers used to increase the swelling of the samples. Filler added in an amount of 50–100 phr. The elastomeric compositions were prepared using laboratory roller at a temperature of 60 ± 5° C. Profiling was performed on a syringe-machine at a temperature of 120° C. Extrusion indicator of the mixtures were evaluated on a 10-point scale (German-Russian system. It is found that high swelling products provided using field Azerbaijan bentonite. It is noted that the dosage of bentonite than 150 w.p. deteriorates technological properties of bentonite cords. It has been shown that activation of the bentonite and sodium carbonate chloride can significantly improve product swelling, wherein the bentonite content of the composition was 150–200 w.p.

  19. Elastomeric composites with tuned electromagnetic characteristics

    International Nuclear Information System (INIS)

    Wheeland, Sara; Bayatpur, Farhad; Amirkhizi, Alireza V; Nemat-Nasser, Sia

    2013-01-01

    This paper presents a novel elastomeric composite that exhibits a deformation-induced change in chirality. Previous efforts primarily dealt with a coil array in air without chiral tuning. Here, a composite is created that consists of an array of parallel, metallic helices of the same handedness embedded in a polymer matrix. The chiral response of the composite depends on pitch, coil diameter, wire thickness and coil spacing; however, pitch has the greatest effect on electromagnetic performance. The present study explores this effect by using helical elements to construct a chiral medium that can be mechanically stretched to adjust pitch. This adjustment directly affects the overall chirality of the composite. A prototype sample of the composite, fabricated for operation between 5.5–12.5 GHz, demonstrates repeatable elastic deformation. Using a transmit/receive measurement setup, the composite scattering response is measured over the frequency interval. The results indicate substantial tuning of chirality through deformation. An increase in axial strain of up to 30% yields a ∼18% change in axial chirality. (paper)

  20. Baxter elastomeric pumps: Feasibility of weight estimates.

    Science.gov (United States)

    Chambers, Carole R; Pabia, Mica; Sawyer, Michael; Tang, Patricia A

    2017-09-01

    Purpose Elastomeric pumps are used to infuse a 46-h fluorouracil protocol and patients are asked to visually inspect the pump daily. The pump has a variability of ±10% and there are additional patient variables that can increase this. The feasibility of weighing the pump rather than a visual inspection along with the secondary objective to confirm the pump's variability in real world conditions was undertaken. Methods Empty pumps were weighed using both pharmacy and kitchen scales. Pumps upon completion of the 46-h infusion were also weighed using both pharmacy and kitchen scales. Results The kitchen scale was as accurate as the pharmacy grade scale. Disconnected pumps showed the expected variability from using these infusor pumps along with a few showing greater variability likely due to patient variables. Conclusion Weighing pumps appears to be feasible both at the pharmacy and home level. Next steps would be to weigh pumps during the infusion to validate an alternate method to simple visual inspection for patients to confirm proper infusing of the pump at their home.

  1. Sterilizing elastomeric chains without losing mechanical properties. Is it possible?

    Directory of Open Access Journals (Sweden)

    Matheus Melo Pithon

    2015-06-01

    Full Text Available OBJECTIVE: To investigate the effects of different sterilization/disinfection methods on the mechanical properties of orthodontic elastomeric chains. METHODS: Segments of elastomeric chains with 5 links each were sent for sterilization by cobalt 60 (Co60 (20 KGy gamma ray technology. After the procedure, the elastomeric chains were contaminated with clinical samples of Streptococcus mutans. Subsequently, the elastomeric chains were submitted to sterilization/disinfection tests carried out by means of different methods, forming six study groups, as follows: Group 1 (control - without contamination, Group 2 (70°GL alcohol, Group 3 (autoclave, Group 4 (ultraviolet, Group 5 (peracetic acid and Group 6 (glutaraldehyde. After sterilization/disinfection, the effectiveness of these methods, by Colony forming units per mL (CFU/mL, and the mechanical properties of the material were assessed. Student's t-test was used to assess the number of CFUs while ANOVA and Tukey's test were used to assess elastic strength. RESULTS: Ultraviolet treatment was not completely effective for sterilization. No loss of mechanical properties occurred with the use of the different sterilization methods (p > 0.05. CONCLUSION: Biological control of elastomeric chains does not affect their mechanical properties.

  2. 40 CFR 427.40 - Applicability; description of the asbestos paper (elastomeric binder) subcategory.

    Science.gov (United States)

    2010-07-01

    ... asbestos paper (elastomeric binder) subcategory. 427.40 Section 427.40 Protection of Environment... SOURCE CATEGORY Asbestos Paper (Elastomeric Binder) Subcategory § 427.40 Applicability; description of the asbestos paper (elastomeric binder) subcategory. The provisions of this subpart are applicable to...

  3. Enhancing retention of partial dentures using elastomeric retention rings

    Directory of Open Access Journals (Sweden)

    Kakkirala Revathi

    2015-01-01

    Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

  4. Active containment systems incorporating modified pillared clays

    International Nuclear Information System (INIS)

    Lundie, P.; McLeod, N.

    1997-01-01

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation

  5. Water condensation on ultrahydrophobic flexible micro pillar surface

    Science.gov (United States)

    Narhe, Ramchandra

    2016-05-01

    We investigated the growth dynamics of water drops in controlled condensation on ultrahydrophobic geometrically patterned polydimethylsiloxane (PDMS) cylindrical micro pillars. At the beginning, the condensed drops size is comparable to the pattern dimensions. The interesting phenomenon we observe is that, as the condensation progresses, water drops between the pillars become unstable and enforced to grow in the upward direction along the pillars surface. The capillary force of these drops is of the order of μ\\text{N} and acts on neighboring pillars. That results into bending of the pillars. Pillars bending enhances the condensation and favors the most energetically stable Wenzel state.

  6. Rib-pillar mining at Sigma Colliery

    Energy Technology Data Exchange (ETDEWEB)

    De Beer, J J.S.; Hunter, F; Neethling, A F [Sigma Colliery, Sasolburg (South Africa)

    1991-06-01

    The paper describes the rib-pillar extraction method now used at Sigma Colliery in the Orange Free State. In this method, access roadways (with a high safety factor) are developed into a block of coal suitable for total extraction; pillars that have a low safety factor are then formed and extracted immediately. The method, together with the current practices of labour management, has resulted in better utilization of the coal resources and capital, increased production and labour productivity, and improved safety. 11 figs.

  7. Scattering of spermatozoa off cylindrical pillars

    Science.gov (United States)

    Bukatin, Anton; Lushi, Enkeleida; Kantsler, Vasily

    2017-11-01

    The motion of micro-swimmers in structured environments, even though crucial in processes such as in vivo and in vitro egg fertilization, is still not completely understood. We combine microfluidic experiments with mathematical modeling of 3D swimming near convex surfaces to quantify the dynamics of individual sperm cells in the proximity of cylindrical pillars. Our results show that the hydrodynamic and contact forces that account for the shape asymmetry and flagellar motion, are crucial in correctly describing the dynamics observed in the experiments. Last, we discuss how the size of the cylindrical obstacles determines whether the swimmers scatter off or get trapped circling the pillar.

  8. Field emission from a single nanomechanical pillar

    International Nuclear Information System (INIS)

    Kim, Hyun S; Qin Hua; Westphall, Michael S; Smith, Lloyd M; Blick, Robert H

    2007-01-01

    We measured field emission from a silicon nanopillar mechanically oscillating between two electrodes. The pillar has a height of about 200 nm and a diameter of 50 nm, allowing resonant mechanical excitations at radio frequencies. The tunnelling barriers for field emission are mechanically modulated via displacement of the gold island on top of the pillar. We present a rich frequency-dependent response of the emission current in the frequency range of 300-400 MHz at room temperature. Modified Fowler-Nordheim field emission is observed and attributed to the mechanical oscillations of the nanopillar

  9. Elastomeric Cellular Structure Enhanced by Compressible Liquid Filler

    Science.gov (United States)

    Sun, Yueting; Xu, Xiaoqing; Xu, Chengliang; Qiao, Yu; Li, Yibing

    2016-05-01

    Elastomeric cellular structures provide a promising solution for energy absorption. Their flexible and resilient nature is particularly relevant to protection of human bodies. Herein we develop an elastomeric cellular structure filled with nanoporous material functionalized (NMF) liquid. Due to the nanoscale infiltration in NMF liquid and its interaction with cell walls, the cellular structure has a much enhanced mechanical performance, in terms of loading capacity and energy absorption density. Moreover, it is validated that the structure is highly compressible and self-restoring. Its hyper-viscoelastic characteristics are elucidated.

  10. Preliminary creep and pillar closure data for shales

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Russell, J.E.

    1987-10-01

    The results of fourteen laboratory creep tests on model pillars of four different shales are reported. Initial pillar stresses range from 6.9 MPa (1000 psi) to 69 MPa (10,000 psi) and temperatures range from ambient to 100 0 C. Laboratory response data are used to evaluate the parameters in the transient power-law pillar closure equation similar to that previously used for model pillars of rock salt. The response of the model pillars of shale shows many of the same characteristics as for rock salt. Deformation is enhanced by higher stresses and temperatures, although the shale pillars are not as sensitive to either stress or temperature as are pillars of rock salt. These test results must be considered very preliminary since they represent the initial, or scoping, phase of a comprehensive model pillar test program that will lead to the development and validation of creep laws for clay-rich rocks. 11 refs., 9 figs., 7 tabs

  11. Empirical pillar design methods review report: Final report

    International Nuclear Information System (INIS)

    1988-02-01

    This report summarizes and evaluates empirical pillar design methods that may be of use during the conceptual design of a high-level nuclear waste repository in salt. The methods are discussed according to category (i.e, main, submain, and panel pillars; barrier pillars; and shaft pillars). Of the 21 identified for main, submain, and panel pillars, one method, the Confined Core Method, is evaluated as being most appropriate for conceptual design. Five methods are considered potentially applicable. Of six methods identified for barrier pillars, one method based on the Load Transfer Distance concept is considered most appropriate for design. Based on the evaluation of 25 methods identified for shaft pillars, an approximate sizing criterion is proposed for use in conceptual design. Aspects of pillar performance relating to creep, ground deformation, interaction with roof and floor rock, and response to high temperature environments are not adequately addressed by existing empirical design methods. 152 refs., 22 figs., 14 tabs

  12. Elastomeric neutron shielding material and process of production

    International Nuclear Information System (INIS)

    John, G.; Knorr, W.

    1987-01-01

    Elastomeric neutron shielding material made of plastic with high hydrogen content, characterized in that the shielding material is a polymeric reaction product of a reaction between (a) polyol on the base of polybutadiene which compares with polyethylene with regard to hydrogen content, and (b) aliphatic diisocyanate, and in that the hydrogen content is higher than 8 weight per cent. (orig.) [de

  13. Stress-state monitoring of coal pillars during room and pillar extraction

    Czech Academy of Sciences Publication Activity Database

    Waclawik, Petr; Ptáček, Jiří; Koníček, Petr; Kukutsch, Radovan; Němčík, J.

    2016-01-01

    Roč. 15, č. 2 (2016), s. 49-56 ISSN 2300-3960 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : stress-state monitoring * room and pillar * coal pillar Subject RIV: DH - Mining , incl. Coal Mining http://www.sciencedirect.com/science/article/pii/S2300396016300180

  14. Effects of pillar height and junction depth on the performance of radially doped silicon pillar arrays for solar energy applications

    NARCIS (Netherlands)

    Elbersen, R.; Vijselaar, Wouter Jan, Cornelis; Tiggelaar, Roald M.; Gardeniers, Johannes G.E.; Huskens, Jurriaan

    2016-01-01

    The effects of pillar height and junction depth on solar cell characteristics are investigated to provide design rules for arrays of such pillars in solar energy applications. Radially doped silicon pillar arrays are fabricated by deep reactive ion etching of silicon substrates followed by the

  15. Extending and implementing the Persistent ID pillars

    Science.gov (United States)

    Car, Nicholas; Golodoniuc, Pavel; Klump, Jens

    2017-04-01

    The recent double decade anniversary of scholarly persistent identifier use has triggered journal special editions such as "20 Years of Persistent Identifiers". For such a publication, it is apt to consider the longevity of some persistent identifier (PID) mechanisms (Digital Object Identifiers) and the partial disappearance of others (Life Sciences IDs). We have previously postulated a set of "PID Pillars" [1] which are design principles aimed at ensuring PIDs can survive technology and social change and thus persist for the long term that we have drawn from our observations of PIDs at work over many years. The principles: describe how to ensure identifiers' system and organisation independence; codify the delivery of essential PID system functions; mandate a separation of PID functions from data delivery mechanisms; and require generation of policies detailing how change is handled. In this presentation, first we extend on our previous work of introducing the pillars by refining their descriptions, giving specific suggestions for each and presenting some work that addresses them. Second, we propose a baseline data model for persistent identifiers that, if used, would assist the separation of PID metadata and PID system functioning. This would allow PID system function specifics to change over time (e.g. resolver services or even resolution protocols) and yet preserve the PIDs themselves. Third, we detail our existing PID system — the PID Service [2] — that partially implements the pillars and describe both its successes and shortcomings. Finally, we describe our planned next-generation system that will aim to use the baseline data model and fully implement the pillars.

  16. The role of the nature of pillars in the structural and magnetic properties of magnetic pillared vlays

    DEFF Research Database (Denmark)

    Bachir, Cherifa; Lan, Yanhua; Mereacre, Valeriu

    2011-01-01

    of pillared clays by examining in detail the influence of the calcination temperature and the nature of different pillared clays on these properties. Magnetic layered systems from different pillared clays were prepared and characterized. Firstly, Ti-, Al-, and Zr-pillared clays (Ti-PILCs, Al-PILCs, and Zr......-PILCs, respectively) were produced at different calcination temperatures and then magnetic pillared clays (Ti-M-PILCs, Al-M-PILCs, and Zr-M-PILCs) were prepared at ambient temperature. The synthesis involves a reduction in aqueous solution of the original Fe-exchanged pillared clay using NaBH4. The structural....... Similar experiments with Al- and Zr-pillars have been discussed. A correlation between the XRF data, porosity, FF calculation, and magnetic properties led to the conclusion that the sample Al-M-PILC previously calcined at 500 degrees C was the most stable material after the magnetization process. The same...

  17. Merensky pillar strength formulae based on back-analysis of pillar failures at Impala Platinum

    CSIR Research Space (South Africa)

    Watson, BP

    2008-08-01

    Full Text Available , with and without a large flanking area of mining. Such factors were generally less than 1.2 (20% correction), and were, where feasible, checked using Equation [1]4. This equation may be used if there is a large sea of mining with roughly uniform convergence... for pillars that are allowed to punch, as well as for pillars that are surrounded by an infinitely strong rock mass; high density mesh and varying brittleness Table IV Material and model properties �3 Co �0 �res �pr �0 �res (MPa) (MPa) (m�) A 2 15 55 50...

  18. Catalytic Wastewater Treatment Using Pillared Clays

    Science.gov (United States)

    Perathoner, Siglinda; Centi, Gabriele

    After introduction on the use of solid catalysts in wastewater treatment technologies, particularly advanced oxidation processes (AOPs), this review discussed the use of pillared clay (PILC) materials in three applications: (i) wet air catalytic oxidation (WACO), (ii) wet hydrogen peroxide catalytic oxidation (WHPCO) on Cu-PILC and Fe-PILC, and (iii) behavior of Ti-PILC and Fe-PILC in the photocatalytic or photo-Fenton conversion of pollutants. Literature data are critically analyzed to evidence the main direction to further investigate, in particularly with reference to the possible practical application of these technologies to treat industrial, municipal, or agro-food production wastewater.

  19. Quality factors of nonideal micro pillars

    DEFF Research Database (Denmark)

    Gregersen, Niels; Nielsen, Torben Roland; Tromborg, Bjarne

    2007-01-01

    The influence of fabrication-induced imperfections and material absorption on the quality (Q) factor of a microcavity pillar is studied numerically. The dependence on sidewall inclination, selective underetch, and intrinsic loss is quantified. The authors show that imperfections can lead to an im...... to an improvement in Q and that a sidewall inclination angle of less than 1° causes a dramatic change in the Q factor. The variations in Q can be attributed to a delicate balance between effective index contrasts, mode overlap, and higher-order mode contributions....

  20. Supercapacitors based on pillared graphene nanostructures.

    Science.gov (United States)

    Lin, Jian; Zhong, Jiebin; Bao, Duoduo; Reiber-Kyle, Jennifer; Wang, Wei; Vullev, Valentine; Ozkan, Mihrimah; Ozkan, Cengiz S

    2012-03-01

    We describe the fabrication of highly conductive and large-area three dimensional pillared graphene nanostructure (PGN) films from assembly of vertically aligned CNT pillars on flexible copper foils for applications in electric double layer capacitors (EDLC). The PGN films synthesized via a one-step chemical vapor deposition process on flexible copper foils exhibit high conductivity with sheet resistance as low as 1.6 ohms per square and possessing high mechanical flexibility. Raman spectroscopy indicates the presence of multi walled carbon nanotubes (MWCNT) and their morphology can be controlled by the growth conditions. It was discovered that nitric acid treatment can significantly increase the specific capacitance of the devices. EDLC devices based on PGN electrodes (surface area of 565 m2/g) demonstrate enhanced performance with specific capacitance value as high as 330 F/g extracted from the current density-voltage (CV) measurements and energy density value of 45.8 Wh/kg. The hybrid graphene-CNT nanostructures are attractive for applications including supercapacitors, fuel cells and batteries.

  1. Performance testing of elastomeric seal materials under low and high temperature conditions: Final report

    Energy Technology Data Exchange (ETDEWEB)

    BRONOWSKI,DAVID R.

    2000-06-01

    The US Department of Energy Offices of Defense Programs and Civilian Radioactive Waste Management jointly sponsored a program to evaluate elastomeric O-ring seal materials for radioactive material shipping containers. The report presents the results of low- and high-temperature tests conducted on 27 common elastomeric compounds.

  2. Periodically structured Si pillars for high-performing heterojunction photodetectors

    Science.gov (United States)

    Melvin David Kumar, M.; Yun, Ju-Hyung; Kim, Joondong

    2015-03-01

    A periodical array of silicon (Si) micro pillar structures was fabricated on Si substrates using PR etching process. Indium tin oxide (ITO) layer of 80 nm thickness was deposited over patterned Si substrates so as to make ITO/n-Si heterojunction devices. The influences of width and period of pillars on the optical and electrical properties of prepared devices were investigated. The surface morphology of the Si substrates revealed the uniform array of pillar structures. The 5/10 (width/period) Si pillar pattern reduced the optical reflectance to 6.5% from 17% which is of 5/7 pillar pattern. The current rectifying ratio was found higher for the device in which the pillars are situated in optimum periods. At both visible (600 nm) and near infrared (900 nm) range of wavelengths, the 5/7 and 5/10 pillar patterned device exhibited the better photoresponses which are suitable for making advanced photodetectors. This highly transmittance and photoresponsive pillar patterned Si substrates with an ITO layer would be a promising device for various photoelectric applications.

  3. Interaction of Reinforced Elastomeric Bearings in Bridge Construction

    Directory of Open Access Journals (Sweden)

    Nittmannová Ľubica

    2016-03-01

    Full Text Available The aim of this paper is to demonstrate the behavior of reinforced elastomeric bearings under various loads. They are made of special types of bearings. The experimental verification of these special bearings has been tested on various types of loading. The results of the experimental measurements are compared with the results of the numerical modeling and calculations according to the standard assumptions in STN EN 1337-3. In the conclusion, the results are summarized for the selected types of bearings.

  4. Elastically stretchable thin film conductors on an elastomeric substrate

    Science.gov (United States)

    Jones Harris, Joyelle Elizabeth

    Imagine a large, flat screen television that can be rolled into a small cylinder after purchase in the store and then unrolled and mounted onto the wall of a home. The electronic devices within the television must be able to withstand large deformation and tensile strain. Consider a robot that is covered with an electronic skin that simulates human skin. The skin would enable the machine to lift an elderly person with care and sensitivity. The skin will endure repeated deformation with the highest tensile strains being experienced at the robot's joints. These applications and many others will benefit from stretchable electronic circuitry. While several different methods have been employed to create stretchable electronics, all methods use a common tool -- stretchable conductors. Therefore, the goal of this thesis work was to fabricate elastically stretchable conductors that can be used in stretchable electronics. We deposited Au thin films on an elastomeric substrate, and the resulting conductors remained electrically continuous when stretched by 30% and more. We developed photolithographic processes that can be used to pattern elastically stretchable conductors with a 10 mum resolution. We fabricated bi-level stretchable conductors that are separated by an elastomeric insulator and are electrically connected through via holes in the insulator. We applied our bi-level conductors to create a stretchable resistor-inductor-capacitor (RLC) circuit with a tunable resonant frequency. We also used stretchable conductors to measure action potentials in biological samples. This thesis describes the fabrication and application of our elastically stretchable conductors.

  5. Adjustment of Part Properties for an Elastomeric Laser Sintering Material

    Science.gov (United States)

    Wegner, A.; Ünlü, T.

    2018-03-01

    Laser sintering of polymers is gaining more and more importance within the field of small series productions. Polyamide 12 is predominantly used, although a variety of other materials are also available for the laser sintering process. For example, elastomeric, rubberlike materials offer very different part property profiles. Those make the production of flexible parts like, e.g., sealings, flexible tubes or shoe soles possible because they offer high part ductility and low hardness. At the chair for manufacturing technology, a new elastomeric laser sintering material has been developed and then commercialized by a spin-off from university. The aim of the presented study was the analysis of the new material's properties. Proof was found that Shore hardness can be modified by varying the parameter settings. Therefore, the correlation between process parameters, energy input, Shore hardness and other part properties like mechanical properties were analyzed. Based on these results, suitable parameter settings were established which lead to the possibility of producing parts with different Shore hardnesses.

  6. Mechanically programmed shape change in laminated elastomeric composites.

    Science.gov (United States)

    Robertson, Jaimee M; Torbati, Amir H; Rodriguez, Erika D; Mao, Yiqi; Baker, Richard M; Qi, H Jerry; Mather, Patrick T

    2015-07-28

    Soft, anisotropic materials, such as myocardium in the heart and the extracellular matrix surrounding cells, are commonly found in nature. This anisotropy leads to specialized responses and is imperative to material functionality, yet few soft materials exhibiting similar anisotropy have been developed. Our group introduced an anisotropic shape memory elastomeric composite (A-SMEC) composed of non-woven, aligned polymer fibers embedded in an elastomeric matrix. The composite exhibited shape memory (SM) behavior with significant anisotropy in room-temperature shape fixing. Here, we exploit this anisotropy by bonding together laminates with oblique anisotropy such that tensile deformation at room temperature - mechanical programming - results in coiling. This response is a breakthrough in mechanical programming, since non-affine shape change is achieved by simply stretching the layered A-SMECs at room temperature. We will show that pitch and curvature of curled geometries depend on fiber orientations and the degree of strain programmed into the material. To validate experimental results, a model was developed that captures the viscoplastic response of A-SMECs. Theoretical results correlated well with experimental data, supporting our conclusions and ensuring attainability of predictable curling geometries. We envision these smart, soft, shape changing materials will have aerospace and medical applications.

  7. Fold catastrophe model of dynamic pillar failure in asymmetric mining

    Energy Technology Data Exchange (ETDEWEB)

    Yue Pan; Ai-wu Li; Yun-song Qi [Qingdao Technological University, Qingdao (China). College of Civil Engineering

    2009-01-15

    A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This graph contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions. 11 refs., 8 figs.

  8. Barrier pillar between production panels in coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Zingano, Andre Cezar; Koppe, Jair Carlos; Costa, Joao Felipe C.L. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

    2007-07-01

    The function of the barrier pillar is to protect the mining panel in activity from the abutment load of adjacent mining panels that were mined. In the case of underground mines in Santa Catarina State, the barrier pillar has functioned to protect the main entries of the mine against pillar failure from old mining panels. The objective of this paper is to verify the application of the empirical method to design barrier pillars as proposed by Peng (1986), using numerical simulation following the mining geometry of the coal mines in Santa Catarina State. Two-dimensional numerical models were built taking into account the geometry of the main entries and mining panels for different overburden thickness, and considering the geomechanical properties for the rock mass that forms the roof-pillar-floor system for the Bonito coal vein. The results of the simulations showed that the empirical method to determine the barrier pillar width is valid for the studied coal vein and considered mine geometry. Neither did the pillar at the main entry become overstressed due to adjacent mine panels, nor did the roof present any failure due to stress redistribution. 9 refs., 6 figs., 5 tabs.

  9. A guide to the suitability of elastomeric seal materials for use in radioactive material transport packages

    International Nuclear Information System (INIS)

    Vince, D.J.

    2004-01-01

    Elastomeric seals are a frequently favoured method of sealing Radioactive Material Transport (RMT) packages. The sealing technology has been proven for many years in a wide range of industrial applications. The requirements of the RMT package applications, however, are significantly different from those commonly found in other industries. This guide outlines the Regulatory performance requirements placed on an RMT package sealing system by TS-R-1, and then summarises the material, environment and geometry characteristics of elastomeric seals relevant to RMT applications. Tables in the guide list typical material properties for a range of elastomeric materials commonly used in RMT packages

  10. POROUS MEMBRANE TEMPLATED SYNTHESIS OF POLYMER PILLARED LAYER

    Institute of Scientific and Technical Information of China (English)

    Zhong-wei Niu; Dan Li; Zhen-zhong Yang

    2003-01-01

    The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates to synthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and the layer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm the methodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.

  11. The old pillars of new retailing.

    Science.gov (United States)

    Berry, L L

    2001-04-01

    Despite the harsh realities of retailing, the illusion persists that magical tools can help companies overcome the problems of fickle consumers, price-slashing competitors, and mood swings in the economy. Such wishful thinking holds that retailers will thrive if only they communicate better with customers through e-mail, employ hidden cameras to learn how customers make purchase decisions, and analyze scanner data to tailor special offers and manage inventory. But the truth is, there are no quick fixes. In the course of his extensive research on dozens of retailers, Leonard Berry found that the best companies create value for their customers in five interlocking ways. Whether you're running a physical store, a catalog business, an e-commerce site, or a combination of the three, you have to offer your customers superior solutions to their needs, treat them with respect, and connect with them on an emotional level. You also have to set prices fairly and make it easy for people to find what they need, pay for it quickly, and then move on. None of these pillars is new, and each sounds exceedingly simple, but don't be fooled--implementing these axioms in the real world is surprisingly difficult. The author illustrates how some retailers have built successful operations by attending to these commonsense ways of dealing with their customers and how others have failed to do so.

  12. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.

  13. Elastomeric polymer resonant waveguide grating based pressure sensor

    International Nuclear Information System (INIS)

    Song, Fuchuan; Xie, Antonio Jou; Seo, Sang-Woo

    2014-01-01

    In this paper, we demonstrate an elastomeric polymer resonant waveguide grating structure to be used as a pressure sensor. The applied pressure is measured by optical resonance spectrum peak shift. The sensitivity—as high as 86.74 pm psi −1 or 12.58 pm kPa −1 —has been experimentally obtained from a fabricated sensor. Potentially, the sensitivity of the demonstrated sensor can be tuned to different pressure ranges by the choices of elastic properties and layer thicknesses of the waveguide and cladding layers. The simulation results agree well with experimental results and indicate that the dominant effect on the sensor is the change of grating period when external pressure is applied. Based on the two-dimensional planar structure, the demonstrated sensor can be used to measure applied surface pressure optically, which has potential applications for optical ultrasound imaging and pressure wave detection/mapping

  14. Seismic isolation of nuclear power plants using elastomeric bearings

    Science.gov (United States)

    Kumar, Manish

    Seismic isolation using low damping rubber (LDR) and lead-rubber (LR) bearings is a viable strategy for mitigating the effects of extreme earthquake shaking on safety-related nuclear structures. Although seismic isolation has been deployed in nuclear structures in France and South Africa, it has not seen widespread use because of limited new build nuclear construction in the past 30 years and a lack of guidelines, codes and standards for the analysis, design and construction of isolation systems specific to nuclear structures. The nuclear accident at Fukushima Daiichi in March 2011 has led the nuclear community to consider seismic isolation for new large light water and small modular reactors to withstand the effects of extreme earthquakes. The mechanical properties of LDR and LR bearings are not expected to change substantially in design basis shaking. However, under shaking more intense than design basis, the properties of the lead cores in lead-rubber bearings may degrade due to heating associated with energy dissipation, some bearings in an isolation system may experience net tension, and the compression and tension stiffness may be affected by the horizontal displacement of the isolation system. The effects of intra-earthquake changes in mechanical properties on the response of base-isolated nuclear power plants (NPPs) were investigated using an advanced numerical model of a lead-rubber bearing that has been verified and validated, and implemented in OpenSees and ABAQUS. A series of experiments were conducted at University at Buffalo to characterize the behavior of elastomeric bearings in tension. The test data was used to validate a phenomenological model of an elastomeric bearing in tension. The value of three times the shear modulus of rubber in elastomeric bearing was found to be a reasonable estimate of the cavitation stress of a bearing. The sequence of loading did not change the behavior of an elastomeric bearing under cyclic tension, and there was no

  15. Linear dimensional stability of elastomeric impression materials over time.

    Science.gov (United States)

    Garrofé, Analía B; Ferrari, Beatriz A; Picca, Mariana; Kaplan, Andrea E

    2011-01-01

    The purpose of this study was to evaluate the linear dimensional stability of different elastomeric impression materials over time. A metal mold was designed with its custom trays, which were made of thermoplastic sheets (Sabilex sheets 0.125 mm thick). Three impressions were taken of it with each of the following: the polyvinylsiloxane Examix-GC-(AdEx), Aquasil-Dentsply-(AdAq) and Panasil-Kettenbach-(AdPa), and the polydimethylsiloxane Densell-Dental Medrano-(CoDe), Speedex-Coltene-(CoSp) and Lastic-Kettenbach-(CoLa). All impressions were taken with putty and light-body materials using a one-step technique. Standardized digital photographs were taken at different time intervals (0, 15, 30, 60, 120 minutes; 24 hours; 7 and 14 days), using an "ad-hoc" device, and analyzed using software (Image Tool) by measuring the distance between lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. The initial and final values for mean and SD were: AdEx: 1.32 (0.01) and 1.31 (0.00); AdAq: 1.32 (0.00) and 1.32 (0.00), AdPa: 1.327 (0.006) and 1.31 (0.00); CoDe: 1.32 (0.00) and 1.32 (0.01); CoSp: 1.327 (0.006) and 1.31 (0.00), CoLa: 1.327 (0.006) and 1.303 (0.006). Statistical evaluation showed that both material and time have significant effects. Under the conditions in this study we conclude that time would significantly affect the lineal dimensional stability of elastomeric impression materials.

  16. Engineered elastomeric proteins with dual elasticity can be controlled by a molecular regulator.

    Science.gov (United States)

    Cao, Yi; Li, Hongbin

    2008-08-01

    Elastomeric proteins are molecular springs that confer excellent mechanical properties to many biological tissues and biomaterials. Depending on the role performed by the tissue or biomaterial, elastomeric proteins can behave as molecular springs or shock absorbers. Here we combine single-molecule atomic force microscopy and protein engineering techniques to create elastomeric proteins that can switch between two distinct types of mechanical behaviour in response to the binding of a molecular regulator. The proteins are mechanically labile by design and behave as entropic springs with an elasticity that is governed by their configurational entropy. However, when a molecular regulator binds to the protein, it switches into a mechanically stable state and can act as a shock absorber. These engineered proteins effectively mimic and combine the two extreme forms of elastic behaviour found in natural elastomeric proteins, and thus represent a new type of smart nanomaterial that will find potential applications in nanomechanics and material sciences.

  17. Flexible Connection Elastomeric Rubber as a Pounding Resisting Element between Two Adjacent Buildings

    Directory of Open Access Journals (Sweden)

    Yuskar Lase

    2013-03-01

    Full Text Available To solve pounding problem of two adjacent buildings, structural designer usually employs a dilatation between the structures or make the two structures as a monolith structure. Other alternative is by using an elastomeric rubber as a pounding resisting element between the two structures. Effectiveness in applying elastomeric rubber component as flexible connection of two adjacent structures is the main focus of this paper. Various simulations such as structure models, earthquake excitations and openings in gap element are studied. Observation of maximum structural responses will be performed for structure model with elastomeric rubber in comparison with (1 monolith structure model and (2 structure model with rigid element (steel element. Simulation results show that application of elastomeric rubber component to prevent structures from pounding problem provides advantages especially in reducing internal forces in the shorter building. However, it slightly increases displacement of both structures.

  18. Correlation between in vitro Elastomeric Force Degradation and Glass Transition Temperature determined by Dynamic Mechanical Analysis

    Directory of Open Access Journals (Sweden)

    Manu Krishnan

    2012-01-01

    Conclusion: Tg can be considered as a dependable parameter in envisaging the force properties of an elastomeric chain. Clinically, it suggested that a polymer with higher Tg can give higher or optimum levels of force for tooth movement.

  19. Evaluation of the cytotoxicity of elastomeric ligatures after sterilisation with 0.25% peracetic acid.

    Science.gov (United States)

    Pithon, Matheus Melo; dos Santos, Rogerio Lacerda; Judice, Renata Lima Pasini; de Assuncao, Paulo Sergio; Restle, Luciana

    2013-11-01

    Sterilisation using peracetic acid (PAA) has been advocated for orthodontic elastic bands. However, cane-loaded elastomeric ligatures can also become contaminated during processing, packaging, and manipulation before placement in the oral cavity and are therefore susceptible, and possible causes, of cross-contamination. To test the hypothesis that 0.25% peracetic acid (PAA), following the sterilisation of elastomers, influences the cytotoxicity of elastomeric ligatures on L929 cell lines. Four hundred and eighty silver elastomeric ligatures were divided into 4 groups of 120 ligatures to produce, Group TP (latex natural, bulk pack, TP Orthodontics), Group M1 (Polyurethane, bulk pack, Morelli), Group M2 (Polyurethane, cane-loaded, Morelli) and Group U (Polyurethane, cane-loaded, Uniden). Of the 120 ligatures in each group, 100 were sterilised in 0.25% PAA at time intervals (N = 20) of 1 hour, 2 hours, 3 hours, 4 hours and 5 hours. The 20 remaining elastomeric ligatures in each group were not sterilised and served as controls. Cytotoxicity was assessed using L929 cell lines and a dye-uptake method. Analysis of variance (ANOVA), followed by the Tukey post hoc test (p < 0.05) determined statistical relevance. There was a significant difference between TP, Morelli and Uniden elastomerics (p < 0.05), but no difference between the two types of Morelli elastomerics at the 1 hour time interval. In addition, there was a significant difference between Group CC and the other groups assessed, except between Groups CC and TP at the 1 hour time interval. The non-sterilised elastomeric ligatures showed similar cell viability to that observed after 1 hour of standard sterilisation. PAA did not significantly influence the cytotoxicity of elastomeric ligatures after a sterilisation time of 1 hour and is therefore recommended for clinical use.

  20. Analysis of the Influence of Food Colorings in Esthetic Orthodontic Elastomeric Ligatures.

    Science.gov (United States)

    Dias da Silva, Vanessa; de Lima, Eduardo Martinelli S; Dias, Caroline; Osório, Leandro Berni

    2016-01-01

    The purpose of this study was to evaluate in vitro the color changes of esthetic orthodontic elastomeric ligatures of different shades when exposed to four food colorings commonly found in the diet of patients. The sample consisted of esthetic orthodontic elastomeric ligatures in the colors pearl, pearl blue, pearl white and colorless, which were immersed for 72 hours in five different solutions: distilled water (control group), coffee, tea, Coca-Cola ® and wine. The color changes of the esthetic orthodontic elastomeric ligatures were measured with the aid of a spectrophotometer, at T1 - as provided by the manufacturer; and T2 - after colorings process. The results indicated that the esthetic orthodontic elastomeric ligatures of all initial hues are susceptible to pigmentation. Among the evaluated colors, all changed the finished look and the color of the samples tested. In ascending order, the color of the samples was as follows: distilled water, Coca-Cola ® , black tea, wine and coffee. The substances that have a greater potential for pigmentation in esthetic orthodontic elastomeric ligatures were black tea, wine and coffee, respectively. All shades of esthetic orthodontic elastomeric ligatures are susceptible to color change.

  1. Current practice and guidelines for the safe design of water barrier pillars

    CSIR Research Space (South Africa)

    Rangasamy, T

    2001-08-01

    Full Text Available adjacent to barrier pillars was conducted to ascertain the relationship between compartment water head, barrier pillar width and flow rates for combinations of roof bound, coal bound and floor bound flow. The results obtained from the instrumentation... pillars. A survey of South African Collieries revealed that water leakage associated with barrier pillars can be classed into seven predominant geotechnical flow categories. Through extensive numerical modelling and case history matching, barrier pillar...

  2. Superhydrophobic analyte concentration utilizing colloid-pillar array SERS substrates.

    Science.gov (United States)

    Wallace, Ryan A; Charlton, Jennifer J; Kirchner, Teresa B; Lavrik, Nickolay V; Datskos, Panos G; Sepaniak, Michael J

    2014-12-02

    The ability to detect a few molecules present in a large sample is of great interest for the detection of trace components in both medicinal and environmental samples. Surface enhanced Raman spectroscopy (SERS) is a technique that can be utilized to detect molecules at very low absolute numbers. However, detection at trace concentration levels in real samples requires properly designed delivery and detection systems. The following work involves superhydrophobic surfaces that have as a framework deterministic or stochastic silicon pillar arrays formed by lithographic or metal dewetting protocols, respectively. In order to generate the necessary plasmonic substrate for SERS detection, simple and flow stable Ag colloid was added to the functionalized pillar array system via soaking. Native pillars and pillars with hydrophobic modification are used. The pillars provide a means to concentrate analyte via superhydrophobic droplet evaporation effects. A ≥ 100-fold concentration of analyte was estimated, with a limit of detection of 2.9 × 10(-12) M for mitoxantrone dihydrochloride. Additionally, analytes were delivered to the surface via a multiplex approach in order to demonstrate an ability to control droplet size and placement for scaled-up uses in real world applications. Finally, a concentration process involving transport and sequestration based on surface treatment selective wicking is demonstrated.

  3. Pessimistic Determination of Mechanical Conditions and Micro/macroeconomic Evaluation of Mine Pillar Replacement

    Science.gov (United States)

    Chen, Qingfa; Zhao, Fuyu

    2017-12-01

    Numerous pillars are left after mining of underground mineral resources using the open stope method or after the first step of the partial filling method. The mineral recovery rate can, however, be improved by replacement recovery of pillars. In the present study, the relationships among the pillar type, minimum pillar width, and micro/macroeconomic factors were investigated from two perspectives, namely mechanical stability and micro/macroeconomic benefit. Based on the mechanical stability formulas for ore and artificial pillars, the minimum width for a specific pillar type was determined using a pessimistic criterion. The microeconomic benefit c of setting an ore pillar, the microeconomic benefit w of artificial pillar replacement, and the economic net present value (ENPV) of the replacement process were calculated. The values of c and w were compared with respect to ENPV, based on which the appropriate pillar type and economical benefit were determined.

  4. Landslides in the area of the Jastrzebie town protective pillar

    Energy Technology Data Exchange (ETDEWEB)

    Rybicki, S

    1986-01-01

    Analyzes 76 landslides in the area of the safety pillar of Jastrzebie in the Rybnik coal region. Of 76 landslides 60% fell on natural slopes with an angle of 25-50 degrees, 22% on natural slopes with a 5-25 degree angle, 10% on man-made cuts and 8% on embankments. About 78% of the landslides was associated with water bearing layers. Of the 76 landslides 32 were situated in the safety pillar and 44 close to the pillar. Thirty-three landslides were closely associated with underground mining: 30 landslides were caused by longwall mining (landslide position was related to working face position), a further 3 were associated with mining in general. Statistical data on landslides associated with underground coal mining are analyzed: landslide area, angle of slope inclination, height, landslide range, water conditions, types of soils, types of mining areas classified according to effects of mining damage. 8 refs.

  5. Fabrication of Pillar Shaped Electrode Arrays for Artificial Retinal Implants

    Directory of Open Access Journals (Sweden)

    Sung June Kim

    2008-09-01

    Full Text Available Polyimide has been widely applied to neural prosthetic devices, such as the retinal implants, due to its well-known biocompatibility and ability to be micropatterned. However, planar films of polyimide that are typically employed show a limited ability in reducing the distance between electrodes and targeting cell layers, which limits site resolution for effective multi-channel stimulation. In this paper, we report a newly designed device with a pillar structure that more effectively interfaces with the target. Electrode arrays were successfully fabricated and safely implanted inside the rabbit eye in suprachoroidal space. Optical Coherence Tomography (OCT showed well-preserved pillar structures of the electrode without damage. Bipolar stimulation was applied through paired sites (6:1 and the neural responses were successfully recorded from several regions in the visual cortex. Electrically evoked cortical potential by the pillar electrode array stimulation were compared to visual evoked potential under full-field light stimulation.

  6. Thermal stability of the elastomeric anti-trauma pad

    Directory of Open Access Journals (Sweden)

    Olszewska Karolina

    2017-06-01

    Full Text Available The elastomeric anti-trauma pad (EA-TP based on shear thickening fluid (STF has been developed. Dynamic oscillatory shear experiment was conducted at constant strain amplitude of 5%. STF composed of 25% of volume fraction of 7 nm Fumed Silica, dispersed in polypropylene glycol with molar mass 400 gmol−1 shows elastic properties in entire investigated range of the frequency. Ballistic tests of EA-TP with 7.62 mm × 39 mm PS bullets were performed according to the PN-V-87000:2011 standard. The studies revealed about 60% reduction of the average backface signature depth (BSD for the EA-TP, when compared to the nowadays commonly used soft insert. The ATR-FTIR analysis confirmed slight impact of the elevated temperature and air (oxygen on the chemical degradation of the EA-TP surface. The UV-VIS spectroscopy has allowed to notice colour deviation of the aged samples towards green and yellow, as well as lack of dye resistance to accelerated aging process. Thermographic analysis has shown no visible changes of the EA-TP surface and sub-surface during accelerated aging process. The aforementioned small changes on the surface of EA-TP did not affect the ballistic properties of composite armour. EA-TP insert maintains ballistic properties after accelerated aging process which was simulating the period of 6 years according to ASTM F1980 – 07:2002 standard.

  7. Diffusion of nanoparticles in solution through elastomeric membrane

    Science.gov (United States)

    Zemzem, Mohamed; Vinches, Ludwig; Hallé, Stéphane

    2017-04-01

    Diffusion phenomena encountered in mass transfer of liquids play an important role in many technological processes of polymer manufacturing and use. In addition and alongside the notable growth of nanoparticles use, particularly when in suspension in liquid solutions, it has become important to pay some attention to their interactions with polymeric structures. The aim of this work is to evaluate some diffusion parameters of gold nanoparticle solutions as well as of their liquid carrier (water) through elastomeric membranes. Gravimetric method was chosen as the main technique to quantify swelling phenomena and to assess kinetic properties. The dynamic liquid uptake measurements were conducted on gold nanoparticles (5 nm and 50 nm in diameter) in aqueous solutions when brought into contact with two types of nitrile material samples. Results showed that diffusion mechanism of the liquids lies between Fickian and sub-Fickian modes. Slight deviations were noticed with the gold nanoparticle solutions. A growth in liquid interaction with the rubbery structure in presence of the nanoparticles was also observed from comparison of K factor (characteristic of the elastomer-liquid interaction). Difference between the characteristics of the two membranes was also reported using this parameter. Besides, diffusion coefficients testified the impact of the membrane thickness on the penetration process, while no significant effect of the nature of the nanoparticle solution can be seen on this coefficient.

  8. Diffusion of nanoparticles in solution through elastomeric membrane

    International Nuclear Information System (INIS)

    Zemzem, Mohamed; Vinches, Ludwig; Hallé, Stéphane

    2017-01-01

    Diffusion phenomena encountered in mass transfer of liquids play an important role in many technological processes of polymer manufacturing and use. In addition and alongside the notable growth of nanoparticles use, particularly when in suspension in liquid solutions, it has become important to pay some attention to their interactions with polymeric structures. The aim of this work is to evaluate some diffusion parameters of gold nanoparticle solutions as well as of their liquid carrier (water) through elastomeric membranes. Gravimetric method was chosen as the main technique to quantify swelling phenomena and to assess kinetic properties. The dynamic liquid uptake measurements were conducted on gold nanoparticles (5 nm and 50 nm in diameter) in aqueous solutions when brought into contact with two types of nitrile material samples. Results showed that diffusion mechanism of the liquids lies between Fickian and sub-Fickian modes. Slight deviations were noticed with the gold nanoparticle solutions. A growth in liquid interaction with the rubbery structure in presence of the nanoparticles was also observed from comparison of K factor (characteristic of the elastomer-liquid interaction). Difference between the characteristics of the two membranes was also reported using this parameter. Besides, diffusion coefficients testified the impact of the membrane thickness on the penetration process, while no significant effect of the nature of the nanoparticle solution can be seen on this coefficient. (paper)

  9. Strain-dependent dynamic compressive properties of magnetorheological elastomeric foams

    Science.gov (United States)

    Wereley, Norman M.; Perez, Colette; Choi, Young T.

    2018-05-01

    This paper addresses the strain-dependent dynamic compressive properties (i.e., so-called Payne effect) of magnetorheological elastomeric foams (MREFs). Isotropic MREF samples (i.e., no oriented particle chain structures), fabricated in flat square shapes (nominal size of 26.5 mm x 26.5 mm x 9.5 mm) were synthesized by randomly dispersing micron-sized iron oxide particles (Fe3O4) into a liquid silicone foam in the absence of magnetic field. Five different Fe3O4 particle concentrations of 0, 2.5, 5.0, 7.5, and 10 percent by volume fraction (hereinafter denoted as vol%) were used to investigate the effect of particle concentration on the dynamic compressive properties of the MREFs. The MREFs were sandwiched between two multi-pole flexible plate magnets in order to activate the magnetorheological (MR) strengthening effect. Under two different pre-compression conditions (i.e., 35% and 50%), the dynamic compressive stresses of the MREFs with respect to dynamic strain amplitudes (i.e., 1%-10%) were measured by using a servo-hydraulic testing machine. The complex modulus (i.e., storage modulus and loss modulus) and loss factors of the MREFs with respect to dynamic strain amplitudes were presented as performance indices to evaluate their strain-dependent dynamic compressive behavior.

  10. Strain-dependent dynamic compressive properties of magnetorheological elastomeric foams

    Directory of Open Access Journals (Sweden)

    Norman M. Wereley

    2018-05-01

    Full Text Available This paper addresses the strain-dependent dynamic compressive properties (i.e., so-called Payne effect of magnetorheological elastomeric foams (MREFs. Isotropic MREF samples (i.e., no oriented particle chain structures, fabricated in flat square shapes (nominal size of 26.5 mm x 26.5 mm x 9.5 mm were synthesized by randomly dispersing micron-sized iron oxide particles (Fe3O4 into a liquid silicone foam in the absence of magnetic field. Five different Fe3O4 particle concentrations of 0, 2.5, 5.0, 7.5, and 10 percent by volume fraction (hereinafter denoted as vol% were used to investigate the effect of particle concentration on the dynamic compressive properties of the MREFs. The MREFs were sandwiched between two multi-pole flexible plate magnets in order to activate the magnetorheological (MR strengthening effect. Under two different pre-compression conditions (i.e., 35% and 50%, the dynamic compressive stresses of the MREFs with respect to dynamic strain amplitudes (i.e., 1%-10% were measured by using a servo-hydraulic testing machine. The complex modulus (i.e., storage modulus and loss modulus and loss factors of the MREFs with respect to dynamic strain amplitudes were presented as performance indices to evaluate their strain-dependent dynamic compressive behavior.

  11. Unification of reactor elastomeric sealing based on material

    International Nuclear Information System (INIS)

    Sinha, N.K.; Raj, Baldev

    2012-01-01

    The unification of elastomeric sealing applications of Indian nuclear reactors based on a few qualified fluoroelastomer/perfluoroelastomer compounds and standardized approaches for finite element analysis (FEA) based design, manufacturing process and antifriction coatings is discussed. It is shown that the advance polymer architecture based Viton ® formulation developed for inflatable seals of 500 MWe Prototype Fast Breeder Reactor (PFBR) and its four basic variations can encompass other sealing applications of PFBR with minimum additional efforts on development and validation. Changing the blend ratio of Viton ® GBL 200S and 600S in inflatable seal formulation could extend its use to Pressurized Heavy Water Reactors (PHWRs). The higher operating temperature of Advanced Heavy Water Reactor (AHWR) seals expands the choice to perfluoroelastomers. FEA based on plane-strain/axisymmetric modeling (with Mooney–Rivlin as the basic constitutive model), seal manufacture by cold feed extrusion and injection molding as well as plasma Teflon-like coating belonging to two variations obtained from the development of inflatable seals provide the necessary standardization for unification. The gains in simplification of design, development and operation of seals along with the enhancements of safety and reliability are expected to be substantial.

  12. Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

    Science.gov (United States)

    Darmawan, A.; Widiarsih

    2018-04-01

    The manufacture of membrane support from cobalt aluminium pillared clay has been conducted. This research was conducted by mixing a clay suspension with pillared solution prepared from the mixture of Co(NO3)2.6H2O and AlCl3.6H2O. The molar ratio between Al and Co was 75:25 and the ratio of [OH-]/[metal] was 2. The clay suspension was stirred for 24 hours at room temperature, filtered and dried. The dried clay was then calcined at 200°C, 300°C and 400°C with a ramp rate of 2°C/min. Aluminium-cobalt-pillared clay was then characterized by XRD and GSA and moulded become a membrane support for subsequent tests on dye filtration. The XRD analysis showed that basal spacing (d 001) value of aluminium cobalt was 19.49 Å, which was higher than the natural clay of 15.08Å however, the basal spacing decreased with increasing calcination temperature. The result of the GSA analysis showed that the pore diameter of the aluminium cobalt pillared clay membrane was almost the same as that of natural clay that were 34.5Å and 34.2Å, respectively. Nevertheless, the pillared clay has a more uniform pore size distribution. The results of methylene blue filtration measurements demonstrated that the membrane filter support could well which shown by a clear filtrate at all concentrations tested. The value of rejection and flux decreased with the increasing concentration of methylene blue. The values of dye rejection and water flux reached 99.89% and 5. 80 x 10-6 kg min-1, respectively but they decreased with increasing concentration of methylene blue. The results of this study indicates that the aluminium-pillared clay cobalt could be used as membrane materials especially for ultrafiltration.

  13. Development of a method to estimate coal pillar loading

    CSIR Research Space (South Africa)

    Roberts, DP

    2002-09-01

    Full Text Available to the panel width to depth ratio, the percentage extraction and the stiffness of the surrounding strata influence the validity of the tributary area method. An underground test was conducted to assess the magnitude of changes in pillar stress. Various... stress measurement devices were installed in test pillars just prior to mining. The stress changes were monitored and compared with numerical modelling results. It was found that stresses increased by between 0.3 MPa and 0.5 MPa and that the stresses...

  14. Hydraulic method of working large super-drift pillars

    Energy Technology Data Exchange (ETDEWEB)

    Rad' ko, B.V.; Syroezhkin, P.V.; Durov, V.S.

    1987-03-01

    Describes the method of hydraulic coal extraction introduced in the Pioneer mine belonging to the Dobropol'eugol' coal association. This method was found to reduce the number of collection and ventilation roadways needed significantly, increase their stability, reduce coal loss and increase safety, particularly when mining pillars up to 80 m high. Large scale diagram of hydraulic mining layout shows: ventilation gate, hydraulic monitors, mine roadway, cross-cut, and collection roadways. A table shows pillar dimensions and depth and economic savings for different seams in the mine.

  15. Static frictional resistance with the slide low-friction elastomeric ligature system.

    Science.gov (United States)

    Jones, Steven P; Ben Bihi, Saida

    2009-11-01

    This ex-vivo study compared the static frictional resistance of a low-friction ligation system against a conventional elastomeric module, and studied the effect of storage in a simulated oral environment on the static frictional resistance of both ligation systems. Eighty stainless steel brackets were tested by sliding along straight lengths of 0.018 inch round and 0.019 x 0.025 inch rectangular stainless steel wires ligated with either conventional elastomerics or the Slide system (Leone, Florence, Italy). During the tests the brackets and wires were lubricated with artificial saliva. A specially constructed jig assembly was used to hold the bracket and archwire securely. The jig was clamped in an Instron universal load testing machine. Crosshead speed was controlled via a microcomputer connected to the Instron machine. The static frictional forces at 0 degree bracket/wire angulation were measured for both systems, fresh from the pack and after storage in artificial saliva at 37 degrees C for 24 hours. The results of this investigation demonstrated that the Slide ligatures produced significantly lower static frictional resistance than conventional elastomeric modules in the fresh condition and after 24 hours of storage in a simulated oral environment (p static frictional resistance of conventional elastomeric modules and the Slide system (p = 0.525). The claim by the manufacturer that the Slide system produces lower frictional resistance than conventional elastomeric modules is upheld.

  16. Tribological properties and morphology of bimodal elastomeric nitrile butadiene rubber networks

    International Nuclear Information System (INIS)

    Guo, Yin; Wang, Jiaxu; Li, Kang; Ding, Xingwu

    2013-01-01

    Highlights: • Bimodal elastomeric NBR as a new material was developed. • The structure of bimodal elastomeric NBR networks was determined. • The relationship between structure and mechanical properties was investigated. • The tribological properties and mechanisms of bimodal NBR were analyzed. • The benefits of bimodal NBR in the field of tribology were discussed. - Abstract: Bimodal nitrile butadiene rubber (NBR) was examined in this study. The molecular structure was determined by dynamic mechanical analysis and transmission electron microscopy. The relationship between the structure and the mechanical properties related to elastomeric tribological properties was investigated. The properties and the mechanisms of friction and wear of bimodal elastomeric NBR networks were also analyzed. The lubricating characteristics of bimodal NBR networks were revealed based on the mechanisms of friction and wear. Results show that bimodal NBR networks are similar to bimodal polydimethylsiloxane networks. The form and density of the network structure can be controlled from elastomeric networks to thermosetting resin networks. The mechanical properties of bimodal NBR networks, such as elasticity, elongation at break, fatigue characteristic, tensile strength, elastic modulus, and thermal stability can be precisely controlled following the variation in network structure. The friction, wear, and lubrication of bimodal NBR networks can be clearly described according to the principles of tribology. Common elastomers cannot simultaneously reduce friction and wear because of the different mechanisms of friction and wear; however, bimodal elastomer networks can efficiently address this problem

  17. The role of elastomeric pumps in postoperative analgesia in orthopaedics and factors affecting their flow rate.

    Science.gov (United States)

    Theodorides, Anthony Andreas

    2017-12-01

    Elastomeric pumps are mechanical devices composed of an elastomeric balloon reservoir into which the drug to be infused is stored, a protective casing (used by some manufacturers), a flow controller and a wound catheter. In orthopaedics they are used to provide continuous local infiltration analgesia. In this way patients rely less on other routes of analgesia and thus avoid their systemic side effects. Studies have shown good response to analgesia with these pumps for the first 24 hours but their benefit is not as clear at 48 and 72 hours. There are numerous factors that affect the flow rate of elastomeric pumps. Some are inherent to all elastomeric pumps such as: the pressure exerted by the elastomeric balloon, catheter size, the vertical height of the pump in relation to the wound, viscosity and partial filling. There are also other factors which vary according to the manufacturer such as: the optimal temperature to obtain the desired flow rate as this directly affects viscosity, the dialysate that the analgesic drug is mixed with (ie normal saline or 5% dextrose), and the storage conditions of the fluid to be infused. It is thus essential to follow the clinical guidelines provided by the manufacturer in order to obtain the desired flow rate. Copyright the Association for Perioperative Practice.

  18. Force decay of elastomeric chains - a mechanical design and product comparison study.

    Science.gov (United States)

    Balhoff, David A; Shuldberg, Matthew; Hagan, Joseph L; Ballard, Richard W; Armbruster, Paul C

    2011-03-01

    To evaluate the percentage force decay of elastomeric chain products utilizing three different design mechanisms simulating canine retraction; and to evaluate the percentage force decay of elastomeric chain products from four different companies. In vitro, laboratory study. LSUHSC Dental School, New Orleans, LA, USA. Closed (non-spaced), grey elastomeric chains from four companies were selected for the study. Three acrylic resin jigs were constructed to provide a framework for three simulated space closure mechanisms. The 6-5-3, the chain loop, and the 6-3 were the configuration mechanisms used in the study. An electronic force gauge was used to measure the percentage force decay associated with each elastomeric chain over 28 days at preselected times. There was a significant difference in the mean percentage force decay for the three different mechanisms (P < 0·001). For all four companies, the 6-3 mechanical design had the smallest mean percentage force decay. There was a significant difference in the mean percentage force decay for the different companies (P < 0·001). For all three mechanisms, Ormco had the smallest percentage force decay while Unitek had the highest percentage force decay. The significant difference in the mean percentage force decay for the different mechanisms suggests that the 6-3 design is a more efficient means of closing extraction spaces utilizing elastomeric chains.

  19. Development and validation of a method to predict coal pillar life in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Merwe, J.N. [Pretoria Univ., Dept. of Mining Engineering (South Africa)

    2005-07-01

    One of the most difficult aspects of mine closure procedures, is to predict the long term stability of pillars in the case of coal mining. In South African coal mining, pillars have been designed since the late 1960's with the aid of a pillar strength formula based on statistical analysis of failed pillar cases by the well known team of Salamon and Munro. They developed the widely used power formula for pillar strength. Since that time, however, the data base of failed pillars has effectively doubled in size and re-analysis of the new data indicated that the original pillar strength of small pillars may have been over estimated. The data was then extensively re-analysed and a more effective linear formula for pillar strength was found. The most important differences between the two formulae are that the predicted strength of small pillars are lower and the strength of larger pillars, higher with the new formula. However, neither of the two methods explicitly cater for the prediction of the expected time of stability of coal pillars. No direct correlation between the safety factors and the period of stability of pillars could be found. It was then determined that the most frequent mode of pillar failure was by progressive scaling. Using the new formula to determine a minimum value of pillar safety factor (i.e. the safety factor at which failure can be taken as guaranteed to occur), the final sizes - after scaling - at which the failed pillars had to be in order to fail, were determined. The differences between the original dimensions and the postulated final dimensions were then used to calculate a rate of pillar scaling. The rate was then re-applied to the original data bases of both failed and intact pillar cases and distinct differences were found. The projected lives of the failed pillars were substantially shorter than the projected lives of the intact pillars. While this inspired confidence in the procedure, it was still based on an assumed and unproven

  20. Development and validation of a method to predict coal pillar life in South Africa

    International Nuclear Information System (INIS)

    Van Der Merwe, J.N.

    2005-01-01

    One of the most difficult aspects of mine closure procedures, is to predict the long term stability of pillars in the case of coal mining. In South African coal mining, pillars have been designed since the late 1960's with the aid of a pillar strength formula based on statistical analysis of failed pillar cases by the well known team of Salamon and Munro. They developed the widely used power formula for pillar strength. Since that time, however, the data base of failed pillars has effectively doubled in size and re-analysis of the new data indicated that the original pillar strength of small pillars may have been over estimated. The data was then extensively re-analysed and a more effective linear formula for pillar strength was found. The most important differences between the two formulae are that the predicted strength of small pillars are lower and the strength of larger pillars, higher with the new formula. However, neither of the two methods explicitly cater for the prediction of the expected time of stability of coal pillars. No direct correlation between the safety factors and the period of stability of pillars could be found. It was then determined that the most frequent mode of pillar failure was by progressive scaling. Using the new formula to determine a minimum value of pillar safety factor (i.e. the safety factor at which failure can be taken as guaranteed to occur), the final sizes - after scaling - at which the failed pillars had to be in order to fail, were determined. The differences between the original dimensions and the postulated final dimensions were then used to calculate a rate of pillar scaling. The rate was then re-applied to the original data bases of both failed and intact pillar cases and distinct differences were found. The projected lives of the failed pillars were substantially shorter than the projected lives of the intact pillars. While this inspired confidence in the procedure, it was still based on an assumed and unproven rate

  1. In situ measurements of Merensky pillar behaviour at Impala Platinum

    CSIR Research Space (South Africa)

    Watson, BP

    2009-12-01

    Full Text Available to stabilize the stoping excavations. This paper describes the in situ measurement, of stress within a Merensky pillar from Impala Platinum. These measurements were used to derive a stress-strain curve that includes pre and post failure behaviour. 2D FLAC...

  2. Charge transport in nanoscale vertical organic semiconductor pillar devices

    NARCIS (Netherlands)

    Wilbers, J.G.E.; Xu, B.; Bobbert, P.A.; de Jong, M.P.; van der Wiel, W.G.

    2017-01-01

    We report charge transport measurements in nanoscale vertical pillar structures incorporating ultrathin layers of the organic semiconductor poly(3-hexylthiophene) (P3HT). P3HT layers with thickness down to 5 nm are gently top-contacted using wedging transfer, yielding highly reproducible, robust

  3. Mine flooding and barrier pillar hydrology in the Pittsburgh basin

    International Nuclear Information System (INIS)

    Leavitt, B.R.

    1999-01-01

    Pennsylvania began requiring barrier pillars between mines as early as 1930. The Ashley formula, resulting from a early commission on the problem, requires 20 feet of coal plus a thickness of coal equal to four times the seam height plus an additional thickness of coal equal to one tenth of the overburden thickness, or the maximum potential hydraulic head. For a 6-foot thick coal seam under 400 feet of cover, the barrier would be 20+24+40=84 feet. The Ashley formula is intended to protect coal miners from a catastrophic failure of a barrier pillar which has a high head of water impounded behind it. The paper gives several examples of flooded and unflooded mines and the performance of their barrier pillars with respect to acid mine drainage. It is concluded that for all practical purposes, barrier pillars designed with the Ashley formula are able to hydrologically isolate mines from one another. This hydrologic isolation promotes the inundation of closed mines. Inundation effectively stops acid formation, thus, fully inundated mines do not represent a perpetual source of acid mine drainage. Infiltrating ground water improves the mine water chemistry resulting in a net alkaline discharge which has greatly lowered iron concentrations. The best locations for acid mine drainage treatment plants is at the lowest surface elevation above the mine with mine flooded to near that elevation

  4. Adequate plasma drug concentrations suggest that amoxicillin can be administered by continuous infusion using elastomeric pumps.

    Science.gov (United States)

    Arensdorff, Lyne; Boillat-Blanco, Noémie; Decosterd, Laurent; Buclin, Thierry; de Vallière, Serge

    2017-09-01

    Elastomeric pumps can be useful for the administration of antibiotics in the outpatient setting. To determine amoxicillin degradation in elastomeric pumps, as well as the effectiveness of amoxicillin treatment administered by elastomeric pumps. Antibiotic degradation was measured in elastomeric pumps filled with 6 g of amoxicillin in 240 mL of NaCl 0.9% by drawing samples at 12 h intervals when stored in the fridge for 48 h and when worn around the waist for 24 h. Subsequently nine patients were treated with continuous infusions of 8 or 12 g of amoxicillin per day. Plasma amoxicillin concentrations were measured on each visit to the outpatient parenteral antibiotic therapy unit. Clinical outcome was verified 3 months after the end of treatment. Amoxicillin degradation in elastomeric pumps reached 10% after 48 h in the fridge and an additional 30% when worn around the waist for 24 h. Mean plasma drug concentrations achieved with 12 g of amoxicillin per day were 18.5 mg/L (95% CI 13.5-23.5), which is largely above the MIC of amoxicillin-susceptible bacteria. Nine patients treated for various complicated infections were cured and had no unexpected adverse effects. Adequate plasma drug concentrations and favourable clinical outcomes suggest that amoxicillin can be administered by continuous infusion using elastomeric pumps. This treatment modality does not fulfil formal requirements regarding pharmaceutical stability, but the resulting safety impact in patients is probably limited. Therapeutic drug monitoring and a close clinical follow-up are recommended if this route of administration is chosen. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Mechanical properties of pillared-graphene nanostructures using molecular dynamics simulations

    International Nuclear Information System (INIS)

    Wang, Chih-Hao; Fang, Te-Hua; Sun, Wei-Li

    2014-01-01

    The deformation behaviour and mechanical properties of three-dimensional (3D) pillared graphene are investigated using molecular dynamics simulations. The Tersoff–Brenner many-body potential model is employed to evaluate the interactions between 3D pillared-graphene carbon atoms and nanotube carbons. The Lennard-Jones potential model is used to compute the interactions between a conical indenter and 3D pillared-graphene carbon atoms. The effects of the size and geometric structure of 3D pillared-graphene are evaluated in terms of the indentation force and contact stiffness. The simulation results for an armchair nanotube of 3D pillared graphene show that the contact stiffness increases with increasing chiral vector of the 3D-pillared graphene. However, the adhesive force sharply decreases with increasing chiral vector of the 3D-pillared graphene. A zigzag nanotube of 3D-pillared graphene exhibits better mechanical properties compared with those of the armchair nanotube. (paper)

  6. Eco-Friendly Magnetic Iron Oxide Pillared Montmorillonite for Advanced Catalytic Degradation of Dichlorophenol

    Science.gov (United States)

    Eco-friendly pillared montmorillonites, in which the pillars consist of iron oxide are expected to have interesting and unusual magnetic properties that are applicable for environmental decontamination. Completely “green” and effective composite was synthesized using mild reactio...

  7. Baxter elastomeric pumps: Weighing as an alternative to visual inspection.

    Science.gov (United States)

    Cusano, Ellen L; Ali, Raafi; Sawyer, Michael B; Chambers, Carole R; Tang, Patricia A

    2018-04-01

    Purpose Elastomeric pumps are used to administer 46-hour infusions of 5-fluorouracil (5FU). Baxter suggests patients visually monitor their pumps to ensure that infusions are proceeding correctly. This can be confusing and lead to concerns about under- or over-dosing. Baxter has not considered weighing pumps as a validated method for monitoring. This study aims to validate weighing as a more accurate method for patients and healthcare professionals, and describe real life Baxter Infusor™ variability. Methods Patients who had been started on a 46-hour 5FU infusion returned to the clinic approximately 24 h after starting treatment. The pump was weighed on a StarFrit kitchen scale, and date, time, and weights recorded. Patients were asked if they had a preference for weighing or visually inspecting their pump. Results Pumps ( n = 103) were weighed between 17.25 and 27.5 h after connection. The average weight of a pump was 189 g. Of 103 pumps weighed, 99 weighed less than expected, corresponding to average flow rates of 5.69 mL/h over the elapsed time. The expected flow rate is 5 mL/h with 10% variability. Average flow rates within the 17.25- to 27.5-hour window were 4.561 mL/h, which is 8.78% slower than expected, but within the 10% known variability. Forty-seven percent of patients didn't have a preference for either method, but for those who did have a preference, more than twice as many preferred weighing. Conclusion With proper education, weighing Baxter Infusors at home with kitchen scales can be an accepted and objective alternative to the current recommendation of visual inspection.

  8. Effect of storage period on the accuracy of elastomeric impressions

    Directory of Open Access Journals (Sweden)

    Eduardo Batista Franco

    2007-06-01

    Full Text Available AIMS: To investigate the effect of the storage period on the accuracy of recently developed elastomeric materials. METHODS: Simultaneous impressions of a steel die were taken using a polyether (I: Impregum Soft Heavy and Light body, 3M ESPE and vinyl polysiloxane (P: Perfectim Blue Velvet and Flexi-Velvet, J.Morita. The trays were loaded with the heavy-bodied impression materials while the light-bodied impression materials were simultaneously spread on the steel die. The impressions were poured after 2 hours, 24 hours, and 7 days. Impressions were stored at approximately 55% relative humidity and room temperature. Ten replicas were produced for each experimental condition (n=60. Accuracy of the stone dies was assessed with a depth-measuring microscope. The difference in height between the surface of the stone die and a standard metallic ring was recorded in micrometers at four demarcated points, by two independent examiners. Data were submitted to two-way ANOVA and Tukey test (a = 0.05. RESULTS: Significant differences were found among the groups. Smaller discrepancies were observed when pouring was performed up to 24 hours (I-2h= 65.0 ± 15.68 µm; I-24h= 81.6 ± 11.13 µm for the polyether, and up to 7 days for the vinyl polysiloxane (P-2h= 79.1 ± 13.82 µm; P-24h= 96.8 ± 6.02 µm; P-7d= 81.4 ± 4.3 µm. Significant dimensional discrepancies, however, were observed when polyether was stored for 7 days (I-7d= 295.3 ± 17.4 µm. CONCLUSION: Storage may significantly affect the dimensional accuracy of impressions and, thus, a maximum period and storage condition should be specified for the recently developed materials.

  9. Elastomeric Properties of Poly(glycerol sebacate) (PGS) Based Nanoparticle Composites

    Science.gov (United States)

    Chung, Hyun-Joong; Li, Xinda; Hong, Albert T.-L.

    2014-03-01

    Owing to the unique combination of biocompatible, biodegradable, and elastomeric properties, poly(glycerol sebacate) and their derivatives are an emerging class of biomaterials for soft tissue replacement, drug delivery, tissue adhesive, and hard tissue regeneration. The mechanical properties of the polyester have been tailored to match a wide range of target organs, ranging from cardiac muscle to bones, by manipulating the process parameters to modulate cross-linking density. In the present study, we applied nanoparticles and cross-linking agents to further optimize their elastomeric properties. Especially, the study aims to enhance the practically important, but less studied, property of tear resistance. Microscopic origin of the property enhancement is discussed.

  10. A statistical physics consideration about the strength of small size metallic glass pillars

    NARCIS (Netherlands)

    Chen, Changqiang; Pei, Yutao; De Hosson, Jeff Th. M.; Skrotzki, W; Oertel, CG; Biermann, H; Heilmaier, M

    2010-01-01

    We have fabricated micro-/nano-pillars of a Zr-based metallic glass, Zr(50)Ti(16.5)Cu(15)Ni(18.5), with pillar tip diameters ranging from similar to 750 nm to similar to 110 nm. These pillars were mechanically tested quantitatively in-situ in a Transmission Electron Microscope (TEM). Due to a slight

  11. Determine the need to research the time-related stability decay of bord and pillar systems

    CSIR Research Space (South Africa)

    Oberholzer, JW

    1997-07-01

    Full Text Available in decisions regarding research work that could be conducted to investigate the time related decay of bord and pillar workings. As the working consist of pillars of varying shapes and sizes the study concentrated mainly on the aspects of pillar decay...

  12. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  13. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    International Nuclear Information System (INIS)

    Haycox, Jon; Pettitt, Will; Young, R. Paul

    2005-11-01

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set shows an intense

  14. The effect of dietary pigmentation on the esthetic appearance of clear orthodontic elastomeric modules

    Directory of Open Access Journals (Sweden)

    Nabeel F Talic

    2016-01-01

    Conclusions: Coffee and tea are strong staining media that should be avoided by patients who opted to have esthetic appliances for their orthodontic treatment. Elastomeric modules manufactured by AU showed higher staining optical properties as compared to the other two companies, which could be related to the manufacturing processing of these modules.

  15. Physical and Chemical Stability of Urapidil in 0.9% Sodium Chloride in Elastomeric Infusion Pump.

    Science.gov (United States)

    Tomasello, Cristina; Leggieri, Anna; Rabbia, Franco; Veglio, Franco; Baietto, Lorena; Fulcheri, Chiara; De Nicolò, Amedeo; De Perri, Giovanni; D'Avolio, Antonio

    2016-01-01

    Urapidil is an antihypertensive agent, usually administered through intravenous bolus injection, slow-intravenous infusion, or continuous-drug infusion by perfusor. Since to date no evidences are available on drug stability in elastomeric pumps, patients have to be hospitalized. The purpose of this study was to validate an ultra-performance liquid chromatographic method to evaluate urapidil stability in an elastomeric infusion pump, in order to allow continuous infusion as home-care treatment. Analyses were conducted by diluting urapidil in an elastomeric pump. Two concentrations were evaluated: 1.6 mg/mL and 3.3 mg/mL. For the analyses, a reverse-phase ultra-performance liquid chromatographic- photodiode array detection instrument was used. Stressed degradation, pH changes, and visual clarity were used as stability indicators up to 10 days after urapidil solution preparation. The drug showed no more than 5% degradation during the test period at room temperature. No pH changes and no evidences of incompatibility were observed. Stress tests resulted in appreciable observation of degradation products. Considering the observed mean values, urapidil hydrochloride in sodium chloride 0.9% in elastomeric infusion pumps is stable for at least 10 days. These results indicate that this treatment could be administered at home for a prolonged duration (at least 7 days) with a satisfactory response. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  16. Numerical Analysis on Failure Modes and Mechanisms of Mine Pillars under Shear Loading

    Directory of Open Access Journals (Sweden)

    Tianhui Ma

    2016-01-01

    Full Text Available Severe damage occurs frequently in mine pillars subjected to shear stresses. The empirical design charts or formulas for mine pillars are not applicable to orebodies under shear. In this paper, the failure process of pillars under shear stresses was investigated by numerical simulations using the rock failure process analysis (RFPA 2D software. The numerical simulation results indicate that the strength of mine pillars and the corresponding failure mode vary with different width-to-height ratios and dip angles. With increasing dip angle, stress concentration first occurs at the intersection between the pillar and the roof, leading to formation of microcracks. Damage gradually develops from the surface to the core of the pillar. The damage process is tracked with acoustic emission monitoring. The study in this paper can provide an effective means for understanding the failure mechanism, planning, and design of mine pillars.

  17. Crystallography of Representative MOFs Based on Pillared Cyanonickelate (PICNIC Architecture

    Directory of Open Access Journals (Sweden)

    Winnie Wong-Ng

    2016-09-01

    Full Text Available The pillared layer motif is a commonly used route to porous coordination polymers or metal organic frameworks (MOFs. Materials based on the pillared cyano-bridged architecture, [Ni’(LNi(CN4]n (L = pillar organic ligands, also known as PICNICs, have been shown to be especially diverse where pore size and pore functionality can be varied by the choice of pillar organic ligand. In addition, a number of PICNICs form soft porous structures that show reversible structure transitions during the adsorption and desorption of guests. The structural flexibility in these materials can be affected by relatively minor differences in ligand design, and the physical driving force for variations in host-guest behavior in these materials is still not known. One key to understanding this diversity is a detailed investigation of the crystal structures of both rigid and flexible PICNIC derivatives. This article gives a brief review of flexible MOFs. It also reports the crystal structures of five PICNICS from our laboratories including three 3-D porous frameworks (Ni-Bpene, NI-BpyMe, Ni-BpyNH2, one 2-D layer (Ni-Bpy, and one 1-D chain (Ni-Naph compound. The sorption data of BpyMe for CO2, CH4 and N2 is described. The important role of NH3 (from the solvent of crystallization as blocking ligands which prevent the polymerization of the 1-D chains and 2-D layers to become 3D porous frameworks in the Ni-Bpy and Ni-Naph compounds is also addressed.

  18. Effect of Commonly Used Beverage, Soft Drink, and Mouthwash on Force Delivered by Elastomeric Chain: A Comparative In Vitro Study

    OpenAIRE

    Kumar, Kiran; Shetty, Sharath; Krithika, M J; Cyriac, Bobby

    2014-01-01

    Background: The objective was to evaluate and compare the effect of Coca-Cola®, tea, Listerine® mouthwash on the force delivered by elastomeric chain in vitro. Materials and Methods: Four specimen groups (distilled water, Coca-Cola®, tea, Listerine® mouthwash) with a total sample size of 480 specimens. A specimen is described as a four link grey close elastomeric chain. Jigs, each with a series of pins set 25 mm apart, was used to hold stretched elastomeric chains at a...

  19. The flow Rate Accuracy of Elastomeric Infusion Pumps After Repeated Filling.

    Science.gov (United States)

    Mohseni, Masood; Ebneshahidi, Amin

    2014-05-01

    One of the frequent applications of elastomeric infusion pumps is postoperative pain management. In daily practice, the disposable pumps get refilled with modified medication combinations in the successive days; although, the accuracy of infusion rates is unknown to clinicians. Our aim was to evaluate the effect of repeated filling on the delivery rate accuracy of an elastomeric pump available in our market. We examined 10 elastomeric infusion pumps (BOT-802, Nanchang Biotek Medical Device Company, China) with 100 mL capacity and nominal flow of 5 mL/h. Each pump was filled for three times, accounting for 30 series of experiments. A microset scaled in mL was used to measure the pump deliveries. Flow profile and reliability of infusion rate were analyzed after repeated use. The mean flow rate in the three series of measurements showed a gradual increase; however, the difference was not statistically significant (5.01 ± 0.07 vs. 5.03 ± 0.06 vs. 5.06 ± 0.08 mL/h; P = 0.81). The percentage of the flow rate error (deviation from 5 mL/h ± 15%) was 100% in the first and second hours of infusion, 96% in the third hour, 60% in the 20th hour and zero percent in the rest of the infusion time. This study indicated that the delivery rate accuracy of elastomeric infusion pumps is preserved after repeated usage. These laboratory findings suggested that elastomeric pumps could be safely refilled in the successive days to provide postoperative analgesia.

  20. Allowable pillar to diameter ratio for strategic petroleum reserve caverns.

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L.; Park, Byoung Yoon

    2011-05-01

    This report compiles 3-D finite element analyses performed to evaluate the stability of Strategic Petroleum Reserve (SPR) caverns over multiple leach cycles. When oil is withdrawn from a cavern in salt using freshwater, the cavern enlarges. As a result, the pillar separating caverns in the SPR fields is reduced over time due to usage of the reserve. The enlarged cavern diameters and smaller pillars reduce underground stability. Advances in geomechanics modeling enable the allowable pillar to diameter ratio (P/D) to be defined. Prior to such modeling capabilities, the allowable P/D was established as 1.78 based on some very limited experience in other cavern fields. While appropriate for 1980, the ratio conservatively limits the allowable number of oil drawdowns and hence limits the overall utility and life of the SPR cavern field. Analyses from all four cavern fields are evaluated along with operating experience gained over the past 30 years to define a new P/D for the reserve. A new ratio of 1.0 is recommended. This ratio is applicable only to existing SPR caverns.

  1. Effect of structural discontinuities on coal pillar strength as a basis for improving safety in the design of coal pillar systems.

    CSIR Research Space (South Africa)

    Esterhuizen, GS

    1998-12-01

    Full Text Available The stability of underground coal mines depends on the integrity of the pillars which are required to support the overlying strata. Should the pillars collapse, the safety of the persons in the workings will be threatened. The strength of a coal...

  2. Deformation-driven diffusion and plastic flow in amorphous granular pillars.

    Science.gov (United States)

    Li, Wenbin; Rieser, Jennifer M; Liu, Andrea J; Durian, Douglas J; Li, Ju

    2015-06-01

    We report a combined experimental and simulation study of deformation-induced diffusion in compacted quasi-two-dimensional amorphous granular pillars, in which thermal fluctuations play a negligible role. The pillars, consisting of bidisperse cylindrical acetal plastic particles standing upright on a substrate, are deformed uniaxially and quasistatically by a rigid bar moving at a constant speed. The plastic flow and particle rearrangements in the pillars are characterized by computing the best-fit affine transformation strain and nonaffine displacement associated with each particle between two stages of deformation. The nonaffine displacement exhibits exponential crossover from ballistic to diffusive behavior with respect to the cumulative deviatoric strain, indicating that in athermal granular packings, the cumulative deviatoric strain plays the role of time in thermal systems and drives effective particle diffusion. We further study the size-dependent deformation of the granular pillars by simulation, and find that different-sized pillars follow self-similar shape evolution during deformation. In addition, the yield stress of the pillars increases linearly with pillar size. Formation of transient shear lines in the pillars during deformation becomes more evident as pillar size increases. The width of these elementary shear bands is about twice the diameter of a particle, and does not vary with pillar size.

  3. Is static friction affected by aging and amount of elastomeric ligatures in orthodontic sliding mechanics? An in-vitro investigation.

    Science.gov (United States)

    Lo Giudice, A; Portelli, M; Militi, A; Spinuzza, P; Bellocchio, A M; Nucera, R; Marcolina, M; Ghilardi, G; Manuelli, M; Lucchese, A

    2018-03-15

    In straight-wire mechanics, friction can significantly influence the forces expressed by wires. The aim of this study is to assess whether the aging and the sum of elastomeric ligatures affect the static friction during orthodontic space closure. A 0.017x 0.025-in SS was drawn throughout a 3-bracket experimental model and engaged with elastomeric ligatures. Before performing the test, the ligatures were soaked in artificial saliva for 48 hours (Group 1), 2 weeks (Group 2) and 4 weeks (Group 3); brand-new ligatures were also tested as control group (Group 4). The resistance to sliding (RS) was recorded at 3 different numerical configurations of ligatures using a customized testing machine and tests were repeated for ten times. Data of RS were statistically analysed by using two way analysis of variance (ANOVA) and Tukey’s multiple comparison tests. RS was found to increase systematically when more elastomeric ligatures were included in the wire engaging system. At two weeks of immersion in artificial saliva elastomeric ligatures showed the lowest values of RS while they became significantly more frictional after immersion for 4 weeks. The results of this study showed that in multi-bracket orthodontic therapy, the RS increases with the number of elastomeric ligatures involved for arch-wire engagement. Differently from the frictional behavior of elastomeric modules, the aging of these ligatures does not influence their incremental effect of frictional forces.

  4. Ordered microporous layered lanthanide 1,3,5-benzenetriphosphonates pillared with cationic organic molecules.

    Science.gov (United States)

    Araki, Takahiro; Kondo, Atsushi; Maeda, Kazuyuki

    2015-04-13

    Novel isomorphous pillared-layer-type crystalline lanthanide 1,3,5-benzenetriphosphonates were prepared with bpy and dbo as organic pillars (LnBP-bpy and LnBP-dbo; Ln: Ce, Pr, and Nd). Ab initio crystal structure solution using synchrotron X-ray powder diffraction data revealed that the organic pillars do not exist as neutral coordinating ligands but as cationic molecules. Especially the LnBP-dbo phases have ordered interlayer space filled with water molecules between the dbo pillars, and the interlayer water is successfully removed by heating under vacuum with slightly distorted but basically retained pillared layer structures. Microporosity of the materials is confirmed by adsorption of nitrogen, carbon dioxide, and hydrogen gases. Such microporous layered metal phosphonates pillared with cationic molecules should be unprecedented and should offer new strategies to design ordered microporous materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Constraint effects of model coal pillar geometry on its strength

    Energy Technology Data Exchange (ETDEWEB)

    Wahab Khair, A.; Danqing Xu (West Virgina University, Morgantown, WV (United States))

    1994-06-01

    Coal and rock specimens with various diameter/height ratios (D/H) were subjected to compressive test in the laboratory. The deformation and failure characteristics of specimens were studied. The study showed that the D/H ratio of specimens significantly affects the deformation, failure characteristics, and the strength of material. The results provide a better understanding of the mechanism of D/H ratio effect on the strength of materials. The magnitude and mechanism of D/H ratio effect was compared with the effect of confining pressure, and contrasted to size effect. The application of the study to pillar design is discussed. 3 refs., 10 figs.

  6. Argilas pilarizadas - uma introdução An introduction to pillared clays

    Directory of Open Access Journals (Sweden)

    Fernando J. Luna

    1999-02-01

    Full Text Available The synthesis, characterization and some applications in catalysis of pillared clays are described at an introductory level. The use of x-ray diffraction, surface area measurements, thermal analysis, IR spectrophotometry and solid-state NMR in the characterization of pillared clays is briefly discussed. Pillarization followed by doping or introduction of metal clusters into clays could lead to the development of selective heterogeneous catalysts.

  7. Sensitivity improvement of a fibre Bragg grating pH sensor with elastomeric coating

    Science.gov (United States)

    Yulianti, Ian; Supa'at, A. S. M.; Idrus, Sevia M.; Kurdi, Ojo; Anwar, M. R. S.

    2012-01-01

    A new optical pH sensor based on fibre Bragg grating (FBG) is demonstrated. The sensor consists of a FBG coated with pH sensitive hydrogel. The sensing was performed through the detection of wavelength shifts resulting from the induced strain on the FBG due to mechanical expansion of the hydrogel. An elastomeric coating was applied before the hydrogel coating to improve the sensitivity. The sensor performance was investigated by simulating the hydrogel swelling and the strain induced on the FBG. The swelling of hydrogel due to pH change was modelled using a free-energy function and was solved using the finite element method. With silicone rubber as the elastomer material, the results show that the sensitivity was improved by up to 66% compared to that of the FBG pH sensor without elastomeric coating.

  8. Sensitivity improvement of a fibre Bragg grating pH sensor with elastomeric coating

    International Nuclear Information System (INIS)

    Yulianti, Ian; Supa'at, A S M; Idrus, Sevia M; Anwar, M R S; Kurdi, Ojo

    2012-01-01

    A new optical pH sensor based on fibre Bragg grating (FBG) is demonstrated. The sensor consists of a FBG coated with pH sensitive hydrogel. The sensing was performed through the detection of wavelength shifts resulting from the induced strain on the FBG due to mechanical expansion of the hydrogel. An elastomeric coating was applied before the hydrogel coating to improve the sensitivity. The sensor performance was investigated by simulating the hydrogel swelling and the strain induced on the FBG. The swelling of hydrogel due to pH change was modelled using a free-energy function and was solved using the finite element method. With silicone rubber as the elastomer material, the results show that the sensitivity was improved by up to 66% compared to that of the FBG pH sensor without elastomeric coating

  9. Effects of atmospheric pressure conditions on flow rate of an elastomeric infusion pump.

    Science.gov (United States)

    Wang, Jong; Moeller, Anna; Ding, Yuanpang Samuel

    2012-04-01

    The effects of pressure conditions, both hyperbaric and hypobaric, on the flow rate of an elastomeric infusion pump were investigated. The altered pressure conditions were tested with the restrictor outlet at two different conditions: (1) at the same pressure condition as the Infusor elastomeric balloon and (2) with the outlet exposed to ambient conditions. Five different pressure conditions were tested. These included ambient pressure (98-101 kilopascals [kPa]) and test pressures controlled to be 10 or 20 kPa below or 75 or 150 kPa above the ambient pressure. A theoretical calculation based on the principles of fluid mechanics was also used to predict the pump's flow rate at various ambient conditions. The conditions in which the Infusor elastomeric pump and restrictor outlet were at the same pressure gave rise to average flow rates within the ±10% tolerance of the calculated target flow rate of 11 mL/hr. The flow rate of the Infusor pump decreased when the pressure conditions changed from hypobaric to ambient. The flow rate increased when the pressure conditions changed from hyperbaric to ambient. The flow rate of the Infusor elastomeric pump was not affected when the balloon reservoir and restrictor outlet were at the same pressure. The flow rate varied from 58.54% to 377.04% of the labeled flow rate when the pressure applied to the reservoir varied from 20 kPa below to 150 kPa above the pressure applied to the restrictor outlet, respectively. The maximum difference between observed flow rates and those calculated by applying fluid mechanics was 4.9%.

  10. Hybrid magnetorheological fluid–elastomeric lag dampers for helicopter stability augmentation

    International Nuclear Information System (INIS)

    Hu Wei; Wereley, Norman M

    2008-01-01

    A laboratory demonstration of a hybrid magnetorheological fluid–elastomeric (MRFE) damper is investigated for adjustable or programmable lag mode damping in helicopters, so that damping requirements can be varied as a function of different flight conditions. The laboratory demonstration of this hybrid MRFE lag damper consists of a double lap shear elastomeric damper in parallel with two magnetorheological (MR) flow mode dampers. This is compared to a damper where only elastomeric materials are implemented, i.e., a double lap shear specimen. The relationship between the output force and the quasi-steady harmonic displacement input to a flow mode MR damper is exploited, where the output force can be adjusted as a function of applied magnetic field. Equivalent viscous damping is used to compare the damping characteristics of the hybrid damper to a conventional elastomeric damper under steady-state sinusoidal displacement excitation. To demonstrate feasibility, a hybrid MRFE damper test setup is designed, and single frequency (lag frequency or rotor in-plane bending frequency) and dual frequency (lag frequency and rotor frequency) tests are conducted under different magnetic fields. The hybrid MRFE damper exhibits amplitude-dependent damping behavior. However, with application of a magnetic field, the damping level is controlled to a specific damping level objective as a function of displacement amplitude. Similarly, under dual frequency conditions, damping degradation at the lag frequency, because of lag motion at the rotor frequency, can also be recovered by increasing magnetic field. A time-domain analysis is developed to study the nonlinear dynamic behavior of the hybrid MRFE damper. Using rate-dependent elasto-slides, the amplitude-dependent behavior of the hybrid MRFE damper is accurately reconstructed using both constant and current-dependent (i.e. controllable) parameters. The analysis is physically motivated and can be applied to the elastomer and MR fluid

  11. Antibiotic stability related to temperature variations in elastomeric pumps used for outpatient parenteral antimicrobial therapy (OPAT).

    Science.gov (United States)

    Voumard, Rachel; Van Neyghem, Niklas; Cochet, Camille; Gardiol, Céline; Decosterd, Laurent; Buclin, Thierry; de Valliere, Serge

    2017-05-01

    Elastomeric pumps can be used for the continuous administration of antimicrobials in the outpatient setting. A potentially limiting factor in their use is the stability of antimicrobials. To investigate under real-life conditions the temperature variations of antibiotic solutions contained in elastomeric pumps, and to examine under such conditions the stability of five antibiotics. Healthy volunteers carried the elastomeric pumps in carry pouches during their daily activities. A thermologger measured the temperatures every 15 min over 24 h. Antibiotic concentrations were measured by HPLC coupled to tandem MS. During daytime, the temperature of solutions in the pumps increased steadily, warming to >30°C. During the night, when the pumps were kept attached to the waist, the temperatures reached up to 33°C. The use of white carry pouches avoided excessive temperature increases. Over seven experiments, cefazolin, cefepime, piperacillin and tazobactam were found to be stable over 24 h. Flucloxacillin showed a mean decrease in concentration of 11% ( P  = 0.001). Real-life situations can cause significant temperature rises in elastomeric pumps, thereby potentially increasing the risk of antibiotic degradation. Patients should be instructed to avoid situations causing excessive temperature increases. Despite these temperature variations, cefazolin, cefepime, piperacillin and tazobactam were found to be stable over 24 h. A moderate degradation was noticed for flucloxacillin, albeit most probably not to an extent that might impair anti-infective efficacy. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Friction produced by types of elastomeric ligatures in treatment mechanics with the preadjusted appliance.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo

    2006-03-01

    The objective was to compare the frictional forces generated by new nonconventional passive elastomeric ligatures (NCL) and conventional elastomeric ligatures (CL) under dry conditions. An experimental model reproducing the right buccal segment of the upper arch and consisting of five stainless steel 0.022-inch preadjusted brackets (from the second premolar through the central incisor) was used to assess both static and kinetic frictional forces produced by NCL and CL. The frictional forces generated by the 0.019 x 0.025-inch stainless steel wire with the two types of elastomeric ligatures were recorded by sliding the wire into the aligned brackets. The friction produced by the 0.014-inch superelastic nickel titanium wire was evaluated both in the presence of aligned brackets and of three-mm misaligned canine bracket. The amount of both static and kinetic frictions were minimal (<10 g) in the NCL group in the presence of aligned brackets with both types of wires, whereas it ranged from a minimum of 95.6 g for the 0.014-inch superelastic nickel titanium wire to a maximum of 590.7 g for the 0.019 x 0.025-inch stainless steel wire when using CL. The amount of both static and kinetic frictions in the presence of a misaligned canine bracket in the NCL group were less than half of that shown by the CL group. A recently developed passive ligature system is able to produce significantly lower levels of frictional forces in vitro when compared with conventional elastomeric modules.

  13. Manipulating the optical properties of CdSe/ZnSSe quantum dot based monolithic pillar microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Seyfried, Moritz; Kalden, Joachim; Lohmeyer, Henning; Sebald, Kathrin; Gutowski, Juergen [Semiconductor Optics, Institute of Solid state Physics, University of Bremen (Germany); Kruse, Carsten; Hommel, Detlef, E-mail: Seyfried@ifp.uni-bremen.d [Semiconductor Epitaxy, Institute of Solid state Physics, University of Bremen (Germany)

    2010-02-01

    A customization of the optical properties of pillar microcavities on the desired applications is essential for their future use as quantum-optical devices. Therefore, all-epitaxial cavities with CdSe quantum dot embedded in pillar structures with different geometries have been realized by focused-ion-beam etching. The quality factors of circularly shaped pillar microcavities have been measured and their dependence on the excitation power is discussed. As a possibility to achieve polarized light emission, asymmetrically shaped microcavities are presented. Examples of an elliptically shaped pillar as well as of photonic molecules are investigated with respect to their photoluminescence characteristics and polarization.

  14. In silico simulation and in vitro evaluation of an elastomeric scaffold using ultrasonic shear wave imaging

    Science.gov (United States)

    Yu, Jiao; Nie, Erwei; Zhu, Yanying; Hong, Yi

    2018-03-01

    Biodegradable elastomeric scaffolds for soft tissue repair represent a growing area of biomaterials research. Mechanical strength is one of the key factors to consider in the evaluation of candidate materials and the designs for tissue scaffolds. It is desirable to develop non-invasive evaluation methods of the mechanical property of scaffolds which would provide options for monitoring temporal mechanical property changes in situ. In this paper, we conduct in silico simulation and in vitro evaluation of an elastomeric scaffold using a novel ultrasonic shear wave imaging (USWI). The scaffold is fabricated from a biodegradable elastomer, poly(carbonate urethane) urea using salt leaching method. A numerical simulation is performed to test the robustness of the developed inversion algorithm for the elasticity map reconstruction which will be implemented in the phantom experiment. The generation and propagation of shear waves in a homogeneous tissue-mimicking medium with a circular scaffold inclusion is simulated and the elasticity map is well reconstructed. A PVA phantom experiment is performed to test the ability of USWI combined with the inversion algorithm to non-invasively characterize the mechanical property of a porous, biodegradable elastomeric scaffold. The elastic properties of the tested scaffold can be easily differentiated from the surrounding medium in the reconstructed image. The ability of the developed method to identify the edge of the scaffold and characterize the elasticity distribution is demonstrated. Preliminary results in this pilot study support the idea of applying the USWI based method for non-invasive elasticity characterization of tissue scaffolds.

  15. Puncture mechanics of soft elastomeric membrane with large deformation by rigid cylindrical indenter

    Science.gov (United States)

    Liu, Junjie; Chen, Zhe; Liang, Xueya; Huang, Xiaoqiang; Mao, Guoyong; Hong, Wei; Yu, Honghui; Qu, Shaoxing

    2018-03-01

    Soft elastomeric membrane structures are widely used and commonly found in engineering and biological applications. Puncture is one of the primary failure modes of soft elastomeric membrane at large deformation when indented by rigid objects. In order to investigate the puncture failure mechanism of soft elastomeric membrane with large deformation, we study the deformation and puncture failure of silicone rubber membrane that results from the continuous axisymmetric indentation by cylindrical steel indenters experimentally and analytically. In the experiment, effects of indenter size and the friction between the indenter and the membrane on the deformation and puncture failure of the membrane are investigated. In the analytical study, a model within the framework of nonlinear field theory is developed to describe the large local deformation around the punctured area, as well as to predict the puncture failure of the membrane. The deformed membrane is divided into three parts and the friction contact between the membrane and indenter is modeled by Coulomb friction law. The first invariant of the right Cauchy-Green deformation tensor I1 is adopted to predict the puncture failure of the membrane. The experimental and analytical results agree well. This work provides a guideline in designing reliable soft devices featured with membrane structures, which are present in a wide variety of applications.

  16. Preliminary SEM Observations on the Surface of Elastomeric Impression Materials after Immersion or Ozone Disinfection

    Science.gov (United States)

    Prombonas, Anthony; Yannikakis, Stavros; Karampotsos, Thanasis; Katsarou, Martha-Spyridoula; Drakoulis, Nikolaos

    2016-01-01

    Introduction Surface integrity of dental elastomeric impression materials that are subjected to disinfection is of major importance for the quality of the final prosthetic restorations. Aim The aim of this qualitative Scanning Electronic Microscopy (SEM) study was to reveal the effects of immersion or ozone disinfection on the surface of four dental elastomeric impression materials. Materials and Methods Four dental elastomeric impression material brands were used (two vinyl polysiloxane silicones, one polyether, and one vinyl polyether silicone). Total of 32 specimens were fabricated, eight from each impression material. Specimens were immersion (0.525% sodium hypochlorite solution or 0.3% benzalkonium chloride solution) or ozone disinfected or served as controls and examined with SEM. Results Surface degradation was observed on several speci-mens disinfected with 0.525% sodium hypochlorite solution. Similar wavy-wrinkling surface structures were observed in almost all specimens, when treated either with 0.3% benzalkonium chloride solution or ozone. Conclusion The SEM images obtained from this study revealed that both immersion disinfectants and ozone show similar impression material surface alterations. Ozone seems to be non-inferior as compared to immersion disinfectants, but superior as to environmental protection. PMID:28208993

  17. Initial Tensile and Residual Forces of Pigmented Elastomeric Ligatures from Various Brands

    Science.gov (United States)

    Wichai, Wassana; Anuwongnukroh, Niwat; Dechkunakorn, Surachai; Kaypetch, Rattiporn; Tua-ngam, Peerapong

    2017-11-01

    This study aimed to investigate the initial tensile and residual forces of pigmented elastomeric ligatures (clear, pink, and metallic) from three commercial brands - Brand 1 (USA), Brand 2 (USA), and Brand 3(China). Twelve elastomeric ligatures of each brand and color were evaluated for initial tensile and residual forces after stretching for 28 days at 37°C by a Universal Testing Machine. The results showed that the highest initial tensile force was 14.78 N, 20.71 N, and 15.1 N for the metallic color of Brand-1, pink color of Brand -2, and metallic color of Brand -3, respectively. There were significant (ptensile force of each brand, except clear and metallic color of Brand-1 & 3 and pink color of Brand-2 & 3. Similarly, among the pigmented ligatures from each brand, significant (ptensile force, except metallic color of Brand-1 & 3. Brand-3 had the highest residual force after 28 days, whereas the loss of force was 80-90% in Brand-1 & 2 and 20-30% in Brand-3. There were also significant (ptensile and residual forces among the three pigmented elastomeric ligatures of the three commercial brands.

  18. Forces released during alignment with a preadjusted appliance with different types of elastomeric ligatures.

    Science.gov (United States)

    Franchi, Lorenzo; Baccetti, Tiziano

    2006-05-01

    The purpose of this in-vitro study was to compare the forces generated by new nonconventional elastomeric ligatures (NCEL) and conventional elastomeric ligatures (CEL) during leveling and aligning phases. The testing model consisted of 5 stainless steel 0.022-in preadjusted brackets for second premolar, first premolar, canine, lateral incisor, and central incisor. The canine bracket was welded to a sliding bar that allowed for different vertical positions. The forces generated by 3 sizes of wires (0.012-, 0.014-, and 0.016-in superelastic nickel-titanium) with the 2 types of elastomeric ligatures at different amounts of upward canine misalignment (1.5, 3, 4.5, and 6 mm) were recorded. Significant differences between CEL and NCEL were found for all tested variables (P <.01) with the exception of the 0.014- and 0.016-in wires at canine misalignment of 1.5 mm. A noticeable amount of force was generated with the NCEL at all 4 canine positions with all 3 wire sizes (from about 50 to about 150 g). With 4.5 mm of canine misalignment or more, the average amount of released force with the CEL was approximately zero.

  19. Investigation of the recycling of tires to elastomeric requirements by techniques of thermal compression

    Science.gov (United States)

    Nadal Gisbert, Antonio V.

    In this work is investigated the recycling of tires to elastomeric requirements by thermal compression. The production of recycled products is carried out starting from the powder, of elastomeric nature, coming from the grinding of used tires denominated GTR (Ground Tire Rubber) of different grain size, although the fundamental objective is the recycling of powder of 0,2mm grain size. The process of forming used for obtaining the recycled product is thermal compression, due to its simplicity and low cost. The composition of the powder has been analyzed and also the influence, on the elastomeric characteristics of the recycled product, of different parameters: Grain size, compact pressure, temperature, time, thickness of the recycled product and combination of sizes. At last we give an hypothesis that justifies the mechanism that gives cohesion to the powder GTR and allows their recycling. We also have carried out an analysis of the investigation lines, at the present, on the recycling of tires in general and an economic study of the viability of the recycled product in front of present products in the market, agglomerated with polyurethane, that have their application in using it in different types of floors.

  20. Policy framework for utilisation. A pillar of better accessibility

    International Nuclear Information System (INIS)

    2008-01-01

    The goals and frameworks for traffic and transport policy for the Netherlands to 2020 are described in the Mobility Document. Whereas government policy previously viewed mobility as a problem or as something permissible, the assumption is now that mobility is a must. Mobility, for people as well as goods, is a prerequisite for society and the economy to function well. The Mobility Document contains ambitious goals to deal with current and anticipated traffic and transport problems: door to door, faster, cleaner and safer. Three interrelated pillars are to help achieve these goals: Building, Pricing and Utilisation. Work is being done on the Building and Pricing pillars; Utilisation is elaborated further in this policy framework. The Policy Framework for Utilisation is an elaboration of the Mobility Document for the 2008-2020 period and aims for faster, cleaner, safer travel from door to door. The purpose of this policy framework is to describe the direction of development of utilisation, in terms of content as well as process, to indicate actions that are required and to provide perspective on the expected effects. The policy framework is in line with current developments or plans, caters to new opportunities (technological and otherwise), encourages the innovative potential of the market and provides room for joint ventures between the government and the market. It will result in actions for the short term and provide direction for activities and developments for the longer term

  1. Study on the optimum design of bus window pillar join40t; Bus window pillar ketsugo buzai no saiteki sekkei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Tomioka, N [Nihon University, Tokyo (Japan); Lim, S; Kim, M; Lee, H; Kang, S; Bae, D

    1997-10-01

    Automobile body structure is generally assembled using various spot welded box sectional members. Especially, in the case of the bus, the shape of window pillar joint is assembled m T-type. This T-type member has some problem such as high stress concentration, low fatigue strength and structural rigidity. Therefore, in this report, performed a study on the optimum design of the bus window pillar joint for such problem by FEM analysis and experiments. 1 ref., 10 figs., 2 tabs.

  2. Numerical Approach for Goaf-Side Entry Layout and Yield Pillar Design in Fractured Ground Conditions

    Science.gov (United States)

    Jiang, Lishuai; Zhang, Peipeng; Chen, Lianjun; Hao, Zhen; Sainoki, Atsushi; Mitri, Hani S.; Wang, Qingbiao

    2017-11-01

    Entry driven along goaf-side (EDG), which is the development of an entry of the next longwall panel along the goaf-side and the isolation of the entry from the goaf with a small-width yield pillar, has been widely employed in China over the past several decades . The width of such a yield pillar has a crucial effect on EDG layout in terms of the ground control, isolation effect and resource recovery rate. Based on a case study, this paper presents an approach for evaluating, designing and optimizing EDG and yield pillar by considering the results from numerical simulations and field practice. To rigorously analyze the ground stability, the numerical study begins with the simulation of goaf-side stress and ground conditions. Four global models with identical conditions, except for the width of the yield pillar, are built, and the effect of pillar width on ground stability is investigated by comparing aspects of stress distribution, failure propagation, and displacement evolution during the entire service life of the entry. Based on simulation results, the isolation effect of the pillar acquired from field practice is also considered. The suggested optimal yield pillar design is validated using a field test in the same mine. Thus, the presented numerical approach provides references and can be utilized for the evaluation, design and optimization of EDG and yield pillars under similar geological and geotechnical circumstances.

  3. The Sloan-C Pillars: Towards a Balanced Approach to Measuring Organizational Learning

    Science.gov (United States)

    Yeo, Kee Meng; Mayadas, A. Frank

    2010-01-01

    The Sloan Pillars have set the standard for university-wide online learning program assessment for more than a dozen years. In this paper, the authors propose the extension of the Pillars to corporate e-learning, offering an alternative to traditional enterprise learning assessments. Claiming that conventional methods stress individual courses or…

  4. Workshops around the pillar system design computer program produced in SIMRAC project GAP334

    CSIR Research Space (South Africa)

    York, G

    2000-03-01

    Full Text Available with the actual Pillar System Design program. Four workshops were held, three in the Bushveld Complex, and one at the Conference Centre at CSIR Miningtek. The delegates comprised most of the industry rock mechanics practitioners who deal with pillar system design...

  5. Numerical modeling for longwall pillar design: a case study from a typical longwall panel in China

    Science.gov (United States)

    Zhang, Guangchao; Liang, Saijiang; Tan, Yunliang; Xie, Fuxing; Chen, Shaojie; Jia, Hongguo

    2018-02-01

    This paper presents a new numerical modeling procedure and design principle for longwall pillar design with the assistance of numerical simulation of FLAC3D. A coal mine located in Yanzhou city, Shandong Province, China, was selected for this case study. A meticulously validated numerical model was developed to investigate the stress changes across the longwall pillar with various sizes. In order to improve the reliability of the numerical modeling, a calibration procedure is undertaken to match the Salamon and Munro pillar strength formula for the coal pillar, while a similar calibration procedure is used to estimate the stress-strain response of a gob. The model results demonstrated that when the coal pillar width was 7-8 m, most of the vertical load was carried by the panel rib, whilst the gateroad was overall in a relatively low stress environment and could keep its stability with proper supports. Thus, the rational longwall pillar width was set as 8 m and the field monitoring results confirmed the feasibility of this pillar size. The proposed numerical simulation procedure and design principle presented in this study could be a viable alternative approach for longwall pillar design for other similar projects.

  6. An Evaluation of the Effect of Various Gloves on Polymerization Inhibition of Elastomeric Impression Materials: An In vitro Study.

    Science.gov (United States)

    Hiremath, Vinuta; Vinayakumar, G; Ragher, Mallikarjuna; Rayannavar, Sounyala; Bembalagi, Mahantesh; Ashwini, B L

    2017-11-01

    Latex protective barriers such as gloves and rubber dam material have been used widely in restorative procedures for crown and bridge. However, the chemical used during latex glove fabrication is thought to inhibit the polymerization of elastomeric impression materials used for impression making which has a detrimental effect on the dimensional accuracy and surface definition of resultant casts used for restorative procedures. The objectives of the study were to examine the surface of different elastomeric impressions on contact with various gloves. This clinical study included a total of eighty specimens of two types of the putty elastomeric impression material were hand manipulated by wearing three different gloves materials and is placed on a marked area of a clean and alcohol-treated glass slab at room temperature. The specimens examined for any signs of polymerization inhibition. The specimen will be rated as being "inhibited" if any residue remains on the glass slab and absence of the above will result as "no inhibition." The results showed no interference with the polymerization inhibition of the selected elastomers followed by the nitrile glove. The latex gloves showed inhibited set of the elastomeric impression material but set after sometime confirming time-dependent inhibition of the impression material. This study shows that the use of latex and sometime nitrile gloves during crown and bridge procedures should be contraindicated and the use of vinyl gloves should be stressed when working with elastomeric impression materials.

  7. An evaluation of the effect of various gloves on polymerization inhibition of elastomeric impression materials: An In vitro study

    Directory of Open Access Journals (Sweden)

    Vinuta Hiremath

    2017-01-01

    Full Text Available Background: Latex protective barriers such as gloves and rubber dam material have been used widely in restorative procedures for crown and bridge. However, the chemical used during latex glove fabrication is thought to inhibit the polymerization of elastomeric impression materials used for impression making which has a detrimental effect on the dimensional accuracy and surface definition of resultant casts used for restorative procedures. The objectives of the study were to examine the surface of different elastomeric impressions on contact with various gloves. Materials and Methods: This clinical study included a total of eighty specimens of two types of the putty elastomeric impression material were hand manipulated by wearing three different gloves materials and is placed on a marked area of a clean and alcohol-treated glass slab at room temperature. The specimens examined for any signs of polymerization inhibition. The specimen will be rated as being “inhibited” if any residue remains on the glass slab and absence of the above will result as “no inhibition.” Results: The results showed no interference with the polymerization inhibition of the selected elastomers followed by the nitrile glove. The latex gloves showed inhibited set of the elastomeric impression material but set after sometime confirming time-dependent inhibition of the impression material. Conclusion: This study shows that the use of latex and sometime nitrile gloves during crown and bridge procedures should be contraindicated and the use of vinyl gloves should be stressed when working with elastomeric impression materials.

  8. Four pillars of radio astronomy Mills, Christiansen, Wild, Bracewell

    CERN Document Server

    Frater, R H; Wendt, H W

    2017-01-01

    This is the story of Bernie Mills, Chris Christiansen, Paul Wild and Ron Bracewell, members of a team of radio astronomers that would lead Australia, and the world, into this new field of research. Each of the four is remembered for his remarkable work: Mills for the development the cross type instrument that now bears his name; Christiansen for the application of rotational synthesis techniques; Wild for the masterful joining of observations and theory to elicit the nature of the solar atmosphere; Bracewell for his contribution to imaging theory. As well, these Four Pillars are remembered for creating a remarkable environment for scientific discovery and for influencing the careers of future generations. Their pursuit of basic science helped pave the way for technological developments in areas ranging from Wi-Fi to sonar to medical imaging to air navigation, and for underpinning the foundations of modern cosmology and astrophysics.

  9. Integrated analysis of rock mass deformation within shaft protective pillar

    Directory of Open Access Journals (Sweden)

    Ewa Warchala

    2016-01-01

    Full Text Available The paper presents an analysis of the rock mass deformation resulting from mining in the vicinity of the shaft protection pillar. A methodology of deformation prediction is based on a deterministic method using Finite Element Method (FEM. The FEM solution is based on the knowledge of the geomechanical properties of the various geological formations, tectonic faults, types of mining systems, and the complexity of the behaviour of the rock mass. The analysis gave the stress and displacement fields in the rock mass. Results of the analysis will allow for design of an optimal mining system. The analysis is illustrated by an example of the shaft R-VIII Rudna Mine KGHM Polish Copper SA.

  10. Environmental management as a pillar for sustainable development.

    Science.gov (United States)

    Mikulčić, Hrvoje; Duić, Neven; Dewil, Raf

    2017-12-01

    There is a growing concern about how to minimize the impact of human activities on the environment. Already nowadays, in some places adaptation efforts are needed in order to avoid the irreversibility of negative human activities. Due to climate changes, and corresponding environmental and social changes, there is a great need for a more sustainable development of mankind. Over the years, research studies that analyzed the sustainable development of different communities with a multi-disciplinary approach, stressed the necessity of preserving the environment for next generations. Therefore, responsible and conscientious management of the environment is a pillar of the sustainable development concept. This review introduction article provides an overview of the recent top scientific publications related to sustainable development that mostly originated from previous SDEWES conferences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Three Pillars for the Neural Control of Appetite.

    Science.gov (United States)

    Sternson, Scott M; Eiselt, Anne-Kathrin

    2017-02-10

    The neural control of appetite is important for understanding motivated behavior as well as the present rising prevalence of obesity. Over the past several years, new tools for cell type-specific neuron activity monitoring and perturbation have enabled increasingly detailed analyses of the mechanisms underlying appetite-control systems. Three major neural circuits strongly and acutely influence appetite but with notably different characteristics. Although these circuits interact, they have distinct properties and thus appear to contribute to separate but interlinked processes influencing appetite, thereby forming three pillars of appetite control. Here, we summarize some of the key characteristics of appetite circuits that are emerging from recent work and synthesize the findings into a provisional framework that can guide future studies.

  12. Integrated pillar scatterers for speeding up classification of cell holograms.

    Science.gov (United States)

    Lugnan, Alessio; Dambre, Joni; Bienstman, Peter

    2017-11-27

    The computational power required to classify cell holograms is a major limit to the throughput of label-free cell sorting based on digital holographic microscopy. In this work, a simple integrated photonic stage comprising a collection of silica pillar scatterers is proposed as an effective nonlinear mixing interface between the light scattered by a cell and an image sensor. The light processing provided by the photonic stage allows for the use of a simple linear classifier implemented in the electric domain and applied on a limited number of pixels. A proof-of-concept of the presented machine learning technique, which is based on the extreme learning machine (ELM) paradigm, is provided by the classification results on samples generated by 2D FDTD simulations of cells in a microfluidic channel.

  13. Evaporation-driven clustering of microscale pillars and lamellae

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Hong; Kim, Jungchul; Kim, Ho-Young, E-mail: hyk@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826 (Korea, Republic of)

    2016-02-15

    As a liquid film covering an array of micro- or nanoscale pillars or lamellae evaporates, its meniscus pulls the elastic patterns together because of capillary effects, leading to clustering of the slender microstructures. While this elastocapillary coalescence may imply various useful applications, it is detrimental to a semiconductor manufacturing process called the spin drying, where a liquid film rinses patterned wafers until drying. To understand the transient mechanism underlying such self-organization during and after liquid evaporation, we visualize the clustering dynamics of polymer micropatterns. Our visualization experiments reveal that the patterns clumped during liquid evaporation can be re-separated when completely dried in some cases. This restoration behavior is explained by considering adhesion energy of the patterns as well as capillary forces, which leads to a regime map to predict whether permanent stiction would occur. This work does not only extend our understanding of micropattern stiction, but also suggests a novel path to control and prevent pattern clustering.

  14. Cu Pillar Low Temperature Bonding and Interconnection Technology of for 3D RF Microsystem

    Science.gov (United States)

    Shi, G. X.; Qian, K. Q.; Huang, M.; Yu, Y. W.; Zhu, J.

    2018-03-01

    In this paper 3D interconnects technologies used Cu pillars are discussed with respect to RF microsystem. While 2.5D Si interposer and 3D packaging seem to rely to cu pillars for the coming years, RF microsystem used the heterogeneous chip such as GaAs integration with Si interposers should be at low temperature. The pillars were constituted by Cu (2 micron) -Ni (2 micron) -Cu (3 micron) -Sn (1 micron) multilayer metal and total height is 8 micron on the front-side of the wafer by using electroplating. The wafer backside Cu pillar is obtained by temporary bonding, thinning and silicon surface etching. The RF interposers are stacked by Cu-Sn eutectic bonding at 260 °C. Analyzed the reliability of different pillar bonding structure.

  15. Develop guidelines for the design of pillar systems for shallow and intermediate depth, tabular, hard rock mines and provide a methodology for assessing hangingwall stability and support requirements for the panels between pillars

    CSIR Research Space (South Africa)

    York, G

    1998-12-01

    Full Text Available The design of hard rock pillars, in shallow to intermediate depth hard rock mines, has been redefined as the determination of the pillar system load bearing capacity. This entails the ability to design each of the components of the pillar system...

  16. Multiple refraction switches realized by stretching elastomeric scatterers in sonic crystals

    Directory of Open Access Journals (Sweden)

    Y. Huang

    2015-02-01

    Full Text Available The effect of out-of-plane pre-stretch on the 2D sonic crystal with stretchable elastomeric scatterers is explored. The hyperelastic scatterers are characterized by a compressible neo-Hookean model. The Dirichlet-to-Neumann (DtN map is adopted to obtain the band structure and equi-frequency contours. We focus on the first passband and find that a variety of switching functionalities for refraction behaviors can be realized in selected frequencies under a specific pre-stretch range. These refraction switches enable an active control of wave propagation and are applicable in advanced technologies where switchable and multifunctional sonic crystals are required.

  17. Optical Manipulation of Shape-Morphing Elastomeric Liquid Crystal Microparticles Doped with Gold Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y. R.; Evans, J. S.; Lee, T.; Senyuk, B.; Keller, P.; He, S. L.; Smalyukh, I. I.

    2012-06-11

    We demonstrate facile optical manipulation of shape of birefringent colloidal microparticles made from liquid crystal elastomers. Using soft lithography and polymerization, we fabricate elastomeric microcylinders with weakly undulating director oriented on average along their long axes. These particles are infiltrated with gold nanospheres acting as heat transducers that allow for an efficient localized transfer of heat from a focused infrared laser beam to a submicrometer region within a microparticle. Photothermal control of ordering in the liquid crystal elastomer using scanned beams allows for a robust control of colloidal particles, enabling both reversible and irreversible changes of shape. Possible applications include optomechanics, microfluidics, and reconfigurable colloidal composites with shape-dependent self-assembly.

  18. Elastomeric thermal interface materials with high through-plane thermal conductivity from carbon fiber fillers vertically aligned by electrostatic flocking.

    Science.gov (United States)

    Uetani, Kojiro; Ata, Seisuke; Tomonoh, Shigeki; Yamada, Takeo; Yumura, Motoo; Hata, Kenji

    2014-09-03

    Electrostatic flocking is applied to create an array of aligned carbon fibers from which an elastomeric thermal interface material (TIM) can be fabricated with a high through-plane thermal conductivity of 23.3 W/mK. A high thermal conductivity can be achieved with a significantly low filler level (13.2 wt%). As a result, this material retains the intrinsic properties of the matrix, i.e., elastomeric behavior. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Mechanism of the Topotactic Formation of gamma-Zirconium Phosphate Covalently Pillared with Diphosphonate Groups.

    Science.gov (United States)

    Alberti, G.; Giontella, E.; Murcia-Mascarós, S.; Vivani, R.

    1998-09-07

    The topotactic reaction of gamma-ZrPO(4)[O(2)P(OH)(2)].2H(2)O (gamma-ZrP) with benzenediphosphonic acid was examined in water and in acetone-water mixtures. This reaction was found to take place in water only on the external surface of the microcrystals, and pillared compounds were never obtained, even after very long reaction times. On the contrary, covalently pillared compounds were quickly obtained in acetone-water mixtures. The mechanism of the latter topotactic reaction was investigated by determining the rate of the phosphate groups released and the rate of the benzenediphosphonates taken up by gamma-ZrP over a long time (50 days). These data showed that pillared derivatives of gamma-ZrP can be obtained because colloidal dispersions of exfoliated lamellae are formed in acetone-water mixtures. The diphosphonate group acts initially as a monovalent species, replacing only one dihydrogen phosphate group on the surface of the exfoliated gamma-lamellae. The colloidal and partially derivatized lamellae thus formed can interact with each other by forming polylamellar pillared systems. When the number of pillared lamellae exceeds a given value (usually 5-6), flocculation of the colloidal gamma-ZrP takes place. Topotactic reactions between packets of pillared lamellae may also continue in the flocculated system. Therefore, the average number of the pillared lamellae slowly increases over time.

  20. Low-temperature pyrolysis of oily sludge: roles of Fe/Al-pillared bentonites

    Directory of Open Access Journals (Sweden)

    Jia Hanzhong

    2017-09-01

    Full Text Available Pyrolysis is potentially an effective treatment of oily sludge for oil recovery, and the addition of a catalyst is expected to affect its pyrolysis behavior. In the present study, Fe/Al-pillared bentonite with various Fe/Al ratios as pyrolysis catalyst is prepared and characterized by XRD, N2 adsorption, and NH3-TPD. The integration of Al and Fe in the bentonite interlayers to form pillared clay is evidenced by increase in the basal spacing. As a result, a critical ratio of Fe/Al exists in the Fe/Al-pillared bentonite catalytic pyrolysis for oil recovery from the sludge. The oil yield increases with respect to increase in Fe/Al ratio of catalysts, then decreases with further increasing of Fe/Al ratio. The optimum oil yield using 2.0 wt% of Fe/Al 0.5-pillared bentonite as catalyst attains to 52.46% compared to 29.23% without catalyst addition in the present study. In addition, the addition of Fe/Al-pillared bentonite catalyst also improves the quality of pyrolysis-produced oil and promotes the formation of CH4. Fe/Al-pillared bentonite provides acid center in the inner surface, which is beneficial to the cracking reaction of oil molecules in pyrolysis process. The present work implies that Fe/Al-pillared bentonite as addictive holds great potential in industrial pyrolysis of oily sludge.

  1. The Los Alamos Science Pillars The Science of Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Joshua E. [Los Alamos National Laboratory; Peterson, Eugene J. [Los Alamos National Laboratory

    2012-09-13

    As a national security science laboratory, Los Alamos is often asked to detect and measure the characteristics of complex systems and to use the resulting information to quantify the system's behavior. The Science of Signatures (SoS) pillar is the broad suite of technical expertise and capability that we use to accomplish this task. With it, we discover new signatures, develop new methods for detecting or measuring signatures, and deploy new detection technologies. The breadth of work at Los Alamos National Laboratory (LANL) in SoS is impressive and spans from the initial understanding of nuclear weapon performance during the Manhattan Project, to unraveling the human genome, to deploying laser spectroscopy instrumentation on Mars. Clearly, SoS is a primary science area for the Laboratory and we foresee that as it matures, new regimes of signatures will be discovered and new ways of extracting information from existing data streams will be developed. These advances will in turn drive the development of sensing instrumentation and sensor deployment. The Science of Signatures is one of three science pillars championed by the Laboratory and vital to supporting our status as a leading national security science laboratory. As with the other two pillars, Materials for the Future and Information Science and Technology for Predictive Science (IS&T), SoS relies on the integration of technical disciplines and the multidisciplinary science and engineering that is our hallmark to tackle the most difficult national security challenges. Over nine months in 2011 and 2012, a team of science leaders from across the Laboratory has worked to develop a SoS strategy that positions us for the future. The crafting of this strategy has been championed by the Chemistry, Life, and Earth Sciences Directorate, but as you will see from this document, SoS is truly an Institution-wide effort and it has engagement from every organization at the Laboratory. This process tapped the insight and

  2. Optimization of pillar electrodes in subretinal prosthesis for enhanced proximity to target neurons

    Science.gov (United States)

    Flores, Thomas; Lei, Xin; Huang, Tiffany; Lorach, Henri; Dalal, Roopa; Galambos, Ludwig; Kamins, Theodore; Mathieson, Keith; Palanker, Daniel

    2018-06-01

    Objective. High-resolution prosthetic vision requires dense stimulating arrays with small electrodes. However, such miniaturization reduces electrode capacitance and penetration of electric field into tissue. We evaluate potential solutions to these problems with subretinal implants based on utilization of pillar electrodes. Approach. To study integration of three-dimensional (3D) implants with retinal tissue, we fabricated arrays with varying pillar diameter, pitch, and height, and implanted beneath the degenerate retina in rats (Royal College of Surgeons, RCS). Tissue integration was evaluated six weeks post-op using histology and whole-mount confocal fluorescence imaging. The electric field generated by various electrode configurations was calculated in COMSOL, and stimulation thresholds assessed using a model of network-mediated retinal response. Main results. Retinal tissue migrated into the space between pillars with no visible gliosis in 90% of implanted arrays. Pillars with 10 μm height reached the middle of the inner nuclear layer (INL), while 22 μm pillars reached the upper portion of the INL. Electroplated pillars with dome-shaped caps increase the active electrode surface area. Selective deposition of sputtered iridium oxide onto the cap ensures localization of the current injection to the pillar top, obviating the need to insulate the pillar sidewall. According to computational model, pillars having a cathodic return electrode above the INL and active anodic ring electrode at the surface of the implant would enable six times lower stimulation threshold, compared to planar arrays with circumferential return, but suffer from greater cross-talk between the neighboring pixels. Significance. 3D electrodes in subretinal prostheses help reduce electrode-tissue separation and decrease stimulation thresholds to enable smaller pixels, and thereby improve visual acuity of prosthetic vision.

  3. Acid–base properties of pillared interlayered clays with single and mixed Zr–Al oxide pillars prepared from Tunisian-interstratified illite–smectite

    Directory of Open Access Journals (Sweden)

    Saida Mnasri

    2017-12-01

    Full Text Available Interstratified illite–smectite clay samples from Tunisia have been used in order to prepare Al, Zr and Zr–Al-pillared clays. Several Al/metal, OH/metal ratios were used in order to investigate the effect on the chemical and physical properties, specifically the point of zero charge (PZC of the synthesized pillared clays. The structure of the pillared materials is studied by XRD and cationic exchange capacity. The textural property is investigated by the nitrogen adsorption/desorption method. The acid–base chemistry “surface acidity” of these products was analysed by using mass and potentiometric titration in order to determine the PZC and the equilibrium constants (pKa of each sample. The resulting materials exhibited basal spacings in the range of 17.4–20.5 Å, with high surface areas (134–199 m2 g−1. Titration curves obtained by acid–base potentiometric titration for the starting material showed an indistinct cross-over point at about pH = 7.3, whereas in the case of pillared samples, points were observed at the acidic region between 4 and 6. In addition, the calculated pKas values of pillared clays show a shifting to the acidic values compared to the untreated sample.

  4. Xenon-129 NMR study of the microporous structure of clays and pillared clays

    International Nuclear Information System (INIS)

    Tsiao, C.; Carrado, K.A.

    1990-01-01

    129 Xe NMR studies have been carried out using xenon gas adsorbed in clays and pillared clays. Data from the measurements provide information on the pore structure of clays before and after pillaring. The results indicate that the effective pore diameter of montmorillonite increases, for example, from 5.4 Angstrom to 8.0 Angstrom after pillaring cheto-montmorillonite with aluminum polyoxohydroxy Keggin cations. The data are consistent with X-ray powder diffraction results, which show a corresponding increase in the interlamellar gallery height from 5.6 Angstrom to 8.4 Angstrom

  5. InGaN micro-LED-pillar as the building block for high brightness emitters

    KAUST Repository

    Shen, Chao; Cha, Dong Kyu; Ng, Tien Khee; Ooi, Boon S.; Yang, Yang

    2013-01-01

    In summary, we confirmed the improved electrical and optical characteristics, with reduced efficiency droop in InGaN μLED-pillars when these devices were scaled down in size. We demonstrated that strain relief contributed to further improvement in EQE characteristics in small InGaN μLED-pillars (D < 50 μm), apart from the current spreading effect. The μLED-pillar can be deployed as the building block for large effective-area, high brightness emitter. © 2013 IEEE.

  6. A constrained maximization formulation to analyze deformation of fiber reinforced elastomeric actuators

    Science.gov (United States)

    Singh, Gaurav; Krishnan, Girish

    2017-06-01

    Fiber reinforced elastomeric enclosures (FREEs) are soft and smart pneumatic actuators that deform in a predetermined fashion upon inflation. This paper analyzes the deformation behavior of FREEs by formulating a simple calculus of variations problem that involves constrained maximization of the enclosed volume. The model accurately captures the deformed shape for FREEs with any general fiber angle orientation, and its relation with actuation pressure, material properties and applied load. First, the accuracy of the model is verified with existing literature and experiments for the popular McKibben pneumatic artificial muscle actuator with two equal and opposite families of helically wrapped fibers. Then, the model is used to predict and experimentally validate the deformation behavior of novel rotating-contracting FREEs, for which no prior literature exist. The generality of the model enables conceptualization of novel FREEs whose fiber orientations vary arbitrarily along the geometry. Furthermore, the model is deemed to be useful in the design synthesis of fiber reinforced elastomeric actuators for general axisymmetric desired motion and output force requirement.

  7. Sulcus reproduction with elastomeric impression materials: a new in vitro testing method.

    Science.gov (United States)

    Finger, Werner J; Kurokawa, Rie; Takahashi, Hidekazu; Komatsu, Masashi

    2008-12-01

    Aim of this study was to investigate the depth reproduction of differently wide sulci with elastomeric impression materials by single- and double-mix techniques using a tooth and sulcus model, simulating clinical conditions. Impressions with one vinyl polysiloxane (VPS; FLE), two polyethers (PE; IMP and P2), and one hybrid VPS/PE elastomer (FUS) were taken from a truncated steel cone with a circumferential 2 mm deep sulcus, 50, 100 or 200 microm wide. The "root surface" was in steel and the "periodontal tissue" in reversible hydrocolloid. Single-mix impressions were taken with light-body (L) or monophase (M) pastes, double-mix impressions with L as syringe and M or heavy-body (H) as tray materials (n=8). Sulcus reproduction was determined by 3D laser topography of impressions at eight locations, 45 degrees apart. Statistical data analysis by ANOVA and multiple comparison tests (pimpression materials only: FLE=IMP>FUS=P2. At 50 and 100 microm width, significant differences were found between materials (IMP>FUS=FLE>P2) and techniques (L+H=L+M>M>L). The sulcus model is considered useful for screening evaluation of elastomeric impression materials ability to reproduce narrow sulci. All tested materials and techniques reproduced 200 microm wide sulci to almost nominal depth. Irrespective of the impression technique used, IMP showed the best penetration ability in 50 and 100 microm sulci. Double-mix techniques are more suitable to reproduce narrow sulci than single-mix techniques.

  8. Power turbine dynamics - An evaluation of a shear-mounted elastomeric damper

    Science.gov (United States)

    Zorzi, E. S.; Walton, J.; Cunningham, R.

    1983-01-01

    As an alternative to the more conventional squeeze-film bearing damper designs, a Viton-70 shear-mounted, elastomeric damper was built and tested in a T-55 power turbine high-speed balancing rig. This application demonstrated, for the first time, the feasibility of using elastomers as the primary rotor damping source in production turbine engine hardware. The shear-mounted damper design was selected because of its compatibility with actual gas turbine engine radial space constraints, its accommodation of both the radial and axial thrust loads present in gas turbine engines, and its capability of controlled axial preload. Test results showed that the Viton-70 elastomeric damper operated successfully and provided excellent control of both synchronous and nonsynchronous vibrations through all phases of testing to the maximum rotor speed of 1676 rad/s (16,000 rpm). Excellent correlation between the predicted and experienced critical speeds, mode shapes, and log decrements for the power turbine rotor and elastomer damper assembly was also achieved.

  9. Experiment-Based Sensitivity Analysis of Scaled Carbon-Fiber-Reinforced Elastomeric Isolators in Bonded Applications

    Directory of Open Access Journals (Sweden)

    Farshad Hedayati Dezfuli

    2016-01-01

    Full Text Available Fiber-reinforced elastomeric isolators (FREIs are a new type of elastomeric base isolation systems. Producing FREIs in the form of long laminated pads and cutting them to the required size significantly reduces the time and cost of the manufacturing process. Due to the lack of adequate information on the performance of FREIs in bonded applications, the goal of this study is to assess the performance sensitivity of 1/4-scale carbon-FREIs based on the experimental tests. The scaled carbon-FREIs are manufactured using a fast cold-vulcanization process. The effect of several factors including the vertical pressure, the lateral cyclic rate, the number of rubber layers, and the thickness of carbon fiber-reinforced layers are explored on the cyclic behavior of rubber bearings. Results show that the effect of vertical pressure on the lateral response of base isolators is negligible. However, decreasing the cyclic loading rate increases the lateral flexibility and the damping capacity. Additionally, carbon fiber-reinforced layers can be considered as a minor source of energy dissipation.

  10. A new UV-curing elastomeric substrate for rapid prototyping of microfluidic devices

    Science.gov (United States)

    Alvankarian, Jafar; Yeop Majlis, Burhanuddin

    2012-03-01

    Rapid prototyping in the design cycle of new microfluidic devices is very important for shortening time-to-market. Researchers are facing the challenge to explore new and suitable substrates with simple and efficient microfabrication techniques. In this paper, we introduce and characterize a UV-curing elastomeric polyurethane methacrylate (PUMA) for rapid prototyping of microfluidic devices. The swelling and solubility of PUMA in different chemicals is determined. Time-dependent measurements of water contact angle show that the native PUMA is hydrophilic without surface treatment. The current monitoring method is used for measurement of the electroosmotic flow mobility in the microchannels made from PUMA. The optical, physical, thermal and mechanical properties of PUMA are evaluated. The UV-lithography and molding process is used for making micropillars and deep channel microfluidic structures integrated to the supporting base layer. Spin coating is characterized for producing different layer thicknesses of PUMA resin. A device is fabricated and tested for examining the strength of different bonding techniques such as conformal, corona treating and semi-curing of two PUMA layers in microfluidic application and the results show that the bonding strengths are comparable to that of PDMS. We also report fabrication and testing of a three-layer multi inlet/outlet microfluidic device including a very effective fluidic interconnect for application demonstration of PUMA as a promising new substrate. A simple micro-device is developed and employed for observing the pressure deflection of membrane made from PUMA as a very effective elastomeric valve in microfluidic devices.

  11. Frictional resistance of orthodontic wires tied with 3 types of elastomeric ligatures

    Directory of Open Access Journals (Sweden)

    Amanda Carneiro da Cunha

    2011-12-01

    Full Text Available The aims of this study were to determine and compare frictional resistance obtained by low-friction and conventional elastomeric ligatures in the presence of artificial saliva, and observe whether this variable changed after 21 days. Super Slick® low-friction elastomeric ligatures and conventional ligatures of the brands TP conventional® and Unitek® were placed on standard edgewise maxillary central incisor metal brackets, slot .022" × .028" tying rectangular orthodontic wires .018" × .025". Three experimental groups were arranged according to the type of ligature and a control group in which no wires were used. The friction values obtained between the bracket/wire/ligature set were measured using a Universal Test Machine at a speed of 20 mm/minute, at two experimental time intervals: T0 - immediately after specimen fabrication; and T1 - 21 days after fabrication and immersion in artificial saliva at 37 ºC. Conventional Unitek ligatures and the low-friction ligature (Super Slick showed the lowest friction values at T0. After 21 days (T1, however, conventional Unitek ligatures presented the lowest value. All groups assessed from T0 to T1 showed a numerical reduction in friction values, suggesting that time, heat and humidity may cause elastic degradation, however this was not verified statistically (P > 0.05.

  12. New pillars of evolutionary theory in the light of genomics

    International Nuclear Information System (INIS)

    Lopez Carrascal, Camilo Ernesto

    2011-01-01

    The evolutionist theory proposed by Darwin is one of the fundamental pillars in biology. Darwin's theory was solidified with the modern synthesis of evolutionary biology thanks to the rediscovery of Mendel's work, which laid the genetic basis of heredity. In recent years, great progress has been acquired in the sequencing and analyses of complete genomes, which have provided several elements to discuss some Darwinists tenets of evolution. The evidence of gene duplication and whole-genome duplication, the horizontal gene transfer and the endosymbiosis process question the idea that evolution proceeds through the gradual accumulation of infinitesimally small random changes. The new evidence of neutral selection on the genomics context reveals other mechanisms of evolution not necessarily related with the idea of progress or with an adaptationist program as was originally stated by the Darwin's theory. in this paper, I present these and other concepts such as gene regulation, molecular mechanisms of development and some environmental aspects (epigenesis and phenotypic plasticity) as starting points to think in the necessity to update the evolutionary theory which in my opinion should be more inclusive, pluralistic and consistent with our current knowledge.

  13. METHOD FOR PROVIDING SHAPED BIODEGRADABLE AND ELASTOMERIC STRUCTURES OF (CO) POLYMERS OF 1,3-TRIMETHYLENE CARBONATE (TMC), SHAPED BIODEGRADABLE AND ELASTOMERIC STRUCTURES, AND THE USE OF THESE STRUCTURES

    NARCIS (Netherlands)

    Grijpma, D.W.; Pêgo, A.P.; Feijen, Jan

    2004-01-01

    The present invention relates to methods for providing shaped biodegradable and elastomeric structures of (co)polymers of 1,3­trimethylene carbonate (TMC) with improved (mechanical) properties which can be used for tissue or tissue component support, generation or regeneration. Such shaped

  14. Surface tension-induced PDMS micro-pillars with controllable tips and tilt angles

    KAUST Repository

    Li, Huawei; Fan, Yiqiang; Conchouso Gonzalez, David; Foulds, Ian G.

    2013-01-01

    This paper reports a novel method to fabricate three-dimensional (3D) polydimethylsiloxane (PDMS) micro-pillars using a CO2 laser-machined poly(methyl methacrylate) (PMMA) mold with through-holes. This method eliminates the requirements of expensive and complicated facilities to fabricate a 3D mold. The micro-pillars were formed by the capillary force that draws PDMS into the through-holes of the PMMA mold. The tilt angles of the micro-pillars depend on the tilt angles of the through-holes in the mold, and the concave and convex micro-lens tip shapes of the PDMS micro-pillars can be modified by changing the surface wettability of the PMMA through-holes.

  15. Wettability transition of plasma-treated polystyrene micro/nano pillars-aligned patterns

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available This paper reports the wettability transition of plasma-treated polystyrene (PS micro/nano pillars-aligned patterns. The micro/nano pillars were prepared using hot embossing on silicon microporous template and alumina nanoporous template, which were fabricated by ultraviolet (UV lithography and inductive coupled plasma (ICP etching, and two-step anodic oxidation, respectively. The results indicate that the combination of micro/nano patterning and plasma irradiation can easily regulate wettabilities of PS surfaces, i.e. from hydrophilicity to hydrophobicity, or from hydrophobicity to superhydrophilicity. During the wettability transition from hydrophobicity to hydrophilicity there is only mild hydrophilicity loss. After plasma irradiation, moreover, the wettability of PS micro/nano pillars-aligned patterns is more stable than that of flat PS surfaces. The observed wettability transition and wettability stability of PS micro/nano pillars-aligned patterns are new phenomena, which may have potential in creating programmable functional polymer surfaces.

  16. Design and construction of porous metal-organic frameworks based on flexible BPH pillars

    Science.gov (United States)

    Hao, Xiang-Rong; Yang, Guang-sheng; Shao, Kui-Zhan; Su, Zhong-Min; Yuan, Gang; Wang, Xin-Long

    2013-02-01

    Three metal-organic frameworks (MOFs), [Co2(BPDC)2(4-BPH)·3DMF]n (1), [Cd2(BPDC)2(4-BPH)2·2DMF]n (2) and [Ni2(BDC)2(3-BPH)2 (H2O)·4DMF]n (3) (H2BPDC=biphenyl-4,4'-dicarboxylic acid, H2BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N'-dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has "single-pillared" MOF-5-like motif with inner cage diameters of up to 18.6 Å. Framework 2 has "double pillared" MOF-5-like motif with cage diameters of 19.2 Å while 3 has "double pillared" 8-connected framework with channel diameters of 11.0 Å. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework.

  17. Effect of orientation and loading rate on compression behavior of small-scale Mo pillars

    International Nuclear Information System (INIS)

    Schneider, A.S.; Clark, B.G.; Frick, C.P.; Gruber, P.A.; Arzt, E.

    2009-01-01

    Recently, much work has focused on the size effect in face centered cubic (fcc) structures, however few pillar studies have focused on body centered cubic (bcc) metals. This paper explores the role of bcc crystal structure on the size effect, through compression testing of [001] and [235] Molybdenum (Mo) small-scale pillars manufactured by focused ion beam (FIB). The pillar diameters ranged from 200 nm to 5 μm. Results show that the relationship between yield stress and diameter exhibits an inverse relationship (σ y ∝ d -0.22 for [001] Mo and σ y ∝ d -0.34 for [235] Mo) weaker than that observed for face centered cubic (fcc) metals (σ y ∝ d -0.6to-1.0 ). Additional tests at various loading rates revealed that small-scale Mo pillars exhibit a strain rate sensitivity similar to bulk Mo.

  18. Trajectory generation algorithm for smooth movement of a hybrid-type robot Rocker-Pillar

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Min; Choi, Dong Kyu; Kim, Jong Won [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Kim, Hwa Soo [Dept. of Mechanical System Engineering, Kyonggi University, Suwon (Korea, Republic of)

    2016-11-15

    While traveling on rough terrain, smooth movement of a mobile robot plays an important role in carrying out the given tasks successfully. This paper describes the trajectory generation algorithm for smooth movement of hybrid-type mobile robot Rocker-Pillar by adjusting the angular velocity of its caterpillar as well as each wheel velocity in such a manner to minimize a proper index for smoothness. To this end, a new Smoothness index (SI) is first suggested to evaluate the smoothness of movement of Rocker-Pillar. Then, the trajectory generation algorithm is proposed to reduce the undesired oscillations of its Center of mass (CoM). The experiment are performed to examine the movement of Rocker-Pillar climbing up the step whose height is twice larger than its wheel radius. It is verified that the resulting SI is improved by more than 40 % so that the movement of Rocker-Pillar becomes much smoother by the proposed trajectory algorithm.

  19. Surface tension-induced PDMS micro-pillars with controllable tips and tilt angles

    KAUST Repository

    Li, Huawei

    2013-12-21

    This paper reports a novel method to fabricate three-dimensional (3D) polydimethylsiloxane (PDMS) micro-pillars using a CO2 laser-machined poly(methyl methacrylate) (PMMA) mold with through-holes. This method eliminates the requirements of expensive and complicated facilities to fabricate a 3D mold. The micro-pillars were formed by the capillary force that draws PDMS into the through-holes of the PMMA mold. The tilt angles of the micro-pillars depend on the tilt angles of the through-holes in the mold, and the concave and convex micro-lens tip shapes of the PDMS micro-pillars can be modified by changing the surface wettability of the PMMA through-holes.

  20. A micro-pillar array to trap magnetic beads in microfluidic systems

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    A micro-pillar array (MPA) is proposed in this paper to trap and separate magnetic beads (MBs) in microfluidic systems. MBs are used in many biomedical applications due to being compatible in dimension to biomolecules, the large surface area

  1. Criticality studies: One of the two pillars of criticality safety at the Belgonucleaire MOX plant

    International Nuclear Information System (INIS)

    Lance, B.; Maldague, T.; Evrard, G.; Renard, A.; Kockerols, P.

    2001-01-01

    The present paper focuses on the criticality studies performed by the Engineering Division of Belgonucleaire. These are one of the two pillars of the criticality prevention implemented for the Belgonucleaire MOX producing plant. (author)

  2. Non-lithographic method of forming ordered arrays of silicon pillars and macropores

    International Nuclear Information System (INIS)

    Mills, David; Kolasinski, Kurt W

    2005-01-01

    Micrometre-scale Si pillars are formed by chemically enhanced laser ablation using nanosecond excimer laser irradiation of a Si single crystal in the presence of SF 6 . We demonstrate the importance of precursor holes in determining the positioning of the pillars and show that we can control the initiation of precursor holes by ruling a grating into the Si substrate prior to irradiation. A rule defines an edge from which the laser light diffracts. Near-field amplification of the laser intensity enhances the formation of the precursor holes and aligns them parallel to the rule. The pillars can be thinned and eventually removed by wet chemical etching in aqueous KOH, resulting first in ordered arrays of extremely high aspect ratio pillars (e.g. tens of micrometres in length, with ∼ 10 nm tips) and then macropores. The shape of the macropore is determined by crystallography and the anisotropy of the wet etchant

  3. Biomimetic elastomeric, conductive and biodegradable polycitrate-based nanocomposites for guiding myogenic differentiation and skeletal muscle regeneration.

    Science.gov (United States)

    Du, Yuzhang; Ge, Juan; Li, Yannan; Ma, Peter X; Lei, Bo

    2018-03-01

    Artificial muscle-like biomaterials have gained tremendous interests owing to their broad applications in regenerative medicine, wearable devices, bioelectronics and artificial intelligence. Unfortunately, key challenges are still existed for current materials, including biomimetic viscoelasticity, biocompatibility and biodegradation, multifunctionality. Herein, for the first time, we develop highly elastomeric, conductive and biodegradable poly (citric acid-octanediol-polyethylene glycol)(PCE)-graphene (PCEG) nanocomposites, and demonstrate their applications in myogenic differentiation and guiding skeletal muscle tissue regeneration. In PCEG nanocomposites, PCE provides the biomimetic elastomeric behavior, and the addition of reduced graphene oxide (RGO) endows the enhanced mechanical strength and conductivity. The highly elastomeric behavior, significantly enhanced modulus (400%-800%), strength (200%-300%) of PCEG nanocomposites with controlled biodegradability and electrochemical conductivity were achieved. The myoblasts proliferation and myogenic differentiation were significantly improved by PCEG nanocomposite. Significantly high in vivo biocompatibility of PCEG nanocomposites was observed when implanted in the subcutaneous tissue for 4 weeks in rats. PCEG nanocomposites could significantly enhance the muscle fibers and blood vessels formation in vivo in a skeletal muscle lesion model of rat. This study may provide a novel strategy to develop multifunctional elastomeric nanocomposites with high biocompatibility for potential soft tissue regeneration and stretchable bioelectronic devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Glass interface effect on high-strain-rate tensile response of a soft polyurethane elastomeric polymer material

    NARCIS (Netherlands)

    Fan, J.T.; Weerheijm, J.; Sluys, L.J.

    2015-01-01

    The glass interface effect on dynamic tensile response of a soft polyurethane elastomeric polymer material has been investigated by subjecting a glass-polymer system of this polymer material matrix embedded a single 3 mm-diameter glass particle to impact loading in a split Hopkinson tension bar

  5. Fabrication, characterization, and biocompatibility assessment of a novel elastomeric nanofibrous scaffold: A potential scaffold for soft tissue engineering

    DEFF Research Database (Denmark)

    Shamirzaei Jeshvaghani, Elham; Ghasemi-Mobarakeh, Laleh; Mansurnezhad, Reza

    2017-01-01

    With regard to flexibility and strength properties requirements of soft biological tissue, elastomeric materials could be more beneficial in soft tissue engineering applications. The present work investigates the use of an elastic polymer, (polycaprolactone fumarate [PCLF]), for fabricating...... experiments and its application for engineering of soft tissues subjected to in vivo cyclic mechanical stresses....

  6. Design and construction of porous metal-organic frameworks based on flexible BPH pillars

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Xiang-Rong; Yang, Guang-sheng; Shao, Kui-Zhan [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China); Su, Zhong-Min, E-mail: zmsu@nenu.edu.cn [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China); Yuan, Gang; Wang, Xin-Long [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China)

    2013-02-15

    Three metal-organic frameworks (MOFs), [Co{sub 2}(BPDC){sub 2}(4-BPH){center_dot}3DMF]{sub n} (1), [Cd{sub 2}(BPDC){sub 2}(4-BPH){sub 2}{center_dot}2DMF]{sub n} (2) and [Ni{sub 2}(BDC){sub 2}(3-BPH){sub 2} (H{sub 2}O){center_dot}4DMF]{sub n} (3) (H{sub 2}BPDC=biphenyl-4,4 Prime -dicarboxylic acid, H{sub 2}BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N Prime -dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has 'single-pillared' MOF-5-like motif with inner cage diameters of up to 18.6 A. Framework 2 has 'double pillared' MOF-5-like motif with cage diameters of 19.2 A while 3 has 'double pillared' 8-connected framework with channel diameters of 11.0 A. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework. - Graphical abstract: By insertion of flexible BPH pillars based on 'pillaring' strategy, three metal-organic frameworks are obtained showing that the porous frameworks can be constructed in a much greater variety. Highlights: Black-Right-Pointing-Pointer Frameworks 1 and 2 have MOF-5 like motif. Black-Right-Pointing-Pointer The cube-like cages in 1 and 2 are quite large, comparable to the IRMOF-10. Black-Right-Pointing-Pointer Framework 1 is 'single-pillared' mode while 2 is 'double-pillared' mode. Black-Right-Pointing-Pointer PXRD and gas adsorption analysis show that 3 is a dynamic porous framework.

  7. Effect of commonly used beverage, soft drink, and mouthwash on force delivered by elastomeric chain: a comparative in vitro study.

    Science.gov (United States)

    Kumar, Kiran; Shetty, Sharath; Krithika, M J; Cyriac, Bobby

    2014-06-01

    The objective was to evaluate and compare the effect of Coca-Cola®, tea, Listerine® mouthwash on the force delivered by elastomeric chain in vitro. Four specimen groups (distilled water, Coca-Cola®, tea, Listerine® mouthwash) with a total sample size of 480 specimens. A specimen is described as a four link grey close elastomeric chain. Jigs, each with a series of pins set 25 mm apart, was used to hold stretched elastomeric chains at a constant length. These jigs allowed for complete submersion of the elastomeric chain in a water bath throughout the test period, as well as the dipping of elastomeric chains in respective control and test solutions. For 60 s, twice a day, groups were exposed to the respective solutions, the two daily exposure was separated by 9 h and force measurements were taken at six time points during the experiment, that is, 1 h, 24 h, 7 days, 14 days, 21 days, and 28 days. Force measurements were made by Instron machine by a single blinded examiner with the help of a second examiner. It was found out that there was highly significant difference between groups control, Coca-Cola®, Listerine®, and tea as well as there was highly significant (p Coca-Cola® and the Listerine® group reached a plateau between 7 and 21 days then decrease between 21 and 28 days. The tea group showed plateau phase between 7 and 28 days. After 28 days in the control group, 25% force decay occurred while the test groups force decay of 30-50% occurred. Coca-Cola®, Listerine® mouthwash, and tea cause an increase in force decay of elastomeric chains over time. Tea caused highest force decay followed by Listerine® and Coca-Cola® when compared to control group. How to cite the article: Kumar K, Shetty S, Krithika MJ, Cyriac B. Effect of commonly used beverage, soft drink, and mouthwash on force delivered by elastomeric chain: A comparative in vitro study. J Int Oral Health 2014;6(3):7-10.

  8. Rock mechanics of crown pillars between cut-and-fill stopes at the Mount Isa mine

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. F.; Bridges, M. C.

    1980-05-15

    At both levels, the leading stopes experienced bad ground conditions due to high stresses in the stope's backs when the crown pillars were about 35 m high. At 9 level, cut-and-fill mining stopped and most of the crown pillars were extracted by a slot-and-massfire method. At 11 level, cut-and-fill mining continued. Shear displacement along bedding planes began within and around the crown pillars of the leading stopes at 11 level, and spread through other crown pillars and to the hangingwall of the stoping system. Destressing and good ground conditions occurred where shear occurred, with further concentrations of stress in other areas. Crown pillars are being extracted to leave minimal 1:2 height to width diaphragms under the stopes above. Ground behavior of the 11 level crown pillars was investigated by observation, stress measurement, regional surveying of displacement and finite element models. An explanation of the ground behavior has evolved from this work. Bedding planes with an estimated angle of sliding friction of 10/sup 0/ were the main factor determining the behavior of this area.

  9. Removal of nitrate by zero-valent iron and pillared bentonite

    International Nuclear Information System (INIS)

    Li Jianfa; Li Yimin; Meng Qingling

    2010-01-01

    The pillared bentonite prepared by intercalating poly(hydroxo Al(III)) cations into bentonite interlayers was used together with Fe(0) for removing nitrate in column experiments. The obvious synergetic effect on nitrate removal was exhibited through uniformly mixing the pillared bentonite with Fe(0). In such a mixing manner, the nitrate was 100% removed, and the removal efficiency was much higher than the simple summation of adsorption by the pillared bentonite and reduction by Fe(0). The influencing factors such as bentonite type, amount of the pillared bentonite and initial pH of nitrate solutions were investigated. In this uniform mixture, the pillared bentonite could adsorb nitrate ions, and facilitated the mass transfer of nitrate onto Fe(0) surface, then accelerated the nitrate reduction. The pillared bentonite could also act as the proton-donor, and helped to keep the complete nitrate removal for at least 10 h even when the nitrate solution was fed at nearly neutral pH.

  10. Beyond DSM-5 and IQ Scores: Integrating the Four Pillars to Forensic Evaluations.

    Science.gov (United States)

    Delgado, Sergio V; Barzman, Drew H

    2017-03-01

    The current adult and child forensic psychiatrist is well trained, familiar, and comfortable with the use of the semi-structured Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, APA 2013 (DSM-5) [In APA, 2003] interview style. The author's assertion is not that this method is invalid or unreliable; rather, that it can be complemented by integrating elements of the defendant's four pillar assessment. Assessing the four pillars expands on the information provided by a semi-structured DSM-5-style interview in psychiatry. The four pillars are the foundation of a person's personality; temperament, cognition (learning abilities or weaknesses), cognitive flexibility (theory of mind) and internal working models of attachment, within the backdrop of the family and of the social and cultural environment in which they have lived. The importance of the study of four pillars is based on the understanding that human behavior and psychopathology as a complex and multifaceted process that includes the level of social-emotional maturity and cognitive abilities (In Delgado et al. Contemporary Psychodynamic Psychotherapy for Children and Adolescents: Integrating Intersubjectivity and Neuroscience. Springer, Berlin, 2015). The four pillars are not new concepts, rather they had been studied by separate non-clinical disciplines, and had not been integrated to the clinical practice. As far as we know, it wasn't until Delgado et al. (Contemporary Psychodynamic Psychotherapy for Children and Adolescents: Integrating Intersubjectivity and Neuroscience. Springer, Berlin, 2015) incorporated the four pillars in a user-friendly manner to clinical practice.

  11. Asymmetric liquid wetting and spreading on surfaces with slanted micro-pillar arrays

    KAUST Repository

    Yang, Xiaoming

    2013-01-01

    Uni-directional liquid spreading on asymmetric silicone-fabricated nanostructured surfaces has recently been reported. In this work, uniformly deflected polydimethylsiloxane (PDMS) micro-pillars covered with silver films were fabricated. Asymmetric liquid wetting and spreading behaviors in a preferential direction were observed on the slanted micro-pillar surfaces and a micro-scale thin liquid film advancing ahead of the bulk liquid droplet was clearly observed by high-speed video imaging. It is found that the slanted micro-pillar array is able to promote or inhibit the propagation of this thin liquid film in different directions by the asymmetric capillary force. The spreading behavior of the bulk liquid was guided and finally controlled by this micro-scale liquid film. Different spreading regimes are defined by the relationship between the liquid intrinsic contact angle and the critical angles, which were determined by the pillar height, pillar deflection angle and inter-pillar spacing. © The Royal Society of Chemistry 2013.

  12. Methods for polarized light emission from CdSe quantum dot based monolithic pillar microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Seyfried, Moritz; Kalden, Joachim; Sebald, Kathrin; Gutowski, Juergen; Kruse, Carsten; Hommel, Detlef [Institute of Solid State Physics, University of Bremen (Germany)

    2010-07-01

    A lifting of the polarization degeneracy of the fundamental cavity mode in pillar microcavities (MCs) would allow for controlling the polarization state of the emitted photons. Therefore, monolithic VCSEL structures were grown by molecular beam epitaxy containing either one CdSe/ZnSSe quantum dot layer or three quantum well layers as active material. By using focused-ion-beam etching, MC pillars with different geometries were prepared out of the planar samples. Among these are circularly shaped pillar MCs with diameters in the range from 500 nm up to 4 {mu}m and quality factors of up to 7860, elliptically shaped MCs, and so-called photonic molecules consisting of circular pillar MCs which are connected by small bars. Polarization dependent photoluminescence investigations of the fundamental cavity mode reveal a lifting of the polarization degeneracy for all three types of MCs. The energy splitting of up to 0.42 meV in the circularly shaped pillar MCs is probably caused by anisotropic strain conditions within the sample and directly dependent on the pillar diameter, whereas the larger energy splitting of up to 0.72 meV for the photonic molecules or even 4.5 meV for the elliptically shaped MC is based on their asymmetric cross sections.

  13. Molecular modeling of the elastomeric properties of repeating units and building blocks of resilin, a disordered elastic protein.

    Science.gov (United States)

    Khandaker, Md Shahriar K; Dudek, Daniel M; Beers, Eric P; Dillard, David A; Bevan, David R

    2016-08-01

    The mechanisms responsible for the properties of disordered elastomeric proteins are not well known. To better understand the relationship between elastomeric behavior and amino acid sequence, we investigated resilin, a disordered rubber-like protein, found in specialized regions of the cuticle of insects. Resilin of Drosophila melanogaster contains Gly-rich repetitive motifs comprised of the amino acids, PSSSYGAPGGGNGGR, which confer elastic properties to resilin. The repetitive motifs of insect resilin can be divided into smaller partially conserved building blocks: PSS, SYGAP, GGGN and GGR. Using molecular dynamics (MD) simulations, we studied the relative roles of SYGAP, and its less common variants SYSAP and TYGAP, on the elastomeric properties of resilin. Results showed that SYGAP adopts a bent structure that is one-half to one-third the end-to-end length of the other motifs having an equal number of amino acids but containing SYSAP or TYGAP substituted for SYGAP. The bent structure of SYGAP forms due to conformational freedom of glycine, and hydrogen bonding within the motif apparently plays a role in maintaining this conformation. These structural features of SYGAP result in higher extensibility compared to other motifs, which may contribute to elastic properties at the macroscopic level. Overall, the results are consistent with a role for the SYGAP building block in the elastomeric properties of these disordered proteins. What we learned from simulating the repetitive motifs of resilin may be applicable to the biology and mechanics of other elastomeric biomaterials, and may provide us the deeper understanding of their unique properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The four pillars of education - learning by value

    Science.gov (United States)

    Czerniak-Czyżniak, Marta

    2017-04-01

    Nature is a great laboratory and a place of research. Observing and being with nature tells us how to acquire knowledge, how to work in a group, how to protect nature and how to behave in its environment. There are four important elements of contemporary education. Many scientific achievements and inventions created by observation and imitation of nature. Teaching nature can take into account the four pillars of education presented in the report for the United Nations Jacques Delors: Learning to KNOW - by discovering, experiencing, develop interests Learn to ACT - by activity, experimentation, creativity and courage Learning to LIVE TOGETHER - through group work, help and care Learn to BE - safe, helpful, experience and maintain social contacts Teaching through action is extremely important for the development of the child-man* (Piaget, 2006). The thinking originates primarily from the action. Therefore, students should undertake independent research activities, perform experiments and conduct observations and thus raise questions about the world, looking for meanings and solutions. Adults (a teacher, a person with a passion) are to be the support in the search for knowledge. The following poster is the summary of Project „Environmental Education for Sustainable Development in teacher training" co-financed by Norwegian as well national funds. The aim of the project is to increase environment al awareness and strengthenknowledge about the environment and cli mate change among students of Elary childhood education, to exchange Polish-Norwegian experience on outdoor nature education didactics in the first grades of primary school, to develop a didactics of the outdoor education and to implement it in program of an early childhood education study. *Piaget, J. (2006) How a child imagines the world, Warsaw: PWN Publishing

  15. Mechanics of nanowire/nanotube in-surface buckling on elastomeric substrates

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, J; Huang, Y [Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208 (United States); Ryu, S Y; Paik, U [Division of Materials Science and Engineering, Hanyang University, 17 Hangdang-dong, Sungdong-gu, Seoul 133-791 (Korea, Republic of); Hwang, K-C [Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Rogers, J A, E-mail: y-huang@northwestern.edu, E-mail: jrogers@uiuc.edu [Department of Materials Science and Engineering, Frederick-Seitz Materials Research Laboratory and Beckman Institute, University of Illinois at Urbana-Champaign, Illinois 61801 (United States)

    2010-02-26

    A continuum mechanics theory is established for the in-surface buckling of one-dimensional nanomaterials on compliant substrates, such as silicon nanowires on elastomeric substrates observed in experiments. Simple analytical expressions are obtained for the buckling wavelength, amplitude and critical buckling strain in terms of the bending and tension stiffness of the nanomaterial and the substrate elastic properties. The analysis is applied to silicon nanowires, single-walled carbon nanotubes, multi-walled carbon nanotubes, and carbon nanotube bundles. For silicon nanowires, the measured buckling wavelength gives Young's modulus to be 140 GPa, which agrees well with the prior experimental studies. It is shown that the energy for in-surface buckling is lower than that for normal (out-of-surface) buckling, and is therefore energetically favorable.

  16. Mechanics of nanowire/nanotube in-surface buckling on elastomeric substrates

    International Nuclear Information System (INIS)

    Xiao, J; Huang, Y; Ryu, S Y; Paik, U; Hwang, K-C; Rogers, J A

    2010-01-01

    A continuum mechanics theory is established for the in-surface buckling of one-dimensional nanomaterials on compliant substrates, such as silicon nanowires on elastomeric substrates observed in experiments. Simple analytical expressions are obtained for the buckling wavelength, amplitude and critical buckling strain in terms of the bending and tension stiffness of the nanomaterial and the substrate elastic properties. The analysis is applied to silicon nanowires, single-walled carbon nanotubes, multi-walled carbon nanotubes, and carbon nanotube bundles. For silicon nanowires, the measured buckling wavelength gives Young's modulus to be 140 GPa, which agrees well with the prior experimental studies. It is shown that the energy for in-surface buckling is lower than that for normal (out-of-surface) buckling, and is therefore energetically favorable.

  17. Silicon micro-masonry using elastomeric stamps for three-dimensional microfabrication

    International Nuclear Information System (INIS)

    Keum, Hohyun; Eisenhaure, Jeffrey D; Kim, Seok; Carlson, Andrew; Ning, Hailong; Mihi, Agustin; Braun, Paul V; Rogers, John A

    2012-01-01

    We present a micromanufacturing method for constructing microsystems, which we term ‘micro-masonry’ based on individual manipulation, influenced by strategies for deterministic materials assembly using advanced forms of transfer printing. Analogous to masonry in construction sites, micro-masonry consists of the preparation, manipulation, and binding of microscale units to assemble microcomponents and microsystems. In this paper, for the purpose of demonstration, we used microtipped elastomeric stamps as manipulators and built three dimensional silicon microstructures. Silicon units of varied shapes were fabricated in a suspended format on donors, retrieved, delivered, and placed on a target location on a receiver using microtipped stamps. Annealing of the assembled silicon units permanently bound them and completed the micro-masonry procedure. (paper)

  18. The effect of rinsing time periods on wettability of elastomeric impression materials: in vitro study

    Directory of Open Access Journals (Sweden)

    Özlem Acar

    2016-01-01

    Full Text Available OBJECTIVE: The aim of this study was to determine whether different rinsing time periods affected the wettability of polymerized elastomeric impression materials. MATERIALS AND METHOD: Panasil Contact Plus (PCP, Panasil Contact Non-Surfactant (PCNS, Panasil Initial Contact (PIC, Express (EXP and Impregum (IMP impression materials were tested. Standardized samples were rinsed with water for 10 s, 15 s or 20 s, and the wettability was determined by contact angle measurement through an evaluation period of 60 seconds (n=7. Non-rinsed groups were used as control. Measurements were made at 5 time points (at 0, 6, 15, 30 and 60 seconds. Kruskal Wallis test and Conover’s multiple comparison tests were used for all multiple comparisons. Bonferroni adjustment was applied for controlling Type I error (p0.002. CONCLUSION: Rinsing the surfactant-containing polyvinylsiloxane impression materials decreased their wettability, whereas no such effect was seen for the surfactant free polyvinylsiloxane and polyether impression materials.

  19. Active shape-morphing elastomeric colloids in short-pitch cholesteric liquid crystals.

    Science.gov (United States)

    Evans, Julian S; Sun, Yaoran; Senyuk, Bohdan; Keller, Patrick; Pergamenshchik, Victor M; Lee, Taewoo; Smalyukh, Ivan I

    2013-05-03

    Active elastomeric liquid crystal particles with initial cylindrical shapes are obtained by means of soft lithography and polymerization in a strong magnetic field. Gold nanocrystals infiltrated into these particles mediate energy transfer from laser light to heat, so that the inherent coupling between the temperature-dependent order and shape allows for dynamic morphing of these particles and well-controlled stable shapes. Continuous changes of particle shapes are followed by their spontaneous realignment and transformations of director structures in the surrounding cholesteric host, as well as locomotion in the case of a nonreciprocal shape morphing. These findings bridge the fields of liquid crystal solids and active colloids, may enable shape-controlled self-assembly of adaptive composites and light-driven micromachines, and can be understood by employing simple symmetry considerations along with electrostatic analogies.

  20. Optimization of fractional composition of the excipient in the elastomeric covering for asphalt highways

    Directory of Open Access Journals (Sweden)

    E. M. Nurullaev

    2013-04-01

    Full Text Available The computational method of optimum fractional composition of a dispersible filler of polymeric composite on the basis of three-dimensionally linked elastomer is developed according to non-linear programming. The coefficient of dynamic viscosity of polymeric suspension or the initial module of a viscoelasticity of the join solidification low-molecular rubbers with the final functional groups, filled by many fractional dioxide of silicon are considered as criteria of optimization. Influence of the limiting volume filling on energy of mechanical destruction was investigated. The elastomeric material is offered for use as a covering of asphalt highways in the form of a frost-proof waterproofing layer, which allowing multiply to increase operating properties.

  1. Relations between Eastern four pillars theory and Western measures of personality traits.

    Science.gov (United States)

    Jung, Seung Ah; Yang, Chang Soon

    2015-05-01

    The present study investigated the validity of personality classification using four pillars theory, a tradition in China and northeastern Asia. Four pillars analyses were performed for 148 adults on the basis of their birth year, month, day, and hour. Participants completed two personality tests, the Korean version of Temperament and Character Inventory-Revised-Short Version (TCI) and the Korean Inventory of Interpersonal Problems; scores were correlated with four pillars classification elements. Mean difference tests (e.g., t-test, ANOVA) were compared with groups classified by four pillars index. There were no significant correlations between personality scale scores and total yin/yang number (i.e., the 8 heavenly or earthly stems), and no significant between-groups results for classifications by yin/yang day stem and the five elements. There were significant but weak (r=0.18-0.29) correlations between the five elements and personality scale scores. For the six gods and personality scales, there were significant but weak (r=0.18-0.25) correlations. Features predicted by four pillars theory were most consistent when participants were grouped according to the yin/yang of the day stem and dominance of yin/yang numbers in the eight heavenly or earthly stems. Although the major criteria of four pillars theory were not independently correlated with personality scale scores, correlations emerged when participants were grouped according to the composite yin/yang variable. Our results suggest the utility of four pillars theory (beyond fortune telling or astrology) for classifying personality traits and making behavioral predictions.

  2. Relations between Eastern Four Pillars Theory and Western Measures of Personality Traits

    Science.gov (United States)

    Jung, Seung Ah

    2015-01-01

    Purpose The present study investigated the validity of personality classification using four pillars theory, a tradition in China and northeastern Asia. Materials and Methods Four pillars analyses were performed for 148 adults on the basis of their birth year, month, day, and hour. Participants completed two personality tests, the Korean version of Temperament and Character Inventory-Revised-Short Version (TCI) and the Korean Inventory of Interpersonal Problems; scores were correlated with four pillars classification elements. Mean difference tests (e.g., t-test, ANOVA) were compared with groups classified by four pillars index. Results There were no significant correlations between personality scale scores and total yin/yang number (i.e., the 8 heavenly or earthly stems), and no significant between-groups results for classifications by yin/yang day stem and the five elements. There were significant but weak (r=0.18-0.29) correlations between the five elements and personality scale scores. For the six gods and personality scales, there were significant but weak (r=0.18-0.25) correlations. Features predicted by four pillars theory were most consistent when participants were grouped according to the yin/yang of the day stem and dominance of yin/yang numbers in the eight heavenly or earthly stems. Conclusion Although the major criteria of four pillars theory were not independently correlated with personality scale scores, correlations emerged when participants were grouped according to the composite yin/yang variable. Our results suggest the utility of four pillars theory (beyond fortune telling or astrology) for classifying personality traits and making behavioral predictions. PMID:25837175

  3. Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

    Energy Technology Data Exchange (ETDEWEB)

    Ebraert, Evert, E-mail: eebraert@b-phot.org; Rwamucyo, Ben; Thienpont, Hugo; Van Erps, Jürgen

    2016-12-15

    Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 μm-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 × 10{sup 4} μm{sup −2}, with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 ± 1 μm and a bottom-diameter of 151 ± 3 μm. The smallest fabricated pillars have a top-diameter of 57 ± 5 μm. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 × 63.7 μm. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using ∼100 μm-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air–gap is present between the fibers at the telecom wavelength of 1550 nm. The ∼140 μm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications.

  4. Utilizing stretch-tunable thermochromic elastomeric opal films as novel reversible switchable photonic materials.

    Science.gov (United States)

    Schäfer, Christian G; Lederle, Christina; Zentel, Kristina; Stühn, Bernd; Gallei, Markus

    2014-11-01

    In this work, the preparation of highly thermoresponsive and fully reversible stretch-tunable elastomeric opal films featuring switchable structural colors is reported. Novel particle architectures based on poly(diethylene glycol methylether methacrylate-co-ethyl acrylate) (PDEGMEMA-co-PEA) as shell polymer are synthesized via seeded and stepwise emulsion polymerization protocols. The use of DEGMEMA as comonomer and herein established synthetic strategies leads to monodisperse soft shell particles, which can be directly processed to opal films by using the feasible melt-shear organization technique. Subsequent UV crosslinking strategies open access to mechanically stable and homogeneous elastomeric opal films. The structural colors of the opal films feature mechano- and thermoresponsiveness, which is found to be fully reversible. Optical characterization shows that the combination of both stimuli provokes a photonic bandgap shift of more than 50 nm from 560 nm in the stretched state to 611 nm in the fully swollen state. In addition, versatile colorful patterns onto the colloidal crystal structure are produced by spatial UV-induced crosslinking by using a photomask. This facile approach enables the generation of spatially cross-linked switchable opal films with fascinating optical properties. Herein described strategies for the preparation of PDEGMEMA-containing colloidal architectures, application of the melt-shear ordering technique, and patterned crosslinking of the final opal films open access to novel stimuli-responsive colloidal crystal films, which are expected to be promising materials in the field of security and sensing applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Three-Dimensional Elastomeric Scaffolds Designed with Cardiac-Mimetic Structural and Mechanical Features

    Science.gov (United States)

    Neal, Rebekah A.; Jean, Aurélie; Park, Hyoungshin; Wu, Patrick B.; Hsiao, James; Engelmayr, George C.; Langer, Robert

    2013-01-01

    Tissue-engineered constructs, at the interface of material science, biology, engineering, and medicine, have the capacity to improve outcomes for cardiac patients by providing living cells and degradable biomaterials that can regenerate the native myocardium. With an ultimate goal of both delivering cells and providing mechanical support to the healing heart, we designed three-dimensional (3D) elastomeric scaffolds with (1) stiffnesses and anisotropy mimicking explanted myocardial specimens as predicted by finite-element (FE) modeling, (2) systematically varied combinations of rectangular pore pattern, pore aspect ratio, and strut width, and (3) structural features approaching tissue scale. Based on predicted mechanical properties, three scaffold designs were selected from eight candidates for fabrication from poly(glycerol sebacate) by micromolding from silicon wafers. Large 20×20 mm scaffolds with high aspect ratio features (5:1 strut height:strut width) were reproducibly cast, cured, and demolded at a relatively high throughput. Empirically measured mechanical properties demonstrated that scaffolds were cardiac mimetic and validated FE model predictions. Two-layered scaffolds providing fully interconnected pore networks were fabricated by layer-by-layer assembly. C2C12 myoblasts cultured on one-layered scaffolds exhibited specific patterns of cell elongation and interconnectivity that appeared to be guided by the scaffold pore pattern. Neonatal rat heart cells cultured on two-layered scaffolds for 1 week were contractile, both spontaneously and in response to electrical stimulation, and expressed sarcomeric α-actinin, a cardiac biomarker. This work not only demonstrated several scaffold designs that promoted functional assembly of rat heart cells, but also provided the foundation for further computational and empirical investigations of 3D elastomeric scaffolds for cardiac tissue engineering. PMID:23190320

  6. Flexible Pillared Graphene-Paper Electrodes for High-Performance Electrochemical Supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gongkai; Sun, Xiang; Lu, Fengyuan; Sun, Hongtao; Yu, Mingpeng; Jiang, Weilin; Liu, Changsheng; Lian, Jie

    2011-12-08

    Flexible graphene paper (GP) pillared by carbon black (CB) nanoparticles using a simple vacuum filtration method is developed as a high-performance electrode material for supercapacitors. Through the introduction of CB nanoparticles as spacers, the self-restacking of graphene sheets during the filtration process is mitigated to a great extent. The pillared GP-based supercapacitors exhibit excellent electrochemical performances and cyclic stabilities compared with GP without the addition of CB nanoparticles. At a scan rate of 10 mV s-1, the specific capacitance of the pillared GP is 138 F g-1 and 83.2 F g-1 with negligible 3.85% and 4.35% capacitance degradation after 2000 cycles in aqueous and organic electrolytes, respectively. At an extremely fast scan rate of 500 mV s-1, the specific capacitance can reach 80 F g-1 in aqueous electrolyte. No binder is needed for assembling the supercapacitor cells and the pillared GP itself may serve as a current collector due to its intrinsic high electrical conductivity. Finally, the pillared GP has great potential in the development of promising flexible and ultralight-weight supercapacitors for electrochemical energy storage.

  7. Flexible pillared graphene-paper electrodes for high-performance electrochemical supercapacitors.

    Science.gov (United States)

    Wang, Gongkai; Sun, Xiang; Lu, Fengyuan; Sun, Hongtao; Yu, Mingpeng; Jiang, Weilin; Liu, Changsheng; Lian, Jie

    2012-02-06

    Flexible graphene paper (GP) pillared by carbon black (CB) nanoparticles using a simple vacuum filtration method is developed as a high-performance electrode material for supercapacitors. Through the introduction of CB nanoparticles as spacers, the self-restacking of graphene sheets during the filtration process is mitigated to a great extent. The pillared GP-based supercapacitors exhibit excellent electrochemical performances and cyclic stabilities compared with GP without the addition of CB nanoparticles. At a scan rate of 10 mV s(-1) , the specific capacitance of the pillared GP is 138 F g(-1) and 83.2 F g(-1) with negligible 3.85% and 4.35% capacitance degradation after 2000 cycles in aqueous and organic electrolytes, respectively. At an extremely fast scan rate of 500 mV s (-1) , the specific capacitance can reach 80 F g(-1) in aqueous electrolyte. No binder is needed for assembling the supercapacitor cells and the pillared GP itself may serve as a current collector due to its intrinsic high electrical conductivity. The pillared GP has great potential in the development of promising flexible and ultralight-weight supercapacitors for electrochemical energy storage. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Strain relief InGaN/GaN MQW micro-pillars for high brightness LEDs

    KAUST Repository

    Shen, Chao

    2013-01-01

    Micro-structured group-III-nitrides are considered as promising strain relief structures for high efficiency solid state lighting. In this work, the strain field in InGaN/GaN multi-quantum wells (MQWs) micro-pillars is investigated using micro-Raman spectroscopy and the design of micro-pillars were studied experimentally. We distinguished the strained and strain-relieved signatures of the GaN layer from the E2 phonon peak split from the Raman scattering signatures at 572 cm-1 and 568 cm-1, respectively. The extent of strain relief is examined considering the height and size of micro-pillars fabricated using focused ion beam (FIB) micro-machining technique. A significant strain relief can be achieved when one micro-machined through the entire epi-layers, 3 μm in our study. The dependence of strain relief on micro-pillar diameter (D) suggested that micro-pillar with D < 3 μm showed high degree of strain relief. Our results shed new insights into designing strain-relieved InGaN/GaN microstructures for high brightness light emitting diode arrays. © 2013 IEEE.

  9. Estimating the coordinates of pillars and posts in the parking lots for intelligent parking assist system

    Science.gov (United States)

    Choi, Jae Hyung; Kuk, Jung Gap; Kim, Young Il; Cho, Nam Ik

    2012-01-01

    This paper proposes an algorithm for the detection of pillars or posts in the video captured by a single camera implemented on the fore side of a room mirror in a car. The main purpose of this algorithm is to complement the weakness of current ultrasonic parking assist system, which does not well find the exact position of pillars or does not recognize narrow posts. The proposed algorithm is consisted of three steps: straight line detection, line tracking, and the estimation of 3D position of pillars. In the first step, the strong lines are found by the Hough transform. Second step is the combination of detection and tracking, and the third is the calculation of 3D position of the line by the analysis of trajectory of relative positions and the parameters of camera. Experiments on synthetic and real images show that the proposed method successfully locates and tracks the position of pillars, which helps the ultrasonic system to correctly locate the edges of pillars. It is believed that the proposed algorithm can also be employed as a basic element for vision based autonomous driving system.

  10. Reverse engineering of B-pillar with 3D optical scanning for manufacturing of non-uniform thickness part

    OpenAIRE

    Islam Md. Tasbirul; Abdullah A.B.; Mahmud Mohamad Zihad

    2017-01-01

    This paper presents reverse engineering (RE) of a complex automobile structural part, B-pillar. As a major part of the automobile body-in white (BiW), B-pillar has substantial opportunity for weight reduction by introducing variable thickness across its sections. To leverage such potential, an existing B-pillar was reverse engineered with a 3D optical scanner and computer aided design (CAD) application. First, digital data (i.e. in meshes) of exiting B-pillar was obtained by the scanner, and ...

  11. Evolution and Engineering of Precisely Controlled Ge Nanostructures on Scalable Array of Ordered Si Nano-pillars

    Science.gov (United States)

    Wang, Shuguang; Zhou, Tong; Li, Dehui; Zhong, Zhenyang

    2016-06-01

    The scalable array of ordered nano-pillars with precisely controllable quantum nanostructures (QNs) are ideal candidates for the exploration of the fundamental features of cavity quantum electrodynamics. It also has a great potential in the applications of innovative nano-optoelectronic devices for the future quantum communication and integrated photon circuits. Here, we present a synthesis of such hybrid system in combination of the nanosphere lithography and the self-assembly during heteroepitaxy. The precise positioning and controllable evolution of self-assembled Ge QNs, including quantum dot necklace(QDN), QD molecule(QDM) and quantum ring(QR), on Si nano-pillars are readily achieved. Considering the strain relaxation and the non-uniform Ge growth due to the thickness-dependent and anisotropic surface diffusion of adatoms on the pillars, the comprehensive scenario of the Ge growth on Si pillars is discovered. It clarifies the inherent mechanism underlying the controllable growth of the QNs on the pillar. Moreover, it inspires a deliberate two-step growth procedure to engineer the controllable QNs on the pillar. Our results pave a promising avenue to the achievement of desired nano-pillar-QNs system that facilitates the strong light-matter interaction due to both spectra and spatial coupling between the QNs and the cavity modes of a single pillar and the periodic pillars.

  12. The possibility of increasing the efficiency of accessible coal deposits by optimizing dimensions of protective pillars or the scope of exploitation

    Science.gov (United States)

    Bańka, Piotr; Badura, Henryk; Wesołowski, Marek

    2017-11-01

    One of the ways to protect objects exposed to the influences of mining exploitation is establishing protective pillars for them. Properly determined pillar provides effective protection of the object for which it was established. Determining correct dimensions of a pillar requires taking into account contradictory requirements. Protection measures against the excessive influences of mining exploitation require designing the largest possible pillars, whereas economic requirements suggest a maximum reduction of the size of resources left in the pillar. This paper presents algorithms and programs developed for determining optimal dimensions of protective pillars for surface objects and shafts. The issue of designing a protective pillar was treated as a nonlinear programming task. The objective function are the resources left in a pillar while nonlinear limitations are the deformation values evoked by the mining exploitation. Resources in the pillar may be weighted e.g. by calorific value or by the inverse of output costs. The possibility of designing pillars of any polygon shape was taken into account. Because of the applied exploitation technologies the rectangular pillar shape should be considered more advantageous than the oval one, though it does not ensure the minimization of resources left in a pillar. In this article there is also presented a different approach to the design of protective pillars, which instead of fixing the pillar boundaries in subsequent seams, the length of longwall panels of the designed mining exploitation is limited in a way that ensures the effective protection of an object while maximizing the extraction ratio of the deposit.

  13. Catalysis as a foundational pillar of green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Anastas, Paul T. [White House Office of Science and Technology Policy, Department of Chemistry, University of Nottingham Nottingham, (United Kingdom); Kirchhoff, Mary M. [U.S. Environmental Protection Agency and Trinity College, Washington, DC (United States); Williamson, Tracy C. [U.S. Environmental Protection Agency, Washington, DC (United States)

    2001-11-30

    Catalysis is one of the fundamental pillars of green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. The design and application of new catalysts and catalytic systems are simultaneously achieving the dual goals of environmental protection and economic benefit. Green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is an overarching approach that is applicable to all aspects of chemistry. From feedstocks to solvents, to synthesis and processing, green chemistry actively seeks ways to produce materials in a way that is more benign to human health and the environment. The current emphasis on green chemistry reflects a shift away from the historic 'command-and-control' approach to environmental problems that mandated waste treatment and control and clean up through regulation, and toward preventing pollution at its source. Rather than accepting waste generation and disposal as unavoidable, green chemistry seeks new technologies that are cleaner and economically competitive. Utilizing green chemistry for pollution prevention demonstrates the power and beauty of chemistry: through careful design, society can enjoy the products on which we depend while benefiting the environment. The economic benefits of green chemistry are central drivers in its advancement. Industry is adopting green chemistry methodologies because they improve the corporate bottom line. A wide array of operating costs are decreased through the use of green chemistry. When less waste is generated, environmental compliance costs go down. Treatment and disposal become unnecessary when waste is eliminated. Decreased solvent usage and fewer processing steps lessen the material and energy costs of manufacturing and increase material efficiency. The environmental, human health, and the economic advantages realized through green chemistry

  14. Utilization of the UV laser with picosecond pulses for the formation of surface microstructures on elastomeric plastics

    Science.gov (United States)

    Antoszewski, B.; Tofil, S.; Scendo, M.; Tarelnik, W.

    2017-08-01

    Elastomeric plastics belong to a wide range of polymeric materials with special properties. They are used as construction material for seals and other components in many branches of industry and, in particular, in the biomedical industry, mechatronics, electronics and chemical equipment. The micromachining of surfaces of these materials can be used to build micro-flow, insulating, dispensing systems and chemical and biological reactors. The paper presents results of research on the effects of micro-machining of selected elastomeric plastics using a UV laser emitting picosecond pulses. The authors see the prospective application of the developed technology in the sealing technique in particular to shaping the sealing pieces co-operating with the surface of the element. The result of the study is meant to show parameters of the UV laser’s performance when producing typical components such as grooves, recesses for optimum ablation in terms of quality and productivity.

  15. Microscopic Pillars and Tubes Fabricated by Using Fish Dentine as a Molding Template

    Directory of Open Access Journals (Sweden)

    Weiqun Li

    2014-08-01

    Full Text Available Biomaterials in nature exhibit delicate structures that are greatly beyond the capability of the current manufacturing techniques. Duplicating these structures and applying them in engineering may help enhance the performance of traditional functional materials and structures. Inspired by gecko’s hierarchical micro- and nano-fibrillar structures for adhesion, in this work we fabricated micro-pillars and tubes by adopting the tubular dentine of black carp fish teeth as molding template. The adhesion performances of the fabricated micro-pillars and tubes were characterized and compared. It was found that the pull-off force of a single pillar was about twice of that of the tube with comparable size. Such unexpected discrepancy in adhesion was analyzed based on the contact mechanics theories.

  16. Numerical Simulations of Pillar Structured Solid State Thermal Neutron Detector Efficiency and Gamma Discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Conway, A; Wang, T; Deo, N; Cheung, C; Nikolic, R

    2008-06-24

    This work reports numerical simulations of a novel three-dimensionally integrated, {sup 10}boron ({sup 10}B) and silicon p+, intrinsic, n+ (PIN) diode micropillar array for thermal neutron detection. The inter-digitated device structure has a high probability of interaction between the Si PIN pillars and the charged particles (alpha and {sup 7}Li) created from the neutron - {sup 10}B reaction. In this work, the effect of both the 3-D geometry (including pillar diameter, separation and height) and energy loss mechanisms are investigated via simulations to predict the neutron detection efficiency and gamma discrimination of this structure. The simulation results are demonstrated to compare well with the measurement results. This indicates that upon scaling the pillar height, a high efficiency thermal neutron detector is possible.

  17. Unusual mechanism of capillary condensation in pores modified with chains forming pillars.

    Science.gov (United States)

    Borówko, M; Patrykiejew, A; Sokołowski, S

    2011-08-07

    Density functional approach is applied to study the phase behavior of Lennard-Jones(12,6) fluid in pillared slit-like pores. Our focus is in the evaluation of phase transitions in fluid adsorbed in the pore of a fixed width. If the length of pillars is sufficiently large, we observe additional phase transitions of the first and second order due to the symmetry breaking of the distribution of chain segments and fluid species with respect to the slit-like pore center. Re-entrant symmetry changes and additional critical, critical end points and tricritical points then are observed. The scenario of phase changes is sensitive to the energy of fluid-solid interaction, the amount, and the length of the pillars. Quantitative trends and qualitative changes of the phase diagrams topology are examined depending on the values of these parameters.

  18. Reactive bonding mediated high mass loading of individualized single-walled carbon nanotubes in an elastomeric polymer

    Science.gov (United States)

    Zhao, Liping; Li, Yongjin; Qiu, Jishan; You, Jichun; Dong, Wenyong; Cao, Xiaojun

    2012-09-01

    A reactive chemical bonding strategy was developed for the incorporation of a high mass loading of individual single-wall carbon nanotubes (SWCNTs) into an elastomeric matrix using a reactive ionic liquid as a linker. This method simultaneously prevented the agglomeration of SWCNTs and caused strong interfacial bonding, while the electronic properties of the SWCNTs remained intact. As a result, the high conductivity of the carbon nanotubes (CNTs) and the flexibility of the elastomeric matrix were retained, producing optimum electrical and mechanical properties. A composite material with a loading of 20 wt% SWCNTs was fabricated with excellent mechanical properties and a high conductivity (9500 S m-1). The method could be used to form transparent thin conductive films that could tolerate over 800 bend cycles at a bending angle of 180° while maintaining a constant sheet resistance.A reactive chemical bonding strategy was developed for the incorporation of a high mass loading of individual single-wall carbon nanotubes (SWCNTs) into an elastomeric matrix using a reactive ionic liquid as a linker. This method simultaneously prevented the agglomeration of SWCNTs and caused strong interfacial bonding, while the electronic properties of the SWCNTs remained intact. As a result, the high conductivity of the carbon nanotubes (CNTs) and the flexibility of the elastomeric matrix were retained, producing optimum electrical and mechanical properties. A composite material with a loading of 20 wt% SWCNTs was fabricated with excellent mechanical properties and a high conductivity (9500 S m-1). The method could be used to form transparent thin conductive films that could tolerate over 800 bend cycles at a bending angle of 180° while maintaining a constant sheet resistance. Electronic supplementary information (ESI) available: Conductivity test of the SEBS-SWCNTs film, transmission spectra and sheet resistance for the spin-coated SEBS-SWCNTs thin films on PET slides. See DOI: 10

  19. The effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with orthodontic elastomeric separator placement

    Directory of Open Access Journals (Sweden)

    M. Abu Al-Melh

    2017-01-01

    Full Text Available Abstract Background The initial placement of orthodontic elastomeric separators can be uncomfortable and painful. Therefore, it is important to relieve this disturbing sensation to create a discomfort or pain-free orthodontic visit. The purpose of this study was to investigate the effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with the placement of orthodontic elastomeric separators. Methods Fifty subjects aging between 20–35 years were included in this study. In the maxillary arch, a lidocaine/prilocaine topical anesthetic was placed around the ginigval margins of the premolar and molar on side. On the other side, a placebo agent was placed around the ginigval margins of the premolar and molar. After two minutes, an elastomeric separator was placed between the premolar and molar on both sides. The subjects were then asked to report their findings on a Verbal Scale and a Visual Analogue Scale every second minute for a period of 10 min. The subjects were also given a questionnaire to evaluate the overall impression on the topical anesthetic use. Results The overall mean discomfort/pain score was found to be significantly lower (p < 0.001 with the topical anesthetic than with the placebo. Repeated measures ANOVA with a Greenhouse-Geisser correction determined that mean pain scores were statistically significantly low with the 10-min time duration (F (1.54,42.2 = 40.7, p = 0.001, with an estimated grand mean (8.37, 95% CI 6.75–9.98. The questionnaire responses revealed that 87% of the subjects reported an overall satisfaction and agreement with the topical anesthetic than with the placebo or no difference (13% after the initial separator placement. Conclusions The discomfort and pain resulting from the initial placement of orthodontic elastomeric separators can be significantly reduced with the lidocaine/prilocaine topical anesthetic.

  20. Cell motility regulation on a stepped micro pillar array device (SMPAD) with a discrete stiffness gradient.

    Science.gov (United States)

    Lee, Sujin; Hong, Juhee; Lee, Junghoon

    2016-02-28

    Our tissues consist of individual cells that respond to the elasticity of their environment, which varies between and within tissues. To better understand mechanically driven cell migration, it is necessary to manipulate the stiffness gradient across a substrate. Here, we have demonstrated a new variant of the microfabricated polymeric pillar array platform that can decouple the stiffness gradient from the ECM protein area. This goal is achieved via a "stepped" micro pillar array device (SMPAD) in which the contact area with the cell was kept constant while the diameter of the pillar bodies was altered to attain the proper mechanical stiffness. Using double-step SU-8 mold fabrication, the diameter of the top of every pillar was kept uniform, whereas that of the bottom was changed, to achieve the desired substrate rigidity. Fibronectin was immobilized on the pillar tops, providing a focal adhesion site for cells. C2C12, HeLa and NIH3T3 cells were cultured on the SMPAD, and the motion of the cells was observed by time-lapse microscopy. Using this simple platform, which produces a purely physical stimulus, we observed that various types of cell behavior are affected by the mechanical stimulus of the environment. We also demonstrated directed cell migration guided by a discrete rigidity gradient by varying stiffness. Interestingly, cell velocity was highest at the highest stiffness. Our approach enables the regulation of the mechanical properties of the polymeric pillar array device and eliminates the effects of the size of the contact area. This technique is a unique tool for studying cellular motion and behavior relative to various stiffness gradients in the environment.

  1. Aespoe Pillar Stability Experiment. Final 2D coupled thermo-mechanical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, Anders; Staub, Isabelle; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

    2004-02-01

    A site scale Pillar Stability Experiment is planned in the Aespoe Hard Rock Laboratory. One of the experiment's aims is to demonstrate the possibilities of predicting spalling in the fractured rock mass. In order to investigate the probability and conditions for spalling in the pillar 'prior to experiment' numerical simulations have been undertaken. This report presents the results obtained from 2D coupled thermo-mechanical numerical simulations that have been done with the Finite Element based programme JobFem. The 2D numerical simulations were conducted at two different depth levels, 0.5 and 1.5 m below tunnel floor. The in situ stresses have been confirmed with convergence measurements during the excavation of the tunnel. After updating the mechanical and thermal properties of the rock mass the final simulations have been undertaken. According to the modelling results the temperature in the pillar will increase from the initial 15.2 deg up to 58 deg after 120 days of heating. Based on these numerical simulations and on the thermal induced stresses the total stresses are expected to exceed 210 MPa at the border of the pillar for the level at 0.5 m below tunnel floor and might reach 180-182 MPa for the level at 1.5 m below tunnel floor. The stresses are slightly higher at the border of the confined hole. Upon these results and according to the rock mechanical properties the Crack Initiation Stress is exceeded at the border of the pillar already after the excavation phase. These results also illustrate that the Crack Damage Stress is exceeded only for the level at 0.5 m below tunnel floor and after at least 80 days of heating. The interpretation of the results shows that the required level of stress for spalling can be reached in the pillar.

  2. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    International Nuclear Information System (INIS)

    Wanne, Toivo; Johansson, Erik; Potyondy, David

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  3. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wanne, Toivo; Johansson, Erik; Potyondy, David [Saanio and Riekkola Oy, Helsinki (Finland)

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  4. Experimental study of the retention properties of a cyclo olefin polymer pillar array column in reversed-phase mode

    NARCIS (Netherlands)

    Illa, Xavi; de Malsche, Wim; Gardeniers, Johannes G.E.; Desmet, Gert; Romano-Rodriguez, Albert

    2010-01-01

    Experimental measurements to study the retention capacity and band broadening under retentive conditions using micromachined non-porous pillar array columns fabricated in cyclo olefin polymer are presented. In particular, three columns with different depths but with the same pillar structure have

  5. Width design for gobs and isolated coal pillars based on overall burst-instability prevention in coal mines

    Directory of Open Access Journals (Sweden)

    Junfei Zhang

    2016-08-01

    Full Text Available An investigation was conducted on the overall burst-instability of isolated coal pillars by means of the possibility index diagnosis method (PIDM. First, the abutment pressure calculation model of the gob in side direction was established to derive the abutment pressure distribution curve of the isolated coal pillar. Second, the overall burst-instability ratio of the isolated coal pillars was defined. Finally, the PIDM was utilized to judge the possibility of overall burst-instability and recoverability of isolated coal pillars. The results show that an overall burst-instability may occur due to a large gob width or a small pillar width. If the width of the isolated coal pillar is not large enough, the shallow coal seam will be damaged at first, and then the high abutment pressure will be transferred to the deep coal seam, which may cause an overall burst-instability accident. This approach can be adopted to design widths of gobs and isolated coal pillars and to evaluate whether an existing isolated coal pillar is recoverable in skip-mining mines.

  6. Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar

    CSIR Research Space (South Africa)

    Watson, BP

    2008-08-01

    Full Text Available of falls of ground in already dangerous areas, and the larger pillars decrease the extraction ratio. This paper describes the evaluation of stress measurements conducted in two boreholes over a crush pillar with dimensions 2.5 m x 4.0 m, and a height of 1...

  7. In-use Stability of Ceftaroline Fosamil in Elastomeric Home Infusion Systems and MINI-BAG Plus Containers.

    Science.gov (United States)

    Bhattacharya, Sisir; Parekh, Satish; Dedhiya, Mahendra

    2015-01-01

    The objective of this study was to determine in-use stability of ceftaroline fosamil infusion solution of concentrations up to 12 mg/mL in elastomeric home infusion system prefilled with 0.9% Sodium Chloride Injection USP or 5% Dextrose Injection USP and MINI-BAG Plus Container delivery devices prefilled with 0.9% sodium chloride injection. In-use ceftaroline fosamil infusion solution (12 mg/mL) was prepared for elastomeric home infusion systems (Homepump Eclipse, Baxter Intermate, and AccuRx Elastomeric Pump) pre-filled with either 0.9% sodium chloride injection or 5% dextrose; or Baxter MINI-BAG Plus Containers pre-filled with 0.9% Sodium Chloride Injection USP (4 mg/mL to 12 mg/mL ceftaroline fosamil in final solution). The systems were stored refrigerated for 24 hours followed by up to 6 hours of storage at room temperature. Samples were analyzed at various time points for assay and degradation product by a validated stability-indicating high-performance liquid chromatography method. In-use ceftaroline fosamil infusion solution, ranging from 4-mg/mL to a maximum of 12-mg/mL concentration, in elastomeric home infusion systems prefilled with 0.9% sodium chloride injection or 5% dextrose, and MINI-BAG Plus Containers prefilled with 0.9% sodium chloride injection were chemically stable for up to 24 hours refrigerated at 2°C to 8°C (36°F to 46°F) and up to 6 hours at room temperature and had acceptable compatibility with material used. Ceftaroline fosamil (4 mg/mL to 12 mg/mL) maintains its potency for up to 24 hours refrigerated at 2°C to 8°C (36°F to 46°F) and up to 6 hours of storage at room temperature upon reconstitution in infusion solution with 0.9% sodium chloride or 5% dextrose when used in elastomeric home infusion system and MINI-BAG Plus Containers delivery devices prefilled with 0.9% sodium chloride injection.

  8. Electrical characterization of Ge–Sb–Te phase change nano-pillars using conductive atomic force microscopy

    International Nuclear Information System (INIS)

    Bae, Byeong-Ju; Hong, Sung-Hoon; Hwang, Seon-Yong; Hwang, Jae-Yeon; Yang, Ki-Yeon; Lee, Heon

    2009-01-01

    The electrical characteristic of phase change material was studied in nano-scale using nanoimprint lithography and a conducting atomic force microscopy measurement system. Nanoimprint lithography was used to fabricate the nano-scale phase change material pattern. A Pt-coated AFM tip was used as a top electrode to measure the electrical characteristics of the GST nano-pillar. The GST nano-pillar, which is 200 nm in diameter, was amorphized by 2 V and 5 ns reset pulse and was then brought back to the crystalline phase by applying 1.3 V and 150 ns set pulse. Using this measurement system, the GST nano-pillar was switched between the amorphous and crystalline phases more than five times. The results of the reset and the set current measurement with the GST nano-pillar sizes show that the reset and the set currents also decreased with the decrease of the GST pillar size

  9. USHPRR FUEL FABRICATION PILLAR: FABRICATION STATUS, PROCESS OPTIMIZATIONS, AND FUTURE PLANS

    Energy Technology Data Exchange (ETDEWEB)

    Wight, Jared M.; Joshi, Vineet V.; Lavender, Curt A.

    2018-03-12

    The Fuel Fabrication (FF) Pillar, a project within the U.S. High Performance Research Reactor Conversion program of the National Nuclear Security Administration’s Office of Material Management and Minimization, is tasked with the scale-up and commercialization of high-density monolithic U-Mo fuel for the conversion of appropriate research reactors to use of low-enriched fuel. The FF Pillar has made significant steps to demonstrate and optimize the baseline co-rolling process using commercial-scale equipment at both the Y-12 National Security Complex (Y-12) and BWX Technologies (BWXT). These demonstrations include the fabrication of the next irradiation experiment, Mini-Plate 1 (MP-1), and casting optimizations at Y-12. The FF Pillar uses a detailed process flow diagram to identify potential gaps in processing knowledge or demonstration, which helps direct the strategic research agenda of the FF Pillar. This paper describes the significant progress made toward understanding the fuel characteristics, and models developed to make informed decisions, increase process yield, and decrease lifecycle waste and costs.

  10. Straightforward Generation of Pillared, Microporous Graphene Frameworks for Use in Supercapacitors.

    Science.gov (United States)

    Yuan, Kai; Xu, Yazhou; Uihlein, Johannes; Brunklaus, Gunther; Shi, Lei; Heiderhoff, Ralf; Que, Mingming; Forster, Michael; Chassé, Thomas; Pichler, Thomas; Riedl, Thomas; Chen, Yiwang; Scherf, Ullrich

    2015-11-01

    Microporous, pillared graphene-based frameworks are generated in a simple functionalization/coupling procedure starting from reduced graphene oxide. They are used for the fabrication of high-performance supercapacitor devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Pretest parametric calculations for the heated pillar experiment in the WIPP In-Situ Experimental Area

    International Nuclear Information System (INIS)

    Branstetter, L.J.

    1983-03-01

    Results are presented for a pretest parametric study of several configurations and heat loads for the heated pillar experiment (Room H) in the Waste Isolation Pilot Plant (WIPP) In Situ Experimental Area. The purpose of this study is to serve as a basis for selection of a final experiment geometry and heat load. The experiment consists of a pillar of undisturbed rock salt surrounded by an excavated annular room. The pillar surface is covered by a blanket heat source which is externally insulated. A total of five thermal and ten structural calculations are described in a four to five year experimental time frame. Results are presented which include relevant temperature-time histories, deformations, rock salt stress component and effective stress profiles, and maximum stresses in anhydrite layers which are in close proximity to the room. Also included are predicted contours of a conservative post-processed measure of potential salt failure. Observed displacement histories are seen to be highly dependent on pillar and room height, but insensitive to other geometrical variations. The use of a tensile cutoff across slidelines is seen to produce more accurate predictions of anhydrite maximum stress, but to have little effect on rock salt stresses. The potential for salt failure is seen to be small in each case for the time frame of interest, and is only seen at longer times in the center of the room floor

  12. Reproductive natural history and successful juvenile propagation of the threatened Caribbean Pillar Coral Dendrogyra cylindrus

    NARCIS (Netherlands)

    Marhaver, K.L.; Vermeij, M.J.A.; Medina, M.M.

    2015-01-01

    Background: The Caribbean pillar coral Dendrogyra cylindrus was recently listed as a threatened species under the United States Endangered Species Act. One of the major threats to this species is its low, virtually undetectable recruitment rate. To our knowledge, sexually-produced recruits have

  13. The use of virtual reality to simulate room and pillar operations

    Energy Technology Data Exchange (ETDEWEB)

    Crawshaw, S A.M.; Denby, B; McClarnon, D [Long-Airdox International Limited, Ilkeston (United Kingdom)

    1997-01-01

    Virtual Reality systems allow a user to interact with dynamic three-dimensional computer models of real world situations. The authors show how the complexity of room and pillar mining operations may be mirrored in a user-configurable system. Additionally, an understanding is gained of the mining method, and the operation of equipment in the actual working environment. 1 ref., 5 figs.

  14. Aespoe Pillar Stability Experiment. Modelling of fracture development of APSE by FRACOD

    International Nuclear Information System (INIS)

    Rinne, Mikael; Baotang Shen; Lee, Hee-Suk

    2004-03-01

    An in-situ experiment has started at Aespoe HRL to investigate the stability of a pillar between two closely located boreholes of deposition hole scale. This full-scale experiment is named the Aespoe Pillar Stability Experiment (APSE). One of the holes will be pressurized with 0.8 MPa water pressure to simulate confinement by backfill. Thermal stresses will be applied in the pillar by the use of electric heaters to reach the spalling conditions. To quantify the degree of damage during the experiment, an Acoustic Emission (AE) system will be used and strain measurements will be installed. FRACOD is a two dimensional BEM/DDM code for fracturing analysis in rock material. Here it has been used to model the rock mass response during the planned sequences of excavation-confinement-heating. The models predict the stress and displacement fields, fracture initiation and propagation, coalescence and the final failure of the rock mass. The presences of pre-existing fractures, which may have significant influence on the pillar behaviour, have also been considered in the modelling. This report summarises the modelling work using FRACOD to simulate the various experimental stages

  15. Mechanical properties of nano and bulk Fe pillars using molecular dynamics and dislocation dynamics simulation

    Directory of Open Access Journals (Sweden)

    S. K. Deb Nath

    2017-10-01

    Full Text Available Using molecular dynamics simulation, tension and bending tests of a Fe nanopillar are carried out to obtain its Young’s modulus and yield strength. Then the comparative study of Young’s modulus and yield strength of a Fe nanopillar under bending and tension are carried out varying its diameter in the range of diameter 1-15nm. We find out the reasons why bending Young’s modulus and yield strength of a Fe nanopillar are higher than those of tension Young’s modulus and yield strength of a Fe nanopillar. Using the mobility parameters of bulk Fe from the experimental study [N. Urabe and J. Weertman, Materials Science and Engineering 18, 41 (1975], its temperature dependent stress-strain relationship, yield strength and strain hardening modulus are obtained from the dislocation dynamics simulations. Strain rate dependent yield strength and strain hardening modulus of bulk Fe pillars under tension are studied. Temperature dependent creep behaviors of bulk Fe pillars under tension are also studied. To verify the soundness of the present dislocation dynamics studies of the mechanical properties of bulk Fe pillars under tension, the stress vs. strain relationship and dislocation density vs. strain of bulk Fe pillars obtained by us are compared with the published results obtained by S. Queyreau, G. Monnet, and B. Devincre, International Journal of Plasticity 25, 361 (2009.

  16. Strength Reduction of Coal Pillar after CO2 Sequestration in Abandoned Coal Mines

    Directory of Open Access Journals (Sweden)

    Qiuhao Du

    2017-02-01

    Full Text Available CO2 geosequestration is currently considered to be the most effective and economical method to dispose of artificial greenhouse gases. There are a large number of coal mines that will be scrapped, and some of them are located in deep formations in China. CO2 storage in abandoned coal mines will be a potential option for greenhouse gas disposal. However, CO2 trapping in deep coal pillars would induce swelling effects of coal matrix. Adsorption-induced swelling not only modifies the volume and permeability of coal mass, but also causes the basic physical and mechanical properties changing, such as elastic modulus and Poisson ratio. It eventually results in some reduction in pillar strength. Based on the fractional swelling as a function of time and different loading pressure steps, the relationship between volumetric stress and adsorption pressure increment is acquired. Eventually, this paper presents a theory model to analyze the pillar strength reduction after CO2 adsorption. The model provides a method to quantitatively describe the interrelation of volumetric strain, swelling stress, and mechanical strength reduction after gas adsorption under the condition of step-by-step pressure loading and the non-Langmuir isothermal model. The model might have a significantly important implication for predicting the swelling stress and mechanical behaviors of coal pillars during CO2 sequestration in abandoned coal mines.

  17. The Decade of Education for Sustainable Development: Towards four pillars of learning

    OpenAIRE

    Shivali Lawale; Aline Bory-Adams

    2010-01-01

    Education for sustainable development is a paradigm shift in education which goes beyond the traditional realms of education. Shivali Lawale and Aline Bory-Adams assess how education for sustainable development could build sustainable societies through the Decade of Education for sustainable development. They explore how to build a conceptual framework based on the four pillars of learning proposed by the Delors Report.

  18. Promoting Family Literacy through the Five Pillars of Family and Community Engagement (FACE)

    Science.gov (United States)

    Kuo, Nai-Cheng

    2016-01-01

    Family literacy involves factors beyond what is done at home between parents and children. To help preservice teachers develop their understanding of the multiple dimensions of family literacy, this study uses the five pillars of family and community engagement (FACE)--early literacy, family involvement, access to books, expanded learning, and…

  19. The Sloan-C Pillars and Boundary Objects As a Framework for Evaluating Blended Learning

    Science.gov (United States)

    Laumakis, Mark; Graham, Charles; Dziuban, Chuck

    2009-01-01

    The authors contend that blended learning represents a boundary object; a construct that brings together constituencies from a variety of backgrounds with each of these cohorts defining the object somewhat differently. The Sloan-C Pillars (learning effectiveness, access, cost effectiveness, student satisfaction, and faculty satisfaction) provide…

  20. Causes of falls of hangingwall over gullies adjacent to stabilizing strike pillars

    CSIR Research Space (South Africa)

    Turner, PA

    1987-08-01

    Full Text Available This report discusses the occurrence of falls of ground in strike gullies. Falls of hangingwall over strike gullies on the up-dip side of strike stabilizing pillars in longwall mining systems were investigated. Gullies were examined in both...

  1. Fabrication and characterization of Au dimer antennas on glass pillars with enhanced plasmonic response

    Directory of Open Access Journals (Sweden)

    Sadeghi Pedram

    2017-06-01

    Full Text Available We report on the fabrication and dark-field spectroscopy characterization of Au dimer nanoantennas placed on top of SiO2 nanopillars. The reported process enables the fabrication of nanopillar dimers with gaps down to 15 nm and heights up to 1 μm. A clear dependence of the plasmonic resonance position on the dimer gap is observed for smaller pillar heights, showing the high uniformity and reproducibility of the process. It is shown how increasing the height of nanopillars significantly affects the recorded elastic scattering spectra from Au nanoantennas. The results are compared to finite-difference time-domain (FDTD and finite-element method (FEM simulations. Additionally, measured spectra are accompanied by dark-field microscopy images of the dimers, showing the pronounced change in color. Placing nanoantennas on nanopillars with a height comparable to the in-plane dimer dimensions results in an enhancement of the scattering response, which can be understood through reduced interaction of the near-fields with the substrate. When increasing the pillar height further, scattering by the pillars themselves manifests itself as a strong tail at lower wavelengths. Additionally, strong directional scattering is expected as a result of the interface between the nanoantennas and nanopillars, which is taken into account in simulations. For pillars of height close to the plasmonic resonance wavelength, the scattering spectra become more complex due to additional scattering peaks as a result of larger geometrical nonuniformities.

  2. A diabetic retinopathy detection method using an improved pillar K-means algorithm.

    Science.gov (United States)

    Gogula, Susmitha Valli; Divakar, Ch; Satyanarayana, Ch; Rao, Allam Appa

    2014-01-01

    The paper presents a new approach for medical image segmentation. Exudates are a visible sign of diabetic retinopathy that is the major reason of vision loss in patients with diabetes. If the exudates extend into the macular area, blindness may occur. Automated detection of exudates will assist ophthalmologists in early diagnosis. This segmentation process includes a new mechanism for clustering the elements of high-resolution images in order to improve precision and reduce computation time. The system applies K-means clustering to the image segmentation after getting optimized by Pillar algorithm; pillars are constructed in such a way that they can withstand the pressure. Improved pillar algorithm can optimize the K-means clustering for image segmentation in aspects of precision and computation time. This evaluates the proposed approach for image segmentation by comparing with Kmeans and Fuzzy C-means in a medical image. Using this method, identification of dark spot in the retina becomes easier and the proposed algorithm is applied on diabetic retinal images of all stages to identify hard and soft exudates, where the existing pillar K-means is more appropriate for brain MRI images. This proposed system help the doctors to identify the problem in the early stage and can suggest a better drug for preventing further retinal damage.

  3. Pillarization and Islam: Church-state traditions and Muslim claims for recognition in the Netherlands

    NARCIS (Netherlands)

    Maussen, M.

    2012-01-01

    Public policy responses to Muslim immigration in the Netherlands are often presented as crucially shaped by ‘pillarization’. This article takes issue with this perception by challenging two related assumptions. On the one hand, that the Dutch church-state model is essentially about pillarization

  4. synthesis, characterization and catalytic activity of the pillared molecular sieve MCM-36

    NARCIS (Netherlands)

    He, Y.; Nivarthy, G.S.; Eder, F.; Eder, F.; Seshan, Kulathuiyer; Lercher, J.A.

    1998-01-01

    MCM-36 materials were prepared by swelling the layered MCM-22 precursors with large organic molecules and then pillaring the resulting material with polymeric silica. A mesopore region with 0.25–0.3 nm thickness between the microporous layers was identified. The BET surface area obtained for MCM-36

  5. Silicon based near infrared photodetector using self-assembled organic crystalline nano-pillars

    Energy Technology Data Exchange (ETDEWEB)

    Ajiki, Yoshiharu, E-mail: yoshiharu-ajiki@ot.olympus.co.jp, E-mail: isao@i.u-tokyo.ac.jp [Micromachine Center, 67 Kanda Sakumagashi, Chiyoda-ku, Tokyo 100-0026 (Japan); Kan, Tetsuo [Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yahiro, Masayuki; Hamada, Akiko; Adachi, Chihaya [Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Adachi, Junji [Office for Strategic Research Planning, Kyushu University, 6-10-1 Hakozaki, Higashi, Fukuoka 812-8581 (Japan); Matsumoto, Kiyoshi [IRT Research Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Shimoyama, Isao, E-mail: yoshiharu-ajiki@ot.olympus.co.jp, E-mail: isao@i.u-tokyo.ac.jp [Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); IRT Research Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    2016-04-11

    We propose a silicon (Si) based near-infrared photodetector using self-assembled organic crystalline nano-pillars, which were formed on an n-type Si substrate and were covered with an Au thin-film. These structures act as antennas for near-infrared light, resulting in an enhancement of the light absorption on the Au film. Because the Schottky junction is formed between the Au/n-type Si, the electron excited by the absorbed light can be detected as photocurrent. The optical measurement revealed that the nano-pillar structures enhanced the responsivity for the near-infrared light by 89 (14.5 mA/W) and 16 (0.433 mA/W) times compared with those of the photodetector without nano-pillars at the wavelengths of 1.2 and 1.3 μm, respectively. Moreover, no polarization dependency of the responsivity was observed, and the acceptable incident angle ranged from 0° to 30°. These broad responses were likely to be due to the organic nano-pillar structures' having variation in their orientation, which is advantageous for near-infrared detector uses.

  6. Effect of ultrasound on the structural and textural properties of copper-impregnated cerium-modified zirconium-pillared bentonite

    International Nuclear Information System (INIS)

    Tomul, Fatma

    2011-01-01

    In this study, the synthesis of zirconium-pillared bentonite modified with cerium was performed via two different methods by the application of conventional and ultrasonic treatments during the intercalation stage. To synthesise copper-impregnated pillared clays by wet impregnation, cerium-modified zirconium-pillared clays were used as supportive materials after being calcined at 300 °C. Ultrasonic treatment significantly decreased the required processing time compared with the conventional treatment of the synthesised pillared bentonites. Chemical analysis confirmed the incorporation of Zr 4+ , Ce 4+ and Cu 2+ species into the pillared bentonites. X-ray diffraction (XRD) patterns of zirconium- and cerium/zirconium-pillared bentonites prepared by conventional treatment show that one large d-spacing above 3.5 nm corresponds to the mesoporous delaminated part, and another small d-spacing above 1.7 nm is indicative of the microporous pillared part. Zirconium- and cerium/zirconium-pillared bentonites prepared via ultrasonic treatment exhibited similar results, with the same high d-spacing but with a second low-intensity d-spacing above 1.9 nm. The delaminated structures of the pillared bentonites synthesised by both methods were conserved after copper impregnation. Nitrogen-adsorption isotherm analysis showed that the textural characteristics of products synthesised by ultrasonic treatment were comparable to those of products synthesised by conventional treatment. Fourier-transform infrared spectroscopy (FTIR) analyses showed the presence of Brønsted- and Lewis-acid sites, and zirconium-pillared clays synthesised by conventional treatment exhibited increased numbers of Brønsted- and Lewis-acid sites after cerium addition and copper impregnation. However, the products synthesised by ultrasonic treatment exhibited an increased number of Brønsted- and Lewis-acid sites after cerium addition, but a decreased number of acid sites after copper impregnation.

  7. Static characterization of a soft elastomeric capacitor for non destructive evaluation applications

    International Nuclear Information System (INIS)

    Saleem, Hussam; Laflamme, Simon; Zhang, Huanhuan; Geiger, Randall; Kessler, Michael; Rajan, Krishna

    2014-01-01

    A large and flexible strain transducer consisting of a soft elastomeric capacitor (SEC) has been proposed by the authors. Arranged in a network setup, the sensing strategy offers tremendous potential at conducting non-destructive evaluation of large-scale surfaces. In prior work, the authors have demonstrated the performance of the sensor at tracking strain history, localizing cracks, and detecting vibration signatures. In this paper, we characterize the static performance of the proposed SEC. The characterization includes sensitivity of the signal, and temperature and humidity dependences. Tests are conducted on a simply supported aluminum beam subjected to bending as well as on a free standing sensor. The performance of the SEC is compared against off-the-shelf resistance-based strain gauges with resolution of 1 με. A sensitivity of 1190 pF/ε is obtained experimentally, in agreement with theory. Results also show the sensor linearity over the given level of strain, showing the promise of the SEC at monitoring of surface strain

  8. Static characterization of a soft elastomeric capacitor for non destructive evaluation applications

    Science.gov (United States)

    Saleem, Hussam; Laflamme, Simon; Zhang, Huanhuan; Geiger, Randall; Kessler, Michael; Rajan, Krishna

    2014-02-01

    A large and flexible strain transducer consisting of a soft elastomeric capacitor (SEC) has been proposed by the authors. Arranged in a network setup, the sensing strategy offers tremendous potential at conducting non-destructive evaluation of large-scale surfaces. In prior work, the authors have demonstrated the performance of the sensor at tracking strain history, localizing cracks, and detecting vibration signatures. In this paper, we characterize the static performance of the proposed SEC. The characterization includes sensitivity of the signal, and temperature and humidity dependences. Tests are conducted on a simply supported aluminum beam subjected to bending as well as on a free standing sensor. The performance of the SEC is compared against off-the-shelf resistance-based strain gauges with resolution of 1 μɛ. A sensitivity of 1190 pF/ɛ is obtained experimentally, in agreement with theory. Results also show the sensor linearity over the given level of strain, showing the promise of the SEC at monitoring of surface strain.

  9. Caterpillar locomotion-inspired valveless pneumatic micropump using a single teardrop-shaped elastomeric membrane

    KAUST Repository

    So, Hongyun; Pisano, Albert P.; Seo, Young Ho

    2014-01-01

    This paper presents a microfluidic pump operated by an asymmetrically deformed membrane, which was inspired by caterpillar locomotion. Almost all mechanical micropumps consist of two major components of fluid halting and fluid pushing parts, whereas the proposed caterpillar locomotion-inspired micropump has only a single, bilaterally symmetric membrane-like teardrop shape. A teardrop-shaped elastomeric membrane was asymmetrically deformed and then consecutively touched down to the bottom of the chamber in response to pneumatic pressure, thus achieving fluid pushing. Consecutive touchdown motions of the teardrop-shaped membrane mimicked the propagation of a caterpillar's hump during its locomotory gait. The initial touchdown motion of the teardrop-shaped membrane at the centroid worked as a valve that blocked the inlet channel, and then, the consecutive touchdown motions pushed fluid in the chamber toward the tail of the chamber connected to the outlet channel. The propagation of the touchdown motion of the teardrop-shaped membrane was investigated using computational analysis as well as experimental studies. This caterpillar locomotion-inspired micropump composed of only a single membrane can provide new opportunities for simple integration of microfluidic systems. © the Partner Organisations 2014.

  10. Patterning the Stiffness of Elastomeric Nanocomposites by Magnetophoretic Control of Cross-linking Impeder Distribution

    Directory of Open Access Journals (Sweden)

    Suvojit Ghosh

    2015-01-01

    Full Text Available We report a novel method to pattern the stiffness of an elastomeric nanocomposite by selectively impeding the cross-linking reactions at desired locations while curing. This is accomplished by using a magnetic field to enforce a desired concentration distribution of colloidal magnetite nanoparticles (MNPs in the liquid precursor of polydimethysiloxane (PDMS elastomer. MNPs impede the cross-linking of PDMS; when they are dispersed in liquid PDMS, the cured elastomer exhibits lower stiffness in portions containing a higher nanoparticle concentration. Consequently, a desired stiffness pattern is produced by selecting the required magnetic field distribution a priori. Up to 200% variation in the reduced modulus is observed over a 2 mm length, and gradients of up to 12.6 MPa·mm−1 are obtained. This is a significant improvement over conventional nanocomposite systems where only small unidirectional variations can be achieved by varying nanoparticle concentration. The method has promising prospects in additive manufacturing; it can be integrated with existing systems thereby adding the capability to produce microscale heterogeneities in mechanical properties.

  11. Synthesis of polyester urethane urea and fabrication of elastomeric nanofibrous scaffolds for myocardial regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Jamadi, Elham Sadat; Ghasemi-Mobarakeh, Laleh [Department of Textile engineering, Isfahan university of technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Morshed, Mohammad, E-mail: morshed@cc.iut.ac.ir [Department of Textile engineering, Isfahan university of technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Sadeghi, Morteza [Department of Chemical Engineering, Isfahan university of technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Prabhakaran, Molamma P., E-mail: nanotechmpp@gmail.com [Department of Mechanical Engineering, Faculty of Engineering, 2 Engineering Drive 3, National University of Singapore, Singapore 117576 (Singapore); Ramakrishna, Seeram [Department of Mechanical Engineering, Faculty of Engineering, 2 Engineering Drive 3, National University of Singapore, Singapore 117576 (Singapore)

    2016-06-01

    Fabrication of bioactive scaffolds is one of the most promising strategies to reconstruct the infarcted myocardium. In this study, we synthesized polyester urethane urea (PEUU), further blended it with gelatin and fabricated PEUU/G nanofibrous scaffolds. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffraction were used for the characterization of the synthesized PEUU and properties of nanofibrous scaffolds were evaluated using scanning electron microscopy (SEM), ATR-FTIR, contact angle measurement, biodegradation test, tensile strength analysis and dynamic mechanical analysis (DMA). In vitro biocompatibility studies were performed using cardiomyocytes. DMA analysis showed that the scaffolds could be reshaped with cyclic deformations and might remain stable in the frequencies of the physiological activity of the heart. On the whole, our study suggests that aligned PEUU/G 70:30 nanofibrous scaffolds meet the required specifications for cardiac tissue engineering and could be used as a promising construct for myocardial regeneration. - Highlights: • PEUU was synthesized to fabricate elastomeric scaffolds for myocardial regeneration. • FTIR, DSC and XRD analysis showed that polymer synthesis was well. • PEUU/gelatin nanofibrous scaffolds could be reshaped with cyclic deformations of the heart. • Gelatin in structure of PEUU nanofibers improved proliferation of cardiomyocytes. • Aligned PEUU/gelatin 70:30 nanofibrous scaffold support the alignment of cardiomyocytes.

  12. Highly Magneto-Responsive Elastomeric Films Created by a Two-Step Fabrication Process

    KAUST Repository

    Marchi, Sophie

    2015-08-24

    An innovative method for the preparation of elastomeric magnetic films with increased magneto-responsivity is presented. Polymeric films containing aligned magnetic microchains throughout their thickness are formed upon the magnetophoretic transport and assembly of microparticles during polymer curing. The obtained films are subsequently magnetized at a high magnetic field of 3 T directed parallel to the orientation of the microchains. We prove that the combination of both alignment of the particles along a favorable direction during curing and the subsequent magnetization of the solid films induces an impressive increase of the films’ deflection. Specifically, the displacements reach few millimeters, up to 85 times higher than those of the nontreated films with the same particle concentration. Such a process can improve the performance of the magnetic films without increasing the amount of magnetic fillers and, thus, without compromising the mechanical properties of the resulting composites. The proposed method can be used for the fabrication of magnetic films suitable as components in systems in which large displacements at relatively low magnetic fields are required, such as sensors and drug delivery or microfluidic systems, especially where remote control of valves is requested to achieve appropriate flow and mixing of liquids.

  13. Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery

    Science.gov (United States)

    De Falco, Iris; Gerboni, Giada; Cianchetti, Matteo; Menciassi, Arianna

    2015-01-01

    In recent years, soft robotics technologies have aroused increasing interest in the medical field due to their intrinsically safe interaction in unstructured environments. At the same time, new procedures and techniques have been developed to reduce the invasiveness of surgical operations. Minimally Invasive Surgery (MIS) has been successfully employed for abdominal interventions, however standard MIS procedures are mainly based on rigid or semi-rigid tools that limit the dexterity of the clinician. This paper presents a soft and high dexterous manipulator for MIS. The manipulator was inspired by the biological capabilities of the octopus arm, and is designed with a modular approach. Each module presents the same functional characteristics, thus achieving high dexterity and versatility when more modules are integrated. The paper details the design, fabrication process and the materials necessary for the development of a single unit, which is fabricated by casting silicone inside specific molds. The result consists in an elastomeric cylinder including three flexible pneumatic actuators that enable elongation and omni-directional bending of the unit. An external braided sheath improves the motion of the module. In the center of each module a granular jamming-based mechanism varies the stiffness of the structure during the tasks. Tests demonstrate that the module is able to bend up to 120° and to elongate up to 66% of the initial length. The module generates a maximum force of 47 N, and its stiffness can increase up to 36%. PMID:26650236

  14. Methodology for Evaluating Raw Material Changes to RSRM Elastomeric Insulation Materials

    Science.gov (United States)

    Mildenhall, Scott D.; McCool, Alex (Technical Monitor)

    2001-01-01

    The Reusable Solid Rocket Motor (RSRM) uses asbestos and silicon dioxide filled acrylonitrile butadiene rubber (AS-NBR) as the primary internal insulation to protect the case from heat. During the course of the RSRM Program, several changes have been made to the raw materials and processing of the AS-NBR elastomeric insulation material. These changes have been primarily caused by raw materials becoming obsolete. In addition, some process changes have been implemented that were deemed necessary to improve the quality and consistency of the AS-NBR insulation material. Each change has been evaluated using unique test efforts customized to determine the potential impacts of the specific raw material or process change. Following the evaluations, the various raw material and process changes were successfully implemented with no detectable effect on the performance of the AS-NBR insulation. This paper will discuss some of the raw material and process changes evaluated, the methodology used in designing the unique test plans, and the general evaluation results. A summary of the change history of RSRM AS-NBR internal insulation is also presented.

  15. Influence of particle arrangement on the permittivity of an elastomeric composite

    Directory of Open Access Journals (Sweden)

    Peiying J. Tsai

    2017-01-01

    Full Text Available Elastomers are used as dielectric layers contained between the parallel conductive plates of capacitors. The introduction of filler particles into an elastomer changes its permittivity ε. When particle organization in a composite is intentionally varied, this alters its capacitance. Using numerical simulations, we examine how conductive particle chains introduced into polydimethylsiloxane (PDMS alter ε. The effects of filler volume fraction ψ, interparticle d and interchain spacing a, zigzag angle θ between adjacent particles and overall chain orientation, particle size r, and clearance h between particles and the conductive plates are characterized. When filler particles are organized into chainlike structures rather than being just randomly distributed in the elastomer matrix, ε increases by as much as 85%. When particles are organized into chainlike forms, ε increases with increasing ψ and a, but decreases with increasing d and θ. A composite containing smaller particles has a higher ε when ψ<9% while larger particles provide greater enhancement when ψ is larger than that value. To enhance ε, adjacent particles must be interconnected and the overall chain direction should be oriented perpendicular to the conductive plates. These results are useful for additive manufacturing on electrical applications of elastomeric composites.

  16. Highly Magneto-Responsive Elastomeric Films Created by a Two-Step Fabrication Process

    KAUST Repository

    Marchi, Sophie; Casu, Alberto; Bertora, Franco; Athanassiou, Athanassia; Fragouli, Despina

    2015-01-01

    An innovative method for the preparation of elastomeric magnetic films with increased magneto-responsivity is presented. Polymeric films containing aligned magnetic microchains throughout their thickness are formed upon the magnetophoretic transport and assembly of microparticles during polymer curing. The obtained films are subsequently magnetized at a high magnetic field of 3 T directed parallel to the orientation of the microchains. We prove that the combination of both alignment of the particles along a favorable direction during curing and the subsequent magnetization of the solid films induces an impressive increase of the films’ deflection. Specifically, the displacements reach few millimeters, up to 85 times higher than those of the nontreated films with the same particle concentration. Such a process can improve the performance of the magnetic films without increasing the amount of magnetic fillers and, thus, without compromising the mechanical properties of the resulting composites. The proposed method can be used for the fabrication of magnetic films suitable as components in systems in which large displacements at relatively low magnetic fields are required, such as sensors and drug delivery or microfluidic systems, especially where remote control of valves is requested to achieve appropriate flow and mixing of liquids.

  17. Caterpillar locomotion-inspired valveless pneumatic micropump using a single teardrop-shaped elastomeric membrane

    KAUST Repository

    So, Hongyun

    2014-01-01

    This paper presents a microfluidic pump operated by an asymmetrically deformed membrane, which was inspired by caterpillar locomotion. Almost all mechanical micropumps consist of two major components of fluid halting and fluid pushing parts, whereas the proposed caterpillar locomotion-inspired micropump has only a single, bilaterally symmetric membrane-like teardrop shape. A teardrop-shaped elastomeric membrane was asymmetrically deformed and then consecutively touched down to the bottom of the chamber in response to pneumatic pressure, thus achieving fluid pushing. Consecutive touchdown motions of the teardrop-shaped membrane mimicked the propagation of a caterpillar\\'s hump during its locomotory gait. The initial touchdown motion of the teardrop-shaped membrane at the centroid worked as a valve that blocked the inlet channel, and then, the consecutive touchdown motions pushed fluid in the chamber toward the tail of the chamber connected to the outlet channel. The propagation of the touchdown motion of the teardrop-shaped membrane was investigated using computational analysis as well as experimental studies. This caterpillar locomotion-inspired micropump composed of only a single membrane can provide new opportunities for simple integration of microfluidic systems. © the Partner Organisations 2014.

  18. Optimal elastomeric scaffold leaflet shape for pulmonary heart valve leaflet replacement.

    Science.gov (United States)

    Fan, Rong; Bayoumi, Ahmed S; Chen, Peter; Hobson, Christopher M; Wagner, William R; Mayer, John E; Sacks, Michael S

    2013-02-22

    Surgical replacement of the pulmonary valve (PV) is a common treatment option for congenital pulmonary valve defects. Engineered tissue approaches to develop novel PV replacements are intrinsically complex, and will require methodical approaches for their development. Single leaflet replacement utilizing an ovine model is an attractive approach in that candidate materials can be evaluated under valve level stresses in blood contact without the confounding effects of a particular valve design. In the present study an approach for optimal leaflet shape design based on finite element (FE) simulation of a mechanically anisotropic, elastomeric scaffold for PV replacement is presented. The scaffold was modeled as an orthotropic hyperelastic material using a generalized Fung-type constitutive model. The optimal shape of the fully loaded PV replacement leaflet was systematically determined by minimizing the difference between the deformed shape obtained from FE simulation and an ex-vivo microCT scan of a native ovine PV leaflet. Effects of material anisotropy, dimensional changes of PV root, and fiber orientation on the resulting leaflet deformation were investigated. In-situ validation demonstrated that the approach could guide the design of the leaflet shape for PV replacement surgery. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Biodegradable, elastomeric coatings with controlled anti-proliferative agent release for magnesium-based cardiovascular stents.

    Science.gov (United States)

    Gu, Xinzhu; Mao, Zhongwei; Ye, Sang-Ho; Koo, Youngmi; Yun, Yeoheung; Tiasha, Tarannum R; Shanov, Vesselin; Wagner, William R

    2016-08-01

    Vascular stent design continues to evolve to further improve the efficacy and minimize the risks associated with these devices. Drug-eluting coatings have been widely adopted and, more recently, biodegradable stents have been the focus of extensive evaluation. In this report, biodegradable elastomeric polyurethanes were synthesized and applied as drug-eluting coatings for a relatively new class of degradable vascular stents based on Mg. The dynamic degradation behavior, hemocompatibility and drug release were investigated for poly(carbonate urethane) urea (PCUU) and poly(ester urethane) urea (PEUU) coated magnesium alloy (AZ31) stents. Poly(lactic-co-glycolic acid) (PLGA) coated and bare stents were employed as control groups. The PCUU coating effectively slowed the Mg alloy corrosion in dynamic degradation testing compared to PEUU-coated, PLGA-coated and bare Mg alloy stents. This was confirmed by electron microscopy, energy-dispersive x-ray spectroscopy and magnesium ion release experiments. PCUU-coating of AZ31 was also associated with significantly reduced platelet adhesion in acute blood contact testing. Rat vascular smooth muscle cell (rSMC) proliferation was successfully inhibited when paclitaxel was released from pre-loaded PCUU coatings. The corrosion retardation, low thrombogenicity, drug loading capacity, and high elasticity make PCUU an attractive option for drug eluting coating on biodegradable metallic cardiovascular stents. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Accuracy of a new elastomeric impression material for complete-arch dental implant impressions.

    Science.gov (United States)

    Baig, Mirza R; Buzayan, Muaiyed M; Yunus, Norsiah

    2018-05-01

    The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone (VPES) and polyether (PE), and to test the effect of splinting of impression copings on the accuracy of implant casts. Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05. The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05). The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions. © 2018 John Wiley & Sons Australia, Ltd.

  1. Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery.

    Science.gov (United States)

    De Falco, Iris; Gerboni, Giada; Cianchetti, Matteo; Menciassi, Arianna

    2015-11-14

    In recent years, soft robotics technologies have aroused increasing interest in the medical field due to their intrinsically safe interaction in unstructured environments. At the same time, new procedures and techniques have been developed to reduce the invasiveness of surgical operations. Minimally Invasive Surgery (MIS) has been successfully employed for abdominal interventions, however standard MIS procedures are mainly based on rigid or semi-rigid tools that limit the dexterity of the clinician. This paper presents a soft and high dexterous manipulator for MIS. The manipulator was inspired by the biological capabilities of the octopus arm, and is designed with a modular approach. Each module presents the same functional characteristics, thus achieving high dexterity and versatility when more modules are integrated. The paper details the design, fabrication process and the materials necessary for the development of a single unit, which is fabricated by casting silicone inside specific molds. The result consists in an elastomeric cylinder including three flexible pneumatic actuators that enable elongation and omni-directional bending of the unit. An external braided sheath improves the motion of the module. In the center of each module a granular jamming-based mechanism varies the stiffness of the structure during the tasks. Tests demonstrate that the module is able to bend up to 120° and to elongate up to 66% of the initial length. The module generates a maximum force of 47 N, and its stiffness can increase up to 36%.

  2. Durability assessment of soft elastomeric capacitor skin for SHM of wind turbine blades

    Science.gov (United States)

    Downey, Austin; Pisello, Anna Laura; Fortunati, Elena; Fabiani, Claudia; Luzi, Francesca; Torre, Luigi; Ubertini, Filippo; Laflamme, Simon

    2018-03-01

    Renewable energy production has become a key research driver during the last decade. Wind energy represents a ready technology for large-scale implementation in locations all around the world. While important research is conducted to optimize wind energy production efficiency, a critical issue consists of monitoring the structural integrity and functionality of these large structures during their operational life cycle. This paper investigates the durability of a soft elastomeric capacitor strain sensing membrane, designed for structural health monitoring of wind turbines, when exposed to aggressive environmental conditions. The sensor is a capacitor made of three thin layers of an SEBS polymer in a sandwich configuration. The inner layer is doped with titania and acts as the dielectric, while the external layers are filled with carbon black and work as the conductive plates. Here, a variety of samples, not limited to the sensor configuration but also including its dielectric layer, were fabricated and tested within an accelerated weathering chamber (QUV) by simulating thermal, humidity, and UV radiation cycles. A variety of other tests were performed in order to characterize their mechanical, thermal, and electrical performance in addition to their solar reflectance. These tests were carried out before and after the QUV exposures of 1, 7, 15, and 30 days. The tests showed that titania inclusions improved the sensor durability against weathering. These findings contribute to better understanding the field behavior of these skin sensors, while future developments will concern the analysis of the sensing properties of the skin after aging.

  3. Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport.

    Science.gov (United States)

    Sheng, Zhizhi; Wang, Honglong; Tang, Yongliang; Wang, Miao; Huang, Lizhi; Min, Lingli; Meng, Haiqiang; Chen, Songyue; Jiang, Lei; Hou, Xu

    2018-02-01

    The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores' deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.

  4. Influence of particle arrangement on the permittivity of an elastomeric composite

    Science.gov (United States)

    Tsai, Peiying J.; Nayak, Suchitra; Ghosh, Suvojit; Puri, Ishwar K.

    2017-01-01

    Elastomers are used as dielectric layers contained between the parallel conductive plates of capacitors. The introduction of filler particles into an elastomer changes its permittivity ɛ. When particle organization in a composite is intentionally varied, this alters its capacitance. Using numerical simulations, we examine how conductive particle chains introduced into polydimethylsiloxane (PDMS) alter ɛ. The effects of filler volume fraction ψ, interparticle d and interchain spacing a, zigzag angle θ between adjacent particles and overall chain orientation, particle size r, and clearance h between particles and the conductive plates are characterized. When filler particles are organized into chainlike structures rather than being just randomly distributed in the elastomer matrix, ɛ increases by as much as 85%. When particles are organized into chainlike forms, ɛ increases with increasing ψ and a, but decreases with increasing d and θ. A composite containing smaller particles has a higher ɛ when ψ <9 % while larger particles provide greater enhancement when ψ is larger than that value. To enhance ɛ, adjacent particles must be interconnected and the overall chain direction should be oriented perpendicular to the conductive plates. These results are useful for additive manufacturing on electrical applications of elastomeric composites.

  5. Evaluating 8 pillars of Total Productive Maintenance (TPM) implementation and their contribution to manufacturing performance

    Science.gov (United States)

    Adesta, E. Y. T.; Prabowo, H. A.; Agusman, D.

    2018-01-01

    TPM is one method to improve manufacturing performance through an emphasis on maintenance that involves everyone in the organization. Research on the application of TPM and its relevance to the manufacturing performance has been performed quite a lot. However, to the best of our knowledge, a study that deliberates how the application of 8 pillars TPM (especially in developing countries) is still hard to find. This paper attempts to evaluate in more detail about how the 8 pillars of TPM are applied in Indonesia and their impact on manufacturing performance. This research is a pilot study with a target of 50 companies. From the results of data collection, only 22 companies (44%) are eligible to process. Data processing was performed using SPSS and Smart PLS tools. From the validity and reliability tests, it can be seen that all items/indicators for TPM pillars are valid and reliable with correlation value (R) of 0.614 - 0.914 and with Cronbach’s alpha equal to 0.753. As for the Manufacturing Performance construct, the Delivery indicator was not valid. In overall, the model is reliable with Cronbach’s alpha of 0.710. From the results of Confirmatory Factors Analysis (CFA) for TPM, it can be seen that four indicators (pillars) are highly significant while four other indicators are less significant. For MP, three indicators are significant, and two are not significant. In general, the structural model of the relationship between TPM and MP is relatively strong and positive with values R = 0.791, and R squared = 0.626. This means that the TPM Pillars can explain 62.6% MP variability construct variable, while the other 37.4% can be explained by unrelated variables.

  6. An array of ordered pillars with retentive properties for pressure-driven liquid chromatography fabricated directly from an unmodified cyclo olefin polymer

    NARCIS (Netherlands)

    Illa, Xavi; de Malsche, Wim; Bomer, Johan G.; Gardeniers, Johannes G.E.; Eijkel, Jan C.T.; Morante, Joan Ramon; Romano-Rodriguez, Albert; Desmet, Gert

    2009-01-01

    The current paper describes the development and characterization of a pillar array chip that is constructed out of a sandwich of cyclo olefin polymer (COP) sheets. The silicon master of a 5 cm long pillar array was embossed into the COP, yielding 4.3 µm deep pillars of 15.3 µm diameter with an

  7. Study of colloidal properties of natural and Al-pillared smectite and removal of copper ions from an aqueous solution.

    Science.gov (United States)

    Sartor, Lucas Resmini; de Azevedo, Antonio Carlos; Andrade, Gabriel Ramatis Pugliese

    2015-01-01

    In this study, an Al-pillared smectite was synthesized and changes in its colloidal properties were investigated. The pillaring solution was prepared by mixing 0.4 mol L(-1) NaOH and 0.2 mol L(-1) AlCl3.6H2O solutions. Intercalated clays were heated to obtain the pillared clay, and X-ray diffractometry (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy and N2 sorption/desorption isotherms analysis were done to characterize the changes in clay properties. Moreover, adsorption experiments were carried out in order to evaluate the capacity of the pillared clays to remove Cu2+ from an aqueous solution and to characterize the interaction between adsorbent and adsorbate. The results indicate that the natural clay has a basal spacing of 1.26 nm, whereas the pillared clays reached 1.78 nm (500°C) and 1.80 nm (350°C) after calcination. XRF analysis revealed an increase in the Al3+ in the pillared clay as compared to the natural clay. The surface area and pore volume (micro and mesoporous) were higher for the pillared clays. Experimental data from the adsorption experiment were fit to Langmuir and Freundlich and Temkin adsorption models, and the former one was the best fit (highest r2 value) for all the clays and lower standard deviation (Δg%) for the natural clay. On the other hand, the Temkin model exhibited Δg% value lower for the pillared clays. Thermodynamics parameters demonstrate that the Cu2+ adsorption process is spontaneous for all the clays, but with higher values for the pillared materials. In addition, application of the Dubinin-Radushkevich model revealed that the bond between the metal and the clay are weak, characterizing a physisorption.

  8. Forces released during alignment with a preadjusted appliances with SPEED supercable wire and different types of elastomeric ligatures

    Directory of Open Access Journals (Sweden)

    Suruchi Jatol-Tekade

    2016-01-01

    Full Text Available Introduction: The purpose of this in vitro study was to evaluate a new combination of wire and ligature to reduce friction further by combining slide ligatures and supercable wires. Materials and Methods: The testing model consisted of five stainless steel 0.022 inch preadjusted brackets for second premolar, first premolar, canine, lateral incisor, and central incisor. The canine bracket was welded to a sliding bar that allowed different vertical positions. The forces generated by five sizes of wires superelastic nickel-titanium (SE Ni-Ti (Unitek Nitinol Super-Elastic Archwire of diameter 0.012", 0.014", 0.016", 0.018", and 0.020" inch and three sizes of SPEED supercable wires (0.016", 0.018", and 0.022" inch with the two types of elastomeric ligatures; conventional elastomeric ligatures (CELs (Unitek, silver mini modules, with inside diameter of 1.3 mm and thickness of 0.9 mm and nonconventional elastomeric ligatures (NCELs (Slide, Leone Orthodontic Products, Sesto Fiorentino, Firenze, Italy at different amounts of upward canine misalignment (CM (1.5, 3, 4.5, and 6 mm were recorded. Results and Conclusions: Significant differences between CEL and NCEL were found for all tested variables (P - 0.01 a noticeable amount of force was generated with the NCEL at all four canine positions with all three wire sizes (from about 50 to about 150 g. With 4.5 mm of CM or more, the average amount of released force with the CEL was approximately zero.

  9. Summary of experimental tests of elastomeric seismic isolation bearings for use in nuclear reactor plants

    International Nuclear Information System (INIS)

    Seidensticker, R.W.; Chang, Y.W.; Kulak, R.F.

    1992-01-01

    This paper describes an experimental test program for isolator bearings which was developed to help establish the viability of using laminated elastomer bearings for base isolation of nuclear reactor plants. The goal of the test program is to determine the performance characteristics of laminated seismic isolation bearings under a wide range of loadings. Tests were performed on scale-size laminated seismic isolators both within the design shear strain range to determine the response of the bearing under expected earthquake loading conditions, and beyond the design range to determine failure modes and to establish safety margins. Three types of bearings, each produced from a different manufacturer, have been tested: (1) high shape factor-high damping-high shear modulus bearings; (2) medium shape factor-high damping-high shear modulus bearings; and (3) medium shape factor-high damping-low shear modulus bearings. All of these tests described in this report were performed at the Earthquake Engineering Research Center at the University of California, Berkeley, with technical assistance from ANL. The tests performed on the three types of bearings have confirmed the high performance characteristics of the high damping-high and low shear modulus elastomeric bearings. The bearings have shown that they are capable of having extremely large shear strains before failure occurs. The most common failure mechanism was the debonding of the top steel plate from the isolators. This failure mechanism can be virtually eliminated by improved manufacturing quality control. The most important result of the failure test of the isolators is the fact that bearings can sustain large horizontal displacement, several times larger than the design value, with failure. Their performance in moderate and strong earthquakes will be far superior to conventional structures

  10. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E.; Kang, Yunqing [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Findlay, Michael W. [Department of Plastic and Reconstructive Surgery, Stanford University, Stanford, CA (United States); University of Melbourne Department of Surgery, Royal Melbourne Hospital, Parkville, VIC (Australia); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States)

    2015-04-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10{sup −6} cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts.

  11. Linear dimensional changes in plaster die models using different elastomeric materials

    Directory of Open Access Journals (Sweden)

    Jefferson Ricardo Pereira

    2010-09-01

    Full Text Available Dental impression is an important step in the preparation of prostheses since it provides the reproduction of anatomic and surface details of teeth and adjacent structures. The objective of this study was to evaluate the linear dimensional alterations in gypsum dies obtained with different elastomeric materials, using a resin coping impression technique with individual shells. A master cast made of stainless steel with fixed prosthesis characteristics with two prepared abutment teeth was used to obtain the impressions. References points (A, B, C, D, E and F were recorded on the occlusal and buccal surfaces of abutments to register the distances. The impressions were obtained using the following materials: polyether, mercaptan-polysulfide, addition silicone, and condensation silicone. The transfer impressions were made with custom trays and an irreversible hydrocolloid material and were poured with type IV gypsum. The distances between identified points in gypsum dies were measured using an optical microscope and the results were statistically analyzed by ANOVA (p < 0.05 and Tukey's test. The mean of the distances were registered as follows: addition silicone (AB = 13.6 µm, CD=15.0 µm, EF = 14.6 µm, GH=15.2 µm, mercaptan-polysulfide (AB = 36.0 µm, CD = 36.0 µm, EF = 39.6 µm, GH = 40.6 µm, polyether (AB = 35.2 µm, CD = 35.6 µm, EF = 39.4 µm, GH = 41.4 µm and condensation silicone (AB = 69.2 µm, CD = 71.0 µm, EF = 80.6 µm, GH = 81.2 µm. All of the measurements found in gypsum dies were compared to those of a master cast. The results demonstrated that the addition silicone provides the best stability of the compounds tested, followed by polyether, polysulfide and condensation silicone. No statistical differences were obtained between polyether and mercaptan-polysulfide materials.

  12. Effect of Microstructure Constraints on the Homogenized Elastic Constants of Elastomeric Sylgard/GMB Syntactic Foam.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steck, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    Previous numerical studies of Sylgard filled with glass microballoons (GMB) have relied on various microstructure idealizations to achieve a large range of volume fractions with high mesh quality. This study investigates how different microstructure idealizations and constraints affect the apparent homogenized elastic constants in the virgin state of the material, in which all GMBs are intact and perfectly bonded to the Sylgard matrix, and in the fully damaged state of the material in which all GMBs are destroyed. In the latter state, the material behaves as an elastomeric foam. Four microstructure idealizations are considered relating to how GMBs are packed into a representative volume element (RVE): (1) no boundary penetration nor GMB-GMB overlap, (2) GMB-GMB overlap, (3) boundary penetration, and (4) boundary penetration and GMB-GMB overlap. First order computational homogenization with kinematically uniform displacement boundary conditions (KUBCs) was employed to determine the homogenized (apparent) bulk and shear moduli for the four microstructure idealizations in the intact and fully broken GMB material states. It was found that boundary penetration has a significant effect on the shear modulus for microstructures with intact GMBs, but that neither boundary penetration nor GMB overlap have a significant effect on homogenized properties for microstructures with fully broken GMBs. The primary conclusion of the study is that future investigations into Sylgard/GMB micromechanics should either force GMBs to stay within the RVE fully and/or use periodic BCs (PBCs) to eliminate the boundary penetration issues. The implementation of PBCs requires the improvement of existing tools in Sandia’s Sierra/SM code.

  13. Investigation of Pre- and Post-Swelling Behavior of Elastomeric Material

    Directory of Open Access Journals (Sweden)

    M Akhtar

    2013-06-01

    Full Text Available In the last ten years, a new type of modern polymer, known as swelling elastomer, has been used extensively as a sealing element in the oil and gas industry. These elastomers have been instrumental in various new applications such as water shut off, zonal isolation, and sidetracking. Though swell packers can significantly reduce costs and increase productivity, their failure can lead to serious losses. The integrity and reliability of swelling elastomer seals under different field conditions is a major concern. The investigation of changes in material behavior over a specified swelling period is a necessary first step for performance evaluation of elastomer seals. The current study is based on experimental analysis of changes in geometric and mechanical behavior (hardness, tensile, compressive, bulk of an elastomeric material due to swelling. Tests were carried out before and after various stages of swelling. Specimens were placed in saline water (0.6% and 12% concentrations at a temperature of 50°C, with the total swelling period being one month. Swelling, hardness, compression, and bulk tests were conducted using disc samples, while ring samples were used for tensile experiments. A small test rig was designed and constructed for determination of bulk modulus. Stress-strain curves under tension and compression, and pressure volumetric-strain curves were obtained for specimens subjected to different swelling periods. Due to the fast-swell nature of the elastomer, there were sharp changes in mechanical properties within the first few days of swelling for both salinities. Elastic modulus derived from tensile and compressive tests showed a 90% decrease in the first few days. Bulk modulus showed fluctuation in its variation with an increasing swelling period. There was a small effect of salinity only during the first 5 or 6 days.

  14. Model calibration for a soft elastomeric capacitor sensor considering slippage under fatigue cracks

    Science.gov (United States)

    Kong, Xiangxiong; Li, Jian; Bennett, Caroline; Collins, William; Laflamme, Simon

    2016-04-01

    A newly-developed soft elastomeric capacitor (SEC) strain sensor has shown promise in fatigue crack monitoring. The SECs exhibit high levels of ductility and hence do not break under excessive strain when the substrate cracks due to slippage or de-bonding between the sensor and epoxy. The actual strain experienced by a SEC depends on the amount of slippage, which is difficult to simulate numerically, making it challenging to accurately predict the response of a SEC near a crack. In this paper, a two-step approach is proposed to simulate the capacitance response of a SEC. First, a finite element (FE) model of a steel compact tension specimen was analyzed under cyclic loading while the cracking process was simulated based on an element removal technique. Second, a rectangular boundary was defined near the crack region. The SEC outside the boundary was assumed to have perfect bond with the specimen, while that inside the boundary was assumed to deform freely due to slippage. A second FE model was then established to simulate the response of the SEC within the boundary subject to displacements at the boundary from the first FE model. The total simulated capacitance was computed from the model results by combining the computed capacitance inside and outside the boundary. The performance of the simulation incorporating slippage was evaluated by comparing the model results with the experimental data from the test performed on a compact tension specimen. The FE model considering slippage showed results that matched the experimental findings more closely than the FE model that did not consider slippage.

  15. Force decay evaluation of thermoplastic and thermoset elastomeric chains: A mechanical design comparison.

    Science.gov (United States)

    Masoud, Ahmed I; Tsay, T Peter; BeGole, Ellen; Bedran-Russo, Ana K

    2014-11-01

    To compare the following over a period of 8 weeks: (1) force decay between thermoplastic (TP) and thermoset (TS) elastomeric chains; (2) force decay between light (200-g) and heavy (350-g) initial forces; and (3) force decay between direct chains and chain loops (stretched from one pin around the second pin and back to the first pin). TP and TS chains were obtained from American Orthodontics™ (AOTP, AOTS) and ORMCO™ (OrTP, OrTS). Each of the four chain groups was subdivided into four subgroups with 10 specimens per subgroup: (1) direct chains light force, (2) direct chains heavy force, (3) chain loops light force, and (4) chain loops heavy force. The experiment was performed in artificial saliva (pH of 6.75) at 37°C. A significant difference was found between TP and TS chains, with an average mean difference of around 20% more force decay found in the TP chains (P < .001, α  =  .05). There was no significant difference between direct chains and chain loops except in OrTP, in which direct chains showed more force decay. There was also no significant difference in force decay identified when using light vs heavy forces. TS chains decayed less than TP chains, and chain loop retraction was beneficial only when using OrTP chains. Contrary to the interchangeable use of TP and TS chains in the published literature and in clinical practice, this study demonstrates that they perform differently under stress and that a clear distinction should be made between the two.

  16. On propagation of axisymmetric waves in pressurized functionally graded elastomeric hollow cylinders

    Science.gov (United States)

    Wu, Bin; Su, Yipin; Liu, Dongying; Chen, Weiqiu; Zhang, Chuanzeng

    2018-05-01

    Soft materials can be designed with a functionally graded (FG) property for specific applications. Such material inhomogeneity can also be found in many soft biological tissues whose functionality is only partly understood to date. In this paper, we analyze the axisymmetric guided wave propagation in a pressurized FG elastomeric hollow cylinder. The cylinder is subjected to a combined action of axial pre-stretch and pressure difference applied to the inner and outer cylindrical surfaces. We consider both torsional waves and longitudinal waves propagating in the FG cylinder made of incompressible isotropic elastomer, which is characterized by the Mooney-Rivlin strain energy function but with the material parameters varying with the radial coordinate in an affine way. The pressure difference generates an inhomogeneous deformation field in the FG cylinder, which dramatically complicates the superimposed wave problem described by the small-on-large theory. A particularly efficient approach is hence employed which combines the state-space formalism for the incremental wave motion with the approximate laminate or multi-layer technique. Dispersion relations for the two types of axisymmetric guided waves are then derived analytically. The accuracy and convergence of the proposed approach is validated numerically. The effects of the pressure difference, material gradient, and axial pre-stretch on both the torsional and the longitudinal wave propagation characteristics are discussed in detail through numerical examples. It is found that the frequency of axisymmetric waves depends nonlinearly on the pressure difference and the material gradient, and an increase in the material gradient enhances the capability of the pressure difference to adjust the wave behavior in the FG cylinder. This work provides a theoretical guidance for characterizing FG soft materials by in-situ ultrasonic nondestructive evaluation and for designing tunable waveguides via material tailoring along

  17. Elastomeric Thermal Insulation Design Considerations in Long, Aluminized Solid Rocket Motors

    Science.gov (United States)

    Martin, Heath T.

    2017-01-01

    An all-new sounding rocket was designed at NASA's Marshall Space Flight Center that featured an aft finocyl, aluminized solid propellant grain and silica-filled ethylene-propylene-diene monomer (SFEPDM) internal insulation. Upon the initial static firing of the first of this new design, the solid rocket motor (SRM) case failed thermally just upstream of the aft closure early in the burn time. Subsequent fluid modeling indicated that the high-velocity combustion-product jets emanating from the fin-slots in the propellant grain were likely inducing a strongly swirling flow, thus substantially increasing the severity of the convective environment on the exposed portion of the SFEPDM insulation in this region. The aft portion of the fin-slots in another of the motors were filled with propellant to eliminate the possibility of both direct jet impingement on the exposed SFEPDM and the appearance of strongly swirling flow in the aft region of the motor. When static-fired, this motor's case still failed in the same axial location, and, though somewhat later than for the first static firing, still in less than 1/3rd of the desired burn duration. These results indicate that the extreme material decomposition rates of the SFEPDM in this application are not due to gas-phase convection or shear but rather to interactions with burning aluminum or alumina slag. Further comparisons with between SFEPDM performance in this design and that in other hot-fire tests provide insight into the mechanisms of SFEPDM decomposition in SRM aft domes that can guide the upcoming redesign effort, as well as other future SRM designs. These data also highlight the current limitations of modeling elastomeric insulators solely with diffusion-controlled, gas-phase thermochemistry in SRM regions with significant viscous shear and/or condense-phase impingement or flow.

  18. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    International Nuclear Information System (INIS)

    Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Zenhausern, Frederic; Rivera, Andrew; Birdsell, Dawn N; Wagner, David M

    2015-01-01

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30–100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis. (paper)

  19. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    International Nuclear Information System (INIS)

    Mercado-Pagán, Ángel E.; Kang, Yunqing; Findlay, Michael W.; Yang, Yunzhi

    2015-01-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10 −6 cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts

  20. The thermal and mechanical properties of a low-density glass-fiber-reinforced elastomeric ablation material

    Science.gov (United States)

    Engelke, W. T.; Robertson, R. W.; Bush, A. L.; Pears, C. D.

    1974-01-01

    An evaluation of the thermal and mechanical properties was performed on a molded low-density elastomeric ablation material designated as Material B. Both the virgin and charred states were examined to provide meaningful inputs to the design of a thermal protection system. Chars representative of the flight chars formed during ablation were prepared in a laboratory furnace from 600 K to 1700 K and properties of effective thermal conductivity, heat capacity, porosity and permeability were determined on the furnace chars formed at various temperature levels within the range. This provided a boxing of the data which will enable the prediction of the transient response of the material during flight ablation.

  1. Develop guidelines for the design of pillar systems for shallow and intermediate depth, tabular, hard rock mines and provide methodology for assessing hangingwall stability and support requirements for the panels between pillars

    CSIR Research Space (South Africa)

    Haile, AT

    1995-12-01

    Full Text Available The overall view of the research being conducted at Impala platinum was to improve pillar design techniques through a rock testing programme, underground instrumentation and back analysis. The laboratory rock testing programme has provided a useful...

  2. PILLARED ZEOLITES AMENDMENTS INFLUENCE FROM POLLUTED SOIL ON HEAVY METALS BIOACCUMULATION IN TOMATOES

    Directory of Open Access Journals (Sweden)

    SMARANDA MASU

    2007-05-01

    Full Text Available Due to anthropic activities, the presence of metals in polluted soils has effects on plants development and metals bioaccumulation into trophic levels. In this paper, were followed experiments regarding the tomatoes development into polluted soils with 43.4 – 58.4 mg Cd/kg d.s. and 500- 633 mg Pb/kg d.s. Nickel, zinc and copper content in soils are in the range of diffuse pollution values. Comparatively, an experiment was realized with polluted soils and amended with pillared zeolites. Pillared zeolites change metals distribution in soil fractions and their solubility. Tomato plants grew onto polluted soils, but did not present fruits. Tomatoes from polluted and amended soils presented fruits and metals in tissues (Zn  Cu  Ni. Zinc concentration was five times greater then Ni. Fruits do not accumulate cadmium and lead.

  3. An experimental investigation of wind pressures on square pillars in tornado-like vortices

    International Nuclear Information System (INIS)

    Iwatani, Yoshiharu; Maruta, Eizou; Kanda, Makoto; Hattori, Yousuke; Hamano, Naoki; Matsuura, Takeshi

    1992-01-01

    This report describes a laboratory simulation of tornado-like vortices and laboratory measurements of steady wind loads on model structures in tornado-like vortices. The variations of wind direction and wind speed of tornado-like vortices and ground surface pressure under tornado-like vortices with the swirl ratio, Reynolds number and the surface roughness were investigated. Wind pressure distributions on square pillars were measured in tornado-like vortices. It was observed in the experiment that the negative pressures on the roof faces of square pillars were high and distributed rather uniformly but these on the side faces differed greatly from place to place and locally became high. The high pressure regions on the side faces were close to ground surface in the case where the model structures stood in the center of tornado-like vortex, and became higher as the increase of distance between the model structures and the center of tornado-like vortices. (author)

  4. A superhydrophobic chip based on SU-8 photoresist pillars suspended on a silicon nitride membrane

    KAUST Repository

    Marinaro, Giovanni; Accardo, Angelo; De Angelis, Francesco; Dane, Thomas; Weinhausen, Britta; Burghammer, Manfred; Riekel, Christian

    2014-01-01

    We developed a new generation of superhydrophobic chips optimized for probing ultrasmall sample quantities by X-ray scattering and fluorescence techniques. The chips are based on thin Si3N4 membranes with a tailored pattern of SU-8 photoresist pillars. Indeed, aqueous solution droplets can be evaporated and concentrated at predefined positions using a non-periodic pillar pattern. We demonstrated quantitatively the deposition and aggregation of gold glyconanoparticles from the evaporation of a nanomolar droplet in a small spot by raster X-ray nanofluorescence. Further, raster nanocrystallography of biological objects such as rod-like tobacco mosaic virus nanoparticles reveals crystalline macro-domain formation composed of highly oriented nanorods. © 2014 the Partner Organisations.

  5. A superhydrophobic chip based on SU-8 photoresist pillars suspended on a silicon nitride membrane

    KAUST Repository

    Marinaro, Giovanni

    2014-07-28

    We developed a new generation of superhydrophobic chips optimized for probing ultrasmall sample quantities by X-ray scattering and fluorescence techniques. The chips are based on thin Si3N4 membranes with a tailored pattern of SU-8 photoresist pillars. Indeed, aqueous solution droplets can be evaporated and concentrated at predefined positions using a non-periodic pillar pattern. We demonstrated quantitatively the deposition and aggregation of gold glyconanoparticles from the evaporation of a nanomolar droplet in a small spot by raster X-ray nanofluorescence. Further, raster nanocrystallography of biological objects such as rod-like tobacco mosaic virus nanoparticles reveals crystalline macro-domain formation composed of highly oriented nanorods. © 2014 the Partner Organisations.

  6. Analisis dan Perancangan Aplikasi Berbasis Web E-Procurement di PT Pillar Utama Contrindo

    Directory of Open Access Journals (Sweden)

    Sartika Kurniali

    2012-12-01

    Full Text Available The aim of this research is to analyze the current business process at the procurement department at PT Pillar Utama Contrindo as well as develop a web based e-procurement application prototype to supportprocurement process at the company. Interview, survey, as well as analysis and design to develop the prototype are used in the research. The research results in an e-procurement application prototype built to minimize errors on related document filling, help the company to get best price on their supply, and increase control. It can be concluded from the research that the protoype can be implemented to be a tool for the users to decide the best supplier, obtain the best price, and increase control in buying process at PT Pillar Utama Contrindo.

  7. High-Q submicron-diameter quantum-dot microcavity pillars for cavity QED experiments

    DEFF Research Database (Denmark)

    Gregersen, Niels; Lermer, Matthias; Dunzer, Florian

    As/AlAs micropillar design where Bloch-wave engineering is employed to significally enhance the cavity mode confinement in the submicron diameter regime. We demonstrate a record-high vacuum Rabi splitting of 85 µeV of the strong coupling for pillars incorporating quantum dots with modest oscillator strength f ≈ 10....... It is well-known that light-matter interaction depends on the photonic environment, and thus proper engineering of the optical mode in microcavity systems is central to obtaining the desired functionality. In the strong coupling regime, the visibility of the Rabi splitting is described by the light...... coupling in micropillars relied on quantum dots with high oscillator strengths f > 50, our advanced design allows for the observation of strong coupling for submicron diameter quantum dot-pillars with standard f ≈ 10 oscillator strength. A quality factor of 13600 and a vacuum Rabi splitting of 85 µe...

  8. A micro-pillar array to trap magnetic beads in microfluidic systems

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2012-12-01

    A micro-pillar array (MPA) is proposed in this paper to trap and separate magnetic beads (MBs) in microfluidic systems. MBs are used in many biomedical applications due to being compatible in dimension to biomolecules, the large surface area available to attach biomolecules, and the fact that they can be controlled by a magnetic field. Trapping and separating these labeled biomolecules is an important step toward achieving reliable and accurate quantification for disease diagnostics. Nickel Iron (Ni50Fe 50) micro-pillars were fabricated on a Silicon (Si) substrate by standard microfabrication techniques. Experimental results showed that MBs could be trapped on the MPA at the single bead level and separated from other non-target particles. This principle can easily be extended to trap and separate target biomolecules in heterogeneous biological samples. © 2012 IEEE.

  9. The Issue of Data Protection and Data Security in the (Pre-Lisbon EU Third Pillar

    Directory of Open Access Journals (Sweden)

    Maria O'Neill

    2010-06-01

    Full Text Available The key functional operability in the pre-Lisbon PJCCM pillar of the EU is the exchange of intelligence and information amongst the law enforcement bodies of the EU. The twin issues of data protection and data security within what was the EU’s third pillar legal framework therefore come to the fore. With the Lisbon Treaty reform of the EU, and the increased role of the Commission in PJCCM policy areas, and the integration of the PJCCM provisions with what have traditionally been the pillar I activities of Frontex, the opportunity for streamlining the data protection and data security provisions of the law enforcement bodies of the post-Lisbon EU arises. This is recognised by the Commission in their drafting of an amending regulation for Frontex , when they say that they would prefer “to return to the question of personal data in the context of the overall strategy for information exchange to be presented later this year and also taking into account the reflection to be carried out on how to further develop cooperation between agencies in the justice and home affairs field as requested by the Stockholm programme.” The focus of the literature published on this topic, has for the most part, been on the data protection provisions in Pillar I, EC. While the focus of research has recently sifted to the previously Pillar III PJCCM provisions on data protection, a more focused analysis of the interlocking issues of data protection and data security needs to be made in the context of the law enforcement bodies, particularly with regard to those which were based in the pre-Lisbon third pillar. This paper will make a contribution to that debate, arguing that a review of both the data protection and security provision post-Lisbon is required, not only in order to reinforce individual rights, but also inter-agency operability in combating cross-border EU crime. The EC’s provisions on data protection, as enshrined by Directive 95/46/EC, do not apply

  10. Dense high-aspect ratio 3D carbon pillars on interdigitated microelectrode arrays

    DEFF Research Database (Denmark)

    Amato, Letizia; Heiskanen, Arto; Hansen, Rasmus

    2015-01-01

    In this work we present high-aspect ratio carbon pillars (1.4 μm in diameter and ∼11 μm in height) on top of interdigitated electrode arrays to be used for electrochemical applications. For this purpose, different types of 2D and 3D pyrolysed carbon structures were fabricated and characterised...... of pyrolysed carbon films with increased film resistance due to oxidation during storage....

  11. Environmental Remediation and Sorption of Metal Cations Using Aluminum Pillared Nano-Bentonite

    Science.gov (United States)

    Rifai, Rifai; Abou El Safa, Magda

    2015-04-01

    The release of heavy metal cations into the environment is a potential threat to water and soil quality. Some clay minerals play an important role, as physical and chemical barriers, for the isolation of metal-rich wastes and to adsorb heavy metals as well as to avoid their environmental dispersion. In the present study, the bentonitic clay (southeast El-Hammam City, Egypt) was subjected to pillaring using hydroxyl-aluminum solution. The XRD patterns of the Aluminum Pillared Nano-Bentonite (APNB) showed severe alteration of the crystal structure after pillaring. Poly metal solutions with different metal concentrations of Cu, Co, Ni, Zn, Cd and Pb (0.001, 0.005 and 0.01 moles), and pH (1, 2.5, 5 and 6) were subjected to treatment by the APNB. The removal process is very rapid and spontaneous and the contact time may be short (several minutes) for most adsorption to occur. The criterion for environmental remediation of APNB is less stringent and a short contact time is sufficient. The rate of Cu2+, Zn2+, Co2+, Cd2+, Ni2+ and Pb2+sorption remained higher or equal to the CEC. The sorption of metal ions by APNB are complex and probably involve several mechanisms. In general, APNB can be used to immobilize Cu2+, Zn2+, Co2+, Cd2+, Ni2+ and Pb2+ to any extent. For each metal ion, the most effective immobilization occurs over a particular pH around 5. According to the experimental data obtained, the uptake amount of the studied cations by APNB increased with increasing solution pH, sorbent dose and contact time. The preference of the APNB adsorption for heavy metal ions that are through the cation exchange processes decreases in the order: Cu2+>Zn2+>Co2+>Cd2+ >Ni2+ >Pb2+. Keywords: Bentonitic clay, Egypt, Aluminum Pillared Nano-Bentonite, heavy metal, environmental remediation

  12. Use of Pillared Clay-Based Catalysts for Wastewater Treatment through Fenton-Like Processes

    OpenAIRE

    J. Herney-Ramírez; Luis M. Madeira

    2010-01-01

    Clays, both natural and physical-chemically modified, are attractive materials for the preparation of supported catalysts. In this chapter, a review is made regarding the use of pillared interlayered clays (PILCs) in heterogeneous Fenton-like advanced oxidation processes. Their applications in pollutants degradation is summarized, with particular emphasis on the effect of the main operating conditions (e.g., initial H2O2 or parent compound concentration, catalyst load, pH, or temperature) on ...

  13. Analysis of the situation in the textile industry in Мacedonia through four quality pillars

    OpenAIRE

    Mitreva, Elizabeta; Risteski, Sanja; Srebrenkoska, Vineta; Lazarevski, Ilija

    2016-01-01

    In this paper is elaborated and confirmed the need of projection and implementation of total quality management (TQM) system within Macedonian textile factories. Quality should be required not only in the production process, but in all parts of the business processes, even in the way the employees behave. An analysis is made on the situation in the textile industry in Macedonia and its progress through the four quality pillars: internal standardization, statistical process control appliance, ...

  14. Porphyrinic supramolecular daisy chains incorporating pillar[5]arene-viologen host-guest interactions

    KAUST Repository

    Fathalla, Maher; Strutt, Nathan; Srinivasan, Sampath; Katsiev, Khabiboulakh; Hartlieb, Karel J.; Bakr, Osman; Stoddart, J. Fraser

    2015-01-01

    A porphyrin functionalised with pillar[5]arene and a viologen at its 5- and 15-meso positions assembles in a head-to-tail manner, producing linear supramolecular daisy chains in dichloromethane. At high concentrations, it forms an organogel which has been investigated by electron microscopy and rheological measurements, paving the way for the preparation of other functional supramolecular assemblies which harness viologen"⊂" pillararene host-guest interactions.

  15. UNESCO: The four pillars of ‘postmodern education’”

    OpenAIRE

    Silva, Lenildes Ribeiro

    2008-01-01

    This article sets out to establish a relationship between discussions on education mentioned in the report to UNESCO – Education: a treasure to discover – and Lyotard’s post-modernity discourse. It presents the proposal for education from this report, highlighting the four pillars of education: learning to know, learning to do, learning to be and live together, taking as their starting point the relationship between the process of globalization and the discourse of postmodernity and these pil...

  16. A framework for work-based learning: basic pillars and the interactions between them

    OpenAIRE

    Ferrández Berrueco, María Reina; Kekale, Tauno; Devins, David

    2016-01-01

    Purpose – European policy is placing an increasing emphasis on involving employers and labour market institutions in the design and delivery of higher education (HE) programmes that match curricula to current and future needs of the economy. The purpose of this paper is to investigate the curriculum development process for work-based learning (WBL) programmes and to connect it to the basic pillars, organizational and pedagogical strategies and key stages that enable higher education instit...

  17. Porphyrinic supramolecular daisy chains incorporating pillar[5]arene-viologen host-guest interactions

    KAUST Repository

    Fathalla, Maher

    2015-05-18

    A porphyrin functionalised with pillar[5]arene and a viologen at its 5- and 15-meso positions assembles in a head-to-tail manner, producing linear supramolecular daisy chains in dichloromethane. At high concentrations, it forms an organogel which has been investigated by electron microscopy and rheological measurements, paving the way for the preparation of other functional supramolecular assemblies which harness viologen"⊂" pillararene host-guest interactions.

  18. Preparation and extraction of sloping seams without leaving inter-drift coal pillars

    Energy Technology Data Exchange (ETDEWEB)

    Artamonov, N S; Bormotov, I N; Brovko, I I

    1977-10-01

    A description is given of mining three coal seams in the Kuznetsk Basin without leaving coal pillars because they could not withstand the stress of the induced reference pressure. This system reduced coal losses in 1976 in comparison to 1970 and eliminated local accumulations of methane by withdrawing it through the excavated area. The system was noted to have the disadvantage of additional expenditures for timber supports. 2 figures.

  19. Enhanced photocatalytic activity of microwave treated TiO2 pillared montmorillonite

    International Nuclear Information System (INIS)

    Sun Shenmei; Jiang Yinshan; Yu Lixin; Li Fangfei; Yang Zhengwen; Hou Tianyi; Hu Daqiang; Xia Maosheng

    2006-01-01

    TiO 2 pillared montmorillonite synthesized by microwave irradiation, exhibited good photocatalytic degradation performance of methyl orange, whose pseudo first order reaction rate constant was nearly four times than that of conventional method, because of its enhanced crystalline, preferred anatase phase and improved porosity performance, which were analysed by X-ray diffraction (XRD), far Fourier transform infrared ray spectroscopy (FTIR) and nitrogen adsorption isotherms

  20. Fabrication method to create high-aspect ratio pillars for photonic coupling of board level interconnects

    Science.gov (United States)

    Debaes, C.; Van Erps, J.; Karppinen, M.; Hiltunen, J.; Suyal, H.; Last, A.; Lee, M. G.; Karioja, P.; Taghizadeh, M.; Mohr, J.; Thienpont, H.; Glebov, A. L.

    2008-04-01

    An important challenge that remains to date in board level optical interconnects is the coupling between the optical waveguides on printed wiring boards and the packaged optoelectronics chips, which are preferably surface mountable on the boards. One possible solution is the use of Ball Grid Array (BGA) packages. This approach offers a reliable attachment despite the large CTE mismatch between the organic FR4 board and the semiconductor materials. Collimation via micro-lenses is here typically deployed to couple the light vertically from the waveguide substrate to the optoelectronics while allowing for a small misalignment between board and package. In this work, we explore the fabrication issues of an alternative approach in which the vertical photonic connection between board and package is governed by a micro-optical pillar which is attached both to the board substrate and to the optoelectronic chips. Such an approach allows for high density connections and small, high-speed detector footprints while maintaining an acceptable tolerance between board and package. The pillar should exhibit some flexibility and thus a high-aspect ratio is preferred. This work presents and compares different fabrication methods and applies different materials for such high-aspect ratio pillars. The different fabrication methods are: photolithography, direct laser writing and deep proton writing. The selection of optical materials that was investigated is: SU8, Ormocers, PU and a multifunctional acrylate polymer. The resulting optical pillars have diameters ranging from 20um up to 80um, with total heights ranging between 30um and 100um (symbol for micron). The aspect-ratio of the fabricated structures ranges from 1.5 to 5.

  1. Rockburst Disaster Prediction of Isolated Coal Pillar by Electromagnetic Radiation Based on Frictional Effect

    Science.gov (United States)

    Zhao, Tongbin; Yin, Yanchun; Xiao, Fukun; Tan, Yunliang; Zou, Jianchao

    2014-01-01

    Based on the understanding that charges generated during coal cracking are due to coal particle friction, a microstructure model was developed by considering four different variation laws of friction coefficient. Firstly, the frictional energy release of coal sample during uniaxial compressive tests was investigated and discussed. Then electromagnetic radiation method was used to predict the potential rockburst disaster in isolated coal pillar mining face, Muchengjian Colliery. The results indicate that the friction coefficient of coal particles decreases linearly with the increase of axial loading force. In predicting the strain-type rockburst, the high stress state of coal must be closely monitored. Field monitoring shows that electromagnetic radiation signal became abnormal before the occurrence of rockburst during isolated coal pillar mining. Furthermore, rockburst tends to occur at the early and ending stages of isolated coal pillar extraction. Mine-site investigation shows the occurrence zone of rockburst is consistent with the prediction, proving the reliability of the electromagnetic radiation method to predict strain-type rockburst disaster. PMID:25054186

  2. The pillar of metropolitan greatness: The long making of archeological objects in Paris (1711-2001).

    Science.gov (United States)

    Van Damme, Stéphane

    2017-09-01

    Over three centuries after the 1711 discovery in the choir of Notre-Dame in Paris of a square-section stone bas-relief (the Pillar of the Boatmen) with depictions of several deities, both Gaulish and Roman, the blocks comprising it were analyzed as a symbol of Parisian power, if not autonomy, vis-à-vis the Roman Empire. Variously considered as local, national, or imperial representations, the blocks were a constant object of admiration, interrogation, and speculation among antiquarians of the Republic of Letters. They were also boundary objects - products of the emergence of a Parisian archeology dated from 1711. If this science reflected the tensions and ambiguities of a local regime of knowledge situated in a national context, it also helped to coordinate archeological work between different institutions and actors. This paper would like to assess the specific role played by the Pillar of the Boatmen as a fetish object in this process. To what extent could an archeological artifact influence this reshaping of urban representation, this change of scales? By following the three-century career of the pillar's blocks as composite objects, which some have identified as merely stones or a column, it is possible to understand the multiple dimensions that defined the object as archeological - as an artifact that contributed to the relocating of the historical city center - and the multiple approaches that transform existing remains into knowledgeable objects.

  3. A Monte Carlo model for the intermittent plasticity of micro-pillars

    International Nuclear Information System (INIS)

    Ng, K S; Ngan, A H W

    2008-01-01

    Earlier compression experiments on micrometre-sized aluminium pillars, fabricated by focused-ion beam milling, using a flat-punch nanoindenter revealed that post-yield deformation during constant-rate loading was jerky with interspersing strain bursts and linear elastic segments. Under load hold, the pillars crept mainly by means of sporadic strain bursts. In this work, a Monte Carlo simulation model is developed, with two statistics gathered from the load-ramp experiments as input, to account for the jerky deformation during the load ramp as well as load hold. Under load-ramp conditions, the simulations successfully captured other experimental observations made independently from the two inputs, namely, the diverging behaviour of the jerky stress–strain response at higher stresses, the increase in burst frequency and burst size with stress and the overall power-law distribution of the burst size. The model also predicts creep behaviour agreeable with the experimental observations, namely, the occurrence of sporadic bursts with frequency depending on stress, creep time and pillar dimensions

  4. Empirical approach for designing of support system in mechanized coal pillar mining

    Energy Technology Data Exchange (ETDEWEB)

    Kushwaha, A.; Singh, S.K.; Tewari, S.; Sinha, A. [Central Institute of Mining & Fuel Research, Dhanbad (India)

    2010-10-15

    Mechanized room-and-pillar system of coal pillar mining using side dump loading machine or load haul dumper machine, or by continuous miner, is the presently most dominant under ground method of extraction in India. Under this method of extraction, strata control is a major problem affecting safety and productivity of the mine. As per existing Director General of Mine Safety guidelines, systematic support rules must be followed at the depillaring faces irrespective of immediate roof rock type and competency. Therefore, there is a high chance that sometimes these systematic support rules give unnecessarily high support, or sometimes inadequate support, which may lead to roof failure at the face. As a result, there is a big loss of life and material including coal in terms of left-outribs/stooks and other associated mining equipment deployed at the faces. Therefore, in the present paper, authors attempted to develop generalized empirical equations for estimating the required support load density at different places of the face based on geotechnical parameters of the mine and physico-mechanical properties of the immediate roof rocks for designing of support system during mechanized coal pillar mining.

  5. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials.

    Science.gov (United States)

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2014-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m 2 g -1 , has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m 2 g -1 /N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m 2 g -1 ) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m 2 g -1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent.

  6. Model of care for a changing healthcare system: are there foundational pillars for design?

    Science.gov (United States)

    Booker, Catriona; Turbutt, Adam; Fox, Robyn

    2016-04-01

    Currently, healthcare organisations are being challenged to provide optimal clinical services within budget limitations while simultaneously being confronted by aging consumers and labour and skill shortages. Within this dynamic and changing environment, the ability to remain responsive to patient needs while managing these issues poses further challenges. Development or review of the model of care (MOC) may provide a possible solution to support efficiencies in service provision. Although MOC are not readily understood or appreciated as an efficiency strategy, they can be more easily explained by considering several recurring pillars when developing or redesigning an MOC. Generic and recurring foundational pillars include integrated care models, team functioning and communication, leadership, change management and lean thinking. These foundational pillars should be incorporated into the development and application of MOC in order to achieve desired outcomes. However, sustainability requires continuous review to enable improvement and must be integrated into routine business. Moreover, successful review of MOC requires collaboration and commitment by all stakeholders. Leaders are critical to motivating clinicians and stakeholders in the review process. Further, it is imperative that leaders engage stakeholders to commit to support the agreed strategies designed to provide efficient and comprehensive healthcare services. Redesign of MOC can significantly improve patient care by applying the agreed strategies. In the current healthcare environment, these strategies can favourably affect healthcare expenditure and, at the same time, improve the quality of interprofessional health services.

  7. Surface displacements and pillar stresses associated with nuclear waste disposal in salt

    International Nuclear Information System (INIS)

    Hardy, M.P.; St John, C.M.

    1977-01-01

    A numerical model for regional analysis of stresses and displacement, resulting from heat generating waste placement in underground salt excavations, is presented. The model, which is an extension of that described by McClain and Starfield (1971), is based upon the displacement discontinuity method of stress analysis. It incorporates an empirical characterization of creep behavior of material on the excavation horizon and accounts for thermally induced stresses and displacements. The versatility of this approach is illustrated by the results of three relatively short simulations of test scale disposal facilities at shallow and greater depths. In addition, a three-dimensional code was used to evaluate the surface displacement history for a full-scale repository. This latter code, a thermoelastic analysis, gives an upper bound for the surface movements. It is concluded that the pillar stresses are the result of a complex non-linear interaction of many variables, and the maximum pillar stress can reach several multiples of the tributory-area pillar stress

  8. Planning maximum extraction of a safety pillar in the Most surface mine

    Energy Technology Data Exchange (ETDEWEB)

    Helis, P; Hess, L; Kubiznak, K [SHR - Banske Projekty, Teplice (Czechoslovakia)

    1990-11-01

    Discusses planned coal surface mining in the Most mine in the area of the Hnevin safety pillar with coal reserves amounting to about 7.5 Mt. The following aspects are evaluated: coal reserves and their distribution in the pillar, coal seam thickness and dip angles, water conditions, water influx rates, mechanical properties of the overburden and strata situated in the seam floor, slope stability and hazards of landslides, effects of water influx on landslide hazards, types of bucket wheel excavators used for overburden removal and mining, types of belt conveyors used for mine haulage, stackers, position of mining equipment in the mine. A scheme developed by Banske Projekty Teplice for partial extraction of the safety pillar would result in extraction of 4.5 Mt coal. About 1.7 Mt coal would be left in a safety coal layer about 10.0 m thick situated in the floor in zones with landslide hazards. KU 300 bucket wheel excavators, belt conveyors 1,200 mm wide and ZP 2,500 stackers would be used. 4 refs.

  9. Rockburst Disaster Prediction of Isolated Coal Pillar by Electromagnetic Radiation Based on Frictional Effect

    Directory of Open Access Journals (Sweden)

    Tongbin Zhao

    2014-01-01

    Full Text Available Based on the understanding that charges generated during coal cracking are due to coal particle friction, a microstructure model was developed by considering four different variation laws of friction coefficient. Firstly, the frictional energy release of coal sample during uniaxial compressive tests was investigated and discussed. Then electromagnetic radiation method was used to predict the potential rockburst disaster in isolated coal pillar mining face, Muchengjian Colliery. The results indicate that the friction coefficient of coal particles decreases linearly with the increase of axial loading force. In predicting the strain-type rockburst, the high stress state of coal must be closely monitored. Field monitoring shows that electromagnetic radiation signal became abnormal before the occurrence of rockburst during isolated coal pillar mining. Furthermore, rockburst tends to occur at the early and ending stages of isolated coal pillar extraction. Mine-site investigation shows the occurrence zone of rockburst is consistent with the prediction, proving the reliability of the electromagnetic radiation method to predict strain-type rockburst disaster.

  10. Influence of a Large Pillar on the Optimum Roadway Position in an Extremely Close Coal Seam

    Directory of Open Access Journals (Sweden)

    Li Yang

    2016-01-01

    Full Text Available Based on the mining practice in an extremely close coal seam, theoretical analysis was conducted on the vertical stress distribution of the floor strata under a large coal pillar. The vertical stress distribution regulation of a No. 5 coal seam was revealed. To obtain the optimum position of the roadway that bears the supporting pressure of a large coal pillar, numerical modeling was applied to analyze the relation among the stress distribution of the roadway surrounding the rock that bears the supporting pressure of a large coal pillar, the plastic zone distribution of the roadway surrounding the rock, the surrounding rock deformation, and the roadway layout position. The theoretical calculation results of the stress value, stress variation rate, and influencing range of the stress influencing angle showed that the reasonable malposition of the No. 5 coal seam roadway was an inner malposition of 4 m. The mining practice showed the following: the layout of No. 25301 panel belt roadway at the position of the inner malposition of 4 m was reasonable, the roadway support performance was favourable without deformation, and ground pressure was not obvious. The research achievement of this study is the provision of a reference for roadway layouts under similar conditions.

  11. Basel’s Forgotten Pillar: The Myth of Market Discipline on the Forefront of Basel III

    Directory of Open Access Journals (Sweden)

    Vahit Ferhan Benli

    2016-01-01

    Full Text Available Although Basel II fortified the first two pillars with market transparency enhancing Pillar III disclosures and encouraged the usage of major Credit Rating Agencies (CRAs such as Moody’s, Standard and Poor’s, and Fitch as quasi governmental authorities to overcome asymmetric informational problems on risk and capital adequacy fronts of the global financial system, the recent global financial crisis has proven just the opposite. The banks and regulators were not in a position to truly assess the risk and capital adequacy frameworks of the global and domestic financial institutions based on the assessments of the rating agencies. To overcome the problem of informational asymmetry for the market participants, the Basel Committee on Banking Supervision set out new proposals for enhanced Pillar III disclosures in the areas of credit risks and capital reporting standards on the forefront of Basel III that would come into effect on April 1, 2016. This paper is a critical evaluation of the new reporting proposals of BCBS within the critical role of the credit rating agencies.

  12. The 5 Clinical Pillars of Value for Total Joint Arthroplasty in a Bundled Payment Paradigm.

    Science.gov (United States)

    Kim, Kelvin; Iorio, Richard

    2017-06-01

    Our large, urban, tertiary, university-based institution reflects on its 4-year experience with Bundled Payments for Care Improvement. We will describe the importance of 5 clinical pillars that have contributed to the early success of our bundled payment initiative. We are convinced that value-based care delivered through bundled payment initiatives is the best method to optimize patient outcomes while rewarding surgeons and hospitals for adapting to the evolving healthcare reforms. We summarize a number of experiences and lessons learned since the implementation of Bundled Payments for Care Improvement at our institution. Our experience has led to the development of more refined clinical pathways and coordination of care through evidence-based approaches. We have established that the success of the bundled payment program rests on the following 5 main clinical pillars: (1) optimizing patient selection and comorbidities; (2) optimizing care coordination, patient education, shared decision making, and patient expectations; (3) using a multimodal pain management protocol and minimizing narcotic use to facilitate rapid rehabilitation; (4) optimizing blood management, and standardizing venous thromboembolic disease prophylaxis treatment by risk standardizing patients and minimizing the use of aggressive anticoagulation; and (5) minimizing post-acute facility and resource utilization, and maximizing home resources for patient recovery. From our extensive experience with bundled payment models, we have established 5 clinical pillars of value for bundled payments. Our hope is that these principles will help ease the transition to value-based care for less-experienced healthcare systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. In situ synthesis, characterization, and catalytic performance of tungstophosphoric acid encapsulated into the framework of mesoporous silica pillared clay.

    Science.gov (United States)

    Li, Baoshan; Liu, Zhenxing; Han, Chunying; Ma, Wei; Zhao, Songjie

    2012-07-01

    Mesoporous silica pillared clay (SPC) incorporated with tungstophosphoric acid (HPW) has been synthesized via in situ introducing P and W source in the acidic suspension of the clay interlayer template during the formation of the silica pillared clay. The samples were characterized by XRD, XRF, FT-IR, TG-DTA, N(2) adsorption-desorption, and SEM techniques. The results showed that the HPW formed by in situ method has been effectively introduced into the framework of mesoporous silica pillared clay and its Keggin structure remained perfectly after formation of the materials. In addition, samples with similar HPW loadings were also prepared by impregnation method using SPC as the support. HPW in the incorporated samples was better dispersed into the silica pillared clay than in the impregnated samples. The results of catalytic tests indicated that the encapsulated materials demonstrated better catalytic performance than the impregnated samples in oxidative desulfurization (ODS) of dibenzothiophene (DBT). Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Template-directed synthesis of pillared-porous carbon nanosheet architectures: High-performance electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhuangjun; Liu, Yang; Yan, Jun; Wang, Qian; Wei, Tong [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin (China); Ning, Guoqing [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, Changping (China); Zhi, Linjie [National Center for Nanoscience and Technology of China, Zhongguancun, Beijing (China); Wei, Fei [Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing (China)

    2012-04-15

    3D pillared-porous carbon nanosheets with supporting carbon pillars between the carbon layers is prepared by the carbonization of pitch on porous MgO templates. This unique structure endows the high-rate transportation of electrolyte ions and electrons throughout the electrode matrix, resulting in excellent electrochemical performance. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Comparative Evaluation of Dimensional Accuracy of Elastomeric Impression Materials when Treated with Autoclave, Microwave, and Chemical Disinfection.

    Science.gov (United States)

    Kamble, Suresh S; Khandeparker, Rakshit Vijay; Somasundaram, P; Raghav, Shweta; Babaji, Rashmi P; Varghese, T Joju

    2015-09-01

    Impression materials during impression procedure often get infected with various infectious diseases. Hence, disinfection of impression materials with various disinfectants is advised to protect the dental team. Disinfection can alter the dimensional accuracy of impression materials. The present study was aimed to evaluate the dimensional accuracy of elastomeric impression materials when treated with different disinfectants; autoclave, chemical, and microwave method. The impression materials used for the study were, dentsply aquasil (addition silicone polyvinylsiloxane syringe and putty), zetaplus (condensation silicone putty and light body), and impregum penta soft (polyether). All impressions were made according to manufacturer's instructions. Dimensional changes were measured before and after different disinfection procedures. Dentsply aquasil showed smallest dimensional change (-0.0046%) and impregum penta soft highest linear dimensional changes (-0.026%). All the tested elastomeric impression materials showed some degree of dimensional changes. The present study showed that all the disinfection procedures produce minor dimensional changes of impression material. However, it was within American Dental Association specification. Hence, steam autoclaving and microwave method can be used as an alternative method to chemical sterilization as an effective method.

  16. Elastomeric Structural Attachment Concepts for Aircraft Flap Noise Reduction - Challenges and Approaches to Hyperelastic Structural Modeling and Analysis

    Science.gov (United States)

    Sreekantamurthy, Thammaiah; Turner, Travis L.; Moore, James B.; Su, Ji

    2014-01-01

    Airframe noise is a significant part of the overall noise of transport aircraft during the approach and landing phases of flight. Airframe noise reduction is currently emphasized under the Environmentally Responsible Aviation (ERA) and Fixed Wing (FW) Project goals of NASA. A promising concept for trailing-edge-flap noise reduction is a flexible structural element or link that connects the side edges of the deployable flap to the adjacent main-wing structure. The proposed solution is distinguished by minimization of the span-wise extent of the structural link, thereby minimizing the aerodynamic load on the link structure at the expense of increased deformation requirement. Development of such a flexible structural link necessitated application of hyperelastic materials, atypical structural configurations and novel interface hardware. The resulting highly-deformable structural concept was termed the FLEXible Side Edge Link (FLEXSEL) concept. Prediction of atypical elastomeric deformation responses from detailed structural analysis was essential for evaluating feasible concepts that met the design constraints. The focus of this paper is to describe the many challenges encountered with hyperelastic finite element modeling and the nonlinear structural analysis of evolving FLEXSEL concepts. Detailed herein is the nonlinear analysis of FLEXSEL concepts that emerged during the project which include solid-section, foamcore, hollow, extended-span and pre-stressed concepts. Coupon-level analysis performed on elastomeric interface joints, which form a part of the FLEXSEL topology development, are also presented.

  17. The Effect of Herbal Mouthwashes on the Force Decay of Elastomeric Chains: An In-vitro Study

    Directory of Open Access Journals (Sweden)

    Mohammed Nahidh

    2017-10-01

    Full Text Available Background: This in vitro study aimed to evaluate the effect of four herbal mouthwashes on the force decay of two types of clear short elastomeric chains (Regular and Extreme at various time intervals. Materials and methods: Four hundred forty pieces of both types of elastomeric chains with 19 mm length were utilized in this study. The force was measured, using digital scale immediately, after one-day immersion in distilled water and after 1, 2, 3 and 4 weeks immersion in the specific mouthwash for one minute twice daily then washed and kept in distilled water at 37°C. Force decay was calculated and compared among different elastic types, mouthwashes and time intervals using t-test and one-way ANOVA then Tukey’s tests. Results: The force degradation of regular type was significantly higher than extreme one. With time, the force decay increased significantly in both types. There was non-significant difference among the mouthwashes in the first and second weeks while the opposite in the third and fourth especially with the control group. Conclusions: The extreme type is preferred over the regular one because of its low force decay and the tested mouthwashes have no clinical significant effect on the force degradation over time in comparison with distilled water.

  18. Low-level laser therapy effects on pain perception related to the use of orthodontic elastomeric separators

    Directory of Open Access Journals (Sweden)

    Rachel D'Aurea Furquim

    2015-06-01

    Full Text Available INTRODUCTION: Some patients refer to pre-banding orthodontic separation as a painful orthodontic procedure. Low-level laser therapy (LLLT has been reported to have local analgesic effect. OBJECTIVE: The aim of this single-blind study was to investigate the perception of pain caused by orthodontic elastomeric separators with and without a single LLLT application (6J. METHODS: The sample comprised 79 individuals aged between 13 and 34 years old at orthodontic treatment onset. Elastomeric separators were placed in first maxillary molars at mesial and distal surfaces and kept in place for three days. The volunteers scored pain intensity on a visual analogue scale (VAS after 6 and 12 hours, and after the first, second and third days. One third of patients received laser applications, whereas another third received placebo applications and the remaining ones were controls. Applications were performed in a split-mouth design. Thus, three groups (laser, placebo and control were assessed. RESULTS: No differences were found among groups considering pain perception in all periods observed. CONCLUSION: The use of a single-dose of LLLT did not cause significant reduction in orthodontic pain perception. Overall pain perception due to orthodontic separator placement varied widely and was usually mild.

  19. Solving the critical thermal bowing in 3C-SiC/Si(111) by a tilting Si pillar architecture

    Science.gov (United States)

    Albani, Marco; Marzegalli, Anna; Bergamaschini, Roberto; Mauceri, Marco; Crippa, Danilo; La Via, Francesco; von Känel, Hans; Miglio, Leo

    2018-05-01

    The exceptionally large thermal strain in few-micrometers-thick 3C-SiC films on Si(111), causing severe wafer bending and cracking, is demonstrated to be elastically quenched by substrate patterning in finite arrays of Si micro-pillars, sufficiently large in aspect ratio to allow for lateral pillar tilting, both by simulations and by preliminary experiments. In suspended SiC patches, the mechanical problem is addressed by finite element method: both the strain relaxation and the wafer curvature are calculated at different pillar height, array size, and film thickness. Patches as large as required by power electronic devices (500-1000 μm in size) show a remarkable residual strain in the central area, unless the pillar aspect ratio is made sufficiently large to allow peripheral pillars to accommodate the full film retraction. A sublinear relationship between the pillar aspect ratio and the patch size, guaranteeing a minimal curvature radius, as required for wafer processing and micro-crack prevention, is shown to be valid for any heteroepitaxial system.

  20. In-plane confinement and waveguiding of surface acoustic waves through line defects in pillars-based phononic crystal

    Directory of Open Access Journals (Sweden)

    Abdelkrim Khelif

    2011-12-01

    Full Text Available We present a theoretical analysis of an in-plane confinement and a waveguiding of surface acoustic waves in pillars-based phononic crystal. The artificial crystal is made up of cylindrical pillars placed on a semi-infinite medium and arranged in a square array. With a well-chosen of the geometrical parameters, this pillars-based system can display two kinds of complete band gaps for guided waves propagating near the surface, a low frequency gap based on locally resonant mode of pillars as well as a higher frequency gap appearing at Bragg scattering regime. In addition, we demonstrate a waveguiding of surface acoustic wave inside an extended linear defect created by removing rows of pillars in the perfect crystal. We discuss the transmission and the polarization of such confined mode appearing in the higher frequency band gap. We highlight the strong similarity of such defect mode and the Rayleigh wave of free surface medium. An efficient finite element analysis is used to simulate the propagation of guided waves through silicon pillars on a silicon substrate.

  1. Plaque retention by self-ligating vs elastomeric orthodontic brackets: quantitative comparison of oral bacteria and detection with adenosine triphosphate-driven bioluminescence.

    NARCIS (Netherlands)

    Pellegrini, P.; Sauerwein, R.W.; Finlayson, T.; McLeod, J.; Covell, D.A.; Maier, T.; Machida, C.A.

    2009-01-01

    INTRODUCTION: Enamel decalcification is a common problem in orthodontics. The objectives of this randomized clinical study were to enumerate and compare plaque bacteria surrounding 2 bracket types, self-ligating (SL) vs elastomeric ligating (E), and to determine whether adenosine triphosphate

  2. Sixteen-week analysis of unaltered elastomeric chain relating in-vitro force degradation with in-vivo extraction space tooth movement.

    Science.gov (United States)

    Evans, Kristin S; Wood, Cory M; Moffitt, Allen H; Colgan, John A; Holman, J Kevin; Marshall, Steven D; Pope, D Spencer; Sample, Lew B; Sherman, Stephen L; Sinclair, Peter M; Trulove, Tim S

    2017-04-01

    The purposes of this study were to evaluate whether unaltered elastomeric chain can continue to move teeth for 16 weeks and to relate it to the amount of force remaining for the same batch of elastomeric chains. The in-vivo portion of the study had a sample of 30 paired extraction space sites from 22 subjects who were measured for closure of the space every 28 days. The altered side elastomeric chain served as the control and was replaced at 28-day intervals whereas the experimental side remained unaltered. In the in-vitro portion of the study, 100 each of 2-unit and 3-unit segments of the same batch of elastomeric chains were placed in a water bath, and the force was measured for 20 of each segment length at the 28-day measurement points. Statistically significant amounts of space closure occurred at both the altered and unaltered sites at all measurement time points. The mean space closure at the altered sites was minimally greater than that observed at the paired unaltered sites. The mean differences of space closure between the altered and unaltered sites ranged from a minimum of -0.05 mm at 4 weeks to a maximum of -0.14 mm at 8 weeks. The elastomeric chain force degraded rapidly by 4 weeks but continued a gradual diminution of force to 86 g at 16 weeks. Unaltered elastomeric chain continued to move teeth into extraction spaces for 16 weeks in this sample from both statistically and clinically significant standpoints. There were minimal and statistically insignificant differences in the mean space closure measurements between the paired altered and unaltered sites. The elastomeric chain force at 16 weeks was less than 100 g, yet at the same time point, teeth continued to move clinically. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  3. THE SYNTHESIS OF Cr2O3-PILLARED MONTMORILLONITE (CrPM AND ITS USAGE FOR HOST MATERIAL OF p-NITROANILINE

    Directory of Open Access Journals (Sweden)

    Karna Wijaya

    2010-06-01

    Full Text Available The synthesis of Cr2O3-pillared montmorillonite (CrPM and its usage for host material of p-nitroaniline have been conducted. The Cr2O3-pillared montmorillonite clays was prepared by a direct ion exchange method. First, the polyhydroxychromium as a pillaring spesies was intercalated into the interlayer region of the montmorillonite clays (purified clay in the monocation form, result in a montmorillonite-polyoxychromium intercalation compound. The precursors/pillaring spesies was not stable, hence it must be stabilized by calcination in order to transform the polyoxychromium via dehydration and dehydroxylation processes into Cr2O3. This oxide constituts the so-called pillar that prop the clay layers apart to a relatively large distance. The Cr2O3-pillared clays as a host material was added into ethanol solution saturated with p-nitroaniline, and mixture was stirred for 24 h at room temperature. The Na-montmorillonite, Cr2O3-pillared clay and p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM were characterized by X-Ray Diffraction (XRD, Gas Sorption Analysis, Infrared Spectroscopy (FTIR and Activated Neutron Analysis (ANA methods. The result of research showed that basal spacing (d001 of Cr2O3-pillared montmorillonite (CrPM was 18,55 Å, meanwhile the basal spacing of the hydrated Na-montmorillonite was 14,43 Å. The specific surface area of the Cr2O3-pillared montmorillonite was 174,308 m2/g, whereas p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM was 133,331641 m2/g. This fact indicated that p-nitroaniline has been included into the pore of the Cr2O3-pillared clay.   Keyword: montmorillonite, pillared-clay, ion exchange, intercalate.

  4. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    International Nuclear Information System (INIS)

    Staub, Isabelle; Andersson, J. Christer; Magnor, Bjoern

    2004-03-01

    An extensive characterization programme has been performed in the drift, TASQ, excavated for the Aespoe Pillar Stability Experiment, APSE, including the rock volume that will host the experiment pillar between the two deposition holes. The two major objectives with the characterization has been to 1) derive material properties for the final numerical modelling of the experiment and 2) to ensure that the pillar location is suitable from a structural and rock mechanical point of view. In summary the following activities have been performed: Geological mapping of the drift, the pilot holes cores and deposition hole DQ0066G01. 3D-visualisation of the geological mapping in the experiment (pillar) volume of TASQ. Convergence measurements during the excavation and back calculation of the results for determination of the stress tensor and the rock mass Young's modulus. Laboratory tests on core samples from the 15Φ76 mm core boreholes drilled around the pillar volume for determination of: compressive strength, thermal properties and fracture properties. P-wave velocity measurements on core samples and between boreholes for estimation of the excavation damaged zone and rock mass properties. The geological mapping and the 3D-visualisation gives a good description of the TASQ drift in general and the experiment volume in the drift in particular. The fracturing of the drift follows the pattern of the rest of Aespoe. Three fracture sets have been mapped in TASQ. The major fracture set is sub-vertical and trending NW, in principle parallel to σ 1 . This set is the most conductive at Aespoe and is the only water bearing set in TASQ. A second less pronounced set is trending NE, parallel to TASQ, and is also sub-vertical. The third set is sub-horizontal. It is interesting to note that the third set is the only one that almost completely consists of sealed fractures. The first two sets have mostly open fractures. One unique feature in the drift is a heavily oxidized brittle

  5. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle [Golder Associates AB, Uppsala (Sweden); Andersson, J. Christer; Magnor, Bjoern

    2004-03-01

    An extensive characterization programme has been performed in the drift, TASQ, excavated for the Aespoe Pillar Stability Experiment, APSE, including the rock volume that will host the experiment pillar between the two deposition holes. The two major objectives with the characterization has been to 1) derive material properties for the final numerical modelling of the experiment and 2) to ensure that the pillar location is suitable from a structural and rock mechanical point of view. In summary the following activities have been performed: Geological mapping of the drift, the pilot holes cores and deposition hole DQ0066G01. 3D-visualisation of the geological mapping in the experiment (pillar) volume of TASQ. Convergence measurements during the excavation and back calculation of the results for determination of the stress tensor and the rock mass Young's modulus. Laboratory tests on core samples from the 15{phi}76 mm core boreholes drilled around the pillar volume for determination of: compressive strength, thermal properties and fracture properties. P-wave velocity measurements on core samples and between boreholes for estimation of the excavation damaged zone and rock mass properties. The geological mapping and the 3D-visualisation gives a good description of the TASQ drift in general and the experiment volume in the drift in particular. The fracturing of the drift follows the pattern of the rest of Aespoe. Three fracture sets have been mapped in TASQ. The major fracture set is sub-vertical and trending NW, in principle parallel to {sigma}{sub 1}. This set is the most conductive at Aespoe and is the only water bearing set in TASQ. A second less pronounced set is trending NE, parallel to TASQ, and is also sub-vertical. The third set is sub-horizontal. It is interesting to note that the third set is the only one that almost completely consists of sealed fractures. The first two sets have mostly open fractures. One unique feature in the drift is a heavily

  6. Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method.

    Science.gov (United States)

    Motalov, V B; Karasev, N S; Ovchinnikov, N L; Butman, M F

    2017-01-01

    The thermal emission of alkali metal ions from Al 30 -pillared montmorillonite in comparison with its natural form was studied by mass spectrometry in the temperature range 770-930 K. The measurements were carried out on a magnetic mass spectrometer MI-1201. For natural montmorillonite, the densities of the emission currents ( j ) decrease in the mass spectrum in the following sequence (T = 805 K, A/cm 2 ): K + (4.55 · 10 -14 ), Cs + (9.72 · 10 -15 ), Rb + (1.13 · 10 -15 ), Na + (1.75 · 10 -16 ), Li + (3.37 · 10 -17 ). For Al 30 -pillared montmorillonite, thermionic emission undergoes temperature-time changes. In the low-temperature section of the investigated range (770-805 K), the value of j increases substantially for all ions in comparison with natural montmorillonite (T = 805 K, A/cm 2 ): Cs + (6.47 · 10 -13 ), K + (9.44 · 10 -14 ), Na + (3.34 · 10 -15 ), Rb + (1.77 · 10 -15 ), and Li + (4.59 · 10 -16 ). A reversible anomaly is observed in the temperature range 805-832 K: with increasing temperature, the value of j of alkaline ions falls abruptly. This effect increases with increasing ionic radius of M + . After a long heating-up period, this anomaly disappears and the ln j - 1/ T dependence acquires a classical linear form. The results are interpreted from the point of view of the dependence of the efficiency of thermionic emission on the phase transformations of pillars.

  7. Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method

    Directory of Open Access Journals (Sweden)

    V. B. Motalov

    2017-01-01

    Full Text Available The thermal emission of alkali metal ions from Al30-pillared montmorillonite in comparison with its natural form was studied by mass spectrometry in the temperature range 770–930 K. The measurements were carried out on a magnetic mass spectrometer MI-1201. For natural montmorillonite, the densities of the emission currents (j decrease in the mass spectrum in the following sequence (T = 805 K, A/cm2: K+ (4.55 · 10−14, Cs+ (9.72 · 10−15, Rb+ (1.13 · 10−15, Na+ (1.75 · 10−16, Li+ (3.37 · 10−17. For Al30-pillared montmorillonite, thermionic emission undergoes temperature-time changes. In the low-temperature section of the investigated range (770–805 K, the value of j increases substantially for all ions in comparison with natural montmorillonite (T = 805 K, A/cm2: Cs+ (6.47 · 10−13, K+ (9.44 · 10−14, Na+ (3.34 · 10−15, Rb+ (1.77 · 10−15, and Li+ (4.59 · 10−16. A reversible anomaly is observed in the temperature range 805–832 K: with increasing temperature, the value of j of alkaline ions falls abruptly. This effect increases with increasing ionic radius of M+. After a long heating-up period, this anomaly disappears and the lnj-1/T dependence acquires a classical linear form. The results are interpreted from the point of view of the dependence of the efficiency of thermionic emission on the phase transformations of pillars.

  8. Thermal conductivity of pillared graphene-epoxy nanocomposites using molecular dynamics

    Science.gov (United States)

    Lakshmanan, A.; Srivastava, S.; Ramazani, A.; Sundararaghavan, V.

    2018-04-01

    Thermal conductivity in a pillared graphene-epoxy nanocomposite (PGEN) is studied using equilibrium molecular dynamics simulations. PGEN is a proposed material for advanced thermal management applications because it combines high in-plane conductivity of graphene with high axial conductivity of a nanotube to significantly enhance the overall conductivity of the epoxy matrix material. Anisotropic conductivity of PGEN has been compared with that of pristine and functionalized carbon nanotube-epoxy nanocomposites, showcasing the advantages of the unique hierarchical structure of PGEN. Compared to pure carbon allotropes, embedding the epoxy matrix also promotes a weaker dependence of conductivity on thermal variations. These features make this an attractive material for thermal management applications.

  9. The synthesis and application of pillared clays prepared from charge reduced montmorillonite

    Science.gov (United States)

    Engwall, Erik Edwin

    The synthesis of pillared interlayered clays (PILCs) makes use of the cation exchange capacity (CEC) of clay minerals to prop their structures open with large hydroxy-metal cations. Homo-ionic Ca-Montmorillonite with a CEC of 83.9 meq/100 g has been partially exchanged with varied amounts of Li+ and heated to 200°C for 24 hours. These have been used to produce Zr and Al PILCs making use of ethanol/water synthesis solutions to overcome the hydrophobic nature of the clay. For the Zr-PILC system, the d(001) spacings determined by x-ray diffraction (XRD) were relatively constant at 19.0--20.1 A with respect to changing the unpillared CEC. The Zr-PILCs had type I isotherms for argon at 87 K and for benzene, p-xylene and 1,3,5-trimethylbenzene adsorption at 30°C. Several Al-PILC synthesis procedures were evaluated and all produced materials whose adsorption capacity decreased with decreasing unpillared CEC. This reduction in adsorption capacity with unpillared CEC could be partially overcome by the combined use of ethanol/water pillaring solutions with ethanol/water washing. Previously unreported d(001) values in the range of 26.8 to 29.8 A were observed in Al-PILCs and were often bimodal with the expected values of about 18 A. These larger d(001) values were most prevalent at lower CEC values, if pillaring conditions favored the formation of polymeric species other than the Keggin cation. A new micropore size distribution model was developed to better understand PILC pore structure. The new model was compared to the Horvath and Kawazoe (1983) model (HK) and the Cheng and Yang (1994) model (CY) using argon adsorption at 87 K on Zr and Al-PILCs. The interlayer spacings determined by XRD for the test PILCs were 9.5 and 8.5 A for Zr and Al-PILCs respectively. Pore sizes predicted by the new model were 7.5 and 7.3 A for Zr and Al-PILCs respectively. The new model consistently predicts values that are closer to the interlayer spacing than either the HK or CY models. The new

  10. Multiwavelength Imaging Of YSOs With Disk In South Pillars Of Eta Carina

    Science.gov (United States)

    Reyes, J. A.; Porras, B. A.

    2013-04-01

    We present multiwavelength imaginery and spectral energy distributions (SEDs) of 15 Young Stellar Objects (YSOs) with disk components lying on the South Pillars region close to Eta Carina (η Car). The SEDs include IR fluxes from 2MASS, IRAC, MSX, AKARI, and MIPS-24 μm, and 1.1 mm flux from AzTEC camera at the ASTE antenna. Millimeter fluxes help to constrain the number of fitted models, which provide the list of physical parameters for the star, the disk and the envelope. We then compare the parameters of the YSOs and their spatial location within the star forming region.

  11. Is active management of mandatory pension funds in Croatia creating value for second pillar fund members?

    Directory of Open Access Journals (Sweden)

    Petar-Pierre Matek

    2015-09-01

    Full Text Available This paper analyses Croatian mandatory pension funds’ investment returns during the 2005-2014 period using performance attribution methodology. Results from active investment management are compared to a long-term policy return. Such analysis is essential to shed light on the contribution of active portfolio management in the second pillar pension scheme. Evidence suggests that in the period analysed portfolio managers have added value through active management decisions. In addition, we determined the sources of portfolio return by breaking down active return into policy, tactical asset allocation and security selection effect.

  12. International criminal justice: a pillar for the international rule of law

    Directory of Open Access Journals (Sweden)

    Gonzalo Aguilar Cavallo

    2012-12-01

    Full Text Available The international criminal justice has experienced a rapid change over the past years. This circumstance has underscored the need for interaction and complementation between international and domestic law. Some authors consider that the international criminal justice, and the activities of its tribunals, jeopardize the legality of international law. Our vision is that international criminal justice is a central pillar of the rule of law, at the national and the international levels. Far from undermining the legality of international law, international criminal justice paves the way towards a true international public order.

  13. Towards development of lignin reinforced elastomeric compounds with reduced energy dissipation

    Science.gov (United States)

    Bahl, Kushal

    This research deals with development of lignin as reinforcing filler for elastomeric compounds. Lignins are naturally abundant and cost competitive wood derivatives possessing strong mechanical properties and offering reactive functional groups on their surfaces. The presence of the functional groups imparts polarity to the lignin molecules and makes them incompatible with non-polar elastomers. Also, the large particle size of lignin does not produce desired mechanical reinforcement. The present study deals with solving the outstanding issues associated with the use of lignin as fillers for polymeric compounds. In addition, the work specifically focuses on producing rubber compounds with reduced energy dissipation via partial replacement of carbon black with lignin. The first part of this study is devoted to suppression of the polarity of lignin and achievement of compatibility with rubber matrix via modification of lignosulfonates (LS) with cyclohexylamine (CA). CA reduces the polarity of lignin via interactions originating from proton transfer and hydrogen bonding. X-ray Photoelectron Spectroscopy (XPS) confirms the attachment of CA on the surfaces of lignin. The mechanical properties of rubber compounds increase substantially along with improvement in cure properties and increase in crosslink density in the presence of LS particles modified with CA. The tensile strength and storage modulus show an increase by 45% and 41% respectively. The values of the 100% modulus and elongation at break also improve by 35% and 60% respectively. The second part of this study exploits the non-covalent interactions between lignin and carbon black (CB) for the design of novel hybrid filler particles exhibiting lower energy loss in rubber compounds. The hybrid fillers offer unique morphology consisting of coating layers of lignin on carbon black particle aggregates. It is found that such coating layers are formed due to pi-pi interactions between lignin and carbon black. Raman

  14. Improvement in current density of nano- and micro-structured Si solar cells by cost-effective elastomeric stamp process

    Science.gov (United States)

    Jeon, Kiseok; Jee, Hongsub; Lim, Sangwoo; Park, Min Joon; Jeong, Chaehwan

    2018-03-01

    Effective incident light should be controlled for improving the current density of solar cells by employing nano- and micro-structures on silicon surface. The elastomeric stamp process, which is more cost effective and simpler than conventional photolithography, was proposed for the fabrication of nano- and micro-structures. Polydimethylsiloxane (PDMS) was poured on a mother pattern with a diameter of 6 μm and a spacing of 2 μm; then, curing was performed to create a PDMS mold. The regular micropattern was stamped on a low-viscosity resin-coated silicon surface, followed by the simple reactive ion etching process. Nano-structures were formed using the Ag-based electroless etching process. As etching time was increased to 6 min, reflectance decreased to 4.53% and current density improved from 22.35 to 34.72 mA/cm2.

  15. Experimental study of the retention properties of a cyclo olefin polymer pillar array column in reversed-phase mode.

    Science.gov (United States)

    Illa, Xavi; De Malsche, Wim; Gardeniers, Han; Desmet, Gert; Romano-Rodríguez, Albert

    2010-11-01

    Experimental measurements to study the retention capacity and band broadening under retentive conditions using micromachined non-porous pillar array columns fabricated in cyclo olefin polymer are presented. In particular, three columns with different depths but with the same pillar structure have been fabricated via hot embossing and pressure-assisted thermal bonding. Separations of a mixture of four coumarins using varying mobile phase compositions have been monitored to study the relation between the retention factor and the ratio of organic solvent in the aqueous mobile phase. Moreover, the linear relation between the retention and the surface/volume ratio predicted in theory has been observed, achieving retention factors up to k=2.5. Under the same retentive conditions, minimal reduced plate height values of h(min)=0.4 have been obtained at retention factors of k=1.2. These experimental results are compared with the case of non-porous and porous silicon pillars. Similar results for the plate heights are achieved while retention factors are higher than the non-porous silicon column and considerably smaller than the porous pillar column, given the non-porous nature of the used cyclo olefin polymer. The feasibility of using this polymer column as an alternative to the pillar array silicon columns is corroborated.

  16. Reverse engineering of B-pillar with 3D optical scanning for manufacturing of non-uniform thickness part

    Directory of Open Access Journals (Sweden)

    Islam Md. Tasbirul

    2017-01-01

    Full Text Available This paper presents reverse engineering (RE of a complex automobile structural part, B-pillar. As a major part of the automobile body-in white (BiW, B-pillar has substantial opportunity for weight reduction by introducing variable thickness across its sections. To leverage such potential, an existing B-pillar was reverse engineered with a 3D optical scanner and computer aided design (CAD application. First, digital data (i.e. in meshes of exiting B-pillar was obtained by the scanner, and subsequently, this information was utilized in developing a complete 3D CAD model. CATIA V5 was used in the modeling where some of the essential work benches were “Digitized Shape Editor”, “Quick Surface Reconstruction”, “Wireframe and Surface Design”, “Freestyle”, “Generation Shape Design” and “Part design”. In the final CAD design, five different thicknesses were incorporated successfully in order to get a B-pillar with non-uniform sections. This research opened opportunities for thickness optimization and mold tooling design in real time manufacturing.

  17. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    International Nuclear Information System (INIS)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

    2017-01-01

    Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O_2−CF_4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO_2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  18. The molecular environment of the pillar-like features in the H II region G46.5-0.2

    Science.gov (United States)

    Paron, S.; Celis Peña, M.; Ortega, M. E.; Fariña, C.; Petriella, A.; Rubio, M.; Ashley, R. P.

    2017-10-01

    At the interface of H II regions and molecular gas, peculiar structures appear, some of them with pillar-like shapes. Understanding their origin is important for characterizing triggered star formation and the impact of massive stars on the interstellar medium. In order to study the molecular environment and influence of radiation on two pillar-like features related to the H II region G46.5-0.2, we performed molecular line observations with the Atacama Submillimeter Telescope Experiment and spectroscopic optical observations with the Isaac Newton Telescope. From the optical observations, we identified the star that is exciting the H II region as spectral type O4-6. The molecular data allowed us to study the structure of the pillars and an HCO+ cloud lying between them. In this HCO+ cloud, which has no well-defined 12CO counterpart, we found direct evidence of star formation: two molecular outflows and two associated near-IR nebulosities. The outflow axis orientation is perpendicular to the direction of the radiation flow from the H II region. Several Class I sources are also embedded in this HCO+ cloud, showing that it is usual that young stellar objects (YSOs) form large associations occupying a cavity bounded by pillars. On the other hand, it was confirmed that the radiation-driven implosion (RDI) process is not occurring in one of the pillar tips.

  19. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Gong, Lijun [Research and Development Department, Guangzhou Fastprint Circuit Tech Co., Ltd., Guangzhou 510663 (China); He, Wei, E-mail: heweiz@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research and Development Department, Guangdong Guanghua Sci-Tech Co., Ltd., Shantou 515000 (China)

    2017-07-31

    Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O{sub 2}−CF{sub 4} low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO{sub 2} by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  20. Radiation resistance of elastomeric O-rings in mixed neutron and gamma fields: Testing methodology and experimental results

    Science.gov (United States)

    Zenoni, A.; Bignotti, F.; Donzella, A.; Donzella, G.; Ferrari, M.; Pandini, S.; Andrighetto, A.; Ballan, M.; Corradetti, S.; Manzolaro, M.; Monetti, A.; Rossignoli, M.; Scarpa, D.; Alloni, D.; Prata, M.; Salvini, A.; Zelaschi, F.

    2017-11-01

    Materials and components employed in the presence of intense neutron and gamma fields are expected to absorb high dose levels that may induce deep modifications of their physical and mechanical properties, possibly causing loss of their function. A protocol for irradiating elastomeric materials in reactor mixed neutron and gamma fields and for testing the evolution of their main mechanical and physical properties with absorbed dose has been developed. Four elastomeric compounds used for vacuum O-rings, one fluoroelastomer polymer (FPM) based and three ethylene propylene diene monomer rubber (EPDM) based, presently available on the market have been selected for the test. One EPDM is rated as radiation resistant in gamma fields, while the other elastomers are general purpose products. Particular care has been devoted to dosimetry calculations, since absorbed dose in neutron fields, unlike pure gamma fields, is strongly dependent on the material composition and, in particular, on the hydrogen content. The products have been tested up to about 2 MGy absorbed dose. The FPM based elastomer, in spite of its lower dose absorption in fast neutron fields, features the largest variations of properties, with a dramatic increase in stiffness and brittleness. Out of the three EPDM based compounds, one shows large and rapid changes in the main mechanical properties, whereas the other two feature more stable behaviors. The performance of the EPDM rated as radiation resistant in pure gamma fields does not appear significantly better than that of the standard product. The predictive capability of the accelerated irradiation tests performed as well as the applicable concepts of threshold of radiation damage is discussed in view of the use of the examined products in the selective production of exotic species facility, now under construction at the Legnaro National Laboratories of the Italian Istituto Nazionale di Fisica Nucleare. It results that a careful account of dose rate effects

  1. Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires.

    Science.gov (United States)

    Leite, Vanessa Vieira; Lopes, Murilo Baena; Gonini Júnior, Alcides; Almeida, Marcio Rodrigues de; Moura, Sandra Kiss; Almeida, Renato Rodrigues de

    2014-01-01

    To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire. Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a 0.10-in ligating wire was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten observations were carried out for each bracket-archwire angulation combination. Brackets were mounted in a special appliance, positioned at 90 degrees in relation to the wire and tested in two angulations. Frictional test was performed in a Universal Testing Machine at 5 mm/min and 10 mm of displacement. The means (MPa) were submitted to ANOVA and Tukey's test set at 5% of significance. The surfaces of wires and brackets were observed at SEM. Steel-tied brackets (16.48 ± 8.31) showed higher means of frictional resistance than elastomeric-tied brackets (4.29 ± 2.16 ) and self-ligating brackets (1.66 ± 1.57) (P 0.05). No statistical differences (P > 0.05) were found between zero (7.76 ± 8.46) and five-degree (7.19 ± 7.93) angulations. Friction was influenced not only by the type of bracket, but also by the ligating systems. Different morphological aspects were observed for the brackets and wires studied.

  2. Building method (concreting) for an offshore platform equipped with several cantilevered pillars. Fremgangsmaate for fremstilling (stoeping) av en fralandsplattform som har flere mot hverandre hellende stoetteben

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, O.

    1985-07-29

    The invention deals with a building method for an offshore platform made of concrete comprising several cantilevered pillars. In accordance with the invention, the building work is to be started in a dry dock, and can be completed in the same place or in deep water. The pillars and the foundation are made as separate structures. The foundation can also be made as separate structures for each of the pillars. The vertical positioned pillars are made by means of moving forms, and finally put into cantilevered position and permanently connected to the foundation and the upper end arrangement. The structure then is to be completed in the normal way. 7 drawings.

  3. Adsorption of cadmium onto Al{sub 13}-pillared acid-activated montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Yan Liangguo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: xiaoquan@rcees.ac.cn; Wen Bei [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Owens, Gary [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Boulevard, South Australia 5095 (Australia)

    2008-08-15

    The optimal preparation conditions for Al{sub 13}-pillared acid-activated Na{sup +}-montmorillonite (Al{sub 13}-PAAMt) were (1) an acid-activated Na{sup +}-montmorillonite (Na{sup +}-Mt) solution of pH 3.0, (2) a OH{sup -}/Al{sup 3+} molar ratio of 2.4 and (3) Al{sup 3+}/Na{sup +}-Mt ratio of 1.0 mmol g{sup -1}. The effects of OH{sup -}/Al{sup 3+} and Al{sup 3+}/Na{sup +}-Mt ratios on the adsorption of Cd{sup 2+} onto Al{sub 13}-PAAMt were studied. A comparison of the adsorption of Cd{sup 2+} onto Al{sub 13}-PAAMt, Al{sub 13}-pillared Na{sup +}-montmorillonite (Al{sub 13}-PMt) and Na{sup +}-Mt suggested that Al{sub 13}-PAAMt had higher adsorption affinity for Cd{sup 2+} than the other two adsorbents. A pseudo-second-order model described the adsorption kinetics well. Cadmium adsorption followed the Langmuir two-site equation, while desorption was hysteretic.

  4. Writing and functionalisation of suspended DNA nanowires on superhydrophobic pillar arrays

    KAUST Repository

    Miele, Ermanno; Accardo, Angelo; Falqui, Andrea; Marini, Monica; Giugni, Andrea; Leoncini, Marco; De Angelis, Francesco De; Krahne, Roman; Di Fabrizio, Enzo M.

    2014-01-01

    Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three-phase contact line (TCL) of DNA-loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic-metal-semiconductor nanowires by growing ZnO nanocrystals onto the metal-coated nanowires.

  5. High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

    Science.gov (United States)

    Gupta, Bipin Kumar; Kedawat, Garima; Gangwar, Amit Kumar; Nagpal, Kanika; Kashyap, Pradeep Kumar; Srivastava, Shubhda; Singh, Satbir; Kumar, Pawan; Suryawanshi, Sachin R.; Seo, Deok Min; Tripathi, Prashant; More, Mahendra A.; Srivastava, O. N.; Hahm, Myung Gwan; Late, Dattatray J.

    2018-01-01

    The vertical aligned carbon nanotubes (CNTs)-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si) wafer substrate at 775 °C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness) as a barrier layer and iron (Fe, 1.5 nm thickness) as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2-30 walls with an inner diameter of 3-8 nm. Raman spectrum analysis shows G-band at 1580 cm-1 and D-band at 1340 cm-1. The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm2 at 1.2V/μm), low turn-on field (0.6 V/μm) and field enhancement factor (6917) with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources.

  6. High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

    Directory of Open Access Journals (Sweden)

    Bipin Kumar Gupta

    2018-01-01

    Full Text Available The vertical aligned carbon nanotubes (CNTs-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si wafer substrate at 775 °C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness as a barrier layer and iron (Fe, 1.5 nm thickness as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2–30 walls with an inner diameter of 3–8 nm. Raman spectrum analysis shows G-band at 1580 cm−1 and D-band at 1340 cm−1. The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm2 at 1.2V/μm, low turn-on field (0.6 V/μm and field enhancement factor (6917 with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources.

  7. Studies of adsorption of pillarized and organofunctionalized smectite clay for Th"4"+ removal

    International Nuclear Information System (INIS)

    Guerra, D.J.L.; Menonca, E.S.; Silva, R.A.R.; Lara, W.

    2012-01-01

    A natural smectite clay sample was taken from the Amazon region, Amazonas State, Brazil. Zirconium polyoxycations were inserted into the smectite structure in a pillaring process. The pillarized smectite was organofunctionalized with the compound 3-mercaptopropyltrimethoxysilane. The natural and modified clay samples were used for the adsorption of tetravalent thorium cation from aqueous solution in a batch process. The adsorption process was fitted to equilibrium and kinetic models. The effects of stirring time, adsorbent dosage and pH on the adsorption capacity demonstrated that 90 min is sufficient to reach equilibrium at room temperature at pH 6.0. From the cation/basic center interactions for each smectite at the solid-liquid interface, the equilibrium constant and exothermic thermal effects were calculated with calorimetric methodology. By considering the net interactive number of moles for thorium cation and the equilibrium constant, the enthalpy, (-7.2 ± 0.11 to -7.0 ± 0.11 kJ mol"-"1) and negative Gibbs free energy, (-22.4 ± 0.1 to -23.1 ± 0.1 kJ mol"-"1) were calculated. These values enabled determination of the positive entropy, (51.2 ± 0.1 to 54.1 ± 0.1 JK"-"1mol"-"1). All liquid/solid interface adsorptions were spontaneous in nature and enthalpically driven.

  8. Morphology dependent field emission characteristics of ZnS/silicon nanoporous pillar array

    Science.gov (United States)

    Wang, Ling Li; Zhao, Cheng Zhou; Kang, Li Ping; Liu, De Wei; Zhao, Hui Chun; Hao, Shan Peng; Zhang, Yuan Kai; Chen, Zhen Ping; Li, Xin Jian

    2016-10-01

    Through depositing zinc sulphide (ZnS) nanoparticals on silicon nanoporous pillar array (Si-NPA) and crater-shaped silicon nanoporous pillar array (c-Si-NPA) by chemical bath deposition (CBD) method, ZnS/Si-NPA and c-ZnS/Si-NPA were prepared and the field emission (FE) properties of them were investigated. The turn-on electric fields of were 3.8 V/mm for ZnS/Si-NPA and 5.0 V/mm for c-ZnS/Si-NPA, respectively. The lower turn-on electric fields of ZnS/Si-NPA than that of c-ZnS/Si-NPA were attributed to the different electric distribution of the field emitters causing by the different surface morphology of the two samples, which was further demonstrated via the simulated results by finite element modeling. The FN curves for the ZnS/Si-NPA showed two-slope behavior. All the results indicate that the morphology play an important role in the FE properties and designing an appropriate top morphology for the emitter is a very efficient way to improve the FE performance.

  9. Large spin current injection in nano-pillar-based lateral spin valve

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Tatsuya [Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan); Ohnishi, Kohei; Kimura, Takashi, E-mail: t-kimu@phys.kyushu-u.ac.jp [Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan); Research Center for Quantum Nano-Spin Sciences, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan)

    2016-08-26

    We have investigated the influence of the injection of a large pure spin current on a magnetization process of a non-locally located ferromagnetic dot in nano-pillar-based lateral spin valves. Here, we prepared two kinds of the nano-pillar-type lateral spin valve based on Py nanodots and CoFeAl nanodots fabricated on a Cu film. In the Py/Cu lateral spin valve, although any significant change of the magnetization process of the Py nanodot has not been observed at room temperature. The magnetization reversal process is found to be modified by injecting a large pure spin current at 77 K. Switching the magnetization by the nonlocal spin injection has also been demonstrated at 77 K. In the CoFeAl/Cu lateral spin valve, a room temperature spin valve signal was strongly enhanced from the Py/Cu lateral spin valve because of the highly spin-polarized CoFeAl electrodes. The room temperature nonlocal switching has been demonstrated in the CoFeAl/Cu lateral spin valve.

  10. High acidity unilamellar zeolite MCM-56 and its pillared and delaminated derivatives.

    Science.gov (United States)

    Gil, Barbara; Makowski, Wacław; Marszalek, Bartosz; Roth, Wieslaw J; Kubu, Martin; Čejka, Jiři; Olejniczak, Zbigniew

    2014-07-21

    The unilamellar form of zeolite MWW, MCM-56, which is obtained by direct hydrothermal synthesis has been studied with regard to acidity and porosity in its original and post-synthesis modified pillared and delaminated forms. The acidity measured by FTIR was found to be only slightly lower than the highly active 3-D MWW forms, MCM-22 and MCM-49. Pivalonitrile adsorption, which is a measure of spatial openness, showed 50% accessibility vs. MCM-22/49. It highlights the potential of MCM-56 as a layered material with increased access to acid sites because it does not entail laborious post-synthesis modification. Swelling, pillaring and delamination of MCM-56 are facile but result in a reduction in the number of Brønsted acid sites (BAS) while increasing accessibility to pivalonitrile. The delamination procedure involving sonication and acidification of the highly basic mother liquor produces the most visible increase in surface area and access to all BAS. The accompanying doubling of the solid yield and the decrease in absolute number of BAS suggest significant precipitation of dissolved silica generated during swelling and sonication in high pH medium. The viability of separating surfactant covered layers upon sonication with the consequence of exposing hydrophobic hydrocarbon tails to aqueous environment is addressed.

  11. Writing and functionalisation of suspended DNA nanowires on superhydrophobic pillar arrays

    KAUST Repository

    Miele, Ermanno

    2014-08-08

    Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three-phase contact line (TCL) of DNA-loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic-metal-semiconductor nanowires by growing ZnO nanocrystals onto the metal-coated nanowires.

  12. Cerium Modified Pillared Montmorillonite Supported Cobalt Catalysts for Fischer Tropsch Synthesis

    International Nuclear Information System (INIS)

    Ahmad, N.; Ali, Z.; Abbas, S. M.; Hussain, F.

    2015-01-01

    Fischer-Tropsch (FT) synthesis was accomplished over Al-pillared Montmorillonite supported 20 wt% Co modified with different weight% of cerium catalysts. These catalysts were prepared by impregnation method while structural characterizations of the prepared samples were performed by XRD, TPR, NH/sub 3/TPD, TGA, BET, XRF and SEM techniques. The Fischer Tropsch reaction was studied in fixed bed micro catalytic reactor at temperature range of 220, 260 and 275 degree C and at different pressure (1, 5 and 10 bars). From the activity results, it was found that by pillaring NaMMT with Al higher catalytic activity and lower methane selectivity of NaMMT was achieved. Furthermore, the results of FT synthesis reaction revealed that cerium incorporation increased the dispersion of Co/sub 3/O/sub 4/ on the surface and consequently resulted in enhanced catalytic activity. Additionally, the C/sub 5/-C/sub 12/ hydrocarbons and methane selectivity increased while C/sub 22+/ hydrocarbons selectivity was decreased over cerium modified catalysts. Higher reaction temperature (>220 degree C) resulted in significant enhancement in CO conversion and methane selectivity. Though, increase in pressure from 1 to 10 bars eventually resulted in increase in C/sub 5+/ hydrocarbons and decrease in methane and C/sub 2/-C/sub 5/ hydrocarbons selectivity. (author)

  13. Formation of Pillars at the Boundaries between HII Regions and Molecular Clouds

    International Nuclear Information System (INIS)

    Mizuta, A; Kane, J O; Pound, M W; Remington, B A; Ryutov, D D; Takabe, H

    2006-01-01

    We investigate numerically the hydrodynamic instability of an ionization front (IF) accelerating into a molecular cloud, with imposed initial perturbations of different amplitudes. When the initial amplitude is small, the imposed perturbation is completely stabilized and does not grow. When the initial perturbation amplitude is large enough, roughly the ratio of the initial amplitude to wavelength is greater than 0.02, portions of the IF temporarily separate from the molecular cloud surface, locally decreasing the ablation pressure. This causes the appearance of a large, warm HI region and triggers nonlinear dynamics of the IF. The local difference of the ablation pressure and acceleration enhances the appearance and growth of a multimode perturbation. The stabilization usually seen at the IF in the linear regimes does not work due to the mismatch of the modes of the perturbations at the cloud surface and in density in HII region above the cloud surface. Molecular pillars are observed in the late stages of the large amplitude perturbation case. The velocity gradient in the pillars is in reasonably good agreement with that observed in the Eagle Nebula. The initial perturbation is imposed in three different ways: in density, in incident photon number flux, and in the surface shape. All cases show both stabilization for a small initial perturbation and large growth of the second harmonic by increasing amplitude of the initial perturbation above a critical value

  14. Modeling plastic deformation of post-irradiated copper micro-pillars

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, Tamer, E-mail: tcrosby@ucla.edu; Po, Giacomo, E-mail: gpo@ucla.edu; Ghoniem, Nasr M., E-mail: ghoniem@ucla.edu

    2014-12-15

    We present here an application of a fundamentally new theoretical framework for description of the simultaneous evolution of radiation damage and plasticity that can describe both in situ and ex situ deformation of structural materials [1]. The theory is based on the variational principle of maximum entropy production rate; with constraints on dislocation climb motion that are imposed by point defect fluxes as a result of irradiation. The developed theory is implemented in a new computational code that facilitates the simulation of irradiated and unirradiated materials alike in a consistent fashion [2]. Discrete Dislocation Dynamics (DDD) computer simulations are presented here for irradiated fcc metals that address the phenomenon of dislocation channel formation in post-irradiated copper. The focus of the simulations is on the role of micro-pillar boundaries and the statistics of dislocation pinning by stacking-fault tetrahedra (SFTs) on the onset of dislocation channel and incipient surface crack formation. The simulations show that the spatial heterogeneity in the distribution of SFTs naturally leads to localized plastic deformation and incipient surface fracture of micro-pillars.

  15. Pillared Graphene: A New 3-D Innovative Network Nanostructure Augments Hydrogen Storage

    Science.gov (United States)

    Georgios, Dimitrakakis K.; Emmanuel, Tylianakis; George, Froudakis E.

    2009-08-01

    Nowadays, people have turned into finding an alternative power source for everyday applications. One of the most promising energy fuels is hydrogen. It can be used as an energy carrier at small portable devices (e.g. laptops and/or cell phones) up to larger, like cars. Hydrogen is considered as the perfect fuel. It can be burnt in combustion engines and the only by-product is water. For hydrogen-powered vehicles a big liming factor is the gas tank and is the reason for not using widely hydrogen in automobile applications. According to United States' Department of Energy (D.O.E.) the target for reversible hydrogen storage in mobile applications is 6% wt. and 45 gr. H2/L and these should be met by 2010. After their synthesis Carbon Nanotubes (CNTs) were considered as ideal candidates for hydrogen storage especially after some initially incorrect but invitingly results. As it was proven later, pristine carbon nanotubes cannot achieve D.O.E.'s targets in ambient conditions of pressure and temperature. Therefore, a way to increase their hydrogen storage capacity should be found. An attempt was done by doping CNTs with alkali metal atoms. Although the results were promising, even that increment was not enough. Consequently, new architectures were suggested as materials that could potentially enhance hydrogen storage. In this work a novel three dimensional (3-D) nanoporous carbon structure called Pillared Graphene (Figure 1) is proposed for augmented hydrogen storage in ambient conditions. Pillared Graphene consists of parallel graphene sheets and CNTs that act like pillars and support the graphene sheets. The entire structure (Figure 1) can be resembled like a building in its early stages of construction, where the floors are represented by graphene sheets and the pillars are the CNTs. As shown in Figure 1, CNTs do not penetrate the structure from top to bottom. Instead, they alternately go up and down, so that on the same plane do not exist two neighboring CNTs with the

  16. Numerical Analysis of Warpage Induced by Thermo-Compression Bonding Process of Cu Pillar Bump Flip Chip Package

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Young; Jung, Hoon Sun; Lee, Jung Hoon; Choa, Sung-Hoon [Seoul Nat’l Univ. of Science and Technology, Seoul (Korea, Republic of)

    2017-06-15

    In flip chip technology, the conventional solder bump has been replaced with a copper (Cu) pillar bump owing to its higher input/output (I/O) density, finer pitch, and higher reliability. However, Cu pillar bump technology faces several issues, such as interconnect shorting and higher low-k stress due to stiffer Cu pillar structure when the conventional reflow process is used. Therefore, the thermal compression bonding (TCB) process has been adopted in the flip chip attachment process in order to reduce the package warpage and stress. In this study, we investigated the package warpage induced during the TCB process using a numerical analysis. The warpage of the TCB process was compared with that of the reflow process.

  17. Tunable waveguide and cavity in a phononic crystal plate by controlling whispering-gallery modes in hollow pillars

    DEFF Research Database (Denmark)

    Jin, Yabin; Fernez, Nicolas; Pennec, Yan

    2016-01-01

    We investigate the properties of a phononic crystal plate with hollow pillars and introduce the existence of whispering-gallery modes (WGMs). We show that by tuning the inner radius of the hollow pillar, these modes can merge inside both Bragg and low frequency band gaps, deserving phononic crystal...... and acoustic metamaterial applications. These modes can be used as narrow pass bands for which the quality factor can be greatly enhanced by the introduction of an additional cylinder between the hollow cylinder and the plate. We discuss some functionalities of these confined WGM in both Bragg and low...

  18. THE EFFECT OF INNER DIAPHRAGMS AND NON-CONTINUOUS SILL SECTION ON THE STIFFNESS OF AUTOMOTIVE B-PILLAR

    Directory of Open Access Journals (Sweden)

    C.F. Tan

    2017-11-01

    Full Text Available The paper discusses the knowledge on the behaviour of T-frame under specific loading will be obtained by experimental methods in order to investigate the deflection of the vehicle B-pillar or T-frame. In addition, a series of T-frame were designed with inner diaphragm at various location in the sill member in order to investigate the effect of inner diaphragm and noncontinuous closed hat section in the sill member. Lastly, the results from the experimental tests were compared with the finite element analysis results to demonstrate the effectiveness of the inner diaphragm in the automotive B-pillar.

  19. Thermally switchable adhesions of polystyrene-block-poly(n-isopropylacrylamide) copolymer pillar array mimicking climb attitude of geckos

    Science.gov (United States)

    Chen, Jem-Kun; Wang, Jing-Hong; Chang, Jia-Yaw; Fan, Shih-Kang

    2012-09-01

    Inspired by the gecko foot pad, we fabricated polystyrene-block-poly(N-isopropylacrylamide) (PS-b-PNIPAAm) copolymer pillar array to mimic climbing attitude of a gecko, alternately attach to and detach from a surface. The pillar array structure of the PS segment significantly enhances both of the hydrophilic and hydrophobic property of PNIPAAm segment tips at 25 and 50 °C, respectively, which could generate alternating adhesive forces of approximately 120 and 11 nN. The dramatic change in adhesive and friction force difference at 25 and 50 °C may guide the design of bio-inspired artificial analogues, which could approach gecko's climbing behavior.

  20. Stability of penicillin G sodium diluted with 0.9% sodium chloride injection or 5% dextrose injection and stored in polyvinyl chloride bag containers and elastomeric pump containers.

    Science.gov (United States)

    Hossain, Mirza Akram; Friciu, Mihaela; Aubin, Sebastien; Leclair, Grégoire

    2014-04-15

    The stability of penicillin G sodium solutions stored in polyvinyl chloride (PVC) bags or elastomeric pump containers was studied. Test samples were prepared by diluting powdered penicillin G sodium (10 million units/10-mL vial) to solutions of 2,500 or 50,000 units/mL with 0.9% sodium chloride injection or 5% dextrose injection. The preparations were transferred to 250-mL PVC bags and elastomeric pump containers. All samples were prepared in triplicate and stored at 5°C. Chemical stability was measured by a stability-indicating high-performance liquid chromatographic (HPLC) assay and by pH evaluation. Particulate matter was evaluated according to compendial standards using a light-obscuration particle count test. Preparations were visually examined throughout the study. After 21 days of storage, all test samples remained chemically stable, with an HPLC assay recovery value of more than 90% of the initial value. After 28 days, all samples prepared with either diluent and stored in PVC bags, as well as the samples diluted to 2,500 units/mL with sodium chloride injection and stored in elastomeric pump containers, did not meet the recovery acceptance limit. For all test samples, the mean pH consistently decreased during storage, from about 6.4 to about 5.5. Particle counts remained acceptable throughout the study, and no change in appearance was observed. Penicillin G for injection (2,500 and 50,000 units/mL) diluted in 0.9% sodium chloride injection or 5% dextrose injection and stored at 5°C in PVC containers or elastomeric pump containers was physically and chemically stable for a period of at least 21 days.

  1. "Learning to Do" as a Pillar of Education and Its Links to Entrepreneurial Studies in Higher Education: European Contexts and Approaches

    Science.gov (United States)

    Miclea, Mircea

    2004-01-01

    The author links the "learning to do" pillar, one of the four pillars of the Delors Report of 1996 , "Learning: The Treasure Within", to the principles and purposes of an entrepreneurial university and the aims of the European Commission and the Bologna Process to enhance the employability of graduates of higher education. An entrepreneurial…

  2. Ademe et Vous. International Newsletter No. 35, December 2015. COP21: one objective, four pillars

    International Nuclear Information System (INIS)

    Martin, Valerie; Seguin-Jacques, Catherine; Tappero, Denis

    2015-12-01

    Content: - COP21: one objective, four pillars: With COP21 providing a platform for intergovernmental negotiations, ADEME is actively working alongside with non-state actors to foster an environment conducive to success. - ADEME, a stakeholder of COP21: ADEME has been particularly proactive when it comes to mobilising non-state actors in the context of COP21, and has made the most of its presence at Le Bourget to announce a number of new initiatives covering a number of the 12 themes that make up the Lima-Paris Action Agenda. - Innovation exhibited at COP21: Giving the public an opportunity to be within reach of the world of tomorrow: This is the aim of the Innov'Climat exhibition, initiated by ADEME back in July and developed for COP21

  3. Investigation of activated Al-pillared clay efficiency in vegetable oil purification

    Directory of Open Access Journals (Sweden)

    Lomić Gizela A.

    2004-01-01

    Full Text Available This paper represents a contribution to the applicability of natural clays and their derivates as adsorbents in the process of purification of vegetable oil. Investigation of textural properties of raw and purified clay samples reveals that during acid activation and Al-pillaring, BET and micropore surface area increases significantly. However, bleaching capacity of clay and its derivates is not determined by using sample surface area, but rather sample total pore volume. Surface area, especially micropore surface area contributes to removal of smaller molecules. This was confirmed by successful elimination of moisture and volatile materials by samples with an appropriate micropore structure. Used samples of clay and its derivates do not significantly influence acid and peroxide values of raw sunflower oil during its treatment.

  4. Supramolecular Drug Delivery Systems Based on Water-Soluble Pillar[n]arenes.

    Science.gov (United States)

    Wu, Xuan; Gao, Lei; Hu, Xiao-Yu; Wang, Leyong

    2016-06-01

    Supramolecular drug delivery systems (SDDSs), including various kinds of nanostructures that are assembled by reversible noncovalent interactions, have attracted considerable attention as ideal drug carriers owing to their fascinating ability to undergo dynamic switching of structure, morphology, and function in response to various external stimuli, which provides a flexible and robust platform for designing and developing functional and smart supramolecular nano-drug carriers. Pillar[n]arenes represent a new generation of macrocyclic hosts, which have unique structures and excellent properties in host-guest chemistry. This account describes recent progress in our group to develop pillararene-based stimuli-responsive supramolecular nanostructures constructed by reversible host-guest interactions for controllable anticancer drug delivery. The potential applications of these supramolecular drug carriers in cancer treatment and the fundamental questions facing SDDSs are also discussed. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Ultra-fast magnetization reversal in magnetic nano-pillars by spin-polarized current

    Energy Technology Data Exchange (ETDEWEB)

    Devolder, T. [Institut d' Electronique Fondamentale, UMR 8622 CNRS, Universite Paris Sud, Ba-circumflex timent 220, 91405 Orsay (France)]. E-mail: thibaut.devolder@ief.u-psud.fr; Tulapurkar, A. [NanoElectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan); CREST, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi 332-0012 (Japan); Yagami, K. [SSNC, Semiconductor Technology Development Group, SONY Corporation, Atsugi, Kanagawa 243-0014 (Japan); Crozat, P. [Institut d' Electronique Fondamentale, UMR 8622 CNRS, Universite Paris Sud, Ba-circumflex timent 220, 91405 Orsay (France); Chappert, C. [Institut d' Electronique Fondamentale, UMR 8622 CNRS, Universite Paris Sud, Ba-circumflex timent 220, 91405 Orsay (France); Fukushima, A. [NanoElectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan); CREST, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi 332-0012 (Japan); Suzuki, Y. [NanoElectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan); CREST, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi 332-0012 (Japan)

    2005-02-01

    We study the speed limitations of the magnetization switching resulting from spin transfer in pillar-shaped CoFe/Cu/CoFe spin valves. The quasi-static critical currents are Ic-=-2mA for the antiparallel (AP) to parallel (P) configuration and Ic+=+4.6mA for the P to AP transition. Current pulses of duration down to 100ps and amplitude of 4I{sub c} trigger switching at 300K. The switching is probabilistic for lower current pulses. The P to AP transition speed is not much temperature dependant from 50 to 300K. In contrast, the AP to P transition is thermally inhibited and is much faster at 150K than at 300K. This thermal inhibition highlights the importance of the macrospin coherency and of the thermally excited spin waves with finite wave vector parallel to the magnetization. Our results validate spin-transfer switching for fast memory applications.

  6. Ultra-fast magnetization reversal in magnetic nano-pillars by spin-polarized current

    International Nuclear Information System (INIS)

    Devolder, T.; Tulapurkar, A.; Yagami, K.; Crozat, P.; Chappert, C.; Fukushima, A.; Suzuki, Y.

    2005-01-01

    We study the speed limitations of the magnetization switching resulting from spin transfer in pillar-shaped CoFe/Cu/CoFe spin valves. The quasi-static critical currents are Ic-=-2mA for the antiparallel (AP) to parallel (P) configuration and Ic+=+4.6mA for the P to AP transition. Current pulses of duration down to 100ps and amplitude of 4I c trigger switching at 300K. The switching is probabilistic for lower current pulses. The P to AP transition speed is not much temperature dependant from 50 to 300K. In contrast, the AP to P transition is thermally inhibited and is much faster at 150K than at 300K. This thermal inhibition highlights the importance of the macrospin coherency and of the thermally excited spin waves with finite wave vector parallel to the magnetization. Our results validate spin-transfer switching for fast memory applications

  7. The relation between district raise in the multiple coal seams and its pillars

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, X. [Jiaozuo Institute of Technology, Jiaozuo (China). Dept. of Mining Engineering

    2002-02-01

    Based on the geological condition of multiple coal seams mining in No.8 Colliery of Pingdingshan Coal Group, the behaviours of the front abutment pressure in each of the coal seams and the fixed abutment pressure are observed. The main cause of deformation and damage to the galleries is the increasing value of the valid load coefficient of the surrounding rock. The rational pillar width of the district raise is studied when its two side seams have been mined, and the layout question of district raise in the different set of seams is also studied. The conclusions derived from the study are useful guiding reference for the design of district raise layout in deep multiple coal seams mining. 6 refs., 3 figs., 1 tab.

  8. The Third Pillar of the Basel Accord: Evidence of borrower discipline in the Kyrgyz banking system

    Directory of Open Access Journals (Sweden)

    Edgar Demetrio Tovar-García

    2016-07-01

    Full Text Available We empirically study the asset side of market discipline in the banking system of the Kyrgyz Republic, examining whether borrowers are willing to pay higher interest rates to high-quality banks. Based on dynamic panel models and a dataset with bank information from 23 banks over the period 2010–2012, our findings suggest the presence of market discipline induced by borrowers. In other words, banks with higher capital ratios and liquidity charge higher interest rates on loans. This result has several implications for the banking policy in Kyrgyzstan, where we can recommend to policymakers a disclosure policy following the Third Pillar of Basel III, because not only can the bank's creditors use bank information to penalize the excessive bank risk, but borrowers can also use this information to discipline their banks.

  9. THE IMPACT OF ICT SECTOR ON THE SOCIAL PILLAR OF SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    TEODORESCU ANA-MARIA

    2016-06-01

    Full Text Available The human being is the main axis in setting sustainable development goals. Sustainable development, through its components - economic and environmental, has only one beneficiary - the human factor who benefits of income, education, good quality environmental factors, and enjoy inter and intra-generational equity. Information technology and communications contributes to fulffiling the goals of sustainable development through access to information society services (e-health, e-government, e-learning, access to education. This article presents the sustainable development objectives and the impact of ICT sector on the social pillar of sustainable development. I used a theoretical research and qualitative analysis of the data. I presented values indicators at the european level, the lowest and highest value, and recorded values for Romania.

  10. Pillars of Creation among Destruction: Star Formation in Molecular Clouds near R136 in 30 Doradus

    Science.gov (United States)

    Kalari, Venu M.; Rubio, Mónica; Elmegreen, Bruce G.; Guzmán, Viviana V.; Zinnecker, Hans; Herrera, Cinthya N.

    2018-01-01

    We present new sensitive CO(2–1) observations of the 30 Doradus region in the Large Magellanic Cloud. We identify a chain of three newly discovered molecular clouds that we name KN1, KN2, and KN3 lying within 2–14 pc in projection from the young massive cluster R136 in 30 Doradus. Excited H2 2.12 μm emission is spatially coincident with the molecular clouds, but ionized Brγ emission is not. We interpret these observations as the tails of pillar-like structures whose ionized heads are pointing toward R136. Based on infrared photometry, we identify a new generation of stars forming within this structure.

  11. Preparation of Pillar[5]arene-Based [2]Rotaxanes by a Stopper-Exchange Strategy.

    Science.gov (United States)

    Nierengarten, Iwona; Meichsner, Eric; Holler, Michel; Pieper, Pauline; Deschenaux, Robert; Delavaux-Nicot, Béatrice; Nierengarten, Jean-François

    2018-01-02

    A pillar[5]arene-containing rotaxane building block bearing exchangeable stoppers has been prepared in multigram scale quantities with high yields from the reaction of 2,4-dinitrophenol (DNP) with the inclusion complex resulting from the association of dodecanedioyl chloride with 1,4-diethoxypillar[5]arene. Stopper exchange reactions have been achieved by treatment of the resulting DNP diester with various amines through an addition-elimination mechanism preventing the unthreading of the axle component during the reaction and thus preserving the [2]rotaxane structures. The resulting diamide [2]rotaxane derivatives have thus been obtained in good to excellent yields. Importantly, [2]rotaxanes difficult or impossible to prepare by direct introduction of the two stoppers in a single synthetic step are now easily available. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. PREPARATION AND CATALYTIC ACTIVITY FOR ISOPROPYL BENZENE CRACKING OF Co, Mo AND Co/Mo-Al2O3-PILLARED MONTMORILLONITE CATALYSTS

    Directory of Open Access Journals (Sweden)

    Hasanudin Hasanudin

    2010-06-01

    Full Text Available It has been prepared Co, Mo and Co/Mo-Al2O3-pillared montmorillonite catalysts using montmorillonite clay  as raw material. The structure and porosity of the catalysts were determined using N2 adsorption-desorption and FT-IR spectroscopy analysis methods. Isopropyl benzene cracking using these catalysts were used to test the catalytic activity and performance of Co, Mo and Co/Mo-Al2O3-pillared montmorillonites.  Characterization results showed that pillarization resulted in the increase of the total pore volume and specific surface area of the clay. Meanwhile, transition metals (Co, Mo and Co/Mo loaded on Al2O3-pillared monmorillonites could increase the catalytic activity of the catalysts for isopropyl benzene cracking significantly.   Keywords: pillared monmorillonite, isopropyl benzene  and cracking catalyst

  13. Effects of focused ion beam milling on the compressive behavior of directionally solidified micro-pillars and the nanoindentation response of an electro-polished surface

    International Nuclear Information System (INIS)

    Shim, Sang Hoon; Bei, Hongbin; Miller, Michael K; Pharr, George Mathews; George, Easo P

    2009-01-01

    Focused ion beam (FIB) milling is the typical way in which micro-pillars are fabricated to study small-scale plasticity and size effects in uniaxial compression. However, FIB milling can introduce defects into the milled pillars. To investigate the effects of FIB damage on mechanical behavior, we tested Mo-alloy micro-pillars that were FIB milled following directional solidification, and compared their compressive response to pillars that were not FIB milled. We also FIB milled at glancing incidence a Mo-alloy single-crystal surface, and compared its nanoindentation response to an electro-polished surface of the same crystal. Consequences for the interpretation of data obtained from FIB milled micro-pillars are discussed

  14. Design and construction of porous metal–organic frameworks based on flexible BPH pillars

    International Nuclear Information System (INIS)

    Hao, Xiang-Rong; Yang, Guang-sheng; Shao, Kui-Zhan; Su, Zhong-Min; Yuan, Gang; Wang, Xin-Long

    2013-01-01

    Three metal–organic frameworks (MOFs), [Co 2 (BPDC) 2 (4-BPH)·3DMF] n (1), [Cd 2 (BPDC) 2 (4-BPH) 2 ·2DMF] n (2) and [Ni 2 (BDC) 2 (3-BPH) 2 (H 2 O)·4DMF] n (3) (H 2 BPDC=biphenyl-4,4′-dicarboxylic acid, H 2 BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N′-dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has “single-pillared” MOF-5-like motif with inner cage diameters of up to 18.6 Å. Framework 2 has “double pillared” MOF-5-like motif with cage diameters of 19.2 Å while 3 has “double pillared” 8-connected framework with channel diameters of 11.0 Å. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework. - Graphical abstract: By insertion of flexible BPH pillars based on “pillaring” strategy, three metal–organic frameworks are obtained showing that the porous frameworks can be constructed in a much greater variety. Highlights: ► Frameworks 1 and 2 have MOF-5 like motif. ► The cube-like cages in 1 and 2 are quite large, comparable to the IRMOF-10. ► Framework 1 is “single-pillared” mode while 2 is “double-pillared” mode. ► PXRD and gas adsorption analysis show that 3 is a dynamic porous framework.

  15. A family of porous lonsdaleite-e networks obtained through pillaring of decorated kagomé lattice sheets

    KAUST Repository

    Schoedel, Alexander; Boyette, Wesley; Wojtas, Łukasz; Eddaoudi, Mohamed; Zaworotko, Michael J.

    2013-01-01

    A new and versatile class of metal-organic materials (MOMs) with augmented lonsdaleite-e (lon-e-a) topology is presented herein. This family of lon-e nets are built by pillaring of hexagonal two-dimensional kagomé (kag) lattices constructed from well-known [Zn2(CO2R)4] paddlewheel molecular building blocks (MBBs) connected by 1,3- benzenedicarboxylate (bdc2-) linkers. The pillars are [Cr 3(μ3-O)(RCO2)]6 trigonal prismatic primary MBBs decorated by six pyridyl moieties (tp-PMBB-1). The three-fold symmetry (D3h) of tp-PMBB-1 is complementary with the alternating orientation of the axial sites of the paddlewheel MBBs and enables triple cross-linking of the kag layers by each pillar. These MOMs represent the first examples of axial-to-axial pillared undulating kag layers, and they are readily fine-tuned because the bdc2- moieties can be varied at their 5-position without changing the overall structure. This lon-e platform possesses functionalized hexagonal channels since the kag lattices are necessarily eclipsed. The effects of the substituent at the 5-positions of the bdc 2- linkers upon gas adsorption, particularly the heats of adsorption of carbon dioxide and methane, were studied. © 2013 American Chemical Society.

  16. Theoretical Investigations of CO 2 and H 2 Sorption in an Interpenetrated Square-Pillared Metal–Organic Material

    KAUST Repository

    Pham, Tony; Forrest, Katherine A.; McLaughlin, Keith; Tudor, Brant; Nugent, Patrick; Hogan, Adam; Mullen, Ashley; Cioce, Christian R.; Zaworotko, Michael J.; Space, Brian

    2013-01-01

    Simulations of CO2 and H2 sorption and separation were performed in [Cu(dpa)2SiF6-i], a metal-organic material (MOM) consisting of an interpenetrated square grid of Cu2+ ions coordinated to 4,4′-dipyridylacetylene (dpa) rings and pillars of SiF6 2

  17. Analysis of Äspö Pillar Stability Experiment: Continuous thermo-mechanical model development and calibration

    Czech Academy of Sciences Publication Activity Database

    Blaheta, Radim; Byczanski, Petr; Čermák, M.; Hrtus, Rostislav; Kohut, Roman; Kolcun, Alexej; Malík, Josef; Sysala, Stanislav

    2013-01-01

    Roč. 5, č. 2 (2013), s. 124-135 ISSN 1674-7755 Institutional support: RVO:68145535 Keywords : in situ pillar stability experiment * model calibration by back analysis * continuous mechanics * damage of granite rocks * Finite element method (FEM) Subject RIV: BA - General Mathematics http://www.sciencedirect.com/science/article/pii/S1674775513000103

  18. Single macroscopic pillars as model system for bioinspired adhesives: influence of tip dimension, aspect ratio, and tilt angle.

    Science.gov (United States)

    Micciché, Maurizio; Arzt, Eduard; Kroner, Elmar

    2014-05-28

    The goal of our study is to better understand the design parameters of bioinspired dry adhesives inspired by geckos. For this, we fabricated single macroscopic pillars of 400 μm diameter with different aspect ratios and different tip shapes (i.e., flat tips, spherical tips with different radii, and mushroom tips with different diameters). Tilt-angle-dependent adhesion measurements showed that although the tip shape of the pillars strongly influences the pull-off force, the pull-off strength is similar for flat and mushroom-shaped tips. We found no tilt-angle dependency of adhesion for spherical tip structures and, except for high tilt angle and low preload experiments, no tilt-angle effect for mushroom-tip pillars. For flat-tip pillars, we found a strong influence of tilt angle on adhesion, which decreased linearly with increasing aspect ratio. The experiments show that for the tested aspect ratios between 1 and 5, a linear decrease of tilt-angle dependency is found. The results of our studies will help to design bioinspired adhesives for application on smooth and rough surfaces.

  19. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    Science.gov (United States)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

    2017-07-01

    The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O2sbnd CF4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of Csbnd O, Osbnd Cdbnd O, Cdbnd O and sbnd NO2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  20. Single-step direct fabrication of pillar-on-pore hybrid nanostructures in anodizing aluminum for superior superhydrophobic efficiency.

    Science.gov (United States)

    Jeong, Chanyoung; Choi, Chang-Hwan

    2012-02-01

    Conventional electrochemical anodizing processes of metals such as aluminum typically produce planar and homogeneous nanopore structures. If hydrophobically treated, such 2D planar and interconnected pore structures typically result in lower contact angle and larger contact angle hysteresis than 3D disconnected pillar structures and, hence, exhibit inferior superhydrophobic efficiency. In this study, we demonstrate for the first time that the anodizing parameters can be engineered to design novel pillar-on-pore (POP) hybrid nanostructures directly in a simple one-step fabrication process so that superior surface superhydrophobicity can also be realized effectively from the electrochemical anodization process. On the basis of the characteristic of forming a self-ordered porous morphology in a hexagonal array, the modulation of anodizing voltage and duration enabled the formulation of the hybrid-type nanostructures having controlled pillar morphology on top of a porous layer in both mild and hard anodization modes. The hybrid nanostructures of the anodized metal oxide layer initially enhanced the surface hydrophilicity significantly (i.e., superhydrophilic). However, after a hydrophobic monolayer coating, such hybrid nanostructures then showed superior superhydrophobic nonwetting properties not attainable by the plain nanoporous surfaces produced by conventional anodization conditions. The well-regulated anodization process suggests that electrochemical anodizing can expand its usefulness and efficacy to render various metallic substrates with great superhydrophilicity or -hydrophobicity by directly realizing pillar-like structures on top of a self-ordered nanoporous array through a simple one-step fabrication procedure.

  1. The role of education in the culture of four pillar poverty to establish the nationalism of young generation

    Science.gov (United States)

    Sarmini; Warsono

    2018-01-01

    Globalization as an international integration process brings several positive and negative impacts due to the exchange of world views, products, thoughts, and other cultural aspects that can diminish the values of national identity. Four pillars of nationality are needed as a foundation to counteract the negative effects of globalization, therefore a culturally, educative, legal and structural approach is needed so that the younger generation can truly understand and safeguard the four pillars of our nationality. So far the government has also played little role in building the four pillars into an education. This research intends to see how the role of education can build young generation of nationalism by using research design in the form of content analysis. The population in this study is the Education Office of Sidoarjo Regency, which is the level of Junior High School Education Unit. However, given the scope and breadth of the district of Sidoarjo, a representative sample is determined using FGD (Focus Group Discussion) data collection techniques and questionnaires that will be analyzed using written policy descriptions or unwritten policies. Through a series of research stages, it can be concluded that there are still many principals who have not integrated the culture of the four pillars of nationalism into a written and unwritten document covering intracurricular, extracurricular, school culture and through community participation.

  2. Mining the 510 coal seam prone to rock bursts and below a coal support pillar in a seam above

    Energy Technology Data Exchange (ETDEWEB)

    Major, M; Gebala, W

    1983-10-01

    The 510 coal seam, situated at a depth of 760 m below a support pillar left in an overlying coal seam, was mined by a system of longwall faces from 1979 to 1982. The seam was prone to rock bursts. Energy of rock bursts which occurred in the mine ranged from 10/SUP/5 to 10/SUP/6 J. The coal seam, 10 m thick, was mined by slicing. Faces were 140 m long. Stress concentrations caused by the suppport pillar left in the overlying coal seam were calculated. Curves which describe stress fluctuations were plotted. Rock burst hazards were determined by drilling. Drilling intervals depended on hazard degree and position of the test site in relation to the support pillar in the overlying coal seam. The face was 3 m high. Supports used in 2 gate roads were reinforced by steel and timber supports. Strong timber boards were placed at canopies of powered supports used at the working face. The face was situated at an angle of 10 degrees to the pillar axis. In the zone of critical stresses water infusion and shock blasting were used for rock burst prevention. These methods, plus reinforcement of the supports in gate roads and at the working face, guaranteed safe mining and prevented rock bursts. (8 refs.)

  3. The Effect of Mining Activity on the Surface in the Safety Shaft Pillar Area of Mayrau Mine

    Czech Academy of Sciences Publication Activity Database

    Živor, Roman; Klos, Pavel; Pechoč, Jiří; Brož, Milan

    M-24(340) (2002), s. 227-235 ISSN 0138-015X. [Polish-Czech-Slovakian Symposium on Mining Geophysics /28./. Niedzica, 11.06.2001-13.06.2001] R&D Projects: GA AV ČR IBS3086005 Institutional research plan: CEZ:AV0Z3046908 Keywords : shaft pillar * mining * surface subsidence Subject RIV: DH - Mining, incl. Coal Mining

  4. A family of porous lonsdaleite-e networks obtained through pillaring of decorated kagomé lattice sheets

    KAUST Repository

    Schoedel, Alexander

    2013-09-25

    A new and versatile class of metal-organic materials (MOMs) with augmented lonsdaleite-e (lon-e-a) topology is presented herein. This family of lon-e nets are built by pillaring of hexagonal two-dimensional kagomé (kag) lattices constructed from well-known [Zn2(CO2R)4] paddlewheel molecular building blocks (MBBs) connected by 1,3- benzenedicarboxylate (bdc2-) linkers. The pillars are [Cr 3(μ3-O)(RCO2)]6 trigonal prismatic primary MBBs decorated by six pyridyl moieties (tp-PMBB-1). The three-fold symmetry (D3h) of tp-PMBB-1 is complementary with the alternating orientation of the axial sites of the paddlewheel MBBs and enables triple cross-linking of the kag layers by each pillar. These MOMs represent the first examples of axial-to-axial pillared undulating kag layers, and they are readily fine-tuned because the bdc2- moieties can be varied at their 5-position without changing the overall structure. This lon-e platform possesses functionalized hexagonal channels since the kag lattices are necessarily eclipsed. The effects of the substituent at the 5-positions of the bdc 2- linkers upon gas adsorption, particularly the heats of adsorption of carbon dioxide and methane, were studied. © 2013 American Chemical Society.

  5. Accuracy of a new ring-opening metathesis elastomeric dental impression material with spray and immersion disinfection.

    Science.gov (United States)

    Kronström, Mats H; Johnson, Glen H; Hompesch, Richard W

    2010-01-01

    A new elastomeric impression material has been formulated with a ring-opening metathesis chemistry. In addition to other properties of clinical significance, the impression accuracy must be confirmed. The purpose of this study was to compare the accuracy of the new elastomeric impression material with vinyl polysiloxane and polyether following both spray and immersion disinfection. Impressions of a modified dentoform with a stainless steel crown preparation in the lower right quadrant were made, and type IV gypsum working casts and dies were formed. Anteroposterior (AP), cross-arch (CA), buccolingual (BL), mesiodistal (MD), occlusogingivobuccal (OGB), and occlusogingivolingual (OGL) dimensions were measured using a microscope. Working cast and die dimensions were compared to those of the master model. The impression materials were a newly formulated, ring-opening metathesis-polymerization impression material (ROMP Cartridge Tray and ROMP Volume Wash), vinyl polysiloxane (VPS, Aquasil Ultra Monophase/LV), and a polyether (PE, Impregum Penta Soft/Permadyne Garant L). Fifteen impressions with each material were made, of which 5 were disinfected by spray for 10 minutes (CaviCide), 5 were disinfected by immersion for 90 minutes (ProCide D), and 5 were not disinfected. There were significant cross-product interactions with a 2-way ANOVA, so a 1-way ANOVA and Dunnett's T3 multiple comparison test were used to compare the dimensional changes of the 3 impression materials, by disinfection status and for each location (alpha=.05). For ROMP, there were no significant differences from the master, for any dimension, when comparing the control and 2 disinfectant conditions. No significant differences were detected among the 3 impression materials for CA, BL, and MD. The working die dimensions of OGB and OGL for VPS with immersion disinfection were significantly shorter than with PE and ROMP (P<.05). Overall, the AP dimension was more accurate than CA, and the BL of working dies

  6. Nonlinear analysis of r.c. framed buildings retrofitted with elastomeric and friction bearings under near-fault earthquakes

    Science.gov (United States)

    Mazza, Mirko

    2015-12-01

    Reinforced concrete (r.c.) framed buildings designed in compliance with inadequate seismic classifications and code provisions present in many cases a high vulnerability and need to be retrofitted. To this end, the insertion of a base isolation system allows a considerable reduction of the seismic loads transmitted to the superstructure. However, strong near-fault ground motions, which are characterised by long-duration horizontal pulses, may amplify the inelastic response of the superstructure and induce a failure of the isolation system. The above considerations point out the importance of checking the effectiveness of different isolation systems for retrofitting a r.c. framed structure. For this purpose, a numerical investigation is carried out with reference to a six-storey r.c. framed building, which, primarily designed (as to be a fixed-base one) in compliance with the previous Italian code (DM96) for a medium-risk seismic zone, has to be retrofitted by insertion of an isolation system at the base for attaining performance levels imposed by the current Italian code (NTC08) in a high-risk seismic zone. Besides the (fixed-base) original structure, three cases of base isolation are studied: elastomeric bearings acting alone (e.g. HDLRBs); in-parallel combination of elastomeric and friction bearings (e.g. high-damping-laminated-rubber bearings, HDLRBs and steel-PTFE sliding bearings, SBs); friction bearings acting alone (e.g. friction pendulum bearings, FPBs). The nonlinear analysis of the fixed-base and base-isolated structures subjected to horizontal components of near-fault ground motions is performed for checking plastic conditions at the potential critical (end) sections of the girders and columns as well as critical conditions of the isolation systems. Unexpected high values of ductility demand are highlighted at the lower floors of all base-isolated structures, while re-centring problems of the base isolation systems under near-fault earthquakes are

  7. Determination of concrete cover thickness in a reinforced concrete pillar by observation of the scattered electromagnetic field

    Science.gov (United States)

    Di Gregorio, Pietro Paolo; Frezza, Fabrizio; Mangini, Fabio; Pajewski, Lara

    2017-04-01

    The electromagnetic scattered field by a reinforced concrete structure is calculated by means of frequency-domain numerical simulations and by making use of the scattered-field formulation. The concrete pillar, used as supporting architectural element, is modelled as a parallelepiped shell made of concrete material inside which are present steel bars. In order to make the model simpler, the steel bars are supposed running parallel to the air-pillar interface. To excite the model, a linearly-polarized plane wave impinging normally with respect to the pillars surface, is adopted. We consider two different polarizations in order to determine the most useful in terms of scattered-field sensitivity. Moreover, a preliminary frequency sweep allows us to choose the most suitable operating frequency depending on the dimensions of the pillar cross-section, the steel bars cross-section and the concrete cover. All the three components of the scattered field are monitored along a line just above the interface air-pillar. The electromagnetic properties of the materials employed in this study are present in the literature and, since a frequency-domain technique is adopted, no further approximation is needed. The results obtained for different values of the concrete cover are compared, with the goal of determining the scattered field dependence on the concrete cover thickness. Considering different concrete cover thicknesses, we want to provide an electromagnetic method to obtain this useful parameter by observation of the scattered electromagnetic field. One of the practical applications of this study in the field of Civil Engineering may be the use of ground penetrating radar (GPR) techniques to monitor the thickness of the concrete that separates the metal bars embedded in the pillar from the outer surface. A correct distance is useful because the concrete cover serves as a protection against external agents avoiding corrosion of the bars that might prejudice the reinforced

  8. A physical and numerical modelling investigation of the roadway stability in longwall mining, with and without narrow pillar protection

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, H.; Fowell, R.J. [Suleyman Demirel University, Isparta (Turkey)

    2004-03-01

    The drivage of the supply gate of a development panel in the presumed low stress zone adjacent to the loader gate of an excavated panel with a very small width of intervening pillar between the two entries, known as skin-to-skin working, resulted in an extensive fall of the supply gate roof at Bilsthorpe colliery in 1993. This fall left a question over the application of skin-to-skin drivage of gate entries supported primarily by rock bolts. To investigate the possible reasons behind this fall, both physical and numerical modelling studies were carried out. Physical and numerical models were successful in demonstrating the potential danger of the working method with the rock bolt support system employed. Development of a shear failure plane from the rib edge into roof strata of the loader gate and development of the second shear failure plane at the abutment side of the supply gate exposed the supply gate to the fall of large rock blocks released by shear failure zones. Models demonstrated that the fall of the supply gate roof was not due to the inability of the rock bolts to prevent bed separation, but it was the method of working that made the bolts ineffective due to the height of the block delineated by the shear failure planes. Further physical and numerical models were undertaken to investigate the influence of 5, 7.5 and 10 in wide intervening pillars between the entries on the stability of the rock bolt supported supply gate roof. These studies showed that a 7.5 in or 10 in wide pillar would have prevented development of failure zones and fall of the roof while a 5 in pillar was found to be an undersized pillar width causing the development of extensive failure zones in the roof.

  9. Phase separation and mechanical properties of an elastomeric biomaterial from spider wrapping silk and elastin block copolymers.

    Science.gov (United States)

    Muiznieks, Lisa D; Keeley, Fred W

    2016-10-01

    Elastin and silk spidroins are fibrous, structural proteins with elastomeric properties of extension and recoil. While elastin is highly extensible and has excellent recovery of elastic energy, silks are particularly strong and tough. This study describes the biophysical characterization of recombinant polypeptides designed by combining spider wrapping silk and elastin-like sequences as a strategy to rationally increase the strength of elastin-based materials while maintaining extensibility. We demonstrate a thermo-responsive phase separation and spontaneous colloid-like droplet formation from silk-elastin block copolymers, and from a 34 residue disordered region of Argiope trifasciata wrapping silk alone, and measure a comprehensive suite of tensile mechanical properties from cross-linked materials. Silk-elastin materials exhibited significantly increased strength, toughness, and stiffness compared to an elastin-only material, while retaining high failure strains and low energy loss upon recoil. These data demonstrate the mechanical tunability of protein polymer biomaterials through modular, chimeric recombination, and provide structural insights into mechanical design. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 693-703, 2016. © 2016 Wiley Periodicals, Inc.

  10. Evaluation of the performance of elastomeric pumps in practice: are we under-delivering on chemotherapy treatments?

    Science.gov (United States)

    Salman, Dahlia; Biliune, Jurga; Kayyali, Reem; Ashton, Jane; Brown, Peter; McCarthy, Tim; Vikman, Elin; Barton, Stephen; Swinden, Julian; Nabhani-Gebara, Shereen

    2017-12-01

    Elastomeric pumps are widely used to facilitate ambulatory chemotherapy, and studies have shown that they are safe and well received by patients. Despite these advantages, their end of infusion time can fluctuate significantly. The aim of this research was to observe the performance of these pumps in real practice and to evaluate patients' satisfaction. This was a two-phase study conducted at three cancer units over 6 months. Phase-1 was an observational study recording the status of pumps at the scheduled disconnection time and noting remaining volume of infusion. Phase-2 was a survey of patients and their perception/satisfaction. Ethical approval was granted. A total of 92 cases were observed covering 50 cases disconnected at hospital and 42 disconnected at home. The infusion in 40% of hospital disconnection cases was slow, with patients arriving at hospital with unfinished pumps; 58% of these had an estimated remaining volume which exceeded 10 mL with 35% exceeded 20 mL. In 73% of these cases, and regardless of the remaining volume, the patient was disconnected and the pump was discarded. The performance of pumps varied, which affected nurse workload and patients' waiting-times. A smart system is an option to monitor the performance of pumps and to predict their accuracy.

  11. Atomic force microscopy and nanoindentation investigation of polydimethylsiloxane elastomeric substrate compliancy for various sputtered thin film morphologies.

    Science.gov (United States)

    Maji, Debashis; Das, Soumen

    2018-03-01

    Crack free electrically continuous metal thin films over soft elastomeric substrates play an integral part in realization of modern day flexible bioelectronics and biosensors. Under nonoptimized deposition conditions, delamination, and/or cracking of the top film as well as the underlying soft substrate hinders optimal performance of these devices. Hence it is very important to understand and control not only the various deposition factors like power, time, or deposition pressure but also investigate the various interfacial physics playing a critical role in assuring thin film adhesion and substrate compliancy. In the present study, various nanomechanical information of the underlying substrate, namely, crack profile, average roughness, Young's modulus, and adhesion force were studied for uncracked and cracked polydimethylsiloxane (PDMS) surfaces along with pristine and conventional plasma treated PDMS samples as control. Quantification of the above parameters were done using three-dimensional surface profiler, scanning electron microscopy, nanoindentation, and atomic force microscopy techniques to elucidate the modulus range, average roughness, and adhesion force. Comparative analysis with control revealed remarkable similarity between increased modulus values, increased surface roughness, and reduced adhesion force accounting for reduced substrate compliancy and resulting in film cracking or buckling which are critical for development of various bioflexible devices. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 725-737, 2018. © 2017 Wiley Periodicals, Inc.

  12. Heat shrink ability of electron-beam-modified thermoplastic elastomeric films from blends of ethylene-vinylacetate copolymer and polyethylene

    International Nuclear Information System (INIS)

    Chattopadhyay, S.; Chaki, T.K.; Bhowmick, Anil K.

    2000-01-01

    The heat shrink ability of electron-beam-irradiated thermoplastic elastomeric films from blends of ethylene-vinylacetate copolymer (EVA) and low-density polyethylene (LDPE) has been investigated in this paper. The effects of temperature, time and extent of stretching and shrinkage temperature and time have been reported. Based on the above data, the optimized conditions in terms of high heat shrinkage and low amnesia rating have been evaluated. Influence of radiation doses (0-500 kGy), multifunctional sensitizer levels (ditri methylol propane tetraacrylate, DTMPTA), and blend proportions on heat shrink ability has been explained with the help of gel fraction and X-ray data. With the increase in radiation dose, gel fraction increases, which in turn gives rise to low values of heat shrinkage and amnesia rating. At a constant radiation dose and blend ratio, percent heat shrinkage is found to decrease with increase in DTMPTA level. Gel content increases with the increase in EVA content of the blend at a constant radiation dose and monomer level, giving rise to decrease in heat shrink ability. Heat shrinkage increases with the increase in percent crystallinity, although the amnesia rating follows the reverse trend.

  13. Heat shrink ability of electron-beam-modified thermoplastic elastomeric films from blends of ethylene-vinylacetate copolymer and polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S.; Chaki, T.K.; Bhowmick, Anil K. E-mail: anilkb@rtc.iitkgp.ernet.in

    2000-11-01

    The heat shrink ability of electron-beam-irradiated thermoplastic elastomeric films from blends of ethylene-vinylacetate copolymer (EVA) and low-density polyethylene (LDPE) has been investigated in this paper. The effects of temperature, time and extent of stretching and shrinkage temperature and time have been reported. Based on the above data, the optimized conditions in terms of high heat shrinkage and low amnesia rating have been evaluated. Influence of radiation doses (0-500 kGy), multifunctional sensitizer levels (ditri methylol propane tetraacrylate, DTMPTA), and blend proportions on heat shrink ability has been explained with the help of gel fraction and X-ray data. With the increase in radiation dose, gel fraction increases, which in turn gives rise to low values of heat shrinkage and amnesia rating. At a constant radiation dose and blend ratio, percent heat shrinkage is found to decrease with increase in DTMPTA level. Gel content increases with the increase in EVA content of the blend at a constant radiation dose and monomer level, giving rise to decrease in heat shrink ability. Heat shrinkage increases with the increase in percent crystallinity, although the amnesia rating follows the reverse trend.

  14. Replacement of thermal column elastomeric gasket in pool type research reactors based on ageing and radiation degradation

    International Nuclear Information System (INIS)

    Garai, S.K.

    2006-01-01

    Pool type research reactors are designed with Thermal column facilities to irradiate samples at different flux levels of thermal neutrons. The sealing of demineralised pool water between stainless steel lined pool wall and the Aluminium Thermal column plate is achieved by an elastomeric gasket. The gasket joint is subjected to pool water temperature ranging from 25degC to 45degC and radiation field of the order of 104 -106 R/hr. The gasket loses its sealing properties due to ageing and radiation degradation after a few years, leading to the leakage and loss of the pool water. Though degradation of the gasket is, generally, predictable, some amount of uncertainty always remains in the leakage rate. The paper describes the study of a few elastomers in radiation environment and replacement of the Thermal column gasket of a swimming pool type research reactor. It includes the details of features like planning and scheduling, the actual sequential execution of the job, various problems encountered and corrective measures applied, engineering and radiological safety measures adopted, development of remote tools, disassembly and reassembly procedure and finally satisfactory completion of the site job in high radiation environment with minimum time and man rem consumption. (author)

  15. Pillar size optimization design of isolated island panel gob-side entry driving in deep inclined coal seam—case study of Pingmei No. 6 coal seam

    Science.gov (United States)

    Zhang, Shuai; Wang, Xufeng; Fan, Gangwei; Zhang, Dongsheng; Jianbin, Cui

    2018-06-01

    There is a perception that deep roadways are difficult to maintain. To reverse this and to improve the recovery rate of coal resources, gob-side entry driving is widely used in coal mines, especially deep-mining coal mines, in China. Determination of the reasonable pillar size through in situ observation and experimentation plays a vital role for roadway maintenance. Based on the geological conditions of Pingmei No.6 coal seam, a theoretical analysis, numerical simulation, and industrial experiments are carried out to calculate the reasonable width of chain pillars, analyze the lateral support stress distribution law near the gob side, investigate the relationship between the coal pillar stress distribution, roadway surrounding rock stress distribution, roadway surrounding rock deformation and the coal pillar width. The results indicate that 5 m wide coal pillars can ensure that the chain pillars are at a lower stress level and the deformation of roadway surrounding rock is in a more reasonable range. Industrial experiments show that when the chain pillar width is 5 m, the deformation of roadway surrounding rock can meet the requirements of working face safe production. The numerical results agreed well with field measurement and observations, and the industrial experiments results further validated the results of the numerical simulation.

  16. Improvement of thermoelectric properties induced by uniquely ordered lattice field in Bi2Se0.5Te2.5 pillar array

    International Nuclear Information System (INIS)

    Tan, Ming; Hao, Yanming; Wang, Gangzhi

    2014-01-01

    In this study, it was found that uniquely ordered lattice field favors transport of carriers but hinder that of phonons. The n-Bi 2 Se 0.5 Te 2.5 pillar array film was successfully achieved by a simple ion beam assisted deposition technique. This oriented pillar array structure is clear with pillar diameter of about 30 nm, exhibiting a uniquely ordered lattice field. The properties of the ordered Bi 2 Se 0.5 Te 2.5 pillar array were greatly enhanced in comparison with those of the ordinary film. The Bi 2 Se 0.5 Te 2.5 pillar array with a thermoelectric dimensionless figure-of-merit ZT=1.28 was obtained at room temperature. The in-plane transport mechanisms of the ordered pillar array and the ordinary structures, lattice field model, are proposed and investigated. The specially ordered lattice field is the main reason for the properties enhancement observed in the Bi 2 Se 0.5 Te 2.5 film. Introduction of such ordered lattice field into TE films is therefore a very promising approach. - Graphical abstract: In this study, it was found that uniquely ordered lattice field favors transport of carriers but hinder that of phonons. The Bi 2 Se 0.5 Te 2.5 pillar array film with a thermoelectric dimensionless figure-of-merit ZT=1.28 was obtained at room temperature. The in-plane transport mechanisms of the ordered pillar array and the ordinary structures, the lattice field model, are proposed and investigated. The specially ordered lattice field is the main reason for the properties enhancement observed in the Bi 2 Se 0.5 Te 2.5 pillar array. Introduction of such uniquely ordered lattice field into TE films is therefore a very promising approach. In (a) TEM and (b) HRTEM images of the ordered Bi 2 Se 0.5 Te 2.5 column array. - Highlights: • Uniquely ordered Bi 2 Se 0.5 Te 2.5 pillar array was achieved by an IBAD method. • The pillar array with an ordered lattice field exhibits attractive TE property. • The transport mechanism of such ordered pillar array is proposed and

  17. Time to Add a Fifth Pillar to Bedside Physical Examination: Inspection, Palpation, Percussion, Auscultation, and Insonation.

    Science.gov (United States)

    Narula, Jagat; Chandrashekhar, Y; Braunwald, Eugene

    2018-04-01

    Inspection, palpation, percussion, and auscultation have been the 4 pillars of clinical bedside medicine. Although these basic methods of physical examination have served us well, traditional bedside examination, for a number of reasons including diminishing interest and expertise, performs well less than what is required of a modern diagnostic strategy. Improving the performance of physical examination is vital given that it is crucial to guide diagnostic possibilities and further testing. Current efforts at improving physical examination skills during medical training have not been very successful, and incorporating appropriate technology at the bedside might improve its performance. Selective use of bedside ultrasound (or insonation) can be one such strategy that could be incorporated as the fifth component of the physical examination. Seeing pathology through imaging might improve interest in physical examination among trainees, and permit appropriate downstream testing and possibly superior decision making. Current ultrasound technology makes this feasible, and further miniaturization of ultrasound devices and reduced cost will allow for routine use at the bedside. It is time to have a wider debate and a possible consensus about updates required to enhance current paradigms of physical examination.

  18. Immobilization of heavy metals on pillared montmorillonite with a grafted chelate ligand

    International Nuclear Information System (INIS)

    Brown, Loren; Seaton, Kenneth; Mohseni, Ray; Vasiliev, Aleksey

    2013-01-01

    Highlights: • Mesoporous organoclay for immobilization of heavy metal cations was obtained. • The material has a porous structure with high contents of surface adsorption sites. • Leaching of heavy metals from soil reduced in the presence of this adsorbent. • The adsorbent demonstrated high effectiveness in neutral and acidic media. -- Abstract: The objective of this work was the development of an efficient adsorbent for irreversible immobilization of heavy metals in contaminated soils. The adsorbent was prepared by pillaring of montmorillonite with silica followed by grafting of a chelate ligand on its surface. Obtained adsorbent was mesoporous with high content of adsorption sites. Its structure was studied by BET adsorption of N 2 , dynamic light scattering, and scanning electron microscopy. The adsorption capacity of the organoclay was measured by its mixing with contaminated kaolin and soil samples and by analysis of heavy metal contents in leachate. Deionized water and 50% acetic acid were used for leaching of metals from the samples. As it was demonstrated by the experiments, the adsorbent was efficient in immobilization of heavy metals not only in neutral aqueous media but also in the presence of weak acid. As a result, the adsorbent can be used for reduction of heavy metal leaching from contaminated sites

  19. The European Union as a Security Actor: Moving Beyond the Second Pillar

    Directory of Open Access Journals (Sweden)

    Kamil Zwolski

    2009-04-01

    Full Text Available It is suggested in this article that there is a discrepancy between, on the one hand, literature that focuses on the European Union (EU as a security actor and, on the other, contemporary security studies literature. This difference concerns the fact that the literature on the EU as a security actor treats security in a narrower sense than how it is approached in the literature on security studies. Over the past few decades, security studies literature has begun to fully acknowledge that the concept of security has broadened beyond traditional ‘hard’ security concerns and can encompass many different issues, for example the security implications of climate change. However, the literature on the EU as a security actor very often associates security only with the second pillar of the EU’s organisational structure; in particular the intergovernmental cooperation embodied by the Common Foreign and Security Policy (CFSP and the European Security and Defence Policy (ESDP. The main purpose of this article is to utilise the broader security studies approach to security as a means to expand the understanding of security in the context of the EU’s performance on the international stage. This is important because it allows the Union’s �����actorness’ in the field of security to be examined in a more holistic manner.

  20. Corrugated metal surface with pillars for terahertz surface plasmon polariton waveguide components

    KAUST Repository

    Yuehong, Xu

    2018-01-12

    In the terahertz regime, due to perfect conductivity of most metals, it is hard to realize a strong confinement of Surface plasmon polaritons (SPPs) although a propagation loss could be sufficiently low. We experimentally demonstrated a structure with periodic pillars arranged on a thin metal surface that supports bound modes of spoof SPPs at terahertz (THz) frequencies. By using scanning near-field THz microscopy, the electric field distribution above the metal surface within a distance of 130 μm was mapped. The results proved that this structure could guide spoof SPPs propagating along subwavelength waveguides, and at the same time reduce field expansion into free space. Further, for the development of integrated optical circuits, several components including straight waveguide, S-bend, Y-splitter and directional couplers were designed and characterized by the same method. We believe that the waveguide components proposed here will pave a new way for the development of flexible, wideband and compact photonic circuits operating at THz frequencies.

  1. Tomorrow’s Universities and the Seven Pillars of the Knowledge Revolution

    Directory of Open Access Journals (Sweden)

    Ismail Serageldin

    2013-09-01

    Full Text Available The emerging Knowledge Revolution goes beyond the changing technologies and the challenges and opportunities they create to include the structure of knowledge and how it is transmitted inter-generationally and across countries. There are seven major features of that profound transformation, which I call “The Seven Pillars of the New Knowledge Revolution”. These are: (i Parsing, Life & Organization; (ii Image & Text; (iii Humans & Machines; (iv Complexity & Chaos; (v Computation & Research; (vi Convergence & Transformation; and (vii Pluridisciplinarity & Policy. This diagnosis has profound implications on how one should think about the design and management of our institutions of learning, starting not only with universities, but also the school system, as well as our research institutions (whether in universities or in public and private labs, and the supporting institutions of knowledge (like museums, libraries and archives. Radical proposals are advanced for the content, method, participants and organizational setting of education, as well as the role of the University as mediator of transitions, its relationship with society and economy, as well as its physical presence, governance structure and the values it should promote. Core functions and curricula for the future, along with the possibility of a global university consortium, are discussed.

  2. Corrugated metal surface with pillars for terahertz surface plasmon polariton waveguide components

    KAUST Repository

    Yuehong, Xu; Yanfeng, Li; Chunxiu, Tian; Jiaguang, Han; Quan, Xu; Xueqian, Zhang; Xixiang, Zhang; Ying, Zhang; Weili, Zhang

    2018-01-01

    In the terahertz regime, due to perfect conductivity of most metals, it is hard to realize a strong confinement of Surface plasmon polaritons (SPPs) although a propagation loss could be sufficiently low. We experimentally demonstrated a structure with periodic pillars arranged on a thin metal surface that supports bound modes of spoof SPPs at terahertz (THz) frequencies. By using scanning near-field THz microscopy, the electric field distribution above the metal surface within a distance of 130 μm was mapped. The results proved that this structure could guide spoof SPPs propagating along subwavelength waveguides, and at the same time reduce field expansion into free space. Further, for the development of integrated optical circuits, several components including straight waveguide, S-bend, Y-splitter and directional couplers were designed and characterized by the same method. We believe that the waveguide components proposed here will pave a new way for the development of flexible, wideband and compact photonic circuits operating at THz frequencies.

  3. Preparation of Al/Fe-Pillared Clays: Effect of the Starting Mineral.

    Science.gov (United States)

    Muñoz, Helir-Joseph; Blanco, Carolina; Gil, Antonio; Vicente, Miguel-Ángel; Galeano, Luis-Alejandro

    2017-11-28

    Four natural clays were modified with mixed polyoxocations of Al/Fe for evaluating the effect of the physicochemical properties of the starting materials (chemical composition, abundance of expandable clay phases, cationic exchange capacity and textural properties) on final physicochemical and catalytic properties of Al/Fe-PILCs. The aluminosilicate denoted C2 exhibited the highest potential as starting material in the preparation of Al/Fe-PILC catalysts, mainly due to its starting cationic exchange capacity (192 meq/100 g) and the dioctahedral nature of the smectite phase. These characteristics favored the intercalation of the mixed (Al 13- x /Fe x ) 7+ Keggin-type polyoxocations, stabilizing a basal spacing of 17.4 Å and high increase of the BET surface (194 m²/g), mainly represented in microporous content. According to H₂-TPR analyses, catalytic performance of the incorporated Fe in the Catalytic Wet Peroxide Oxidation (CWPO) reaction strongly depends on the level of location in mixed Al/Fe pillars. Altogether, such physicochemical characteristics promoted high performance in CWPO catalytic degradation of methyl orange in aqueous medium at very mild reaction temperatures (25.0 ± 1.0 °C) and pressure (76 kPa), achieving TOC removal of 52% and 70% of azo-dye decolourization in only 75 min of reaction under very low concentration of clay catalyst (0.05 g/L).

  4. GaN and LED structures grown on pre-patterned silicon pillar arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shunfeng; Fuendling, Soenke; Soekmen, Uensal; Merzsch, Stephan; Neumann, Richard; Peiner, Erwin; Wehmann, Hergo-Heinrich; Waag, Andreas [Institut fuer Halbleitertechnik, TU Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig (Germany); Hinze, Peter; Weimann, Thomas [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Jahn, Uwe; Trampert, Achim; Riechert, Henning [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvoigteiplatz 5-7, 10117 Berlin (Germany)

    2010-01-15

    GaN nanorods (or nanowires) have attracted great interest in a variety of applications, e.g. high-efficiency light emitting diodes, monolithic white light emission and optical interconnection due to their superior properties. In contrast to the mostly investigated self-assembled growth of GaN nanorods, we performed GaN nanorod growth by pre-patterning of the Si substrates. The pattern was transferred to Si substrates by photolithography and cryo-temperature inductively-coupled plasma etching. These Si templates then were used for further GaN nanorod growth by metal-organic vapour phase epitaxy (MOVPE). The low temperature AlN nucleation layer had to be optimized since it differs from its 2D layer counterpart on the surface area and orientations. We found a strong influence of diffusion processes, i.e. the GaN grown on top of the Si nanopillars can deplete the GaN around the Si pillars. Transmission electron microscopy measurements demonstrated clearly that the threading dislocations bend to the side facets of the pyramidal GaN nanostructures and terminate. Cathodoluminescence measurements reveal a difference of In composition and/or thickness of InGaN quantum wells on the different facets of the pyramidal GaN nanostructures. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. The Single Supervisory Mechanism: the Building Pillar of the European Banking Union

    Directory of Open Access Journals (Sweden)

    Luigi Chiarella

    2016-07-01

    Full Text Available One of the lessons learned from the 2008 financial crisis is that when a bank in Europe goes into trouble the ensuing effects can reach far beyond the immediate threat to its depositors and shareholders. In particular, the crisis has revealed the extent to which irresponsible behavior in the banking sector could undermine the foundations of the financial system and threaten the real economy, turning a banking crisis into a sovereign debt crisis as occurred in the eurozone in 2011. In response to this lesson, Member States first tried to address the systemic fragility of their banking systems through national policy tools, but countries that share a common currency and are more interdependent required more integrated responses. Therefore, at the euro area summit in June 2012, the European Council agreed to break the vicious circle between banks and sovereign debt and decided to create a banking union that would allow a centralized supervision for banks in the euro area through a newly established Single Supervisory Mechanism (SSM and a centralized resolution scheme. The SSM became operational in November 2014 and represents the building pillar of the banking union. The purpose of this paper is then to provide, after a brief description of the background (Par. 1, an analysis of the Single Supervisory Mechanism, illustrating its functioning (Par. 2, then focusing on the position and the powers of the ECB within it (Par. 3 and finally pointing out some remarks on the potential weaknesses of the new regime (Par. 4.

  6. Structural optimization of interpenetrated pillared-layer coordination polymers for ethylene/ethane separation.

    Science.gov (United States)

    Kishida, Keisuke; Horike, Satoshi; Watanabe, Yoshihiro; Tahara, Mina; Inubushi, Yasutaka; Kitagawa, Susumu

    2014-06-01

    With the goal of achieving effective ethylene/ethane separation, we evaluated the gas sorption properties of four pillared-layer-type porous coordination polymers with double interpenetration, [Zn2(tp)2(bpy)]n (1), [Zn2(fm)2(bpe)]n (2), [Zn2(fm)2(bpa)]n (3), and [Zn2(fm)2(bpy)]n (4) (tp = terephthalate, bpy = 4,4'-bipyridyl, fm = fumarate, bpe = 1,2-di(4-pyridyl)ethylene and bpa = 1,2-di(4-pyridyl)ethane). It was found that 4, which contains the narrowest pores of all of these compounds, exhibited ethylene-selective sorption profiles. The ethylene selectivity of 4 was estimated to be 4.6 at 298 K based on breakthrough experiments using ethylene/ethane gas mixtures. In addition, 4 exhibited a good regeneration ability compared with a conventional porous material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Mining a coal seam with caving in a protective pillar of a mine shaft. [Poland

    Energy Technology Data Exchange (ETDEWEB)

    Szymura, G; Dilling, R; Kowalski, A

    1984-01-01

    Mining the 620 seam is evaluated (from 1.5 to 1.7 m thick at a depth of 468 m in the protective pillar of the upcast mine shaft used for ventilation, manriding and transport of materials in the Pstrowski mine in Upper Silesia). The shaft is 496 m deep, has a diameter of 3.5 m and its liners are made of bricks. Ground subsidence caused by underground mining influenced: the head frame above the shaft, residential buildings, a church, railway tracks and a river bed. A system of shortwall mining with caving was used. Deformation of shaft liners was reduced by advanced cutting of a coal block 30x30 m around the shaft. A system of timber cribbings and yielding elements was used. Design of support systems used around the shaft is shown in 3 schemes. Shaft deformation was within permissible limits. The maximum ground subsidence (0.95 m) occurred in the river area. Ground subsidence in the area of the church ranged from 0.75 to 0.81 m and in the head frame area 0.84 m. Accuracy of ground subsidence and shaft deformation forecasting was high. 4 references.

  8. Volumetric Analysis of 3-D-Cultured Colonies in Wet Alginate Spots Using 384-Pillar Plate.

    Science.gov (United States)

    Lee, Dong Woo; Choi, Yea-Jun; Lee, Sang-Yun; Kim, Myoung-Hee; Doh, Il; Ryu, Gyu Ha; Choi, Soo-Mi

    2018-06-01

    The volumetric analysis of three-dimensional (3-D)-cultured colonies in alginate spots has been proposed to increase drug efficacy. In a previously developed pillar/well chip platform, colonies within spots are usually stained and dried for analysis of cell viability using two-dimensional (2-D) fluorescent images. Since the number of viable cells in colonies is directly related to colony volume, we proposed the 3-D analysis of colonies for high-accuracy cell viability calculation. The spots were immersed in buffer, and the 3-D volume of each colony was calculated from the 2-D stacking fluorescent images of the spot with different focal positions. In the experiments with human gastric carcinoma cells and anticancer drugs, we compared cell viability values calculated using the 2-D area and 3-D volume of colonies in the wet and dried alginate spots, respectively. The IC 50 value calculated using the 3-D volume of the colonies (9.5 μM) was less than that calculated in the 2-D area analysis (121.5 μM). We observed that the colony showed a more sensitive drug response regarding volume calculated from the 3-D image reconstructed using several confocal images than regarding colony area calculated in the 2-D analysis.

  9. Aespoe Pillar Stability Experiment. Summary of preparatory work and predictive modelling

    International Nuclear Information System (INIS)

    Andersson, J. Christer

    2004-11-01

    The Aespoe Pillar Stability Experiment, APSE, is a large scale rock mechanics experiment for research of the spalling process and the possibility for numerical modelling of it. The experiment can be summarized in three objectives: Demonstrate the current capability to predict spalling in a fractured rock mass; Demonstrate the effect of backfill (confining pressure) on the rock mass response; and Comparison of 2D and 3D mechanical and thermal predicting capabilities. This report is a summary of the works that has been performed in the experiment prior to the heating of the rock mass. The major activities that have been performed and are discussed herein are: 1) The geology of the experiment drift in general and the experiment volume in particular. 2) The design process of the experiment and thoughts behind some of the important decisions. 3) The monitoring programme and the supporting constructions for the instruments. 4) The numerical modelling, approaches taken and a summary of the predictions. In the end of the report there is a comparison of the results from the different models. Included is also a comparison of the time needed for building, realizing and make changes in the different models

  10. Struggles against the pillars of agribusiness in Argentina: GMOs, agrotoxics and CONABIA

    Directory of Open Access Journals (Sweden)

    Cecilia Carrizo

    2014-10-01

    Full Text Available Provided with the contributions of the linguistic turn, our perspective conceives political theorizing as an intervention of the researcher in an intersubjective context in which a public issue is debated. We focus on those contexts in which the exercise and claim for rights against the consequences of agribusiness is thematized: diseases and deaths, siteclearances and evictions of indigenous and peasant communities, omission or complicit actions of the state institutions among other issues. We consider these diverse and sustained over time practices as struggles for recognition that put in tension the complacent “consensus of the commodities”, its concepts, practices, institutions and effects. We present the struggles against the pillars of agribusiness in Argentina: GMOs, pesticides and the National Commission on Agricultural Biotechnology (CONABIA. As a result of our research there are contributions that uncover the web of relationships impacted by agribusiness, the public problems generated and currently generates the technological innovation in this field, and the limits and possibilities for resolution. Also we offer glimpse into the structure, criteria and operation, also made invisible: the body of the official political system with responsibilities in this case in our country, the National Commission for Agricultural Technology (CONABIA.

  11. Friction Hydro-Pillar Processing of a High Carbon Steel: Joint Structure and Properties

    Science.gov (United States)

    Kanan, Luis Fernando; Vicharapu, Buchibabu; Bueno, Antonio Fernando Burkert; Clarke, Thomas; De, Amitava

    2018-04-01

    A coupled experimental and theoretical study is reported here on friction hydro-pillar processing of AISI 4140 steel, which is a novel solid-state joining technique to repair and fill crack holes in thick-walled components by an external stud. The stud is rotated and forced to fill a crack hole by plastic flow. During the process, frictional heating occurs along the interface of the stud and the wall of crack hole leading to thermal softening of the stud that eases its plastic deformation. The effect of the stud force, its rotational speed and the total processing time on the rate of heat generation and resulting transient temperature field is therefore examined to correlate the processing variables with the joint structure and properties in a systematic and quantitative manner, which is currently scarce in the published literature. The results show that a gentler stud force rate and greater processing time can promote proper filling of the crack hole and facilitate a defect-free joint between the stud and original component.

  12. Evaluating Pillar Industry's Transformation Capability: A Case Study of Two Chinese Steel-Based Cities.

    Science.gov (United States)

    Li, Zhidong; Marinova, Dora; Guo, Xiumei; Gao, Yuan

    2015-01-01

    Many steel-based cities in China were established between the 1950s and 1960s. After more than half a century of development and boom, these cities are starting to decline and industrial transformation is urgently needed. This paper focuses on evaluating the transformation capability of resource-based cities building an evaluation model. Using Text Mining and the Document Explorer technique as a way of extracting text features, the 200 most frequently used words are derived from 100 publications related to steel- and other resource-based cities. The Expert Evaluation Method (EEM) and Analytic Hierarchy Process (AHP) techniques are then applied to select 53 indicators, determine their weights and establish an index system for evaluating the transformation capability of the pillar industry of China's steel-based cities. Using real data and expert reviews, the improved Fuzzy Relation Matrix (FRM) method is applied to two case studies in China, namely Panzhihua and Daye, and the evaluation model is developed using Fuzzy Comprehensive Evaluation (FCE). The cities' abilities to carry out industrial transformation are evaluated with concerns expressed for the case of Daye. The findings have policy implications for the potential and required industrial transformation in the two selected cities and other resource-based towns.

  13. Immobilization of heavy metals on pillared montmorillonite with a grafted chelate ligand.

    Science.gov (United States)

    Brown, Loren; Seaton, Kenneth; Mohseni, Ray; Vasiliev, Aleksey

    2013-10-15

    The objective of this work was the development of an efficient adsorbent for irreversible immobilization of heavy metals in contaminated soils. The adsorbent was prepared by pillaring of montmorillonite with silica followed by grafting of a chelate ligand on its surface. Obtained adsorbent was mesoporous with high content of adsorption sites. Its structure was studied by BET adsorption of N2, dynamic light scattering, and scanning electron microscopy. The adsorption capacity of the organoclay was measured by its mixing with contaminated kaolin and soil samples and by analysis of heavy metal contents in leachate. Deionized water and 50% acetic acid were used for leaching of metals from the samples. As it was demonstrated by the experiments, the adsorbent was efficient in immobilization of heavy metals not only in neutral aqueous media but also in the presence of weak acid. As a result, the adsorbent can be used for reduction of heavy metal leaching from contaminated sites. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Electrolytic Manganese Dioxide Coatings on High Aspect Ratio Micro-Pillar Arrays for 3D Thin Film Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yafa Zargouni

    2017-05-01

    Full Text Available In this work, we present the electrochemical deposition of manganese dioxide (MnO2 thin films on carbon-coated TiN/Si micro-pillars. The carbon buffer layer, grown by plasma enhanced chemical vapor deposition (PECVD, is used as a protective coating for the underlying TiN current collector from oxidation, during the film deposition, while improving the electrical conductivity of the stack. A conformal electrolytic MnO2 (EMD coating is successfully achieved on high aspect ratio C/TiN/Si pillar arrays by tailoring the deposition process. Lithiation/Delithiation cycling tests have been performed. Reversible insertion and extraction of Li+ through EMD structure are observed. The fabricated stack is thus considered as a good candidate not only for 3D micorbatteries but also for other energy storage applications.

  15. Electrolytic Manganese Dioxide Coatings on High Aspect Ratio Micro-Pillar Arrays for 3D Thin Film Lithium Ion Batteries.

    Science.gov (United States)

    Zargouni, Yafa; Deheryan, Stella; Radisic, Alex; Alouani, Khaled; Vereecken, Philippe M

    2017-05-27

    In this work, we present the electrochemical deposition of manganese dioxide (MnO₂) thin films on carbon-coated TiN/Si micro-pillars. The carbon buffer layer, grown by plasma enhanced chemical vapor deposition (PECVD), is used as a protective coating for the underlying TiN current collector from oxidation, during the film deposition, while improving the electrical conductivity of the stack. A conformal electrolytic MnO₂ (EMD) coating is successfully achieved on high aspect ratio C/TiN/Si pillar arrays by tailoring the deposition process. Lithiation/Delithiation cycling tests have been performed. Reversible insertion and extraction of Li⁺ through EMD structure are observed. The fabricated stack is thus considered as a good candidate not only for 3D micorbatteries but also for other energy storage applications.

  16. Effect of the platinum content on the microstructure and micropore size distribution of Pt/alumina-pillared clays.

    Science.gov (United States)

    Barrera-Vargas, M; Valencia-Rios, J; Vicente, M A; Korili, S A; Gil, A

    2005-12-15

    The aim of this work is to study the effect of the platinum content (0-1.8 wt % Pt) on the microstructure of an alumina-pillared clay. For this purpose, the nitrogen physisorption data at -196 degrees C, the micropore size distributions of the supported platinum catalysts, and the hydrogen chemisorption results at 30 degrees C have been analyzed and compared. The preparation of the catalysts has modified the textural properties of the Al-pillared clay support, giving rise to a loss of surface area and micropore volume. After reduction at 420 degrees C, the presence of dispersed metallic platinum with mean crystallite size in the 22-55 A range has been found by hydrogen adsorption. Comparison of all results reveals that the platinum species block the micropore entrances by steric hindrance to nitrogen access as the platinum content increases.

  17. Teaching population health and community-based care across diverse clinical experiences: integration of conceptual pillars and constructivist learning.

    Science.gov (United States)

    Valentine-Maher, Sarah K; Van Dyk, Elizabeth J; Aktan, Nadine M; Bliss, Julie Beshore

    2014-03-01

    Nursing programs are challenged to prepare future nurses to provide care and affect determinants of health for individuals and populations. This article advances a pedagogical model for clinical education that builds concepts related to both population-level care and direct care in the community through a contextual learning approach. Because the conceptual pillars and hybrid constructivist approach allow for conceptual learning consistency across experiences, the model expands programmatic capacity to use diverse community clinical sites that accept only small numbers of students. The concept-based and hybrid constructivist learning approach is expected to contribute to the development of broad intellectual skills and lifelong learning. The pillar concepts include determinants of health and nursing care of population aggregates; direct care, based on evidence and best practices; appreciation of lived experience of health and illness; public health nursing roles and relationship to ethical and professional formation; and multidisciplinary collaboration. Copyright 2014, SLACK Incorporated.

  18. A continuous flow micro filtration device for plasma/blood separation using submicron vertical pillar gap structures

    International Nuclear Information System (INIS)

    Kang, Tae Goo; Ji, Hongmiao; Lim, Pei Yi; Chen, Yu; Yoon, Yong-Jin

    2014-01-01

    This work demonstrates a continuous flow plasma/blood separator using a vertical submicron pillar gap structure. The working principle of the proposed separator is based on size exclusion of cells through cross-flow filtration, in which only plasma is allowed to pass through submicron vertical pillars located tangential to the main flow path of the blood sample. The maximum filtration efficiency of 99.9% was recorded with a plasma collection rate of 0.67 µl min −1 for an input blood flow rate of 12.5 µl min −1 . The hemolysis phenomenon was observed for an input blood flow rate above 30 µl min −1 . Based on the experimental results, we can conclude that the proposed device shows potential for the application of on-chip plasma/blood separation as a part of integrated point-of-care (POC) diagnostics systems. (technical note)

  19. An investigation into UV light exposure as an experimental model for artificial aging on tensile strength and force delivery of elastomeric chain.

    Science.gov (United States)

    Wahab, Siti Waznah; Bister, Dirk; Sherriff, Martyn

    2014-02-01

    This study investigated the effect of ultraviolet type A light (UVA) exposure on the tensile properties of elastomeric chain. UVA light exposure was used as model for artificial aging, simulating prolonged storage of elastomeric chain. Tensile strength (n = 60) was measured after exposing Ormco, Forestadent and 3M chains to UVA light for 0, 2, 3, and 4 weeks. Force decay was measured (n = 60) using chain exposed for 5, 10, and 14 days. The chains were subsequently stretched at a constant distance and the resulting forces measured at 0, 1, 24 hours and 7, 14, 21, and 28 days. This test simulated a clinical scenario of pre-stretching and subsequent shortening of elastomeric chain. Tensile strength had statistically significant difference and was directly related to the duration of ultraviolet (UV) light exposure. Forestadent chain, which had the second highest value for the 'as received' product, showed the most consistent values over time with the lowest degradation. Ormco showed the lowest values for 'as received' as well as after UV exposure; 3M chain had the highest loss of tensile strength. Force decay was also significantly different. UV light exposure of 10 days or more appears to mark a 'watershed' between products: 3M had most survivors, Forestadent chain had some survivors, depending on the time the chain was stretched for. None of the Ormco product survived UV light exposure for more than 5 days. UVA light exposure may be used as a model for artificial aging as it reduces force delivery and tensile strength of exposed chains.

  20. Effects of breathing frequency and flow rate on the total inward leakage of an elastomeric half-mask donned on an advanced manikin headform.

    Science.gov (United States)

    He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; McKay, Roy; Bergman, Michael S; Zhuang, Ziqing

    2014-03-01

    The objective of this study was to investigate the effects of breathing frequency and flow rate on the total inward leakage (TIL) of an elastomeric half-mask donned on an advanced manikin headform and challenged with combustion aerosols. An elastomeric half-mask respirator equipped with P100 filters was donned on an advanced manikin headform covered with life-like soft skin and challenged with aerosols originated by burning three materials: wood, paper, and plastic (polyethylene). TIL was determined as the ratio of aerosol concentrations inside (C in) and outside (C out) of the respirator (C in/C out) measured with a nanoparticle spectrometer operating in the particle size range of 20-200nm. The testing was performed under three cyclic breathing flows [mean inspiratory flow (MIF) of 30, 55, and 85 l/min] and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). A completely randomized factorial study design was chosen with four replicates for each combination of breathing flow rate and frequency. Particle size, MIF, and combustion material had significant (P plastic aerosol produced higher mean TIL values than wood and paper aerosols. The effect of the breathing frequency was complex. When analyzed using all combustion aerosols and MIFs (pooled data), breathing frequency did not significantly (P = 0.08) affect TIL. However, once the data were stratified according to combustion aerosol and MIF, the effect of breathing frequency became significant (P plastic combustion aerosol. The effect of breathing frequency on TIL is less significant than the effects of combustion aerosol and breathing flow rate for the tested elastomeric half-mask respirator. The greatest TIL occurred when challenged with plastic aerosol at 30 l/min and at a breathing frequency of 30 breaths/min.

  1. Distributional effects and structural change induced by various CAP Pillar 1 proposals; the case of the Czech Republic

    OpenAIRE

    Ratinger, Tomas; Foltyn, Ivan; Jelinek, Ladislav; Kristkova, Zuzana

    2012-01-01

    This paper deals with the potential effects of the CAP pillar 1 on farm incomes and structural changes. It uses a dynamic Computable General Equilibrium model and a specific analysis on distributional effects. The effect of payments ceiling in the current CAP 2020 proposal with subtracting labour costs will bring only insignificant payment reduction for most farmers except large extensive beef breeders whose direct payments will drop by 13% on average. However, if the condition on labour cost...

  2. THE EVALUATION OF EIGHT PILLARS TOTAL PRODUCTIVE MAINTENANCE (TPM IMPLEMENTATION AND THEIR IMPACT ON OVERALL EQUIPMENT EFFECTIVENESS (OEE AND WASTE

    Directory of Open Access Journals (Sweden)

    Herry Agung Prabowo

    2018-02-01

    Full Text Available In this global era where the level of competition is higher, in addition to the influence of the suitable marketing strategy is also required strategy from the side of production/productivity. PT. XYZ is a company engaged in the manufacturing of snacks especially biscuits. The problem that often occurs in this company is the number of biscuits that are not in accordance with the standard and the production does not reach the target set because the machine suddenly breaks down frequently. To overcome the problems PT. XYZ then choose to implement the Total Productive Maintenance (TPM strategy. This study aims to evaluate the implementation of 8 TPM Pillars and measure the effects on manufacturing performance in the form of Overall Equipment Effectiveness (OEE and Waste. This study uses questionnaire-based survey method. The number of samples distributed is 40 units. Which returned and filled 33 questionnaires and which is worth to be processed as many as 30 samples. Then tested the validity and reliability of data using SPSS program. Validity critical value R = 0.361 for n = 30 and error rate 5%. For reliability test, R value = 0.60 was selected. From the validity test, there are 7 items of questions that are not valid so it is not included in the next process. For the reliability test of the questionnaire is quite reliable with the value of Cronbach's alpha of 0.811. From the CFA analysis, only 6 of 8 TPM pillars are significant while for manufacturing performance only OEE variable is significant. Correlation between 8 Pillars of TPM and manufacturing performance is Strong enough with a value of R = 0.862, which also means 74.3% (R2 variable manufacturing performance can be explained/influenced by variable 8 Pillar TPM and 26.7% the rest by other variables.

  3. Is something wrong with the second pillar in Switzerland?: Gender inequalities from a perspective of two Private Occupational Pension Institutions

    OpenAIRE

    Kucera, Jacqueline; Suter, Christian; Halford, Susan; Crettaz, Eric

    2015-01-01

    Inequalities and old age pension systems have been analyzed in depth by many scholars. This study tackles the question of gender inequalities in a propaedeutic manner and asks: “Is something wrong with the second pillar in Switzerland?” By perceiving the occupational pension system as secure and safe, the focus of this thesis lies in the idea of guaranteeing equality for future pensions. The thesis asks whether gender inequalities occur through the mechanism of interpretation of the Federal L...

  4. Development of a time-dependent energy model to calculate the mining-induced stress over gates and pillars

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaei

    2015-06-01

    Full Text Available Generally, longwall mining-induced stress results from the stress relaxation due to destressed zone that occurs above the mined panel. Knowledge of induced stress is very important for accurate design of adjacent gateroads and intervening pillars which helps to raise the safety and productivity of longwall mining operations. This study presents a novel time-dependent analytical model for determination of the longwall mining-induced stress and investigates the coefficient of stress concentration over adjacent gates and pillars. The model is developed based on the strain energy balance in longwall mining incorporated to a rheological constitutive model of caved materials with time-varying parameters. The study site is the Tabas coal mine of Iran. In the proposed model, height of destressed zone above the mined panel, total longwall mining-induced stress, abutment angle, induced vertical stress, and coefficient of stress concentration over neighboring gates and intervening pillars are calculated. To evaluate the effect of proposed model parameters on the coefficient of stress concentration due to longwall mining, sensitivity analysis is performed based on the field data and experimental constants. Also, the results of the proposed model are compared with those of existing models. The comparative results confirm a good agreement between the proposed model and the in situ measurements. According to the obtained results, it is concluded that the proposed model can be successfully used to calculate the longwall mining-induced stress. Therefore, the optimum design of gate supports and pillar dimensions would be attainable which helps to increase the mining efficiency.

  5. Ensuring Support for Research and Quality Improvement (QI) Networks: Four Pillars of Sustainability?An Emerging Framework

    OpenAIRE

    Holve, Erin

    2013-01-01

    Multi-institutional research and quality improvement (QI) projects using electronic clinical data (ECD) hold great promise for improving quality of care and patient outcomes but typically require significant infrastructure investments both to initiate and maintain the project over its duration. Consequently, it is important for these projects to think holistically about sustainability to ensure their long-term success. Four ?pillars? of sustainability are discussed based on the experiences of...

  6. The Evaluation of the II pillar pension’s funds: an integrated approach using multi-criteria decision methods

    OpenAIRE

    Novickytė, Lina; Rabikauskaitė, Viktorija

    2017-01-01

    Lithuania has had a significant reform path in the last twenty-five years like other communist bloc countries during the intense changes in the world. Changes and transformations took place in various areas including social security system. Since 2004 have been significant developments legalizing the three-pillar old age pension system supported by the World Bank. Currently, the pension funds operating more than ten years and their assessment still have not stopped being the centre of numerou...

  7. The evaluation of the II pillar pension’s funds: an integrated approach using multi-criteria decision methods

    OpenAIRE

    Novickytė,Lina; Rabikauskaitė,Viktorija

    2017-01-01

    Lithuania has had a significant reform path in the last twenty-five years like other communist bloc countries during the intense changes in the world. Changes and transformations took place in various areas including social security system. Since 2004 have been significant developments legalizing the three-pillar old age pension system supported by the World Bank. Currently, the pension funds operating more than ten years and their assessment still have not stopped being the centre of numerou...

  8. Effectiveness of nickel-titanium springs vs elastomeric chains in orthodontic space closure: A systematic review and meta-analysis.

    Science.gov (United States)

    Mohammed, H; Rizk, M Z; Wafaie, K; Almuzian, M

    2018-02-01

    The aim of this study is to explore the effectiveness of nickel titanium closing springs (NiTi-CS) and elastomeric power chains (EPC) in orthodontic space closure and to assess the adverse periodontal effects, cost efficiency and patient-centred outcomes between both of these methods. An electronic search of online databases (Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Scopus, LILACS and Web of Science), reference lists and grey literature as well as hand search were conducted without language restriction up to November/2017. Two authors blindly and in duplicate were involved in study selection, quality assessment and the extraction of data. Only randomized clinical trials (RCTs) were included. The quality of the studies was assessed using the Cochrane Collaboration's risk of bias tool. 95% confidence intervals and mean difference for continuous data were calculated. A meta-analysis that generated a random-effect model for the comparable outcomes was conducted, and heterogeneity was measured using I 2 statistic. Of 187 records, 4 RCTs met the criteria and were included in the quantitative synthesis featuring 290 test quadrants. Faster space closure with NiTi-CS was observed with a mean difference of (0.20 mm/month, 95% CI: 0.12 to 0.28). Loss of anchorage appears to be similar within both groups when synthesized qualitatively. With exception to anchorage loss, secondary outcomes could not be investigated in the included trials. There is a moderate quality of evidence suggesting a faster orthodontic space closure with the NiTi-CS when compared to EPC. A comparable amount of anchorage loss was observed regardless of the utilized method of space closure. Further high-quality RCTs with parallel-groups, reporting on the adverse effects and patient-centred values, are recommended. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Quasi-Static Behavior of Palm-Based Elastomeric Polyurethane: For Strengthening Application of Structures under Impulsive Loadings

    Directory of Open Access Journals (Sweden)

    H. M. Chandima Chathuranga Somarathna

    2016-05-01

    Full Text Available In recent years, attention has been focused on elastomeric polymers as a potential retrofitting material considering their capability in contributing towards the impact resistance of various structural elements. A comprehensive understanding of the behavior and the morphology of this material are essential to propose an effective and feasible alternative to existing structural strengthening and retrofitting materials. This article presents the findings obtained from a series of experimental investigations to characterize the physical, mechanical, chemical and thermal behavior of eight types of palm-based polyurethane (PU elastomers, which were synthesized from the reaction between palm kernel oil-based monoester polyol (PKO-p and 4,4-diphenylmethane diisocyanate (MDI with polyethylene glycol (PEG as the plasticizer via pre-polymerization. Fourier transform infrared (FT-IR spectroscopy analysis was conducted to examine the functional groups in PU systems. Mechanical and physical behavior was studied with focus on elongation, stresses, modulus, energy absorption and dissipation, and load dispersion capacities by conducting hardness, tensile, flexural, Izod impact, and differential scanning calorimetry tests. Experimental results suggest that the palm-based PU has positive effects as a strengthening and retrofitting material against dynamic impulsive loadings both in terms of energy absorption and dissipation, and load dispersion. In addition, among all PUs with different plasticizer contents, PU2 to PU8 (which contain 2% to 8% (w/w PEG with respect to PKO-p content show the best correlation with mechanical response under quasi-static conditions focusing on energy absorption and dissipation and load dispersion characteristics.

  10. Formation of zeolite-like zinc 1,3,5-benzenetriphosphonate open-frameworks by topotactic pillaring of anionic layers.

    Science.gov (United States)

    Maeda, Kazuyuki; Takamatsu, Ryohei; Mochizuki, Miki; Kawawa, Kanako; Kondo, Atsushi

    2013-08-07

    An ab initio powder X-ray crystal structure analysis revealed that layered zinc 1,3,5-benzenetriphosphonates containing interlayer tetramethylammonium (ZBP-TMA) or 4,4'-bipyridinium cations (ZBP-bpy) are transformed to novel isomorphous 3D open-framework compounds ZBP-M (M: K, Rb, and Cs) by treatment in aqueous alkali metal chloride solutions. ZBP-Ms have a pillared layer-type of anionic framework containing 2D zigzag channels connected with cage-like spaces. The potassium atoms in ZBP-K are located near 8MR windows in the 2D zigzag channels, and the potassium cations are successfully exchanged with ammonium cations retaining the open-framework structure. The ammonium form (ZBP-NH4) showed remarkable cation exchange selectivity for Rb(+) and Cs(+) in a mixture of alkali metal cations. It is assumed that zinc ions partially dissolved from the starting layered ZBP precursors are intercalated in ZBP layers to form pillared layered 3D open-frameworks. These results clearly show that topotactic pillared layer approaches are applicable not only to zeolite-related materials but also to novel open-framework metal organophosphonates.

  11. Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

    International Nuclear Information System (INIS)

    Ito, Kota; Miura, Atsushi; Iizuka, Hideo; Toshiyoshi, Hiroshi

    2015-01-01

    Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed to the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics

  12. Inclined-wall regular micro-pillar-arrayed surfaces covered entirely with an alumina nanowire forest and their improved superhydrophobicity

    International Nuclear Information System (INIS)

    Kim, Dae-Ho; Lee, Dongyun; Cho, Chae-Ryong; Kim, Soo-Hyung; Lee, Deug-Woo; Kim, Jong-Man; Kim, Yongsung; Kang, Jae-Wook; Hong, Suck Won

    2011-01-01

    This paper reports a multiple-scale hierarchically structured superhydrophobic surface that is composed of inclined-wall regular micro-pillar arrays covered entirely with an alumina nanowire forest (ANF) to improve the surface wettability. The multiple-scaled structures were fabricated stably using a simple batch process based on an anisotropic chemical silicon etching process and a subsequent time-controlled anodic aluminum oxide technique. The surface wetting properties of the mono-roughened surfaces with inclined-wall micro-pillar arrays, which are normally in the Wenzel wetting regime, could be transitioned perfectly to the slippery Cassie mode and enhanced greatly in the Wenzel regime in cases of a high- and low-density of the micro-pillars, respectively, by easily amplifying the intrinsic contact angle through the entire coverage of the ANF on the micro-roughened surfaces. The wettability of the proposed multiple-scaled surfaces could also be predicted using analytic surface models and the experimental results agreed greatly with the wetting trends estimated theoretically due to the geometrical regularity of the base micro-structures

  13. Reduced-Pressure Chemical Vapor Deposition Growth of Isolated Ge Crystals and Suspended Layers on Micrometric Si Pillars.

    Science.gov (United States)

    Skibitzki, Oliver; Capellini, Giovanni; Yamamoto, Yuji; Zaumseil, Peter; Schubert, Markus Andreas; Schroeder, Thomas; Ballabio, Andrea; Bergamaschini, Roberto; Salvalaglio, Marco; Miglio, Leo; Montalenti, Francesco

    2016-10-05

    In this work, we demonstrate the growth of Ge crystals and suspended continuous layers on Si(001) substrates deeply patterned in high aspect-ratio pillars. The material deposition was carried out in a commercial reduced-pressure chemical vapor deposition reactor, thus extending the "vertical-heteroepitaxy" technique developed by using the peculiar low-energy plasma-enhanced chemical vapor deposition reactor, to widely available epitaxial tools. The growth process was thoroughly analyzed, from the formation of small initial seeds to the final coalescence into a continuous suspended layer, by means of scanning and transmission electron microscopy, X-ray diffraction, and μ-Raman spectroscopy. The preoxidation of the Si pillar sidewalls and the addition of hydrochloric gas in the reactants proved to be key to achieve highly selective Ge growth on the pillars top only, which, in turn, is needed to promote the formation of a continuous Ge layer. Thanks to continuum growth models, we were able to single out the different roles played by thermodynamics and kinetics in the deposition dynamics. We believe that our findings will open the way to the low-cost realization of tens of micrometers thick heteroepitaxial layer (e.g., Ge, SiC, and GaAs) on Si having high crystal quality.

  14. Mean wall-shear stress measurements using the micro-pillar shear-stress sensor MPS3

    International Nuclear Information System (INIS)

    Große, S; Schröder, W

    2008-01-01

    A new sensor to measure the mean turbulent wall-shear stress in turbulent flows is described. The wall-shear stress sensor MPS 3 has been tested in a well-defined fully developed turbulent pipe flow at Reynolds numbers Re b based on the bulk velocity U b and the pipe diameter D in the range of Re b = 10 000–20 000. The results demonstrate a convincing agreement of the mean wall-shear stress obtained with the new sensor technique with analytical and experimental results from the literature. The sensor device consists of a flexible micro-pillar that extends from the wall into the viscous sublayer. Bending due to the exerting fluid forces, the pillar-tip deflection serves as a measure for the local wall-shear stress. The sensor concept, calibration techniques, the achievable accuracy and error estimates, the fields of application and the sensor limits will be discussed. Furthermore, a first estimate of the pillar dynamic response will be derived showing the potential of the sensor to also measure the turbulent fluctuating wall-shear stress

  15. Controlling the photochemical reaction of an azastilbene derivative in water using a water-soluble pillar[6]arene.

    Science.gov (United States)

    Xia, Danyu; Wang, Pi; Shi, Bingbing

    2017-09-20

    Photochemistry plays an important role in our lives. It has also been a common tool in the laboratory to construct complicated systems from small molecules. Supramolecular chemistry provides an opportunity to solve some of the problems in controlling photochemical reactions via non-covalent interactions. By using confining media and weak interactions between the medium and the reactant molecule, the excited state behavior of molecules has been successfully manipulated. Pillararenes, a new class of macrocyclic hosts, have rarely been used in the field of photochemical investigations, such as the controlling of photo-induced reactions. Herein, we explore a synthetic macrocyclic host, a water-soluble pillar[6]arene, as a controlling tool to manipulate the photo-induced reactions (hydration) in water. A host-guest system in water based on a water-soluble pillar[6]arene and an azastilbene derivative, (E)-4,4'-dimethyl-4,4'-diazoniastilbene diiodide, has been constructed. Then this water-soluble pillar[6]arene was successfully employed to control the photohydration of the azastilbene derivative in water as a "protective agent".

  16. Fe/Ti co-pillared clay for enhanced arsenite removal and photo oxidation under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Guang Dong Electric Power Design Institute, China Energy Engineering Group Co. Ltd., Guangzhou 510663 (China); Cai, Xiaojiao [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Guo, Jingwei [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); The 718th Research Institute of CSIC, Handan 056027 (China); Zhou, Shimin [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Na, Ping, E-mail: naping@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2015-01-01

    Graphical abstract: - Highlights: • An iron and titanium co-pillared montmorillonite (Fe-Ti/MMT) was synthesized for arsenite removal. • Variety of characterization results indicated that Fe and Ti species were pillared in MMT. • A possible mechanism of arsenite adsorption/oxidation with UV light was established. • The participation of Fe component can promote the process of photocatalytic oxidation in Fe-Ti/MMT + As(III) system. • Fe-Ti/MMT can function as both photocatalyst and adsorbent for arsenite removal. - Abstract: A series of iron and titanium co-pillared montmorillonites (Fe-Ti/MMT) were prepared using hydrolysis of inserted titanium and different iron content in montmorillonite (MMT). The Fe-Ti/MMT were characterized by X-ray fluorescence, N{sub 2} adsorption and desorption, X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the effective insertion of Fe species and TiO{sub 2} in the MMT. The Fe-Ti/MMT was used to remove arsenite (As(III)) from aqueous solutions under different conditions. The result of As(III) adsorption under UV irradiation showed that the photo activity can be enhanced by incorporating Fe and Ti in MMT. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the hydroxyl groups bonded to metal oxide (M–OH) played an important role in the adsorption of As(III)

  17. Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp [Toyota Central Research and Development Laboratories, Nagakute, Aichi 480-1192 (Japan); Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Miura, Atsushi; Iizuka, Hideo [Toyota Central Research and Development Laboratories, Nagakute, Aichi 480-1192 (Japan); Toshiyoshi, Hiroshi [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

    2015-02-23

    Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed to the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics.

  18. Counter-rotating type tidal stream power unit boarded on pillar (performances and flow conditions of tandem propellers)

    Science.gov (United States)

    Usui, Yuta; Kanemoto, Toshiaki; Hiraki, Koju

    2013-12-01

    The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fruitful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propellers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger.

  19. Verification of the fulfilment of the purposes of Basel II, Pillar 3 through application of the web log mining methods

    Directory of Open Access Journals (Sweden)

    M. Munk

    2012-01-01

    Full Text Available The objective of the paper is the verification of the fulfilment of the purposes of Basel II, Pillar 3 – market discipline during the recent financial crisis. The objective of the paper is to describe the current state of the working out of the project that is focused on the analysis of the market participants’ interest in mandatory disclosure of financial information by a commercial bank by means of advanced methods of web log mining. The output of the realized project will be the verification of the assumptions related to the purposes of Basel III by means of the web mining methods, the recommendations for possible reduction of mandatory disclosure of information under Basel II and III, the proposal of the methodology for data preparation for web log mining in this application domain and the generalised procedure for users’ behaviour modelling dependent on time. The schedule of the project has been divided into three phases. The paper deals with its first phase that is focusing on the data pre-processing, analysis and evaluation of the required information under Basel II, Pillar 3 since 2008 and its disclosure into the web site of a commercial bank. The authors introduce the methodologies for data preparation and known heuristic methods for path completion into web log files with respect to the particularity of investigated application domain. They propose scientific methods for modelling users’ behaviour of the webpages related to Pillar 3 with respect to time.

  20. Simple scaling laws for the evaporation of droplets pinned on pillars: Transfer-rate- and diffusion-limited regimes.

    Science.gov (United States)

    Hernandez-Perez, Ruth; García-Cordero, José L; Escobar, Juan V

    2017-12-01

    The evaporation of droplets can give rise to a wide range of interesting phenomena in which the dynamics of the evaporation are crucial. In this work, we find simple scaling laws for the evaporation dynamics of axisymmetric droplets pinned on millimeter-sized pillars. Different laws are found depending on whether evaporation is limited by the diffusion of vapor molecules or by the transfer rate across the liquid-vapor interface. For the diffusion-limited regime, we find that a mass-loss rate equal to 3/7 of that of a free-standing evaporating droplet brings a good balance between simplicity and physical correctness. We also find a scaling law for the evaporation of multicomponent solutions. The scaling laws found are validated against experiments of the evaporation of droplets of (1) water, (2) blood plasma, and (3) a mixture of water and polyethylene glycol, pinned on acrylic pillars of different diameters. These results shed light on the macroscopic dynamics of evaporation on pillars as a first step towards the understanding of other complex phenomena that may be taking place during the evaporation process, such as particle transport and chemical reactions.

  1. Simple scaling laws for the evaporation of droplets pinned on pillars: Transfer-rate- and diffusion-limited regimes

    Science.gov (United States)

    Hernandez-Perez, Ruth; García-Cordero, José L.; Escobar, Juan V.

    2017-12-01

    The evaporation of droplets can give rise to a wide range of interesting phenomena in which the dynamics of the evaporation are crucial. In this work, we find simple scaling laws for the evaporation dynamics of axisymmetric droplets pinned on millimeter-sized pillars. Different laws are found depending on whether evaporation is limited by the diffusion of vapor molecules or by the transfer rate across the liquid-vapor interface. For the diffusion-limited regime, we find that a mass-loss rate equal to 3/7 of that of a free-standing evaporating droplet brings a good balance between simplicity and physical correctness. We also find a scaling law for the evaporation of multicomponent solutions. The scaling laws found are validated against experiments of the evaporation of droplets of (1) water, (2) blood plasma, and (3) a mixture of water and polyethylene glycol, pinned on acrylic pillars of different diameters. These results shed light on the macroscopic dynamics of evaporation on pillars as a first step towards the understanding of other complex phenomena that may be taking place during the evaporation process, such as particle transport and chemical reactions.

  2. Behavior of a New Elastomeric material used as polyolefinic geo membrane in waterproofing; Comportamiento de un nuevo material elastomerico utilizado como geomembrana poliolefinica en impermeabilizacion

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Aguilar, E.; Vara, T. A; Soriano, J.; Garcia, F.; Castillo, F.

    2011-07-01

    Two decades ago that Balsas de Tenerife (BALTEN) and the Centro de Estudios y Experimentacion de Obras Publicas (CEDEX), in its experimental field of the south of the Tenerife Island have installed a series of materials to known their behaviour over time. These products among which was placed over a dozen years ago, on an elastomeric polyolefin. This work presents the performance of this synthetic geo membrane, focusing on the evolution in the time of the tensile properties static puncture, low temperature folding, dynamic impact, joint strength (shear and peeling test), optical microscopy of reflection nd scanning electron microscopy. (Author) 11 refs.

  3. A non-symmetric pillar[5]arene based on triazole-linked 8-oxyquinolines as a sequential sensor for thorium(IV) followed by fluoride ions.

    Science.gov (United States)

    Fang, Yuyu; Li, Caixia; Wu, Lei; Bai, Bing; Li, Xing; Jia, Yiming; Feng, Wen; Yuan, Lihua

    2015-09-07

    A novel non-symmetric pillar[5]arene bearing triazole-linked 8-oxyquinolines at one rim was synthesized and demonstrated as a sequential fluorescence sensor for thorium(iv) followed by fluoride ions with high sensitivity and selectivity.

  4. Globules and pillars in Cygnus X. I. Herschel far-infrared imaging of the Cygnus OB2 environment

    Science.gov (United States)

    Schneider, N.; Bontemps, S.; Motte, F.; Blazere, A.; André, Ph.; Anderson, L. D.; Arzoumanian, D.; Comerón, F.; Didelon, P.; Di Francesco, J.; Duarte-Cabral, A.; Guarcello, M. G.; Hennemann, M.; Hill, T.; Könyves, V.; Marston, A.; Minier, V.; Rygl, K. L. J.; Röllig, M.; Roy, A.; Spinoglio, L.; Tremblin, P.; White, G. J.; Wright, N. J.

    2016-06-01

    The radiative feedback of massive stars on molecular clouds creates pillars, globules and other features at the interface between the H II region and molecular cloud. Optical and near-infrared observations from the ground as well as with the Hubble or Spitzer satellites have revealed numerous examples of such cloud structures. We present here Herschel far-infrared observations between 70 μm and 500 μm of the immediate environment of the rich Cygnus OB2 association, performed within the Herschel imaging survey of OB Young Stellar objects (HOBYS) program. All of the observed irradiated structures were detected based on their appearance at 70 μm, and have been classified as pillars, globules, evaporating gasous globules (EGGs), proplyd-like objects, and condensations. From the 70 μm and 160 μm flux maps, we derive the local far-ultraviolet (FUV) field on the photon dominated surfaces. In parallel, we use a census of the O-stars to estimate the overall FUV-field, that is 103-104 G0 (Habing field) close to the central OB cluster (within 10 pc) and decreases down to a few tens G0, in a distance of 50 pc. From a spectral energy distribution (SED) fit to the four longest Herschel wavelengths, we determine column density and temperature maps and derive masses, volume densities and surface densities for these structures. We find that the morphological classification corresponds to distinct physical properties. Pillars and globules are massive (~500 M⊙) and large (equivalent radius r ~ 0.6 pc) structures, corresponding to what is defined as "clumps" for molecular clouds. EGGs and proplyd-likeobjects are smaller (r ~ 0.1 and 0.2 pc) and less massive (~10 and ~30 M⊙). Cloud condensations are small (~0.1 pc), have an average mass of 35 M⊙, are dense (~6 × 104 cm-3), and can thus be described as molecular cloud "cores". All pillars and globules are oriented toward the Cyg OB2 association center and have the longest estimated photoevaporation lifetimes, a few million

  5. A comparative UV-vis-diffuse reflectance study on the location and interaction of cerium ions in Al- and Zr-pillared montmorillonite clays

    International Nuclear Information System (INIS)

    Rao, G. Ranga; Mishra, Braja Gopal

    2005-01-01

    The environment, location and interaction of the Ce 3+ ions in the micropores of Al- and Zr-pillared clays have been studied by UV-vis-diffuse reflectance spectroscopy (UV-vis-DRS). The DRS spectra show that the chemical environment of the Ce 3+ ions in cerium exchanged clay is different from that of the Al- and Zr-pillared clays. The Al-Ce pillared clays (Al-Ce-PM) show four distinct absorption bands at 224, 263, 294 and 342 nm in the UV region which are attributed to 4f → 5d interconfigurational transitions of Ce 3+ ions associated with alumina pillars. The O 2- → Ce 3+ charge transfer band observed at 263 nm for Ce-exchanged and Al-Ce-PM clays is blue shifted by 10 nm for Ce-Zr-pillared clays (Ce-Zr-PM) due to fully hydrated Ce 3+ ions. The Ce 3+ ions are incorporated in the Al- and Zr-pillars possibly as AlCeO 3 and Ce x Zr 1-x O 2 particles upon heat treatment

  6. Thermo-mechanical effects from a KBS-3 type repository. Performance of pillars between repository tunnels

    International Nuclear Information System (INIS)

    Hakami, E.; Olofsson, Stig-Olof

    2000-03-01

    The aim of this study has been to investigate how the rock mass, in the near field of a KBS-3 type repository, will be affected by the excavation of tunnels and deposition holes and the thermal load from the deposited waste. The three-dimensional finite difference program FLAC 3D was used to perform numerical simulation of the rock mass behaviour. The rock mass was modelled as a homogeneous and isotropic continuum. The initial area heat intensity of the repository was assumed to be 10 W/m 2 in all models. The results show that in the middle of the pillar between the repository tunnels the temperature reaches a maximum of about 70 deg C after 55 years of deposition. The extent of areas where the rock is predicted to yield depends on the assumed quality of the rock mass and the initial in-situ stress field. The volume of yielded rock reaches a maximum after about 200 years after deposition. For a rock mass with internal friction angle of 45 deg and cohesion of 5 MPa (using a Mohr-Coulomb material model), the extent of yielded rock is limited to about 1.5 m behind the excavation periphery. The largest rock displacements are found in the tunnel floor at the upper part of the deposition holes. Tension and shear failure in the periphery of the excavations is predicted to occur during the rock excavation, with a depth extension depending on the magnitude and orientation of the in-situ stresses, as well as on the rock mass quality. Both the excavation effects and the then-no-mechanical effects are smallest when the major principal stress is oriented parallel with the deposition tunnels. The maximum convergence between tunnel walls was calculated to occur after 200 years and be about 9 mm, in the model assuming a rock mass with 5 MPa cohesion, 45 deg internal friction angle and maximum horizontal stress perpendicular to the tunnel. In this study confining effects from the buffer and backfill material was neglected. The effective stress concept was used in most of the models

  7. Unsteady wall pressure field of a model A-pillar conical vortex

    Energy Technology Data Exchange (ETDEWEB)

    Hoarau, C. [Laboratoire d' Etudes Aerodynamiques, LEA UMR CNRS/Universite de Poitiers/ENSMA 6609, Teleport 2, 1 Av. Clement Ader, BP 40109, 86961 Futuroscope Chasseneuil (France); Boree, J. [Laboratoire d' Etudes Aerodynamiques, LEA UMR CNRS/Universite de Poitiers/ENSMA 6609, Teleport 2, 1 Av. Clement Ader, BP 40109, 86961 Futuroscope Chasseneuil (France)], E-mail: jacques.boree@lea.ensma.fr; Laumonier, J.; Gervais, Y. [Laboratoire d' Etudes Aerodynamiques, LEA UMR CNRS/Universite de Poitiers/ENSMA 6609, Teleport 2, 1 Av. Clement Ader, BP 40109, 86961 Futuroscope Chasseneuil (France)

    2008-06-15

    The spatio-temporal properties of the unsteady wall pressure field of a model A-pillar conical vortex are studied in this paper by combining 2 component LDV measurements and multi-point pressure measurements using off-set microphones. The model body has sharp edges. Detailed LDV measurements are presented and discussed in the vortex region. The fluctuating velocities are the signature of both an unsteady behaviour of the organised vortical structure interacting with the wall and of finer scale turbulence carried by the unsteady flow. A spectral analysis of the fluctuating pressure under the vortex core is used to analyse the link between the temporal and spatial scales of the unsteady aerodynamics and the wall pressure field. We show that the conical vortex is a guide for the velocity perturbations and that their hydrodynamic pressure footprint is transported at the measured mean axial velocity in a local reference frame aligned with the vortex core. Two distinct peaks of coherence can then be associated with perturbations having (i) a length scale of the order of the full length of the conical structure; (ii) a length scale of the order of the width of the structure. These perturbations may correspond to a global meandering of the structure (low frequency contribution) and to large scale perturbations generated during the rolling-up of the unsteady vortex sheet. Notably, the energy containing higher frequency parts of the PSD are only weakly correlated when distant sensors are considered. The three distinct contributions extracted here have a significant impact as far as Cp' is concerned and should be transmitted in very different ways by the car structure because the frequency and length scale range is very distinct.

  8. Unsteady wall pressure field of a model A-pillar conical vortex

    International Nuclear Information System (INIS)

    Hoarau, C.; Boree, J.; Laumonier, J.; Gervais, Y.

    2008-01-01

    The spatio-temporal properties of the unsteady wall pressure field of a model A-pillar conical vortex are studied in this paper by combining 2 component LDV measurements and multi-point pressure measurements using off-set microphones. The model body has sharp edges. Detailed LDV measurements are presented and discussed in the vortex region. The fluctuating velocities are the signature of both an unsteady behaviour of the organised vortical structure interacting with the wall and of finer scale turbulence carried by the unsteady flow. A spectral analysis of the fluctuating pressure under the vortex core is used to analyse the link between the temporal and spatial scales of the unsteady aerodynamics and the wall pressure field. We show that the conical vortex is a guide for the velocity perturbations and that their hydrodynamic pressure footprint is transported at the measured mean axial velocity in a local reference frame aligned with the vortex core. Two distinct peaks of coherence can then be associated with perturbations having (i) a length scale of the order of the full length of the conical structure; (ii) a length scale of the order of the width of the structure. These perturbations may correspond to a global meandering of the structure (low frequency contribution) and to large scale perturbations generated during the rolling-up of the unsteady vortex sheet. Notably, the energy containing higher frequency parts of the PSD are only weakly correlated when distant sensors are considered. The three distinct contributions extracted here have a significant impact as far as Cp' is concerned and should be transmitted in very different ways by the car structure because the frequency and length scale range is very distinct

  9. Ultrahigh and Selective SO2 Uptake in Inorganic Anion-Pillared Hybrid Porous Materials.

    Science.gov (United States)

    Cui, Xili; Yang, Qiwei; Yang, Lifeng; Krishna, Rajamani; Zhang, Zhiguo; Bao, Zongbi; Wu, Hui; Ren, Qilong; Zhou, Wei; Chen, Banglin; Xing, Huabin

    2017-07-01

    The efficient capture of SO 2 is of great significance in gas-purification processes including flue-gas desulfurization and natural-gas purification, but the design of porous materials with high adsorption capacity and selectivity of SO 2 remains very challenging. Herein, the selective recognition and dense packing of SO 2 clusters through multiple synergistic host-guest and guest-guest interactions by controlling the pore chemistry and size in inorganic anion (SiF 6 2- , SIFSIX) pillared metal-organic frameworks is reported. The binding sites of anions and aromatic rings in SIFSIX materials grasp every atom of SO 2 firmly via S δ+ ···F δ- electrostatic interactions and O δ- ···H δ+ dipole-dipole interactions, while the guest-guest interactions between SO 2 molecules further promote gas trapping within the pore space, which is elucidated by first-principles density functional theory calculations and powder X-ray diffraction experiments. These interactions afford new benchmarks for the highly efficient removal of SO 2 from other gases, even if at a very low SO 2 concentration. Exceptionally high SO 2 capacity of 11.01 mmol g -1 is achieved at atmosphere pressure by SIFSIX-1-Cu, and unprecedented low-pressure SO 2 capacity is obtained in SIFSIX-2-Cu-i (4.16 mmol g -1 SO 2 at 0.01 bar and 2.31 mmol g -1 at 0.002 bar). More importantly, record SO 2 /CO 2 selectivity (86-89) and excellent SO 2 /N 2 selectivity (1285-3145) are also achieved. Experimental breakthrough curves further demonstrate the excellent performance of these hybrid porous materials in removing low-concentration SO 2 . © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Evaluation and comparison of dimensional accuracy of newly introduced elastomeric impression material using 3D laser scanners: an in vitro study.

    Science.gov (United States)

    Pandita, Amrita; Jain, Teerthesh; Yadav, Naveen S; Feroz, S M A; Pradeep; Diwedi, Akankasha

    2013-03-01

    Aim of the present study was to comparatively evaluate dimensional accuracy of newely introduced elastomeric impression material after repeated pours at different time intervals. In the present study a total of 20 (10 + 10) impressions of master model were made from vinyl polyether silicone and vinyl polysiloxane impression material. Each impression was repeatedly poured at 1, 24 hours and 14 days. Therefore, a total of 60 casts were obtained. Casts obtained were scanned with three-dimensional (3D) laser scanner and measurements were done. Vinyl polyether silicone produced overall undersized dies, with greatest change being 0.14% only after 14 days. Vinyl polysiloxane produced smaller dies after 1 and 24 hours and larger dies after 14 days, differing from master model by only 0.07% for the smallest die and to 0.02% for the largest die. All the deviations measured from the master model with both the impression materials were within a clinically acceptable range. In a typical fixed prosthodontic treatment accuracy of prosthesis is critical as it determines the success, failure and the prognosis of treatment including abutments. This is mainly dependent upon fit of prosthesis which in turn is dependent on dimensional accuracy of dies, poured from elastomeric impressions.

  11. Novel elastomeric fibrous networks produced from poly(xylitol sebacate)2:5 by core/shell electrospinning: fabrication and mechanical properties.

    Science.gov (United States)

    Li, Yuan; Thouas, George A; Chen, Qizhi

    2014-12-01

    Fabrication of nonlinear elastic materials that resemble biological tissues remains a challenge in biomaterials research. Here, a new fabrication protocol to produce elastomeric fibrous scaffolds was established, using the core/shell electrospinning technique. A prepolymer of poly(xylitol sebacate) with a 2:5mol ratio of xylitol:sebacic acid (PXS2:5) was first formulated, then co-electrospun with polyvinyl alcohol (PVA - 95,000Mw). After cross-linking of core polymer PXS2:5, the PVA shells were rinsed off in water, leaving a porous elastomeric network of PXS2:5 fibres. Under aqueous conditions, the PXS2:5 fibrous scaffolds exhibited stable, nonlinear J-shaped stress-strain curves, with large average rupture elongation (76%) and Young׳s modulus (~1.0MPa), which were in the range of muscle tissue. Rupture elongation of PXS2:5 was also much higher when electrospun, compared to 2D solid sheets (45%). In direct contact with cell monolayers under physiological conditions, PXS2:5 scaffolds were as biocompatible as those made of poly-l-lactic acid (PLLA), with improvements over culture medium alone. In conclusion, the newly developed porous PXS2:5 scaffolds show tissue-like mechanical properties and excellent biocompatibility, making them very promising for bioengineering of soft tissues and organs. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Rumen metabolism and absorption of a 14C-labelled elastomeric copolymer and its value as a roughage substitute for cattle

    International Nuclear Information System (INIS)

    Bartley, E.E.; Meyer, R.M.; Call, E.P.

    1981-01-01

    Several synthetic elastomeric and plastomeric polymers were tested for suitability as artificial roughages. They were fed to rumenfistulated cattle fed grain only. Several of the polymers were regurgitated, remasticated and reswallowed, and they formed thin strands of intermeshed fiber that produced a large, loosely woven hay-like mass that floated on the rumen contents. An elastomeric polymer consisting of copolymers of 80 to 90% ethylene and 10 to 20% propylene, with a tensile strength at yield of 45.7 kg/cm2, a hardness of 30 units (Shore D hardness scale) and a tensile strength at 300% elongation of 51.0 kg/cm2, was selected for further testing. The copolymer was fed at about 90 g/head daily for 127 days to cattle fed grain only. At slaughter, rumens contained an average of 8.0 kg copolymer (dry basis). Cattle fed the copolymer had healthier rumen papillae and epithelia of the abomasum and small intestines than did control animals fed grain only. Using 14 C-labeled copolymer, we found that the copolymer was not degraded by rumen microorganisms or acid-pepsin solution. When 14 C-labeled copolymer was fed to milking cows, no 14 C activity was found in milk, blood or urine. Upon slaughter, about 100% of the 14 C activity was recovered from digesta and feces. We concluded that the copolymer was not absorbed from the digestive tract

  13. Synthesis of SnO2 pillared carbon using long chain alkylamine grafted graphene oxide: an efficient anode material for lithium ion batteries.

    Science.gov (United States)

    Reddy, M Jeevan Kumar; Ryu, Sung Hun; Shanmugharaj, A M

    2016-01-07

    With the objective of developing new advanced composite materials that can be used as anodes for lithium ion batteries (LIBs), herein we describe the synthesis of SnO2 pillared carbon using various alkylamine (hexylamine; dodecylamine and octadecylamine) grafted graphene oxides and butyl trichlorotin precursors followed by its calcination at 500 °C for 2 h. While the grafted alkylamine induces crystalline growth of SnO2 pillars, thermal annealing of alkylamine grafted graphene oxide results in the formation of amorphous carbon coated graphene. Field emission scanning electron microscopy (FE-SEM) results reveal the successful formation of SnO2 pillared carbon on the graphene surface. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy characterization corroborates the formation of rutile SnO2 crystals on the graphene surface. A significant rise in the BET surface area is observed for SnO2 pillared carbon, when compared to pristine GO. Electrochemical characterization studies of SnO2 pillared carbon based anode materials showed an enhanced lithium storage capacity and fine cyclic performance in comparison with pristine GO. The initial specific capacities of SnO2 pillared carbon are observed to be 1379 mA h g(-1), 1255 mA h g(-1) and 1360 mA h g(-1) that decrease to 750 mA h g(-1), 643 mA h g(-1) and 560 mA h g(-1) depending upon the chain length of grafted alkylamine on the graphene surface respectively. Electrochemical impedance spectral analysis reveals that the exchange current density of SnO2 pillared carbon based electrodes is higher, corroborating its enhanced electrochemical activity in comparison with GO based electrodes.

  14. Effects of PCB Pad Metal Finishes on the Cu-Pillar/Sn-Ag Micro Bump Joint Reliability of Chip-on-Board (COB) Assembly

    Science.gov (United States)

    Kim, Youngsoon; Lee, Seyong; Shin, Ji-won; Paik, Kyung-Wook

    2016-06-01

    While solder bumps have been used as the bump structure to form the interconnection during the last few decades, the continuing scaling down of devices has led to a change in the bump structure to Cu-pillar/Sn-Ag micro-bumps. Cu-pillar/Sn-Ag micro-bump interconnections differ from conventional solder bump interconnections in terms of their assembly processing and reliability. A thermo-compression bonding method with pre-applied b-stage non-conductive films has been adopted to form solder joints between Cu pillar/Sn-Ag micro bumps and printed circuit board vehicles, using various pad metal finishes. As a result, various interfacial inter-metallic compounds (IMCs) reactions and stress concentrations occur at the Cu pillar/Sn-Ag micro bumps joints. Therefore, it is necessary to investigate the influence of pad metal finishes on the structural reliability of fine pitch Cu pillar/Sn-Ag micro bumps flip chip packaging. In this study, four different pad surface finishes (Thin Ni ENEPIG, OSP, ENEPIG, ENIG) were evaluated in terms of their interconnection reliability by thermal cycle (T/C) test up to 2000 cycles at temperatures ranging from -55°C to 125°C and high-temperature storage test up to 1000 h at 150°C. The contact resistances of the Cu pillar/Sn-Ag micro bump showed significant differences after the T/C reliability test in the following order: thin Ni ENEPIG > OSP > ENEPIG where the thin Ni ENEPIG pad metal finish provided the best Cu pillar/Sn-Ag micro bump interconnection in terms of bump joint reliability. Various IMCs formed between the bump joint areas can account for the main failure mechanism.

  15. Resource reliability, accessibility and governance: pillars for managing water resources to achieve water security in Nepal

    Science.gov (United States)

    Biggs, E. M.; Duncan, J.; Atkinson, P.; Dash, J.

    2013-12-01

    As one of the world's most water-abundant countries, Nepal has plenty of water yet resources are both spatially and temporally unevenly distributed. With a population heavily engaged in subsistence farming, whereby livelihoods are entirely dependent on rain-fed agriculture, changes in freshwater resources can substantially impact upon survival. The two main sources of water in Nepal come from monsoon precipitation and glacial runoff. The former is essential for sustaining livelihoods where communities have little or no access to perennial water resources. Much of Nepal's population live in the southern Mid-Hills and Terai regions where dependency on the monsoon system is high and climate-environment interactions are intricate. Any fluctuations in precipitation can severely affect essential potable resources and food security. As the population continues to expand in Nepal, and pressures build on access to adequate and clean water resources, there is a need for institutions to cooperate and increase the effectiveness of water management policies. This research presents a framework detailing three fundamental pillars for managing water resources to achieve sustainable water security in Nepal. These are (i) resource reliability; (ii) adequate accessibility; and (iii) effective governance. Evidence is presented which indicates that water resources are adequate in Nepal to sustain the population. In addition, aspects of climate change are having less impact than previously perceived e.g. results from trend analysis of precipitation time-series indicate a decrease in monsoon extremes and interannual variation over the last half-century. However, accessibility to clean water resources and the potential for water storage is limiting the use of these resources. This issue is particularly prevalent given the heterogeneity in spatial and temporal distributions of water. Water governance is also ineffective due to government instability and a lack of continuity in policy

  16. Optimization of silver-assisted nano-pillar etching process in silicon

    International Nuclear Information System (INIS)

    Azhari, Ayu Wazira; Sopian, Kamaruzzaman; Desa, Mohd Khairunaz Mat; Zaidi, Saleem H.

    2015-01-01

    Graphical abstract: - Highlights: • Statistical analysis for synthesis of nano-pillar in crystalline Si substrates is presented. • Model is in good agreement with experimental for the etching rate and lateral etching respectively. • Optimum values for all parameters in fabrication of nanostructured Si are attained. - Abstract: In this study, a respond surface methodology (RSM) model is developed using three-level Box–Behnken experimental design (BBD) technique. This model is developed to investigate the influence of metal-assisted chemical etching (MACE) process variables on the nanopillars profiles created in single crystalline silicon (Si) substrate. Design-Expert ® software (version 7.1) is employed in formulating the RSM model based on five critical process variables: (A) concentration of silver (Ag), (B) concentration of hydrofluoric acid (HF), (C) concentration of hydrogen peroxide (H 2 O 2 ), (D) deposition time, and (E) etching time. This model is supported by data from 46 experimental configurations. Etched profiles as a function of lateral etching rate, vertical etching rate, height, size and separation between the Si trenches and etching uniformity are characterized using field emission scanning electron microscope (FE-SEM). A quadratic regression model is developed to correlate critical process variables and is validated using the analysis of variance (ANOVA) methodology. The model exhibits near-linear dependence of lateral and vertical etching rates on both the H 2 O 2 concentration and etching time. The predicted model is in good agreement with the experimental data where R 2 is equal to 0.80 and 0.67 for the etching rate and lateral etching respectively. The optimized result shows minimum lateral etching with the average pore size of about 69 nm while the maximum etching rate is estimated at around 360 nm/min. The model demonstrates that the etching process uniformity is not influenced by either the etchant concentration or the etching time

  17. Earle K. Plyler Prize Lecture: The Three Pillars of Ultrafast Molecular Science - Time, Phase, Intensity

    Science.gov (United States)

    Stolow, Albert

    We discuss the probing and control of molecular wavepacket dynamics in the context of three main `pillars' of light-matter interaction: time, phase, intensity. Time: Using short, coherent laser pulses and perturbative matter-field interactions, we study molecular wavepackets with a focus on the ultrafast non-Born-Oppenheimer dynamics, that is, the coupling of electronic and nuclear motions. Time-Resolved Photoelectron Spectroscopy (TRPES) is a powerful ultrafast probe of these processes in polyatomic molecules because it is sensitive both electronic and vibrational dynamics. Ideally, one would like to observe these ultrafast processes from the molecule's point of view - the Molecular Frame - thereby avoiding loss of information due to orientational averaging. This can be achieved by Time-Resolved Coincidence Imaging Spectroscopy (TRCIS) which images 3D recoil vectors of both photofragments and photoelectrons, in coincidence and as a function of time, permitting direct Molecular Frame imaging of valence electronic dynamics during a molecular dynamics. Phase: Using intermediate strength non-perturbative interactions, we apply the second order (polarizability) Non-Resonant Dynamic Stark Effect (NRDSE) to control molecular dynamics without any net absorption of light. NRDSE is also the interaction underlying molecular alignment and applies to field-free 1D of linear molecules and field-free 3D alignment of general (asymmetric) molecules. Using laser alignment, we can transiently fix a molecule in space, yielding a more general approach to direct Molecular Frame imaging of valence electronic dynamics during a chemical reaction. Intensity: In strong (ionizing) laser fields, a new laser-matter physics emerges for polyatomic systems wherein both the single active electron picture and the adiabatic electron response, both implicit in the standard 3-step models, can fail dramatically. This has important consequences for all attosecond strong field spectroscopies of

  18. An adhesive bonding method with microfabricating micro pillars to prevent clogging in a microchannel

    International Nuclear Information System (INIS)

    Chen, Pin-Chuan; Liu, Yu-Min; Chou, Huang-Chieh

    2016-01-01

    Thermoplastics are widely used in the fabrication of microfluidic chips, due to their low cost, flexibility in manufacturing, and applicability in large-scale production. This paper presents a novel bonding method for the assembly of thermoplastic microfluidic chips, with the aim of preventing the flow of UV adhesive into microchannels during the bonding process. The proposed bonding methodology depends primarily on controlling the thickness of the UV adhesive, which is achieved by using spin-coating for the uniform UV adhesive in conjunction with the microfabrication of short pillars for keeping a uniform gap between the two bonded surfaces. In this study, two devices with serpentine microchannels (cross-sectional area of 500 μm  ×  500 μm and 200 μm  ×  200 μm) were fabricated on PMMA substrates using a micromilling machine, whereupon a hydrophobic coating was applied to the walls of 200 μm  ×  200 μm microchannels in order to prevent clogging, which might otherwise be caused by the seepage of UV adhesive into the channels. A variety of experiments were used to characterize the quality of bonding, the results of which reveal the following: (1) no leakage was observed in either of the microfluidic chips; (2) the hydrophobic coating proved highly effective in preventing the flow of UV adhesive into the smaller microchannels; (3) the average amount of clogging inside 500 μm  ×  500 μm microchannels was 1.13% with standard deviation of 0.55%, while the average amount of clogging inside 200 μm  ×  200 μm microchannels was 1.65% with standard deviation of 0.92%; (4) the average thickness of the UV adhesive in a 500 μm  ×  500 μm microfluidic chip was 32 μm with standard deviation of 2 μm, whereas the average thickness of the UV adhesive in a 200 μm  ×  200 μm microfluidic chip was 31 μm with standard deviation of 1.2 μm; (5) the two chips possess sufficient bonding strength to withstand

  19. Optimization of silver-assisted nano-pillar etching process in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Azhari, Ayu Wazira, E-mail: ayuwazira@unimap.edu.my [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, Bangi, Selangor 43650 (Malaysia); School of Environmental Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Sopian, Kamaruzzaman [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, Bangi, Selangor 43650 (Malaysia); Desa, Mohd Khairunaz Mat [School of Electrical and Electronic Engineering, Universiti Sains Malaysia, Nibong Tebal, Pulau Pinang, 14300 (Malaysia); Zaidi, Saleem H. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, Bangi, Selangor 43650 (Malaysia)

    2015-12-01

    Graphical abstract: - Highlights: • Statistical analysis for synthesis of nano-pillar in crystalline Si substrates is presented. • Model is in good agreement with experimental for the etching rate and lateral etching respectively. • Optimum values for all parameters in fabrication of nanostructured Si are attained. - Abstract: In this study, a respond surface methodology (RSM) model is developed using three-level Box–Behnken experimental design (BBD) technique. This model is developed to investigate the influence of metal-assisted chemical etching (MACE) process variables on the nanopillars profiles created in single crystalline silicon (Si) substrate. Design-Expert{sup ®} software (version 7.1) is employed in formulating the RSM model based on five critical process variables: (A) concentration of silver (Ag), (B) concentration of hydrofluoric acid (HF), (C) concentration of hydrogen peroxide (H{sub 2}O{sub 2}), (D) deposition time, and (E) etching time. This model is supported by data from 46 experimental configurations. Etched profiles as a function of lateral etching rate, vertical etching rate, height, size and separation between the Si trenches and etching uniformity are characterized using field emission scanning electron microscope (FE-SEM). A quadratic regression model is developed to correlate critical process variables and is validated using the analysis of variance (ANOVA) methodology. The model exhibits near-linear dependence of lateral and vertical etching rates on both the H{sub 2}O{sub 2} concentration and etching time. The predicted model is in good agreement with the experimental data where R{sup 2} is equal to 0.80 and 0.67 for the etching rate and lateral etching respectively. The optimized result shows minimum lateral etching with the average pore size of about 69 nm while the maximum etching rate is estimated at around 360 nm/min. The model demonstrates that the etching process uniformity is not influenced by either the etchant

  20. Using the 4 Pillars Practice Transformation Program to Increase Pneumococcal Immunizations for Older Adults: A Cluster-Randomized Trial.

    Science.gov (United States)

    Zimmerman, Richard K; Brown, Anthony E; Pavlik, Valory N; Moehling, Krissy K; Raviotta, Jonathan M; Lin, Chyongchiou J; Zhang, Song; Hawk, Mary; Kyle, Shakala; Patel, Suchita; Ahmed, Faruque; Nowalk, Mary Patricia

    2017-01-01

    To test the effectiveness of a step-by step, evidence-based guide, the 4 Pillars Practice Transformation Program, to increase adult pneumococcal vaccination. Randomized controlled cluster trial (RCCT) in Year 1 (June 1, 2013 to May 31, 2014) and pre-post study in Year 2 (June 1, 2014 to January 31, 2015) with data analyzed in 2016. Baseline year was June 1, 2012, to May 31, 2013. Demographic and vaccination data were derived from deidentified electronic medical record extractions. Primary care practices (n = 25) stratified according to metropolitan area (Houston, Pittsburgh), location (rural, urban, suburban), and type (family medicine, internal medicine), randomized to receive the intervention in Year 1 (n = 13) or Year 2 (n = 12). Individuals aged 65 and older at baseline (N = 18,107; mean age 74.2; 60.7% female, 16.5% non-white, 15.7% Hispanic). The 4 Pillars Program, provider education, and one-on-one coaching of practice-based immunization champions. Outcome measures were 23-valent pneumococcal polysaccharide vaccine (PPSV) and pneumococcal conjugate vaccine (PCV) vaccination rates and percentage point (PP) changes in vaccination rates. In the Year 1 RCCT, PPSV vaccination rates increased significantly in all intervention and control groups, with average increases ranging from 6.5 to 8.7 PP (P < .001). The intervention was not related to greater likelihood of PPSV vaccination. In the Year 2 pre-post study, the likelihood of PPSV and PCV vaccination was significantly higher in the active intervention sites than the maintenance sites in Pittsburgh but not in Houston. In a RCCT, PPSV vaccination rates increased in the intervention and control groups in Year 1. In a pre-post study, private primary care practices actively participating in the 4 Pillars Practice Transformation Program improved PPSV and PCV uptake significantly more than practices that were in the maintenance phase of the study. © 2016, Copyright the Authors Journal compilation © 2016, The American

  1. A pillar-layered metal-organic framework as luminescent sensor for selective and reversible response of chloroform

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kun; Li, Shuni; Jiang, Yucheng; Hu, Mancheng; Zhai, Quan-Guo, E-mail: zhaiqg@snnu.edu.cn

    2017-03-15

    A new 3D metal-organic framework, namely, (Zn{sub 4}(H{sub 2}BPTC){sub 2}(HCOO){sub 4}){sub n} (SNNU-1, H{sub 4}BPTC=biphenyl-3,3',5,5'-tetracarboxylic acid, SNNU=Shaanxi Normal University) has been solvothermal synthesized. Four independent tetrahedral Zn atoms are connected by organic ligands to form a 2D Zn-H{sub 2}BPTC layer, which is further bridged by in-situ generated HCOO{sup -} to give the 3D pillar-layered framework of SNNU-1. Unique Zn and H{sub 2}BPTC all act as 4-connected nodes leading to a new 4,4,4-connected topological net with point symbol of (4·5·6{sup 2}·8{sup 2})(4·5{sup 2}·6{sup 2}·8)(5{sup 2}·6{sup 3}·7). Notably, intense blue emission band is observed for SNNU-1, which exhibits solvent-dependent effect. Compared to other common organic solvents, chloroform can specially improve the photoluminescent intensity of SNNU-1. Further repeated response and release experiments clearly showed that SNNU-1 can act as luminescent sensor for selective and reversible detection of chloroform. - Graphical abstract: Zn{sup 2+} ions are bridged by aromatic tetracarboxylate ligands and inorganic formate anions to give a microporous pillar layered open-framework, which exhibits not only strong photoluminescence but also selective and reversible luminescent sensing for chloroform. - Highlights: • Novel Zn-tetracarboxylate-formate microporous pillar layered open-framework. • New 4,4,4-connected topology and rod-packing net. • Solvent-dependent photoluminescent intensity. • Selective and reversible response for chloroform.

  2. Ensuring Support for Research and Quality Improvement (QI) Networks: Four Pillars of Sustainability-An Emerging Framework.

    Science.gov (United States)

    Holve, Erin

    2013-01-01

    Multi-institutional research and quality improvement (QI) projects using electronic clinical data (ECD) hold great promise for improving quality of care and patient outcomes but typically require significant infrastructure investments both to initiate and maintain the project over its duration. Consequently, it is important for these projects to think holistically about sustainability to ensure their long-term success. Four "pillars" of sustainability are discussed based on the experiences of EDM Forum grantees and other research and QI networks. These include trust and value, governance, management, and financial and administrative support. Two "foundational considerations," adaptive capacity and policy levers, are also discussed.

  3. Impact of the limitations of state-of-the-art micro-fabrication processes on the performance of pillar array columns for liquid chromatography.

    Science.gov (United States)

    Op de Beeck, Jeff; De Malsche, Wim; Tezcan, Deniz S; De Moor, Piet; Desmet, Gert

    2012-05-25

    We report on the practical limitations of the current state-of-the-art in micro-fabrication technology to produce the small pillar sizes that are needed to obtain high efficiency pillar array columns. For this purpose, nine channels with a different pillar diameter, ranging from 5 to 0.5 μm were fabricated using state-of the-art deep-UV lithography and deep reactive ion etching (DRIE) etching technology. The obtained results strongly deviated from the theoretically expected trend, wherein the minimal plate height (H(min)) would reduce linearly with the pillar diameter. The minimal plate height decreases from 1.7 to 1.2 μm when going from 4.80 to 3.81 μm diameter pillars, but as the dimensions are further reduced, the minimal plate heights rise again to values around 2 μm. The smallest pillar diameter even produced the worst minimal plate height (4 μm). An in-depth scanning electron microscopy (SEM) inspection of the different channels clearly reveals that these findings can be attributed to the micro-fabrication limitations that are inevitably encountered when exploring the limits of deep-UV lithography and DRIE etching processes. When the target dimensions of the design approach the etching resolution limits, the band broadening increases in a strongly non-linear way with the decreased pillar dimensions. This highly non-linear relationship can be understood from first principles: when the machining error is of the order of 100-200 nm and when the target design size for the inter-pillar distance is of the order of 250 nm, this inevitably leads to pores that will range in size between 50 and 450 nm that we want to highlight with our paper highly non-linear relationship. This highly non-linear relationship can be understood from first principles: when the machining error is of the order of 100-200 nm and when the target design size for the inter-pillar distance is of the order of 250 nm, this inevitably leads to pores that will range in size between 50 and 450

  4. Material versatility using replica molding for large-scale fabrication of high aspect-ratio, high density arrays of nano-pillars

    International Nuclear Information System (INIS)

    Li, Y; Menon, C; Ng, H W; Gates, B D

    2014-01-01

    Arrays of high aspect-ratio (AR) nano-pillars have attracted a lot of interest for various applications, such as for use in solar cells, surface acoustic sensors, tissue engineering, bio-inspired adhesives and anti-reflective surfaces. Each application may require a different structural material, which can vary in the required chemical composition and mechanical properties. In this paper, a low cost fabrication procedure is proposed for large scale, high AR and high density arrays of nano-pillars. The proposed method enables the replication of a master with high fidelity, using the subsequent replica molds multiple times, and preparing arrays of nano-pillars in a variety of different materials. As an example applied to bio-inspired dry adhesion, polymeric arrays of nano-pillars are prepared in this work. Thermoset and thermoplastic nano-pillar arrays are examined using an atomic force microscope to assess their adhesion strength and its uniformity. Results indicate the proposed method is robust and can be used to reliably prepare nano-structures with a high AR. (paper)

  5. Synthesis of pillar and microsphere-like magnesium oxide particles and their fluoride adsorption performance in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Gool; Ha, Jong-Wook; Sohn, Eun-Ho; Park, In Jun; Lee, Soo-Bok [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2017-10-15

    We synthesized pillar and microsphere-like MgO particles and their fluoride removal performance. Samples of MgO were synthesized by calcination of precursors derived from MgCO{sub 3}·3H{sub 2}O and characterized using field emission scanning electron microscopy, X-ray diffraction, and N{sub 2} adsorption-desorption isotherms. The fluoride removal performance of the MgO samples was investigated in terms of adsorption kinetics and adsorption equilibrium. The effects of pH and the presence of other anions on the fluoride adsorption were also considered. The adsorption capacities of pillar and microsphere-like MgO particles were 151.51 and 166.66mg/g, respectively. The pH of the aqueous solutions did not significantly affect the fluoride adsorption at pH 9 or lower. Except for phosphate, the effect of co-existing anions on fluoride adsorption was not considerable. Fluoride removal occurred through the substitution of hydroxyl groups on the surface of MgO with fluorides.

  6. Degradation of methylene blue using pillared TiO2 on de-oiled spent bleaching clay

    Science.gov (United States)

    Hindryawati, N.; Panggabean, A. S.; Fadillah, N. D.; Erwin; Daniel

    2018-04-01

    Degradation of methylene blue (MB) using pillared TiO2 onto spent bleaching clay has been conducted. Activation of deoiled spent bleaching clay (DSBC) has been done using acid, followed by pillarization with TiO2 using rarasaponin from Klerak fruit as surfactant. From the X-ray diffraction results show the mineral on DSBC is rectorite with dioctahedral mica layer and dioctahedral smectite with ratio 2:1. This molecule have formula Na.Al4(Si, Al)8.O20.(OH)4. H2O and after calcinations the pattern TiO2 was appearance at 2θ: 27.4460°, 36.0850°, 54.3216° and 56.6403°. In order to test the catalytic performance of Ti-DSBC for photodegradation of MB under UV light was conducted under several reaction conditions. The highest degradation of MB was 90 % within 50 minutes and Ti-DSBC can be reused until 5 cycles with percent degradation MB was 84 %.

  7. Effect of Manganese Promotion on Al-Pillared Montmorillonite Supported Cobalt Nanoparticles for Fischer-Tropsch Synthesis

    International Nuclear Information System (INIS)

    Ahmad, N.; Hussain, S. T.; Abbas, S. M.; Khan, Y.; Muhammad, B.; Ali, N.

    2013-01-01

    The effect of Mn-promotion on high surface area Al-pillared montmorillonite (AlMMT) supported Co nanoparticles prepared by hydrothermal method have been investigated. A series of different weight% Mn-promoted Co nanoparticles were prepared and characterized by XRD, TPR, TGA, BET and SEM techniques. An increase in the surface area of MMT is observed with Al-pillaring. Fischer-Tropsch catalytic activity of the as prepared catalysts was studied in a fixed bed micro reactor at 225 .deg. C, H 2 /CO = 2 and at 1 atm pressure. The data showed that by the addition of Mn the selectivity of C 1 dropped drastically while that of C 2 -C 12 hydrocarbons increased significantly over all the Mn-promoted Co/AlMMT catalysts. The C 13 -C 20 hydrocarbons remained almost same for all the catalysts while the selectivity of C 21+ long chain hydrocarbons decreased considerably with the addition of Mn. The catalyst with 3.5%Mn showed lowest C 21+ and highest C 2 -C 12 hydrocarbons selectivity due to cracking of long chain hydrocarbons over acidic sites of MMT

  8. The Troy Microneedle: A Rapidly Separating, Dissolving Microneedle Formed by Cyclic Contact and Drying on the Pillar (CCDP.

    Directory of Open Access Journals (Sweden)

    Miroo Kim

    Full Text Available In dissolving microneedle (DMN-mediated therapy, complete and rapid delivery of DMNs is critical for the desired efficacy. Traditional patch-based DMN delivery, however, may fail due to incomplete delivery from insufficient skin insertion or rapid separation of microneedles due to their strong bond to the backing film. Here, we introduce the Troy microneedle, which was created by cyclic contact and drying on the pillar (CCDP, and which enabled simultaneous complete and rapid delivery of DMN. This CCDP process could be flexibly repeated to achieve a specific desired drug dose in a DMN. We evaluated DMN separation using agarose gel, and the Troy microneedle achieved more complete and rapid separation than other, more deeply dipped DMN, primarily because of the Troy's minimal junction between the DMN and pillar. When Troy microneedles were applied to pig cadaver skin, it took only 15 s for over 90% of encapsulated rhodamine B to be delivered, compared to 2 h with application of a traditional DMN patch. In vivo skin penetration studies demonstrated rapid DMN-separation of Troy microneedles still in solid form before dissolution. The Troy microneedle overcomes critical issues associated with the low penetration efficiency of flat patch-based DMN and provides an innovative route for DMN-mediated therapy, combining patient convenience with the desire drug efficacy.

  9. The Troy Microneedle: A Rapidly Separating, Dissolving Microneedle Formed by Cyclic Contact and Drying on the Pillar (CCDP).

    Science.gov (United States)

    Kim, Miroo; Yang, Huisuk; Kim, Suyong; Lee, Chisong; Jung, Hyungil

    2015-01-01

    In dissolving microneedle (DMN)-mediated therapy, complete and rapid delivery of DMNs is critical for the desired efficacy. Traditional patch-based DMN delivery, however, may fail due to incomplete delivery from insufficient skin insertion or rapid separation of microneedles due to their strong bond to the backing film. Here, we introduce the Troy microneedle, which was created by cyclic contact and drying on the pillar (CCDP), and which enabled simultaneous complete and rapid delivery of DMN. This CCDP process could be flexibly repeated to achieve a specific desired drug dose in a DMN. We evaluated DMN separation using agarose gel, and the Troy microneedle achieved more complete and rapid separation than other, more deeply dipped DMN, primarily because of the Troy's minimal junction between the DMN and pillar. When Troy microneedles were applied to pig cadaver skin, it took only 15 s for over 90% of encapsulated rhodamine B to be delivered, compared to 2 h with application of a traditional DMN patch. In vivo skin penetration studies demonstrated rapid DMN-separation of Troy microneedles still in solid form before dissolution. The Troy microneedle overcomes critical issues associated with the low penetration efficiency of flat patch-based DMN and provides an innovative route for DMN-mediated therapy, combining patient convenience with the desire drug efficacy.

  10. Applications of a computer model to the analysis of rock-backfill interaction in pillar recovery operations

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, T. J.E. [Dames and Moore, London, England, United Kingdom; Shillabeer, J. H. [Dames and Moore, Toronto (Canada); Herget, G. [CANMET, Ottawa (Canada)

    1980-05-15

    This paper describes the application of a computer model to the analysis of backfill stability in pillar recovery operations with particular reference to two case studies. An explicit finite difference computer program was developed for the purpose of modelling the three-dimensional interaction of rock and backfill in underground excavations. Of particular interest was the mechanics of stress transfer from the rock mass to the pillars and then the backfill. The need, therefore, for a model to allow for the three-dimensional effects and the sequence of operations is evident. The paper gives a brief description of the computer program, descriptions of the mines, the sequences of operations and how they were modelled, and the results of the analyses in graphical form. For both case studies, failure of the backfill was predicted at certain stages. Subsequent reports from the mines indicate that such failures did not occur at the relevant stage. The paper discusses the validity of the model and concludes that the approach accurately represents the principles of rock mechanics in cut-and-fill mining and that further research should be directed towards determining the input parameters to an equal degree of sophistication.

  11. Aespoe Pillar Stability Experiment. Final experiment design, monitoring results and observations

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Christer [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Eng, Anders [Acuo Engineering AB, Linkoeping (Sweden)

    2005-12-15

    The field part of the Aespoe Pillar Stability Experiment at the Aespoe Hard Rock Laboratory (HRL) was finished in 2004. The experiment was designed to induce and monitor the process of brittle failure, spalling, in a fractured rock mass under controlled conditions. The field part was successfully conducted and a large data set was obtained. This report presents the final design of the experiment, the results of the monitoring, and the observations made during the spalling process and when the spalled rock was removed. When heating of the rock was initiated the rock responded quickly. After only a few days the spalling process was activated in the notch, as indicated by the acoustic emission system, and shortly thereafter displacement readings were recorded. Contraction (radial expansion) of the rock was recorded by several instruments before the notch reached the instrument levels. This contraction is probably the result of a 3D re-distribution of the stresses. The temperature increase in the system was both slower and reached a steady state much earlier than predicted by the numerical models. The propagation of the notch was therefore halted after approximately one month of heating. The power to the electrical heaters was therefore doubled. Spalling then started up again, and in one month's time it had propagated to a depth of approximately five metres in the hole. A second steady state was now reached, but this time the heater power was kept constant for a while to let the rock settle before the confinement pressure was reduced from 700 kPa to 0 in decrements of 50 kPa. The rock mass response to the pressure drop was very limited until the pressure was lowered to approximately 200 kPa (the atmospheric pressure is not included in the given pressure values). Large displacements and a high acoustic emission hit frequency were then measured in the open hole. After the de-pressurization of the confined hole, the heaters were left on for approximately one week

  12. Key pillars of data interoperability in Earth Sciences - INSPIRE and beyond

    Science.gov (United States)

    Tomas, Robert; Lutz, Michael

    2013-04-01

    The well-known heterogeneity and fragmentation of data models, formats and controlled vocabularies of environmental data limit potential data users from utilising the wealth of environmental information available today across Europe. The main aim of INSPIRE1 is to improve this situation and give users possibility to access, use and correctly interpret environmental data. Over the past years number of INSPIRE technical guidelines (TG) and implementing rules (IR) for interoperability have been developed, involving hundreds of domain experts from across Europe. The data interoperability specifications, which have been developed for all 34 INSPIRE spatial data themes2, are the central component of the TG and IR. Several of these themes are related to the earth sciences, e.g. geology (including hydrogeology, geophysics and geomorphology), mineral and energy resources, soil science, natural hazards, meteorology, oceanography, hydrology and land cover. The following main pillars for data interoperability and harmonisation have been identified during the development of the specifications: Conceptual data models describe the spatial objects and their properties and relationships for the different spatial data themes. To achieve cross-domain harmonization, the data models for all themes are based on a common modelling framework (the INSPIRE Generic Conceptual Model3) and managed in a common UML repository. Harmonised vocabularies (or code lists) are to be used in data exchange in order to overcome interoperability issues caused by heterogeneous free-text and/or multi-lingual content. Since a mapping to a harmonized vocabulary could be difficult, the INSPIRE data models typically allow the provision of more specific terms from local vocabularies in addition to the harmonized terms - utilizing either the extensibility options or additional terminological attributes. Encoding. Currently, specific XML profiles of the Geography Markup Language (GML) are promoted as the standard

  13. Evaluation of the Performance of O-rings Made with Different Elastomeric Polymers in Simulated Geothermal Environments at 300°C

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, Toshifumi [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pyatina, Tatiana [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Redline, Erica Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McElhanon, James R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-12-01

    This paper aims to evaluate the survival of O-rings made with six different elastomeric polymers, EPDM, type I- and II-FKM, FEPM, FFKM, and FSR, in five different simulated geothermal environments at 300°C. It further defines the relative strengths and weaknesses of the materials in each environment. The environments tested were: 1) non-aerated steam-cooling cycles, 2) aerated steam-cooling cycles, 3) water-based drilling fluid, 4) CO2-rich geo-brine fluid, and, 5) heat-cool water quenching cycles. Following exposure, the extent of oxidation, oxidationinduced degradation, thermal behaviors, micro-defects, permeation depths of ionic species present in environments throughout the O-ring, silicate-related scale-deposition, and changes in mechanical properties were assessed.

  14. Bio-Inspired Wide-Angle Broad-Spectrum Cylindrical Lens Based on Reflections from Micro-Mirror Array on a Cylindrical Elastomeric Membrane

    Directory of Open Access Journals (Sweden)

    Chi-Chieh Huang

    2014-06-01

    Full Text Available We present a wide-angle, broad-spectrum cylindrical lens based on reflections from an array of three-dimensional, high-aspect-ratio micro-mirrors fabricated on a cylindrical elastomeric substrate, functionally inspired by natural reflecting superposition compound eyes. Our device can perform one-dimensional focusing and beam-shaping comparable to conventional refraction-based cylindrical lenses, while avoiding chromatic aberration. The focal length of our cylindrical lens is 1.035 mm, suitable for micro-optical systems. Moreover, it demonstrates a wide field of view of 152° without distortion, as well as modest spherical aberrations. Our work could be applied to diverse applications including laser diode collimation, barcode scanning, holography, digital projection display, microlens arrays, and optical microscopy.

  15. Preparación y propiedades de una arcilla montmorillonita pilareada con polihidroxicationes de aluminio Preparation and properties of a montmorillonite clay pillared with aluminium polyhydroxications

    Directory of Open Access Journals (Sweden)

    Sibele B. C. Pergher

    1999-09-01

    Full Text Available Montmorillonite clay from Brazil was pillared with aluminium polyhydroxications. The influence of Al/Mont ratio and calcination temperature in the properties of the prepared materials was studied. Results showed that the pillarization process increases the basal spaces of the natural clay from 9,7 to 18,5Å and the superficial area from 41 to ~230m2/g. The calcination process at different temperatures showed that the pillared material was stable until 600oC but the adequate temperature for calcination was 450oC. Materials prepared with different Al/Mont ratios showed the maximum Al incorporation for ratios >10meq Al/g and a good distribution for rations >15meq Al/g.

  16. Origin, Development and Decline of Monolithic Pillars and the Continuity of the Tradition in Polylithic, Non-Lithic and Structural Forms

    Directory of Open Access Journals (Sweden)

    S. Krishnamurthy

    2016-02-01

    Full Text Available The present paper deals with one such creations of Man, i.e. the tradition of erecting free standing monolithic pillars - its origin, growth and decline and the continuity of the tradition of erecting such pillars in its changed polylithic (from Greek word polloi = many + lithic = stone, non-lithic and structural forms. No exact reason can be found, pointing it to be the exact cause for the decline in the tradition of erecting monolithic pillar and its transformation. In this paper the authors try to analyse various phenomenon likesocio-political, economic and technical aspects which may have lead to their decline and subsequently their continuity in a changed form in Indian context.

  17. [In vitro study of the flow duration of antibiotics solutions prepared in elastomeric infusion devices: effect of cold storage for 3 to 7days].

    Science.gov (United States)

    Grangeon-Chapon, C; Robein-Dobremez, M-J; Pin, I; Trouiller, P; Allenet, B; Foroni, L

    2015-09-01

    Within the cystic fibrosis patients' home care, EMERAA network ("Together against Cystic fibrosis in Rhone-Alpes and Auvergne") organizes parenteral antibiotics cures at home prepared in elastomeric infusion devices by hospital pharmacies. However, patients and nurses found that the durations of infusion with these devices were often longer than the nominal duration of infusion indicated by their manufacturer. This study aimed to identify the potential different causes in relation to these discordances. Three hundred and ninety devices of two different manufacturers are tested in different experimental conditions: three antibiotics each at two different doses, duration of cold storage (three days or seven days) or immediate tests without cold storage, preparation and storage of the solution in the device (protocol Device) or transfer in the device just before measurement (protocol Pocket). All tests highlighted a longer flow duration for devices prepared according to the protocol Device versus the protocol Pocket (P=0.004). Flow duration is increased in the case of high doses of antibiotics with high viscosity such as piperacilline/tazobactam. The results of this in vitro study showed the impact of: (1) the time between the filling of the device and the flow of the solution; (2) cold storage of elastomeric infusion devices; (3) concentration of antibiotics and therefore the viscosity of the solution to infuse. It is therefore essential that health care teams are aware of factors, which may lead to longer infusion durations with these infusion devices. When the additional time for infusion remain acceptable, it should be necessary to inform the patient and to relativize these lengthening compared to many benefits that these devices provide for home care. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. Laboratory evaluation of the particle size effect on the performance of an elastomeric half-mask respirator against ultrafine combustion particles.

    Science.gov (United States)

    He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; Yermakov, Michael; McKay, Roy; Haruta, Hiroki; Kimura, Kazushi

    2013-08-01

    This study quantified the particle size effect on the performance of elastomeric half-mask respirators, which are widely used by firefighters and first responders exposed to combustion aerosols. One type of elastomeric half-mask respirator equipped with two P-100 filters was donned on a breathing manikin while challenged with three combustion aerosols (originated by burning wood, paper, and plastic). Testing was conducted with respirators that were fully sealed, partially sealed (nose area only), or unsealed to the face of a breathing manikin to simulate different faceseal leakages. Three cyclic flows with mean inspiratory flow (MIF) rates of 30, 85, and 135 L/min were tested for each combination of sealing condition and combustion material. Additional testing was performed with plastic combustion particles at other cyclic and constant flows. Particle penetration was determined by measuring particle number concentrations inside and outside the respirator with size ranges from 20 to 200 nm. Breathing flow rate, particle size, and combustion material all had significant effects on the performance of the respirator. For the partially sealed and unsealed respirators, the penetration through the faceseal leakage reached maximum at particle sizes >100 nm when challenged with plastic aerosol, whereas no clear peaks were observed for wood and paper aerosols. The particles aerosolized by burning plastic penetrated more readily into the unsealed half-mask than those aerosolized by the combustion of wood and paper. The difference may be attributed to the fact that plastic combustion particles differ from wood and paper particles by physical characteristics such as charge, shape, and density. For the partially sealed respirator, the highest penetration values were obtained at MIF = 85 L/min. The unsealed respirator had approximately 10-fold greater penetration than the one partially sealed around the bridge of the nose, which indicates that the nose area was the primary leak

  19. Diameter dependence of emission power in MgO-based nano-pillar spin-torque oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bochong; Kubota, Hitoshi, E-mail: hit-kubota@aist.go.jp; Yakushiji, Kay; Tamaru, Shingo; Arai, Hiroko; Imamura, Hiroshi; Fukushima, Akio; Yuasa, Shinji [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)

    2016-06-20

    The dependence on diameter of the emission power in MgO-based nano-pillar spin torque oscillators (STOs) was systematically investigated. A maximum emission power of over 2.5 μW was obtained around 300 nm in diameter, which is the largest reported to date among the out-of-plane precession STOs. By analyzing physical quantities, precession cone angle of the free-layer magnetization was evaluated. In the diameter range below 300 nm, the increase in power was mainly due to the increase of the injected current. The power decrease above 300 nm is possibly attributed to the decrease in the averaged precession cone angle, suggesting spatial phase difference of magnetization precession. This study provides the method for estimating the optimum STO diameter, which is of great importance in practical use.

  20. Risk analysis of the proxy life-cycle investments in the second pillar pension scheme in Croatia

    Directory of Open Access Journals (Sweden)

    Renata Kovačević

    2015-03-01

    Full Text Available In this article we analyze the expected risk of pension funds with different risk profiles in the proxy life-cycle model of investments for the 2nd pillar pension scheme in Croatia. The benefits of implementing proxy life-cycle investments, compared to the previous model of mandatory pension funds investments, are clearly visible in the total expected amount of accumulated savings from the risk/return perspective. However, those benefits are partially diminished by the fact that the expected risk of a pension fund with the lowest risk profile is not substantially different from the expected risk of a pension fund with a medium risk profile, due to the lack of diversification. Additionally, we analyze the robustness of the proxy life-cycle model to a sudden and severe market shock, where we determine the presence of risk for those members who choose to switch to a pension fund with a lower risk profile at an unfavorable moment.

  1. SERS activity of Au nanoparticles coated on an array of carbon nanotube nested into silicon nanoporous pillar

    International Nuclear Information System (INIS)

    Jiang Weifen; Zhang Yanfeng; Wang Yusheng; Xu Lei; Li Xinjian

    2011-01-01

    A novel composite structure, Au nanoparticles coated on a nest-shaped array of carbon nanotube nested into a silicon nanoporous pillar array (Au/NACNT/Si-NPA), was fabricated for surface-enhanced Raman scattering (SERS). The morphology of the Au/NACNT/Si-NPA composite structure was characterized with the aid of scanning electron microscopy, X-ray diffraction instrumentation and Transmission electron microscopy. Compared with SERS of rhodamine 6G (R6G) adsorbed on SERS-active Au substrate reported, the SERS signals of R6G adsorbed on these gold nanoparticles were obviously improved. This was attributed to the enlarged specific surface area for adsorption of target molecules brought by the nest-shaped CNTs structure.

  2. Preparation, characterization and application in deep catalytic ODS of the mesoporous silica pillared clay incorporated with phosphotungstic acid.

    Science.gov (United States)

    Li, Baoshan; Liu, Zhenxing; Liu, Jianjun; Zhou, Zhiyuan; Gao, Xiaohui; Pang, Xinmei; Sheng, Huiting

    2011-10-15

    Mesoporous silica pillared clay (SPC) materials with different contents of H(3)PW(12)O(40) (HPW) heteropoly acid were synthesized by introducing HPW into clay interlayer template in an acidic suspension using sol-gel method. Samples with similar HPW loadings were also prepared by impregnation method using SPC as the support. The results of the characterizations showed that HPW was dispersed more homogeneously in the encapsulated samples than in the impregnated samples. The encapsulated materials exhibited better catalytic performance than the impregnated samples in oxidative desulfurization of dibenzothiophene-containing model oil. The sulfur removal reached up to 98.6% for the model oil under the experiential conditions. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Temperature-dependent photoluminescence and mechanism of CdS thin film grown on Si nanoporous pillar array

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Ling Ling [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); College of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000 (China); Li, Yan Tao [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); School of Material Science and Engineering, Henan University of Technology, Zhengzhou 454052 (China); Hu, Chu Xiong [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); Li, Xin Jian, E-mail: lixj@zzu.edu.cn [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China)

    2015-09-15

    Highlights: • CdS/silicon nanoporous pillar array (CdS/Si-NPA) was prepared by a CBD method. • The PL spectrum of CdS/Si-NPA was measured at different temperatures, from 10 to 300 K. • The PL spectrum was composed of four emission bands, obeying different mechanisms. • The PL degradation with temperature was due to phonon-induced escape of carriers. - Abstract: Si-based cadmium sulfide (CdS) is a prospective semiconductor system in constructing optoelectronic nanodevices, and this makes the study on the factors which may affect its optical and electrical properties be of special importance. Here we report that CdS thin film was grown on Si nanoporous pillar array (Si-NPA) by a chemical bath deposition method, and the luminescent properties of CdS/Si-NPA as well as its mechanism were studied by measuring and analyzing its temperature-dependent photoluminescence (PL) spectrum. The low-temperature measurement disclosed that the PL spectrum of CdS/Si-NPA could be decomposed into four emission bands, a blue band, a green band, a red band and an infrared band. The blue band was due to the luminescence from Si-NPA substrate, and the others originate from the CdS thin film. With temperature increasing, the peak energy, PL intensity and peak profile shape for the PL bands from CdS evolves differently. Through theoretical and fitting analyses, the origins of the green, red and infrared band are attributed to the near band-edge emission, the radiative recombination from surface defects to Cd vacancies and those to S interstitials, respectively. The cause of PL degradation is due to the thermal quenching process, a phonon-induced electron escape but with different activation energies. These results might provide useful information for optimizing the preparing parameters to promote the performance of Si-based CdS optoelectronic devices.

  4. A Single-Molecule Propyne Trap: Highly Efficient Removal of Propyne from Propylene with Anion-Pillared Ultramicroporous Materials.

    Science.gov (United States)

    Yang, Lifeng; Cui, Xili; Yang, Qiwei; Qian, Siheng; Wu, Hui; Bao, Zongbi; Zhang, Zhiguo; Ren, Qilong; Zhou, Wei; Chen, Banglin; Xing, Huabin

    2018-03-01

    Propyne/propylene (C 3 H 4 /C 3 H 6 ) separation is a critical process for the production of polymer-grade C 3 H 6 . However, optimization of the structure of porous materials for the highly efficient removal of C 3 H 4 from C 3 H 6 remains challenging due to their similar structures and ultralow C 3 H 4 concentration. Here, it is first reported that hybrid ultramicroporous materials with pillared inorganic anions (SiF 6 2- = SIFSIX, NbOF 5 2- = NbOFFIVE) can serve as highly selective C 3 H 4 traps for the removal of trace C 3 H 4 from C 3 H 6 . Especially, it is revealed that the pyrazine-based ultramicroporous material with square grid structure for which the pore shape and functional site disposition can be varied in 0.1-0.5 Å scale to match both the shape and interacting sites of guest molecule is an interesting single-molecule trap for C 3 H 4 molecule. The pyrazine-based single-molecule trap enables extremely high C 3 H 4 uptake under ultralow concentration (2.65 mmol g -1 at 3000 ppm, one C 3 H 4 per unit cell) and record selectivity over C 3 H 6 at 298 K (>250). The single-molecule binding mode for C 3 H 4 within ultramicroporous material is validated by X-ray diffraction experiments and modeling studies. The breakthrough experiments confirm that anion-pillared ultramicroporous materials set new benchmarks for the removal of ultralow concentration C 3 H 4 (1000 ppm on SIFSIX-3-Ni, and 10 000 ppm on SIFSIX-2-Cu-i) from C 3 H 6 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The role of SiGe buffer in growth and relaxation of Ge on free-standing Si(001) nano-pillars.

    Science.gov (United States)

    Zaumseil, P; Kozlowski, G; Schubert, M A; Yamamoto, Y; Bauer, J; Schülli, T U; Tillack, B; Schroeder, T

    2012-09-07

    We study the growth and relaxation processes of Ge nano-clusters selectively grown by chemical vapor deposition on free-standing 90 nm wide Si(001) nano-pillars with a thin Si(0.23)Ge(0.77) buffer layer. We found that the dome-shaped SiGe layer with a height of about 28 nm as well as the Ge dot deposited on top of it partially relaxes, mainly by elastic lattice bending. The Si nano-pillar shows a clear compliance behavior-an elastic response of the substrate on the growing film-with the tensile strained top part of the pillar. Additional annealing at 800 °C leads to the generation of misfit dislocation and reduces the compliance effect significantly. This example demonstrates that despite the compressive strain generated due to the surrounding SiO(2) growth mask it is possible to realize an overall tensile strain in the Si nano-pillar and following a compliant substrate effect by using a SiGe buffer layer. We further show that the SiGe buffer is able to improve the structural quality of the Ge nano-dot.

  6. Effect of PW12–GPK on the acid characteristics of Ni-, Pd- and Pt- catalysts deposited onto pillared Al montmorillonite

    Directory of Open Access Journals (Sweden)

    D. Zhumadullaev

    2012-03-01

    Full Text Available Acid characteristics of Ni-, Pd-, Pt- catalyzers , deposited to Al pillared CaH montmorillonite modified by heteropolyacid H3PW12O40·xH2O (PW12 by ammonia thermoadsorbtion method has been studied.

  7. A randomised controlled trial on the Four Pillars Approach in managing pregnant women with anaemia in Yogyakarta-Indonesia: a study protocol

    NARCIS (Netherlands)

    Widyawati, W.; Jans, S.; Bor, H.; Siswishanto, R.; Dillen, J. van; Lagro-Janssen, A.

    2014-01-01

    BACKGROUND: Anaemia is a common health problem among pregnant women and a contributing factor with a major influence on maternal mortality in Indonesia. The Four Pillars Approach is a new approach to anaemia in pregnancy, combining four strategies to improve antenatal and delivery care. The primary

  8. Percentual de degradação das forças liberadas por ligaduras elásticas Force decay rate of orthodontic elastomeric ligatures

    Directory of Open Access Journals (Sweden)

    Emanoela Volles de Souza

    2008-04-01

    Full Text Available OBJETIVO: avaliar ligaduras elásticas da marca Morelli, dos tipos modular e bengala, nas cores cinza e cristal para determinação do percentual de degradação das forças geradas pelas mesmas. METODOLOGIA: as ligaduras elásticas foram estiradas em estiletes de aço inoxidável com diâmetro de 4mm, imersas em solução de saliva artificial a 37ºC, sendo a intensidade das forças liberadas medidas nos tempos de zero hora, 24 horas, 1 semana, 2 semanas, 3 semanas e 4 semanas, em máquina de ensaios de tração. RESULTADOS E CONCLUSÕES: as ligaduras do tipo bengala liberaram, em média e no período de 4 semanas, maior intensidade de força que as do tipo modular. O percentual de degradação das forças liberadas por todas as ligaduras aumentou de forma acentuada entre zero e 24 horas e de forma gradativa após este período, com exceção do 28º dia quando, provavelmente, houve perda das propriedades elásticas das ligaduras. Não foi observado um comportamento constante das ligaduras bengala e modular em relação às cores cinza e cristal.PURPOSE: to evaluate gray and clear module and cane-loaded elastomeric ligatures of the brand Morelli to determine the percentage of decay of the forces they deliver. METHODS: the elastomeric ligatures were stretched over 4mm diameter stainless steel dowels and placed in synthetic saliva bath at 37ºC. The intensity of the forces delivered were taken at start, after 24 hours, one week, two weeks, three weeks and four weeks at a tensile test machine. RESULTS AND CONCLUSIONS: the cane-loaded ligatures delivered, in a period of 4 weeks, in average, greater force intensity than the modules. The percentage of force decay of all ligatures increased rapidly between zero and 24 hours and gradually after that period, except for the 28th day, when probably there was a loss of elastic properties of the ligatures. The researchers did not note any constant behavior in the cane-loaded and module ligatures in relation

  9. Pillarization of layer double hydroxides (Mg/Al with keggin type K4[α-SiW12O40]•nH2O and its application as adsorbent of procion red dye

    Directory of Open Access Journals (Sweden)

    Intan Permata Sari

    2017-07-01

    Full Text Available Pillarization of layered double hydroxides with polyoxometalate K4[α-SiW12O40]•nH2O at various times i.e. 3, 6, 9, 12, 24, 36 and 48 hours has been done. The pillared product was characterized by FT-IR spectrophotometer and XRD. The optimum pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O was used as an adsorbent of procion red dye. The results of characterization using FT-IR spectrophotometer is not yet show the optimum pillarization process. The characterisation using XRD the successfully of pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O showing the existence of diffraction angle 8.5o with intensity 355. Furthermore, the pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O with time variation of 12 hours was applied as an adsorbent of procion red dye. The results show the adsorption rate was 0.523 min-1, the highest of absorption capacity at 70oC was 10.8 mol/g, the highest energy of absorption 70 oC was 125 kJ/mol. The enthalpy (∆H and entropy (∆S, decrease as the increasing concentration of procion red dye. Keywords: layered double hydroxides, polyoxometalate, pillaration, procion red, adsorption

  10. A randomised controlled trial on the Four Pillars Approach in managing pregnant women with anaemia in Yogyakarta-Indonesia: a study protocol.

    Science.gov (United States)

    Widyawati, Widyawati; Jans, Suze; Bor, Hans; Siswishanto, Rukmono; van Dillen, Jeroen; Lagro-Janssen, Antoine L M

    2014-05-07

    Anaemia is a common health problem among pregnant women and a contributing factor with a major influence on maternal mortality in Indonesia. The Four Pillars Approach is a new approach to anaemia in pregnancy, combining four strategies to improve antenatal and delivery care. The primary objective of this study is to measure the effectiveness of the Four Pillars Approach. The barriers, the facilitators, and the patients' as well as the midwives' satisfaction with the Four Pillars Approach will also be measured. This study will use a cluster randomised controlled trial. This intervention study will be conducted in the Public Health Centres with basic emergency obstetric care in Yogyakarta Special Province and in Central Java Province. We will involve all the Public Health Centres (24) with emergency obstetric care in Yogyakarta Special Province. Another 24 Public Health Centres with emergency obstetric care in Central Java Province which have similarities in their demographic, population characteristics, and facilities will also be involved. Each Public Health Centre will be asked to choose two or three nurse-midwives to participate in this study. For the intervention group, the Public Health Centres in Yogyakarta Special Province, training on the Four Pillars Approach will be held prior to the model's implementation. Consecutively, we will recruit 360 pregnant women with anaemia to take part in part in the study to measure the effectiveness of the intervention. The outcome measurements are the differences in haemoglobin levels between the intervention and control groups in the third trimester of pregnancy, the frequency of antenatal care attendance, and the presence of a nurse-midwife during labour. Qualitative data will be used to investigate the barriers and facilitating factors, as to nurse-midwives' satisfaction with the implementation of the Four Pillars Approach. If the Four Pillars Approach is effective in improving the outcome for pregnant women with anaemia

  11. A Case Study: Analyzing City Vitality with Four Pillars of Activity-Live, Work, Shop, and Play.

    Science.gov (United States)

    Griffin, Matt; Nordstrom, Blake W; Scholes, Jon; Joncas, Kate; Gordon, Patrick; Krivenko, Elliott; Haynes, Winston; Higdon, Roger; Stewart, Elizabeth; Kolker, Natali; Montague, Elizabeth; Kolker, Eugene

    2016-03-01

    This case study evaluates and tracks vitality of a city (Seattle), based on a data-driven approach, using strategic, robust, and sustainable metrics. This case study was collaboratively conducted by the Downtown Seattle Association (DSA) and CDO Analytics teams. The DSA is a nonprofit organization focused on making the city of Seattle and its Downtown a healthy and vibrant place to Live, Work, Shop, and Play. DSA primarily operates through public policy advocacy, community and business development, and marketing. In 2010, the organization turned to CDO Analytics ( cdoanalytics.org ) to develop a process that can guide and strategically focus DSA efforts and resources for maximal benefit to the city of Seattle and its Downtown. CDO Analytics was asked to develop clear, easily understood, and robust metrics for a baseline evaluation of the health of the city, as well as for ongoing monitoring and comparisons of the vitality, sustainability, and growth. The DSA and CDO Analytics teams strategized on how to effectively assess and track the vitality of Seattle and its Downtown. The two teams filtered a variety of data sources, and evaluated the veracity of multiple diverse metrics. This iterative process resulted in the development of a small number of strategic, simple, reliable, and sustainable metrics across four pillars of activity: Live, Work, Shop, and Play. Data during the 5 years before 2010 were used for the development of the metrics and model and its training, and data during the 5 years from 2010 and on were used for testing and validation. This work enabled DSA to routinely track these strategic metrics, use them to monitor the vitality of Downtown Seattle, prioritize improvements, and identify new value-added programs. As a result, the four-pillar approach became an integral part of the data-driven decision-making and execution of the Seattle community's improvement activities. The approach described in this case study is actionable, robust, inexpensive

  12. Positional isomerism-driven two 3D pillar-layered metal-organic frameworks: Syntheses, topological structures and photoluminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yayong; Zhao, Siwei; Ma, Haoran; Han, Yi; Liu, Kang; Wang, Lei, E-mail: inorchemwl@126.com

    2016-06-15

    Two novel three-dimensional (3D) pillar-layered metal-organic frameworks (MOFs), namely [Zn{sub 2}(μ{sub 2}-OH)(boaba)(1,4-bmimb)]{sub n} (1) and {[Zn_5K_2(μ_2-H_2O)_2(boaba)_4(1,2-bmimb)_2(H_2O)_2]·H_2O}{sub n} (2), were prepared by hydrothermal reactions (H{sub 3}boaba=3,5-bis-oxyacetate-benzoic acid; 1,4-bmimb=1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene; 1,2-bmimb =1,2-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene). Notably, 1 exhibits a (3,5)-connected binodal (6{sup 3})(6{sup 9}·8)-gra net with binuclear [Zn{sub 2}(μ{sub 2}-OH)(COO)]{sup 2+} clusters, while 2 shows a novel (4,4,5,9)-connected 4-nodal net constructed from the unique Zn(II)-K(I) heterometal rod-like substructures. The results indicate that the disposition of the 2-methylimidazolyl groups of bis(imidazole) ligands have a significant effect on structural diversity. Moreover, the photoluminescence properties of 1 and 2 have been investigated. - Graphical abstract: Two novel 3D pillar-layered metal-organic coordination networks with aromatic multicarboxylate anion and bis(imidazole) ligands have been synthesized and structurally characterized. Display Omitted - Highlights: • It is rarely reported that metal-organic frameworks prepared with 3,5-bis-oxyacetate-benzoic acid. • Two metal-organic frameworks based on positional isomeric ligands were synthesized and structurally characterized. • Compond 1 displays unique (3,5)-connected binodal gra topology. • Compound 2 exhibits (4,4,5,9)-connected 4-nodal topology based on the Zn(II)-K(I) heterometal rod-like substructures. • The photoluminescence properties of compound 1 and 2 have been investigated.

  13. Contact behavior analysis of elastomeric x-ring under uniform squeeze rate and internal pressure before and after forcing-out using the photoelastic experimental hybrid method

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Dong, Bai [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

    2015-05-15

    Many different types of elastomeric rings have been developed to suit various needs in industry. The X-ring was introduced as a result of the limitations of O-rings that twist, especially during dynamic application. A better understanding of the behavior and the stress distribution of the X-ring under a uniform squeeze rate and internal pressure is needed. We analyzed the contact stresses and internal stresses developed in an X-ring before and after forcing-out by using the photoelastic experimental hybrid method, ascertained the packing ability of an X-ring, and studied the failure criterion of an X-ring under uniform squeeze rate and internal pressure. Forcing-out in the X-ring occurred when the internal pressure was 3.92 MPa. After forcing-out, at an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merged one contact side of the upper side immensely. Even after extrusion of the X-ring, the X-ring can be used to effectively contain the fluid. This is because the effects of extrusion on the X-ring affected the stress distribution of only two lobes close to the assembly gap and the two lobes are merge into one lobe. In addition, our experimental results show that the maximum shear failure criterion is suitable for the prediction of failure in X-ring seals.

  14. Warm/cool-tone switchable thermochromic material for smart windows by orthogonally integrating properties of pillar[6]arene and ferrocene.

    Science.gov (United States)

    Wang, Sai; Xu, Zuqiang; Wang, Tingting; Xiao, Tangxin; Hu, Xiao-Yu; Shen, Ying-Zhong; Wang, Leyong

    2018-04-30

    Functional materials play a vital role in the fabrication of smart windows, which can provide a more comfortable indoor environment for humans to enjoy a better lifestyle. Traditional materials for smart windows tend to possess only a single functionality with the purpose of regulating the input of solar energy. However, different color tones also have great influences on human emotions. Herein, a strategy for orthogonal integration of different properties is proposed, namely the thermo-responsiveness of ethylene glycol-modified pillar[6]arene (EGP6) and the redox-induced reversible color switching of ferrocene/ferrocenium groups are orthogonally integrated into one system. This gives rise to a material with cooperative and non-interfering dual functions, featuring both thermochromism and warm/cool tone-switchability. Consequently, the obtained bifunctional material for fabricating smart windows can not only regulate the input of solar energy but also can provide a more comfortable color tone to improve the feelings and emotions of people in indoor environments.

  15. Characterization of electronic structures from CdS/Si nanoheterostructure array based on silicon nanoporous pillar array

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yong, E-mail: liyong@pdsu.edu.cn [Department of Physics and Solar Energy Research Center, Pingdingshan University, Pingdingshan 467000 (China); Song, Xiao Yan [Department of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou 450045 (China); Song, Yue Li; Ji, Peng Fei; Zhou, Feng Qun; Tian, Ming Li; Huang, Hong Chun [Department of Physics and Solar Energy Research Center, Pingdingshan University, Pingdingshan 467000 (China); Li, Xin Jian [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China)

    2016-02-15

    Highlights: • CdS/Si nanoheterostructure array has been fabricated through a CBD method. • The electronic properties have been investigated by the I–V and C–V techniques. • The onset voltages, characteristic frequency and built-in potential are investigated. • The electronic structures can be tuned through the annealing treatments. - Abstract: The electronic properties of heterostructures are very important to its applications in the field of optoelectronic devices. Understanding and control of electronic properties are very necessary. CdS/Si nanoheterostructure array have been fabricated through growing CdS nanocrystals on the silicon nanoporous pillar array using a chemical bath deposition method. The electronic properties of CdS nanoheterostructure array have been investigated by the current–voltage, complex impedance spectroscopy and capacitance–voltage techniques. The onset voltages, characteristic frequency and built-in potential are gradually increased with increasing the annealing temperature. It is indicated that the electronic structures of CdS/Si nanoheterostructure array can be tuned through the annealing treatments.

  16. Supramolecular Host-Guest System as Ratiometric Fe3+ Ion Sensor Based on Water-Soluble Pillar[5]arene.

    Science.gov (United States)

    Yao, Qianfang; Lü, Baozhong; Ji, Chendong; Cai, Yang; Yin, Meizhen

    2017-10-18

    Developing a specific, ratiometric, and reversible detection method for metal ions is significant to guard against the threat of metal-caused environmental pollution and organisms poisoning. Here a supramolecular host-guest system (WP5⊃G) based on water-soluble pillar[5]arene (WP5) and water-soluble quaternized perylene diimide derivative (G) was constructed. Morphological transformation was achieved during the process of adding WP5 into G aqueous solution, and a fluorescence "turn-off" phenomenon was observed which was caused by supramolecular photoinduced electron transfer (PET). Meanwhile, hydrophobic effect and electrostatic interaction played important roles in this supramolecular process, which was confirmed by isothermal titration calorimeter (ITC) and ζ potential experiments. Furthermore, the supramolecular host-guest system could be a "turn-on" fluorescent probe for Fe 3+ ion detection through the process of interdicting supramolecular PET. Moreover, the Fe 3+ ion detection showed specific, ratiometric, and reversible performances with a detection limit of 2.13 × 10 -7 M, which might have great potentials in biological and environmental monitoring.

  17. Bioactive wound healing, bioaesthetics and biosurgery: three pillars of product development. Interview with Geoff MacKay.

    Science.gov (United States)

    MacKay, Geoff

    2006-03-01

    Tissue regeneration specialist company Organogenesis Inc. was one of the first biotech companies formed. Incorporated in 1985, the company was originally a spin-off from a research program at MIT. For the first 10-15 years, Organogenesis was heavily research based, but then gradually moved into development. The company's flagship product is Apligraf--a living, bilayered skin construct with two FDA-approved indications: diabetic foot ulcers and venous leg ulcers. As Apligraf neared the market, it was necessary to 'graft' a manufacturing capability onto the company. As a consequence the company moved south from Massachusetts's cradle of biotechnology to Canton, MA, USA. Having experienced many of the highs and lows that characterize the biotech industry, the company is now consolidating its position as a center of expertise in commercializing living, cell-based products. The company has now built a sales, marketing and reimbursement team with the unique skill set to integrate novel technology into the US healthcare system. President & Chief Executive Officer Geoff MacKay takes great pride in the leading role that Organogenesis is playing in ushering in the field of tissue regeneration. Here, he discusses with Regenerative Medicine's Elisa Manzotti the 'three pillars' of the Organogenesis pipeline: bioactive wound healing, bioaesthetics and biosurgery. He focuses both on the rewards, and the trials and tribulations, of the commercialization of living cell-based technology.

  18. Effect of ring rotation upon gas adsorption in SIFSIX-3-M (M = Fe, Ni) pillared square grid networks.

    Science.gov (United States)

    Elsaidi, Sameh K; Mohamed, Mona H; Simon, Cory M; Braun, Efrem; Pham, Tony; Forrest, Katherine A; Xu, Wenqian; Banerjee, Debasis; Space, Brian; Zaworotko, Michael J; Thallapally, Praveen K

    2017-03-01

    Dynamic and flexible metal-organic frameworks (MOFs) that respond to external stimuli, such as stress, light, heat, and the presence of guest molecules, hold promise for applications in chemical sensing, drug delivery, gas separations, and catalysis. A greater understanding of the relationship between flexible constituents in MOFs and gas adsorption may enable the rational design of MOFs with dynamic moieties and stimuli-responsive behavior. Here, we detail the effect of subtle structural changes upon the gas sorption behavior of two "SIFSIX" pillared square grid frameworks, namely SIFSIX-3-M (M = Ni, Fe). We observe a pronounced inflection in the Xe adsorption isotherm in the Ni variant. With evidence from X-ray diffraction studies, density functional theory, and molecular simulations, we attribute the inflection to a disordered to ordered transition of the rotational configurations of the pyrazine rings induced by sorbate-sorbent interactions. We also address the effect of cage size, temperature, and sorbate on the guest-induced ring rotation and the adsorption isotherms. The absence of an inflection in the Xe adsorption isotherm in SIFSIX-3-Fe and in the Kr, N 2 , and CO 2 adsorption isotherms in SIFSIX-3-Ni suggest that the inflection is highly sensitive to the match between the size of the cage and the guest molecule.

  19. Nanoscale Origins of the Size Effect in the Compression Response of Single Crystal Ni-Base Superalloy Micro-Pillars

    Directory of Open Access Journals (Sweden)

    Siqi Ying

    2018-04-01

    Full Text Available Nickel superalloys play a pivotal role in enabling power-generation devices on land, sea, and in the air. They derive their strength from coherent cuboidal precipitates of the ordered γ’ phase that is different from the γ matrix in composition, structure and properties. In order to reveal the correlation between elemental distribution, dislocation glide and the plastic deformation of micro- and nano-sized volumes of a nickel superalloy, a combined in situ nanoindentation compression study was carried out with a scanning electron microscope (SEM on micro- and nano-pillars fabricated by focused ion beam (FIB milling of Ni-base superalloy CMSX4. The observed mechanical response (hardening followed by softening was correlated with the progression of crystal slip that was revealed using FIB nano-tomography and energy-dispersive spectroscopy (EDS elemental mapping. A hypothesis was put forward that the dependence of material strength on the size of the sample (micropillar diameter is correlated with the characteristic dimension of the structural units (γ’ precipitates. By proposing two new dislocation-based models, the results were found to be described well by a new parameter-free Hall–Petch equation.

  20. Characterization of electronic structures from CdS/Si nanoheterostructure array based on silicon nanoporous pillar array

    International Nuclear Information System (INIS)

    Li, Yong; Song, Xiao Yan; Song, Yue Li; Ji, Peng Fei; Zhou, Feng Qun; Tian, Ming Li; Huang, Hong Chun; Li, Xin Jian

    2016-01-01

    Highlights: • CdS/Si nanoheterostructure array has been fabricated through a CBD method. • The electronic properties have been investigated by the I–V and C–V techniques. • The onset voltages, characteristic frequency and built-in potential are investigated. • The electronic structures can be tuned through the annealing treatments. - Abstract: The electronic properties of heterostructures are very important to its applications in the field of optoelectronic devices. Understanding and control of electronic properties are very necessary. CdS/Si nanoheterostructure array have been fabricated through growing CdS nanocrystals on the silicon nanoporous pillar array using a chemical bath deposition method. The electronic properties of CdS nanoheterostructure array have been investigated by the current–voltage, complex impedance spectroscopy and capacitance–voltage techniques. The onset voltages, characteristic frequency and built-in potential are gradually increased with increasing the annealing temperature. It is indicated that the electronic structures of CdS/Si nanoheterostructure array can be tuned through the annealing treatments.