Stiff, light, strong and ductile: nano-structured High Modulus Steel.

Science.gov (United States)

Springer, H; Baron, C; Szczepaniak, A; Uhlenwinkel, V; Raabe, D

2017-06-05

Structural material development for lightweight applications aims at improving the key parameters strength, stiffness and ductility at low density, but these properties are typically mutually exclusive. Here we present how we overcome this trade-off with a new class of nano-structured steel - TiB 2 composites synthesised in-situ via bulk metallurgical spray-forming. Owing to the nano-sized dispersion of the TiB 2 particles of extreme stiffness and low density - obtained by the in-situ formation with rapid solidification kinetics - the new material has the mechanical performance of advanced high strength steels, and a 25% higher stiffness/density ratio than any of the currently used high strength steels, aluminium, magnesium and titanium alloys. This renders this High Modulus Steel the first density-reduced, high stiffness, high strength and yet ductile material which can be produced on an industrial scale. Also ideally suited for 3D printing technology, this material addresses all key requirements for high performance and cost effective lightweight design.

Elastic Modulus at High Frequency of Polymerically Stabilized Suspensions

NARCIS (Netherlands)

Nommensen, P.A.; Duits, Michael H.G.; van den Ende, Henricus T.M.; Mellema, J.

2000-01-01

The elastic moduli of polymerically stabilized suspensions consisting of colloidal silica particles coated with endgrafted PDMS (Mn = 80 000) in heptane, were measured as a function of concentration. And the elastic modulus at high frequency G'.. was quantitatively described by model calculations

Connection between fragility, mean-squared displacement and shear modulus in two van der Waals bonded glass-forming liquids

DEFF Research Database (Denmark)

Hansen, Henriette Wase; Frick, Bernhard; Hecksher, Tina

2017-01-01

The temperature dependence of the high-frequency shear modulus measured in the kHz range is compared with the mean-squared displacement measured in the nanosecond range for the two van der Waals bonded glass-forming liquids cumene and 5-polyphenyl ether. This provides an experimental test for the...... for the assumption connecting two versions of the shoving model for the non-Arrhenius temperature dependence of the relaxation time in glass formers. The two versions of the model are also tested directly and both are shown to work well for these liquids....

Effect of young’s modulus on springback for low, medium and high carbon steels during cold drawing of seamless tubes

Science.gov (United States)

Karanjule, D. B.; Bhamare, S. S.; Rao, T. H.

2018-04-01

Cold drawing is widely used deformation process for seamless tube manufacturing. Springback is one of the major problem faced in tube drawing. Springback is due to the elastic energy stored in the tubes during forming process. It is found that this springback depends upon Young’s modulus of the material. This paper reports mechanical testing of three grades of steels viz. low carbon steel, medium carbon steel and high carbon steel to measure their Young’s modulus and corresponding springback. The results shows that there is 10-20 % variation in the Young’s modulus and inverse proportion between the springback and Young’s modulus. More the percentage of carbon, more the strength, less the value of Young’s modulus and more will springback. The study further leads to identify optimum die semi angle of 15 degree, land width of 10 mm and drawing speed of 8, 6 and 4 m/min for least springback in all the three grades respectively and die semi angle as a most dominant factor causing springback.

Ultra high energy gamma-ray astronomy

International Nuclear Information System (INIS)

Wdowczyk, J.

1986-01-01

The experimental data on ultra high energy γ-rays are reviewed and a comparison of the properties of photon and proton initiated shower is made. The consequences of the existence of the strong ultra high energy γ-ray sources for other observations is analysed and possible mechanisms for the production of ultra high energy γ-rays in the sources are discussed. It is demonstrated that if the γ-rays are produced via cosmic ray interactions the sources have to produce very high fluxes of cosmic ray particles. In fact it is possible that a small number of such sources can supply the whole Galactic cosmic ray flux

Do ultra-orphan medicinal products warrant ultra-high prices? A review

Directory of Open Access Journals (Sweden)

Picavet E

2013-06-01

Full Text Available Eline Picavet,1 David Cassiman,2 Steven Simoens1 1Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; 2Department of Hepatology, University Hospital Leuven, Leuven, Belgium Abstract: Ultra-orphan medicinal products (ultra-OMPs are intended for the treatment, prevention, or diagnosis of ultra-rare diseases, ie, life-threatening or chronically debilitating diseases that affect less than one per 50,000 individuals. Recently, high prices for ultra-OMPs have given rise to debate on the sustainability and justification of these prices. The aim of this article is to review the international scientific literature on the pricing of ultra-OMPs and to provide an overview of the current knowledge on the drivers of ultra-OMP pricing. The pricing process of ultra-OMPs is a complex and nontransparent issue. Evidence in the literature seems to indicate that ultra-OMPs are priced according to rarity and what the manufacturer believes the market will bear. Additionally, there appears to be a trend between the price of an ultra-OMP and the number of available alternatives. Patients, third-party payers, and pharmaceutical companies could benefit from more transparent pricing strategies. With a view to containing health care costs, it is likely that cost-sharing strategies, such as performance-based risk sharing arrangements, will become increasingly more important. However, it is vital that any measures for price control are consistent with the intended goals of the incentives to promote the development of new OMPs. Ideally, a balance must be struck between attaining affordable prices for ultra-OMPs and securing a realistic return on investment for the pharmaceutical industry. Keywords: ultra-orphan medicinal product, ultra-rare disease, pricing

Effect of electron beam radiation on the structure and mechanical properties of ultra high molecular weight polyethylene fibers

International Nuclear Information System (INIS)

Li Shujun; Sun Weijun; Liu Xiuju; Gao Yongzhong; Li Huisheng

1998-01-01

Ultra high molecular weight polyethylene fibers have been crosslinked by electron beam. The structure and mechanical properties of them have been investigated in different irradiation atmospheres. The obtained results show that the gel content and crosslinking density increase with the increase of dose, the swelling ratio and average molecular weight of crosslinked net decrease with the increase of dose, the tensile strength and failure elongation decrease with the increase of dose, the tensile modulus increases with the increase of dose. When the samples are irradiated in air, vacuum and acetylene atmospheres, the effect of irradiation in acetylene atmosphere is best

Fatigue life of high strength steel for cold forming

Directory of Open Access Journals (Sweden)

R. Ulewicz

2017-01-01

Full Text Available The article presents the results of fatigue tests carried out on STRENX-type high-strength cold forming steel. For high-cycle fatigue tests carried out using low cycle loading frequencies of around 30 Hz, a ROTOFLEX machine was used. For ultra high-cycle tests, a KAUP-ZU testing machine was employed, which enables fatigue tests to be performed with symetric specimen loading (R = -1 and at a frequency of f ≈ 20 kHz. The relationships σa = f(N were determined experimentally in the high and ultra high-cycle region for STRENX high-strength steel. To determine the fatigue crack initiation mechanism, the fractographic analysis of fatigue fractures was made.

Ultra-high-speed Optical Signal Processing using Silicon Photonics

DEFF Research Database (Denmark)

Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...... of the ultra-fast nonlinear response of silicon photonic waveguides. These chips offer ultra-broadband wavelength operation, ultra-high timing resolution and ultra-fast response, and when used appropriately offer energy-efficient switching. In this presentation we review some all-optical functionalities based...... on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show...

Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

Science.gov (United States)

Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

2017-09-01

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fracture toughness measurements on a glass bonded sodalite high-level waste form

International Nuclear Information System (INIS)

DiSanto, T.; Goff, K. M.; Johnson, S. G.; O'Holleran, T. P.

1999-01-01

The electrometallurgical treatment of metallic spent nuclear fuel produces two high-level waste streams; cladding hulls and chloride salt. Argonne National Laboratory is developing a glass bonded sodalite waste form to immobilize the salt waste stream. The waste form consists of 75 Vol.% crystalline sodalite (containing the salt) with 25 Vol.% of an ''intergranular'' glassy phase. Microindentation fracture toughness measurements were performed on representative samples of this material using a Vickers indenter. Palmqvist cracking was confirmed by post-indentation polishing of a test sample. Young's modulus was measured by an acoustic technique. Fracture toughness, microhardness, and Young's modulus values are reported, along with results from scanning electron microscopy studies

Impact Of Elastic Modulus Degradation On Springback In Sheet Metal Forming

International Nuclear Information System (INIS)

Halilovic, Miroslav; Stok, Boris; Vrh, Marko

2007-01-01

Strain recovery after removal of forming loads, commonly defined as springback, is of great concern in sheet metal forming, in particular with regard to proper prediction of the final shape of the part. To control the problem a lot of work has been done, either by minimizing the springback on the material side or by increasing the estimation precision in corresponding process simulations. Unfortunately, by currently available software springback still cannot be adequately predicted, because most analyses of springback are using linear, isotropic and constant Young's modulus and Poisson's ratio. But, as it was measured and reported, none of it is true. The aim of this work is to propose an upgraded mechanical model which takes evolution of damage and related orthotropic stiffness degradation into account. Damage is considered by inclusion of ellipsoidal cavities, and their influence on the stiffness degradation is taken in accordance with the Mori-Tanaka theory, adopting the GTN model for plastic flow. In order to improve the numerical springback prediction, two major things are important: first, the correct evaluation of the stress-strain state at the end of the forming process, and second, correctness of the elastic properties used in the elastic relaxation analysis. Since in modelling of the forming process we adopt a damage constitutive model with orthotropic stiffness degradation considered, a corresponding damage parameters identification upon specific experimental tests data must be performed first, independently of the metal forming modelling. An improved identification of material parameters, which simultaneously considers tensile test results with different type of specimens and using neural network, is proposed. With regard to the case in which damage in material is neglected it is shown in the article how the springback of a formed part differs, when we take orthotropic damage evolution into consideration

Characterization of Impact Damage in Ultra-High Performance Concrete Using Spatially Correlated Nanoindentation/SEM/EDX

Science.gov (United States)

Moser, R. D.; Allison, P. G.; Chandler, M. Q.

2013-12-01

Little work has been done to study the fundamental material behaviors and failure mechanisms of cement-based materials including ordinary Portland cement concrete and ultra-high performance concretes (UHPCs) under high strain impact and penetration loads at lower length scales. These high strain rate loadings have many possible effects on UHPCs at the microscale and nanoscale, including alterations in the hydration state and bonding present in phases such as calcium silicate hydrate, in addition to fracture and debonding. In this work, the possible chemical and physical changes in UHPCs subjected to high strain rate impact and penetration loads were investigated using a novel technique wherein nanoindentation measurements were spatially correlated with images using scanning electron microscopy and chemical composition using energy dispersive x-ray microanalysis. Results indicate that impact degrades both the elastic modulus and indentation hardness of UHPCs, and in particular hydrated phases, with damage likely occurring due to microfracturing and debonding.

A high-damping magnetorheological elastomer with bi-directional magnetic-control modulus for potential application in seismology

Energy Technology Data Exchange (ETDEWEB)

Yu, Miao, E-mail: yumiao@cqu.edu.cn; Qi, Song; Fu, Jie; Zhu, Mi [Key Lab for Optoelectronic Technology and Systems, Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044 (China)

2015-09-14

A high-damping magnetorheological elastomer (MRE) with bi-directional magnetic-control modulus is developed. This MRE was synthesized by filling NdFeB particles into polyurethane (PU)/ epoxy (EP) interpenetrating network (IPN) structure. The anisotropic samples were prepared in a permanent magnetic field and magnetized in an electromagnetic field of 1 T. Dynamic mechanical responses of the MRE to applied magnetic fields are investigated through magneto-rheometer, and morphology of MREs is observed via scanning electron microscope (SEM). Test result indicates that when the test field orientation is parallel to that of the sample's magnetization, the shear modulus of sample increases. On the other hand, when the orientation is opposite to that of the sample's magnetization, shear modulus decreases. In addition, this PU/EP IPN matrix based MRE has a high-damping property, with high loss factor and can be controlled by applying magnetic field. It is expected that the high damping property and the ability of bi-directional magnetic-control modulus of this MRE offer promising advantages in seismologic application.

Determination of Lubricant Bulk Modulus in Metal Forming by Means of a Simple Laboratory Test and Inverse FEM Analysis

DEFF Research Database (Denmark)

Hafis, S. M.; Christiansen, P.; Martins, P. A. F.

2016-01-01

The influence of workpiece surface topography on friction, lubrication and final surface equality in metal forming operations is well known and has been pointed out by many researchers.This is especially the case when liquid lubricants are applied in situations, where increased surface roughness ...... couples lubricant flow with plastic deformation of the metal directly. Results show that the proposed procedure allows determining an approximate bulk modulus for the lubricant.......The influence of workpiece surface topography on friction, lubrication and final surface equality in metal forming operations is well known and has been pointed out by many researchers.This is especially the case when liquid lubricants are applied in situations, where increased surface roughness...... facilitates the lubricant entrainment, pressurization and possible escape by micro-plasto-hydrodynamic lubrication. In order to model these mechanisms an important lubricant propertyd esignated as the bulk modulus is needed for characterizing the compressibility of the lubricant. The present paper describes...

Stretchers and compressors for ultra-high power laser systems

Energy Technology Data Exchange (ETDEWEB)

Yakovlev, I V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

2014-05-30

This review is concerned with pulse stretchers and compressors as key components of ultra-high power laser facilities that take advantage of chirped-pulse amplification. The potentialities, characteristics, configurations and methods for the matching and alignment of these devices are examined, with particular attention to the history of the optics of ultra-short, ultra-intense pulses before and after 1985, when the chirped-pulse amplification method was proposed, which drastically changed the view of the feasibility of creating ultra-high power laser sources. The review is intended primarily for young scientists and experts who begin to address the amplification and compression of chirped pulses, experts in laser optics and all who are interested in scientific achievements in the field of ultra-high power laser systems. (review)

Ultra high field magnetic resonance imaging

International Nuclear Information System (INIS)

Lethimonnier, F.; Vedrine, P.

2007-01-01

Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ultra-high-field system of unprecedented power that is designed for research on human subjects. The level of the magnetic field and the scale required will make this joint French-German project to build the magnet a breakthrough in the international arena. (authors)

Cavity resonance absorption in ultra-high bandwidth CRT deflection structure by a resistive load

Science.gov (United States)

Dunham, M.E.; Hudson, C.L.

1993-05-11

An improved ultra-high bandwidth helical coil deflection structure for a cathode ray tube is described comprising a first metal member having a bore therein, the metal walls of which form a first ground plane; a second metal member coaxially mounted in the bore of the first metal member and forming a second ground plane; a helical deflection coil coaxially mounted within the bore between the two ground planes; and a resistive load disposed in one end of the bore and electrically connected to the first and second ground planes, the resistive load having an impedance substantially equal to the characteristic impedance of the coaxial line formed by the two coaxial ground planes to inhibit cavity resonance in the structure within the ultra-high bandwidth of operation. Preferably, the resistive load comprises a carbon film on a surface of an end plug in one end of the bore.

High Heat Load Properties of Ultra Fine Grain Tungsten

International Nuclear Information System (INIS)

Zhou, Z.; Du, J.; Ge, C.; Linke, J.; Pintsuk, G.; Song, S.X.

2007-01-01

Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 μm, 1 μm and 3 μm were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m 2 respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m 2 . Particle erosions occurred for tungsten with 3 μm size at 0.33 GW/m 2 and for tungsten with 0.2 and 1 μm size at 0.55 GW/m 2 . The weight loss of tungsten with 0.2, 1 and 3 μm size are 2,0.1,0.6 mg respectively at 0.88 GW/m 2 . The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 μm size has the best performance. (authors)

High Heat Load Properties of Ultra Fine Grain Tungsten

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.; Du, J.; Ge, C. [Lab. of Special Ceramic and P/M, University of Science and Technology, 100083 Beijing (China); Linke, J.; Pintsuk, G. [FZJ-Forschungszentrum Juelich GmbH, Association Euratom-FZJ, Institut fur Plasmaphysik, Postfach 1913, D-52425 Juelich (Germany); Song, S.X. [Research Center on Fusion Materials (RCFM), University of Science and Technology Beijing (USTB), 100083 Beijing (China)

2007-07-01

Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 {mu}m, 1 {mu}m and 3 {mu}m were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m{sup 2} respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m{sup 2}. Particle erosions occurred for tungsten with 3 {mu}m size at 0.33 GW/m{sup 2} and for tungsten with 0.2 and 1 {mu}m size at 0.55 GW/m{sup 2}. The weight loss of tungsten with 0.2, 1 and 3 {mu}m size are 2,0.1,0.6 mg respectively at 0.88 GW/m{sup 2}. The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 {mu}m size has

Multi-beam laser heterodyne measurement with ultra-precision for Young modulus based on oscillating mirror modulation

Science.gov (United States)

Li, Y. Chao; Ding, Q.; Gao, Y.; Ran, L. Ling; Yang, J. Ru; Liu, C. Yu; Wang, C. Hui; Sun, J. Feng

2014-07-01

This paper proposes a novel method of multi-beam laser heterodyne measurement for Young modulus. Based on Doppler effect and heterodyne technology, loaded the information of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by mass variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain value of Young modulus of the sample by the calculation. This novel method is used to simulate measurement for Young modulus of wire under different mass by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.3%.

A Study on Accelerated Thermal Aging of High Modulus Carbon/Epoxy Composite Material

Directory of Open Access Journals (Sweden)

Ju Min Kyung

2015-01-01

Full Text Available Composite materials have been used increasingly for various space applications due to the favorable characteristic of high modulus to density ratio and potential for near-zero coefficient of thermal expansion. In composite system, depending on the orientation of fibers, strength and stiffness can be changed so that the optimum structure can be accomplished. This is because the coefficient of thermal expansion (CTE of carbon fibers is negative. For spacecraft and orbiting space structure, which are thermally cycled by moving through the earth' shadow for at least 5 years, it is necessary to investigate the change of properties of the material over time. In this study, thermal aging of epoxy matrix/high modulus carbon fiber composite materials are accelerated to predict the long term creep property. Specimens are tested at various temperatures of 100~140°C with dynamic mechanical analysis to obtain creep compliances that are functions of time and temperature. Using Time Temperature Superposition method, creep compliance curves at each temperature are shifted to the reference temperature by shift factor and a master curve is generated at the reference temperature. This information is useful to predict the long term thermal aging of high modulus composite material for spacecraft application.

Determination of the bulk modulus of hydroxycancrinite, a possible zeolitic precursor in geopolymers, by high-pressure synchrotron X-ray diffraction

KAUST Repository

Oh, Jae Eun

2011-11-01

Crystalline zeolitic materials, such as hydroxycancrinite, hydroxysodalite, herschelite and nepheline, are often synthesized from geopolymerization using fly-ash and solutions of NaOH at high temperatures. Comprised mainly of 6-membered aluminosilicate rings that act as basic building units, their crystal structures may provide insight into the reaction products formed in NaOH-activated fly ash-based geopolymers. Recent research indicates that the hydroxycancrinite and hydroxysodalite may play an important role as possible analogues of zeolitic precursor in geopolymers. Herein is reported a high pressure synchrotron study of the behavior of hydroxycancrinite exposed to pressures up to 6.1 GPa in order to obtain its bulk modulus. A refined equation of state for hydroxycancrinite yielded a bulk modulus of Ko = 46 ± 5 GPa (assuming Ko′ = 4.0) for a broad range of applied pressure. When low pressure values are excluded from the fit and only the range of 2.5 and 6.1 GPa is considered, the bulk modulus of hydroxycancrinite was found to be Ko = 46.9 ± 0.9 GPa (Ko′ = 4.0 ± 0.4, calculated). Comparison with the literature shows that all zeolitic materials possessing single 6-membered rings (i.e., hydroxycancrinite, sodalite and nepheline) have similar bulk moduli. © 2011 Elsevier Ltd. All rights reserved.

Systems and methods for advanced ultra-high-performance InP solar cells

Science.gov (United States)

Wanlass, Mark

2017-03-07

Systems and Methods for Advanced Ultra-High-Performance InP Solar Cells are provided. In one embodiment, an InP photovoltaic device comprises: a p-n junction absorber layer comprising at least one InP layer; a front surface confinement layer; and a back surface confinement layer; wherein either the front surface confinement layer or the back surface confinement layer forms part of a High-Low (HL) doping architecture; and wherein either the front surface confinement layer or the back surface confinement layer forms part of a heterointerface system architecture.

Construction of a high modulus asphalt (HiMA) trial section Ethekwini: South Africa's first practical experience with design, manufacturing and paving of HiMA

CSIR Research Space (South Africa)

Nkgapele, M

2012-07-01

Full Text Available A trial section was paved with the recently introduced High Modulus Asphalt (HiMA) technology on South Coast road in eThekwini (Durban). The trial section forms part of an effort to transfer HiMA technology to South Africa, in an initiative aimed...

Ultra-high resolution protein crystallography

International Nuclear Information System (INIS)

Takeda, Kazuki; Hirano, Yu; Miki, Kunio

2010-01-01

Many protein structures have been determined by X-ray crystallography and deposited with the Protein Data Bank. However, these structures at usual resolution (1.5< d<3.0 A) are insufficient in their precision and quantity for elucidating the molecular mechanism of protein functions directly from structural information. Several studies at ultra-high resolution (d<0.8 A) have been performed with synchrotron radiation in the last decade. The highest resolution of the protein crystals was achieved at 0.54 A resolution for a small protein, crambin. In such high resolution crystals, almost all of hydrogen atoms of proteins and some hydrogen atoms of bound water molecules are experimentally observed. In addition, outer-shell electrons of proteins can be analyzed by the multipole refinement procedure. However, the influence of X-rays should be precisely estimated in order to derive meaningful information from the crystallographic results. In this review, we summarize refinement procedures, current status and perspectives for ultra high resolution protein crystallography. (author)

Application of diffusion barriers to high modulus fibers

Science.gov (United States)

Veltri, R. D.; Douglas, F. C.; Paradis, E. L.; Galasso, F. S.

1977-01-01

Barrier layers were coated onto high-modulus fibers, and nickel and titanium layers were overcoated as simulated matrix materials. The objective was to coat the high-strength fibers with unreactive selected materials without degrading the fibers. The fibers were tungsten, niobium, and single-crystal sapphire, while the materials used as barrier coating layers were Al2O3, Y2O3, TiC, ZrC, WC with 14% Co, and HfO2. An ion-plating technique was used to coat the fibers. The fibers were subjected to high-temperature heat treatments to evaluate the effectiveness of the barrier layer in preventing fiber-metal interactions. Results indicate that Al2O3, Y2O3, and HfO2 can be used as barrier layers to minimize the nickel-tungsten interaction. Further investigation, including thermal cycling tests at 1090 C, revealed that HfO2 is probably the best of the three.

Low velocity impact behaviour of ultra high strength concrete panels

Indian Academy of Sciences (India)

Ultra high strength concrete; panel; drop weight test; impact analysis;. ABAQUS. 1. Introduction. Ultra high strength concrete ... Knight (2012) investigated the dynamic behaviour of steel fibre reinforced concrete plates under impact loading with ...

Radiobiological response to ultra-short pulsed megavoltage electron beams of ultra-high pulse dose rate.

Science.gov (United States)

Beyreuther, Elke; Karsch, Leonhard; Laschinsky, Lydia; Leßmann, Elisabeth; Naumburger, Doreen; Oppelt, Melanie; Richter, Christian; Schürer, Michael; Woithe, Julia; Pawelke, Jörg

2015-08-01

In line with the long-term aim of establishing the laser-based particle acceleration for future medical application, the radiobiological consequences of the typical ultra-short pulses and ultra-high pulse dose rate can be investigated with electron delivery. The radiation source ELBE (Electron Linac for beams with high Brilliance and low Emittance) was used to mimic the quasi-continuous electron beam of a clinical linear accelerator (LINAC) for comparison with electron pulses at the ultra-high pulse dose rate of 10(10) Gy min(-1) either at the low frequency of a laser accelerator or at 13 MHz avoiding effects of prolonged dose delivery. The impact of pulse structure was analyzed by clonogenic survival assay and by the number of residual DNA double-strand breaks remaining 24 h after irradiation of two human squamous cell carcinoma lines of differing radiosensitivity. The radiation response of both cell lines was found to be independent from electron pulse structure for the two endpoints under investigation. The results reveal, that ultra-high pulse dose rates of 10(10) Gy min(-1) and the low repetition rate of laser accelerated electrons have no statistically significant influence (within the 95% confidence intervals) on the radiobiological effectiveness of megavoltage electrons.

Effects of nano-silica on mechanical performance and microstructure of ultra-high performance concrete

Energy Technology Data Exchange (ETDEWEB)

Mendes, T. M., E-mail: thiagomendes@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Londrina, PR (Brazil). Departamento de Engenharia Ambiental; Repette, W.L., E-mail: wellington.repette@gmail.br [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Civil; Reis, P.J., E-mail: pjlondrina@yahoo.com.br [Univeridade Estadual de Londrina (UEL), PR (Brazil). Lab. de Fisica Nuclear Aplicada

2017-07-15

The use of nanoparticles in ultra-high strength concretes can result in a positive effect on mechanical performance of these cementitious materials. This study evaluated mixtures containing 10 and 20 wt% of silica fume, for which the optimum nano-silica content was determined, i.e. the quantity of nano-silica that resulted on the higher gain of strength. The physical characterization of raw materials was done in terms of particle size distribution, density and specific surface area. Chemical and mineralogical compositions of materials were obtained through fluorescence and X-ray diffraction. The mechanical performance was evaluated by compressive strength, flexural strength and dynamic elastic modulus measurements. The microstructural analysis of mixtures containing nano-silica was performed by X-ray diffraction, thermogravimetry, mercury intrusion porosimetry and scanning electron microscopy. Obtained results indicate an optimum content of nano-silica of 0.62 wt%, considering compressive and flexural strengths. This performance improvement was directly related to two important microstructural aspects: the packing effect and pozzolanic reaction of nano-silica. (author)

Effects of nano-silica on mechanical performance and microstructure of ultra-high performance concrete

International Nuclear Information System (INIS)

Mendes, T. M.; Repette, W.L.; Reis, P.J.

2017-01-01

The use of nanoparticles in ultra-high strength concretes can result in a positive effect on mechanical performance of these cementitious materials. This study evaluated mixtures containing 10 and 20 wt% of silica fume, for which the optimum nano-silica content was determined, i.e. the quantity of nano-silica that resulted on the higher gain of strength. The physical characterization of raw materials was done in terms of particle size distribution, density and specific surface area. Chemical and mineralogical compositions of materials were obtained through fluorescence and X-ray diffraction. The mechanical performance was evaluated by compressive strength, flexural strength and dynamic elastic modulus measurements. The microstructural analysis of mixtures containing nano-silica was performed by X-ray diffraction, thermogravimetry, mercury intrusion porosimetry and scanning electron microscopy. Obtained results indicate an optimum content of nano-silica of 0.62 wt%, considering compressive and flexural strengths. This performance improvement was directly related to two important microstructural aspects: the packing effect and pozzolanic reaction of nano-silica. (author)

Ultra high temperature latent heat energy storage and thermophotovoltaic energy conversion

OpenAIRE

Datas Medina, Alejandro; Ramos Cabal, Alba; Martí Vega, Antonio; Cañizo Nadal, Carlos del; Luque López, Antonio

2016-01-01

A conceptual energy storage system design that utilizes ultra high temperature phase change materials is presented. In this system, the energy is stored in the form of latent heat and converted to electricity upon demand by TPV (thermophotovoltaic) cells. Silicon is considered in this study as PCM (phase change material) due to its extremely high latent heat (1800 J/g or 500 Wh/kg), melting point (1410 C), thermal conductivity (~25 W/mK), low cost (less than $2/kg or $4/kWh) and a...

High modulus asphalt (EME) technology transfer to South Africa and Australia: shared experiences

CSIR Research Space (South Africa)

Denneman, E

2015-08-01

Full Text Available The paper describes experiences with the implementation of French enrobés à module élevé (EME) (high modulus asphalt) technology in South Africa and Australia. Tentative performance specifications for EME mixes were set in the two countries based...

High modulus invert analog glass compositions containing beryllia

Science.gov (United States)

Bacon, J. F. (Inventor)

1974-01-01

Glass compositions having a Young's modulus of at least 15 million psi and a specific modulus of at least 110 million inches consisting essentially of, in mols, 10-45% SiO2, 2-15% Li2O, 3-34% BeO, 12-36% of at least one bivalent oxide selected from the group consisting of CaO, ZnO, MgO and CuO, 10-39% of at least one trivalent oxide selected from the group consisting of Al2O3, B2O3, La2O3, Y2O3 and the mixed rare earth oxides, the total number of said bivalent and trivalent oxides being at least three, and up to 10% of a tetravalent oxide selected from the group consisting of ZrO2, TiO2 and CeO2.

New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

International Nuclear Information System (INIS)

Ueda, Kenichi

2006-01-01

An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti 3+ :Al 2 O 3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10 -2 to 67 x 10 3 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti 3+ :Al 2 O 3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

Ultra-high wear resistance of ultra-nanocrystalline diamond film: Correlation with microstructure and morphology

Science.gov (United States)

Rani, R.; Kumar, N.; Lin, I.-Nan

2016-05-01

Nanostructured diamond films are having numerous unique properties including superior tribological behavior which is promising for enhancing energy efficiency and life time of the sliding devices. High wear resistance is the principal criterion for the smooth functioning of any sliding device. Such properties are achievable by tailoring the grain size and grain boundary volume fraction in nanodiamond film. Ultra-nanocrystalline diamond (UNCD) film was attainable using optimized gas plasma condition in a microwave plasma enhanced chemical vapor deposition (MPECVD) system. Crystalline phase of ultra-nanodiamond grains with matrix phase of amorphous carbon and short range ordered graphite are encapsulated in nanowire shaped morphology. Film showed ultra-high wear resistance and frictional stability in micro-tribological contact conditions. The negligible wear of film at the beginning of the tribological contact was later transformed into the wearless regime for prolonged sliding cycles. Both surface roughness and high contact stress were the main reasons of wear at the beginning of sliding cycles. However, the interface gets smoothened due to continuous sliding, finally leaded to the wearless regime.

Expectations for ultra-high energy interactions

International Nuclear Information System (INIS)

Feynman, R.P.

1978-01-01

Strong interactions at ultra-high energies are discussed with emphasis on the hadrons produced in high energy collisions. Evidence is considered that quantum chromodynamics might be the right theory, and also some estimates are given of quantum chromodynamics asymptotic-freedom phenomena, the work under discussion being very preliminary. 6 references

Design of a 5.8 GHz Multi-Modulus Prescaler

OpenAIRE

Myklebust, Vidar

2006-01-01

A 64-modulus prescaler operating at 5.8 GHz has been designed in a 0.18 μm CMOS process. The prescaler uses a four-phase high-speed ÷4 circuit at the input, composed of two identical cascaded ÷2 circuits implemented in pseudo-NMOS. The high-speed divider is followed by a two-bits phase switching stage, which together with the input divider forms a ÷4/5/6/7 circuit. The phase switching stage is mostly implemented in complementary CMOS. After this follows four identical ÷2/3 cells with local fe...

Super Boiler: First Generation, Ultra-High Efficiency Firetube Boiler

Energy Technology Data Exchange (ETDEWEB)

None

2006-06-01

This factsheet describes a research project whose goal is to develop and demonstrate a first-generation ultra-high-efficiency, ultra-low emissions, compact gas-fired package boiler (Super Boiler), and formulate a long-range RD&D plan for advanced boiler technology out to the year 2020.

Fracture Mechanisms of Zirconium Diboride Ultra-High Temperature Ceramics under Pulse Loading

Science.gov (United States)

Skripnyak, Vladimir V.; Bragov, Anatolii M.; Skripnyak, Vladimir A.; Lomunov, Andrei K.; Skripnyak, Evgeniya G.; Vaganova, Irina K.

2015-06-01

Mechanisms of failure in ultra-high temperature ceramics (UHTC) based on zirconium diboride under pulse loading were studied experimentally by the method of SHPB and theoretically using the multiscale simulation method. The obtained experimental and numerical data are evidence of the quasi-brittle fracture character of nanostructured zirconium diboride ceramics under compression and tension at high strain rates and the room temperatures. Damage of nanostructured porous zirconium diboride -based UHTC can be formed under stress pulse amplitude below the Hugoniot elastic limit. Fracture of nanostructured ultra-high temperature ceramics under pulse and shock-wave loadings is provided by fast processes of intercrystalline brittle fracture and relatively slow processes of quasi-brittle failure via growth and coalescence of microcracks. A decrease of the shear strength can be caused by nano-voids clusters in vicinity of triple junctions between ceramic matrix grains and ultrafine-grained ceramics. This research was supported by grants from ``The Tomsk State University Academic D.I. Mendeleev Fund Program'' and also N. I. Lobachevski State University of Nizhny Novgorod (Grant of post graduate mobility).

Ultra high resolution tomography

Energy Technology Data Exchange (ETDEWEB)

Haddad, W.S.

1994-11-15

Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

75 FR 81284 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Draft...

Science.gov (United States)

2010-12-27

... Frequency and Ultra High Frequency Active SONAR Technology; Draft Programmatic Environmental Assessment and... Programmatic Environmental Assessment (PEA) for the Nationwide Use of High Frequency (HF) and Ultra High... potential impacts of each alternative on the human and natural environments. DATES: Comments and related...

Ultra low density biodegradable shape memory polymer foams with tunable physical properties

Science.gov (United States)

Singhal, Pooja; Wilson, Thomas S.; Cosgriff-Hernandez, Elizabeth; Maitland, Duncan J.

2017-12-12

Compositions and/or structures of degradable shape memory polymers (SMPs) ranging in form from neat/unfoamed to ultra low density materials of down to 0.005 g/cc density. These materials show controllable degradation rate, actuation temperature and breadth of transitions along with high modulus and excellent shape memory behavior. A method of m ly low density foams (up to 0.005 g/cc) via use of combined chemical and physical aking extreme blowing agents, where the physical blowing agents may be a single compound or mixtures of two or more compounds, and other related methods, including of using multiple co-blowing agents of successively higher boiling points in order to achieve a large range of densities for a fixed net chemical composition. Methods of optimization of the physical properties of the foams such as porosity, cell size and distribution, cell openness etc. of these materials, to further expand their uses and improve their performance.

Atomic beam formed by the vaporization of a high velocity pellet

International Nuclear Information System (INIS)

Foster, C.A.; Hendricks, C.D.

1974-01-01

A description of an atomic beam formed by vaporizing an electrostatically accelerated high velocity pellet is given. Uniformly sized droplets of neon will be formed by the mechanical disintegration of liquid jet and frozen by adiabatic vaporization in vacuum. The pellets produced will be charged and accelerated by contacting a needle held at high potential. The accelerated pellets will be vaporized forming a pulse of mono-energetic atoms. The advantages are that a wide range of energies will be possible. The beam will be mono-energetic. The beam is inheretly pulsed, allowing a detailed time of flight velocity distribution measurement. The beam will have a high instantaneous intensity. The beam will be able to operate into an ultra high vacuum chamber

Physico-chemical characterization of polyethylene of ultra high molecular weight modified with gamma irradiation and heavy ions

International Nuclear Information System (INIS)

Lagarde, M; Del Grosso, M; Fasce, D; Dommarco, R; Laino, S; Fasce, L.A

2012-01-01

The ultra high molecular weight polyethylene (UHMWPE) is a biomaterial widely used in total joint replacement. In this work, the effect of two different irradiation techniques on UHMWPE is analyzed. One technique involves gamma irradiation (γ) followed by a thermal treatment, thus modifying the material bulk. The other implies swift heavy ion irradiation (SHI), which have an effect only on the near surface layers. The surface nanomechanical properties are evaluated from depth sensing indentation experiments, while changes in crystallinity and chemical structure are determined by DSC and Raman spectroscopy. The results show that even when both techniques are able to improve the UHMWPE wear behavior, the effect on other mechanical properties and molecular structure modification is different. The γ irradiated sample exhibits lower crystallinity, hardness and modulus than the pristine UHMWPE, while the SHI irradiated sample exhibits higher crystallinity and enhanced mechanical properties than the later

Shock characterization of an ultra-high strength concrete

International Nuclear Information System (INIS)

Erzar, B.; Pontiroli, C.; Buzaud, E.

2016-01-01

Nowadays, the design of protective structures may imply ultra-high performance concretes. These materials present a compressive strength 5 times higher than standard concretes. However, few reliable data on the shock response of such materials are available in the literature. Thus, a characterization of an ultra-high strength concrete has been conducted by means of hydrostatic and triaxial tests in the quasi-static regime, and plate impact experiments for shock response. Data have been gathered up to 6 GPa and a simple modelling approach has been applied to get a reliable representation of the shock compression of this concrete. (authors)

Solutions for ultra-high speed optical wavelength conversion and clock recovery

DEFF Research Database (Denmark)

Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

2006-01-01

This paper reports on our recent advances in ultra-fast optical communications relying on ultra-short pulses densely stacked in ultra-high bit rate serial data signals at a single wavelength. The paper describes details in solutions for the network functionalities of wavelength conversion and clock...... recovery at bit rates up to 320 Gb/s...

The variation in elastic modulus throughout the compression of foam materials

International Nuclear Information System (INIS)

Sun, Yongle; Amirrasouli, B.; Razavi, S.B.; Li, Q.M.; Lowe, T.; Withers, P.J.

2016-01-01

We present a comprehensive experimental study of the variation in apparent unloading elastic modulus of polymer (largely elastic), aluminium (largely plastic) and fibre-reinforced cement (quasi-brittle) closed-cell foams throughout uniaxial compression. The results show a characteristic “zero-yield-stress” response and thereafter a rapid increase in unloading modulus during the supposedly “elastic” regime of the compressive stress–strain curve. The unloading modulus then falls with strain due to the localised cell-wall yielding or failure in the pre-collapse stage and the progressive cell crushing in the plateau stage, before rising sharply during the densification stage which is associated with global cell crushing and foam compaction. A finite element model based on the actual 3D cell structure of the aluminium foam imaged by X-ray computed tomography (CT) predicts an approximately linear fall of elastic modulus from zero strain until a band of collapsed cells forms. It shows that the subsequent gradual decrease in modulus is caused by the progressive collapse of cells. The elastic modulus rises sharply after the densification initiation strain has been reached. However, the elastic modulus is still well below that of the constituent material even when the “fully” dense state is approached. This work highlights the fact that the unloading elastic modulus varies throughout compression and challenges the idea that a constant elastic modulus can be applied in a homogenised foam model. It is suggested that the most representative value of elastic modulus may be obtained by extrapolating the measured unloading modulus to zero strain.

Sintering of ultra high molecular weight polyethylene

Indian Academy of Sciences (India)

Abstract. Ultra high molecular weight polyethylene (UHMWPE) is a high performance polymer having low coefficient of friction, good abrasion resistance, good chemical ... In this study, we report our results on compaction and sintering behaviour of two grades of UHMWPE with reference to the powder morphology, sintering ...

Experimental Young's modulus calculations

International Nuclear Information System (INIS)

Chen, Y.; Jayakumar, R.; Yu, K.

1994-01-01

Coil is a very important magnet component. The turn location and the coil size impact both mechanical and magnetic behavior of the magnet. The Young's modulus plays a significant role in determining the coil location and size. Therefore, Young's modulus study is essential in predicting both the analytical and practical magnet behavior. To determine the coil Young's modulus, an experiment has been conducted to measure azimuthal sizes of a half quadrant QSE101 inner coil under different loading. All measurements are made at four different positions along an 8-inch long inner coil. Each measurement is repeated three times to determine the reproducibility of the experiment. To ensure the reliability of this experiment, the same measurement is performed twice with a open-quotes dummy coil,close quotes which is made of G10 and has the same dimension and similar azimuthal Young's modulus as the inner coil. The difference between the G10 azimuthal Young's modulus calculated from the experiments and its known value from the manufacturer will be compared. Much effort has been extended in analyzing the experimental data to obtain a more reliable Young's modulus. Analysis methods include the error analysis method and the least square method

Ultra-low noise supercontinuum source for ultra-high resolution optical coherence tomography at 1300 nm

Science.gov (United States)

Gonzalo, I. B.; Maria, M.; Engelsholm, R. D.; Feuchter, T.; Leick, L.; Moselund, P. M.; Podoleanu, A.; Bang, O.

2018-02-01

Supercontinuum (SC) sources are of great interest for many applications due to their ultra-broad optical bandwidth, good beam quality and high power spectral density [1]. In particular, the high average power over large bandwidths makes SC light sources excellent candidates for ultra-high resolution optical coherence tomography (UHR-OCT) [2-5]. However, conventional SC sources suffer from high pulse-to-pulse intensity fluctuations as a result of the noise-sensitive nonlinear effects involved in the SC generation process [6-9]. This intensity noise from the SC source can limit the performance of OCT, resulting in a reduced signal-to-noise ratio (SNR) [10-12]. Much work has been done to reduce the noise of the SC sources for instance with fiber tapers [7,8] or increasing the repetition rate of the pump laser for averaging in the spectrometer [10,12]. An alternative approach is to use all-normal dispersion (ANDi) fibers [13,14] to generate SC light from well-known coherent nonlinear processes [15-17]. In fact, reduction of SC noise using ANDi fibers compared to anomalous dispersion SC pumped by sub-picosecond pulses has been recently demonstrated [18], but a cladding mode was used to stabilize the ANDi SC. In this work, we characterize the noise performance of a femtosecond pumped ANDi based SC and a commercial SC source in an UHR-OCT system at 1300 nm. We show that the ANDi based SC presents exceptional noise properties compared to a commercial source. An improvement of 5 dB in SNR is measured in the UHR-OCT system, and the noise behavior resembles that of a superluminiscent diode. This preliminary study is a step forward towards development of an ultra-low noise SC source at 1300 nm for ultra-high resolution OCT.

A task specific uncertainty analysis method for least-squares-based form characterization of ultra-precision freeform surfaces

International Nuclear Information System (INIS)

Ren, M J; Cheung, C F; Kong, L B

2012-01-01

In the measurement of ultra-precision freeform surfaces, least-squares-based form characterization methods are widely used to evaluate the form error of the measured surfaces. Although many methodologies have been proposed in recent years to improve the efficiency of the characterization process, relatively little research has been conducted on the analysis of associated uncertainty in the characterization results which may result from those characterization methods being used. As a result, this paper presents a task specific uncertainty analysis method with application in the least-squares-based form characterization of ultra-precision freeform surfaces. That is, the associated uncertainty in the form characterization results is estimated when the measured data are extracted from a specific surface with specific sampling strategy. Three factors are considered in this study which include measurement error, surface form error and sample size. The task specific uncertainty analysis method has been evaluated through a series of experiments. The results show that the task specific uncertainty analysis method can effectively estimate the uncertainty of the form characterization results for a specific freeform surface measurement

Fast, High Resolution, and Wide Modulus Range Nanomechanical Mapping with Bimodal Tapping Mode.

Science.gov (United States)

Kocun, Marta; Labuda, Aleksander; Meinhold, Waiman; Revenko, Irène; Proksch, Roger

2017-10-24

Tapping mode atomic force microscopy (AFM), also known as amplitude modulated (AM) or AC mode, is a proven, reliable, and gentle imaging mode with widespread applications. Over the several decades that tapping mode has been in use, quantification of tip-sample mechanical properties such as stiffness has remained elusive. Bimodal tapping mode keeps the advantages of single-frequency tapping mode while extending the technique by driving and measuring an additional resonant mode of the cantilever. The simultaneously measured observables of this additional resonance provide the additional information necessary to extract quantitative nanomechanical information about the tip-sample mechanics. Specifically, driving the higher cantilever resonance in a frequency modulated (FM) mode allows direct measurement of the tip-sample interaction stiffness and, with appropriate modeling, the set point-independent local elastic modulus. Here we discuss the advantages of bimodal tapping, coined AM-FM imaging, for modulus mapping. Results are presented for samples over a wide modulus range, from a compliant gel (∼100 MPa) to stiff materials (∼100 GPa), with the same type of cantilever. We also show high-resolution (subnanometer) stiffness mapping of individual molecules in semicrystalline polymers and of DNA in fluid. Combined with the ability to remain quantitative even at line scan rates of nearly 40 Hz, the results demonstrate the versatility of AM-FM imaging for nanomechanical characterization in a wide range of applications.

All-electron study of ultra-incompressible superhard material ReB2: structural and electronic properties

International Nuclear Information System (INIS)

Yan-Ling, Li; Guo-Hua, Zhong; Zhi, Zeng

2009-01-01

This paper investigates the structural and electronic properties of rhenium diboride by first-principles calculation based on density functional theory. The obtained results show that the calculated equilibrium structural parameters of ReB 2 are in excellent agreement with experimental values. The calculated bulk modulus is 361 GPa in comparison with that of the experiment. The compressibility of ReB 2 is lower than that of well-known OsB 2 . The anisotropy of the bulk modulus is confirmed by c/a ratio as a function of pressure curve and the bulk modulus along different axes along with the electron density distribution. The high bulk modulus is attributed to the strong covalent bond between Re-d and B-p orbitals and the wider pseudogap near the Fermi level, which could be deduced from both electron charge density distribution and density of states. The band structure and density of states of ReB 2 exhibit that this material presents metallic behavior. The good metallicity and ultra-incompressibility of ReB 2 might suggest its potential application as pressure-proof conductors. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

OsB 2 and RuB 2, ultra-incompressible, hard materials: First-principles electronic structure calculations

Science.gov (United States)

Chiodo, S.; Gotsis, H. J.; Russo, N.; Sicilia, E.

2006-07-01

Recently it has been reported that osmium diboride has an unusually large bulk modulus combined with high hardness, and consequently is a most interesting candidate as an ultra-incompressible and hard material. The electronic and structural properties of the transition metal diborides OsB 2 and RuB 2 have been calculated within the local density approximation (LDA). It is shown that the high hardness is the result of covalent bonding between transition metal d states and boron p states in the orthorhombic structure.

Improved integration of ultra-thin high-k dielectrics in few-layer MoS2 FET by remote forming gas plasma pretreatment

Science.gov (United States)

Wang, Xiao; Zhang, Tian-Bao; Yang, Wen; Zhu, Hao; Chen, Lin; Sun, Qing-Qing; Zhang, David Wei

2017-01-01

The effective and high-quality integration of high-k dielectrics on two-dimensional (2D) crystals is essential to the device structure engineering and performance improvement of field-effect transistor (FET) based on the 2D semiconductors. We report a 2D MoS2 transistor with ultra-thin Al2O3 top-gate dielectric (6.1 nm) and extremely low leakage current. Remote forming gas plasma pretreatment was carried out prior to the atomic layer deposition, providing nucleation sites with the physically adsorbed ions on the MoS2 surface. The top gate MoS2 FET exhibited excellent electrical performance, including high on/off current ratio over 109, subthreshold swing of 85 mV/decade and field-effect mobility of 45.03 cm2/V s. Top gate leakage current less than 0.08 pA/μm2 at 4 MV/cm has been obtained, which is the smallest compared with the reported top-gated MoS2 transistors. Such an optimized integration of high-k dielectric in 2D semiconductor FET with enhanced performance is very attractive, and it paves the way towards the realization of more advanced 2D nanoelectronic devices and integrated circuits.

Young's modulus of a copper-stabilized niobium-titanium superconductive wire

International Nuclear Information System (INIS)

Ledbetter, H.M.; Moulder, J.C.; Austin, M.W.

1980-01-01

Young's modulus was determined for a 0.6-mm-dia niobium-titanium superconductive wire. Two methods were used: continuous-wave-resonance and laser-pulse-excitation. Young's moduli were also determined for the components - copper and Nb-Ti - in both wire and bulk forms. Some mechanical-deformation effects on Young's modulus were also measured. From the component' elastic moduli, that of the composite was predicted accurately by a simple rule-of-mixtures relationship

Weld Metallurgy and Mechanical Properties of High Manganese Ultra-high Strength Steel Dissimilar Welds

Science.gov (United States)

Dahmen, Martin; Lindner, Stefan; Monfort, Damien; Petring, Dirk

The increasing demand for ultra-high strength steels in vehicle manufacturing leads to the application of new alloys. This poses a challenge on joining especially by fusion welding. A stainless high manganese steel sheet with excellent strength and deformation properties stands in the centre of the development. Similar and dissimilar welds with a metastable austenitic steel and a hot formed martensitic stainless steel were performed. An investigation of the mixing effects on the local microstructure and the hardness delivers the metallurgical features of the welds. Despite of carbon contents above 0.4 wt.% none of the welds have shown cracks. Mechanical properties drawn from tensile tests deliver high breaking forces enabling a high stiffness of the joints. The results show the potential for the application of laser beam welding for joining in assembly of structural parts.

Evaluation of linear polymerization shrinkage, flexural strength and modulus of elasticity of dental composites

Directory of Open Access Journals (Sweden)

Gabriela Queiroz de Melo Monteiro

2010-03-01

Full Text Available Linear polymerization shrinkage (LPS, flexural strength (FS and modulus of elasticity (ME of 7 dental composites (Filtek Z350™, Filtek Z250™/3M ESPE; Grandio™, Polofil Supra™/VOCO; TPH Spectrum™, TPH3™, Esthet-X™/Denstply were measured. For the measurement of LPS, composites were applied to a cylindrical metallic mold and polymerized (n = 8. The gap formed at the resin/mold interface was observed using scanning electron microscopy (1500×. For FS and ME, specimens were prepared according to the ISO 4049 specifications (n = 10. Statistical analysis of the data was performed with one-way ANOVA and the Tukey test. TPH Spectrum presented significantly higher LPS values (29.45 µm. Grandio had significantly higher mean values for FS (141.07 MPa and ME (13.91 GPa. The relationship between modulus of elasticity and polymerization shrinkage is the main challenge for maintenance of the adhesive interface, thus composites presenting high shrinkage values, associated with a high modulus of elasticity tend to disrupt the adhesive interface under polymerization.

Ultra-high Efficiency DC-DC Converter using GaN Devices

DEFF Research Database (Denmark)

Ramachandran, Rakesh

2016-01-01

properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...

Ultra-high energy cosmic rays and prompt TeV gamma rays from ...

Indian Academy of Sciences (India)

physics pp. 789-792. Ultra-high energy cosmic rays and prompt. TeV gamma rays from gamma ray bursts ... The origin of the observed ultra-high energy cosmic ray (UHECR) events with ... are proton and electron rest mass, respectively.

Scaling violations at ultra-high energies

International Nuclear Information System (INIS)

Tung, W.K.

1979-01-01

The paper discusses some of the features of high energy lepton-hadron scattering, including the observed (Bjorken) scaling behavior. The cross-sections where all hadron final states are summed over, are examined and the general formulas for the differential cross-section are examined. The subjects of scaling, breaking and phenomenological consequences are studied, and a list of what ultra-high energy neutrino physics can teach QCD is given

Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres

Directory of Open Access Journals (Sweden)

Luiz Claudio Pardini

2002-10-01

Full Text Available Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus. Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i ASTM D 3379M, and (ii interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.

Development of Dynamic Compaction Technology for Ultra High Strength Powder Products

International Nuclear Information System (INIS)

Rhee, Chang Kyu; Lee, M. K.; Uhm, Y. R.; Park, J. J.; Lee, J. G.; Ivanov, V. V.; Hong, S. J.

2007-04-01

A synthesis of ultra fine powder and its compaction have been considered as a new generation and high value added technology in various industrial fields such as automobile, machine tool, electronic chip, sensor and catalyst because of its special characteristics of high toughness, strength and wear resistance which are not shown in conventional process. In this study, ultra hard and fine powders, such as Fe-Si, CuNi and Al 2 O 3 , have been fabricated by the pulsed wire evaporation (PWE) method and mechanical alloying (MA) method. In addition, with ultra hard and fine powders, the magnetic core, diamond tool and water jet nozzle with high density were made by a uniaxial dynamic compaction for the purpose of the real industrial application

Ultra high-energy cosmic ray composition

International Nuclear Information System (INIS)

Longley, N.P.

1993-01-01

The Soudan 2 surface-underground cosmic ray experiment can simultaneously measure surface shower size, underground muon multiplicity, and underground muon separation for ultra high energy cosmic ray showers. These measurements are sensitive to the primary composition. Analysis for energies from 10 1 to 10 4 TeV favors a light flux consisting of predominantly H and He nuclei

Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

DEFF Research Database (Denmark)

Hansen, Lars Pilegaard

1995-01-01

Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bar...... and the fire resistance. Such a fibre reinforced ultra high-strength material has been used to develop a simple joint solution between slab elements in a column - slab building system....

Ultra high performance concrete made with rice husk ash for reduced autogenous shrinkage

NARCIS (Netherlands)

Van Breugel, K.; Van Tuan, N.

2014-01-01

Ultra High Strength Concrete (UHPC) is generally made with low w/c mixtures and by adding silica fume. Low w/c mixtures, however, exhibit high autogenous shrinkage, while a high amount of silica fume increases the price of these mixtures. For designing ultra high strength mixtures with low

Ultra-high field MRI: Advancing systems neuroscience towards mesoscopic human brain function

NARCIS (Netherlands)

Dumoulin, Serge O; Fracasso, A.; Van der Zwaag, W.; Siero, Jeroen C W; Petridou, Natalia

2018-01-01

Human MRI scanners at ultra-high magnetic field strengths of 7 T and higher are increasingly available to the neuroscience community. A key advantage brought by ultra-high field MRI is the possibility to increase the spatial resolution at which data is acquired, with little reduction in image

Phase and Microstructural Correlation of Spark Plasma Sintered HfB2-ZrB2 Based Ultra-High Temperature Ceramic Composites

Directory of Open Access Journals (Sweden)

Ambreen Nisar

2017-07-01

Full Text Available The refractory diborides (HfB2 and ZrB2 are considered as promising ultra-high temperature ceramic (UHTCs where low damage tolerance limits their application for the thermal protection system in re-entry vehicles. In this regard, SiC and CNT have been synergistically added as the sintering aids and toughening agents in the spark plasma sintered (SPS HfB2-ZrB2 system. Herein, a novel equimolar composition of HfB2 and ZrB2 has shown to form a solid-solution which then allows compositional tailoring of mechanical properties (such as hardness, elastic modulus, and fracture toughness. The hardness of the processed composite is higher than the individual phase hardness up to 1.5 times, insinuating the synergy of SiC and CNT reinforcement in HfB2-ZrB2 composites. The enhanced fracture toughness of CNT reinforced composite (up to a 196% increment surpassing that of the parent materials (ZrB2/HfB2-SiC is attributed to the synergy of solid solution formation and enhanced densification (~99.5%. In addition, the reduction in the analytically quantified interfacial residual tensile stress with SiC and CNT reinforcements contribute to the enhancement in the fracture toughness of HfB2-ZrB2-SiC-CNT composites, mandatory for aerospace applications.

A Delay Time Measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) for a High Temperature Experiment

International Nuclear Information System (INIS)

Koo, Kil Mo; Kim, Sang Baik

2010-01-01

The temperature measurement of very high temperature core melt is of importance in a high temperature as the molten pool experiment in which gap formation between core melt and the reactor lower head, and the effect of the gap on thermal behavior are to be measured. The existing temperature measurement techniques have some problems, which the thermocouple, one of the contact methods, is restricted to under 2000 .deg. C, and the infrared thermometry, one of the non-contact methods, is unable to measure an internal temperature and very sensitive to the interference from reacted gases. In order to solve these problems, the delay time technique of ultrasonic wavelets due to high temperature has two sorts of stage. As a first stage, a delay time measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) is suggested. As a second stage, a molten material temperature was measured up to 2300 .deg. C. Also, the optimization design of the UTS (ultrasonic temperature sensor) with persistence at the high temperature was suggested in this paper. And the utilization of the theory suggested in this paper and the efficiency of the developed system are performed by special equipment and some experiments supported by KRISS (Korea Research Institute of Standard and Science)

Estimation Of Young’s Modulus Of Elesticity By The Form Finding Of Grid Shell Structures By The Dynamic Relaxation Method

Directory of Open Access Journals (Sweden)

Grančičová Ivana

2015-12-01

Full Text Available The paper is basically focused on the process of form finding by the dynamic relaxation method (DRM with the aid of computational tools that enable us to make many calculations with different inputs. There are many important input values with a significant impact on the course of the calculations and the resulting displacement of a structure. One of these values is Young’s modulus of elasticity. This value has a considerable impact on the final displacement of a grid shell structure and the resulting internal forces.

Ultra-high pressure water jet: Baseline report

International Nuclear Information System (INIS)

1997-01-01

The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems

All-optical ultra-high-speed OFDM to Nyquist-WDM conversion

DEFF Research Database (Denmark)

Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

2015-01-01

We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER <10−9 performance for all channels.......We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER

Nanocomposites of TiO2/cyanoethylated cellulose with ultra high dielectric constants

International Nuclear Information System (INIS)

Madusanka, Nadeesh; Shivareddy, Sai G; Hiralal, Pritesh; Choi, Youngjin; Amaratunga, Gehan A J; Eddleston, Mark D; Oliver, Rachel A

2016-01-01

A novel dielectric nanocomposite containing a high permittivity polymer, cyanoethylated cellulose (CRS) and TiO 2 nanoparticles was successfully prepared with different weight percentages (10%, 20% and 30%) of TiO 2 . The intermolecular interactions and morphology within the polymer nanocomposites were analysed. TiO 2 /CRS nanofilms on SiO 2 /Si wafers were used to form metal–insulator–metal type capacitors. Capacitances and loss factors in the frequency range of 1 kHz–1 MHz were measured. At 1 kHz CRS-TiO 2 nanocomposites exhibited ultra high dielectric constants of 118, 176 and 207 for nanocomposites with 10%, 20% and 30% weight of TiO 2 respectively, significantly higher than reported values of pure CRS (21), TiO 2 (41) and other dielectric polymer-TiO 2 nanocomposite films. Furthermore, all three CRS-TiO 2 nanocomposites show a loss factor <0.3 at 1 kHz and low leakage current densities (10 −6 –10 −7 A cm −2 ). Leakage was studied using conductive atomic force microscopy and it was observed that the leakage is associated with TiO 2 nanoparticles embedded in the CRS polymer matrix. A new class of ultra high dielectric constant hybrids using nanoscale inorganic dielectrics dispersed in a high permittivity polymer suitable for energy management applications is reported. (paper)

ULTRA-SHARP nonoscillatory convection schemes for high-speed steady multidimensional flow

Science.gov (United States)

Leonard, B. P.; Mokhtari, Simin

1990-01-01

For convection-dominated flows, classical second-order methods are notoriously oscillatory and often unstable. For this reason, many computational fluid dynamicists have adopted various forms of (inherently stable) first-order upwinding over the past few decades. Although it is now well known that first-order convection schemes suffer from serious inaccuracies attributable to artificial viscosity or numerical diffusion under high convection conditions, these methods continue to enjoy widespread popularity for numerical heat transfer calculations, apparently due to a perceived lack of viable high accuracy alternatives. But alternatives are available. For example, nonoscillatory methods used in gasdynamics, including currently popular TVD schemes, can be easily adapted to multidimensional incompressible flow and convective transport. This, in itself, would be a major advance for numerical convective heat transfer, for example. But, as is shown, second-order TVD schemes form only a small, overly restrictive, subclass of a much more universal, and extremely simple, nonoscillatory flux-limiting strategy which can be applied to convection schemes of arbitrarily high order accuracy, while requiring only a simple tridiagonal ADI line-solver, as used in the majority of general purpose iterative codes for incompressible flow and numerical heat transfer. The new universal limiter and associated solution procedures form the so-called ULTRA-SHARP alternative for high resolution nonoscillatory multidimensional steady state high speed convective modelling.

Ultra Fast, High Rep Rate, High Voltage Spark Gap Pulser

Science.gov (United States)

1995-07-01

current rise time. The spark gap was designed to have a coaxial geometry reducing its inductance. Provisions were made to pass flowing gas between the...ULTRA FAST, HIGH REP RATE, HIGH VOLTAGE SPARK GAP PULSER Robert A. Pastore Jr., Lawrence E. Kingsley, Kevin Fonda, Erik Lenzing Electrophysics and...Modeling Branch AMSRL-PS-EA Tel.: (908)-532-0271 FAX: (908)-542-3348 U.S. Army Research Laboratory Physical Sciences Directorate Ft. Monmouth

Fast and sensitive analysis of beta blockers by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

Science.gov (United States)

Tomková, Jana; Ondra, Peter; Kocianová, Eva; Václavík, Jan

2017-07-01

This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid-liquid extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. After liquid-liquid extraction, beta blockers were separated on a reverse-phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 μm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients. Copyright © 2016 John Wiley & Sons, Ltd.

Status of Ultra-High Energy Cosmic Rays

CERN Multimedia

CERN. Geneva

2015-01-01

I will review the recent results on Ultra-High energy cosmic rays obtained by the Auger and Telescope Array Observatories, and discuss some of the Astrophysical scenarios that could account for them, a connection with LHC results  as well as the possible connections to neutrino and gamma ray observations.

Imaging Frontostriatal Function in Ultra-High-Risk, Early, and Chronic Schizophrenia During Executive Processing

Science.gov (United States)

Morey, Rajendra A.; Inan, Seniha; Mitchell, Teresa V.; Perkins, Diana O.; Lieberman, Jeffrey A.; Belger, Aysenil

2009-01-01

Context Individuals experiencing prodromal symptoms of schizophrenia (ultra-high-risk group) demonstrate impaired performance on tasks of executive function, attention, and working memory. The neurobiological underpinnings of such executive deficits in ultra-high-risk individuals remains unclear. Objective We assessed frontal and striatal functions during a visual oddball continuous performance task, in ultra-high-risk, early, and chronic schizophrenic patients with the use of functional magnetic resonance imaging. Design Cross-sectional case-control design. Setting Community; outpatient clinic. Patients Fifty-two individuals (control, n = 16; ultra-high risk, n = 10; early, n = 15; chronic, n = 11) from a referred clinical sample and age- and sex-matched control volunteers underwent scanning. Main Outcome Measures Percentage of active voxels and percentage signal change calculated for the anterior cingulate gyrus (ACG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), basal ganglia, and thalamus. Performance on the visual oddball task was measured with percentage of hits and d′ (a measure based on the hit rate and the false-alarm rate). Results The ultra-high-risk group showed significantly smaller differential activation between task-relevant and task-irrelevant stimuli in the frontal regions (ACG, IFG, MFG) than the control group. Frontostriatal activation associated with target stimuli in the early and chronic groups was significantly lower than the control group, while the ultra-high-risk group showed a trend toward the early group. Conclusions Our findings suggest that prefrontal function begins to decline before the onset of syndromally defined illness and hence may represent a vulnerability marker in assessing the risk of developing psychotic disorders among ultra-high-risk individuals. PMID:15753238

High rate response of ultra-high-performance fiber-reinforced concretes under direct tension

Energy Technology Data Exchange (ETDEWEB)

Tran, Ngoc Thanh [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Tran, Tuan Kiet [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Department of Civil Engineering and Applied Mechanics, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan, Thu Duc District, Ho Chi Minh City (Viet Nam); Kim, Dong Joo, E-mail: djkim75@sejong.ac.kr [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of)

2015-03-15

The tensile response of ultra-high-performance fiber-reinforced concretes (UHPFRCs) at high strain rates (5–24 s{sup −} {sup 1}) was investigated. Three types of steel fibers, including twisted, long and short smooth steel fibers, were added by 1.5% volume content in an ultra high performance concrete (UHPC) with a compressive strength of 180 MPa. Two different cross sections, 25 × 25 and 25 × 50 mm{sup 2}, of tensile specimens were used to investigate the effect of the cross section area on the measured tensile response of UHPFRCs. Although all the three fibers generated strain hardening behavior even at high strain rates, long smooth fibers produced the highest tensile resistance at high rates whereas twisted fiber did at static rate. The breakages of twisted fibers were observed from the specimens tested at high strain rates unlike smooth steel fibers. The tensile behavior of UHPFRCs at high strain rates was clearly influenced by the specimen size, especially in post-cracking strength.

Soliton-based ultra-high speed optical communications

Indian Academy of Sciences (India)

All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

Ultra high energy cosmic rays and magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Stanev, Todor; Engel, Ralph; Alvarez-Muniz, Jaime; Seckel, David

2002-07-01

We follow the propagation of ultra high energy protons in the presence of random and regular magnetic fields and discuss some of the changes in the angular and energy distributions of these particles introduced by the scattering in the magnetic fields.

Ultra high energy cosmic rays and magnetic fields

International Nuclear Information System (INIS)

Stanev, Todor; Engel, Ralph; Alvarez-Muniz, Jaime; Seckel, David

2002-01-01

We follow the propagation of ultra high energy protons in the presence of random and regular magnetic fields and discuss some of the changes in the angular and energy distributions of these particles introduced by the scattering in the magnetic fields

Specific features of high-cycle and ultra-high-cycle fatigue

Czech Academy of Sciences Publication Activity Database

Lukáš, Petr; Kunz, Ludvík

2002-01-01

Roč. 25, - (2002), s. 747-753 ISSN 8756-758X R&D Projects: GA AV ČR KSK1010104; GA AV ČR IAA2041002 Institutional research plan: CEZ:AV0Z2041904 Keywords : ultra high cycle fatigue * fatigue mechanisms * cyclic plastic deformation Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.701, year: 2002

Laser beam welding of new ultra-high strength and supra-ductile steels

OpenAIRE

Dahmen, M.

2015-01-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting t...

Functional aluminum alloys for ultra high vacuum use

International Nuclear Information System (INIS)

Kato, Yutaka; Tsukamoto, Kenji; Isoyama, Eizo

1985-01-01

Ultra high vacuum systems made of aluminum alloys are actively developed. The reasons for using aluminum alloys are low residual radioactivity, light weight, good machinability, good thermal conductivity, non-magnetism. The important function required for ultra high vacuum materials is low outgassing rate, but surface gas on ordinary aluminum is much. Then the research on aluminum surface structure with low outgassing rate has been made and the special extrusion method, that is, extrusion method with the conditions of preventing air from entering inside of pipe and of taking in mixture gas of Ar + O 2 , was developed. 6063 alloy obtained by special extrusion method showed low outgassing rate (2 x 10 -13 Torr. 1/s. cm 2 ) by only 150 deg C, 24 h baking. For the future it will be important to develop aluminum alloys with low dynamic outgassing rate as well as low static outgassing rate. (author)

The study of stiffness modulus values for AC-WC pavement

Science.gov (United States)

Lubis, AS; Muis, Z. A.; Iskandar, T. D.

2018-02-01

One of the parameters of the asphalt mixture in order for the strength and durability to be achieved as required is the stress-and-strain showing the stiffness of a material. Stiffness modulus is a very necessary factor that will affect the performance of asphalt pavements. If the stiffness modulus value decreases there will be a cause of aging asphalt pavement crack easily when receiving a heavy load. The high stiffness modulus asphalt concrete causes more stiff and resistant to bending. The stiffness modulus value of an asphalt mixture material can be obtained from the theoretical (indirect methods) and laboratory test results (direct methods). For the indirect methods used Brown & Brunton method, and Shell Bitumen method; while for the direct methods used the UMATTA tool. This study aims to determine stiffness modulus values for AC-WC pavement. The tests were conducted in laboratory that used 3 methods, i.e. Brown & Brunton Method, Shell Bitumen Method and Marshall Test as a substitute tool for the UMATTA tool. Hotmix asphalt made from type AC-WC with pen 60/70 using a mixture of optimum bitumen content was 5.84% with a standard temperature variation was 60°C and several variations of temperature that were 30, 40, 50, 70 and 80°C. The stiffness modulus value results obtained from Brown & Brunton Method, Shell Bitumen Method and Marshall Test which were 1374,93 Mpa, 235,45 Mpa dan 254,96 Mpa. The stiffness modulus value decreases with increasing temperature of the concrete asphalt. The stiffness modulus value from the Bitumen Shell method and the Marshall Test has a relatively similar value.The stiffness modulus value from the Brown & Brunton method is greater than the Bitumen Shell method and the Marshall Test, but can not measure the stiffness modulus value at temperature above 80°C.

Properties of polymethyl methacrylate-based nanocomposites: Reinforced with ultra-long chitin nanofiber extracted from crab shells

International Nuclear Information System (INIS)

Chen, Chuchu; Li, Dagang; Hu, Qinqin; Wang, Ru

2014-01-01

Highlights: • Using waste crab shells to develop high-performance composites by simple method. • Combining the anatomic analysis of crab shell with the design of composite. • Introducing a 4-step all-mechanical treatment to prepare ultra-long chitin fiber. • Incorporation of chitin nanofiber improves properties of PMMA/Chitin composite. - Abstract: Ultra-long chitin nanofibers were incorporated into polymethyl methacrylate (PMMA) resin to prepared PMMA/Chitin nanocomposites with improved properties. Transmission electron microscopy (TEM) images showed that through the introduced 4-step all-mechanical treatment, the average aspect ratio of the obtained chitin fiber was up to 1000 with the length at dozens of micron range. Due to the laminated structure formed by “layer-by-layer” effect, tensile strength and Young’s modulus of the prepared composite were significantly enhanced after the filling of chitin nanofibers, as compared with neat PMMA. Light transmittance test indicated that increasing the fiber content causes little light scattering because the nano-scalar network which is smaller enough than the visible wavelength could well preserve the original transparency of PMMA. Furthermore, chitin nanofiber film with extremely low thermal expansion improved the thermal stability of PMMA in a great degree. This could lead to various commercial applications including flexible electronic printing, organic thin-film photovoltaic devices, and is a significantly environmental move towards the sustainable utilization of marine-river crab shell wastes

Laser beam welding of new ultra-high strength and supra-ductile steels

Science.gov (United States)

Dahmen, Martin

2015-03-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

The Time Lens Concept Applied to Ultra-High-Speed OTDM Signal Processing

DEFF Research Database (Denmark)

Clausen, Anders; Palushani, Evarist; Mulvad, Hans Christian Hansen

2013-01-01

This survey paper presents some of the applications where the versatile time-lens concept successfully can be applied to ultra-high-speed serial systems by offering expected needed functionalities for future optical communication networks.......This survey paper presents some of the applications where the versatile time-lens concept successfully can be applied to ultra-high-speed serial systems by offering expected needed functionalities for future optical communication networks....

Resilient modulus characteristics of soil subgrade with geopolymer additive in peat

Science.gov (United States)

Zain, Nasuhi; Hadiwardoyo, Sigit Pranowo; Rahayu, Wiwik

2017-06-01

Resilient modulus characteristics of peat soil are generally very low with high potential of deformation and low bearing capacity. The efforts to improve the peat subgrade resilient modulus characteristics is required, one among them is by adding the geopolymer additive. Geopolymer was made as an alternative to replace portland cement binder in the concrete mix in order to promote environmentally friendly, low shrinkage value, low creep value, and fire resistant material. The use of geopolymer to improve the mechanical properties of peat as a road construction subgrade, hence it becomes important to identify the effect of geopolymer addition on the resilient modulus characteristics of peat soil. This study investigated the addition of 0% - 20% geopolymer content on peat soil derived from Ogan Komering Ilir, South Sumatera Province. Resilient modulus measurement was performed by using cyclic triaxial test to determine the resilience modulus model as a function of deviator stresses and radial stresses. The test results showed that an increase in radial stresses did not necessarily lead to an increase in modulus resilient, and on the contrary, an increase in deviator stresses led to a decrease in modulus resilient. The addition of geopolymer in peat soil provided an insignificant effect on the increase of resilient modulus value.

Floating liquid bridge tensile behavior: Electric-field-induced Young's modulus measurements

Science.gov (United States)

Teschke, Omar; Mendez Soares, David; Valente Filho, Juracyr Ferraz

2013-12-01

A floating bridge is formed spontaneously when high voltage is applied to polar fluids in two capillary tubes that were in contact and then separated. This bridge bends under its own weight, and its bending profile was used to calculate its Young's modulus. For electric field intensities of ˜106 V/m, water bridges exhibit viscoelastic behavior, with Young's moduli of ˜24 MPa; dimethylsulfoxide (DMSO) bridges exhibited Young's moduli of ˜60 kPa. The scheme devised to measure the voltage drop across the water bridge for high voltages applied between the electrodes shows that the bulk water resistance decreases with increasing voltage.

Ultra high performance liquid chromatography of seized drugs

NARCIS (Netherlands)

Lurie, I.S.

2010-01-01

The primary goal of this thesis is to investigate the use of ultra high performance liquid chromatography (UHPLC) for the analysis of seized drugs. This goal was largely achieved and significant progress was made in achieving improved separation and detection of drugs of forensic interest.

Arc Shape Characteristics with Ultra-High-Frequency Pulsed Arc Welding

Directory of Open Access Journals (Sweden)

Mingxuan Yang

2017-01-01

Full Text Available Arc plasma possesses a constriction phenomenon with a pulsed current. The constriction is created by the Lorentz force, the radial electromagnetic force during arc welding, which determines the energy distribution of the arc plasma. Welding experiments were carried out with ultra-high-frequency pulsed arc welding (UHFP-AW. Ultra-high-speed camera observations were produced for arc surveillance. Hue-saturation-intensity (HSI image analysis was used to distinguish the regions of the arc plasma that represented the heat energy distribution. The measurement of arc regions indicated that, with an ultra-high-frequency pulsed arc, the constriction was not only within the decreased arc geometry, but also within the constricted arc core region. This can be checked by the ratio of the core region to the total area. The arc core region expanded significantly at 40 kHz at 60 A. A current level of 80 A caused a decrease in the total region of the arc. Meanwhile, the ratio of the core region to the total increased. It can be concluded that arc constriction depends on the increased area of the core region with the pulsed current (>20 kHz.

Manganese oxide micro-supercapacitors with ultra-high areal capacitance

Science.gov (United States)

Wang, Xu; Myers, Benjamin D.; Yan, Jian; Shekhawat, Gajendra; Dravid, Vinayak; Lee, Pooi See

2013-05-01

A symmetric micro-supercapacitor is constructed by electrochemically depositing manganese oxide onto micro-patterned current collectors. High surface-to-volume ratio of manganese oxide and short diffusion distance between electrodes give an ultra-high areal capacitance of 56.3 mF cm-2 at a current density of 27.2 μA cm-2.A symmetric micro-supercapacitor is constructed by electrochemically depositing manganese oxide onto micro-patterned current collectors. High surface-to-volume ratio of manganese oxide and short diffusion distance between electrodes give an ultra-high areal capacitance of 56.3 mF cm-2 at a current density of 27.2 μA cm-2. Electronic supplementary information (ESI) available: Experimental procedures; optical images of micro-supercapacitors; areal capacitances of samples M-0.3C, M-0.6C and M-0.9C; illustration of interdigital finger electrodes; Nyquist plot of Co(OH)2 deposited on micro-electrodes. See DOI: 10.1039/c3nr00210a

Elastic modulus, thermal expansion, and specific heat at a phase transition

International Nuclear Information System (INIS)

Testardi, L.R.

1975-01-01

The interrelation of the elastic modulus, thermal-expansion coefficient, and specific heat of a transformed phase relative to the untransformed phase is calculated assuming a particular but useful form of the thermodynamic potential. For second-order phase transitions where this potential applies, measurements of modulus, expansion, and specific heat can yield the general (longitudinal as well as shear) first- and second-order stress (or strain) dependences of the transition temperature and of the order parameter at absolute zero. An exemplary application to one type of phase transition is given

Ultra-High-Energy Cosmic Rays

CERN Document Server

Dova, M.T.

2015-05-22

The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 10 17 eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written version of a series of lectures devoted to UHECR at the 2013 CERN-Latin-American School of High-Energy Physics. We present anintroduction to acceleration mechanisms of charged particles to the highest energies in astrophysical objects, their propagation from the sources to Earth, and the experimental techniques for their detection. We also discuss some of the relevant observational results from Telescope Array and Pierre Auger Observatory. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

Variation of the Young's modulus with plastic strain applying to elastoplastic software

International Nuclear Information System (INIS)

Morestin, F.; Boivin, M.

1993-01-01

Work hardening of steel involves modifications of the elastic properties of the material, for instance, an increase of its yield stress. It may be also the cause of an appreciable decrease of the Young's modulus. This property decreases as plastic strain increases. Experiments with a microcomputer controlled tensile test machine indicated that diminution could reach more than 10% of the initial value, after only 5% of plastic strain. In spite of this fact, lots of elastoplastic softwares don't combine the decrease of the Young's modulus with plastification though it may involve obvious differences among results. As an application we have developed a software which computes the deformation of steel sheet in press forming, after springback. This software takes into account the decrease of the Young's modulus and its results are very close to experimental values. Quite arbitrarily, we noticed a recovery of the Young's modulus of plastified specimens after few days but not for all steels tested. (author)

Relationship between low-temperature boson heat capacity peak and high-temperature shear modulus relaxation in a metallic glass

International Nuclear Information System (INIS)

Vasiliev, A. N.; Voloshok, T. N.; Granato, A. V.; Joncich, D. M.; Mitrofanov, Yu. P.; Khonik, V. A.

2009-01-01

Low-temperature (2 K≤T≤350 K) heat capacity and room-temperature shear modulus measurements (ν=1.4 MHz) have been performed on bulk Pd 41.25 Cu 41.25 P 17.5 in the initial glassy, relaxed glassy, and crystallized states. It has been found that the height of the low-temperature Boson heat capacity peak strongly correlates with the changes in the shear modulus upon high-temperature annealing. It is this behavior that was earlier predicted by the interstitialcy theory, according to which dumbbell interstitialcy defects are responsible for a number of thermodynamic and kinetic properties of crystalline, (supercooled) liquid, and solid glassy states.

Ultra-wideband high-efficiency reflective linear-to-circular polarization converter based on metasurface at terahertz frequencies.

Science.gov (United States)

Jiang, Yannan; Wang, Lei; Wang, Jiao; Akwuruoha, Charles Nwakanma; Cao, Weiping

2017-10-30

The polarization conversion of electromagnetic (EM) waves, especially linear-to-circular (LTC) polarization conversion, is of great significance in practical applications. In this study, we propose an ultra-wideband high-efficiency reflective LTC polarization converter based on a metasurface in the terahertz regime. It consists of periodic unit cells, each cell of which is formed by a double split resonant square ring, dielectric layer, and fully reflective gold mirror. In the frequency range of 0.60 - 1.41 THz, the magnitudes of the reflection coefficients reach approximately 0.7, and the phase difference between the two orthogonal electric field components of the reflected wave is close to 90° or -270°. The results indicate that the relative bandwidth reaches 80% and the efficiency is greater than 88%, thus, ultra-wideband high-efficiency LTC polarization conversion has been realized. Finally, the physical mechanism of the polarization conversion is revealed. This converter has potential applications in antenna design, EM measurement, and stealth technology.

Process for preparing polyolefin gel articles as well as for preparing herefrom articles having a high tensile strength and modulus

NARCIS (Netherlands)

1990-01-01

A process is described for the preparation of highly stretchable high-molecular weight polyolefin gel articles and polyolefin gel articles prepared therefrom having combined high tensile strength and high modulus, wherein an initial shaped article of the polyolefin is exposed to or contacted with a

SimProp: a simulation code for ultra high energy cosmic ray propagation

International Nuclear Information System (INIS)

Aloisio, R.; Grillo, A.F.; Boncioli, D.; Petrera, S.; Salamida, F.

2012-01-01

A new Monte Carlo simulation code for the propagation of Ultra High Energy Cosmic Rays is presented. The results of this simulation scheme are tested by comparison with results of another Monte Carlo computation as well as with the results obtained by directly solving the kinetic equation for the propagation of Ultra High Energy Cosmic Rays. A short comparison with the latest flux published by the Pierre Auger collaboration is also presented

Experimental determination of bulk modulus of 14Å tobermorite using high pressure synchrotron X-ray diffraction

KAUST Repository

Oh, Jae Eun; Clark, Simon M.; Wenk, Hans-Rudolf; Monteiro, Paulo J.M.

2012-01-01

Using a diamond anvil cell, 14 Å tobermorite, a structural analogue of calcium silicate hydrates (C-S-H), was examined by high-pressure synchrotron X-ray diffraction up to 4.8 GPa under hydrostatic conditions. The bulk modulus of 14 Å tobermorite was calculated, K o = 47 GPa. Comparison of the current results with previous high pressure studies on C-S-H(I) indicates that: (1) the compression behavior of the lattice parameters a and b of 14 Å tobermorite and C-S-H(I) are very similar, implying that both materials may have very similar Ca-O layers, and also implying that an introduction of structural defects into the Ca-O layers may not substantially change in-plane incompressibility of the ab plane of 14 Å tobermorite; and (2) the bulk modulus values of 14 Å tobermorite and C-S-H(I) are dominated by the incompressibility of the lattice parameter c, which is directly related to the interlayer spacing composed of dreierketten silicate chains, interlayer Ca, and water molecules. © 2011 Elsevier Ltd. All rights reserved.

Experimental determination of bulk modulus of 14Å tobermorite using high pressure synchrotron X-ray diffraction

KAUST Repository

Oh, Jae Eun

2012-02-01

Using a diamond anvil cell, 14 Å tobermorite, a structural analogue of calcium silicate hydrates (C-S-H), was examined by high-pressure synchrotron X-ray diffraction up to 4.8 GPa under hydrostatic conditions. The bulk modulus of 14 Å tobermorite was calculated, K o = 47 GPa. Comparison of the current results with previous high pressure studies on C-S-H(I) indicates that: (1) the compression behavior of the lattice parameters a and b of 14 Å tobermorite and C-S-H(I) are very similar, implying that both materials may have very similar Ca-O layers, and also implying that an introduction of structural defects into the Ca-O layers may not substantially change in-plane incompressibility of the ab plane of 14 Å tobermorite; and (2) the bulk modulus values of 14 Å tobermorite and C-S-H(I) are dominated by the incompressibility of the lattice parameter c, which is directly related to the interlayer spacing composed of dreierketten silicate chains, interlayer Ca, and water molecules. © 2011 Elsevier Ltd. All rights reserved.

Ultra-thin ZnSe: Anisotropic and flexible crystal structure

Energy Technology Data Exchange (ETDEWEB)

Bacaksiz, C., E-mail: cihanbacaksiz@iyte.edu.tr [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Senger, R.T. [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Sahin, H. [Department of Photonics, Izmir Institute of Technology, 35430 Izmir (Turkey)

2017-07-01

Highlights: • Ultra-thin ZnSe is dynamically stable. • Ultra-thin ZnSe is electronically direct-gap semiconductor. • Ultra-thin ZnSe is ultra-flexible. • Ultra-thin ZnSe is mechanically in-plane anisotropic. - Abstract: By performing density functional theory-based calculations, we investigate the structural, electronic, and mechanical properties of the thinnest ever ZnSe crystal . The vibrational spectrum analysis reveals that the monolayer ZnSe is dynamically stable and has flexible nature with its soft phonon modes. In addition, a direct electronic band gap is found at the gamma point for the monolayer structure of ZnSe. We also elucidate that the monolayer ZnSe has angle dependent in-plane elastic parameters. In particular, the in-plane stiffness values are found to be 2.07 and 6.89 N/m for the arm-chair and zig-zag directions, respectively. The angle dependency is also valid for the Poisson ratio of the monolayer ZnSe. More significantly, the in-plane stiffness of the monolayer ZnSe is the one-tenth of Young modulus of bulk zb-ZnSe which indicates that the monolayer ZnSe is a quite flexible single layer crystal. With its flexible nature and in-plane anisotropic mechanical properties, the monolayer ZnSe is a good candidate for nanoscale mechanical applications.

Ultra-thin ZnSe: Anisotropic and flexible crystal structure

International Nuclear Information System (INIS)

Bacaksiz, C.; Senger, R.T.; Sahin, H.

2017-01-01

Highlights: • Ultra-thin ZnSe is dynamically stable. • Ultra-thin ZnSe is electronically direct-gap semiconductor. • Ultra-thin ZnSe is ultra-flexible. • Ultra-thin ZnSe is mechanically in-plane anisotropic. - Abstract: By performing density functional theory-based calculations, we investigate the structural, electronic, and mechanical properties of the thinnest ever ZnSe crystal . The vibrational spectrum analysis reveals that the monolayer ZnSe is dynamically stable and has flexible nature with its soft phonon modes. In addition, a direct electronic band gap is found at the gamma point for the monolayer structure of ZnSe. We also elucidate that the monolayer ZnSe has angle dependent in-plane elastic parameters. In particular, the in-plane stiffness values are found to be 2.07 and 6.89 N/m for the arm-chair and zig-zag directions, respectively. The angle dependency is also valid for the Poisson ratio of the monolayer ZnSe. More significantly, the in-plane stiffness of the monolayer ZnSe is the one-tenth of Young modulus of bulk zb-ZnSe which indicates that the monolayer ZnSe is a quite flexible single layer crystal. With its flexible nature and in-plane anisotropic mechanical properties, the monolayer ZnSe is a good candidate for nanoscale mechanical applications.

An enhanced method to determine the Young’s modulus of technical single fibres by means of high resolution digital image correlation

Science.gov (United States)

Huether, Jonas; Rupp, Peter; Kohlschreiber, Ina; André Weidenmann, Kay

2018-04-01

To obtain mechanical tensile properties of materials it is customary to equip the specimen directly with a device to measure strain and Young’s modulus correctly and only within the measuring length defined by the standards. Whereas a variety of tools such as extensometers, strain gauges and optical systems are available for specimens on coupon level, no market-ready tools to measure strains of single fibres during single fibre tensile tests are available. Although there is a standard for single fibre testing, the procedures described there are only capable of measuring strains of the whole testing setup rather than the strain of the fibre. Without a direct strain measurement on the specimen, the compliance of the test rig itself influences the determination of the Young’s modulus. This work aims to fill this gap by establishing an enhanced method to measure strains directly on the tested fibre and thus provide accurate values for Young’s modulus. It is demonstrated that by applying and then optically tracking fluorescing polymeric beads on single glass fibres, Young’s modulus is determined directly and with high repeatability, without a need to measure at different measuring lengths or compensating for the system compliance. Employing this method to glass fibres, a Young’s modulus of approximately 82.5 GPa was determined, which is in the range of values obtained by applying a conventional procedure. This enhanced measuring technology achieves high accuracy and repeatability while reducing scatter of the data. It was demonstrated that the fluorescing beads do not affect the fibre properties.

Nanocrystalline β-Ti alloy with high hardness, low Young's modulus and excellent in vitro biocompatibility for biomedical applications

International Nuclear Information System (INIS)

Xie, Kelvin Y.; Wang, Yanbo; Zhao, Yonghao; Chang, Li; Wang, Guocheng; Chen, Zibin; Cao, Yang; Liao, Xiaozhou; Lavernia, Enrique J.; Valiev, Ruslan Z.; Sarrafpour, Babak; Zoellner, Hans; Ringer, Simon P.

2013-01-01

High strength, low Young's modulus and good biocompatibility are desirable but difficult to simultaneously achieve in metallic implant materials for load bearing applications, and these impose significant challenges in material design. Here we report that a nano-grained β-Ti alloy prepared by high-pressure torsion exhibits remarkable mechanical and biological properties. The hardness and modulus of the nano-grained Ti alloy were respectively 23% higher and 34% lower than those of its coarse-grained counterpart. Fibroblast cell attachment and proliferation were enhanced, demonstrating good in vitro biocompatibility of the nano-grained Ti alloy, consistent with demonstrated increased nano-roughness on the nano-grained Ti alloy. Results suggest that the nano-grained β-Ti alloy may have significant application as an implant material in dental and orthopedic applications. - Highlights: • A bulk nanocrystalline β-Ti alloy was produced by high-pressure torsion processing. • Excellent mechanical properties for biomedical implants were obtained. • Enhanced in vitro biocompatibility was also demonstrated

Elastic modulus and internal friction of SOFC electrolytes at high temperatures under controlled atmospheres

Science.gov (United States)

Kushi, Takuto; Sato, Kazuhisa; Unemoto, Atsushi; Hashimoto, Shinichi; Amezawa, Koji; Kawada, Tatsuya

2011-10-01

Mechanical properties such as Young's modulus, shear modulus, Poisson's ratio and internal friction of conventional electrolyte materials for solid oxide fuel cells, Zr0.85Y0.15 O1.93 (YSZ), Zr0.82Sc0.18O1.91 (ScSZ), Zr0.81Sc0.18Ce0.01O2-δ (ScCeSZ), Ce0.9Gd0.1O2-δ (GDC), La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (LSGMC), La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM), were evaluated by a resonance method at temperatures from room temperature to 1273 K in various oxygen partial pressures. The Young's modulus of GDC gradually decreased with increasing temperature in oxidizing conditions. The Young's moduli of the series of zirconia and lanthanum gallate based materials drastically decreased in an intermediate temperature range and increased slightly with increasing temperature at higher temperatures. The Young's modulus of GDC considerably decreased above 823 K in reducing atmospheres in response to the change of oxygen nonstoichiometry. However, temperature dependences of the Young's moduli of ScCeSZ and LSGMC in reducing atmospheres did not show any significant differences with those in oxidizing atmospheres.

Study on creep of fiber reinforced ultra-high strength concrete based on strength

Science.gov (United States)

Peng, Wenjun; Wang, Tao

2018-04-01

To complement the creep performance of ultra-high strength concrete, the long creep process of fiber reinforced concrete was studied in this paper. The long-term creep process and regularity of ultra-high strength concrete with 0.5% PVA fiber under the same axial compression were analyzed by using concrete strength (C80/C100/C120) as a variable. The results show that the creep coefficient of ultra-high strength concrete decreases with the increase of concrete strength. Compared with ACI209R (92), GL2000 models, it is found that the predicted value of ACI209R (92) are close to the experimental value, and the creep prediction model suitable for this experiment is proposed based on ACI209R (92).

Exploration of coal-based pitch precursors for ultra-high thermal conductivity graphite fibers. Final report

Energy Technology Data Exchange (ETDEWEB)

Deshpande, G.V. [Amoco Performance Products, Inc., Alpharetta, GA (United States)

1996-12-27

Goal was to explore the utility of coal-based pitch precursors for use in ultra high thermal conductivity carbon (graphite) fibers. From graphite electrode experience, it was established that coal-based pitches tend to form more highly crystalline graphite at lower temperatures. Since the funding was limited to year 1 effort of the 3 year program, the goal was only partially achieved. The coal-base pitches can form large domain mesophase in spite of high N and O contents. The mesophase reactivity test performed on one of the variants of coal-based pitch (DO84) showed that it was not a good candidate for carbon fiber processing. Optimization of WVU`s isotropic pitch process is required to tailor the pitch for carbon fiber processing. The hetero atoms in the coal pitch need to be reduced to improve mesophase formation.

Bond behavior of reinforcing steel in ultra-high performance concrete.

Science.gov (United States)

2014-10-01

Ultra-High Performance Concrete (UHPC) is a relatively new class of advanced cementitious composite : materials, which exhibits high compressive [above 21.7 ksi (150 MPa)] and tensile [above 0.72 ksi (5 MPa)] : strengths. The discrete steel fiber rei...

The influence of removing sizing on strength and stiffness of conventional and high modulus E-glass fibres

DEFF Research Database (Denmark)

Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

2016-01-01

Two types of E-glass fibres, a conventional and a high modulus where the last one in the following will be denoted as ECR-glass fibre, were investigated regarding density, diameter, stiffness and strength. The fibres were analysed as pristine and after sizing removal treatments. The sizing was re...

Long-term pavement performance monitoring and the revision of performance criteria for high modulus asphalt in South Africa

CSIR Research Space (South Africa)

Komba, Julius

2016-09-01

Full Text Available Enrobé à Module Élevé (EME) technology, a High Modulus Asphalt (HiMA), was originally developed in France. The technology is primarily suitable for construction of heavily trafficked routes, airports and container terminals. The key performance...

The Young's modulus of high-aspect-ratio carbon/carbon nanotube composite microcantilevers by experimental and modeling validation

International Nuclear Information System (INIS)

Zhou, Peng; Yang, Xiao; He, Liang; Hao, Zhimeng; Luo, Wen; Xiong, Biao; Xu, Xu; Niu, Chaojiang; Yan, Mengyu; Mai, Liqiang

2015-01-01

This paper reports the Young's modulus of a carbon nanotube (CNT)-reinforced carbon/CNT (C/CNT) composite microcantilevers measured by laser Doppler vibrometer and validated by finite element method. Also, the microfabrication process of the high-aspect-ratio C/CNT microcantilever arrays based on silicon micromolding and pyrolysis is presented in detail. With the in-plane natural resonant frequencies of the microcantilevers measured by a laser Doppler vibrometer, a single degree of freedom (SDoF) model based on Euler-Bernoulli (E-B) beam theory is used to calculate the Young's modulus of this composite. To figure out whether this SDoF model can be applied to these composite microcantilevers, the finite element (FE) simulation of these microcantilevers was performed. The Young's modulus of C/CNT composite microcantilevers fabricated by the pyrolysis process at 600 °C is 9391 MPa, and a good agreement between the results from experiments and FE simulation is obtained

Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

International Nuclear Information System (INIS)

Pemmasani, Sai Pramod; Rajulapati, Koteswararao V.; Ramakrishna, M.; Valleti, Krishna; Gundakaram, Ravi C.; Joshi, Shrikant V.

2013-01-01

This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure. - Highlights: • Microstructure of a triple layer nitride coating studied at multiple length scales. • Phases identified by EDS, EBSD and SAED (TEM). • Nanolayered, nanocomposite structure of the coating studied using FIB and TEM. • Modulus mapping identified moduli variation even in a nani-multilayer architecture

Ultra-high Performance Liquid Chromatography in Steroid Analysis

OpenAIRE

Salonen, Fanny

2017-01-01

The latest version of liquid chromatography is ultra-high performance (or pressure) chromatography (UHPLC). In the technique, short and narrow-bore columns with particle sizes below 3 µm are used. The extremely high pressure used results in very short analysis times, excellent separation, and good resolution. This makes UHPLC a good choice for steroidal analysis. Steroids are a highly interesting area of study; they can be recognized as biomarkers for several diseases and are a relevant topic...

The changes of red blood cell viscoelasticity and sports anemia in male 24-hr ultra-marathoners

Directory of Open Access Journals (Sweden)

Che-Hung Liu

2018-05-01

Full Text Available Background: In endurance sports, stress, dehydration and release of chemical factors have been associated with red blood cell (RBC alterations of structure and function, which may contribute to sports anemia, a well-observed phenomenon during long-distance running. Until now, the investigation of the changes of viscoelastic properties of RBC membrane, a decisive factor of RBC deformability to avoid hemolysis, is lacking, especially in an Oriental population. Methods: nineteen runners were prospectively recruited into our study. Hematological parameters were analyzed before and immediately after the 2015 Taipei 24H Ultra-Marathon Festival, Taiwan. Video particle tracking microrheology was used to determine viscoelastic properties of each RBC sample by calculating the dynamic elastic modulus G′(f and the viscous modulus G″(f at frequency f = 20 Hz. Results: Haptoglobin, RBC count, hemoglobin, hematocrit, mean cell hemoglobin, plasma free hemoglobin and unsaturated iron-binding capacity values of the recruited runners showed a statistically significant drop in the post-race values. Blood concentration of reticulocyte and ferritin were significantly higher at post-race compared with pre-race. 15 out of the 19 runners had a concurrent change in the elastic and the viscous moduli of their RBCs. Changes in the elastic and the viscous moduli were correlated with changes in the RBC count, hemoglobin and hematocrit. Conclusion: Viscoelasticity properties, the elastic modulus G′(f and the viscous modulus G″(f of RBCs are associated with endurance exercise-induced anemia. Keywords: Clinical sports medicine, Red blood cell, Sports anemia, Ultra-marathon, Viscoelastic properties

Encoding methods for B1+ mapping in parallel transmit systems at ultra high field

Science.gov (United States)

Tse, Desmond H. Y.; Poole, Michael S.; Magill, Arthur W.; Felder, Jörg; Brenner, Daniel; Jon Shah, N.

2014-08-01

Parallel radiofrequency (RF) transmission, either in the form of RF shimming or pulse design, has been proposed as a solution to the B1+ inhomogeneity problem in ultra high field magnetic resonance imaging. As a prerequisite, accurate B1+ maps from each of the available transmit channels are required. In this work, four different encoding methods for B1+ mapping, namely 1-channel-on, all-channels-on-except-1, all-channels-on-1-inverted and Fourier phase encoding, were evaluated using dual refocusing acquisition mode (DREAM) at 9.4 T. Fourier phase encoding was demonstrated in both phantom and in vivo to be the least susceptible to artefacts caused by destructive RF interference at 9.4 T. Unlike the other two interferometric encoding schemes, Fourier phase encoding showed negligible dependency on the initial RF phase setting and therefore no prior B1+ knowledge is required. Fourier phase encoding also provides a flexible way to increase the number of measurements to increase SNR, and to allow further reduction of artefacts by weighted decoding. These advantages of Fourier phase encoding suggest that it is a good choice for B1+ mapping in parallel transmit systems at ultra high field.

Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity

Science.gov (United States)

Li, Xinwei; Bamba, Motoaki; Zhang, Qi; Fallahi, Saeed; Gardner, Geoff C.; Gao, Weilu; Lou, Minhan; Yoshioka, Katsumasa; Manfra, Michael J.; Kono, Junichiro

2018-06-01

A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger's equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch-Siegert shift. Here, we report the vacuum Bloch-Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch-Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.

Ultra high energy cosmic rays

International Nuclear Information System (INIS)

Watson, A.A.

1986-01-01

Cosmic radiation was discovered 70 years ago but its origin remains an open question. The background to this problem is outlined and attempts to discover the origin of the most energetic and rarest group above 10 15 eV are described. Measurements of the energy spectrum and arrival direction pattern of the very highest energy particles, mean energy about 6 x 10 19 eV, are used to argue that these particles originate outside our galaxy. Recent evidence from the new field of ultra high energy γ-ray astronomy are discussed in the context of a galactic origin hypothesis for lower energy cosmic rays. (author)

Ultra-High Field Magnets for X-Ray and Neutron Scattering using High Temperature Superconductors

Energy Technology Data Exchange (ETDEWEB)

Winn, Barry L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States); Bird, M. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Breneman, Bruce C. [General Atomics, San Diego, CA (United States); Coffey, Michael [Cryomagnetics, Oak Ridge, TN (United States); Cutler, Roy I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duckworth, Robert C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Erwin, R. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Hahn, Seungyong [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Hernandez, Yamali [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Herwig, Kenneth W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holland, Leo D. [General Atomics, San Diego, CA (United States); Lonergan, Kevin M. [Oxford Instruments, Abingdon (United Kingdom); Melhem, Ziad [Oxford Instruments, Abingdon (United Kingdom); Minter, Stephen J. [Cryomagnetics, Oak Ridge, TN (United States); Nelson, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Paranthaman, M. Parans [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pierce, Josh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruff, Jacob [Cornell Univ., Ithaca, NY (United States); Shen, Tengming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherline, Todd E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smeibidl, Peter G. [Helmholtz-Zentrum Berlin (HZB), (Germany); Tennant, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); van der Laan, Danko [Advanced Conductor Technologies, LLC, Boulder, CO (United States); Wahle, Robert J. [Helmholtz-Zentrum Berlin (HZB), (Germany); Zhang, Yifei [SuperPower, Inc., Schenectady, NY (United States)

2017-01-01

X-ray and neutron scattering techniques are capable of acquiring information about the structure and dynamics of quantum matter. However, the high-field magnet systems currently available at x-ray and neutron scattering facilities in the United States are limited to fields of 16 tesla (T) at maximum, which precludes applications that require and/or study ultra-high field states of matter. This gap in capability—and the need to address it—is a central conclusion of the 2005 National Academy of Sciences report by the Committee on Opportunities in High Magnetic Field Science. To address this gap, we propose a magnet development program that would more than double the field range accessible to scattering experiments. With the development and use of new ultra-high field–magnets, the program would bring into view new worlds of quantum matter with profound impacts on our understanding of advanced electronic materials.

Ultra high resolution soft x-ray tomography

International Nuclear Information System (INIS)

Haddad, W.S.; Trebes, J.E.; Goodman, D.M.

1995-01-01

Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5μm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼1000 Angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 Angstrom, however some features were clearly reconstructed with a depth resolution of ∼1000 Angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to ∼1200 Angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

Ultra high resolution soft x-ray tomography

International Nuclear Information System (INIS)

Haddad, W.S.; Trebes, J.E.; Goodman, D.M.; Lee, H.R.; McNulty, I.; Zalensky, A.O.

1995-01-01

Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5 microm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼ 1,000 angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼ 6,000 angstrom, however some features were clearly reconstructed with a depth resolution of ∼ 1,000 angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution, bringing it down to ∼ 1,200 angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

Resilient modulus of black cotton soil

Directory of Open Access Journals (Sweden)

K.H. Mamatha

2017-03-01

Full Text Available Resilient modulus (MR values of pavement layers are the basic input parameters for the design of pavements with multiple layers in the current mechanistic empirical pavement design guidelines. As the laboratory determination of resilient modulus is costly, time consuming and cumbersome, several empirical models are developed for the prediction of resilient modulus for different regions of the world based on the database of resilient modulus values of local soils. For use of these relationships there is a need to verify the suitability of these models for local conditions. Expansive clay called black cotton soil (BC soil is found in several parts of India and is characterized by low strength and high compressibility. This soil shows swell – shrink behaviour upon wetting and drying and are problematic. The BC soil shows collapse behaviour on soaking and therefore the strength of the soil needs to be improved. Additive stabilization is found to be very effective in stabilizing black cotton soils and generally lime is used to improve the strength and durability of the black cotton soil. In this paper, the results of repeated load tests on black cotton soil samples for the determination of MR under soaked and unsoaked conditions at a relative compaction levels of 100% and 95% of both standard and modified proctor conditions are reported. The results indicate that the black cotton soil fails to meet the density requirement of the subgrade soil and shows collapse behaviour under soaked condition. To overcome this, lime is added as an additive to improve the strength of black cotton soil and repeated load tests were performed as per AASHTO T 307 - 99 for MR determination. The results have shown that the samples are stable under modified proctor condition with MR values ranging from 36 MPa to 388 MPa for a lime content of 2.5% and curing period ranging from 7 to 28 days. Also, it is observed that, the CBR based resilient modulus is not in agreement

Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

OpenAIRE

Tagnit-Hamou Arezki; Zidol Ablam; Soliman Nancy; Deschamps Joris; Omran Ahmed

2018-01-01

Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G pro...

Ultra-High-Efficiency Apodized Grating Coupler Using a Fully Etched Photonic Crystal

DEFF Research Database (Denmark)

Ding, Yunhong; Peucheret, Christophe; Ou, Haiyan

2013-01-01

We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated.......We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated....

High-energy green supercapacitor driven by ionic liquid electrolytes as an ultra-high stable next-generation energy storage device

Science.gov (United States)

Thangavel, Ranjith; Kannan, Aravindaraj G.; Ponraj, Rubha; Thangavel, Vigneysh; Kim, Dong-Won; Lee, Yun-Sung

2018-04-01

Development of supercapacitors with high energy density and long cycle life using sustainable materials for next-generation applications is of paramount importance. The ongoing challenge is to elevate the energy density of supercapacitors on par with batteries, while upholding the power and cyclability. In addition, attaining such superior performance with green and sustainable bio-mass derived compounds is very crucial to address the rising environmental concerns. Herein, we demonstrate the use of watermelon rind, a bio-waste from watermelons, towards high energy, and ultra-stable high temperature green supercapacitors with a high-voltage ionic liquid electrolyte. Supercapacitors assembled with ultra-high surface area, hierarchically porous carbon exhibits a remarkable performance both at room temperature and at high temperature (60 °C) with maximum energy densities of ∼174 Wh kg-1 (25 °C), and 177 Wh kg-1 (60 °C) - based on active mass of both electrodes. Furthermore, an ultra-high specific power of ∼20 kW kg-1 along with an ultra-stable cycling performance with 90% retention over 150,000 cycles has been achieved even at 60 °C, outperforming supercapacitors assembled with other carbon based materials. These results demonstrate the potential to develop high-performing, green energy storage devices using eco-friendly materials for next generation electric vehicles and other advanced energy storage systems.

The instantaneous shear modulus in the shoving model

DEFF Research Database (Denmark)

Dyre, J. C.; Wang, W. H.

2012-01-01

We point out that the instantaneous shear modulus G∞ of the shoving model for the non-Arrhenius temperature dependence of viscous liquids’ relaxation time is the experimentally accessible highfrequency plateau modulus, not the idealized instantaneous affine shear modulus that cannot be measured....... Data for a large selection of metallic glasses are compared to three different versions of the shoving model. The original shear-modulus based version shows a slight correlation to the Poisson ratio, which is eliminated by the energy-landscape formulation of the model in which the bulk modulus plays...

Modulus D-term inflation

Science.gov (United States)

Kadota, Kenji; Kobayashi, Tatsuo; Saga, Ikumi; Sumita, Keigo

2018-04-01

We propose a new model of single-field D-term inflation in supergravity, where the inflation is driven by a single modulus field which transforms non-linearly under the U(1) gauge symmetry. One of the notable features of our modulus D-term inflation scenario is that the global U(1) remains unbroken in the vacuum and hence our model is not plagued by the cosmic string problem which can exclude most of the conventional D-term inflation models proposed so far due to the CMB observations.

Adaptive sensor-based ultra-high accuracy solar concentrator tracker

Science.gov (United States)

Brinkley, Jordyn; Hassanzadeh, Ali

2017-09-01

Conventional solar trackers use information of the sun's position, either by direct sensing or by GPS. Our method uses the shading of the receiver. This, coupled with nonimaging optics design allows us to achieve ultra-high concentration. Incorporating a sensor based shadow tracking method with a two stage concentration solar hybrid parabolic trough allows the system to maintain high concentration with acute accuracy.

Fiber based hydrophones for ultra-high energy neutrino detection

NARCIS (Netherlands)

Buis, E.J.; Doppenberg, E.J.J.; Eijk, D. van; Lahmann, R.; Nieuwland, R.A.; Toet, P.M.

2014-01-01

It is a well studied process [1, 2] that energy deposition of cosmic ray particles in water that generate thermo-acoustic signals. Hydrophones of sufficient sensitivity could measure this signal and provide a means of detecting ultra-high energetic cosmic neutrinos. We investigate optical

High-efficiency water-loaded microwave antenna in ultra-high-frequency band

Science.gov (United States)

Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

2018-03-01

High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

Design of a broadband ultra-large area acoustic cloak based on a fluid medium

Science.gov (United States)

Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Jiang, Ping

2014-10-01

A broadband ultra-large area acoustic cloak based on fluid medium was designed and numerically implemented with homogeneous metamaterials according to the transformation acoustics. In the present work, fluid medium as the body of the inclusion could be tuned by changing the fluid to satisfy the variant acoustic parameters instead of redesign the whole cloak. The effective density and bulk modulus of the composite materials were designed to agree with the parameters calculated from the coordinate transformation methodology by using the effective medium theory. Numerical simulation results showed that the sound propagation and scattering signature could be controlled in the broadband ultra-large area acoustic invisibility cloak, and good cloaking performance has been achieved and physically realized with homogeneous materials. The broadband ultra-large area acoustic cloaking properties have demonstrated great potentials in the promotion of the practical applications of acoustic cloak.

The Heart of China revisited: II Early Paleozoic (ultra)high-pressure and (ultra)high-temperature metamorphic Qinling orogenic collage

Science.gov (United States)

Bader, Thomas; Franz, Leander; Ratschbacher, Lothar; de Capitani, Christian; Webb, A. Alexander G.; Yang, Zhao; Pfänder, Jörg A.; Hofmann, Mandy; Linnemann, Ulf

2013-07-01

Orogens with multiple (ultra)high-pressure ((U)HP) and (ultra)high-temperature ((U)HT) metamorphic events provide a complex but telling record of oceanic and continental interaction. The Early Paleozoic history of the "Heart of China," the Qinling orogenic collage, offers snapshots of at least three (U)HP and two (U)HT metamorphic events. The preservation of remnants of both oceanic and continental domains together with a ≥110 Myr record of magmatism allows the reconstruction of the processes that resulted in this disparate metamorphism. Herein, we first illuminate the pressure-temperature-time (P-T-t) evolution of the Early Paleozoic (U)HP and (U)HT events by refining the petrographic descriptions and P-T estimates, assess published, and employ new U/Th-Pb zircon, monazite, and titanite, and 40Ar-39Ar phengite geochronology to date the magmatic and metamorphic events. Then we explore how the metamorphic and magmatic events are related tectonically and how they elucidate the affinities among the various complexes in the Qinling orogenic collage. We argue that a Meso-Neoproterozoic crustal fragment—the Qinling complex—localized subduction-accretion events that involved subduction, oceanic-arc formation, and back-arc spreading along its northern margin, and mtantle-wedge exhumation and spreading-ridge subduction along its southern margin.

Young’s modulus of multi-layer microcantilevers

Directory of Open Access Journals (Sweden)

Zhikang Deng

2017-12-01

Full Text Available A theoretical model for calculating the Young’s modulus of multi-layer microcantilevers with a coating is proposed, and validated by a three-dimensional (3D finite element (FE model using ANSYS parametric design language (APDL and atomic force microscopy (AFM characterization. Compared with typical theoretical models (Rayleigh-Ritz model, Euler-Bernoulli (E-B beam model and spring mass model, the proposed theoretical model can obtain Young’s modulus of multi-layer microcantilevers more precisely. Also, the influences of coating’s geometric dimensions on Young’s modulus and resonant frequency of microcantilevers are discussed. The thickness of coating has a great influence on Young’s modulus and resonant frequency of multi-layer microcantilevers, and the coating should be considered to calculate Young’s modulus more precisely, especially when fairly thicker coating is employed.

The effect of chromic acid treatment on the mechanical and tribological properties of aramid fibre reinforced ultra-high molecular weight polyethylene composite

NARCIS (Netherlands)

Hofste, JM; Pennings, AJ; Schut, J.A.

1998-01-01

Surface oxidation of ultra-high molecular weight polyethylene (UHMWPE) powder has an influence on the mixing procedure of chopped fibres and UHMWPE powder. Due to this oxidation hydrogen bonds can be formed between the fibres and powder particles, leading to a more homogeneous fibre-powder mixture.

The elastic modulus of alumina-zirconia composite using through transmission ultrasonics

International Nuclear Information System (INIS)

Tan, K.S.; Hing, P.

1996-01-01

The elastic modulus of unstabilized Al 2 O 3 -ZrO 2 composites is determined from ultrasonic velocities and density measurements. The dynamic elastic modulus and the density of the green unstabilized Al 2 O 3 -ZrO 2 follow the rule of mixture. However, the elastic modulus and density of the sintered Al 2 O 3 -ZrO 2 do not follow the rule of mixture. The elastic modulus and diametrical compressive fracture stress of the Al 2 O 3 can be enhanced by (1) a high green (before sintering) compacting pressure and (2) addition of about 3wt% unstabilized ZrO 2 at a sintering time of two hours at 1550 degC. The ZrO 2 is found to improve the bulk density of the composite by a reduction in the porosity. This improves the elastic modulus and the diametrical compressive fracture stress. The thermal expansion on cooling with > 25wt% ZrO 2 in the Al 2 O 3 matrix has also been established. (author)

Determination of Young's Modulus of Graphene by Raman Spectroscopy

Science.gov (United States)

Lee, Jae-Ung; Yoon, Duhee; Cheong, Hyeonsik

2012-02-01

The mechanical properties of graphene are interesting research subjects because its Young's modulus and strength are extremely high. Values of ˜1 TPa for the Young's modulus have been reported [Lee et al. Science, 321, 385 (2008), Koenig et al. Nat. Nanotech. 6, 543 (2011)]. We made a graphene sample on a SiO2/Si substrate with closed-bottom holes by mechanical exfoliation. A pressure difference across the graphene membrane was applied by putting the sample in a vacuum chamber. This pressure difference makes the graphene membrane bulge upward like a balloon. By measuring the shifts of the Raman G and 2D bands, we estimated the amount of strain on the graphene membrane. By comparing the strain estimated from the Raman measurements with numerical simulations based on the finite element method, we obtained the Young's modulus of graphene.

Properties of matter at ultra-high densities

International Nuclear Information System (INIS)

Banerjee, B.; Chitre, S.M.

1975-01-01

The recent discovery of pulsars and their subsequent identification with neutron stars has given a great impetus to the study of the behaviour of matter at ultra high densities. The object of these studies is to calculate the equation of state as a function of density. In this paper, the properties of electrically neutral, cold (T=0) matter at unusually high densities has been reviewed. The physics of the equation of state of such matter divides quite naturally in four density ranges. (i) At the very lowest densities the state of minimum energy is a lattice of 56 Fe atoms. This state persists upto 10 7 g/cm 3 . (ii) In the next density region the nuclei at the lattice sites become neutron rich because the high electron Fermi energy makes inverse beta decay possible. (iii) At a density 4.3 x 10 11 the nuclei become so neutron rich that the neutrons start 'dripping' out of the nuclei and form a gas. This density range is characterised by large, neutron-rich nuclei immersed in a neutron gas. (iv) At a density 2.4 x 10 14 g/cm 3 , the nuclei disappear and a fluid of uniform neutron matter with a small percentage of protons and electrons results. The above four density ranges have been discussed in detail as the equation of state is now well established upto the nuclear density 3 x 10 14 g/cm 3 . The problems of extending the equation of state beyond this density are also touched upon. (author)

Modification of Ultra-High Vacuum Surfaces Using Free Radicals

CERN Document Server

Vorlaufer, G

2002-01-01

In ultra-high vacuum systems outgassing from vacuum chamber walls and desorption of surface adsorbates are usually the factors which determine pressure and residual gas composition. In particular in beam vacuum systems of accelerators like the LHC, where surfaces are exposed to intense synchrotron radiation and bombardment by energetic ions and electrons, surface properties like the molecular desorption yield or secondary electron yield can strongly influence the performance of the accelerator. Well-established treatment methods like vacuum bake-out or glow-discharge cleaning have been successfully applied in the past to condition ultra-high vacuum surfaces, but these methods are sometimes difficult to carry out, for example if the vacuum chambers are not accessible. In this work, an alternative treatment method is investigated. This method is based on the strong chemical reactivity of free radicals, electrically neutral fragments of molecules. Free radicals (in the case of this work, nitrogen and oxygen radi...

Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers

Science.gov (United States)

Kalita, Viktor M.; Snarskii, Andrei A.; Shamonin, Mikhail; Zorinets, Denis

2017-03-01

The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016), 10.1103/PhysRevE.93.062503]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Padé approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles.

Investigation and basic evaluation for ultra-high burnup fuel cladding material

International Nuclear Information System (INIS)

Ioka, Ikuo; Nagase, Fumihisa; Futakawa, Masatoshi; Kiuchi, Kiyoshi

2001-03-01

In ultra-high burnup of the power reactor, it is an essential problem to develop the cladding with excellent durability. First, development history and approach of the safety assessment of Zircaloy for the high burnup fuel were summarized in the report. Second, the basic evaluation and investigation were carried out on the material with high practicability in order to select the candidate materials for the ultra-high burnup fuel. In addition, the basic research on modification technology of the cladding surface was carried out from the viewpoint of the addition of safety margin as a cladding. From the development history of the zirconium alloy including the Zircaloy, it is hard to estimate the results of in-pile test from those of the conventional corrosion test (out-pile test). Therefore, the development of the new testing technology that can simulate the actual environment and the elucidation of the corrosion-controlling factor of the cladding are desired. In cases of RIA (Reactivity Initiated Accident) and LOCA (Loss of Coolant Accident), it seems that the loss of ductility in zirconium alloys under heavy irradiation and boiling of high temperature water restricts the extension of fuel burnup. From preliminary evaluation on the high corrosion-resistance materials (austenitic stainless steel, iron or nickel base superalloys, titanium alloy, niobium alloy, vanadium alloy and ferritic stainless steel), stabilized austenitic stainless steels with a capability of future improvement and high-purity niobium alloys with a expectation of the good corrosion resistance were selected as candidate materials of ultra-high burnup cladding. (author)

A two-crown finite element technique for the determination of tearing modulus

International Nuclear Information System (INIS)

Suo, X.Z.; Combescure, A.

1989-01-01

The importance of approach to the subject of crack instability for the design of structures containing cracks has increased considerably over the last few years. The tearing modulus theory recently enunciated by Paris and co-workers has emerged as one of the leading criterions for stable crack growth and for instability, and the estimation of T termed Tearing modulus in the theory has since been extensively investigated theoretically as well as experimentally. Analytical methods exist for calculating the tearing modulus of various crack configurations in simple-shaped structures under certain loading conditions. However, for arbitrary structures under general loading, more sophisticated calculation techniques are required. Extending the virtual crack extension method introduced independently by Hellen and Parks, a new numerical approach for calculating the tearing modulus is presented hereafter and put in a form suitable for the instability analysis of structures containing one single crack or several interacting cracks. As it is well-known that the calculation of the energy release rate in elasticity by the virtual crack extension method is related to a stiffness derivative to which only a small region around the crack tip has a contribution, the technique described in the paper shows that it would be reasonable to evaluate the tearing modulus, or rather, the second derivative of potential energy with respect to the crack length, by means of two stiffness derivative calculations in two crowns around the crack tip. In particular, when one crown is strictly included in another one, computation is largely curtailed at this point with some saving of computer time, but a very accurate value of tearing modulus is obtained. As an interesting consequence, an another expression of the tearing modulus is carried out. In Section 4: the classical tearing modulus is proved to be precisely equivalent to a line integral which is independent of integration path. Numerical example

Evaluating strength at ultra-high temperatures-Methods and results

International Nuclear Information System (INIS)

Voelkl, Rainer; Fischer, Bernd; Beschliesser, Manuel; Glatzel, Uwe

2008-01-01

Proprietary equipment for mechanical testing at ultra-high temperatures by ohmic heating is outlined. Strain is measured with a video extensometer with an accuracy of up to Δε-bar∼±0.00025%. Stability and accuracy of the test system are evaluated on Pt- and refractory alloys. These specially designed and built test facilities are compared to commercially available high-vacuum test chambers with tungsten heater

[Reparative Osteogenesis and Angiogenesis in Low Intensity Electromagnetic Radiation of Ultra-High Frequency].

Science.gov (United States)

Iryanov, Y M; Kiryanov, N A

2015-01-01

Non-drug correction of reparative bone tissue regeneration in different pathological states - one of the most actual problems of modern medicine. Our aim was to conduct morphological analysis of the influence of electromagnetic radiation of ultra-high frequency and low intensity on reparative osteogenesis and angiogenesis in fracture treatment under transosseous osteosynthesis. A controlled nonrandomized study was carried out. In the experiment conducted on rats we modeled tibial fracture with reposition and fixation of the bone fragments both in control and experimental groups. In the animals of the experimental group the fracture zone was exposed to low intensity electromagnetic radiation of ultra-high frequency. Exposure simulation was performed in the control group. The operated bones were examined using radiography, light and electronic microscopy, X-ray electronic probe microanalysis. It has been established that electromagnetic radiation of ultra-high frequency sessions in fracture treatment stimulate secretory activity and degranulation of mast cells, produce microcirculatory bed vascular permeability increase, endotheliocyte migration phenotype expression, provide endovascular endothelial outgrowth formation, activate reparative osteogenesis and angiogenesis while fracture reparation becomes the one of the primary type. The full periosteal, intermediary and intraosteal bone union was defined in 28 days. Among the therapeutic benefits of electromagnetic radiation of ultra-high frequency in fracture treatment we can detect mast cell secretorv activity stimulation and endovascular anziozenesis activation.

Probing physics at extreme energies with cosmic ultra-high energy ...

Indian Academy of Sciences (India)

testing new particle physics. Keywords. Ultra-high ... conventional theories of CR origin based on acceleration of charged particles in powerful ... Before discussing specific scenarios for UHECR origin we give a short account of the numerical ...

ATLAS and ultra high energy cosmic ray physics

Directory of Open Access Journals (Sweden)

Pinfold James

2017-01-01

Full Text Available After a brief introduction to extended air shower cosmic ray physics the current and future deployment of forward detectors at ATLAS is discussed along with the various aspects of the current and future ATLAS programs to explore hadronic physics. The emphasis is placed on those results and future plans that have particular relevance for high-energy, and ultra high-energy, cosmic ray physics. The possible use of ATLAS as an “underground” cosmic muon observatory is briefly considered.

Inactivation of Bacillus spores inoculated in milk by Ultra High Pressure Homogenization.

Science.gov (United States)

Amador Espejo, Genaro Gustavo; Hernández-Herrero, M M; Juan, B; Trujillo, A J

2014-12-01

Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. Ultra High-Pressure Homogenization conditions at 300 MPa with Ti = 75 and 85 °C were capable of a spore inactivation of ∼5 log CFU/mL. Furthermore, under these processing conditions, commercial sterility (evaluated as the complete inactivation of the inoculated spores) was obtained in milk, with the exception of G. stearothermophilus and B. subtilis treated at 300 MPa with Ti = 75 °C. The results showed that G. stearothermophilus and B. subtilis have higher resistance to the Ultra High-Pressure Homogenization treatments applied than the other microorganisms inoculated and that a treatment performed at 300 MPa with Ti = 85 °C was necessary to completely inactivate these microorganisms at the spore level inoculated (∼1 × 10(6) CFU/mL). Besides, a change in the resistance of B. licheniformis, B. sporothermodurans, G. stearothermophilus and B. subtilis spores was observed as the inactivation obtained increased remarkably in treatments performed with Ti between 65 and 75 °C. This study provides important evidence of the suitability of UHPH technology for the inactivation of spores in high numbers, leading to the possibility of obtaining commercially sterile milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of ultra high pressure homogenization treatment on the bioactive compounds of soya milk.

Science.gov (United States)

Toro-Funes, N; Bosch-Fusté, J; Veciana-Nogués, M T; Vidal-Carou, M C

2014-01-01

Ultra high pressure homogenization (UHPH) is a useful novel technology to obtain safe and high-quality liquid foods. The effect of UHPH at 200 and 300 MPa in combination with different inlet temperatures (Tin) (55, 65 and 75 °C) on the bioactive compounds of soya milk was studied. Total phytosterols increased with the higher combination of pressure and temperature. The main phytosterol was β-sitosterol, followed by stigmasterol and campesterol. Total tocopherols in UHPH-treated soya milks decreased as the temperature and pressure increased. UHPH treatment also affected the different chemical forms of tocopherols. No biogenic amines were detected in any of the analyzed soya milks. Meanwhile, the polyamines SPD and SPM were found in all soya milks, being stable to the UHPH treatment. Total isoflavones increased with the higher combination of pressure and temperature. No differences in the isoflavone profile were found, with β-glucoside conjugates being the predominant form. Copyright © 2013 Elsevier Ltd. All rights reserved.

On the common modulus attack into the LUC4,6 cryptosystem

Science.gov (United States)

Wong, Tze Jin; Said, Mohd Rushdan Md; Othman, Mohamed; Koo, Lee Feng

2015-05-01

The LUC4,6 cryptosystem is a system analogy with RSA cryptosystem and extended from LUC and LUC3 cryptosystems. The process of encryption and decryption are derived from the fourth order linear recurrence sequence and based on Lucas function. This paper reports an investigation into the common modulus attack on the LUC4,6 cryptosystem. In general, the common modulus attack will be succeeded if the sender sends the plaintext to two users used same RSA-modulus and both of encryption keys of them are relatively prime to each other. However, based on the characteristics of high order Lucas sequence, the LUC4,6 cryptosystem is unattackable

Ultra-high vacuum technology for accelerators

CERN Multimedia

CERN. Geneva. Audiovisual Unit; Hilleret, Noël; Strubin, Pierre M

2002-01-01

The lectures will start with a review of the basics of vacuum physics required to build Ultra High Vacuum (UHV) systems, such as static and dynamic outgassing. Before reviewing the various pumping and measurement devices, including the most modern one like Non Evaporable Getter (NEG) coatings, an overview of adequate materials to be used in UHV systems will be given together with their treatment (e.g. cleaning procedures and bake out). Practical examples based on existing or future accelerators will be used to illustrate the topics. Finally, a short overview of modern vacuum controls and interlocks will be given.

Ultra-high vacuum photoelectron linear accelerator

Science.gov (United States)

Yu, David U.L.; Luo, Yan

2013-07-16

An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

Proton probing of ultra-thin foil dynamics in high intensity regime

Science.gov (United States)

Prasad, Rajendra; Aktan, Esin; Aurand, Bastian; Cerchez, Mirela; Willi, Oswald

2017-10-01

The field of laser driven ion acceleration has been enriched significantly over the past decade, thanks to the advanced laser technologies. Already, from 100s TW class systems, laser driven sources of particles and radiations are being considered in number of potential applications in science and medicine due to their unique properties. New physical effects unearthed at these systems may help understand and conduct successful experiments at several PW class multi-beam facilities with high rep rate systems, e.g. ELI. Here we present the first experimental results on ultra-thin foil dynamics irradiated by an ultra-high intensity (1020 W/cm2) , ultra-high contrast (10-12) laser pulse at ARCTURUS laser facility at HHU Duesseldorf. By employing the elegant proton probing technique it is observed that for the circular polarization of laser light, a 100nm thin target is pushed forward as a compressed layer due to the radiation pressure of light. Whereas, the linear polarization seems to decompress the target drastically. 2D particle-in-cell simulations corroborate the experimental findings. Our results confirm the previous simulation studies investigating the fundamental role played by light polarization, finite focus spot size effect and eventually electron heating including the oblique incidence at the target edges.

Structure and bulk modulus of Ln-doped UO{sub 2} (Ln = La, Nd) at high pressure

Energy Technology Data Exchange (ETDEWEB)

Rittman, Dylan R., E-mail: drittman@stanford.edu [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Park, Sulgiye; Tracy, Cameron L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Zhang, Lei [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Palomares, Raul I.; Lang, Maik [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Navrotsky, Alexandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Mao, Wendy L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Ewing, Rodney C. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States)

2017-07-15

The structure of lanthanide-doped uranium dioxide, Ln{sub x}U{sub 1-x}O{sub 2-0.5x+y} (Ln = La, Nd), was investigated at pressures up to ∼50–55 GPa. Samples were synthesized with different lanthanides at different concentrations (x ∼ 0.2 and 0.5), and all were slightly hyperstoichiometric (y ∼ 0.25–0.4). In situ high-pressure synchrotron X-ray diffraction was used to investigate their high-pressure phase behavior and determine their bulk moduli. All samples underwent a fluorite-to-cotunnite phase transformation with increasing pressure. The pressure of the phase transformation increased with increasing hyperstoichiometry, which is consistent with results from previous computational simulations. Bulk moduli are inversely proportional to both the ionic radius of the lanthanide and its concentration, as quantified using a weighted cationic radius ratio. This trend was found to be consistent with the behavior of other elastic properties measured for Ln-doped UO{sub 2}, such as Young's modulus. - Highlights: •Ln-doped UO{sub 2} transforms from fluorite to cotunnite at high pressure. •Transition pressure increases with increasing hyperstoichiometry. •Bulk modulus decreases with increasing Ln-dopant radius and concentration.

Experiences of ultra-low-crud high-nickel control in Onagawa nuclear power station

International Nuclear Information System (INIS)

Saito, M.; Goto, Y.; Shinomiya, T.; Sato, M.; Yamazaki, K.; Hirasawa, H.; Yotsuyanagi, T.

2002-01-01

We have adopted various countermeasures for worker dose reduction to plants in Onagawa Nuclear Power Station. ''Ni/Fe ratio control'' has been adopted to Unit 1, and ''ultra-low-crud high-nickel control'' has been adopted to Unit 2 and 3, along with other countermeasures like wide utilization of low Co materials, for the purpose of dose rate reduction of primary recirculation piping which is thought to be one of the main exposure sources. In this paper, we describe, first, the reason and background that ultra-low-crud high-nickel control has been adopted to Unit 2, and, second, water chemistry of Unit 2 up to the 5. cycle under ultra-low-crud high-nickel control compared to that of Unit 1 under Ni/Fe ratio control. Following those, we show brief analysis of the fuel crud of Unit 2 and water chemistry of Unit 3 only at the startup stage. (authors)

Evaluation of the use of polymer modified bitumen in the production of high modulus asphalt for heavily-trafficked roads

CSIR Research Space (South Africa)

Komba, Julius J

2015-05-01

Full Text Available Enrobé à Module Élevé (EME) technology, a High Modulus Asphalt (HiMA), has been introduced to South Africa to provide an optimum solution for the design and construction of heavily trafficked roads. Implementation of EME technology in South Africa...

Determining the complex modulus of alginate irreversible hydrocolloid dental material.

Science.gov (United States)

King, Shalinie; See, Howard; Thomas, Graham; Swain, Michael

2008-11-01

The aim of the study is to investigate the visco-elastic response of an alginate irreversible hydrocolloid dental impression material during setting. A novel squeeze film Micro-Fourier Rheometer (MFR, GBC Scientific Equipment, Australia) was used to determine the complex modulus of an alginate irreversible hydrocolloid dental impression material (Algident, ISO 1563 Class A Type 1, Dentalfarm Australia Pty. Ltd.) during setting after mixing. Data was collected every 30s for 10 min in one study and every 10 min for a total of 60 min in another study. A high level of repeatability was observed. The results indicate that the MFR is capable of recording the complex shear modulus of alginate irreversible hydrocolloid for 60 min from the start of mixing and to simultaneously report the changing visco-elastic parameters at all frequencies between 1 Hz and 100 Hz. The storage modulus shows a dramatic increase to 370% of its starting value after 6 min and then reduces to 55% after 60 min. The loss modulus increases to a maximum of 175% of its starting value after 10 min and then reduces to 94% after 60 min. The MFR enables the changes in the complex modulus through the complete setting process to be followed. It is anticipated this approach may provide a better method to compare the visco-elastic properties of impression materials and assist with identification of optimum types for different clinical requirements. The high stiffness of the instrument and the use of band-limited pseudo-random noise as the input signal are the main advantages of this technique over conventional rheometers for determining the changes in alginate visco-elasticity.

High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries

Science.gov (United States)

Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

2014-04-22

A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics. In another aspect, the electrolyte exhibits a conductivity drop when the temperature of electrolyte increases over a threshold temperature, thereby providing a shutoff mechanism for preventing thermal runaway in lithium battery cells.

Nanocrystalline β-Ti alloy with high hardness, low Young's modulus and excellent in vitro biocompatibility for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Xie, Kelvin Y. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Wang, Yanbo, E-mail: yanbo.wang@sydney.edu.au [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Zhao, Yonghao [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Chang, Li; Wang, Guocheng; Chen, Zibin; Cao, Yang [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Liao, Xiaozhou, E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Lavernia, Enrique J. [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States); Valiev, Ruslan Z. [Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, K. Marksa 12, Ufa 450000 (Russian Federation); Sarrafpour, Babak; Zoellner, Hans [The Cellular and Molecular Pathology Research Unit, Department of Oral Pathology and Oral Medicine, Faculty of Dentistry, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia)

2013-08-01

High strength, low Young's modulus and good biocompatibility are desirable but difficult to simultaneously achieve in metallic implant materials for load bearing applications, and these impose significant challenges in material design. Here we report that a nano-grained β-Ti alloy prepared by high-pressure torsion exhibits remarkable mechanical and biological properties. The hardness and modulus of the nano-grained Ti alloy were respectively 23% higher and 34% lower than those of its coarse-grained counterpart. Fibroblast cell attachment and proliferation were enhanced, demonstrating good in vitro biocompatibility of the nano-grained Ti alloy, consistent with demonstrated increased nano-roughness on the nano-grained Ti alloy. Results suggest that the nano-grained β-Ti alloy may have significant application as an implant material in dental and orthopedic applications. - Highlights: • A bulk nanocrystalline β-Ti alloy was produced by high-pressure torsion processing. • Excellent mechanical properties for biomedical implants were obtained. • Enhanced in vitro biocompatibility was also demonstrated.

Static and Dynamic Behavior of High Modulus Hybrid Boron/Glass/Aluminum Fiber Metal Laminates

Science.gov (United States)

Yeh, Po-Ching

2011-12-01

This dissertation presents the investigation of a newly developed hybrid fiber metal laminates (FMLs) which contains commingled boron fibers, glass fibers, and 2024-T3 aluminum sheets. Two types of hybrid boron/glass/aluminum FMLs are developed. The first, type I hybrid FMLs, contained a layer of boron fiber prepreg in between two layers of S2-glass fiber prepreg, sandwiched by two aluminum alloy 2024-T3 sheets. The second, type II hybrid FMLs, contained three layer of commingled hybrid boron/glass fiber prepreg layers, sandwiched by two aluminum alloy 2024-T3 sheets. The mechanical behavior and deformation characteristics including blunt notch strength, bearing strength and fatigue behavior of these two types of hybrid boron/glass/aluminum FMLs were investigated. Compared to traditional S2-glass fiber reinforced aluminum laminates (GLARE), the newly developed hybrid boron/glass/aluminum fiber metal laminates possess high modulus, high yielding stress, and good blunt notch properties. From the bearing test result, the hybrid boron/glass/aluminum fiber metal laminates showed outstanding bearing strength. The high fiber volume fraction of boron fibers in type II laminates lead to a higher bearing strength compared to both type I laminates and traditional GLARE. Both types of hybrid FMLs have improved fatigue crack initiation lives and excellent fatigue crack propagation resistance compared to traditional GLARE. The incorporation of the boron fibers improved the Young's modulus of the composite layer in FMLs, which in turn, improved the fatigue crack initiation life and crack propagation rates of the aluminum sheets. Moreover, a finite element model was established to predict and verify the properties of hybrid boron/glass/aluminum FMLs. The simulated results showed good agreement with the experimental results.

Social cognition in patients at ultra-high risk for psychosis

DEFF Research Database (Denmark)

Glenthøj, Louise B.; Fagerlund, Birgitte; Hjorthøj, Carsten

2016-01-01

Objective: Patients at ultra-high risk (UHR) for psychosis show significant impairments in functioning. It is essential to determine which factors influence functioning, as it may have implications for intervention strategies. This study examined whether social cognitive abilities and clinical...

Thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure at high pressures and temperatures

International Nuclear Information System (INIS)

Sun Xiaowei; Liu Zijiang; Chen Qifeng; Chu Yandong; Wang Chengwei

2006-01-01

The thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure were estimated by using the constant temperature and pressure molecular dynamics technique with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction at high pressures and temperatures. It is shown that the calculated thermodynamic parameters including linear thermal expansion coefficient, isothermal bulk modulus and its pressure derivative are in good agreement with the available experimental data and the latest theoretical results. At an extended pressure and temperature ranges, linear thermal expansion coefficient and isothermal bulk modus have also been predicted. The thermodynamic properties of ZnO with NaCl-type cubic structure are summarized in the pressure 0-150 GPa ranges and the temperature up to 3000 K

Material Selection for an Ultra High Strength Steel Component Based on the Failure Criteria of CrachFEM

International Nuclear Information System (INIS)

Kessler, L.; Beier, Th.; Werner, H.; Horstkott, D.; Dell, H.; Gese, H.

2005-01-01

An increasing use of combining more than one process step is noticed for coupling crash simulations with the results of forming operations -- mostly by inheriting the forming history like plastic strain and material hardening. Introducing a continuous failure model allows a further benefit of these coupling processes; it sometimes can even be the most attractive result of such a work. In this paper the algorithm CrachFEM for fracture prediction has been used to generate more benefit of the successive forming and crash simulations -- especially for ultra high strength steels. The choice and selection of the material grade in combination with the component design can therefore be done far before the prototyping might show an unsuccessful crash result; and in an industrial applicable manner

Young’s Modulus and Poisson’s Ratio of Monolayer Graphyne

Directory of Open Access Journals (Sweden)

H. Rouhi

2013-09-01

Full Text Available Despite its numerous potential applications, two-dimensional monolayer graphyne, a novel form of carbon allotropes with sp and sp2 carbon atoms, has received little attention so far, perhaps as a result of its unknown properties. Especially, determination of the exact values of its elastic properties can pave the way for future studies on this nanostructure. Hence, this article describes a density functional theory (DFT investigation into elastic properties of graphyne including surface Young’s modulus and Poisson’s ratio. The DFT analyses are performed within the framework of generalized gradient approximation (GGA, and the Perdew–Burke–Ernzerhof (PBE exchange correlation is adopted. This study indicates that the elastic modulus of graphyne is approximately half of that of graphene due to its lower number of bonds.

Diamond dispersed cemented carbide produced without using ultra high pressure equipment

International Nuclear Information System (INIS)

Moriguchi, H.; Tsuzuki, K.; Ikegaya, A.

2001-01-01

We have developed a composite material of dispersed diamond particles in cemented carbide without using ultra high pressure equipment. The developed diamond dispersed cemented carbide combines the excellent properties of cemented carbide with diamond and also provides 1.5 times improved fracture toughness over that of cemented carbide. They also show 10 times higher wear resistance over that of cemented carbide in a wear resistance test against bearing steel, and 5 times greater grindability than diamond compacts. Because ultra high pressure equipment is not used to produce the developed material, large compacts over 100 mm in diameter can be manufactured. The developed material showed 10-25 times higher wear resistance in real use as wear-resistant tools such as centerless blades and work-rests. (author)

Small compression modulus of the flux line lattice and large density fluctuations at high fields may explain peak effect

International Nuclear Information System (INIS)

Brandt, E.H.

1976-01-01

The elastic properties of the flux line lattice in Type II superconductors as calculated from the Ginsburg-Landau theory are discussed. They are non-local on a length scale much larger than the flux line distance and divergent at Hsub(c2). The compression modulus may become much smaller than its long-wavelength limit, B 2 /4π, and if the deformation is not homogeneous, at Hsub(c2) the modulus vanishes as (Hsub(c2) - B) 2 . At arbitrary induction the compression modulus of strain waves with wavelengths of several flux line distances is of the order of the (small) shear modulus. (author)

Thermal compression modulus of polarized neutron matter

International Nuclear Information System (INIS)

Abd-Alla, M.

1990-05-01

We applied the equation of state for pure polarized neutron matter at finite temperature, calculated previously, to calculate the compression modulus. The compression modulus of pure neutron matter at zero temperature is very large and reflects the stiffness of the equation of state. It has a little temperature dependence. Introducing the spin excess parameter in the equation of state calculations is important because it has a significant effect on the compression modulus. (author). 25 refs, 2 tabs

Achieving Mixtures of Ultra-High Performance Concrete

Directory of Open Access Journals (Sweden)

Mircea POPA

2013-07-01

Full Text Available Ultra-High Performance Concrete (UHPC is a relatively new concrete. According to [11] UHPC is that concrete which features compressive strength over C100/115 class. Up to this point standards for this type of concrete were not adopted, although its characteristic strength exceeds those specified in [33]. Its main property is high compressive strength. This provides the possibility of reducing the section of elements (beams or columns made of this type of concrete, while the load capacity remains high. The study consists in blending mixtures of UHPC made of varying proportions of materials. The authors have obtained strengths of up to 160 MPa. The materials used are: Portland cement, silica fume, quartz powder, steel fibers, superplasticiser, sand and crushed aggregate for concrete - andesite.

mrsFAST-Ultra: a compact, SNP-aware mapper for high performance sequencing applications.

Science.gov (United States)

Hach, Faraz; Sarrafi, Iman; Hormozdiari, Farhad; Alkan, Can; Eichler, Evan E; Sahinalp, S Cenk

2014-07-01

High throughput sequencing (HTS) platforms generate unprecedented amounts of data that introduce challenges for processing and downstream analysis. While tools that report the 'best' mapping location of each read provide a fast way to process HTS data, they are not suitable for many types of downstream analysis such as structural variation detection, where it is important to report multiple mapping loci for each read. For this purpose we introduce mrsFAST-Ultra, a fast, cache oblivious, SNP-aware aligner that can handle the multi-mapping of HTS reads very efficiently. mrsFAST-Ultra improves mrsFAST, our first cache oblivious read aligner capable of handling multi-mapping reads, through new and compact index structures that reduce not only the overall memory usage but also the number of CPU operations per alignment. In fact the size of the index generated by mrsFAST-Ultra is 10 times smaller than that of mrsFAST. As importantly, mrsFAST-Ultra introduces new features such as being able to (i) obtain the best mapping loci for each read, and (ii) return all reads that have at most n mapping loci (within an error threshold), together with these loci, for any user specified n. Furthermore, mrsFAST-Ultra is SNP-aware, i.e. it can map reads to reference genome while discounting the mismatches that occur at common SNP locations provided by db-SNP; this significantly increases the number of reads that can be mapped to the reference genome. Notice that all of the above features are implemented within the index structure and are not simple post-processing steps and thus are performed highly efficiently. Finally, mrsFAST-Ultra utilizes multiple available cores and processors and can be tuned for various memory settings. Our results show that mrsFAST-Ultra is roughly five times faster than its predecessor mrsFAST. In comparison to newly enhanced popular tools such as Bowtie2, it is more sensitive (it can report 10 times or more mappings per read) and much faster (six times or

Multilayer ultra-high-temperature ceramic coatings

Science.gov (United States)

Loehman, Ronald E [Albuquerque, NM; Corral, Erica L [Tucson, AZ

2012-03-20

A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

Ultra high frequency induction welding of powder metal compacts

Directory of Open Access Journals (Sweden)

Çavdar, Uǧur

2014-06-01

Full Text Available The application of the iron based Powder Metal (PM compacts in Ultra High Frequency Induction Welding (UHFIW were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined.Soldadura por inducción de ultra alta frecuencia de polvos de metal compactados. Se ha realizado un estudio de la aplicación de polvos de metal (PM de base hierro compactados por soldadura por inducción de ultra alta frecuencia (UHFIW. Estos polvos de metal compactados se utilizan para producir engranajes. Este estudio investiga los métodos de uni.n de los materiales de PM con UHFIW en su aplicación en la industria. La máxima tensión y la máxima deformación de los polvos de metal compactados soldados fueron determinadas por flexión en tres puntos y prueba de resistencia. Se determinó la microdureza y la microestructura de los polvos compactados por soldadura por inducción.

Dynamic modulus of nanosilica modified porous asphalt

Science.gov (United States)

Arshad, A. K.; Masri, K. A.; Ahmad, J.; Samsudin, M. S.

2017-11-01

Porous asphalt (PA) is a flexible pavement layer with high interconnected air void contents and constructed using open-graded aggregates. Due to high temperature environment and increased traffic volume in Malaysia, PA may have deficiencies particularly in rutting and stiffness of the mix. A possible way to improve these deficiencies is to improve the asphalt binder used. Binder is normally modified using polymer materials to improve its properties. However, nanotechnology presently is being gradually used for asphalt modification. Nanosilica (NS), a byproduct of rice husk and palm oil fuel ash is used as additive in this study. The aim of this study is to enhance the rutting resistance and stiffness performance of PA using NS. This study focused on the performance of PA in terms of dynamic modulus with the addition of NS modified binder to produce better and more durable PA. From the result of Dynamic SPT Test, it shows that the addition of NS was capable in enhancing the stiffness and rutting resistance of PA. The addition of NS also increase the dynamic modulus value of PA by 50%.

Maximisation of the ratio of microhardness to the Young's modulus of Ti-12Mo-13Nb alloy through microstructure changes.

Science.gov (United States)

Gabriel, Sinara B; de Almeida, Luiz H; Nunes, Carlos A; Dille, Jean; Soares, Glória A

2013-08-01

Alloys for orthopaedic and dentistry applications require high mechanical strength and a low Young's modulus to avoid stress shielding. Metastable β titanium alloys appear to fulfil these requirements. This study investigated the correlation of phases precipitated in a Ti-12Mo-13Nb alloy with changes in hardness and the Young's modulus. The alloy was produced by arc melting under an argon atmosphere, after which, it was heat treated and cold forged. Two different routes of heat treatment were employed. Phase transformations were studied by employing X-ray diffraction and transmission electron microscopy. Property characterisation was based on Vickers microhardness tests and Young's modulus measurements. The highest ratio of microhardness to the Young's modulus was obtained using thermomechanical treatment, which consists of heating at 1000°C for 24h, water quenching, cold forging to reduce 80% of the area, and ageing at 500°C for 24h, where the final microstructure consisted of an α phase dispersed in a β matrix. The α phase appeared in two different forms: as fine lamellas (with 240±100 nm length) and massive particles of 200-500 nm size. Copyright © 2013 Elsevier B.V. All rights reserved.

Mechanical characteristics of ultra-long horizontal nanocantilevers grown by real-time feedback control on focused-ion-beam chemical vapour deposition

International Nuclear Information System (INIS)

Guo, Dengji; Warisawa, Shin’ichi; Ishihara, Sunao; Kometani, Reo

2015-01-01

Focused-ion-beam chemical vapour deposition (FIB-CVD) has been repeatedly proved to be a useful tool for the growth of three-dimensional (3D) micro- and nano-structures. The strategy of real-time feedback control on FIB-CVD was previously proposed and experimentally demonstrated to be effective for growing ultra-long horizontal nanocantilevers. To fabricate various nanoelectromechanical systems that consist of such types of nanocantilever structures, the mechanical characteristics of ultra-long horizontal nanocantilevers should be investigated. In this study, nanocantilevers with an overhang length of up to 35 μm were grown by using a 30 kV Ga + FIB, a beam current of 0.50 pA and phenanthrene (C 14 H 10 ) as the gas source to deposit a diamond-like carbon structure. The Young’s modulus of each nanocantilever was measured by bending the nanocantilever with a nanopillar whose Young’s modulus was known. The average density of each nanocantilever was calculated from the Young’s modulus and the measured resonant frequency. We found that the mechanical characteristics of each nanocantilever depended on the length of the nanocantilever if the strategy of real-time feedback control was applied in fabrication. The Young’s moduli and the averaged densities of the nanocantilevers with a length of 11 to 34 μm were found to be 86 to 254 GPa and 1950 to 5750 kg m −3 , respectively. With the increase of the overhang length, the Young’s modulus and the average density were found to gradually increase. (paper)

Ultra-high efficiency, fast graphene micro-heater on silicon

DEFF Research Database (Denmark)

Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn

2017-01-01

We demonstrate an ultra-high efficiency and fast graphene microheater on silicon photonic crystal waveguide. By taking advantage of slow-light effect, a tuning efficiency of 1.07 nm/mW and power consumption per free spectral range of 3.99 mW. A fast rise and decay times (10% to 90%) of only 750 ns...

Theory of thermal expansivity and bulk modulus

International Nuclear Information System (INIS)

Kumar, Munish

2005-01-01

The expression for thermal expansivity and bulk modulus, claimed by Shanker et al. to be new [Physica B 233 (1977) 78; 245 (1998) 190; J. Phys. Chem. Solids 59 (1998) 197] are compared with the theory of high pressure-high temperature reported by Kumar and coworkers. It is concluded that the Shanker formulation and the relations based on this are equal to the approach of Kumar et al. up to second order

A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

Energy Technology Data Exchange (ETDEWEB)

Feister, S., E-mail: feister.7@osu.edu; Orban, C. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Nees, J. A. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Center for Ultra-Fast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Morrison, J. T. [Fellow, National Research Council, Washington, D.C. 20001 (United States); Frische, K. D. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Chowdhury, E. A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

2014-11-15

Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

3-D FDTD simulation of shear waves for evaluation of complex modulus imaging.

Science.gov (United States)

Orescanin, Marko; Wang, Yue; Insana, Michael

2011-02-01

The Navier equation describing shear wave propagation in 3-D viscoelastic media is solved numerically with a finite differences time domain (FDTD) method. Solutions are formed in terms of transverse scatterer velocity waves and then verified via comparison to measured wave fields in heterogeneous hydrogel phantoms. The numerical algorithm is used as a tool to study the effects on complex shear modulus estimation from wave propagation in heterogeneous viscoelastic media. We used an algebraic Helmholtz inversion (AHI) technique to solve for the complex shear modulus from simulated and experimental velocity data acquired in 2-D and 3-D. Although 3-D velocity estimates are required in general, there are object geometries for which 2-D inversions provide accurate estimations of the material properties. Through simulations and experiments, we explored artifacts generated in elastic and dynamic-viscous shear modulus images related to the shear wavelength and average viscosity.

Effect of an 8K ultra-high-definition television system in a case of laparoscopic gynecologic surgery.

Science.gov (United States)

Aoki, Yoichi; Matsuura, Masahiko; Chiba, Toshio; Yamashita, Hiromasa

2017-09-01

Various endoscopic devices have been developed for advanced minimally invasive surgery. We recently applied a new 8K ultra-high-definition television system during laparoscopic treatment of endometriosis. The procedure, which is described in detail, stands as the first reported application of an 8K ultra-high-definition system for laparoscopic gynecologic surgery. Comparison is made between depiction of the lesion by the new system and depiction by a full high-definition system. Improved diagnostic accuracy resulted from the increased image resolution, and we believe that this and other advantages will lead to widespread acceptance and further application of 8K ultra-high-definition systems in the field of gynecologic surgery.

Magnetic resonance imaging and spectroscopy at ultra high fields

International Nuclear Information System (INIS)

Neuberger, Thomas

2009-01-01

The goal of the work presented in this thesis was to explore the possibilities and limitations of MRI / MRS using an ultra high field of 17.6 tesla. A broad range of specific applications and MR methods, from MRI to MRSI and MRS were investigated. The main foci were on sodium magnetic resonance spectroscopic imaging of rodents, magnetic resonance spectroscopy of the mouse brain, and the detection of small amounts of iron labeled stem cells in the rat brain using MRI Sodium spectroscopic imaging was explored since it benefits tremendously from the high magnetic field. Due to the intrinsically low signal in vivo, originating from the low concentrations and short transverse relaxation times, only limited results have been achieved by other researchers until now. Results in the literature include studies conducted on large animals such as dogs to animals as small as rats. No studies performed on mice have been reported, despite the fact that the mouse is the most important laboratory animal due to the ready availability of transgenic strains. Hence, this study concentrated on sodium MRSI of small rodents, mostly mice (brain, heart, and kidney), and in the case of the brain on young rats. The second part of this work concentrated on proton magnetic resonance spectroscopy of the rodent brain. Due to the high magnetic field strength not only the increasing signal but also the extended spectral resolution was advantageous for such kind of studies. The difficulties/limitations of ultra high field MRS were also investigated. In the last part of the presented work detection limits of iron labeled stem cells in vivo using magnetic resonance imaging were explored. The studies provided very useful benchmarks for future researchers in terms of the number of labeled stem cells that are required for high-field MRI studies. Overall this work has shown many of the benefits and the areas that need special attention of ultra high fields in MR. Three topics in MRI, MRS and MRSI were

Magnetic resonance imaging and spectroscopy at ultra high fields

Energy Technology Data Exchange (ETDEWEB)

Neuberger, Thomas

2009-06-23

The goal of the work presented in this thesis was to explore the possibilities and limitations of MRI / MRS using an ultra high field of 17.6 tesla. A broad range of specific applications and MR methods, from MRI to MRSI and MRS were investigated. The main foci were on sodium magnetic resonance spectroscopic imaging of rodents, magnetic resonance spectroscopy of the mouse brain, and the detection of small amounts of iron labeled stem cells in the rat brain using MRI Sodium spectroscopic imaging was explored since it benefits tremendously from the high magnetic field. Due to the intrinsically low signal in vivo, originating from the low concentrations and short transverse relaxation times, only limited results have been achieved by other researchers until now. Results in the literature include studies conducted on large animals such as dogs to animals as small as rats. No studies performed on mice have been reported, despite the fact that the mouse is the most important laboratory animal due to the ready availability of transgenic strains. Hence, this study concentrated on sodium MRSI of small rodents, mostly mice (brain, heart, and kidney), and in the case of the brain on young rats. The second part of this work concentrated on proton magnetic resonance spectroscopy of the rodent brain. Due to the high magnetic field strength not only the increasing signal but also the extended spectral resolution was advantageous for such kind of studies. The difficulties/limitations of ultra high field MRS were also investigated. In the last part of the presented work detection limits of iron labeled stem cells in vivo using magnetic resonance imaging were explored. The studies provided very useful benchmarks for future researchers in terms of the number of labeled stem cells that are required for high-field MRI studies. Overall this work has shown many of the benefits and the areas that need special attention of ultra high fields in MR. Three topics in MRI, MRS and MRSI were

High-performance UV detector made of ultra-long ZnO bridging nanowires

International Nuclear Information System (INIS)

Li Yanbo; Della Valle, Florent; Simonnet, Mathieu; Yamada, Ichiro; Delaunay, Jean-Jacques

2009-01-01

A nanowatt UV photoconductive detector made up of ultra-long (∼100 μm) ZnO bridging nanowires has been fabricated by a single-step chemical vapor deposition (CVD) process. The electrodes, forming comb-shaped thick ZnO layers, and the sensing elements, consisting of ZnO nanowires bridging the electrodes, were fabricated simultaneously in a single-step CVD process. The device showed drastic changes (10-10 5 times) in current under a wide range of UV irradiances (10 -8 -10 -2 W cm -2 ). Moreover, the detector exhibited fast response (rise and decay times of the order of 1 s) to UV illumination in air, but no response to visible light (hν<3.2 eV). Our approach provides a simple and cost-effective way to fabricate high-performance 'visible-blind' UV detectors.

In situ determination of a rock mass modulus using a high resolution tiltmeter

Energy Technology Data Exchange (ETDEWEB)

Saleh, B.; Husein Malkawi, A.I. [University of Jordan, Amman (Jordan); Blum, P.A. [Universite Pierre et Marie Curie, 75 - Paris (France)

1996-04-01

A very sensitive, compact tiltmeter made of melted silica, developed for the measurement of small deformations of various civil engineering structures, was described. The instrument is capable of giving a continuous record and was used to establish a new approach to directly evaluating the in situ average elastic rock mass modulus. Such information is important in decision making during the design stages of large civil engineering works, such as dams, nuclear plant facilities, and underground structures. Five tiltmeters were installed on the facades of the Louvre in Paris to study the deformation induced by internal structural work and by the impact of the Paris metro traffic movement. The data was used to determine displacement using the Boussinesq equation. Results were consistent with typical elastic rock-mass modulus for the rock found in the museum`s foundations. 13 refs., 1 tab., 10 figs.

Ultra-high energy cosmic rays: Setting the stage

Science.gov (United States)

Sokolsky, P.

2013-06-01

The history of ultra-high energy cosmic ray physics is reviewed from the post-war era of arrays such as Volcano Ranch, Haverah Park and Akeno to the development of air-fluorescence and current hybrid arrays. The aim of this paper is to present the background information needed for a better understanding of the current issues in this field that are discussed in much greater depth in the rest of this conference.

Ultra-high energy cosmic rays: Setting the stage

Directory of Open Access Journals (Sweden)

Sokolsky P.

2013-06-01

Full Text Available The history of ultra-high energy cosmic ray physics is reviewed from the post-war era of arrays such as Volcano Ranch, Haverah Park and Akeno to the development of air-fluorescence and current hybrid arrays. The aim of this paper is to present the background information needed for a better understanding of the current issues in this field that are discussed in much greater depth in the rest of this conference.

Ultra-high-field magnets for future hadron colliders

International Nuclear Information System (INIS)

McIntyre, P.M.; Shen, W.

1997-01-01

Several new concepts in magnetic design and coil fabrication are being incorporated into designs for ultra-high field collider magnets: a 16 Tesla block-coil dual dipole, also using Nb 3 Sn cable, featuring simple pancake coil construction and face-loaded prestress geometry; a 330 T/m block-coil quadrupole; and a ∼ 20 Tesla pipe-geometry dual dipole, using A15 or BSCCO tape. Field design and fabrication issues are discussed for each magnet

A Two-Step Methodology to Study the Influence of Aggregation/Agglomeration of Nanoparticles on Young's Modulus of Polymer Nanocomposites

Science.gov (United States)

Ma, Xinyue; Zare, Yasser; Rhee, Kyong Yop

2017-12-01

A two-step technique based on micromechanical models is suggested to determine the influence of aggregated/agglomerated nanoparticles on Young's modulus of polymer nanocomposites. The nanocomposite is assumed to include nanoparticle aggregation/agglomeration and effective matrix phases. This method is examined for different samples, and the effects of important parameters on the modulus are investigated. Moreover, the highest and the lowest levels of predicted modulus are calculated based on the current methodology. The suggested technique can correctly predict Young's modulus for the samples assuming the aggregation/agglomeration of nanoparticles. Additionally, the aggregation/agglomeration of nanoparticles decreases Young's modulus of polymer nanocomposites. It is demonstrated that the high modulus of nanoparticles is not sufficient to obtain a high modulus in nanocomposites, and the surface chemistry of components should be adjusted to prevent aggregation/agglomeration and to disperse nano-sized particles in the polymer matrix.

Research on precision grinding technology of large scale and ultra thin optics

Science.gov (United States)

Zhou, Lian; Wei, Qiancai; Li, Jie; Chen, Xianhua; Zhang, Qinghua

2018-03-01

The flatness and parallelism error of large scale and ultra thin optics have an important influence on the subsequent polishing efficiency and accuracy. In order to realize the high precision grinding of those ductile elements, the low deformation vacuum chuck was designed first, which was used for clamping the optics with high supporting rigidity in the full aperture. Then the optics was planar grinded under vacuum adsorption. After machining, the vacuum system was turned off. The form error of optics was on-machine measured using displacement sensor after elastic restitution. The flatness would be convergenced with high accuracy by compensation machining, whose trajectories were integrated with the measurement result. For purpose of getting high parallelism, the optics was turned over and compensation grinded using the form error of vacuum chuck. Finally, the grinding experiment of large scale and ultra thin fused silica optics with aperture of 430mm×430mm×10mm was performed. The best P-V flatness of optics was below 3 μm, and parallelism was below 3 ″. This machining technique has applied in batch grinding of large scale and ultra thin optics.

Ultra-high density aligned Carbon-nanotube with controled nano-morphology for supercapacitors

Science.gov (United States)

Ghaffari, Mehdi; Zhao, Ran; Liu, Yang; Zhou, Yue; Cheng, Jiping; Guzman de Villoria, Roberto; Wardle, B. L.; Zhang, Q. M.

2012-02-01

Recent advances in fabricating controlled-morphology vertically aligned carbon nanotubes (VA-CNTs) with ultrahigh volume fractioncreate unique opportunities for developing unconventional supercapacitors with ultra-high energy density, power density, and long charge/discharge cycle life.Continuous paths through inter-VA-CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast discharge speed. We investigate the charge-discharge characteristics of VA-CNTs with >20 vol% of CNT and ionic liquids as electrolytes. By employing both the electric and electromechanical spectroscopes, as well as nanostructured materials characterization, the ion transport and storage behaviors in porous electrodes are studied. The results suggest pathways for optimizing the electrode morphology in supercapacitorsusing ultra-high volume fraction VA-CNTs to further enhance performance.

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

Czech Academy of Sciences Publication Activity Database

Alvarez-Muñiz, J.; Soares, E.A.; Berlin, A.; Bogdan, M.; Boháčová, Martina; Bonifazi, C.; Carvalho, W.R.; de Mello Neto, J.R.T.; San Luis, P.F.; Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L.C.; Richardson, M.; Rouille D’Orfeuil, B.; Santos, E.M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

2013-01-01

Roč. 719, Aug (2013), s. 70-80 ISSN 0168-9002 Institutional support: RVO:68378271 Keywords : ultra high energy cosmic rays * radio-detection * microwave * GHz Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.316, year: 2013

Flavor characterization of sugar-added pennywort (Centella asiatica L.) juices treated with ultra-high pressure and thermal processes.

Science.gov (United States)

Apichartsrangkoon, Arunee; Wongfhun, Pronprapa; Gordon, Michael H

2009-01-01

The flavor characteristics of pennywort juices with added sugar treated by ultra-high pressure, pasteurization, and sterilization were investigated using solid phase microextraction combined with gas chromatography-mass spectrometry. It was found that sesquiterpene hydrocarbons comprised the major class of volatile components present and the juices had a characteristic aroma due to the presence of volatiles including beta-caryophyllene and humulene and alpha-copaene. In comparison with heated juices, HPP-treated samples could retain more volatile compounds such as linalool and geraniol similar to those present in fresh juice, whereas some volatiles such as alpha-terpinene and ketone class were apparently formed by thermal treatment. All processing operations produced juice that was not significantly different in the concentration of total volatiles. Practical Application: Pennywort juice is considered a nutraceutical drink for health benefits. Therefore, to preserve all aroma and active components in this juice, a nonthermal process such as ultra-high pressure should be a more appropriate technique for retention of its nutritive values than pasteurization and sterilization.

A highly selective molecularly imprinted electrochemiluminescence sensor for ultra-trace beryllium detection

International Nuclear Information System (INIS)

Li, Jianping; Ma, Fei; Wei, Xiaoping; Fu, Cong; Pan, Hongcheng

2015-01-01

Graphical abstract: A novel molecular imprinted electrochemiluminescence sensor was fabricated for ultra-trace Be 2+ detection with an extremely lower detection limit based on the luminol–H 2 O 2 ECL system. - Highlights: • A novel molecular imprinted electrochemiluminescence sensor was fabricated for ultra-trace Be 2+ detection. • Imprint cavities in the MIPs from elution the Be–PAR complex could provide more recognition sites for analytes. • ECL emission produced by the luminol–H 2 O 2 ECL system, which was applied to detect Be 2+ . • It gave an extremely lower detection limit (2.35 × 10 −11 mol L −1 ) than the reported methods. - Abstract: A new molecularly imprinted electrochemiluminescence (ECL) sensor was proposed for highly sensitive and selective determination of ultratrace Be 2+ determination. The complex of Be 2+ with 4-(2-pyridylazo)-resorcinol (PAR) was chosen as the template molecule for the molecularly imprinted polymer (MIP). In this assay, the complex molecule could be eluted from the MIP, and the cavities formed could then selectively recognize the complex molecules. The cavities formed could also work as the tunnel for the transfer of probe molecules to produce sound responsive signal. The determination was based on the intensity of the signal, which was proportional to the concentrations of the complex molecule in the sample solution, and the Be 2+ concentration could then be determined indirectly. The results showed that in the range of 7 × 10 −11 mol L −1 to 8.0 × 10 −9 mol L −1 , the ECL intensity had a linear relationship with the Be 2+ concentrations, with the limit of detection of 2.35 × 10 −11 mol L −1 . This method was successfully used to detect Be 2+ in real water samples

The adhesive properties of chlorinated ultra-high molecular weight polyethylene

NARCIS (Netherlands)

Menting, H.N.A.M.; Voets, P.E.L.; Lemstra, P.J.

1995-01-01

Ultra-high molecular weight polyethylene (UHMW-PE) is well known for its abrasion and chemical resistance. Recently we developed a new application for UHMW-PE as a liner in elastomeric hoses. It was found that the adhesion between UHMW-PE and elastomers such as ethylene-propylene-diene monomer

Ultra-stiff metallic glasses through bond energy density design.

Science.gov (United States)

Schnabel, Volker; Köhler, Mathias; Music, Denis; Bednarcik, Jozef; Clegg, William J; Raabe, Dierk; Schneider, Jochen M

2017-07-05

The elastic properties of crystalline metals scale with their valence electron density. Similar observations have been made for metallic glasses. However, for metallic glasses where covalent bonding predominates, such as metalloid metallic glasses, this relationship appears to break down. At present, the reasons for this are not understood. Using high energy x-ray diffraction analysis of melt spun and thin film metallic glasses combined with density functional theory based molecular dynamics simulations, we show that the physical origin of the ultrahigh stiffness in both metalloid and non-metalloid metallic glasses is best understood in terms of the bond energy density. Using the bond energy density as novel materials design criterion for ultra-stiff metallic glasses, we are able to predict a Co 33.0 Ta 3.5 B 63.5 short range ordered material by density functional theory based molecular dynamics simulations with a high bond energy density of 0.94 eV Å -3 and a bulk modulus of 263 GPa, which is 17% greater than the stiffest Co-B based metallic glasses reported in literature.

High Bulk Modulus of Ionic Liquid and Effects on Performance of Hydraulic System

Directory of Open Access Journals (Sweden)

Milan Kambic

2014-01-01

Full Text Available Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication, and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus, compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems’ dynamic responses.

High bulk modulus of ionic liquid and effects on performance of hydraulic system.

Science.gov (United States)

Kambic, Milan; Kalb, Roland; Tasner, Tadej; Lovrec, Darko

2014-01-01

Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication), and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus), compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems' dynamic responses.

Thermal characterization of Ag and Ag + N ion implanted ultra-high molecular weight polyethylene (UHMWPE)

Science.gov (United States)

Sokullu Urkac, E.; Oztarhan, A.; Tihminlioglu, F.; Kaya, N.; Ila, D.; Muntele, C.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tek, Z.

2007-08-01

Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 1017 ion/cm2 and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE.

High and ultra-high resolution metabolite mapping of the human brain using 1H FID MRSI at 9.4T.

Science.gov (United States)

Nassirpour, Sahar; Chang, Paul; Henning, Anke

2018-03-01

Magnetic resonance spectroscopic imaging (MRSI) is a promising technique for mapping the spatial distribution of multiple metabolites in the human brain. These metabolite maps can be used as a diagnostic tool to gain insight into several biochemical processes and diseases in the brain. In comparison to lower field strengths, MRSI at ultra-high field strengths benefits from a higher signal to noise ratio (SNR) as well as higher chemical shift dispersion, and hence spectral resolution. This study combines the benefits of an ultra-high field magnet with the advantages of an ultra-short TE and TR single-slice FID-MRSI sequence (such as negligible J-evolution and loss of SNR due to T 2 relaxation effects) and presents the first metabolite maps acquired at 9.4T in the healthy human brain at both high (voxel size of 97.6µL) and ultra-high (voxel size of 24.4µL) spatial resolutions in a scan time of 11 and 46min respectively. In comparison to lower field strengths, more anatomically-detailed maps with higher SNR from a larger number of metabolites are shown. A total of 12 metabolites including glutamate (Glu), glutamine (Gln), N-acetyl-aspartyl-glutamate (NAAG), Gamma-aminobutyric acid (GABA) and glutathione (GSH) are reliably mapped. Comprehensive description of the methodology behind these maps is provided. Copyright © 2016 Elsevier Inc. All rights reserved.

Born dry in the photoevaporation desert: Kepler's ultra-short-period planets formed water-poor

Science.gov (United States)

Lopez, Eric D.

2017-11-01

Recent surveys have uncovered an exciting new population of ultra-short-period (USP) planets with orbital periods less than a day. These planets typically have radii ≲1.5 R⊕, indicating that they likely have rocky compositions. This stands in contrast to the overall distribution of planets out to ∼100 d, which is dominated by low-density sub-Neptunes above 2 R⊕, which must have gaseous envelopes to explain their size. However, on the USP orbits, planets are bombarded by intense levels of photoionizing radiation and consequently gaseous sub-Neptunes are extremely vulnerable to losing their envelopes to atmospheric photoevaporation. Using models of planet evolution, I show that the rocky USP planets can easily be produced as the evaporated remnants of sub-Neptunes with H/He envelopes and that we can therefore understand the observed dearth of USP sub-Neptunes as a natural consequence of photoevaporation. Critically however, planets on USP orbits could often retain their envelopes if they are formed with very high-metallicity water-dominated envelopes. Such water-rich planets would commonly be ≳2 R⊕ today, which is inconsistent with the observed evaporation desert, indicating that most USP planets likely formed from water-poor material within the snow-line. Finally, I examine the special case of 55 Cancri e and its possible composition in the light of recent observations, and discuss the prospects for further characterizing this population with future observations.

Ultra high spatial and temporal resolution breast imaging at 7T.

Science.gov (United States)

van de Bank, B L; Voogt, I J; Italiaander, M; Stehouwer, B L; Boer, V O; Luijten, P R; Klomp, D W J

2013-04-01

There is a need to obtain higher specificity in the detection of breast lesions using MRI. To address this need, Dynamic Contrast-Enhanced (DCE) MRI has been combined with other structural and functional MRI techniques. Unfortunately, owing to time constraints structural images at ultra-high spatial resolution can generally not be obtained during contrast uptake, whereas the relatively low spatial resolution of functional imaging (e.g. diffusion and perfusion) limits the detection of small lesions. To be able to increase spatial as well as temporal resolution simultaneously, the sensitivity of MR detection needs to increase as well as the ability to effectively accelerate the acquisition. The required gain in signal-to-noise ratio (SNR) can be obtained at 7T, whereas acceleration can be obtained with high-density receiver coil arrays. In this case, morphological imaging can be merged with DCE-MRI, and other functional techniques can be obtained at higher spatial resolution, and with less distortion [e.g. Diffusion Weighted Imaging (DWI)]. To test the feasibility of this concept, we developed a unilateral breast coil for 7T. It comprises a volume optimized dual-channel transmit coil combined with a 30-channel receive array coil. The high density of small coil elements enabled efficient acceleration in any direction to acquire ultra high spatial resolution MRI of close to 0.6 mm isotropic detail within a temporal resolution of 69 s, high spatial resolution MRI of 1.5 mm isotropic within an ultra high temporal resolution of 6.7 s and low distortion DWI at 7T, all validated in phantoms, healthy volunteers and a patient with a lesion in the right breast classified as Breast Imaging Reporting and Data System (BI-RADS) IV. Copyright © 2012 John Wiley & Sons, Ltd.

Ultra-processed products are becoming dominant in the global food system.

Science.gov (United States)

Monteiro, C A; Moubarac, J-C; Cannon, G; Ng, S W; Popkin, B

2013-11-01

The relationship between the global food system and the worldwide rapid increase of obesity and related diseases is not yet well understood. A reason is that the full impact of industrialized food processing on dietary patterns, including the environments of eating and drinking, remains overlooked and underestimated. Many forms of food processing are beneficial. But what is identified and defined here as ultra-processing, a type of process that has become increasingly dominant, at first in high-income countries, and now in middle-income countries, creates attractive, hyper-palatable, cheap, ready-to-consume food products that are characteristically energy-dense, fatty, sugary or salty and generally obesogenic. In this study, the scale of change in purchase and sales of ultra-processed products is examined and the context and implications are discussed. Data come from 79 high- and middle-income countries, with special attention to Canada and Brazil. Results show that ultra-processed products dominate the food supplies of high-income countries, and that their consumption is now rapidly increasing in middle-income countries. It is proposed here that the main driving force now shaping the global food system is transnational food manufacturing, retailing and fast food service corporations whose businesses are based on very profitable, heavily promoted ultra-processed products, many in snack form. © 2013 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of the International Association for the Study of Obesity.

Structural modifications of ultra-high molecular weight polyethylene (UHMWPE) processed in attritor type mill

International Nuclear Information System (INIS)

Gabriel, Melina C.; Carvalho, Benjamim de M.; Pinheiro, Luis A.; Cintho, Osvaldo M.; Capocchi, Jose D.T.; Kubaski, Evaldo T.

2009-01-01

Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene that has a high melt viscosity, hence its processing becomes very difficult. High-energy mechanical milling provides physical and chemical changes in polymers that have been studied recently. In order to study these changes in UHMWPE, powder of this polymer was mechanical milled in attritor type mill with a ball-to-powder weight ratio of 40:1 for 8 hours, varying the rotation speed: 200, 300, 400, 500 e 600 rpm. The polymer was characterized by scanning electron microscopy (SEM) and xray diffraction (XRD). From the XRD results it was noted that as the rotation speed increased the monoclinic phase also increased up to 500 rpm. For 600 rpm, the amount of monoclinic phase apparently decreased. At this rotation speed, the deformation rate probably increased the process temperature, allowing the monoclinic phase to return to its initial structural orthorhombic form. (author)

Influence of substrate modulus on gecko adhesion

Science.gov (United States)

Klittich, Mena R.; Wilson, Michael C.; Bernard, Craig; Rodrigo, Rochelle M.; Keith, Austin J.; Niewiarowski, Peter H.; Dhinojwala, Ali

2017-03-01

The gecko adhesion system fascinates biologists and materials scientists alike for its strong, reversible, glue-free, dry adhesion. Understanding the adhesion system’s performance on various surfaces can give clues as to gecko behaviour, as well as towards designing synthetic adhesive mimics. Geckos encounter a variety of surfaces in their natural habitats; tropical geckos, such as Gekko gecko, encounter hard, rough tree trunks as well as soft, flexible leaves. While gecko adhesion on hard surfaces has been extensively studied, little work has been done on soft surfaces. Here, we investigate for the first time the influence of macroscale and nanoscale substrate modulus on whole animal adhesion on two different substrates (cellulose acetate and polydimethylsiloxane) in air and find that across 5 orders of magnitude in macroscale modulus, there is no change in adhesion. On the nanoscale, however, gecko adhesion is shown to depend on substrate modulus. This suggests that low surface-layer modulus may inhibit the gecko adhesion system, independent of other influencing factors such as macroscale composite modulus and surface energy. Understanding the limits of gecko adhesion is vital for clarifying adhesive mechanisms and in the design of synthetic adhesives for soft substrates (including for biomedical applications and wearable electronics).

Innovative Ultra-High Efficiency Cryogenic Actuators for Rocket Test Facilities, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The SBIR Phase I project will develop advanced ultra-high efficiency cryogenic actuators for NASA cryogenic fluid transfer application. The actuator will have low...

Low modulus and bioactive Ti/α-TCP/Ti-mesh composite prepared by spark plasma sintering.

Science.gov (United States)

Guo, Yu; Tan, Yanni; Liu, Yong; Liu, Shifeng; Zhou, Rui; Tang, Hanchun

2017-11-01

A titanium mesh scaffold composite filled with Ti/α-TCP particles was prepared by spark plasma sintering (SPS). The microstructures and interfacial reactions of the composites were investigated by scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The compressive strength and elastic modulus were also measured. In vitro bioactivity and biocompatibility was evaluated by using simulated body fluid and cells culture, respectively. After high temperature sintering, Ti oxides, Ti x P y and CaTiO 3 were formed. The formation of Ti oxides and Ti x P y were resulted from the diffusion of O and P elements from α-TCP to Ti. CaTiO 3 was the reaction product of Ti and α-TCP. The composite of 70Ti/α-TCP incorporated with Ti mesh showed a high compressive strength of 589MPa and a low compressive modulus of 30GPa. The bioactivity test showed the formation of a thick apatite layer on the composite and well-spread cells attachment. A good combination of mechanical properties and bioactivity indicated a high potential application of Ti/α-TCP/Ti-mesh composite for orthopedic implants. Copyright © 2017. Published by Elsevier B.V.

Intervention in individuals at ultra-high risk for psychosis: a review and future directions

DEFF Research Database (Denmark)

McGorry, Patrick D; Nelson, Barnaby; Amminger, G Paul

2009-01-01

OBJECTIVE: Over the last 15 years, a focus on early intervention in psychotic disorders has emerged. Initially, the early psychosis movement focused on timely recognition and phase-specific treatment of first-episode psychosis. However, early psychosis researchers suspected that pushing the point...... of intervention even further back to the prodromal phase of psychotic disorders may result in even better outcomes. This article reviews intervention research in the ultra-high-risk phase of psychotic disorders. DATA SOURCES: A literature search of intervention trials with ultra-high-risk cohorts published after...

Preamplifier with ultra low frequency cutoff for infrasonic condenser microphone

DEFF Research Database (Denmark)

Kinnerup, Rasmus Trock; Marbjerg, Kresten; Rasmussen, Per

2012-01-01

low frequencies becomes a challenge. The electric preamplifier presented in this paper together with a prepolarized condenser microphone form a measurement system. The developed preamplifier connects the microphone signal directly to the input of an operational amplifier with ultra high input...

Variable modulus cellular structures using pneumatic artificial muscles

Science.gov (United States)

Pontecorvo, Michael E.; Niemiec, Robert J.; Gandhi, Farhan S.

2014-04-01

This paper presents a novel variable modulus cellular structure based on a hexagonal unit cell with pneumatic artificial muscle (PAM) inclusions. The cell considered is pin-jointed, loaded in the horizontal direction, with three PAMs (one vertical PAM and two horizontal PAMs) oriented in an "H" configuration between the vertices of the cell. A method for calculation of the hexagonal cell modulus is introduced, as is an expression for the balance of tensile forces between the horizontal and vertical PAMs. An aluminum hexagonal unit cell is fabricated and simulation of the hexagonal cell with PAM inclusions is then compared to experimental measurement of the unit cell modulus in the horizontal direction with all three muscles pressurized to the same value over a pressure range up to 758 kPa. A change in cell modulus by a factor of 1.33 and a corresponding change in cell angle of 0.41° are demonstrated experimentally. A design study via simulation predicts that differential pressurization of the PAMs up to 2068 kPa can change the cell modulus in the horizontal direction by a factor of 6.83 with a change in cell angle of only 2.75°. Both experiment and simulation show that this concept provides a way to decouple the length change of a PAM from the change in modulus to create a structural unit cell whose in-plane modulus in a given direction can be tuned based on the orientation of PAMs within the cell and the pressure supplied to the individual muscles.

Ultra-high resolution X-ray structures of two forms of human recombinant insulin at 100 K.

Science.gov (United States)

Lisgarten, David R; Palmer, Rex A; Lobley, Carina M C; Naylor, Claire E; Chowdhry, Babur Z; Al-Kurdi, Zakieh I; Badwan, Adnan A; Howlin, Brendan J; Gibbons, Nicholas C J; Saldanha, José W; Lisgarten, John N; Basak, Ajit K

2017-08-01

The crystal structure of a commercially available form of human recombinant (HR) insulin, Insugen (I), used in the treatment of diabetes has been determined to 0.92 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16,000 keV (λ = 0.77 Å). Refinement carried out with anisotropic displacement parameters, removal of main-chain stereochemical restraints, inclusion of H atoms in calculated positions, and 220 water molecules, converged to a final value of R = 0.1112 and R free  = 0.1466. The structure includes what is thought to be an ordered propanol molecule (POL) only in chain D(4) and a solvated acetate molecule (ACT) coordinated to the Zn atom only in chain B(2). Possible origins and consequences of the propanol and acetate molecules are discussed. Three types of amino acid representation in the electron density are examined in detail: (i) sharp with very clearly resolved features; (ii) well resolved but clearly divided into two conformations which are well behaved in the refinement, both having high quality geometry; (iii) poor density and difficult or impossible to model. An example of type (ii) is observed for the intra-chain disulphide bridge in chain C(3) between Sγ6-Sγ11 which has two clear conformations with relative refined occupancies of 0.8 and 0.2, respectively. In contrast the corresponding S-S bridge in chain A(1) shows one clearly defined conformation. A molecular dynamics study has provided a rational explanation of this difference between chains A and C. More generally, differences in the electron density features between corresponding residues in chains A and C and chains B and D is a common observation in the Insugen (I) structure and these effects are discussed in detail. The crystal structure, also at 0.92 Å and 100 K, of a second commercially available form of human recombinant insulin, Intergen (II), deposited in the Protein Data Bank as 3W7Y which remains otherwise unpublished is compared here

A swimming pool array for ultra high energy showers

Science.gov (United States)

Yodh, Gaurang B.; Shoup, Anthony; Barwick, Steve; Goodman, Jordan A.

1992-11-01

A very preliminary design concept for an array using water Cherenkov counters, built out of commercially available backyard swimming pools, to sample the electromagnetic and muonic components of ultra high energy showers at large lateral distances is presented. The expected performance of the pools is estimated using the observed lateral distributions by scintillator and water Cherenkov arrays at energies above 1019 eV and simulations.

Use of an ultrasonic device for the determination of elastic modulus of dentin.

Science.gov (United States)

Miyazaki, Masashi; Inage, Hirohiko; Onose, Hideo

2002-03-01

The mechanical properties of dentin substrate are one of the important factors in determining bond strength of dentin bonding systems. The purpose of this study was to determine the elastic modulus of dentin substrate with the use of an ultrasonic device. The dentin disks of about 1 mm thickness were obtaining from freshly extracted human third molars, and the dentin disk was shaped in a rectangular form with a line diamond point. The size and weight of each specimen was measured to calculate the density of the specimen. The ultrasonic equipment employed in this study was composed of a Pulser-Receiver (Model 5900PR, Panametrics), transducers (V155, V156, Panametrics) and an oscilloscope. The measured two-way transit time through the dentin disk was divided by two to account for the down-and-back travel path, and then multiplied by the velocity of sound in the test material. Measuring the longitudinal and share wave sound velocity determine elastic modulus. The mean elastic modulus of horizontally sectioned specimens was 21.8 GPa and 18.5 GPa for the vertically sectioned specimens, and a significant difference was found between the two groups. The ultrasonic method used in this study shows considerable promise for determination of the elastic modulus of the tooth substrate.

Equal channel angular extrusion of ultra-high molecular weight polyethylene

Energy Technology Data Exchange (ETDEWEB)

Reinitz, Steven D., E-mail: Steven.D.Reinitz.TH@Dartmouth.edu; Engler, Alexander J.; Carlson, Evan M.; Van Citters, Douglas W.

2016-10-01

Ultra-high molecular weight polyethylene (UHMWPE), a common bearing surface in total joint arthroplasty, is subject to material property tradeoffs associated with conventional processing techniques. For orthopaedic applications, radiation-induced cross-linking is used to enhance the wear resistance of the material, but cross-linking also restricts relative chain movement in the amorphous regions and hence decreases toughness. Equal Channel Angular Extrusion (ECAE) is proposed as a novel mechanism by which entanglements can be introduced to the polymer bulk during consolidation, with the aim of imparting the same tribological benefits of conventional processing without complete inhibition of chain motion. ECAE processing at temperatures near the crystalline melt for UHMWPE produces (1) increased entanglements compared to control materials; (2) increasing entanglements with increasing temperature; and (3) mechanical properties between values for untreated polyethylene and for cross-linked polyethylene. These results support additional research in ECAE-processed UHMWPE for joint arthroplasty applications. - Highlights: • A new processing method for ultra-high molecular weight polyethylene is introduced. • The process produces a highly entangled polyethylene material. • Entanglements are hypothesized to enhance the wear resistance of polyethylene. • This process eliminates the trade-off between mechanical and wear properties.

Thermal characterization of Ag and Ag + N ion implanted ultra-high molecular weight polyethylene (UHMWPE)

Energy Technology Data Exchange (ETDEWEB)

Sokullu Urkac, E. [Department of Materials Science, Izmir High Technology Institute, Gulbahcekoyu Urla, Izmir (Turkey)]. E-mail: emelsu@gmail.com; Oztarhan, A. [Bioengineering Department, Ege University, Bornova, Izmir 35100 (Turkey); Tihminlioglu, F. [Department of Chemical Engineering, Izmir High Technology Institute, Gulbahcekoyu Urla, Izmir (Turkey); Kaya, N. [Bioengineering Department, Ege University, Bornova, Izmir 35100 (Turkey); Ila, D. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Muntele, C. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Budak, S. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Oks, E. [H C Electronics Institute, Tomsk (Russian Federation); Nikolaev, A. [H C Electronics Institute, Tomsk (Russian Federation); Ezdesir, A. [R and D Department, PETKIM Holding A.S., Aliaga, Izmir 35801 (Turkey); Tek, Z. [Department of Physics, Celal Bayar University, Manisa (Turkey)

2007-08-15

Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE ). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 10{sup 17} ion/cm{sup 2} and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE.

Determining the Gaussian Modulus and Edge Properties of 2D Materials: From Graphene to Lipid Bilayers

Science.gov (United States)

Zelisko, Matthew; Ahmadpoor, Fatemeh; Gao, Huajian; Sharma, Pradeep

2017-08-01

The dominant deformation behavior of two-dimensional materials (bending) is primarily governed by just two parameters: bending rigidity and the Gaussian modulus. These properties also set the energy scale for various important physical and biological processes such as pore formation, cell fission and generally, any event accompanied by a topological change. Unlike the bending rigidity, the Gaussian modulus is, however, notoriously difficult to evaluate via either experiments or atomistic simulations. In this Letter, recognizing that the Gaussian modulus and edge tension play a nontrivial role in the fluctuations of a 2D material edge, we derive closed-form expressions for edge fluctuations. Combined with atomistic simulations, we use the developed approach to extract the Gaussian modulus and edge tension at finite temperatures for both graphene and various types of lipid bilayers. Our results possibly provide the first reliable estimate of this elusive property at finite temperatures and appear to suggest that earlier estimates must be revised. In particular, we show that, if previously estimated properties are employed, the graphene-free edge will exhibit unstable behavior at room temperature. Remarkably, in the case of graphene, we show that the Gaussian modulus and edge tension even change sign at finite temperatures.

Bayesian Multiresolution Variable Selection for Ultra-High Dimensional Neuroimaging Data.

Science.gov (United States)

Zhao, Yize; Kang, Jian; Long, Qi

2018-01-01

Ultra-high dimensional variable selection has become increasingly important in analysis of neuroimaging data. For example, in the Autism Brain Imaging Data Exchange (ABIDE) study, neuroscientists are interested in identifying important biomarkers for early detection of the autism spectrum disorder (ASD) using high resolution brain images that include hundreds of thousands voxels. However, most existing methods are not feasible for solving this problem due to their extensive computational costs. In this work, we propose a novel multiresolution variable selection procedure under a Bayesian probit regression framework. It recursively uses posterior samples for coarser-scale variable selection to guide the posterior inference on finer-scale variable selection, leading to very efficient Markov chain Monte Carlo (MCMC) algorithms. The proposed algorithms are computationally feasible for ultra-high dimensional data. Also, our model incorporates two levels of structural information into variable selection using Ising priors: the spatial dependence between voxels and the functional connectivity between anatomical brain regions. Applied to the resting state functional magnetic resonance imaging (R-fMRI) data in the ABIDE study, our methods identify voxel-level imaging biomarkers highly predictive of the ASD, which are biologically meaningful and interpretable. Extensive simulations also show that our methods achieve better performance in variable selection compared to existing methods.

Systematic Calibration for Ultra-High Accuracy Inertial Measurement Units

Directory of Open Access Journals (Sweden)

Qingzhong Cai

2016-06-01

Full Text Available An inertial navigation system (INS has been widely used in challenging GPS environments. With the rapid development of modern physics, an atomic gyroscope will come into use in the near future with a predicted accuracy of 5 × 10−6°/h or better. However, existing calibration methods and devices can not satisfy the accuracy requirements of future ultra-high accuracy inertial sensors. In this paper, an improved calibration model is established by introducing gyro g-sensitivity errors, accelerometer cross-coupling errors and lever arm errors. A systematic calibration method is proposed based on a 51-state Kalman filter and smoother. Simulation results show that the proposed calibration method can realize the estimation of all the parameters using a common dual-axis turntable. Laboratory and sailing tests prove that the position accuracy in a five-day inertial navigation can be improved about 8% by the proposed calibration method. The accuracy can be improved at least 20% when the position accuracy of the atomic gyro INS can reach a level of 0.1 nautical miles/5 d. Compared with the existing calibration methods, the proposed method, with more error sources and high order small error parameters calibrated for ultra-high accuracy inertial measurement units (IMUs using common turntables, has a great application potential in future atomic gyro INSs.

Influence of curing regimes on compressive strength of ultra high

Indian Academy of Sciences (India)

The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

Kinetic and thermodynamic analysis of ultra-high pressure and heat ...

African Journals Online (AJOL)

Purpose: To undertake comparative kinetic and thermodynamic analyses of the interaction of bovine serum albumin (BSA) with IgG pre-treated with ultra-high pressure (UHP) and moderate heat. Methods: BSA solutions were processed at 100 – 600 MPa and 25 – 40 °C. We applied an optical biosensor based on surface ...

Widely tunable single-/dual-wavelength fiber lasers with ultra-narrow linewidth and high OSNR using high quality passive subring cavity and novel tuning method.

Science.gov (United States)

Feng, Ting; Ding, Dongliang; Yan, Fengping; Zhao, Ziwei; Su, Hongxin; Yao, X Steve

2016-08-22

High stability single- and dual-wavelength compound cavity erbium-doped fiber lasers (EDFLs) with ultra-narrow linewidth, high optical signal to noise ratio (OSNR) and widely tunable range are demonstrated. Different from using traditional cascaded Type-1/Type-2 fiber rings as secondary cavities, we nest a Type-1 ring inside a Type-2 ring to form a passive subring cavity to achieve single-longitudinal-mode (SLM) lasing with ultra-narrow linewidth for the first time. We also show that the SLM lasing stability can be further improved by inserting a length of polarization maintaining fiber in the Type-2 ring. Using a uniform fiber Bragg grating (FBG) and two superimposed FBGs as mode restricting elements, respectively, we obtain a single-wavelength EDFL with a linewidth as narrow as 715 Hz and an OSNR as high as 73 dB, and a dual-wavelength EDFL with linewidths less than 1 kHz and OSNRs higher than 68 dB for both lasing wavelengths. Finally, by employing a novel self-designed strain adjustment device capable of applying both the compression and tension forces to the FBGs for wavelength tuning, we achieve the tuning range larger than 10 nm for both of the EDFLs.

Fibrous Fillers to Manufacture Ultra High Ash/Performance Paper

Energy Technology Data Exchange (ETDEWEB)

Dr. VIjay K. Mathur

2009-04-30

The paper industry is one of the largest users of energy and emitters of CO2 in the US manufacturing industry. In addition to that, it is facing tremendous financial pressure due to lower cost imports. The fine paper industry has shrunk from 15 million tons per year production to 10 million tons per year in the last 5 years. This has resulted in mill closures and job loses. The AF&PA and the DOE formed a program called Agenda 2020 to help in funding to develop breakthrough technologies to provide help in meeting these challenges. The objectives of this project were to optimize and scale-up Fibrous Fillers technology, ready for commercial deployment and to develop ultra high ash/high performance paper using Fibrous Fillers. The goal was to reduce energy consumption, carbon footprint, and cost of manufacturing paper and related industries. GRI International (GRI) has been able to demonstrate the techno - economic feasibility and economic advantages of using its various products in both handsheets as well as in commercial paper mills. GRI has also been able to develop sophisticated models that demonstrate the effect of combinations of GRI's fillers at multiple filler levels. GRI has also been able to develop, optimize, and successfully scale-up new products for use in commercial paper mills.

Dielectric and modulus studies of polycrystalline BaZrO3 ceramic

Science.gov (United States)

Saini, Deepash S.; Singh, Sunder; Kumar, Anil; Bhattacharya, D.

2018-05-01

In the present work, dielectric and modulus studies of polycrystalline BaZrO3 ceramic, prepared by modified combustion method followed by conventional sintering, are investigated over the frequency range of 100 Hz to 106 Hz at different temperatures from 250 to 500 °C in air. The high value of dielectric constant (ɛ' ˜ 103) of BaZrO3 at high temperature and low frequency can be attributed to the Maxwell-Wagner polarization mechanism as well as to the thermally activated mechanism of charge carriers. Electric modulus reveal two type relaxations in the 250 °C to 800 °C temperature region as studied at different frequencies over 100 Hz to 106 Hz in air.

Radio reconstruction of the mass of ultra-high cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Dorosti, Qader [Institut fuer Kernphysik (IKP), KIT (Germany)

2015-07-01

Detection of ultra-high energy cosmic rays can reveal the processes of the most violent sources in the Universe, which yet has to be determined. Interaction of cosmic rays with the Earth's atmosphere results in cascades of secondary particles, i.e. air showers. Many of such particles are electrons and positrons. The induced electrons and positrons interact with the geomagnetic field and induce radio emissions. Detection of air showers along with the detection of induced radio emissions can furnish a precise measurement of the direction, energy and mass of ultra-high energy cosmic rays. The Auger Engineering Radio Array consists of 124 radio stations measuring radio emission from air showers, in order to reconstruct the energy, direction and mass of cosmic rays. In this contribution, we present a method which employs a reduced hyperbolic model to describe the shape of radio wave front. We have investigated that the parameters of the reduced hyperbolic model are sensitive to the mass of cosmic rays. The obtained results are presented in this talk.

An investigation of laser cutting quality of 22MnB5 ultra high strength steel using response surface methodology

Science.gov (United States)

Tahir, Abdul Fattah Mohd; Aqida, Syarifah Nur

2017-07-01

In hot press forming, changes of mechanical properties in boron steel blanks have been a setback in trimming the final shape components. This paper presents investigation of kerf width and heat affected zone (HAZ) of ultra high strength 22MnB5 steel cutting. Sample cutting was conducted using a 4 kW Carbon Dioxide (CO2) laser machine with 10.6 μm wavelength with the laser spot size of 0.2 mm. A response surface methodology (RSM) using three level Box-Behnken design of experiment was developed with three factors of peak power, cutting speed and duty cycle. The parameters were optimised for minimum kerf width and HAZ formation. Optical evaluation using MITUTOYO TM 505 were conducted to measure the kerf width and HAZ region. From the findings, laser duty cycle was crucial to determine cutting quality of ultra-high strength steel; followed by cutting speed and laser power. Meanwhile, low power intensity with continuous wave contributes the narrowest kerf width formation and least HAZ region.

Effects of the ultra-high pressure on structure and α-glucosidase inhibition of polysaccharide from Astragalus.

Science.gov (United States)

Zhu, Zhen-Yuan; Luo, You; Dong, Guo-Ling; Ren, Yuan-Yuan; Chen, Li-Jing; Guo, Ming-Zhu; Wang, Xiao-Ting; Yang, Xue-Ying; Zhang, Yongmin

2016-06-01

A novel homogeneous polysaccharide fraction (APS) was extracted from Astragalus by hot water and purified by Sephadex G-100 and G-75 column. Its molecular weight was 693kDa. APS and APS with ultra-high pressure treatment exhibited significant inhibitory abilities on a-glucosidase, inhibition rate from high to low in order was 400MPa-APS, 300MPa-APS, 500MPa-APS and APS. The inhibition ​percentage of 400MPa-APS (1.5mg/mL) was 49% (max.). This suggested that the inhibitory activity of APS on a-glucosidase was improved by ultra-high pressure treatment. FT-IR, SEM, CD spectra, atomic force microscope and Congo red test analysis of APS and 400MPa-APS showed ultra-high pressure treatment didn't change the preliminary structure but had an effect on its advanced structure. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultra high frequency induction welding of powder metal compacts

Energy Technology Data Exchange (ETDEWEB)

Cavdar, U.; Gulsahin, I.

2014-10-01

The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)

Ultra high frequency induction welding of powder metal compacts

International Nuclear Information System (INIS)

Cavdar, U.; Gulsahin, I.

2014-01-01

The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)

Rapid determination of the various native forms of vitamin B6 and B2 in cow's milk using ultra-high performance liquid chromatography.

Science.gov (United States)

Schmidt, A; Schreiner, M G; Mayer, H K

2017-06-02

As the formation of pyridoxal phosphate, the active cofactor of vitamin B 6 , is dependent on riboflavin 5-phosphate, we propose a fast and simple ultra-high performance liquid chromatography method for the simultaneous determination of the native B 6 vitamers pyridoxal, pyridoxine, pyridoxamine, their mono phosphorus esters and 4-pyridoxic acid as well as vitamin B 2 as riboflavin and its phosphorus ester riboflavin 5-phosphate in milk. Separation was achieved under 6.0min by reversed-phase and pH gradient elution. Sample preparation was optimized regarding various acids and pH levels. Changes in those parameters led to significant deviations of sample matrix breakdown efficiency. The optimized method was then validated regarding specificity, accuracy, precision, linearity, range, detection and quantification limits. As the method performed satisfactory, is was used to study commercial liquid cow's milk (n=31), regarding effects of the employed preservation technique (pasteurization, extended shelf-life, ultra-high temperature) on the composition and content of B 6 and B 2 vitamers. In cow's milk, vitamin B 6 mostly consists of pyridoxal and its phosphate ester, with pyridoxal phosphate being the bulk component. The catabolite of the vitamin B 6 metabolism, 4-pyridoxic acid was present in significant amounts in all studied samples, with up to 2.69μmolL -1 . Vitamin B 2 was present as riboflavin and its phosphate ester up to 12.86μmolL -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

Deformation and degradation of polymers in ultra-high-pressure liquid chromatography

NARCIS (Netherlands)

Uliyanchenko, E.; van der Wal, S.; Schoenmakers, P.J.

2011-01-01

Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles

Static modulus of elasticity of concrete measured by the ultrasonic method

Directory of Open Access Journals (Sweden)

Sena Rodrigues, S.

2003-12-01

Full Text Available Lately, a huge number of accidents caused by problems found in the durability of concrete structures due to inappropriate project design, lack of control of quality during the project s execution, inadequate maintenance practices and an aggressive environment has been reported. This finding has required from the professionals constant inspections and evaluations of the real conditions of all concrete structures. In order to perform those inspections, one should know not only the elastic modulus to analyze the concrete structural behaviour but also to investigate its performance, since the strains may yield cracks able to compromise the durability- of structures. Non-destructive testing techniques, particularly the ultrasonic testing, are performed to evaluate and determine the quality of a concrete structure or element. Currently, such essays have been widely researched and analyzed all over the world because they enable the examination of structures without damaging them. The purpose of the present study was to correlate the ultrasonic pulse velocity and the elastic modulus of several concrete specimens molded with a range of water-cement ratios, different kinds of aggregates and curing methods. All the concrete specimens were tested in different ages to determine the pulse velocity and the static modulus of elasticity standardized according to KBR 8522, through mechanical extensometers, electrical strain gauge and LVTD inductive transducer.

Recientemente se ha registrado un gran número de accidentes causados por problemas relacionados con la durabilidad de las estructuras de hormigón y debidos a un inadecuado proyecto de diseño, ausencia de control de calidad durante la ejecución del proyecto, prácticas inadecuadas de construcción y un ambiente agresivo. Este hallazgo ha dado lugar a que los ingenieros realicen constantes inspecciones y evaluaciones de la condición real de todas las estructuras de hormigón. Para llevar a cabo

Photonic Technologies for Ultra-High-Speed Information Highways

DEFF Research Database (Denmark)

Bouchoule, S; Lèfevre, R.; Legros, E.

1999-01-01

The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press....

Design and Implementation of Wideband Exciter for an Ultra-high Resolution Airborne SAR System

Directory of Open Access Journals (Sweden)

Jia Ying-xin

2013-03-01

Full Text Available According to an ultra-high resolution airborne SAR system with better than 0.1 m resolution, a wideband Linear Frequency Modulated (LFM pulse compression exciter with 14.8 GHz carrier and 3.2 GHz bandwidth is designed and implemented. The selection of signal generation scheme and some key technique points for wideband LFM waveform is presented in detail. Then, an acute test and analysis of the LFM signal is performed. The final airborne experiments demonstrate the validity of the LFM source which is one of the subsystems in an ultra-high resolution airborne SAR system.

Effective elastic modulus of isolated gecko setal arrays.

Science.gov (United States)

Autumn, K; Majidi, C; Groff, R E; Dittmore, A; Fearing, R

2006-09-01

Conventional pressure sensitive adhesives (PSAs) are fabricated from soft viscoelastic materials that satisfy Dahlquist's criterion for tack with a Young's modulus (E) of 100 kPa or less at room temperature and 1 Hz. In contrast, the adhesive on the toes of geckos is made of beta-keratin, a stiff material with E at least four orders of magnitude greater than the upper limit of Dahlquist's criterion. Therefore, one would not expect a beta-keratin structure to function as a PSA by deforming readily to make intimate molecular contact with a variety of surface profiles. However, since the gecko adhesive is a microstructure in the form of an array of millions of high aspect ratio shafts (setae), the effective elastic modulus (E(eff)) is much lower than E of bulk beta-keratin. In the first test of the E(eff) of a gecko setal adhesive, we measured the forces resulting from deformation of isolated arrays of tokay gecko (Gekko gecko) setae during vertical compression, and during tangential compression at angles of +45 degrees and -45 degrees . We tested the hypothesis that E(eff) of gecko setae falls within Dahlquist's criterion for tack, and evaluated the validity of a model of setae as cantilever beams. Highly linear forces of deformation under all compression conditions support the cantilever model. E(eff) of setal arrays during vertical and +45 degrees compression (along the natural path of drag of the setae) were 83+/-4.0 kPa and 86+/-4.4 kPa (means +/- s.e.m.), respectively. Consistent with the predictions of the cantilever model, setae became significantly stiffer when compressed against the natural path of drag: E(eff) during -45 degrees compression was 110+/-4.7 kPa. Unlike synthetic PSAs, setal arrays act as Hookean elastic solids; setal arrays function as a bed of springs with a directional stiffness, assisting alignment of the adhesive spatular tips with the contact surface during shear loading.

A superplastic Al-Li-Cu-Mg-Zr powder alloy with high hardness and modulus

International Nuclear Information System (INIS)

Phillips, V.A.

1986-01-01

Structure/property studies were made on an experimental Al-3.18% Li-4.29% Cu-1.17% Mg-0.18% Zr powder alloy, which is of the low density/high modulus type. Alloy powder was made by the P and W/GPD rapid solidification rate (RSR) process, canned, and extruded to bar. The density was 2.458 x 10/sup 6/ g/m/sup 3/. The material was solution-treated, and aged at 149 0 C(300 0 F), 171 0 C(340 0 F), and 193 0 C(380 0 F), using hardness tests to determine the aging curves. Testpieces solution-treated at 516 0 C(961 0 F) showed an average yield strength (0.2% offset) of 43.3 ksi (299 MPa) and ultimate tensile strength of 50.0 ksi (345 MPa), with 1% elongation, which increased to 73.0 ksi (503 MPa) and 73.1 ksi (504 MPa), respectively, with only 0.2% elongation, on peak aging at 193 0 C(380 0 F), with a modulus of elasticity of 11.4 x 10/sup 6/ psi (78.3 GPa). Hardness values reached 90-92 R/sub B/ on aging at 149-193 0 C(300-380 0 F). The as-extruded alloy showed superplastic behavior at 400-500 0 C(752-932 0 F) with elongations of 80-185% on 25.6 mm, peaking at 450 0 C(842 0 F). An RSR Al-2.53% Li-2.82% Mn-0.02% Zr extruded allow showed only 18-23% elongation at 400-500 0 C(752-932 0 F)

High modulus rare earth and beryllium containing silicate glass compositions. [for glass reinforcing fibers

Science.gov (United States)

Bacon, J. F. (Inventor)

1976-01-01

Glass compositions having a Young's modulus of at least 16 million psi and a specific modulus of at least 110 million inches consisting essentially of approximately, by weight, 20 to 43% SiO2, 8 to 21% Al2O3, 4 to 10% BeO, 27 to 58% of at least one oxide selected from a first group consisting of Y2O3, La2O3, Nd2O3, Ce2O3, Ce2O3, and the mixed rare earth oxides, and 3 to 12% of at least one oxide selected from a second group consisting of MgO, ZrO2, ZnO and CaO are described. The molar ratio of BeO to the total content of the first group oxides is from 1.0 to 3.0.

Ultra high risk of psychosis on committal to a young offender prison: an unrecognised opportunity for early intervention

Directory of Open Access Journals (Sweden)

Flynn Darran

2012-08-01

Full Text Available Abstract Background The ultra high risk state for psychosis has not been studied in young offender populations. Prison populations have higher rates of psychiatric morbidity and substance use disorders. Due to the age profile of young offenders one would expect to find a high prevalence of individuals with pre-psychotic or ultra-high risk mental states for psychosis (UHR. Accordingly young offender institutions offer an opportunity for early interventions which could result in improved long term mental health, social and legal outcomes. In the course of establishing a mental health in-reach service into Ireland’s only young offender prison, we sought to estimate unmet mental health needs. Methods Every third new committal to a young offenders prison was interviewed using the Comprehensive Assessment of At-Risk Mental States (CAARMS to identify the Ultra High Risk (UHR state and a structured interview for assessing drug and alcohol misuse according to DSM-IV-TR criteria, the Developmental Understanding of Drug Misuse and Dependence - Short Form (DUNDRUM-S. Results Over a twelve month period 171 young male offenders aged 16 to 20 were assessed. Of these 39 (23%, 95% confidence interval 18% to 30% met UHR criteria. UHR states peaked at 18 years, were associated with lower SOFAS scores for social and occupational function and were also associated with multiple substance misuse. The relationship with lower SOFAS scores persisted even when co-varying for multiple substance misuse. Conclusions Although psychotic symptoms are common in community samples of children and adolescents, the prevalence of the UHR state in young offenders was higher than reported for community samples. The association with impaired function also suggests that this may be part of a developing disorder. Much more attention should be paid to the relationship of UHR states to substance misuse and to the health needs of young offenders.

Novel PVA-DNA nanoparticles prepared by ultra high pressure technology for gene delivery

International Nuclear Information System (INIS)

Kimura, Tsuyoshi; Okuno, Akira; Miyazaki, Kozo; Furuzono, Tsutomu; Ohya, Yuichi; Ouchi, Tatsuro; Mutsuo, Shingo; Yoshizawa, Hidekazu; Kitamura, Yoshiro; Fujisato, Toshiyta; Kishida, Akio

2004-01-01

Polyvinyl alcohol (PVA)-DNA nanoparticles have been developed by ultra high pressure (UHP) technology. Mixture solutions of DNA and PVA having various molecular weights (Mw) and degree of saponifications (DS) were treated under 10,000 atmospheres (981 MPa) condition at 40 deg. C for 10 min. Agarose gel electrophoresis and scanning electron microscope observation revealed that the PVA-DNA nanoparticles with average diameter of about 200 nm were formed. Using PVA of higher Mw and degree of saponifications, the amount of nanoparticles formed increased. The driving force of nanoparticle formation was the hydrogen bonding between DNA and PVA. In order to apply the PVA-DNA nanoparticles for gene delivery, the cytotoxicity and the cellular uptake of them were investigated using Raw264 cell lines. The cell viability was not influenced whether the presence of the PVA-DNA nanoparticles. Further, the nanoparticles internalized into cells were observed by fluorescent microscope. These results indicates that the PVA-DNA nanoparticles prepared by UHP technology showed be useful as drug carrier, especially for gene delivery

Hardon cross sections at ultra high energies

International Nuclear Information System (INIS)

Yodh, G.B.

1987-01-01

A review of results on total hadronic cross sections at ultra high energies obtained from a study of longitudinal development of cosmic ray air showers is given. The experimental observations show that proton-air inelastic cross section increases from 275 mb to over 500 mb as the collision energy in the center of mass increases from 20 GeV to 20 TeV. The proton-air inelastic cross section, obtained from cosmic ray data at √s = 30 TeV, is compared with calculations using various different models for the energy variation of the parameters of the elementary proton-proton interaction. Three conclusions are derived

A CATALOG OF ULTRA-COMPACT HIGH VELOCITY CLOUDS FROM THE ALFALFA SURVEY: LOCAL GROUP GALAXY CANDIDATES?

International Nuclear Information System (INIS)

Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P.

2013-01-01

We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34 Jy km s –1 , median angular diameters of 10', and median velocity widths of 23 km s –1 . We show that the full UCHVC population cannot easily be associated with known populations of high velocity clouds. Of the 59 clouds presented here, only 11 are also present in the compact cloud catalog extracted from the commensal GALFA-HI survey, demonstrating the utility of this separate dataset and analysis. Based on their sky distribution and observed properties, we infer that the ALFALFA UCHVCs are consistent with the hypothesis that they may be very low mass galaxies within the Local Volume. In that case, most of their baryons would be in the form of gas, and because of their low stellar content, they remain unidentified by extant optical surveys. At distances of ∼1 Mpc, the UCHVCs have neutral hydrogen (H I) masses of ∼10 5 -10 6 M ☉ , H I diameters of ∼2-3 kpc, and indicative dynamical masses within the H I extent of ∼10 7 -10 8 M ☉ , similar to the Local Group ultra-faint dwarf Leo T. The recent ALFALFA discovery of the star-forming, metal-poor, low mass galaxy Leo P demonstrates that this hypothesis is true in at least one case. In the case of the individual UCHVCs presented here, confirmation of their extragalactic nature will require further work, such as the identification of an optical counterpart to constrain their distance.

Processing and evaluation of the AGS Booster ultra-high vaccum system

International Nuclear Information System (INIS)

Hseuh, H.C.; Mapes, M.; Schnitzenbaumer, P.; Shen, B.; Sikora, R.; Stattel, P.

1991-01-01

The AGS Booster is a synchrotron for the acceleration of both protons and heavy ions. To minimize the beam loss due to charge exchange of the partially stripped, low Β very heavy ions with the residual gas molecules, pressure of low 10 -11 Torr is required for the 200 m booster ring. To achieve this ultra high vacuum, chemical cleaning, vacuum furnace degassing and insitu bake were employed for all chambers and beam components. Using these procedures, vacuums of low 10 -11 Torr have been routinely achieved during the testing of individual half cells and beam components, and during the commissioning of the vacuum sectors. In this paper, the design and layout of chambers, flanges and bakeout hardware is briefly described. The vacuum processing of different components and the results of bakeout and evaluation are summarized. The experience gained during the construction and commissioning of this ultra-high vacuum system is also given. 3 refs., 3 figs., 1 tab

Investigations in the mechanism of carbothermal reduction of yttria stabilized zirconia for ultra-high temperature ceramics application and its influence on yttria contained in it

Science.gov (United States)

Sondhi, Anchal

Zirconium carbide (ZrC) is a high modulus ceramic with an ultra-high melting temperature and, consequently, is capable of withstanding extreme environments. Carbon-carbon composites (CCCs) are important structural materials in current commercial and future hypersonic aircraft; however, these materials may be susceptible to degradation when exposed to elevated temperatures during extreme velocities. At speeds of exceeding Mach 5, intense heating of leading edges of the aircraft triggers rapid oxidation of carbon in CCCs resulting in degradation of the structure and probable failure. Environmental/thermal barrier coatings (EBC/TBC) are employed to protect airfoil structures from extreme conditions. Yttria stabilized zirconia (YSZ) is a well-known EBC/TBC material currently used to protect metallic turbine blades and other aerospace structures. In this work, 3 mol% YSZ has been studied as a potential EBC/TBC on CCCs. However, YSZ is an oxygen conductor and may not sufficiently slow the oxidation of the underlying CCC. Under appropriate conditions, ZrC can form at the interface between CCC and YSZ. Because ZrC is a poor oxygen ion conductor in addition to its stability at high temperatures, it can reduce the oxygen transport to the CCC and thus increase the service lifetime of the structure. This dissertation investigates the thermodynamics and kinetics of the YSZ/ZrC/CCC system and the resulting structural changes across multiple size scales. A series of experiments were conducted to understand the mechanisms and species involved in the carbothermal reduction of ZrO2 to form ZrC. 3 mol% YSZ and graphite powders were uniaxially pressed into pellets and reacted in a graphite (C) furnace. Rietveld x-ray diffraction phase quantification determined that greater fractions of ZrC were formed when carbon was the majority mobile species. These results were validated by modeling the process thermochemically and were confirmed with additional experiments. Measurements were

78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

Science.gov (United States)

2013-11-26

... Frequency and Ultra High Frequency Active SONAR Technology; Final Programmatic Environmental Assessment and... each alternative on the human and natural environments. FOR FURTHER INFORMATION CONTACT: If you have... Programmatic Environmental Assessment The scope of the PEA focuses on potential impacts associated with the...

Structure and Young modulus of age hardening elinvar 45NKhT

International Nuclear Information System (INIS)

Baraz, V.R.; Strizhak, V.A.; Tsykin, D.N.

1996-01-01

The influence of quenching and ageing on structural features and Young modulus of precipitation hardening elinvar alloy 45 NKhT is under study. It is shown that the quenched alloy possesses a decreased elastic modulus which value drops with a quenching temperature increase. The ally ageing results in restoration of elastic modulus. The temperature range of Young modulus stability is shown to be independent of heat treatment conditions. The anomalies of elastic modulus in quenched alloy are conditioned by structural and magnetoelastic factors. The mechanisms of continuous and discontinuous precipitation mechanism has no effect on efficiency of Young modulus restoration. 13 refs., 6 figs

Influence of cold-working and subsequent heat-treatment on young's modulus and strength of Co-Ni-Cr-Mo alloy

International Nuclear Information System (INIS)

Otomo, Takuma; Matsumoto, Hiroaki; Chiba, Akihiko; Nomura, Naoyuki

2009-01-01

Changes in Young's modulus of the Co-31 mass%Ni-19 mass%Cr-10 mass%Mo alloy (Co-Ni based alloy) with cold-swaging, combined with heat-treatment at temperatures from 673 to 1323 K, was investigated to enhance the Young's modulus of Co-Ni based alloy. After cold-swaging, the Co-Ni based alloy, forming fiber deformation texture, shows the Young's modulus of 220 GPa. Furthermore, after ageing the cold-swaged alloy at temperature from 673 to 1323 K, the Young's modulus increased to 230 GPa, accompanied by a decrease in the internal fiction and an increase in the tensile strength. This suggests that the increment in Young's modulus is caused by a moving of the vacancies to the dislocation cores and a continuous locking of the dislocations along their entire length with solute atoms (trough model). By annealing at 1323 K after cold swaging, Young's modulus slightly increased to 236 GPa. On the other hand, the tensile strength decreases to almost the same value as that before cold swaging due to recrystallization. These results suggest that the Young's modulus and the strength in the present alloy are simultaneously enhanced by the continuous dislocation locking during aging as well as the formation of fiber deformation texture. (author)

Ultra-high performance fiber-reinforced concrete (UHPFRC) for infrastructure rehabilitation Volume II : behavior of ultra-high strength concrete bridge deck panels compared to conventional stay-in-place deck panels

Science.gov (United States)

2017-08-01

The remarkable features of ultra-high performance concrete (UHPC) have been reported. Its application in bridge construction has been an active research area in recent years, attributed to its higher compressive strength, higher ductility and reduced...

Long range surface plasmon resonance with ultra-high penetration depth for self-referenced sensing and ultra-low detection limit using diverging beam approach

Energy Technology Data Exchange (ETDEWEB)

Isaacs, Sivan, E-mail: sivan.isaacs@gmail.com; Abdulhalim, Ibrahim [Department of Electro-Optical Engineering and TheIlse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); NEW CREATE Programme, School of Materials Science and Engineering, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602 (Singapore)

2015-05-11

Using an insulator-metal-insulator structure with dielectric having refractive index (RI) larger than the analyte, long range surface plasmon (SP) resonance exhibiting ultra-high penetration depth is demonstrated for sensing applications of large bioentities at wavelengths in the visible range. Based on the diverging beam approach in Kretschmann-Raether configuration, one of the SP resonances is shown to shift in response to changes in the analyte RI while the other is fixed; thus, it can be used as a built in reference. The combination of the high sensitivity, high penetration depth and self-reference using the diverging beam approach in which a dark line is detected of the high sensitivity, high penetration depth, self-reference, and the diverging beam approach in which a dark line is detected using large number of camera pixels with a smart algorithm for sub-pixel resolution, a sensor with ultra-low detection limit is demonstrated suitable for large bioentities.

A Monte-Carlo simulation of the equilibrium beam polarization in ultra-high energy electron (positron) storage rings

Energy Technology Data Exchange (ETDEWEB)

Duan, Zhe, E-mail: zhe.duan@ihep.ac.cn [Key Laboratory of Particle Acceleration Physics and Technology, Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China); University of Chinese Academy of Sciences, 100049 Beijing (China); Bai, Mei [Forschungszentrum Jülich GmbH, 52428 Jülich (Germany); Barber, Desmond P. [Deutsches Elektronen-Synchrotron, DESY, 22607 Hamburg (Germany); Qin, Qing [Key Laboratory of Particle Acceleration Physics and Technology, Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China)

2015-09-01

With the recently emerging global interest in building a next generation of circular electron–positron colliders to study the properties of the Higgs boson, and other important topics in particle physics at ultra-high beam energies, it is also important to pursue the possibility of implementing polarized beams at this energy scale. It is therefore necessary to set up simulation tools to evaluate the beam polarization at these ultra-high beam energies. In this paper, a Monte-Carlo simulation of the equilibrium beam polarization based on the Polymorphic Tracking Code (PTC) (Schmidt et al., 2002 [1]) is described. The simulations are for a model storage ring with parameters similar to those of proposed circular colliders in this energy range, and they are compared with the suggestion (Derbenev et al., 1979 [2]) that there are different regimes for the spin dynamics underlying the polarization of a beam in the presence of synchrotron radiation at ultra-high beam energies. In particular, it has been suggested that the so-called “correlated” crossing of spin resonances during synchrotron oscillations at current energies evolves into “uncorrelated” crossing of spin resonances at ultra-high energies.

A Monte-Carlo simulation of the equilibrium beam polarization in ultra-high energy electron (positron) storage rings

International Nuclear Information System (INIS)

Duan, Zhe; Bai, Mei; Barber, Desmond P.; Qin, Qing

2015-04-01

With the recently emerging global interest in building a next generation of circular electron-positron colliders to study the properties of the Higgs boson, and other important topics in particle physics at ultra-high beam energies, it is also important to pursue the possibility of implementing polarized beams at this energy scale. It is therefore necessary to set up simulation tools to evaluate the beam polarization at these ultra-high beam energies. In this paper, a Monte-Carlo simulation of the equilibrium beam polarization based on the Polymorphic Tracking Code(PTC) (Schmidt et al., 2002) is described. The simulations are for a model storage ring with parameters similar to those of proposed circular colliders in this energy range, and they are compared with the suggestion (Derbenev et al., 1978) that there are different regimes for the spin dynamics underlying the polarization of a beam in the presence of synchrotron radiation at ultra-high beam energies. In particular, it has been suggested that the so-called ''correlated'' crossing of spin resonances during synchrotron oscillations at current energies, evolves into ''uncorrelated'' crossing of spin resonances at ultra-high energies.

Comparison of ultra-high performance supercritical fluid chromatography and ultra-high performance liquid chromatography for the separation of spirostanol saponins.

Science.gov (United States)

Zhu, Ling-Ling; Zhao, Yang; Xu, Yong-Wei; Sun, Qing-Long; Sun, Xin-Guang; Kang, Li-Ping; Yan, Ren-Yi; Zhang, Jie; Liu, Chao; Ma, Bai-Ping

2016-02-20

Spirostanol saponins are important active components of some herb medicines, and their isolation and purification are crucial for the research and development of traditional Chinese medicines. We aimed to compare the separation of spirostanol saponins by ultra-high performance supercritical fluid chromatography (UHPSFC) and ultra-high performance liquid chromatography (UHPLC). Four groups of spirostanol saponins were separated respectively by UHPSFC and UHPLC. After optimization, UHPSFC was performed with a HSS C18 SB column or a Diol column and with methanol as the co-solvent. A BEH C18 column and mobile phase containing water (with 0.1% formic acid) and acetonitrile were used in UHPLC. We found that UHPSFC could be performed automatically and quickly. It is effective in separating the spirostanol saponins which share the same aglycone and vary in sugar chains, and is very sensitive to the number and the position of hydroxyl groups in aglycones. However, the resolution of spirostanol saponins with different aglycones and the same sugar moiety by UHPSFC was not ideal and could be resolved by UHPLC instead. UHPLC is good at differentiating the variation in aglycones, and is influenced by double bonds in aglycones. Therefore, UHPLC and UHPSFC are complementary in separating spirostanol saponins. Considering the naturally produced spirostanol saponins in herb medicines are different both in aglycones and in sugar chains, a better separation can be achieved by combination of UHPLC and UHPSFC. UHPSFC is a powerful technique for improving the resolution when UHPLC cannot resolve a mixture of spirostanol saponins and vice versa. Copyright © 2015 Elsevier B.V. All rights reserved.

Functional magnetic resonance imaging with ultra-high fields

International Nuclear Information System (INIS)

Windischberger, C.; Schoepf, V.; Sladky, R.; Moser, E.; Fischmeister, F.P.S.

2010-01-01

Functional magnetic resonance imaging (fMRI) is currently the primary method for non-invasive functional localization in the brain. With the emergence of MR systems with field strengths of 4 Tesla and above, neuronal activation may be studied with unprecedented accuracy. In this article we present different approaches to use the improved sensitivity and specificity for expanding current fMRT resolution limits in space and time based on several 7 Tesla studies. In addition to the challenges that arise with ultra-high magnetic fields possible solutions will be discussed. (orig.) [de

Multigene Genetic Programming for Estimation of Elastic Modulus of Concrete

Directory of Open Access Journals (Sweden)

Alireza Mohammadi Bayazidi

2014-01-01

Full Text Available This paper presents a new multigene genetic programming (MGGP approach for estimation of elastic modulus of concrete. The MGGP technique models the elastic modulus behavior by integrating the capabilities of standard genetic programming and classical regression. The main aim is to derive precise relationships between the tangent elastic moduli of normal and high strength concrete and the corresponding compressive strength values. Another important contribution of this study is to develop a generalized prediction model for the elastic moduli of both normal and high strength concrete. Numerous concrete compressive strength test results are obtained from the literature to develop the models. A comprehensive comparative study is conducted to verify the performance of the models. The proposed models perform superior to the existing traditional models, as well as those derived using other powerful soft computing tools.

SU-F-J-45: Sparing Normal Tissue with Ultra-High Dose Rate in Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Feng, Y [DCH Reg. Medical Center, Tuscaloosa, AL (United States)

2016-06-15

Purpose: To spare normal tissue by reducing the location uncertainty of a moving target, we proposed an ultra-high dose rate system and evaluated. Methods: High energy electrons generated with a linear accelerator were injected into a storage ring to be accumulated. The number of the electrons in the ring was determined based on the prescribed radiation dose. The dose was delivered within a millisecond, when an online imaging system found that the target was in the position that was consistent with that in a treatment plan. In such a short time period, the displacement of the target was negligible. The margin added to the clinical target volume (CTV) could be reduced that was evaluated by comparing of volumes between CTV and ITV in 14 cases of lung stereotactic body radiation therapy (SBRT) treatments. A design of the ultra-high dose rate system was evaluated based clinical needs and the recent developments of low energy (a few MeV) electron storage ring. Results: This design of ultra-high dose rate system was feasible based on the techniques currently available. The reduction of a target volume was significant by reducing the margin that accounted the motion of the target. ∼50% volume reduction of the internal target volume (ITV) could be achieved in lung SBRT treatments. Conclusion: With this innovation of ultra-high dose rate system, the margin of target is able to be significantly reduced. It will reduce treatment time of gating and allow precisely specified gating window to improve the accuracy of dose delivering.

Live Ultra-High Definition from the International Space Station

Science.gov (United States)

Grubbs, Rodney; George, Sandy

2017-01-01

The first ever live downlink of Ultra-High Definition (UHD) video from the International Space Station (ISS) was the highlight of a 'Super Session' at the National Association of Broadcasters (NAB) in April 2017. The Ultra-High Definition video downlink from the ISS all the way to the Las Vegas Convention Center required considerable planning, pushed the limits of conventional video distribution from a space-craft, and was the first use of High Efficiency Video Coding (HEVC) from a space-craft. The live event at NAB will serve as a pathfinder for more routine downlinks of UHD as well as use of HEVC for conventional HD downlinks to save bandwidth. HEVC may also enable live Virtual Reality video downlinks from the ISS. This paper will describe the overall work flow and routing of the UHD video, how audio was synchronized even though the video and audio were received many seconds apart from each other, and how the demonstration paves the way for not only more efficient video distribution from the ISS, but also serves as a pathfinder for more complex video distribution from deep space. The paper will also describe how a 'live' event was staged when the UHD coming from the ISS had a latency of 10+ seconds. Finally, the paper will discuss how NASA is leveraging commercial technologies for use on-orbit vs. creating technology as was required during the Apollo Moon Program and early space age.

Fabricating high-energy quantum dots in ultra-thin LiFePO4 nanosheets using a multifunctional high-energy biomolecule-ATP

DEFF Research Database (Denmark)

Zhang, X.D.; Bi, Z.Y.; He, W.

2014-01-01

By using a multifunctional high-energy biomolecule—adenosine triphosphate (ATP)—we fabricated highenergy quantum dots (HEQDs) with a feature size of less than 10 nm and used them in high-power lithium-ion batteries. We introduced high-energy phosphate bonds into the crystal structure of LiFePO4...... nanoparticles and synthesized the mesoporous biocarbon nanowire coated LiFePO4 with HEQDs (MBCNW-LFP-HEQDs) by using ATP as a phosphorus source, a nucleating agent, a structural template and a biocarbon source. HEGDs were homogeneously formed inside the ultra-thin LiFePO4 nanosheet and the mesoporous biocarbon...... nanowire network structure was coated on the surface of the nanosheet. In LiFePO4 nanoparticles, HEQDs result in more storage sites of Li+ ions and easier transfer kinetics of electrons and lithium ions, where the kinetic transformation path between LiFePO4 and FePO4 is rather different from the path...

Ultra-high sensitive hydrazine chemical sensor based on low-temperature grown ZnO nanoparticles

International Nuclear Information System (INIS)

Mehta, S.K.; Singh, Kulvinder; Umar, Ahmad; Chaudhary, G.R.; Singh, Sukhjinder

2012-01-01

Graphical abstract: Systematic representation of the fabricated amperometric hydrazine chemical sensor based on ZnO NPs/Au modified electrode. Highlights: ► Synthesis of well-crystalline ZnO NPs has been achieved in aqueous solution. ► ZnO NPs act as efficient electron mediators for hydrazine sensor. ► Extremely high sensitivity and low-detection limit have been obtained. - Abstract: Using well-crystalline ZnO nanoparticles (NPs), an ultra high sensitive hydrazine amperometric sensor has been fabricated and reported in this paper. The ZnO NPs have been synthesized by very simple aqueous solution process at 90 °C and characterized in detail in terms of their morphological, compositional, structural and optical properties. The detailed investigations reveal that the synthesized products are well-crystalline NPs, possessing wurtzite hexagonal phase and exhibit good optical properties. The fabricated amperometric hydrazine sensor exhibits ultra-high sensitivity of ∼97.133 μA cm −2 μM −1 and very low-detection limit of 147.54 nM. To the best of our knowledge, this is the first report in which an ultra-high sensitivity and low-detection limit have been obtained for the hydrazine chemical sensor based on ZnO nanostructures.

Ultra-Lightweight, High Efficiency Silicon-Carbide (SIC) Based Power Electronic Converters, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business of Innovation Research Phase I proposal seeks to investigate and prove the feasibility of developing highly efficient, ultra-lightweight SiC...

Muscle shear elastic modulus is linearly related to muscle torque over the entire range of isometric contraction intensity.

Science.gov (United States)

Ateş, Filiz; Hug, François; Bouillard, Killian; Jubeau, Marc; Frappart, Thomas; Couade, Mathieu; Bercoff, Jeremy; Nordez, Antoine

2015-08-01

Muscle shear elastic modulus is linearly related to muscle torque during low-level contractions (torque over the entire range of isometric contraction and (ii) the influence of the size of the region of interest (ROI) used to average the shear modulus value. Ten healthy males performed two incremental isometric little finger abductions. The joint torque produced by Abductor Digiti Minimi was considered as an index of muscle torque and elastic modulus. A high coefficient of determination (R(2)) (range: 0.86-0.98) indicated that the relationship between elastic modulus and torque can be accurately modeled by a linear regression over the entire range (0% to 100% of MVC). The changes in shear elastic modulus as a function of torque were highly repeatable. Lower R(2) values (0.89±0.13 for 1/16 of ROI) and significantly increased absolute errors were observed when the shear elastic modulus was averaged over smaller ROI, half, 1/4 and 1/16 of the full ROI) than the full ROI (mean size: 1.18±0.24cm(2)). It suggests that the ROI should be as large as possible for accurate measurement of muscle shear modulus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kissinger method applied to the crystallization of glass-forming liquids: Regimes revealed by ultra-fast-heating calorimetry

Energy Technology Data Exchange (ETDEWEB)

Orava, J., E-mail: jo316@cam.ac.uk [Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Greer, A.L., E-mail: alg13@cam.ac.uk [Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2015-03-10

Highlights: • Study of ultra-fast DSC applied to the crystallization of glass-forming liquids. • Numerical modeling of DSC traces at heating rates exceeding 10 orders of magnitude. • Identification of three regimes in Kissinger plots. • Elucidation of the effect of liquid fragility on the Kissinger method. • Modeling to study the regime in which crystal growth is thermodynamically limited. - Abstract: Numerical simulation of DSC traces is used to study the validity and limitations of the Kissinger method for determining the temperature dependence of the crystal-growth rate on continuous heating of glasses from the glass transition to the melting temperature. A particular interest is to use the wide range of heating rates accessible with ultra-fast DSC to study systems such as the chalcogenide Ge{sub 2}Sb{sub 2}Te{sub 5} for which fast crystallization is of practical interest in phase-change memory. Kissinger plots are found to show three regimes: (i) at low heating rates the plot is straight, (ii) at medium heating rates the plot is curved as expected from the liquid fragility, and (iii) at the highest heating rates the crystallization rate is thermodynamically limited, and the plot has curvature of the opposite sign. The relative importance of these regimes is identified for different glass-forming systems, considered in terms of the liquid fragility and the reduced glass-transition temperature. The extraction of quantitative information on fundamental crystallization kinetics from Kissinger plots is discussed.

Kissinger method applied to the crystallization of glass-forming liquids: Regimes revealed by ultra-fast-heating calorimetry

International Nuclear Information System (INIS)

Orava, J.; Greer, A.L.

2015-01-01

Highlights: • Study of ultra-fast DSC applied to the crystallization of glass-forming liquids. • Numerical modeling of DSC traces at heating rates exceeding 10 orders of magnitude. • Identification of three regimes in Kissinger plots. • Elucidation of the effect of liquid fragility on the Kissinger method. • Modeling to study the regime in which crystal growth is thermodynamically limited. - Abstract: Numerical simulation of DSC traces is used to study the validity and limitations of the Kissinger method for determining the temperature dependence of the crystal-growth rate on continuous heating of glasses from the glass transition to the melting temperature. A particular interest is to use the wide range of heating rates accessible with ultra-fast DSC to study systems such as the chalcogenide Ge 2 Sb 2 Te 5 for which fast crystallization is of practical interest in phase-change memory. Kissinger plots are found to show three regimes: (i) at low heating rates the plot is straight, (ii) at medium heating rates the plot is curved as expected from the liquid fragility, and (iii) at the highest heating rates the crystallization rate is thermodynamically limited, and the plot has curvature of the opposite sign. The relative importance of these regimes is identified for different glass-forming systems, considered in terms of the liquid fragility and the reduced glass-transition temperature. The extraction of quantitative information on fundamental crystallization kinetics from Kissinger plots is discussed

Ultra-relativistic heavy ions and cosmic rays

International Nuclear Information System (INIS)

McLerran, L.

1983-05-01

The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher energy density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

Science.gov (United States)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-06-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

Science.gov (United States)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-03-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

NARCIS (Netherlands)

Hageman, J.C.L.; Meier, Robert J.; Heinemann, M.; Groot, R.A. de

1997-01-01

The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa.

Determination of elastic modulus of ceramics using ultrasonic testing

Science.gov (United States)

Sasmita, Firmansyah; Wibisono, Gatot; Judawisastra, Hermawan; Priambodo, Toni Agung

2018-04-01

Elastic modulus is important material property on structural ceramics application. However, bending test as a common method for determining this property require particular specimen preparation. Furthermore, elastic modulus of ceramics could vary because it depends on porosity content. For structural ceramics industry, such as ceramic tiles, this property is very important. This drives the development of new method to improve effectivity or verification method as well. In this research, ultrasonic testing was conducted to determine elastic modulus of soda lime glass and ceramic tiles. The experiment parameter was frequency of probe (1, 2, 4 MHz). Characterization of density and porosity were also done for analysis. Results from ultrasonic testing were compared with elastic modulus resulted from bending test. Elastic modulus of soda-lime glass based on ultrasonic testing showed excellent result with error 2.69% for 2 MHz probe relative to bending test result. Testing on red and white ceramic tiles were still contained error up to 41% and 158%, respectively. The results for red ceramic tile showed trend that 1 MHz probe gave better accuracy in determining elastic modulus. However, testing on white ceramic tile showed different trend. It was due to the presence of porosity and near field effect.

Chemical Abundance Measurements of Ultra-Faint Dwarf Galaxies Discovered by the Dark Energy Survey

Science.gov (United States)

Nagasawa, Daniel; Marshall, Jennifer L.; Simon, Joshua D.; Hansen, Terese; Li, Ting; Bernstein, Rebecca; Balbinot, Eduardo; Drlica-Wagner, Alex; Pace, Andrew; Strigari, Louis; Pellegrino, Craig; DePoy, Darren L.; Suntzeff, Nicholas; Bechtol, Keith; Dark Energy Suvey

2018-01-01

We present chemical abundance analysis results derived from high-resolution spectroscopy of ultra-faint dwarfs discovered by the Dark Energy Survey. Ultra-faint dwarf galaxies preserve a fossil record of the chemical abundance patterns imprinted by the first stars in the Universe. High-resolution spectroscopic observations of member stars in several recently discovered Milky Way satellites reveal a range of abundance patterns among ultra-faint dwarfs suggesting that star formation processes in the early Universe were quite diverse. The chemical content provides a glimpse not only of the varied nucleosynthetic processes and chemical history of the dwarfs themselves, but also the environment in which they were formed. We present the chemical abundance analysis of these objects and discuss possible explanations for the observed abundance patterns.

Formation and stability of .beta.-structure in biodegradable ultra-high-molecular-weight poly(3-hydroxybutyrate) by infrared, Raman, and quantum chemical calculation studies

Czech Academy of Sciences Publication Activity Database

Murakami, R.; Sato, H.; Dybal, Jiří; Iwata, T.; Ozaki, Y.

2007-01-01

Roč. 48, č. 9 (2007), s. 2672-2680 ISSN 0032-3861 R&D Projects: GA ČR GA203/05/0425 Grant - others:Ministry of Education, Culture, Sports, Science and Technology(JP) 18750107 Institutional research plan: CEZ:AV0Z40500505 Keywords : ultra-high-molecular-weight poly(hydroxybutyrate) * .beta.-form * Raman spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.065, year: 2007

Two-way and three-way approaches to ultra high performance liquid chromatography-photodiode array dataset for the quantitative resolution of a two-component mixture containing ciprofloxacin and ornidazole.

Science.gov (United States)

Dinç, Erdal; Ertekin, Zehra Ceren; Büker, Eda

2016-09-01

Two-way and three-way calibration models were applied to ultra high performance liquid chromatography with photodiode array data with coeluted peaks in the same wavelength and time regions for the simultaneous quantitation of ciprofloxacin and ornidazole in tablets. The chromatographic data cube (tensor) was obtained by recording chromatographic spectra of the standard and sample solutions containing ciprofloxacin and ornidazole with sulfadiazine as an internal standard as a function of time and wavelength. Parallel factor analysis and trilinear partial least squares were used as three-way calibrations for the decomposition of the tensor, whereas three-way unfolded partial least squares was applied as a two-way calibration to the unfolded dataset obtained from the data array of ultra high performance liquid chromatography with photodiode array detection. The validity and ability of two-way and three-way analysis methods were tested by analyzing validation samples: synthetic mixture, interday and intraday samples, and standard addition samples. Results obtained from two-way and three-way calibrations were compared to those provided by traditional ultra high performance liquid chromatography. The proposed methods, parallel factor analysis, trilinear partial least squares, unfolded partial least squares, and traditional ultra high performance liquid chromatography were successfully applied to the quantitative estimation of the solid dosage form containing ciprofloxacin and ornidazole. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Temperature dependence of Young's modulus of silica refractories

Czech Academy of Sciences Publication Activity Database

Gregorová, E.; Černý, Martin; Pabst, W.; Esposito, L.; Zanelli, C.; Hamáček, J.; Kutzendorfer, J.

2015-01-01

Roč. 41, č. 1 (2015), s. 1129-1138 ISSN 0272-8842 Institutional support: RVO:67985891 Keywords : mechanical properties * elastic modulus (Young's modulus ) * SiO2 * Silica brick materials (cristobalite, tridymite) Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.758, year: 2015

A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement

Directory of Open Access Journals (Sweden)

Guodong Zhang

2018-03-01

Full Text Available With the development of energetic materials (EMs and microelectromechanical systems (MEMS initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor’s sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa−1. The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size.

Ultra-fast framing camera tube

Science.gov (United States)

Kalibjian, Ralph

1981-01-01

An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

Kinome expression profiling of human neuroblastoma tumors identifies potential drug targets for ultra high-risk patients.

Science.gov (United States)

Russo, Roberta; Cimmino, Flora; Pezone, Lucia; Manna, Francesco; Avitabile, Marianna; Langella, Concetta; Koster, Jan; Casale, Fiorina; Raia, Maddalena; Viola, Giampietro; Fischer, Matthias; Iolascon, Achille; Capasso, Mario

2017-10-01

Neuroblastoma (NBL) accounts for >7% of malignancies in patients younger than 15 years. Low- and intermediate-risk patients exhibit excellent or good prognosis after treatment, whereas for high-risk (HR) patients, the estimated 5-year survival rates is still <40%. The ability to stratify HR patients that will not respond to standard treatment strategies is critical for informed treatment decisions. In this study, we have generated a specific kinome gene signature, named Kinome-27, which is able to identify a subset of HR-NBL tumors, named ultra-HR NBL, with highly aggressive clinical behavior that not adequately respond to standard treatments. We have demonstrated that NBL cell lines expressing the same kinome signature of ultra-HR tumors (ultra-HR-like cell lines) may be selectively targeted by the use of two drugs [suberoylanilide hydroxamic acid (SAHA) and Radicicol], and that the synergic combination of these drugs is able to block the ultra-HR-like cells in G2/M phase of cell cycle. The use of our signature in clinical practice will allow identifying patients with negative outcome, which would benefit from new and more personalized treatments. Preclinical in vivo studies are needed to consolidate the SAHA and Radicicol treatment in ultra-HR NBL patients. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The evolution of the stellar mass functions of star-forming and quiescent galaxies to z = 4 from the COSMOS/ultraVISTA survey

DEFF Research Database (Denmark)

Muzzin, Adam; Marchesini, Danilo; Stefano, Mauro

2013-01-01

We present measurements of the stellar mass functions (SMFs) of star-forming and quiescent galaxies to z = 4 using a sample of 95,675 Ks -selected galaxies in the COSMOS/UltraVISTA field. The SMFs of the combined population are in good agreement with previous measurements and show that the stellar...

Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings

Science.gov (United States)

Kats, Mikhail A.; Byrnes, Steven J.; Blanchard, Romain; Kolle, Mathias; Genevet, Patrice; Aizenberg, Joanna; Capasso, Federico

2013-09-01

Recently a new class of optical interference coatings was introduced which comprises ultra-thin, highly absorbing dielectric layers on metal substrates. We show that these lossy coatings can be augmented by an additional transparent subwavelength layer. We fabricated a sample comprising a gold substrate, an ultra-thin film of germanium with a thickness gradient, and several alumina films. The experimental reflectivity spectra showed that the additional alumina layer increases the color range that can be obtained, in agreement with calculations. More generally, this transparent layer can be used to enhance optical absorption, protect against erosion, or as a transparent electrode for optoelectronic devices.

Enhancing ultra-high CPV passive cooling using least-material finned heat sinks

Energy Technology Data Exchange (ETDEWEB)

Micheli, Leonardo, E-mail: lm409@exeter.ac.uk; Mallick, Tapas K., E-mail: T.K.Mallick@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Fernandez, Eduardo F., E-mail: E.Fernandez-Fernandez2@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Almonacid, Florencia, E-mail: facruz@ujaen.es [Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Reddy, K. S., E-mail: ksreddy@iitm.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036 (India)

2015-09-28

Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151$/W{sub p} is expected for a passive least-material heat sink developed for 4000x applications.

Proposal of Design Formulae for Equivalent Elasticity of Masonry Structures Made with Bricks of Low Modulus

Directory of Open Access Journals (Sweden)

Muhammad Ridwan

2017-01-01

Full Text Available Bricks of low elastic modulus are occasionally used in some developing countries, such as Indonesia and India. Most of the previous research efforts focused on masonry structures built with bricks of considerably high elastic modulus. The objective of this study is to quantify the equivalent elastic modulus of lower-stiffness masonry structures, when the mortar has a higher modulus of elasticity than the bricks, by employing finite element (FE simulations and adopting the homogenization technique. The reported numerical simulations adopted the two-dimensional representative volume elements (RVEs using quadrilateral elements with four nodes. The equivalent elastic moduli of composite elements with various bricks and mortar were quantified. The numerically estimated equivalent elastic moduli from the FE simulations were verified using previously established test data. Hence, a new simplified formula for the calculation of the equivalent modulus of elasticity of such masonry structures is proposed in the present study.

Pseudo-variables method to calculate HMA relaxation modulus through low-temperature induced stress and strain

International Nuclear Information System (INIS)

Canestrari, Francesco; Stimilli, Arianna; Bahia, Hussain U.; Virgili, Amedeo

2015-01-01

Highlights: • Proposal of a new method to analyze low-temperature cracking of bituminous mixtures. • Reliability of the relaxation modulus master curve modeling through Prony series. • Suitability of the pseudo-variables approach for a close form solution. - Abstract: Thermal cracking is a critical failure mode for asphalt pavements. Relaxation modulus is the major viscoelastic property that controls the development of thermally induced tensile stresses. Therefore, accurate determination of the relaxation modulus is fundamental for designing long lasting pavements. This paper proposes a reliable analytical solution for constructing the relaxation modulus master curve by measuring stress and strain thermally induced in asphalt mixtures. The solution, based on Boltzmann’s Superposition Principle and pseudo-variables concepts, accounts for time and temperature dependency of bituminous materials modulus, avoiding complex integral transformations. The applicability of the solution is demonstrated by testing a reference mixture using the Asphalt Thermal Cracking Analyzer (ATCA) device. By applying thermal loadings on restrained and unrestrained asphalt beams, ATCA allows the determination of several parameters, but is still unable to provide reliable estimations of relaxation properties. Without them the measurements from ATCA cannot be used in modeling of pavement behavior. Thus, the proposed solution successfully integrates ATCA experimental data. The same methodology can be applied to all test methods that concurrently measure stress and strain. The statistical parameters used to evaluate the goodness of fit show optimum correlation between theoretical and experimental results, demonstrating the accuracy of this mathematical approach

Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

Energy Technology Data Exchange (ETDEWEB)

Yano, Y., E-mail: yano.yasuhide@jaea.go.jp [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T. [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Ukai, S.; Oono, N. [Materials Science and Engineering, Faculty of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Kimura, A. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, S. [Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Torimaru, T. [Nippon Nuclear Fuel Development Co., Ltd., 2163, Narita-cho, Oarai-machi, Ibaraki, 311-1313 (Japan)

2017-04-15

Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900–1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

Science.gov (United States)

Yano, Y.; Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T.; Ukai, S.; Oono, N.; Kimura, A.; Hayashi, S.; Torimaru, T.

2017-04-01

Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900-1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

Design and Fabrication of a Piezoresistive Pressure Sensor for Ultra High Temperature Environment

International Nuclear Information System (INIS)

Zhao, L B; Zhao, Y L; Jiang, Z D

2006-01-01

In order to solve the pressure measurement problem in the harsh environment, a piezoresistive pressure sensor has been developed, which can be used under high temperature above 200 deg. C and is able to endure instantaneous ultra high temperature (2000deg. C, duration≤2s) impact. Based on the MEMS (Micro Electro-Mechanical System) and integrated circuit technology, the piezoresistive pressure sensor's sensitive element was fabricated and constituted by silicon substrate, a thin buried silicon dioxide layer, four p-type resistors in the measuring circuit layer by boron ion implantation and photolithography, the top SiO2 layer by oxidation, stress matching Si3N4 layer, and a Ti-Pt-Au beam lead layer for connecting p-type resistors by sputtering. In order to decrease the leak-current influence to sensor in high temperature above 200deg. C, the buried SiO2 layer with the thickness 367 nm was fabricated by the SIMOX (Separation by Implantation of Oxygen) technology, which was instead of p-n junction to isolate the upper measuring circuit layer from Si substrate. In order to endure instantaneous ultra high temperature impact, the mechanical structure with cantilever and diaphragm and transmitting beam was designed. By laser welding and high temperature packaging technology, the high temperature piezoresistive pressure sensor was fabricated with range of 120MPa. After the thermal compensation, the sensor's thermal zero drift k 0 and thermal sensitivity drift k s were easy to be less than 3x10 -4 FS/deg. C. The experimental results show that the developed piezoresistive pressure sensor has good performances under high temperature and is able to endure instantaneous ultra high temperature impact, which meets the requirements of modern industry, such as aviation, oil, engine, etc

Ultra-high current density thin-film Si diode

Science.gov (United States)

Wang, Qi [Littleton, CO

2008-04-22

A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

On Young's modulus of multi-walled carbon nanotubes

Indian Academy of Sciences (India)

WINTEC

load transfer in nanocomposites. In the present work, CNT/Al ... calculations. The theoretical modulus of the graphene sheet is supposed to be 1060 GPa (Harris 2004). The reason why multi-walled nanotubes have a modulus > 1060 GPa (that of graphene sheet) is currently not understood. However, in the present paper, ...

A CATALOG OF ULTRA-COMPACT HIGH VELOCITY CLOUDS FROM THE ALFALFA SURVEY: LOCAL GROUP GALAXY CANDIDATES?

Energy Technology Data Exchange (ETDEWEB)

Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P., E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States)

2013-05-01

We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34 Jy km s{sup -1}, median angular diameters of 10', and median velocity widths of 23 km s{sup -1}. We show that the full UCHVC population cannot easily be associated with known populations of high velocity clouds. Of the 59 clouds presented here, only 11 are also present in the compact cloud catalog extracted from the commensal GALFA-HI survey, demonstrating the utility of this separate dataset and analysis. Based on their sky distribution and observed properties, we infer that the ALFALFA UCHVCs are consistent with the hypothesis that they may be very low mass galaxies within the Local Volume. In that case, most of their baryons would be in the form of gas, and because of their low stellar content, they remain unidentified by extant optical surveys. At distances of {approx}1 Mpc, the UCHVCs have neutral hydrogen (H I) masses of {approx}10{sup 5}-10{sup 6} M{sub Sun }, H I diameters of {approx}2-3 kpc, and indicative dynamical masses within the H I extent of {approx}10{sup 7}-10{sup 8} M{sub Sun }, similar to the Local Group ultra-faint dwarf Leo T. The recent ALFALFA discovery of the star-forming, metal-poor, low mass galaxy Leo P demonstrates that this hypothesis is true in at least one case. In the case of the individual UCHVCs presented here, confirmation of their extragalactic nature will require further work, such as the identification of an optical counterpart to constrain their distance.

An Ultra-low Frequency Modal Testing Suspension System for High Precision Air Pressure Control

Directory of Open Access Journals (Sweden)

Qiaoling YUAN

2014-05-01

Full Text Available As a resolution for air pressure control challenges in ultra-low frequency modal testing suspension systems, an incremental PID control algorithm with dead band is applied to achieve high-precision pressure control. We also develop a set of independent hardware and software systems for high-precision pressure control solutions. Taking control system versatility, scalability, reliability, and other aspects into considerations, a two-level communication employing Ethernet and CAN bus, is adopted to complete such tasks as data exchange between the IPC, the main board and the control board ,and the pressure control. Furthermore, we build a single set of ultra-low frequency modal testing suspension system and complete pressure control experiments, which achieve the desired results and thus confirm that the high-precision pressure control subsystem is reasonable and reliable.

Disentangled solid state and metastable polymer melt; a solvent free route to high-modulus high-strength tapes and films of UHMWPE

Science.gov (United States)

Rastogi, Sanjay

2013-03-01

Ultra High Molecular Weight Polyethylene (UHMWPE) having average molar mass greater than a million g/mol is an engineering polymer. Due to its light-weight, high abrasion resistance and biocompatibility it is used for demanding applications such as body armour, prostheses etc. At present, because of its high melt viscosity to achieve the uniaxial/biaxial properties in the form of fibers/films the polymer is processed via solution route where nearly 95wt% of the solvent is used to process 5wt% of the polymer. In past several attempts have been made to process the polymer without using any solvent. However, compared to the solvent processing route the achieved mechanical properties were rather poor. Here we show that by controlled synthesis it is feasible to obtain UHMWPE that could be processed free of solvent to make uniaxial tapes and biaxial films, having unprecedented mechanical properties, exceeding that of the solution spun fibers. We address some of the fundamental aspects of chemistry, physics, rheology and processing for the development of desired morphological features to achieve the ultimate mechanical properties in tapes and films. The paper will also address the metastable melt state obtained on melting of the disentangled crystals and its implication on rheology in linear and nonlinear viscoelastic region. Solid state NMR studies will be applied to establish disentangled state in solid state to the polymerisation conditions. References: Macromolecules 2011, 44(14), 5558-5568; Nature Materials 2005, 4, 635-641; Phys Rev Lett 2006, 96(21), 218303-218205. The authors acknowledge financial support by the Dutch Polymer Institute.

Low-modulus PMMA bone cement modified with castor oil.

Science.gov (United States)

López, Alejandro; Hoess, Andreas; Thersleff, Thomas; Ott, Marjam; Engqvist, Håkan; Persson, Cecilia

2011-01-01

Some of the current clinical and biomechanical data suggest that vertebroplasty causes the development of adjacent vertebral fractures shortly after augmentation. These findings have been attributed to high injection volumes as well as high Young's moduli of PMMA bone cements compared to that of the osteoporotic cancellous bone. The aim of this study was to evaluate the use of castor oil as a plasticizer for PMMA bone cements. The Young's modulus, yield strength, maximum polymerization temperature, doughing time, setting time and the complex viscosity curves during curing, were determined. The cytotoxicity of the materials extracts was assessed on cells of an osteoblast-like cell line. The addition of up to 12 wt% castor oil decreased yield strength from 88 to 15 MPa, Young's modulus from 1500 to 446 MPa and maximum polymerization temperature from 41.3 to 25.6°C, without affecting the setting time. However, castor oil seemed to interfere with the polymerization reaction, giving a negative effect on cell viability in a worst-case scenario.

Effect of a High Density of Stacking Faults on the Young's Modulus of GaAs Nanowires.

Science.gov (United States)

Chen, Yujie; Burgess, Tim; An, Xianghai; Mai, Yiu-Wing; Tan, H Hoe; Zou, Jin; Ringer, Simon P; Jagadish, Chennupati; Liao, Xiaozhou

2016-03-09

Stacking faults (SFs) are commonly observed crystalline defects in III-V semiconductor nanowires (NWs) that affect a variety of physical properties. Understanding the effect of SFs on NW mechanical properties is critical to NW applications in nanodevices. In this study, the Young's moduli of GaAs NWs with two distinct structures, defect-free single crystalline wurtzite (WZ) and highly defective wurtzite containing a high density of SFs (WZ-SF), are investigated using combined in situ compression transmission electron microscopy and finite element analysis. The Young's moduli of both WZ and WZ-SF GaAs NWs were found to increase with decreasing diameter due to the increasing volume fraction of the native oxide shell. The presence of a high density of SFs was further found to increase the Young's modulus by 13%. This stiffening effect of SFs is attributed to the change in the interatomic bonding configuration at the SFs.

Asphalt mix characterization using dynamic modulus and APA testing.

Science.gov (United States)

2005-11-01

final report summarizes two research efforts related to asphalt mix characterization: dynamic modulus and Asphalt Pavement Analyzer testing. One phase of the research consisted of a laboratory-based evaluation of dynamic modulus of Oregon dense-grade...

UltraSail CubeSat Solar Sail Flight Experiment

Science.gov (United States)

Carroll, David; Burton, Rodney; Coverstone, Victoria; Swenson, Gary

2013-01-01

UltraSail is a next-generation, highrisk, high-payoff sail system for the launch, deployment, stabilization, and control of very large (km2 class) solar sails enabling high payload mass fractions for interplanetary and deep space spacecraft. UltraSail is a non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation- flying microsatellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 km2, sail subsystem area densities approaching 1 g/m2, and thrust levels many times those of ion thrusters used for comparable deep space missions. UltraSail can achieve outer planetary rendezvous, a deep-space capability now reserved for high-mass nuclear and chemical systems. There is a twofold rationale behind the UltraSail concept for advanced solar sail systems. The first is that sail-andboom systems are inherently size-limited. The boom mass must be kept small, and column buckling limits the boom length to a few hundred meters. By eliminating the boom, UltraSail not only offers larger sail area, but also lower areal density, allowing larger payloads and shorter mission transit times. The second rationale for UltraSail is that sail films present deployment handling difficulties as the film thickness approaches one micrometer. The square sail requires that the film be folded in two directions for launch, and similarly unfolded for deployment. The film is stressed at the intersection of two folds, and this stress varies inversely with the film thickness. This stress can cause the film to yield, forming a permanent crease, or worse, to perforate. By rolling the film as UltraSail does, creases are prevented. Because the film is so thin, the roll thickness is small. Dynamic structural analysis of UltraSail coupled with dynamic control analysis shows that the system can be designed to eliminate longitudinal torsional waves created while controlling the pitch of the blades

Direct measurement of elastic modulus of Nb 3Sn using extracted filaments from superconducting composite wire and resin impregnation method

Science.gov (United States)

Hojo, M.; Matsuoka, T.; Hashimoto, M.; Tanaka, M.; Sugano, M.; Ochiai, S.; Miyashita, K.

2006-10-01

Young's modulus of Nb3Sn filaments in Nb3Sn/Cu superconducting composite wire was investigated in detail. Nb3Sn filaments were first extracted from composite wire. Nitric acid and hydrofluoric acid were used to remove copper stabilizer, Nb3Sn/Nb barrier and bronze. Then, Nb3Sn filaments were impregnated with epoxy resin to form simple filament bundle composite rods. A large difference in Young's moduli of filaments and epoxy resin enhance the accuracy of the measurement of Nb3Sn filament modulus. The ratio of Nb3Sn to Nb in filaments and the number of filaments in the fiber bundle composite rods were used in the final calculation of the Young's modulus of Nb3Sn. The obtained modulus of 127 GPa was the lower bound of the already reported values.

Direct measurement of elastic modulus of Nb3Sn using extracted filaments from superconducting composite wire and resin impregnation method

International Nuclear Information System (INIS)

Hojo, M.; Matsuoka, T.; Hashimoto, M.; Tanaka, M.; Sugano, M.; Ochiai, S.; Miyashita, K.

2006-01-01

Young's modulus of Nb 3 Sn filaments in Nb 3 Sn/Cu superconducting composite wire was investigated in detail. Nb 3 Sn filaments were first extracted from composite wire. Nitric acid and hydrofluoric acid were used to remove copper stabilizer, Nb 3 Sn/Nb barrier and bronze. Then, Nb 3 Sn filaments were impregnated with epoxy resin to form simple filament bundle composite rods. A large difference in Young's moduli of filaments and epoxy resin enhance the accuracy of the measurement of Nb 3 Sn filament modulus. The ratio of Nb 3 Sn to Nb in filaments and the number of filaments in the fiber bundle composite rods were used in the final calculation of the Young's modulus of Nb 3 Sn. The obtained modulus of 127 GPa was the lower bound of the already reported values

Durability and smart condition assessment of ultra-high performance concrete in cold climates.

Science.gov (United States)

2016-12-31

The goals of this study were to develop ecological ultra-high performance concrete (UHPC) with local materials and supplementary cementitious materials and to evaluate the long-term performance of UHPC in cold climates using effective mechanical test...

Frequency-dependent complex modulus of the uterus: preliminary results

Energy Technology Data Exchange (ETDEWEB)

Kiss, Miklos Z [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Hobson, Maritza A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Varghese, Tomy [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Harter, Josephine [Department of Surgical Pathology, University of Wisconsin, Madison, WI 53706 (United States); Kliewer, Mark A [Department of Radiology, University of Wisconsin, Madison, WI 53706 (United States); Hartenbach, Ellen M [Department of Obstetrics and Gynecology, University of Wisconsin, Madison, WI 53706 (United States); Zagzebski, James A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States)

2006-08-07

The frequency-dependent complex moduli of human uterine tissue have been characterized. Quantification of the modulus is required for developing uterine ultrasound elastography as a viable imaging modality for diagnosing and monitoring causes for abnormal uterine bleeding and enlargement, as well assessing the integrity of uterine and cervical tissue. The complex modulus was measured in samples from hysterectomies of 24 patients ranging in age from 31 to 79 years. Measurements were done under small compressions of either 1 or 2%, at low pre-compression values (either 1 or 2%), and over a frequency range of 0.1-100 Hz. Modulus values of cervical tissue monotonically increased from approximately 30-90 kPa over the frequency range. Normal uterine tissue possessed modulus values over the same range, while leiomyomas, or uterine fibroids, exhibited values ranging from approximately 60-220 kPa.

Frequency-dependent complex modulus of the uterus: preliminary results

International Nuclear Information System (INIS)

Kiss, Miklos Z; Hobson, Maritza A; Varghese, Tomy; Harter, Josephine; Kliewer, Mark A; Hartenbach, Ellen M; Zagzebski, James A

2006-01-01

The frequency-dependent complex moduli of human uterine tissue have been characterized. Quantification of the modulus is required for developing uterine ultrasound elastography as a viable imaging modality for diagnosing and monitoring causes for abnormal uterine bleeding and enlargement, as well assessing the integrity of uterine and cervical tissue. The complex modulus was measured in samples from hysterectomies of 24 patients ranging in age from 31 to 79 years. Measurements were done under small compressions of either 1 or 2%, at low pre-compression values (either 1 or 2%), and over a frequency range of 0.1-100 Hz. Modulus values of cervical tissue monotonically increased from approximately 30-90 kPa over the frequency range. Normal uterine tissue possessed modulus values over the same range, while leiomyomas, or uterine fibroids, exhibited values ranging from approximately 60-220 kPa

Design and evaluation of a single-span bridge using ultra-high performance concrete.

Science.gov (United States)

2009-09-01

"Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possib...

Three-dimensional fine structure of the organization of microtubules in neurite varicosities by ultra-high voltage electron microscope tomography.

Science.gov (United States)

Nishida, Tomoki; Yoshimura, Ryoichi; Endo, Yasuhisa

2017-09-01

Neurite varicosities are highly specialized compartments that are involved in neurotransmitter/ neuromodulator release and provide a physiological platform for neural functions. However, it remains unclear how microtubule organization contributes to the form of varicosity. Here, we examine the three-dimensional structure of microtubules in varicosities of a differentiated PC12 neural cell line using ultra-high voltage electron microscope tomography. Three-dimensional imaging showed that a part of the varicosities contained an accumulation of organelles that were separated from parallel microtubule arrays. Further detailed analysis using serial sections and whole-mount tomography revealed microtubules running in a spindle shape of swelling in some other types of varicosities. These electron tomographic results showed that the structural diversity and heterogeneity of microtubule organization supported the form of varicosities, suggesting that a different distribution pattern of microtubules in varicosities is crucial to the regulation of varicosities development.

Assessment of dynamic modulus of high density polypropylene waste fiber reinforcement in asphalt concrete

Directory of Open Access Journals (Sweden)

Hassan S. OTUOZE

2015-12-01

Full Text Available Traditional asphalt tests like Hveem and Marshall tests are at best mere characterization than effective test of pavement field performance because of complex viscoelastic behavior of asphalt. Mechanical properties otherwise called simple performance tests (SPT are performance criteria of asphalt. Dynamic modulus among other SPT’s like permanent deformation, fatigue cracking, thermal cracking, moisture susceptibility, shear and friction properties; determines stress-strain to time-temperature relationships that imparts on strength, service life and durability. The test followed the recommendations of NCHRP 1-37a (2004 and mixes were prepared using 0, 0.5, 1.0 and 1.5% HDPP contents. The parameters tested for dynamic modulus, /E*/, are stiffness, recoverable strain (ε, and phase angle (ξ. Time – temperature superposition (TTS called master curve was fitted using sigmoidal curve to interpolate the parameters beyond measured data set so as to observe the viscoelastic behavior outside the physical properties. The performance of 0.5% HDPP asphalt is better enhanced than the conventional asphalt to improve upon strength, service and durability.

Low modulus Ti–Nb–Hf alloy for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

González, M., E-mail: Marta.Gonzalez.Colominas@upc.edu [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Peña, J. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Gil, F.J.; Manero, J.M. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Ciber-BBN (Spain)

2014-09-01

β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37 °C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress–strain curves showed the lowest elastic modulus (42 GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (E{sub OCP}), but was similar in terms of corrosion current density (i{sub CORR}) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response. - Highlights: • Presents low elastic modulus and high strength and elastic deformability. • Exhibits good biocompatibility in terms of cytotoxicity and cell response. • Corrosion resistance of this alloy is good, similar to that of Ti grade II. • Potential candidate for implants used to substitute failed hard tissue.

Cell wall elasticity: I. A critique of the bulk elastic modulus approach and an analysis using polymer elastic principles

Science.gov (United States)

Wu, H. I.; Spence, R. D.; Sharpe, P. J.; Goeschl, J. D.

1985-01-01

The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The bulk modulus describes stress/strain relations of solid, homogeneous bodies undergoing small deformations, whereas the plant cell is best described as a thin-shelled, fluid-filled structure with a polymer base. Because cell walls possess a polymer structure, an alternative method of mechanical analysis is presented using polymer elasticity principles. This initial study presents the groundwork of polymer mechanics as would be applied to cell walls and discusses how the matrix and microfibrillar network induce nonlinear stress/strain relationships in the cell wall in response to turgor pressure. In subsequent studies, these concepts will be expanded to include anisotropic expansion as regulated by the microfibrillar network.

Cosmic-ray ultra high-energy multijet family event

International Nuclear Information System (INIS)

Zou Bao-tang; Wang Cheng-rui; Ren Jing-ru

1987-01-01

A cosmic-ray ultra-high-energy multijet family event with visible energy of about 1500 TeV and five large cores is reported. This event was found in the 1980-1981 exposure of the Mt. Kambala (5500 M a.s.l.) emulsion-chamber experiment. The family characteristics are analyzed and compared with other cosmic ray events in the same energy range. The production and fragmentation characteristics of the five jets are studied and compared with the experimental results of accelerators and emulsion chamber C-jets as well as with QCD predictions above the TeV range. Some features on hadronic interactions in the TeV range are discussed

Sensitive determination of the Young's modulus of thin films by polymeric microcantilevers

DEFF Research Database (Denmark)

Colombi, Paolo; Bergese, Paolo; Bontempi, Elza

2013-01-01

A method for the highly sensitive determination of the Young's modulus of TiO2 thin films exploiting the resonant frequency shift of a SU-8 polymer microcantilever (MC) is presented. Amorphous TiO2 films with different thickness ranging from 10 to 125 nm were grown at low temperature (90 °C......) with subnanometer thickness resolution on SU-8 MC arrays by means of atomic layer deposition. The resonant frequencies of the MCs were measured before and after coating and the elastic moduli of the films were determined by a theoretical model developed for this purpose. The Young's modulus of thicker TiO2 films...... (>75 nm) was estimated to be about 110 GPa, this value being consistent with the value of amorphous TiO2. On the other hand we observed a marked decrease of the Young's modulus for TiO2 films with a thickness below 50 nm. This behavior was found not to be related to a decrease of the film mass density...

Design of Ultra High Performance Fiber Reinforced Concrete Shells

DEFF Research Database (Denmark)

Jepsen, Michael S.; Lambertsen, Søren Heide; Damkilde, Lars

2013-01-01

Fiber Reinforced Concrete shell. The major challenge in the design phase has been securing sufficient stiffness of the structure while keeping the weight at a minimum. The weight/stiffness issue has been investigated by means of the finite element method, to optimize the structure regarding overall......The paper treats the redesign of the float structure of the Wavestar wave energy converter. Previously it was designed as a glass fiber structure, but due to cost reduction requirements a redesign has been initiated. The new float structure will be designed as a double curved Ultra High Performance...

Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling

DEFF Research Database (Denmark)

Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth

2013-01-01

Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility...

Design and characterization of ultra-stretchable monolithic silicon fabric

KAUST Repository

Rojas, Jhonathan Prieto

2014-10-13

Stretchable electronic systems can play instrumental role for reconfigurable macro-electronics such as distributed sensor networks for wearable and bio-integrated electronics. Typically, polymer composite based materials and its deterministic design as interconnects are used to achieve such systems. Nonetheless, non-polymeric inorganic silicon is the predominant material for 90% of electronics. Therefore, we report the design and fabrication of an all silicon based network of hexagonal islands connected through spiral springs to form an ultra-stretchable arrangement for complete compliance to highly asymmetric shapes. Several design parameters are considered and their validation is carried out through finite element analysis. The fabrication process is based on conventional microfabrication techniques and the measured stretchability is more than 1000% for single spirals and area expansions as high as 30 folds in arrays. The reported method can provide ultra-stretchable and adaptable electronic systems for distributed network of high-performance macro-electronics especially useful for wearable electronics and bio-integrated devices.

Design and characterization of ultra-stretchable monolithic silicon fabric

KAUST Repository

Rojas, Jhonathan Prieto; Carreno, Armando Arpys Arevalo; Foulds, I. G.; Hussain, Muhammad Mustafa

2014-01-01

Stretchable electronic systems can play instrumental role for reconfigurable macro-electronics such as distributed sensor networks for wearable and bio-integrated electronics. Typically, polymer composite based materials and its deterministic design as interconnects are used to achieve such systems. Nonetheless, non-polymeric inorganic silicon is the predominant material for 90% of electronics. Therefore, we report the design and fabrication of an all silicon based network of hexagonal islands connected through spiral springs to form an ultra-stretchable arrangement for complete compliance to highly asymmetric shapes. Several design parameters are considered and their validation is carried out through finite element analysis. The fabrication process is based on conventional microfabrication techniques and the measured stretchability is more than 1000% for single spirals and area expansions as high as 30 folds in arrays. The reported method can provide ultra-stretchable and adaptable electronic systems for distributed network of high-performance macro-electronics especially useful for wearable electronics and bio-integrated devices.

Compressive Strength and Modulus of Elasticity of Concrete with Cubed Waste Tire Rubbers as Coarse Aggregates

Science.gov (United States)

Haryanto, Y.; Hermanto, N. I. S.; Pamudji, G.; Wardana, K. P.

2017-11-01

One feasible solution to overcome the issue of tire disposal waste is the use of waste tire rubber to replace aggregate in concrete. We have conducted an experimental investigation on the effect of rubber tire waste aggregate in cuboid form on the compressive strength and modulus of elasticity of concrete. The test was performed on 72 cylindrical specimens with the height of 300 mm and diameter of 150 mm. We found that the workability of concrete with waste tire rubber aggregate has increased. The concrete density with waste tire rubber aggregate was decreased, and so was the compressive strength. The decrease of compressive strength is up to 64.34%. If the content of waste tire rubber aggregate is more than 40%, then the resulting concrete cannot be categorized as structural concrete. The modulus of elasticity decreased to 59.77%. The theoretical equation developed to determine the modulus of elasticity of concrete with rubber tire waste aggregate has an accuracy of 84.27%.

Investigation of statistical relationship between dynamic modulus and thermal strength of asphalt concrete

International Nuclear Information System (INIS)

Qadir, A.; Gular, M.

2011-01-01

Dynamic modulus is a performance indicator for asphalt concrete and is used to qualify asphalt mixtures based on stress-strain characteristics under repeated loading. Moreover, the low temperature cracking of asphalt concrete mixes are measured in terms of fracture strength and fracture temperature. Dynamic modulus test was selected as one of the simple performance tests in the AASHTO 2002 guidelines to rate mixtures according to permanent deformation performance. However, AASHTO 2002 guidelines is silent in relating dynamic modulus values to low temperature cracking, probably because of weak correlations reported between these two properties. The present study investigates the relation between these two properties under the influence of aggregate type and mix gradation. Mixtures were prepared with two types of aggregate and gradations, while maintaining the binder type and air voids constant. The mixtures were later tested for dynamic modulus and fracture strength using thermal stress restrained specimen test (TSRST). Results indicate that there exists a fair correlation between the thermal fracture strength and stiffness at a selected test temperature and frequency level. These correlations are highly dependent upon the type of aggregate and mix gradation. (author)

Young's modulus of individual ZnO nanowires

International Nuclear Information System (INIS)

Jiang, Dayong; Tian, Chunguang; Liu, Qingfei; Zhao, Man; Qin, Jieming; Hou, Jianhua; Gao, Shang; Liang, Qingcheng; Zhao, Jianxun

2014-01-01

We used a contact-mode atomic force microscopy (AFM) to study the mechanical properties of an individual ZnO nanowire in the open air. It is noteworthy that the Young's modulus can be determined by an AFM tip compressing a single nanowire on a rigid substrate, which can bring more repeatability and accuracy for the measurements. In particular, the calculated radial Young's modulus of ZnO nanowires is consistent with the data of ZnO bulks and thin films. We also present the Young's modulus with different diameters, and all these are discussed deeply

Ultra-high-ohmic microstripline resistors for Coulomb blockade devices

International Nuclear Information System (INIS)

Lotkhov, Sergey V

2013-01-01

In this paper, we report on the fabrication and low-temperature characterization of ultra-high-ohmic microstripline resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage–current characteristics were measured at temperatures down to T ∼ 20 mK for films with sheet resistivities as high as ∼7 kΩ, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show the promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current. (paper)

Ring-like spatial distribution of laser accelerated protons in the ultra-high-contrast TNSA-regime

Science.gov (United States)

Becker, G. A.; Tietze, S.; Keppler, S.; Reislöhner, J.; Bin, J. H.; Bock, L.; Brack, F.-E.; Hein, J.; Hellwing, M.; Hilz, P.; Hornung, M.; Kessler, A.; Kraft, S. D.; Kuschel, S.; Liebetrau, H.; Ma, W.; Polz, J.; Schlenvoigt, H.-P.; Schorcht, F.; Schwab, M. B.; Seidel, A.; Zeil, K.; Schramm, U.; Zepf, M.; Schreiber, J.; Rykovanov, S.; Kaluza, M. C.

2018-05-01

The spatial distribution of protons accelerated from submicron-thick plastic foil targets using multi-terawatt, frequency-doubled laser pulses with ultra-high temporal contrast has been investigated experimentally. A very stable, ring-like beam profile of the accelerated protons, oriented around the target’s normal direction has been observed. The ring’s opening angle has been found to decrease with increasing foil thicknesses. Two-dimensional particle-in-cell simulations reproduce our results indicating that the ring is formed during the expansion of the proton density distribution into the vacuum as described by the mechanism of target-normal sheath acceleration. Here—in addition to the longitudinal electric fields responsible for the forward acceleration of the protons—a lateral charge separation leads to transverse field components accelerating the protons in the lateral direction.

Fabrication of high quality, ultra-long fiber Bragg gratings: up to 2 million periods in phase.

Science.gov (United States)

Gagné, Mathieu; Loranger, Sébastien; Lapointe, Jerome; Kashyap, Raman

2014-01-13

The fabrication and characterization of high quality ultra-long (up to 1m) fiber Bragg gratings (FBGs) is reported. A moving phase mask and an electro-optic phase-modulation (EOPM) based interferometer are used with a high precision 1-meter long translation stage and compared. A novel interferometer position feedback scheme to simplify the fabrication process is proposed and analyzed. The ultra-long uniform FBGs show near perfect characteristics of a few picometers bandwidth, symmetrical, near theory-matching group-delay and transmission spectra. Grating characterization using optical backscattering reflectometry and chirped FBGs are also demonstrated. Limitations of the schemes are discussed.

Study of application technology of ultra-high speed computer to the elucidation of complex phenomena

International Nuclear Information System (INIS)

Sekiguchi, Tomotsugu

1996-01-01

The basic design of numerical information library in the decentralized computer network was explained at the first step of constructing the application technology of ultra-high speed computer to the elucidation of complex phenomena. Establishment of the system makes possible to construct the efficient application environment of ultra-high speed computer system to be scalable with the different computing systems. We named the system Ninf (Network Information Library for High Performance Computing). The summary of application technology of library was described as follows: the application technology of library under the distributed environment, numeric constants, retrieval of value, library of special functions, computing library, Ninf library interface, Ninf remote library and registration. By the system, user is able to use the program concentrating the analyzing technology of numerical value with high precision, reliability and speed. (S.Y.)

Kernel based methods for accelerated failure time model with ultra-high dimensional data

Directory of Open Access Journals (Sweden)

Jiang Feng

2010-12-01

Full Text Available Abstract Background Most genomic data have ultra-high dimensions with more than 10,000 genes (probes. Regularization methods with L1 and Lp penalty have been extensively studied in survival analysis with high-dimensional genomic data. However, when the sample size n ≪ m (the number of genes, directly identifying a small subset of genes from ultra-high (m > 10, 000 dimensional data is time-consuming and not computationally efficient. In current microarray analysis, what people really do is select a couple of thousands (or hundreds of genes using univariate analysis or statistical tests, and then apply the LASSO-type penalty to further reduce the number of disease associated genes. This two-step procedure may introduce bias and inaccuracy and lead us to miss biologically important genes. Results The accelerated failure time (AFT model is a linear regression model and a useful alternative to the Cox model for survival analysis. In this paper, we propose a nonlinear kernel based AFT model and an efficient variable selection method with adaptive kernel ridge regression. Our proposed variable selection method is based on the kernel matrix and dual problem with a much smaller n × n matrix. It is very efficient when the number of unknown variables (genes is much larger than the number of samples. Moreover, the primal variables are explicitly updated and the sparsity in the solution is exploited. Conclusions Our proposed methods can simultaneously identify survival associated prognostic factors and predict survival outcomes with ultra-high dimensional genomic data. We have demonstrated the performance of our methods with both simulation and real data. The proposed method performs superbly with limited computational studies.

Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

Energy Technology Data Exchange (ETDEWEB)

Chubar, Oleg [Brookhaven National Laboratory, Upton, NY 11973 (United States); Geloni, Gianluca [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Kocharyan, Vitali [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Madsen, Anders [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Saldin, Evgeni; Serkez, Svitozar [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Shvyd’ko, Yuri, E-mail: shvydko@aps.anl.gov [Argonne National Laboratory, Argonne, IL 60439 (United States); Sutter, John [Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom)

2016-02-12

This article explores novel opportunities for ultra-high-resolution inelastic X-ray scattering (IXS) at high-repetition-rate self-seeded XFELs. These next-generation light sources are promising a more than three orders of magnitude increase in average spectral flux compared with what is possible with storage-ring-based radiation sources. In combination with the advanced IXS spectrometer described here, this may become a real game-changer for ultra-high-resolution X-ray spectroscopies, and hence for the studies of dynamics in condensed matter systems. Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm{sup −1} spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm{sup −1} are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 10{sup 12} photons s{sup −1} in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

Detecting ultra high energy neutrinos with LOFAR

International Nuclear Information System (INIS)

Mevius, M.; Buitink, S.; Falcke, H.; Hörandel, J.; James, C.W.; McFadden, R.; Scholten, O.; Singh, K.; Stappers, B.; Veen, S. ter

2012-01-01

The NuMoon project aims to detect signals of Ultra High Energy (UHE) Cosmic Rays with radio telescopes on Earth using the Lunar Cherenkov technique at low frequencies (∼150MHz). The advantage of using low frequencies is the much larger effective detecting volume, with as trade-off the cut-off in sensitivity at lower energies. A first upper limit on the UHE neutrino flux from data of the Westerbork Radio Telescope (WSRT) has been published, while a second experiment, using the new LOFAR telescope, is in preparation. The advantages of LOFAR over WSRT are the larger collecting area, the better pointing accuracy and the use of ring buffers, which allow the implementation of a sophisticated self-trigger algorithm. The expected sensitivity of LOFAR reaches flux limits within the range of some theoretical production models.

Concept of modular flexure-based mechanisms for ultra-high precision robot design

Directory of Open Access Journals (Sweden)

M. Richard

2011-05-01

Full Text Available This paper introduces a new concept of modular flexure-based mechanisms to design industrial ultra-high precision robots, which aims at significantly reducing both the complexity of their design and their development time. This modular concept can be considered as a robotic Lego, where a finite number of building bricks is used to quickly build a high-precision robot. The core of the concept is the transformation of a 3-D design problem into several 2-D ones, which are simpler and well-mastered. This paper will first briefly present the theoretical bases of this methodology and the requirements of both types of building bricks: the active and the passive bricks. The section dedicated to the design of the active bricks will detail the current research directions, mainly the maximisation of the strokes and the development of an actuation sub-brick. As for the passive bricks, some examples will be presented, and a discussion regarding the establishment of a mechanical solution catalogue will conclude the section. Last, this modular concept will be illustrated with a practical example, consisting in the design of a 5-degree of freedom ultra-high precision robot.

The Promise and Challenges of Ultra High Bypass Ratio Engine Technology and Integration

Science.gov (United States)

Hughes, Chris

2011-01-01

In this presentation, an overview of the research being conducted by the ERA Project in Ultra High Bypass aircraft propulsion and in partnership with Pratt & Whitney with their Geared TurboFan (GTF) is given. The ERA goals are shown followed by a discussion of what areas need to be addressed on the engine to achieve the goals and how the GTF is uniquely qualified to meet the goals through a discussion of what benefits the cycle provides. The first generation GTF architecture is then shown highlighting the areas of collaboration with NASA, and the fuel burn, noise and emissions reductions possible based on initial static ground test and flight test data of the first GTF engine. Finally, a 5 year technology roadmap is presented focusing on Ultra High Bypass propulsion technology research areas that are being pursued and being planned by ERA and P&W under their GTF program.

A note on the applied tearing modulus (Tsub(J)sup(app)) in ductile instability testing and analysis

International Nuclear Information System (INIS)

Saka, Masumi; Takahashi, Hideaki; Abe, Hiroyuki; Ando, Kotoji.

1984-01-01

In the evaluation of the soundness of the structures made of high toughness materials, it is a very important problem to clarify by what dynamic condition the transition from the stable propagation of ductile cracks to ductile unstable breaking is controlled. As a criterion for ductile unstable breaking, Paris et al. proposed that an applied tearing modulus is not smaller than a material tearing modulus, based on J-integral. In order to make highly reliable forecast on the starting point of ductile unstable breaking, it is necessary to sufficiently examine the features of an applied tearing modulus. In this study, referring to the test results of the ductile unstable breaking of ITCT test pieces of A508 steel for reactor pressure vessels, the features of the changing tendency of an applied tearing modulus accompanying crack development and the cause of these features were examined in detail. Moreover, the errors in the theoretical forecast of J-integral and the amount of crack development at the start of ductile unstable breaking in relation to the above features were examined. The test pieces and the experimental method, the method of analysis, the experimental results, the features of an applied tearing modulus and the accuracy of forecast are reported. (Kako, I.)

Ultra-High Density Single Nanometer-Scale Anodic Alumina Nanofibers Fabricated by Pyrophosphoric Acid Anodizing

Science.gov (United States)

Kikuchi, Tatsuya; Nishinaga, Osamu; Nakajima, Daiki; Kawashima, Jun; Natsui, Shungo; Sakaguchi, Norihito; Suzuki, Ryosuke O.

2014-12-01

Anodic oxide fabricated by anodizing has been widely used for nanostructural engineering, but the nanomorphology is limited to only two oxides: anodic barrier and porous oxides. Therefore, the discovery of an additional anodic oxide with a unique nanofeature would expand the applicability of anodizing. Here we demonstrate the fabrication of a third-generation anodic oxide, specifically, anodic alumina nanofibers, by anodizing in a new electrolyte, pyrophosphoric acid. Ultra-high density single nanometer-scale anodic alumina nanofibers (1010 nanofibers/cm2) consisting of an amorphous, pure aluminum oxide were successfully fabricated via pyrophosphoric acid anodizing. The nanomorphologies of the anodic nanofibers can be controlled by the electrochemical conditions. Anodic tungsten oxide nanofibers can also be fabricated by pyrophosphoric acid anodizing. The aluminum surface covered by the anodic alumina nanofibers exhibited ultra-fast superhydrophilic behavior, with a contact angle of less than 1°, within 1 second. Such ultra-narrow nanofibers can be used for various nanoapplications including catalysts, wettability control, and electronic devices.

Ultra-high Q terahertz whispering-gallery modes in a silicon resonator

Science.gov (United States)

Vogt, Dominik Walter; Leonhardt, Rainer

2018-05-01

We report on the first experimental demonstration of terahertz (THz) whispering-gallery modes (WGMs) with an ultra-high quality factor of 1.5 × 104 at 0.62 THz. The WGMs are observed in a high resistivity float zone silicon spherical resonator coupled to a sub-wavelength silica waveguide. A detailed analysis of the coherent continuous wave THz spectroscopy measurements combined with a numerical model based on Mie-Debye-Aden-Kerker theory allows us to unambiguously identify the observed higher order radial THz WGMs.

Motivation for an SSC detector with ultra-high resolution photon detection

International Nuclear Information System (INIS)

Gunion, J.F.; Kane, G.

1992-01-01

It is well known that incorporating ultra-high resolution photon detection into a general purpose detector for the SSC will be extremely difficult. The authors will argue that the physics signals that could be missed without such resolution are of such importance that a special purpose detector designed specifically for photon final state modes should be constructed, if sufficient resolution cannot be achieved with general purpose detectors. The potentially great value of these signals as a probe of extremely high mass scales is stressed

Post-mortem inference of the human hippocampal connectivity and microstructure using ultra-high field diffusion MRI at 11.7 T.

Science.gov (United States)

Beaujoin, Justine; Palomero-Gallagher, Nicola; Boumezbeur, Fawzi; Axer, Markus; Bernard, Jeremy; Poupon, Fabrice; Schmitz, Daniel; Mangin, Jean-François; Poupon, Cyril

2018-06-01

The human hippocampus plays a key role in memory management and is one of the first structures affected by Alzheimer's disease. Ultra-high magnetic resonance imaging provides access to its inner structure in vivo. However, gradient limitations on clinical systems hinder access to its inner connectivity and microstructure. A major target of this paper is the demonstration of diffusion MRI potential, using ultra-high field (11.7 T) and strong gradients (750 mT/m), to reveal the extra- and intra-hippocampal connectivity in addition to its microstructure. To this purpose, a multiple-shell diffusion-weighted acquisition protocol was developed to reach an ultra-high spatio-angular resolution with a good signal-to-noise ratio. The MRI data set was analyzed using analytical Q-Ball Imaging, Diffusion Tensor Imaging (DTI), and Neurite Orientation Dispersion and Density Imaging models. High Angular Resolution Diffusion Imaging estimates allowed us to obtain an accurate tractography resolving more complex fiber architecture than DTI models, and subsequently provided a map of the cross-regional connectivity. The neurite density was akin to that found in the histological literature, revealing the three hippocampal layers. Moreover, a gradient of connectivity and neurite density was observed between the anterior and the posterior part of the hippocampus. These results demonstrate that ex vivo ultra-high field/ultra-high gradients diffusion-weighted MRI allows the mapping of the inner connectivity of the human hippocampus, its microstructure, and to accurately reconstruct elements of the polysynaptic intra-hippocampal pathway using fiber tractography techniques at very high spatial/angular resolutions.

Regional variation in wood modulus of elasticity (stiffness) and modulus of rupture (strength) of planted loblolly pine in the United States

Science.gov (United States)

Antony Finto; Lewis Jordan; Laurence R. Schimleck; Alexander Clark; Ray A. Souter; Richard F. Daniels

2011-01-01

Modulus of elasticity (MOE), modulus of rupture (MOR), and specific gravity (SG) are important properties for determining the end-use and value of a piece of lumber. This study addressed the variation in MOE, MOR, and SG with physiographic region, tree height, and wood type. Properties were measured from two static bending samples (dimensions 25.4 mm × 25.4 mm × 406.4...

Ultra-high performance concrete : a state-of-the-art report for the bridge community.

Science.gov (United States)

2013-06-01

"The term Ultra-High Performance Concrete (UHPC) refers to a relatively new class of advanced cementitious : composite materials whose mechanical and durability properties far surpass those of conventional concrete. This : class of concrete has been ...

Ultra light weight refractory material for high temperature applications

Energy Technology Data Exchange (ETDEWEB)

Finke, V.; Kern, H. [Rath GmbH, Meissen (Germany); Springer, M. [Aug. Rath jun. GmbH, Vienna (Austria)

2007-07-01

The requirements on companies running high temperature processes, i.e. at temperatures about 1000 C and above, have increased dramatically within the last few years. For technological, economical and ecological purposes each application has to be checked carefully. As well the political discussion regarding environmental pollution, greenhouse effect and emission trading and the guidelines for climate and environmental protection exert massive influence on thermal process technology and pose an appropriate challenge for the companies. Next to costs of labour and raw materials the costs for energy and environmental costs play a decisive role more and more. The pressure on the management thereby incurred may have a lasting effect on innovations regarding increase of energy efficiency, decrease of CO{sub 2}-emission and often on non negligible increase of productivity. Mainly against the background of the highly scheduled European aims for emission reduction and also in consideration of the still proceeding globalisation the usage of state-of-the-art refractory technics in thermal process technology is of particular importance for business success, for reducing of environmental impact and last but not least for conservation and safeguarding of jobs in Europe and Germany. The applications for products made from high-temperature insulation wool in high temperature applications have strongly increased during the last five years. Especially the production capacities of polycrystalline wool (aluminium oxide wool e.g. Altra B72) have been doubled within the last three years. Primarily ultra light weight products made from HTIW are used in industrial furnaces with application temperatures above 1000 C and / or with high thermo-mechanical (thermal shock) and chemical exposure. The outstanding and essential advantages of these materials are obviously: Ultra light weight material with high resilience and flexibility, Optimised energy consumption (energy saving up to 50% compared

Opto-electrical approaches for high efficiency and ultra-thin c-Si solar cells

NARCIS (Netherlands)

Ingenito, A.; Isabella, O.; Zeman, M.

2014-01-01

The need for cost reduction requires using less raw material and cost-effective processes without sacrificing the conversion efficiency. For keeping high the generated photo-current, an advanced light trapping scheme for ultra-thin silicon wafers is here proposed, exhibiting absorptances up to 99%

Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

Czech Academy of Sciences Publication Activity Database

Fujii, T.; Malacari, M.; Bertaina, M.; Casolino, E.; Dawson, B.; Horváth, P.; Hrabovský, M.; Jiang, J.; Mandát, Dušan; Matalon, A.; Matthews, J.N.; Motloch, P.; Palatka, Miroslav; Pech, Miroslav; Privitera, P.; Schovánek, Petr; Takizawa, Y.; Thomas, S.B.; Trávníček, Petr; Yamazaki, K.

2016-01-01

Roč. 74, Feb (2016), s. 64-72 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) LG13007 Institutional support: RVO:68378271 Keywords : ultra-high energy cosmic rays * fluorescence detector * extensive air shower Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.257, year: 2016

Young’s modulus of [111] germanium nanowires

Energy Technology Data Exchange (ETDEWEB)

Maksud, M.; Palapati, N. K. R.; Subramanian, A., E-mail: asubramanian@vcu.edu [Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Yoo, J. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Harris, C. T. [Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2015-11-01

This paper reports a diameter-independent Young’s modulus of 91.9 ± 8.2 GPa for [111] Germanium nanowires (Ge NWs). When the surface oxide layer is accounted for using a core-shell NW approximation, the YM of the Ge core approaches a near theoretical value of 147.6 ± 23.4 GPa. The ultimate strength of a NW device was measured at 10.9 GPa, which represents a very high experimental-to-theoretical strength ratio of ∼75%. With increasing interest in this material system as a high-capacity lithium-ion battery anode, the presented data provide inputs that are essential in predicting its lithiation-induced stress fields and fracture behavior.

Ultrasonic Monitoring of Setting and Strength Development of Ultra-High-Performance Concrete.

Science.gov (United States)

Yoo, Doo-Yeol; Shin, Hyun-Oh; Yoon, Young-Soo

2016-04-19

In this study, the setting and tensile strength development of ultra-high-performance concrete (UHPC) at a very early age was investigated by performing the penetration resistance test (ASTM C403), as well as the direct tensile test using the newly developed test apparatus, and taking ultrasonic pulse velocity (UPV) measurements. In order to determine the optimum surface treatment method for preventing rapid surface drying of UHPC, four different methods were examined: plastic sheet, curing cover, membrane-forming compound, and paraffin oil. Based on the test results, the use of paraffin oil was found to be the best choice for measuring the penetration resistance and the UPV, and attaching the plastic sheet to the exposed surface was considered to be a simple method for preventing the rapid surface drying of UHPC elements. An S-shaped tensile strength development at a very early age (before 24 h) was experimentally obtained, and it was predicted by a power function of UPV. Lastly, the addition of shrinkage-reducing and expansive admixtures resulted in more rapid development of penetration resistance and UPV of UHPC.

Ultra-high-aspect-orthogonal and tunable three dimensional polymeric nanochannel stack array for BioMEMS applications

Science.gov (United States)

Heo, Joonseong; Kwon, Hyukjin J.; Jeon, Hyungkook; Kim, Bumjoo; Kim, Sung Jae; Lim, Geunbae

2014-07-01

Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even roll the stack array to form a radial-uniformly distributed nanochannel array. The roll can be cut at discretionary lengths for incorporation with a micro/nanofluidic device. As examples, we demonstrated ion concentration polarization with the device for Ohmic-limiting/overlimiting current-voltage characteristics and preconcentrated charged species. The density of the nanochannel array was lower than conventional nanoporous membranes, such as anodic aluminum oxide membranes (AAO). However, accurate controllability over the nanochannel array dimensions enabled multiplexed one microstructure-on-one nanostructure interfacing for valuable biological/biomedical microelectromechanical system (BioMEMS) platforms, such as nano-electroporation.Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even

Determination of elastic modulus in nickel alloy from ultrasonic ...

Indian Academy of Sciences (India)

als scientists, and solid-state theorists; they connect to tech- nological, structural economics and safety, to various mate- rials phenomena and to their fundamental interatomic forces. (Ledbetter 1983). In any material which is a multiphase alloy, the elastic modulus is determined by the modulus of the indi- vidual phases and ...

Ultra-Lightweight High Efficiency Nanostructured Materials and Coatings for Deep Space Mission Environments, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NanoSonic has developed a nanostructured spray self-assembly manufacturing method that has resulted in ultra-lightweight ( 1000%), and multi-layer, high efficiency...

2 filler on the dielectric permittivity and electrical modulus of PMMA

Indian Academy of Sciences (India)

The real and imaginary part of the dielectric permittivity decreased with the increase in frequency but increased with temperature. The electrical conductivity measurement showed a plateau-like behaviour in the low-frequency region and dispersion in the high-frequency region. The frequency-dependent electrical modulus ...

Ultra-high polarity ceramics induced extrinsic high permittivity of polymers contributing to high permittivity of 2-2 series composites

Science.gov (United States)

Feng, Yefeng; Zhang, Jianxiong; Hu, Jianbing; Peng, Cheng; He, Renqi

2018-01-01

Induced polarization at interface has been confirmed to have significant impact on the dielectric properties of 2-2 series composites bearing Si-based semi-conductor sheet and polymer layer. By compositing, the significantly elevated high permittivity in Si-based semi-conductor sheet should be responsible for the obtained high permittivity in composites. In that case, interface interaction could include two aspects namely a strong electrostatic force from high polarity polymeric layer and a newborn high polarity induced in Si-based ceramic sheet. In this work, this class of interface induced polarization was successfully extended into another 2-2 series composite system made up of ultra-high polarity ceramic sheet and high polarity polymer layer. By compositing, the greatly improved high permittivity in high polarity polymer layer was confirmed to strongly contribute to the high permittivity achieved in composites. In this case, interface interaction should consist of a rather large electrostatic force from ultra-high polarity ceramic sheet with ionic crystal structure and an enhanced high polarity induced in polymer layer based on a large polarizability of high polarity covalent dipoles in polymer. The dielectric and conductive properties of four designed 2-2 series composites and their components have been detailedly investigated. Increasing of polymer inborn polarity would lead to a significant elevating of polymer overall polarity in composite. Decline of inherent polarities in two components would result in a mild improving of polymer total polarity in composite. Introducing of non-polarity polymeric layer would give rise to a hardly unaltered polymer overall polarity in composite. The best 2-2 composite could possess a permittivity of ˜463 at 100 Hz 25.7 times of the original permittivity of polymer in it. This work might offer a facile route for achieving the promising composite dielectrics by constructing the 2-2 series samples from two high polarity

Ultra high energy cosmic rays above 10 GeV: Hints to new physics ...

Indian Academy of Sciences (India)

Ultra high energy cosmic rays; physics beyond standard model. ... The origin of the observed cosmic ray (CR) events above 10ѕј eV — the so-called ex- .... to arise simply from decay of some supermassive particles (of mass> 10ѕЅ eV) ...

O-Ring sealing arrangements for ultra-high vacuum systems

Science.gov (United States)

Kim, Chang-Kyo; Flaherty, Robert

1981-01-01

An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

Surface functionalization of solid state ultra-high molecular weight polyethylene through chemical grafting

Science.gov (United States)

Sherazi, Tauqir A.; Rehman, Tayyiba; Naqvi, Syed Ali Raza; Shaikh, Ahson Jabbar; Shahzad, Sohail Anjum; Abbas, Ghazanfar; Raza, Rizwan; Waseem, Amir

2015-12-01

The surface of ultra-high molecular weight polyethylene (UHMWPE) powder was functionalized with styrene using chemical grafting technique. The grafting process was initiated through radical generation on base polymer matrix in the solid state by sodium thiosulfate, while peroxides formed at radical sites during this process were dissociated by ceric ammonium nitrate. Various factors were optimized and reasonably high level of monomer grafting was achieved, i.e., 15.6%. The effect of different acids as additive and divinyl benzene (DVB) as a cross-linking agent was also studied. Post-grafting sulfonation was conducted to introduce the ionic moieties to the grafted polymer. Ion-exchange capacity (IEC) was measured experimentally and is found to be 1.04 meq g-1, which is in close agreement with the theoretical IEC values. The chemical structure of grafted and functionalized polymer was characterized by attenuated total reflection infrared spectroscopy (ATR-FTIR) and thermal properties were investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis depicts that the presence of radicals on the polymer chain accelerates the thermal decomposition process. The results signify that the chemical grafting is an effective tool for substantial surface modification and subsequent functionalization of polyethylene.

First-principles study of optical, elastic anisotropic and thermodynamic properties of TiN under high temperature and high pressure

Directory of Open Access Journals (Sweden)

R. Yang

2017-12-01

Full Text Available The optical, elastic anisotropic and thermodynamic properties of TiN in the NaCl (B1 structure are analyzed in detail in the temperature range from 0 to 2000 K and the pressure range from 0 to 20 GPa. From the calculated dielectric constants, a first order isostructural phase transition between 29 and 30 GPa is found for TiN. The absorption spectra exhibit high values ranging from the far infrared region to the ultra-violet one. The anisotropy value of Young's modulus of TiN is smaller than that of c-BN at 0 GPa and the anisotropy of TiN clearly increases with an increase of pressure. The effects of pressure and temperature on the bulk modulus, Grüneisen parameter, Gibbs free energy, and Debye temperature are significant. The Grüneisen parameter of TiN is much larger than that of c-BN. At temperatures below 1000 K, TiN's heat capacity is much larger than that of c-BN.

Ultra-short laser pulses. Petawatt and femtosecond

International Nuclear Information System (INIS)

Lemoine, P.

1999-01-01

This book deals with a series of new results obtained thanks to the use of ultra-short laser pulses. This branch of physics has made incredible progresses during the last 25 years. Ultra-short laser pulses offer the opportunity to explore the domain of ultra-high energies and of ultra-short duration events. Applications are various, from controlled nuclear fusion to eye surgery and to more familiar industrial applications such as electronics. (J.S.)

Radiobiological influence of megavoltage electron pulses of ultra-high pulse dose rate on normal tissue cells.

Science.gov (United States)

Laschinsky, Lydia; Karsch, Leonhard; Leßmann, Elisabeth; Oppelt, Melanie; Pawelke, Jörg; Richter, Christian; Schürer, Michael; Beyreuther, Elke

2016-08-01

Regarding the long-term goal to develop and establish laser-based particle accelerators for a future radiotherapeutic treatment of cancer, the radiobiological consequences of the characteristic short intense particle pulses with ultra-high peak dose rate, but low repetition rate of laser-driven beams have to be investigated. This work presents in vitro experiments performed at the radiation source ELBE (Electron Linac for beams with high Brilliance and low Emittance). This accelerator delivered 20-MeV electron pulses with ultra-high pulse dose rate of 10(10) Gy/min either at the low pulse frequency analogue to previous cell experiments with laser-driven electrons or at high frequency for minimizing the prolonged dose delivery and to perform comparison irradiation with a quasi-continuous electron beam analogue to a clinically used linear accelerator. The influence of the different electron beam pulse structures on the radiobiological response of the normal tissue cell line 184A1 and two primary fibroblasts was investigated regarding clonogenic survival and the number of DNA double-strand breaks that remain 24 h after irradiation. Thereby, no considerable differences in radiation response were revealed both for biological endpoints and for all probed cell cultures. These results provide evidence that the radiobiological effectiveness of the pulsed electron beams is not affected by the ultra-high pulse dose rates alone.

Radiobiological influence of megavoltage electron pulses of ultra-high pulse dose rate on normal tissue cells

International Nuclear Information System (INIS)

Laschinsky, Lydia; Karsch, Leonhard; Schuerer, Michael; Lessmann, Elisabeth; Beyreuther, Elke; Oppelt, Melanie; Pawelke, Joerg; Richter, Christian

2016-01-01

Regarding the long-term goal to develop and establish laser-based particle accelerators for a future radiotherapeutic treatment of cancer, the radiobiological consequences of the characteristic short intense particle pulses with ultra-high peak dose rate, but low repetition rate of laser-driven beams have to be investigated. This work presents in vitro experiments performed at the radiation source ELBE (Electron Linac for beams with high Brilliance and low Emittance). This accelerator delivered 20-MeV electron pulses with ultra-high pulse dose rate of 10"1"0 Gy/min either at the low pulse frequency analogue to previous cell experiments with laser-driven electrons or at high frequency for minimizing the prolonged dose delivery and to perform comparison irradiation with a quasi-continuous electron beam analogue to a clinically used linear accelerator. The influence of the different electron beam pulse structures on the radiobiological response of the normal tissue cell line 184A1 and two primary fibroblasts was investigated regarding clonogenic survival and the number of DNA double-strand breaks that remain 24 h after irradiation. Thereby, no considerable differences in radiation response were revealed both for biological endpoints and for all probed cell cultures. These results provide evidence that the radiobiological effectiveness of the pulsed electron beams is not affected by the ultra-high pulse dose rates alone. (orig.)

The temperature dependence of the isothermal bulk modulus at 1 bar pressure

International Nuclear Information System (INIS)

Garai, J.; Laugier, A.

2007-01-01

It is well established that the product of the volume coefficient of thermal expansion and the bulk modulus is nearly constant at temperatures higher than the Debye temperature. Using this approximation allows predicting the values of the bulk modulus. The derived analytical solution for the temperature dependence of the isothermal bulk modulus has been applied to ten substances. The good correlations to the experiments indicate that the expression may be useful for substances for which bulk modulus data are lacking

Phenomenology of mixed modulus-anomaly mediation in fluxed string compactifications and brane models

International Nuclear Information System (INIS)

Choi, Kiwoon; Jeong, Kwang-Sik; Okumura, Ken-ichi

2005-01-01

In some string compactifications, for instance the recently proposed KKLT set-up, light moduli are stabilized by nonperturbative effects at supersymmetric AdS vacuum which is lifted to a dS vacuum by supersymmetry breaking uplifting potential. In such models, soft supersymmetry breaking terms are determined by a specific mixed modulus-anomaly mediation in which the two mediations typically give comparable contributions to soft parameters. Similar pattern of soft terms can arise also in brane models to stabilize the radion by nonperturbative effects. We examine some phenomenological consequences of this mixed modulus-anomaly mediation, including the pattern of low energy sparticle spectrum and the possibility of electroweak symmetry breaking. It is noted that adding the anomaly-mediated contributions at M GUT amounts to replacing the messenger scale of the modulus mediation by a mirage messenger scale (m 3/2 /M Pl ) α/2 M GUT where α = m 3/2 /[M 0 ln (M Pl /m 3/2 )] for M 0 denoting the modulus-mediated contribution to the gaugino mass at M GUT . The minimal KKLT set-up predicts α = 1. As a consequence, for α = O(1), the model can lead to a highly distinctive pattern of sparticle masses at TeV scale, particularly when α = 2

Record power, ultra-broadband supercontinuum source based on highly GeO2 doped silica fiber

DEFF Research Database (Denmark)

Jain, Deepak; Sidharthan, R.; Moselund, Peter M.

2016-01-01

the potential of germania based photonic crystal fiber or a step-index fiber supercontinuum source for high power ultra-broad band emission being by pumped a 1060 nm or a 1550 nm laser source. To the best of our knowledge, this is the record power, ultra-broadband, and all-fiberized supercontinuum light source...... based on silica and germania fiber ever demonstrated to the date. (C) 2016 Optical Society of America......We demonstrate highly germania doped fibers for mid-infrared supercontinuum generation. Experiments ensure a highest output power of 1.44 W for a broadest spectrum from 700 nm to 3200 nm and 6.4 W for 800 nm to 2700 nm from these fibers, while being pumped by a broadband Erbium-Ytterbium doped...

Li-Ion, Ultra-capacitor Based Hybrid Energy Module

National Research Council Canada - National Science Library

Daboussi, Zaher; Paryani, Anil; Khalil, Gus; Catherino, Henry; Gargies, Sonya

2007-01-01

.... To determine the optimum utilization of ultra-capacitors in applications where high power density and high energy density are required, an optimized Li-Ion/Ultra-capacitor Hybrid Energy Module (HEM...

Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

International Nuclear Information System (INIS)

Abd-Elnaiem, Alaa M.; Mebed, A.M.; El-Said, Waleed Ahmed; Abdel-Rahim, M.A.

2014-01-01

Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes

Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

Energy Technology Data Exchange (ETDEWEB)

Abd-Elnaiem, Alaa M., E-mail: alaa.abd-elnaiem@science.au.edu.eg [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Mebed, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Department of Physics, Faculty of Science, Al-Jouf University, Sakaka 2014 (Saudi Arabia); El-Said, Waleed Ahmed [Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Abdel-Rahim, M.A. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

2014-11-03

Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes.

Commercialization of Ultra-Hard Ceramics for Cutting Tools Final Report CRADA No. TC0279.0

Energy Technology Data Exchange (ETDEWEB)

Landingham, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Neumann, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-15

This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and Greenleaf Corporation (Greenleaf) to develop the technology for forming unique precursor nano-powders process that can be consolidated into ceramic products for industry. LLNL researchers have developed a solgel process for forming nano-ceramic powders. The nano powders are highly tailorable, allowing the explicit design of desired properties that lead to ultra hard materials with fine grain size. The present CRADA would allow the two parties to continue the development of the sol-gel process and the consolidation process in order to develop an industrially sound process for the manufacture of these ultra-hard materials.

Comparison of Elastic Modulus and Compressive Strength of Ariadent and Harvard Polycarboxylate Cement and Vitremer Resin Modified Glass Ionomer

Directory of Open Access Journals (Sweden)

Ahmadian Khoshemehr Leila

2009-09-01

Full Text Available Background: Luting agents are used to attach indirect restoration into or on the tooth. Poor mechanical properties of cement may be a cause of fracture of this layer and lead to caries and restoration removal. The purpose of this study was to compare the elastic modulus and compressive strength of Ariadent (A Poly and Harvard polycarboxylate (H Poly cements and Vitremer resin modified glass ionomer (RGl.Materials & Methods: In this experimental study 15 specimens were prepared form each experimental cement in Laboratory of Tehran Oil Refining Company. The cylindrical specimens were compressed in Instron machine after 24 hours. Elastic modulus and compressive strength were calculated from stress/strain curve of each specimen. One way ANOVA and Tukey tests were used for statistical analysis and P values<0.05 were considered to be statistically significant.Results: The mean elastic modulus and mean compressive strength were 2.2 GPa and 87.8MPa in H poly, 2.4 GPa and 56.5 MPa in A Poly, and 0.8GPa and 105.6 MPa in RGI, respectively. Statistical analysis showed that compressive strength and elastic modulus of both polycarboxylate cements were significantly different from hybrid ionomer (P<0.05, but the difference between elastic modulus of two types of polycarboxilate cements was not statistically significant. Compressive strength of two polycarboxilate cements were significantly different (P<0.05. Conclusion: An ideal lutting agent must have the best mechanical properties. Between the tested luttins RGl cement had the lowest elastic modulus and the highest compressive strength, but the A poly cement had the highest elastic modulus and the lowest compressive strength. Therefore none of them was the best.

Maximisation of the ratio of microhardness to the Young's modulus of Ti–12Mo–13Nb alloy through microstructure changes

Energy Technology Data Exchange (ETDEWEB)

Gabriel, Sinara B., E-mail: sinara@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil); Centro Universitário de Volta Redonda, Volta Redonda, RJ (Brazil); Almeida, Luiz H. de [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil); Nunes, Carlos A. [Universidade de São Paulo, Departamento de Engenharia de Materiais, C.P. 116, Lorena, SP 12.600-970 (Brazil); Dille, Jean [Université Libre de Bruxelles, Chemical and Materials Department, Av. F. Roosevelt 50, C. P. 194/03, Brussels (Belgium); Soares, Glória A. [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil)

2013-08-01

Alloys for orthopaedic and dentistry applications require high mechanical strength and a low Young's modulus to avoid stress shielding. Metastable β titanium alloys appear to fulfil these requirements. This study investigated the correlation of phases precipitated in a Ti–12Mo–13Nb alloy with changes in hardness and the Young's modulus. The alloy was produced by arc melting under an argon atmosphere, after which, it was heat treated and cold forged. Two different routes of heat treatment were employed. Phase transformations were studied by employing X-ray diffraction and transmission electron microscopy. Property characterisation was based on Vickers microhardness tests and Young's modulus measurements. The highest ratio of microhardness to the Young's modulus was obtained using thermomechanical treatment, which consists of heating at 1000 °C for 24 h, water quenching, cold forging to reduce 80% of the area, and ageing at 500 °C for 24 h, where the final microstructure consisted of an α phase dispersed in a β matrix. The α phase appeared in two different forms: as fine lamellas (with 240 ± 100 nm length) and massive particles of 200–500 nm size. - Highlights: • The work presents microstructure change and properties of Ti–12Mo–13Nb alloy. • The better condition was achieved by the α phase distributed in the β matrix. • The values obtained were higher than of the Ti–6Al–4V alloy and cp Ti.

Ultra-high performance liquid chromatography tandem high-resolution mass spectrometry study of tricyclazole photodegradation products in water.

Science.gov (United States)

Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Bolfi, Bianca; Marengo, Emilio

2015-06-01

This paper reports the study of the photodegradation reactions that tricyclazole can naturally undergo, under the action of sunlight, in aqueous solutions of standard tricyclazole and of the commercial BEAM(TM) formulation. The analyses are carried out by ultra-high performance liquid chromatography technique coupled with high-resolution tandem mass spectrometry. Analysis of both tricyclazole and BEAM(TM) water solutions undergone to hydrolysis does not evidence new chromatographic peaks with respect to the not treated solutions. On the contrary, analysis of the same samples subjected to sunlight irradiation shows a decreased intensity of tricyclazole signal and the presence of new chromatographic peaks. Two photodegradation products of tricyclazole have been identified, one of which has been also quantified, being the commercial standard available. The pattern is similar for the solutions of the standard fungicide and of the BEAM(TM) formulation. The results obtained from eco-toxicological tests show that toxicity of tricyclazole standard solutions is greater than that of the irradiated ones, whereas toxicity levels of all the BEAM(TM) solutions investigated (non-irradiated, irradiated, and hydrolyzed) are comparable and lower than those shown by tricyclazole standard solutions. Experiments performed in paddy water solution show that there is no difference in the degradation products formed.

OTR profile measurement of a LINAC electron beam with portable ultra high-speed camera

International Nuclear Information System (INIS)

Mogi, T.; Nisiyama, S.; Tomioka, S.; Enoto, T.

2004-01-01

We have studied on and developed a portable ultra high-speed camera, and so applied to measurement of a LINAC electron beam. We measured spatial OTR profiles of a LINAC electron beam using this camera with temporal resolution 80ns. (author)

Non-monotonic variations of the nucleation free energy in a glass-forming ultra-soft particles fluid.

Science.gov (United States)

Desgranges, Caroline; Delhommelle, Jerome

2018-06-18

Using molecular dynamics simulation, we study the impact of the degree of supercooling on the crystal nucleation of ultra-soft particles, modeled with the Gaussian core potential. Focusing on systems with a high number density, our simulations reveal dramatically different behaviors as the degree of supercooling is varied. In the moderate supercooling regime, crystal nucleation proceeds as expected from classical nucleation theory, with a decrease in the free energy of nucleation, as well as in the size of the critical nucleus, as supercooling is increased. On the other hand, in the large supercooling regime, we observe an unusual reversal of behavior with an increase in the free energy of nucleation and in the critical size, as supercooling is increased. This unexpected result is analyzed in terms of the interplay between the glass transition and the crystal nucleation process. Specifically, medium range order crystal-like domains, with structural features different from that of the crystal nucleus, are found to form throughout the system when the supercooling is very large. These, in turn, play a pivotal role in the increase in the free energy of nucleation, as well as in the critical size, as the temperature gets closer to the glass transition.

Ultra-High Gradient S-band Linac for Laboratory and Industrial Applications

Science.gov (United States)

Faillace, L.; Agustsson, R.; Dolgashev, V.; Frigola, P.; Murokh, A.; Rosenzweig, J.; Yakimenko, V.

2010-11-01

A strong demand for high gradient structures arises from the limited real estate available for linear accelerators. RadiaBeam Technologies is developing a Doubled Energy Compact Accelerator (DECA) structure: an S-band standing wave electron linac designed to operate at accelerating gradients of up to 50 MV/m. In this paper, we present the radio-frequency design of the DECA S-band accelerating structure, operating at 2.856 GHz in the π-mode. The structure design is heavily influenced by NLC collaboration experience with ultra high gradient X-band structures; S-band, however, is chosen to take advantage of commonly available high power S-band klystrons.

Synthesis of ultra-thin tellurium nanoflakes on textiles for high-performance flexible and wearable nanogenerators

Energy Technology Data Exchange (ETDEWEB)

He, Wen; Van Ngoc, Huynh; Qian, Yong Teng; Hwang, Jae Seok; Yan, Ya Ping [Department of Physics and Interdisciplinary Course of Physics and Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do (Korea, Republic of); Choi, Hongsoo [Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-873, Daegu (Korea, Republic of); Kang, Dae Joon, E-mail: djkang@skku.edu [Department of Physics and Interdisciplinary Course of Physics and Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do (Korea, Republic of)

2017-01-15

Highlights: • Ultra-thin tellurium (Te) nanoflakes were successfully grown on textile and used as an active piezoelectric material. • Te nanoflake nanogenerator device was systematically studied by bending and compressing test. • The ultra-high output power during compressing test can light up 10 LEDs without any external power source. • The device can offer a breakthrough in applying tellurium nanoflakes into high-performance flexible and wearable piezoelectric nanogenerator. - Abstract: We report that ultra-thin tellurium (Te) nanoflakes were successfully grown on a sample of a gold-coated textile, which then was used as an active piezoelectric material. An output voltage of 4 V and a current of 300 nA were obtained from the bending test under a driving frequency of 10 Hz. To test the practical applications, Te nanoflake nanogenerator (TFNG) device was attached to the subject’s arm, and mechanical energy was converted to electrical energy by means of periodic arm-bending motions. The optimized open-circuit voltage and short-circuit current density of approximately 125 V and 17 μA/cm{sup 2}, respectively, were observed when a TFNG device underwent a compression test with a compressive force of 8 N and driving frequency of 10 Hz. This high-power generation enabled the instantaneous powering of 10 green light-emitting diodes that shone without any assistance from an external power source.

Enhancing thermal reliability of fiber-optic sensors for bio-inspired applications at ultra-high temperatures

Science.gov (United States)

Kang, Donghoon; Kim, Heon-Young; Kim, Dae-Hyun

2014-07-01

The rapid growth of bio-(inspired) sensors has led to an improvement in modern healthcare and human-robot systems in recent years. Higher levels of reliability and better flexibility, essential features of these sensors, are very much required in many application fields (e.g. applications at ultra-high temperatures). Fiber-optic sensors, and fiber Bragg grating (FBG) sensors in particular, are being widely studied as suitable sensors for improved structural health monitoring (SHM) due to their many merits. To enhance the thermal reliability of FBG sensors, thermal sensitivity, generally expressed as αf + ξf and considered a constant, should be investigated more precisely. For this purpose, the governing equation of FBG sensors is modified using differential derivatives between the wavelength shift and the temperature change in this study. Through a thermal test ranging from RT to 900 °C, the thermal sensitivity of FBG sensors is successfully examined and this guarantees thermal reliability of FBG sensors at ultra-high temperatures. In detail, αf + ξf has a non-linear dependence on temperature and varies from 6.0 × 10-6 °C-1 (20 °C) to 10.6 × 10-6 °C-1 (650 °C). Also, FBGs should be carefully used for applications at ultra-high temperatures due to signal disappearance near 900 °C.

Determination of young's modulus of PZT-influence of cantilever orientation

NARCIS (Netherlands)

Nazeer, H.; Woldering, L.A.; Abelmann, Leon; Elwenspoek, Michael Curt

Calculation of the resonance frequency of cantilevers fabricated from an elastically anisotropic material requires the use of an effective Young’s modulus. In this paper a technique to determine the appropriate effective Young’s modulus for arbitrary cantilever geometries is introduced. This

Young's Modulus of Wurtzite and Zinc Blende InP Nanowires.

Science.gov (United States)

Dunaevskiy, Mikhail; Geydt, Pavel; Lähderanta, Erkki; Alekseev, Prokhor; Haggrén, Tuomas; Kakko, Joona-Pekko; Jiang, Hua; Lipsanen, Harri

2017-06-14

The Young's modulus of thin conical InP nanowires with either wurtzite or mixed "zinc blende/wurtzite" structures was measured. It has been shown that the value of Young's modulus obtained for wurtzite InP nanowires (E [0001] = 130 ± 30 GPa) was similar to the theoretically predicted value for the wurtzite InP material (E [0001] = 120 ± 10 GPa). The Young's modulus of mixed "zinc blende/wurtzite" InP nanowires (E [111] = 65 ± 10 GPa) appeared to be 40% less than the theoretically predicted value for the zinc blende InP material (E [111] = 110 GPa). An advanced method for measuring the Young's modulus of thin and flexible nanostructures is proposed. It consists of measuring the flexibility (the inverse of stiffness) profiles 1/k(x) by the scanning probe microscopy with precise control of loading force in nanonewton range followed by simulations.

Micro-damage propagation in ultra-high vacuum seals

CERN Document Server

Lutkiewicz, P; Garion, C

2010-01-01

The paper addresses a fundamental problem of tightness of ultra-high vacuum systems (UHV) at cryogenic temperatures in the light of continuum damage mechanics (CDM). The problem of indentation of a rigid punch into an elastic-plastic half-space is investigated based on rate independent plasticity with mixed kinematic and isotropic hardening. The micro-damage fields are modeled by using an anisotropic approach with a kinetic law of damage evolution suitable for ductile materials and cryogenic temperatures. The model has been experimentally validated and the results are used to predict the onset of macro-cracking (loss of tightness) and the corresponding load (contact pressure). The algorithm is applied in the design of UHV systems for particle accelerators. (C) 2009 Published by Elsevier Ltd.

Thermal behavior of Ni (99.967% and 99.5% purity) deformed to an ultra-high strain by high pressure torsion

DEFF Research Database (Denmark)

Zhang, H.W.; Huang, Xiaoxu; Pippan, R.

2010-01-01

Polycrystalline Ni of two purities (99.967% (4N) and 99.5% (2N)) was deformed to an ultra-high strain of εvM = 100 (εvM, von Mises strain) by high pressure torsion at room temperature. The 4N and 2N samples at this strain are nanostructured with an average boundary spacing of 100 nm, a high density...

Ultra high energy electrons powered by pulsar rotation.

Science.gov (United States)

Mahajan, Swadesh; Machabeli, George; Osmanov, Zaza; Chkheidze, Nino

2013-01-01

A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

Chemical fingerprint of Ganmaoling granule by double-wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

Science.gov (United States)

Lou, Qiong; Ye, Xiaolan; Zhou, Yingyi; Li, Hua; Song, Fenyun

2015-06-01

A method incorporating double-wavelength ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C18 column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4-O-caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

submitter Projects for ultra-high-energy circular colliders at CERN

CERN Document Server

Bogomyagkov, A V; Levichev, E B; Piminov, P A; Sinyatkin, S V; Shatilov, D N; Benedict, M; Oide, K; Zimmermann, F

2016-01-01

Within the Future Circular Collider (FCC) design study launched at CERN in 2014, it is envisaged to construct hadron (FCC-hh) and lepton (FCC-ee) ultra-high-energy machines aimed to replace the LHC upon the conclusion of its research program. The Budker Institute of Nuclear Physics is actively involved in the development of the FCC-ee electron–positron collider. The Crab Waist (CR) scheme of the collision region that has been proposed by INP and will be implemented at FCC-ee is expected to provide high luminosity over a broad energy range. The status and development of the FCC project are described, and its parameters and limitations are discussed for the lepton collider in particular.

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Amaral Soares, E. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Berlin, A.; Bogdan, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Boháčová, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Bonifazi, C. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Carvalho, W.R. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Facal San Luis, P., E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); and others

2013-08-11

We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique.

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

International Nuclear Information System (INIS)

Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W.R.; Mello Neto, J.R.T. de; Facal San Luis, P.; Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.

2013-01-01

We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique

The spheromak as a prototype for ultra-high-field superconducting magnets

International Nuclear Information System (INIS)

Furth, H.P.; Jardin, S.C.

1987-08-01

In view of current progress in the development of superconductor materials, the ultimate high-field limit of superconducting magnets is likely to be set by mechanical stress problems. Maximum field strength should be attainable by means of approximately force-free magnet windings having favorable ''MHD'' stability properties (so that small winding errors will not grow). Since a low-beta finite-flux-hole spheromak configuration qualifies as a suitable prototype, the theoretical and experimental spheromak research effort of the past decade has served to create a substantial technical basis for the design of ultra-high-field superconducting coils. 11 refs

Elastic modulus of tree frog adhesive toe pads.

Science.gov (United States)

Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

2011-10-01

Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

Ultra High Temperature and Multifunctional Ceramic Matrix Composite – Coating Systems for Light-Weight Space and Aero Systems

Data.gov (United States)

National Aeronautics and Space Administration — Revolutionary ultra-high temperature, high mechanical loading capable, oxidation resistant, durable ceramic coatings and light-weight fiber-reinforced Ceramic Matrix...

High Frequency Acoustic Microscopy for the Determination of Porosity and Young's Modulus in High Burnup Uranium Dioxide Nuclear Fuel

Science.gov (United States)

Marchetti, Mara; Laux, Didier; Cappia, Fabiola; Laurie, M.; Van Uffelen, P.; Rondinella, V. V.; Wiss, T.; Despaux, G.

2016-06-01

During irradiation UO2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of both porosity and elastic properties in high burnup UO2 pellet can be investigated via high frequency acoustic microscopy. For this purpose ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A UO2 pellet with a burnup of 67 GWd/tU was characterized using the acoustic microscope installed in the hot cells of the JRC-ITU at a 90 MHz frequency, with methanol as coupling liquid. VR was measured at different radial positions. A good agreement was found, when comparing the porosity values obtained via acoustic microscopy with those determined using SEM image analysis, especially in the areas close to the centre. In addition, Young's modulus was calculated and its radial profile was correlated to the corresponding burnup profile and to the hardness radial profile data obtained by Vickers micro-indentation.

An ultra-high vacuum scanning tunneling microscope operating at sub-Kelvin temperatures and high magnetic fields for spin-resolved measurements

Science.gov (United States)

Salazar, C.; Baumann, D.; Hänke, T.; Scheffler, M.; Kühne, T.; Kaiser, M.; Voigtländer, R.; Lindackers, D.; Büchner, B.; Hess, C.

2018-06-01

We present the construction and performance of an ultra-low-temperature scanning tunneling microscope (STM), working in ultra-high vacuum (UHV) conditions and in high magnetic fields up to 9 T. The cryogenic environment of the STM is generated by a single-shot 3He magnet cryostat in combination with a 4He dewar system. At a base temperature (300 mK), the cryostat has an operation time of approximately 80 h. The special design of the microscope allows the transfer of the STM head from the cryostat to a UHV chamber system, where samples and STM tips can be easily exchanged. The UHV chambers are equipped with specific surface science treatment tools for the functionalization of samples and tips, including high-temperature treatments and thin film deposition. This, in particular, enables spin-resolved tunneling measurements. We present test measurements using well-known samples and tips based on superconductors and metallic materials such as LiFeAs, Nb, Fe, and W. The measurements demonstrate the outstanding performance of the STM with high spatial and energy resolution as well as the spin-resolved capability.

Improvement of performance of ultra-high performance concrete based composite material added with nano materials

Directory of Open Access Journals (Sweden)

Pang Jinchang

2016-03-01

Full Text Available Ultra-high performance concrete (UHPC, a kind of composite material characterized by ultra high strength, high toughness and high durability. It has a wide application prospect in engineering practice. But there are some defects in concrete. How to improve strength and toughness of UHPC remains to be the target of researchers. To obtain UHPC with better performance, this study introduced nano-SiO2 and nano-CaCO3 into UHPC. Moreover, hydration heat analysis, X-Ray Diffraction (XRD, mercury intrusion porosimetry (MIP and nanoindentation tests were used to explore hydration process and microstructure. Double-doped nanomaterials can further enhance various mechanical performances of materials. Nano-SiO2 can promote early progress of cement hydration due to its high reaction activity and C-S-H gel generates when it reacts with cement hydration product Ca(OH2. Nano-CaCO3 mainly plays the role of crystal nucleus effect and filling effect. Under the combined action of the two, the composite structure is denser, which provides a way to improve the performance of UHPC in practical engineering.

Ultra high risk of psychosis on committal to a young offender prison: an unrecognised opportunity for early intervention.

LENUS (Irish Health Repository)

Flynn, Darran

2012-08-01

The ultra high risk state for psychosis has not been studied in young offender populations. Prison populations have higher rates of psychiatric morbidity and substance use disorders. Due to the age profile of young offenders one would expect to find a high prevalence of individuals with pre-psychotic or ultra-high risk mental states for psychosis (UHR). Accordingly young offender institutions offer an opportunity for early interventions which could result in improved long term mental health, social and legal outcomes. In the course of establishing a mental health in-reach service into Ireland\\'s only young offender prison, we sought to estimate unmet mental health needs.

A novel ultra-high vacuum manipulator with six degrees of freedom

International Nuclear Information System (INIS)

Auciello, O.; Lulich, C.; Alonso, E.V.; Baragiola, R.A.

1977-01-01

An ultra-high vacuum goniometer of novel design for use in experiments with ion beams is described. The goniometer uses a wire system to transmit movements, is bakeable to 200 0 C and is reproducible in its angular positions to within 1.3 X 10 -4 rad (0.008 0 ). It allows a sample to be rotated around two axes over 360 0 , around a third over 180 0 , and to be translated along three perpendicular axes. (Auth.)

An ultra low-power off-line APDM-based switchmode power supply with very high conversion efficiency

DEFF Research Database (Denmark)

Nielsen, Nils

2001-01-01

This article describes the results from the research work on design of a ultra low power off-line power supply with very high conversion efficiency. The input voltage is 230 VAC nominal and output voltage is 5 VDC. By ultra low power levels, an output power level in the area ranging from 50 m......W and up to 1000 mW is meant. The small power supply is intended for use as a standby power supply in mains operated equipment, which requires a small amount of power in standby mode....

Cortico-Striatal GABAergic and Glutamatergic Dysregulations in Subjects at Ultra-High Risk for Psychosis Investigated with Proton Magnetic Resonance Spectroscopy

Science.gov (United States)

Reyes-Madrigal, Francisco; Mao, Xiangling; León-Ortiz, Pablo; Rodríguez-Mayoral, Oscar; Solís-Vivanco, Rodolfo; Favila, Rafael; Graff-Guerrero, Ariel; Shungu, Dikoma C.

2016-01-01

Background: Dysregulations of the major inhibitory and excitatory amino neurotransmitter systems of γ-aminobutyric acid and glutamate, respectively, have been described in patients with schizophrenia. However, it is unclear whether these abnormalities are present in subjects at ultra-high risk for psychosis. Methods: Twenty-three antipsychotic naïve subjects at ultra-high risk and 24 healthy control subjects, matched for age, sex, handedness, cigarette smoking, and parental education, underwent proton magnetic resonance spectroscopy scans in the dorsal caudate bilaterally and the medial prefrontal cortex at 3T. Levels of γ-aminobutyric acid and of the combined resonance of glutamate and glutamine (Glx) were obtained using the standard J-editing technique and expressed as peak area ratios relative to the synchronously acquired unsuppressed voxel water signal. Results: Higher levels of γ-aminobutyric acid (P<.001) and Glx (P=.007) were found in the dorsal caudate of the subjects at ultra-high risk than in the healthy controls. In the medial prefrontal cortex, likewise, both γ-aminobutyric acid (P=.03) and Glx (P=.006) levels were higher in the ultra-high risk group than in the healthy controls. No group differences were found for any of the other metabolites (N-acetylaspartate, total choline, or total creatine) in the 2 regions of interest. Conclusions: This study presents the first evidence of abnormal elevations, in subjects at ultra-high risk, of γ-aminobutyric acid and Glx in 2 brain regions that have been implicated in the pathophysiology of psychosis, warranting longitudinal studies to assess whether these neurotransmitter abnormalities can serve as noninvasive biomarkers of conversion risk to psychosis as well as of illness progression and treatment response. PMID:26364273

Looking for Galaxies in All the Right Places: A Search for Stellar Populations in ALFALFA’s Ultra-compact High Velocity Clouds

Science.gov (United States)

Janesh, William; Rhode, Katherine L.; Salzer, John J.; Janowiecki, Steven; Adams, Elizabeth; Haynes, Martha P.; Giovanelli, Riccardo; Cannon, John M.

2018-01-01

Nearby gas-rich dwarf galaxies are excellent laboratories for investigating the baryonic feedback processes that govern star formation and galaxy evolution in galaxies at the extreme end of the mass function. Detecting and studying such objects may help resolve the well-known tension between cosmological model predictions for low-mass dark matter halos and observations. The ALFALFA neutral hydrogen (Hi) survey has detected a sample of isolated ultra-compact high-velocity Hi clouds (UCHVCs) with kinematic properties that make them likely members of the Local Volume, but that have no optical counterparts in existing optical surveys. This UCHVC sample possesses Hi properties (at 1 Mpc, Hi masses of ~105-106 M⊙, Hi diameters of ~2-3 kpc, and dynamical masses of ~107-108 M⊙) similar to other known ultra-faint dwarf galaxies like Leo T. Following the discovery of Leo P, an extremely metal-poor, gas-rich star-forming dwarf galaxy associated with an ALFALFA UCHVC, we have initiated a campaign to obtain deep optical imaging of 56 UCHVCs using the wide field-of-view, high-resolution ODI camera on the WIYN 3.5-m telescope. Here we present a brief overview of our campaign to search for resolved stellar populations associated with the UCHVCs in our optical images, and initial results from our survey.After creating a stellar catalog from the pipeline-reduced and stacked ODI g- and i-band images, we apply a color-magnitude filter tuned for old, metal-poor stellar populations to select red giant branch stars at distances between 250 kpc and 2 Mpc. The spatial distribution of the stars selected by the filter is then smoothed, and overdensities in the fields are identified. Of the 22 targets analyzed to date, seven have associated stellar populations detected at a high confidence (92% to 99.9% significance). The detected objects have a range of distances (from 350 kpc to 1.6 Mpc) and have optical properties similar to those of ultra-faint dwarf galaxies. These objects have

Nanometer size wear debris generated from ultra high molecular weight polyethylene in vivo

Czech Academy of Sciences Publication Activity Database

Lapčíková, Monika; Šlouf, Miroslav; Dybal, Jiří; Zolotarevova, E.; Entlicher, G.; Pokorný, D.; Gallo, J.; Sosna, A.

2009-01-01

Roč. 266, 1-2 (2009), s. 349-355 ISSN 0043-1648 R&D Projects: GA MŠk 2B06096 Institutional research plan: CEZ:AV0Z40500505 Keywords : ultra high molecular weight polyethylene * nanometer size wear debris * morphology of wear particles Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.771, year: 2009

Ultra-rare mutation in long-range enhancer predisposes to thyroid carcinoma with high penetrance.

Directory of Open Access Journals (Sweden)

Huiling He

Full Text Available Thyroid cancer shows high heritability but causative genes remain largely unknown. According to a common hypothesis the genetic predisposition to thyroid cancer is highly heterogeneous; being in part due to many different rare alleles. Here we used linkage analysis and targeted deep sequencing to detect a novel single-nucleotide mutation in chromosome 4q32 (4q32A>C in a large pedigree displaying non-medullary thyroid carcinoma (NMTC. This mutation is generally ultra-rare; it was not found in 38 NMTC families, in 2676 sporadic NMTC cases or 2470 controls. The mutation is located in a long-range enhancer element whose ability to bind the transcription factors POU2F and YY1 is significantly impaired, with decreased activity in the presence of the C- allele compared with the wild type A-allele. An enhancer RNA (eRNA is transcribed in thyroid tissue from this region and is greatly downregulated in NMTC tumors. We suggest that this is an example of an ultra-rare mutation predisposing to thyroid cancer with high penetrance.

Ultra-High-Contrast Laser Acceleration of Relativistic Electrons in Solid Targets

Energy Technology Data Exchange (ETDEWEB)

Higginson, Drew Pitney [Univ. of California, San Diego, CA (United States)

2013-01-01

The cone-guided fast ignition approach to Inertial Con nement Fusion requires laser-accelerated relativistic electrons to deposit kilojoules of energy within an imploded fuel core to initiate fusion burn. One obstacle to coupling electron energy into the core is the ablation of material, known as preplasma, by laser energy proceeding nanoseconds prior to the main pulse. This causes the laser-absorption surface to be pushed back hundreds of microns from the initial target surface; thus increasing the distance that electrons must travel to reach the imploded core. Previous experiments have shown an order of magnitude decrease in coupling into surrogate targets when intentionally increasing the amount of preplasma. Additionally, for electrons to deposit energy within the core, they should have kinetic energies on the order of a few MeV, as less energetic electrons will be stopped prior to the core and more energetic electrons will pass through the core without depositing much energy. Thus a quantitative understanding of the electron energy spectrum and how it responds to varied laser parameters is paramount for fast ignition. For the rst time, this dissertation quantitatively investigates the acceleration of electrons using an ultra-high-contrast laser. Ultra-high-contrast lasers reduce the laser energy that reaches the target prior to the main pulse; drastically reducing the amount of preplasma. Experiments were performed in a cone-wire geometry relevant to fast ignition. These experiments irradiated the inner-tip of a Au cone with the laser and observed electrons that passed through a Cu wire attached to the outer-tip of the cone. The total emission of K x-rays is used as a diagnostic to infer the electron energy coupled into the wire. Imaging the x-ray emission allowed an e ective path-length of electrons within the wire to be determined, which constrained the electron energy spectrum. Experiments were carried out on the ultra-high-contrast Trident laser at Los

Comparison between bulk and thin foil ion irradiation of ultra high purity Fe

Energy Technology Data Exchange (ETDEWEB)

Prokhodtseva, A., E-mail: anna.prokhodtseva@psi.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland); Décamps, B. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS-IN2P3-Univ. Paris-Sud 11, UMR 8609, Bât. 108, 91405 Orsay (France); Schäublin, R. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland)

2013-11-15

Accumulation of radiation damage in ultra high purity iron under self ion irradiation without and with simultaneous He implantation was investigated in bulk and thin foil form to assess, on the one hand, the effect of free surfaces and, on the other hand, the influence of He. Specimens were irradiated at room temperature to a dose of 0.8 dpa and ∼900 appm He content. We found in thin foils after irradiation with single beam a majority of a{sub 0} 〈1 0 0〉 type loops, while in the presence of He it is the ½ a{sub 0} 〈1 1 1〉 type loops that prevail. In single beam irradiated bulk samples most of the loops are of ½ a{sub 0} 〈1 1 1〉 type. In both bulk and thin foils density of defects visible in transmission electron microscope is considerably higher when He is implanted with prevailing ½ a{sub 0} 〈1 1 1〉 dislocation loops, indicating that He stabilizes them.

Standardizing lightweight deflectometer modulus measurements for compaction quality assurance : research summary.

Science.gov (United States)

2017-09-01

The mechanistic-empirical pavement design method requires the elastic resilient modulus as the key input for characterization of geomaterials. Current density-based QA procedures do not measure resilient modulus. Additionally, the density-based metho...

Optical Method for Detecting Displacements and Strains at Ultra-High Temperatures During Thermo-Mechanical Testing

Science.gov (United States)

Smith, Russell W. (Inventor); Rivers, H. Kevin (Inventor); Sikora, Joseph G. (Inventor); Roth, Mark C. (Inventor); Johnston, William M. (Inventor)

2016-01-01

An ultra-high temperature optical method incorporates speckle optics for sensing displacement and strain measurements well above conventional measurement techniques. High temperature pattern materials are used which can endure experimental high temperature environments while simultaneously having a minimum optical aberration. A purge medium is used to reduce or eliminate optical distortions and to reduce, and/or eliminate oxidation of the target specimen.

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition.

Science.gov (United States)

Yoo, Young Jin; Lee, Gil Ju; Jang, Kyung-In; Song, Young Min

2017-08-29

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.  We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.  Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

A comparative study of noise in supercontinuum light sources for ultra-high resolution optical coherence tomography

DEFF Research Database (Denmark)

Maria J., Sanjuan-Ferrer,; Bravo Gonzalo, Ivan; Bondu, Magalie

2017-01-01

Supercontinuum (SC) light is a well-established technology, which finds applications in several domains ranging from chemistry to material science and imaging systems [1-2]. More specifically, its ultra-wide optical bandwidth and high average power make it an ideal tool for Optical Coherence...... Tomography (OCT). Over the last 5 years, numerous examples have demonstrated its high potential [3-4] in this context. However, SC light sources present pulse-to-pulse intensity variation that can limit the performance of any OCT system [5] by degrading their signal to noise ratio (SNR). To this goal, we...... have studied and compared the noise of several SC light sources and evaluated how their noise properties affect the performance of Ultra-High Resolution OCT (UHR-OCT) at 1300 nm. We have measured several SC light sources with different parameters (pulse length, energy, seed repetition rate, etc.). We...

A Prediction Method of Tensile Young's Modulus of Concrete at Early Age

Directory of Open Access Journals (Sweden)

Isamu Yoshitake

2012-01-01

Full Text Available Knowledge of the tensile Young's modulus of concrete at early ages is important for estimating the risk of cracking due to restrained shrinkage and thermal contraction. However, most often, the tensile modulus is considered equal to the compressive modulus and is estimated empirically based on the measurements of compressive strength. To evaluate the validity of this approach, the tensile Young's moduli of 6 concrete and mortar mixtures are measured using a direct tension test. The results show that the tensile moduli are approximately 1.0–1.3-times larger than the compressive moduli within the material's first week of age. To enable a direct estimation of the tensile modulus of concrete, a simple three-phase composite model is developed based on random distributions of coarse aggregate, mortar, and air void phases. The model predictions show good agreement with experimental measurements of tensile modulus at early age.

Enhancing thermal reliability of fiber-optic sensors for bio-inspired applications at ultra-high temperatures

International Nuclear Information System (INIS)

Kang, Donghoon; Kim, Heon-Young; Kim, Dae-Hyun

2014-01-01

The rapid growth of bio-(inspired) sensors has led to an improvement in modern healthcare and human–robot systems in recent years. Higher levels of reliability and better flexibility, essential features of these sensors, are very much required in many application fields (e.g. applications at ultra-high temperatures). Fiber-optic sensors, and fiber Bragg grating (FBG) sensors in particular, are being widely studied as suitable sensors for improved structural health monitoring (SHM) due to their many merits. To enhance the thermal reliability of FBG sensors, thermal sensitivity, generally expressed as α f + ξ f and considered a constant, should be investigated more precisely. For this purpose, the governing equation of FBG sensors is modified using differential derivatives between the wavelength shift and the temperature change in this study. Through a thermal test ranging from RT to 900 °C, the thermal sensitivity of FBG sensors is successfully examined and this guarantees thermal reliability of FBG sensors at ultra-high temperatures. In detail, α f + ξ f has a non-linear dependence on temperature and varies from 6.0 × 10 −6  °C −1 (20 °C) to 10.6 × 10 −6  °C −1 (650 °C). Also, FBGs should be carefully used for applications at ultra-high temperatures due to signal disappearance near 900 °C. (paper)

Child Maltreatment and Clinical Outcome in Individuals at Ultra-High Risk for Psychosis in the EU-GEI High Risk Study

NARCIS (Netherlands)

Kraan, Tamar C.; Velthorst, Eva; Themmen, Manouk; Valmaggia, Lucia; Kempton, Matthew J.; McGuire, Phillip; Van Os, Jim; Rutten, Bart P.F.; Smit, Filip; De Haan, Lieuwe; Van Der Gaag, Mark; McGuire, Philip; Valmaggia, Lucia R.; Calem, Maria; Tognin, Stefania; Modinos, Gemma; Burger, Nadine; Van Dam, Daniella S.; Barrantes-Vidal, Neus; Domínguez-Martínez, Tecelli; Cristóbal-Narváez, Paula; Kwapil, Thomas R.; Monsonet-Bardají, Manel; Hinojosa, Lídia; Riecher-Rössler, Anita; Borgwardt, Stefan; Rapp, Charlotte; Ittig, Sarah; Studerus, Erich; Smieskova, Renata; Bressan, Rodrigo; Gadelha, Ary; Brietzke, Elisa; Asevedo, Graccielle; Asevedo, Elson; Zugman, Andre; Ruhrmann, Stephan; Gebhard, Dominika; Arnhold, Julia; Klosterkötter, Joachim; Nordholm, Dorte; Randers, Lasse; Krakauer, Kristine; Naumann, Tanya Louise; Glenthøj, Louise Birkedal; Nordentoft, Merete; De Hert, Marc; Van Winkel, Ruud; Nelson, Barnaby; McGorry, Patrick

2018-01-01

Background: Child maltreatment has been associated with a wide range of mental disorders in adulthood. Whether child maltreatment is specifically associated with psychosis risk in individuals at ultra-high risk (UHR) for psychosis, or leads to a general vulnerability for overall psychopathology in

Young modulus variation of a brickwork masonry element submitted to high temperatures

Directory of Open Access Journals (Sweden)

Maciá, M. E.

2013-03-01

Full Text Available In order to understand the thermal behavior of the masonry elements submitted to high temperatures we need to know the variation of their thermal properties with regard to the temperature. Submitted to high temperatures clay brick masonry presents thermomechanical effects (as the variation of Young's modulus, the thermal expansion of the unit and the mortar, spalling, losses of resistance … as well as variation of the properties of the material as result of its degradation. In this article the variation of the module of elasticity of the unit and the mortar is described with regard to high temperatures according to the state of the knowledge. In this article is also exposed the results obtained from the experimental program carried out on elements of clay brick masonry submitted to high temperatures in order to observe the variation of Young's module related to temperature.

La definición del comportamiento térmico de los elementos de fábrica sometidos a la acción del fuego requiere del conocimiento de la variación de sus propiedades termomecánicas con respecto a la temperatura. Ante las altas temperaturas la fábrica cerámica presenta efectos termomecánicos, como la variación del módulo de Young entre otros, así como la variación de las propiedades del material debidas a la degradación del mismo. En este artículo se describe la variación del módulo de elasticidad de la pieza y el mortero con respecto a altas temperaturas según el estado del conocimiento y se exponen los resultados obtenidos del programa experimental llevado a cabo sobre elementos de fábrica sometidos a altas temperaturas con el fin de observar la variación del módulo de Young con respecto a la temperatura.

Determination of resilient modulus values for typical plastic soils in Wisconsin.

Science.gov (United States)

2011-09-01

"The objectives of this research are to establish a resilient modulus test results database and to develop : correlations for estimating the resilient modulus of Wisconsin fine-grained soils from basic soil properties. A : laboratory testing program ...

Advances in Computational High-Resolution Mechanical Spectroscopy HRMS Part II: Resonant Frequency – Young's Modulus

International Nuclear Information System (INIS)

Majewski, M; Magalas, L B

2012-01-01

In this paper, we compare the values of the resonant frequency f 0 of free decaying oscillations computed according to the parametric OMI method (Optimization in Multiple Intervals) and nonparametric DFT-based (discrete Fourier transform) methods as a function of the sampling frequency. The analysis is carried out for free decaying signals embedded in an experimental noise recorded for metallic samples in a low-frequency resonant mechanical spectrometer. The Yoshida method (Y), the Agrez' method (A), and new interpolated discrete Fourier transform (IpDFT) methods, that is, the Yoshida-Magalas (YM) and (YM C ) methods developed by the authors are carefully compared for the resonant frequency f 0 = 1.12345 Hz and the logarithmic decrement, δ = 0.0005. Precise estimation of the resonant frequency (Youngs' modulus ∼ f 0 2 ) for real experimental conditions, i.e., for exponentially damped harmonic signals embedded in an experimental noise, is a complex task. In this work, various computing methods are analyzed as a function of the sampling frequency used to digitize free decaying oscillations. The importance of computing techniques to obtain reliable and precise values of the resonant frequency (i.e. Young's modulus) in materials science is emphasized.

Glimpses of black hole formation/evaporation in highly inelastic, ultra-planckian string collisions

CERN Document Server

Addazi, Andrea; Veneziano, Gabriele

2017-02-22

We revisit possible glimpses of black-hole formation by looking at ultra-planckian string-string collisions at very high final-state multiplicity. We compare, in particular, previous results using the optical theorem, the resummation of ladder diagrams at arbitrary loop order, and the AGK cutting rules, with the more recent study of $2 \\rightarrow N$ scattering at $N \\sim s M_P^{-2} \\gg 1$. We argue that some apparent tension between the two approaches disappears once a reinterpretation of the latter's results in terms of suitably defined infrared-safe cross sections is adopted. Under that assumption, the typical final state produced in an ultra-planckian collision does indeed appear to share some properties with those expected from the evaporation of a black hole of mass $\\sqrt{s}$, although no sign of thermalization is seen to emerge at this level of approximation.

Dislocation loops in ultra-high purity Fe(Cr) alloys after 7.2 MeV proton irradiation

Science.gov (United States)

Chen, J.; Duval, F.; Jung, P.; Schäublin, R.; Gao, N.; Barthe, M. F.

2018-05-01

Ultra-high purity Fe(Cr) alloys (from 0 wt% Cr to 14 wt% Cr) were 3D homogeneously irradiated by 0-7.2 MeV protons to 0.3 dpa at nominal temperatures from 270 °C to 500 °C. Microstructural changes were observed by transmission electron microscopy (TEM). The results showed that evolution of dislocation loops depends on the Cr content. Below 300 °C, large ½ a0 loops are dominating. Above 300 °C, a0 loops with a habit plane {100} appear. Loop sizes of both types are more or less the same. At temperatures from 310 °C to 400 °C, a0 loops form clusters with the same {100} habit plane as the one of the loops forming them. This indicates that loops of the same variant start gliding under mutual elastic interaction. At 500 °C, dislocation loops form disc shaped clusters about 1000 nm in diameter and sitting on {111} and/or {100} planes in the pure Fe samples. Based on these observations a quantitative analysis of the dislocation loops configurations and their temperature dependence is made, leading to an understanding of the basic mechanisms of formation of these loops.

Point source search techniques in ultra high energy gamma ray astronomy

International Nuclear Information System (INIS)

Alexandreas, D.E.; Biller, S.; Dion, G.M.; Lu, X.Q.; Yodh, G.B.; Berley, D.; Goodman, J.A.; Haines, T.J.; Hoffman, C.M.; Horch, E.; Sinnis, C.; Zhang, W.

1993-01-01

Searches for point astrophysical sources of ultra high energy (UHE) gamma rays are plagued by large numbers of background events from isotropic cosmic rays. Some of the methods that have been used to estimate the expected number of background events coming from the direction of a possible source are found to contain biases. Search techniques that avoid this problem are described. There is also a discussion of how to optimize the sensitivity of a search to emission from a point source. (orig.)

Advanced Ultra-High Speed Motor for Drilling

Energy Technology Data Exchange (ETDEWEB)

Impact Technologies LLC; University of Texas at Arlington

2007-03-31

Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

The bulk modulus of cubic spinel selenides: an experimental and theoretical study

DEFF Research Database (Denmark)

Waskowska, A.; Gerward, Leif; Olsen, J.S.

2009-01-01

It is argued that mainly the selenium sublattice determines the overall compressibility of the cubic spinel selenides, AB2Se4, and that the bulk modulus for these compounds is about 100GPa. The hypothesis is supported by experiments using high-pressure X-ray diffraction and synchrotron radiation...

The lateral characteristics of several ultra-high energy photon and hadron families

International Nuclear Information System (INIS)

Buja, Z.; Gladysz, E.; Mazurkiewicz, J.; Mikocki, S.; Szarska, M.; Zawiejski, L.

1980-01-01

In a thick lead X-ray film emulsion chamber of the Experiment Pamir, 8 ultra-high energy photon and hadron families were detected. They are considered to be almost ''pure'' families. The compound lateral characteristics for photon families indicate an existence of two groups of particles which have different average transverse momenta. A quite well visible azimuthal asymmetry in the number and transverse momenta values of produced particles is observed. (author)

Fatigue Life Prediction of High Modulus Asphalt Concrete Based on the Local Stress-Strain Method

Directory of Open Access Journals (Sweden)

Mulian Zheng

2017-03-01

Full Text Available Previously published studies have proposed fatigue life prediction models for dense graded asphalt pavement based on flexural fatigue test. This study focused on the fatigue life prediction of High Modulus Asphalt Concrete (HMAC pavement using the local strain-stress method and direct tension fatigue test. First, the direct tension fatigue test at various strain levels was conducted on HMAC prism samples cut from plate specimens. Afterwards, their true stress-strain loop curves were obtained and modified to develop the strain-fatigue life equation. Then the nominal strain of HMAC course determined using finite element method was converted into local strain using the Neuber method. Finally, based on the established fatigue equation and converted local strain, a method to predict the pavement fatigue crack initiation life was proposed and the fatigue life of a typical HMAC overlay pavement which runs a risk of bottom-up cracking was predicted and validated. Results show that the proposed method was able to produce satisfactory crack initiation life.

Compact printed two dipole array antenna with a high front-back ratio for ultra-high-frequency radio-frequency identification handheld reader applications

DEFF Research Database (Denmark)

Liu, Qi; Zhang, Shuai; He, Sailing

2015-01-01

A printed two-dipole array antenna with a high front-back ratio is proposed for ultra-high-frequency (UHF) radio-frequency identification handheld readers. The proposed antenna is a parasitic dual-element array with the ends of both elements folded back towards each other for additional coupling....

Pre-pulse inhibition and striatal dopamine in subjects at an ultra-high risk for psychosis

NARCIS (Netherlands)

de Koning, Mariken B.; Bloemen, Oswald J. N.; van Duin, Esther D. A.; Booij, Jan; Abel, Kathryn M.; de Haan, Lieuwe; Linszen, Don H.; van Amelsvoort, Thérèse A. M. J.

2014-01-01

Reduced prepulse inhibition (PPI) of the acoustic startle response is thought to represent a robust biomarker in schizophrenia. Reduced PPI has been demonstrated in subjects at ultra high risk (UHR) for developing psychosis. Imaging studies report disruption of striatal dopaminergic

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

Mechanical properties of novel forms of graphyne under strain: A density functional theory study

Science.gov (United States)

Majidi, Roya

2017-06-01

The mechanical properties of two forms of graphyne sheets named α-graphyne and α2-graphyne under uniaxial and biaxial strains were studied. In-plane stiffness, bulk modulus, and shear modulus were calculated based on density functional theory. The in-plane stiffness, bulk modulus, and shear modulus of α2-graphyne were found to be larger than that of α-graphyne. The maximum values of supported uniaxial and biaxial strains before failure were determined. The α-graphyne was entered into the plastic region with the higher magnitude of tension in comparison to α2-graphyne. The mechanical properties of α-graphyne family revealed that these forms of graphyne are proper materials for use in nanomechanical applications.

Generation of ultra-short relativistic-electron-bunch by a laser wakefield

NARCIS (Netherlands)

Khachatryan, A.G.; Boller, Klaus J.; van Goor, F.A.

2003-01-01

The possibility of the generation of an ultra-short (about one micron long) relativistic (up to a few GeVs) electron-bunch in a moderately nonlinear laser wakefield excited in an underdense plasma by an intense laser pulse is investigated. The ultra-short bunch is formed by trapping, effective

Case study: dairies utilizing ultra-high stocking density grazing in Pennsylvania and New York

Science.gov (United States)

Ultra-high stocking density (UHSD) grazing has gained interest in the forage industry. Proponents of UHSD emphasize increased forage use efficiency and soil improvement by grazing mature forage with stocking densities up to 560,425 kg ha**-1 of beef cattle on small paddocks with rest periods of up t...

The Effect of Annealing on the Elastic Modulus of Orthodontic Wires

Science.gov (United States)

Higginbottom, Kyle

Introduction: Nickel Titanium orthodontic wires are currently used in orthodontic treatment due to their heat activated properties and their delivery of constant force. The objective of this study was to determine the effect of annealing on the elastic modulus of Nickel Titanium, Stainless Steel and Beta-titanium (TMA) wires. Different points along the wire were tested in order to determine how far from the annealed ends the elastic modulus of the wires was affected. Methods: Eighty (80) orthodontic wires consisting of 4 equal groups (SS/TMA/Classic NitinolRTM/Super Elastic NitinolRTM) were used as the specimens for this study. All wires were measured and marked at 5mm measurements, and cut into 33.00mm sections. The wires were heated with a butane torch until the first 13.00mm of the wires were red hot. Load deflection tests using an InstronRTM universal testing machine were run at 5mm distances from the end of the wire that had been annealed. The change in elastic modulus was then determined. Results: There was a significant difference (F = 533.001, p = 0.0005) in the change in elastic modulus for the four distances. There was also a significant difference (F = 57.571, p = 0.0005) in the change in elastic modulus for the four wire types. There was a significant interaction (F = 19.601, p = 0.005) between wire type and distance, however this interaction negated the differences between the wires. Conclusion: 1) There are significant differences in the changes in elastic modulus between the areas of the wires within the annealed section and those areas 5mm and 10mm away from the annealed section. The change in elastic modulus within the annealed section was significantly greater at 8 mm than it was at 13mm, and this was significantly greater than 18mm and 23mm (5mm and 10mm beyond the annealed section). However, there was no statistical difference in the change in elastic modulus between 5mm and 10mm away from the annealed section (18mm and 23mm respectively). 2

Effects of creep and oxidation on reduced modulus in high-temperature nanoindentation

International Nuclear Information System (INIS)

Li, Yan; Fang, Xufei; Lu, Siyuan; Yu, Qingmin; Hou, Guohui; Feng, Xue

2016-01-01

Nanoindentation tests were performed on single crystal Ni-based superalloy at temperatures ranging from 20 °C to 800 °C in inert environment. Load-displacement curves at temperatures higher than 500 °C exhibit obvious creep inferred by increasing displacements at load-holding segments. Load-displacement curves obtained at 800 °C also display negative unloading stiffness. Examination of the microstructure beneath the indented area using Transmission Electron Microscope (TEM) reveals abundant dislocation piling up as well as oxide formation on the substrate. A method considering the creep effect is proposed to calculate the reduced modulus. In addition, a dimensionless ratio relating indentation depth and oxide film thickness is introduced to explain the oxidation effect on the mechanical properties derived from the load-displacement curves.

P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

Directory of Open Access Journals (Sweden)

S. Weber

2017-07-01

Full Text Available ELI-Beamlines (ELI-BL, one of the three pillars of the Extreme Light Infrastructure endeavour, will be in a unique position to perform research in high-energy-density-physics (HEDP, plasma physics and ultra-high intensity (UHI (>1022W/cm2 laser–plasma interaction. Recently the need for HED laboratory physics was identified and the P3 (plasma physics platform installation under construction in ELI-BL will be an answer. The ELI-BL 10 PW laser makes possible fundamental research topics from high-field physics to new extreme states of matter such as radiation-dominated ones, high-pressure quantum ones, warm dense matter (WDM and ultra-relativistic plasmas. HEDP is of fundamental importance for research in the field of laboratory astrophysics and inertial confinement fusion (ICF. Reaching such extreme states of matter now and in the future will depend on the use of plasma optics for amplifying and focusing laser pulses. This article will present the relevant technological infrastructure being built in ELI-BL for HEDP and UHI, and gives a brief overview of some research under way in the field of UHI, laboratory astrophysics, ICF, WDM, and plasma optics.

Ultra high field magnetic resonance imaging; L'imagerie par resonance magnetique a ultra-haut champ. L'aimant, piece maitresse de l'imageur. Memo C: les principales techniques d'imagerie medicale

Energy Technology Data Exchange (ETDEWEB)

Lethimonnier, F. [CEA Saclay, Institut d' Imagerie Biomedicale - NeuroSpin, Dir. des Sciences du Vivant, 91 - Gif-sur-Yvette (France); Vedrine, P. [CEA Saclay, Direction des Sciences de la Matiere, 91 - Gif-sur-Yvette (France)

2008-07-01

Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ultra-high-field system of unprecedented power that is designed for research on human subjects. The level of the magnetic field and the scale required will make this joint French-German project to build the magnet a breakthrough in the international arena. (authors)

Pulse shaping for all-optical signal processing of ultra-high bit rate serial data signals

DEFF Research Database (Denmark)

Palushani, Evarist

The following thesis concerns pulse shaping and optical waveform manipulation for all-optical signal processing of ultra-high bit rate serial data signals, including generation of optical pulses in the femtosecond regime, serial-to-parallel conversion and terabaud coherent optical time division...

High frequency acoustic microscopy for the determination of porosity and Young's modulus in high burnup uranium dioxide nuclear fuel

International Nuclear Information System (INIS)

Marchetti, M.; Laux, D.; Cappia, F.; Laurie, M.; Van Uffelen, P.; Rondinella, V.V.; Despaux, G.

2015-01-01

During irradiation UO 2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of the porosity and of elastic properties in high burnup UO 2 pellet can be investigated via high frequency acoustic microscopy. Ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A 67 MWd/kgU UO 2 pellet was characterized using the acoustic microscope installed in the hot cells of the Institute of Transuranium Elements: 90 MHz frequency was applied, methanol was used as coupling liquid and VR was measured at different radial positions. By comparing the porosity values obtained via acoustic microscopy with those determined using ceramographic image analysis a good agreement was found, especially in the areas close to the centre. In addition Young's modulus was calculated and its radial profile was correlated to the corresponding burnup profile. (authors)

Fracture Toughness and Elastic Modulus of Epoxy-Based Nanocomposites with Dopamine-Modified Nano-Fillers

Directory of Open Access Journals (Sweden)

Kwang Liang Koh

2017-07-01

Full Text Available This paper examines the effect of surface treatment and filler shape factor on the fracture toughness and elastic modulus of epoxy-based nanocomposite. Two forms of nanofillers, polydopamine-coated montmorillonite clay (D-clay and polydopamine-coated carbon nanofibres (D-CNF were investigated. It was found that Young’s modulus increases with increasing D-clay and D-CNF loading. However, the fracture toughness decreases with increased D-clay loading but increases with increased D-CNF loading. Explanations have been provided with the aid of fractographic analysis using electron microscope observations of the crack-filler interactions. Fractographic analysis suggests that although polydopamine provides a strong adhesion between the fillers and the matrix, leading to enhanced elastic stiffness, the enhancement prohibits energy release via secondary cracking, resulting in a decrease in fracture toughness. In contrast, 1D fibre is effective in increasing the energy dissipation during fracture through crack deflection, fibre debonding, fibre break, and pull-out.

Fracture Toughness and Elastic Modulus of Epoxy-Based Nanocomposites with Dopamine-Modified Nano-Fillers

Science.gov (United States)

Koh, Kwang Liang; Ji, Xianbai; Lu, Xuehong; Lau, Soo Khim; Chen, Zhong

2017-01-01

This paper examines the effect of surface treatment and filler shape factor on the fracture toughness and elastic modulus of epoxy-based nanocomposite. Two forms of nanofillers, polydopamine-coated montmorillonite clay (D-clay) and polydopamine-coated carbon nanofibres (D-CNF) were investigated. It was found that Young’s modulus increases with increasing D-clay and D-CNF loading. However, the fracture toughness decreases with increased D-clay loading but increases with increased D-CNF loading. Explanations have been provided with the aid of fractographic analysis using electron microscope observations of the crack-filler interactions. Fractographic analysis suggests that although polydopamine provides a strong adhesion between the fillers and the matrix, leading to enhanced elastic stiffness, the enhancement prohibits energy release via secondary cracking, resulting in a decrease in fracture toughness. In contrast, 1D fibre is effective in increasing the energy dissipation during fracture through crack deflection, fibre debonding, fibre break, and pull-out. PMID:28773136

Characterization of a high performance ultra-thin heat pipe cooling module for mobile hand held electronic devices

Science.gov (United States)

Ahamed, Mohammad Shahed; Saito, Yuji; Mashiko, Koichi; Mochizuki, Masataka

2017-11-01

In recent years, heat pipes have been widely used in various hand held mobile electronic devices such as smart phones, tablet PCs, digital cameras. With the development of technology these devices have different user friendly features and applications; which require very high clock speeds of the processor. In general, a high clock speed generates a lot of heat, which needs to be spreaded or removed to eliminate the hot spot on the processor surface. However, it is a challenging task to achieve proper cooling of such electronic devices mentioned above because of their confined spaces and concentrated heat sources. Regarding this challenge, we introduced an ultra-thin heat pipe; this heat pipe consists of a special fiber wick structure named as "Center Fiber Wick" which can provide sufficient vapor space on the both sides of the wick structure. We also developed a cooling module that uses this kind of ultra-thin heat pipe to eliminate the hot spot issue. This cooling module consists of an ultra-thin heat pipe and a metal plate. By changing the width, the flattened thickness and the effective length of the ultra-thin heat pipe, several experiments have been conducted to characterize the thermal properties of the developed cooling module. In addition, other experiments were also conducted to determine the effects of changes in the number of heat pipes in a single module. Characterization and comparison of the module have also been conducted both experimentally and theoretically.

Fuel conversion efficiency improvements in a highly boosted spark-ignition engine with ultra-expansion cycle

International Nuclear Information System (INIS)

Li, Tie; Zheng, Bin; Yin, Tao

2015-01-01

Highlights: • Ultra-expansion cycle SI engine is investigated. • An improvement of 9–26% in BSFC at most frequently operated conditions is obtained. • At high and medium loads, BSFC improvement is attributed to the increased combustion efficiency and reduced exhaust energy. • At low loads, reduction in pumping loss and exhaust energy is the primary contributors to BSFC improvement. • Technical challenge in practical application of this type of engine is discussed. - Abstract: A four-cylinder, intake boosted, port fuel injection (PFI), spark-ignition (SI) engine is modified to a three-cylinder engine with the outer two cylinders working in the conventional four stroke cycle and with the inner cylinder working only with the expansion and exhausting strokes. After calibration and validation of the engine cycle simulation models using the experimental data in the original engine, the performance of the three-cylinder engine with the ultra-expansion cycle is numerically studied. Compared to the original engine, the fuel consumptions under the most-frequently operated conditions are improved by 9–26% and the low fuel consumption area on the operating map are drastically enlarged for the ultra-expansion cycle engine with the proper design. Nonetheless, a higher intake boosting is needed for the ultra-expansion cycle engine to circumvent the significant drop in the wide-open-throttle (WOT) performance, and compression ratio of the combustion cylinder must be reduced to avoid knocking combustion. Despite of the reduced compression ratio, however, the total expansion ratio is increased to 13.8 with the extra expansion of the working gas in the inner cylinder. Compared to the conventional engine, the theoretical thermal efficiency is therefore increased by up to above 4.0% with the ultra-expansion cycle over the most load range. The energy balance analysis shows that the increased combustion efficiency, reduced exhaust energy and the extra expansion work in the

Geometrical modulus of a casting and its influence on solidification process

Directory of Open Access Journals (Sweden)

F. Havlicek

2011-10-01

Full Text Available Object: The work analyses the importance of the known criterion for evaluating the controlled solidification of castings, so called geometrical modulus defined by N. Chvorinov as the first one. Geometrical modulus influences the solidification process. The modulus has such specificity that during the process of casting formation it is not a constant but its initial value decreases with the solidification progress because the remaining melt volume can decrease faster than its cooling surface.Methodology: The modulus is determined by a simple calculation from the ratio of the casting volume after pouring the metal in the mould to the cooled mould surface. The solidified metal volume and the cooled surface too are changed during solidification. That calculation is much more complicated. Results were checked up experimentally by measuring the temperatures in the cross-section of heavy steel castings during cooling them.Results: The given experimental results have completed the original theoretical calculations by Chvorinov and recent researches done with use of numerical calculations. The contribution explains how the geometrical modulus together with the thermal process in the casting causes the higher solidification rate in the axial part of the casting cross-section and shortening of solidification time. Practical implications: Change of the geometrical modulus negatively affects the casting internal quality. Melt feeding by capillary filtration in the dendritic network in the casting central part decreases and in such a way the shrinkage porosity volume increases. State of stress character in the casting is changed too and it increases.

Glimpses of black hole formation/evaporation in highly inelastic, ultra-planckian string collisions

Energy Technology Data Exchange (ETDEWEB)

Addazi, Andrea [Dipartimento di Fisica, Università di L’Aquila,67010 Coppito, L’Aquila (Italy); LNGS, Laboratori Nazionali del Gran Sasso,67010 Assergi (Italy); Bianchi, Massimo [Dipartimento di Fisica, Università di Roma Tor Vergata andI.N.F.N. Sezione di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Veneziano, Gabriele [Collége de France,11 place M. Berthelot, 75005 Paris (France); Theory Division, CERN,CH-1211 Geneva 23 (Switzerland); Dipartimento di Fisica, Università di Roma La Sapienza,00185 Roma (Italy)

2017-02-22

We revisit possible glimpses of black-hole formation by looking at ultra-planckian string-string collisions at very high final-state multiplicity. We compare, in particular, previous results using the optical theorem, the resummation of ladder diagrams at arbitrary loop order, and the AGK cutting rules, with the more recent study of 2→N scattering at N∼sM{sub P}{sup −2}≫1. We argue that some apparent tension between the two approaches disappears once a reinterpretation of the latter’s results in terms of suitably defined infrared-safe cross sections is adopted. Under that assumption, the typical final state produced in an ultra-planckian collision does indeed appear to share some properties with those expected from the evaporation of a black hole of mass √s, although no sign of thermalization is seen to emerge at this level of approximation.

High platinum utilization in ultra-low Pt loaded PEM fuel cell cathodes prepared by electrospraying

Energy Technology Data Exchange (ETDEWEB)

Martin, S.; Garcia-Ybarra, P.L.; Castillo, J.L. [Dept. Fisica Matematica y de Fluidos, Facultad de Ciencias, UNED, Senda del Rey 9, 28040 Madrid (Spain)

2010-10-15

Cathode electrodes for proton exchange membrane fuel cells (PEMFCs) with ultra-low platinum loadings as low as 0.012 mg{sub Pt}cm{sup -2} have been prepared by the electrospray method. The electrosprayed layers have nanostructured fractal morphologies with dendrites formed by clusters (about 100 nm diameter) of a few single catalyst particles rendering a large exposure surface of the catalyst. Optimization of the control parameters affecting this morphology has allowed us to overcome the state of the art for efficient electrodes prepared by electrospraying. Thus, using these cathodes in membrane electrode assemblies (MEAs), a high platinum utilization in the range 8-10 kW g{sup -1} was obtained for the fuel cell operating at 40 C and atmospheric pressure. Moreover, a platinum utilization of 20 kW g{sup -1} was attained under more suitable operating conditions (70 C and 3.4 bar over-pressure). These results substantially improve the performances achieved previously with other low platinum loading electrodes prepared by electrospraying. (author)

Fiscal 1996 survey report. `Ultra high electronic technology development promotion project` under consignment from NEDO; 1996 nendo kenkyu seika hokokusho. Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku jigyo `chosentan denshi gijutsu kaihatsu sokushin jigyo`

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

For the purpose of establishing ultra high technology of a next next generation level which is a basic technology in the electronic information field, a key to the realization of the high grade information society and a common technology base giving marked influences to the wide range industrial field, the R and D was started of ultra fine processing process technology, technologies on limit measuring/analysis/control and new functional electronic materials. Themes of the R and D are electronic beam direct picture drawing system technology, ultra short wavelength electromagnetic radiation patterning/system technology, ultra fine sensitizing technology to draw pictures on metal and crystal surfaces using ultra short wavelength laser beams, shading system technology of shading mask to be used to the process of drawing ultra high accuracy and complicated figures, ultra high tech plasma reactive measuring/analysis/control technologies which become the base of ultra thin films and ultra fine etching using plasma, ultra high tech cleaning base technology, ultra high sensitivity medium technology, new functional element/film formation technology, etc. 137 refs., 358 figs., 38 tabs.

On the role of API in determining porosity, pore structure and bulk modulus of the skeletal material in pharmaceutical tablets formed with MCC as sole excipient.

Science.gov (United States)

Ridgway, Cathy; Bawuah, Prince; Markl, Daniel; Zeitler, J Axel; Ketolainen, Jarkko; Peiponen, Kai-Erik; Gane, Patrick

2017-06-30

The physical properties and mechanical integrity of pharmaceutical tablets are of major importance when loading with active pharmaceutical ingredient(s) (API) in order to ensure ease of processing, control of dosage and stability during transportation and handling prior to patient consumption. The interaction between API and excipient, acting as functional extender and binder, however, is little understood in this context. The API indomethacin is combined in this study with microcrystalline cellulose (MCC) at increasing loading levels. Tablets from the defined API/MCC ratios are made under conditions of controlled porosity and tablet thickness, resulting from different compression conditions, and thus compaction levels. Mercury intrusion porosimetry is used to establish the accessible pore volume, pore size distribution and, adopting the observed region of elastic intrusion-extrusion at high pressure, an elastic bulk modulus of the skeletal material is recorded. Porosity values are compared to previously published values derived from terahertz (THz) refractive index data obtained from exactly the same tablet sample sets. It is shown that the elastic bulk modulus is dependent on API wt% loading under constant tablet preparation conditions delivering equal dimensions and porosity. The findings are considered of novel value in respect to establishing consistency of tablet production and optimisation of physical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Registration of Crystallization Process of Ultra-Lightweight Mg-Li Alloys with Use of ATND Method

Directory of Open Access Journals (Sweden)

A. Białobrzeski

2007-07-01

Full Text Available Magnesium alloys are characterized by advantageous ratio of strength and/or elastic modulus to density, that is, can sustain static and dynamic loads similar to iron and aluminium, and additionally feature good vibration damping. Castings from magnesium alloys are lighter with about 20 – 30% than aluminium alloys and with 50 – 75% than iron alloys, that is why they are used in aviation and rocket industry and everywhere the weight of a product is of important significance for conditions of its operation. Also automotive industry introduces to vehicle’s structure an elements (castings manufactured from such alloys. On metallic matrix of magnesium alloys with lithium are also manufactured a composites reinforced with e.g. ceramic fiber, which are used as lightweight and resistant structure materials. The paper presents an attempt of implementation of ATND method (Thermal-Voltage-Derivative Analysis to monitoring of crystallization process of ultra-lightweight Mg-Li alloys. Investigated magnesium alloys with contents of about 2,3% Li, 10% Li and 11 % Li were produced in the Foundry Research Institute. Registration of melting and crystallization processes was made with use of the ATND method. Results of preliminary tests are shown in graphical form.

Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

International Nuclear Information System (INIS)

Kim, Nohyu; Yang, Seung Yong

2016-01-01

The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method

Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

Energy Technology Data Exchange (ETDEWEB)

Kim, Nohyu; Yang, Seung Yong [School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan (Korea, Republic of)

2016-02-15

The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method.

Graphene electric double layer capacitor with ultra-high-power performance

International Nuclear Information System (INIS)

Miller, John R.; Outlaw, R.A.; Holloway, B.C.

2011-01-01

We have demonstrated, for the first time, efficient 120 Hz filtering by an electric double layer capacitor (EDLC). The key to this ultra-high-power performance is electrodes made from vertically oriented graphene nanosheets grown directly on metal current collectors. This design minimized both electronic and ionic resistance and produced capacitors having RC time-constants of less than 200 μs. Significantly, graphene nanosheets have a preponderance of exposed edge planes that greatly increase stored charge over designs relying on basal plane surfaces. Collectively these factors make vertically oriented graphene nanosheet electrodes ideally suited for producing high-frequency EDLCs. Capacitors constructed with these electrodes are predicted to be significantly smaller than aluminum electrolyte capacitors that they could functionally replace plus be manufactured using standard semiconductor process equipment, creating interesting commercial opportunities.

Examining Young's modulus for wood

International Nuclear Information System (INIS)

Perkalskis, Benjamin S; Freeman, J Reuben; Suhov, Alexander

2004-01-01

Symmetry considerations, dimensional analysis and simple approximations are used to derive a formula for Young's modulus of a simple anisotropic system, a straight-layer wood bar whose fibre axis makes an angle with respect to the bar's longitudinal axis. Agreement between the derived formula and experiment (carried out in far from ideal conditions) is within 10%. Improvements and extensions are suggested for this undergraduate physics experiment

Temperature, Frequency and Young’s Modulus of a Wineglass

Directory of Open Access Journals (Sweden)

Amitta Miller

2015-01-01

Full Text Available A crystal soda-lime wineglass, heated to temperatures ranging from 25 °C to 150 °C, was tapped and the frequency recorded. It was shown that the relative change in the frequency at different temperatures can be used to determine the effect of temperature on Young’s Modulus of the glass. This simple method of tapping a wineglass is proposed as an effective way of determining the relative effect of temperature on Young’ Modulus of glass.

High-capacity optical long data memory based on enhanced Young's modulus in nanoplasmonic hybrid glass composites.

Science.gov (United States)

Zhang, Qiming; Xia, Zhilin; Cheng, Yi-Bing; Gu, Min

2018-03-22

Emerging as an inevitable outcome of the big data era, long data are the massive amount of data that captures changes in the real world over a long period of time. In this context, recording and reading the data of a few terabytes in a single storage device repeatedly with a century-long unchanged baseline is in high demand. Here, we demonstrate the concept of optical long data memory with nanoplasmonic hybrid glass composites. Through the sintering-free incorporation of nanorods into the earth abundant hybrid glass composite, Young's modulus is enhanced by one to two orders of magnitude. This discovery, enabling reshaping control of plasmonic nanoparticles of multiple-length allows for continuous multi-level recording and reading with a capacity over 10 terabytes with no appreciable change of the baseline over 600 years, which opens new opportunities for long data memory that affects the past and future.

Performance analysis of InSb based QWFET for ultra high speed applications

International Nuclear Information System (INIS)

Subash, T. D.; Gnanasekaran, T.; Divya, C.

2015-01-01

An indium antimonide based QWFET (quantum well field effect transistor) with the gate length down to 50 nm has been designed and investigated for the first time for L-band radar applications at 230 GHz. QWFETs are designed at the high performance node of the International Technology Road Map for Semiconductors (ITRS) requirements of drive current (Semiconductor Industry Association 2010). The performance of the device is investigated using the SYNOPSYS CAD (TCAD) software. InSb based QWFET could be a promising device technology for very low power and ultra-high speed performance with 5–10 times low DC power dissipation. (semiconductor devices)

A useful PET probe [11C]BU99008 with ultra-high specific radioactivity for small animal PET imaging of I2-imidazoline receptors in the hypothalamus

International Nuclear Information System (INIS)

Kawamura, Kazunori; Shimoda, Yoko; Yui, Joji; Zhang, Yiding; Yamasaki, Tomoteru; Wakizaka, Hidekatsu; Hatori, Akiko; Xie, Lin; Kumata, Katsushi; Fujinaga, Masayuki; Ogawa, Masanao; Kurihara, Yusuke; Nengaki, Nobuki; Zhang, Ming-Rong

2017-01-01

Introduction: A positron emission tomography (PET) probe with ultra-high specific radioactivity (SA) enables measuring high receptor specific binding in brain regions by avoiding mass effect of the PET probe itself. It has been reported that PET probe with ultra-high SA can detect small change caused by endogenous or exogenous ligand. Recently, Kealey et al. developed [ 11 C]BU99008, a more potent PET probe for I 2 -imidazoline receptors (I 2 Rs) imaging, with a conventional SA (mean 76 GBq/μmol) showed higher specific binding in the brain. Here, to detect small change of specific binding for I 2 Rs caused by endogenous or exogenous ligand in an extremely small region, such as hypothalamus in the brain, we synthesized and evaluated [ 11 C]BU99008 with ultra-high SA as a useful PET probe for small-animal PET imaging of I 2 Rs. Methods: [ 11 C]BU99008 was prepared by [ 11 C]methylation of N-desmethyl precursor with [ 11 C]methyl iodide. Biodistribution, metabolite analysis, and brain PET studies were conducted in rats. Results: [ 11 C]BU99008 with ultra-high SA in the range of 5400–16,600 GBq/μmol were successfully synthesized (n = 7), and had appropriate radioactivity for in vivo study. In the biodistribution study, the mean radioactivity levels in all investigated tissues except for the kidney did not show significant difference between [ 11 C]BU99008 with ultra-high SA and that with conventional SA. In the metabolite analysis, the percentage of unchanged [ 11 C]BU99008 at 30 min after the injection of probes with ultra-high and conventional SA was similar in rat brain and plasma. In the PET study of rats' brain, radioactivity level (AUC 30–60 min ) in the hypothalamus of rats injected with [ 11 C]BU99008 with ultra-high SA (64 [SUV ∙ min]) was significantly higher than that observed for that with conventional SA (50 [SUV ∙ min]). The specific binding of [ 11 C]BU99008 with ultra-high SA (86% of total binding) for I 2 R was higher than that of

Resilient modulus for unbound granular materials and subgrade soils in Egypt

Directory of Open Access Journals (Sweden)

Mousa Rabah

2017-01-01

Full Text Available Mechanistic Empirical (ME pavement design methods started to gain attention especially the last couple of years in Egypt and the Middle East. One of the challenges facing the spread of these methods in Egypt is lack of advanced properties of local soil and asphalt, which are needed as input data in ME design. Resilient modulus (Mr for example is an important engineering property that expresses the elastic behavior of soil/unbound granular materials (UGMs under cyclic traffic loading for ME design. In order to overcome the scarcity of the resilient modulus data for soil/UGMs in Egypt, a comprehensive laboratory testing program was conducted to measure resilient modulus of typical UGMs and subgrade soils typically used in pavement construction in Egypt. The factors that affect the resilient modulus of soil/UGMs were reviewed, studied and discussed. Finally, the prediction accuracy of the most well-known Mr Prediction models for the locally investigated materials was investigated.

Ultra-high-energy cosmic rays from radio galaxies

Science.gov (United States)

Eichmann, B.; Rachen, J. P.; Merten, L.; van Vliet, A.; Becker Tjus, J.

2018-02-01

Radio galaxies are intensively discussed as the sources of cosmic rays observed above about 3 × 1018 eV, called ultra-high energy cosmic rays (UHECRs). We present a first, systematic approach that takes the individual characteristics of these sources into account, as well as the impact of the extragalactic magnetic-field structures up to a distance of 120 Mpc. We use a mixed simulation setup, based on 3D simulations of UHECRs ejected by observed, individual radio galaxies taken out to a distance of 120 Mpc, and on 1D simulations over a continuous source distribution contributing from beyond 120 Mpc. Additionally, we include the ultra-luminous radio galaxy Cygnus A at a distance of about 250 Mpc, as its contribution is so strong that it must be considered as an individual point source. The implementation of the UHECR ejection in our simulation setup, both that of individual radio galaxies and the continuous source function, is based on a detailed consideration of the physics of radio jets and standard first-order Fermi acceleration. This allows to derive the spectrum of ejected UHECR as a function of radio luminosity, and at the same time provides an absolute normalization of the problem involving only a small set of parameters adjustable within narrow constraints. We show that the average contribution of radio galaxies taken over a very large volume cannot explain the observed features of UHECRs measured at Earth. However, we obtain excellent agreement with the spectrum, composition, and arrival-direction distribution of UHECRs measured by the Pierre Auger Observatory, if we assume that most UHECRs observed arise from only two sources: the ultra-luminous radio galaxy Cygnus A, providing a mostly light composition of nuclear species dominating up to about 6 × 1019 eV, and the nearest radio galaxy Centaurus A, providing a heavy composition dominating above 6 × 1019 eV . Here we have to assume that extragalactic magnetic fields out to 250 Mpc, which we did not

Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI

International Nuclear Information System (INIS)

Ciobanu, Luisa; Reynaud, Olivier; Le Bihan, Denis; Uhrig, Lynn; Jarraya, Bechir

2012-01-01

During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T2'*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7 T and 17.2 T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine). We showed that the brain/vessels contrast in T2'*- weighted images at 17.2 T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7 T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation. (authors)

Influence of dynamic dislocation drag on amplitude dependences of damping decrement and modulus defect in lead

International Nuclear Information System (INIS)

Soifer, Y.M.; Golosovskii, M.A.; Kobelev, N.P.

1981-01-01

A study was made of the amplitude dependences of the damping decrement and the modulus defect in lead at low temperatures at frequencies of 100 kHz and 5 MHz. It was shown that in pure lead at high frequencies a change in the amplitude dependences of the damping decrement and the modulus defect under the superconducting transition is due mainly to the change in the losses caused by the dynamic drag of dislocations whereas in measurements at low frequencies the influence of the superconducting transition is due to the change in the conditions of dislocation unpinning from point defects. The influence of the dynamic dislocation drag on the amplitude dependences of the damping decrement and the modulus defect is calculated and a method is presented for experimental estimation of the contribution of dynamic effects to the amplitude-dependent internal friction

Estimation of Elastic Modulus of Intact Rocks by Artificial Neural Network

Science.gov (United States)

Ocak, Ibrahim; Seker, Sadi Evren

2012-11-01

The modulus of elasticity of intact rock ( E i) is an important rock property that is used as an input parameter in the design stage of engineering projects such as dams, slopes, foundations, tunnel constructions and mining excavations. However, it is sometimes difficult to determine the modulus of elasticity in laboratory tests because high-quality cores are required. For this reason, various methods for predicting E i have been popular research topics in recently published literature. In this study, the relationships between the uniaxial compressive strength, unit weight ( γ) and E i for different types of rocks were analyzed, employing an artificial neural network and 195 data obtained from laboratory tests carried out on cores obtained from drilling holes within the area of three metro lines in Istanbul, Turkey. Software was developed in Java language using Weka class libraries for the study. To determine the prediction capacity of the proposed technique, the root-mean-square error and the root relative squared error indices were calculated as 0.191 and 92.587, respectively. Both coefficients indicate that the prediction capacity of the study is high for practical use.

Porous carbon with small mesoporesas an ultra-high capacity adsorption medium

Science.gov (United States)

Gao, Biaofeng; Zhou, Haitao; Chen, De; Yang, Jianhong

2017-10-01

Resins (732-type), abundant and inexpensive resources were used to prepare porous carbon with small mesopores (CSM) by carbonization and post-chemical-activation with potassium hydroxide (KOH). The N2 adsorption measurements revealed that CSM had high surface areas (1776.5 m2 g-1), large pore volumes (1.10 cm3 g-1), and nearly optimal narrow small mesopore sizes ranging from 2 to 7 nm. CSM was used as adsorbent to investigate the adsorption behavior for Rhodamine B (RhB). Due to the optimal pore size distributions (PSD), intensive-stacking interaction, S-doped, and electrostatic attraction, the CSM exhibited an ultra-high-capacity of 1590 mg g-1 for RhB in aqueous solutions.

Recent Ultra High Energy neutrino bounds and multimessenger observations with the Pierre Auger Observatory

Science.gov (United States)

Zas, Enrique

2018-01-01

The overall picture of the highest energy particles produced in the Universe is changing because of measurements made with the Pierre Auger Observatory. Composition studies of cosmic rays point towards an unexpected mixed composition of intermediate mass nuclei, more isotropic than anticipated, which is reshaping the future of the field and underlining the priority to understand composition at the highest energies. The Observatory is competitive in the search for neutrinos of all flavors above about 100 PeV by looking for very inclined showers produced deep in the atmosphere by neutrinos interacting either in the atmosphere or in the Earth's crust. It covers a large field of view between -85° and 60° declination in equatorial coordinates. Neutrinos are expected because of the existence of ultra high energy cosmic rays. They provide valuable complementary information, their fluxes being sensitive to the primary cosmic ray masses and their directions reflecting the source positions. We report the results of the neutrino search providing competitive bounds to neutrino production and strong constraints to a number of production models including cosmogenic neutrinos due to ultra high energy protons. We also report on two recent contributions of the Observatory to multimessenger studies by searching for correlations of neutrinos both with cosmic rays and with gravitational waves. The correlations of the directions of the highest energy astrophysical neutrinos discovered with IceCube with the highest energy cosmic rays detected with the Auger Observatory and the Telescope Array revealed an excess that is not statistically significant and is being monitored. The targeted search for neutrinos correlated with the discovery of the gravitational wave events GW150914 and GW151226 with advanced LIGO has led to the first bounds on the energy emitted by black hole mergers in Ultra-High Energy Neutrinos.

Recent Ultra High Energy neutrino bounds and multimessenger observations with the Pierre Auger Observatory

Directory of Open Access Journals (Sweden)

Zas Enrique

2017-01-01

Full Text Available The overall picture of the highest energy particles produced in the Universe is changing because of measurements made with the Pierre Auger Observatory. Composition studies of cosmic rays point towards an unexpected mixed composition of intermediate mass nuclei, more isotropic than anticipated, which is reshaping the future of the field and underlining the priority to understand composition at the highest energies. The Observatory is competitive in the search for neutrinos of all flavors above about 100 PeV by looking for very inclined showers produced deep in the atmosphere by neutrinos interacting either in the atmosphere or in the Earth’s crust. It covers a large field of view between −85◦ and 60◦ declination in equatorial coordinates. Neutrinos are expected because of the existence of ultra high energy cosmic rays. They provide valuable complementary information, their fluxes being sensitive to the primary cosmic ray masses and their directions reflecting the source positions. We report the results of the neutrino search providing competitive bounds to neutrino production and strong constraints to a number of production models including cosmogenic neutrinos due to ultra high energy protons. We also report on two recent contributions of the Observatory to multimessenger studies by searching for correlations of neutrinos both with cosmic rays and with gravitational waves. The correlations of the directions of the highest energy astrophysical neutrinos discovered with IceCube with the highest energy cosmic rays detected with the Auger Observatory and the Telescope Array revealed an excess that is not statistically significant and is being monitored. The targeted search for neutrinos correlated with the discovery of the gravitational wave events GW150914 and GW151226 with advanced LIGO has led to the first bounds on the energy emitted by black hole mergers in Ultra-High Energy Neutrinos.

Ultra-high-speed inversion recovery echo planar MR imaging

International Nuclear Information System (INIS)

Stehling, M.K.; Ordidge, R.J.; Coxon, R.; Chapman, B.; Houseman, A.M.; Guifoyle, D.; Blamire, A.; Gibbs, P.; Mansfield, P.

1988-01-01

Fast two-dimensional FT MR imaging techniques such as fast low-angle shot do not allow inversion recovery (IR). Rapid repetition of low-angle pulses is incompatible with a 180 0 inversion pulse. Echo planar imaging (EPI) can be applied in conjunction with IR, because after preparation of the spin system, a complete image is acquired. Data acquisition in less than 100 msec and real-time display allows interactive optimization of inversion time (4.0-9,000 msec) with little time penalty. The authors have applied IR EPI to the study of the brain, liver, and kidneys in normal volunteers and patients. Technical details are presented, and the applications of this first ultra-high-speed IR technique will be shown

Thickness dependence of nanofilm elastic modulus

Czech Academy of Sciences Publication Activity Database

Fedorchenko, Alexander I.; Wang, A. B.; Cheng, H.H.

2009-01-01

Roč. 94, č. 15 (2009), s. 152111-152113 ISSN 0003-6951 Institutional research plan: CEZ:AV0Z20760514 Keywords : nanofilm * elastic modulus * thickness dependence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.554, year: 2009 http://link.aip.org/link/?APPLAB/94/152111/1

Ultra-high vacuum system of the Brookhaven National Synchrotron Light Source

International Nuclear Information System (INIS)

Foerster, C.L.

1995-01-01

The rings of the National Synchrotron Light Source (NSLS) have been supplying light to numerous users for approximately a decade and recently a fully conditioned machine vacuum at design currents was obtained. A brief description of the x-ray storage ring, the VUV storage ring and their current supply is given along with some of their features. The ultra-high vacuum system employed for the storage rings and their advantages for the necessary stored beam environments are discussed including, a brief history of time. 15 refs., 2 tabs., 8 figs

Estimation of Bulk modulus and microhardness of tetrahedral semiconductors

International Nuclear Information System (INIS)

Gorai, Sanjay Kumar

2012-01-01

A general empirical formula was found for calculating of bulk modulus (B) and microhardness (H) from electronegativity and principal quantum number of II-VI, III-V semiconductors. Constant C1, appearing the in the expression of bulk modulus and constants C2 and C3, appearing in the expression of microhardness and the exponent M have following values respectively The numerical values of C1,C2, C3 and M are respectively 206.6, 8.234, 1.291, -1.10 for II-VI 72.4, 31.87, 7.592, -0.95 for III-V semiconductors. Both electro-negativity and principal quantum number can effectively reflect on the chemical bonding behaviour of constituent atoms in these semiconductors. The calculated values of bulk modulus and microhardness are in good agreement with the reported values in the literature. Present study helps in designing novel semiconductor materials, and to further explore the mechanical properties of these semiconductors.

Ultra low bit-rate speech coding

CERN Document Server

Ramasubramanian, V

2015-01-01

"Ultra Low Bit-Rate Speech Coding" focuses on the specialized topic of speech coding at very low bit-rates of 1 Kbits/sec and less, particularly at the lower ends of this range, down to 100 bps. The authors set forth the fundamental results and trends that form the basis for such ultra low bit-rates to be viable and provide a comprehensive overview of various techniques and systems in literature to date, with particular attention to their work in the paradigm of unit-selection based segment quantization. The book is for research students, academic faculty and researchers, and industry practitioners in the areas of speech processing and speech coding.

Ultra-high resolution flat-panel volume CT: fundamental principles, design architecture, and system characterization

International Nuclear Information System (INIS)

Gupta, Rajiv; Brady, Tom; Grasruck, Michael; Suess, Christoph; Schmidt, Bernhard; Stierstorfer, Karl; Popescu, Stefan; Flohr, Thomas; Bartling, Soenke H.

2006-01-01

Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to observe the perfusion of an entire organ, such as the brain, liver, or kidney, tomographically (e.g., after a transplant or ischemic event). By virtue of its higher resolution, one can directly visualize the trabecular structure of bone. This paper describes the basic design architecture of VCT. Three key technical challenges, viz., scatter correction, dynamic range extension, and temporal resolution improvement, must be addressed for successful implementation of a VCT scanner. How these issues are solved in a VCT prototype and the modifications necessary to enable ultra-high resolution volumetric scanning are described. The fundamental principles of scatter correction and dose reduction are illustrated with the help of an actual prototype. The image quality metrics of this prototype are characterized and compared with a multi-detector CT (MDCT). (orig.)

Ultra-high resolution flat-panel volume CT: fundamental principles, design architecture, and system characterization

Energy Technology Data Exchange (ETDEWEB)

Gupta, Rajiv; Brady, Tom [Massachusetts General Hospital, Department of Radiology, Founders House, FND-2-216, Boston, MA (United States); Grasruck, Michael; Suess, Christoph; Schmidt, Bernhard; Stierstorfer, Karl; Popescu, Stefan; Flohr, Thomas [Siemens Medical Solutions, Forchheim (Germany); Bartling, Soenke H. [Hannover Medical School, Department of Neuroradiology, Hannover (Germany)

2006-06-15

Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to observe the perfusion of an entire organ, such as the brain, liver, or kidney, tomographically (e.g., after a transplant or ischemic event). By virtue of its higher resolution, one can directly visualize the trabecular structure of bone. This paper describes the basic design architecture of VCT. Three key technical challenges, viz., scatter correction, dynamic range extension, and temporal resolution improvement, must be addressed for successful implementation of a VCT scanner. How these issues are solved in a VCT prototype and the modifications necessary to enable ultra-high resolution volumetric scanning are described. The fundamental principles of scatter correction and dose reduction are illustrated with the help of an actual prototype. The image quality metrics of this prototype are characterized and compared with a multi-detector CT (MDCT). (orig.)

Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

Science.gov (United States)

You, J. H.; Höschen, T.; Lindig, S.

2006-01-01

Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated.

Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

International Nuclear Information System (INIS)

You, J.H.; Hoeschen, T.; Lindig, S.

2006-01-01

Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated

Young's modulus of defective graphene sheet from intrinsic thermal vibrations

International Nuclear Information System (INIS)

Thomas, Siby; Mrudul, M S; Ajith, K M; Valsakumar, M C

2016-01-01

Classical molecular dynamics simulations have been performed to establish a relation between thermally excited ripples and Young's modulus of defective graphene sheet within a range of temperatures. The presence of the out-of-plane intrinsic ripples stabilizes the graphene membranes and the mechanical stability is analyzed by means of thermal mean square vibration amplitude in the long wavelength regime. We observed that the presence of vacancy and Stone-Wales (SW) defects reduces the Young's modulus of graphene sheets. Graphene sheet with vacancy defects possess superior Young's modulus to that of a sheet with Stone-Wales defects. The obtained room temperature Young's modulus of pristine and defective graphene sheet is ∼ 1 TPa, which is comparable to the results of earlier experimental and atomistic simulation studies. (paper)

Modelling of radiation losses for ion acceleration at ultra-high laser intensities

Directory of Open Access Journals (Sweden)

Capdessus Remi

2013-11-01

Full Text Available Radiation losses of charged particles can become important in ultra high intensity laser plasma interaction. This process is described by the radiation back reaction term in the electron equation of motion. This term is implemented in the relativistic particle-in-cell code by using a renormalized Lorentz-Abraham-Dirac model. In the hole boring regime case of laser ion acceleration it is shown that radiation losses results in a decrease of the piston velocity.

Developing the elastic modulus measurement of asphalt concrete using the compressive strength test

Science.gov (United States)

Setiawan, Arief; Suparma, Latif Budi; Mulyono, Agus Taufik

2017-11-01

Elastic modulus is a fundamental property of an asphalt mixture. An analytical method of the elastic modulus is needed to determine the thickness of flexible pavement. It has a role as one of the input values on a stress-strain analysis in the finite element method. The aim of this study was to develop the measurement of the elastic modulus by using compressive strength testing. This research used a set of specimen mold tool and Delta Dimensi software to record strain changes occurring in the proving ring of compression machine and the specimens. The elastic modulus of the five types of aggregate gradation and 2 types of asphalt were measured at optimum asphalt content. Asphalt Cement 60/70 and Elastomer Modified Asphalt (EMA) were used as a binder. Manufacturing success indicators of the specimens used void-in-the-mix (VIM) 3-5 % criteria. The success rate of the specimen manufacturing was more than 76%. Thus, the procedure and the compressive strength test equipment could be used for the measurement of the elastic modulus. The aggregate gradation and asphalt types significantly affected the elastic modulus of the asphalt concrete.

Young's Modulus of Single-Crystal Fullerene C Nanotubes

Directory of Open Access Journals (Sweden)

Tokushi Kizuka

2012-01-01

Full Text Available We performed bending tests on single-crystal nanotubes composed of fullerene C70 molecules by in situ transmission electron microscopy with measurements of loading forces by an optical deflection method. The nanotubes with the outer diameters of 270–470 nm were bent using simple-beam and cantilever-beam loading by the piezomanipulation of silicon nanotips. Young's modulus of the nanotubes increased from 61 GPa to 110 GPa as the outer diameter decreased from 470 nm to 270 nm. Young's modulus was estimated to be 66% of that of single-crystal C60 nanotubes of the same outer diameter.

Search for Ultra High-Energy Neutrinos with AMANDA-II

International Nuclear Information System (INIS)

IceCube Collaboration; Klein, Spencer; Ackermann, M.

2007-01-01

A search for diffuse neutrinos with energies in excess of 10 5 GeV is conducted with AMANDA-II data recorded between 2000 and 2002. Above 10 7 GeV, the Earth is essentially opaque to neutrinos. This fact, combined with the limited overburden of the AMANDA-II detector (roughly 1.5 km), concentrates these ultra high-energy neutrinos at the horizon. The primary background for this analysis is bundles of downgoing, high-energy muons from the interaction of cosmic rays in the atmosphere. No statistically significant excess above the expected background is seen in the data, and an upper limit is set on the diffuse all-flavor neutrino flux of E 2 Φ 90%CL -7 GeV cm -2 s -1 sr -1 valid over the energy range of 2 x 10 5 GeV to 10 9 GeV. A number of models which predict neutrino fluxes from active galactic nuclei are excluded at the 90% confidence level

Evaluation of Ultra-High Temperature Ceramics for Aeropropulsion Use

Science.gov (United States)

Levine, Stanley R.; Opila, Elizabeth J.; Halbig, Michael C.; Kiser, James D.; Singh, Mrityunjay; Salem, Jonathan A.

2001-01-01

Among the ultra-high temperature ceramics (UHTC) are a group of materials consisting of zirconium diboride or hafnium diboride plus silicon carbide, and in some instances, carbon. These materials offer a good combination of properties that make them candidates for airframe leading edges on sharp-bodied reentry vehicles. These UHTC perform well in the environment for such applications, i.e., air at low pressure. The purpose of this study was to examine three of these materials under conditions more representative of a propulsion environment, i.e., higher oxygen partial pressure and total pressure. Results of strength and fracture toughness measurements, furnace oxidation and high velocity thermal shock exposures are presented for ZrB2 plus 20 volume % SiC, ZrB2 plus 14 volume % SiC plus 30 volume % C, and SCS-9a SiC fiber reinforced ZrB2 plus 20 volume % SiC. The poor oxidation resistance of UHTCs is the predominant factor limiting their applicability to propulsion applications.

Extension induced phase separation and crystallization in semidilute solutions of ultra high molecular weight polyethylene

DEFF Research Database (Denmark)

Wingstrand, Sara Lindeblad; Imperiali, Luna; Stepanyan, Roman

2018-01-01

Abstract We investigate the influence of controlled uniaxial extension on various flow induced phenomena in semidilute solutions of ultra high molecular weight polyethylene (UHMwPE). Concentrations range from 9 w% to 29 w% and the choice of solvent is paraffin oil (PO). The start-up extensional b...

Overview of lunar detection of ultra-high energy particles and new plans for the SKA

NARCIS (Netherlands)

James, Clancy W.; Alvarez-Muñiz, Jaime; Bray, Justin D.; Buitink, Stijn; Dagkesamanskii, Rustam D.; Ekers, Ronald D.; Falcke, Heino; Gayley, Ken; Huege, Tim; Mevius, Maaijke; Mutel, Rob; Scholten, Olaf; Spencer, Ralph; ter Veen, Sander; Winchen, Tobias

2017-01-01

The lunar technique is a method for maximising the collection area for ultra-high-energy (UHE) cosmic ray and neutrino searches. The method uses either ground-based radio telescopes or lunar orbiters to search for Askaryan emission from particles cascading near the lunar surface. While experiments

Super soft silicone elastomers with high dielectric permittivity

DEFF Research Database (Denmark)

Madsen, Frederikke Bahrt; Yu, Liyun; Hvilsted, Søren

2015-01-01

Dielectric elastomers (DEs) have many favourable properties. The obstacle of high driving voltages, however, limits the commercial viability of the technology at present. Driving voltage can be lowered by decreasing the Young’s modulus and increasing the dielectric permittivity of silicone...... elastomers. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE. New soft elastomer matrices with high dielectric permittivity and low Young’s modulus, with no loss of mechanical stability, were prepared by two different...... approaches using chloropropyl-functional silicone polymers. The first approach was based on synthesised chloropropyl-functional copolymers that were cross-linkable and thereby formed the basis of new silicone networks with high dielectric permittivity (e.g. a 43% increase). These networks were soft without...

How far does a big push really push? : Mitigating ultra-poverty in Bangladesh

NARCIS (Netherlands)

F.A. Misha (Farzana); W.A. Raza (Wameq); J. Ara (Jinnat); E. Van de Poel (Ellen)

2014-01-01

textabstractBRAC implemented the Challenging the Frontiers of Poverty Reduction: Specially Targeted Ultra-Poor (CFPR) program in 2002 to mitigate ultra-poverty in the poorest districts of Bangladesh, providing multifaceted support in the form of asset-transfer, food-stipends, education, healthcare

APPLICATION OF ULTRA-HIGH PERFORMANCE CONCRETE TO PEDESTRIAN CABLE-STAYED BRIDGES

Directory of Open Access Journals (Sweden)

CHI-DONG LEE

2013-06-01

Full Text Available The use of ultra-high performance concrete (UHPC, which enables reducing the cross sectional dimension of the structures due to its high strength, is expected in the construction of the super-long span bridges. Unlike conventional concrete, UHPC experiences less variation of material properties such as creep and drying shrinkage and can reduce uncertainties in predicting time-dependent behavior over the long term. This study describes UHPC’s material characteristics and benefits when applied to super-long span bridges. A UHPC girder pedestrian cable-stayed bridge was designed and successfully constructed. The UHPC reduced the deflections in both the short and long term. The cost analysis demonstrates a highly competitive price for UHPC. This study indicates that UHPC has a strong potential for application in the super-long span bridges.

Short cellulosic fiber/starch acetate composites — micromechanical modeling of Young’s modulus

DEFF Research Database (Denmark)

Madsen, Bo; Joffe, Roberts; Peltola, Heidi

2011-01-01

This study is presented to predict the Young’s modulus of injection-molded short cellulosic fiber/plasticized starch acetate composites with variable fiber and plasticizer content. A modified rule of mixtures model is applied where the effect of porosity is included, and where the fiber weight...... (density and Young’s modulus). The measured Young’s modulus of the composites varies in the range 1.1—8.3 GPa, and this is well predicted by the model calculations. A property diagram is presented to be used for the tailor-making of composites with Young’s modulus in the range 0.2—10 GPa....

Evaluation report on research and development of an ultra-advanced processing system. 3; Chosentan kako system no kenkyu kaihatsu ni kansuru hyoka hokokusho. 3

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-08-01

This paper describes comprehensive evaluation on the following technologies as the ultra-advanced processing system: (1) large output excimer laser, (2) high-density ion beam, (3) an ultra-precision machining device, (4) ultra-advanced processing, (5) measurement and evaluation, and (6) comprehensive test. In the item (1), research and development was performed on such technologies as output increasing, output stabilization and beam formation, having achieved the targets. In the item (2), research and development was performed on such technologies as beam convergence, plasma control, ion transportation, high-frequency quadruple pole acceleration, and large-capacity class ion beam, having achieved the targets. In the item (3), research and development was performed on form creation and ultra-precision machining, having achieved the targets. In the item (4), research and development was performed on formation of high function thin films to apply the laser abrasion process to large area, ion surface modification, wide band area optics, high reflectance optics, ion injection, dynamic mixing, and modification of ultra high-grade metal surface, having achieved the targets. In the item (5), research and development was performed on high-accuracy roughness measurement, shape measurement, optical property evaluation, a wavelength meter, ultra advanced processing standard measurement, and environment correction technology, having achieved the targets. In the item (6), comprehensive demonstration was carried out on the component technologies. (NEDO)

Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

Science.gov (United States)

Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

2016-02-08

Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

Modular correction method of bending elastic modulus based on sliding behavior of contact point

International Nuclear Information System (INIS)

Ma, Zhichao; Zhao, Hongwei; Zhang, Qixun; Liu, Changyi

2015-01-01

During the three-point bending test, the sliding behavior of the contact point between the specimen and supports was observed, the sliding behavior was verified to affect the measurements of both deflection and span length, which directly affect the calculation of the bending elastic modulus. Based on the Hertz formula to calculate the elastic contact deformation and the theoretical calculation of the sliding behavior of the contact point, a theoretical model to precisely describe the deflection and span length as a function of bending load was established. Moreover, a modular correction method of bending elastic modulus was proposed, via the comparison between the corrected elastic modulus of three materials (H63 copper–zinc alloy, AZ31B magnesium alloy and 2026 aluminum alloy) and the standard modulus obtained from standard uniaxial tensile tests, the universal feasibility of the proposed correction method was verified. Also, the ratio of corrected to raw elastic modulus presented a monotonically decreasing tendency as the raw elastic modulus of materials increased. (technical note)

Formation of a highly doped ultra-thin amorphous carbon layer by ion bombardment of graphene

Science.gov (United States)

Piotr Michałowski, Paweł; Pasternak, Iwona; Ciepielewski, Paweł; Guinea, Francisco; Strupiński, Włodek

2018-07-01

Ion bombardment of graphene leads to the formation of defects which may be used to tune properties of the graphene based devices. In this work, however, we present that the presence of the graphene layer on a surface of a sample has a significant impact on the ion bombardment process: broken sp2 bonds react with the incoming ions and trap them close to the surface of the sample, preventing a standard ion implantation. For an ion bombardment with a low impact energy and significant dose (in the range of 1014 atoms cm‑2) an amorphization of the graphene layer is observed but at the same time, most of the incoming ions do not penetrate the sample but stop at the surface, thus forming a highly doped ultra-thin amorphous carbon layer. The effect may be used to create thin layers containing desired atoms if no other technique is available. This approach is particularly useful for secondary ion mass spectrometry where a high concentration of Cs at the surface of a sample significantly enhances the negative ionization probability, allowing it to reach better detection limits.

Consumers' conceptualization of ultra-processed foods.

Science.gov (United States)

Ares, Gastón; Vidal, Leticia; Allegue, Gimena; Giménez, Ana; Bandeira, Elisa; Moratorio, Ximena; Molina, Verónika; Curutchet, María Rosa

2016-10-01

Consumption of ultra-processed foods has been associated with low diet quality, obesity and other non-communicable diseases. This situation makes it necessary to develop educational campaigns to discourage consumers from substituting meals based on unprocessed or minimally processed foods by ultra-processed foods. In this context, the aim of the present work was to investigate how consumers conceptualize the term ultra-processed foods and to evaluate if the foods they perceive as ultra-processed are in concordance with the products included in the NOVA classification system. An online study was carried out with 2381 participants. They were asked to explain what they understood by ultra-processed foods and to list foods that can be considered ultra-processed. Responses were analysed using inductive coding. The great majority of the participants was able to provide an explanation of what ultra-processed foods are, which was similar to the definition described in the literature. Most of the participants described ultra-processed foods as highly processed products that usually contain additives and other artificial ingredients, stressing that they have low nutritional quality and are unhealthful. The most relevant products for consumers' conceptualization of the term were in agreement with the NOVA classification system and included processed meats, soft drinks, snacks, burgers, powdered and packaged soups and noodles. However, some of the participants perceived processed foods, culinary ingredients and even some minimally processed foods as ultra-processed. This suggests that in order to accurately convey their message, educational campaigns aimed at discouraging consumers from consuming ultra-processed foods should include a clear definition of the term and describe some of their specific characteristics, such as the type of ingredients included in their formulation and their nutritional composition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of Audiovisual Content in Ultra High Definition (UHD: Immersive Experience for Multimedia Viewing Screen TV and Smartphones

Directory of Open Access Journals (Sweden)

Francisco Javier MONTEMAYOR RUIZ

2016-06-01

Full Text Available This research analyzes the production of audiovisual content in ultra high definition (UHD as a catalyst factor of the new narratological discourse implanted in the media to the expressive, interactive and immersive possibilities obtained with the use of UHD 4K and 8K for viewing on large screen and, especially, in the 'fourth screen'. Through indepth interviews with experts from the academic and professional media world it is to establish an overview of the convergence of technology and industry of content creation, where the products are evolving to as for the entertainment needs of digital natives and adapting to new forms of consumption across multiple platforms, facing, in this way, a new business model for both industry technology industry and for the entire audiovisual sector.