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...

Pluto/Charon exploration utilizing a bi-modal PBR nuclear propulsion/power system

Science.gov (United States)

Venetoklis, Peter S.

1995-01-01

The paper describes a Pluto/Charon orbiter utilizing a bi-modal nuclear propulsion and power system based on the Particle Bed Reactor. The orbiter is sized for launch to Nuclear-Safe orbit atop a Titan IV or equivalent launch veicle. The bi-modal system provides thermal propulsion for Earth orbital departure and Pluto orbital capture, and 10 kWe of electric power for payload functions and for in-system maneuvering with ion thrusters. Ion thrusters are used to perform inclination changes about Pluto, a transfer from low Pluto orbit to low Charon orbit, and inclination changes about charon. A nominal payload can be deliverd in as little as 15 years, 1000 kg in 17 years, and close to 2000 kg in 20 years. Scientific return is enormously aided by the availability of up to 10 kWe, due to greater data transfer rates and more/better instruments. The bi-modal system can provide power at Pluto/Charon for 10 or more years, enabling an extremely robust, scientifically rewarding, and cost-effective exploration mission.

Application of a bi-modal PBR nuclear propulsion and power system to military missions

Science.gov (United States)

Venetoklis, Peter S.

1995-01-01

The rapid proliferation of arms technology and space access combined with current economic realities in the United States are creating ever greater demands for more capable space-based military assets. The paper illustrates that bi-modal nuclear propulsion and power based on the Particle Bed Reactor (PBR) is a high-leverage tehcnology that can maximize utility while minimizing cost. Mission benefits offered by the bi-modal PBR, including enhanced maneuverability, lifetime, survivability, payload power, and operational flexibility, are discussed. The ability to deliver desired payloads on smaller boosters is also illustrated. System descriptions and parameters for 10 kWe and 100 kWe power output levels are summarized. It is demonstrated via design exercise that bi-modal PBR dramtically enhances performance of a military satellite in geosynchronous orbit, increasing payload mass, payload power, and maneuverability.

Programmable Ultra-Lightweight System Adaptable Radio Satellite Base Station

Science.gov (United States)

Varnavas, Kosta; Sims, Herb

2015-01-01

With the explosion of the CubeSat, small sat, and nanosat markets, the need for a robust, highly capable, yet affordable satellite base station, capable of telemetry capture and relay, is significant. The Programmable Ultra-Lightweight System Adaptable Radio (PULSAR) is NASA Marshall Space Flight Center's (MSFC's) software-defined digital radio, developed with previous Technology Investment Programs and Technology Transfer Office resources. The current PULSAR will have achieved a Technology Readiness Level-6 by the end of FY 2014. The extensibility of the PULSAR will allow it to be adapted to perform the tasks of a mobile base station capable of commanding, receiving, and processing satellite, rover, or planetary probe data streams with an appropriate antenna.

Accelerometer-based estimation and modal velocity feedback vibration control of a stress-ribbon bridge with pneumatic muscles

International Nuclear Information System (INIS)

Liu, Xiaohan; Goldack, Arndt; Schlaich, Mike; Schauer, Thomas; Bleicher, Achim

2016-01-01

Lightweight footbridges are very elegant but also prone to vibration. By employing active vibration control, smart footbridges could accomplish not only the architectural concept but also the required serviceability and comfort. Inertial sensors such as accelerometers allow the estimation of nodal velocities and displacements. A Kalman filter together with a band-limited multiple Fourier linear combiner (BMFLC) is applied to enable a drift-free estimation of these signals for the quasi-periodic motion under pedestrian excitation without extra information from other kinds of auxiliary sensors. The modal velocities of the structure are determined by using a second Kalman filter with the known applied actuator forces as inputs and the estimated nodal displacement and velocities as measurements. The obtained multi-modal velocities are then used for feedback control. An ultra-lightweight stress-ribbon footbridge built in the Peter-Behrens- Halle at the Technische Universitat Berlin served as the research object. Using two inertial sensors in optimal points we can estimate the dominant modal characteristics of this bridge. Real-time implementation and evaluation results of the proposed estimator will be presented in comparison to signals derived from classical displacement encoders. The real-time estimated modal velocities were applied in a multi-modal velocity feedback vibration control scheme with lightweight pneumatic muscle actuators. Experimental results demonstrate the feasibility of using inertial sensors for active vibration control of lightweight footbridges. (paper)

Accelerometer-based estimation and modal velocity feedback vibration control of a stress-ribbon bridge with pneumatic muscles

Science.gov (United States)

Liu, Xiaohan; Schauer, Thomas; Goldack, Arndt; Bleicher, Achim; Schlaich, Mike

2016-09-01

Lightweight footbridges are very elegant but also prone to vibration. By employing active vibration control, smart footbridges could accomplish not only the architectural concept but also the required serviceability and comfort. Inertial sensors such as accelerometers allow the estimation of nodal velocities and displacements. A Kalman filter together with a band-limited multiple Fourier linear combiner (BMFLC) is applied to enable a drift-free estimation of these signals for the quasi-periodic motion under pedestrian excitation without extra information from other kinds of auxiliary sensors. The modal velocities of the structure are determined by using a second Kalman filter with the known applied actuator forces as inputs and the estimated nodal displacement and velocities as measurements. The obtained multi-modal velocities are then used for feedback control. An ultra-lightweight stress-ribbon footbridge built in the Peter-Behrens- Halle at the Technische Universitat Berlin served as the research object. Using two inertial sensors in optimal points we can estimate the dominant modal characteristics of this bridge. Real-time implementation and evaluation results of the proposed estimator will be presented in comparison to signals derived from classical displacement encoders. The real-time estimated modal velocities were applied in a multi-modal velocity feedback vibration control scheme with lightweight pneumatic muscle actuators. Experimental results demonstrate the feasibility of using inertial sensors for active vibration control of lightweight footbridges.

Bi-objective optimization for multi-modal transportation routing planning problem based on Pareto optimality

Directory of Open Access Journals (Sweden)

Yan Sun

2015-09-01

Full Text Available Purpose: The purpose of study is to solve the multi-modal transportation routing planning problem that aims to select an optimal route to move a consignment of goods from its origin to its destination through the multi-modal transportation network. And the optimization is from two viewpoints including cost and time. Design/methodology/approach: In this study, a bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. Minimizing the total transportation cost and the total transportation time are set as the optimization objectives of the model. In order to balance the benefit between the two objectives, Pareto optimality is utilized to solve the model by gaining its Pareto frontier. The Pareto frontier of the model can provide the multi-modal transportation operator (MTO and customers with better decision support and it is gained by the normalized normal constraint method. Then, an experimental case study is designed to verify the feasibility of the model and Pareto optimality by using the mathematical programming software Lingo. Finally, the sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case. Findings: The calculation results indicate that the proposed model and Pareto optimality have good performance in dealing with the bi-objective optimization. The sensitivity analysis also shows the influence of the variation of the demand and supply on the multi-modal transportation organization clearly. Therefore, this method can be further promoted to the practice. Originality/value: A bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. The Pareto frontier based sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case.

MITEE: A new nuclear engine concept for ultra fast, lightweight solar system exploration missions

Science.gov (United States)

Powell, James; Paniagua, John; Ludewig, Hans; Maise, George; Todosow, Michael

1998-01-01

A new ultra compact nuclear engine concept, MITEE (MIniature R_eactor E_nginE_), is described, and its performance evaluated for various solar system exploration missions. The MITEE concept is based on the Particle Bed Reactor (PBR), with modifications that enable a smaller, lighter nuclear engine. A range of MITEE Engine designs is described. Representative design parameters for the baseline MITEE reactor are: 75MW(th) power level, 1000 second Isp, 100 kilogram mass, 10 MW/Liter fuel element power density, 39 cm core diameter/height. Total engine mass, including turbo pump assembly, nozzles, controls, and contingency, is estimated to be 200 kilograms. Using the MITEE engine, ultra fast, lightweight solar system exploration missions are enabled. A range of such missions has been analyzed using the MULIMP code, and are described.

'Bi-modal' isoscalar giant dipole strength in 58Ni

International Nuclear Information System (INIS)

Nayak, B.K.; Garg, U.; Hedden, M.; Koss, M.; Li, T.; Liu, Y.; Madhusudhana Rao, P.V.; Zhu, S.; Itoh, M.; Sakaguchi, H.; Takeda, H.; Uchida, M.; Yasuda, Y.; Yosoi, M.; Fujimura, H.; Fujiwara, M.; Hara, K.; Kawabata, T.; Akimune, H.; Harakeh, M.N.

2006-01-01

The strength distribution of the isoscalar giant dipole resonance (ISGDR) in 58 Ni has been obtained over the energy range 10.5-49.5 MeV via extreme forward angle scattering (including 0 deg.) of 386 MeV α particles. We observe a 'bi-modal' E1 strength distribution for the first time in an A<90 nucleus. The observed ISGDR strength distribution is in reasonable agreement with the predictions of a recent RPA calculation

NIAC Phase I Study Final Report on Large Ultra-Lightweight Photonic Muscle Space Structures

Science.gov (United States)

Ritter, Joe

2016-01-01

way to make large inexpensive deployable mirrors where the cost is measured in millions, not billions like current efforts. For example we seek an interim goal within 10 years of a Hubble size (2.4m) primary mirror weighing 1 pound at a cost of 10K in materials. Described here is a technology using thin ultra lightweight materials where shape can be controlled simply with a beam of light, allowing imaging with incredibly low mass yet precisely shaped mirrors. These " Photonic Muscle" substrates will eventually make precision control of giant s p a c e apertures (mirrors) possible. OCCAM substrates make precision control of giant ultra light-weight mirror apertures possible. This technology is posed to create a revolution in remote sensing by making large ultra lightweight space telescopes a fiscal and material reality over the next decade.

Magnetic field induced superconductor-insulator transitions for ultra-thin Bi films on the different underlayers

International Nuclear Information System (INIS)

Makise, K; Kawaguti, T; Shinozaki, B

2009-01-01

This work shows the experimental results of the superconductor-insulator (S-I) transition for ultra-thin Bi films in magnetic fields. The quench-condensed (q-c) Bi film onto insulating underlayers have been interpreted to be homogeneous. In contrast, the Bi film without underlayers has been regarded as a granular film. The electrical transport properties of ultra-thin metal films near the S-I transition depend on the structure of the film. In order to confirm the effect of the underlayer to the homogeneity of the superconducting films, we investigate the characteristics of S-I transitions of q-c nominally homogeneous Bi films on underlayers of two insulating materials, SiO, and Sb. Under almost the same deposition condition except for the material of underlayer, we prepared the Bi films by repeating the additional deposition and performed in-situ electrical measurement. It is found that the transport properties near the S-I transitions show the remarkable difference between two films on different underlayers. As for Bi films on SiO, it turned out that the temperature dependence of resistance per square R sq (T) of the field-tuned transition and the thickness-tuned transition shows similar behavior; it was a thermally activated form. On the other hand, the R sq (T) of Bi films on Sb for thickness-tuned S-I transition showed logarithmic temperature dependence, but that for field-tuned S-I transition showed a thermally activated form.

Bi-Modal Face and Speech Authentication: a BioLogin Demonstration System

OpenAIRE

Marcel, Sébastien; Mariéthoz, Johnny; Rodriguez, Yann; Cardinaux, Fabien

2006-01-01

This paper presents a bi-modal (face and speech) authentication demonstration system that simulates the login of a user using its face and its voice. This demonstration is called BioLogin. It runs both on Linux and Windows and the Windows version is freely available for download. Bio\\-Login is implemented using an open source machine learning library and its machine vision package.

The Bi-Modal Organization: Balancing Autopoiesis and Fluid Social Networks for Sustainability

Science.gov (United States)

Smith, Peter A. C.; Sharicz, Carol Ann

2013-01-01

Purpose: The purpose of this paper is to assist an organization to restructure as a bi-modal organization in order to achieve sustainability in today's highly complex business world. Design/methodology/approach: The paper is conceptual and is based on relevant literature and the authors' research and practice. Findings: Although fluid…

Comparative study of Ta, TaN and Ta/TaN bi-layer barriers for Cu-ultra low-k porous polymer integration

International Nuclear Information System (INIS)

Yang, L.Y.; Zhang, D.H.; Li, C.Y.; Foo, P.D.

2004-01-01

Tantalum (Ta), TaN and bilayer Ta/TaN barriers deposited on ultra-low-k porous polymer (ULKPP) and the thermal stability of their structures are comparatively investigated using various techniques. The Ta/ultra-low-k polymer shows the smallest sheet resistance, but the poorest thermal stability, while TaN on the ultra-low-k polymer shows the highest resistance but the best thermal stability. The bi-layer Ta/TaN barrier takes the advantage of both Ta and TaN barriers and gives reasonable resistance and thermal stability. The electrical tests indicate that the Cu lines with the TaN and bi-layer Ta/TaN barriers exhibit the smaller leakage current and higher breakdown voltage compared with the Cu lines with the Ta barrier. The better thermal stability of the TaN and the bi-layer Ta/TaN barriers is mainly due to the amorphous/nanostructure and less grain boundaries of the barriers. In addition, the texture discontinuity at the Ta/TaN interfaces in the bi-layers barrier also plays an important role in reducing mutual diffusion of Ta atoms in the Ta barrier and some atoms in the ultra-low-k porous polymer

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.

Design and Experimental Verification of Deployable/Inflatable Ultra-Lightweight Structures

Science.gov (United States)

Pai, P. Frank

2004-01-01

Because launch cost of a space structural system is often proportional to the launch volume and mass and there is no significant gravity in space, NASA's space exploration programs and various science missions have stimulated extensive use of ultra-lightweight deployable/inflatable structures. These structures are named here as Highly Flexible Structures (HFSs) because they are designed to undergo large displacements, rotations, and/or buckling without plastic deformation under normal operation conditions. Except recent applications to space structural systems, HFSs have been used in many mechanical systems, civil structures, aerospace vehicles, home appliances, and medical devices to satisfy space limitations, provide special mechanisms, and/or reduce structural weight. The extensive use of HFSs in today's structural engineering reveals the need of a design and analysis software and a database system with design guidelines for practicing engineers to perform computer-aided design and rapid prototyping of HFSs. Also to prepare engineering students for future structural engineering requires a new and easy-to- understand method of presenting the complex mathematics of the modeling and analysis of HFSs. However, because of the high flexibility of HFSs, many unique challenging problems in the modeling, design and analysis of HFSs need to be studied. The current state of research on HFSs needs advances in the following areas: (1) modeling of large rotations using appropriate strain measures, (2) modeling of cross-section warpings of structures, (3) how to account for both large rotations and cross- section warpings in 2D (two-dimensional) and 1D structural theories, (4) modeling of thickness thinning of membranes due to inflation pressure, pretension, and temperature change, (5) prediction of inflated shapes and wrinkles of inflatable structures, (6) development of efficient numerical methods for nonlinear static and dynamic analyses, and (7) filling the gap between

Electronic structure of superconducting Bi2212 crystal by angle resolved ultra violet photoemission

International Nuclear Information System (INIS)

Saini, N.L.; Shrivastava, P.; Garg, K.B.

1993-01-01

The electronic structure of a high quality superconducting Bi 2 Sr 2 CaCu 2 Osub(8+δ) (Bi2212) single crystal is studied by angle resolved ultra violet photoemission (ARUPS) using He I (21.2 eV). Our results appear to show two bands crossing the Fermi level in ΓX direction of the Brillouin zone as reported by Takahashi et al. The bands at higher binding energy do not show any appreciable dispersion. The nature of the states near the Fermi level is discussed and the observed band structure is compared with the band structure calculations. (author)

Small Low Mass Advanced PBR's for Bi-Modal Operation

Science.gov (United States)

Ludewig, Hans; Todosow, Michael; Powell, James R.

1994-07-01

A preliminary assessment is made of a low mass bi-modal reactor for use as a propulsion unit and as a heat source for generating electricity. This reactor is based on the particle bed reactor (PBR) concept. It will be able to generate both thrust and electricity simultaneously. This assessment indicates that the reactor can generate approximately 6.8 (4) N of thrust using hydrogen as a coolant, and 100 KWe using a closed Brayton cycle (CBC) power conversion system. Two cooling paths pass through the reactor allowing simultaneous operation of both modes. The development of all the components for this reactor are within the experience base of the NTP project.

Modal parameter determination of a lightweight aerospace panel using laser Doppler vibrometer measurements

Science.gov (United States)

de Sousa, Kleverson C.; Domingues, Allan C.; Pereira, Pedro P. de S.; Carneiro, Sergio H.; de Morais, Marcus V. G.; Fabro, Adriano T.

2016-06-01

The experimental determination of modal parameters, i.e. natural frequencies, mode shapes and damping ratio, are key in characterizing the dynamic behaviour of structures. Typically, such parameters are obtained from dynamic measurements using one or a set of accelerometers, for response measurements, along with force transducers from an impact hammer or an electrodynamic actuator, i.e. a shaker. However, lightweight structures, commonly applied in the aerospace industry, can be significantly affected by the added mass from accelerometers. Therefore, non-contact measurement techniques, like Laser Doppler Vibrometer (LDV), are a more suitable approach in determining the dynamic characteristics of such structures. In this article, the procedures and results of a modal test for a honeycomb sandwich panel for aerospace applications are presented and discussed. The main objectives of the test are the identification of natural frequencies and mode shapes in order to validate a numerical model, as well as the identification of the damping characteristics of the panel. A validated numerical model will be necessary for future detailed response analysis of the satellite, including vibroacoustic investigations to account for acoustic excitations encountered during launching. The numerical model using homogenised material properties is updated to fit the experimental results and very good agreement between experimental and numerically obtained natural frequencies and mode shapes.

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.

Fabrication and imaging study of ultrasound/fluorescence bi-modal contrast agent based on polymeric microbubbles

International Nuclear Information System (INIS)

Xing Zhanwen; Ke Hengte; Wang Jinrui; Zhao Bo; Qu Enze; Yue Xiuli; Dai Zhifei

2013-01-01

Objective: To fabricate an ultrasound/fluorescence bi-modal contrast agent by encapsulating fluorescent quantum dots into polymeric ultrasound contrast agent microbubbles. Methods: Polylactic acid (PLA, 500 mg), (1R)-(+)-camphor (50 mg) and CdSe/ZnS quantum dots (0.5 ml, 2.3 μmol/L)were dissolved or dispersed in dichloromethane (10 ml) to form in an organic phase. Ammonium carbonate solution and poly (vinyl alcohol) solution were employed as the internal and external water phase, respectively. The fluorescent microbubbles were generated using double emulsion solvent evaporation and lyophilization methods. The morphology and illumination were characterized by scanning electron microscopy (SEM) and fluorescence spectrophotometry. Synchronized contrast-enhanced ultrasound and fluorescence imaging was acquired by injecting fluorescent microbubbles into the silicone tube coupled to a self-made ultrasound/fluorescence imaging device. Ultrasound/fluorescence bi-modal in vivo imaging was acquired on the kidney of New Zealand rabbits and suckling mice. Results: The fluorescent microbubbles were hollow spheres with an averaged diameter of (1.62 ± 1.47) μm. More than 99% of these microbubbles were less than 8 μm in diameter, which met the size criteria for ultrasound contrast agents. The fluorescence emission peak of the microbubbles appeared at 632 nm, indicating that good luminescence properties of quantum dots were maintained. In vitro ultrasound/fluorescence imaging showed no echoic signal when the silicone tube was filled with saline, but there was a strong echo when filled with fluorescent microbubbles. The liquid column with fluorescent microbubbles emitted red luminescence under ultraviolet irradiation. The kidney of the rabbit was remarkably enhanced after the administration of fluorescent microbubbles. Bright fluorescence could be observed at the injection site of the suckling mice via subcutaneous injection. Conclusions: A bi-modal but single contrast agent

Knowledge Engineering Aspects of Affective Bi-Modal Educational Applications

Science.gov (United States)

Alepis, Efthymios; Virvou, Maria; Kabassi, Katerina

This paper analyses the knowledge and software engineering aspects of educational applications that provide affective bi-modal human-computer interaction. For this purpose, a system that provides affective interaction based on evidence from two different modes has been developed. More specifically, the system's inferences about students' emotions are based on user input evidence from the keyboard and the microphone. Evidence from these two modes is combined by a user modelling component that incorporates user stereotypes as well as a multi criteria decision making theory. The mechanism that integrates the inferences from the two modes has been based on the results of two empirical studies that were conducted in the context of knowledge engineering of the system. The evaluation of the developed system showed significant improvements in the recognition of the emotional states of users.

Bi-Modal Micro-Cathode Arc Thruster for Cube Satellites

Science.gov (United States)

Chiu, Dereck

A new concept design, named the Bi-Modal Micro-Cathode Arc Thruster (BM-muCAT), has been introduced utilizing features from previous generations of muCATs and incorporating a multi-propellant functionality. This arc thruster is a micro-Newton level thruster based off of vacuum arc technology utilizing an enhanced magnetic field. Adjusting the magnetic field allows the thrusters performance to be varied. The goal of this thesis is to present a new generation of micro-cathode arc thrusters utilizing a bi-propellant, nickel and titanium, system. Three experimental procedures were run to test the new designs capabilities. Arc rotation experiment was used as a base experiment to ensure erosion was occurring uniformly along each electrode. Ion utilization efficiency was found, using an ion collector, to be up to 2% with the nickel material and 2.5% with the titanium material. Ion velocities were also studied using a time-of-flight method with an enhanced ion detection system. This system utilizes double electrostatic probes to measure plasma propagation. Ion velocities were measured to be 10km/s and 20km/s for nickel and titanium without a magnetic field. With an applied magnetic field of 0.2T, nickel ion velocities almost doubled to about 17km/s, while titanium ion velocities also increased to about 30km/s.

Experimental study of the Fermi–Pasta–Ulam recurrence in a bi-modal electrical transmission line

International Nuclear Information System (INIS)

Farota, Abdou K; Faye, Mansour M

2013-01-01

We report on the experimental observation of the Fermi–Pasta–Ulam (FPU) recurrence in an experimental bi-modal nonlinear transmission line. The FPU recurrence is observed in the two transmission modes known as the low frequency mode and the high frequency mode. In each case, a spectrum analysis is performed in order to study the waves along the line. (paper)

Development of ultra-lightweight slurries with high compressive strength for use in oil wells

Energy Technology Data Exchange (ETDEWEB)

Suzart, J. Walter P. [Halliburton Company, Houston, TX (United States); Farias, A.C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Ribeiro, Danilo; Fernandes, Thiago; Santos, Reened [Halliburton Energy Services Aberdeen, Scotland (United Kingdom)

2008-07-01

Formations with low fracture gradients or depleted reservoirs often lead to difficult oil well cementing operations. Commonly employed cement slurries (14.0 to 15.8 lb/gal), generate an equivalent circulating density (ECD) higher than the fracture gradient and ultimately lead to formation damage, lost circulation and a decreased top of cement. Given the high price of oil, companies are investing in those and other wells that are difficult to explore. Naturally, lightweight cement slurries are used to reduce the ECD (10.0 to 14.0 lb/gal), using additives to trap water and stabilize the slurry. However, when the density reaches 11.0 lb/gal, the increase in water content may cause a change in characteristics. The focus of this study is extreme cases where it is necessary to employ ultra-lightweight cement slurries (5.5 to 10.0 lb/gal). Foamed slurries have been widely used, and the objective is to set an alternative by developing cement slurries containing uncompressible microspheres, aiming for a density of 7.5 lb/gal as well as high compressive strength. Another benefit in contrast to preparing foamed cement slurries is that there is no requirement for special equipment in the field. Routine laboratory tests such as fluid-loss control, sedimentation, thickening time, free water, compressive strength, and rheology (at room and high temperatures) were performed. Thus, it was concluded that the proposed cement slurries can be used in oil wells. (author)

Modality and Task Switching Interactions using Bi-Modal and Bivalent Stimuli

Science.gov (United States)

Sandhu, Rajwant; Dyson, Benjamin J.

2013-01-01

Investigations of concurrent task and modality switching effects have to date been studied under conditions of uni-modal stimulus presentation. As such, it is difficult to directly compare resultant task and modality switching effects, as the stimuli afford both tasks on each trial, but only one modality. The current study investigated task and…

New technologies for the actuation and controls of large aperture lightweight quality mirrors

Science.gov (United States)

Lih, S. S.; Yang, E. H.; Gullapalli, S. N.; Flood, R.

2003-01-01

This paper presents a set of candidate components: MEMS based large stroke (>100 microns) ultra lightweight (0.01 gm) discrete inch worm actuator technology, and a distributed actuator technology, in the context of a novel lightweight active flexure-hinged substrate concept that uses the nanolaminate face sheet.

Modal analysis for floors in lightweight buildings

DEFF Research Database (Denmark)

Sjökvist, Lars-Göran; Brunskog, Jonas

2007-01-01

of acoustical prediction methods for those houses. The calculation standard EN 12354 is under evaluation since it cannot include most of the wooden houses that are built. It is important during such a work to have a great understanding of the acoustical behaviour for the wooden houses. The floors in lightweight...... constructions usually consist of plates that are stiffened by beams and by the dividing walls. In this study the wave equation for a plate is expanded by Fourier series and an analytical solution in terms of the eigenmodes of the entire system is presented. The studied system consists of one lightweigt floor...

Advanced lightweight optics development for space applications

International Nuclear Information System (INIS)

Bilbro, James W.

1998-01-01

A considerable amount of effort over the past year has been devoted to exploring ultra-lightweight optics for two specific NASA programs, the Next Generation Space Telescope (NGST), and the High Throughput X-ray Spectrometer (HTXS). Experimental investigations have been undertaken in a variety of materials including glass, composites, nickel, beryllium, Carbon fiber reinforced Silicon Carbide (CSiC), Reaction Bonded Silicon Carbide, Chemical Vapor Deposited Silicon Carbide, and Silicon. Overall results of these investigations will be summarized, and specific details will be provided concerning the in-house development of ultra-lightweight nickel replication for both grazing incidence and normal incidence optics. This will include x-ray test results of the grazing incidence optic and cryogenic test results of the normal incidence optic. The status of two 1.5 meter diameter demonstration mirrors for NGST will also be presented. These two demonstrations are aimed at establishing the capability to manufacture and test mirrors that have an areal density of 15 kilograms per square meter. Efforts in thin membrane mirrors and Fresnel lenses will also be briefly discussed

Precision Membrane Optical Shell (PMOS) Technology for Lightweight LIDAR Apertures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Precision membrane optical shell (PMOS) technology is an innovative combination of 1) ultra lightweight optically smooth membrane thin films, 2) advanced mold based...

Lightweight Design of an HTS Coil for the VASIMR Experiment, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In this Phase II SBIR contract Tai-Yang Research Company of Tennessee proposes to design, fabricate, and test an ultra-lightweight High Temperature Superconducting...

A Bi-Modal Routing Problem with Cyclical and One-Way Trips: Formulation and Heuristic Solution

Directory of Open Access Journals (Sweden)

Grinde Roger B.

2017-12-01

Full Text Available A bi-modal routing problem is solved using a heuristic approach. Motivated by a recreational hiking application, the problem is similar to routing problems in business with two transport modes. The problem decomposes into a set covering problem (SCP and an asymmetric traveling salesperson problem (ATSP, corresponding to a hiking time objective and a driving distance objective. The solution algorithm considers hiking time first, but finds all alternate optimal solutions, as inputs to the driving distance problem. Results show the trade-offs between the two objectives.

Fruit-80: A Secure Ultra-Lightweight Stream Cipher for Constrained Environments

Directory of Open Access Journals (Sweden)

Vahid Amin Ghafari

2018-03-01

Full Text Available In Fast Software Encryption (FSE 2015, while presenting a new idea (i.e., the design of stream ciphers with the small internal state by using a secret key, not only in the initialization but also in the keystream generation, Sprout was proposed. Sprout was insecure and an improved version of Sprout was presented in FSE 2017. We introduced Fruit stream cipher informally in 2016 on the web page of IACR (eprint and few cryptanalysis were published on it. Fortunately, the main structure of Fruit was resistant. Now, Fruit-80 is presented as a final version which is easier to implement and is secure. The size of LFSR and NFSR in Fruit-80 is only 80 bits (for 80-bit security level, while for resistance to the classical time-memory-data tradeoff (TMDTO attacks, the internal state size should be at least twice that of the security level. To satisfy this rule and to design a concrete cipher, we used some new design ideas. It seems that the bottleneck of designing an ultra-lightweight stream cipher is TMDTO distinguishing attacks. A countermeasure was suggested, and another countermeasure is proposed here. Fruit-80 is better than other small-state stream ciphers in terms of the initialization speed and area size in hardware. It is possible to redesign many of the stream ciphers and achieve significantly smaller area size by using the new idea.

Lightweight Metal Rubber Wire and Cable for Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this NASA STTR program is to produce ultra-lightweight electrical wire and cable harnesses to reduce the liftoff weight of future space flight...

Innovative, Lightweight Thoraeus RubberTM for MMOD and Space Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NanoSonic offers an innovative manufacturing process to yield ultra-lightweight radiation shielding nanocomposites by exploiting the concept of the Thoraeus filter...

Implantable electronics: emerging design issues and an ultra light-weight security solution.

Science.gov (United States)

Narasimhan, Seetharam; Wang, Xinmu; Bhunia, Swarup

2010-01-01

Implantable systems that monitor biological signals require increasingly complex digital signal processing (DSP) electronics for real-time in-situ analysis and compression of the recorded signals. While it is well-known that such signal processing hardware needs to be implemented under tight area and power constraints, new design requirements emerge with their increasing complexity. Use of nanoscale technology shows tremendous benefits in implementing these advanced circuits due to dramatic improvement in integration density and power dissipation per operation. However, it also brings in new challenges such as reliability and large idle power (due to higher leakage current). Besides, programmability of the device as well as security of the recorded information are rapidly becoming major design considerations of such systems. In this paper, we analyze the emerging issues associated with the design of the DSP unit in an implantable system. Next, we propose a novel ultra light-weight solution to address the information security issue. Unlike the conventional information security approaches like data encryption, which come at large area and power overhead and hence are not amenable for resource-constrained implantable systems, we propose a multilevel key-based scrambling algorithm, which exploits the nature of the biological signal to effectively obfuscate it. Analysis of the proposed algorithm in the context of neural signal processing and its hardware implementation shows that we can achieve high level of security with ∼ 13X lower power and ∼ 5X lower area overhead than conventional cryptographic solutions.

ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS

Science.gov (United States)

ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS.Chong S. Kim, SC. Hu*, PA Jaques*, US EPA, National Health and Environmental Effects Research Laboratory, ...

Bi-modal radiofrequency treatment for coexisting neuralgia and neuropathy in adjacent divisions of the trigeminal nerve.

Science.gov (United States)

Bhatjiwale, M; Bhatjiwale, M; Naik, L D; Chopade, P

2018-05-29

Trigeminal neuralgia and deafferentation neuropathic pain, or trigeminal neuropathy, are different symptomatologies, rarely reported to present together. The case of a 65-year-old gentleman suffering from trigeminal neuralgia of the maxillary and mandibular division is reported. He first underwent an infraorbital neurectomy that was complicated by deafferentation neuropathic pain, whilst his mandibular neuralgia continued. He was treated successfully for both the neuropathic and neuralgic symptoms in the same session using ultra-extended euthermic pulsed radiofrequency treatment for the maxillary division (V2) and radiofrequency thermocoagulation for the mandibular division (V3). This report is novel in describing the use of dual modalities in the same session for two distinct coexisting clinical entities in two different divisions of the same cranial nerve. The use of ultra-extended pulsed radiofrequency treatment for neuropathic pain in this case is also unique. Nearly 2years after the procedure, the patient continues to have complete pain relief. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

A Lightweight Compact Multi-Spectral Imager Using Novel Computer-Generated Micro-Optics and Spectral-Extraction Algorithms

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this NASA Early-stage research proposal is to demonstrate an ultra-compact, lightweight broadband hyper- and multi-spectral imaging system that is...

Strongly compressed Bi (111) bilayer films on Bi{sub 2}Se{sub 3} studied by scanning tunneling microscopy

Energy Technology Data Exchange (ETDEWEB)

Zhang, K. F.; Yang, Fang; Song, Y. R. [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Canhua; Qian, Dong; Gao, C. L.; Jia, Jin-Feng [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093 (China)

2015-09-21

Ultra-thin Bi films show exotic electronic structure and novel quantum effects, especially the widely studied Bi (111) film. Using reflection high-energy electron diffraction and scanning tunneling microscopy, we studied the structure and morphology evolution of Bi (111) thin films grown on Bi{sub 2}Se{sub 3}. A strongly compressed, but quickly released in-plane lattice of Bi (111) is found in the first three bilayers. The first bilayer of Bi shows a fractal growth mode with flat surface, while the second and third bilayer show a periodic buckling due to the strong compression of the in-plane lattice. The lattice slowly changes to its bulk value with further deposition of Bi.

Attractive mechanical properties of a lightweight highly sensitive bi layer thermistor: polycarbonate/organic molecular conductor

International Nuclear Information System (INIS)

Laukhina, E; Lebedev, V; Rovira, C; Laukhin, V; Veciana, J

2016-01-01

The paper covers some of the basic mechanical characteristics of a recently developed bi layer thermistor: polycarbonate/(001) oriented layer of organic molecular conductor α’-(BEDT-TTF) 2 I x Br 3-x , were BEDT-TTF=bis(ethylenedithio)tetrathiafulvalen. The nano and macro mechanical properties have been studied in order to use this flexible, low cost thermistor in sensing applications by proper way. The nano-mechanical properties of the temperature sensitive semiconducting layer of α’-(BEDT-TTF) 2 I x Br 3-x were tested using nanoindentation method. The value of Young's modulus in direction being perpendicular to the layer plan was found as 9.0 ±1.4 GPa. The macro mechanical properties of the thermistor were studied using a 5848 MicroTester. The tensile tests showed that basic mechanical characteristics of the thermistor are close to those of polycarbonate films. This indicates a good mechanical strength of the developed sensor. Therefore, the thermistor can be used in technologies that need to be instrumented with highly robustness lightweight low cost temperature sensors. The paper also reports synthetic details on fabricating temperature sensing e-textile. As the temperature control is becoming more and more important in biomedical technologies like healthcare monitoring, this work strongly contributes on the ongoing research on engineering sensitive conducting materials for biomedical applications. (paper)

Cut-Elimination and Proof Search for Bi-Intuitionistic Tense Logic

OpenAIRE

Gore, Rajeev; Postniece, Linda; Tiu, Alwen

2010-01-01

We consider an extension of bi-intuitionistic logic with the traditional modalities from tense logic Kt. Proof theoretically, this extension is obtained simply by extending an existing sequent calculus for bi-intuitionistic logic with typical inference rules for the modalities used in display logics. As it turns out, the resulting calculus, LBiKt, seems to be more basic than most intuitionistic tense or modal logics considered in the literature, in particular, those studied by Ewald and Simps...

Bi-orthogonality conditions for power flow analysis in fluid-loaded elastic cylindrical shells

DEFF Research Database (Denmark)

Ledet, Lasse; Sorokin, Sergey V.; Larsen, Jan Balle

2015-01-01

The paper addresses the classical problem of time-harmonic forced vibrations of a fluid-loaded cylindrical shell considered as a multi-modal waveguide carrying infinitely many waves. Firstly, a modal method for formulation of Green’s matrix is derived by means of modal decomposition. The method...... builds on the recent advances on bi-orthogonality conditions for multi-modal waveguides, which are derived here for an elastic fluid-filled cylindrical shell. Subsequently, modal decomposition is applied to the bi-orthogonality conditions to formulate explicit algebraic equations to express the modal...... vibro-acoustic waveguide is subjected to separate pressure and velocity acoustical excitations. Further, it has been found and justified that the bi-orthogonality conditions can be used as a ’root finder’ to solve the dispersion equation. Finally, it is discussed how to predict the response of a fluid...

On the bi-orthogonality conditions for multi-modal elastic waveguides

DEFF Research Database (Denmark)

Sorokin, Sergey

2013-01-01

The bi-orthogomality conditions in terms of generalised forces and displacements are derived from the reciprocity relations for a hierarchy of elastic waveguides, which support several travelling and evanescent modes (free waves). In the simple cases of waves in a straight beam and axisymmetric...... waves in a thin elastic cylindrical shell, these conditions are formulated as identities in an explicit form via wavenumbers. The forced vibrations of these waveguides under localised excitation are also considered with these identities being employed. The bi-orthogonality conditions in more advanced...... cases, specifically, for non-axisymmetric waves in an elastic cylindrical shell and for waves in an elastic helical spring, are derived, but not presented in an explicit form via wavenumbers. The results obtained for the hierarchy of waveguides are discussed in view of the classical bi...

Data Mining of Chemogenomics Data Using Bi-Modal PLS Methods and Chemical Interpretation for Molecular Design.

Science.gov (United States)

Hasegawa, Kiyoshi; Funatsu, Kimito

2014-12-01

Chemogenomics is a new strategy in drug discovery for interrogating all molecules capable of interacting with all biological targets. Because of the almost infinite number of drug-like organic molecules, bench-based experimental chemogenomics methods are not generally feasible. Several in silico chemogenomics models have therefore been developed for high-throughput screening of large numbers of drug candidate compounds and target proteins. In previous studies, we described two novel bi-modal PLS approaches. These methods provide a significant advantage in that they enable direct connections to be made between biological activities and ligand and protein descriptors. In this special issue, we review these two PLS-based approaches using two different chemogenomics datasets for illustration. We then compare the predictive and interpretive performance of the two methods using the same congeneric data set. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Ultra-Lightweight Encryption Scheme in Underwater Acoustic Networks

Directory of Open Access Journals (Sweden)

Chunyan Peng

2016-01-01

Full Text Available We tackle a fundamental security problem in underwater acoustic networks (UANs. The S-box in the existing block encryption algorithm is more energy consuming and unsuitable for resources-constrained UANs. In this paper, instead of S-box, we present a lightweight, 8-round iteration block cipher algorithm for UANs communication based on chaotic theory and increase the key space by changing the number of iteration round. We further propose secure network architecture of UANs. By analysis, our algorithm can resist brute-force searches and adversarial attacks. Simulation results show that, compared with traditional AES-128 and PRESENT algorithms, our cryptographic algorithm can make a good trade-off between security and overhead, has better energy efficiency, and applies to UANs.

Broadband low-frequency sound isolation by lightweight adaptive metamaterials

Science.gov (United States)

Liao, Yunhong; Chen, Yangyang; Huang, Guoliang; Zhou, Xiaoming

2018-03-01

Blocking broadband low-frequency airborne noises is highly desirable in lots of engineering applications, while it is extremely difficult to be realized with lightweight materials and/or structures. Recently, a new class of lightweight adaptive metamaterials with hybrid shunting circuits has been proposed, demonstrating super broadband structure-borne bandgaps. In this study, we aim at examining their potentials in broadband sound isolation by establishing an analytical model that rigorously combines the piezoelectric dynamic couplings between adaptive metamaterials and acoustics. Sound transmission loss of the adaptive metamaterial is investigated with respect to both the frequency and angular spectrum to demonstrate their sound-insulation effects. We find that efficient sound isolation can indeed be pursued in the broadband bi-spectrum for not only the case of the small resonator's periodicity where only one mode relevant to the mass-spring resonance exists, but also for the large-periodicity scenario, so that the total weight can be even lighter, in which the multiple plate-resonator coupling modes appear. In the latter case, the negative spring stiffness provided by the piezoelectric stack has been utilized to suppress the resonance-induced high acoustic transmission. Such kinds of adaptive metamaterials could open a new approach for broadband noise isolation with extremely lightweight structures.

Lightweight high-performance 1-4 meter class spaceborne mirrors: emerging technology for demanding spaceborne requirements

Science.gov (United States)

Hull, Tony; Hartmann, Peter; Clarkson, Andrew R.; Barentine, John M.; Jedamzik, Ralf; Westerhoff, Thomas

2010-07-01

Pending critical spaceborne requirements, including coronagraphic detection of exoplanets, require exceptionally smooth mirror surfaces, aggressive lightweighting, and low-risk cost-effective optical manufacturing methods. Simultaneous development at Schott for production of aggressively lightweighted (>90%) Zerodur® mirror blanks, and at L-3 Brashear for producing ultra-smooth surfaces on Zerodur®, will be described. New L-3 techniques for large-mirror optical fabrication include Computer Controlled Optical Surfacing (CCOS) pioneered at L-3 Tinsley, and the world's largest MRF machine in place at L-3 Brashear. We propose that exceptional mirrors for the most critical spaceborne applications can now be produced with the technologies described.

Production of lightweight aggregates from washing aggregate sludge and fly ash

Science.gov (United States)

González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Rodas, Magdalena

2010-05-01

Increasing generation of wastes is one of the main environmental problems in industrialised countries. Heat treatment at high temperatures can convert some types of wastes into ceramic products with a wide range of microstructural features and properties (Bethanis et al., 2004). A lightweight aggregate (LWA) is a granular material with a bulk density (bd) not exceeding 1.20 g/cm3 or with a particle density not exceeding 2.00 g/cm3 (UNE-EN-13055-1, 2003). They have become a focus of interest because the low particle density and the low bulk density entail a decrease in the load transmitted to the ground, and less work and effort are required to transport them (De' Gennaro et al., 2004). The benefits associated with these low densities, which are due to the formation of voids and pores, are very good thermal and acoustic insulation and materials with a good resistance to fire (Benbow, 1987; Fakhfakh et al., 2007). The objective was to recycle fly ash, used motor oil from cars and mineral wastes from washing aggregate sludge, in order to obtain a usable material such as lightweight aggregates, and also to ensure that they are of good quality for different applications. Raw materials have been physically, chemically and mineralogically characterized. On the basis of the results obtained, they were mixed, milled to a grain size of less than 200 μm (Yasuda, 1991), formed into pellets, pre-heated for 5 min and sintered in a rotary kiln at 1150°C, 1175°C, 1200°C and 1225°C for 10 and 15 min at each temperature (Theating). Effects of raw material characteristics, heating temperature and dwell time on the following LWAs properties were determined: loss on ignition (LOI), bloating index (BI), loose bulk density (bd), apparent and dry particle density (ad, dd), voids (H), water absorption (WA24h) and compressive strength (S). The products obtained were lightweight aggregates in accordance with norm UNE-EN-13055-1 (bd ≤1.20 g/cm3 or particle density ≤2.00 g/cm3). LWAs

A Baseband Ultra-Low Noise SiGe:C BiCMOS 0.25 µm Amplifier And Its Application For An On-Chip Phase-Noise Measurement Circuit

OpenAIRE

Godet , Sylvain; Tournier , Éric; Llopis , Olivier; Cathelin , Andreia; Juyon , Julien

2009-01-01

4 pages; International audience; The design and realization of an ultra-low noise operational amplifier is presented. Its applications are integrated low-frequency noise measurements in electronic devices and on-chip phase-noise measurement circuit. This paper discusses the SiGe:C BiCMOS 0.25 µm design improvements used for low noise applications. The proposed three-stage operational amplifier uses parallel bipolar transistor connection as input differential pair for low noise behavior. This ...

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...

Large-Scale Molded Silicon Oxycarbide Composite Components for Ultra-Low-Cost Lightweight Mirrors, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Next-generation telescopes need mirrors that are extremely stable, lightweight, and affordable. Semplastics has developed a novel, innovative ceramic material which...

Programmable Ultra Lightweight System Adaptable Radio (PULSAR) Low Cost Telemetry - Access from Space Advanced Technologies or Down the Middle

Science.gov (United States)

Sims. Herb; Varnavas, Kosta; Eberly, Eric

2013-01-01

Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 1990's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast, presently qualified satellite transponder applications were developed during the early 1960's space program. Programmable Ultra Lightweight System Adaptable Radio (PULSAR, NASA-MSFC SDR) technology revolutionizes satellite transponder technology by increasing data through-put capability by, at least, an order of magnitude. PULSAR leverages existing Marshall Space Flight Center SDR designs and commercially enhanced capabilities to provide a path to a radiation tolerant SDR transponder. These innovations will (1) reduce the cost of NASA Low Earth Orbit (LEO) and Deep Space transponders, (2) decrease power requirements, and (3) a commensurate volume reduction. Also, PULSAR increases flexibility to implement multiple transponder types by utilizing the same hardware with altered logic - no analog hardware change is required - all of which can be accomplished in orbit. This provides high capability, low cost, transponders to programs of all sizes. The final project outcome would be the introduction of a Technology Readiness Level (TRL) 7 low-cost CubeSat to SmallSat telemetry system into the NASA Portfolio.

Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K0.5Bi0.5TiO3-BaTiO3-Na0.5Bi0.5TiO3 piezoelectric materials.

Science.gov (United States)

Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

2015-02-26

We synthesized grain-oriented lead-free piezoelectric materials in (K0.5Bi0.5TiO3-BaTiO3-xNa0.5Bi0.5TiO3 (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d33 ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectric materials.

MINERVA - a multi-modal radiation treatment planning system

Energy Technology Data Exchange (ETDEWEB)

Wemple, C.A. E-mail: cew@enel.gov; Wessol, D.E.; Nigg, D.W.; Cogliati, J.J.; Milvich, M.L.; Frederickson, C.; Perkins, M.; Harkin, G.J

2004-11-01

Researchers at the Idaho National Engineering and Environmental Laboratory and Montana State University have undertaken development of MINERVA, a patient-centric, multi-modal, radiation treatment planning system. This system can be used for planning and analyzing several radiotherapy modalities, either singly or combined, using common modality independent image and geometry construction and dose reporting and guiding. It employs an integrated, lightweight plugin architecture to accommodate multi-modal treatment planning using standard interface components. The MINERVA design also facilitates the future integration of improved planning technologies. The code is being developed with the Java Virtual Machine for interoperability. A full computation path has been established for molecular targeted radiotherapy treatment planning, with the associated transport plugin developed by researchers at the Lawrence Livermore National Laboratory. Development of the neutron transport plugin module is proceeding rapidly, with completion expected later this year. Future development efforts will include development of deformable registration methods, improved segmentation methods for patient model definition, and three-dimensional visualization of the patient images, geometry, and dose data. Transport and source plugins will be created for additional treatment modalities, including brachytherapy, external beam proton radiotherapy, and the EGSnrc/BEAMnrc codes for external beam photon and electron radiotherapy.

Interaction of submonolayer Bi films with the Si(100) surface

International Nuclear Information System (INIS)

Goryachko, A.M.; Melnik, P.V.; Nakhodkin, M.G.

1999-01-01

Scanning tunneling microscopy and Auger electron spectroscopy were used to investigate interaction of submonolayer Bi films with the Si(100)-2x1 surface. Ultra small Bi amounts (≤ 0.15ML) do not form ordered structures, if deposited at room temperature. Annealing at 400 degree C causes Bi to coalesce into small islands of the densely packed 2x1 phase. Simultaneously, vacancy clusters are produced in the substrate, which remain after desorption of Bi at 600 degree C. In contrast, room temperature deposition and thermal desorption of larger Bi amounts (≥ 0.25 ML) produces vacancies grouped into lines. Further annealing of such a substrate in the temperature range of 600 degree C ≤ T ≤ 750 degree C causes the phase transition between the Si(100)-2xn and Si(100)-c(4x4)

Technological developments for ultra-lightweight, large aperture, deployable mirror for space telescopes

Science.gov (United States)

Zuccaro Marchi, Alessandro; D'Amato, Francesco; Gallieni, Daniele; Biasi, Roberto; Molina, Marco; Duò, Fabrizio; Ruder, Nikolaus; Salinari, Piero; Lisi, Franco; Riccardi, Armando; Gambicorti, Lisa; Simonetti, Francesca; Pereira do Carmo, Joao Pedro N.

2017-11-01

The increasing interest on space telescopes for scientific applications leads to implement the manufacturing technology of the most critical element, i.e. the primary mirror: being more suitable a large aperture, it must be lightweight and deployable. The presented topic was originally addressed to a spaceborne DIAL (Differential Absorption LIDAR) mission operating at 935.5 nm for the measurement of water vapour profile in atmosphere, whose results were presented at ICSO 2006 and 2008. Aim of this paper is to present the latest developments on the main issues related to the fabrication of a breadboard, covering two project critical areas identified during the preliminary studies: the design and performances of the long-stroke actuators used to implement the mirror active control and the mirror survivability to launch via Electrostatic Locking (EL) between mirror and backplane. The described work is developed under the ESA/ESTEC contract No. 22321/09/NL/RA. The lightweight mirror is structured as a central sector surrounded by petals, all of them actively controlled to reach the specified shape after initial deployment and then maintained within specs for the entire mission duration. The presented study concerns: a) testing the Carbon Fiber Reinforced Plastic (CFRP) backplane manufacturing and EL techniques, with production of suitable specimens; b) actuator design optimisation; c) design of the deployment mechanism including a high precision latch; d) the fabrication of thin mirrors mock-ups to validate the fabrication procedure for the large shells. The current activity aims to the construction of an optical breadboard capable of demonstrating the achievement of all these coupled critical aspects: optical quality of the thin shell mirror surface, actuators performances and back-plane - EL subsystem functionality.

An Analog Correlator for Ultra-Wideband Receivers

Directory of Open Access Journals (Sweden)

Tu Chunjiang

2005-01-01

Full Text Available We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to . As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to , which is sufficient for detection by the comparator. The circuit dissipates about from double voltage supplies of and using SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.

Operational Modal Analysis of the Cablestayed Footbridge

Science.gov (United States)

Kortiš, Ján; Daniel, Ľuboš; Farbák, Matúš; Maliar, Lukáš; Škarupa, Milan

2017-12-01

Modern architecture leads to design subtle bridge structures that are more sensitive to increased dynamic loading than the massive ones. This phenomenon can be especially observed on lightweight steel structures such as suspended footbridges. As a result, it is necessary to know precisely its dynamic characteristics, such as natural frequencies, natural shapes and damping of construction. This information can be used for further analysis such as damage detection, system identification, health monitoring, etc. or also for the design of new types of construction. For this purpose, classical modal analysis using trigger load or harmonic vibration exciter in combination with acceleration sensors is used in practice. However, there are many situations where it is not possible to stop the traffic or operation of the bridge. The article presents an experimental measurement of the dynamic parameters of the structure at the operating load using the operational modal analysis.

Operational Modal Analysis of the Cablestayed Footbridge

Directory of Open Access Journals (Sweden)

Kortiš Ján

2017-12-01

Full Text Available Modern architecture leads to design subtle bridge structures that are more sensitive to increased dynamic loading than the massive ones. This phenomenon can be especially observed on lightweight steel structures such as suspended footbridges. As a result, it is necessary to know precisely its dynamic characteristics, such as natural frequencies, natural shapes and damping of construction. This information can be used for further analysis such as damage detection, system identification, health monitoring, etc. or also for the design of new types of construction. For this purpose, classical modal analysis using trigger load or harmonic vibration exciter in combination with acceleration sensors is used in practice. However, there are many situations where it is not possible to stop the traffic or operation of the bridge. The article presents an experimental measurement of the dynamic parameters of the structure at the operating load using the operational modal analysis.

Light-weight plastination.

Science.gov (United States)

Steinke, Hanno; Rabi, Suganthy; Saito, Toshiyuki; Sawutti, Alimjan; Miyaki, Takayoshi; Itoh, Masahiro; Spanel-Borowski, Katharina

2008-11-20

Plastination is an excellent technique which helps to keep the anatomical specimens in a dry, odourless state. Since the invention of plastination technique by von Hagens, research has been done to improve the quality of plastinated specimens. In this paper, we have described a method of producing light-weight plastinated specimens using xylene along with silicone and in the final step, substitute xylene with air. The finished plastinated specimens were light-weight, dry, odourless and robust. This method requires less use of resin thus making the plastination technique more cost-effective. The light-weight specimens are easy to carry and can easily be used for teaching.

Deployable auxetic shape memory alloy cellular antenna demonstrator: design, manufacturing and modal testing

International Nuclear Information System (INIS)

Jacobs, S; Coconnier, C; DiMaio, D; Scarpa, F; Martinez, J; Toso, M

2012-01-01

This work describes the design, manufacturing and testing of a deployable antenna for deep-space missions based on a hybrid honeycomb truss made of shape memory alloy (SMA). The deployable characteristics are enhanced by the equivalent auxetic (negative Poisson’s ratio) behaviour of the cellular configuration. Specific emphasis is placed on the modal analysis techniques used to test the lightweight SMA structure. (paper)

Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting

Energy Technology Data Exchange (ETDEWEB)

Mascarin, Anthony [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hannibal, Ted [Idaho National Lab. (INL), Idaho Falls, ID (United States); Raghunathan, Anand [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ivanic, Ziga [Idaho National Lab. (INL), Idaho Falls, ID (United States); Francfort, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-04-01

The U.S. Department of Energy’s Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. The strategic targets were a 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. The baseline vehicle was an average of several available vehicles in this class. Mass and cost breakdowns from several sources were used, including original equipment manufacturers’ (OEMs’) input through U.S. Department of Energy’s Vehicle Technologies Office programs and public presentations, A2Mac1 LLC’s teardown information, Lotus Engineering Limited and FEV, Inc. breakdowns in their respective lightweighting studies, and IBIS Associates, Inc.’s decades of experience in automotive lightweighting and materials substitution analyses. Information on lightweighting strategies in this analysis came from these same sources and the ongoing U.S. Department of Energy-funded Vehma International of America, Inc. /Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, and many United States Council for Automotive Research’s/United States Automotive Materials Partnership LLC lightweight materials programs.

Production of lightweight Geopolymer concrete using artificial local lightweight aggregate

Directory of Open Access Journals (Sweden)

Abbas Waleed

2018-01-01

Full Text Available Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K, respectively.

UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

International Nuclear Information System (INIS)

None

1998-01-01

The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of ''as-generated'' slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for ''as-generated'' slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1400 and 1700 F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications. The project goals are to be accomplished in two phases: Phase I, comprising the production of LWA and ULWA from slag at the large pilot scale, and

Lightweight Active Object Retrieval with Weak Classifiers.

Science.gov (United States)

Czúni, László; Rashad, Metwally

2018-03-07

In the last few years, there has been a steadily growing interest in autonomous vehicles and robotic systems. While many of these agents are expected to have limited resources, these systems should be able to dynamically interact with other objects in their environment. We present an approach where lightweight sensory and processing techniques, requiring very limited memory and processing power, can be successfully applied to the task of object retrieval using sensors of different modalities. We use the Hough framework to fuse optical and orientation information of the different views of the objects. In the presented spatio-temporal perception technique, we apply active vision, where, based on the analysis of initial measurements, the direction of the next view is determined to increase the hit-rate of retrieval. The performance of the proposed methods is shown on three datasets loaded with heavy noise.

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.

Nanocrystalline Aluminum Truss Cores for Lightweight Sandwich Structures

Science.gov (United States)

Schaedler, Tobias A.; Chan, Lisa J.; Clough, Eric C.; Stilke, Morgan A.; Hundley, Jacob M.; Masur, Lawrence J.

2017-12-01

Substitution of conventional honeycomb composite sandwich structures with lighter alternatives has the potential to reduce the mass of future vehicles. Here we demonstrate nanocrystalline aluminum-manganese truss cores that achieve 2-4 times higher strength than aluminum alloy 5056 honeycombs of the same density. The scalable fabrication approach starts with additive manufacturing of polymer templates, followed by electrodeposition of nanocrystalline Al-Mn alloy, removal of the polymer, and facesheet integration. This facilitates curved and net-shaped sandwich structures, as well as co-curing of the facesheets, which eliminates the need for extra adhesive. The nanocrystalline Al-Mn alloy thin-film material exhibits high strength and ductility and can be converted into a three-dimensional hollow truss structure with this approach. Ultra-lightweight sandwich structures are of interest for a range of applications in aerospace, such as fairings, wings, and flaps, as well as for the automotive and sports industries.

Last results of technological developments for ultra-lightweight, large aperture, deployable mirror for space telescopes

Science.gov (United States)

Gambicorti, Lisa; D'Amato, Francesco; Vettore, Christian; Duò, Fabrizio; Guercia, Alessio; Patauner, Christian; Biasi, Roberto; Lisi, Franco; Riccardi, Armando; Gallieni, Daniele; Lazzarini, Paolo; Tintori, Matteo; Zuccaro Marchi, Alessandro; Pereira do Carmo, Joao

2017-11-01

The aim of this work is to describe the latest results of new technological concepts for Large Aperture Telescopes Technology (LATT) using thin deployable lightweight active mirrors. This technology is developed under the European Space Agency (ESA) Technology Research Program and can be exploited in all the applications based on the use of primary mirrors of space telescopes with large aperture, segmented lightweight telescopes with wide Field of View (FOV) and low f/#, and LIDAR telescopes. The reference mission application is a potential future ESA mission, related to a space borne DIAL (Differential Absorption Lidar) instrument operating around 935.5 nm with the goal to measure water vapor profiles in atmosphere. An Optical BreadBoard (OBB) for LATT has been designed for investigating and testing two critical aspects of the technology: 1) control accuracy in the mirror surface shaping. 2) mirror survivability to launch. The aim is to evaluate the effective performances of the long stroke smart-actuators used for the mirror control and to demonstrate the effectiveness and the reliability of the electrostatic locking (EL) system to restraint the thin shell on the mirror backup structure during launch. The paper presents a comprehensive vision of the breadboard focusing on how the requirements have driven the design of the whole system and of the various subsystems. The manufacturing process of the thin shell is also presented.

Regularity, variability and bi-stability in the activity of cerebellar purkinje cells.

Science.gov (United States)

Rokni, Dan; Tal, Zohar; Byk, Hananel; Yarom, Yosef

2009-01-01

Recent studies have demonstrated that the membrane potential of Purkinje cells is bi-stable and that this phenomenon underlies bi-modal simple spike firing. Membrane potential alternates between a depolarized state, that is associated with spontaneous simple spike firing (up state), and a quiescent hyperpolarized state (down state). A controversy has emerged regarding the relevance of bi-stability to the awake animal, yet recordings made from behaving cat Purkinje cells have demonstrated that at least 50% of the cells exhibit bi-modal firing. The robustness of the phenomenon in vitro or in anaesthetized systems on the one hand, and the controversy regarding its expression in behaving animals on the other hand suggest that state transitions are under neuronal control. Indeed, we have recently demonstrated that synaptic inputs can induce transitions between the states and suggested that the role of granule cell input is to control the states of Purkinje cells rather than increase or decrease firing rate gradually. We have also shown that the state of a Purkinje cell does not only affect its firing but also the waveform of climbing fiber-driven complex spikes and the associated calcium influx. These findings call for a reconsideration of the role of Purkinje cells in cerebellar function. In this manuscript we review the recent findings on Purkinje cell bi-stability and add some analyses of its effect on the regularity and variability of Purkinje cell activity.

Regularity, variabilty and bi-stability in the activity of cerebellar Purkinje cells

Directory of Open Access Journals (Sweden)

Dan Rokni

2009-11-01

Full Text Available Recent studies have demonstrated that the membrane potential of Purkinje cells is bi-stable and that this phenomenon underlies bi-modal simple spike firing. Membrane potential alternates between a depolarized state, that is associated with spontaneous simple spike firing (up state, and a quiescent hyperpolarized state (down state. A controversy has emerged regarding the relevance of bi-stability to the awake animal, yet recordings made from behaving cat Purkinje cells have demonstrated that at least 50% of the cells exhibit bi-modal firing. The robustness of the phenomenon in-vitro or in anaesthetized systems on the one hand, and the controversy regarding its expression in behaving animals on the other hand suggest that state transitions are under neuronal control. Indeed, we have recently demonstrated that synaptic inputs can induce transitions between the states and suggested that the role of granule cell input is to control the states of Purkinje cells rather than increase or decrease firing rate gradually. We have also shown that the state of a Purkinje cell does not only affect its firing but also the waveform of climbing fiber-driven complex spikes and the associated calcium influx. These findings call for a reconsideration of the role of Purkinje cells in cerebellar function. In this manuscript we review the recent findings on Purkinje cell bi-stability and add some analyses of its effect on the regularity and variability of Purkinje cell activity.

Lightweight Active Object Retrieval with Weak Classifiers

Directory of Open Access Journals (Sweden)

László Czúni

2018-03-01

Full Text Available In the last few years, there has been a steadily growing interest in autonomous vehicles and robotic systems. While many of these agents are expected to have limited resources, these systems should be able to dynamically interact with other objects in their environment. We present an approach where lightweight sensory and processing techniques, requiring very limited memory and processing power, can be successfully applied to the task of object retrieval using sensors of different modalities. We use the Hough framework to fuse optical and orientation information of the different views of the objects. In the presented spatio-temporal perception technique, we apply active vision, where, based on the analysis of initial measurements, the direction of the next view is determined to increase the hit-rate of retrieval. The performance of the proposed methods is shown on three datasets loaded with heavy noise.

Intercomparison of modal and sectional aerosol microphysics representations within the same 3-D global chemical transport model

Directory of Open Access Journals (Sweden)

G. W. Mann

2012-05-01

Full Text Available In the most advanced aerosol-climate models it is common to represent the aerosol particle size distribution in terms of several log-normal modes. This approach, motivated by computational efficiency, makes assumptions about the shape of the particle distribution that may not always capture the properties of global aerosol. Here, a global modal aerosol microphysics module (GLOMAP-mode is evaluated and improved by comparing against a sectional version (GLOMAP-bin and observations in the same 3-D global offline chemistry transport model. With both schemes, the model captures the main features of the global particle size distribution, with sub-micron aerosol approximately unimodal in continental regions and bi-modal in marine regions. Initial bin-mode comparisons showed that the current values for two size distribution parameter settings in the modal scheme (mode widths and inter-modal separation sizes resulted in clear biases compared to the sectional scheme. By adjusting these parameters in the modal scheme, much better agreement is achieved against the bin scheme and observations. Annual mean surface-level mass of sulphate, sea-salt, black carbon (BC and organic carbon (OC are within 25% in the two schemes in nearly all regions. Surface level concentrations of condensation nuclei (CN, cloud condensation nuclei (CCN, surface area density and condensation sink also compare within 25% in most regions. However, marine CCN concentrations between 30° N and 30° S are systematically 25–60% higher in the modal model, which we attribute to differences in size-resolved particle growth or cloud-processing. Larger differences also exist in regions or seasons dominated by biomass burning and in free-troposphere and high-latitude regions. Indeed, in the free-troposphere, GLOMAP-mode BC is a factor 2–4 higher than GLOMAP-bin, likely due to differences in size-resolved scavenging. Nevertheless, in most parts of the atmosphere, we conclude that bin

The new airfoil model NACA0015, modal analysis and flutter properties

Czech Academy of Sciences Publication Activity Database

Kozánek, Jan; Vlček, Václav; Zolotarev, Igor

2017-01-01

Roč. 46, June (2017), s. 698-706 ISSN 0307-904X Institutional support: RVO:61388998 Keywords : aeroelasticity * subsonic flow * self-excited vibration * modal analysis * kinematics Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 2.350, year: 2016 http://www.sciencedirect.com/science/article/pii/S0307904X1730135X

MINERVA: A multi-modality plug-in-based radiation therapy treatment planning system

International Nuclear Information System (INIS)

Wemple, C. A.; Wessol, D. E.; Nigg, D. W.; Cogliati, J. J.; Milvich, M.; Fredrickson, C. M.; Perkins, M.; Harkin, G. J.; Hartmann-Siantar, C. L.; Lehmann, J.; Flickinger, T.; Pletcher, D.; Yuan, A.; DeNardo, G. L.

2005-01-01

Researchers at the INEEL, MSU, LLNL and UCD have undertaken development of MINERVA, a patient-centric, multi-modal, radiation treatment planning system, which can be used for planning and analysing several radiotherapy modalities, either singly or combined, using common treatment planning tools. It employs an integrated, lightweight plug-in architecture to accommodate multi-modal treatment planning using standard interface components. The design also facilitates the future integration of improved planning technologies. The code is being developed with the Java programming language for inter-operability. The MINERVA design includes the image processing, model definition and data analysis modules with a central module to coordinate communication and data transfer. Dose calculation is performed by source and transport plug-in modules, which communicate either directly through the database or through MINERVA's openly published, extensible markup language (XML)-based application programmer's interface (API). All internal data are managed by a database management system and can be exported to other applications or new installations through the API data formats. A full computation path has been established for molecular-targeted radiotherapy treatment planning, with additional treatment modalities presently under development. (authors)

High-flexibility, noncollapsing lightweight hose

Science.gov (United States)

Williams, D.A.

1993-04-20

A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

Vibro-acoustics of lightweight sandwich structures

CERN Document Server

Lu, Tianjian

2014-01-01

Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

Predictive values of Bi-Rads categories 3, 4 and 5 in non-palpable breast masses evaluated by mammography, ultrasound and magnetic resonance imaging; Valores preditivos das categorias 3, 4 e 5 do sistema Bi-Rads em lesoes mamarias nodulares nao-palpaveis avaliadas por mamografia, ultra-sonografia e ressonancia magnetica

Energy Technology Data Exchange (ETDEWEB)

Roveda Junior, Decio; Fleury, Eduardo de Castro Faria [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas. Servico de Diagnostico por Imagem]. E-mail: decio.jr@uol.com.br; Piato, Sebastiao [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Clinica Ginecologica; Oliveira, Vilmar Marques de [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Ginecologia Geral; Rinaldi, Jose Francisco [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Clinica de Mastologia; Ferreira, Carlos Alberto Pecci [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Clinica Medica. Servico de Imagenologia Mamaria

2007-03-15

Objective: To evaluate the predictive value of BI-RADS{sup TM} categories 3, 4 and 5 in non-palpable breast masses assessed by mammography, ultrasound and magnetic resonance imaging. Materials And Methods: Twenty-nine patients with BI-RADS categories 3, 4 and 5 non-palpable breast masses identified by mammograms were submitted to complementary ultrasound and magnetic resonance imaging studies, besides excisional biopsy. In total, 30 biopsies were performed. The lesions as well as their respective BI-RADS classification into 3, 4 and 5 were correlated with the histopathological results. The predictive values calculation was made by means of specific mathematical equations. Results: Negative predictive values for category 3 were: mammography, 69.23%; ultrasound, 70.58%; and magnetic resonance imaging, 100%. Positive predictive values for category 4 were: mammography, 63.63%; ultrasound, 50%; and magnetic resonance imaging, 30.76%. For category 5, positive predictive values were: mammography and ultrasound, 100%; and magnetic resonance imaging, 92.85%. Conclusion: For category 3, the negative predictive value of magnetic resonance imaging was high, and for categories 4 and 5, the positive predictive values of the three modalities were moderate. (author)

Cryptanalysis of Some Lightweight Symmetric Ciphers

DEFF Research Database (Denmark)

Abdelraheem, Mohamed Ahmed Awadelkareem Mohamed Ahmed

In recent years, the need for lightweight encryption systems has been increasing as many applications use RFID and sensor networks which have a very low computational power and thus incapable of performing standard cryptographic operations. In response to this problem, the cryptographic community...... on a variant of PRESENT with identical round keys. We propose a new attack named the Invariant Subspace Attack that was specifically mounted against the lightweight block cipher PRINTcipher. Furthermore, we mount several attacks on a recently proposed stream cipher called A2U2....... of the international standards in lightweight cryptography. This thesis aims at analyzing and evaluating the security of some the recently proposed lightweight symmetric ciphers with a focus on PRESENT-like ciphers, namely, the block cipher PRESENT and the block cipher PRINTcipher. We provide an approach to estimate...

Design optimization of the distributed modal filtering rod fiber for increasing single mode bandwidth

DEFF Research Database (Denmark)

Jørgensen, Mette Marie; Petersen, Sidsel Rübner; Laurila, Marko

2012-01-01

. Large preform tolerances are compensated during the fiber draw resulting in ultra low NA fibers with very large cores. In this paper, design optimization of the SM bandwidth of the DMF rod fiber is presented. Analysis of band gap properties results in a fourfold increase of the SM bandwidth compared...... LMA fiber amplifiers having high pump absorption through a pump cladding that is decoupled from the outer fiber. However, achieving ultra low NA for single-mode (SM) guidance is challenging, and thus different design strategies must be applied to filter out higher order modes (HOMs). The novel...... distributed modal filtering (DMF) design presented here enables SM guidance, and previous results have shown a SM mode field diameter of 60 μm operating in a 20 nm SM bandwidth. The DMF rod fiber has high index ring-shaped inclusions acting as resonators enabling SM guidance through modal filtering of HOMs...

Investigation on Wall Panel Sandwiched With Lightweight Concrete

Science.gov (United States)

Lakshmikandhan, K. N.; Harshavardhan, B. S.; Prabakar, J.; Saibabu, S.

2017-08-01

The rapid population growth and urbanization have made a massive demand for the shelter and construction materials. Masonry walls are the major component in the housing sector and it has brittle characteristics and exhibit poor performance against the uncertain loads. Further, the structure requires heavier sections for carrying the dead weight of masonry walls. The present investigations are carried out to develop a simple, lightweight and cost effective technology for replacing the existing wall systems. The lightweight concrete is developed for the construction of sandwich wall panel. The EPS (Expanded Polystyrene) beads of 3 mm diameter size are mixed with concrete and developed a lightweight concrete with a density 9 kN/m3. The lightweight sandwich panel is cast with a lightweight concrete inner core and ferrocement outer skins. This lightweight wall panel is tested for in-plane compression loading. A nonlinear finite element analysis with damaged plasticity model is carried out with both material and geometrical nonlinearities. The experimental and analytical results were compared. The finite element study predicted the ultimate load carrying capacity of the sandwich panel with reasonable accuracy. The present study showed that the lightweight concrete is well suitable for the lightweight sandwich wall panels.

FY2016 Lightweight Materials Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-10-31

The Lightweight Materials research and development (R&D) area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing lightweight materials for passenger and commercial vehicles. This report describes the progress made on the research and development projects funded by the Lightweight Materials area.

LIGHT-WEIGHT LOAD-BEARING STRUCTURE

DEFF Research Database (Denmark)

2009-01-01

The invention relates to a light-weight load-bearing structure (1) with optimized compression zone (2), where along one or more compression zones (2) in the structure (1) to be cast a core (3) of strong concrete is provided, which core (3) is surrounded by concrete of less strength (4) compared...... to the core (3) of strong concrete. The invention also relates to a method of casting of light-weight load-bearing structures (1) with optimized compression zone (2) where one or more channels, grooves, ducts, pipes and/or hoses (5) formed in the load-bearing structure (1) serves as moulds for moulding one...... or more cores (3) of strong concrete in the light-weight load-bearing structure (1)....

An ultra-lightweight design for imperceptible plastic electronics.

Science.gov (United States)

Kaltenbrunner, Martin; Sekitani, Tsuyoshi; Reeder, Jonathan; Yokota, Tomoyuki; Kuribara, Kazunori; Tokuhara, Takeyoshi; Drack, Michael; Schwödiauer, Reinhard; Graz, Ingrid; Bauer-Gogonea, Simona; Bauer, Siegfried; Someya, Takao

2013-07-25

Electronic devices have advanced from their heavy, bulky origins to become smart, mobile appliances. Nevertheless, they remain rigid, which precludes their intimate integration into everyday life. Flexible, textile and stretchable electronics are emerging research areas and may yield mainstream technologies. Rollable and unbreakable backplanes with amorphous silicon field-effect transistors on steel substrates only 3 μm thick have been demonstrated. On polymer substrates, bending radii of 0.1 mm have been achieved in flexible electronic devices. Concurrently, the need for compliant electronics that can not only be flexed but also conform to three-dimensional shapes has emerged. Approaches include the transfer of ultrathin polyimide layers encapsulating silicon CMOS circuits onto pre-stretched elastomers, the use of conductive elastomers integrated with organic field-effect transistors (OFETs) on polyimide islands, and fabrication of OFETs and gold interconnects on elastic substrates to realize pressure, temperature and optical sensors. Here we present a platform that makes electronics both virtually unbreakable and imperceptible. Fabricated directly on ultrathin (1 μm) polymer foils, our electronic circuits are light (3 g m(-2)) and ultraflexible and conform to their ambient, dynamic environment. Organic transistors with an ultra-dense oxide gate dielectric a few nanometres thick formed at room temperature enable sophisticated large-area electronic foils with unprecedented mechanical and environmental stability: they withstand repeated bending to radii of 5 μm and less, can be crumpled like paper, accommodate stretching up to 230% on prestrained elastomers, and can be operated at high temperatures and in aqueous environments. Because manufacturing costs of organic electronics are potentially low, imperceptible electronic foils may be as common in the future as plastic wrap is today. Applications include matrix-addressed tactile sensor foils for health care and

Compliant lightweight non-invasive standalone “Marine Skin” tagging system

KAUST Repository

Nassar, Joanna M.

2018-04-16

Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment, including the diverse fauna it contains, as a function of animal behavior and size, as well as equipment longevity. To match animal morphology and activity within the surrounding marine environment, here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system, integrating Bluetooth, memory chip, and high performance physical sensors. The sensory tag is mounted on a swimming crab (Portunus pelagicus) and is capable of continuous logging of depth, temperature, and salinity within the harsh ocean environment. The fully packaged, ultra-lightweight (<2.4 g in water), and compliant “Marine Skin” system does not have any wired connection enabling safe and weightless cutting-edge approach to monitor and assess marine life and the ecosystem’s health to support conservation and management of marine ecosystems.

Mix design and properties of fly ash waste lightweight aggregates in structural lightweight concrete

Directory of Open Access Journals (Sweden)

Manu S. Nadesan

2017-12-01

Full Text Available Concrete is one of the most widely used construction materials and has the ability to consume industrial wastes in high volume. As the demand for concrete is increasing, one of the effective ways to reduce the undesirable environmental impact of the concrete is by the use of waste and by-product materials as cement and aggregate substitutes in concrete. One such waste material is fly ash, which is produced in large quantities from thermal power plants as a by-product. A substantial amount of fly ash is left unused posing environmental and storage problems. The production of sintered lightweight aggregate with fly ash is an effective method to dispose of fly ash in large quantities. Due to lack of a proper mix design procedure, the production and application of lightweight aggregate in structural concrete are not much entertained. The absorption characteristic of lightweight aggregate is a major concern, while developing the mix proportioning of lightweight concretes. The present study is an attempt to establish a new mix design procedure for the development of sintered fly ash lightweight aggregate concretes, which is simple and more reliable than the existing procedures. Also, the proposed methodology has been validated by developing a spectrum of concretes having water cement ratios varying from 0.25 to 0.75. From the study, it is obvious that the development of 70 MPa concrete is possible by using cement alone without any additives. Also, it is ensured that all the concretes have densities less than 2000 kg/m3.

Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

NARCIS (Netherlands)

Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

1998-01-01

At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

NARCIS (Netherlands)

Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

1999-01-01

At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

Security Isolation Strategy Mechanism for Lightweight Virtualization Environment

Directory of Open Access Journals (Sweden)

Liu Qian

2017-01-01

Full Text Available For cloud service providers, lightweight virtualization is a more economical way of virtualization. While the user is worried about the safety of applications and data of the container, due to the container sharing the underlying interface and the kernel, therefore the security and trusted degree of lightweight virtualization container isolation mechanism is critical for the promotion of lightweight virtualization service. Because the user cannot directly participate in the process of the construction and management of container isolation mechanism, it is difficult for them to establish confidence in the security and trusted degree of container isolation mechanism. Based on the research and analysis of system credible and virtualization isolation mechanism, this paper puts forward a set of lightweight virtualization security isolation strategy mechanism, divides lightweight virtualization container storage address space into several parts, puts forward the definition of lightweight virtualization security isolation, gives the formal description and proof of container security isolation strategy, and combines with related technology to verify the feasibility of lightweight virtualization security isolation strategy mechanism. The mechanism has important guiding significance for cloud services providers to deploy container security isolation.

Ultra-light-weight high torque density brushless PM machine design: considering driving-cycle of a four-wheel drive race car (EVER15-138)

NARCIS (Netherlands)

Paulides, J.J.H.; Encica, L.; Beernaert, T.F.; Velden, van der H.H.F.; Parfant, A.G.P.; Lomonova, E.A.

2015-01-01

This paper explores the design of an ultra-light-weight power and torque dense motor to enhance the performance of a light-weight electric racing vehicle. Such a racing vehicle is to compete in formula student racing events. The state-of-the-art powertrain in these vehicles are axial-field machines

Synthesis and Mechanical Characterisation of an Ultra-Fine Grained Ti-Mg Composite

Directory of Open Access Journals (Sweden)

Markus Alfreider

2016-08-01

Full Text Available The importance of lightweight materials such as titanium and magnesium in various technical applications, for example aerospace, medical implants and lightweight construction is well appreciated. The present study is an attempt to combine and improve the mechanical properties of these two materials by forming an ultra-fine grained composite. The material, with a composition of 75 vol% (88.4 wt% Ti and 25 vol% (11.4 wt% Mg , was synthesized by powder compression and subsequently deformed by high-pressure torsion. Using focused ion beam machining, miniaturised compression samples were prepared and tested in-situ in a scanning electron microscope to gain insights into local deformation behaviour and mechanical properties of the nanocomposite. Results show outstanding yield strength of around 1250 MPa, which is roughly 200 to 500 MPa higher than literature reports of similar materials. The failure mode of the samples is accounted for by cracking along the phase boundaries.

The modular modality frame model: continuous body state estimation and plausibility-weighted information fusion.

Science.gov (United States)

Ehrenfeld, Stephan; Butz, Martin V

2013-02-01

Humans show admirable capabilities in movement planning and execution. They can perform complex tasks in various contexts, using the available sensory information very effectively. Body models and continuous body state estimations appear necessary to realize such capabilities. We introduce the Modular Modality Frame (MMF) model, which maintains a highly distributed, modularized body model continuously updating, modularized probabilistic body state estimations over time. Modularization is realized with respect to modality frames, that is, sensory modalities in particular frames of reference and with respect to particular body parts. We evaluate MMF performance on a simulated, nine degree of freedom arm in 3D space. The results show that MMF is able to maintain accurate body state estimations despite high sensor and motor noise. Moreover, by comparing the sensory information available in different modality frames, MMF can identify faulty sensory measurements on the fly. In the near future, applications to lightweight robot control should be pursued. Moreover, MMF may be enhanced with neural encodings by introducing neural population codes and learning techniques. Finally, more dexterous goal-directed behavior should be realized by exploiting the available redundant state representations.

Lightweight Composite Materials for Heavy Duty Vehicles

Energy Technology Data Exchange (ETDEWEB)

Pruez, Jacky; Shoukry, Samir; Williams, Gergis; Shoukry, Mark

2013-08-31

The main objective of this project is to develop, analyze and validate data, methodologies and tools that support widespread applications of automotive lightweighting technologies. Two underlying principles are guiding the research efforts towards this objective: • Seamless integration between the lightweight materials selected for certain vehicle systems, cost-effective methods for their design and manufacturing, and practical means to enhance their durability while reducing their Life-Cycle-Costs (LCC). • Smooth migration of the experience and findings accumulated so far at WVU in the areas of designing with lightweight materials, innovative joining concepts and durability predictions, from applications to the area of weight savings for heavy vehicle systems and hydrogen storage tanks, to lightweighting applications of selected systems or assemblies in light–duty vehicles.

Lightweight Phase-Change Material For Solar Power

Science.gov (United States)

Stark, Philip

1993-01-01

Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

Energy Technology Data Exchange (ETDEWEB)

Abbasi, R.; Othman, M. Abou Bakr [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Allen, C. [University of Kansas, Lawrence, KS 66045 (United States); Beard, L. [Purdue University, West Lafayette, IN 47907 (United States); Belz, J. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Besson, D. [University of Kansas, Lawrence, KS 66045 (United States); Moscow Engineering and Physics Institute, 31 Kashirskaya Shosse, Moscow 115409 (Russian Federation); Byrne, M.; Farhang-Boroujeny, B.; Gardner, A. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT 84106 (United States); Hanlon, W. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Hanson, J. [University of Kansas, Lawrence, KS 66045 (United States); Jayanthmurthy, C. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Kunwar, S. [University of Kansas, Lawrence, KS 66045 (United States); Larson, S.L. [Utah State University, Logan, Utah 84322 (United States); Myers, I., E-mail: isaac@cosmic.utah.edu [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Prohira, S.; Ratzlaff, K. [University of Kansas, Lawrence, KS 66045 (United States); Sokolsky, P. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Takai, H. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

2014-12-11

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

International Nuclear Information System (INIS)

Abbasi, R.; Othman, M. Abou Bakr; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W.H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S.L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Takai, H.

2014-01-01

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

Science.gov (United States)

Abbasi, R.; Othman, M. Abou Bakr; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W. H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S. L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Takai, H.; Thomson, G. B.; Von Maluski, D.

2014-12-01

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest "conventional" cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

Ultra-micro trace element contents in spices from Sri Lanka

International Nuclear Information System (INIS)

Chery, C.C.; Herremans, S.; Van Lierde, V.; Vanhaecke, F.; Jasekera, R.

2008-01-01

Spices were analyzed by ICP-MS for determination of the ultra-micro trace elements in the human adult, Bi, Cd, Co, Ni, Pd, Pt, Se, Sn, Te, Tl, to complement previous results obtained by INAA and by EDXRF. The spices, originating from Sri Lanka, were curry, chilli powder and turmeric powders, coriander, cinnamon, black pepper, fennel, rampeh and curry leaves, and cumin. The analytical procedure was validated by analyzing the certified reference materials NIST SRM 1572 Citrus Leaves and NIST SRM 1573 Tomato Leaves. The results indicate that spices may contribute well to the daily optimal uptake of nutrients of a human adult. The adequacy of spices as a reference material with certified ultra micro trace elements is suggested. (author)

Lightweight males of Podisus nigrispinus (Heteroptera: Pentatomidae neglect lightweight females due low reproductive fitness

Directory of Open Access Journals (Sweden)

A. I. A. Pereira

Full Text Available Abstract Sexual choice by male stink bugs is important because females that experience food shortages lay fewer eggs with lower viability compared with well-fed females. In this study, we investigated whether Podisus nigrispinus (Dallas (Heteroptera: Pentatomidae males fed with a low-quality diet during its nymphal stage show selectivity for sexual partners resulting in high-quality progeny. Lightweight males and females were obtained from nymphs fed weekly with Tenebrio molitor L. (Coleoptera: Tenebrionidae pupae. By contrast, heavyweight males and females were fed three times a week and received an extra nutritional source: cotton leaves, Gossypium hirsutum L. (Malvaceae. Lightweight males preferred to mate with heavy females (77.78 ± 14.69%, whereas heavyweight males did not discriminated between light or heavyweight females. Females mated with lightweight males showed similar levels of reproduction to those mated with heavyweight males. The results provide an indication of the importance of male and female body weight for sexual selection in Asopinae stink bugs.

Positive Predictive Value of BI-RADS Categorization in an Asian Population

Directory of Open Access Journals (Sweden)

Yah-Yuen Tan

2004-07-01

Full Text Available The Breast Imaging Reporting And Data System (BI-RADS categorization of mammograms is useful in estimating the risk of malignancy, thereby guiding management decisions. However, in Asian women, in whom breast density is increased, the sensitivity of mammography is correspondingly lower. We sought to determine the positive predictive value of BI-RADS categorization for malignancy in our Asian population and, hence, its value in helping us to choose between the various modalities for breast biopsy. We retrospectively reviewed all patients with occult breast lesions detected on mammography or ultrasound who underwent needle-localization open breast biopsy (NLOB in our institution over a 6-year period. There were 470 biopsies in 427 patients; 16% of lesions were malignant. The positive predictive value of BI-RADS 4 and 5 lesions for cancer was 0.27 and 0.84, respectively. While most BI-RADS 5 mass lesions were invasive cancers, the majority of calcifications in this category were in situ carcinomas. We conclude that BI-RADS remains useful in aiding decision-making for biopsy in our Asian population. Based on positive predictive values, we recommend percutaneous breast biopsy for initial evaluation of lesions categorized as BI-RADS 4 or less. For BI-RADS 5 lesions with microcalcifications, open surgical biopsy as a diagnostic and therapeutic procedure may be more appropriate. In the case of a BI-RADS 5 lesion associated with a mass, initial percutaneous biopsy may be useful for diagnosis, followed by a planned single-stage surgical procedure as necessary.

Carbody structural lightweighting based on implicit parameterized model

Science.gov (United States)

Chen, Xin; Ma, Fangwu; Wang, Dengfeng; Xie, Chen

2014-05-01

Most of recent research on carbody lightweighting has focused on substitute material and new processing technologies rather than structures. However, new materials and processing techniques inevitably lead to higher costs. Also, material substitution and processing lightweighting have to be realized through body structural profiles and locations. In the huge conventional workload of lightweight optimization, model modifications involve heavy manual work, and it always leads to a large number of iteration calculations. As a new technique in carbody lightweighting, the implicit parameterization is used to optimize the carbody structure to improve the materials utilization rate in this paper. The implicit parameterized structural modeling enables the use of automatic modification and rapid multidisciplinary design optimization (MDO) in carbody structure, which is impossible in the traditional structure finite element method (FEM) without parameterization. The structural SFE parameterized model is built in accordance with the car structural FE model in concept development stage, and it is validated by some structural performance data. The validated SFE structural parameterized model can be used to generate rapidly and automatically FE model and evaluate different design variables group in the integrated MDO loop. The lightweighting result of body-in-white (BIW) after the optimization rounds reveals that the implicit parameterized model makes automatic MDO feasible and can significantly improve the computational efficiency of carbody structural lightweighting. This paper proposes the integrated method of implicit parameterized model and MDO, which has the obvious practical advantage and industrial significance in the carbody structural lightweighting design.

Experimental study on microstructure characters of foamed lightweight soil

Science.gov (United States)

Qiu, Youqiang; Li, Yongliang; Li, Meixia; Liu, Yaofu; Zhang, Liujun

2018-01-01

In order to verify the microstructure of foamed lightweight soil and its characters of compressive strength, four foamed lightweight soil samples with different water-soild ratio were selected and the microstructure characters of these samples were scanned by electron microscope. At the same time, the characters of compressive strength of foamed lightweight soil were analyzed from the microstructure. The study results show that the water-soild ratio has a prominent effect on the microstructure and compressive strength of foamed lightweight soil, with the decrease of water-solid ratio, the amount and the perforation of pores would be reduced significantly, thus eventually forming a denser and fuller interior structure. Besides, the denser microstructure and solider pore-pore wall is benefit to greatly increase mechanical intensity of foamed lightweight soil. In addition, there are very few acicular ettringite crystals in the interior of foamed lightweight soil, its number is also reduced with the decrease in water-soild ratio.

ULTRA-FAINT DWARF GALAXIES AS A TEST OF EARLY ENRICHMENT AND METALLICITY-DEPENDENT STAR FORMATION

International Nuclear Information System (INIS)

Tassis, Konstantinos; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

2012-01-01

The close relation of star formation with molecular gas indicated by observations and assumed in recent models implies that the efficiency with which galaxies convert their gas into stars depends on gas metallicity. This is because abundance of molecular hydrogen is sensitive to abundance of dust, which catalyzes formation of H 2 and helps to shield it from dissociating radiation. In this study, we point out that in the absence of significant pre-enrichment by Population III stars forming out of zero metallicity gas, such H 2 -based star formation is expected to leave an imprint in the form of bi-modality in the metallicity distribution among dwarf galaxies and in the metallicity distribution of stars within individual galaxies. The bi-modality arises because when gas metallicity (and dust abundance) is low, formation of molecular gas is inefficient, the gas consumption timescale is long, and star formation and metal enrichment proceed slowly. When metallicity reaches a critical threshold value star formation and enrichment accelerate, which leads to rapid increase in both stellar mass and metallicity of galaxies. We demonstrate this process both using a simple analytical model and full cosmological simulations. In contrast, the observed metallicity distributions of dwarf galaxies or stars within them are not bi-modal. We argue that this discrepancy points to substantial early stochastic pre-enrichment by Population III stars to levels Z ∼ 10 –2 Z ☉ in dense, star-forming regions of early galaxies.

Selective laser melting of hypereutectic Al-Si40-powder using ultra-short laser pulses

Science.gov (United States)

Ullsperger, T.; Matthäus, G.; Kaden, L.; Engelhardt, H.; Rettenmayr, M.; Risse, S.; Tünnermann, A.; Nolte, S.

2017-12-01

We investigate the use of ultra-short laser pulses for the selective melting of Al-Si40-powder to fabricate complex light-weight structures with wall sizes below 100 μ {m} combined with higher tensile strength and lower thermal expansion coefficient in comparison to standard Al-Si alloys. During the cooling process using conventional techniques, large primary silicon particles are formed which impairs the mechanical and thermal properties. We demonstrate that these limitations can be overcome using ultra-short laser pulses enabling the rapid heating and cooling in a non-thermal equilibrium process. We analyze the morphology characteristics and micro-structures of single tracks and thin-walled structures depending on pulse energy, repetition rate and scanning velocity utilizing pulses with a duration of 500 {fs} at a wavelength of 1030 {nm}. The possibility to specifically change and optimize the microstructure is shown.

Microstructure, mechanical properties, castability and in vitro biocompatibility of Ti-Bi alloys developed for dental applications.

Science.gov (United States)

Qiu, K J; Liu, Y; Zhou, F Y; Wang, B L; Li, L; Zheng, Y F; Liu, Y H

2015-03-01

In this study, the microstructure, mechanical properties, castability, electrochemical behaviors, cytotoxicity and hemocompatibility of Ti-Bi alloys with pure Ti as control were systematically investigated to assess their potential applications in the dental field. The experimental results showed that, except for the Ti-20Bi alloy, the microstructure of all other Ti-Bi alloys exhibit single α-Ti phase, while Ti-20Bi alloy is consisted of mainly α-Ti phase and a small amount of BiTi2 and BiTi3 phases. The tensile strength, hardness and wear resistance of Ti-Bi alloys were demonstrated to be improved monotonically with the increase of Bi content. The castability test showed that Ti-2Bi alloy increased the castability of pure Ti by 11.7%. The studied Ti-Bi alloys showed better corrosion resistance than pure Ti in both AS (artificial saliva) and ASFL (AS containing 0.2% NaF and 0.3% lactic acid) solutions. The concentrations of both Ti ion and Bi ion released from Ti-Bi alloys are extremely low in AS, ASF (AS containing 0.2% NaF) and ASL (AS containing 0.3% lactic acid) solutions. However, in ASFL solution, a large number of Ti and Bi ions are released. In addition, Ti-Bi alloys produced no significant deleterious effect to L929 cells and MG63 cells, similar to pure Ti, indicating a good in vitro biocompatibility. Besides, both L929 and MG63 cells perform excellent cell adhesion ability on Ti-Bi alloys. The hemolysis test exhibited that Ti-Bi alloys have an ultra-low hemolysis percentage below 1% and are considered nonhemolytic. To sum up, the Ti-2Bi alloy exhibits the optimal comprehensive performance and has great potential for dental applications. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Infinte Periodic Structure of Lightweight Elements

DEFF Research Database (Denmark)

Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

2013-01-01

Lightweight wooden structures have become more popular as a sustainable, environmental- friendly and cost-effective alternative to concrete, steel and masonry buildings. However, there are certain drawbacks regarding noise and vibration due to the smaller weight and stiffness of wooden buildings....... Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two...

Preparation and characterization of PtRu/C, PtBi/C, PtRuBi/C electrocatalysts for direct electro-oxidation of ethanol in PEM fuels cells using the method of reduction by sodium borohydride

International Nuclear Information System (INIS)

Brandalise, Michele

2010-01-01

Pt/C, PtBi/C, PtRu/C and PtRuBi/C electrocatalysts were prepared by a borohydride reduction methodology and tested for ethanol oxidation. This methodology consists in mix a solution with sodium hydroxide and sodium borohydride to a mixture containing water/isopropyl alcohol, metallic precursors and the Vulcan XC 72 carbon support. It was studied the addition method of borohydride (drop by drop addition or rapid addition). The obtained electrocatalysts were characterized by energy dispersive X ray spectroscopy (EDX), thermogravimetric analysis (TGA), X ray diffraction (XRD), transmission electron microscope (TEM) and cyclic voltammetry. The ethanol electro-oxidation was studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were tested in real conditions of operation by unit cell tests. The stability of PtRuBi/C electrocatalysts was evaluated by cyclic voltammetry, chronoamperometry using the ultra-thin porous coating technique and ring-disk electrode. The PtRuBi/C electro catalyst apparently presented a good performance for ethanol electro-oxidation but experimental evidences showed accentuated bismuth dissolution. (author)

Experimental Study on Fatigue Performance of Foamed Lightweight Soil

Science.gov (United States)

Qiu, Youqiang; Yang, Ping; Li, Yongliang; Zhang, Liujun

2017-12-01

In order to study fatigue performance of foamed lightweight soil and forecast its fatigue life in the supporting project, on the base of preliminary tests, beam fatigue tests on foamed lightweight soil is conducted by using UTM-100 test system. Based on Weibull distribution and lognormal distribution, using the mathematical statistics method, fatigue equations of foamed lightweight soil are obtained. At the same time, according to the traffic load on real road surface of the supporting project, fatigue life of formed lightweight soil is analyzed and compared with the cumulative equivalent axle loads during the design period of the pavement. The results show that even the fatigue life of foamed lightweight soil has discrete property, the linear relationship between logarithmic fatigue life and stress ratio still performs well. Especially, the fatigue life of Weibull distribution is more close to that derived from the lognormal distribution, in the instance of 50% guarantee ratio. In addition, the results demonstrated that foamed lightweight soil as subgrade filler has good anti-fatigue performance, which can be further adopted by other projects in the similar research domain.

Lightweight, Thermally Insulating Structural Panels

Science.gov (United States)

Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

1996-01-01

Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

InP-DHBT-on-BiCMOS technology with fT/fmax of 400/350 GHz for heterogeneous integrated millimeter-wave sources

DEFF Research Database (Denmark)

Kraemer, Tomas; Ostermay, Ina; Jensen, Thomas

2013-01-01

-100 GHz. The 0.8 × 5 μm2 InP DHBTs show fT/fmax of 400/350 GHz with an output power of more than 26 mW at 96 GHz. These are record values for a heterogeneously integrated transistor on silicon. As a circuit example, a 164-GHz signal source is presented. It features a voltage-controlled oscillator in Bi......This paper presents a novel InP-SiGe BiCMOS technology using wafer-scale heterogeneous integration. The vertical stacking of the InP double heterojunction bipolar transistor (DHBT) circuitry directly on top of the BiCMOS wafer enables ultra-broadband interconnects with

Millimeter-wave silicon-based ultra-wideband automotive radar transceivers

Science.gov (United States)

Jain, Vipul

Since the invention of the integrated circuit, the semiconductor industry has revolutionized the world in ways no one had ever anticipated. With the advent of silicon technologies, consumer electronics became light-weight and affordable and paved the way for an Information-Communication-Entertainment age. While silicon almost completely replaced compound semiconductors from these markets, it has been unable to compete in areas with more stringent requirements due to technology limitations. One of these areas is automotive radar sensors, which will enable next-generation collision-warning systems in automobiles. A low-cost implementation is absolutely essential for widespread use of these systems, which leads us to the subject of this dissertation---silicon-based solutions for automotive radars. This dissertation presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors. The first CMOS 22-29-GHz pulse-radar receiver front-end for ultra-wideband radars is presented. The chip includes a low noise amplifier, I/Q mixers, quadrature voltage-controlled oscillators, pulse formers and variable-gain amplifiers. Fabricated in 0.18-mum CMOS, the receiver achieves a conversion gain of 35-38.1 dB and a noise figure of 5.5-7.4 dB. Integration of multi-mode multi-band transceivers on a single chip will enable next-generation low-cost automotive radar sensors. Two highly-integrated silicon ICs are designed in a 0.18-mum BiCMOS technology. These designs are also the first reported demonstrations of mm-wave circuits with high-speed digital circuits on the same chip. The first mm-wave dual-band frequency synthesizer and transceiver, operating in the 24-GHz and 77-GHz bands, are demonstrated. All

Lightweight Cryptography for Passive RFID Tags

DEFF Research Database (Denmark)

David, Mathieu

2012-01-01

were mostly unsatisfactory. As a conclusion, a new branch of cryptography, commonly called Lightweight Cryptography, emerged to address the issues of these tiny ubiquitous devices. This Thesis presents a comprehensive engineering to lightweight cryptography, proposes a classification and explores its...... various ramifications by giving key examples in each of them. We select two of these branches, ultralightweight cryptography and symmetric-key cryptography, and propose a cryptographic primitive in each of them. In the case of symmetric-key cryptography, we propose a stream cipher that has a footprint...... of an integrator for a particular application. Finally, we conclude that the research for finding robust cryptographic primitive in the branch of lightweight cryptography still has some nice days ahead, and that providing a secure cryptosystem for printed electronics RFID tags remains an open research topic....

FY2015 Lightweight Materials R&D Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-09-30

The Lightweight Materials research and development (R&D) area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing lightweight materials for passenger and commercial vehicles. This report describes the progress made on the research and development projects funded by the Lightweight Materials area.

Vehicle Lightweighting: Mass Reduction Spectrum Analysis and Process Cost Modeling

Energy Technology Data Exchange (ETDEWEB)

Mascarin, Anthony [IBIS Associates, Inc., Waltham, MA (United States); Hannibal, Ted [IBIS Associates, Inc., Waltham, MA (United States); Raghunathan, Anand [Energetics Inc., Columbia, MD (United States); Ivanic, Ziga [Energetics Inc., Columbia, MD (United States); Clark, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-03-01

The U.S. Department of Energy’s Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. In the first two phases of this effort examined combinations of strategies aimed at achieving strategic targets of 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. These results have been reported in the Idaho National Laboratory report INL/EXT-14-33863 entitled Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting published in March 2015. The data for these strategies were drawn from many sources, including Lotus Engineering Limited and FEV, Inc. lightweighting studies, U.S. Department of Energy-funded Vehma International of America, Inc./Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, many United States Council for Automotive Research’s/United States Automotive Materials Partnership LLC lightweight materials programs, and IBIS Associates, Inc.’s decades of experience in automotive lightweighting and materials substitution analyses.

Vehicle Lightweighting: Mass Reduction Spectrum Analysis and Process Cost Modeling

International Nuclear Information System (INIS)

Mascarin, Anthony; Hannibal, Ted; Raghunathan, Anand; Ivanic, Ziga; Clark, Michael

2016-01-01

The U.S. Department of Energy's Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. In the first two phases of this effort examined combinations of strategies aimed at achieving strategic targets of 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. These results have been reported in the Idaho National Laboratory report INL/EXT-14-33863 entitled Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting published in March 2015. The data for these strategies were drawn from many sources, including Lotus Engineering Limited and FEV, Inc. lightweighting studies, U.S. Department of Energy-funded Vehma International of America, Inc./Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, many United States Council for Automotive Research's/United States Automotive Materials Partnership LLC lightweight materials programs, and IBIS Associates, Inc.'s decades of experience in automotive lightweighting and materials substitution analyses.

Broad band and enhanced photocatalytic behaviour of Ho3+-doped Bi2O3 micro-rods

Science.gov (United States)

Prasad, Neena; Karthikeyan, Balasubramanian

2018-06-01

Band-gap-tuned Bi2O3 micro-rods were synthesized using simple co-precipitation method by doping 5 wt% Ho3+ to mitigate the concentration of toxic dye from the polluted water using it as a photocatalyst. Structure and morphology of the prepared samples were identified using powder X-ray diffraction technique and scanning electron microscopy (SEM). Elemental composition and chemical state of the prepared samples were analyzed from the X-ray photoelectron spectroscopy (XPS). Considerable absorption in IR region was observed for Ho3+ doped Bi2O3 due to the electronic transitions of 5I8→5F4, 5I8→5F5, and 5I8→5I5, 5I6. The excellent ultra-violet (UV), white and infrared light (IR)-driven photocatalytic activity were suggested for pure and doped Bi2O3 samples. Ho3+-doped Bi2O3 micro-rods exhibits a better photocatalytic activity under white light irradiation. The consequence of the bandgap and the synergetic effect of Ho3+ and Bi2O3 on the photocatalytic degradation of MB were investigated.

Atmospheric profiles of Black Carbon at remote locations using light-weight airborne Aethalometers

Science.gov (United States)

Hansen, A. D.; Močnik, G.; Drinovec, L.; Lenarcic, M.

2012-12-01

While measurements of atmospheric aerosols are routinely performed at ground-level around the world, there is far less knowledge of their concentrations at altitude: yet this data is a crucial requirement for our understanding of the dispersion of pollutants of anthropogenic origin, with their associated effects on radiative forcing, cloud condensation, and other adverse phenomena. Black Carbon (BC) is a unique tracer for combustion emissions, and can be detected rapidly and with great sensitivity by filter-based optical methods. It has no non-combustion sources and is not transformed by atmospheric processes. Recent technical advances have developed light-weight miniaturized instruments which can be operated on light aircraft or carried aboard commercial passenger flights. From January to April 2012, a single-seat ultra-light aircraft flew around the world on a scientific, photographic and environmental-awareness mission. The flight track crossed all seven continents and all major oceans, with altitudes up to 8.9 km ASL. The aircraft carried a custom-developed high-sensitivity dual-wavelength light-weight Aethalometer, operating at 370 and 880 nm with special provision to compensate for the effects of changing pressure, temperature and humidity. The instrument recorded BC concentrations with high temporal resolution and sensitivity better than 5 ng/m3. We present examples of data from flight tracks over remote oceans, uninhabited land masses, and densely populated areas, analyzing the spectral dependence of absorption to infer the contributions to BC from fossil fuel vs. biomass combustion, and aggregating the data into vertical profiles. The regional and long range transport of BC may be investigated using back-trajectories. We have also operated miniature instruments in the passenger cabins of long-distance commercial aircraft. Since there are no combustion sources within the cabin, any BC in the ventilation air must necessarily have originated from the outside

High Speed, Low Cost Telemetry Access from Space Development Update on Programmable Ultra Lightweight System Adaptable Radio (PULSAR)

Science.gov (United States)

Simms, William Herbert, III; Varnavas, Kosta; Eberly, Eric

2014-01-01

Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 1990's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast, the foundations of transponder technology presently qualified for satellite applications were developed during the early space program of the 1960's. Conventional transponders are built to a specific platform and must be redesigned for every new bus while the SDR is adaptive in nature and can fit numerous applications with no hardware modifications. A SDR uses a minimum amount of analog / Radio Frequency (RF) components to up/down-convert the RF signal to/from a digital format. Once the signal is digitized, all processing is performed using hardware or software logic. Typical SDR digital processes include; filtering, modulation, up/down converting and demodulation. NASA Marshall Space Flight Center (MSFC) Programmable Ultra Lightweight System Adaptable Radio (PULSAR) leverages existing MSFC SDR designs and commercial sector enhanced capabilities to provide a path to a radiation tolerant SDR transponder. These innovations (1) reduce the cost of NASA Low Earth Orbit (LEO) and Deep Space standard transponders, (2) decrease power requirements, and (3) commensurately reduce volume. A second pay-off is the increased SDR flexibility by allowing the same hardware to implement multiple transponder types simply by altering hardware logic - no change of hardware is required - all of which will ultimately be accomplished in orbit. Development of SDR technology for space applications will provide a highly capable, low cost transponder to programs of all sizes. The MSFC PULSAR Project results in a Technology Readiness Level (TRL) 7 low-cost telemetry system available to Smallsat and CubeSat missions, as well as other platforms. This paper documents the continued development and

Similarities and differences in anthropometry and training between recreational male 100-km ultra-marathoners and marathoners.

Science.gov (United States)

Rüst, Christoph Alexander; Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas

2012-01-01

Several recent investigations showed that the best marathon time of an individual athlete is also a strong predictor variable for the race time in a 100-km ultra-marathon. We investigated similarities and differences in anthropometry and training characteristics between 166 100-km ultra-marathoners and 126 marathoners in recreational male athletes. The association of anthropometric variables and training characteristics with race time was assessed by using bi- and multi-variate analysis. Regarding anthropometry, the marathoners had a significantly lower calf circumference (P marathoners. Considering training characteristics, the marathoners completed significantly fewer hours (P marathoners. In the marathoners, percent body fat (P = 0.002) was positively and speed in running training (P marathon race times. In conclusion, these data suggest that performance in both marathoners and 100-km ultra-marathoners is inversely related to body fat. Moreover, marathoners rely more on speed in running during training whereas ultra-marathoners rely on volume in running training.

Olive pomace based lightweight concrete, an experimental approach and contribution

Directory of Open Access Journals (Sweden)

Lynda Amel Chaabane

2018-01-01

Full Text Available Due to conventional aggregates resources depletion, material recycling has become an economic and ecologic alternative. In this paper, locally available natural residues such as olive pomace were investigated, when partially incorporated in the concrete formulation, since the mechanical characteristics of lightweight aggregate concrete strongly depend on its properties and proportions. Lightweight aggregates are more deformable than the cement matrix because of their high porosity, and their influence on the concrete strength remains complex. The purpose of this paper is to investigate the aggregates properties on lightweight concrete mechanical behaviour through an experimental approach. In addition, the different substitution sequences and the W/C ratio on lightweight concrete behaviour were evaluated, in order to determine the W/C ratio influence on the improvement of the lightweight concrete mechanical properties while knowing that the mixing water quantity gives the cement paste manoeuvrability and mechanical strength effects. The last part of this paper, therefore, was to provide statistical survey for estimating strength and weight reduction through the different natural aggregate substitutions to improve the lightweight concrete properties. The results achieved in a significant olive-pomace lower adhesion with the matrix after the cement setting, making the lightweight concrete mechanical strength weak. However, this work can open several perspectives: Results modeling and correlation with an experimental approach, the evolution and determination of lightweight concrete characteristics when exposed to high temperatures and thermohydric properties.

Testosterone and BMD in elite male lightweight rowers

DEFF Research Database (Denmark)

Vinther, A; Kanstrup, I-L; Christiansen, E

2008-01-01

The purpose of the present study was to investigate if a relationship between BMD and testosterone levels could be identified in elite male lightweight rowers. Thirteen male lightweight national team rowers had their BMD measured in a DEXA scanner. Plasma concentrations of total testosterone (TT)...

The Design of a Lightweight RFID Middleware

Directory of Open Access Journals (Sweden)

Fengqun Lin

2009-10-01

Full Text Available Radio Frequency Identification (RFID middleware is often regarded as the central nervous system of RFID systems. In this paper, a lightweight RFID middleware is designed and implemented without the need of an Application Level Events (ALE structure, and its implementation process is described using a typical commerical enterprise. A short review of the current RFID middleware research and development is also included. The characteristics of RFID middleware are presented with a two-centric framework. The senarios of RFID data integration based on the simplified structure are provided to illuminats the design and implementation of the lightweight middleware structure and its development process. The lightweight middleware is easy to maintain and extend because of the simplified and streamlined structure and the short development cycle.

Lightweight landscape enhancing design through minimal mass structures

CERN Document Server

Spinelli, Luigi; Monticelli, Carol; Pedrali, Paolo

2016-01-01

This book explains how lightweight materials and structures can be deployed in buildings to meet high environmental and aesthetic standards and emphasizes how the concept of lightness in building technology and design dovetails with the desire to enhance landscape. The first part of the book, on lightweight construction, aims to foster the use of membranes within the specific climatic context and in particular considers how lightweight materials and innovative technologies can enrich the quality of temporary spaces. The second part focuses exclusively on landscape, presenting novel approaches in the search for visual lightness and the quest to improve urban spaces. Particular attention is paid to the Italian experience, where the traditional appreciation of brick and stone has limited the scope for use of lightweight structures and membrane materials, often relegating them to a secondary or inappropriate role. The reader will come to appreciate how this attitude demeans a very advanced productive sector and n...

Uncertainty and Variation of Vibration in Lightweight Structures

DEFF Research Database (Denmark)

Dickow, Kristoffer Ahrens

2012-01-01

Multi-family dwellings and offices build from lightweight materials are becoming a cost efficient and environmentally friendly alternative to traditional heavy structures.......Multi-family dwellings and offices build from lightweight materials are becoming a cost efficient and environmentally friendly alternative to traditional heavy structures....

Architectured Bi{sub 2}S{sub 3} nanoflowers: photoenhanced field emission study

Energy Technology Data Exchange (ETDEWEB)

Warule, Sambhaji S.; Kashid, Ranjit V.; Shinde, Deodatta R. [University of Pune, Center for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics (India); Chaudhari, Nilima S.; Kale, Bharat B., E-mail: kbbb1@yahoo.com [Centre for Materials for Electronics Technology (C-MET), Department of Information Technology, Government of India (India); More, Mahendra A., E-mail: mam@physics.unipune.ac.in [University of Pune, Center for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics (India)

2012-06-15

In the present investigation, we demonstrate a facile hydrothermal/solvothermal route to fabricate elegant Bi{sub 2}S{sub 3} nanoflowers in large scale with highly oriented (001) surfaces. The synthesis route was observed to radically determine the overall morphology of the resultant product. Under hydrothermal conditions (12 h), formation of Bi{sub 2}S{sub 3} flowers on nickel foil composed with the self-assembled tapered nanorods were obtained. Whereas after prolonged reaction time (24 h), formation of ultra long micro belts were observed. Interestingly, the architectured Bi{sub 2}S{sub 3} flowers obtained by solvothermal route are seen to be composed with self assembled nanorods and it was also observed that the synthesis duration influences their shape, size, and areal density. Finding of such unique nanostructures on nickel foil arose by hydrothermal route exemplify a prominent photoenhanced field emission upon visible light illumination, which is attributed to the photoconductivity of Bi{sub 2}S{sub 3}. It is noteworthy that the field emission studies reveal low turn-on field of {approx}1.04 V/{mu}m, required to draw an emission current density of {approx}0.1 {mu}A/cm{sup 2}, which is found to be lower than the earlier reports. The average emission current is observed to be stable over the duration of 3 h. In addition, field emission behavior of a single Bi{sub 2}S{sub 3} flower (pasted on a tungsten microtip) has also been investigated. The high sensitivity and fast response of photoenhanced emission current switching indicate the Bi{sub 2}S{sub 3} nanoflowers as a promising candidate for micro/nano-optoelectronic devices.Graphical abstract.

Production of lightweight refractory material by hydrothermal process

International Nuclear Information System (INIS)

Sulejmani, Ramiz B.

2002-01-01

Many different processes of production of lightweight refractories are well known over the World. Traditional production of lightweight refractories is by addition of combustibles or by a special frothing process. This work is concerned with hydrothermal of lightweight refractories from rice husk ash. The rice husk ash, used in present investigations were from Kocani region, R. Macedonia. The chemical analysis of the rice husk ash shows that it contains 91,8 - 93,7% SiO 2 and some alkaline and alkaline earth oxides. Microscopic and X - ray diffraction examinations of the rice husk ash have shown that it is composed of cristobalite, tridimite and amorphous silica. The composition of the mixture for lightweight refractory brick production is 93,4% rice husk ash and 6,6% Ca(OH) 2 . The mixtures were well mixed, moistened and pressed at 5 - 10 MPa. The hydrothermal reactions between calcium hydroxide and rice husk ash over the temperature range 80 - 160 o C were investigated. The period of autoclave treatment was from 2 to 72 h. After the hydrothermal treatment of the samples, the mineralogical composition, bulk density, density, cold crushing strength, porosity, refractoriness and thermal expansion were examined. Analysing the properties of the obtained samples it can be concluded that from rice husk ash and calcium hydroxide under hydrothermal condition it is possible to obtain lightweight acid refractory material with high quality.(Author)

Lightweight superconducting alternators

International Nuclear Information System (INIS)

Keim, T.A.

1988-01-01

One of the most efficient and most lightweight means of converting high-temperature heat energy to electricity is a turboalternator set. Turboalternators are potentially important components of burst-mode power systems, either chemical or nuclear powered. Also, they are probable key components in future electric propulsion systems. Existing examples of multimegawatt turbomachines have been optimized for a variety of aerospace uses, ranging from aircraft propulsion to rocket engine fuel pump drives. There is no corresponding history of multimegawatt alternators built to aerospace standards of mass, performance, and reliability. This paper discusses one of the few such development efforts presently in progress, and gives an indication of possible future potential. In large power ratings, superconducting generators offer substantial power density, specific weight, and efficiency advantages over competing technologies. A program at GE has led to the construction of a lightweight high-voltage 20-MW generator with a superconducting field winding. The first part of this paper describes the design of the generator. The second projects the capabilities of the generator to other ratings

Design of Light-Weight High-Entropy Alloys

Directory of Open Access Journals (Sweden)

Rui Feng

2016-09-01

Full Text Available High-entropy alloys (HEAs are a new class of solid-solution alloys that have attracted worldwide attention for their outstanding properties. Owing to the demand from transportation and defense industries, light-weight HEAs have also garnered widespread interest from scientists for use as potential structural materials. Great efforts have been made to study the phase-formation rules of HEAs to accelerate and refine the discovery process. In this paper, many proposed solid-solution phase-formation rules are assessed, based on a series of known and newly-designed light-weight HEAs. The results indicate that these empirical rules work for most compositions but also fail for several alloys. Light-weight HEAs often involve the additions of Al and/or Ti in great amounts, resulting in large negative enthalpies for forming solid-solution phases and/or intermetallic compounds. Accordingly, these empirical rules need to be modified with the new experimental data. In contrast, CALPHAD (acronym of the calculation of phase diagrams method is demonstrated to be an effective approach to predict the phase formation in HEAs as a function of composition and temperature. Future perspectives on the design of light-weight HEAs are discussed in light of CALPHAD modeling and physical metallurgy principles.

STRENGTH OF NANOMODIFIED HIGH-STRENGTH LIGHTWEIGHT CONCRETES

Directory of Open Access Journals (Sweden)

NOZEMTСEV Alexandr Sergeevich

2013-02-01

Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.

Lightweight geopolymer composites as structural elements with improved insulation capacity

Directory of Open Access Journals (Sweden)

Kakali Glikeria

2018-01-01

Full Text Available This study concerns the development of lightweight fly ash based geopolymers which can be applied as alternatives to the traditional lightweight concrete. Different kinds of expanded polystyrene were used as lightweight agents. The results showed that lightweight geopolymers were successfully prepared, exhibiting compressive strength and density in the range 7.70 – 29.57 MPa and 0.97 – 1.57 g/cm3, respectively. The product containing 3% w/w of commercial expanded polystyrene possesses low thermal conductivity (0.16 W/mK combined with sufficient mechanical strengths (11 MPa, excellent stability and fire resistance while its water absorption is comparable to that of conventional construction materials (cement mortars, concrete.

Optical constants, dispersion energy parameters and dielectric properties of ultra-smooth nanocrystalline BiVO4 thin films prepared by rf-magnetron sputtering

Science.gov (United States)

Sarkar, S.; Das, N. S.; Chattopadhyay, K. K.

2014-07-01

BiVO4 thin films have been prepared through radio frequency (rf) magnetron sputtering of a pre-fabricated BiVO4 target on ITO coated glass (ITO-glass) substrate and bare glass substrates. BiVO4 target material was prepared through solid-state reaction method by heating Bi2O3 and V2O5 mixture at 800 °C for 8 h. The films were characterized by X-ray diffraction, UV-Vis spectroscopy, LCR meter, field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy. BiVO4 thin films deposited on the ITO-glass substrate are much smoother compared to the thin films prepared on bare glass substrate. The rms surface roughness calculated from the AFM images comes out to be 0.74 nm and 4.2 nm for the films deposited on the ITO-glass substrate and bare glass substrate for the deposition time 150 min respectively. Optical constants and energy dispersion parameters of these extra-smooth BiVO4 thin films have been investigated in detail. Dielectric properties of the BiVO4 thin films on ITO-glass substrate were also investigated. The frequency dependence of dielectric constant of the BiVO4 thin films has been measured in the frequency range from 20 Hz to 2 MHz. It was found that the dielectric constant increased from 145 to 343 at 20 Hz as the film thickness increased from 90 nm to 145 nm (deposition time increased from 60 min to 150 min). It shows higher dielectric constant compared to the literature value of BiVO4.

Lightweight Robotic Excavation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Robust, lightweight, power-efficient excavation robots are mission enablers for lunar outposts and surface systems. Lunar excavators of this type cost-effectively...

FY2014 Lightweight Materials R&D Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None

2015-03-01

The Lightweight Materials research and development (R&D) area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing lightweight materials for passenger and commercial vehicles.

Environmental assessment of lightweight electric vehicles

CERN Document Server

Egede, Patricia

2017-01-01

This monograph adresses the challenge of the environmental assessment of leightweight electric vehicles. It poses the question whether the use of lightweight materials in electric vehicles can reduce the vehicles’ environmental impact and compares the environmental performance of a lightweight electric vehicle (LEV) to other types of vehicles. The topical approach focuses on methods from life cycle assessment (LCA), and the book concludes with a comprehensive concept on the environmental assessment of LEVs. The target audience primarily comprises LCA practitioners from research institutes and industry, but it may also be beneficial for graduate students specializing in the field of environmental assessment.

Ultra-Low-Power Design and Hardware Security Using Emerging Technologies for Internet of Things

Directory of Open Access Journals (Sweden)

Jiann-Shiun Yuan

2017-09-01

Full Text Available In this review article for Internet of Things (IoT applications, important low-power design techniques for digital and mixed-signal analog–digital converter (ADC circuits are presented. Emerging low voltage logic devices and non-volatile memories (NVMs beyond CMOS are illustrated. In addition, energy-constrained hardware security issues are reviewed. Specifically, light-weight encryption-based correlational power analysis, successive approximation register (SAR ADC security using tunnel field effect transistors (FETs, logic obfuscation using silicon nanowire FETs, and all-spin logic devices are highlighted. Furthermore, a novel ultra-low power design using bio-inspired neuromorphic computing and spiking neural network security are discussed.

Innovative lightweight substrate for stable optical benches and mirrors

Science.gov (United States)

Rugi Grond, E.; Herren, A.; Mérillat, S.; Fermé, J. J.

2017-11-01

High precision space optics, such as spectrometers, relay optics, and filters, require ultra stable, lightweight platforms. These equipped platforms have on one side to survive the launch loads, on the other side they have to maintain their stability also under the varying thermal loads occurring in space. Typically such platforms have their equipment (prisms, etalons, beam expanders, etc.) mounted by means of classical bonding, hydro-catalytic bonding or optical contacting. Therefore such an optical bench requires to provide an excellent flatness, minimal roughness and is usually made of the same material as the equipment it carries (glass, glass ceramics). For space systems, mass is a big penalty, therefore such optical platforms are in most cases light weighted by means of machining features (i.e. pockets). Besides of being not extremely mass efficient, such pockets reduce the load carrying capability of the base material significantly. The challenge for Oerlikon Space, in this context, was to develop, qualify and deliver such optical benches, providing a substantial mass reduction compared to actual light weighted systems, while maintaining most of the full load carrying capacity of the base material. Additionally such a substrate can find an attractive application for mirror substrates. The results of the first development and of the first test results will be presented.

Reuse of thermosetting plastic waste for lightweight concrete.

Science.gov (United States)

Panyakapo, Phaiboon; Panyakapo, Mallika

2008-01-01

This paper presents the utilization of thermosetting plastic as an admixture in the mix proportion of lightweight concrete. Since this type of plastic cannot be melted in the recycling process, its waste is expected to be more valuable by using as an admixture for the production of non-structural lightweight concrete. Experimental tests for the variation of mix proportion were carried out to determine the suitable proportion to achieve the required properties of lightweight concrete, which are: low dry density and acceptable compressive strength. The mix design in this research is the proportion of plastic, sand, water-cement ratio, aluminum powder, and lignite fly ash. The experimental results show that the plastic not only leads to a low dry density concrete, but also a low strength. It was found that the ratio of cement, sand, fly ash, and plastic equal to 1.0:0.8:0.3:0.9 is an appropriate mix proportion. The results of compressive strength and dry density are 4.14N/mm2 and 1395 kg/m3, respectively. This type of concrete meets most of the requirements for non-load-bearing lightweight concrete according to ASTM C129 Type II standard.

Lightweight autonomous chemical identification system (LACIS)

Science.gov (United States)

Lozos, George; Lin, Hai; Burch, Timothy

2012-06-01

Smiths Detection and Intelligent Optical Systems have developed prototypes for the Lightweight Autonomous Chemical Identification System (LACIS) for the US Department of Homeland Security. LACIS is to be a handheld detection system for Chemical Warfare Agents (CWAs) and Toxic Industrial Chemicals (TICs). LACIS is designed to have a low limit of detection and rapid response time for use by emergency responders and could allow determination of areas having dangerous concentration levels and if protective garments will be required. Procedures for protection of responders from hazardous materials incidents require the use of protective equipment until such time as the hazard can be assessed. Such accurate analysis can accelerate operations and increase effectiveness. LACIS is to be an improved point detector employing novel CBRNE detection modalities that includes a militaryproven ruggedized ion mobility spectrometer (IMS) with an array of electro-resistive sensors to extend the range of chemical threats detected in a single device. It uses a novel sensor data fusion and threat classification architecture to interpret the independent sensor responses and provide robust detection at low levels in complex backgrounds with minimal false alarms. The performance of LACIS prototypes have been characterized in independent third party laboratory tests at the Battelle Memorial Institute (BMI, Columbus, OH) and indoor and outdoor field tests at the Nevada National Security Site (NNSS). LACIS prototypes will be entering operational assessment by key government emergency response groups to determine its capabilities versus requirements.

Bi-Force

DEFF Research Database (Denmark)

Sun, Peng; Speicher, Nora K; Röttger, Richard

2014-01-01

of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... comparative analysis of biclustering algorithms for gene expressiondata. Brief. Bioinform., 14:279-292.) and compared Bi-Force against eight existing tools: FABIA, QUBIC, Cheng and Church, Plaid, BiMax, Spectral, xMOTIFs and ISA. To this end, a suite of synthetic datasets as well as nine large gene expression...

Development of a self-compacting gypsum-based lightweight composite

NARCIS (Netherlands)

Yu, Q.; Brouwers, H.J.H.

2012-01-01

This article addresses experiments and theories of a self-compacting gypsum-based lightweight composite (SGLC). A ß-hemihydrate is used as binder and lightweight aggregate (LWA, 0–2 mm in different size ranges) is used as aggregate into this composite. The mix of the new composite is designed based

Preparation and properties of visible light responsive Y3+ doped Bi5Nb3O15 photocatalysts for Ornidazole decomposition

International Nuclear Information System (INIS)

Zhao, Jie; Yao, Binghua; He, Qiang; Zhang, Ting

2012-01-01

Highlights: ► A novel Y 3+ -Bi 5 Nb 3 O 15 material was prepared. ► Y 3+ -Bi 5 Nb 3 O 15 is firstly used for the photocatalytic degradation of Ornidazole. ► Possible pathway of Ornidazole degradation in aqueous solution is proposed. - Abstract: Nanoparticle of Bi 5 Nb 3 O 15 doped with Y 3+ was prepared for the first time by the sol–gel method combined with impregnation. The degradation of Ornidazole reacting with Y 3+ -Bi 5 Nb 3 O 15 was investigated to explore the feasibility of using Y 3+ -Bi 5 Nb 3 O 15 to treat antibiotics in wastewater. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV–vis diffuse reflectance spectrum and X-ray photoelectron spectroscopy. The results showed that the Y 3+ -Bi 5 Nb 3 O 15 exhibited single-crystalline orthorhombic structure with small particle size (20–100 nm); additionally, its UV–vis absorbance edges significantly shift to the visible-light region. The as-prepared nanoparticles exhibited a high photocatalytic activity in the decomposition of Ornidazole and several possible pathways of degradation of Ornidazole were proposed according to the results of ultra-performance liquid chromatography tandem mass spectrometry.

Reducing supply chain energy use in next-generation vehicle lightweighting

Energy Technology Data Exchange (ETDEWEB)

Hanes, Rebecca J.; Das, Sujit; Carpenter, Alberta

2016-09-29

Vehicle lightweighting reduces the amount of fuel consumed in a vehicle's use phase, but depending on what lightweight materials replace the conventional materials, and in what amounts, the manufacturing energy may increase or decrease. For carbon fiber reinforced polymer (CFRP), a next-generation lightweighting material, the increase in vehicle manufacturing energy is greater than the fuel savings, resulting in a net increase in energy consumption over a vehicle's manufacturing and use relative to a standard non-lightweighted car. [1] This work explores ways to reduce the supply chain energy of CFRP lightweighted vehicles through alternative production technologies and energy efficiency improvements. The objective is to determine if CFRP can offer energy savings comparable to or greater than aluminum, a conventional lightweighting material. Results of this analysis can be used to inform additional research and development efforts in CFRP production and future directions in lightweight vehicle production. The CFRP supply chain is modeled using the Material Flows through Industry (MFI) scenario modeling tool, which calculates 'mine to materials' energy consumption, material inventories and greenhouse gas emissions for industrial supply chains. In this analysis, the MFI tool is used to model the supply chains of two lightweighted vehicles, an aluminum intensive vehicle (AIV) and a carbon fiber intensive vehicle (CFV), under several manufacturing scenarios. Vehicle specifications are given in [1]. Scenarios investigated cover alternative carbon fiber (CF) feedstocks and energy efficiency improvements at various points in the vehicle supply chains. The alternative CF feedstocks are polyacrylonitrile, lignin and petroleum-derived mesophase pitch. Scenarios in which the energy efficiency of CF and CFRP production increases are explored using sector efficiency potential values, which quantify the reduction in energy consumption achievable when process

Mechanical Properties of Steel Fiber Reinforced all Lightweight Aggregate Concrete

Science.gov (United States)

Yang, Y. M.; Li, J. Y.; Zhen, Y.; Nie, Y. N.; Dong, W. L.

2018-05-01

In order to study the basic mechanical properties and failure characteristics of all lightweight aggregate concrete with different volume of steel fiber (0%, 1%, 2%), shale ceramsite is used as light coarse aggregate. The shale sand is made of light fine aggregate and mixed with different volume of steel fiber, and the mix proportion design of all lightweight aggregate concrete is carried out. The cubic compressive strength, axial compressive strength, flexural strength, splitting strength and modulus of elasticity of steel fiber all lightweight aggregate concrete were studied. Test results show that the incorporation of steel fiber can restrict the cracking of concrete, improve crack resistance; at the same time, it shows good plastic deformation ability and failure morphology. It lays a theoretical foundation for further research on the application of all lightweight aggregate concrete in structural systems.

Lightweight, Ultra-High-Temperature, CMC-Lined Carbon/Carbon Structures

Science.gov (United States)

Wright, Matthew J.; Ramachandran, Gautham; Williams, Brian E.

2011-01-01

Carbon/carbon (C/C) is an established engineering material used extensively in aerospace. The beneficial properties of C/C include high strength, low density, and toughness. Its shortcoming is its limited usability at temperatures higher than the oxidation temperature of carbon . approximately 400 C. Ceramic matrix composites (CMCs) are used instead, but carry a weight penalty. Combining a thin laminate of CMC to a bulk structure of C/C retains all of the benefits of C/C with the high temperature oxidizing environment usability of CMCs. Ultramet demonstrated the feasibility of combining the light weight of C/C composites with the oxidation resistance of zirconium carbide (ZrC) and zirconium- silicon carbide (Zr-Si-C) CMCs in a unique system composed of a C/C primary structure with an integral CMC liner with temperature capability up to 4,200 F (.2,315 C). The system effectively bridged the gap in weight and performance between coated C/C and bulk CMCs. Fabrication was demonstrated through an innovative variant of Ultramet fs rapid, pressureless melt infiltration processing technology. The fully developed material system has strength that is comparable with that of C/C, lower density than Cf/SiC, and ultra-high-temperature oxidation stability. Application of the reinforced ceramic casing to a predominantly C/C structure creates a highly innovative material with the potential to achieve the long-sought goal of long-term, cyclic high-temperature use of C/C in an oxidizing environment. The C/C substructure provided most of the mechanical integrity, and the CMC strengths achieved appeared to be sufficient to allow the CMC to perform its primary function of protecting the C/C. Nozzle extension components were fabricated and successfully hot-fire tested. Test results showed good thermochemical and thermomechanical stability of the CMC, as well as excellent interfacial bonding between the CMC liner and the underlying C/C structure. In particular, hafnium-containing CMCs on

Performance of Lightweight Natural-Fiber Reinforced Concrete

Directory of Open Access Journals (Sweden)

Hardjasaputra Harianto

2017-01-01

Full Text Available Concrete, the most common construction material, has negligible tension capacity. However, a reinforcement material such as natural fibers, can be used to improve the tensile properties of concrete. This paper presents experiments conducted on Super Lightweight Concrete mixed with coconut fibers (SLNFRC. Coconut fibers are regarded as one of the toughest natural fibers to strengthen concrete. Coconut fiber reinforced composites have been considered as a sustainable construction material because the fibers are derived from waste. These wastes, which are available in large quantities in Asia, have to be extracted from the husk of coconut fruits and must pass a mechanical process before being added to a concrete mixture. The Super Lightweight Concrete was made by mixing concrete paste with foam agent that can reduce the overall weight of concrete up to 60% with compressive strength up to 6 MPa. The Super Lightweight Concrete is intended to be used for non-structural walls, as alternative conventional construction materials such as brick walls. The influence of coconut fibers content in increasing the flexural tensile strength of Super Lightweight Concrete was studied in this research. The fiber content studied include 0%, 0.1%, 0.175%, and 0.25% by weight of cement content. Sixteen specimens of SLNFRC mini beams of 60 mm x 60 mm x 300 mm were tested to failure to investigate their flexural strengths. The optimum percent fibers yielding higher tensile strength was found to be 0.175%

A MAC Mode for Lightweight Block Ciphers

DEFF Research Database (Denmark)

Luykx, Atul; Preneel, Bart; Tischhauser, Elmar Wolfgang

2016-01-01

Lightweight cryptography strives to protect communication in constrained environments without sacrificing security. However, security often conflicts with efficiency, shown by the fact that many new lightweight block cipher designs have block sizes as low as 64 or 32 bits. Such low block sizes lead...... no effect on the security bound, allowing an order of magnitude more data to be processed per key. Furthermore, LightMAC is incredibly simple, has almost no overhead over the block cipher, and is parallelizable. As a result, LightMAC not only offers compact authentication for resource-constrained platforms...

Light-weight Mutual Authentication with Non-repudiation

Directory of Open Access Journals (Sweden)

V. Clupek

2018-04-01

Full Text Available In this paper, we focused on a problem of authentication on low-cost devices. We have proposed a new light-weight protocol for mutual authentication of communication entities with non-repudiation of realized events. The protocol is simple and suitable for implementation on low-cost devices. Non-repudiation of realized events is achieved by involving a Trusted Third Party (TTP to the communication. The proposed protocol uses only an appropriate lightweight hash function and pre-shared secret data. Security of the proposed protocol was verified by the BAN (Burrows-Abadi-Needham logic.

Cases of Lightweight Structures for Polar Areas

DEFF Research Database (Denmark)

Pedreros, Jessica Fernandoy; Christ, Julian; Shepherd, Paul

2017-01-01

The paper focuses on what the authors call ‘Polar Lightweight Structures’. The first part presents a collection of lightweight structures (LWS) designed and built for Antarctic conditions, with the aim of demonstrating the diversity of approaches attempted by designers. The second part of the paper...... presents two studies where different computational methods were applied for the design of generic LWS based on the local conditions of two particular Polar locations; namely, the Arctic region and Glacier Union in the Antarctic plateau. Both studies were conducted independently with the aim...

Experimental verification of a novel MEMS multi-modal vibration energy harvester for ultra-low power remote sensing nodes

Science.gov (United States)

Iannacci, J.; Sordo, G.; Serra, E.; Kucera, M.; Schmid, U.

2015-05-01

In this work, we discuss the verification and preliminary experimental characterization of a MEMS-based vibration Energy Harvester (EH) design. The device, named Four-Leaf Clover (FLC), is based on a circular-shaped mechanical resonator with four petal-like mass-spring cascaded systems. This solution introduces several mechanical Degrees of Freedom (DOFs), and therefore enables multiple resonant modes and deformation shapes in the vibrations frequency range of interest. The target is to realize a wideband multi-modal EH-MEMS device, that overcomes the typical narrowband working characteristics of standard cantilevered EHs, by ensuring flexible and adaptable power source to ultra-low power electronics for integrated remote sensing nodes (e.g. Wireless Sensor Networks - WSNs) in the Internet of Things (IoT) scenario, aiming to self-powered and energy autonomous smart systems. Finite Element Method simulations of the FLC EH-MEMS show the presence of several resonant modes for vibrations up to 4-5 kHz, and level of converted power up to a few μW at resonance and in closed-loop conditions (i.e. with resistive load). On the other hand, the first experimental tests of FLC fabricated samples, conducted with a Laser Doppler Vibrometer (LDV), proved the presence of several resonant modes, and allowed to validate the accuracy of the FEM modeling method. Such a good accordance holds validity for what concerns the coupled field behavior of the FLC EH-MEMS, as well. Both measurements and simulations performed at 190 Hz (i.e. out of resonance) showed the generation of power in the range of nW (Root Mean Square - RMS values). Further steps of this work will include the experimental characterization in a full range of vibrations, aiming to prove the whole functionality of the FLC EH-MEMS proposed design concept.

Bi-induced band gap reduction in epitaxial InSbBi alloys

Energy Technology Data Exchange (ETDEWEB)

Rajpalke, M. K.; Linhart, W. M.; Birkett, M.; Alaria, J.; Veal, T. D., E-mail: T.Veal@liverpool.ac.uk [Stephenson Institute for Renewable Energy and Department of Physics, School of Physical Sciences, University of Liverpool, Liverpool L69 7ZF (United Kingdom); Yu, K. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Bomphrey, J. J.; Jones, T. S.; Ashwin, M. J., E-mail: M.J.Ashwin@warwick.ac.uk [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Sallis, S.; Piper, L. F. J. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

2014-11-24

The properties of molecular beam epitaxy-grown InSb{sub 1−x}Bi{sub x} alloys are investigated. Rutherford backscattering spectrometry shows that the Bi content increases from 0.6% for growth at 350 °C to 2.4% at 200 °C. X-ray diffraction indicates Bi-induced lattice dilation and suggests a zinc-blende InBi lattice parameter of 6.626 Å. Scanning electron microscopy reveals surface InSbBi nanostructures on the InSbBi films for the lowest growth temperatures, Bi droplets at intermediate temperatures, and smooth surfaces for the highest temperature. The room temperature optical absorption edge was found to change from 172 meV (7.2 μm) for InSb to ∼88 meV (14.1 μm) for InSb{sub 0.976}Bi{sub 0.024}, a reduction of ∼35 meV/%Bi.

Conserved role of unc-79 in ethanol responses in lightweight mutant mice.

Directory of Open Access Journals (Sweden)

David J Speca

2010-08-01

Full Text Available The mechanisms by which ethanol and inhaled anesthetics influence the nervous system are poorly understood. Here we describe the positional cloning and characterization of a new mouse mutation isolated in an N-ethyl-N-nitrosourea (ENU forward mutagenesis screen for animals with enhanced locomotor activity. This allele, Lightweight (Lwt, disrupts the homolog of the Caenorhabditis elegans (C. elegans unc-79 gene. While Lwt/Lwt homozygotes are perinatal lethal, Lightweight heterozygotes are dramatically hypersensitive to acute ethanol exposure. Experiments in C. elegans demonstrate a conserved hypersensitivity to ethanol in unc-79 mutants and extend this observation to the related unc-80 mutant and nca-1;nca-2 double mutants. Lightweight heterozygotes also exhibit an altered response to the anesthetic isoflurane, reminiscent of unc-79 invertebrate mutant phenotypes. Consistent with our initial mapping results, Lightweight heterozygotes are mildly hyperactive when exposed to a novel environment and are smaller than wild-type animals. In addition, Lightweight heterozygotes exhibit increased food consumption yet have a leaner body composition. Interestingly, Lightweight heterozygotes voluntarily consume more ethanol than wild-type littermates. The acute hypersensitivity to and increased voluntary consumption of ethanol observed in Lightweight heterozygous mice in combination with the observed hypersensitivity to ethanol in C. elegans unc-79, unc-80, and nca-1;nca-2 double mutants suggests a novel conserved pathway that might influence alcohol-related behaviors in humans.

Shock Response of Lightweight Adobe Masonry

Science.gov (United States)

Sauer, C.; Bagusat, F.; Heine, A.; Riedel, W.

2018-04-01

The behavior of a low density and low-strength building material under shock loading is investigated. The considered material is lightweight adobe masonry characterized by a density of 1.2 g/cm3 and a quasi-static uniaxial compressive strength of 2.8 MPa. Planar-plate-impact (PPI) tests with velocities in between 295 and 950 m/s are performed in order to obtain Hugoniot data and to derive parameters for an equation of state (EOS) that captures the occurring phenomenology of porous compaction and subsequent unloading. The resulting EOS description is validated by comparing the experimental free surface velocity time curves with those obtained by numerical simulations of the performed PPI tests. The non-linear compression behavior, including the pore compaction mechanism, constitutes a main ingredient for modelling the response of adobe to blast and high-velocity impact loading. We hence present a modeling approach for lightweight adobe which can be applied to such high rate loading scenarios in future studies. In general, this work shows that PPI tests on lightweight and low-strength geological materials can be used to extract Hugoniot data despite significant material inhomogeneity. Furthermore, we demonstrate that a homogenous material model is able to numerically describe such a material under shock compression and release with a reasonable accuracy.

Dispersion interactions between neighboring Bi atoms in (BiH3 )2 and Te(BiR2 )2.

Science.gov (United States)

Haack, Rebekka; Schulz, Stephan; Jansen, Georg

2018-03-13

Triggered by the observation of a short Bi⋯Bi distance and a BiTeBi bond angle of only 86.6° in the crystal structure of bis(diethylbismuthanyl)tellurane quantum chemical computations on interactions between neighboring Bi atoms in Te(BiR 2 ) 2 molecules (R = H, Me, Et) and in (BiH 3 ) 2 were undertaken. Bi⋯Bi distances atoms were found to significantly shorten upon inclusion of the d shells of the heavy metal atoms into the electron correlation treatment, and it was confirmed that interaction energies from spin component-scaled second-order Møller-Plesset theory (SCS-MP2) agree well with coupled-cluster singles and doubles theory including perturbative triples (CCSD(T)). Density functional theory-based symmetry-adapted perturbation theory (DFT-SAPT) was used to study the anisotropy of the interplay of dispersion attraction and steric repulsion between the Bi atoms. Finally, geometries and relative stabilities of syn-syn and syn-anti conformers of Te(BiR 2 ) 2 (R = H, Me, Et) and interconversion barriers between them were computed. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

3D-printed lightweight drones

DEFF Research Database (Denmark)

Geiger, Raphael

2018-01-01

New Materials within additive manufacturing offer new potentials for drone production - especially in lightweight design. Flying drones benefit significantly from this developments. In regards to quality assurance the technical challenge is to offer a complete quality control within production. T...

On modal cross-coupling in the asymptotic modal limit

Science.gov (United States)

Culver, Dean; Dowell, Earl

2018-03-01

The conditions under which significant modal cross-coupling occurs in dynamical systems responding to high-frequency, broadband forcing that excites many modes is studied. The modal overlap factor plays a key role in the analysis of these systems as the modal density (the ratio of number of modes to the frequency bandwidth) becomes large. The modal overlap factor is effectively the ratio of the width of a resonant peak (the damping ratio times the resonant frequency) to the average frequency interval between resonant peaks (or rather, the inverse of the modal density). It is shown that this parameter largely determines whether substantial modal cross-coupling occurs in a given system's response. Here, two prototypical systems are considered. The first is a simple rectangular plate whose significant modal cross-coupling is the exception rather than the norm. The second is a pair of rectangular plates attached at a point where significant modal cross-coupling is more likely to occur. We show that, for certain cases of modal density and damping, non-negligible cross coupling occurs in both systems. Under similar circumstances, the constraint force between the two plates in the latter system becomes broadband. The implications of this for using Asymptotic Modal Analysis (AMA) in multi-component systems are discussed.

Feasibility Study on Manufacturing Lightweight Aggregates from Water Purification Sludge

Science.gov (United States)

Peng, Ching-Fang; Chen, How-Ji

2018-02-01

This study mainly discussed the feasibility of manufacturing lightweight aggregates from water purification sludge in Taiwan. They were analysed for the physical and chemical composition before the sintering test for lightweight aggregates in a laboratory. Then the physical and mechanical properties of the synthesized aggregates were assessed. The result showed that the chemical composition of sludge in the water purification plants was within the appropriate range for manufacturing lightweight aggregate as proposed in the literature. The sintering test demonstrated that the particle density of aggregates from the ten types of water purification sludge were mostly less than 1.8 g/cm3. In addition, the dry unit weight, the organic impurity, the ignition loss, and other characteristics of synthesized aggregates met the requirement of CNS standards, while its water absorption and crushing strength also fulfilled the general commercial specifications. Therefore, reclamation of water purification sludge for production of lightweight aggregate is indeed feasible.

High Efficency Lightweight Radiators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — XC Associates proposes to build on prior work to develop and characterize a very high efficiency, lightweight radiator constructed from high thermal conductivity...

Miniature CRLH-based ultra wideband antenna with gain enhancement for wireless communication applications

Directory of Open Access Journals (Sweden)

Mohammad Alibakhshi-Kenari

2016-06-01

Full Text Available A novel miniaturized ultra wideband (UWB antenna based on composite right/left-handed (CRLH metamaterial unit cells for modern wireless communication applications is presented. The physical size of the small and compact antenna is 15×7.87×1.6 mm3 or 0.15λo×0.07λo×0.01λo in terms of the free-space wavelength at 3 GHz. The proposed antenna covers an impedance bandwidth of 3–10.6 GHz, which is equivalent to a fractional bandwidth of 111%. The gain and efficiency of the antenna are greater than 2.89 dBi and 38.54%, respectively, with a peak gain of 9.41 dBi and a peak efficiency of 99.93%. The characteristics of the antenna were validated with measured results obtained from a fabricated prototype to establish the proof of concept.

Lightweighting Impacts on Fuel Economy, Cost, and Component Losses

Energy Technology Data Exchange (ETDEWEB)

Brooker, A. D.; Ward, J.; Wang, L.

2013-01-01

The Future Automotive Systems Technology Simulator (FASTSim) is the U.S. Department of Energy's high-level vehicle powertrain model developed at the National Renewable Energy Laboratory. It uses a time versus speed drive cycle to estimate the powertrain forces required to meet the cycle. It simulates the major vehicle powertrain components and their losses. It includes a cost model based on component sizing and fuel prices. FASTSim simulated different levels of lightweighting for four different powertrains: a conventional gasoline engine vehicle, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a battery electric vehicle (EV). Weight reductions impacted the conventional vehicle's efficiency more than the HEV, PHEV and EV. Although lightweighting impacted the advanced vehicles' efficiency less, it reduced component cost and overall costs more. The PHEV and EV are less cost effective than the conventional vehicle and HEV using current battery costs. Assuming the DOE's battery cost target of $100/kWh, however, the PHEV attained similar cost and lightweighting benefits. Generally, lightweighting was cost effective when it costs less than $6/kg of mass eliminated.

Reducing CO2 Emissions through Lightweight Design and Manufacturing

Science.gov (United States)

Carruth, Mark A.; Allwood, Julian M.; Milford, Rachel L.

2011-05-01

To meet targeted 50% reductions in industrial CO2 emissions by 2050, demand for steel and aluminium must be cut. Many steel and aluminium products include redundant material, and the manufacturing routes to produce them use more material than is necessary. Lightweight design and optimized manufacturing processes offer a means of demand reduction, whilst creating products to perform the same service as existing ones. This paper examines two strategies for demand reduction: lightweight product design; and minimizing yield losses through the product supply chain. Possible mass savings are estimated for specific case-studies on metal-intensive products, such as I-beams and food cans. These estimates are then extrapolated to other sectors to produce a global estimate for possible demand reductions. Results show that lightweight product design may offer potential mass savings of up to 30% for some products, whilst yield in the production of others could be improved by over 20%. If these two strategies could be combined for all products, global demand for steel and aluminium would be reduced by nearly 50%. The impact of demand reduction on CO2 emissions is presented, and barriers to the adoption of new, lightweight technologies are discussed.

Facile synthesis of Bi/BiOCl composite with selective photocatalytic properties

International Nuclear Information System (INIS)

Chen, Dongling; Zhang, Min; Lu, Qiuju; Chen, Junfang; Liu, Bitao; Wang, Zhaofeng

2015-01-01

This paper presents a novel and facile method to fabricate Bi/BiOCl composites with dominant (001) facets in situ via a microwave reduction route. Different characterization techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission scanning electron microscopy (TEM), UV–vis diffuse reflectance spectrometry (DRS), X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR), cathodoluminescence spectrum (CL), and lifetime, have been employed to investigate the structure, optical and electrical properties of the Bi/BiOCl composites. The experimental results show that the introduction of Bi particles can efficiently enhance the photocatalytic performance of BiOCl for the degradation of several dyes under ultraviolet (UV) light irradiation, especially for negative charged methyl orange (MO). Unlike the UV photocatalytic performance, such Bi/BiOCl composite shows higher degradation efficiency towards rhodamine B (RhB) than MO and methylene blue (MB) under visible light irradiation. This special photocatalytic performance can be ascribed to the synergistic effect between oxygen vacancies and Bi particles. This work provides new insights about the photodegradation mechanisms of MO, MB and RhB under UV and visible light irradiation, which would be helpful to guide the selection of an appropriate catalyst for other pollutants. - Highlights: • Bi/BiOCl composites were synthesized via a microwave reduction. • Tunable selectivity photocatalytic activity can be achieved. • Photodegradation mechanism under UV and visible light were proposed

Adaptable Optical Fiber Displacement-Curvature Sensor Based on a Modal Michelson Interferometer with a Tapered Single Mode Fiber.

Science.gov (United States)

Salceda-Delgado, G; Martinez-Rios, A; Selvas-Aguilar, R; Álvarez-Tamayo, R I; Castillo-Guzman, A; Ibarra-Escamilla, B; Durán-Ramírez, V M; Enriquez-Gomez, L F

2017-06-02

A compact, highly sensitive optical fiber displacement and curvature radius sensor is presented. The device consists of an adiabatic bi-conical fused fiber taper spliced to a single-mode fiber (SMF) segment with a flat face end. The bi-conical taper structure acts as a modal coupling device between core and cladding modes for the SMF segment. When the bi-conical taper is bent by an axial displacement, the symmetrical bi-conical shape of the tapered structure is stressed, causing a change in the refractive index profile which becomes asymmetric. As a result, the taper adiabaticity is lost, and interference between modes appears. As the bending increases, a small change in the fringe visibility and a wavelength shift on the periodical reflection spectrum of the in-fiber interferometer is produced. The displacement sensitivity and the spectral periodicity of the device can be adjusted by the proper selection of the SMF length. Sensitivities from around 1.93 to 3.4 nm/mm were obtained for SMF length between 7.5 and 12.5 cm. Both sensor interrogations, wavelength shift and visibility contrast, can be used to measure displacement and curvature radius magnitudes.

Bismuth-boron multiple bonding in BiB_2O"- and Bi_2B"-

International Nuclear Information System (INIS)

Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng

2017-01-01

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB_2O"- and Bi_2B"-, containing triple and double B-Bi bonds are presented. The BiB_2O"- and Bi_2B"- clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB_2O"- ([Bi≡B-B≡O]"-) and Bi_2B"- ([Bi=B=Bi]"-), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

The modulation and reconstruction of a BiO layer of cuprate Bi2212

International Nuclear Information System (INIS)

Fan Wei; Zeng, Z

2011-01-01

Studies based on ab initio density functional theory show that the modulated structures of BiO surfaces of cuprate Bi2212 superconductors are spontaneously formed and closely related to the reconstructions of BiO surfaces. The reconstructions of BiO layers occur both on the surface and in the bulk, accompanied with the formations of BiO-zigzag chains and Bi 2 O 2 quadrilaterals. The structural modulations of the BiO surface are along the b axis, perpendicular to the BiO-zigzag chains along the a axis. Our calculations provide a unified understanding of the formation of modulating structures in Bi2212. Another interesting result is that electronic structures of BiO surfaces are significantly influenced by the CuO 2 layer beneath because of the structural modulations and reconstructions.

Acoustic Modeling of Lightweight Structures: A Literature Review

Science.gov (United States)

Yang, Shasha; Shen, Cheng

2017-10-01

This paper gives an overview of acoustic modeling for three kinds of typical lightweight structures including double-leaf plate system, stiffened single (or double) plate and porous material. Classical models are citied to provide frame work of theoretical modeling for acoustic property of lightweight structures; important research advances derived by our research group and other authors are introduced to describe the current state of art for acoustic research. Finally, remaining problems and future research directions are concluded and prospected briefly

Novel Bi/BiOBr/AgBr composite microspheres: Ion exchange synthesis and photocatalytic performance

Science.gov (United States)

Lyu, Jianchang; Li, Zhenlu; Ge, Ming

2018-06-01

Novel Bi/BiOBr/AgBr composite microspheres were prepared by a rational in situ ion exchange reaction between Bi/BiOBr microspheres and AgNO3. The characteristic of the as-obtained ternary microspheres was tested by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL). Under visible light irradiation, Bi/BiOBr/AgBr microspheres exhibited an excellent photocatalytic efficiency for rhodamine B (RhB) degradation, which was about 1.4 and 4.9 times as high as that of Bi/BiOBr and BiOBr/AgBr, demonstrating that the highest separation efficiency of charge carriers in the heterostructured Bi/BiOBr/AgBr. The photocatalytic activity of Bi/BiOBr/AgBr microspheres just exhibited a slight decrease after three consecutive cycles. The photocatalytic mechanism investigation confirmed that the superoxide radicals (O2•-) were the dominant reactive oxygen species for RhB degradation in Bi/BiOBr/AgBr suspension.

NATO Advanced Research Workshop on Boron Rich Solids Sensors for Biological and Chemical Detection, Ultra High Temperature Ceramics, Thermoelectrics, Armor

CERN Document Server

Orlovskaya, Nina

2011-01-01

The objective of this book is to discuss the current status of research and development of boron-rich solids as sensors, ultra-high temperature ceramics, thermoelectrics, and armor. Novel biological and chemical sensors made of stiff and light-weight boron-rich solids are very exciting and efficient for applications in medical diagnoses, environmental surveillance and the detection of pathogen and biological/chemical terrorism agents. Ultra-high temperature ceramic composites exhibit excellent oxidation and corrosion resistance for hypersonic vehicle applications. Boron-rich solids are also promising candidates for high-temperature thermoelectric conversion. Armor is another very important application of boron-rich solids, since most of them exhibit very high hardness, which makes them perfect candidates with high resistance to ballistic impact. The following topical areas are presented: •boron-rich solids: science and technology; •synthesis and sintering strategies of boron rich solids; •microcantileve...

Photocatalytic activity of Bi_2WO_6/Bi_2S_3 heterojunctions: the facilitation of exposed facets of Bi_2WO_6 substrate

International Nuclear Information System (INIS)

Yan, Long; Wang, Yufei; Shen, Huidong; Zhang, Yu; Li, Jian; Wang, Danjun

2017-01-01

Highlights: • Bi_2S_3/Bi_2WO_6 hybrids with exposed (020) Bi_2WO_6 facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi_2S_3 was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi_2S_3/Bi_2WO_6 hybrid architectures with exposed (020) Bi_2WO_6 facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi_2S_3 was formed on the surface of Bi_2WO_6 during the anion exchange process, thus leading to the transformation from the Bi_2WO_6 to Bi_2S_3/Bi_2WO_6. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi_2S_3/Bi_2WO_6 catalysts. Under visible light irradiation, the Bi_2S_3/Bi_2WO_6-TAA displayed the excellent visible light photoactivities compared with pure Bi_2S_3, Bi_2WO_6 and other composite photocatalysts. The efficient photocatalytic activity of the Bi_2S_3/Bi_2WO_6-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi_2WO_6 facets. Active species trapping experiments revealed that h"+ and O_2·"− are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

Cross-modal discrepancies in coarticulation and the integration of speech information: the McGurk effect with mismatched vowels.

Science.gov (United States)

Green, K P; Gerdeman, A

1995-12-01

Two experiments examined the impact of a discrepancy in vowel quality between the auditory and visual modalities on the perception of a syllable-initial consonant. One experiment examined the effect of such a discrepancy on the McGurk effect by cross-dubbing auditory /bi/ tokens onto visual /ga/ articulations (and vice versa). A discrepancy in vowel category significantly reduced the magnitude of the McGurk effect and changed the pattern of responses. A 2nd experiment investigated the effect of such a discrepancy on the speeded classification of the initial consonant. Mean reaction times to classify the tokens increased when the vowel information was discrepant between the 2 modalities but not when the vowel information was consistent. These experiments indicate that the perceptual system is sensitive to cross-modal discrepancies in the coarticulatory information between a consonant and its following vowel during phonetic perception.

EFFECTS OF LIGHTWEIGHT MULLITE-SILICA RICH GLASS COMPOSITE AGGREGATES ON PROPERTIES OF CASTABLES

Directory of Open Access Journals (Sweden)

Li Y.

2013-09-01

Full Text Available Mullite-silica rich glass (MSRG composite is a material which is more efficient than chamotte for refractory utilization of clay. The effects of lightweight MSRG composite aggregate on the properties of refractory castables were studied by XRD, SEM and EDS, etc. Comparing with a common lightweight chamotte aggregate, it was found that the hot modulus of rupture, refractoriness under load and thermal shock resistance of the castable with lightweight MSRG aggregate were higher than those of the castable with a common lightweight chamotte aggregate because MSRG did not contain silica crystalline phases and contained a liquid phase with very high viscosity at high temperature. The castables with lightweight chamotte aggregate have higher thermal expansion because of existence of cristobalite and quartz, and have lower thermal conductivity because of higher porosity.

Heterojunction BiOI/Bi2MoO6 nanocomposite with much enhanced photocatalytic activity

International Nuclear Information System (INIS)

Li, Wen Ting; Zheng, Yi Fan; Yin, Hao Yong; Song, Xu Chun

2015-01-01

BiOI/Bi 2 MoO 6 heterostructures with different amounts of BiOI were successfully prepared via a facile deposition method. The obtained BiOI/Bi 2 MoO 6 photocatalysts exhibited much higher visible light (λ > 420 nm) induced photocatalytic activity compared with single Bi 2 MoO 6 and BiOI photocatalysts. 20 % BiOI/Bi 2 MoO 6 nanocomposite exhibited the highest photocatalytic activity with almost all RhB decomposed within 70 min. However, excess BiOI covering on the surface of Bi 2 MoO 6 can inversely reduce the photocatalytic activity. The enhanced photocatalytic activities could be resulted from the function of the novel p–n heterojunction interface between Bi 2 MoO 6 and BiOI, which could separate photoinduced carriers efficiently. Possible mechanisms on the basis of the relative band positions were also discussed

Spongent: A lightweight hash function

DEFF Research Database (Denmark)

Bogdanov, Andrey; Knežević, Miroslav; Leander, Gregor

2011-01-01

This paper proposes spongent - a family of lightweight hash functions with hash sizes of 88 (for preimage resistance only), 128, 160, 224, and 256 bits based on a sponge construction instantiated with a present-type permutation, following the hermetic sponge strategy. Its smallest implementations...

Multiferroic BiFeO3-BiMnO3 Nanocheckerboard From First Principles

OpenAIRE

Palova, L.; Chandra, P.; Rabe, K. M.

2010-01-01

We present a first principles study of an unusual heterostructure, an atomic-scale checkerboard of BiFeO3-BiMnO3, and compare its properties to the two bulk constituent materials, BiFeO3 and BiMnO3. The "nanocheckerboard" is found to have a multiferroic ground state with the desired properties of each constituent: polar and ferrimagnetic due to BiFeO3 and BiMnO3, respectively. The effect of B-site cation ordering on magnetic ordering in the BiFeO3-BiMnO3 system is studied. The checkerboard ge...

Reconfigurable, Bi-Directional Flexfet Level Shifter for Low-Power, Rad-Hard Integration

Science.gov (United States)

DeGregorio, Kelly; Wilson, Dale G.

2009-01-01

Two prototype Reconfigurable, Bi-directional Flexfet Level Shifters (ReBiLS) have been developed, where one version is a stand-alone component designed to interface between external low voltage and high voltage, and the other version is an embedded integrated circuit (IC) for interface between internal low-voltage logic and external high-voltage components. Targeting stand-alone and embedded circuits separately allows optimization for these distinct applications. Both ReBiLS designs use the commercially available 180-nm Flex fet Independently Double-Gated (IDG) SOI CMOS (silicon on insulator, complementary metal oxide semiconductor) technology. Embedded ReBiLS circuits were integrated with a Reed-Solomon (RS) encoder using CMOS Ultra-Low-Power Radiation Tolerant (CULPRiT) double-gated digital logic circuits. The scope of the project includes: creation of a new high-voltage process, development of ReBiLS circuit designs, and adjustment of the designs to maximize performance through simulation, layout, and manufacture of prototypes. The primary technical objectives were to develop a high-voltage, thick oxide option for the 180-nm Flexfet process, and to develop a stand-alone ReBiLS IC with two 8-channel I/O busses, 1.8 2.5 I/O on the low-voltage pins, 5.0-V-tolerant input and 3.3-V output I/O on the high-voltage pins, and 100-MHz minimum operation with 10-pF external loads. Another objective was to develop an embedded, rad-hard ReBiLS I/O cell with 0.5-V low-voltage operation for interface with core logic, 5.0-V-tolerant input and 3.3-V output I/O pins, and 100-MHz minimum operation with 10- pF external loads. A third objective was to develop a 0.5- V Reed-Solomon Encoder with embedded ReBilS I/O: Transfer the existing CULPRiT RS encoder from a 0.35-micron bulk-CMOS process to the ASI 180-nm Flexfet, rad-hard SOI Process. 0.5-V low-voltage core logic. 5.0-V-tolerant input and 3.3-V output I/O pins. 100-MHz minimum operation with 10- pF external loads. The stand

Lightweight panel study 2012: Perceptions and usage by North American wood products manufacturers

Science.gov (United States)

Urs Buehlmann; Matt Bumgardner; Karl D. Forth

2012-01-01

Lightweight panels (panels made of two thin panels on the outside and a lightweight material in the core) can offer enhanced performance, reduced material use, and new design opportunities over traditional types of panels. Opportunities exist for the adoption of lightweight panels by the secondary wood industry in North America, as 62 percent of respondents to a recent...

Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

OpenAIRE

Chen Kuo-Wei

2016-01-01

This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with ...

Southern Regional Center for Lightweight Innovative Design

Energy Technology Data Exchange (ETDEWEB)

Wang, Paul T. [Mississippi State Univ., Mississippi State, MS (United States)

2012-12-01

The Southern Regional Center for Lightweight Innovative Design (SRCLID) has developed an experimentally validated cradle-to-grave modeling and simulation effort to optimize automotive components in order to decrease weight and cost, yet increase performance and safety in crash scenarios. In summary, the three major objectives of this project are accomplished: To develop experimentally validated cradle-to-grave modeling and simulation tools to optimize automotive and truck components for lightweighting materials (aluminum, steel, and Mg alloys and polymer-based composites) with consideration of uncertainty to decrease weight and cost, yet increase the performance and safety in impact scenarios; To develop multiscale computational models that quantify microstructure-property relations by evaluating various length scales, from the atomic through component levels, for each step of the manufacturing process for vehicles; and To develop an integrated K-12 educational program to educate students on lightweighting designs and impact scenarios. In this final report, we divided the content into two parts: the first part contains the development of building blocks for the project, including materials and process models, process-structure-property (PSP) relationship, and experimental validation capabilities; the second part presents the demonstration task for Mg front-end work associated with USAMP projects.

Titanium Nanocomposite: Lightweight Multifunction Structural Material

Data.gov (United States)

National Aeronautics and Space Administration — We propose to research and develop lightweight metal matrix nanocomposites (MMnC) using a Titanium (Ti) metal matrix. Ti MMnC will crosscut the advancement of both...

Lightweight enterprise architectures

CERN Document Server

Theuerkorn, Fenix

2004-01-01

STATE OF ARCHITECTUREArchitectural ChaosRelation of Technology and Architecture The Many Faces of Architecture The Scope of Enterprise Architecture The Need for Enterprise ArchitectureThe History of Architecture The Current Environment Standardization Barriers The Need for Lightweight Architecture in the EnterpriseThe Cost of TechnologyThe Benefits of Enterprise Architecture The Domains of Architecture The Gap between Business and ITWhere Does LEA Fit? LEA's FrameworkFrameworks, Methodologies, and Approaches The Framework of LEATypes of Methodologies Types of ApproachesActual System Environmen

Southern Regional Center for Lightweight Innovative Design

Energy Technology Data Exchange (ETDEWEB)

Horstemeyer, Mark F. [Mississippi State Univ., Mississippi State, MS (United States); Wang, Paul [Mississippi State Univ., Mississippi State, MS (United States)

2011-12-27

The three major objectives of this Phase III project are: To develop experimentally validated cradle-to-grave modeling and simulation tools to optimize automotive and truck components for lightweighting materials (aluminum, steel, and Mg alloys and polymer-based composites) with consideration of uncertainty to decrease weight and cost, yet increase the performance and safety in impact scenarios; To develop multiscale computational models that quantify microstructure-property relations by evaluating various length scales, from the atomic through component levels, for each step of the manufacturing process for vehicles; and To develop an integrated K-12 educational program to educate students on lightweighting designs and impact scenarios.

Lightweight Space Tug body structure

International Nuclear Information System (INIS)

Lager, J.R.

1976-01-01

Lightweight honeycomb sandwich construction using a wide variety of metal and fibrous composite faceskins was used in the design of a typical Space Tug skirt structure. Relatively low magnitude combined loading of axial compression and torsion resulted in designs using ultrathin faceskins, light-weight honeycomb cores, and thin faceskin/core adhesive bond layers. Two of the designs with metal faceskins (aluminum and titanium) and four with fibrous composite faceskins (using combinations of fiberglass, boron, and graphite) were evaluated through the fabrication and structural test of a series of small development panels. The two most promising concepts with aluminum and graphite/epoxy faceskins, were further evaluated through the fabrication and structural test of larger compression and shear panels. All panels tested exceeded design ultimate load levels, thereby, verifying the structural integrity of the selected designs. Projected skirt structural weights for the graphite/epoxy and aluminum concepts fall within original weight guidelines established for the Space Tug vehicle

Development of lightweight mortars targeted on the high strength, low density and low permeability

NARCIS (Netherlands)

Spiesz, P.R.; Yu, Q.; Brouwers, H.J.H.; Uzoegbo, H.C.; Schmidt, W.

2013-01-01

This article presents a mix design methodology for the development of cement-based lightweight mortars. Expanded-glass lightweight aggregates were used in this study as the lightweight material. The mix design was developed applying the packing theory using the modified Andreasen and Andersen model

46 CFR 170.200 - Estimated lightweight vertical center of gravity.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Estimated lightweight vertical center of gravity. 170... Centers of Gravity § 170.200 Estimated lightweight vertical center of gravity. (a) Each tank vessel that... calculations required by §§ 170.170 and 172.065, the vertical center of gravity of a tank vessel in the...

Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

Directory of Open Access Journals (Sweden)

Chen Kuo-Wei

2016-01-01

Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

In-situ synthesis of nanofibers with various ratios of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} for effective trichloroethylene photocatalytic degradation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yifan [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of); Park, Mira [Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Kim, Hak Yong [Department of BIN Convergence Technology, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Ding, Bin [College of Textiles, Donghua University, Shanghai 201620 (China); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of)

2016-10-30

Highlights: • BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers were synthesized by in-situ method. • Photodegradation behavior of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers was measured under solar light irradiation. • BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4}/PAN fibers exhibited the highest photocatalytic activity. • Photocatalytic mechanism was discussed in detail. - Abstract: In this work, BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} (x + y + z = 1) composite nanofibers were prepared through electrospinning and the sol-gel methods. Photocatalytic degradation of trichloroethylene (TCE) by BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN nanofibers was systematically investigated via gas chromatography (GC). Optimum photocatalytic activity was achieved with BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} fibers under solar light irradiation. X-ray photoelectron spectroscopy (XPS) peaks due to C−O and C=O were observed at 286.0 and 288.3 eV, respectively, it indicated that the BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} mixture had been successfully doped on the polyacrylonitrile (PAN) fibers. Furthermore, X-ray diffraction (XRD) results also confirmed that we had synthesized the as-prepared composite nanofibers successfully. Photocatalytic activities of BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} were up to 3 times higher than the pure BiOCl, BiOBr and BiOI samples, respectively.

Optical gain in GaAsBi-based quantum-well diode lasers (Conference Presentation)

Science.gov (United States)

Marko, Igor P.; Broderick, Christopher A.; Jin, Shirong; Ludewig, Peter; Stolz, Wolfgang; Volz, Kerstin; Rorison, Judy M.; O'Reilly, Eoin P.; Sweeney, Stephen J.

2017-02-01

GaAsBi offers the possibility to develop near-IR semiconductor lasers such that the spin-orbit-split-off energy (ΔSO) is greater than the bandgap (Eg) in the active region with lasing wavelengths in the datacom/telecom range of 1.3-1.6 μm. This promises to suppress the dominant efficiency-limiting loss processes as Auger recombination, involving the generation of "hot" holes in the spin-orbit split-off band (the so-called "CHSH" process), and inter-valence band absorption (IVBA), where emitted photons are re-absorbed in the active region, thereby increasing the internal optical losses and negatively impacting upon the laser characteristics being responsible for the main energy consumption. In addition to growth and fabrication processes refinement, a key aspect of efforts to continue the advancement of the GaAsBi material system for laser applications is to develop a quantitative understanding of the impact of Bi on key device parameters. In this work, we present the first experimental measurements of the absorption, spontaneous emission, and optical gain spectra of GaAsBi/AlGaAs QW lasers using a segmented contact method and a theoretical analysis of these devices, which shows good quantitative agreement with the experiment. Internal optical losses of 10-15 cm-1 and peak modal gain of 24 cm-1 are measured at threshold and a peak material gain is estimated to be 1500 cm-1 at current density of 2 kA/cm-2, which agrees well with the calculated value of 1560 cm-1. The theoretical calculations also enabled us to identify and quantify Bi composition variations across the wafer and Bi-induced inhomogeneous broadening of the optical spectra.

Modality

DEFF Research Database (Denmark)

Klinge, Alex; Müller, Henrik Høeg

Modality: Studies in Form and Function reflects the diversity of theoretical frameworks and the heterogeneity of linguistic phenomena under the general heading of modality. Researchers in the fields of logic, philosophy and linguistics have for many years been pondering the elusive nature...... of modality and grappled with ways of capturing it. The 11 studies included here cover the span from contributions that seek to clarify controversial theoretical constructs to studies which take an empirical approach to linguistic categories and cross-linguistic typological issues. The key concepts addressed...

Facile Fabrication of BiOI/BiOCl Immobilized Films With Improved Visible Light Photocatalytic Performance

Directory of Open Access Journals (Sweden)

Yingxian Zhong

2018-03-01

Full Text Available HIGHLIGHTSA facial method was used to fabricate BiOI/BiOCl film at room temperature.30% BiOI/BiOCl showed an excellent photocatalytic activity and stability.Improvement of photocatalytic activity was owed to expanded visible light absorption and high separation efficiency of charge.Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after five recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

Influence of photoinduced Bi-related self-doping on the photocatalytic activity of BiOBr nanosheets

Energy Technology Data Exchange (ETDEWEB)

Wu, Dan [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Yue, Songtao; Wang, Wei [College of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); An, Tiacheng, E-mail: antc99@gig.ac.cn [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Guiying [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Ye, Liqun [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061 (China); Yip, Ho Yin [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Wong, Po Keung, E-mail: pkwong@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China)

2017-01-01

Highlights: • Bi{sup 5+} self-doped BiOBr nanosheets are achieved under UV irradiation. • Bi{sup 5+} is formed due to the oxidation of surface Bi{sup 3+} by photoexcited h{sup +} of BiOBr. • Two photoinduced h{sup +} mediated oxidation processes happen simultaneously. • Self-doped BiOBr is superior in phenol degradation and bacterial inactivation. • Bi{sup 5+} electron trapping induced photocatalytic enhancement mechanism is proposed. - Abstract: Under UV irradiation, self-doped Bi{sup 5+} is evidenced to be generated on the surface of BiOBr nanosheets, but with well-preserved crystal structure and morphology compared with pure counterpart. Bi{sup 5+} self-doping BiOBr (BiOBr-4) exhibits distinct photocatalytic mode for dyes degradation, as compared with pure BiOBr nanosheets. These photodegradation distinctions are mainly due to the simultaneous occurrence of two photoinduced hole (h{sup +}) mediated oxidation processes on the BiOBr surfaces: (1) a portion of photoexcited h{sup +} participates in the photocatalytic oxidation of dyes, and (2) partial h{sup +} involves the oxidation of Bi{sup 3+} to Bi{sup 5+}. Notably, BiOBr-4 nanosheets comparatively show superior photocatalytic activity for the phenol decomposition as well as the bacterial inactivation. Besides Bi{sup 5+} induced narrowed bandgap and enhanced light adsorption capacity, significantly, the oxidative Bi{sup 5+} acts as electron traps to promote the photoexcited electron-hole separation and accelerate h{sup +} migration, resulting in the considerable photocatalytic enhancement of BiOBr-4 nanosheets. These novel findings will not only give new insights into the photocatalytic mechanism but also explore new route to enhance photocatalytic performance of Bi-based materials.

Nano-Channels Early Formation Investigation on Stainless Steel 316Ti after Immersion in Molten Pb-Bi

Directory of Open Access Journals (Sweden)

Abu Khalid Rivai

2017-04-01

Full Text Available Pb-Bi (lead-bismuth eutectic-LBE is a coolant of one of main candidates for the future nuclear reactor in the world (Generation IV reactors i.e. LFR (Lead alloy-cooled Fast Reactor, and also a spallation target material for ADS (Accelerator Driven Transmutation System. However, the development of fuel cladding and structural materials in LBE environment, especially at high temperature, is a critical issue for the deployment of LFR and ADS. This is because of the corrosive characteristic of LBE to metals as constituent materials of fuel cladding and structural of the reactors. In this study, corrosion test of a high-chromium austenitic steel i.e. SS316Ti in liquid Pb-Bi at 550ºC has been carried out for about 300 hours. The characterization using SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscope showed that an iron oxide as the outer layer and a chromium oxide as the inner layer on the surface of the specimen were formed which protected the steel specimen from corrosion and dissolution attack of Pb-Bi. However, small amount of Pb-Bi could penetrate into the iron oxide layer through ultra-thin channels. Atomic Force Microscopy (AFM was employed to investigate the phenomena of the channels formation. The results of the nano-scale investigation showed clearly the formation of the channels.

Literature Review of Shear Performance of Light-weight Steel Framing Wall Panels

Science.gov (United States)

Zhang, Zhuangnan; Liu, Shen; Liu, Hong

2018-03-01

In this paper, a comprehensive review of light-weight steel framing wall panels was carried out. The structure and force characteristics of light-weight steel framing wall panels were introduced. The testing and theoretical research results on the shear behaviour of light-weight steel framing wall panels were summarized in the domestic and foreign. And combined with the existing standards in China, the author's views and ideas are put forward to the problems in the research field of this kind of structural system.

Compact, Light-weight and Cost-effective Microscope based on Lensless Incoherent Holography for Telemedicine Applications

Science.gov (United States)

Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O.; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

2010-01-01

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing ~46 grams with dimensions smaller than 4.2cm × 4.2cm × 5.8cm that achieves sub-cellular resolution over a large field of view of ~24 mm2. This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings. PMID:20401422

Bi3+–Pr3+ energy transfer processes and luminescent properties of LuAG:Bi,Pr and YAG:Bi,Pr single crystalline films

International Nuclear Information System (INIS)

Zorenko, Y.; Gorbenko, V.; Savchyn, V.; Zorenko, T.; Nikl, M.; Mares, J.A.; Beitlerova, A.; Jary, V.

2013-01-01

Absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300 K for the double doped with Bi 3+ –Pr 3+ and separately doped with Bi 3+ and Pr 3+ Lu 3 Al 5 O 12 (LuAG) and Y 3 Al 5 O 12 (YAG) single crystalline film (SCF) phosphors grown by the liquid phase epitaxy method. The emission bands in the UV range arising from the intrinsic radiative transitions of Bi 3+ based centers, and emission bands in the visible range, related to the luminescence of excitons localized around Bi 3+ based centers, were identified both in Bi–Pr and Bi-doped LuAG and YAG SCFs. The energy transfer processes from the host lattice simultaneously to Bi 3+ and Pr 3+ ions and from Bi 3+ to Pr 3+ ions were investigated. Competition between Pr 3+ and Bi 3+ ions in the energy transfer processes from the LuAG and YAG hosts was evidenced. The strong decrease of the intensity of Pr 3+ luminescence both in LuAG:Pr and YAG:Pr SCFs phosphors, grown from Bi 2 O 3 flux, is observed due to the quenching influence of Bi 3+ flux related impurity. Due to overlap of the UV emission band of Bi 3+ centers with the f–d absorption bands of Pr 3+ ions in the UV range and the luminescence of excitons localized around Bi ions with the f–f absorption bands of Pr 3+ ions in the visible range, an effective energy transfer from Bi 3+ ions to Pr 3+ ions takes place in LuAG:Bi,Pr and YAG:Bi,Pr SCFs, resulting in the appearance of slower component in the decay kinetics of the Pr 3+ d–f luminescence. -- Highlights: • Bi and Pr doped film phosphor grown by liquid phase epitaxy method. • Energy transfer from Bi 3+ to Pr 3+ ions. • Strong quenching of the Pr 3+ luminescence by Bi 3+ co-dopant

Facile Fabrication of BiOI/BiOCl Immobilized Films with Improved Visible Light Photocatalytic Performance

Science.gov (United States)

Zhong, Yingxian; Liu, Yuehua; Wu, Shuang; Zhu, Yi; Chen, Hongbin; Yu, Xiang; Zhang, Yuanming

2018-03-01

Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after 5 recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

The use of spent glauconite in lightweight aggregate production

OpenAIRE

Franus, Wojciech; Franus, Małgorzata; Latosińska, Jolanta; Wójcik, Rafał

2011-01-01

The presented work has shown an application of spent glauconite bed after purification of wastewater for production of lightweight expanded clay aggregates. Sewage, from which it was removed Zn ions, came from technological line (zincworks) of Communication Equipment Factory „PZL” Świdnik. Spent glauconite bed was used as an additive in lightweight aggregate production which was obtained using plastic method by sintering, at temperature 1140 ºC and 1200 ºC, of spent glauconite amouts 10, 15, ...

Some aspects to improve sound insulation prediction models for lightweight elements

NARCIS (Netherlands)

Gerretsen, E.

2007-01-01

The best approach to include lightweight building elements in prediction models for airborne and impact sound insulation between rooms, as in EN 12354, is not yet completely clear. Two aspects are at least of importance, i.e. to derive the sound reduction index R for lightweight elements for

On the electronic structure and thermoelectric properties of BiTeBr and BiTeI single crystals and of BiTeI with the addition of BiI3 and CuI

International Nuclear Information System (INIS)

Kulbachinskii, Vladimir A.; Kytin, Vladimir G.; Kudryashov, Alexey A.; Kuznetsov, Alexei N.; Shevelkov, Andrei V.

2012-01-01

The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering model. Because of larger thermopower BiTeBr exhibits a twice higher thermoelectric figure-of-merit near room temperature, ZT=0.17, compared to BiTeI. The addition of 1 mass% of BiI 3 or CuI to BiTeI decreases the mobility of electrons by two orders of magnitude, leading to significantly lower electrical conductivity, but at the same time effectively reduces the thermal conductivity. The prospects of further enhancing the thermoelectric efficiency are briefly discussed. - Graphical abstract: View of the crystal structure of BiTeBr is shown in the figure The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering

Multi-component lightweight gearwheels with deep-drawn wheel body for automotive applications

Science.gov (United States)

Benkert, Tim; Hiller, Maria; Volk, Wolfram

2017-09-01

Multi-component gearwheels offer great lightweight opportunities for automotive applications. An assembly of a gear ring and a wheel body joined by press fit replaces the monolithic gearwheel. To save weight, the wheel body uses lightweight design. This lightweight design influences the assembled gearwheel’s mechanical properties like stiffness, weight and torque capacity. Further, the wheel body material influences the mentioned properties as well. In this paper, the effects of the lightweight wheel body manufactured by deep-drawing on the mechanical properties of the assembled gearwheel are investigated. Three different wheel body designs are examined regarding their stiffness and weight compared to a reference gearwheel. Using the best design, the influence of five materials with increasing yield strength on the maximum torque the gearwheel can transmit is studied. All research is done virtually using Abaqus 6.12-3.

Sequential injection/bead injection lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by ETAAS and ICPMS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald; Miró, Manuel

2003-01-01

are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material...

Evolução das lesões histológicas e ultra-estruturais no fígado de ovinos e bovinos experimentalmente intoxicados por Myoporum laetum

OpenAIRE

Bonel-Raposo Josiane; Driemeier David; Barros Severo Sales; Gevehr-Fernandes Cristina

2003-01-01

Amostras de Myoporum laetum foram colhidas durante a primavera e verão e administradas a cinco ovinos e seis bovinos em doses únicas de 20 e 30 g/kg. Biópsias hepáticas foram colhidas antes (controles) e 1, 3 e 7 dias após a dosagem da planta. Estas biópsias foram analisadas histológica e ultra-estruturalmente. Os sinais clínicos, em ovinos, caracterizaram-se, especialmente, por depressão, diminuição dos movimentos ruminais, fezes ressequidas, tenesmo, ranger de dentes, dispnéia e lesões típi...

Ceramic/polymer functionally graded material (FGM) lightweight armor system

Energy Technology Data Exchange (ETDEWEB)

Petrovic, J.J.; McClellan, K.J.

1998-12-31

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

International Nuclear Information System (INIS)

Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying

2013-01-01

Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

Synthesis and characterization of novel PPy/Bi{sub 2}O{sub 2}CO{sub 3} composite with improved photocatalytic activity for degradation of Rhodamine-B

Energy Technology Data Exchange (ETDEWEB)

Wang, Qizhao, E-mail: wangqizhao@163.com [College of Chemistry and Chemical Engineering, Northwest Normal University, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education of China, Key Laboratory of Gansu Polymer Materials, Lanzhou 730070 (China); Zheng, Longhui; Chen, Yutao; Fan, Jiafeng [College of Chemistry and Chemical Engineering, Northwest Normal University, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education of China, Key Laboratory of Gansu Polymer Materials, Lanzhou 730070 (China); Huang, Haohao, E-mail: scuthhh@hotmail.com [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Su, Bitao [College of Chemistry and Chemical Engineering, Northwest Normal University, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education of China, Key Laboratory of Gansu Polymer Materials, Lanzhou 730070 (China)

2015-07-15

Highlights: • A new photocatalyst PPy/Bi{sub 2}O{sub 2}CO{sub 3} was synthesized by a simple hydrothermal method. • The PPy/Bi{sub 2}O{sub 2}CO{sub 3} photocatalyst shows enhanced degradation activity of RhB under UV light irradiation. • A photocatalytic mechanism is proposed based on the synergistic effect of PPy and Bi{sub 2}O{sub 2}CO{sub 3}. - Abstract: Photocatalyst Bi{sub 2}O{sub 2}CO{sub 3} modified by polypyrrole (PPy) was synthesized via a facile hydrothermal method. As-prepared PPy/Bi{sub 2}O{sub 2}CO{sub 3} composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis diffuse reflectance spectroscopy (DRS). Presence of PPy did not affect the crystal structure, but exerted great influence on the photocatalytic activity of Bi{sub 2}O{sub 2}CO{sub 3} and enhanced absorption band of pure Bi{sub 2}O{sub 2}CO{sub 3}. The photocatalytic activities of the PPy/Bi{sub 2}O{sub 2}CO{sub 3} samples were determined by photocatalytic degradation of Rhodamine-B (RhB) under ultra violet (UV) irradiation and 0.75 wt.% PPy/Bi{sub 2}O{sub 2}CO{sub 3} composite showed the highest photocatalytic activity. The enhanced photocatalytic performance could be attributed to the synergistic effect of PPy and Bi{sub 2}O{sub 2}CO{sub 3}. A possible photocatalytic mechanism of the PPy/Bi{sub 2}O{sub 2}CO{sub 3} photocatalysts was proposed in order to guide the further improvement of its photocatalytic performance.

Spatial profile of thermoelectric effects during Peltier pulsing in Bi and Bi/MnBi eutectic

Science.gov (United States)

Silberstein, R. P.; Larson, D. J., Jr.

1987-01-01

The spatial profile of the thermal transients that occur during and following the current pulsing associated with Peltier Interface Demarcation during directional solidification is studied. Results for pure Bi are presented in detail and compared with corresponding results for the Bi/MnBi eutectic. Significant thermal transients occur throughout the sample that can be accounted for by the Peltier effect, the Thomson effect, and Joule heating. These effects are separated and their behavior is studied as a function of time, current density, and position with respect to the solid/liquid interface.

Compact, Lightweight Servo-Controllable Brakes

Science.gov (United States)

Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

2010-01-01

Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

State diagram of Pr-Bi system

International Nuclear Information System (INIS)

Abulkhaev, V.L.; Ganiev, I.N.

1994-01-01

By means of thermal differential analysis, X-ray and microstructural analysis the state diagram of Pr-Bi system was studied. Following intermetallic compounds were defined in the system: Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 , Pr Bi, PrBi 2 , Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 and PrBi 2 . The data analysis on Ln-Bi diagram allowed to determine the regularity of change of properties of intermetallic compounds in the line of rare earth elements of cerium subgroup.

Acoustic performance and microstructural analysis of bio-based lightweight concrete containing miscanthus

NARCIS (Netherlands)

Chen, Yuxuan; Yu, Q. L.; Brouwers, H. J.H.

2017-01-01

Miscanthus Giganteus (i.e. Elephant Grass) is a cost-effective and extensively available ecological resource in many agricultural regions. This article aims at a fundamental research on a bio-based lightweight concrete using miscanthus as aggregate, i.e. miscanthus lightweight concrete (MLC), with

Effects of Na incorporation and plasma treatment on Bi{sub 2}S{sub 3} ultra-thin layers

Energy Technology Data Exchange (ETDEWEB)

Moreno-Garcia, H., E-mail: hamog@ier.unam.mx [Laboratorio de Espectroscopía, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Messina, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo” S/N, C.P. 63155 Tepic, Nayarit (Mexico); Calixto-Rodriguez, M. [Universidad Tecnológica Emiliano Zapata del Estado de Morelos, Av. Universidad Tecnológica No. 1, C.P. 62760 Emiliano Zapata, Morelos (Mexico); Martínez, H. [Laboratorio de Espectroscopía, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico)

2016-04-01

As-deposited bismuth sulfide thin films prepared by means of a chemical bath deposition were treated with argon AC plasma. In this paper, we present the results on the physical modifications which were observed when a pre-treatment, containing a solution of 1 M sodium hydroxide, was applied to the glass substrates before depositing the bismuth sulfide. The bismuth sulfide thin films were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy, UV–VIS, and electrical measurements. The XRD analysis demonstrated an enhancement in the crystalline properties, as well as an increment in the crystal size. The energy band gap value was calculated as 1.60 eV. Changes in photoconductivity (σ{sub p}) values were also observed due to the pre-treatment in NaOH. A value of σ{sub p} = 6.2 × 10{sup −6} (Ω cm){sup −1} was found for samples grown on substrates without pre-treatment, and a value of σ{sub p} = 0.28 (Ω cm){sup −1} for samples grown on substrates with pre-treatment. Such σ{sub p} values are optimal for the improvement of solar cells based on Bi{sub 2}S{sub 3} thin films as absorber material. - Highlights: • We report our findings about Na incorporation and plasma treatment on Bi{sub 2}S{sub 3} thin layers. • The Na pre-treatment improves the structural and electrical properties of Bi{sub 2}S{sub 3} films. • The E{sub g} value was 1.60 eV for films with pre-treatment with NaOH and treatment in Ar plasma.

Development of lightweight THUNDER with fiber composite layers

Science.gov (United States)

Yoon, Kwang J.; Shin, Sukjoon; Kim, Jusik; Park, Hoon C.; Kwak, Moon K.

2000-06-01

This paper is concerned with design, manufacturing and performance test of lightweight THUNDER using a top fiber composite layer with near-zero CTE, a PZT ceramic wafer and a bottom glass/epoxy layer with high CTE. The main point of this design is to replace the heavy metal layers of THUNDER by the lightweight fiber reinforced plastic layers without losing capabilities to generate high force and displacement. It is possible to save weight up to about 30 percent if we replace the metallic backing materials by the light fiber composite layer. We can also have design flexibility by selecting the fiber direction and the size of prepreg layers. In addition to the lightweight advantage and design flexibility, the proposed device can be manufactured without adhesive layers when we use epoxy resin prepreg system. Glass/epoxy prepregs, a ceramic wafer with electrode surfaces, and a graphite/epoxy prepreg were simply stacked and cured at an elevated temperature by following autoclave bagging process. It was found that the manufactured composite laminate device had a sufficient curvature after detaching form a flat mold. From experimental actuation tests, it was observed that the developed actuator could generate larger actuation displacement than THUNDER.

One-step growth of nanosheet-assembled BiOCl/BiOBr microspheres for highly efficient visible photocatalytic performance

Science.gov (United States)

Zhang, Jinfeng; Lv, Jiali; Dai, Kai; Liang, Changhao; Liu, Qi

2018-02-01

In this work, we have developed a simple synthetic approach of nanosheet-assembled BiOCl/BiOBr microspheres by an ethylene glycol (EG)-assisted hydrothermal method. The crystalline form, morphology, chemical composition, optical performance and surface area of BiOCl/BiOBr microspheres were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy spectra (EDX), UV-vis diffuse reflectance spectroscopy (DRS) analysis, high resolution X-ray photoelectron spectra (XPS) and N2 adsorption-desorption isotherms. BiOCl/BiOBr microspheres were nanosheet-assembled particles, which possessed visible light absorption under LED light irridation. Additionally, the methylene blue (MB) photodegradation performance of different BiOCl/BiOBr microspheres irradiated under 410 nm LED light arrays were investigated, the results exhibited that as-prepared BiOCl/BiOBr products showed higher catalytic effiency than pure BiOCl or BiOBr. By optimizing the composition ration of the BiOCl and BiOBr, up to 93% degradation rate can be obtained in the 40%BiOCl/BiOBr microspheres. Finally, the photocatalytic mechanism of BiOCl/BiOBr microspheres had been proposed.

Durability of Geopolymer Lightweight Concrete Infilled LECA in Seawater Exposure

Science.gov (United States)

Razak, R. A.; Abdullah, M. M. A. B.; Yahya, Z.; Hamid, M. S. A.

2017-11-01

This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.

LIGHTWEIGHT CONCRETE BASED GRANSHLAK

Directory of Open Access Journals (Sweden)

NETESA M. I.

2016-02-01

Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

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

Hybrid Electrostatic/Flextensional Mirror for Lightweight, Large-Aperture, and Cryogenic Space Telescopes

Science.gov (United States)

Patrick, Brian; Moore, James; Hackenberger, Wesley; Jiang, Xiaoning

2013-01-01

A lightweight, cryogenically capable, scalable, deformable mirror has been developed for space telescopes. This innovation makes use of polymer-based membrane mirror technology to enable large-aperture mirrors that can be easily launched and deployed. The key component of this innovation is a lightweight, large-stroke, cryogenic actuator array that combines the high degree of mirror figure control needed with a large actuator influence function. The latter aspect of the innovation allows membrane mirror figure correction with a relatively low actuator density, preserving the lightweight attributes of the system. The principal components of this technology are lightweight, low-profile, high-stroke, cryogenic-capable piezoelectric actuators based on PMN-PT (piezoelectric lead magnesium niobate-lead titanate) single-crystal configured in a flextensional actuator format; high-quality, low-thermal-expansion polymer membrane mirror materials developed by NeXolve; and electrostatic coupling between the membrane mirror and the piezoelectric actuator assembly to minimize problems such as actuator print-through.

Volume changes in unrestrained structural lightweight concrete.

Science.gov (United States)

1964-08-01

In this study a comparator-type measuring system was developed to accurately determine volume change characteristics of one structural lightweight concrete. The specific properties studied were the coefficient of linear thermal expansion and unrestra...

HOKES/POKES : Light-weight resource sharing

NARCIS (Netherlands)

Bos, Herbert; Samwel, Bart

2003-01-01

In this paper, we explain mechanisms for providing embedded network processors and other low-level programming environments with light-weight support for safe resource sharing. The solution consists of a host part, known as HOKES, and a network processor part, known as POKES. As common operating

Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification.

Science.gov (United States)

Evans, A; Whelehan, P; Thomson, K; Brauer, K; Jordan, L; Purdie, C; McLean, D; Baker, L; Vinnicombe, S; Thompson, A

2012-07-10

The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients. One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained. For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02). Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.

Computational imaging using lightweight diffractive-refractive optics

KAUST Repository

Peng, Yifan

2015-11-23

Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

Computational imaging using lightweight diffractive-refractive optics

KAUST Repository

Peng, Yifan; Fu, Qiang; Amata, Hadi; Su, Shuochen; Heide, Felix; Heidrich, Wolfgang

2015-01-01

Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

Resonant modal group theory of membrane-type acoustical metamaterials for low-frequency sound attenuation

Science.gov (United States)

Ma, Fuyin; Wu, Jiu Hui; Huang, Meng

2015-09-01

In order to overcome the influence of the structural resonance on the continuous structures and obtain a lightweight thin-layer structure which can effectively isolate the low-frequency noises, an elastic membrane structure was proposed. In the low-frequency range below 500 Hz, the sound transmission loss (STL) of this membrane type structure is greatly higher than that of the current sound insulation material EVA (ethylene-vinyl acetate copo) of vehicle, so it is possible to replace the EVA by the membrane-type metamaterial structure in practice engineering. Based on the band structure, modal shapes, as well as the sound transmission simulation, the sound insulation mechanism of the designed membrane-type acoustic metamaterials was analyzed from a new perspective, which had been validated experimentally. It is suggested that in the frequency range above 200 Hz for this membrane-mass type structure, the sound insulation effect was principally not due to the low-level locally resonant mode of the mass block, but the continuous vertical resonant modes of the localized membrane. So based on such a physical property, a resonant modal group theory is initially proposed in this paper. In addition, the sound insulation mechanism of the membrane-type structure and thin plate structure were combined by the membrane/plate resonant theory.

The Modal Dimension

Directory of Open Access Journals (Sweden)

Giluano Torrengo

2018-05-01

Full Text Available Space and time are two obvious candidates as dimensions of reality. Yet, are they the only two dimensions of reality? Famously, David Lewis maintained the doctrine of ―modal realism‖, the thesis that possible worlds exist and are entities as concrete as the actual world that we live in. In this paper, I will explore the idea that modality can be construed as a dimension along with space and time. However, although Lewis‘ modal realism is the main source of inspiration for this construal of modality, I will argue that something else is required for having a modal dimension.

Morphology of Burned Ultra-low Density Fiberboards

Directory of Open Access Journals (Sweden)

Min Niu

2015-09-01

Full Text Available The synergistic effect of two fire retardants, a Si-Al compound and chlorinated paraffin, was tested on ultra-low density fiberboards (ULDFs. To further understand the mechanism of fire retardancy, morphologies of unburned and burned ULDFs were studied using a scanning electron microscope with energy dispersive spectroscopy. It was found that as the volume of the burned ULDFs shrank, some crevices appeared. In addition, less fly ash formed on the top of specimens, and more bottom ashes remained in the original framework, with a clear network of structure built by the fibers. Carbon was almost absent in the fly ash; however, the weight ratio of C in the bottom ashes reached the maximum (> 43% of the composition. Oxygen, Al, and Si appeared to have varying weight ratios for different ashes. Oxygen content increased with increasing Si and Al contents. Furthermore, Cl sharply decreased to less than 1% after combustion. Therefore, upon combustion, it was found that almost all of the substances in ULDFs, except for the Si-Al compound, were pyrolyzed to volatile carbon oxides and Cl compounds, especially the fly ash and lightweight C compounds.

Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

Energy Technology Data Exchange (ETDEWEB)

Cui, J., E-mail: jun.cui@pnnl.gov; Choi, J. P.; Li, G.; Polikarpov, E.; Darsell, J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Kramer, M. J.; Zarkevich, N. A.; Wang, L. L.; Johnson, D. D. [Materials Sciences and Engineering Division, Ames Laboratory, Ames, Iowa 50011 (United States); Marinescu, M. [Electron Energy Corporation, Landisville, Pennsylvania 17538 (United States); Huang, Q. Z.; Wu, H. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102 (United States); Vuong, N. V.; Liu, J. P. [Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2014-05-07

MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 μ{sub B} at 50 K and 300 K, respectively.

Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

Energy Technology Data Exchange (ETDEWEB)

Cui, J; Choi, JP; Li, G; Polikarpov, E; Darsell, J; Kramer, MJ; Zarkevich, NA; Wang, LL; Johnson, DD; Marinescu, M; Huang, QZ; Wu, H; Vuong, NV; Liu, JP

2014-05-07

MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 mu(B) at 50 K and 300 K, respectively. (C) 2014 AIP Publishing LLC.

Strength properties of cement slurries with lightweights applied in oil and gas wells

International Nuclear Information System (INIS)

Bubnov, A S; Drilling Mud and Cement Slurry (Russian Federation))" data-affiliation=" (Head of Laboratory Drilling Mud and Cement Slurry (Russian Federation))" >Boyko, I A; Drilling Mud and Cement Slurry (Russian Federation))" data-affiliation=" (PhD, Engineer, Laboratory Drilling Mud and Cement Slurry (Russian Federation))" >Khorev, V S

2015-01-01

The article is focused on the cement stone strength properties resulted from lightweight cement slurries that meet GOST-1581-96 (state Standards) requirements. Exfoliated vermiculite, hollow aluminosilicate microspheres (HAMs), diatomite and perlite were used as lightweighting additives

Study on conversion relationships of compressive strength indexes for recycled lightweight aggregate concrete

Science.gov (United States)

Zhang, Xiang-gang; Yang, Jian-hui; Kuang, Xiao-mei

2017-01-01

In order to study cube compressive strength and axial compressive strength of recycled lightweight aggregate concrete(RLAC), and conversion relationship between the two, with the replacement rate of recycled lightweight coarse aggregate as change parameters, 15 standard cube test specimens and 15 standard prism test specimens were produced to carry out the test. Then compressive strength of test specimens were measured, and the law of different replacement rate of recycled lightweight coarse aggregate influencing compressive strength of RLAC was analyzed, as the method of statistical regression adopted, the conversion relationships between of cube compressive strength and axial compressive strength of RLAC was obtained. It is shown that compressive strength of RLAC are lower than compressive strength of ordinary concrete; and that compressive strength of RLAC gradually decreases as replacement rate of recycled lightweight coarse aggregate increases; as well as, the conversion relationship between axial compressive strength and cube compressive strength of RLAC is different from ordinary concrete; based on the experimental data, conversion relationship formula between compressive strength indexes of RLAC was established. It is suggested that the replacement rate of recycled lightweight aggregate should be controlled within 25%.

Experimental study on the effect of volcanic residue on the performance of recycled lightweight aggregate concrete

Science.gov (United States)

Xiao, Li-guang; Li, Ji-heng; Liu, Qing-shun

2017-08-01

Recycled lightweight aggregate concrete prepared with waste brick recycled light aggregate has high water absorption, large apparent density and poor frost resistance. The technical measures of regen-erating lightweight aggregate concrete with modified waste bricks from volcanic slag are put forward. The effects of volcanic slag on the properties of waste lightweight aggregate concrete were studied. The experi-mental results show that volcanic slag can significantly reduce the apparent density of recycled lightweight aggregate concrete and improve its frost resistance.

Cryptanalysis of Compact-LWE and Related Lightweight Public Key Encryption

Directory of Open Access Journals (Sweden)

Dianyan Xiao

2018-01-01

Full Text Available In the emerging Internet of Things (IoT, lightweight public key cryptography plays an essential role in security and privacy protection. With the approach of quantum computing era, it is important to design and evaluate lightweight quantum-resistant cryptographic algorithms applicable to IoT. LWE-based cryptography is a widely used and well-studied family of postquantum cryptographic constructions whose hardness is based on worst-case lattice problems. To make LWE friendly to resource-constrained IoT devices, a variant of LWE, named Compact-LWE, was proposed and used to design lightweight cryptographic schemes. In this paper, we study the so-called Compact-LWE problem and clarify that under certain parameter settings it can be solved in polynomial time. As a consequence, our result leads to a practical attack against an instantiated scheme based on Compact-LWE proposed by Liu et al. in 2017.

Mechanical Properties of Fiber Reinforced Lightweight Concrete Containing Surfactant

Directory of Open Access Journals (Sweden)

Yoo-Jae Kim

2010-01-01

Full Text Available Fiber reinforced aerated lightweight concrete (FALC was developed to reduce concrete's density and to improve its fire resistance, thermal conductivity, and energy absorption. Compression tests were performed to determine basic properties of FALC. The primary independent variables were the types and volume fraction of fibers, and the amount of air in the concrete. Polypropylene and carbon fibers were investigated at 0, 1, 2, 3, and 4% volume ratios. The lightweight aggregate used was made of expanded clay. A self-compaction agent was used to reduce the water-cement ratio and keep good workability. A surfactant was also added to introduce air into the concrete. This study provides basic information regarding the mechanical properties of FALC and compares FALC with fiber reinforced lightweight concrete. The properties investigated include the unit weight, uniaxial compressive strength, modulus of elasticity, and toughness index. Based on the properties, a stress-strain prediction model was proposed. It was demonstrated that the proposed model accurately predicts the stress-strain behavior of FALC.

Global EiBI-monopole

Directory of Open Access Journals (Sweden)

JIN Xinghua

2014-04-01

Full Text Available A global EiBI-monopole problem is studied under EiBI gravitational theory.The equations of global EiBI-monopole are derived in the curved spacetime and the relation between the spacetime metric and auxiliary metric is found.In the case of a very small parameter,an asymptotic form of equations is given.The series solutions of global EiBI-monopole at infinity are found.

Mechanical and Physical Properties of Hydrophobized Lightweight Aggregate Concrete with Sewage Sludge.

Science.gov (United States)

Suchorab, Zbigniew; Barnat-Hunek, Danuta; Franus, Małgorzata; Łagód, Grzegorz

2016-04-27

This article is focused on lightweight aggregate-concrete modified by municipal sewage sludge and lightweight aggregate-concrete obtained from light aggregates. The article presents laboratory examinations of material physical parameters. Water absorptivity of the examined material was decreased by the admixture of water emulsion of reactive polysiloxanes. Water transport properties were determined using Time Domain Reflectometry, an indirect technique for moisture detection in porous media. Together with basic physical parameters, the heat conductivity coefficient λ was determined for both types of lightweight aggregate-concrete. Analysis of moisture and heat properties of the examined materials confirmed the usefulness of light aggregates supplemented with sewage sludge for prospective production.

Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS)

OpenAIRE

Butler, J.J.; Park, H.; Barnes, P.Y.; Early, E.A.; Eijk-Olij, C. van; Zoutman, A.E.; Buller-Leeuwen, S. van; Groote Schaarsberg, J.

2002-01-01

The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those instruments. To assess the ability of laboratories to provide accurate Ultra Violet (UV) diffuse BRDF measurements, a BRDF measurement comparison was initiated by the NASA Total Ozone Mapping Spectrom...

Experimental modal analysis

Energy Technology Data Exchange (ETDEWEB)

Ibsen, Lars Bo; Liingaard, M.

2006-12-15

This technical report concerns the basic theory and principles for experimental modal analysis. The sections within the report are: Output-only modal analysis software, general digital analysis, basics of structural dynamics and modal analysis and system identification. (au)

Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

Energy Technology Data Exchange (ETDEWEB)

Punkki, J

1996-12-31

Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

Energy Technology Data Exchange (ETDEWEB)

Punkki, J.

1995-12-31

Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

Energy-efficient light scooter; Energieeffizienter Leicht-Scooter im Gewichtsbereich eines Mofa

Energy Technology Data Exchange (ETDEWEB)

Fuchs, A

2005-07-01

This report for the Swiss Federal Office of Energy (SFOE) presents the results of feasibility study on the development of an energy-efficient lightweight scooter. The report looks at the low energy consumption and low CO{sub 2} emissions of ultra-lightweight vehicles and presents a market analysis. The state-of-the-art of electrically-powered two-wheel vehicles is reviewed. Further topics include technical feasibility, drive-system components and battery-management systems. Safety considerations and economical feasibility are examined, as are functional requirements. A vision for a ultra-lightweight scooter is presented and industrial production aspects are reviewed.

Lightweight and Energy Efficient Heat Pump, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Future Spacecraft from the JPL will require increasingly sophisticated thermal control technology. A need exists for efficient, lightweight Vapor Compression Cycle...

Ultrathin g-C3N4 Nanosheet-Modified BiOCl Hierarchical Flower-Like Plate Heterostructure with Enhanced Photostability and Photocatalytic Performance

Directory of Open Access Journals (Sweden)

Tiekun Jia

2017-08-01

Full Text Available A novel ultrathin g-C3N4 nanosheet-modified BiOCl hierarchical flower-like plate heterostructure (abbreviated as BC/CN was constructed via a thermal polymerization of urea precursor followed with hydrolysis route. The as-prepared samples were well characterized by various analytical techniques. The morphological observation showed that hierarchical flower-like BiOCl nanoplates were discretely anchored on the surface of ultra-thin C3N4 nanosheets. The photocatalytic performance of the as-prepared photocatalysts was evaluated by degradation of methylene blue (MB under visible-light irradiation. The results showed that BC/CN photocatalyst exhibited enhanced photostability and photocatalytic performance in the degradation process. On the basis of experimental results and the analysis of band energy structure, it could be inferred that the enhanced photocatalytic performance of BC/CN photocatalyst was intimately related with the hybridization of hierarchical flower-like BiOCl nanoplates with ultrathin g-C3N4 nanosheets, which provided good adsorptive capacity, extended light absorption, suppressed the recombination of photo-generated electron–hole pairs, and facilitated charge transfer efficiently.

Metaphysical Modality, Modality of Predicate and the Theory of "Decisive Necessity”

Directory of Open Access Journals (Sweden)

L. Nabavi

2010-01-01

Full Text Available Aristotle in the Organon (1949: 9,30 a ,15-19 explicitly states that in a categorical syllogism when the minor premise is absolute (without modality operator and the major is necessary, the conclusion will be necessary too. This Aristotle's view has been the source of many conflicts and disputes in the history of logic. The famous logicians and historians of logic in the twentieth century as "Nicholas Rescher" and "Becker" believe that Aristotle's view is justifiable and defensible (at least compared to the first figure only if, the modality of major premise is considered as the property of predicate (modality de re. Today, we know very well that the modality of predicate is closely linked to Metaphysical and philosophical Modality. “Shihab al-Din al- Suhrawardi” in the theory of "Decisive (Battateh Necessity” by accepting this base, explicitly states that, in the beginning, the modality must be mentioned as a part of the predicate and then the modality of relation or copula is summarized and reduced to necessity. The modern formalization of the most important part of this theory is as follows: ("x (àAx É à Bx º ("x □ (àAx É à BxThis paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

Topology Optimization of Lightweight Lattice Structural Composites Inspired by Cuttlefish Bone

Science.gov (United States)

Hu, Zhong; Gadipudi, Varun Kumar; Salem, David R.

2018-03-01

Lattice structural composites are of great interest to various industries where lightweight multifunctionality is important, especially aerospace. However, strong coupling among the composition, microstructure, porous topology, and fabrication of such materials impedes conventional trial-and-error experimental development. In this work, a discontinuous carbon fiber reinforced polymer matrix composite was adopted for structural design. A reliable and robust design approach for developing lightweight multifunctional lattice structural composites was proposed, inspired by biomimetics and based on topology optimization. Three-dimensional periodic lattice blocks were initially designed, inspired by the cuttlefish bone microstructure. The topologies of the three-dimensional periodic blocks were further optimized by computer modeling, and the mechanical properties of the topology optimized lightweight lattice structures were characterized by computer modeling. The lattice structures with optimal performance were identified.

Cross-modal versus within-modal recall: differences in behavioral and brain responses.

Science.gov (United States)

Butler, Andrew J; James, Karin H

2011-10-31

Although human experience is multisensory in nature, previous research has focused predominantly on memory for unisensory as opposed to multisensory information. In this work, we sought to investigate behavioral and neural differences between the cued recall of cross-modal audiovisual associations versus within-modal visual or auditory associations. Participants were presented with cue-target associations comprised of pairs of nonsense objects, pairs of nonsense sounds, objects paired with sounds, and sounds paired with objects. Subsequently, they were required to recall the modality of the target given the cue while behavioral accuracy, reaction time, and blood oxygenation level dependent (BOLD) activation were measured. Successful within-modal recall was associated with modality-specific reactivation in primary perceptual regions, and was more accurate than cross-modal retrieval. When auditory targets were correctly or incorrectly recalled using a cross-modal visual cue, there was re-activation in auditory association cortex, and recall of information from cross-modal associations activated the hippocampus to a greater degree than within-modal associations. Findings support theories that propose an overlap between regions active during perception and memory, and show that behavioral and neural differences exist between within- and cross-modal associations. Overall the current study highlights the importance of the role of multisensory information in memory. Copyright © 2011 Elsevier B.V. All rights reserved.

High photocatalytic performance of BiOI/Bi{sub 2}WO{sub 6} toward toluene and Reactive Brilliant Red

Energy Technology Data Exchange (ETDEWEB)

Li Huiquan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Key Laboratory of Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Cui Yumin, E-mail: cuiyumin0908@163.com [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Hong Wenshan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China)

2013-01-01

Graphical abstract: When BiOI/Bi{sub 2}WO{sub 6} catalyst was exposed to UV or visible light, the electrons in the valence band of Bi{sub 2}WO{sub 6} would be excited into the conduction band and then injected into the more positive conduction band of BiOI. Therefore, the photoelectrons were generated from Bi{sub 2}WO{sub 6} and transferred across the interface between BiOI and Bi{sub 2}WO{sub 6} to the surface of BiOI, leaving the photogenerated holes in the valence band of Bi{sub 2}WO{sub 6}. In this way, the photoinduced electron-hole pairs were effectively separated. Highlights: Black-Right-Pointing-Pointer BiOI sensitized Bi{sub 2}WO{sub 6} catalysts were successfully prepared by a facile method. Black-Right-Pointing-Pointer The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits higher photoactivities than P25. Black-Right-Pointing-Pointer A possible transfer process of photogenerated carriers was proposed. - Abstract: BiOI sensitized nano-Bi{sub 2}WO{sub 6} photocatalysts with different BiOI contents were successfully synthesized by a facile deposition method at room temperature, and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL) spectra, UV-vis diffuse reflection spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area measurements. The photocatalytic activity of BiOI/Bi{sub 2}WO{sub 6} was evaluated by the photo-degradation of Reactive Brilliant Red (X-3B) in suspended solution and toluene in gas phase. It has been shown that the BiOI/Bi{sub 2}WO{sub 6} catalysts exhibit a coexistence of both tetragonal BiOI and orthorhombic Bi{sub 2}WO{sub 6} phases. With increasing BiOI content, the absorption intensity of BiOI/Bi{sub 2}WO{sub 6} catalysts increases in the 380-600 nm region and the absorption edge shifts significantly to longer wavelengths as compared to pure Bi{sub 2}WO{sub 6}. The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits

Properties and shaping of lightweight ceramics based on phosphate-bonded hollow silica microspheres

NARCIS (Netherlands)

With, de G.; Verweij, H.

1986-01-01

The values for the Young's modulus, strength, fracture toughness and thermal conductivity of lightweight ceramics based on phosphate-bonded hollow silica microspheres are reported as a function of the processing conditions. They are compared with the relevant data for other lightweight ceramic

Comparison of Mechanical Properties of Lightweight and Normal Weight Concretes Reinforced with Steel Fibers

Directory of Open Access Journals (Sweden)

A. Ali

2018-04-01

Full Text Available Compared to conventional concrete, lightweight concrete is more brittle in nature however, in many situations its application is advantageous due to its lower weight. The associated brittleness issue can be, to some extent, addressed by incorporation of discrete fibers. It is now established that fibers modify some fresh and hardened concrete properties. However, evaluation of those properties for lightweight fiber-reinforced concrete (LWFC against conventional/normal weight concrete of similar strength class has not been done before. Current study not only discusses the change in these properties for lightweight concrete after the addition of steel fibers, but also presents a comparison of these properties with conventional concrete with and without fibers. Both the lightweight and conventional concrete were reinforced with similar types and quantity of fibers. Hooked end steel fibers were added in the quantities of 0, 20, 40 and 60kg/m3. For similar compressive strength class, results indicate that compared to normal weight fiber-reinforced concrete (NWFC, lightweight fiber-reinforced concrete (LWFC has better fresh concrete properties, but performs poorly when tested for hardened concrete properties.

MLED_BI: a new BI Design Approach to Support Multilingualism in Business Intelligence

Directory of Open Access Journals (Sweden)

Nedim Dedić

2017-11-01

Full Text Available Existing approaches to support Multilingualism (ML in Business Intelligence (BI create problems for business users, present a number of challenges from the technical perspective, and lead to issues with logical dependence in the star schema. In this paper, we propose MLED_BI (Multilingual Enabled Design for Business Intelligence, a novel BI design approach to support the application of ML in BI Environment, which overcomes the issues and problems found with existing approaches. The approach is based on a revision of the data warehouse dimensional modelling approach and treats the Star Schema as a higher level entity. This paper describes MLED_BI and the validation and evaluation approach used.

Ga-Bi-Te system

International Nuclear Information System (INIS)

Rustamov, P.G.; Seidova, N.A.; Shakhbazov, M.G.; AN Azerbajdzhanskoj SSR, Baku. Inst. Neorganicheskoj i Fizicheskoj Khimii)

1976-01-01

To elucidate the nature of interaction in the system Ga-Bi-Te, a study has been made of sections GaTe-Bi 2 Te 3 , Ga 2 Te 3 -Bi, GaTe-Bi and Bi 2 Te 3 -Ga. The alloys have been prepared by direct melting of the components or their alloys with subsequent homogenizin.o annealing at 400 deg C. The study has been made by the methods of differential thermal, microstructural analysis and by microhardness measurements. On the basis of literature data and data obtained a projection of the liquidus surface of the phase diagram for the system Ga-Bi-Te has been constructed. In the ternary system there are 17 curves of monovariant equilibrium dividing the liquidus into 10 fields of primary crystallization of phases, 9 points of non-variant equilibrium of which 4 points are triple eutectics and 5 points are triple peritectics

Development of lightweight concrete mixes for construction industry at the state of Arkansas

Science.gov (United States)

Almansouri, Mohammed Abdulwahab

As the construction industry evolved, the need for more durable, long lasting infrastructure increased. Therefore, more efforts have been put to find new methods to improve the properties of the concrete to prolong the service life of the structural elements. One of these methods is the use of lightweight aggregate as an internal curing agent to help reducing self-desiccation and shrinkage. This research studied the effects of using locally available lightweight aggregate (expanded clay), as a partial replacement of normal weight aggregate in the concrete matrix. The concrete mixtures contained lightweight aggregate with a replacement percentage of 12.5, 25, 37.5, and 50 percent by volume. Fresh properties as well as compressive strength, modulus of rupture, and drying shrinkage were measured. While was effective in reducing drying shrinkage, the use of lightweight aggregate resulted in slightly reducing both the compressive strength and modulus of rupture.

Operational Modal Analysis Tutorial

DEFF Research Database (Denmark)

Brincker, Rune; Andersen, Palle

of modal parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the operational technology offers the user a number of advantages over traditional modal testing. The operational modal technology allows the user to perform a modal......In this paper the basic principles in operational modal testing and analysis are presented and discussed. A brief review of the techniques for operational modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification...

FY 2012 Lightweight Materials Annual Report

Energy Technology Data Exchange (ETDEWEB)

None

2013-04-15

The FY 2012 Annual Progress Report for Lightweight Materials provides a detailed description of the activities and technical accomplishments which focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

Ultra-low carrier concentration and surface-dominant transport in antimony-doped Bi2Se3 topological insulator nanoribbons

KAUST Repository

Hong, Seung Sae; Cha, Judy J.; Kong, Desheng; Cui, Yi

2012-01-01

A topological insulator is the state of quantum matter possessing gapless spin-locking surface states across the bulk band gap, which has created new opportunities from novel electronics to energy conversion. However, the large concentration of bulk residual carriers has been a major challenge for revealing the property of the topological surface state by electron transport measurements. Here we report the surface-state-dominant transport in antimony-doped, zinc oxide-encapsulated Bi2Se3 nanoribbons with suppressed bulk electron concentration. In the nanoribbon with sub-10-nm thickness protected by a zinc oxide layer, we position the Fermi levels of the top and bottom surfaces near the Dirac point by electrostatic gating, achieving extremely low two-dimensional carrier concentration of 2×10 11cm-2. The zinc oxide-capped, antimony-doped Bi 2Se3 nanostructures provide an attractive materials platform to study fundamental physics in topological insulators, as well as future applications. © 2012 Macmillan Publishers Limited. All rights reserved.

Ultra-low carrier concentration and surface-dominant transport in antimony-doped Bi2Se3 topological insulator nanoribbons

KAUST Repository

Hong, Seung Sae

2012-03-27

A topological insulator is the state of quantum matter possessing gapless spin-locking surface states across the bulk band gap, which has created new opportunities from novel electronics to energy conversion. However, the large concentration of bulk residual carriers has been a major challenge for revealing the property of the topological surface state by electron transport measurements. Here we report the surface-state-dominant transport in antimony-doped, zinc oxide-encapsulated Bi2Se3 nanoribbons with suppressed bulk electron concentration. In the nanoribbon with sub-10-nm thickness protected by a zinc oxide layer, we position the Fermi levels of the top and bottom surfaces near the Dirac point by electrostatic gating, achieving extremely low two-dimensional carrier concentration of 2×10 11cm-2. The zinc oxide-capped, antimony-doped Bi 2Se3 nanostructures provide an attractive materials platform to study fundamental physics in topological insulators, as well as future applications. © 2012 Macmillan Publishers Limited. All rights reserved.

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

International Nuclear Information System (INIS)

Xiong Ka; Wang Weichao; Alshareef, Husam N; Gupta, Rahul P; Gnade, Bruce E; Cho, Kyeongjae; White, John B

2010-01-01

We investigate the electronic structures and stability for Ni/Bi 2 Te 3 , NiTe/Bi 2 Te 3 , Co/Bi 2 Te 3 and CoTe 2 /Bi 2 Te 3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi 2 Te 3 . The interface formation energy for Co/Bi 2 Te 3 interfaces is much lower than that of Ni/Bi 2 Te 3 interfaces. Furthermore, we found that NiTe on Bi 2 Te 3 is more stable than Ni, while the formation energies for Co and CoTe 2 on Bi 2 Te 3 are comparable.

Proportioning of Lightweight Concrete by the Inclusions of Expanded Polystyrene Beads (EPS and Foam Agent

Directory of Open Access Journals (Sweden)

Eethar Thanon Dawood

2016-10-01

Full Text Available This paper illustrates the performance of lightweight concrete using various amounts of expanded polystyrene beads (EPS and different amounts of foam agent to produce lightweight concrete. The objective of this paper is to produce lightweight concrete with good workability and strength, by different mix proportion of foam agent (0.4, 0.6, 0.8, 1, 1.2 kg/m3 and varying water cement ratio (w/c depending on the flow. Besides, various proportions using different percentages of EPS in order of volume fractions are used. The flow range used in the study is 110-130%. Each mix proportion is tested for compressive strength, modulus of rupture, density and voids ratio. The results gives acceptable ranges of strength for lightweight concrete produced by the inclusions of EPS beads and foam concrete. Therefore, the lightweight concrete produced in this work can be used for structural applications like multistory building frames, floors, bridges and prestressed or precast elements. 

Radiological assessment of breast density by visual classification (BI-RADS) compared to automated volumetric digital software (Quantra): implications for clinical practice.

Science.gov (United States)

Regini, Elisa; Mariscotti, Giovanna; Durando, Manuela; Ghione, Gianluca; Luparia, Andrea; Campanino, Pier Paolo; Bianchi, Caterina Chiara; Bergamasco, Laura; Fonio, Paolo; Gandini, Giovanni

2014-10-01

This study was done to assess breast density on digital mammography and digital breast tomosynthesis according to the visual Breast Imaging Reporting and Data System (BI-RADS) classification, to compare visual assessment with Quantra software for automated density measurement, and to establish the role of the software in clinical practice. We analysed 200 digital mammograms performed in 2D and 3D modality, 100 of which positive for breast cancer and 100 negative. Radiological density was assessed with the BI-RADS classification; a Quantra density cut-off value was sought on the 2D images only to discriminate between BI-RADS categories 1-2 and BI-RADS 3-4. Breast density was correlated with age, use of hormone therapy, and increased risk of disease. The agreement between the 2D and 3D assessments of BI-RADS density was high (K 0.96). A cut-off value of 21% is that which allows us to best discriminate between BI-RADS categories 1-2 and 3-4. Breast density was negatively correlated to age (r = -0.44) and positively to use of hormone therapy (p = 0.0004). Quantra density was higher in breasts with cancer than in healthy breasts. There is no clear difference between the visual assessments of density on 2D and 3D images. Use of the automated system requires the adoption of a cut-off value (set at 21%) to effectively discriminate BI-RADS 1-2 and 3-4, and could be useful in clinical practice.

Meditations on Metaphysical Modality

OpenAIRE

Willis, Edmund Lindsay James

2011-01-01

Although metaphysical modality has been much discussed and exploited by philosophers, its precise nature is often left unanalysed and obscure. This dissertation marks an attempt to understand it better. After examining modality in general, the specific topic is introduced through consideration of the views of Kripke and Lewis. Comparisons are then made with logical, scientific and conceptual modalities. Finally, it is argued that metaphysical modality is that variety of modality which is alet...

Ultra-high vacuum compatible optical chopper system for synchrotron x-ray scanning tunneling microscopy

Energy Technology Data Exchange (ETDEWEB)

Chang, Hao, E-mail: hc000211@ohio.edu [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Cummings, Marvin; Shirato, Nozomi; Stripe, Benjamin; Preissner, Curt; Freeland, John W. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rosenmann, Daniel [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Kersell, Heath; Hla, Saw-Wai [Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rose, Volker, E-mail: vrose@anl.gov [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2016-01-28

High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM.

Pavement evaluation using a portable lightweight deflectometer.

Science.gov (United States)

2012-12-01

The use of Zorn ZFG-3000 portable Lightweight Deflectometer (LWD) in the in-situ : assessment of pavement quality was investigated in this research. A lower load and a : shorter load pulse duration are used in a LWD as compared to a Falling Weight : ...

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

KAUST Repository

Xiong, Ka; Wang, Weichao; Alshareef, Husam N.; Gupta, Rahul P.; White, John B.; Gnade, Bruce E.; Cho, Kyeongjae

2010-01-01

We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

KAUST Repository

Xiong, Ka

2010-03-04

We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

Bismuth-boron multiple bonding in BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}

Energy Technology Data Exchange (ETDEWEB)

Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, RI (United States)

2017-08-01

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}, containing triple and double B-Bi bonds are presented. The BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -} clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB{sub 2}O{sup -} ([Bi≡B-B≡O]{sup -}) and Bi{sub 2}B{sup -} ([Bi=B=Bi]{sup -}), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Microstructure Of MnBi/Bi Eutectic Alloy

Science.gov (United States)

Wilcox, William R.; Eisa, G. F.; Baskaran, B.; Richardson, Donald C.

1988-01-01

Collection of three reports describes studies of directional solidification of MnBi/Bi eutectic alloy. Two of the reports, "Influence of Convection on Lamellar Spacing of Eutectics" and "Influence of Convection on Eutectic Microstructure," establish theoretical foundation for remaining document. Reports seek to quantify effect of convection on concentration field of growing lamellar eutectic. Remaining report, "Study of Eutectic Formation," begins by continuing theoretical developments. New technique under development by one of the authors helps to reveal three-dimensional microstructures of alloys.

Photocatalytic activity of Bi{sub 2}WO{sub 6}/Bi{sub 2}S{sub 3} heterojunctions: the facilitation of exposed facets of Bi{sub 2}WO{sub 6} substrate

Energy Technology Data Exchange (ETDEWEB)

Yan, Long [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Wang, Yufei [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Shen, Huidong; Zhang, Yu [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Li, Jian [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Wang, Danjun, E-mail: yulyanlong@aliyun.com [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China)

2017-01-30

Highlights: • Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrids with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi{sub 2}S{sub 3} was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrid architectures with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi{sub 2}S{sub 3} was formed on the surface of Bi{sub 2}WO{sub 6} during the anion exchange process, thus leading to the transformation from the Bi{sub 2}WO{sub 6} to Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} catalysts. Under visible light irradiation, the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA displayed the excellent visible light photoactivities compared with pure Bi{sub 2}S{sub 3}, Bi{sub 2}WO{sub 6} and other composite photocatalysts. The efficient photocatalytic activity of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi{sub 2}WO{sub 6} facets. Active species trapping experiments revealed that h{sup +} and O{sub 2}·{sup −} are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

Theoretical Study of the Vibration Suppression on a Mistuned Bladed Disk Using a Bi-periodic Piezoelectric Network

Science.gov (United States)

Li, Lin; Deng, Pengcheng; Liu, Jiuzhou; Li, Chao

2018-03-01

The paper deals with the vibration suppression of a bladed disk with a piezoelectric network. The piezoelectric network has a different period (so called bi-period) from that of the bladed disk and there is no inductor in it. The system is simulated by an electromechanical lumped parameter model with two DOFs per sector. The research focuses on suppressing the amplitude magnification or reducing the vibration localization of the mistuned bladed disk. The dynamic equations of the system are derived. Both mechanical mistuning and electrical mistuning have been taken into account. The Modified Modal Assurance Criterion (MMAC) is used to evaluate the vibration suppression ability of the bi-periodic piezoelectric network. The Monte Carlo simulation is used to calculate the MMAC of the system with the random mistuning. As a reference, the forced responses of the bladed disk with and without the piezoelectric network are given. The results show that the piezoelectric network would effectively suppress amplitude magnification induced by mistuning. The vibration amplitude is even smaller than that of the tuned system. The robustness analysis shows that the bi-periodic piezoelectric network can provide a reliable assurance for avoiding the forced response amplification of the mistuned bladed disk. The amplified response induced by the mechanical mistuning with standard deviation 0.2 can be effectively suppressed through the bi-periodic piezoelectric network.

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO3 thin film

International Nuclear Information System (INIS)

Gupta, Surbhi; Gupta, Vinay; Tomar, Monika; James, A. R.; Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar

2014-01-01

Multiferroic Bismuth Ferrite (BiFeO 3 ) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO 3 thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO 3 and Fe 2 O 3 to pure BiFeO 3 phase and, subsequently, to a mixture of BiFeO 3 and Bi 2 O 3 with increase in the concentration of excess Bi from 0% to 15%. BiFeO 3 thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe 2 O 3 ). Deterioration in ferroic properties of BiFeO 3 thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO 3 thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm 2 and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO 3 thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO 3 thin films exhibiting the improved multiferroic properties.

Vacuum improvements for ultra high charge state ion acceleration

International Nuclear Information System (INIS)

Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A

1998-06-01

The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1,115 MeV. At about 5 NeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted ut of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models

Vacuum improvements for ultra high charge state ion acceleration

International Nuclear Information System (INIS)

Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A.

1999-01-01

The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% % to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1115 MeV. At about 5 MeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted out of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models. (authors)

Metaphysical Modality, Modality of Predicate and the Theory of

Directory of Open Access Journals (Sweden)

l nabavi

2010-05-01

This paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

Lightweight cordierite–mullite refractories with low coefficients of ...

Indian Academy of Sciences (India)

of thermal conductivity and high mechanical properties ... compositions and microstructures of lightweight refractories were measured by X-ray .... of matrices were determined by calibration with EDAX ZAF .... Guzman I Ya 2003 Glass Ceram.

Lightweight flywheel containment

Science.gov (United States)

Smith, James R.

2004-06-29

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

OpenAIRE

Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

2015-01-01

A new BiS2-based superconductor Bi2(O,F)S2 was discovered. This is a layered compound consisting of alternate stacking structure of rock-salt-type BiS2 superconducting layer and fluorite-type Bi(O,F) blocking layer. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2, which is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis length increased and decreased, respe...

Lightweight cryptography for constrained devices

DEFF Research Database (Denmark)

Alippi, Cesare; Bogdanov, Andrey; Regazzoni, Francesco

2014-01-01

Lightweight cryptography is a rapidly evolving research field that responds to the request for security in resource constrained devices. This need arises from crucial pervasive IT applications, such as those based on RFID tags where cost and energy constraints drastically limit the solution...... complexity, with the consequence that traditional cryptography solutions become too costly to be implemented. In this paper, we survey design strategies and techniques suitable for implementing security primitives in constrained devices....

A comparison of dose savings of lead and lightweight aprons for shielding of 99m-Technetium radiation

International Nuclear Information System (INIS)

Warren-Forward, H.; Cardew, P.; Smith, B.; Clack, L.; McWhirter, K.; Johnson, S.; Wessel, K.

2007-01-01

Nuclear medicine technologists (NMTs) have the highest effective doses of radiation among medical workers. With increase in the use of lightweight materials in diagnostic radiography, the aim was to compare the effectiveness of lead and lightweight aprons in shielding from 99m-Technetium ( 99m Tc) gamma rays. The doses received from a scattering phantom to the entrance, 9 cm depth and exit of a phantom were measured with LiF:Mg, Cu, P thermoluminescent dosemeters (TLDs). Doses and spectra were assessed without no shielding, with 0.5-mm lead and lightweight aprons. The lead and lightweight aprons decreased entrance surface doses by 76 and 59%, respectively. The spectral analysis showed that the lightweight apron provided better dose reduction at energies 99m Tc labelled radiopharmaceutical. (authors)

Sun Ultra 5

CERN Multimedia

1998-01-01

The Sun Ultra 5 is a 64-bit personal computer based on the UltraSPARC microprocessor line at a low price. The Ultra 5 has been declined in several variants: thus, some models have a processor with less cache memory to further decrease the price of the computer.

Toward predicate approaches to modality

CERN Document Server

Stern, Johannes

2016-01-01

In this volume, the author investigates and argues for, a particular answer to the question: What is the right way to logically analyze modalities from natural language within formal languages? The answer is: by formalizing modal expressions in terms of predicates. But, as in the case of truth, the most intuitive modal principles lead to paradox once the modal notions are conceived as predicates. The book discusses the philosophical interpretation of these modal paradoxes and argues that any satisfactory approach to modality will have to face the paradoxes independently of the grammatical category of the modal notion. By systematizing modal principles with respect to their joint consistency and inconsistency, Stern provides an overview of the options and limitations of the predicate approach to modality that may serve as a useful starting point for future work on predicate approaches to modality. Stern also develops a general strategy for constructing philosophically attractive theories of modal notions conce...

Alkali-silica reactivity of expanded glass granules in structure of lightweight concrete

International Nuclear Information System (INIS)

Bumanis, G; Bajare, D; Korjakins, A; Locs, J

2013-01-01

Main component in the lightweight concrete, which provides its properties, is aggregate. A lot of investigations on alkali silica reaction (ASR) between cement and lightweight aggregates have been done with their results published in the academic literature. Whereas expanded glass granules, which is relatively new product in the market of building materials, has not been a frequent research object. Therefore lightweight granules made from waste glass and eight types of cement with different chemical and mineralogical composition were examined in this research. Expanded glass granules used in this research is commercially available material produced by Penostek. Lightweight concrete mixtures were prepared by using commercial chemical additives to improve workability of concrete. The aim of the study is to identify effect of cement composition to the ASR reaction which occurs between expanded glass granules and binder. Expanded glass granules mechanical and physical properties were determined. In addition, properties of fresh and hardened concrete were determined. The ASR test was processed according to RILEM AAR-2 testing recommendation. Tests with scanning electron microscope and microstructural investigations were performed for expanded glass granules and hardened concrete specimens before and after exposing them in alkali solution

One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres with enhanced photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Qu, Lingling [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Luo, Zhijun, E-mail: lzj@ujs.edu.cn [School of the Environment, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Tang, Chao [Maple Leaf International High School, Zhenjiang 212013 (China)

2013-11-15

Graphical abstract: Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core–shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs). Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation. - Highlights: • One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres. • Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@CRCSs. • Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits enhanced photocatalytic activity under visible light irradiation. - Abstract: Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core-shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs) have been synthesized via a one-step method. The core–shell nanosturctures of the as-prepared samples were confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Raman spectroscopy. The formation of Bi@Bi{sub 2}O{sub 3}@CRCSs core–shell nanosturctures should attribute to the synergetic roles of different functional groups of sodium gluconate. Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation (λ > 420 nm) and shows an O{sub 2}-dependent feature. According to trapping experiments of radicals and holes, hydroxyl radicals were not the main active oxidative species in the photocatalytic degradation of MB, but O{sub 2}·{sup −} are the main active oxidative species.

Lightweight solar array blanket tooling, laser welding and cover process technology

Science.gov (United States)

Dillard, P. A.

1983-01-01

A two phase technology investigation was performed to demonstrate effective methods for integrating 50 micrometer thin solar cells into ultralightweight module designs. During the first phase, innovative tooling was developed which allows lightweight blankets to be fabricated in a manufacturing environment with acceptable yields. During the second phase, the tooling was improved and the feasibility of laser processing of lightweight arrays was confirmed. The development of the cell/interconnect registration tool and interconnect bonding by laser welding is described.

High Strength Lightweight Concrete Made with Ternary Mixtures of Cement-Fly Ash-Silica Fume and Scoria as Aggregate

OpenAIRE

YAŞAR, Ergül; ATIŞ, Cengiz Duran; KILIÇ, Alaettin

2014-01-01

This paper presents part of the results of an ongoing laboratory study carried out to design a structural lightweight high strength concrete (SLWHSC) made with and without ternary mixtures of cement-fly ash-silica fume. In the mixtures, lightweight basaltic-pumice (scoria) aggregate was used. A concrete mixture made with lightweight scoria, and another lightweight scoria concrete mixture incorporating 20% fly ash and 10% silica fume as a cement replacement, were prepared. Two normal...

Adaptive Backstepping Control of Lightweight Tower Wind Turbine

DEFF Research Database (Denmark)

Galeazzi, Roberto; Borup, Kasper Trolle; Niemann, Hans Henrik

2015-01-01

the angular deflection of the tower with respect to the vertical axis in response to variations in wind speed. The controller is shown to guarantee asymptotic tracking of the reference trajectory. The performance of the control system is evaluated through deterministic and stochastic simulations including......This paper investigates the feasibility of operating a wind turbine with lightweight tower in the full load region exploiting an adaptive nonlinear controller that allows the turbine to dynamically lean against the wind while maintaining nominal power output. The use of lightweight structures...... for towers and foundations would greatly reduce the construction cost of the wind turbine, however extra features ought be included in the control system architecture to avoid tower collapse. An adaptive backstepping collective pitch controller is proposed for tower point tracking control, i.e. to modify...

Lightweight self-compacting concrete with light expanded clay aggregate (LECA

Directory of Open Access Journals (Sweden)

Heiza Khaled

2018-01-01

Full Text Available Lightweight concretes have been successfully applied in building constructions for many years due to their favorable material properties, particularly their low specific weight in connection with a high strength, a high capability of thermal insulation and a high durability. The development leading to lightweight self-compacting concrete (LWSCC represents an important advanced step within the recent years. This concrete combines the favorable properties of a lightweight concrete with those of a self-compacting concrete. Research work is aimed on development of (LWSCC with the use of light aggregates “Light expanded clay aggregate (LECA”. In this research, first by specific gravity factor method, twenty different mix designs of (LWSCC were cast and tested to find out the values of slump flow, J-ring , V-funnel and 28 day compressive strength. Based on the results obtained, the best mix design was selected for further investigation. This paper also focuses on studying the effect of changing the reinforcement ratio on reinforced two way slabs when the dimensions were kept constant.

Fundamental Study on the Development of Structural Lightweight Concrete by Using Normal Coarse Aggregate and Foaming Agent

Science.gov (United States)

Lee, Han-Seung; Ismail, Mohamed A.; Woo, Young-Je; Min, Tae-Beom; Choi, Hyun-Kook

2014-01-01

Structural lightweight concrete (SLWC) has superior properties that allow the optimization of super tall structure systems for the process of design. Because of the limited supply of lightweight aggregates in Korea, the development of structural lightweight concrete without lightweight aggregates is needed. The physical and mechanical properties of specimens that were cast using normal coarse aggregates and different mixing ratios of foaming agent to evaluate the possibility of creating structural lightweight concrete were investigated. The results show that the density of SLWC decreases as the dosage of foaming agent increases up to a dosage of 0.6%, as observed by SEM. It was also observed that the foaming agent induced well separated pores, and that the size of the pores ranged from 50 to 100 μm. Based on the porosity of concrete specimens with foaming agent, compressive strength values of structural lightweight foam concrete (SLWFC) were obtained. It was also found that the estimated values from proposed equations for compressive strength and modulus of elasticity of SLWFC, and values obtained by actual measurements were in good agreement. Thus, this study confirms that new structural lightweight concrete using normal coarse aggregates and foaming agent can be developed successfully. PMID:28788691

Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

Science.gov (United States)

Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

2015-02-01

A new BiS2-based superconductor, Bi2(O,F)S2, was discovered. It is a layered compound consisting of alternately stacked structure of rock-salt-type BiS2 superconducting layers and fluorite-type Bi(O,F) blocking layers. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2. This is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis lengths increased and decreased, respectively, and Tc increased to 5.1 K.

A comparison of performance of lightweight mirrors

Science.gov (United States)

Cho, Myung K.; Richard, Ralph M.; Hileman, Edward A.

1990-01-01

Four lightweight solid contoured back mirror shapes (a double arch, a single arch, a modified single arch, and a double concave mirror) and a cellular sandwich lightweight meniscus mirror, have been considered for the primary mirror of the Space Infrared Telescope Facility (SIRTF). A parametric design study using these shapes for the SIRTF 40 inch primary mirror with a focal ratio f/2 is presented. Evaluations of the optical performance and fundamental frequency analyses are performed to compare relative merits of each mirror configuration. Included in these are structural, optical, and frequency analyses for (1) different back contour shapes, (2) different number and location of the support points, and (3) two gravity orientations (ZENITH and HORIZON positions). The finite element program NASTRAN is used to obtain the structural deflections of the optical surface. For wavefront error analysis, FRINGE and PCFRINGE programs are used to evaluate the optical performance. A scaling law relating the optical and structural performance for various mirror contoured back shapes is developed.

Sodium citrate-assisted anion exchange strategy for construction of Bi2O2CO3/BiOI photocatalysts

International Nuclear Information System (INIS)

Song, Peng-Yuan; Xu, Ming; Zhang, Wei-De

2015-01-01

Highlights: • Heterostructured Bi 2 O 2 CO 3 /BiOI microspheres were prepared via anion exchange. • Sodium citrate-assisted anion exchange for construction of composite photocatalysts. • Bi 2 O 2 CO 3 /BiOI composites show high visible light photocatalytic activity. - Abstract: Bi 2 O 2 CO 3 /BiOI heterojuncted photocatalysts were constructed through a facile partial anion exchange strategy starting from BiOI microspheres and urea with the assistance of sodium citrate. The content of Bi 2 O 2 CO 3 in the catalysts was regulated by modulating the amount of urea as a precursor, which was decomposed to generate CO 3 2− in the hydrothermal process. Citrate anion plays a key role in controlling the morphology and composition of the products. The Bi 2 O 2 CO 3 /BiOI catalysts display much higher photocatalytic activity than pure BiOI and Bi 2 O 2 CO 3 towards the degradation of rhodamine B (RhB) and bisphenol A (BPA). The enhancement of photocatalytic activity of the heterojuncted catalysts is attributed to the formation of p–n junction between p-BiOI and n-Bi 2 O 2 CO 3 , which is favorable for retarding the recombination of photoinduced electron-hole pairs. Moreover, the holes are demonstrated to be the main active species for the degradation of RhB and BPA

Supervised Cross-Modal Factor Analysis for Multiple Modal Data Classification

KAUST Repository

Wang, Jingbin

2015-10-09

In this paper we study the problem of learning from multiple modal data for purpose of document classification. In this problem, each document is composed two different modals of data, i.e., An image and a text. Cross-modal factor analysis (CFA) has been proposed to project the two different modals of data to a shared data space, so that the classification of a image or a text can be performed directly in this space. A disadvantage of CFA is that it has ignored the supervision information. In this paper, we improve CFA by incorporating the supervision information to represent and classify both image and text modals of documents. We project both image and text data to a shared data space by factor analysis, and then train a class label predictor in the shared space to use the class label information. The factor analysis parameter and the predictor parameter are learned jointly by solving one single objective function. With this objective function, we minimize the distance between the projections of image and text of the same document, and the classification error of the projection measured by hinge loss function. The objective function is optimized by an alternate optimization strategy in an iterative algorithm. Experiments in two different multiple modal document data sets show the advantage of the proposed algorithm over other CFA methods.

Lightweight design: mass in transit

OpenAIRE

MALBURET, François; KRYSINSKI, Tomasz; NAUZIN, Jean-Paul

2012-01-01

This paper is part of an effort to reduce a vehicle’s CO2 emissions through lightweight design. The originality of the approach consists in harnessing the optimal vehicle architecture with regard to CO2 emissions. Reducing a vehicle’s weight provides an opportunity to reassess performance features like shock, noise, vibrations and road holding, thereby generating additional savings through a virtuous cycle of weight reduction. The paper sheds light on some methodological aspects used by PSA P...

Applications of Foamed Lightweight Concrete

Directory of Open Access Journals (Sweden)

Mohd Sari Kamarul Aini

2017-01-01

Full Text Available Application of foamed concrete is increasing at present due to high demand on foamed concrete structures with good mechanical and physical properties. This paper discusses on the use of basic raw materials, their characteristics, production process, and their application in foamed lightweight concrete with densities between 300 kg/m3 and 1800 kg/m3. It also discusses the factors that influence the strengths and weaknesses of foamed concrete based on studies that were conducted previously.

Manufacture of lightweight aggregates utilizing coal fly ash. Sekitan bai riyo ni yoru jinko keiryo kotsuzai seizo

Energy Technology Data Exchange (ETDEWEB)

Ishii, K [Kyushu Electric Power Co. Inc., Fukuoka (Japan)

1990-11-20

Processing of a large amount of coal ash is a serious problem in considering the locational conditions of coal firing power generation plants. 46% of the coal ash was effectively used in 1985, and the remaining 54% was disposed at landfills on land and sea. Positive promotion of the effective use of coal ash is the necessity. A production method for an artificial lightweight aggregate utilizing coal ash was established by a joint research. The history of the research and development of this artificial lightweight aggregate (brand name: FA-lIGHT), outline of the manufacturing facilities, physical properties and result of use are introduced. The lightweight aggregates are used not only for the construction of multistoried buildings but also used as most suitable aggregates for making lightweight large scale panels and concrete secondary products such as lightweight blocks. FA-LIGHT is most suitable for use in the production of concrete lightweight aggregates, and can be used for hydroponic agriculture and for the improvement of drainage of land. Spread of its use is expected. 5 figs., 5 tabs.

Influence of surface modified basalt fiber on strength of cinder lightweight aggregate concrete

Science.gov (United States)

Xiao, Liguang; Li, Jiheng; Liu, Qingshun

2017-12-01

In order to improve the bonding and bridging effect between volcanic slag lightweight aggregate concrete cement and basalt fiber, The basalt fiber was subjected to etching and roughening treatment by NaOH solution, and the surface of the basalt fiber was treated with a mixture of sodium silicate and micro-silica powder. The influence of modified basalt fiber on the strength of volcanic slag lightweight aggregate concrete was systematically studied. The experimental results show that the modified basalt fiber volcanic slag lightweight aggregate concrete has a flexural strength increased by 47%, the compressive strength is improved by 16% and the toughness is increased by 27% compared with that of the non-fiber.

Ontology learning from interpretations in lightweight description logics

CSIR Research Space (South Africa)

Klarman, S

2015-08-01

Full Text Available International Conference on Inductive Logic programming (ILP), Kyoto, Japan, 20-22 August 2015 Ontology Learning from Interpretations in Lightweight Description Logics Szymon Klarman1 and Katarina Britz2 1 Department of Computer Science, Brunel...

Impact of lightweight and conventional jackhammers on the operator.

Science.gov (United States)

Campbell-Kyureghyan, Naira; Singh, Gurjeet; Otieno, Wilkistar; Cooper, Karen

2012-01-01

Jackhammer manufacturers have recently developed lightweight (45-60 lbs) jackhammers intended to reduce the required lifting and pushing forces during operation. However, the vibration characteristics of the lightweight jackhammers and their effect on muscle activity are currently unknown. The objective of this study was to compare the measured vibration and muscle activity between: (i) conventional (90 lb) and light weight (60 lb) jackhammers, (ii) different pavement type/thickness combinations, and (iii) pneumatic and hydraulic jackhammers. Five jackhammers were tested on 4 and 6 inch thick asphalt and concrete pavements by four experienced operators. Analysis of the results revealed that both weight classes averaged 9.7 m/s(2) at the 20 Hz weighted 1/3 octave band frequency, and the TLV of daily exposure for either weight class of jackhammer was less than 1.5 hours/per day. There was an approximately 33% difference in vibration measured on the hand of the operators due to pavement thickness, 30% due pavement type, and no difference due to power source. Conventional jackhammers overall produced higher muscle activity than lightweight jackhammers. Although selection of the correct jackhammer for the job involves many factors including pavement type and thickness, the results of this research can be used to assist in selecting the appropriate jackhammer.

The utilization of stone ash on cellular lightweight concrete

Science.gov (United States)

Karolina, R.; Sianipar, Y. G. C.

2018-02-01

Lightweight concrete brick is a brick which made of cement, sand, water, and foam as the basic composition. This brick are divided into 2, based on the foam used such as AAC (Autoclave Aerated Concrete) that use aluminium paste and CLC(Cellular Lightweight Concrete) that use foaming agent from BASF as its foaming material. In this trial, the lightweight brick that are ging to be use are the CLC with foaming agent as its foaming material with the mixture of stone ash that are produced by the Stone Crusher with spesific gravity 2666 kg/m3 as their partly sand substitution . In this research, the stone ash variant that are used are 10%, 15%, and 20% from the amount of sand that planned before. After casting, the result of the 10% will receive a reduction of compressive strength while an increasing in absorption as 25.07% and 39.005% and the 15% variant will recieve a reduction of compressive strength as much as 65.8% and a reduction of absorption as much as 17.441% and the 20% variant will recieve a reduction of compressive strength as much as 67.4% while an increasing of absorption as much as 17.956%.

MODELING COMPARATIVE THERMAL PERFORMANCE OF LIGHTWEIGHT FABRICS USING A COMPUTATIONAL DESIGN TOOL

Science.gov (United States)

2017-04-14

3  3.1  Fabric Transport Properties: Water Vapor Diffusion, Air Permeability, Thermal Resistance ... resistance (Ret) for simulated clothing systems composed of lightweight fabrics ...Lightweight)  50% Nylon ‐ 50% Cotton Twill  FR ACU Type III  ( Fire   Resistant  Army Combat Uniform)  FR Blend (Defender M) Ripstop  65% FR Rayon  25% P

Age, sex and (the) race: gender and geriatrics in the ultra-endurance age.

Science.gov (United States)

Whyte, Greg

2014-01-01

Ultra-endurance challenges were once the stuff of legend isolated to the daring few who were driven to take on some of the greatest physical endurance challenges on the planet. With a growing fascination for major physical challenges during the nineteenth century, the end of the Victorian era witnessed probably the greatest ultra-endurance race of all time; Scott and Amundsen's ill-fated race to the South Pole. Ultra-endurance races continued through the twentieth century; however, these events were isolated to the elite few. In the twenty-first century, mass participation ultra-endurance races have grown in popularity. Endurance races once believed to be at the limit of human durability, i.e. marathon running, are now viewed as middle-distance races with the accolade of true endurance going to those willing to travel significantly further in a single effort or over multiple days. The recent series of papers in Extreme Physiology & Medicine highlights the burgeoning research data from mass participation ultra-endurance events. In support of a true 'mass participation' ethos Knetchtle et al. reported age-related changes in Triple and Deca Iron-ultra-triathlon with an upper age of 69 years! Unlike their shorter siblings, the ultra-endurance races appear to present larger gender differences in the region of 20% to 30% across distance and modality. It would appear that these gender differences remain for multi-day events including the 'Marathon des Sables'; however, this gap may be narrower in some events, particularly those that require less load bearing (i.e. swimming and cycling), as evidenced from the 'Ultraman Hawaii' and 'Swiss Cycling Marathon', and shorter (a term I used advisedly!) distances including the Ironman Triathlon where differences are similar to those of sprint and endurance distances i.e. c. 10%. The theme running through this series of papers is a continual rise in participation to the point where major events now require selection races to remain

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO{sub 3} thin film

Energy Technology Data Exchange (ETDEWEB)

Gupta, Surbhi; Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi (India); Tomar, Monika [Department of Physics, Miranda Housea, University of Delhi, Delhi (India); James, A. R. [Defence Metallurgical Research Laboratory, Hyderabad (India); Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar [Department of Electrical and Computer Engineering, College of Engineering, University of Texas at SanAntonio, San Antonio 78249 (United States)

2014-06-21

Multiferroic Bismuth Ferrite (BiFeO{sub 3}) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO{sub 3} thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO{sub 3} and Fe{sub 2}O{sub 3} to pure BiFeO{sub 3} phase and, subsequently, to a mixture of BiFeO{sub 3} and Bi{sub 2}O{sub 3} with increase in the concentration of excess Bi from 0% to 15%. BiFeO{sub 3} thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe{sub 2}O{sub 3}). Deterioration in ferroic properties of BiFeO{sub 3} thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO{sub 3} thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm{sup 2} and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO{sub 3} thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO{sub 3} thin films exhibiting the improved multiferroic properties.

A lightweight universe?

Science.gov (United States)

Bahcall, Neta A.; Fan, Xiaohui

1998-01-01

How much matter is there in the universe? Does the universe have the critical density needed to stop its expansion, or is the universe underweight and destined to expand forever? We show that several independent measures, especially those utilizing the largest bound systems known—clusters of galaxies—all indicate that the mass-density of the universe is insufficient to halt the expansion. A promising new method, the evolution of the number density of clusters with time, provides the most powerful indication so far that the universe has a subcritical density. We show that different techniques reveal a consistent picture of a lightweight universe with only ∼20–30% of the critical density. Thus, the universe may expand forever. PMID:9600898

Investigation of the electronic structure of the BiSBr and BiSeBr clusters by density functional method

International Nuclear Information System (INIS)

Audzijonis, A.; Gaigalas, G.; Zigas, L.; Pauliukas, A.; Zaltauskas, R.; Kvedaravicius, A.; Cerskus, A.

2008-01-01

The energy levels of valence bands (VB) of the BiSBr and BiSeBr crystals have been calculated for investigation of the photoelectron emission spectra of BiSBr, BiSeBr and BiSI crystals. The molecular model of this crystal has been used for the calculation of VB by the Density Functional Theory (DFT) method. The molecular cluster, consisting of 20 molecules of BiSBr, BiSeBr, has been used for calculations of averaged total density of states, including atom vibrations. The spectra of the averaged total density of states from VB of BiSBr and BiSeBr clusters have been compared with the experimental photoelectron emission spectra from VB of BiSI crystals. The results clarify that the atomic vibrations in A 5 B 6 C 7 type crystals with chain structure create a smoother appearance of the averaged total density of state spectrum and the experimental X-ray photoemission spectra (XPS)

Uneven-Layered Coding Metamaterial Tile for Ultra-wideband RCS Reduction and Diffuse Scattering.

Science.gov (United States)

Su, Jianxun; He, Huan; Li, Zengrui; Yang, Yaoqing Lamar; Yin, Hongcheng; Wang, Junhong

2018-05-25

In this paper, a novel uneven-layered coding metamaterial tile is proposed for ultra-wideband radar cross section (RCS) reduction and diffuse scattering. The metamaterial tile is composed of two kinds of square ring unit cells with different layer thickness. The reflection phase difference of 180° (±37°) between two unit cells covers an ultra-wide frequency range. Due to the phase cancellation between two unit cells, the metamaterial tile has the scattering pattern of four strong lobes deviating from normal direction. The metamaterial tile and its 90-degree rotation can be encoded as the '0' and '1' elements to cover an object, and diffuse scattering pattern can be realized by optimizing phase distribution, leading to reductions of the monostatic and bi-static RCSs simultaneously. The metamaterial tile can achieve -10 dB RCS reduction from 6.2 GHz to 25.7 GHz with the ratio bandwidth of 4.15:1 at normal incidence. The measured and simulated results are in good agreement and validate the proposed uneven-layered coding metamaterial tile can greatly expanding the bandwidth for RCS reduction and diffuse scattering.

Luminescence of Bi3+ ions in Y3Al5O12:Bi single crystalline films

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Vistovsky, V.; Nedilko, S.; Nikl, M.

2007-01-01

The absorption and cathodoluminescence spectra of single crystalline films (SCF) of Y 3 Al 5 O 12 :Bi garnet depending on Bi concentration were analyzed. For consideration of the nature of the UV and visible Bi-related emission bands the time-resolved luminescence of Bi 3+ (ns 2 ) ions in YAG:Bi SCF was studied at 10 K under excitation by synchrotron radiation. The difference in the excitation spectra and emission decay of the UV and visible bands has been explained via radiative relaxation from the 3 P 1,0 excited states to the 1 S 0 ground state of the isolated and pair/clustered Bi 3+ emission centers in the garnet lattice, respectively

Neonatal non-invasive respiratory support: synchronised NIPPV, non-synchronised NIPPV or bi-level CPAP: what is the evidence in 2013?

Science.gov (United States)

Roberts, C T; Davis, P G; Owen, L S

2013-01-01

Nasal continuous positive airway pressure (NCPAP) has proven to be an effective mode of non-invasive respiratory support in preterm infants; however, many infants still require endotracheal ventilation, placing them at an increased risk of morbidities such as bronchopulmonary dysplasia. Several other modes of non-invasive respiratory support beyond NCPAP, including synchronised and non-synchronised nasal intermittent positive pressure ventilation (SNIPPV and nsNIPPV) and bi-level positive airway pressure (BiPAP) are now also available. These techniques require different approaches, and the exact mechanisms by which they act remain unclear. SNIPPV has been shown to reduce the rate of reintubation in comparison to NCPAP when used as post-extubation support, but the evidence for nsNIPPV and BiPAP in this context is less convincing. There is some evidence that NIPPV (whether synchronised or non-synchronised) used as primary respiratory support is beneficial, but the variation in study methodology makes this hard to translate confidently into clinical practice. There is currently no evidence to suggest a reduction in mortality or important morbidities such as bronchopulmonary dysplasia, with NIPPV or BiPAP in comparison to NCPAP, and there is a lack of appropriately designed studies in this area. This review discusses the different approaches and proposed mechanisms of action of SNIPPV, nsNIPPV and BiPAP, the challenges of applying the available evidence for these distinct modalities of non-invasive respiratory support to clinical practice, and possible areas of future research. © 2013 S. Karger AG, Basel.

Response of MnBi-Bi eutectic to freezing rate changes

Science.gov (United States)

Nair, M.; Fu, T.-W.; Wilcox, W. R.; Doddi, K.; Ravishankar, P. S.; Larson, D.

1982-01-01

Reference is made to a study by Fu and Wilcox (1981), which treated theoretically the influence on freezing rate of sudden changes in translation rate in the Bridgman-Stockbarger technique. This treatment is extended here to a linear ramped translation rate and an oscillatory freezing rate. It is found that oscillations above a few hertz are highly damped in small-diameter apparatus. An experimental test is carried out of the theoretical predictions for a sudden change of translation rate. The MnBi-Bi eutectic is solidified with current-induced interface demarcation. The experimental results accord reasonably well with theory if the silica ampoule wall is assumed to either (1) contribute only a resistance to heat exchange between the sample and the furnace wall or (2) transmit heat effectively in the axial direction by radiation. In an attempt to explain the fact that a finer microstructure is obtained in space, MnBi-Bi microstructure is determined when the freezing rate is increased or decreased rapidly. Preliminary results suggest that fiber branching does not occur as readily as fiber termination.

Lightweighting Automotive Materials for Increased Fuel Efficiency and Delivering Advanced Modeling and Simulation Capabilities to U.S. Manufacturers

Energy Technology Data Exchange (ETDEWEB)

Hale, Steve

2013-09-11

Abstract The National Center for Manufacturing Sciences (NCMS) worked with the U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), to bring together research and development (R&D) collaborations to develop and accelerate the knowledgebase and infrastructure for lightweighting materials and manufacturing processes for their use in structural and applications in the automotive sector. The purpose/importance of this DOE program: • 2016 CAFÉ standards. • Automotive industry technology that shall adopt the insertion of lightweighting material concepts towards manufacturing of production vehicles. • Development and manufacture of advanced research tools for modeling and simulation (M&S) applications to reduce manufacturing and material costs. • U.S. competitiveness that will help drive the development and manufacture of the next generation of materials. NCMS established a focused portfolio of applied R&D projects utilizing lightweighting materials for manufacture into automotive structures and components. Areas that were targeted in this program: • Functionality of new lightweighting materials to meet present safety requirements. • Manufacturability using new lightweighting materials. • Cost reduction for the development and use of new lightweighting materials. The automotive industry’s future continuously evolves through innovation, and lightweight materials are key in achieving a new era of lighter, more efficient vehicles. Lightweight materials are among the technical advances needed to achieve fuel/energy efficiency and reduce carbon dioxide (CO2) emissions: • Establish design criteria methodology to identify the best materials for lightweighting. • Employ state-of-the-art design tools for optimum material development for their specific applications. • Match new manufacturing technology to production volume. • Address new process variability with new production-ready processes.

Photoreduction of non-noble metal Bi on the surface of Bi{sub 2}WO{sub 6} for enhanced visible light photocatalysis

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaojing [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Yu, Shan; Liu, Yang; Zhang, Qian [The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Zhou, Ying, E-mail: yzhou@swpu.edu.cn [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China)

2017-02-28

Highlights: • Bi{sub 2}WO{sub 6}-Bi composite was synthesized by in situ photoreduction of Bi{sub 2}WO{sub 6}. • Bi{sub 2}WO{sub 6}-Bi exhibits improved photocatalytic efficiency towards degradation of Rhodamine B. • The generation of elemental Bi in Bi{sub 2}WO{sub 6}-Bi induces vacancy and structure distortion of Bi{sub 2}WO{sub 6}. • The surface oxygen adsorption mode changes from hydroxyl group on Bi{sub 2}WO{sub 6} to molecular oxygen on Bi{sub 2}WO{sub 6}-Bi. - Abstract: In this report, Bi{sub 2}WO{sub 6}-Bi composite was prepared through an in situ photoreduction method and was characterized systematically by X-Ray diffraction, transmission electron microscopy, X-Ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The as-prepared Bi{sub 2}WO{sub 6}-Bi maintains the same crystal structure with the pristine Bi{sub 2}WO{sub 6} regardless of some surface defects. Nevertheless, these surface defects result in the change of surface oxygen adsorption mode from hydroxyl to molecular oxygen on Bi{sub 2}WO{sub 6}. Photocatalytic activity over Bi{sub 2}WO{sub 6}-Bi is 2.4 times higher than that of Bi{sub 2}WO{sub 6} towards the degradation of organic dye Rhodamine B (RhB) under visible light irradiation (λ > 420 nm). A deep study shows that cleavage of benzene ring is the main pathway for RhB degradation over Bi{sub 2}WO{sub 6}, but both the benzene cleavage and de-ethylation pathway coexist for RhB decomposition in the presence of Bi{sub 2}WO{sub 6}-Bi as the photocatalyst. Photoelectrochemical study including transient photocurrent tests and electrochemical impedance spectroscopy measurements shows that Bi{sub 2}WO{sub 6}-Bi could facilitate the charge transfer process compared to Bi{sub 2}WO{sub 6}. These data above has indicated a new insight into the promotion mechanism based on Bi related heterostructures.

Annotating Evidence Based Clinical Guidelines : A Lightweight Ontology

NARCIS (Netherlands)

Hoekstra, R.; de Waard, A.; Vdovjak, R.; Paschke, A.; Burger, A.; Romano, P.; Marshall, M.S.; Splendiani, A.

2012-01-01

This paper describes a lightweight ontology for representing annotations of declarative evidence based clinical guidelines. We present the motivation and requirements for this representation, based on an analysis of several guidelines. The ontology provides the means to connect clinical questions

PENGARUH GOOD CORPORATE GOVERNANCE, KINERJA KEUANGAN, MODAL INTELEKTUAL TERHADAP PENGUNGKAPAN MODAL INTELEKTUAL

Directory of Open Access Journals (Sweden)

Gilang Anies Saendy

2015-10-01

Full Text Available Dampak perkembangan globalisasi membutuhkan informasi lebih lanjut, terutama informasi tentang modal intelektual perusahaan. Tapi, dalam kondisi nyata informasi modal intelektual masih rendah, yakni sekitar 27-35%. Objek penelitian ini adalah perbankan yang terdapat dalam direktori Pasar Modal Indonesia (ICMD 2010-2013. Jumlah populasi adalah 36 perbankan dan 17 sampel dengan menggunakan purposive sampling. Metode yang digunakan adalah analisis jalur. Hasil penelitian ini menunjukkan bahwa tidak pengaruh antara pelaksanaan GCG untuk pengungkapan modal intelektual dan kinerja keuangan. Selain itu, ada pengaruh positif antara kinerja modal intelektual terhadap kinerja keuangan dan kinerja keuangan untuk pengungkapan modal intelektual. Selanjutnya, hasil penelitian menunjukkan bahwa tidak efek mediasi melalui kinerja keuangan perusahaan antara implementasi GCG dalam pengungkapan modal intelektual. Hasilnya juga mengatakan ada efek mediasi antara pelaksanaan GCG untuk pengungkapan modal intelektual pikir kinerja modal intelektual. The development due to the increase of globalization gives impact to the need of having more information. One of them is the need to have information on company’s intellectual capital. But, in real condition, intellectual capital information is still low. It is about 27-35%. The objects of this research are banks organized in Indonesian Capital Market Directory (ICMD from 2010-2013. Total populations were 36 banks, and finally 17 samples were selected by using purposive sampling. The method used is path analysis. The results of this research show that there is no influence between GCG’s implementation on intellectual capital disclosure and financial performance. However, there are  positive influences of intellectual capital performance on the financial performance, and financial performance on the disclosure of intellectual capital. Besides, this research said that there is no effect of mediation through the company

Thermal properties of light-weight concrete with waste polypropylene aggregate

Science.gov (United States)

Záleská, Martina; Pokorný, Jaroslav; Pavlíková, Milena; Pavlík, Zbyšek

2017-07-01

Thermal properties of a sustainable light-weight concrete incorporating high volume of waste polypropylene as partial substitution of natural aggregate were studied in the paper. Glass fiber reinforced polypropylene (GFPP), a by-product of PP tubes production, partially substituted fine natural silica aggregate in 10, 20, 30, 40, and 50 mass%. In order to quantify the effect of GFPP use on concrete properties, a reference concrete mix without plastic waste was studied as well. For the applied GFPP, bulk density, matrix density, and particle size distribution were measured. Specific attention was paid to thermal transport and storage properties of GFPP that were examined in dependence on compaction time. For the developed light-weight concrete, thermal properties were accessed using transient impulse technique, whereas the measurement was done in dependence on moisture content, from the dry state to fully water saturated state. Additionally, the investigated thermal properties were plotted as function of porosity. The tested light-weight concrete was found to be prospective construction material possessing improved thermal insulation function. Moreover, the reuse of waste plastics in concrete composition was beneficial both from the environmental and financial point of view considering plastics low biodegradability and safe disposal.

A Stepped Frequency CW SAR for Lightweight UAV Operation

National Research Council Canada - National Science Library

Morrison, Keith

2005-01-01

A stepped-frequency continuous wave (SF-CW) synthetic aperture radar (SAR), with frequency-agile waveforms and real-time intelligent signal processing algorithms, is proposed for operation from a lightweight UAV platform...

Preparation and Characterization of Lightweight Mullite-Silica Rich Glass Aggregates

Directory of Open Access Journals (Sweden)

Nan Li

2011-09-01

Full Text Available Phase compositions, microstructures and properties of four lightweight mullite-silica rich glass aggregates with high strength were investigated by X-ray diffractometry (XRD, scanning electron microscopy (SEM, and FactSage 6.2 software. It was found that the lightweight aggregates with higher Al2O3 content had higher mullite content, porosity and larger mullite crystallites, but lower content and viscosity of melt at elevated temperature. Most of Fe2O3 and TiO2 were incorporated in mullite and most of K2O and Na2O were in glass to reduce viscosity of melt at elevated temperature.

Development of a Direct Methanol Fuel Cell with Lightweight Disc Type Current Collectors

Directory of Open Access Journals (Sweden)

Yean-Der Kuan

2014-05-01

Full Text Available The direct methanol fuel cell (DMFC adopts methanol solution as a fuel suitable for low power portable applications. A miniature, lightweight, passive air-breathing design is therefore desired. This paper presents a novel planar disc-type DMFC with multiple cells containing a novel developed lightweight current collector at both the anode and cathode sides. The present lightweight current collector adopts FR4 Glass/Epoxy as the substrate with the current collecting areas located at the corresponding membrane electrolyte assembly (MEA areas. The current collecting areas are fabricated by sequentially coating a corrosion resistant layer and electrical conduction layer via the thermal evaporation technique. The anode current collector has carved flow channels for fuel transport and production. The cathode current collector has drilled holes for passive air breathing. In order to ensure feasibility in the present concept a 3-cell prototype DMFC module with lightweight disc type current collectors is designed and constructed. Experiments were conducted to measure the cell performance. The results show that the highest cell power output is 54.88 mW·cm−2 and successfully demonstrate the feasibility of this novel design.

FY2010 Annual Progress Report for Lightweighting Materials

Energy Technology Data Exchange (ETDEWEB)

none,

2011-01-15

The Lightweight Materials activity (LM) within the Vehicle Technologies Program focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

The Development of light-weight 2-link robot arm for high radiation area

Energy Technology Data Exchange (ETDEWEB)

Shin, Ho Cheol; Seo, Yong Chil; Jung, Kyung Min; Choi, Young Soo

2009-10-15

A light-weight 2-link robot arm which weight is less than 8kg was developed for treating the small radio-active material in the high radiation area such as nuclear power plants and NDT area. The light-weight 2-link robot arm can be attached on a small mobile robot and carry out tasks. It is a 5 DOF robot arm including a gripper

DFT study on the interfacial properties of vertical and in-plane BiOI/BiOIO3 hetero-structures.

Science.gov (United States)

Dai, Wen-Wu; Zhao, Zong-Yan

2017-04-12

Composite photocatalysts with hetero-structures usually favor the effective separation of photo-generated carriers. In this study, BiOIO 3 was chosen to form a hetero-structure with BiOI, due to its internal polar field and good lattice matching with BiOI. The interfacial properties and band offsets were focused on and analyzed in detail by DFT calculations. The results show that the charge depletion and accumulation mainly occur in the region near the interface. This effect leads to an interfacial electric field and thus, the photo-generated electron-hole pairs can be easily separated and transferred along opposite directions at the interface, which is significant for the enhancement of the photocatalytic activity. Moreover, according to the analysis of band offsets, the vertical BiOI/BiOIO 3 belongs to the type-II hetero-structure, while the in-plane BiOI/BiOIO 3 belongs to the type-I hetero-structure. The former type of hetero-structure has more favorable effects to enhance the photocatalytic activity of BiOI than that of the latter type of hetero-structure. In the case of the vertical BiOI/BiOIO 3 hetero-structure, photo-generated electrons can move from the conduction band of BiOI to that of BiOIO 3 , while holes can move from the valence band of BiOIO 3 to that of BiOI under solar radiation. In addition, the introduced internal electric field functions as a selector that can promote the separation of photo-generated carriers, resulting in the higher photocatalytic quantum efficiency. These findings illustrate the underlying mechanism for the reported experiments, and can be used as a basis for the design of novel highly efficient composite photocatalysts with hetero-structures.

An ion exchange strategy to BiOI/CH{sub 3}COO(BiO) heterojunction with enhanced visible-light photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Han, Qiaofeng, E-mail: hanqiaofeng@njust.edu.cn; Yang, Zhen; Wang, Li; Shen, Zichen; Wang, Xin; Zhu, Junwu; Jiang, Xiaohong

2017-05-01

Highlights: • BiOI/BiOAc heterojunction was firstly synthesized by an ion exchange route. • BiOI/BiOAc exhibited enhanced visible-light-driven photoreactivity for the dyes degradation in comparison with individuals. • Photocatalytic activity of the as-prepared BiOI/BiOAc is better than that prepared by precipitation-deposition method. • Photosensitization effect of BiOI to BiOAc was superior to that of Bi{sub 2}S{sub 3} due to suitable solubility constant. - Abstract: It is very significant to develop CH{sub 3}COO(BiO) (denoted as BiOAc) based photocatalysts for the removal of pollutants due to its non-toxicity and availability. We previously reported that BiOAc exhibited excellent photocatalytic activity for rhodamine B (RhB) degradation under UV light irradiation. Herein, by an ion exchange approach, BiOI/BiOAc heterojunction could be easily obtained. The as-prepared heterojunction possessed enhanced photodegradation activity for multiple dyes including RhB and methyl orange (MO) under visible light illumination in comparison with individual materials. Good visible-light photocatalytic activity of the heterojunction could be attributed to the increased visible light response, effective charge transfer from the modified band position and close interfacial contact due to partial ion exchange method.

Synthesis of chemically bonded BiOCl@Bi{sub 2}WO{sub 6} microspheres with exposed (0 2 0) Bi{sub 2}WO{sub 6} facets and their enhanced photocatalytic activities under visible light irradiation

Energy Technology Data Exchange (ETDEWEB)

Ma, Yongchao [Qingdao Agricultural University, Qingdao 266109 (China); Chen, Zhiwei [School of Life Sciences, Shandong University of Technology, Zibo 255049 (China); Qu, Dan [Qingdao Agricultural University, Qingdao 266109 (China); Shi, Jinsheng, E-mail: jsshiqn@aliyun.com [Qingdao Agricultural University, Qingdao 266109 (China)

2016-01-15

Graphical abstract: - Highlights: • BiOCl@Bi{sub 2}WO{sub 6} composites were prepared via a controlled anion exchange method. • The shell of composites was composed of Bi{sub 2}WO{sub 6} sheets with exposed (0 2 0) facets. • The BiOCl@Bi{sub 2}WO{sub 6} composites showed efficient photocatalytic activity. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}WO{sub 6} photocatalysts has been extensively studied for its photocatalytic activity. However, few works have been conducted on hierarchical Bi{sub 2}WO{sub 6} composite photocatalysts with specifically exposed facets. In this work, we report a facile method to synthesize BiOCl@Bi{sub 2}WO{sub 6} hierarchical composite microspheres. Bi{sub 2}WO{sub 6} nanosheets with specifically exposed (0 2 0) facet were directly formed on the surface of BiOCl precursor microspheres via a controlled anion exchange route between BiOCl and Na{sub 2}WO{sub 4}. The visible-light photocatalytic activity of the BiOCl@Bi{sub 2}WO{sub 6} heterojunction with exposed (0 2 0) facets (denoted as BiOCl@Bi{sub 2}WO{sub 6}) was investigated by degradation of Rhodamine B (RhB) and ciprofloxacin (CIP) aqueous solution under visible light irradiation. The experimental results indicated that the BiOCl@Bi{sub 2}WO{sub 6} composite microsphere with intimate interfacial contacts exhibited improved efficiency for RhB photodegradation in comparison with pure BiOCl and Bi{sub 2}WO{sub 6}. The BiOCl@Bi{sub 2}WO{sub 6} composite microsphere also shows high photocatalytic activity for degradation of CIP under visible light irradiation. The enhanced photocatalytic performance of BiOCl@Bi{sub 2}WO{sub 6}-020 hierarchical microspheres can be ascribed to the improved visible light harvesting ability, high charge separation and transfer. This work will make significant contributions toward the exploration of novel heterostructures with high potential in photocatalytic applications.

Local variation in Bi crystal sites of epitaxial GaAsBi studied by photoelectron spectroscopy and first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Laukkanen, P., E-mail: pekka.laukkanen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Punkkinen, M.P.J., E-mail: marko.punkkinen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Lahti, A. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Puustinen, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Tuominen, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Hilska, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Mäkelä, J.; Dahl, J.; Yasir, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kuzmin, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation (Russian Federation); Osiecki, J.R.; Schulte, K. [The MAX IV laboratory, P. O. Box 118, Lund University, SE-221 00 Lund (Sweden); Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Kokko, K. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

2017-02-28

Highlights: • XPS is used to study bulk-like properties of GaAsBi crystals. • Surface effects are removed from XPS signal by an epitaxial AlAs cap film. • Local variation of Bi composition is found. • The result is consistent with photoluminescence and theoretical results. • Ga vacancies and Bi crystallites are suggested to be dominating defects. - Abstract: Epitaxial Bi-containing III–V crystals (III-V{sub 1-x}Bi{sub x}) have attracted increasing interest due to their potential in infrared applications. Atomic-scale characterization and engineering of bulk-like III-V{sub 1-x}Bi{sub x} properties (e.g., Bi incorporation and defect formation) are challenging but relevant to develop applications. Toward that target, we report here that the traditional surface-science measurement of photoelectron spectroscopy (PES) is a potential, non-destructive method to be combined in the studies of bulk-like properties, when surface effects are properly removed. We have investigated epitaxial GaAs{sub 1-x}Bi{sub x} films, capped by epitaxial AlAs layers, with high-resolution photoelectron spectroscopy. The Bi5d core-level spectra of GaAs{sub 1-x}Bi{sub x} together with ab-initio calculations give direct evidence of variation of Bi bonding environment in the lattice sites. The result agrees with photoluminescence (PL) measurement which shows that the studied GaAs{sub 1-x}Bi{sub x} films include local areas with higher Bi content, which contribute to PL but do not readily appear in x-ray diffraction (XRD). The measured and calculated Bi core-level shifts show also that Ga vacancies and Bi clusters are dominant defects.

Advances of operational modal identification

International Nuclear Information System (INIS)

Zhang, L.

2001-01-01

Operational modal analysis has shown many advantages compared to the traditional one. In this paper, the development of ambient modal identification in time domain is summarized. The mathematical models for modal identification have been presented as unified framework for time domain (TD) System realization algorithms, such as polyrefence (PRCE), extended Ibrahim time domain (EITD) and eigensystem realization algorithm (ERA), etc., and recently developed Stochastic subspace technique (SST). The latest technique named as frequency domain decomposition (FDD) is introduced for operational modal identification, which has many advantages as a frequency domain (FD) technique. Applications of the operational modal analysis in civil and mechanical engineering have shown the success and accuracy of the advanced operational modal identification algorithms- FDD and SST techniques. The major issues of TD and FD operational modal identification are also discussed. (author)

Mixed-Modality Stimulation to Evoke Two Modalities Simultaneously in One Channel for Electrocutaneous Sensory Feedback.

Science.gov (United States)

Choi, Kyunghwan; Kim, Pyungkang; Kim, Kyung-Soo; Kim, Soohyun

2017-12-01

One of the long-standing challenges in upper limb prosthetics is restoring the sensory feedback that is missing due to amputation. Two approaches have previously been presented to provide various types of sensory information to users, namely, multi-modality sensory feedback and using an array of single-modality stimulators. However, the feedback systems used in these approaches were too bulky to be embedded in prosthesis sockets. In this paper, we propose an electrocutaneous sensory feedback method that is capable of conveying two modalities simultaneously with only one electrode. The stimulation method, which we call mixed-modality stimulation, utilizes the phenomenon in which the superposition of two electric pulse trains of different frequencies is able to evoke two different modalities (i.e., pressure and tapping) at the same time. We conducted psychophysical experiments in which healthy subjects were required to recognize the intensity of pressure or the frequency of tapping from mixed-modality or two-channel stimulations. The results demonstrated that the subjects were able to discriminate the features of the two modalities in one electrode during mixed-modality stimulation and that the accuracies of successful recognitions (mean ± standard deviation) for the two feedback variables were 84.3 ± 7% for mixed-modality stimulation and 89.5 ± 6% for two-channel dual-modality stimulation, showing no statistically significant difference. Therefore, mixed-modality stimulation is an attractive method for modulating two modalities independently with only one electrode, and it could be used for implementing a compact sensory feedback system that is able to provide two different types of sensory information from prosthetics.

Calcined clay lightweight ceramics made with wood sawdust and sodium silicate

Energy Technology Data Exchange (ETDEWEB)

Santis, Bruno Carlos de; Rossignolo, Joao Adriano, E-mail: desantis.bruno@gmail.com [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil); Morelli, Marcio Raymundo [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

2016-11-15

This paper aims to study the influence of including wood sawdust and sodium silicate in the production process of calcined clay lightweight ceramics. In the production process first, a sample used by a company that produces ceramic products in Brazil was collected. The sample was analysed by techniques of liquidity (LL) and plasticity (LP) limits, particle size analysis, specific mass, X-ray diffraction (XRD) and X ray fluorescence spectrometry (XRF). From the clay, specimens of pure clay and mixtures with wood sawdust (10%, 20% and 30% by mass) and sodium silicate were produced and fired at a temperature of 900 deg C. These specimens were submitted to tests of water absorption, porosity, specific mass and compressive strength. Results of this research indicate that the incorporation of wood sawdust and sodium silicate in the ceramic paste specimens can be useful to make calcined clay lightweight ceramics with special characteristics (low values of water absorption and specific mass and high values of compressive strength), which could be used to produce calcined clay lightweight aggregates to be used in structural concrete. (author)

Implementation of the Scanning Laser Doppler Vibrometer Combined with a Light-Weight Pneumatic Artificial Muscle Actuator for the Modal Analysis of a Civil Structure

Directory of Open Access Journals (Sweden)

K. Deckers

2012-01-01

Full Text Available The identification of the modal parameters of bridges and other large civil constructions has become an important research issue. Different approaches have been proposed depending on the excitation used: ambient excitations (due to wind, traffic, … or artificial excitations (e.g. impact test with heavy drop weights. In practice it turns out that not all modes are well excited by the ambient forces. Hence the application of an artificial actuator is advisable. The problem is that larger constructions often require large and heavy excitation devices, which are hard to manipulate. Another difficulty encountered in performing a modal analysis on large civil constructions is the necessity for a large number of high sensitivity sensors. Consequently a large number of cables has to be installed resulting in a large setup time.

Calorimetric investigations of U-Bi system

International Nuclear Information System (INIS)

Agarwal, Renu; Joshi, A.R.

2013-01-01

U 0.333 Bi 0.667 is a compound that may form on breach of clad during reactor operation with metallic fuel and lead-bismuth coolant. Therefore, enthalpy of mixing of U-Bi liquid solution in limited composition range and enthalpy of formation of U 0.333 Bi 0.667 compound were measured by high temperature calorimetry. The enthalpy of mixing follows subregular solution model and enthalpy of formation U 0.333 Bi 0.667 from U(l) and Bi(l) at 843 K was -52.5 kJ/mol and -40.8 kJ/mol from U(s) and Bi(s) at 298.15 K. Both enthalpy of mixing and enthalpy of formation of intermetallic compound obtained experimentally were compared with Miedema model values. (author)

Exploratory Bi-factor Analysis: The Oblique Case

OpenAIRE

Jennrich, Robert L.; Bentler, Peter M.

2011-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bi-factor rotation criterion designed to produce a rotated loading mat...

Potential of scrap tire rubber as lightweight aggregate in flowable fill.

Science.gov (United States)

Pierce, C E; Blackwell, M C

2003-01-01

Flowable fill is a self-leveling and self-compacting material that is rapidly gaining acceptance and application in construction, particularly in transportation and utility earthworks. When mixed with concrete sand, standard flowable fill produces a mass density ranging from 1.8 to 2.3 g/cm(3) (115-145 pcf). Scrap tires can be granulated to produce crumb rubber, which has a granular texture and ranges in size from very fine powder to coarse sand-sized particles. Due to its low specific gravity, crumb rubber can be considered a lightweight aggregate. This paper describes an experimental study on replacing sand with crumb rubber in flowable fill to produce a lightweight material. To assess the technical feasibility of using crumb rubber, the fluid- and hardened-state properties of nine flowable fill mixtures were measured. Mixture proportions were varied to investigate the effects of water-to-cement ratio and crumb rubber content on fill properties. Experimental results indicate that crumb rubber can be successfully used to produce a lightweight flowable fill (1.2-1.6 g/cm(3) [73-98 pcf]) with excavatable 28-day compressive strengths ranging from 269 to 1194 kPa (39-173 psi). Using a lightweight fill reduces the applied stress on underlying soils, thereby reducing the potential for bearing capacity failure and minimizing soil settlement. Based on these results, a crumb rubber-based flowable fill can be used in a substantial number of construction applications, such as bridge abutment fills, trench fills, and foundation support fills.

Artificial lightweight aggregates as utilization for future ashes - A case study.

Science.gov (United States)

Sarabèr, Angelo; Overhof, Robert; Green, Terry; Pels, Jan

2012-01-01

In the future, more electricity in the Netherlands will be produced using coal with co-combustion. Due to this, the generated annual ash volume will increase and the chemical composition will be influenced. One of the options for utilization if present markets are saturated and for use of fly ashes with different compositions, is as raw material for lightweight aggregates. This was selected as one of the best utilizations options regarding potential ash volume to be applied, environmental aspects and status of technology. Because of this, a study has been performed to assess the potential utilization of fly ash for the production of lightweight aggregate. Lightweight aggregate has been produced in a laboratory scale rotary kiln. The raw material consisted of class F fly ash with high free lime content. An addition of 8% clay was necessary to get green pellets with sufficient green strength. The basic properties of the produced lightweight aggregate and its behaviour in concrete have been investigated. The concrete has a good compressive strength and its leaching behaviour meets the most stringent requirements of Dutch environmental regulations. The carbon foot print of concrete will be negatively influenced if only the concrete itself is taken into account, but the reduction of the volume weight has advantages regarding design, transport emissions and isolation properties which may counteract this. In the Dutch situation the operational costs are higher than expected potential selling price for the LWA, which implies that the gate fee for the fly ash is negative. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bi-level positive airway pressure ventilation for treating heart failure with central sleep apnea that is unresponsive to continuous positive airway pressure.

Science.gov (United States)

Dohi, Tomotaka; Kasai, Takatoshi; Narui, Koji; Ishiwata, Sugao; Ohno, Minoru; Yamaguchi, Tetsu; Momomura, Shin-Ichi

2008-07-01

Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is associated with a poor prognosis in patients with heart failure (HF). However, some patients do not respond to continuous positive airway pressure (CPAP), so other therapeutic modalities should be considered, such as bi-level positive airway pressure (PAP), which also assists respiration and might be effective for such patients. The 20 patients with HF because of left ventricular systolic dysfunction were assessed: 8 had ischemic etiology, and all had severe CSA according to the apnea - hypopnea index (AHI) determined by polysomnography. All diagnosed patients underwent repeat polysomnography using CPAP. The AHI improved significantly in 11 (AHI or=15). Bi-level PAP titration significantly improved the AHI in the latter group. Those who were unresponsive to CPAP had significantly lower PaCO(2), higher plasma brain natriuretic peptide (BNP), longer mean duration of CSR and fewer obstructive episodes than CPAP responders. After 6 months of positive airway support with either CPAP (n=9) or bi-level PAP (n=7), BNP levels significantly decreased and left ventricular ejection fraction significantly increased. Bi-level PAP could be an effective alternative for patients with HF and pure CSR-CSA who are unresponsive to CPAP.

The Feasibility of Palm Kernel Shell as a Replacement for Coarse Aggregate in Lightweight Concrete

Science.gov (United States)

Itam, Zarina; Beddu, Salmia; Liyana Mohd Kamal, Nur; Ashraful Alam, Md; Issa Ayash, Usama

2016-03-01

Implementing sustainable materials into the construction industry is fast becoming a trend nowadays. Palm Kernel Shell is a by-product of Malaysia’s palm oil industry, generating waste as much as 4 million tons per annum. As a means of producing a sustainable, environmental-friendly, and affordable alternative in the lightweight concrete industry, the exploration of the potential of Palm Kernel Shell to be used as an aggregate replacement was conducted which may give a positive impact to the Malaysian construction industry as well as worldwide concrete usage. This research investigates the feasibility of PKS as an aggregate replacement in lightweight concrete in terms of compressive strength, slump test, water absorption, and density. Results indicate that by using PKS for aggregate replacement, it increases the water absorption but decreases the concrete workability and strength. Results however, fall into the range acceptable for lightweight aggregates, hence it can be concluded that there is potential to use PKS as aggregate replacement for lightweight concrete.

Evaluation of water transfer from saturated lightweight aggregate to cement paste matrix by neutron radiography

International Nuclear Information System (INIS)

Maruyama, I.; Kanematsu, M.; Noguchi, T.; Iikura, H.; Teramoto, A.; Hayano, H.

2009-01-01

In high-strength concrete with low water-cement ratio, self-desiccation occurs due to cement hydration and causes shrinkage and an increased risk of cracking. While high-strength concrete has a denser matrix than normal-strength concrete, resulting in lower permeability, early-age cracks would cancel out this advantage. For the mitigation of this self-desiccation and resultant shrinkage, water-saturated porous aggregate, such as artificial lightweight aggregate, may be used in high-strength concrete. In this contribution, for the purpose of clarification of the volume change of high-strength concrete containing water-saturated lightweight aggregate, water transfer from the lightweight aggregate to cement paste matrix is visualized by neutron radiography. As a result, it is clear that water was supplied to the cement paste matrix in the range 3-8 mm from the surface of the aggregate, and the osmotic forces may yield water transfer around lightweight aggregate in a few hours after mixing.

Evaluating the time-dependent and bond characteristics of lightweight concrete mixes for Kansas prestressed concrete bridges.

Science.gov (United States)

2011-07-01

This report details results from testing that was conducted to determine the bond and time-dependent : characteristics of two lightweight concrete mixes. The lightweight mixes were evaluated to possibly : provide a more cost-effective solution to rep...

MODULTEC - Modular technology for lightweight vehicles; MODULTEC - Modultechnologie fuer Leichtmobile

Energy Technology Data Exchange (ETDEWEB)

Horlacher, M.; Efler, T.; Wegmann, S.

2003-07-01

This final report for the Swiss Federal Office of Energy presents the results of two research projects (MODULTEC I and II) that were carried out between 1995 and 2002. The project's aims were to develop and assess components for light-weight car bodies, study and test novel reinforced plastic materials and to examine the industrial implementation of light-weight vehicles. The report presents details on prototype vehicles and transport systems, as well as crash tests. The development of compound plastics and appropriate adhesives is discussed as is the co-operation with various industrial partners. Various prototype components are described and other associated topics such as recycling, storage of alternative fuels and pedestrian protection issues are discussed.

Metal-bending brake facilitates lightweight, close-tolerance fabrication

Science.gov (United States)

Ercoline, A. L.; Wilton, K. B.

1964-01-01

A lightweight, metal bending brake ensures very accurate bends. Features of the brake that adapt it for making complex reverse bends to close tolerances are a pronounced relief or cutaway of the underside of the bodyplate combined with modification in the leaf design and its suspension.

APE: Authenticated Permutation-Based Encryption for Lightweight Cryptography

DEFF Research Database (Denmark)

Andreeva, Elena; Bilgin, Begül; Bogdanov, Andrey

2015-01-01

The domain of lightweight cryptography focuses on cryptographic algorithms for extremely constrained devices. It is very costly to avoid nonce reuse in such environments, because this requires either a hardware source of randomness, or non-volatile memory to store a counter. At the same time, a lot...

Vibrations in a Multi-Storey Lightweight Building Structure

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard; Kirkegaard, Poul Henning

2013-01-01

This paper provides a quantification of the changes in vibration level that can be expected in a lightweight multi-storey wooden building due to reduced connection stiffness or added nonstructural mass. Firstly, the impact of changes in the floor-to-wall connections is examined. Secondly, a study...

Unusual Concentration Induced Antithermal Quenching of the Bi(2+) Emission from Sr2P2O7:Bi(2.).

Science.gov (United States)

Li, Liyi; Peng, Mingying; Viana, Bruno; Wang, Jing; Lei, Bingfu; Liu, Yingliang; Zhang, Qinyuan; Qiu, Jianrong

2015-06-15

The resistance of a luminescent material to thermal quenching is essential for the application in high power LEDs. Usually, thermal luminescence quenching becomes more and more serious as the activator concentration increases. Conversely, we found here that a red phosphor Sr2P2O7:Bi(2+) is one of the exceptions to this as we studied the luminescence properties at low (10-300 K) and high (300-500 K) temperatures. As Bi(2+) ions are incorporated into Sr2P2O7, they exhibit the emissions at ∼660 and ∼698 nm at room temperature and are encoded, hereafter, as Bi(1) and Bi(2) due to the substitutions for two different crystallographic sites Sr(1) and Sr(2), respectively, in the compound. However, they will not substitute for these sites equally. At lower dopant concentration, they will occupy preferentially Sr(2) sites partially due to size match. As the concentration increases, more Bi(2+) ions start to occupy the Sr(1) sites. This can be verified by the distinct changes of emission intensity ratio of Bi(2) to Bi(1). As environment temperature increases, the thermal quenching happens, but it can be suppressed by the Bi(2+) concentration increase. This becomes even more pronounced in Bi(2+) heavily doped sample as we decompose the broad emission band into separated Bi(1) and Bi(2) Gaussian peaks. For the sample, the Bi(1) emission at ∼660 nm even shows antithermal-quenching particularly at higher temperatures. This phenomenon is accompanied by the blue shift of the overall emission band and almost no changes of lifetimes. A mechanism is proposed due to volume expansion of the unit cell, the increase of Bi(1) content, and temperature dependent energy transfer between Bi(2) and Bi(1). This work helps us better understand the complex luminescent behavior of Bi(2+) doped materials, and it will be helpful to design in the future the heavily doped phosphor for WLEDs with even better resistance to thermal quenching.

Apply lightweight recognition algorithms in optical music recognition

Science.gov (United States)

Pham, Viet-Khoi; Nguyen, Hai-Dang; Nguyen-Khac, Tung-Anh; Tran, Minh-Triet

2015-02-01

The problems of digitalization and transformation of musical scores into machine-readable format are necessary to be solved since they help people to enjoy music, to learn music, to conserve music sheets, and even to assist music composers. However, the results of existing methods still require improvements for higher accuracy. Therefore, the authors propose lightweight algorithms for Optical Music Recognition to help people to recognize and automatically play musical scores. In our proposal, after removing staff lines and extracting symbols, each music symbol is represented as a grid of identical M ∗ N cells, and the features are extracted and classified with multiple lightweight SVM classifiers. Through experiments, the authors find that the size of 10 ∗ 12 cells yields the highest precision value. Experimental results on the dataset consisting of 4929 music symbols taken from 18 modern music sheets in the Synthetic Score Database show that our proposed method is able to classify printed musical scores with accuracy up to 99.56%.

Electric field control of magnetism using BiFeO3-based heterostructures

International Nuclear Information System (INIS)

Heron, J. T.; Schlom, D. G.; Ramesh, R.

2014-01-01

Conventional CMOS based logic and magnetic based data storage devices require the shuttling of electrons for data processing and storage. As these devices are scaled to increasingly smaller dimensions in the pursuit of speed and storage density, significant energy dissipation in the form of heat has become a center stage issue for the microelectronics industry. By taking advantage of the strong correlations between ferroic orders in multiferroics, specifically the coupling between ferroelectric and magnetic orders (magnetoelectricity), new device functionalities with ultra-low energy consumption can be envisioned. In this article, we review the advances and highlight challenges toward this goal with a particular focus on the room temperature magnetoelectric multiferroic, BiFeO 3 , exchange coupled to a ferromagnet. We summarize our understanding of the nature of exchange coupling and the mechanisms of the voltage control of ferromagnetism observed in these heterostructures

The Development of Lightweight Commercial Vehicle Wheels Using Microalloying Steel

Science.gov (United States)

Lu, Hongzhou; Zhang, Lilong; Wang, Jiegong; Xuan, Zhaozhi; Liu, Xiandong; Guo, Aimin; Wang, Wenjun; Lu, Guimin

Lightweight wheels can reduce weight about 100kg for commercial vehicles, and it can save energy and reduce emission, what's more, it can enhance the profits for logistics companies. The development of lightweight commercial vehicle wheels is achieved by the development of new steel for rim, the process optimization of flash butt welding, and structure optimization by finite element methods. Niobium micro-alloying technology can improve hole expansion rate, weldability and fatigue performance of wheel steel, and based on Niobium micro-alloying technology, a special wheel steel has been studied whose microstructure are Ferrite and Bainite, with high formability and high fatigue performance, and stable mechanical properties. The content of Nb in this new steel is 0.025% and the hole expansion rate is ≥ 100%. At the same time, welding parameters including electric upsetting time, upset allowance, upsetting pressure and flash allowance are optimized, and by CAE analysis, an optimized structure has been attained. As a results, the weight of 22.5in×8.25in wheel is up to 31.5kg, which is most lightweight comparing the same size wheels. And its functions including bending fatigue performance and radial fatigue performance meet the application requirements of truck makers and logistics companies.

Advantages and challenges of dissimilar materials in automotive lightweight construction

Science.gov (United States)

Weberpals, Jan-Philipp; Schmidt, Philipp A.; Böhm, Daniel; Müller, Steffen

2015-03-01

The core of future automotive lightweight materials is the joining technology of various material mixes. The type of joining will be essential, particularly in electrified propulsion systems, especially as an improved electrical energy transmission leads to a higher total efficiency of the vehicle. The most evident parts to start the optimization process are the traction battery, the electrical performance modules and the engines. Consequently aluminum plays a very central role for lightweight construction applications. However, the physical-technical requirements of components often require the combination with other materials. Thus the joining of mixed material connections is an essential key technology for many of the current developments, for example in the areas E-Mobility, solar energy and lightweight construction. Due to these advantages mixed material joints are already established in the automotive industry and laser beam remote welding is now a focus technology for mixed material connections. The secret of the laser welding process with mixed materials lies within the different areas of the melting phase diagram depending on the mixing ratio and the cooling down rate. According to that areas with unwanted, prim, intermetallic phases arise in the fusion zone. Therefore, laser welding of mixed material connections can currently only be used with additional filler in the automotive industry.

Modal Logics and Definability

OpenAIRE

Kuusisto, Antti

2013-01-01

In recent years, research into the mathematical foundations of modal logic has become increasingly popular. One of the main reasons for this is the fact that modal logic seems to adapt well to the requirements of a wide range of different fields of application. This paper is a summary of some of the author’s contributions to the understanding of modal definability theory.

Lightweight Thermally Stable Multi-Meter Aperture Submillimeter Reflectors, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Future astrophysics missions will require lightweight, thermally stable, submillimeter reflectors in sizes of 4m and greater. To date, graphite fiber reinforced...

High pressure synthesis of BiS2

DEFF Research Database (Denmark)

Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

crystal structures and electrical properties.1,2 Up until now, the most sulfur rich phase in the Bi-S phase diagram was Bi2S3.3 For BiS2 the Bi atoms have anisotropic charge distribution and more complex structures are expected when comparing the layered structures of transition metal dichalcogenides....... The possibilities of using high pressure synthesis to discover new phases in the Bi-S binary system were investigated as early as the 1960’s.4 The research led to discovery of a compound with BiS2 stoichiometry, but no structure solution of BiS2 was reported. A reason behind making this new phase is to study...... the physical properties since the related compound Bi2S3 is known to be a thermoelectric material.5 In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure...

LETOS -- A Lightweight Execution Tool for Operational Semantics

NARCIS (Netherlands)

Hartel, Pieter H.

A lightweight tool is proposed to aid in the development of operational semantics. To use LETOS an operational semantics must be expressed in its meta-language, which itself is a superset of Miranda. The LETOS compiler is smaller than comparable tools, yet LETOS is powerful enough to support

data sets Simulations in articulating light-weight PRS

NARCIS (Netherlands)

Van den Berg, Bert

2008-01-01

The data sets are output of 3 different steps in the development a simulations of a PRS as described in chapter 3.3: Simulations in articulating light-weight PRS A case for Pedagogy-oriented and Rating-based Hybrid Recommendation Strategies Rob Nadolski, Bert van den Berg, Adriana Berlanga, Hans

Internal friction behavior of liquid Bi-Sn alloys

International Nuclear Information System (INIS)

Wu Aiqing; Guo Lijun; Liu Changsong; Jia Erguang; Zhu Zhengang

2005-01-01

Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480 - bar Cand another at about 830 - bar C. Only a single internal-friction peak at about 830 - bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids

Internal friction behavior of liquid Bi-Sn alloys

Energy Technology Data Exchange (ETDEWEB)

Wu Aiqing [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Guo Lijun [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Liu Changsong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Jia Erguang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Zhu Zhengang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China)]. E-mail: zgzhu@issp.ac.cn

2005-12-01

Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480{sup -}bar Cand another at about 830{sup -}bar C. Only a single internal-friction peak at about 830{sup -}bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids.

NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

International Nuclear Information System (INIS)

Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

2000-01-01

This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be performed

Solvothermal modification of BiOCl nanosheets with Bi nanoparticles using ascorbic acid as reductant and the superoxide radicals dominated photocatalytic performance

Science.gov (United States)

Cui, Zhankui; Gao, Keke; Ge, Suxiang; Fa, Wenjun

2017-11-01

BiOCl nanosheets were solvothermally modified with Bi nanoparticles (NPs) using ascorbic acid as the reductant. The structures of Bi/BiOCl composites were characterized by XRD, Raman spectroscopy, FTIR spectroscopy and SEM. The light absorption properties were measured by UV-vis-NIR spectroscopy. The photocatalytic performances were evaluated by photodegrading methyl orange (MO) and the photocatalytic mechanism was investigated using trapping experiments and a fluorescent probe method. The results show that Bi NPs are uniformly distributed on the surfaces of BiOCl nanosheets and the modification amount of Bi NPs could be well controlled because of the mild property of ascorbic acid as reducing agent. The photocatalytic activities for the composites are improved obviously and the best photocatalytic performance is obtained when the weight ratio of Bi and BiOCl is1:10 and the photochemical reaction rate is 3.5 times that of pure BiOCl nanosheets and 19.7 times of Bi powders. The enhanced photocatalytic efficiency is ascribed to the favorable formation of dominant \\cdot O2- radicals caused by the increased photoinduced electrons from both Bi NPs and BiOCl nanosheets.

Lightweight S-Box Architecture for Secure Internet of Things

Directory of Open Access Journals (Sweden)

A. Prathiba

2018-01-01

Full Text Available Lightweight cryptographic solutions are required to guarantee the security of Internet of Things (IoT pervasiveness. Cryptographic primitives mandate a non-linear operation. The design of a lightweight, secure, non-linear 4 × 4 substitution box (S-box suited to Internet of Things (IoT applications is proposed in this work. The structure of the 4 × 4 S-box is devised in the finite fields GF (24 and GF ((222. The finite field S-box is realized by multiplicative inversion followed by an affine transformation. The multiplicative inverse architecture employs Euclidean algorithm for inversion in the composite field GF ((222. The affine transformation is carried out in the field GF (24. The isomorphic mapping between the fields GF (24 and GF ((222 is based on the primitive element in the higher order field GF (24. The recommended finite field S-box architecture is combinational and enables sub-pipelining. The linear and differential cryptanalysis validates that the proposed S-box is within the maximal security bound. It is observed that there is 86.5% lesser gate count for the realization of sub field operations in the composite field GF ((222 compared to the GF (24 field. In the PRESENT lightweight cipher structure with the basic loop architecture, the proposed S-box demonstrates 5% reduction in the gate equivalent area over the look-up-table-based S-box with TSMC 180 nm technology.

Experimental Validation of a Dynamic Model for Lightweight Robots

Directory of Open Access Journals (Sweden)

Alessandro Gasparetto

2013-03-01

Full Text Available Nowadays, one of the main topics in robotics research is dynamic performance improvement by means of a lightening of the overall system structure. The effective motion and control of these lightweight robotic systems occurs with the use of suitable motion planning and control process. In order to do so, model-based approaches can be adopted by exploiting accurate dynamic models that take into account the inertial and elastic terms that are usually neglected in a heavy rigid link configuration. In this paper, an effective method for modelling spatial lightweight industrial robots based on an Equivalent Rigid Link System approach is considered from an experimental validation perspective. A dynamic simulator implementing the formulation is used and an experimental test-bench is set-up. Experimental tests are carried out with a benchmark L-shape mechanism.

Advances in Modal Logic

DEFF Research Database (Denmark)

Modal logic is a subject with ancient roots in the western logical tradition. Up until the last few generations, it was pursued mainly as a branch of philosophy. But in recent years, the subject has taken new directions with connections to topics in computer science and mathematics. This volume...... is the proceedings of the conference of record in its fi eld, Advances in Modal Logic. Its contributions are state-of-the-art papers. The topics include decidability and complexity results for specifi c modal logics, proof theory of modal logic, logics for reasoning about time and space, provability logic, dynamic...... epistemic logic, and the logic of evidence....

Cross-modal perceptual load: the impact of modality and individual differences.

Science.gov (United States)

Sandhu, Rajwant; Dyson, Benjamin James

2016-05-01

Visual distractor processing tends to be more pronounced when the perceptual load (PL) of a task is low compared to when it is high [perpetual load theory (PLT); Lavie in J Exp Psychol Hum Percept Perform 21(3):451-468, 1995]. While PLT is well established in the visual domain, application to cross-modal processing has produced mixed results, and the current study was designed in an attempt to improve previous methodologies. First, we assessed PLT using response competition, a typical metric from the uni-modal domain. Second, we looked at the impact of auditory load on visual distractors, and of visual load on auditory distractors, within the same individual. Third, we compared individual uni- and cross-modal selective attention abilities, by correlating performance with the visual Attentional Network Test (ANT). Fourth, we obtained a measure of the relative processing efficiency between vision and audition, to investigate whether processing ease influences the extent of distractor processing. Although distractor processing was evident during both attend auditory and attend visual conditions, we found that PL did not modulate processing of either visual or auditory distractors. We also found support for a correlation between the uni-modal (visual) ANT and our cross-modal task but only when the distractors were visual. Finally, although auditory processing was more impacted by visual distractors, our measure of processing efficiency only accounted for this asymmetry in the auditory high-load condition. The results are discussed with respect to the continued debate regarding the shared or separate nature of processing resources across modalities.

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.

Application of orthogonal test method in mix proportion design of recycled lightweight aggregate concrete

Science.gov (United States)

Zhao, Zhanshan; An, Le; Zhang, Yijing; Yuan, Jie

2017-03-01

Recycled lightweight aggregate concrete was made with construction waste and ceramsite brick mainly including brick. Using the orthogonal test method, the mix proportion of recycled lightweight aggregate concrete was studied, and the Influence regularity and significance of water binder ratio, fly ash, sand ratio, the amount of recycled aggregate proportion on the compressive strength of concrete, the strong influence of mass ratio, slump expansion degree was studied. Through the mean and range analysis of the test results, the results show that the water binder ratio has the greatest influence on the 28d intensity of recycled lightweight aggregate concrete. Secondly, the fly ash content, the recycled aggregate replacement rate and the sand ratio have little influence. For the factors of expansion: the proportion of fly ash = water binder ratio sand >sand rate> recycled aggregate replacement rate. When the content of fly ash is about 30%, the expanded degree of recycled lightweight aggregate concrete is the highest, and the workability of that is better and the strength of concrete with 28d and 56d are the highest. When the content of brickbat is about 40% brick particles, the strength of concrete reaches the highest.

Update on wide- and ultra-widefield retinal imaging

Directory of Open Access Journals (Sweden)

Samir S Shoughy

2015-01-01

Full Text Available The peripheral retina is the site of pathology in many ocular diseases and ultra-widefield (UWF imaging is one of the new technologies available to ophthalmologists to manage some of these diseases. Currently, there are several imaging systems used in practice for the purpose of diagnostic, monitoring disease progression or response to therapy, and telemedicine. These include modalities for both adults and pediatric patients. The current systems are capable of producing wide- and UWF color fundus photographs, fluorescein and indocyanine green angiograms, and autofluorescence images. Using this technology, important clinical observations have been made in diseases such as diabetic retinopathy, uveitides, retinal vascular occlusions and tumors, intraocular tumors, retinopathy of prematurity, and age-related macular degeneration. Widefield imaging offers excellent postoperative documentation of retinal detachment surgery. New applications will soon be available to integrate this technology into large volume routine clinical practice.

Evidence for a supra-modal representation of emotion from cross-modal adaptation.

Science.gov (United States)

Pye, Annie; Bestelmeyer, Patricia E G

2015-01-01

Successful social interaction hinges on accurate perception of emotional signals. These signals are typically conveyed multi-modally by the face and voice. Previous research has demonstrated uni-modal contrastive aftereffects for emotionally expressive faces or voices. Here we were interested in whether these aftereffects transfer across modality as theoretical models predict. We show that adaptation to facial expressions elicits significant auditory aftereffects. Adaptation to angry facial expressions caused ambiguous vocal stimuli drawn from an anger-fear morphed continuum to be perceived as less angry and more fearful relative to adaptation to fearful faces. In a second experiment, we demonstrate that these aftereffects are not dependent on learned face-voice congruence, i.e. adaptation to one facial identity transferred to an unmatched voice identity. Taken together, our findings provide support for a supra-modal representation of emotion and suggest further that identity and emotion may be processed independently from one another, at least at the supra-modal level of the processing hierarchy. Copyright © 2014 Elsevier B.V. All rights reserved.

Automated Modal Parameter Estimation for Operational Modal Analysis of Large Systems

DEFF Research Database (Denmark)

Andersen, Palle; Brincker, Rune; Goursat, Maurice

2007-01-01

In this paper the problems of doing automatic modal parameter extraction and how to account for large number of data to process are considered. Two different approaches for obtaining the modal parameters automatically using OMA are presented: The Frequency Domain Decomposition (FDD) technique and...

Designable ultra-smooth ultra-thin solid-electrolyte interphases of three alkali metal anodes.

Science.gov (United States)

Gu, Yu; Wang, Wei-Wei; Li, Yi-Juan; Wu, Qi-Hui; Tang, Shuai; Yan, Jia-Wei; Zheng, Ming-Sen; Wu, De-Yin; Fan, Chun-Hai; Hu, Wei-Qiang; Chen, Zhao-Bin; Fang, Yuan; Zhang, Qing-Hong; Dong, Quan-Feng; Mao, Bing-Wei

2018-04-09

Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm -2 with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.

A Lightweight Distributed Framework for Computational Offloading in Mobile Cloud Computing

Science.gov (United States)

Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

2014-01-01

The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC. PMID:25127245

A lightweight distributed framework for computational offloading in mobile cloud computing.

Directory of Open Access Journals (Sweden)

Muhammad Shiraz

Full Text Available The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs. Therefore, Mobile Cloud Computing (MCC leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC.

Lightweight aluminum shock absorbers; Leichtbau-Stossdaempfer aus Aluminium

Energy Technology Data Exchange (ETDEWEB)

Kusche, R. [Serienentwicklung, ThyssenKrupp Bilstein GmbH, Ennepetal (Germany)

2004-12-01

One way in which the automotive industry is striving to reduce costs and environmental impact is by continuously lowering the fuel consumption of vehicles. To achieve this objective, lightweight materials are increasingly being used in automotive design. Increasing demands are also being made on shock absorber suppliers to reduce weight. (orig.)

High Efficiency Advanced Lightweight Fuel Cell (HEAL-FC), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Infinity's High Efficiency Advanced Lightweight Fuel Cell (HEAL FC) is an improved version of its current fuel cell technology developed for space applications. The...

Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

KAUST Repository

Cheng, Wei; Ren, Shang-Fen

2011-01-01

Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

KAUST Repository

Cheng, Wei

2011-03-10

Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

Modality-specific effects on crosstalk in task switching: evidence from modality compatibility using bimodal stimulation.

Science.gov (United States)

Stephan, Denise Nadine; Koch, Iring

2016-11-01

The present study was aimed at examining modality-specific influences in task switching. To this end, participants switched either between modality compatible tasks (auditory-vocal and visual-manual) or incompatible spatial discrimination tasks (auditory-manual and visual-vocal). In addition, auditory and visual stimuli were presented simultaneously (i.e., bimodally) in each trial, so that selective attention was required to process the task-relevant stimulus. The inclusion of bimodal stimuli enabled us to assess congruence effects as a converging measure of increased between-task interference. The tasks followed a pre-instructed sequence of double alternations (AABB), so that no explicit task cues were required. The results show that switching between two modality incompatible tasks increases both switch costs and congruence effects compared to switching between two modality compatible tasks. The finding of increased congruence effects in modality incompatible tasks supports our explanation in terms of ideomotor "backward" linkages between anticipated response effects and the stimuli that called for this response in the first place. According to this generalized ideomotor idea, the modality match between response effects and stimuli would prime selection of a response in the compatible modality. This priming would cause increased difficulties to ignore the competing stimulus and hence increases the congruence effect. Moreover, performance would be hindered when switching between modality incompatible tasks and facilitated when switching between modality compatible tasks.

Demonstration of surface transport in a hybrid Bi2Se3/Bi2Te3 heterostructure

OpenAIRE

Zhao, Yanfei; Chang, Cui-Zu; Jiang, Ying; DaSilva, Ashley; Sun, Yi; Wang, Huichao; Xing, Ying; Wang, Yong; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Jian

2013-01-01

In spite of much work on topological insulators (TIs), systematic experiments for TI/TI heterostructures remain absent. We grow a high quality heterostructure containing single quintuple layer (QL) of Bi2Se3 on 19 QLs of Bi2Te3 and compare its transport properties with 20 QLs Bi2Se3 and 20 QLs Bi2Te3. All three films are grown on insulating sapphire (0001) substrates by molecular beam epitaxy (MBE). In situ angle-resolved photoemission spectroscopy (ARPES) provides direct evidence that the su...

Effect of oxidant on resputtering of Bi from Bi--Sr--Ca--Cu--O films

International Nuclear Information System (INIS)

Grace, J.M.; McDonald, D.B.; Reiten, M.T.; Olson, J.; Kampwirth, R.T.; Gray, K.E.

1992-01-01

The type and partial pressure of oxidant mixed with argon can affect the selective sputtering of Bi in composite-target, magnetron-sputtered Bi--Sr--Ca--Cu--O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O + 2 , which interacts with the target to produce energetic O - . In contrast, ozone may form lower-energy O - by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y--Ba--Cu--O by others are comparable. Bi in Bi--Sr--Ca--Cu--O behaves as Ba in Y--Ba--Cu--O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi--Sr--Ca--Cu--O is similar to what is observed for Cu in Y--Ba--Cu--O

Developments in Emission Measurements Using Lightweight Sensors and Samplers.

Science.gov (United States)

Lightweight emission measurement systems making use of miniaturized sensors and samplers have been developed for portable and aerial sampling for an array of pollutants. Shoebox-sized systems called “Kolibri”, weighing 3-5 kg, have been deployed on NASA-flown unmanned...

Durability of lightweight concrete : Phase I : concrete temperature study.

Science.gov (United States)

1968-08-01

This report describes a study conducted to determine the temperature gradient throughout the depth of a six inch concrete bridge deck. The bridge deck selected for study was constructed using lightweight concrete for the center spans and sand and gra...

40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Options for incinerators, cement kilns... Technology (MACT) Standards § 270.235 Options for incinerators, cement kilns, lightweight aggregate kilns... incinerator, cement kiln, lightweight aggregate kiln, solid fuel boiler, liquid fuel boiler, or hydrochloric...

Ultra-Wideband Sensors for Improved Magnetic Resonance Imaging, Cardiovascular Monitoring and Tumour Diagnostics

Directory of Open Access Journals (Sweden)

Frank Seifert

2010-12-01

Full Text Available The specific advantages of ultra-wideband electromagnetic remote sensing (UWB radar make it a particularly attractive technique for biomedical applications. We partially review our activities in utilizing this novel approach for the benefit of high and ultra-high field magnetic resonance imaging (MRI and other applications, e.g., for intensive care medicine and biomedical research. We could show that our approach is beneficial for applications like motion tracking for high resolution brain imaging due to the non-contact acquisition of involuntary head motions with high spatial resolution, navigation for cardiac MRI due to our interpretation of the detected physiological mechanical contraction of the heart muscle and for MR safety, since we have investigated the influence of high static magnetic fields on myocardial mechanics. From our findings we could conclude, that UWB radar can serve as a navigator technique for high and ultra-high field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard ECG analysis by complementary information where sole ECG analysis fails. Further analytical investigations have proven the feasibility of this method for intracranial displacements detection and the rendition of a tumour’s contrast agent based perfusion dynamic. Beside these analytical approaches we have carried out FDTD simulations of a complex arrangement mimicking the illumination of a human torso model incorporating the geometry of the antennas applied.

Ultra-wideband sensors for improved magnetic resonance imaging, cardiovascular monitoring and tumour diagnostics.

Science.gov (United States)

Thiel, Florian; Kosch, Olaf; Seifert, Frank

2010-01-01

The specific advantages of ultra-wideband electromagnetic remote sensing (UWB radar) make it a particularly attractive technique for biomedical applications. We partially review our activities in utilizing this novel approach for the benefit of high and ultra-high field magnetic resonance imaging (MRI) and other applications, e.g., for intensive care medicine and biomedical research. We could show that our approach is beneficial for applications like motion tracking for high resolution brain imaging due to the non-contact acquisition of involuntary head motions with high spatial resolution, navigation for cardiac MRI due to our interpretation of the detected physiological mechanical contraction of the heart muscle and for MR safety, since we have investigated the influence of high static magnetic fields on myocardial mechanics. From our findings we could conclude, that UWB radar can serve as a navigator technique for high and ultra-high field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard ECG analysis by complementary information where sole ECG analysis fails. Further analytical investigations have proven the feasibility of this method for intracranial displacements detection and the rendition of a tumour's contrast agent based perfusion dynamic. Beside these analytical approaches we have carried out FDTD simulations of a complex arrangement mimicking the illumination of a human torso model incorporating the geometry of the antennas applied.

Virtual Colonoscopy Screening With Ultra Low-Dose CT and Less-Stressful Bowel Preparation: A Computer Simulation Study

Science.gov (United States)

Wang, Jing; Wang, Su; Li, Lihong; Fan, Yi; Lu, Hongbing; Liang, Zhengrong

2008-10-01

Computed tomography colonography (CTC) or CT-based virtual colonoscopy (VC) is an emerging tool for detection of colonic polyps. Compared to the conventional fiber-optic colonoscopy, VC has demonstrated the potential to become a mass screening modality in terms of safety, cost, and patient compliance. However, current CTC delivers excessive X-ray radiation to the patient during data acquisition. The radiation is a major concern for screening application of CTC. In this work, we performed a simulation study to demonstrate a possible ultra low-dose CT technique for VC. The ultra low-dose abdominal CT images were simulated by adding noise to the sinograms of the patient CTC images acquired with normal dose scans at 100 mA s levels. The simulated noisy sinogram or projection data were first processed by a Karhunen-Loeve domain penalized weighted least-squares (KL-PWLS) restoration method and then reconstructed by a filtered backprojection algorithm for the ultra low-dose CT images. The patient-specific virtual colon lumen was constructed and navigated by a VC system after electronic colon cleansing of the orally-tagged residue stool and fluid. By the KL-PWLS noise reduction, the colon lumen can successfully be constructed and the colonic polyp can be detected in an ultra low-dose level below 50 mA s. Polyp detection can be found more easily by the KL-PWLS noise reduction compared to the results using the conventional noise filters, such as Hanning filter. These promising results indicate the feasibility of an ultra low-dose CTC pipeline for colon screening with less-stressful bowel preparation by fecal tagging with oral contrast.

Lightweight concrete masonry units based on processed granulate of corn cob as aggregate

Directory of Open Access Journals (Sweden)

Faustino, J.

2015-06-01

Full Text Available A research work was performed in order to assess the potential application of processed granulate of corn cob (PCC as an alternative lightweight aggregate for the manufacturing process of lightweight concrete masonry units (CMU. Therefore, CMU-PCC were prepared in a factory using a typical lightweight concrete mixture for non-structural purposes. Additionally, lightweight concrete masonry units based on a currently applied lightweight aggregate such as expanded clay (CMU-EC were also manufactured. An experimental work allowed achieving a set of results that suggest that the proposed building product presents interesting material properties within the masonry wall context. Therefore, this unit is promising for both interior and exterior applications. This conclusion is even more relevant considering that corn cob is an agricultural waste product.En este trabajo de investigación se evaluó la posible aplicación de granulado procesado de la mazorca de maiz como un árido ligero alternativo en el proceso de fabricación de unidades de mampostería de hormigón ligero. Con esta finalidad, se prepararon en una fábrica diversas unidades de mampostería no estructural con granulado procesado de la mazorca de maiz. Además, se fabricaran unidades de mampostería estándar de peso ligero basado en agregados de arcilla expandida. Este trabajo experimental permitió lograr un conjunto de resultados que sugieren que el producto de construcción propuesto presenta interesantes propiedades materiales en el contexto de la pared de mampostería. Por lo tanto, esta solución es prometedora tanto para aplicaciones interiores y exteriores. Esta conclusión es aún más relevante teniendo en cuenta que la mazorca de maíz es un producto de desecho agrícola.

Comparative study of phase structure and dielectric properties for K0.5Bi0.5TiO3-BiAlO3 and LaAlO3-BiAlO3

International Nuclear Information System (INIS)

Hou, Yudong; Zheng, Mupeng; Si, Meiju; Cui, Lei; Zhu, Mankang; Yan, Hui

2013-01-01

In this work, two perovskite-type compounds, K 0.5 Bi 0.5 TiO 3 and LaAlO 3 , have been selected as host material to incorporate with BiAlO 3 using a solid-state reaction route. The phase evolution and dielectric properties for both systems have been investigated in detail. For the K 0.5 Bi 0.5 TiO 3 -BiAlO 3 system, it is interesting to find that when using Bi 2 O 3 , Al 2 O 3 , K 2 CO 3 , and TiO 2 as starting materials, the formed compounds are K 0.5 Bi 0.5 TiO 3 -K 0.5 Bi 4.5 Ti 4 O 15 and Al 2 O 3 only plays a dopant role. There are two distinct dielectric peaks appearing in the patterns of temperature dependence of dielectric constant, corresponding to the phase-transition points of perovskite-type K 0.5 Bi 0.5 TiO 3 and Aurivillius-type K 0.5 Bi 4.5 Ti 4 O 15 , independently. In comparison, using Bi 2 O 3 , Al 2 O 3 , and La 2 O 3 as starting materials, the pure perovskite phase LaAlO 3 -BiAlO 3 can be obtained. Compared to the inherent paraelectric behavior in LaAlO 3 , the diffuse phase-transition phenomena can be observed in the LaAlO 3 -BiAlO 3 binary system, which corresponds well to the Vogel-Fulcher (VF) relationship. Moreover, compared to pure LaAlO 3 , the synthesized LaAlO 3 -BiAlO 3 compound shows enhanced dielectric properties, which are promising in application as gate dielectric materials. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Physical modalities in chronic pain management.

Science.gov (United States)

Rakel, Barbara; Barr, John O

2003-09-01

The following conclusions can be made based on review of the evidence: There is limited but positive evidence that select physical modalities are effective in managing chronic pain associated with specific conditions experienced by adults and older individuals. Overall, studies have provided the most support for the modality of therapeutic exercise. Different physical modalities have similar magnitudes of effects on chronic pain. Therefore, selection of the most appropriate physical modality may depend on the desired functional outcome for the patient, the underlying impairment, and the patient's preference or prior experience with the modality. Certain patient characteristics may decrease the effectiveness of physical modalities, as has been seen with TENS. These characteristics include depression, high trait anxiety, a powerful others locus of control, obesity, narcotic use, and neuroticism. The effect on pain by various modalities is generally strongest in the short-term period immediately after the intervention series, but effects can last as long as 1 year after treatment (e.g., with massage). Most research has tested the effect of physical modalities on chronic low back pain and knee OA. The effectiveness of physical modalities for other chronic pain conditions needs to be evaluated more completely. Older and younger adults often experience similar effects on their perception of pain from treatment with physical modalities. Therefore, use of these modalities for chronic pain in older adults is appropriate, but special precautions need to be taken. Practitioners applying physical modalities need formal training that includes the risks and precautions for these modalities. If practitioners lack formal training in the use of physical modalities, or if modality use is not within their scope of practice, it is important to consult with and refer patients to members of the team who have this specialized training. Use of a multidisciplinary approach to chronic pain

Lightweight Bathrooms with Increased Durability

DEFF Research Database (Denmark)

Morelli, Martin; Brandt, Erik

2017-01-01

vulnerable and less robust than the old type of heavy wet rooms made from concrete and masonry. For example damage due to ingress of water and moisture in a lightweight construction is normally associated with very expensive repair work. However, they might perform fully satisfactorily on condition...... wet room floor made with 2 watertight layers separated by an inorganic layer e.g. fibre reinforced concrete. Both layers are drained to the floor gully in order to reduce the risk of damage from leaks in the watertight layer; i.e. if one layer fails, the layer beneath will be able to provide...

The Dependence of the Physical Mechanical Properties of Expanded-Clay Lightweight Concrete on the Composition

Directory of Open Access Journals (Sweden)

Marija Vaičienė

2011-04-01

Full Text Available Binder material is the most expensive raw component of concrete; thus, scientists are looking for cheaper substitute materials. This paper shows that when manufacturing, a part of the binder material of expanded-clay lightweight concrete can be replaced with active filler. The conducted studies show that technogenic – catalyst waste could act as similar filler. The study also includes the dependence of the physical and mechanical properties of expanded-clay lightweight concrete on the concrete mixture and the chemical composition of the samples obtained. Different formation and composition mixtures of expanded-clay lightweight concrete were chosen to determine the properties of physical-mechanical properties such as density, water absorption and compressive strength.Article in Lithuanian

Crystalline structure and XMCD studies of Co40Fe40B20 grown on Bi2Te3, BiTeI and Bi2Se3

OpenAIRE

Kaveev, A. K.; Sokolov, N. S.; Suturin, S. M.; Zhiltsov, N. S.; Golyashov, V. A.; Tereshchenko, O. E.; Prosvirin, I. P.; Kokh, K. A.; Sawada, M.

2018-01-01

Epitaxial films of Co40Fe40B20 (further - CoFeB) were grown on Bi2Te3(001) and Bi2Se3(001) substrates by laser molecular beam epitaxy (LMBE) technique at 200-400C. Bcc-type crystalline structure of CoFeB with (111) plane parallel to (001) plane of Bi2Te3 was observed, in contrast to polycrystalline CoFeB film formed on Bi2Se3(001) at RT using high-temperature seeding layer. Therefore, structurally ordered ferromagnetic thin films were obtained on the topological insulator surface for the firs...

Thermal analysis and phase diagrams of the LiF BiF{sub 3} e NaF BiF{sub 3} systems; Analise termica e diagramas de fase dos sistemas LiF-BiF{sub 3} e NaF-BiF{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Gerson Hiroshi de Godoy

2013-07-01

Investigations of the binary systems LiF-BiF{sub 3} and NaF-BiF{sub 3} were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF{sub 3}) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF{sub 3} to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF{sub 3} were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF{sub 4}, decomposes into LiF and a liquid phase. The NaF-BiF{sub 3} system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF{sub 3}) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF{sub 4} was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF{sub 4}, NaBiF{sub 4} and a solid solution of NaF and BiF{sub 3} called {sup I.} The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

Screen-detected versus interval cancers: Effect of imaging modality and breast density in the Flemish Breast Cancer Screening Programme

Energy Technology Data Exchange (ETDEWEB)

Timmermans, Lore; Bacher, Klaus; Thierens, Hubert [Ghent University, Department of Basic Medical Sciences, QCC-Gent, Ghent (Belgium); Bleyen, Luc; Herck, Koen van [Ghent University, Centrum voor Preventie en Vroegtijdige Opsporing van Kanker, Ghent (Belgium); Lemmens, Kim; Ongeval, Chantal van; Steen, Andre van [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Martens, Patrick [Centrum voor Kankeropsporing, Bruges (Belgium); Brabander, Isabel de [Belgian Cancer Registry, Brussels (Belgium); Goossens, Mathieu [UZ Brussel, Dienst Kankerpreventie, Brussels (Belgium)

2017-09-15

To investigate if direct radiography (DR) performs better than screen-film mammography (SF) and computed radiography (CR) in dense breasts in a decentralized organised Breast Cancer Screening Programme. To this end, screen-detected versus interval cancers were studied in different BI-RADS density classes for these imaging modalities. The study cohort consisted of 351,532 women who participated in the Flemish Breast Cancer Screening Programme in 2009 and 2010. Information on screen-detected and interval cancers, breast density scores of radiologist second readers, and imaging modality was obtained by linkage of the databases of the Centre of Cancer Detection and the Belgian Cancer Registry. Overall, 67% of occurring breast cancers are screen detected and 33% are interval cancers, with DR performing better than SF and CR. The interval cancer rate increases gradually with breast density, regardless of modality. In the high-density class, the interval cancer rate exceeds the cancer detection rate for SF and CR, but not for DR. DR is superior to SF and CR with respect to cancer detection rates for high-density breasts. To reduce the high interval cancer rate in dense breasts, use of an additional imaging technique in screening can be taken into consideration. (orig.)

Screen-detected versus interval cancers: Effect of imaging modality and breast density in the Flemish Breast Cancer Screening Programme

International Nuclear Information System (INIS)

Timmermans, Lore; Bacher, Klaus; Thierens, Hubert; Bleyen, Luc; Herck, Koen van; Lemmens, Kim; Ongeval, Chantal van; Steen, Andre van; Martens, Patrick; Brabander, Isabel de; Goossens, Mathieu

2017-01-01

To investigate if direct radiography (DR) performs better than screen-film mammography (SF) and computed radiography (CR) in dense breasts in a decentralized organised Breast Cancer Screening Programme. To this end, screen-detected versus interval cancers were studied in different BI-RADS density classes for these imaging modalities. The study cohort consisted of 351,532 women who participated in the Flemish Breast Cancer Screening Programme in 2009 and 2010. Information on screen-detected and interval cancers, breast density scores of radiologist second readers, and imaging modality was obtained by linkage of the databases of the Centre of Cancer Detection and the Belgian Cancer Registry. Overall, 67% of occurring breast cancers are screen detected and 33% are interval cancers, with DR performing better than SF and CR. The interval cancer rate increases gradually with breast density, regardless of modality. In the high-density class, the interval cancer rate exceeds the cancer detection rate for SF and CR, but not for DR. DR is superior to SF and CR with respect to cancer detection rates for high-density breasts. To reduce the high interval cancer rate in dense breasts, use of an additional imaging technique in screening can be taken into consideration. (orig.)

Highly efficient visible-light-induced photocatalytic activity of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Chaiwichian, Saranyoo [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand); Inceesungvorn, Burapat [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wetchakun, Khatcharin [Program of Physics, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani 34000 (Thailand); Phanichphant, Sukon [Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Kangwansupamonkon, Wiyong [National Nanotechnology Center, Thailand Science Park, Phahonyotin Road, Klong 1, Klong Luang, Phathumthani 12120 (Thailand); Wetchakun, Natda, E-mail: natda_we@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand)

2014-06-01

Highlights: • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were obtained using hydrothermal method. • Physicochemical properties played a significant role on photocatalytic efficiency. • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterogeneous structures were greatly enhanced for degradation of MB. • A tentative mechanism of charge transfer process in MB degradation was proposed. - Abstract: The Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were synthesized by hydrothermal method. Physical properties of the heterojunction photocatalyst samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The XRD results indicated that BiVO{sub 4} retain monoclinic and tetragonal structures, while Bi{sub 2}WO{sub 6} presented as orthorhombic structure. The Brunauer, Emmett and Teller (BET) adsorption–desorption of nitrogen gas for specific surface area determination at the temperature of liquid nitrogen was performed on all samples. UV–vis diffuse reflectance spectra (UV–vis DRS) were used to identify the absorption range and band gap energy of the heterojunction photocatalysts. The photocatalytic performance of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts was studied via the photodegradation of methylene blue (MB) under visible light irradiation. The results indicated that the heterojunction photocatalyst at 0.5:0.5 mole ratio of Bi{sub 2}WO{sub 6}:BiVO{sub 4} shows the highest photocatalytic activity.

Exploratory Bi-Factor Analysis: The Oblique Case

Science.gov (United States)

Jennrich, Robert I.; Bentler, Peter M.

2012-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

In-Situ Hydrothermal Synthesis of Bi-Bi2O2CO3 Heterojunction Photocatalyst with Enhanced Visible Light Photocatalytic Activity

Science.gov (United States)

Kar, Prasenjit; Maji, Tuhin Kumar; Nandi, Ramesh; Lemmens, Peter; Pal, Samir Kumar

2017-04-01

Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi-Bi2O2CO3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi-Bi2O2CO3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue (MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi-Bi2O2CO3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.

Facile synthesis of BiOF/Bi{sub 2}O{sub 3}/reduced graphene oxide photocatalyst with highly efficient and stable natural sunlight photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Hu, Limin; Dong, Shuying; Li, Qilu; Feng, Jinglan; Pi, Yunqing; Liu, Menglin [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China); Sun, Jingyu, E-mail: sunjy-cnc@pku.edu.cn [Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Sun, Jianhui, E-mail: sunjh@htu.cn [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China)

2015-06-05

Highlights: • A dual Bi-based ball-shaped material BiOF/Bi{sub 2}O{sub 3} were facilely synthesized. • The composition effect of BiOF/Bi{sub 2}O{sub 3}/RGO hybrid were probed for the first time. • The photocatalytic performances were evaluated upon natural sunlight irradiation. • The composites showed a twofold augmentation in the degradation efficiency. • The hybrid photocatalyst can be easily recycled for three times. - Abstract: A facile and efficient route for the controllable synthesis of BiOF/Bi{sub 2}O{sub 3} nanostructures by hydrolysis method was reported, where the as-prepared BiOF/Bi{sub 2}O{sub 3} was subsequently incorporated with reduced graphene oxide (RGO) sheets to form BiOF/Bi{sub 2}O{sub 3}/RGO composites. The obtained BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites were well characterized with the aid of various techniques to probe their crystallographic, morphological, chemical and optical properties. Photocatalytic capacities of the pure BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites have been investigated by the degradation of Rhodamine B (RhB)-contained wastewater under natural sunlight irradiation. A twofold augmentation of degradation efficiency was in turn observed for BiOF/Bi{sub 2}O{sub 3}/RGO composites compared with that of pure BiOF/Bi{sub 2}O{sub 3} under the natural sunlight irradiation. The optimum conditions, the effects of the active species and stabilities in photocatalytic performances of the BiOF/Bi{sub 2}O{sub 3}/RGO composites have also been probed.

Hot stamping advanced manufacturing technology of lightweight car body

CERN Document Server

Hu, Ping; He, Bin

2017-01-01

This book summarizes the advanced manufacturing technology of original innovations in hot stamping of lightweight car body. A detailed description of the technical system and basic knowledge of sheet metal forming is given, which helps readers quickly understand the relevant knowledge in the field. Emphasis has been placed on the independently developed hot stamping process and equipment, which help describe the theoretical and experimental research on key problems involving stress field, thermal field and phase transformation field in hot stamping process. Also, a description of the formability at elevated temperature and the numerical simulation algorithms for high strength steel hot stamping is given in combination with the experiments. Finally, the book presents some application cases of hot stamping technology such as the lightweight car body design using hot stamping components and gradient hardness components, and the cooling design of the stamping tool. This book is intended for researchers, engineers...

Tl, Bi, and Pb doping in Ba4BiPb2TlO12-δ

International Nuclear Information System (INIS)

Sutto, T.E.; Averill, B.A.

1992-01-01

To determine the effects of different 6s metal concentrations on the superconducting nature of Ba 4 BiPb 2 TlO 12-δ , materials produced via four doping schemes were examined: Ba 4 Bi(Pb, Tl) 3 O 12-δ , Ba 4 -(BiPb) 3 TlO 12-δ , Ba 4 (Bi,Tl) 2 Pb 2 O 12-δ , and Ba 4 Bi x Pb 4-2x Tl x O 12-δ . For the parent compound a value of δ = 0.91 was observed, indicating that approximately 1/4 oxygen atom was missing per cubic subsection of the unit cell. For all samples, the symmetry of the parent compound changed from orthorhombic to tetragonal as the system moved away from the ideal composition. This was usually accompanied by the loss of superconductivity, which exhibited a maximum T c of 10.5 K for the parent compound Ba 4 BiPb 2 TlO 12-δ . Also reported are high-temperature magnetic susceptibility results, which are used to determine the effect of metal substitution on the density of states at the Fermi level. For each set of variants on the parent composition, the onset of superconductivity was accompanied by a significant decrease in the size of the Pauli paramagnetic signal. 16 refs., 6 figs

Considerations about using OLAP Cubes and Self-Service BI Tools for BI Systems’ Development

Directory of Open Access Journals (Sweden)

Gianina MIHAI

2017-12-01

Full Text Available Nowadays, the decision-making process must be an extremely fast one. This is why any decision-maker in a company must obtain information from the multiple available data source used in its transactional systems as easily and as quickly as possible. Business Intelligence (BI systems are the ones that provide the tools necessary for obtaining this information. In this article, we shall present the strengths and weaknesses regarding data analyses in a BI system using OLAP cubes and self-service BI tools.

Bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 with unselectively efficient photocatalytic activity and mechanism insight

Science.gov (United States)

Hao, Lin; Huang, Hongwei; Guo, Yuxi; Du, Xin; Zhang, Yihe

2017-10-01

Fabrication of homo/hetero-junctions by coupling of wide-band gap semiconductor and narrow-band gap semiconductor is desirable as they can achieve a decent balance between photoabsorption and photo-redox ability. Herein, a n-n type bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 was developed by facilely manipulating the basicity in a one-pot hydrothermal process. Compared with BiOCl which only responds to UV light, the photo-responsive range is remarkably extended to visible region. The BiOCl/Bi12O17Cl2 phasejunctions show much higher photocatalytic activity than the single BiOCl and Bi12O17Cl2 toward degradation of methyl orange (MO) under simulated solar light. In particular, it presented a high photo-oxidation ability in degrading diverse industrial contaminants including 2,4-dichlorophenol (2,4-DCP), phenol, bisphenol A (BPA) and tetracycline hydrochloride. Based on a series of photoelectrochemical and photoluminescence measurements, the fortified photocatalytic performance of BiOCl/Bi12O17Cl2 phasejunctions was manifested to be attributed to the efficient separation and transfer efficiencies of photoinduced electron-hole pairs because of the junctional interface formed between BiOCl and Bi12O17Cl2. The study may not only furnish a high-effective photocatalyst in the application of environment purification, but also pave a path to fabricate agnate phase-junctional photocatalyst.

Magnetic Field Sensing Based on Bi-Tapered Optical Fibers Using Spectral Phase Analysis.

Science.gov (United States)

Herrera-Piad, Luis A; Haus, Joseph W; Jauregui-Vazquez, Daniel; Sierra-Hernandez, Juan M; Estudillo-Ayala, Julian M; Lopez-Dieguez, Yanelis; Rojas-Laguna, Roberto

2017-10-20

A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF) span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.

Magnetic Field Sensing Based on Bi-Tapered Optical Fibers Using Spectral Phase Analysis

Directory of Open Access Journals (Sweden)

Luis A. Herrera-Piad

2017-10-01

Full Text Available A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.

Thermal analysis and phase diagrams of the LiF BiF3 e NaF BiF3 systems

International Nuclear Information System (INIS)

Nakamura, Gerson Hiroshi de Godoy

2013-01-01

Investigations of the binary systems LiF-BiF 3 and NaF-BiF 3 were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF 3 ) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF 3 to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF 3 were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF 4 , decomposes into LiF and a liquid phase. The NaF-BiF 3 system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF 3 ) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF 4 was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF 4 , NaBiF 4 and a solid solution of NaF and BiF 3 called I. The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

Ultrasound combined transcutaneous electrical nerve stimulation (UltraTENS) versus phonophoresis of piroxicam (PhP) in symptomatic knee osteoarthritis: A randomized double-blind, controlled trial.

Science.gov (United States)

Boonhong, Jariya; Suntornpiyapan, Phitsanu; Piriyajarukul, Apatchanee

2018-02-02

Ultrasound combined with transcutaneous electrical nerve stimulation (UltraTENS) and phonophoresis of piroxicam (PhP) are combined modality therapy that frequently used in musculoskeletal pain including knee osteoarthritis (OA). But it is lack of a good clinical trial to prove and compare their effects. To compare the effects of UltraTENS with PhP on mild to moderate degree of symptomatic knee OA. Sixty-one patients (55 women), mean age of 63.4 ± 8.1 y, 50-90 mm VAS of knee pain and Kellgren-Lawrence score of grade I-III were randomly allocated into UltraTENS and PhP (N = 31 and 30, respectively). The UltraTENS group received a combined ultrasound with TENS program and a non-drug gel, whereas the PhP group got an ultrasound program with piroxicam gel and sham TENS. All patients were treated for a total of 10 sessions, consisting of five times per week and 10 min per session. Before and after treatment, patients were evaluated knee pain by using the 100-mm VAS and functional performance by Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index. The UltraTENS and PhP groups experienced considerable improvement in both VAS and total WOMAC scores post-treatment (PPhP had better VAS of pain and WOMAC scores but no statistical significance. Results show that UltraTENS and PhP were effective for relieving pain and improve functionality knee OA without significant differences between their effects.

Ultrahigh vacuum STM/STS studies of the Bi-O surface in Bi2Sr2CuOy single crystals

International Nuclear Information System (INIS)

Ikeda, Kazuto; Tomeno, Izumi; Takamuku, Kenshi; Yamaguchi, Koji; Itti, Rittaporn; Koshizuka, Naoki

1992-01-01

Scanning tunneling microscopic and spectroscopic studies were made on cleaved surfaces of Bi 2 Sr 2 CuO y single crystals using an ultrahigh-vacuum scanning tunneling microscope (UHV-STM). The modulation structures of the Bi-O surface were observed at room temperature with atomic resolution. The tunneling spectra showed electronic gap structures similar to those observed for the Bi-O surface of superconducting Bi-2212 single crystals. This suggests that superconductivity is not directly related to the electronic structure observed in the Bi-O plane. (orig.)

Annealing-Induced Bi Bilayer on Bi2Te3 Investigated via Quasi-Particle-Interference Mapping.

Science.gov (United States)

Schouteden, Koen; Govaerts, Kirsten; Debehets, Jolien; Thupakula, Umamahesh; Chen, Taishi; Li, Zhe; Netsou, Asteriona; Song, Fengqi; Lamoen, Dirk; Van Haesendonck, Chris; Partoens, Bart; Park, Kyungwha

2016-09-27

Topological insulators (TIs) are renowned for their exotic topological surface states (TSSs) that reside in the top atomic layers, and hence, detailed knowledge of the surface top atomic layers is of utmost importance. Here we present the remarkable morphology changes of Bi2Te3 surfaces, which have been freshly cleaved in air, upon subsequent systematic annealing in ultrahigh vacuum and the resulting effects on the local and area-averaging electronic properties of the surface states, which are investigated by combining scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and Auger electron spectroscopy (AES) experiments with density functional theory (DFT) calculations. Our findings demonstrate that the annealing induces the formation of a Bi bilayer atop the Bi2Te3 surface. The adlayer results in n-type doping, and the atomic defects act as scattering centers of the TSS electrons. We also investigated the annealing-induced Bi bilayer surface on Bi2Te3 via voltage-dependent quasi-particle-interference (QPI) mapping of the surface local density of states and via comparison with the calculated constant-energy contours and QPI patterns. We observed closed hexagonal patterns in the Fourier transform of real-space QPI maps with secondary outer spikes. DFT calculations attribute these complex QPI patterns to the appearance of a "second" cone due to the surface charge transfer between the Bi bilayer and the Bi2Te3. Annealing in ultrahigh vacuum offers a facile route for tuning of the topological properties and may yield similar results for other topological materials.

Análisis experimental de un motor ultrasónico de elevado par

Directory of Open Access Journals (Sweden)

Mateo Prous, C.

1999-12-01

Full Text Available Ultrasonic engines are useful in several applications due to low weight, small size, good position and speed regulation, and high torque. Nowadays there are only low and medium torque engines. We are working on high torque ultrasonic engines, which can be used as power actuators. Among all possible configurations, we are dealing with a standard piezoelectric ceramic excited one, which works in the no linear zone and resonant mode. A static, modal, harmonic and transitory finite elements analysis is being carrying on. The final goal is to obtain all components design criteria in order to optimise the obtained result. The finite element analysis and motor functioning are explained, showing two prototype results, and describing the improvements of the second one and his reason.

Los motores ultrasónicos son útiles en diversas aplicaciones debido a su poco peso, pequeñas dimensiones, buena regulación de la posición y velocidad, y elevado par. Hoy en día tan sólo existen motores que desarrollan un par bajo o medio. En esta línea, estamos trabajando en motores ultrasónicos de par elevado, que pueden ser utilizados como actuadores de potencia. Entre todas las configuraciones inicialmente propuestas, se está analizando en detalle una que es excitada por cerámica piezoeléctrica estándar, que trabaja en la zona no lineal y en modo resonante. El análisis, realizado por elementos finitos, abarca el estático y el modal, el armónico y el transitorio. En este artículo se describen el funcionamiento del motor y su análisis por elementos finitos, mostrando los resultados experimentales de dos prototipos, y describiendo las mejoras que aporta el segundo debidamente justificadas.

Center for Fundamental and Applied Research in Nanostructured and Lightweight Materials. Final Technical Summary

Energy Technology Data Exchange (ETDEWEB)

Mullins, Michael; Rogers, Tony; King, Julia; Keith, Jason; Cornilsen, Bahne; Allen, Jeffrey; Gilbert, Ryan; Holles, Joseph

2010-09-28

The core projects for this DOE-sponsored Center at Michigan Tech have focused on several of the materials problems identified by the NAS. These include: new electrode materials, enhanced PEM materials, lighter and more effective bipolar plates, and improvement of the carbon used as a current carrier. This project involved fundamental and applied research in the development and testing of lightweight and nanostructured materials to be used in fuel cell applications and for chemical synthesis. The advent of new classes of materials engineered at the nanometer level can produce materials that are lightweight and have unique physical and chemical properties. The grant was used to obtain and improve the equipment infrastructure to support this research and also served to fund seven research projects. These included: 1. Development of lightweight, thermally conductive bipolar plates for improved thermal management in fuel cells; 2. Exploration of pseudomorphic nanoscale overlayer bimetallic catalysts for fuel cells; 3. Development of hybrid inorganic/organic polymer nanocomposites with improved ionic and electronic properties; 4. Development of oriented polymeric materials for membrane applications; 5. Preparation of a graphitic carbon foam current collectors; 6. The development of lightweight carbon electrodes using graphitic carbon foams for battery and fuel cell applications; and 7. Movement of water in fuel cell electrodes.

3D-printing of lightweight cellular composites.

Science.gov (United States)

Compton, Brett G; Lewis, Jennifer A

2014-09-10

A new epoxy-based ink is reported, which enables 3D printing of lightweight cellular composites with controlled alignment of multiscale, high-aspectratio fiber reinforcement to create hierarchical structures inspired by balsa wood. Young's modulus values up to 10 times higher than existing commercially available 3D-printed polymers are attainable, while comparable strength values are maintained. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance of Lightweight Natural-Fiber Reinforced Concrete

OpenAIRE

Hardjasaputra Harianto; Ng Gino; Urgessa Girum; Lesmana Gabriella; Sidharta Steven

2017-01-01

Concrete, the most common construction material, has negligible tension capacity. However, a reinforcement material such as natural fibers, can be used to improve the tensile properties of concrete. This paper presents experiments conducted on Super Lightweight Concrete mixed with coconut fibers (SLNFRC). Coconut fibers are regarded as one of the toughest natural fibers to strengthen concrete. Coconut fiber reinforced composites have been considered as a sustainable construction material beca...

Phase relations and crystal structures in the systems (Bi,Ln)2WO6 and (Bi,Ln)2MoO6 (Ln=lanthanide)

International Nuclear Information System (INIS)

Berdonosov, Peter S.; Charkin, Dmitri O.; Knight, Kevin S.; Johnston, Karen E.; Goff, Richard J.; Dolgikh, Valeriy A.; Lightfoot, Philip

2006-01-01

Several outstanding aspects of phase behaviour in the systems (Bi,Ln) 2 WO 6 and (Bi,Ln) 2 MoO 6 (Ln=lanthanide) have been clarified. Detailed crystal structures, from Rietveld refinement of powder neutron diffraction data, are provided for Bi 1.8 La 0.2 WO 6 (L-Bi 2 WO 6 type) and BiLaWO 6 , BiNdWO 6 , Bi 0.7 Yb 1.3 WO 6 and Bi 0.7 Yb 1.3 WO 6 (all H-Bi 2 WO 6 type). Phase evolution within the solid solution Bi 2- x La x MoO 6 has been re-examined, and a crossover from γ(H)-Bi 2 MoO 6 type to γ-R 2 MoO 6 type is observed at x∼1.2. A preliminary X-ray Rietveld refinement of the line phase BiNdMoO 6 has confirmed the α-R 2 MoO 6 type structure, with a possible partial ordering of Bi/Nd over the three crystallographically distinct R sites. - Graphical abstract: A summary of phase relations in the lanthanide-doped bismuth tungstate and bismuth molybdate systems is presented, together with some additional structural data on several of these phases

Fuzzy Bi-level Decision-Making Techniques: A Survey

Directory of Open Access Journals (Sweden)

Guangquan Zhang

2016-04-01

Full Text Available Bi-level decision-making techniques aim to deal with decentralized management problems that feature interactive decision entities distributed throughout a bi-level hierarchy. A challenge in handling bi-level decision problems is that various uncertainties naturally appear in decision-making process. Significant efforts have been devoted that fuzzy set techniques can be used to effectively deal with uncertain issues in bi-level decision-making, known as fuzzy bi-level decision-making techniques, and researchers have successfully gained experience in this area. It is thus vital that an instructive review of current trends in this area should be conducted, not only of the theoretical research but also the practical developments. This paper systematically reviews up-to-date fuzzy bi-level decisionmaking techniques, including models, approaches, algorithms and systems. It also clusters related technique developments into four main categories: basic fuzzy bi-level decision-making, fuzzy bi-level decision-making with multiple optima, fuzzy random bi-level decision-making, and the applications of bi-level decision-making techniques in different domains. By providing state-of-the-art knowledge, this survey paper will directly support researchers and practitioners in their understanding of developments in theoretical research results and applications in relation to fuzzy bi-level decision-making techniques.

A flexible 3D nitrogen-doped carbon foam@CNTs hybrid hosting TiO2 nanoparticles as free-standing electrode for ultra-long cycling lithium-ion batteries

Science.gov (United States)

Yuan, Wei; Wang, Boya; Wu, Hao; Xiang, Mingwu; Wang, Qiong; Liu, Heng; Zhang, Yun; Liu, Huakun; Dou, Shixue

2018-03-01

Free-standing electrodes have stood out from the electrode pack, owing to their advantage of abandoning the conventional polymeric binder and conductive agent, thus increasing the specific capacity of lithium-ion batteries. Nevertheless, their practical application is hampered by inferior electrical conductivity and complex manufacturing process. To this end, we report here a facile approach to fabricate a flexible 3D N-doped carbon foam/carbon nanotubes (NCF@CNTs) hybrid to act as the current collector and host scaffold for TiO2 particles, which are integrated into a lightweight free-standing electrode (NCF@CNTs-TiO2). In the resulting architecture, ultra-fine TiO2 nanoparticles are homogeneously anchored in situ into the N-doped NCF@CNTs framework with macro- and meso-porous structure, wrapped by a dense CNT layer, cooperatively enhances the electrode flexibility and forms an interconnected conductive network for electron/ion transport. As a result, the as-prepared NCF@CNTs-TiO2 electrode exhibits excellent lithium storage performance with high specific capacity of 241 mAh g-1 at 1 C, superb rate capability of 145 mAh g-1 at 20 C, ultra-long cycling stability with an ultra-low capacity decay of 0.0037% per cycle over 2500 cycles, and excellent thermal stability with ∼94% capacity retention over 100 cycles at 55 °C.

A plate-on-plate sandwiched Z-scheme heterojunction photocatalyst: BiOBr-Bi{sub 2}MoO{sub 6} with enhanced photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Wang, Shengyao [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China); Yang, Xianglong; Zhang, Xuehao; Ding, Xing; Yang, Zixin [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Dai, Ke [College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen, Hao, E-mail: hchenhao@mail.hzau.edu.cn [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China)

2017-01-01

Highlights: • A visible light heterojunction photocatalyst of BiOBr-Bi{sub 2}MoO{sub 6} was simply synthesized. • Carriers transferred efficiently in sandwiched layers causing an enhance activity. • A possible direct Z-scheme charge transfer mechanism of BiOBr-Bi2MoO6 is proposed. - Abstract: In this study, a direct Z-scheme heterojunction BiOBr-Bi{sub 2}MoO{sub 6} with greatly enhanced visible light photocatalytic performance was fabricated via a two-step coprecipitation method. It was indicated that a plate-on-plate heterojunctions be present between BiOBr and Bi{sub 2}MoO{sub 6} through different characterization techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoelectrochemical measurements. The crystal structure and morphology analysis revealed that the heterointerface in BiOBr-Bi{sub 2}MoO{sub 6} occurred mainly on the (001) facets of BiOBr and (001) facets of Bi{sub 2}MoO{sub 6}. The photocatalytic activity of the BiOBr-Bi{sub 2}MoO{sub 6} was investigated by degradation of RhB and about 66.7% total organic carbon (TOC) could be removed. Ciprofloxacin (CIP) was employed to rule out the photosensitization. It was implied that the higher activity of BiOBr-Bi{sub 2}MoO{sub 6} could be attribute to the strong redox ability in the Z-scheme system, which was subsequently confirmed by photoluminescence spectroscopy (PL) and active spices trapping experiments. This study provides a promising platform for Z-scheme heterojunction constructing and also sheds light on highly efficient visible-light-driven photocatalysts designing.

DIALIGN: multiple DNA and protein sequence alignment at BiBiServ.

OpenAIRE

Morgenstern, Burkhard

2004-01-01

DIALIGN is a widely used software tool for multiple DNA and protein sequence alignment. The program combines local and global alignment features and can therefore be applied to sequence data that cannot be correctly aligned by more traditional approaches. DIALIGN is available online through Bielefeld Bioinformatics Server (BiBiServ). The downloadable version of the program offers several new program features. To compare the output of different alignment programs, we developed the program AltA...

[sup 205]Bi/[sup 206]Bi cyclotron production from Pb-isotopes for absorption studies in humans

Energy Technology Data Exchange (ETDEWEB)

Fischer, R.; Dresow, B.; Heinrich, H.C. (Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. Medizinische Biochemie); Wendel, J.; Bechtold, V. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Kernphysik)

1993-12-01

Pb(p,xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from [sup nat]Pb, [sup 206]Pb, and [sup 207]Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth ([sup 209]Bi) was exploited for radiobismuth production. [sup 205]Bi was produced from [sup 206]Pb at 20 MeV with only 2% of [sup 206]Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with [sup 205]Bi for absorption studies in animals and subjects. (Author).

A Lightweight Protocol for Secure Video Streaming.

Science.gov (United States)

Venčkauskas, Algimantas; Morkevicius, Nerijus; Bagdonas, Kazimieras; Damaševičius, Robertas; Maskeliūnas, Rytis

2018-05-14

The Internet of Things (IoT) introduces many new challenges which cannot be solved using traditional cloud and host computing models. A new architecture known as fog computing is emerging to address these technological and security gaps. Traditional security paradigms focused on providing perimeter-based protections and client/server point to point protocols (e.g., Transport Layer Security (TLS)) are no longer the best choices for addressing new security challenges in fog computing end devices, where energy and computational resources are limited. In this paper, we present a lightweight secure streaming protocol for the fog computing "Fog Node-End Device" layer. This protocol is lightweight, connectionless, supports broadcast and multicast operations, and is able to provide data source authentication, data integrity, and confidentiality. The protocol is based on simple and energy efficient cryptographic methods, such as Hash Message Authentication Codes (HMAC) and symmetrical ciphers, and uses modified User Datagram Protocol (UDP) packets to embed authentication data into streaming data. Data redundancy could be added to improve reliability in lossy networks. The experimental results summarized in this paper confirm that the proposed method efficiently uses energy and computational resources and at the same time provides security properties on par with the Datagram TLS (DTLS) standard.

Lightweight Provenance Service for High-Performance Computing

Energy Technology Data Exchange (ETDEWEB)

Dai, Dong; Chen, Yong; Carns, Philip; Jenkins, John; Ross, Robert

2017-09-09

Provenance describes detailed information about the history of a piece of data, containing the relationships among elements such as users, processes, jobs, and workflows that contribute to the existence of data. Provenance is key to supporting many data management functionalities that are increasingly important in operations such as identifying data sources, parameters, or assumptions behind a given result; auditing data usage; or understanding details about how inputs are transformed into outputs. Despite its importance, however, provenance support is largely underdeveloped in highly parallel architectures and systems. One major challenge is the demanding requirements of providing provenance service in situ. The need to remain lightweight and to be always on often conflicts with the need to be transparent and offer an accurate catalog of details regarding the applications and systems. To tackle this challenge, we introduce a lightweight provenance service, called LPS, for high-performance computing (HPC) systems. LPS leverages a kernel instrument mechanism to achieve transparency and introduces representative execution and flexible granularity to capture comprehensive provenance with controllable overhead. Extensive evaluations and use cases have confirmed its efficiency and usability. We believe that LPS can be integrated into current and future HPC systems to support a variety of data management needs.

Calorimetric investigation of Pb-Bi system

International Nuclear Information System (INIS)

Agarwal, Renu; Jat, Ram Avtar; Sen, B.K.

2008-01-01

Enthalpy increment of Pb 0.71 Bi 0.29 compound was determined using high temperature Calvet calorimeter. The data was fit into the following polynomial equation. ΔH(T-298.15 K) J/mol = -10384.96 + 39.23 T - 0.014T 2 - 18970/T. By precipitation method, the enthalpy of formation of the compound of composition Pb 0.68 Bi 0.32 at 448 K, from Pb(l) and Bi(l) was determined to be -2450± 50 J/mol and from Pb(s) and Bi(s) at 298.15 K was calculated to be 4047 J/mol. (author)

X-ray standing wave study of the Bi/GaAs and Bi/GaP interfaces

International Nuclear Information System (INIS)

Herrera-Gomez, A.

1994-04-01

Interfaces are one of the most important elements determining the characteristics of electronic devices. Composite semiconductors, specifically the III-V family, are technologically attractive because of their mobility and optical properties, and also because they offer the possibility of engineering such properties as the size of the band gap. Nevertheless, Si has remained the most utilized semiconductor material, primarily because the fabrication of practical MOSFETs with III-V semiconductors remains elusive. Examples of such complex interfaces are the structures formed by one monolayer of Bi on the (110) surface of GaAs and GaP. While better matched Column V elements form epitaxial continuous monolayers on III-V semiconductor (110) surfaces, Bi is too large to accommodate on GaAs and GaP surfaces with long range order, and vacancies appear to allow relaxation. For the ideal systems, symmetry imposes the presence of only two nonequivalent adatom sites. However, for Bi/GaAs and Bi/GaP, more than two different sites are present because the position of Bi atoms next to a vacancy is not necessarily equivalent to that between other Bi atoms. The geometry of the Bi/GaAs and Bi/GaP systems was determined here by triangulating XSW results from three Bragg planes. A methodology was developed that provides an intrinsic check of the validity of assuming two sites for the overlayer structures. An experimental method was developed that allows the three reflections to be measured on the same sample, thus reducing the number of experimental variables, such as the degree of disorder. The traditional method of analysis was not accurate enough for this data, so a more reliable and faster method of data fitting was developed. A configuration used in the present work, which previously has been widely used, presents an intrinsic multireflection problem. This issue is discussed in depth, and the appropriate method is determined for analyzing the data obtained with this configuration

Correlação entre a graduação histológica de biópsias e do espécimen cirúrgico em câncer da prostata

Directory of Open Access Journals (Sweden)

José Cury

Full Text Available Foram estudados, retrospectivamente, os prontuários de 120 pacientes com câncer localizado da próstata nos estádios clínicos T1, T2 e T3a e que foram submetidos a 1infadenectomia ilíaca e a cirurgia radical da próstata. Todos haviam sido graduados pela escala de Gleason através de biópsias da próstata guiadas pela ultra-sonografia transretal. Correlacionamos a graduação histo1ógica destas biópsias da próstata com a graduação final obtida no exame da peça cirúrgica correspondente e obtivemos exata concordância em 39 pacientes (32,50%. Ao considerarmos a concordância de ± 1unidade, observamos concordância de resultado em 81 pacientes (67,50%. A subgraduação histológica das biópsias prostáticas foi encontrada em 75 pacientes (62,50% dos casos.

Modality independence of order coding in working memory: Evidence from cross-modal order interference at recall.

Science.gov (United States)

Vandierendonck, André

2016-01-01

Working memory researchers do not agree on whether order in serial recall is encoded by dedicated modality-specific systems or by a more general modality-independent system. Although previous research supports the existence of autonomous modality-specific systems, it has been shown that serial recognition memory is prone to cross-modal order interference by concurrent tasks. The present study used a serial recall task, which was performed in a single-task condition and in a dual-task condition with an embedded memory task in the retention interval. The modality of the serial task was either verbal or visuospatial, and the embedded tasks were in the other modality and required either serial or item recall. Care was taken to avoid modality overlaps during presentation and recall. In Experiment 1, visuospatial but not verbal serial recall was more impaired when the embedded task was an order than when it was an item task. Using a more difficult verbal serial recall task, verbal serial recall was also more impaired by another order recall task in Experiment 2. These findings are consistent with the hypothesis of modality-independent order coding. The implications for views on short-term recall and the multicomponent view of working memory are discussed.

Study of the strength characteristics of protein-based lightweight ...

African Journals Online (AJOL)

Compressive strength test was carried out on the protein-based lightweight foamed concrete produced with cement partially replaced by rice husk ash to ascertain its strength characteristics. Standard concrete cubes of 150 x 150 x 150 mm were produced using ordinary Portland cement (OPC), fine aggregate, aqueous ...

Crushing and Fracture of Lightweight Structures

DEFF Research Database (Denmark)

Urban, Jesper

2003-01-01

and Latham (1968). Good agreement between the analytical models and the experiments is found. The crushing behaviour of two high speed ferries has been analysed with the numerical and analytical methods and the results are compared with the existing regulations for high speed craft (HSC). Several failure......The overall objective of the present study has been to develop rational analytical and numerical calculation models to quantify the consequences of collision accidents. The work has primarily been focused on high speed craft (HSC) built in lightweight materials such as aluminium and sandwich...

Quantum interference effects in [Co/Bi]n thin films

Directory of Open Access Journals (Sweden)

Athanasopoulos P.

2014-07-01

Full Text Available Magnetoconductivity (MC, Δσ(Β, and Hall coefficient, RH(B, measurements have been performed in polycrystalline thin films of Bi(15nm, Bi(10nm/Co(1nm/Bi(10nm trilayer and [Co(0.7nm/Bi(2nm]10 multilayer, grown by magnetron scattering. The temperature dependence of RH(B curves reveal the existence of a second conduction channel below 250K, that can be assigned to surface states. MC measurements between ±0.4T show at 5K an interplay between weak-antilocalization (WAL in Bi and Bi/Co/Bi films and weal-localization (WL in [Co/Bi]10 multilayer.

Effect of presaturation and seawater on strength and durability of lightweight concrete

International Nuclear Information System (INIS)

Haque, M.N.

2009-01-01

The internal curing is provided, usually, by the use of some proprietary fine aggregates which provide sufficient water from within to promote the ongoing hydration of cement and hence result in a relatively high performance concrete. Two concretes, one total lightweight concrete (TLWC) and the second sand lightweight concrete (SLWC) of 28 day cube strength of approximately 40 MPa (5800 psi) were designed. A total of six mixes were cast out of these two concretes, 4-TLWC's and 2-SLWC's. The variation in the mixes was due to moisture condition of the aggregates and the use of seawater in mixing and curing of the concretes. The effect of these variations on the cube compressive strength, water permeability, sulphate and chloride content, depth of carbonation and shrinkage of these six concretes was studied. The presaturation of the lightweight aggregates (LWA's used do not seem to have improved the compressive strength, and water permeability of these concretes. The drying shrinkage strains of the concrete using pre saturated aggregates decreased considerably. The application of seawater in making and curing these LWC's increased the compressive strength by about 15%. (author)

Physiology and Pathophysiology in Ultra-Marathon Running

Directory of Open Access Journals (Sweden)

Beat Knechtle

2018-06-01

Full Text Available In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat and training (e.g., high volume and running speed during training characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In

Attempting to realize n-type BiCuSeO

Science.gov (United States)

Zhang, Xiaoxuan; Feng, Dan; He, Jiaqing; Zhao, Li-Dong

2018-02-01

As an intrinsic p-type semiconductor, BiCuSeO has been widely researched in the thermoelectric community, however, n-type BiCuSeO has not been reported so far. In this work, we successfully realized n-type BiCuSeO through carrying out several successive efforts. Seebeck coefficient of BiCuSeO was increased through introducing extra Bi/Cu to fill the Bi/Cu vacancies that may produce holes, and the maximum Seebeck coefficient was increase from +447 μVK-1 for undoped BiCuSeO to +638 μVK-1 for Bi1.04Cu1.05SeO. The Seebeck coefficient of Bi1.04Cu1.05SeO was changed from p-type to n-type through electron doping through introducing Br/I in Se sites, the maximum negative Seebeck coefficient can reach ∼ -465 μVK-1 and -543 μVK-1 for Bi1.04Cu1.05Se1-xIxO and Bi1.04Cu1.05Se1-xBrxO, respectively. Then, after compositing Bi1.04Cu1.05Se0.99Br0.01O with Ag, n-type BiCuSeO can be absolutely obtained in the whole temperature range of 300-873 K, the maximum ZT 0.05 was achieved at 475 K in the Bi1.04Cu1.05Se0.99Br0.01O+15% Ag. Our report indicates that it is possible to realize n-type conducting behaviors in BiCuSeO system.

Mechanical properties of geopolymer lightweight brick with styrofoam pellet

Science.gov (United States)

Abdullah, Mohd Mustafa Al Bakri; Tahir, Muhammad Faheem Mohd; Kadir, Aeslina Abdul; Hussin, Kamarudin; Samson, W. Saiful Iskandar W.

2017-09-01

The utilization of fly ash in brick as partial replacement of cement is gaining immense importance today, mainly on account of the improvement in the long-term durability of brick combined with ecological benefits. In this research, the lightweight brick was produced by using fly ash (class F) as a main material to replace Ordinary Portland Cement (OPC) in the composition of brick. Class F Fly Ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and styrofoam pellet was added to the geopolymer mixture to produce lightweight brick. The brick was prepared in two methods that is wet method and dry method due to different brick composition which is dry method for composition with sand and wet method for composition without sand. The bricks were cured in room temperature at 7 aging days. After 7 days, the compressive strength, water absorption, and density of the brick were investigated, where the optimum ratio for the best bricks has been determined from the lightweight density and has compressive strength more than minimum standard requirement. The best bricks are further produce for curing at 60°C in oven at 28 aging days. Those bricks also were characterized using optical microscope to measure the distribution of styrofoam in brick structure. From the result obtained, the brick that cured at 60°C in oven at 28 aging days has high strength compare to brick that cured in room temperature and at 7 day cured. The water absorption is decreasing as the curing temperature and aging days increased whereas density is increasing.

Upgrading the Center for Lightweighting Automotive Materials and Processing - a GATE Center of Excellence at the University of Michigan-Dearborn

Energy Technology Data Exchange (ETDEWEB)

Mallick, P. K.

2012-08-30

The Center for Lightweighting Materials and Processing (CLAMP) was established in September 1998 with a grant from the Department of Energy’s Graduate Automotive Technology Education (GATE) program. The center received the second round of GATE grant in 2005 under the title “Upgrading the Center for Lightweighting Automotive Materials and Processing”. Using the two grants, the Center has successfully created 10 graduate level courses on lightweight automotive materials, integrated them into master’s and PhD programs in Automotive Systems Engineering, and offered them regularly to the graduate students in the program. In addition, the Center has created a web-based lightweight automotive materials database, conducted research on lightweight automotive materials and organized seminars/symposia on lightweight automotive materials for both academia and industry. The faculty involved with the Center has conducted research on a variety of topics related to design, testing, characterization and processing of lightweight materials for automotive applications and have received numerous research grants from automotive companies and government agencies to support their research. The materials considered included advanced steels, light alloys (aluminum, magnesium and titanium) and fiber reinforced polymer composites. In some of these research projects, CLAMP faculty have collaborated with industry partners and students have used the research facilities at industry locations. The specific objectives of the project during the current funding period (2005 – 2012) were as follows: (1) develop new graduate courses and incorporate them in the automotive systems engineering curriculum (2) improve and update two existing courses on automotive materials and processing (3) upgrade the laboratory facilities used by graduate students to conduct research (4) expand the Lightweight Automotive Materials Database to include additional materials, design case studies and make it more

Lightweight, high-opacity Bible paper by fiber loading

Science.gov (United States)

Klaus Doelle; Oliver Heise; John H. Klungness; Said M. AbuBakr

2000-01-01

This paper has been prepared in order to discuss Fiber Loading™ for lightweight, high-opacity bible paper. Incorporating fillers within pulp fibers has been subject to research since 1960 (Green et al. 1962, Scallan et al. 1985, Allen et al. 1992). Fiber Loading™ is a method for manufacturing precipitated calcium carbonate (PCC) directly within the pulp processing...

Efficient Lightweight AC-AC Power Control for Solar UAV, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A highly efficient and lightweight dual bridge matrix power controller development is proposed that will provide high performance to a solar powered high altitude...

Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2): New one-dimensional Bi-coordination materials—Reversible hydration and topotactic decomposition to α-Bi2O3

International Nuclear Information System (INIS)

Jeon, Hye Rim; Lee, Dong Woo; Ok, Kang Min

2012-01-01

Two one-dimensional bismuth-coordination materials, Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 ) x F (x=1 and 2), have been synthesized by hydrothermal reactions using Bi 2 O 3 , 2,6-NC 5 H 3 (CO 2 H) 2 , HF, and water at 180 °C. Structures of the two materials were determined by single-crystal X-ray diffraction. Although they have different crystal structures, both Bi-organic materials shared a common structural motif, a one-dimensional chain structure consisting of Bi 3+ cations and pyridine dicarboxylate linkers. Detailed structural analyses include infrared spectroscopy, thermogravimetric analysis, and reversible hydration reactions for the coordinated water molecules were reported. Also, thermal decomposition of the rod-shaped Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C led to α-Bi 2 O 3 that maintained the same morphology of the original crystals. - Graphical abstract: Calcination of the Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C results in the α-Bi 2 O 3 rods that maintain the original morphology of the crystals. Highlights: ► Synthesis of one-dimensional chain Bi-organic frameworks. ► Reversible hydration reactions of Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F. ► Topotactic decomposition maintaining the same morphology of the original crystals.

Screen-detected versus interval cancers: Effect of imaging modality and breast density in the Flemish Breast Cancer Screening Programme.

Science.gov (United States)

Timmermans, Lore; Bleyen, Luc; Bacher, Klaus; Van Herck, Koen; Lemmens, Kim; Van Ongeval, Chantal; Van Steen, Andre; Martens, Patrick; De Brabander, Isabel; Goossens, Mathieu; Thierens, Hubert

2017-09-01

To investigate if direct radiography (DR) performs better than screen-film mammography (SF) and computed radiography (CR) in dense breasts in a decentralized organised Breast Cancer Screening Programme. To this end, screen-detected versus interval cancers were studied in different BI-RADS density classes for these imaging modalities. The study cohort consisted of 351,532 women who participated in the Flemish Breast Cancer Screening Programme in 2009 and 2010. Information on screen-detected and interval cancers, breast density scores of radiologist second readers, and imaging modality was obtained by linkage of the databases of the Centre of Cancer Detection and the Belgian Cancer Registry. Overall, 67% of occurring breast cancers are screen detected and 33% are interval cancers, with DR performing better than SF and CR. The interval cancer rate increases gradually with breast density, regardless of modality. In the high-density class, the interval cancer rate exceeds the cancer detection rate for SF and CR, but not for DR. DR is superior to SF and CR with respect to cancer detection rates for high-density breasts. To reduce the high interval cancer rate in dense breasts, use of an additional imaging technique in screening can be taken into consideration. • Interval cancer rate increases gradually with breast density, regardless of modality. • Cancer detection rate in high-density breasts is superior in DR. • IC rate exceeds CDR for SF and CR in high-density breasts. • DR performs better in high-density breasts for third readings and false-positives.

Controlled hydrothermal synthesis of BiOxCly/BiOmIn composites exhibiting visible-light photocatalytic degradation of crystal violet

International Nuclear Information System (INIS)

Jiang, Yu-Rou; Lin, Ho-Pan; Chung, Wen-Hsin; Dai, Yong-Ming; Lin, Wan-Yu; Chen, Chiing-Chang

2015-01-01

Highlights: • This is the first report on a series of BiO x Cl y /BiO m I n heterojunctions. • The BiO x Cl y /BiO m I n composition was controlled by adjusting the growth parameters. • The BiO x Cl y /BiO m I n were indirect semiconductors with a 1.78–2.95-eV bandgap. • The new photocatalysts removed CV at a much faster rate than TiO 2 . • Mechanisms were determined by separating the intermediates using HPLC-MS. - Abstract: A series of BiO x Cl y /BiO m I n composites were prepared using autoclave hydrothermal methods. The composition and morphologies of the BiO x Cl y /BiO m I n composites were controlled by adjusting the experimental conditions: the reaction pH value, temperature, and KCl/KI molar ratio. The products were characterized using X-ray diffraction, scanning electron microscopy-electron dispersive X-ray spectroscopy, UV–vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller specific surface areas, cathodoluminescence, high-resolution transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. The photocatalytic efficiencies of composite powder suspensions were evaluated by monitoring the crystal violet (CV) concentrations. In addition, the quenching effects of various scavengers indicated that the reactive O 2 · − played a major role, and OH· or h + played a minor role in CV degradation. The intermediates formed during the decomposition process were isolated, identified, and characterized using high performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry to elucidate the CV decomposition mechanism

Opto-mechanical Analyses for Performance Optimization of Lightweight Grazing-incidence Mirrors

Science.gov (United States)

Roche, Jacqueline M.; Kolodziejczak, Jeffery J.; Odell, Stephen L.; Elsner, Ronald F.; Weisskopf, Martin C.; Ramsey, Brian; Gubarev, Mikhail V.

2013-01-01

New technology in grazing-incidence mirror fabrication and assembly is necessary to achieve subarcsecond optics for large-area x-ray telescopes. In order to define specifications, an understanding of performance sensitivity to design parameters is crucial. MSFC is undertaking a systematic study to specify a mounting approach, mirror substrate, and testing method. Lightweight mirrors are typically flimsy and are, therefore, susceptible to significant distortion due to mounting and gravitational forces. Material properties of the mirror substrate along with its dimensions significantly affect the distortions caused by mounting and gravity. A parametric study of these properties and their relationship to mounting and testing schemes will indicate specifications for the design of the next generation of lightweight grazing-incidence mirrors. Here we report initial results of this study.

Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

Science.gov (United States)

Zhang, Min; Wei, Zhan-Tao

2018-03-01

Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

Science.gov (United States)

Zhang, Min; Wei, Zhan-Tao

2018-05-01

Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

Reduction in thermal conductivity of BiSbTe lump

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Kaleem [King Saud University, Sustainable Energy Technologies Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia); Wan, C. [Tsinghua University, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Beijing (China); Al-Eshaikh, M.A.; Kadachi, A.N. [King Saud University, Research Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia)

2017-03-15

In this work, systematic investigations on the thermal conductivities of BiSbTe lump, microstructured pristine BiSbTe bulk and single wall carbon nanotubes (SWCNTs)/BiSbTe bulk nanocomposites were performed. BiSbTe lumps were crushed to form a coarse powder (200 μm) and effect of particle size reduction on the effective thermal conductivity of BiSbTe (200 μm) bulk were analyzed. For further reduction in the conductivity, a two pronged strategy has been employed. First, additional refinement of BiSbTe (200 μm) were performed through ball milling in an inert environment. Second, SWCNTs in 0.75, and 1.0 vol% were distributed uniformly in the fine BiSbTe ball milled powder. The results showed that the effective thermal conductivities decrease with the reduction in the particle size from lump to BiSbTe (200 μm) bulk as well as with the addition of SWCNTs accompanied by further refinement of BiSbTe particles. The significant reduction in thermal conductivities of the lump was achieved for pure BiSbTe (200 μm) bulk and 0.75 vol% of SWCNTs/BiSbTe composite. This can be ascribed to the enhanced phonon scattering by the grain boundaries between the nanostructured BiSbTe particles as well as the interfaces between BiSbTe and the low dimensional carbon nanotubes. (orig.)

Bi-stable vocal fold adduction: a mechanism of modal-falsetto register shifts and mixed registration.

Science.gov (United States)

Titze, Ingo R

2014-04-01

The origin of vocal registers has generally been attributed to differential activation of cricothyroid and thyroarytenoid muscles in the larynx. Register shifts, however, have also been shown to be affected by glottal pressures exerted on vocal fold surfaces, which can change with loudness, pitch, and vowel. Here it is shown computationally and with empirical data that intraglottal pressures can change abruptly when glottal adductory geometry is changed relatively smoothly from convergent to divergent. An intermediate shape between large convergence and large divergence, namely, a nearly rectangular glottal shape with almost parallel vocal fold surfaces, is associated with mixed registration. It can be less stable than either of the highly angular shapes unless transglottal pressure is reduced and upper stiffness of vocal fold tissues is balanced with lower stiffness. This intermediate state of adduction is desirable because it leads to a low phonation threshold pressure with moderate vocal fold collision. Achieving mixed registration consistently across wide ranges of F0, lung pressure, and vocal tract shapes appears to be a balancing act of coordinating laryngeal muscle activation with vocal tract pressures. Surprisingly, a large transglottal pressure is not facilitative in this process, exacerbating the bi-stable condition and the associated register contrast.

The effect of oxidant on resputtering of Bi from Bi-Sr-Ca-Cu-O films

Science.gov (United States)

Grace, J. M.; McDonald, D. B.; Reiten, M. T.; Olson, J.; Kampwirth, R. T.; Gray, K. E.

1991-09-01

The type and partial pressure of oxidant mixed with argon can affect the selective resputtering of Bi in composite-target, magnetron-sputtered Bi-Sr-Ca-Cu-O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers, than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O2(+)p , which interacts with the target to produce energetic O(-). In contrast, ozone may form lower-energy O(-) by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y-Ba-Cu-O by others are comparable. Bi in Bi-Sr-Ca-Cu-O behaves as Ba in Y-Ba-Cu-O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi-Sr-Ca-Cu-O is similar to what is observed for Cu in Y-Ba-Cu-O.

Closing the innovation cycle in lightweighting compressor pistons technology

NARCIS (Netherlands)

Wentzel, C.M.; Eijk, A.; Groenewegen, G.; Bergsma, O.K.

2016-01-01

What started out as an exercise in exploring the weight reduction potential of those allegedly “heavy recip crossheads”, turned out to be a fast leap towards implementation of a new hybrid material concept for very lightweight pistons. This was enabled by a next phase in the EFRC R&D group

Lightweight Inexpensive Ozone Lidar Telescope Using a Plastic Fresnel Lens

Science.gov (United States)

DeYoung, Russell J.; Notari, Anthony; Carrion, William; Pliutau, Denis

2014-01-01

An inexpensive lightweight ozone lidar telescope was designed, constructed and operated during an ozone lidar field campaign. This report summarizes the design parameters and performance of the plastic Fresnel lens telescope and shows the ozone lidar performance compared to Zemax calculations.

Predictive values of Bi-Rads categories 3, 4 and 5 in non-palpable breast masses evaluated by mammography, ultrasound and magnetic resonance imaging

International Nuclear Information System (INIS)

Roveda Junior, Decio; Fleury, Eduardo de Castro Faria; Piato, Sebastiao; Oliveira, Vilmar Marques de; Rinaldi, Jose Francisco; Ferreira, Carlos Alberto Pecci

2007-01-01

Objective: To evaluate the predictive value of BI-RADS TM categories 3, 4 and 5 in non-palpable breast masses assessed by mammography, ultrasound and magnetic resonance imaging. Materials And Methods: Twenty-nine patients with BI-RADS categories 3, 4 and 5 non-palpable breast masses identified by mammograms were submitted to complementary ultrasound and magnetic resonance imaging studies, besides excisional biopsy. In total, 30 biopsies were performed. The lesions as well as their respective BI-RADS classification into 3, 4 and 5 were correlated with the histopathological results. The predictive values calculation was made by means of specific mathematical equations. Results: Negative predictive values for category 3 were: mammography, 69.23%; ultrasound, 70.58%; and magnetic resonance imaging, 100%. Positive predictive values for category 4 were: mammography, 63.63%; ultrasound, 50%; and magnetic resonance imaging, 30.76%. For category 5, positive predictive values were: mammography and ultrasound, 100%; and magnetic resonance imaging, 92.85%. Conclusion: For category 3, the negative predictive value of magnetic resonance imaging was high, and for categories 4 and 5, the positive predictive values of the three modalities were moderate. (author)

Preparation and Faraday rotation of Bi-YIG/PMMA nanocomposite

Science.gov (United States)

Fu, H. P.; Hong, R. Y.; Wu, Y. J.; Di, G. Q.; Xu, B.; Zheng, Y.; Wei, D. G.

Bismuth-substituted yttrium iron garnet (Bi-YIG) nanoparticles (NPs) were prepared by coprecipitation and subsequent heating treatment. Thermal gravity-differential thermal analysis was performed to investigate the thermal behavior of the Bi-YIG precursors and to decide the best annealing temperature. Phase formation of garnet NPs was investigated by X-ray powder diffraction. The size of Bi-YIG NPs was investigated by transmission electron microscopy, and the magnetic properties of Bi-YIG NPs were measured using a vibrating sample magnetometer. The results show that the temperature needed for the transformation of Bi-YIG from the amorphous phase to the garnet phase decreases with increasing Bi content, and Bi-YIG NPs with sizes of 28-78 nm are obtained after heating treatment at 650-1000 °C. The saturation magnetization of Bi-YIG NPs increases as the Bi content increases. Moreover, the Faraday rotation of polymethyl methacrylate (PMMA) slices doped with Bi-YIG NPs was investigated. The results indicate that the angle of Faraday rotation increases with increasing Bi content in PMMA composites, and the maximum value of the figure of merit is 1.46°, which is comparable to the value of a sputtered film. The Bi-YIG NPs-doped PMMA slices are new promising materials for magneto-optical devices.

Application of Glass Fiber Waste Polypropylene Aggregate in Lightweight Concrete – thermal properties

Science.gov (United States)

Citek, D.; Rehacek, S.; Pavlik, Z.; Kolisko, J.; Dobias, D.; Pavlikova, M.

2018-03-01

Actual paper focus on thermal properties of a sustainable lightweight concrete incorporating high volume of waste polypropylene aggregate as partial substitution of natural aggregate. In presented experiments a glass fiber reinforced polypropylene (GFPP) which is a by-product of PP tubes production, partially substituted fine natural silica aggregate in 10, 20, 30, 40 and 50 mass %. Results were compared with a reference concrete mix without plastic waste in order to quantify the effect of GFPP use on concrete properties. Main material physical parameters were studied (bulk density, matrix density without air content, and particle size distribution). Especially a thermal transport and storage properties of GFPP were examined in dependence on compaction time. For the developed lightweight concrete, thermal properties were accessed using transient impulse technique, where the measurement was done in dependence on moisture content (from the fully water saturated state to dry state). It was found that the tested lightweight concrete should be prospective construction material possessing improved thermal insulation function and the reuse of waste plastics in concrete composition was beneficial both from the environmental and financial point of view.

Facile synthesis of AgI/BiOI-Bi{sub 2}O{sub 3} multi-heterojunctions with high visible light activity for Cr(VI) reduction

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Shi, Xiaodong; Liu, Enqin [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Crittenden, John C. [The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Ma, Xiangjuan; Zhang, Yi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Cong, Yanqing, E-mail: yqcong@hotmail.com [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China)

2016-11-05

Graphical abstract: Highly visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was developed. - Highlights: • Visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was prepared. • Highly enhanced photocatalytic reduction of Cr(VI) was observed. • k{sub Cr(VI)} on AgI/BiOI-Bi{sub 2}O{sub 3} increased by ca.16 times relative to Bi{sub 2}O{sub 3}. • Decreased E{sub g}, shifted E{sub fb} and reduced charge transfer resistance were observed. • Simultaneous reduction of Cr(VI) and degradation of organics were achieved. - Abstract: AgI sensitized BiOI-Bi{sub 2}O{sub 3} composite (AgI/BiOI-Bi{sub 2}O{sub 3}) with multi-heterojunctions was prepared using simple etching-deposition process. Different characterization techniques were performed to investigate the structural, optical and electrical properties of the as-prepared photocatalysts. It was found that the ternary AgI/BiOI-Bi{sub 2}O{sub 3} composite exhibited: (1) improved photocurrent response, (2) smaller band gap, (3) greatly reduced charge transfer resistance and (4) negative shift of flat band potential, which finally led to easier generation and more efficient separation of photo-generated electron-hole pairs at the hetero-interfaces. Thus, for the reduction of Cr(VI), AgI/BiOI-Bi{sub 2}O{sub 3} exhibited excellent photocatalytic activity under visible light irradiation at near neutral pH. AgI/BiOI-Bi{sub 2}O{sub 3} was optimized when the initial molar ratio of KI to Bi{sub 2}O{sub 3} and AgNO{sub 3} to Bi{sub 2}O{sub 3} was 1:1 and 10%, respectively. The estimated k{sub Cr(VI)} on optimized AgI/BiOI-Bi{sub 2}O{sub 3} was about 16 times that on pure Bi{sub 2}O{sub 3}. Good stability was also observed in cyclic runs, indicating that the current multi-heterostructured photocatalyst is highly desirable for the remediation of Cr(VI)-containing wastewater.

Bimodal extinction without cross-modal extinction.

OpenAIRE

Inhoff, A W; Rafal, R D; Posner, M J

1992-01-01

Three patients with unilateral neurological injury were clinically examined. All showed consistent unilateral extinction in the tactile and visual modalities on simultaneous intramodal stimulation. There was virtually no evidence for cross-modal extinction, however, so that contralateral stimulation of one modality would have extinguished perception of ipsilateral stimuli in the other modality. It is concluded that the attentional system controlling the encoding of tactile and visual stimuli ...

Experimental research on reinforced lightweight plugging composites.

Directory of Open Access Journals (Sweden)

BEKBAEV Arstan Abaevich

2017-08-01

Full Text Available Practical aspects of the well construction show that the use of conventional cementing materials do not always provide the necessary level of quality of well casing when the requirements to resources conservation are enhanced. This is true for such complex geological conditions as the alternation of beds with different formation pressures, low fracturing pressure gradients, drilling with ERD tc. The main problems in well casing under these conditions are the losses of cement slurries, low cement top, low-quality formation isolation, and as the result of this – the emergence of cross-flows. The high quality of well casing will be provided only by means of safe contact between cement stone and limiting surfaces (casing and rock, therefore to use expansion materials for cementing is a well-recognized method. Thus, it is obvious that their application does not give positive results for intervals with a thick filter cake or intervals with cavities, i.e. where space for expansion is greater than the magnitude of the expansion. At the same time it is very challenging to create high-quality cement in formations with abnormally low formation pressure or low fracture gradient. The solution of this problem is the use of lightweight cements, which scarcely expand while hardening. This is due to the fact that lightweight cement slurries are generally obtained by increasing the content of grouting fluid in the solution, resulting in increase of the distance between the crystal hydrates – hardening products, that leads to decrease of crystallization pressure of expansion agents on the space frame of the cement stone]. Moreover, such works as secondary reservoir developing (perforation, well completion and fracturing operations create high dynamic load on the cement stone, which leads to its destruction. The stone can be completely destroyed, that often causes premature flooding of wells and incurring additional costs. In this regard, it is necessary to

In situ grown hierarchical 50%BiOCl/BiOI hollow flowerlike microspheres on reduced graphene oxide nanosheets for enhanced visible-light photocatalytic degradation of rhodamine B

Science.gov (United States)

Su, Xiangde; Yang, Jinjin; Yu, Xiang; Zhu, Yi; Zhang, Yuanming

2018-03-01

50%BiOCl/BiOI/reduced graphene oxide (50%BiOCl/BiOI/rGO) composite photocatalyst was synthesized successfully by a facile one-step solvothermal route in this work. Reduction of graphene oxide (GO) took place in the process of solvothermal reaction and a new Bi-C bond between rGO and 50%BiOCl/BiOI was formed. The introduction of rGO affected the morphology of 50%BiOCl/BiOI, resulting in the transformation of 50%BiOCl/BiOI from solid microspheres to hollow microspheres. Both the introduction of rGO and formation of 50%BiOCl/BiOI hollow microspheres can facilitate the light absorption. The strong interaction between 50%BiOCl/BiOI and rGO and the electrical conductivity of rGO greatly improved the effective separation of photogenerated carriers. Hence, GOB-5 demonstrated the highest photocatalytic activity which was over twice of the pristine 50%BiOCl/BiOI in the presence of visible light. Mechanism study revealed that 50%BiOCl/BiOI generated electrons and holes in the presence of visible light, and holes together with rad O2- generated from reduction of O2 by electrons degraded the pollutant directly. Overall, this work provides an excellent reference to the synthesis of chemically bonded BiOX/BiOY (X, Y = Cl, Br, I)/rGO nanocomposite and helps to promote their applications in environmental protection and photoelectric conversion.

alpha-decay spectroscopy of light odd-odd Bi isotopes - II sup 1 sup 8 sup 6 Bi and the new nuclide sup 1 sup 8 sup 4 Bi

CERN Document Server

Andreyev, A N; Ackermann, D; Münzenberg, G; Hessberger, F P; Hofmann, S; Kojouharov, I; Kindler, B; Lommel, B; Huyse, M; Vel, K V D; Duppen, P V; Heyde, Kris L G

2003-01-01

Alpha-decay of the new nuclide sup 1 sup 8 sup 4 Bi has been studied in the complete-fusion reaction sup 9 sup 3 Nb( sup 9 sup 4 Mo, 3n) sup 1 sup 8 sup 4 Bi at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-alpha, recoil-alpha-gamma analysis and excitation functions measurements. Two alpha-decaying isomeric states in sup 1 sup 8 sup 4 Bi with half-life values of 13(2) ms and 6.6(1.5) ms were identified. The alpha-branching ratio of sup 1 sup 8 sup 0 Tl was deduced for the first time as b subalpha = (2-12)%. Improved data on the fine-structure alpha-decay of sup 1 sup 8 sup 6 Bi were obtained in the sup 9 sup 3 Nb( sup 9 sup 5 Mo, 2n) sup 1 sup 8 sup 6 Bi reaction. A similarity of the decay energies and half-life values of sup 1 sup 8 sup 4 sup , sup 1 sup 8 sup 6 Bi is pointed out and a possible explanation for this effect is suggested.

Lightweight Ultrahigh Temperature CMC-Lined C/C Combustion Chambers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NASA and DoD are seeking high-performance, lightweight liquid rocket combustion chambers with future performance goals that cannot be achieved using state-of-the-art...

Modal logics are coalgebraic

NARCIS (Netherlands)

Cirstea, C.; Kurz, A.; Pattinson, D.; Schröder, L.; Venema, Y.

2011-01-01

Applications of modal logics are abundant in computer science, and a large number of structurally different modal logics have been successfully employed in a diverse spectrum of application contexts. Coalgebraic semantics, on the other hand, provides a uniform and encompassing view on the large

Superstrengthening Bi2Te3 through Nanotwinning

Science.gov (United States)

Li, Guodong; Aydemir, Umut; Morozov, Sergey I.; Wood, Max; An, Qi; Zhai, Pengcheng; Zhang, Qingjie; Goddard, William A.; Snyder, G. Jeffrey

2017-08-01

Bismuth telluride (Bi2Te3 ) based thermoelectric (TE) materials have been commercialized successfully as solid-state power generators, but their low mechanical strength suggests that these materials may not be reliable for long-term use in TE devices. Here we use density functional theory to show that the ideal shear strength of Bi2Te3 can be significantly enhanced up to 215% by imposing nanoscale twins. We reveal that the origin of the low strength in single crystalline Bi2Te3 is the weak van der Waals interaction between the Te1 coupling two Te 1 - Bi - Te 2 - Bi - Te 1 five-layer quint substructures. However, we demonstrate here a surprising result that forming twin boundaries between the Te1 atoms of adjacent quints greatly strengthens the interaction between them, leading to a tripling of the ideal shear strength in nanotwinned Bi2Te3 (0.6 GPa) compared to that in the single crystalline material (0.19 GPa). This grain boundary engineering strategy opens a new pathway for designing robust Bi2Te3 TE semiconductors for high-performance TE devices.

The modal study

International Nuclear Information System (INIS)

Cook, J.R.

1988-01-01

The term ''Modal Study'' refers to a research program conducted for the Nuclear Regulatory Commission (NRC) on the level of protection provided by NRC-certified packages during the shipment of spent nuclear fuel form U.S. power reactors. The objective of the study was to examine the response of the packages to actual highway and railway accident conditions. The Modal Study results show that NRC-certified spent fuel casks would perform their safety functions under severe, actual accident conditions. The study also explains how NRC's cask design conditions, which are expressed in engineering terms, relate to actual accident conditions, with which the public is more familiar. The Modal Study, along with other transportation studies, physical testing of casks, and the spent fuel shipment safety record confirm the view that casks provide a high level of public safety during spent fuel transport

Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

Directory of Open Access Journals (Sweden)

Hansoo Kim, Dong-Woo Suh and Nack J Kim

2013-01-01

Full Text Available Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe–Al–Mn–C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.

Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

Science.gov (United States)

Kim, Hansoo; Suh, Dong-Woo; Kim, Nack J

2013-01-01

Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe–Al–Mn–C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest. PMID:27877553

Fe-Al-Mn-C lightweight structural alloys: a review on the microstructures and mechanical properties.

Science.gov (United States)

Kim, Hansoo; Suh, Dong-Woo; Kim, Nack J

2013-02-01

Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe-Al-Mn-C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.

Comparison of growth texture in round Bi2212 and flat Bi2223 wires and its relation to high critical current density development

OpenAIRE

Kametani, F.; Jiang, J.; Matras, M.; Abraimov, D.; Hellstrom, E. E.; Larbalestier, D. C.

2015-01-01

Why Bi2Sr2CaCu2Ox (Bi2212) allows high critical current density Jc in round wires rather than only in the anisotropic tape form demanded by all other high temperature superconductors is important for future magnet applications. Here we compare the local texture of state-of-the-art Bi2212 and Bi2223 ((Bi,Pb)2Sr2Ca2Cu3O10), finding that round wire Bi2212 generates a dominant a-axis growth texture that also enforces a local biaxial texture (FWHM

Estudio de la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3

Directory of Open Access Journals (Sweden)

Caballero, A. C.

2004-08-01

Full Text Available Ceramic materials based in the ZnO- Bi2O3 system have their principal application as varistors. The binary system ZnO-Bi2O3 is specially relevant to the formation of the microstructure responsable of the varistor behaviour. The study of the different equilibrium phases at high temperatures at the Bi2O3-rich region of the ZnO-Bi2O3 will allow a correct understanding of the microstructural development. Equilibrium phases have been analyzed by XRD, SEM and DTA. Different temperature treatments of samples formulated in the Bi2O3 rich region of the ZnO-Bi2O3 binary system have allowed to determine the phase 19Bi2O3•ZnO as the equilibrium one instead of the 24Bi2O3•ZnO phase.Los materiales cerámicos basados en el sistema binario ZnO-Bi2O3 tienen su principal aplicación en el campo de los varistores. El sistema binario ZnO-Bi2O3 resulta especialmente relevante para la formación de la microestructura funcional de varistores. La determinación de las diferentes fases en equilibrio a alta temperatura en la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3 permitirá interpretar correctamente el desarrollo microestructural. El estudio de las fases en equilibrio se ha llevado a cabo mediante difracción de rayos X, microscopía electrónica de barrido (MEB y análisis térmico diferencial (ATD. Tratamientos a diferentes temperaturas, en la zona rica en Bi2O3 del sistema, han permitido determinar la presencia del compuesto 19Bi2O3•ZnO como fase estable en equilibrio, en lugar del compuesto 24Bi2O3•ZnO.

Perception of Scenes in Different Sensory Modalities: A Result of Modal Completion.

Science.gov (United States)

Gruber, Ronald R; Block, Richard A

2017-01-01

Dynamic perception includes amodal and modal completion, along with apparent movement. It fills temporal gaps for single objects. In 2 experiments, using 6 stimulus presentation conditions involving 3 sensory modalities, participants experienced 8-10 sequential stimuli (200 ms each) with interstimulus intervals (ISIs) of 0.25-7.0 s. Experiments focused on spatiotemporal completion (walking), featural completion (object changing), auditory, completion (falling bomb), and haptic changes (insect crawling). After each trial, participants judged whether they experienced the process of "happening " or whether they simply knew that the process must have occurred. The phenomenon was frequency independent, being reported at short ISIs but not at long ISIs. The phenomenon involves dynamic modal completion and possibly also conceptual processes.

The design of an ultra-low sidelobe offset-fed 1.22m antenna for use in the broadcasting satellite service

Science.gov (United States)

Janky, J. M.

1981-01-01

A feed design and reflector geometry were determined for an ultra low sidelobe offset fed 1.22 meter antenna suitable for use in the 12 GHz broadcasting satellite service. Arbitrary constraints used to evaluate the relative merits of the feed horns and range of f/D geometries are: minimum efficiency of 55 percent, -30 dB first sidelobe level (relative to on axis gain), a 0 dBi plateau beyond the near in sidelobe region, and a Chebyshev polynomial based envelope (borrowed from filter theory) for the region from the -3 dB beamwidth points to the 0 dBi plateau region. This envelope is extremely stringent but the results of this research effort indicate that two steps of corrugated feed and a cluster array of small 1 lambda horns do meet the constraints. A set of performance specifications and a mechanical design suitable for a consumer oriented market in the broadcasting satellite service was developed. Costs for production quantities of 10,000 units/yr. are estimated to be around $150.

Closing the innovation cycle in lightweighting compressor pistons technolog

NARCIS (Netherlands)

Wentzel, C.; Eijk, A.; Groenewegen, G.; Bergsma, O.

2016-01-01

What started out as an exercise in exploring the weight reduction potential of those allegedly “heavy recip crossheads”, turned out to be a fast leap towards implementation of a new hybrid material concept for very lightweight pistons. This was enabled by a next phase in the EFRC R&D group research

FY2013 Lightweight Materials R&D Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

none,

2014-02-01

As part of the U.S. Department of Energy’s (DOE’s) Vehicle Technologies Program (VTO), the Lightweight Materials (LM) activity focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

TiO2/Bi2(BDC)3/BiOCl nanoparticles decorated ultrathin nanosheets with excellent photocatalytic reaction activity and selectivity

International Nuclear Information System (INIS)