Sensitivity Characterization of Pressed Energetic Materials using Flyer Plate Mesoscale Simulations

Science.gov (United States)

Rai, Nirmal; Udaykumar, H. S.

Heterogeneous energetic materials like pressed explosives have complicated microstructure and contain various forms of heterogeneities such as pores, micro-cracks, energetic crystals etc. It is widely accepted that the presence of these heterogeneities can affect the sensitivity of these materials under shock load. The interaction of shock load with the microstructural heterogeneities may leads to the formation of local heated regions known as ``hot spots''. Chemical reaction may trigger at the hot spot regions depending on the hot spot temperature and the duration over which the temperature can be maintained before phenomenon like heat conduction, rarefaction waves withdraws energy from it. There are different mechanisms which can lead to the formation of hot spots including void collapse. The current work is focused towards the sensitivity characterization of two HMX based pressed energetic materials using flyer plate mesoscale simulations. The aim of the current work is to develop mesoscale numerical framework which can perform simulations by replicating the laboratory based flyer plate experiments. The current numerical framework uses an image processing approach to represent the microstructural heterogeneities incorporated in a massively parallel Eulerian code SCIMITAR3D. The chemical decomposition of HMX is modeled using Henson-Smilowitz reaction mechanism. The sensitivity characterization is aimed towards obtaining James initiation threshold curve and comparing it with the experimental results.

New infrared-sensitive photopolymer materials for information storage and processing

Science.gov (United States)

Nagtegaele, Patrice; Galstian, Tigran V.

2001-11-01

In response to the increasing demand of information systems, we need new materials with high performance for storage and processing applications. Available on the market optical storage materials present very useful characteristics but are still limited in the visible spectrum and are expansive. Recently, we have developed holographic polymer dispersed liquid crystal (H-PDLC) materials sensitive in the near infrared region (800 nm to 850 nm). These compounds are based on acrylate monomers and different liquid crystals (LC) and allow highly efficient in-situ recording of holographic optical elements using infra red lasers. Diffraction efficiency above 95% is demonstrated. Photosensitivity of the material, its dark ­development and photochemical stability of recorded gratings are investigated. The angular and spectral selectivities of gratings, recorded in these films are examined for recovering the refractive index modulation profile.

Sensitivity of radiation methods of diagnosis of electric potentials in dielectric materials

International Nuclear Information System (INIS)

Sapozhkov, Yu.I.; Smekalin, L.F.; Yagushkin, N.I.

1985-01-01

On the base of the albedo method the characteristics of radiation methods of diagnosis of electric potentials inside dielectrics, such as sensitivity and resolution are considered. Investigations are carried out for electron energies of tens keV. It is shown that with energy growth the sensitivity to electric field in the dielectrics volume drops. The target atomic number growth reduces the sensitivity approximately 1/lnz. The albedo method resolution in the investigated energy range is constant. The results obtained testify to the usability radiation methods of the diagnosis for control of electric fields of dielectric structural materials in the course of their operation

Global sensitivity analysis of multiscale properties of porous materials

Science.gov (United States)

Um, Kimoon; Zhang, Xuan; Katsoulakis, Markos; Plechac, Petr; Tartakovsky, Daniel M.

2018-02-01

Ubiquitous uncertainty about pore geometry inevitably undermines the veracity of pore- and multi-scale simulations of transport phenomena in porous media. It raises two fundamental issues: sensitivity of effective material properties to pore-scale parameters and statistical parameterization of Darcy-scale models that accounts for pore-scale uncertainty. Homogenization-based maps of pore-scale parameters onto their Darcy-scale counterparts facilitate both sensitivity analysis (SA) and uncertainty quantification. We treat uncertain geometric characteristics of a hierarchical porous medium as random variables to conduct global SA and to derive probabilistic descriptors of effective diffusion coefficients and effective sorption rate. Our analysis is formulated in terms of solute transport diffusing through a fluid-filled pore space, while sorbing to the solid matrix. Yet it is sufficiently general to be applied to other multiscale porous media phenomena that are amenable to homogenization.

Estimation and analysis of the sensitivity of monoenergetic electron radiography of composite materials with fluctuating composition

International Nuclear Information System (INIS)

Rudenko, V.N.; Yunda, N.T.

1978-01-01

A sensitivity analysis of the electron defectoscopy method for composite materials with fluctuating composition has been carried out. Quantitative evaluations of the testing sensitivity depending on inspection conditions have been obtained, and calculations of the instrumental error are shown. Based on numerical calculations, a comparison of error has been carried out between high-energy electron and X-ray testings. It is shown that when testing composite materials with a surface density of up to 7-10 g/cm 2 , the advantage of the electron defectoscopy method as compared to the X-ray one is the higher sensitivity and lower instrumental error. The advantage of the electron defectoscopy method over the X-ray one as regards the sensitivity is greater when a light-atom component is predomenant in the composition. A monoenergetic electron beam from a betatron with an energy of up to 30 MeV should be used for testing materials with a surface density of up to 15 g/cm 2

Effect of carbon microfiber materials on sensitivity of adenosine and hydroxyadenine at carbon microfiber sensors

Directory of Open Access Journals (Sweden)

K.M.M. Abou El-Nour

2015-07-01

Full Text Available The relationship between the sensitivity measurements and microfiber electrodes made from different carbon microfiber materials, such as polyacrylonitrile (PAN T650 and PAN HCB and Pitch P25 was established in this work. The different microfiber electrodes were nanostructured by an electrochemical pretreatment method. Sensitivity of adenosine (ADO and 2,8-dihydroxyadenine (2,8-DHA was measured at different carbon microfiber sensors made from different carbon microfiber materials. Sensitivity of PAN microfiber electrodes for ADO and 2,8-DHA determinations measured at 500 V s−1 vs. SCE is higher than that measured at Pitch P25 microfiber electrodes due to more defects in PAN microfiber electrodes. Adsorption of ADO and 2,8-DHA is greater at PAN HCB electrodes. High conductivity of PAN fibers correlates with sensitivity determinations of the investigated analytes.

Studies on radiation-sensitive nonsilver halide materials, (1)

International Nuclear Information System (INIS)

Komizu, Hideo; Honda, Koichi; Yabe, Akira; Kawasaki, Masami; Fujii, Etsuo

1978-01-01

In order to discover new radiation-sensitive nonsilver halide materials, the coloration based on the formation of Stenhouse salts was studied in the following three systems: (a) furfural-amine/HCl aq/methanol solution, (b) furfural-amine/polyhalogenide/PMMA matrix, (c) furfural-amine/PVC matrix. Firstly, forty-five aromatic amines were surveyed to find out the amines suitable for the color precursors (reactant from furfural and amine) in the system (a). As a result, the five amines, which gave the precursors in good yields by the reaction with furfural, were selected: m-nitroaniline, N-methylaniline, m-methyl-N-methylaniline, aniline, and o-methoxyaniline. Secondly, the coloration induced by electron beam bombardment was studied in the systems (b) and (c) containing the color precursors (the reactants from these amines and furfural). Although the PMMA films containing the color precursors and polyhalogenides were sensitive to electron beam, they were not stable when standing under daylight at room temperature. The PVC films containing the color precursors were very stable and colored to reddish yellow (lambda sub(max) 498 - 545 nm) by electron beam bombardment. The PVC film containing N-methylaniline-furfural was the most sensitive and the increase in absorbance at 498 nm was 0.78 by electron beam bombardment of 60 kV - 7.5 x 10 -7 C/cm 2 . A good linear relationship existed between the degree of coloration and the amounts of electron beam bombardment in the range from 0 to 10 -6 C/cm 2 . (author)

The control of vehicles used in transport of sensitive nuclear material

International Nuclear Information System (INIS)

Loiseau, O.; Larrignon, D.; Autrusson, B.

2010-01-01

Most sensitive nuclear materials are usually shipped in specific vehicles with a reinforced protection; such vehicles are generally escorted, tracked and watched over from a distant control centre. Among the various publications made by the IAEA in relation with the CPPNM, the INFCIRC/225 introduces major recommendations for physical protection of nuclear materials in general and particularly during transport. For instance, the text recommends - for the terrestrial shipment of most sensitive material - the use of vehicles specially designed to resist attack and equipped with a vehicle disabling device. Applying such a recommendation at a state level requires the intervention of a competent authority; the competent authority defines the framework of a validation process starting with the design of the vehicle and ending with the vehicle protection approval. The validation process needs articulating responsibilities between the three major actors who are: the operator in charge of the design, a technical support body in charge of technical evaluation, and the competent authority who is responsible for the final approval of the protection. This paper focuses on the approval process of reinforced protection vehicles in France; it aims at showing how such a process may contribute to the security of nuclear material shipments. The paper notably focuses on the responsibilities of the operators, the competent authority and the technical support organization. This approval process of the protection of a vehicle allows the authority to ensure that the protection setup is effective and operational in order to protect the cargo from a malicious threat. In such a process, the authority defines the threat and the objectives of protection; the authority may choose, in certain case, to recommend protection devices or solutions; the need for recommendation versus objective definition mostly depends on the environment of the vehicle and the constraints induced. The authority may

Development of high Sensitivity Materials for Applications in Magneto-Mechanical Torque Sensor

Energy Technology Data Exchange (ETDEWEB)

Shen, Yuping [Iowa State Univ., Ames, IA (United States)

2003-01-01

The Matteucci effect, which mainly manifests itself as the change of magnetization of a material with torsional stress, is currently of great technological interest because of the search for magnetic torque sensors. Magnetic torque sensors are important to future improvements of automobiles and industrial robots. It is well known that the magnetic state of a material depends on both the external magnetic field and external stress which causes strain and change in magnetization of the material. The former phenomenon has been well understood in both theory and application. However, the magnetic state dependence of stress is not adequately understood and the experimental data is of limited extent. In this project, the Matteucci effect in iron, cobalt, nickel and permalloy rods has been documented when they were in magnetic remanence status along the axis and nickel ring when they were in remanence status along the circumference. The effect of annealing on the magnetomechanical effect in nickel and the temperature dependence of the magnetomechanical sensitivity has also been examined. Factors related to the sensitivity at equilibrium condition have been theoretically developed. it is found in the experiments that the mechanism of magnetic domain wall movement plays an important role rather than the domain rotation. A higher sensitivity was found by domain wall movement mechanism than that by domain rotation mechanism. However, the domain wall movement will result in more hysteresis than domain wall rotation. The dynamic process of Matteucci effect of iron, cobalt, permally, especially as-fabricated and annealed nickel rods have been examined. A tentative explanation for the difference of these in terms of magnetic domain configuration and domain wall movement was given. As a result, another method of configuring and processing magnetic domains to get a linear magnetomechanical response other than that suggested by Garshelis, which was the basic method before the

Low cost transportable device for transference of atmosphere sensitive materials from glove box to SEM

DEFF Research Database (Denmark)

Bentzen, Janet Jonna; Saxild, Finn B.

Moisture or air sensitive materials are often encountered within several highly important fields such as catalyst R&D, pharmaceutical R&D, and battery R&D. Essential to all materials research and development is microstructure characterization, which often implies electron microscopy. Entering the...

LHS (latin hypercubes) sampling of the material properties of steels for the analysis of the global sensitivity in welding numerical simulation

International Nuclear Information System (INIS)

Petelet, Matthieu; Asserin, Olivier; Iooss, Bertrand; Petelet, Matthieu; Loredo, Alexandre

2006-01-01

In this work, the method of sensitivity analysis allowing to identify the inlet data the most influential on the variability of the responses (residual stresses and distortions). Classically, the sensitivity analysis is carried out locally what limits its validity domain to a given material. A global sensitivity analysis method is proposed; it allows to cover a material domain as wide as those of the steels series. A probabilistic modeling giving the variability of the material parameters in the steels series is proposed. The original aspect of this work consists in the use of the sampling method by latin hypercubes (LHS) of the material parameters which forms the inlet data (dependent of temperature) of the numerical simulations. Thus, a statistical approach has been applied to the welding numerical simulation: LHS sampling of the material properties, global sensitivity analysis what has allowed the reduction of the material parameterization. (O.M.)

Sensitivity of acoustic nonlinearity parameter to the microstructural changes in cement-based materials

Science.gov (United States)

Kim, Gun; Kim, Jin-Yeon; Kurtis, Kimberly E.; Jacobs, Laurence J.

2015-03-01

This research experimentally investigates the sensitivity of the acoustic nonlinearity parameter to microcracks in cement-based materials. Based on the second harmonic generation (SHG) technique, an experimental setup using non-contact, air-coupled detection is used to receive the consistent Rayleigh surface waves. To induce variations in the extent of microscale cracking in two types of specimens (concrete and mortar), shrinkage reducing admixture (SRA), is used in one set, while a companion specimen is prepared without SRA. A 50 kHz wedge transducer and a 100 kHz air-coupled transducer are implemented for the generation and detection of nonlinear Rayleigh waves. It is shown that the air-coupled detection method provides more repeatable fundamental and second harmonic amplitudes of the propagating Rayleigh waves. The obtained amplitudes are then used to calculate the relative nonlinearity parameter βre, the ratio of the second harmonic amplitude to the square of the fundamental amplitude. The experimental results clearly demonstrate that the nonlinearity parameter (βre) is highly sensitive to the microstructural changes in cement-based materials than the Rayleigh phase velocity and attenuation and that SRA has great potential to avoid shrinkage cracking in cement-based materials.

Data on the experiments of temperature-sensitive hydrogels for pH-sensitive drug release and the characterizations of materials

Directory of Open Access Journals (Sweden)

Wei Zhang

2018-04-01

Full Text Available This article contains experimental data on the strain sweep, the calibration curve of drug (doxorubicin, DOX and the characterizations of materials. Data included are related to the research article “Injectable and body temperature sensitive hydrogels based on chitosan and hyaluronic acid for pH sensitive drug release” (Zhang et al., 2017 [1]. The strain sweep experiments were performed on a rotational rheometer. The calibration curves were obtained by analyzing the absorbance of DOX solutions on a UV–vis-NIR spectrometer. Molecular weight (Mw of the hyaluronic acid (HA and chitosan (CS were determined by gel permeation chromatography (GPC. The deacetylation degree of CS was measured by acid base titration.

Thick film laser induced forward transfer for deposition of thermally and mechanically sensitive materials

International Nuclear Information System (INIS)

Kattamis, Nicholas T.; Purnick, Priscilla E.; Weiss, Ron; Arnold, Craig B.

2007-01-01

Laser forward transfer processes incorporating thin absorbing films can be used to deposit robust organic and inorganic materials but the deposition of more delicate materials has remained elusive due to contamination and stress induced during the transfer process. Here, we present the approach to high resolution patterning of sensitive materials by incorporating a thick film polymer absorbing layer that is able to dissipate shock energy through mechanical deformation. Multiple mechanisms for transfer as a function of incident laser energy are observed and we show viable and contamination-free deposition of living mammalian embryonic stem cells

Imaging of dental material by polarization-sensitive optical coherence tomography

Science.gov (United States)

Dichtl, Sabine; Baumgartner, Angela; Hitzenberger, Christoph K.; Moritz, Andreas; Wernisch, Johann; Robl, Barbara; Sattmann, Harald; Leitgeb, Rainer; Sperr, Wolfgang; Fercher, Adolf F.

1999-05-01

Partial coherence interferometry (PCI) and optical coherence tomography (OCT) are noninvasive and noncontact techniques for high precision biometry and for obtaining cross- sectional images of biologic structures. OCT was initially introduced to depict the transparent tissue of the eye. It is based on interferometry employing the partial coherence properties of a light source with high spatial coherence ut short coherence length to image structures with a resolution of the order of a few microns. Recently this technique has been modified for cross section al imaging of dental and periodontal tissues. In vitro and in vivo OCT images have been recorded, which distinguish enamel, cemento and dentin structures and provide detailed structural information on clinical abnormalities. In contrast to convention OCT, where the magnitude of backscattered light as a function of depth is imaged, polarization sensitive OCT uses backscattered light to image the magnitude of the birefringence in the sample as a function of depth. First polarization sensitive OCT recordings show, that changes in the mineralization status of enamel or dentin caused by caries or non-caries lesions can result in changes of the polarization state of the light backscattered by dental material. Therefore polarization sensitive OCT might provide a new diagnostic imaging modality in clinical and research dentistry.

14 CFR 1213.107 - Preventing unauthorized release of sensitive but unclassified (SBU) information/material to the...

Science.gov (United States)

2010-01-01

.../material to the news media. (a) All NASA SBU information requires accountability and approval for release... sensitive but unclassified (SBU) information/material to the news media. 1213.107 Section 1213.107 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION RELEASE OF INFORMATION TO NEWS AND...

LiNbO3 :Pr3+ : A Multipiezo Material with Simultaneous Piezoelectricity and Sensitive Piezoluminescence.

Science.gov (United States)

Tu, Dong; Xu, Chao-Nan; Yoshida, Akihito; Fujihala, Masayoshi; Hirotsu, Jou; Zheng, Xu-Guang

2017-06-01

Red-emitting piezoluminescence (elasticoluminescence) is achieved by doping rare earth Pr 3+ into the well-known piezoelectric matrix, LiNbO 3 . By precisely tuning the Li/Nb ratio in nonstoichiometric Li x NbO 3 :Pr 3+ , a material that exhibits an unusually high piezoluminescence intensity, which far exceeds that of any well-known piezoelectric material, is produced. Li x NbO 3 :Pr 3+ shows excellent strain sensitivity at the lowest strain level, with no threshold for stress sensing. These multipiezo properties of sensitive piezoluminescence in a piezoelectric matrix are ideal for microstress sensing, damage diagnosis, electro-mechano-optical energy conversion, and multifunctional control in optoelectronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Material Selection for Dye Sensitized Solar Cells Using Multiple Attribute Decision Making Approach

Directory of Open Access Journals (Sweden)

Sarita Baghel

2014-01-01

Full Text Available Dye sensitized solar cells (DSCs provide a potential alternative to conventional p-n junction photovoltaic devices. The semiconductor thin film plays a crucial role in the working of DSC. This paper aims at formulating a process for the selection of optimum semiconductor material for nanostructured thin film using multiple attribute decision making (MADM approach. Various possible available semiconducting materials and their properties like band gap, cost, mobility, rate of electron injection, and static dielectric constant are considered and MADM technique is applied to select the best suited material. It was found that, out of all possible candidates, titanium dioxide (TiO2 is the best semiconductor material for application in DSC. It was observed that the proposed results are in good agreement with the experimental findings.

Study of extraterrestrial material by means of a high sensitive mass spectrometer, 1

International Nuclear Information System (INIS)

Arai, O.; Kaneko, K.; Kobayashi, K.; Shimamura, T.

1975-01-01

In this report it is described about a high sensitive mass spectrometer for measurement of isotopic abundance of extraterrestrial material. Detecting isotopic anomalies in extraterrestrial matter induced by cosmic ray or solar wind irradiation, we can obtain many informations about interplanetary and/or intersteller space. For this purpose we reform the mass spectrometer of Low Energy Physics Division of INS to improve the sensitivity and the resolution. In section I--VI some improvements of the mass spectrometer (vacuum system, ion source, collector etc.) are described. In section VII--X newly developed ion counting system is discussed. (auth.)

Sensitivity Analysis for Iceberg Geometry Shape in Ship-Iceberg Collision in View of Different Material Models

Directory of Open Access Journals (Sweden)

Yan Gao

2014-01-01

Full Text Available The increasing marine activities in Arctic area have brought growing interest in ship-iceberg collision study. The purpose of this paper is to study the iceberg geometry shape effect on the collision process. In order to estimate the sensitivity parameter, five different geometry iceberg models and two iceberg material models are adopted in the analysis. The FEM numerical simulation is used to predict the scenario and the related responses. The simulation results including energy dissipation and impact force are investigated and compared. It is shown that the collision process and energy dissipation are more sensitive to iceberg local shape than other factors when the elastic-plastic iceberg material model is applied. The blunt iceberg models act rigidly while the sharp ones crush easily during the simulation process. With respect to the crushable foam iceberg material model, the iceberg geometry has relatively small influence on the collision process. The spherical iceberg model shows the most rigidity for both iceberg material models and should be paid the most attention for ice-resist design for ships.

Deposition of hole-transport materials in solid-state dye-sensitized solar cells by doctor-blading

KAUST Repository

Ding, I-Kang

2010-07-01

We report using doctor-blading to replace conventional spin coating for the deposition of the hole-transport material spiro-OMeTAD (2,20,7,70-tetrakis-(N, N-di-p-methoxyphenylamine)- 9,90-spirobifluorene) in solid-state dye-sensitized solar cells. Doctor-blading is a roll-to-roll compatible, large-area coating technique, is capable of achieving the same spiro-OMeTAD pore filling fraction as spin coating, and uses much less material. The average power conversion efficiency of solid-state dye-sensitized solar cells made from doctorblading is 3.0% for 2-lm thick films and 2.0% for 5-lm thick films, on par with devices made with spin coating. Directions to further improve the filling fraction are also suggested. © 2010 Elsevier B.V. All rights reserved.

Study on photon sensitivity of silicon diodes related to materials used for shielding

International Nuclear Information System (INIS)

Moiseev, T.

1999-01-01

Large area silicon diodes used in electronic neutron dosemeters have a significant over-response to X- and gamma-rays, highly non-linear at photon energies below 200 keV. This over-response to photons is proportional to the diode's active area and strongly affects the neutron sensitivity of such dosemeters. Since silicon diodes are sensitive to light and electromagnetic fields, most diode detector assemblies are provided with a shielding, sometimes also used as radiation filter. In this paper, the influence of materials covering the diode's active area is investigated using the MCNP-4A code by estimating the photon induced pulses in a typical silicon wafer (300 μm thickness and 1 cm diameter) when provided with a front case cover. There have been simulated small-size diode front covers made of several materials with low neutron interaction cross-sections like aluminium, TEFLON, iron and lead. The estimated number of induced pulses in the silicon wafer is calculated for each type of shielding at normal photon incidence for several photon energies from 9.8 keV up to 1.15 MeV and compared with that in a bare silicon wafer. The simulated pulse height spectra show the origin of the photon-induced pulses in silicon for each material used as protective cover: the photoelectric effect for low Z front case materials at low-energy incident photons (up to about 65 keV) and the Compton and build-up effects for high Z case materials at higher photon energies. A simple means to lower and flatten the photon response of silicon diodes over an extended X- and gamma rays energy range is proposed by designing a composed photon filter. (author)

Study on Photon Sensitivity of Silicon Diodes Related to Materials Used for Shielding

International Nuclear Information System (INIS)

Moiseev, T.

2000-01-01

Large area Silicon diodes used in electronic neutron dosemeters have a significant over-response to X and gamma rays, highly non-linear at photon energies below 200 keV. This over-response to photons is proportional to the diodes active area and strongly affects the neutron sensitivity of such dosemeters. Since Silicon diodes are sensitive to light and electromagnetic fields, most diode detector assemblies are provided with a shielding, sometimes also used as radiation filter. In this paper, the influence of materials covering the diode's active area is investigated using the MCNP-4A code by estimating the photon induced pulses in a typical silicon wafer (300 μm thickness and 1 cm diameter) when provided with a front case cover. There have been simulated small-size diode front covers made of several materials with low neutron interaction cross-sections like aluminium, TEFLON, iron and lead. The estimated number of induced pulses in the silicon wafer is calculated for each type of shielding at normal photon incidence for several photon energies from 9.8 keV up to 1.15 MeV and compared with that in a bare silicon wafer. The simulated pulse height spectra show the origin of the photon induced pulses in silicon for each material used as protective cover: the photoelectric effect for low Z front case materials at low energy incident photons (up to about 65 keV) and the Compton and build-up effects for high Z case materials at higher photon energies. A simple means to lower and flatten the photon response of silicon diodes over an extended X and gamma rays energy range is proposed by designing a composed photon filter. (author)

Deposition of hole-transport materials in solid-state dye-sensitized solar cells by doctor-blading

KAUST Repository

Ding, I-Kang; Melas-Kyriazi, John; Cevey-Ha, Ngoc-Le; Chittibabu, Kethinni G.; Zakeeruddin, Shaik M.; Grä tzel, Michael; McGehee, Michael D.

2010-01-01

We report using doctor-blading to replace conventional spin coating for the deposition of the hole-transport material spiro-OMeTAD (2,20,7,70-tetrakis-(N, N-di-p-methoxyphenylamine)- 9,90-spirobifluorene) in solid-state dye-sensitized solar cells

Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells.

Science.gov (United States)

Jun, Hieng Kiat; Careem, Mohamed Abdul; Arof, Abdul Kariem

2014-02-10

Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.

Towards highly sensitive strain sensing based on nanostructured materials

International Nuclear Information System (INIS)

Dao, Dzung Viet; Nakamura, Koichi; Sugiyama, Susumu; Bui, Tung Thanh; Dau, Van Thanh; Yamada, Takeo; Hata, Kenji

2010-01-01

This paper presents our recent theoretical and experimental study of piezo-effects in nanostructured materials for highly sensitive, high resolution mechanical sensors. The piezo-effects presented here include the piezoresistive effect in a silicon nanowire (SiNW) and single wall carbon nanotube (SWCNT) thin film, as well as the piezo-optic effect in a Si photonic crystal (PhC) nanocavity. Firstly, the electronic energy band structure of the silicon nanostructure is discussed and simulated by using the First-Principles Calculations method. The result showed a remarkably different energy band structure compared with that of bulk silicon. This difference in the electronic state will result in different physical, chemical, and therefore, sensing properties of silicon nanostructures. The piezoresistive effects of SiNW and SWCNT thin film were investigated experimentally. We found that, when the width of ( 110 ) p-type SiNW decreases from 500 to 35 nm, the piezoresistive effect increases by more than 60%. The longitudinal piezoresistive coefficient of SWCNT thin film was measured to be twice that of bulk p-type silicon. Finally, theoretical investigations of the piezo-optic effect in a PhC nanocavity based on Finite Difference Time Domain (FDTD) showed extremely high resolution strain sensing. These nanostructures were fabricated based on top-down nanofabrication technology. The achievements of this work are significant for highly sensitive, high resolution and miniaturized mechanical sensors

Impedance spectroscopy on pH-sensors with lithium lanthanum titanate sensitive material

International Nuclear Information System (INIS)

Bohnke, Cl.; Fourquet, J.-L.

2003-01-01

The ceramic Li 3x La 2/3-x , 1/3-2x TiO 3 is used, in an all-solid-state configuration, as pH-sensor in aqueous buffer solution. This ceramic displays a pH sensitivity comparable to the one obtained with a commercial glass electrode and does not show any sensitivity to the redox potential of the solution. This is one of the remarkable properties of this ceramic pH-sensor. It is shown in this paper that the reproducibility and the behaviour of the pH-response depend on the morphology of the grain boundaries particularly on the size of the grains. A so-called 'good' pH-response is obtained with a ceramic showing big and homogeneous grains. Complex impedance spectroscopy reveals that such ceramic has a high grain boundary resistance. Furthermore, this electrochemical technique allows us to determine that the interface reaction involved in the pH detection has a time constant of the order of the second. Several assumptions such as ion exchange or acid-base reaction are proposed to explain the sensitivity of the ceramic material to the pH of the solution

Metal Nanoparticles and Carbon-Based Nanostructures as Advanced Materials for Cathode Application in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Pietro Calandra

2010-01-01

Full Text Available We review the most advanced methods for the fabrication of cathodes for dye-sensitized solar cells employing nanostructured materials. The attention is focused on metal nanoparticles and nanostructured carbon, among which nanotubes and graphene, whose good catalytic properties make them ideal for the development of counter electrode substrates, transparent conducting oxide, and advanced catalyst materials.

Nanostructured Semiconductor Materials for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Carmen Cavallo

2017-01-01

Full Text Available Since O’Regan and Grätzel’s first report in 1991, dye-sensitized solar cells (DSSCs appeared immediately as a promising low-cost photovoltaic technology. In fact, though being far less efficient than conventional silicon-based photovoltaics (being the maximum, lab scale prototype reported efficiency around 13%, the simple design of the device and the absence of the strict and expensive manufacturing processes needed for conventional photovoltaics make them attractive in small-power applications especially in low-light conditions, where they outperform their silicon counterparts. Nanomaterials are at the very heart of DSSC, as the success of its design is due to the use of nanostructures at both the anode and the cathode. In this review, we present the state of the art for both n-type and p-type semiconductors used in the photoelectrodes of DSSCs, showing the evolution of the materials during the 25 years of history of this kind of devices. In the case of p-type semiconductors, also some other energy conversion applications are touched upon.

Sensitivity analysis: Interaction of DOE SNF and packaging materials

International Nuclear Information System (INIS)

Anderson, P.A.; Kirkham, R.J.; Shaber, E.L.

1999-01-01

A sensitivity analysis was conducted to evaluate the technical issues pertaining to possible destructive interactions between spent nuclear fuels (SNFs) and the stainless steel canisters. When issues are identified through such an analysis, they provide the technical basis for answering what if questions and, if needed, for conducting additional analyses, testing, or other efforts to resolve them in order to base the licensing on solid technical grounds. The analysis reported herein systematically assessed the chemical and physical properties and the potential interactions of the materials that comprise typical US Department of Energy (DOE) SNFs and the stainless steel canisters in which they will be stored, transported, and placed in a geologic repository for final disposition. The primary focus in each step of the analysis was to identify any possible phenomena that could potentially compromise the structural integrity of the canisters and to assess their thermodynamic feasibility

Novel nanostructured materials to develop oxygen-sensitive films for optical sensors

International Nuclear Information System (INIS)

Fernandez-Sanchez, Jorge F.; Cannas, Rita; Spichiger, Stefan; Steiger, Rolf; Spichiger-Keller, Ursula E.

2006-01-01

Novel nanostructured materials, such as aluminum oxide (AlOOH), silicon oxide (SiO 2 ) or zirconium oxide (ZrO 2 ) embedded into PVA, were investigated as potential matrices to incorporate organometallic compounds (OMCs) for the development of optical oxygen-sensitive sensors which make use of the principle of luminescence quenching. In order to assess the benefits and drawbacks of the nanoporous material, the luminescence quantum yield and the Stern-Volmer constants were investigated and compared with the values shown for the same OMCs solubilized in polymer films (polystyrene). Referred to polymer films, the incorporation of the dyes into nanoporous membranes increased the Stern-Volmer constant by more than a factor of 100. Their response time was less than 1 s and the optode membranes were stable at room temperature for at least 9 months. Sterilization by autoclavation and gamma irradiation resulted in a marginal loss in activity. The photostability and sterilizability of the oxygen-sensitive membranes and the performance of the optodes with respect to of different types of metal oxides are discussed in the paper, as well as the influence of the total pore volume (TPV), the pore diameter (PD), the transparency of the film and the geometry of the pores. The OMCs used in this work were: ETH T -3003 (tris(4,7-bis(4-octylphenyl)-1,10-phenanthroline) ruthenium(II)), N-926 (bis(2-phenylpyridinyl)-N 4 ,N 4 ,N 4 ',N 4 '-tetramethyl-(4,4'-diamine-2,2'-bipyridine) iridium(III) chlorate), N-833 (tetrabutylammonium bis(isothiocyanate) bis(2-phenylpyridinyl)-iridium(III)) and N-837 (tetrabutylammonium bis(cyanate) bis(2-phenylpyridinyl)-iridium(III))

Relationship on the Price Sensitivity and Actual Market Acceptance Degree of Metallic Materials

Directory of Open Access Journals (Sweden)

Jing Muxue

2017-01-01

Full Text Available In order to find out the relationship between the price sensitivity and actual market acceptance degree of metallic materials, the database ensemble learning model is proposed in this paper. Due to the variety and class imbalance of customers, a database marketing model based on supervised clustering and ensemble learning is used for the model. The results show that the database ensemble learning model can thus improve the calculation accuracy and time-efficiency substantially.

Recent Development of Graphene-Based Cathode Materials for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Man-Ning Lu

2016-01-01

Full Text Available Dye-sensitized solar cells (DSSCs have attracted extensive attention for serving as potential low-cost alternatives to silicon-based solar cells. As a vital role of a typical DSSC, the counter electrode (CE is generally employed to collect electrons via the external circuit and speed up the reduction reaction of I3- to I- in the redox electrolyte. The noble Pt is usually deposited on a conductive glass substrate as CE material due to its excellent electrical conductivity, electrocatalytic activity, and electrochemical stability. To achieve cost-efficient DSSCs, reasonable efforts have been made to explore Pt-free alternatives. Recently, the graphene-based CEs have been intensively investigated to replace the high-cost noble Pt CE. In this paper, we provided an overview of studies on the electrochemical and photovoltaic characteristics of graphene-based CEs, including graphene, graphene/Pt, graphene/carbon materials, graphene/conducting polymers, and graphene/inorganic compounds. We also summarize the design and advantages of each graphene-based material and provide the possible directions for designing new graphene-based catalysts in future research for high-performance and low-cost DSSCs.

High-sensitivity green resist material with organic solvent-free spin-coating and tetramethylammonium hydroxide-free water-developable processes for EB and EUV lithography

Science.gov (United States)

Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2015-03-01

We investigated the eco-friendly electron beam (EB) and extreme-ultraviolet (EUV) lithography using a high-sensitive negative type of green resist material derived from biomass to take advantage of organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of TMAH. The material design concept to use the water-soluble resist material with acceptable properties such as pillar patterns with less than 100 nm in high EB sensitivity of 10 μC/cm2 and etch selectivity with a silicon-based middle layer in CF4 plasma treatment was demonstrated for EB and EUV lithography.

Rate sensitivity of mixed mode interface toughness of dissimilar metallic materials: Studied at steady state

DEFF Research Database (Denmark)

Nielsen, Kim Lau; Niordson, Christian Frithiof

2012-01-01

the SSV model [Suo, Z., Shih, C., Varias, A., 1993. A theory for cleavage cracking in the presence of plastic flow. Acta Metall. Mater. 41, 1551–1557] embedded in a steady state finite element formulation, here assuming plane strain conditions and small-scale yielding. Results are presented for a wide......Crack propagation in metallic materials produces plastic dissipation when material in front for the crack tip enters the active plastic zone traveling with the tip, and later ends up being part of the residual plastic strain wake. Thus, the macroscopic work required to advance the crack...... is typically much larger than the work needed in the near tip fracture process. For rate sensitive materials, the amount of plastic dissipation typically depends on the rate at which the material is deformed. A dependency on the crack velocity should therefore be expected. The objective of this paper...

[On the Way to Culture-Sensitive Patient Information Materials: Results of a Focus Group Study].

Science.gov (United States)

Ries, Zivile; Frank, Fabian; Bermejo, Isaac; Kalaitsidou, Chariklia; Zill, Jördis; Dirmaier, Jörg; Härter, Martin; Bengel, Jürgen; Hölzel, Lars

2018-06-01

This study was part of a double-blind randomised controlled trial aimed to evaluate the effects of culture-sensitive patient information materials (PIM) compared with standard translated material. The study aimed to obtain the data for the development of culture sensitive PIM about unipolar depression for the 4 largest migrant groups in Germany (Turkish, Polish, Russian and Italian migration background). A qualitative study using 4 manual-based focus groups (FG), one for each migrant group, with 29 participants (9 with a Turkish (TüG), 8 with a Polish (PoG), 5 with a Russian (RuG) and 7 with an Italian (ItG) migration background) was conducted. The discussions were recorded, transcribed and analyzed using qualitative content analysis. 7 categories were identified. For the (1.) development of a good culture-sensitive PIM an easy language, a clear structure, an assessable extent of information and the avoidance of stereotypes were highlighted cross-culturally in all four FG. RuG and PoG had the largest (2.) lack of information about the German health care system. Concerning the (3.) illness perception RuG named problems with recognizing and understanding depression. PoG, RuG and TüG thematized (4.) feared consequences of the illness and of professional helpseeking. ItG, PoG, RuG had fears concerning (5.) psychotropic drugs as a result from insufficient knowledge about medication. For (6.) doctor-patient relationship cultural specifics were identified in RuG and TüG and for (7.) migration or culture specific reasons for depression in RuG, ItG and TüG. Although the identified categories were relevant for all or for the majority of migrant groups, for most categories specific cultural aspects were discovered. These findings show the importance of a culture sensitive adaptation of PIM. © Georg Thieme Verlag KG Stuttgart · New York.

Controlled synthesis of various ZnO nanostructured materials by capping agents-assisted hydrothermal method for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Akhtar, M. Shaheer; Khan, M. Alam; Yang, O-Bong [School of Semiconductor and Chemical Engineering, Center for Advanced Radiation Technology, Jeon-Ju (Korea); New and Renewable Energy Center, Chonbuk National University, Jeon-Ju (Korea); Jeon, Myung Seok [Photocatalysis and Photoelectrochemistry Research Center, Korea Institute of Energy Research (KIER), Daejon 305-343 (Korea)

2008-11-15

In this work, the morphology of ZnO materials could be controlled by changing the capping agent at constant alkali solution in hydrothermal process. ZnO nanomaterials with the structure of flowers, sheet-spheres and plates were obtained with the capping agent of ammonia, citric acid and oxalic acid, respectively. Thus prepared ZnO nanomaterials were characterized and applied as the photo-anode materials for dye-sensitized solar cell. All synthesized ZnO nanomaterials possessed high crystalline wurtzite structures grown in the (001) direction with the size of 2-4{mu}m, which consist of ZnO units around 20-400 nm. Among them, Sheet-sphere ZnO showed the highest crystallinity, surface area and uniform film morphology, resulting in the significantly improved PV performance with the overall conversion efficiency of 2.61% in dye-sensitized solar cell (DSSC) fabricated with sheet-sphere ZnO. It is notable that the ZnO materials with sphere structure may be the optimal photo-anode material among various ZnO nanomaterials for DSSC. (author)

Equipment of high sensitivity to detect smuggled radioactive materials transported across the ''east-west'' border

International Nuclear Information System (INIS)

Antonovski, A.; Kagan, L.; Stavrov, A.

1998-01-01

An equipment specially developed for the customs radiation control is described. Its sensitivity is higher than requirements of western countries. The equipment ensures an alarm when a radioactive source (both shielded or not) is found in the controlled area, localizes and identifies the source detected, and provides the radiation protection of customs personnel. Most of devices have a non-volatile memory where the radiation situation history is stored and then transferred to PC. The equipment may be used by personnel of special services for secret detection of radioactive materials. Some Belarussian and Russian documents specifying measures to prevent an unauthorized transportation of radioactive materials are discussed. (author)

Ultra-Weak Fiber Bragg Grating Sensing Network Coated with Sensitive Material for Multi-Parameter Measurements

OpenAIRE

Bai, Wei; Yang, Minghong; Hu, Chenyuan; Dai, Jixiang; Zhong, Xuexiang; Huang, Shuai; Wang, Gaopeng

2017-01-01

A multi-parameter measurement system based on ultra-weak fiber Bragg grating (UFBG) array with sensitive material was proposed and experimentally demonstrated. The UFBG array interrogation principle is time division multiplex technology with two semiconductor optical amplifiers as timing units. Experimental results showed that the performance of the proposed UFBG system is almost equal to that of traditional FBG, while the UFBG array system has obvious superiority with potential multiplexing ...

Effects of culture-sensitive adaptation of patient information material on usefulness in migrants: a multicentre, blinded randomised controlled trial.

Science.gov (United States)

Hölzel, Lars P; Ries, Zivile; Kriston, Levente; Dirmaier, Jörg; Zill, Jördis M; Rummel-Kluge, Christine; Niebling, Wilhelm; Bermejo, Isaac; Härter, Martin

2016-11-23

To evaluate the usefulness of culture-sensitive patient information material compared with standard translated material. Multicentre, double-blind randomised controlled trial. 37 primary care practices. 435 adult primary care patients with a migration background with unipolar depressive disorder or non-specific chronic low back pain were randomised. Patients who were unable to read in the language of their respective migration background were excluded. Sufficient data were obtained from 203 women and 106 men. The largest group was of Russian origin (202 patients), followed by those of Turkish (52), Polish (30) and Italian (25) origin. Intervention group: provision of culture-sensitive adapted material. provision of standard translated material. Primary outcome: patient-rated usefulness (USE) assessed immediately after patients received the material. patient-rated usefulness after 8 weeks and 6 months, symptoms of depression (PHQ-9), back pain (Back Pain Core Set) and quality of life (WHO-5) assessed at all time points. Usefulness was found to be significantly higher (t=1.708, one-sided p=0.04) in the intervention group (USE-score=65.08, SE=1.43), compared with the control group (61.43, SE=1.63), immediately after patients received the material, in the intention-to-treat analysis, with a mean difference of 3.65 (one-sided 95% lower confidence limit=0.13). No significant differences were found for usefulness at follow-up (p=0.16, p=0.71). No significant effect was found for symptom severity in depression (p=0.95, p=0.66, p=0.58), back pain (p=0.40, p=0.45, p=0.32) or quality of life (p=0.76, p=0.86, p=0.21), either immediately after receiving the material, or at follow-up (8 weeks; 6 months). Patients with a lower level of dominant society immersion benefited substantially and significantly more from the intervention than patients with a high level of immersion (p=0.005). Cultural adaptation of patient information material provides benefits over high quality

Lower-energy neutron sources for increasing the sensitivity of nuclear gages for measuring the water content of bulk materials

International Nuclear Information System (INIS)

Bailey, S.M.

1977-01-01

The sensitivity of a gage using a nuclear source for measuring the water content of bulk materials, such as plastic concrete, is increased by use of a lithium or fluorine neutron nuclear source. 3 figures

Sensitivity of corneal biomechanical and optical behavior to material parameters using design of experiments method.

Science.gov (United States)

Xu, Mengchen; Lerner, Amy L; Funkenbusch, Paul D; Richhariya, Ashutosh; Yoon, Geunyoung

2018-02-01

The optical performance of the human cornea under intraocular pressure (IOP) is the result of complex material properties and their interactions. The measurement of the numerous material parameters that define this material behavior may be key in the refinement of patient-specific models. The goal of this study was to investigate the relative contribution of these parameters to the biomechanical and optical responses of human cornea predicted by a widely accepted anisotropic hyperelastic finite element model, with regional variations in the alignment of fibers. Design of experiments methods were used to quantify the relative importance of material properties including matrix stiffness, fiber stiffness, fiber nonlinearity and fiber dispersion under physiological IOP. Our sensitivity results showed that corneal apical displacement was influenced nearly evenly by matrix stiffness, fiber stiffness and nonlinearity. However, the variations in corneal optical aberrations (refractive power and spherical aberration) were primarily dependent on the value of the matrix stiffness. The optical aberrations predicted by variations in this material parameter were sufficiently large to predict clinically important changes in retinal image quality. Therefore, well-characterized individual variations in matrix stiffness could be critical in cornea modeling in order to reliably predict optical behavior under different IOPs or after corneal surgery.

Preparation of thermo-sensitive slow releasing material and its application in low tar tobacco

Directory of Open Access Journals (Sweden)

Tian Zhong

2017-04-01

Full Text Available To solve some sensory defects such as fragrance deficiency,strong dry sense,poor satisfaction in the development of ultra-low tar tobacco products,we prepared a new thermo sensitive slow releasing composite material with tobacco aroma.The characterization results showed that the as-prepared thermosensitive particles have better aroma enhancing and slow releasing effects.Also,the aroma components of the tip stick containing thermosensitive particles were detected and its sensory quality was evaluated.The results showed that composite tip stick could enhance the aroma and improve the sensory quality of the cigarettes.

Effect of annealing temperature and dopant concentration on the thermoluminescence sensitivity in LiF:Mg,Cu,Ag material.

Science.gov (United States)

Yahyaabadi, Akram; Torkzadeh, Falamarz; Rezaei Ochbelagh, Dariush; Hosseini Pooya, Seyed Mahdi

2018-04-24

LiF:Mg,Cu,Ag is a new dosimetry material that is similar to LiF:Mg,Cu,P in terms of dosimetric properties. The effect of the annealing temperature in the range of 200 to 350°C on the thermoluminescence (TL) sensitivity and the glow curve structure of this material at different concentrations of silver (Ag) was investigated. It has been demonstrated that the optimum values of the annealing temperature and the Ag concentration are 240°C and 0.1 mol% for better sensitivity, respectively. The TL intensity decreases at annealing temperatures lower than 240°C or higher than 240°C, reaching a minimum at 300°C and then again increases for various Ag concentrations. It was observed that the glow curve structure altered and the area under the low temperature peak as well as the area under the main dosimetric peak decreased with increasing annealing temperature. The position of the main dosimetric peak moved in the direction of higher temperatures, but at 320 and 350°C annealing temperatures, it shifted to lower temperatures. It was also observed that the TL sensitivity could partially be recovered by a combined annealing procedure. Copyright © 2018 John Wiley & Sons, Ltd.

Studies on radiation-sensitive nonsilver halide materials, (2)

International Nuclear Information System (INIS)

Komizu, Hideo; Honda, Koichi; Yabe, Akira; Kawasaki, Masami; Yamanaka, Takeshi.

1980-01-01

Dye-precursors made from furfural and some aniline derivatives become red-colored upon irradiation with ionization radiatios in PVC matrix, forming Stenhouse salts with the HCl evolved from the matrix. The coloration of the precursor from N-methylaniline, having the most excellent potential for dosimetry among the precursors, was studied for the irradiation of electron beam (60 kV) and X-ray (50 - 240 kVp). The following conclusions were obtained for the electron beam bombardment. (1) The response range is 10 -8 - 10 -6 C/cm 2 or 10 3 - 10 5 rad, where good linearity between coloration and charge density exists. (2) The highest sensitivity is obtained when the concentration of the precursor is >=5 wt% for the amount of PVC and the film thickness is >=32 μm. (3) Addition of 25 wt% of DOP enhances not only the sensitivity by ca. 20% but also the stability of the color from several days to several months. (4) The sensitivity is increased by ca. 15% when a conductive base is used for the film. (5) G value for the formation of the dye, i.e., that for the formation of HCl is 13.5 - 15.5. The followings were obtained for the irradiation of X-ray. (1) The response range is 10 3 - 10 5 R or rad. (2) The sensitivity for the absorbed dose is independent of the energy but is approximately proportional to the film thickness. (3) The sensitivity is higher than that for electrons by the factor of ca. 1.6, reflecting the higher G(HCl) value, 23 - 25. (author)

Ultra-Weak Fiber Bragg Grating Sensing Network Coated with Sensitive Material for Multi-Parameter Measurements

Directory of Open Access Journals (Sweden)

Wei Bai

2017-06-01

Full Text Available A multi-parameter measurement system based on ultra-weak fiber Bragg grating (UFBG array with sensitive material was proposed and experimentally demonstrated. The UFBG array interrogation principle is time division multiplex technology with two semiconductor optical amplifiers as timing units. Experimental results showed that the performance of the proposed UFBG system is almost equal to that of traditional FBG, while the UFBG array system has obvious superiority with potential multiplexing ability for multi-point and multi-parameter measurement. The system experimented on a 144 UFBG array with the reflectivity of UFBG ~0.04% for the four target parameters: hydrogen, humidity, temperature and salinity. Moreover, a uniform solution was customized to divide the cross-sensitivity between temperature and other target parameters. It is expected that this scheme will be capable of handling thousands of multi-parameter sensors in a single fiber.

Ultra-Weak Fiber Bragg Grating Sensing Network Coated with Sensitive Material for Multi-Parameter Measurements.

Science.gov (United States)

Bai, Wei; Yang, Minghong; Hu, Chenyuan; Dai, Jixiang; Zhong, Xuexiang; Huang, Shuai; Wang, Gaopeng

2017-06-26

A multi-parameter measurement system based on ultra-weak fiber Bragg grating (UFBG) array with sensitive material was proposed and experimentally demonstrated. The UFBG array interrogation principle is time division multiplex technology with two semiconductor optical amplifiers as timing units. Experimental results showed that the performance of the proposed UFBG system is almost equal to that of traditional FBG, while the UFBG array system has obvious superiority with potential multiplexing ability for multi-point and multi-parameter measurement. The system experimented on a 144 UFBG array with the reflectivity of UFBG ~0.04% for the four target parameters: hydrogen, humidity, temperature and salinity. Moreover, a uniform solution was customized to divide the cross-sensitivity between temperature and other target parameters. It is expected that this scheme will be capable of handling thousands of multi-parameter sensors in a single fiber.

Mathematical model of the heat transfer process taking into account the consequences of nonlocality in structurally sensitive materials

Science.gov (United States)

Kuvyrkin, G. N.; Savelyeva, I. Y.; Kuvshynnikova, D. A.

2018-04-01

Creation of new materials based on nanotechnology is an important direction of modern materials science development. Materials obtained using nanotechnology can possess unique physical-mechanical and thermophysical properties, allowing their effective use in structures exposed to high-intensity thermomechanical effects. An important step in creation and use of new materials is the construction of mathematical models to describe the behavior of these materials in a wide range of changes under external effects. The model of heat conduction of structural-sensitive materials is considered with regard to the medium nonlocality effects. The relations of the mathematical model include an integral term describing the spatial nonlocality of the medium. A difference scheme, which makes it possible to obtain a numerical solution of the problem of nonstationary heat conduction with regard to the influence of the medium nonlocality on space, has been developed. The influence of the model parameters on the temperature distributions is analyzed.

Critical study of some soft-tissue equivalent material. Sensitivity to neutrons of 1 keV to 14 MeV

International Nuclear Information System (INIS)

Kerviler, H. de; Pages, L.; Tardy-Joubert, Ph.

1965-01-01

Authors have studied the elastic and inelastic reactions on various elements contribution to kerma in standard soft tissue and as a function of neutron energy from 1 keV to 14 MeV the ratio of kerma in tissue equivalent material to kerma in soft tissue. The results of calculations are made for materials without hydrogen in view to state exactly their neutron sensitivity and for the following hydrogenous materials: Rossi and Failla plastic, MixD, pure polyethylene and a new CEA tissue equivalent (a magnesium fluoride and polyethylene compound). Results for γ-rays are given. (authors) [fr

Development of Novel Polymeric Materials for Gene Therapy and pH-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, and Analysis

Energy Technology Data Exchange (ETDEWEB)

Anderson, Brian Curtis [Iowa State Univ., Ames, IA (United States)

2002-01-01

The underlying theme of this thesis is the use of polymeric materials in bioapplications. Chapters 2-5 either develop a fundamental understanding of current materials used for bioapplications or establish protocols and procedures used in characterizing and synthesizing novel materials. In chapters 6 and 7 these principles and procedures are applied to the development of materials to be used for gene therapy and drug delivery. Chapter one is an introduction to the ideas that will be necessary to understand the subsequent chapters, as well as a literature review of these topics. Chapter two is a paper that has been published in the ''Journal of Controlled Release'' that examines the mechanism of drug release from a polymer gel, as well as experimental design suggestions for the evaluation of water soluble drug delivery systems. Chapter three is a paper that has been published in the ''Journal of Pharmaceutical Sciences'' that discusses the effect ionic salts have on properties of the polymer systems examined in chapter two. Chapter four is a paper published in the Materials Research Society Fall 2000 Symposium Series dealing with the design and synthesis of a pH-sensitive polymeric drug delivery device. Chapter five is a paper that has been published in the journal ''Biomaterials'' proposing a novel polymer/metal composite for use as a biomaterial in hip arthroplasty surgery. Chapter six is a paper that will appear in an upcoming volume of the Journal ''Biomaterials'' dealing with the synthesis of a novel water soluble cationic polymer with possible applications in non-viral gene therapy. Chapter seven is a paper that has been submitted to ''Macromolecules'' discussing several novel block copolymers based on poly(ethylene glycol) and poly(diethylamino ethyl methacrylate) that possess both pH-sensitive and temperature sensitive properties. Chapter eight contains a

Development of active and sensitive material systems based on composites

Science.gov (United States)

Asanuma, Hiroshi

2002-07-01

This paper describes new concepts proposed by the author to realize active and sensitive structural material systems. Two examples of multifunctional composites were fabricated and evaluated in this study as follows: (1) An active laminate of aluminum plate (works as muscle), epoxy film (as insulator), unidirectional CFRP prepreg (as bone and blood vessel) and copper foil electrode (to apply voltage on CFRP) was made with an embedded optical fiber multiply fractured in the CFRP layer (works as nerve), of which curvature change could be effectively monitored with the fractured optical fiber. (2) A stainless steel fiber/aluminum active composite with embedded Ti oxide/Ti composite fiber was fabricated. The Ti oxide/Ti fiber could work as a sensor for temperature by removing a part of the oxide before embedment to make a metallic contact between the embedded titanium fiber and aluminum matrix to be able to generate thermal electromotive force, and also could work as a sensor for strain and as a heater for actuation. In the both cases, the outputs from their embedded sensors can be used to control their actuations.

Thermo-sensitive intelligent track membrane

International Nuclear Information System (INIS)

Pang Deling; Ren Lihua; Qian Zhilin; Huang Gang; Zhang Jinhua

1999-01-01

Using N-isopropylacryl-amide (NIP AAm) thermo-sensitive function material as monomer and nuclear track microporous membrane (NTMM) as baseline material, a thermo-sensitive intelligent track membrane (TsITM) has been prepared by the over-oxidization and pre-irradiation grafting techniques. The TsITM can be used to make a micro-switch controlled by temperature and to adjust particle screening and osmosis. To obtain sub-micron responsive grafted track pores only a very thin thermo-sensitive layer is needed. The TsITM pores are capable of swelling and shrinking rapidly and respond more sensitively to temperature

Analysis of Catalytic Material Effect on the Photovoltaic Properties of Monolithic Dye-sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Natalita Maulani Nursam

2017-12-01

Full Text Available Dye-sensitized solar cells (DSSC are widely developed due to their attractive appearance and simple fabrication processes. One of the challenges that arise in the DSSC fabrication involves high material cost associated with the cost of conductive substrate. DSSC with monolithic configuration was then developed on the basis of this motivation. In this contribution, titanium dioxide-based monolithic type DSSCs were fabricated on a single fluorine-doped transparent oxide coated glass using porous ZrO2 as spacer. Herein, the catalytic material for the counter-electrode was varied using carbon composite and platinum in order to analyze their effect on the solar cell efficiency. Four-point probe measurement revealed that the carbon composite exhibited slightly higher conductivity with a sheet resistance of 9.8 Ω/sq and 10.9 Ω/sq for carbon and platinum, respectively. Likewise, the photoconversion efficiency of the monolithic cells with carbon counter-electrode almost doubled the efficiency of the cells with platinum counter-electrode. Our results demonstrate that carbon could outperform the performance of platinum as catalytic material in monolithic DSSC.

Microstructure and gas sensitive properties of alpha-Fe2O3-MO2 (M: Sn and Ti) materials prepared by ball milling

DEFF Research Database (Denmark)

Jiang, Jianzhong; Lin, R.; Mørup, Steen

1998-01-01

Metastable alpha-Fe2O3-MO2 (M: Sn and Ti) solid solutions can be synthesized by mechanical alloying. The alloy formation, microstructure, and gas sensitive properties of mechanically milled alpha-Fe2O3-SnO2 materials are discussed. Tin ions in alpha-Fe2O3 are found to occupy the empty octahedral...... holes in the alpha-Fe2O3 lattice. This interstitial model can also describe the structure of alpha-Fe2O3-TiO2 solid solutions. Finally, a correlation of gas sensitive properties with microstructure of alpha-Fe2O3-SnO2 materials is presented....

Investigation of Thermal Interface Materials Using Phase-Sensitive Transient Thermoreflectance Technique: Preprint

Energy Technology Data Exchange (ETDEWEB)

Feng, X.; King, C.; DeVoto, D.; Mihalic, M.; Narumanchi, S.

2014-08-01

With increasing power density in electronics packages/modules, thermal resistances at multiple interfaces are a bottleneck to efficient heat removal from the package. In this work, the performance of thermal interface materials such as grease, thermoplastic adhesives and diffusion-bonded interfaces are characterized using the phase-sensitive transient thermoreflectance technique. A multi-layer heat conduction model was constructed and theoretical solutions were derived to obtain the relation between phase lag and the thermal/physical properties. This technique enables simultaneous extraction of the contact resistance and bulk thermal conductivity of the TIMs. With the measurements, the bulk thermal conductivity of Dow TC-5022 thermal grease (70 to 75 um bondline thickness) was 3 to 5 W/(m-K) and the contact resistance was 5 to 10 mm2-K/W. For the Btech thermoplastic material (45 to 80 μm bondline thickness), the bulk thermal conductivity was 20 to 50 W/(m-K) and the contact resistance was 2 to 5 mm2-K/W. Measurements were also conducted to quantify the thermal performance of diffusion-bonded interface for power electronics applications. Results with the diffusion-bonded sample showed that the interfacial thermal resistance is more than one order of magnitude lower than those of traditional TIMs, suggesting potential pathways to efficient thermal management.

First Principle Modelling of Materials and Processes in Dye-Sensitized Photoanodes for Solar Energy and Solar Fuels

Directory of Open Access Journals (Sweden)

Mariachiara Pastore

2017-01-01

Full Text Available In the context of solar energy exploitation, dye-sensitized solar cells and dye-sensitized photoelectrosynthetic cells offer the promise of low-cost sunlight conversion and storage, respectively. In this perspective we discuss the main successes and limitations of modern computational methodologies, ranging from hybrid and long-range corrected density functionals, GW approaches and multi-reference perturbation theories, in describing the electronic and optical properties of isolated components and complex interfaces relevant to these devices. While computational modelling has had a crucial role in the development of the dye-sensitized solar cells technology, the theoretical characterization of the interface structure and interfacial processes in water splitting devices is still at its infancy, especially concerning the electron and hole transfer phenomena. Quantitative analysis of interfacial charge separation and recombination reactions in multiple metal-oxide/dye/catalyst heterointerfaces, thus, undoubtedly represents the compelling challenge in the field of modern computational material science.

Dye-Sensitized Solar Cells Based on the Principles and Materials of Photosynthesis: Mechanisms of Suppression and Enhancement of Photocurrent and Conversion Efficiency

Directory of Open Access Journals (Sweden)

Hiroyoshi Nagae

2009-10-01

Full Text Available Attempts have been made to develop dye-sensitized solar cells based on the principles and materials of photosynthesis: We first tested photosynthetic pigments, carotenoids (Cars, chlorophylls (Chls and their derivatives, to find sensitizers showing reasonable performance (photocurrent and conversion efficiency. We then tried to introduce the principles of photosynthesis, including electron transfer and energy transfer from Car to Phe a. Also, we tried co-sensitization using the pheophorbide (Phe a and Chl c2 pair which further enhanced the performance of the component sensitizers as follows: Jsc = 9.0 + 13.8 → 14.0 mA cm–2 and η = 3.4 + 4.6 → 5.4%.

Dye-sensitized solar cells based on the principles and materials of photosynthesis: mechanisms of suppression and enhancement of photocurrent and conversion efficiency.

Science.gov (United States)

Koyama, Yasushi; Miki, Takeshi; Wang, Xiao-Feng; Nagae, Hiroyoshi

2009-10-27

Attempts have been made to develop dye-sensitized solar cells based on the principles and materials of photosynthesis: We first tested photosynthetic pigments, carotenoids (Cars), chlorophylls (Chls) and their derivatives, to find sensitizers showing reasonable performance (photocurrent and conversion efficiency). We then tried to introduce the principles of photosynthesis, including electron transfer and energy transfer from Car to Phe a. Also, we tried co-sensitization using the pheophorbide (Phe) a and Chl c(2) pair which further enhanced the performance of the component sensitizers as follows: J(sc) = 9.0 + 13.8 --> 14.0 mA cm(-2) and eta = 3.4 + 4.6 --> 5.4%.

Aluminum-Doped SnO2 Hollow Microspheres as Photoanode Materials for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Binghua Xu

2016-01-01

Full Text Available Al doped SnO2 microspheres were prepared through hydrothermal method. As-prepared SnO2 microspheres were applied as photoanode materials in dye-sensitized solar cells (DSCs. The properties of the assembled DSCs were significantly improved, especially the open-circuit voltage. The reason for the enhancement was explored through the investigation of dark current curves and electrochemistry impedance spectra. These results showed that the Al doping significantly increased the reaction resistance of recombination reactions and restrained the dark current. The efficient lifetime of photoexcited electrons was also obviously lengthened.

Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

Energy Technology Data Exchange (ETDEWEB)

Sobolik, S.R.; Ho, C.K.; Dunn, E. [Sandia National Labs., Albuquerque, NM (United States); Robey, T.H. [Spectra Research Inst., Albuquerque, NM (United States); Cruz, W.T. [Univ. del Turabo, Gurabo (Puerto Rico)

1996-07-01

The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document.

Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

International Nuclear Information System (INIS)

Sobolik, S.R.; Ho, C.K.; Dunn, E.; Robey, T.H.; Cruz, W.T.

1996-07-01

The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document

Further important sensitizers in patients sensitive to fragrances

DEFF Research Database (Denmark)

Frosch, P J; Johansen, J D; Menné, T

2002-01-01

In order to find sensitizers additional to the current fragrance mix (FM) a series of fragrance materials (series II) was evaluated in 6 dermatological centres in Europe. 11 of the test materials were essential oils, the remaining 7 being either mixtures of isomers or simple chemicals of frequent...... materials with the highest reactivity after the FM were ylang-ylang oil (YY) I (2.6%), YY II (2.5%), lemongrass oil (1.6%), narcissus absolute (1.3%), jasmine absolute (1.2%) and sandalwood oil (0.9%). 48 (3.0%) of the patients reacted only to materials of series II and not to FM. 6.0% of 1606 patients gave...

DNA-dispersed graphene/NiO hybrid materials for highly sensitive non-enzymatic glucose sensor

International Nuclear Information System (INIS)

Lv Wei; Jin Fengmin; Guo Quangui; Yang Quanhong; Kang Feiyu

2012-01-01

Highlights: ► We investigated the potential of GNS/NiO/DNA hybrid used as a nonenzymatic sensor. ► DNA is a highly efficient disperse agent for GNS/NiO hybrid than ionic surfactants. ► GNS/NiO/DNA hybrid shows fast electron transfer in the electrochemical reaction. ► GNS/NiO/DNA hybrid shows good detection performance towards glucose. - Abstract: We demonstrate graphene nanosheet/NiO hybrids (GNS/NiO) as the active material for high-performance non-enzymatic glucose sensors. Such sensors are fabricated by DNA-dispersed GNS/NiO suspension deposited on glassy carbon electrodes. ss-DNA shows strong dispersing ability for the GNS/NiO hybrid materials resulting in stable water-dispersible GNS/NiO/DNA hybrids with fully separated layers. The GNS/NiO/DNA hybrids show enhanced electron transfer in the electrocatalytic reaction process, and accordingly, such hybrids modified electrodes show good sensing performance towards glucose and are characterized by large detection ranges, short response periods, low detection limit and high sensitivity and stability.

Superconducting Gamma/Neutron Spectrometer Task 1 Completion Report Evaluation of Candidate Neutron-Sensitive Materials

CERN Document Server

Bell, Z W

2002-01-01

A review of the scientific literature regarding boron- and lithium-containing compounds was completed. Information such as Debye temperature, heat capacity, superconductivity properties, physical and chemical characteristics, commercial availability, and recipes for synthesis was accumulated and evaluated to develop a list of neutron-sensitive materials likely to perform properly in the spectrometer. The best candidate borides appear to be MgB sub 2 (a superconductor with T sub c = 39 K), B sub 6 Si, B sub 4 C, and elemental boron; all are commercially available. Among the lithium compounds are LiH, LiAl, Li sub 1 sub 2 Si sub 7 , and Li sub 7 Sn sub 2. These materials have or are expected to have high Debye temperatures and sufficiently low heat capacities at 100 mK to produce a useful signal. The responses of sup 1 sup 0 B and sup 6 Li to a fission neutron spectrum were also estimated. These demonstrated that the contribution of scattering events is no more than 3% in a boron-based system and 1.5% in a lith...

Photoelectrochemical characteristics of dye-sensitized solar cells incorporating innovative and inexpensive materials

Science.gov (United States)

Harlow, Lisa Jean

The use of energy is going to continue to increase rapidly due to population and economic advances occurring throughout the world. The most widely used energies produce carbon dioxide during their combustion and have finite limits on how much of these resources are available. A strong push to utilizing renewable energy is necessary to keep up with the demand. The only renewable energy that has unlimited supply is solar. Our goal is to find cost-effective alternatives to historically the most extensively used materials in dye-sensitized solar cells. In order to rely on efficiency changes coinciding with the introduction of a new component, a standard baseline of performance is necessary to establish. A reproducible fabrication procedure composed of standard materials was instituted; the efficiency parameters exhibited a less than 10% standard deviation for any set of solar cells. Any modifications to the cell components would be apparent in the change in efficiency. Our cell modifications focused on economical alternatives to the electrolyte, the counter electrode and the chromophore. Solution-based electrolytes were replaced with a non-volatile ionic liquid, 1-methyl-3-propylimidazolium iodide, and then a poly(imidazole-functionalized) silica nanoparticle. Solid-state electrolytes reduce or prevent leakage and could ease manufacturing in large-scale devices. Platinum has been the counter electrode catalyst primarily used with the iodide/triiodide redox couple, but is a rare metal making it rather costly. We reduce platinum loading by introducing a novel counter electrode that employs platinum nanoparticles embedded on a graphene nanoplatelet paper. The highly conductive carbon base also negates the use of the expensive conductive substrate necessary for the platinum catalyst, further reducing cost. We also study the differences in transitioning from ruthenium polypyridyls to iron-based chromophores in dye-sensitized solar cells. Iron introduces low-lying ligand

Nano-particle doped hydroxyapatite material evaluation using spectroscopic polarization sensitive optical coherence tomography

Science.gov (United States)

Strąkowska, Paulina; Trojanowski, Michał; Gardas, Mateusz; Głowacki, Maciej J.; Kraszewski, Maciej; Strąkowski, Marcin R.

2015-03-01

Bio-ceramics such as hydroxyapatite (HAp) are widely used materials in medical applications, especially as an interface between implants and living tissues. There are many ways of creating structures from HAp like electrochemical assisted deposition, biomimetic, electrophoresis, pulsed laser deposition or sol-gel processing. Our research is based on analyzing the parameters of the sol-gel method for creating thin layers of HAp. In order to achieve this, we propose to use Optical Coherence Tomography (OCT) for non-destructive and non-invasive evaluation. Our system works in the IR spectrum range, which is helpful due to the wide range of nanocomposites being opaque in the VIS range. In order to use our method we need to measure two samples, one which is a reference HAp solution and second: a similar HAp solution with nanoparticles introduced inside. We use silver nanoparticles below 300 nm. The aim of this research is to analyze the concentration and dispersion of nanodopants in the bio-ceramic matrix. Furthermore, the quality of the HAp coating and deposition process repetition have been monitored. For this purpose the polarization sensitive OCT with additional spectroscopic analysis is being investigated. Despite the other methods, which are suitable for nanocomposite materials evaluation, the OCT with additional features seems to be one of the few which belong to the NDE/NDT group. Here we are presenting the OCT system for evaluation of the HAp with nano-particles, as well as HAp manufacturing process. A brief discussion on the usefulness of OCT for bio-ceramics materials examination is also being presented.

Performance Maintenance of Dye-Sensitized Solar Cells Using a Latent Heat Storage Material

Science.gov (United States)

Haruki, Naoto; Horibe, Akihiko

2017-07-01

Recently, there has been considerable interest in various renewable energies. Among them, solar cell production has increased markedly because the photovoltaic is a clean and safe power generation method. The dye-sensitized solar cell (DSSC) has attracted much attention as an alternative to silicon solar cells due to lower manufacturing costs and plentiful resources for DSSC production. However, the performance of DSSCs has been limited by their durability and low photoelectric conversion efficiency. Temperature control of DSSCs via phase-change materials (PCMs) is expected to improve performance. In this study, DSSCs were heated or cooled with a heat exchanger copper block that was in contact with a PCM (heptadecane), while being irradiated by a solar simulator light source. The durability and photoelectric conversion efficiency of the DSSC improved under PCM temperature control.

Relationship between RDX properties and sensitivity

Energy Technology Data Exchange (ETDEWEB)

Doherty, Ruth M. [Research, Development, Test and Evaluation Directorate, Naval Surface Warfare Center Indian Head Division, Indian Head, MD 20640-5102 (United States); Watt, Duncan S. [Novare, Level 6 80 Petrie Terrace, Brisbane 4000 (Australia)

2008-02-15

An interlaboratory comparison of seven lots of commercially available RDX was conducted to determine what properties of the nitramine particles can be used to assess whether the RDX has relatively high or relatively low sensitivity. The materials chosen for the study were selected to give a range of HMX content, manufacturing process and reported shock sensitivity. The results of two different shock sensitivity tests conducted on a PBX made with the RDX lots in the study showed that there are measurable differences in the shock sensitivity of the PBXs, but the impact sensitivity for all of the lots is essentially the same. Impact sensitivity is not a good predictor of shock sensitivity for these types of RDX. Although most RDX that exhibits RS has low HMX content, that characteristic alone is not sufficient to guarantee low sensitivity. A range of additional analytical chemistry tests were conducted on the material; two of these (HPLC and DSC) are discussed within. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Radiation-sensitive diacrylates

International Nuclear Information System (INIS)

Demajistre, R.

1976-01-01

Novel diacrylates are prepared by reacting a monohydroxylated acrylic monomer with a polyisocyanate. The reaction product may be polymerized by subjecting to ionizing irradiation, actinic light or to free radical catalysts to form a useful coating material. The diacrylates may also be copolymerized with other radiation sensitive materials. 6 claims, no drawings

Undoped and doped poly(tetraphenylbenzidine) as sensitive material for an impedimetric nitrogen dioxide gas dosimeter

Energy Technology Data Exchange (ETDEWEB)

Marr, I.; Moos, R., E-mail: functional.materials@uni-bayreuth.de [Department of Functional Materials, University of Bayreuth, Bayreuth 95440 (Germany); Neumann, K.; Thelakkat, M. [Department of Macromolecular Chemistry I, Applied Functional Polymers, University of Bayreuth, Bayreuth 95440 (Germany)

2014-09-29

This article presents a nitrogen dioxide (NO{sub 2}) detecting gas dosimeter based on poly(tetraphenylbenzidine) poly(TPD) as nitrogen oxide (NO{sub x}) sensitive layer. Gas dosimeters are suitable devices to determine reliably low levels of analytes over a long period of time. During NO{sub x} exposure, the analyte molecules are accumulated irreversibly in the sensing layer of the dosimeter enhancing the conductivity of the hole conducting poly(TPD), which can be measured by impedance spectroscopy. Due to their possibility for low cost production by simple printing techniques and very good physical, photochemical, and electrochemical properties, poly(TPD)s are suitable for application in gas dosimeters operated at room temperature. We studied the effect of doping with a Co(III)-complex in combination with a conducting salt on the dosimeter behavior. Compared to the undoped material, a strong influence of the doping can be observed: the conductivity of the sensing material increases significantly, the noise of the signal decreases and an unwanted recovery of the sensor signal can be prevented, leading to a NO{sub x} detection limit <10 ppm.

Sensitization of Parker fittings

International Nuclear Information System (INIS)

Wilber, W.W.

1985-09-01

At your request, ferrules from 316 SS Parker-Hannifen compression fittings at the FFTF have been examined and evaluated to determine the metallurgical condition as related to carbide precipitation in grain boundaries (known as sensitization) and the implications this may have with regard to corrosion resistance. To accomplish this, two ferrules from new stock, two ferrules from old stock and two ferrules that had seen service were examined metallurgically. The samples were prepared for optical metallography. They were viewed in both the etched and unetched condition and analyzed on the scanning electron microscope (SEM) for elemental content. It was confirmed that the ferrules from new stock had a 5 mil thick nitrided layer on the ferrule ID at the lead end and that the 316 SS ferrule material was in the sensitized condition, indicating low resistance to aqueous corrosion. The material from old stock had no nitride layer but was in the sensitized condition indicating low resistance to aqueous corrosion. The ferrules that had seen service had not been nitrided and were not sensitized indicating high resistance to aqueous corrosion

Safer energetic materials by a nanotechnological approach

Science.gov (United States)

Siegert, Benny; Comet, Marc; Spitzer, Denis

2011-09-01

Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity. Electronic supplementary information (ESI) available: Experimental details for the preparation of the V2O5@CNF/Al nanothermite; X-ray diffractogram of the V2O5@CNF/Al combustion residue; installation instructions and source code for the nt-timeline program. See DOI: 10.1039/c1nr10292c

Singlet oxygen sensitizing materials based on porous silicone: photochemical characterization, effect of dye reloading and application to water disinfection with solar reactors.

Science.gov (United States)

Manjón, Francisco; Santana-Magaña, Montserrat; García-Fresnadillo, David; Orellana, Guillermo

2010-06-01

Photogeneration of singlet molecular oxygen ((1)O(2)) is applied to organic synthesis (photooxidations), atmosphere/water treatment (disinfection), antibiofouling materials and in photodynamic therapy of cancer. In this paper, (1)O(2) photosensitizing materials containing the dyes tris(4,4'-diphenyl-2,2'-bipyridine)ruthenium(II) (1, RDB(2+)) or tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) (2, RDP(2+)), immobilized on porous silicone (abbreviated RDB/pSil and RDP/pSil), have been produced and tested for waterborne Enterococcus faecalis inactivation using a laboratory solar simulator and a compound parabolic collector (CPC)-based solar photoreactor. In order to investigate the feasibility of its reuse, the sunlight-exposed RDP/pSil sensitizing material (RDP/pSil-a) has been reloaded with RDP(2+) (RDP/pSil-r). Surprisingly, results for bacteria inactivation with the reloaded material have demonstrated a 4-fold higher efficiency compared to those of either RDP/pSil-a, unused RDB/pSil and the original RDP/pSil. Surface and bulk photochemical characterization of the new material (RDP/pSil-r) has shown that the bactericidal efficiency enhancement is due to aggregation of the silicone-supported photosensitizer on the surface of the polymer, as evidenced by confocal fluorescence lifetime imaging microscopy (FLIM). Photogenerated (1)O(2) lifetimes in the wet sensitizer-doped silicone have been determined to be ten times longer than in water. These facts, together with the water rheology in the solar reactor and the interfacial production of the biocidal species, account for the more effective disinfection observed with the reloaded photosensitizing material. These results extend and improve the operational lifetime of photocatalytic materials for point-of-use (1)O(2)-mediated solar water disinfection.

A novel detector based on dual-mode fiber polished half block's characteristics for sensitive monitorings of radiation and materials

International Nuclear Information System (INIS)

Saeed, Ghadirli

2005-01-01

Full text : The overlay index dependence characteristics of the power distribution between two modes of dual-mode fiber polished half blocks is studied. The heat dependence characteristics of a certain overlay index affects the modal power distributions at the input of interferometer sensors used for monitoring the sensitive heat radiation changes. The other fundamental applications such as material recognitions through the index dependence characteristics in the closed chambers is also suggested

The PRIDE (Partnership to Improve Diabetes Education) Toolkit: Development and Evaluation of Novel Literacy and Culturally Sensitive Diabetes Education Materials.

Science.gov (United States)

Wolff, Kathleen; Chambers, Laura; Bumol, Stefan; White, Richard O; Gregory, Becky Pratt; Davis, Dianne; Rothman, Russell L

2016-02-01

Patients with low literacy, low numeracy, and/or linguistic needs can experience challenges understanding diabetes information and applying concepts to their self-management. The authors designed a toolkit of education materials that are sensitive to patients' literacy and numeracy levels, language preferences, and cultural norms and that encourage shared goal setting to improve diabetes self-management and health outcomes. The Partnership to Improve Diabetes Education (PRIDE) toolkit was developed to facilitate diabetes self-management education and support. The PRIDE toolkit includes a comprehensive set of 30 interactive education modules in English and Spanish to support diabetes self-management activities. The toolkit builds upon the authors' previously validated Diabetes Literacy and Numeracy Education Toolkit (DLNET) by adding a focus on shared goal setting, addressing the needs of Spanish-speaking patients, and including a broader range of diabetes management topics. Each PRIDE module was evaluated using the Suitability Assessment of Materials (SAM) instrument to determine the material's cultural appropriateness and its sensitivity to the needs of patients with low literacy and low numeracy. Reading grade level was also assessed using the Automated Readability Index (ARI), Coleman-Liau, Flesch-Kincaid, Fry, and SMOG formulas. The average reading grade level of the materials was 5.3 (SD 1.0), with a mean SAM of 91.2 (SD 5.4). All of the 30 modules received a "superior" score (SAM >70%) when evaluated by 2 independent raters. The PRIDE toolkit modules can be used by all members of a multidisciplinary team to assist patients with low literacy and low numeracy in managing their diabetes. © 2015 The Author(s).

Of 'other' materialities

DEFF Research Database (Denmark)

Jensen, Ole B.

2016-01-01

within the ‘new materiality’ literature in philosophy as well as in cultural theory. Important lessons are drawn in from across different positions such as non-representational theory, the nonhuman turn, Object-Oriented-Ontology to mention a few. It is argued that to create the necessary materially......In this article, the notion of materialities is rearticulated as an important field for the future of mobilities research. We focus on the intersection between situational mobilities research and design/architecture. The vocabulary and material imaginary developed within the latter are an important...... sensitive imaginary, mobilities research should be looking to architecture and design, as well as it may profit from engaging with these new materially sensitive thinkers. The article ends with some concrete themes for future research inspired by these intersections and identifies ‘material pragmatism...

Assessing the cultural in culturally sensitive printed patient-education materials for Chinese Americans with type 2 diabetes.

Science.gov (United States)

Ho, Evelyn Y; Tran, Henrietta; Chesla, Catherine A

2015-01-01

Type 2 diabetes affects Chinese Americans at an alarming rate. To address this health disparity, research in the area of cultural sensitivity and health literacy provides useful guidelines for creating culturally appropriate health education. In this article, we use discourse analysis to examine a group of locally available, Chinese- and English-language diabetes print documents from a surface level and deep structure level of culture. First, we compared these documents to research findings about printed health information to determine whether and how these documents apply current best practices for health literacy and culturally appropriate health communication. Second, we examined how diabetes as a disease and diabetes management is being constructed. The printed materials addressed surface level culture through the use of Chinese language, pictures, foods, and exercises. From a deeper cultural level, the materials constructed diabetes management as a matter of measurement and control that contrasted with previous research suggesting an alternative construction of balance. A nuanced assessment of both surface and deeper levels of culture is essential for creating health education materials that are more culturally appropriate and can lead to increased health literacy and improved health outcomes.

Consideration on the current status and issues of sensitive information management concerning the physical protection of nuclear material and nuclear facilities

International Nuclear Information System (INIS)

Inamura, Tomoaki; Madarame, Haruki

2009-01-01

The confidentiality system concerning the physical protection of nuclear materials and nuclear facilities was enacted by revision of the Nuclear Reactor Regulation Law in 2005. We made a comparative analysis with the information security in governmental agencies or financial sectors, in order to consider the way the sensitive information management concerning the physical protection of nuclear materials and nuclear facilities should be. The considerations in this paper are as follows. (1) In order to secure a suitable level of security, close cooperation should be achieved among related governmental agencies. (2) A cycle that continuously evaluates whether suitable management is performed should be established. (3) Excessive secretiveness should be eliminated. (4) An information-sharing system among the related persons beyond the frame of governmental agencies and electricity companies should be established. (5) Improvement in the social acceptability of the sensitive information management is important. (6) Although it is important to perform evaluation by the consideration of suitable balance with information disclosure, it is also important that it is positively shown to society. (author)

Comparing the effect of a desensitizing material and a self-etch adhesive on dentin sensitivity after periodontal surgery: a randomized clinical trial

Directory of Open Access Journals (Sweden)

Hila Hajizadeh

2017-07-01

Full Text Available Objectives This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS after periodontal surgery. Materials and Methods Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil S3 Bond (Kuraray Dental, G2: Gluma Desensitizer (Heraeus Kulzer, and G3: placebo (water. The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0, 1 day after treatment (T1, after 1 week (T2, and after 1 month (T3 according to visual analog scale (VAS. Results Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil S3 Bond can have some benefits.

Estimation of beam material random field properties via sensitivity-based model updating using experimental frequency response functions

Science.gov (United States)

Machado, M. R.; Adhikari, S.; Dos Santos, J. M. C.; Arruda, J. R. F.

2018-03-01

Structural parameter estimation is affected not only by measurement noise but also by unknown uncertainties which are present in the system. Deterministic structural model updating methods minimise the difference between experimentally measured data and computational prediction. Sensitivity-based methods are very efficient in solving structural model updating problems. Material and geometrical parameters of the structure such as Poisson's ratio, Young's modulus, mass density, modal damping, etc. are usually considered deterministic and homogeneous. In this paper, the distributed and non-homogeneous characteristics of these parameters are considered in the model updating. The parameters are taken as spatially correlated random fields and are expanded in a spectral Karhunen-Loève (KL) decomposition. Using the KL expansion, the spectral dynamic stiffness matrix of the beam is expanded as a series in terms of discretized parameters, which can be estimated using sensitivity-based model updating techniques. Numerical and experimental tests involving a beam with distributed bending rigidity and mass density are used to verify the proposed method. This extension of standard model updating procedures can enhance the dynamic description of structural dynamic models.

Development and testing of culturally sensitive patient information material for Turkish, Polish, Russian and Italian migrants with depression or chronic low back pain (KULTINFO): study protocol for a double-blind randomized controlled trial.

Science.gov (United States)

Hölzel, Lars P; Ries, Zivile; Zill, Jördis M; Kriston, Levente; Dirmaier, Jörg; Härter, Martin; Bermejo, Isaac

2014-07-04

Many of the approximately 15 million people with a migration background living in Germany (19% of the population) are inadequately reached by existing healthcare provision. In the literature, the necessity for cultural adaptation of information material for patients with a migration background is often cited as a measure for improving healthcare.In this study, culturally sensitive information material will be developed and evaluated for patients with a migration background and depression or chronic low back pain. In this respect, it will be examined whether culturally sensitive information material is judged as more useful by the patients than standard translated patient information without cultural adaptation. The implementation and evaluation of culturally sensitive patient information material will occur in the framework of a double-blind randomized controlled parallel-group study in four study centres in Germany. Primary care patients with a Turkish, Polish, Russian or Italian migration background with a diagnosis of depressive disorder or chronic low back pain will be included and randomly allocated to the intervention group or the control group. In the intervention group, culturally sensitive patient information will be handed to the patient at the end of the physician consultation, while in the control group, standard translated patient information material will be provided. The patients will be surveyed by means of questionnaires following the consultation as well as after 8 weeks and 6 months. In addition to the primary outcome (subjective usefulness), several patient- and physician-rated secondary outcomes will be considered. The study will provide an empirical answer to the question of whether persons with a migration background perceive culturally sensitive patient information material as more useful than translated information material without cultural adaptation. Deutsches Register Klinischer Studien (DRKS-ID) DRKS00004241 and Universal Trial Number

A Highly Sensitive Multicommuted Flow Analysis Procedure for Photometric Determination of Molybdenum in Plant Materials without a Solvent Extraction Step

Directory of Open Access Journals (Sweden)

Felisberto G. Santos

2017-01-01

Full Text Available A highly sensitive analytical procedure for photometric determination of molybdenum in plant materials was developed and validated. This procedure is based on the reaction of Mo(V with thiocyanate ions (SCN− in acidic medium to form a compound that can be monitored at 474 nm and was implemented employing a multicommuted flow analysis setup. Photometric detection was performed using an LED-based photometer coupled to a flow cell with a long optical path length (200 mm to achieve high sensitivity, allowing Mo(V determination at a level of μg L−1 without the use of an organic solvent extraction step. After optimization of operational conditions, samples of digested plant materials were analyzed employing the proposed procedure. The accuracy was assessed by comparing the obtained results with those of a reference method, with an agreement observed at 95% confidence level. In addition, a detection limit of 9.1 μg L−1, a linear response (r=0.9969 over the concentration range of 50–500 μg L−1, generation of only 3.75 mL of waste per determination, and a sampling rate of 51 determinations per hour were achieved.

Rapidly processable radiographic material

International Nuclear Information System (INIS)

Brabandere, L.A. de; Borginon, H.A.; Pattyn, H.A.; Pollet, R.J.

1981-01-01

A new rapidly processable radiographic silver halide material is described for use in mammography and non-destructive testing of industrial materials. The radiographic material is used for direct exposure to penetrating radiation without the use of fluorescent-intensifying screens. It consists of a transparent support with a layer of hydrophilic colloid silver halide emulsion on one or both sides. Examples of the preparation of three different silver halide emulsions are given including the use of different chemical sensitizers. These new radiographic materials have good resistance to the formation of pressure marks in rapid processing apparatus and they have improved sensitivity for direct exposure to penetrating radiation compared to conventional radiographic emulsions. (U.K.)

The monolithic multicell: a tool for testing material components in dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Pettersson, H.; Gruszecki, T. [IVF Industrial Research and Development Corporation, Moelndal (Sweden); Bernhard, R. [IVF Industrial Research and Development Corporation, Moelndal (Sweden); The Royal Institute of Technology, Stockholm (Sweden). Center of Molcular Devices, Department of Chemistry; Haeggman, L.; Gorlov, M.; Boschloo, G.; Edvinsson, T.; Kloo, L.; Hagfeldt, A. [The Royal Institute of Technology, Stockholm (Sweden). Center of Molcular Devices, Department of Chemistry

2006-07-01

A multicell is presented as a tool for testing material components in encapsulated dye-sensitized solar cells. The multicell is based on a four-layer monolithic cell structure and an industrial process technology. Each multicell plate includes 24 individual well-encapsulated cells. A sulfur lamp corrected to the solar spectrum has been used to characterize the cells. Efficiencies up to 6.8% at a light-intensity of 1000 W/m{sup su2} (up to 7.5% at 250 W/m{sup 2}) have been obtained with an electrolyte solution based on {upsilon}-butyrolactone. Additionally, a promising long-term stability at cell efficiencies close to 5% at 1000 W/m{sup 2} has been obtained with an electrolyte based on glutaronitrile. The reproducibility of the cell performance before and after exposure to accelerated testing has been high. This means that the multicell can be used as an efficient tool for comparative performance and stability tests. (author)

Sensitivity analysis explains quasi-one-dimensional current transport in two-dimensional materials

DEFF Research Database (Denmark)

Boll, Mads; Lotz, Mikkel Rønne; Hansen, Ole

2014-01-01

We demonstrate that the quasi-one-dimensional (1D) current transport, experimentally observed in graphene as measured by a collinear four-point probe in two electrode configurations A and B, can be interpreted using the sensitivity functions of the two electrode configurations (configurations...... A and B represents different pairs of electrodes chosen for current sources and potential measurements). The measured sheet resistance in a four-point probe measurement is averaged over an area determined by the sensitivity function. For a two-dimensional conductor, the sensitivity functions for electrode...... configurations A and B are different. But when the current is forced to flow through a percolation network, e.g., graphene with high density of extended defects, the two sensitivity functions become identical. This is equivalent to a four-point measurement on a line resistor, hence quasi-1D transport...

Chemistry of high-energy materials

Energy Technology Data Exchange (ETDEWEB)

Klapoetke, Thomas M. [Ludwig-Maximilians-Univ., Muenchen (Germany). Dept. of Chemistry; Maryland Univ., College Park, MD (US). Center of Energetic Concepts Development (CECD)

2011-07-01

The graduate-level textbook Chemistry of High-Energy Materials provides an introduction to and an overview of primary and secondary (high) explosives as well as propellant charges, rocket propellants and pyrotechnics. After a brief historical overview, the main classes of energetic materials are discussed systematically. Thermodynamic aspects, as far as relevant to energetic materials, are discussed, as well as modern computational approaches to predict performance and sensitivity parameters. The most important performance criteria such as detonation velocity, detonation pressure and heat of explosion, as well as the relevant sensitivity parameters suc as impact and friction sensitivity and electrostatic discharge sensitivity are explored in detail. Modern aspects of chemical synthesis including lead-free primary explosives and high-nitrogen compounds are also included in this book together with a discussion of high-energy materials for future defense needs. The most important goal of this book, based on a lecture course which has now been held at LMU Munich for over 12 years, is to increase knowledge and know-how in the synthesis and safe handling of high-energy materials. Society needs now as much as ever advanced explosives, propellant charges, rocket propellants and pyrotechnics to meet the demands in defense and engineering. This book is first and foremost aimed at advanced students in chemistry, engineering and materials sciences. However, it is also intended to provide a good introduction to the chemistry of energetic materials and chemical defense technology for scientists in the defense industry and government-run defense organizations. (orig.)

Finite Element Modeling of Dieless Tube Drawing of Strain Rate Sensitive Material with Coupled Thermo-Mechanical Analysis

Science.gov (United States)

Furushima, Tsuyoshi; Sakai, Takashi; Manabe, Ken-ichi

2004-06-01

Dieless drawing is a unique deformation process without conventional dies, which can achieve a great reduction of wire and tube metals in single pass by means of local heating and cooling approach. In this study, for microtube forming, the dieless drawing process applying superplastic behavior was analyzed by finite element method (FEM) in order to clarify the effect of dieless tube drawing conditions such as tensile speed, moving speed of heating and cooling system, and material properties on deformation behavior of the tube. In the calculation, the material properties were dealt in a special subroutine, whose constitutive equation was defined as σ = Kɛnɛ˙m, and was linked to the solver. A coupled thermo-mechanical analysis was performed for the dieless tube drawing using the FEM. In the thermal analysis of dieless tube drawing, heat transfer was introduced to calculate the heat flux between heating coil and tube surface, and heat conduction in a tube. The influence of dieless tube drawing conditions on deformation behavior was clarified. As a result, for the strain rate sensitive material, the maximum reduction of area and the minimum outer diameter in single pass attain to 90.9% and 2.56mm, respectively. From the result, it is concluded that the dieless tube drawing is essential to produce an extrafine microtube by reason of keeping cylindrical tube diameter ratio constant with extremely high reduction.

Relative sensitivity of formability to anisotropy

International Nuclear Information System (INIS)

Logan, R.W.; Maker, B.N.

1997-01-01

This work compares the relative importance of material anisotropy in sheet forming as compared to other material and process variables. The comparison is made quantitative by the use of normalized dependencies of depth to failure (forming limit is reached) on various measures of anisotropy, as well as strain and rate sensitivity, friction, and tooling. Comparisons are made for a variety of forming processes examined previously in the literature as well as two examples of complex stampings in this work. 7 The examples rover a range from nearly pure draw to nearly pure stretch situations, and show that for materials following a quadratic yield criterion, anisotropy is among the most sensitive parameters influencing formability. For materials following higher-exponent yield criteria, the dependency is milder but is still of the order of most other process parameters. However, depending on the particular forming operation, it is shown that in some cases anisotropy may be ignored, whereas in others its consideration is crucial to a good quality analysis

Ultrahigh humidity sensitivity of graphene oxide.

Science.gov (United States)

Bi, Hengchang; Yin, Kuibo; Xie, Xiao; Ji, Jing; Wan, Shu; Sun, Litao; Terrones, Mauricio; Dresselhaus, Mildred S

2013-01-01

Humidity sensors have been extensively used in various fields, and numerous problems are encountered when using humidity sensors, including low sensitivity, long response and recovery times, and narrow humidity detection ranges. Using graphene oxide (G-O) films as humidity sensing materials, we fabricate here a microscale capacitive humidity sensor. Compared with conventional capacitive humidity sensors, the G-O based humidity sensor has a sensitivity of up to 37800% which is more than 10 times higher than that of the best one among conventional sensors at 15%-95% relative humidity. Moreover, our humidity sensor shows a fast response time (less than 1/4 of that of the conventional one) and recovery time (less than 1/2 of that of the conventional one). Therefore, G-O appears to be an ideal material for constructing humidity sensors with ultrahigh sensitivity for widespread applications.

Materials design and development of functional materials for industry

International Nuclear Information System (INIS)

Asahi, Ryoji; Morikawa, Takeshi; Hazama, Hirofumi; Matsubara, Masato

2008-01-01

It is now well recognized that we are witnessing a golden age of innovation with novel materials, with discoveries that are important for both basic science and industry. With the development of theory along with computing power, quantum materials design-the synthesis of materials with the desired properties in a controlled way via materials engineering on the atomic scale-is becoming a major component of materials research. Computational prediction based on first-principles calculations has helped to find an efficient way to develop materials that are much needed for industry, as we have seen in the successful development of visible-light sensitized photocatalysts and thermoelectric materials. Close collaboration between theory and experiment is emphasized as an essential for success

Signal sensitivity of alternating current potential drop measurement for crack detection of conductive substrate with tunable coating materials through finite element modeling

International Nuclear Information System (INIS)

Rao, Simha Sandeep; Zhao, Huijuan; Liu, Ming; Peng, Fei; Zhang, Bo

2016-01-01

We adopt a finite element numerical modeling approach to investigate the electromagnetic coupling effect of two parallel electric conductors with tunable electric conductivity σ and magnetic permeability μ . For two parallel conductors C and S ( μ C   ⋅  σ C   ≤  μ S   ⋅  σ S ), we find that the shape of current density profile of conductor S is dependent on the product of μ C   ⋅  σ C , while the magnitude is determined by the AC current frequency f . On the other hand, the frequency f affects not only the shape but also the magnitude of the current density profile of conductor C. We further adopt a coplanar model to investigate the signal sensitivity of alternating current potential drop (ACPD) measurement for both surface crack and inner crack detection. We find that with modified coating materials (lower electric conductivity and higher magnetic permeability, compared with the substrate material properties), the crack detection signal sensitivity can be greatly enhanced for both the cracks within the coating and at the coating/substrate interface, where cracks are most commonly encountered in real situations. (paper)

Materials with low DC magnetic susceptibility for sensitive magnetic measurements

International Nuclear Information System (INIS)

Khatiwada, R; Kendrick, R; Khosravi, M; Peters, M; Smith, E; Snow, W M; Dennis, L

2016-01-01

Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium–indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10 −9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within experimental error. These results verify the well-known Wiedemann additivity law for the magnetic susceptibility of inert mixtures of materials and thereby realize the ability to produce materials with small but tunable magnetic susceptibility. For our particular scientific application, we are also looking for materials with the largest possible number of neutrons and protons per unit volume. The gallium–indium alloys fabricated and measured in this work possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature liquid, and the tungsten-bismuth pressed powder mixtures possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature solid. This ratio is a figure of merit for a certain class of precision experiments that search for possible exotic spin-dependent forces of Nature. (paper)

Sensitivity analysis of critical experiment with direct perturbation compared to TSUNAMI-3D sensitivity analysis

International Nuclear Information System (INIS)

Barber, A. D.; Busch, R.

2009-01-01

The goal of this work is to obtain sensitivities from direct uncertainty analysis calculation and correlate those calculated values with the sensitivities produced from TSUNAMI-3D (Tools for Sensitivity and Uncertainty Analysis Methodology Implementation in Three Dimensions). A full sensitivity analysis is performed on a critical experiment to determine the overall uncertainty of the experiment. Small perturbation calculations are performed for all known uncertainties to obtain the total uncertainty of the experiment. The results from a critical experiment are only known as well as the geometric and material properties. The goal of this relationship is to simplify the uncertainty quantification process in assessing a critical experiment, while still considering all of the important parameters. (authors)

Advances in dental materials.

Science.gov (United States)

Fleming, Garry J P

2014-05-01

The dental market is replete with new resorative materials marketed on the basis of novel technological advances in materials chemistry, bonding capability or reduced operator time and/or technique sensitivity. This paper aims to consider advances in current materials, with an emphasis on their role in supporting contemporary clinical practice.

A Triphenylamine-Based Conjugated Polymer with Donor-π-Acceptor Architecture as Organic Sensitizer for Dye-Sensitized Solar Cells.

Science.gov (United States)

Zhang, Wei; Fang, Zhen; Su, Mingjuan; Saeys, Mark; Liu, Bin

2009-09-17

A conjugated polymer containing an electron donating backbone (triphenylamine) and an electron accepting side chain (cyanoacetic acid) with conjugated thiophene units as the linkers has been synthesized. Dye-sensitized solar cells (DSSCs) are fabricated utilizing this material as the dye sensitizer, resulting a typical power conversion efficiency of 3.39% under AM 1.5 G illumination, which represents the highest efficiency for polymer dye-sensitized DSSCs reported so far. The results show the good promise of conjugated polymers as sensitizers for DSSC applications. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Auxetic Mechanical Metamaterials to Enhance Sensitivity of Stretchable Strain Sensors.

Science.gov (United States)

Jiang, Ying; Liu, Zhiyuan; Matsuhisa, Naoji; Qi, Dianpeng; Leow, Wan Ru; Yang, Hui; Yu, Jiancan; Chen, Geng; Liu, Yaqing; Wan, Changjin; Liu, Zhuangjian; Chen, Xiaodong

2018-03-01

Stretchable strain sensors play a pivotal role in wearable devices, soft robotics, and Internet-of-Things, yet these viable applications, which require subtle strain detection under various strain, are often limited by low sensitivity. This inadequate sensitivity stems from the Poisson effect in conventional strain sensors, where stretched elastomer substrates expand in the longitudinal direction but compress transversely. In stretchable strain sensors, expansion separates the active materials and contributes to the sensitivity, while Poisson compression squeezes active materials together, and thus intrinsically limits the sensitivity. Alternatively, auxetic mechanical metamaterials undergo 2D expansion in both directions, due to their negative structural Poisson's ratio. Herein, it is demonstrated that such auxetic metamaterials can be incorporated into stretchable strain sensors to significantly enhance the sensitivity. Compared to conventional sensors, the sensitivity is greatly elevated with a 24-fold improvement. This sensitivity enhancement is due to the synergistic effect of reduced structural Poisson's ratio and strain concentration. Furthermore, microcracks are elongated as an underlying mechanism, verified by both experiments and numerical simulations. This strategy of employing auxetic metamaterials can be further applied to other stretchable strain sensors with different constituent materials. Moreover, it paves the way for utilizing mechanical metamaterials into a broader library of stretchable electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensitivity Analysis of Viscoelastic Structures

Directory of Open Access Journals (Sweden)

A.M.G. de Lima

2006-01-01

Full Text Available In the context of control of sound and vibration of mechanical systems, the use of viscoelastic materials has been regarded as a convenient strategy in many types of industrial applications. Numerical models based on finite element discretization have been frequently used in the analysis and design of complex structural systems incorporating viscoelastic materials. Such models must account for the typical dependence of the viscoelastic characteristics on operational and environmental parameters, such as frequency and temperature. In many applications, including optimal design and model updating, sensitivity analysis based on numerical models is a very usefull tool. In this paper, the formulation of first-order sensitivity analysis of complex frequency response functions is developed for plates treated with passive constraining damping layers, considering geometrical characteristics, such as the thicknesses of the multi-layer components, as design variables. Also, the sensitivity of the frequency response functions with respect to temperature is introduced. As an example, response derivatives are calculated for a three-layer sandwich plate and the results obtained are compared with first-order finite-difference approximations.

PAMTRAK: A personnel and material tracking system

International Nuclear Information System (INIS)

Anspach, D.A.; Anspach, J.P.; Crain, B. Jr.

1996-01-01

There is a need for an automated system for protecting and monitoring sensitive or classified parts and material. Sandia has developed a real-time personnel and material tracking system (PAMTRAK) that has been installed at selected DOE facilities. It safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. It includes remote control and alarm display capabilities and a complementary program in Keyhole to display measured material attributes remotely. This paper describes the design goals, the system components, current installations, and the benefits a site can expect when using PAMTRAK

Discrimination of Naturally Occurring Radioactive Material in Plastic Scintillator Material

International Nuclear Information System (INIS)

Ely, James H.; Kouzes, Richard T.; Geelhood, Bruce D.; Schweppe, John E.; Warner, Ray A.

2003-01-01

Plastic scintillator material is used in many applications for the detection of gamma-rays from radioactive material, primarily due to the sensitivity per unit cost compared to other detection materials. However, the resolution and lack of full-energy peaks in the plastic scintillator material prohibits detailed spectroscopy. Therefore, other materials such as doped sodium iodide are used for spectroscopic applications. The limited spectroscopic information can however be exploited in plastic scintillator materials to provide some discrimination. The discrimination between man-made and naturally occurring sources would be useful in reducing alarm screening for radiation detection applications which target man-made sources. The results of applying the limited energy information from plastic scintillator material for radiation portal monitors are discussed.

Phase change material for temperature control and material storage

Science.gov (United States)

Wessling, Jr., Francis C. (Inventor); Blackwood, James M. (Inventor)

2011-01-01

A phase change material comprising a mixture of water and deuterium oxide is described, wherein the mole fraction of deuterium oxide is selected so that the mixture has a selected phase change temperature within a range between 0.degree. C. and 4.degree. C. The mixture is placed in a container and used for passive storage and transport of biomaterials and other temperature sensitive materials. Gels, nucleating agents, freezing point depression materials and colorants may be added to enhance the characteristics of the mixture.

New Materials for Gas Sensitive Field-Effect Device Studies

OpenAIRE

Salomonsson, Anette

2005-01-01

Gas sensor control is potentially one of the most important techniques of tomorrow for the environment. All over the world cars are preferred for transportation, and accordingly the number of cars increases, unfortunately, together with pollutants. Boilers and powerplants are other sources of pollutants to the environment. Metal-Insulator-Silicon Carbide (MISiC) Field-effect sensors in car applications and boilers have the potential to reduce the amount of pollutants. These devices are sensit...

Energetic materials: crystallization, characterization and insensitive plastic bonded explosives

Energy Technology Data Exchange (ETDEWEB)

Heijden, Antoine E.D.M. van der; Creyghton, Yves L.M.; Marino, Emanuela; Bouma, Richard H.B.; Scholtes, Gert J.H.G.; Duvalois, Willem [TNO Defence, Security and Safety, P. O. Box 45, 2280 AA Rijswijk (Netherlands); Roelands, Marc C.P.M. [TNO Science and Industry, P. O. Box 342, 7300 AH Apeldoorn (Netherlands)

2008-02-15

The product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive containing these energetic materials becomes. The application of submicron or nanometric energetic materials is generally considered to further decrease the sensitiveness of explosives. In order to assess the product quality of energetic materials, a range of analytical techniques is available. Recent attempts within the Reduced-sensitivity RDX Round Robin (R4) have provided the EM community a better insight into these analytical techniques and in some cases a correlation between product quality and shock initiation of plastic bonded explosives containing (RS-)RDX was identified, which would provide a possibility to discriminate between conventional and reduced sensitivity grades. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Supplementary Material for: A global sensitivity analysis approach for morphogenesis models

KAUST Repository

Boas, Sonja

2015-01-01

Abstract Background Morphogenesis is a developmental process in which cells organize into shapes and patterns. Complex, non-linear and multi-factorial models with images as output are commonly used to study morphogenesis. It is difficult to understand the relation between the uncertainty in the input and the output of such ‘black-box’ models, giving rise to the need for sensitivity analysis tools. In this paper, we introduce a workflow for a global sensitivity analysis approach to study the impact of single parameters and the interactions between them on the output of morphogenesis models. Results To demonstrate the workflow, we used a published, well-studied model of vascular morphogenesis. The parameters of this cellular Potts model (CPM) represent cell properties and behaviors that drive the mechanisms of angiogenic sprouting. The global sensitivity analysis correctly identified the dominant parameters in the model, consistent with previous studies. Additionally, the analysis provided information on the relative impact of single parameters and of interactions between them. This is very relevant because interactions of parameters impede the experimental verification of the predicted effect of single parameters. The parameter interactions, although of low impact, provided also new insights in the mechanisms of in silico sprouting. Finally, the analysis indicated that the model could be reduced by one parameter. Conclusions We propose global sensitivity analysis as an alternative approach to study the mechanisms of morphogenesis. Comparison of the ranking of the impact of the model parameters to knowledge derived from experimental data and from manipulation experiments can help to falsify models and to find the operand mechanisms in morphogenesis. The workflow is applicable to all ‘black-box’ models, including high-throughput in vitro models in which output measures are affected by a set of experimental perturbations.

Position-Sensitive Organic Scintillation Detectors for Nuclear Material Accountancy

International Nuclear Information System (INIS)

Hausladen, P.; Newby, J.; Blackston, M.

2015-01-01

Recent years have seen renewed interest in fast organic scintillators with pulse shape properties that enable neutron-gamma discrimination, in part because of the present shortage of He3, but primarily because of the diagnostic value of timing and pulse height information available from such scintillators. Effort at Oak Ridge National Laboratory (ORNL) associated with fast organic scintillators has concentrated on development of position-sensitive fast-neutron detectors for imaging applications. Two aspects of this effort are of interest. First, the development has revisited the fundamental limitations on pulseshape measurement imposed by photon counting statistics, properties of the scintillator, and properties of photomultiplier amplification. This idealized limit can then be used to evaluate the performance of the detector combined with data acquisition and analysis such as free-running digitizers with embedded algorithms. Second, the development of position sensitive detectors has enabled a new generation of fast-neutron imaging instruments and techniques with sufficient resolution to give new capabilities relevant to safeguards. Toward this end, ORNL has built and demonstrated a number of passive and active fast-neutron imagers, including a proof-of-concept passive imager capable of resolving individual fuel pins in an assembly via their neutron emanations. This presentation will describe the performance and construction of position-sensing fast-neutron detectors and present results of imaging measurements. (author)

Prostate Cancer Information Available in Health-Care Provider Offices: An Analysis of Content, Readability, and Cultural Sensitivity.

Science.gov (United States)

Choi, Seul Ki; Seel, Jessica S; Yelton, Brooks; Steck, Susan E; McCormick, Douglas P; Payne, Johnny; Minter, Anthony; Deutchki, Elizabeth K; Hébert, James R; Friedman, Daniela B

2018-07-01

Prostate cancer (PrCA) is the most common cancer affecting men in the United States, and African American men have the highest incidence among men in the United States. Little is known about the PrCA-related educational materials being provided to patients in health-care settings. Content, readability, and cultural sensitivity of materials available in providers' practices in South Carolina were examined. A total of 44 educational materials about PrCA and associated sexual dysfunction was collected from 16 general and specialty practices. The content of the materials was coded, and cultural sensitivity was assessed using the Cultural Sensitivity Assessment Tool. Flesch Reading Ease, Flesch-Kincaid Grade Level, and the Simple Measure of Gobbledygook were used to assess readability. Communication with health-care providers (52.3%), side effects of PrCA treatment (40.9%), sexual dysfunction and its treatment (38.6%), and treatment options (34.1%) were frequently presented. All materials had acceptable cultural sensitivity scores; however, 2.3% and 15.9% of materials demonstrated unacceptable cultural sensitivity regarding format and visual messages, respectively. Readability of the materials varied. More than half of the materials were written above a high-school reading level. PrCA-related materials available in health-care practices may not meet patients' needs regarding content, cultural sensitivity, and readability. A wide range of educational materials that address various aspects of PrCA, including treatment options and side effects, should be presented in plain language and be culturally sensitive.

Measurement and prediction of sensitization development in austenitic stainless steels

International Nuclear Information System (INIS)

Bruemmer, S.M.; Charlot, L.A.; Atteridge, D.G.

1985-10-01

The effects of thermal and thermomechanical treatments on sensitization development in Type 304 and 316 stainless steels have been measured and compared to model predictions. Sensitization development resulting from isothermal, continuous cooling and pipe welding treatments has been evaluated. An empirically-modified, theoretically-based model is shown to accurately predict material degree of sensitization (DOS) as expressed by the electrochemical potentiokinetic reactivation (EPR) test after both simple and complex treatments. Material DOS is also examined using analytical electron microscopy to document grain boundary chromium depletion and is compared to EPR test results. 9 refs., 13 figs

Photographic materials

International Nuclear Information System (INIS)

Jamieson, P.B.

1980-01-01

Radiographic films based on silver halides are normally handled under red or orange safelights to prevent fogging due to their sensitivity to white light. The present invention relates to ultraviolet radiation sensitive material which can be handled under virtually white light without significant fogging. The film material is comprised of a base having at least one layer of a photographic silver halide emulsion and a yellow filter dye screening the emulsion from visible radiation. The silver halide emulsion contains 50-100 mole % of silver chloride, the higher the silver chloride content, the lower the visible light sensitivity. The nature and properties of the yellow filter dye are described. When recording an X-ray image, the film is loaded into the camera under white safelight conditions from which light of wavelength shorter than 400 nm is excluded. The film is in contact with one or more phosphor screens capable when struck by X-rays of emitting ultraviolet radiation, the screens having a peak ultraviolet emission within the wavelength range of 250-380 nm. After X-ray exposure, the film is removed and developed. Two examples illustrating the invention are given. (U.K.)

A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

KAUST Repository

Ball, James M.

2012-01-01

The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin-based dyes. We show that by fusing the porphyrin core to an anthracene unit, we can extend the conjugation length and lower the optical gap, shifting the absorption spectrum into the near-infrared (NIR). All three dyes were tested in dye-sensitized solar cells, using both titanium dioxide and tin dioxide as the electron-transport material. Solar cells incorporating the anthracene-fused porphyrin dye exhibit photocurrent collection at wavelengths up to about 1100 nm, which is the longest reported for a porphyrin-based system. Despite extending the photon absorption bandwidth, device efficiency is found to be low, which is a common property of cells based on porphyrin dyes with NIR absorption. We show that in the present case the efficiency is reduced by inefficient electron injection into the oxide, as opposed to dye regeneration, and highlight some important design considerations for panchromatic sensitizers. © 2012 The Royal Society of Chemistry.

Supplementary Material for: A global sensitivity analysis approach for morphogenesis models

KAUST Repository

Boas, Sonja; Navarro, Marí a; Merks, Roeland; Blom, Joke

2015-01-01

) represent cell properties and behaviors that drive the mechanisms of angiogenic sprouting. The global sensitivity analysis correctly identified the dominant parameters in the model, consistent with previous studies. Additionally, the analysis provided

Sensitization to palladium in Europe

DEFF Research Database (Denmark)

Muris, Joris; Goossens, An; Gonçalo, Margarida

2015-01-01

BACKGROUND: Recently, sodium tetrachloropalladate (Na2 PdCl4 ) was found to be a more sensitive palladium patch test allergen than palladium dichloride (PdCl2 ). OBJECTIVES: To determine the optimal test concentration of Na2 PdCl4 , to evaluate the prevalence of palladium sensitization with Na2 P...... patch test concentration. Sensitization to palladium is almost as prevalent as sensitization to nickel. The sex distribution is different between nickel-sensitized and palladium-sensitized patients, suggesting different sources of exposure.......Cl4 and PdCl2 , and to compare the results with nickel sensitization in a European multicentre study. MATERIALS AND METHODS: In addition to the European or national baseline series including NiSO4 ·6H2 0 5% pet., consecutive patients were tested with PdCl2 and Na2 PdCl4 2%, 3% and 4% pet. in eight...... European dermatology clinics. The age and sex distributions were also evaluated in patients sensitized to nickel and palladium. RESULTS: In total, 1651 patients were tested. Relative to 3% Na2 PdCl4 , 4% Na2 PdCl4 did not add any information. Two per cent Na2 PdCl4 resulted in more doubtful reactions...

Photographic materials

International Nuclear Information System (INIS)

1980-01-01

Radiographic films based on silver halides are normally handled under red or orange safelights to prevent fogging due to their sensitivity to white light. The present invention relates to ultraviolet radiation sensitive material which can be handled under virtually white light without significant fogging. A photographic, chemically sensitised silver halide emulsion is described, containing 50-100 mole % of silver chloride, the higher the silver chloride content, the lower the visible light sensitivity. The remaining silver halide, if any, is silver bromide and/or silver iodide. The silver halide grains are grown in the presence of ammonia, an excess of chloride ions and tetraazaindene growth controller. Examples illustrating the invention are given. (U.K.)

Optimum shape design of incompressible hyperelastic structures with analytical sensitivity analysis

International Nuclear Information System (INIS)

Jarraya, A.; Wali, M.; Dammark, F.

2014-01-01

This paper is focused on the structural shape optimization of incompressible hyperelastic structures. An analytical sensitivity is developed for the rubber like materials. The whole shape optimization process is carried out by coupling a closed geometric shape in R 2 with boundaries, defined by B-splines curves, exact sensitivity analysis and mathematical programming method (S.Q.P: sequential quadratic programming). Design variables are the control points coordinate. The objective function is to minimize Von-Mises stress, constrained to the total material volume of the structure remains constant. In order to validate the exact Jacobian method, the sensitivity calculation is performed: numerically by an efficient finite difference scheme and by the exact Jacobian method. Numerical optimization examples are presented for elastic and hyperelastic materials using the proposed method.

Protease-Sensitive Liposomes in Chemotherapy & Chemoradiotherapy: From Material Development to In Vivo Application in Tumor-Bearing Mice

DEFF Research Database (Denmark)

Brogaard, Rikke Yding; Melander, Fredrik

to enhance therapeutic efficacies. In this thesis, the development, characterization, and evaluation of an advanced liposomal DDS and its potential in chemoradiotherapy is presented from material development to in vivo application in tumor*bearing mice. In the first part of the thesis, we report the design...... concept of the liposomal DDS, which leads to rapid cellular uptake. Various lipid compositions are tested in uptake and cytotoxicity experiments in vitro, followed by in vivo experiments where the ability of the liposomal DDS to accumulate in tumors together with its anti*cancer activity is explored...... in tumor*bearing mice. The in vivo data demonstrates superior anti*cancer activity relative to the free drug and to conventional, long circulating liposomes. This indicates that the MMP*sensitive liposomal DDS holds potential in therapeutic applications. In the second part of the thesis, the potential...

Effect of the temperature in the sensitivity of CaSO4: Dy

International Nuclear Information System (INIS)

Gonzalez, P.R.; Alcantara, B.C.; Azorin, J.; Furetta, C.

2003-01-01

Sensitivity of a Tl material is one of the most important properties for dosimetry. This property is optimized by means of various processes such as the incorporation of different dopants into the matrix material, the application of certain doses of ionizing radiation and carefully controlled thermal treatments among others. Results obtained of studying the sensitivity of diverse preparations of CaSO 4 : Dy submitted different thermal treatments are presented. The material, which presented the highest sensitivity, was that one it was heated to 800 C during one hour. When the temperature was raised over this value it was observed that sensitivity drops again. In other hand, as the heating rate in lowing down, during the readout, the height of the glow curve decreases proportionally. The temperature of the maximum of the main peak also decreases. (Author)

Comparison of materials accounting in conversion and coconversion processes

International Nuclear Information System (INIS)

Dayem, H.A.

1981-01-01

Materials accounting systems performances are compared for plutonium nitrate-to-oxide conversion [Oxalate (III)] and uranium-plutonium coconversion (Coprecal and modified Coprecal). These processes have the same design basis plutonium throughput and achieve this throughput in parallel operating lines. However, the process line configurations differ. In comparing the materials loss detection sensitivities for the three processes, we find better materials loss detection sensitivity for the Oxalate (III) process than for either of the two Coprecal processes, better single-balance detection sensitivity for the original Coprecal than for the modified Coprecal, and better long-term detection sensitivity (> 1d) for the modified Coprecal than for the original Coprecal. Sensivity differences result from differences in in-process inventories, feeding arrangements, and scrap generation

Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells.

Science.gov (United States)

Xu, Lin; Yang, Hai-Bo

2016-06-01

During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensitive maintenance: a cognitive process underlying individual differences in memory for threatening information.

Science.gov (United States)

Peters, Jan H; Hock, Michael; Krohne, Heinz Walter

2012-01-01

Dispositional styles of coping with threat influence memory for threatening information. In particular, sensitizers excel over repressors in their memory for threatening information after long retention intervals, but not after short ones. We therefore suggested that sensitizers, but not repressors, employ active maintenance processes during the retention interval to selectively retain threatening material. Sensitive maintenance was studied in 2 experiments in which participants were briefly exposed to threatening and nonthreatening pictures (Experiment 1, N = 128) or words (Experiment 2, N = 145). Following, we administered unannounced recognition tests before and after an intervening task that generated either high or low cognitive load, assuming that high cognitive load would impede sensitizers' memory maintenance of threatening material. Supporting our hypotheses, the same pattern of results was obtained in both experiments: Under low cognitive load, sensitizers forgot less threat material than repressors did; no such differences were observed under high cognitive load.

Production of sensitivity and false alarm rate

International Nuclear Information System (INIS)

Han Zijie; Kang Wu; Chu Chengsheng; Hao Fanhua; Liu Xiaoya; Cao Lin; Hu Yongbo; Gong Jian; Xiang Yongchun; Zhang Jianhua; Yang Xiangdong

2007-01-01

The false alarm rate and sensitivity in nuclear material monitoring system are affected by alarm principle. Two different alarm principles are studied with theory and experiment analysis in this paper. Our research shows that theory analysis and experiment result are accordant very much. This study provides technology support for designing better alarm principle in nuclear material monitoring system. (authors)

Influence of alloying elements on the irradiation hardening and environmental sensitivity of zirconium alloys

International Nuclear Information System (INIS)

Pettersson, K.; Hallstadius, L.; Bergqvist, H.; Nylund, A.; Wikstroem, C.

1992-01-01

Ten different alloys of zirconium have been tested with regard to the effect of irradiation on their mechanical properties and their sensitivity to environmentally induced failure. Two different environments were used: iodine vapour and liquid cesium with an addition of 2% cadmium. The neutron dose was 10 21 n/cm 2 (E>1MeV) and the irradiation temperature was about 300 degrees C. All alloy additions increased the irradiation hardening. Especially notable was the large effect of titanium and tin on irradiation hardening. A limited amount of transmission electron microscopy was carried out in order to find an explanation to the effects. The testing in different environments showed that there is no clear correlation between environmental sensitivity and yield stress. For materials of similar yield stress an alloyed material tends to be more sensitive to environmental cracking than a material which only contains oxygen as an impurity. There also seems to be an effect of oxygen on the environmental cracking sensitivity. A material with 910 ppm oxygen was considerably more sensitive to cracking than a material with 470 ppm oxygen despite the fact that the yield stress values differed by only 90 MPa

Optical Fiber Sensors Based on Polymeric Sensitive Coatings

Directory of Open Access Journals (Sweden)

Pedro J. Rivero

2018-03-01

Full Text Available Polymer technology is one of the fastest growing fields of contemporary research due to the possibility of using a wide variety of synthetic chemical routes for obtaining a polymeric network with a well-defined structure, resulting in materials with outstanding macroscopic properties. Surface engineering techniques based on the implementation of polymeric structures can be used as an interesting tool for the design of materials with functional properties. In this sense, the use of fabrication techniques for the design of nanostructured polymeric coatings is showing an important growth due to the intrinsic advantages of controlling the structure at a nanoscale level because physical, chemical, or optical properties can be considerably improved in comparison with the bulk materials. In addition, the presence of these sensitive polymeric coatings on optical fiber is a hot topic in the scientific community for its implementation in different market niches because a wide variety of parameters can be perfectly measured with a high selectivity, sensitivity, and fast response time. In this work, the two main roles that a polymeric sensitive matrix can play on an optical fiber for sensing applications are evaluated. In a first section, the polymers are used as a solid support for the immobilization of specific sensitive element, whereas in the second section the polymeric matrix is used as the chemical transducer itself. Additionally, potential applications of the optical fiber sensors in fields as diverse as biology, chemistry, engineering, environmental, industry or medicine will be presented in concordance with these two main roles of the polymeric sensitive matrices.

Fabrication of stimuli-sensitive hydrogel for the removal of cesium

Energy Technology Data Exchange (ETDEWEB)

Yang, Hee-Man; Bong, Sang Bum; Park, Chan Woo; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

The nuclear accident at the Fukushima Daiichi nuclear power station in 2011 released a huge quantity of radioactive contaminants into the environment.1 Among these, cesium Cs-137 is the most problematic contaminant due to its long half-life (30.2 years), and high-energy gamma ray (γ-ray) emissions. 2 Various surface including road, roof, house, building were contaminated with Cs-137. These coating materials have some problems and limitation such as toxic component, and lack of reusability of materials related to the cost. Thus, a more cost-effective and environmental friendly coating materials is still desired. 3 In the present study, the stimuli-sensitive hydrogel were fabricated for the removal of radioactive Cs from solid surface. We describe the morphology, structure, and physical property of these stimuli sensitive hydrogel. In addition, their ability to eliminate cesium was also evaluated. The smart hydrogel coating materials showed an excellent morphology change from the liquid to film by addition of Ca ion. Therefore, the stimuli-sensitive hydrogel demonstrated good potential for the treatment of contaminated surface for the removal of radioactive cesium.

Fabrication of stimuli-sensitive hydrogel for the removal of cesium

International Nuclear Information System (INIS)

Yang, Hee-Man; Bong, Sang Bum; Park, Chan Woo; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon

2015-01-01

The nuclear accident at the Fukushima Daiichi nuclear power station in 2011 released a huge quantity of radioactive contaminants into the environment.1 Among these, cesium Cs-137 is the most problematic contaminant due to its long half-life (30.2 years), and high-energy gamma ray (γ-ray) emissions. 2 Various surface including road, roof, house, building were contaminated with Cs-137. These coating materials have some problems and limitation such as toxic component, and lack of reusability of materials related to the cost. Thus, a more cost-effective and environmental friendly coating materials is still desired. 3 In the present study, the stimuli-sensitive hydrogel were fabricated for the removal of radioactive Cs from solid surface. We describe the morphology, structure, and physical property of these stimuli sensitive hydrogel. In addition, their ability to eliminate cesium was also evaluated. The smart hydrogel coating materials showed an excellent morphology change from the liquid to film by addition of Ca ion. Therefore, the stimuli-sensitive hydrogel demonstrated good potential for the treatment of contaminated surface for the removal of radioactive cesium

Facilitating Effects of Nanoparticles/Materials on Sensitive Immune-Related Lung Disorders

International Nuclear Information System (INIS)

Inoue, K.I.; Takano, H.

2011-01-01

Although the adverse health effects of nanoparticles/materials have been proposed and are being clarified, their facilitating effects on preexisting pathological conditions have not been fully examined. In this paper, we provide insights into the immunotoxicity of nanoparticles/materials as an aggravating factor in hyper susceptible subjects, especially those with immune-related respiratory disorders using our in vivo experimental model. We first exhibit the effects of nanoparticles/materials on lung inflammation induced by bacterial endotoxin (lipopolysaccharide: LPS) in vivo as a disease model in innate immunity, and demonstrated that nanoparticles instilled through both an intratracheal tube and an inhalation system can exacerbate the lung inflammation. Secondly, we introduce the effects of nanoparticles/materials on allergic asthma in vivo as a disease model in adaptive immunity, and showed that repetitive pulmonary exposure to nanoparticles has aggravating effects on allergic airway inflammation, including adjuvant effects on Th2-milieu. Taken together, nanoparticle exposure may synergistically facilitate pathological inflammatory conditions in the lung via both innate and adaptive immunological abnormalities.

Microwave-assisted synthesis of C-doped TiO2 and ZnO hybrid nanostructured materials as quantum-dots sensitized solar cells

Science.gov (United States)

Rangel-Mendez, Jose R.; Matos, Juan; Cházaro-Ruiz, Luis F.; González-Castillo, Ana C.; Barrios-Yáñez, Guillermo

2018-03-01

The microwave-assisted solvothermal synthesis of C-doped TiO2 and ZnO hybrid materials was performed. Saccharose, titanium isopropoxide and zinc acetate were used as organic and inorganic sources for the synthesis. The influence of temperature and reaction time on the textural and optoelectronic properties of the hybrid materials was verified. Carbon quantum-dots of TiO2 and ZnO nanostructured spheres were obtained in a second pot by controlled calcination steps of the precursor hybrid materials. A carefully characterization by adsorption-desorption N2 isotherms, XRD, XPS, SEM, UV-vis/DR and electro- and photo-electrochemistry properties of the carbon quantum-dots TiO2 and ZnO spheres was performed. The photoelectrochemical activity of TiO2-C and ZnO-C films proved to be dependent on the conditions of synthesis. It was found a red-shift in the energy band gap of the semiconductors with values of 3.02 eV and 3.13 eV for the TiO2-C and ZnO-C, respectively, clearly lower than those on bare semiconductors, which is associated with the C-doping effect. From the photo-electrochemistry characterization of C-doped TiO2 and ZnO films can be concluded that the present materials have potential applications as photoelectrodes for quantum-dots sensitized solar cells.

Radiation-sensitive compounds and methods of using same

International Nuclear Information System (INIS)

DeMajistre, R.

1977-01-01

Novel diacrylates are prepared by reacting a monohydroxylated acrylic monomer with a polyisocyanate. The reaction product may be polymerized by subjecting to ionizing irradiation, actinic light or to free radical catalysis to form a useful coating material. The diacrylates may also be copolymerized with other radiation sensitive materials

Maternal sensitivity: a concept analysis.

Science.gov (United States)

Shin, Hyunjeong; Park, Young-Joo; Ryu, Hosihn; Seomun, Gyeong-Ae

2008-11-01

The aim of this paper is to report a concept analysis of maternal sensitivity. Maternal sensitivity is a broad concept encompassing a variety of interrelated affective and behavioural caregiving attributes. It is used interchangeably with the terms maternal responsiveness or maternal competency, with no consistency of use. There is a need to clarify the concept of maternal sensitivity for research and practice. A search was performed on the CINAHL and Ovid MEDLINE databases using 'maternal sensitivity', 'maternal responsiveness' and 'sensitive mothering' as key words. The searches yielded 54 records for the years 1981-2007. Rodgers' method of evolutionary concept analysis was used to analyse the material. Four critical attributes of maternal sensitivity were identified: (a) dynamic process involving maternal abilities; (b) reciprocal give-and-take with the infant; (c) contingency on the infant's behaviour and (d) quality of maternal behaviours. Maternal identity and infant's needs and cues are antecedents for these attributes. The consequences are infant's comfort, mother-infant attachment and infant development. In addition, three positive affecting factors (social support, maternal-foetal attachment and high self-esteem) and three negative affecting factors (maternal depression, maternal stress and maternal anxiety) were identified. A clear understanding of the concept of maternal sensitivity could be useful for developing ways to enhance maternal sensitivity and to maximize the developmental potential of infants. Knowledge of the attributes of maternal sensitivity identified in this concept analysis may be helpful for constructing measuring items or dimensions.

A sensitive detector to prevent smuggling of nuclear material

International Nuclear Information System (INIS)

Bock, H.; Rost, R.; Miller, B.R.

1995-01-01

A drive through detector systems using four plastic scintillators and associated electronics for the detections of small amounts or uranium or plutonium in cars is described. The system has been calibrated with various sample of special nuclear material and the lower detection limits are presented. (author)

Cytological diagnostic of lymphadenitis tuberculosis by eosinophilic material

Science.gov (United States)

Delyuzar; Amir, Z.; Kusumawati, L.

2018-03-01

AFB sputum and chest X-ray are used to identify patients with pulmonary TB. For extrapulmonary TB, fine needle aspiration cytology is needed, even though occasionally found not atypical feature in the form of eosinophilic material with dark brown particles, suspected as TB. This research was to show that eosinophilic material with dark brown particles is accurate as new criteria for the cytological diagnosis of TB. By performing fine needle aspiration biopsy stained with Giemsa, if an eosinophilic material with dark brown particles was encountered, we continued with Ziehl-Neelsen AFB stain and confirmed with PCR. To assess accuracy, we used a diagnostic test to evaluate sensitivity and specificity of eosinophilic material with dark brown particles by using AFB and PCR as the gold standard. The sensitivity and specificity of cytological diagnosis in tuberculosis of eosinophilic material with dark brown particles were 93.65% and 70.99%, respectively if confirmed with AFB. On the other hand, if confirmed with PCR using Mycobacterium tuberculosis DNA, the sensitivity and specificity were 98.95% and 96.79%, respectively. In conclusion, eosinophilic masses with dark brown particles is accurate as new criteria of TB diagnostic cytology with high sensitivity and specificity confirmed with AFB and PCR test.

A sensitive nonenzymatic hydrogen peroxide sensor based on ...

Indian Academy of Sciences (India)

ple, H2O2 is useful for food production, sterilization, clin- ical applications and environmental analyses.1–4 Further, ... and showed a fast response and high sensitivity.9. Gu et al10 have synthesized Cu–. Ni(OH)2 nanocomposites and applied it as the fast and sensitive H2O2 sensor material. Ag nanoparticles were. ∗.

Facilitating Effects of Nanoparticles/Materials on Sensitive Immune-Related Lung Disorders

Directory of Open Access Journals (Sweden)

Ken-ichiro Inoue

2011-01-01

Full Text Available Although the adverse health effects of nanoparticles/materials have been proposed and are being clarified, their facilitating effects on preexisting pathological conditions have not been fully examined. In this paper, we provide insights into the immunotoxicity of nanoparticles/materials as an aggravating factor in hypersusceptible subjects, especially those with immune-related respiratory disorders using our in vivo experimental model. We first exhibit the effects of nanoparticles/materials on lung inflammation induced by bacterial endotoxin (lipopolysaccharide: LPS in vivo as a disease model in innate immunity, and demonstrated that nanoparticles instilled through both an intratracheal tube and an inhalation system can exacerbate the lung inflammation. Secondly, we introduce the effects of nanoparticles/materials on allergic asthma in vivo as a disease model in adaptive immunity, and showed that repetitive pulmonary exposure to nanoparticles has aggravating effects on allergic airway inflammation, including adjuvant effects on Th2-milieu. Taken together, nanoparticle exposure may synergistically facilitate pathological inflammatory conditions in the lung via both innate and adaptive immunological abnormalities.

Relative radiation sensitivity of insulators, stabilizers, and superconductors

International Nuclear Information System (INIS)

Van Konynenburg, R.A.; Guinan, M.W.

1980-12-01

The operating conditions of the magnets including temperature and radiation fields are discussed. Comments were made on the nuclear heating. Components of the magnet system, including the materials used, the important properties, the atomic structure, the damage mechanism, and the effects of room temperature warmup are described. Some failure criteria for the various components are suggested. Available data concerning radiation effects on each component are discussed. Their radiation sensitivities are compared using the conditions calculated for the ETF toroidal field magnet inboard leg, and ranked in order of sensitivity. Comments were made on the implications of this ranking for the directions of future applied materials research

Hazardous materials sensing: An electrical metamaterial approach

Energy Technology Data Exchange (ETDEWEB)

Rawat, Vaishali; Kitture, Rohini [Department of Applied Physics, Defence Institute of Advanced Technology (DIAT), Girinagar, Pune 411025 (India); Kumari, Dimple [Department of Applied Chemistry, Defence Institute of Advanced Technology (DIAT), Girinagar, Pune 411025 (India); Rajesh, Harsh [Society for Applied Microwave Electronics Engineering and Research (SAMEER), IIT-Bombay Campus, Powai, Mumbai (India); Banerjee, Shaibal [Department of Applied Chemistry, Defence Institute of Advanced Technology (DIAT), Girinagar, Pune 411025 (India); Kale, S.N., E-mail: sangeetakale2004@gmail.com [Department of Applied Physics, Defence Institute of Advanced Technology (DIAT), Girinagar, Pune 411025 (India)

2016-10-01

Metamaterials are recently emerging materials exhibiting amazing properties such as extremely miniaturized antennas, waveguides, optical couplers, multiplexers and filters. Such structures also respond to the variation in their ambient conditions when exposed to toxic and hazardous materials, which are especially hazardous to human health. Through this manuscript, we document our studies on three different high energy materials; namely 2- bromo-2nitropropane-1,3-diol (BNP), bis (1,3-diazido prop-2-yl) malonate (AM) and bis (1,3-diazido prop-2-yl) glutarate (AG). A Complementary Split Ring Resonator has been fabricated at resonant frequency of 4.48 GHz using copper on FR4 substrate. The energetic materials were exposed to the sensor and results were monitored using Vector Network Analyzer. The volume of liquids was varied from 0.5 µL to 3 µL. Prominent and explicit shifts in the transmission resonant frequency and amplitude was seen as a signature of each energetic material. The signatures were not only sensitive to the specific toxic group in the material but also to the volume of the liquid subjected to this sensor. The results are correlated with the simulation results, basic chemistry of the materials and permittivity measurements. The ultra-fast reversibility and repeatability, with good sensitivity and specificity of these devices project their applications in sensitive locations, particularly to combat for human security and health issues.

Analysis of the sensitivity of the impact resonance frequency test as a tool to determine the elastic properties of bituminous materials

Directory of Open Access Journals (Sweden)

R. Tauste

2017-07-01

Full Text Available The modulus value of bituminous materials is a key factor in the design of road pavements and the estimation of their life service. This parameter can be measured in laboratory but, unfortunately, this requires the deterioration of the pavement so as the consumption of time and resources. Therefore, this study analyses the feasibility of using impact resonance frequency tests as an alternative to traditional methods for determining the dynamic modulus of bituminous mixtures. The sensitivity of this technique has been studied by analyzing its repeatability and reproducibility, studying the variations in the values measured by modifying the dimensions of the specimens, test temperatures and types of mixture tested. In addition, this non-destructive technique has been compared with other traditional tests used to determine the elastic properties of bituminous materials. The results show that this test could be an interesting tool to characterize the properties and damage state of asphalt layers.

Analysis of the sensitivity of the impact resonance frequency test as a tool to determine the elastic properties of bituminous materials

International Nuclear Information System (INIS)

Tauste, R.; Moreno-Navarro, F.; Gallego, R.; Rubio-Gámez, M.C.

2017-01-01

The modulus value of bituminous materials is a key factor in the design of road pavements and the estimation of their life service. This parameter can be measured in laboratory but, unfortunately, this requires the deterioration of the pavement so as the consumption of time and resources. Therefore, this study analyses the feasibility of using impact resonance frequency tests as an alternative to traditional methods for determining the dynamic modulus of bituminous mixtures. The sensitivity of this technique has been studied by analyzing its repeatability and reproducibility, studying the variations in the values measured by modifying the dimensions of the specimens, test temperatures and types of mixture tested. In addition, this non-destructive technique has been compared with other traditional tests used to determine the elastic properties of bituminous materials. The results show that this test could be an interesting tool to characterize the properties and damage state of asphalt layers. [es

Investigation of electronic band structure and charge transfer mechanism of oxidized three-dimensional graphene as metal-free anodes material for dye sensitized solar cell application

Science.gov (United States)

Loeblein, Manuela; Bruno, Annalisa; Loh, G. C.; Bolker, Asaf; Saguy, Cecile; Antila, Liisa; Tsang, Siu Hon; Teo, Edwin Hang Tong

2017-10-01

Dye-sensitized solar cells (DSSCs) offer an optimal trade-off between conversion-efficiency and low-cost fabrication. However, since all its electrodes need to fulfill stringent work-function requirements, its materials have remained unchanged since DSSC's first report early-90s. Here we describe a new material, oxidized-three-dimensional-graphene (o-3D-C), with a band gap of 0.2 eV and suitable electronic band-structure as alternative metal-free material for DSSCs-anodes. o-3D-C/dye-complex has a strong chemical bonding via carboxylic-group chemisorption with full saturation after 12 sec at capacity of ∼450 mg/g (600x faster and 7x higher than optimized metal surfaces). Furthermore, fluorescence quenching of life-time by 28-35% was measured demonstrating charge-transfer from dye to o-3D-C.

Strain hardening rate sensitivity and strain rate sensitivity in TWIP steels

Energy Technology Data Exchange (ETDEWEB)

Bintu, Alexandra [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Vincze, Gabriela, E-mail: gvincze@ua.pt [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Picu, Catalin R. [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Lopes, Augusto B. [CICECO, Department of Materials and Ceramic Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Grácio, Jose J. [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Barlat, Frederic [Materials Mechanics Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2015-04-01

TWIP steels are materials with very high strength and exceptional strain hardening capability, parameters leading to large energy absorption before failure. However, TWIP steels also exhibit reduced (often negative) strain rate sensitivity (SRS) which limits the post-necking deformation. In this study we demonstrate for an austenitic TWIP steel with 18% Mn a strong dependence of the twinning rate on the strain rate, which results in negative strain hardening rate sensitivity (SHRS). The instantaneous component of SHRS is large and negative, while its transient is close to zero. The SRS is observed to decrease with strain, becoming negative for larger strains. Direct observations of the strain rate dependence of the twinning rate are made using electron microscopy and electron backscatter diffraction, which substantiate the proposed mechanism for the observed negative SHRS.

Strain hardening rate sensitivity and strain rate sensitivity in TWIP steels

International Nuclear Information System (INIS)

Bintu, Alexandra; Vincze, Gabriela; Picu, Catalin R.; Lopes, Augusto B.; Grácio, Jose J.; Barlat, Frederic

2015-01-01

TWIP steels are materials with very high strength and exceptional strain hardening capability, parameters leading to large energy absorption before failure. However, TWIP steels also exhibit reduced (often negative) strain rate sensitivity (SRS) which limits the post-necking deformation. In this study we demonstrate for an austenitic TWIP steel with 18% Mn a strong dependence of the twinning rate on the strain rate, which results in negative strain hardening rate sensitivity (SHRS). The instantaneous component of SHRS is large and negative, while its transient is close to zero. The SRS is observed to decrease with strain, becoming negative for larger strains. Direct observations of the strain rate dependence of the twinning rate are made using electron microscopy and electron backscatter diffraction, which substantiate the proposed mechanism for the observed negative SHRS

Sensitivity to contamination of optical coatings

International Nuclear Information System (INIS)

Macleod, A.

1999-01-01

A simple theory is presented of the sensitivity to contamination of optical coatings, which permits prediction of performance degradation in the presence of small deposit s of absorbing material. Although a major objective is the ability to compare the sensitivities of different coating types, absolute values can be made possible by adopting a standard contamination layer consisting of a 1 Angstrom thickness of carbon. Results are quoted for a number of common thin-film coatings and filters and are sometimes surprising. The common high-reflectance coating is the quarterwave stack and, at its reference wavelength, it has very low sensitivity to contamination. Although minor constructional errors have little effect on the reflectance, they can seriously affect the contamination sensitivity. Further, the level of contamination determines the maximum reflectance it is possible to achieve, regardless of the number of layers in the coating. The admittance diagram helps in understanding the reasons for the very large variations in sensitivity between coatings with quite similar reflectance

Assessment of inhalation dose sensitivity by physicochemical properties of airborne particulates containing naturally occurring radioactive materials

Energy Technology Data Exchange (ETDEWEB)

Kim, Si Young; Choi, Cheol Kyu; Kim, Yong Geon; Choi, Won Chul; Kim, Kwang Pyo [Kyung Hee University, Seoul (Korea, Republic of)

2015-12-15

Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of 0.01μm sized particulates were higher than doses due to 100μm sized particulates by factors of about 100 and 50 for {sup 238}U and {sup 230}Th, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of 11 g·cm{sup -3} and 0.7 g·cm{sup -3} resulted in dose difference by about 60 %. For {sup 238}U, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of {sup 238}U was about 9 times higher than dose for absorption F. For {sup 230}Th, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of {sup 230}Th was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and

Environment-sensitive ion-track membranes

International Nuclear Information System (INIS)

Yoshida, Masaru

1996-01-01

Development of an environment-sensitive porous membrane from ion-track membranes may realize by combining the techniques of ion beam radiation and those of molecular designing and synthesis for intelligent materials. Now, the development of such membrane is progressing with an aim at selecting some specific substances and accurately control its pore size in response to any small environmental stimulus such as temperature change. The authors have been studying the molecular design, synthesis and functional expression of intelligent materials, which are called here as environment-sensitive gels. In this report, the outlines of the apparatus for the production of such porous membrane was described. An organic polymer membrane was irradiated with an ion beam and followed by chemical etching to make ion track pores. Scanning electron microscopic observation for the cross section of the membrane showed that the pore shape varies greatly depending on the ion nuclide used. The characteristics of newly produced porous membranes consisting of CR-30/A-ProDMe and polyethylene-telephtharate were investigated in respect of pore size change responding to temperature. These studies of design, synthesis and functions of such gels would enable to substitute artificial materials for the functions of human sensors. (M.N.). 54 refs

Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

Science.gov (United States)

Hossain, Md. Khalid; Pervez, M. Firoz; Mia, M. N. H.; Mortuza, A. A.; Rahaman, M. S.; Karim, M. R.; Islam, Jahid M. M.; Ahmed, Farid; Khan, Mubarak A.

In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric) sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV-Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell's (DSSC) photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric.

Surrogate indicators of sensitivity in gynecologic cytology: Can they be used to improve the measurement of sensitivity in the laboratory?

Directory of Open Access Journals (Sweden)

Renshaw Andrew

2009-01-01

Full Text Available Background: Measuring the sensitivity of screening in gynecologic cytology in real life is problematic. However, other quality measures may correlate with sensitivity, including the atypical squamous cells (ASC/squamous intraepithelial lesion (SIL ratio. Whether these other measures can function as "surrogate indicators" for sensitivity and improve the assessment of sensitivity in the laboratory is not known. Materials and Methods: We compared multiple quality measures with true screening sensitivity in a variety of situations. Results: The abnormal rate, ASC rate, and ASC/SIL ratio were all highly correlated (r = .83 or greater with sensitivity when the overall laboratory sensitivity was low (85% but became less correlated (.64 or less or uncorrelated when the screening sensitivity was higher (88% or 95%, respectively. Sensitivity was more highly correlated with the abnormal rate than the ASC/SIL ratio at low screening sensitivity. While thresholds could be set that were highly sensitive and specific for suboptimal screening, these thresholds were often less than one standard deviation away from the mean. Conclusion: The correlation of the abnormal rate and the ASC/SIL ratio with sensitivity depends on overall sensitivity. Standards to define minimum screening sensitivity can be defined, but these standards are relatively narrow. These features may limit the utility of these quality measures as surrogates for sensitivity.

Adjoint sensitivity analysis of high frequency structures with Matlab

CERN Document Server

Bakr, Mohamed; Demir, Veysel

2017-01-01

This book covers the theory of adjoint sensitivity analysis and uses the popular FDTD (finite-difference time-domain) method to show how wideband sensitivities can be efficiently estimated for different types of materials and structures. It includes a variety of MATLAB® examples to help readers absorb the content more easily.

Exploring the sensitivity of the zone of inhibition test for leachable biocides from paper and board food contact materials, and improvements thereof.

Science.gov (United States)

Castle, L; Kelly, J; Jickells, S M; Johns, S M; Mountfort, K A

2012-01-01

The zone of inhibition method to test the release of biocides from paper and board food contact materials was evaluated. The method tests the paper by placing a small specimen directly onto culture plates of Bacillus subtilis and Aspergillus niger. The principle is that any extractable biocide will diffuse from the paper into the surrounding nutrient medium and so inhibit growth of the microorganism in the vicinity. The test was found to have insufficient sensitivity for assuring food safety, where detection limits for migration at or below the mg l(-1) (parts per million) level are needed. Also, the test does not mimic the actual or foreseeable conditions of use since most paper/board materials are not intended for direct contact with an aqueous medium for up to 3 days at 30°C (B. subtilis) or 25°C (A. niger), which are the incubation conditions used. The sensitivity of the test was increased approximately 100-fold by preparing a concentrated extract of the paper to be tested and applying this extract to the assay via a blank paper carrier. This was done using methanol as a good solvent for most biocides, as a proof of principle. Other solvents or food simulants could be used to mimic the conditions of use intended for the particular paper/board samples under examination, e.g. contact with dry, fatty, aqueous or acidic foods, hot or cold. Twenty-four plain (unconverted) paper and board samples and 100 food packaging samples were evaluated using the modified procedure. The results revealed that the method has been developed to the stage where background cytotoxic action of normal paper constituents gives a weak response. Unlike the original method, therefore, the modified method with its improved sensitivity and the facility to link with the intended food contact conditions may be considered a suitable bioassay screening test to complement chemical analysis of paper/board for composition and migration.

Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials.

Science.gov (United States)

Janeczek, Maciej; Herman, Katarzyna; Fita, Katarzyna; Dudek, Krzysztof; Kowalczyk-Zając, Małgorzata; Czajczyńska-Waszkiewicz, Agnieszka; Piesiak-Pańczyszyn, Dagmara; Kosior, Piotr; Dobrzyński, Maciej

2016-01-01

Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved four composite restorative materials, one lining material and a dentine bonding agent. The polymerization was conducted with the use of a diode light-curing unit. The measurements of the external surface temperature of the samples were carried out using the Thermovision®550 thermal camera. Results. The examined materials significantly differed in terms of the maximum temperatures values they reached, as well as the time required for reaching the temperatures. A statistically significant positive correlation of the maximum temperature and the sample weight was observed. Conclusions. In clinical practice, it is crucial to bear in mind the risk of thermal damage involved in the application of light-cured materials. It can be reduced by using thin increments of composite materials.

High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

Science.gov (United States)

Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Thual, Monique; Lemaître, Jonathan; Pirasteh, Parastesh; Hardy, Isabelle; Charrier, Joël

2017-11-27

We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10 -6 RIU.

Advanced materials for clean energy

CERN Document Server

Xu (Kyo Jo), Qiang

2015-01-01

Arylamine-Based Photosensitizing Metal Complexes for Dye-Sensitized Solar CellsCheuk-Lam Ho and Wai-Yeung Wongp-Type Small Electron-Donating Molecules for Organic Heterojunction Solar CellsZhijun Ning and He TianInorganic Materials for Solar Cell ApplicationsYasutake ToyoshimaDevelopment of Thermoelectric Technology from Materials to GeneratorsRyoji Funahashi, Chunlei Wan, Feng Dang, Hiroaki Anno, Ryosuke O. Suzuki, Takeyuki Fujisaka, and Kunihito KoumotoPiezoelectric Materials for Energy HarvestingDeepam Maurya, Yongke Yan, and Shashank PriyaAdvanced Electrode Materials for Electrochemical Ca

Polarization sensitivity testing of off-plane reflection gratings

Science.gov (United States)

Marlowe, Hannah; McEntaffer, Randal L.; DeRoo, Casey T.; Miles, Drew M.; Tutt, James H.; Laubis, Christian; Soltwisch, Victor

2015-09-01

Off-Plane reflection gratings were previously predicted to have different efficiencies when the incident light is polarized in the transverse-magnetic (TM) versus transverse-electric (TE) orientations with respect to the grating grooves. However, more recent theoretical calculations which rigorously account for finitely conducting, rather than perfectly conducting, grating materials no longer predict significant polarization sensitivity. We present the first empirical results for radially ruled, laminar groove profile gratings in the off-plane mount which demonstrate no difference in TM versus TE efficiency across our entire 300-1500 eV bandpass. These measurements together with the recent theoretical results confirm that grazing incidence off-plane reflection gratings using real, not perfectly conducting, materials are not polarization sensitive.

A study on strengthening measures of non-proliferation regime through the export control system of sensitive materials, equipment and technology related to nuclear activities

International Nuclear Information System (INIS)

Kikuchi, Masahiro; Kurosawa, Mitsuru; Komizo, Yasuyoshi

2004-01-01

The strengthened safeguards caused from safeguards experiences to Iraq and DPRK leads to the expansion of the IAEA's activities for verification of all nuclear activities as well as verification of nuclear material in the States. The purpose of the activities, of course, includes detection of undeclared exports and imports of specified equipment and non-nuclear material. The Additional Protocol to the agreements between States and the IAEA for the application of safeguards requires to the States to declare the exports and imports information regarding specified equipment and non-nuclear material corresponding to the export control list that is established by the nuclear suppliers group. The Additional Protocol also insists the IAEA's right to access to the location identified by the State to resolve a question related to the declarations. Recently, the IAEA detected the black market group of the sensitive materials, equipment and technologies relevant to the nuclear proliferation through the safeguards activities to Iran and Libya. International community stated deeply concerns to the indecent facts. This paper would discuss and propose the supplemental strengthening measures of non-proliferation regime by effective combination of the safeguards activities under additional protocol and the export control regime. (author)

Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials

Directory of Open Access Journals (Sweden)

Maciej Janeczek

2016-01-01

Full Text Available Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved four composite restorative materials, one lining material and a dentine bonding agent. The polymerization was conducted with the use of a diode light-curing unit. The measurements of the external surface temperature of the samples were carried out using the Thermovision®550 thermal camera. Results. The examined materials significantly differed in terms of the maximum temperatures values they reached, as well as the time required for reaching the temperatures. A statistically significant positive correlation of the maximum temperature and the sample weight was observed. Conclusions. In clinical practice, it is crucial to bear in mind the risk of thermal damage involved in the application of light-cured materials. It can be reduced by using thin increments of composite materials.

Recent Advances in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

F. O. Lenzmann

2007-01-01

Full Text Available This review describes recent advances in the research on dye-sensitized solar cells. After a brief discussion of the general operation principles and a presentation of record efficiencies, stability data and key technology drivers, current trends will be reviewed. The focus of this review is on materials development (sensitizers, nanostructured oxide films, and electrolyte, but commercialization aspects will also be briefly addressed. The review describes the most relevant characteristics and major trends in a compact way.

Research for improved flexible tactile sensor sensitivity

International Nuclear Information System (INIS)

Yun, Hae Yong; Kim, Ho Chan; Lee, In Hwan

2015-01-01

With the development of robotic technologies, in recent years these technologies have been applied to multidisciplinary fields of study. To operate similarly to a human being, many robot technologies require devices that can receive exterior stimulus, temperature, visual data, and the sense of smell, etc. The robot's hand needs sensor devices that can receive exterior stimuli in order to operate similarly to human skin. The flexible tactile sensor for the robot has to be manufactured to have a shape similar to the shape of human skin. The research studied the development of a system and materials that will enable exterior stimuli to be received effectively. This research used carbon nano tube as a material. Carbon nano tube is used because it has a high electrical conductivity and outstanding mechanical characteristics. In addition, the two composite Materials are used to improve the stimulation sensitivity at different rates, the flexible tactile sensor to measure the sensitivity. Using 3D printing technology, the fabrication of a flexible tactile sensor system is introduced.

Research for improved flexible tactile sensor sensitivity

Energy Technology Data Exchange (ETDEWEB)

Yun, Hae Yong; Kim, Ho Chan [Andong National University, Andong (Korea, Republic of); Lee, In Hwan [Chungbuk National University, Chungju (Korea, Republic of)

2015-11-15

With the development of robotic technologies, in recent years these technologies have been applied to multidisciplinary fields of study. To operate similarly to a human being, many robot technologies require devices that can receive exterior stimulus, temperature, visual data, and the sense of smell, etc. The robot's hand needs sensor devices that can receive exterior stimuli in order to operate similarly to human skin. The flexible tactile sensor for the robot has to be manufactured to have a shape similar to the shape of human skin. The research studied the development of a system and materials that will enable exterior stimuli to be received effectively. This research used carbon nano tube as a material. Carbon nano tube is used because it has a high electrical conductivity and outstanding mechanical characteristics. In addition, the two composite Materials are used to improve the stimulation sensitivity at different rates, the flexible tactile sensor to measure the sensitivity. Using 3D printing technology, the fabrication of a flexible tactile sensor system is introduced.

Development of a highly sensitive lithium fluoride thermoluminescence dosimeter

International Nuclear Information System (INIS)

Moraes da Silva, Teresinha de; Campos, Leticia Lucente

1995-01-01

In recent times, LiF: Mg, Cu, P thermoluminescent phosphor has been increasingly in use for radiation monitoring due its high sensitivity and ease of preparation. The Dosimetric Materials Production Laboratory of IPEN, (Nuclear Energy Institute) has developed a simple method to obtain high sensitivity LiF. The preparation method is described. (author). 4 refs., 1 fig., 1 tab

Sensitive silicon PIN-diode dosimeter for fast neutrons and method to control and increase its sensitivity

International Nuclear Information System (INIS)

Swinehart, P.R.; Swartz, J.M.

1978-01-01

With the personnel dosimeter, applicable e.g. in medicine, a dose of 0.1 rad for neutrons with an energy greater than 10 keV can be detected. In the range between 0.1 and 20 rad sensitivity is increased to 5 mV/rad. This sensitivity can be achieved by distributing the mass of the semiconductor material of the diode or equal to four times the reciprocal base width. Appropriate dimensions are 750 μm for the edge length of the end surface resp. diameter and 750 μm up to 5000 μm for the base width. (DG) [de

Multi-parameters sensitivity analysis of natural vibration modal for steel arch bridge

Directory of Open Access Journals (Sweden)

WANG Ying

2014-02-01

Full Text Available Because of the vehicle loads and environmental factors,the behaviors of bridge structure in service is becoming deterioration.The modal parameters are important indexes of structure,so sensitivity analysis of natural vibration is an important way to evaluate the behavior of bridge structure.In this paper,using the finite element software Ansys,calculation model of a steel arch bridge was built,and the natural vibration modals were obtained.In order to compare the different sensitivity of material parameters which may affect the natural vibration modal,5 factors were chosen to perform the calculation.The results indicated that different 5 factors had different sensitivity.The leading factor was elastic modulus of arch rib,and the elastic modulus of suspender had little effect to the sensitivity.Another argument was the opposite sensitivity effect happened between the elastic modulus and density of the material.

Probabilistic Sensitivities for Fatigue Analysis of Turbine Engine Disks

Directory of Open Access Journals (Sweden)

Harry R. Millwater

2006-01-01

Full Text Available A methodology is developed and applied that determines the sensitivities of the probability-of-fracture of a gas turbine disk fatigue analysis with respect to the parameters of the probability distributions describing the random variables. The disk material is subject to initial anomalies, in either low- or high-frequency quantities, such that commonly used materials (titanium, nickel, powder nickel and common damage mechanisms (inherent defects or surface damage can be considered. The derivation is developed for Monte Carlo sampling such that the existing failure samples are used and the sensitivities are obtained with minimal additional computational time. Variance estimates and confidence bounds of the sensitivity estimates are developed. The methodology is demonstrated and verified using a multizone probabilistic fatigue analysis of a gas turbine compressor disk analysis considering stress scatter, crack growth propagation scatter, and initial crack size as random variables.

Sensitivity optimization in whispering gallery mode optical cylindrical biosensors

Science.gov (United States)

Khozeymeh, F.; Razaghi, M.

2018-01-01

Whispering-gallery-mode resonances propagated in cylindrical resonators have two angular and radial orders of l and i. In this work, the higher radial order whispering-gallery-mode resonances, (i = 1 - 4), at a fixed l are examined. The sensitivity of theses resonances is analysed as a function of the structural parameters of the cylindrical resonator like different radii and refractive index of composed material of the resonator. A practical application where cylindrical resonators are used for the measurement of glucose concentration in water is presented as a biosensor demonstrator. We calculate the wavelength shifts of the WG1-4, in several glucose/water solutions, with concentrations spanning from 0.0% to 9.0.% (weight/weight). Improved sensitivity can be achieved using multi-WGM cylindrical resonators with radius of R = 100 μm and resonator composed material of MgF 2 with refractive index of nc = 1.38. Also the effect of polarization on sensitivity is considered for all four WGMs. The best sensitivity of 83.07 nm/RIU for the fourth WGM with transverse magnetic polarization, is reported. These results propose optimized parameters aimed to fast designing of cylindrical resonators as optical biosensors, where both the sensitivity and the geometries can be optimized.

Characterization of sensitization and stress corrosion cracking behavior of stabilized stainless steels under BWR conditions

International Nuclear Information System (INIS)

Kilian, R.; Ilg, U.; Meier, V.; Teichmann, H.; Wachter, O.

1995-01-01

Stress corrosion cracking occurs if the three parameters -- material condition, tensile stress and water chemistry -- are in a critical range. In this study the material conditions especially of Ti- and Nb-stabilized steels are considered. The purpose of this work is to show the influence of the degree of sensitization of Ti- and Nb-stabilized stainless steels on stress corrosion cracking susceptibility in BWR water chemistry. This is an on-going research program. Preliminary results will be presented. Different types of stabilized, and for comparison unstabilized, stainless steels are examined in various heat treatment conditions with regard to their sensitization behavior by EPR tests (double loop) and TEM. The results are plotted in sensitization diagrams. The sensitization behavior depends on many parameters such as carbon content, stabilization element, stabilization ratio and materials history, e.g. solution heat treatment or cold working. The obtained EPR sensitization diagrams are compared with the well known sensitization diagrams from the literature, which were determined by standard IC test according to e.g. German standard DIN 50914 (equivalent to ASTM A 262, Pract. E). Based on the obtained EPR sensitization diagrams material conditions for SSRT tests were selected. The EPR values (Ir/Ia x 100%) of the tested Ti-stabilized stainless steel are in the range of ∼ 0.1--20%. The SSRT tests are carried out in high-temperature water with 0.4 ppm O 2 , a conductivity of 0.5 microS/cm and a strain rate of 1x10 -6-1 . The test temperature is 280 C. Ti-stabilized stainless steel with Ir/Ia x 100% > 1% suffered intergranular stress corrosion cracking under these conditions. The SCC tests for Nb-stabilized stainless steel are still in progress. The correlation between EPR value, chromium depletion and SSRT result will be shown for a selected material condition of sensitized Ti-stabilized stainless steel

Materials-of-Construction Radiation Sensitivity for a Fission Surface Power Convertor

Science.gov (United States)

Bowman, Cheryl L.; Geng, Steven M.; Niedra, Janis M.; Sayir, Ali; Shin, Eugene E.; Sutter, James K.; Thieme, Lanny G.

2007-01-01

A fission reactor combined with a free-piston Stirling convertor is one of many credible approaches for producing electrical power in space applications. This study assumes dual-opposed free-piston Stirling engines/linear alternators that will operate nominally at 825 K hot-end and 425 K cold-end temperatures. The baseline design options, temperature profiles, and materials of construction discussed here are based on historical designs as well as modern convertors operating at lower power levels. This notional design indicates convertors primarily made of metallic components that experience minimal change in mechanical properties for fast neutron fluences less than 10(sup 20) neutrons per square centimeter. However, these radiation effects can impact the magnetic and electrical properties of metals at much lower fluences than are crucial for mechanical property integrity. Moreover, a variety of polymeric materials are also used in common free-piston Stirling designs for bonding, seals, lubrication, insulation and others. Polymers can be affected adversely by radiation doses as low as 10(sup 5) - 10(sup 10) rad. Additionally, the absorbing dose rate, radiation hardness, and the resulting effect (either hardening or softening) varies depending on the nature of the particular polymer. The classes of polymers currently used in convertor fabrication are discussed along possible substitution options. Thus, the materials of construction of prototypic Stirling convertor engines have been considered and the component materials susceptible to damage at the lowest neutron fluences have been identified.

Silk Composite with a Fluoropolymer as a Water-Resistant Protein-Based Material

Directory of Open Access Journals (Sweden)

Keiji Numata

2018-04-01

Full Text Available Silk-based materials are water-sensitive and show different physical properties at different humidities and under wet/dry conditions. To overcome the water sensitivity of silk-based materials, we developed a silk composite material with a fluoropolymer. Blending and coating the silk protein-based materials, such as films and textiles, with the fluoropolymer enhanced the surface hydrophobicity, water vapor barrier properties, and size stability during shrinkage tests. This material design with a protein biopolymer and a fluoropolymer is expected to broaden the applicability of protein-based materials.

Synthesis and characterization of natural dye and counter electrode thin films with different carbon materials for dye-sensitized solar cells.

Science.gov (United States)

Chang, Ho; Chen, Tien-Li; Kao, Mu-Jung; Chen, Chih-Hao; Chien, Shu-Hua; Jiang, Lii-Jenq

2011-08-01

This study aims to deal with the film of the counter electrode of dye-sensitized solar cells (DSSCs) and the preparation, structure and characteristics of the extract of natural dye. This study adopts different commercial carbon materials such as black lead, carbon black and self-made TiO2-MWCNT compound nanoparticle as the film of the counter electrodes. Moreover, for the preparation of natural dyes, anthocyanins and chlorophyll dyes are extracted from mulberry and pomegranate respectively. Furthermore, the extracted anthocyanins and chlorophyll are blended into cocktail dye to complete the preparation of natural dye. Results show that the photoelectric conversion efficiency of the single-layer TiO2-MWCNT counter electrode film and the cocktail dye of the DSSCs is 0.462%.

Well-crystalline porous ZnO-SnO2 nanosheets: an effective visible-light driven photocatalyst and highly sensitive smart sensor material.

Science.gov (United States)

Lamba, Randeep; Umar, Ahmad; Mehta, S K; Kansal, Sushil Kumar

2015-01-01

This work demonstrates the synthesis and characterization of porous ZnO-SnO2 nanosheets prepared by the simple and facile hydrothermal method at low-temperature. The prepared nanosheets were characterized by several techniques which revealed the well-crystallinity, porous and well-defined nanosheet morphology for the prepared material. The synthesized porous ZnO-SnO2 nanosheets were used as an efficient photocatalyst for the photocatalytic degradation of highly hazardous dye, i.e., direct blue 15 (DB 15), under visible-light irradiation. The excellent photocatalytic degradation of prepared material towards DB 15 dye could be ascribed to the formation of ZnO-SnO2 heterojunction which effectively separates the photogenerated electron-hole pairs and possess high surface area. Further, the prepared porous ZnO-SnO2 nanosheets were utilized to fabricate a robust chemical sensor to detect 4-nitrophenol in aqueous medium. The fabricated sensor exhibited extremely high sensitivity of ~ 1285.76 µA/mmol L(-1)cm(-2) and an experimental detection limit of 0.078 mmol L(-1) with a linear dynamic range of 0.078-1.25 mmol L(-1). The obtained results confirmed that the prepared porous ZnO-SnO2 nanosheets are potential material for the removal of organic pollutants under visible light irradiation and efficient chemical sensing applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Antibacterial Activity of Hydrophobic Composite Materials Containing a Visible-Light-Sensitive Photocatalyst

Directory of Open Access Journals (Sweden)

Kentaro Yamauchi

2011-01-01

Full Text Available The conventional superhydrophobic surface offered by PTFE provides no sterilization performance and is not sufficiently repellent against organic liquids. These limit PTFE's application in the field of disinfection and result a lack of durability. N-doped TiO2 photocatalyst added PTFE composite material was developed to remedy these shortcomings. This paper reports the surface characteristics, and the bactericidal and self-cleaning performance of the newly-developed composite material. The material exhibited a contact angle exceeding 150 degrees consistent with its hydrophobicity despite the inclusion of the hydrophilic N-doped TiO2. The surface free energy obtained for this composite was 5.8 mN/m. Even when exposed to a weak fluorescent light intensity (100 lx for 24 hours, the viable cells of gram-negative E. coli on the 12% N-doped TiO2-PTFE film were reduced 5 logs. The higher bactericidal activity was also confirmed on the gram-positive MRSA. Compared with the N-doped TiO2 coating only, the inactivation rate of the composite material was significantly enhanced. Utilizing the N-doped TiO2 with the PTFE composite coating could successfully remove, by UV illumination, oleic acid adsorbed on its surface. These results demonstrate the potential applicability of the novel N-doped TiO2 photocatalyst hydrophobic composite material for both indoor antibacterial action and outdoor contamination prevention.

The first word in material control is material

International Nuclear Information System (INIS)

Martin, H.R.; Wilkey, D.D.

1989-01-01

Material control has tended to rely on containment and access control, augmented by physical inventories, to meet the material control and accounting (MC ampersand A) goals of detecting theft/diversion and providing assurance that all nuclear material (NM) is present. Such systems have significant deficiencies. Material containment strategies are generally based on protection provided at boundaries around the NM and rely on alarms at the boundary for detection of theft/diversion. Assurance that all NM is present requires a negative inference based on the absence of alarms. Additionally, design of effective boundary protection systems requires that the designer be able to anticipate and provide protection for all scenarios that the insider adversary might utilize in removing material from the facility. Access control is an administrative system that cannot protect against malevolent actions by insiders authorized to access the material. Inventories may not provide timely detection of theft/diversion, and the sensitivity of detection depends on the magnitude of the variance of the inventory difference. More effective material control is provided for both material in storage and in process by a material-oriented system designed to detect abnormal events involving NM. Abnormal events are defined as any unauthorized activity involving NM, whether accidental or deliberate, and are assessed to determine the cause of the discrepancy. The designs of material-oriented control systems vary greatly, depending on the operations involved; however, a model system would include the use of process monitoring data for material control and automated surveillance of material in storage

Potassium-doped zinc oxide as photocathode material in dye-sensitized solar cells.

Science.gov (United States)

Bai, Jie; Xu, Xiaobao; Xu, Ling; Cui, Jin; Huang, Dekang; Chen, Wei; Cheng, Yibing; Shen, Yan; Wang, Mingkui

2013-04-01

ZnO nanoparticles are doped with K and applied in p-type dye-sensitized solar cells (DSCs). The microstructure and dynamics of hole transportation and recombination are investigated. The morphology of the K-doped ZnO nanoparticles shows a homogeneous distribution with sizes in the range 30-40 nm. When applied in p-type DSCs in combination with C343 as sensitizer, the K-doped ZnO nanoparticles achieve a photovoltaic power conversion efficiency of 0.012 % at full-intensity sunlight. A further study on the device by transient photovoltage/photocurrent decay measurements shows that the K-doped ZnO nanoparticles have an appreciable hole diffusion coefficient (ca. 10(-6) cm(2) s(-1) ). Compared to the widely used p-type NiO nanoparticles, this advantage is crucial for further improving the efficiency of p-type DSCs. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Time-temperature-sensitization and time-temperature-precipitation behavior of alloy 625

International Nuclear Information System (INIS)

Koehler, M.; Heubner, U.

1996-01-01

Time-Temperature-Sensitization diagrams have been established for a low-carbon version of alloy 625 (UNS N06625). Sensitization in terms of a 50 microm (2 mils) intergranular penetration criterion starts after about 3 h aging time at 750 C (soft annealed condition) or after less than 1 h aging time at 800 C (solution annealed condition) when tested according to ASTM-G 28 method A. Grain boundary precipitation of carbides occurs during aging of both the soft annealed and the solution annealed material, but the soft annealed material exhibits a more pronounced general precipitation of Ni 3 (Nb,Mo) phase giving rise to more distinct loss of ductility. Sensitization of alloy 625 may be retarded by lowering its iron content

Ultra-sensitive EUV resists based on acid-catalyzed polymer backbone breaking

Science.gov (United States)

Manouras, Theodoros; Kazazis, Dimitrios; Koufakis, Eleftherios; Ekinci, Yasin; Vamvakaki, Maria; Argitis, Panagiotis

2018-03-01

The main target of the current work was to develop new sensitive polymeric materials for lithographic applications, focusing in particular to EUV lithography, the main chain of which is cleaved under the influence of photogenerated acid. Resist materials based on the cleavage of polymer main chain are in principle capable to create very small structures, to the dimensions of the monomers that they consist of. Nevertheless, in the case of the commonly used nonchemically amplified materials of this type issues like sensitivity and poor etch resistance limit their areas of application, whereas inadequate etch resistance and non- satisfactory process reliability are the usual problems encountered in acid catalysed materials based on main chain scission. In our material design the acid catalyzed chain cleavable polymers contain very sensitive moieties in their backbone while they remain intact in alkaline ambient. These newly synthesized polymers bear in addition suitable functional groups for the achievement of desirable lithographic characteristics (thermal stability, acceptable glass transition temperature, etch resistance, proper dissolution behavior, adhesion to the substrate). Our approach for achieving acceptable etch resistance, a main drawback in other main chain cleavable resists, is based on the introduction of polyaromatic hydrocarbons in the polymeric backbone, whereas the incorporation of an inorganic component further enhances the etch resistance. Single component systems can also be designed following the proposed approach by the incorporation of suitable PAGs and base quencher molecules in the main chain. Resist formulations based on a random copolymer designed according to the described rules evaluated in EUV exhibit ultrahigh sensitivity, capability for high resolution patterning and overall processing characteristics that make them strong candidates for industrial use upon further optimization.

Measurement and prediction of thermochemical history effects on sensitization development in austenitic stainless steels

International Nuclear Information System (INIS)

Bruemmer, S.M.; Charlot, L.A.

1985-11-01

The effects of thermal and thermomechanical treatments on sensitization development in Type 304 and 316 stainless steels have been measured and compared to model predictions. Sensitization development resulting from isothermal, continuous cooling and pipe welding treatments has been evaluated. An empirically modified, theoretically based model is shown to accurately predict material degree of sensitization (DOS) as expressed by the electrochemical potentiokinetic reactivation (EPR) test after both simple and complex treatments. Material DOS is also examined using analytical electron microscopy to document grain boundary chromium depletion and is compared to EPR test results

Irradiating rubber laminate containing sensitive agent in layer

International Nuclear Information System (INIS)

Bohm, G.G.A.

1979-01-01

Rubber compounds may be sensitized to cure or partially cure when subjected to irradiation. If certain layers of a rubber laminate are treated with sensitizing materials and other layers wth densensitizing materials a composite is produced having cured and uncured layers after it has been subjected to irradiation. This technique enables the production of composite laminates in which predetermined layers have predetermined physical characteristics which are desirable in the manufacture of the ultimate end product, for example, automotive tires. Several chemicals have been found to accelerate the cure of rubber compounds by irradiation and several have been found which inhibit the cure. Paradichlorobenzene (PDCB) and certain of the thioetherpolythiols are effective cure promotors. Effective retarders include aromatic oils, sulfur, sulfur cure accelerators and some rubber antioxidants and/or antiozonants of the substituted diphenylamine type. The dosage of irradiation is dependent upon several variables: the type of rubber, the promotor or retarder utilized, the level of the promotor or retarder, the thickness of the layer of material, the thickness of adjacent layers of materials, the sequence of the layers of material, the number of the layers of material and whether the irradiation is applied to one or both sides of the composite strip. The dosage may be controlled by the amount of energy employed so that the electrons do not completely penetrate the entire strip. This results in the irradiaton of part of the strip, but not the entire strip. (LL)

Nursing students’ understanding of factors influencing ethical sensitivity: A qualitative study

OpenAIRE

Borhani, Fariba; Abbaszadeh, Abbas; Mohsenpour, Mohaddeseh

2013-01-01

Background: Ethical sensitivity is considered as a component of professional competency of nurses. Its effects on improvement of nurses’ ethical performance and the therapeutic relationship between nurses and patients have been reported. However, very limited studies have evaluated ethical sensitivity. Since no previous Iranian research has been conducted in this regard, the present study aimed to review nursing students’ understanding of effective factors on ethical sensitivity. Materials an...

Beam radiation curing of adhesives for flocking on heat-sensitive substrates

International Nuclear Information System (INIS)

Nablo, S.V.; Fussa, A.D.

1979-01-01

A process is described for curing the adhesive used to hold flock fiber material to a heat-sensitive substrate consisting of temperature-sensitive plastic, natural fibers, wood, paper, or paper-foil laminates. An electron-curable adhesive layer (acrylic, epoxy, epoxy esters, acrylic latex, or urethane) a few mils thick is applied to the substrate and a layer of texturing material is attached to the adhesive layer with fibers substantially perpendicular to the layer. The assembly of substrate and adhesively secured material is passed at a rate of about 20 to 80 meters per minute under an unscanned electron curtain beam which possesses an energy of 150 keV +- 30 percent and delivers an electron dose of 2 megarads +- 50 percent to the adhesive layer. (LL)

Passive sensor systems for nuclear material monitoring

International Nuclear Information System (INIS)

Simpson, M.L.; Boatner, L.A.; Holcomb, D.E.; McElhaney, S.A.; Mihalczo, J.T.; Muhs, J.D.; Roberts, M.R.; Hill, N.W.

1993-01-01

Passive fiber optic sensor systems capable of confirming the presence of special nuclear materials in storage or process facilities are being developed at Oak Ridge National Laboratory (ORNL). These sensors provide completely passive, remote measurement capability. No power supplies, amplifiers, or other active components that could degrade system reliability are required at the sensor location. ORNL, through its research programs in scintillator materials, has developed a variety of materials for use in alpha-, beta-, gamma-, and neutron-sensitive scintillator detectors. In addition to sensors for measuring radiation flux, new sensor materials have been developed which are capable of measuring weight, temperature, and source location. An example of a passive sensor for temperature measurement is the combination of a thermophosphor (e.g., rare-earth activated Y 2 O 3 ) with 6 LiF (95% 6 Li). This combination results in a new class of scintillators for thermal neutrons that absorb energy from the radiation particles and remit the energy as a light pulse, the decay rate of which, over a specified temperature range, is temperature dependent. Other passive sensors being developed include pressure-sensitive triboluminescent materials, weight-sensitive silicone rubber fibers, scintillating fibers, and other materials for gamma and neutron detection. The light from the scintillator materials of each sensor would be sent through optical fibers to a monitoring station, where the attribute quantity could be measured and compared with previously recorded emission levels. Confirmatory measurement applications of these technologies are being evaluated to reduce the effort, costs, and employee exposures associated with inventorying stockpiles of highly enriched uranium at the Oak Ridge Y-12 Plant

Variance and covariance calculations for nuclear materials accounting using ''MAVARIC''

International Nuclear Information System (INIS)

Nasseri, K.K.

1987-07-01

Determination of the detection sensitivity of a materials accounting system to the loss of special nuclear material (SNM) requires (1) obtaining a relation for the variance of the materials balance by propagation of the instrument errors for the measured quantities that appear in the materials balance equation and (2) substituting measured values and their error standard deviations into this relation and calculating the variance of the materials balance. MAVARIC (Materials Accounting VARIance Calculations) is a custom spreadsheet, designed using the second release of Lotus 1-2-3, that significantly reduces the effort required to make the necessary variance (and covariance) calculations needed to determine the detection sensitivity of a materials accounting system. Predefined macros within the spreadsheet allow the user to carry out long, tedious procedures with only a few keystrokes. MAVARIC requires that the user enter the following data into one of four data tables, depending on the type of the term in the materials balance equation; the SNM concentration, the bulk mass (or solution volume), the measurement error standard deviations, and the number of measurements made during an accounting period. The user can also specify if there are correlations between transfer terms. Based on these data entries, MAVARIC can calculate the variance of the materials balance and the square root of this variance, from which the detection sensitivity of the accounting system can be determined

Variance and covariance calculations for nuclear materials accounting using 'MAVARIC'

International Nuclear Information System (INIS)

Nasseri, K.K.

1987-01-01

Determination of the detection sensitivity of a materials accounting system to the loss of special nuclear material (SNM) requires (1) obtaining a relation for the variance of the materials balance by propagation of the instrument errors for the measured quantities that appear in the materials balance equation and (2) substituting measured values and their error standard deviations into this relation and calculating the variance of the materials balance. MAVARIC (Materials Accounting VARIance Calculations) is a custom spreadsheet, designed using the second release of Lotus 1-2-3, that significantly reduces the effort required to make the necessary variance (and covariance) calculations needed to determine the detection sensitivity of a materials accounting system. Predefined macros within the spreadsheet allow the user to carry out long, tedious procedures with only a few keystrokes. MAVARIC requires that the user enter the following data into one of four data tables, depending on the type of the term in the materials balance equation; the SNM concentration, the bulk mass (or solution volume), the measurement error standard deviations, and the number of measurements made during an accounting period. The user can also specify if there are correlations between transfer terms. Based on these data entries, MAVARIC can calculate the variance of the materials balance and the square root of this variance, from which the detection sensitivity of the accounting system can be determined

Polyoxometalate-modified TiO2 nanotube arrays photoanode materials for enhanced dye-sensitized solar cells

Science.gov (United States)

Liu, Ran; Sun, Zhixia; Zhang, Yuzhuo; Xu, Lin; Li, Na

2017-10-01

In this work, we prepared for the first time the TiO2 nanotube arrays (TNAs) photoanode with polyoxometalate(POMs)-modified TiO2 electron-transport layer for improving the performance of zinc phthalocyanine(ZnPc)-sensitized solar cells. The as-prepared POMs/TNAs/ZnPc composite photoanode exhibited higher photovoltaic performances than the TNAs/ZnPc photoanode, so that the power conversion efficiency of the solar cell device based on the POMs/TNAs/ZnPc photoanode displayed a notable improvement of 45%. These results indicated that the POMs play a key role in reducing charge recombination in phthalocyanine-sensitized solar cells, together with TiO2 nanotube arrays being helpful for electron transport. The mechanism of the performance improvement was demonstrated by the measurements of electrochemical impedance spectra and open-circuit voltage decay curves. Although the resulting performance is still below that of the state-of-the-art dye-sensitized solar cells, this study presents a new insight into improving the power conversion efficiency of phthalocyanine-sensitized solar cells via polyoxometalate-modified TiO2 nanotube arrays photoanode.

The effect of material composition of 3-dimensional graphene oxide and self-doped polyaniline nanocomposites on DNA analytical sensitivity.

Science.gov (United States)

Yang, Tao; Chen, Huaiyin; Yang, Ruirui; Wang, Xinxing; Nan, Fuxin; Jiao, Kui

2015-09-01

Until now, morphology effects of 2-dimensional or 3-dimensional graphene nanocomposites and the effect of material composition on the biosensors have been rarely reported. In this paper, the various nanocomposites based on graphene oxide and self-doped polyaniline nanofibres for studying the effect of morphology and material composition on DNA sensitivity were directly reported. The isolation and dispersion of graphene oxide were realized via intercalated self-doped polyaniline and ultrasonication, where the ultrasonication prompts the aggregates of graphite oxide to break up and self-doped polyaniline to diffuse into the stacked graphene oxide. Significant electrochemical enhancement has been observed due to the existence of self-doped polyaniline, which bridges the defects for electron transfer and, in the mean time, increases the basal spacing between graphene oxide sheets. Different morphologies can result in different ssDNA surface density, which can further influence the hybridization efficiency. Compared with 2-dimensional graphene oxide, self-doped polyaniline and other morphologies of nanocomposites, 3-dimensional graphene oxide-self-doped polyaniline nanowalls exhibited the highest surface density and hybridization efficiency. Furthermore, the fabricated biosensors presented the broad detection range with the low detection limit due to the specific surface area, a large number of electroactive species, and open accessible space supported by nanowalls. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

Directory of Open Access Journals (Sweden)

Md. Khalid Hossain

Full Text Available In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV–Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell’s (DSSC photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric. Keywords: DSSC, Natural dye, TiO2 photoanode, Dye extracting solvent, Dye-adsorption time

Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials

OpenAIRE

Janeczek, Maciej; Herman, Katarzyna; Fita, Katarzyna; Dudek, Krzysztof; Kowalczyk-Zaj?c, Ma?gorzata; Czajczy?ska-Waszkiewicz, Agnieszka; Piesiak-Pa?czyszyn, Dagmara; Kosior, Piotr; Dobrzy?ski, Maciej

2016-01-01

Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved fo...

3D elemental sensitive imaging using transmission X-ray microscopy.

Science.gov (United States)

Liu, Yijin; Meirer, Florian; Wang, Junyue; Requena, Guillermo; Williams, Phillip; Nelson, Johanna; Mehta, Apurva; Andrews, Joy C; Pianetta, Piero

2012-09-01

Determination of the heterogeneous distribution of metals in alloy/battery/catalyst and biological materials is critical to fully characterize and/or evaluate the functionality of the materials. Using synchrotron-based transmission x-ray microscopy (TXM), it is now feasible to perform nanoscale-resolution imaging over a wide X-ray energy range covering the absorption edges of many elements; combining elemental sensitive imaging with determination of sample morphology. We present an efficient and reliable methodology to perform 3D elemental sensitive imaging with excellent sample penetration (tens of microns) using hard X-ray TXM. A sample of an Al-Si piston alloy is used to demonstrate the capability of the proposed method.

Infiltration of Spiro-MeOTAD hole transporting material into nanotubular TiO{sub 2} electrode for solid-state dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Kuzmych, Oleksandr, E-mail: alexkuzmych@gmail.com [Faculty of Chemistry, Laboratory of Electrochemistry, University of Warsaw, 02-093 Warsaw (Poland); Johansson, Erik M.J.; Nonomura, Kazuteru [Department of Physical and Analytical Chemistry, Uppsala University, Box 259, 751 05 Uppsala (Sweden); Nyberg, Tomas [The Angstrom Laboratory, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Skompska, Magdalena [Faculty of Chemistry, Laboratory of Electrochemistry, University of Warsaw, 02-093 Warsaw (Poland); Hagfeldt, Anders [Department of Physical and Analytical Chemistry, Uppsala University, Box 259, 751 05 Uppsala (Sweden)

2014-09-15

Highlights: • We report infiltration of Spiro-MeOTAD into pores of TiO{sub 2} nanotube (TNT) arrays. • Surface amount of D35 is diffusion limited for TiO{sub 2} mesoporous film but not for TNTs. • Performance of liquid and solid-state solar cells based on TNTs is compared. - Abstract: TiO{sub 2} nanotubes grown by anodic oxidation of Ti thin film deposited on conducting transparent fluoride-doped tin oxide (FTO) substrate were used as a unique geometrically organized template to study the infiltration of Spiro-MeOTAD hole transporting material (HTM) inside straight pores. The TiO{sub 2} nanotube (TNT) array electrode was compared with a mesoporous one in terms of loading with an organic dye of high extinction coefficient. It was shown that it is possible to build a working solid state dye sensitized solar cell device with such a combination of materials and its performance was compared with a device in which the solid state HTM was replaced by a liquid state electrolyte.

Thermally joining and/or coating or thermally separating the workpieces having heat-sensitive coating, comprises restoring coating by thermally coating the coating material after thermally joining and/or coating or thermally separating

OpenAIRE

Riedel, Frank; Winkelmann, Ralf; Puschmann, Markus

2011-01-01

The method for thermally joining and/or coating or thermally separating the workpieces (1), which have a heat-sensitive coating (2), comprises restoring the coating by thermally coating a coating material (3) after thermally joining and/or coating or thermally separating the workpieces. A part of the thermal energy introduced in the workpiece for joining and/or coating or separating or in the workpieces is used for thermally coating the coating material. Two workpieces are welded or soldered ...

Uniform elemental analysis of materials by sputtering and photoionization mass spectrometry

International Nuclear Information System (INIS)

Chun, He; Basler, J.N.; Becker, C.H.

1997-01-01

Analysis of the elemental composition of surfaces commonly involves techniques in which atoms or ions are ablated from the material's surface and detected by mass spectrometry. Secondary-ion mass spectrometry is widely used for detection with high sensitivity (down to a few parts per billion) but technical problems prevent it from being truly quantitative. Some of these problems are circumvented by nonresonant laser post-ionization of sputtered atoms followed by time-of-flight mass spectrometry (surface analysis by laser ionization: SALI). But when there are large differences in ionization probabilities amongst different elements in the material, the detection sensitivity can be non-uniform and accurate quantification remains out of reach. Here we report that highly uniform, quantitative and sensitive analysis of materials can be achieved using a high-energy (5-keV) ion beam for sputtering coupled with a very-high-intensity laser to induce multiphoton ionization of the sputtered atoms. We show uniform elemental sensitivity for several samples containing elements with very different ionization potentials, suggesting that this approach can now be regarded as quantitative for essentially any material. (author)

Low-temperature self-assembled vertically aligned carbon nanofibers as counter-electrode material for dye-sensitized solar cells

International Nuclear Information System (INIS)

Mahpeykar, S M; Tabatabaei, M K; Ghafoori-fard, H; Habibiyan, H; Koohsorkhi, J

2013-01-01

Low-temperature AC–DC PECVD is employed for direct growth of vertically aligned carbon nanofibers (VACNFs) on ordinary transparent conductive glass as counter-electrode material for dye-sensitized solar cells (DSSCs). To the best of our knowledge, this is the first report on utilization of VACNFs grown directly on ordinary FTO-coated glass as a cost-effective catalyst material in DSSCs. According to the FESEM images, the as-grown arrays are well aligned and dense, and offer uniform coverage on the surface of the substrate. In-plane and out-of-plane conductivity measurements reveal their good electrical conductivity, and Raman spectroscopy suggests a high number of electrocatalytic active sites, favoring charge transport at the electrolyte/electrode interface. Hybrid VACNF/Pt electrodes are also fabricated for performance comparison with Pt and VACNF electrodes. X-ray diffraction results verify the crystallization of Pt in hybrid electrodes and further confirm the vertical alignment of carbon nanofibers. Electrochemical characterization indicates that VACNFs provide both high catalytic and good charge transfer capability, which can be attributed to their high surface area, defect-rich and one-dimensional structure, vertical alignment and low contact resistance. As a result, VACNF cells can achieve a comparable performance (∼5.6%) to that of the reference Pt cells (∼6.5%). Moreover, by combination of the excellent charge transport and catalytic ability of VACNFs and the high conductivity of Pt nanoparticles, hybrid VACNF/Pt cells can deliver a performance superior to that of the Pt cells (∼7.2%), despite having a much smaller amount of Pt loading, which raises hopes for low-cost large-scale production of DSSCs in the future. (paper)

Further important sensitizers in patients sensitive to fragrances.

Science.gov (United States)

Frosch, P J; Johansen, J D; Menné, T; Pirker, C; Rastogi, S C; Andersen, K E; Bruze, M; Goossens, A; Lepoittevin, J P; White, I R

2002-08-01

The aim of this study was to determine the frequency of responses to selected fragrance materials in consecutive patients patch tested in 6 dermatological centres in Europe. 1855 patients were evaluated with the 8% fragrance mix (FM) and 14 other frequently used well-defined fragrance chemicals (series I). Each patient was classified regarding a history of adverse reactions to fragrances: certain, probable, questionable, none. Reactions to FM occurred in 11.3% of the subjects. The 6 substances with the highest reactivity following FM were Lyral (2.7%), citral (1.1%), farnesol P (0.5%), citronellol (0.4%), hexyl cinnamic aldehyde (0.3%), and coumarin (0.3%). 41 (2.2%) of the patients reacted only to materials of series I and not to FM. 6.6% of 1855 patients gave a history of adverse reactions to fragrances which was classified as certain. This group reacted to FM only in 41.1%, to series I and FM in 12.0% and to series I only in 7.2%. 74.3% of the 39 patients reacting to both FM and 1 of the materials of series I had any type of positive fragrance history, which was significantly higher in comparison to those with isolated reactions to series I (53.6% of 41), p = 0.04. The study identified further sensitizers relevant for patch testing of patients with contact dermatitis, of which Lyral is the most important single chemical.

Sensitization development in austenitic stainless steel piping

International Nuclear Information System (INIS)

Bruemmer, S.M.; Page, R.E.; Atteridge, D.G.

1984-10-01

Pacific Northwest Laboratory and the Division of Engineering Technology of the US Nuclear Regulatory Commission are conducting a program to determine a method for evaluating welded and rapair-welded stainless steel piping for light-water reactor service. Validated models, based on experimental data, are being developed to predict the degree of sensitization (DOS) and the intergranular stress corrosion cracking (IGSCC) susceptibility in the heat-affected zone (HAZ) of the SS weldments. The cumulative effects of material composition, past fabrication procedures, past service exposure, weldment thermomechanical (TM) history, and projected post-repair component life are being considered. This program will measure and model the development of HAZ TM history and resultant sensitized microstructure in welded and repair-welded piping. An empirical correlation between a material's DOS and its susceptibility to SCC will be determined using slow strain rate tensile tests. Mill heat chemistries and processing/fabrication records already required in the nuclear industry will be used as input for initial DOS predictions

Sensitivity Analysis for Multidisciplinary Systems (SAMS)

Science.gov (United States)

2016-12-01

release. Distribution is unlimited. 14 Server and Client Code Server from geometry import Point, Geometry import math import zmq class Server...public release; Distribution is unlimited. DISTRIBUTION STATEMENT A: Approved for public release. Distribution is unlimited. 19 Example Application Boeing...Materials Conference, 2011. Cross, D. M., Local continuum sensitivity method for shape design derivatives using spatial gradient reconstruction. Diss

The Assessment of Cognitive Emotion Regulation Strategies, Sensory Processing Sensitivity and Anxiety Sensitivity in Patients with Multiple Sclerosis

Directory of Open Access Journals (Sweden)

Esmeil Soleymani

2016-11-01

Full Text Available Abstract Background: The purpose of this study was to compare the cognitive emotional regulation strategies, sensory processing sensitivity and anxiety sensitivity in patients with multiple sclerosis and normal people. Materials and Methods: Statistical population of this study was all of patients with multiple sclerosis that referred to M.S association of Iran in the tehran. Sample of this study was 30 individuals of patients with multiple sclerosis selected by available sampling method and were matched with 30 individuals of normal people. Two groups completed cognitive emotion regulation, high sensory processing sensitivity and anxiety sensitivity questionnaires. Data were analyzed by one-way analysis of variance and Multivariate Analysis of Variance. Results: The results indicated that there is significant difference between two groups in view of cognitive emotion regulation strategies in which the mean of scores of patients with multiple sclerosis in maladaptive strategies of self- blame, catastrophizing and other blame were more than normal people and mean of scores of them in adaptive strategies of positive refocusing, positive reappraisal and putting into perspective were less than normal people. The results also indicated that there is a significant difference between two groups in anxiety sensitivity and sensory processing sensitivity. Conclusion: The most of emotional problems in patients with multiple sclerosis can be the result of more application of maladaptive strategies of cognitive emotion regulation, high sensory processing sensitivity and high anxiety sensitivity.

Designing Material Materialising Design

DEFF Research Database (Denmark)

Nicholas, Paul

2013-01-01

Designing Material Materialising Design documents five projects developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts, School of Architecture. These projects explore the idea that new designed materials might require new design methods....... Focusing on fibre reinforced composites, this book sustains an exploration into the design and making of elastically tailored architectural structures that rely on the use of computational design to predict sensitive interdependencies between geometry and behaviour. Developing novel concepts...

A search for IRSL-Active dosimeters with enhanced sensitivity : a spectroscopic survey

DEFF Research Database (Denmark)

Poolton, N.R.J.; Bøtter-Jensen, L.; Johnson, O.

1997-01-01

The spectral and radiation dose characteristics of a range of previously uninvestigated alumine-silicate materials are surveyed, with the intention of searching for alternative, high sensitivity materials that could potentially be used as InfraRed Stimulated Luminescence (IRSL) dosemeters...

Spectrophotometric and chromatographic determination of insensitive energetic materials: HNS and NTO, in the presence of sensitive nitro-explosives.

Science.gov (United States)

Can, Ziya; Uzer, Ayşem; Tekdemir, Yasemin; Erçağ, Erol; Türker, Lemi; Apak, Reşat

2012-02-15

As there are no molecular spectroscopic determination methods for the most widely used insensitive energetic materials, 2,2',4,4',6,6'-hexanitrostilbene (HNS) and 3-nitro-1,2,4-triazole-5-one (NTO), in the presence of sensitive nitro-explosives, two novel spectrophotometric methods were developed. For HNS and TNT mixtures, both analytes react with dicyclohexylamine (DCHA) forming different colored charge-transfer complexes, which can be resolved by derivative spectroscopy. The spectrophotometric method for NTO measures the 416-nm absorbance of its yellow-colored Na(+)NTO(-) salt formed with NaOH. TNT, if present, is pre-extracted into IBMK as its Meisenheimer anion forming an ion-pair with the cationic surfactant cetyl pyridinium (CP(+)) in alkaline medium, whereas the unextracted NTO is determined in the aqueous phase. The molar absorptivity (ε, L mol(-1)cm(-1)) and limit of quantification (LOQ, mg L(-1)) are as follows: for HNS, ε=2.75 × 10(4) and LOQ=0.48 (in admixture with TNT); for NTO, ε=6.83 × 10(3) and LOQ=0.73. These methods were not affected from nitramines and nitrate esters in synthetic mixtures or composite explosives. The developed methods were statistically validated against HPLC, and the existing chromatographic method was modified so as to enable NTO determination in the presence of TNT. These simple, low-cost, and versatile methods can be used in criminology, remediation/monitoring of contaminated sites, and kinetic stability modeling of munitions containing desensitized energetic materials. Copyright © 2012 Elsevier B.V. All rights reserved.

A new sight towards dye-sensitized solar cells material and theoretical

CERN Document Server

Lin, Hong

2010-01-01

Dye-sensitized solar cell (DSC) technology is emerging, against the current background of drastic consumption-rates of irreplaceable natural resources, as the Cinderella solution to many energy-related problems, Almost since its first appearance, it has been regarded as being the most promising alternative to conventional silicon solar cell technology due to the tremendous advantages of low cost and high theoretical energy-conversion efficiency. Review from Book News Inc.: Eight invited and peer-reviewed papers comprise this special-topic volume on a possible alternative to conventional silico

Probabilistic Sensitivities for Fatigue Analysis of Turbine Engine Disks

OpenAIRE

Harry R. Millwater; R. Wesley Osborn

2006-01-01

A methodology is developed and applied that determines the sensitivities of the probability-of-fracture of a gas turbine disk fatigue analysis with respect to the parameters of the probability distributions describing the random variables. The disk material is subject to initial anomalies, in either low- or high-frequency quantities, such that commonly used materials (titanium, nickel, powder nickel) and common damage mechanisms (inherent defects or su...

Accelerated irradiation test of Gundremmingen reactor vessel trepan material

Energy Technology Data Exchange (ETDEWEB)

Hawthorne, J.R. [Materials Engineering Associates, Inc., Lanham, MD (United States)

1992-08-01

Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279{degrees}C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed.

Accelerated irradiation test of gundremmingen reactor vessel trepan material

International Nuclear Information System (INIS)

Hawthorne, J.R.

1992-08-01

Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279 degrees C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed

Medical imaging: Material change for X-ray detectors

Science.gov (United States)

Rowlands, John A.

2017-10-01

The X-ray sensitivity of radiology instruments is limited by the materials used in their detectors. A material from the perovskite family of semiconductors could allow lower doses of X-rays to be used for medical imaging. See Letter p.87

Synthesis and Exciton Dynamics of Triplet Sensitized Conjugated Polymers

KAUST Repository

Andernach, Rolf

2015-07-22

We report the synthesis of a novel polythiophene-based host-guest copolymer incorporating a Pt-porphyrin complex (TTP-Pt) into the backbone for efficient singlet to triplet polymer exciton sensitization. We elucidated the exciton dynamics in thin films of the material by means of Transient Absorption Spectrosopcy (TAS) on multiple timescales and investigated the mechanism of triplet exciton formation. During sensitization, single exciton diffusion is followed by exciton transfer from the polymer backbone to the complex where it undergoes intersystem crossing to the triplet state of the complex. We directly monitored the triplet exciton back transfer from the Pt-porphyrin to the polymer and find that 60% of the complex triplet excitons are transferred with a time constant of 1087 ps. We propose an equilibrium between polymer and porphyrin triplet states as a result of the low triplet diffusion length in the polymer backbone and hence an increased local triplet population resulting in increased triplet-triplet annihilation. This novel system has significant implications for the design of novel materials for triplet sensitized solar cells and up-conversion layers.

Mobile Techniques for Rapid Detection of Concealed Nuclear Material

International Nuclear Information System (INIS)

Rosenstock, W.; Koeble, T.; Risse, M.; Berky, W.

2015-01-01

To prevent the diversion of nuclear material as well as illicit production, transport and use of nuclear material we investigated in mobile techniques to detect and identify such material in the field as early as possible. For that purpose we use a highly sensitive gamma measurement system installed in a car. It consists of two large volume plastic scintillators, one on each side of the car, each scintillator with 12 l active volume, and two extreme sensitive high purity Germanium detectors with 57 cm 2 crystal diameter, cooled electrically. The measured data are processed immediately with integrated, appropriate analysis software for direct assessment including material identification and classification within seconds. The software for the plastic scintillators can differentiate between natural and artificial radioactivity, thus giving a clear hint for the existence of unexpected material. In addition, the system is equipped with highly sensitive neutron detectors. We have performed numerous measurements by passing different radioactive and nuclear sources in relatively large distances with this measurement car. Even shielded as well as masked material was detected and identified in most of the cases. We will report on the measurements performed in the field (on an exercise area) and in the lab and discuss the capabilities of the system, especially with respect to timeliness and identification. This system will improve the nuclear verification capabilities also. (author)

Novel D–π–A dye sensitizers of polymeric metal complexes with ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 38; Issue 2. Novel D––A dye sensitizers of polymeric metal complexes with triphenylamine derivatives as donor for dye-sensitized solar cells: synthesis, characterization and application. Guipeng Tang Jun Zhou Wei Zhang Jiaomei Hu Dahai Peng Qiufang Xie ...

Methods for the measurement of micro material evidence

International Nuclear Information System (INIS)

Yang Mingtai; Wang Wen; Wu Lunqiang; Dai Changsong

2012-01-01

The micro material evidence has been used in judicature litigation successfully, that must base on impersonal authentication with the advanced and proper methods. The basic principle, main trait, applicable range, analysis minimum and sensitive limit of twelve type instruments used in micro material evidence analysis have been related. Those could supply optional proper methods for micro material evidence. (authors)

Sediment fingerprinting experiments to test the sensitivity of multivariate mixing models

Science.gov (United States)

Gaspar, Leticia; Blake, Will; Smith, Hugh; Navas, Ana

2014-05-01

Sediment fingerprinting techniques provide insight into the dynamics of sediment transfer processes and support for catchment management decisions. As questions being asked of fingerprinting datasets become increasingly complex, validation of model output and sensitivity tests are increasingly important. This study adopts an experimental approach to explore the validity and sensitivity of mixing model outputs for materials with contrasting geochemical and particle size composition. The experiments reported here focused on (i) the sensitivity of model output to different fingerprint selection procedures and (ii) the influence of source material particle size distributions on model output. Five soils with significantly different geochemistry, soil organic matter and particle size distributions were selected as experimental source materials. A total of twelve sediment mixtures were prepared in the laboratory by combining different quantified proportions of the Kruskal-Wallis test, Discriminant Function Analysis (DFA), Principal Component Analysis (PCA), or correlation matrix). Summary results for the use of the mixing model with the different sets of fingerprint properties for the twelve mixed soils were reasonably consistent with the initial mixing percentages initially known. Given the experimental nature of the work and dry mixing of materials, geochemical conservative behavior was assumed for all elements, even for those that might be disregarded in aquatic systems (e.g. P). In general, the best fits between actual and modeled proportions were found using a set of nine tracer properties (Sr, Rb, Fe, Ti, Ca, Al, P, Si, K, Si) that were derived using DFA coupled with a multivariate stepwise algorithm, with errors between real and estimated value that did not exceed 6.7 % and values of GOF above 94.5 %. The second set of experiments aimed to explore the sensitivity of model output to variability in the particle size of source materials assuming that a degree of

Improving the sensitivity of J coupling measurements in solids with application to disordered materials

International Nuclear Information System (INIS)

Guerry, Paul; Brown, Steven P.; Smith, Mark E.

2016-01-01

It has been shown previously that for magic angle spinning (MAS) solid state NMR the refocused INADEQUATE spin-echo (REINE) experiment can usefully quantify scalar (J) couplings in disordered solids. This paper focuses on the two z filter components in the original REINE pulse sequence, and investigates by means of a product operator analysis and fits to density matrix simulations the effects that their removal has on the sensitivity of the experiment and on the accuracy of the extracted J couplings. The first z filter proves unnecessary in all the cases investigated here and removing it increases the sensitivity of the experiment by a factor ∼1.1–2.0. Furthermore, for systems with broad isotropic chemical shift distributions (namely whose full widths at half maximum are greater than 30 times the mean J coupling strength), the second z filter can also be removed, thus allowing whole-echo acquisition and providing an additional √2 gain in sensitivity. Considering both random and systematic errors in the values obtained, J couplings determined by fitting the intensity modulations of REINE experiments carry an uncertainty of 0.2–1.0 Hz (∼1−10 %).

Sensitivity analysis overlaps of friction elements in cartridge seals

Directory of Open Access Journals (Sweden)

Žmindák Milan

2018-01-01

Full Text Available Cartridge seals are self-contained units consisting of a shaft sleeve, seals, and gland plate. The applications of mechanical seals are numerous. The most common example of application is in bearing production for automobile industry. This paper deals with the sensitivity analysis of overlaps friction elements in cartridge seal and their influence on the friction torque sealing and compressive force. Furthermore, it describes materials for the manufacture of sealings, approaches usually used to solution of hyperelastic materials by FEM and short introduction into the topic wheel bearings. The practical part contains one of the approach for measurement friction torque, which results were used to specifying the methodology and precision of FEM calculation realized by software ANSYS WORKBENCH. This part also contains the sensitivity analysis of overlaps friction elements.

The light sensitivity of thermoluminescent materials: LiF:Mg,Cu,P, LiF:Mg,Ti and Al2O3:C

International Nuclear Information System (INIS)

Duggan, L.; Budzanowski, M.; Przegietka, K.; Reitsema, N.; Wong, J.; Kron, T.

2000-01-01

Many thermoluminescence dosimetry (TLD) materials exhibit a variation in read-out with light exposure (including both visible and UV radiation energy) which may cause problems in environmental dosimetry. The aim of the present study was to investigate this for three newer preparations of TLD material - LiF:Mg,Ti (GR-100, DML, China), LiF:Mg,Cu,P (MCP-N, TLD Niewiadomski and Co., Poland) and Al 2 O 3 :C (Stillwater Sciences, USA). TLDs irradiated to 1 or 10 Gy were exposed to light from a calibrated spectral lamp with three to four times higher UV component than sunlight. MCP-N proved to be approximately five times less light sensitive than GR-100. For both materials, the decay of the major glow peaks with increasing light exposure could be described by a single or dual exponential equation. Half lives for the major dosimetry peaks of GR-100, fit to a single exponential, were 1132 min (∼19 h) for peak 4 and 275 min (∼4((1)/(2)) h) for peak 5. The half lives for peak 4 of MCP-N, fit to a dual exponential, were 309 min (∼5 h) and 6627 min (∼4((1/2)) days). For MCP-N, this relates to approximately a loss of half the signal in 14 days of sun exposure (Polish summer). The readout of Al 2 O 3 :C increased with increasing light exposure and saturated after only 5 min at a level 26 times higher than the signal without light exposure

X-ray-sensitive storage phosphors with the optically stable luminescent centres

CERN Document Server

Gorin, G B; Zvezdova, N P; Kochubey, D I; Sedova, Y G; Kochubey, D I; Kulipanov, G N; Lyakh, V V; Pindyurin, V F

2000-01-01

NaCl, KCl, KBr and LiF crystals doped by In, Tl, Ni, Pd and Ca were investigated as X-ray-sensitive materials. Influence of the way of doping of an impurity and growing of a crystal on such parameters of a material as: sensitivity to ionising radiation; radiative, optical and thermal stability of the image, obtained after an irradiation is investigated. As a result of the work, media for recording of the X-ray images are developed. These allow to reproduce the images in a mode of a photoluminescence. Spatial resolution and the dynamic range of registration of the developed materials concede to similar parameters of commercial storage luminophores like 'Image Plates' based on BaFBr : La. At the same time, as distinct from 'Image Plates', the developed radiophotoluminophores allow a long storage and multiple readout of the information recorded.

Constitutive Theory Developed for Monolithic Ceramic Materials

Science.gov (United States)

Janosik, Lesley A.

1998-01-01

With the increasing use of advanced ceramic materials in high-temperature structural applications such as advanced heat engine components, the need arises to accurately predict thermomechanical behavior that is inherently time-dependent and that is hereditary in the sense that the current behavior depends not only on current conditions but also on the material's thermomechanical history. Most current analytical life prediction methods for both subcritical crack growth and creep models use elastic stress fields to predict the time-dependent reliability response of components subjected to elevated service temperatures. Inelastic response at high temperatures has been well documented in the materials science literature for these material systems, but this issue has been ignored by the engineering design community. From a design engineer's perspective, it is imperative to emphasize that accurate predictions of time-dependent reliability demand accurate stress field information. Ceramic materials exhibit different time-dependent behavior in tension and compression. Thus, inelastic deformation models for ceramics must be constructed in a fashion that admits both sensitivity to hydrostatic stress and differing behavior in tension and compression. A number of constitutive theories for materials that exhibit sensitivity to the hydrostatic component of stress have been proposed that characterize deformation using time-independent classical plasticity as a foundation. However, none of these theories allow different behavior in tension and compression. In addition, these theories are somewhat lacking in that they are unable to capture the creep, relaxation, and rate-sensitive phenomena exhibited by ceramic materials at high temperatures. The objective of this effort at the NASA Lewis Research Center has been to formulate a macroscopic continuum theory that captures these time-dependent phenomena. Specifically, the effort has focused on inelastic deformation behavior associated

Intercultural Sensitivity through Short-Term Study Abroad

Science.gov (United States)

Bloom, Melanie; Miranda, Arturo

2015-01-01

One of the foremost-cited rationales for study abroad during college is the development of a global perspective and intercultural sensitivity. Although this argument is mentioned frequently in promotional materials for study abroad, it has not yet been backed by research based on the outcomes of students' study abroad experiences. As more…

Material and process selection using product examples

DEFF Research Database (Denmark)

Lenau, Torben Anker

2001-01-01

The objective of the paper is to suggest a different procedure for selecting materials and processes within the product development work. The procedure includes using product examples in order to increase the number of alternative materials and processes that is considered. Product examples can c...... a search engine, and through hyperlinks can relevant materials and processes be explored. Realising that designers are very sensitive to user interfaces do all descriptions of materials, processes and products include graphical descriptions, i.e. pictures or computer graphics....

Material and process selection using product examples

DEFF Research Database (Denmark)

Lenau, Torben Anker

2002-01-01

The objective of the paper is to suggest a different procedure for selecting materials and processes within the product development work. The procedure includes using product examples in order to increase the number of alternative materials and processes that is considered. Product examples can c...... a search engine, and through hyperlinks can relevant materials and processes be explored. Realising that designers are very sensitive to user interfaces do all descriptions of materials, processes and products include graphical descriptions, i.e. pictures or computer graphics....

Two-Dimensional Materials for Sensing: Graphene and Beyond

Directory of Open Access Journals (Sweden)

Seba Sara Varghese

2015-09-01

Full Text Available Two-dimensional materials have attracted great scientific attention due to their unusual and fascinating properties for use in electronics, spintronics, photovoltaics, medicine, composites, etc. Graphene, transition metal dichalcogenides such as MoS2, phosphorene, etc., which belong to the family of two-dimensional materials, have shown great promise for gas sensing applications due to their high surface-to-volume ratio, low noise and sensitivity of electronic properties to the changes in the surroundings. Two-dimensional nanostructured semiconducting metal oxide based gas sensors have also been recognized as successful gas detection devices. This review aims to provide the latest advancements in the field of gas sensors based on various two-dimensional materials with the main focus on sensor performance metrics such as sensitivity, specificity, detection limit, response time, and reversibility. Both experimental and theoretical studies on the gas sensing properties of graphene and other two-dimensional materials beyond graphene are also discussed. The article concludes with the current challenges and future prospects for two-dimensional materials in gas sensor applications.

Carbon Nanotubes Counter Electrode for Dye-Sensitized Solar Cells Application

Directory of Open Access Journals (Sweden)

Drygała A.

2016-06-01

Full Text Available The influence of the carbon nanotubes counter electrode deposited on the FTO glass substrates on the structure and optoelectrical properties of dye-sensitized solar cells counter electrode (CE was analysed. Carbon materials have been applied in DSSC s in order to produce low-cost solar cells with reasonable efficiency. Platinum is a preferred material for the counter electrode because of its high conductivity and catalytic activity. However, the costs of manufacturing of the platinum counter electrode limit its use to large-scale applications in solar cells. This paper presents the results of examining the structure and properties of the studied layers, defining optical properties of conductive layers and electrical properties of dye-sensitized solar cells manufactured with the use of carbon nanotubes.

Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method

International Nuclear Information System (INIS)

Lee, Seokje; Kim, Ingul; Jang, Moonho; Kim, Jaeki; Moon, Jungwon

2013-01-01

Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using Callosum and Meatball interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle

Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method

Energy Technology Data Exchange (ETDEWEB)

Lee, Seokje; Kim, Ingul [Chungnam National Univ., Daejeon (Korea, Republic of); Jang, Moonho; Kim, Jaeki; Moon, Jungwon [LIG Nex1, Yongin (Korea, Republic of)

2013-04-15

Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using Callosum and Meatball interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle.

Stress sensitive electricity based on Ag/cellulose nanofiber aerogel for self-reporting.

Science.gov (United States)

Yao, Qiufang; Fan, Bitao; Xiong, Ye; Wang, Chao; Wang, Hanwei; Jin, Chunde; Sun, Qingfeng

2017-07-15

A self-reporting aerogel toward stress sensitive slectricity (SSE) was presented using an interconnected 3D fibrous network of Ag nanoparticles/cellulose nanofiber aerogel (Ag/CNF), which was prepared via combined routes of silver mirror reaction and ultrasonication. Sphere-like Ag nanoparticles (AgNPs) with mean diameter of 74nm were tightly anchored in the cellulose nanofiber through by the coherent interfaces as the conductive materials. The as-prepared Ag/CNF as a self-reporting material for SSE not only possessed quick response and sensitivity, but also be easily recovered after 100th compressive cycles without plastic deformation or degradation in compressive strength. Consequently, Ag/CNF could play a viable role in self-reporting materials as a quick electric-stress responsive sensor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computed tomography with thermal neutrons and gaseous position sensitive detector

International Nuclear Information System (INIS)

Souza, Maria Ines Silvani

2001-12-01

A third generation tomographic system using a parallel thermal neutron beam and gaseous position sensitive detector has been developed along three discrete phases. At the first one, X-ray tomographic images of several objects, using a position sensitive detector designed and constructed for this purpose have been obtained. The second phase involved the conversion of that detector for thermal neutron detection, by using materials capable to convert neutrons into detectable charged particles, testing afterwards its performance in a tomographic system by evaluation the quality of the image arising from several test-objects containing materials applicable in the engineering field. High enriched 3 He, replacing the argon-methane otherwise used as filling gas for the X-ray detection, as well as, a gadolinium foil, have been utilized as converters. Besides the pure enriched 3 He, its mixture with argon-methane and later on with propane, have been also tested, in order to evaluate the detector efficiency and resolution. After each gas change, the overall performance of the tomographic system using the modified detector, has been analyzed through measurements of the related parameters. This was done by analyzing the images produced by test-objects containing several materials having well known attenuation coefficients for both thermal neutrons and X-rays. In order to compare the performance of the position sensitive detector as modified to detect thermal neutrons, with that of a conventional BF 3 detector, additional tomographs have been conducted using the last one. The results have been compared in terms of advantages, handicaps and complementary aspects for different kinds of radiation and materials. (author)

Nitrogen-Doped Porous Carbons As Electrode Materials for High-Performance Supercapacitor and Dye-Sensitized Solar Cell.

Science.gov (United States)

Wang, Lan; Gao, Zhiyong; Chang, Jiuli; Liu, Xiao; Wu, Dapeng; Xu, Fang; Guo, Yuming; Jiang, Kai

2015-09-16

Activated N-doped porous carbons (a-NCs) were synthesized by pyrolysis and alkali activation of graphene incorporated melamine formaldehyde resin (MF). The moderate N doping levels, mesopores rich porous texture, and incorporation of graphene enable the applications of a-NCs in surface and conductivity dependent electrode materials for supercapacitor and dye-sensitized solar cell (DSSC). Under optimal activation temperature of 700 °C, the afforded sample, labeled as a-NC700, possesses a specific surface area of 1302 m2 g(-1), a N fraction of 4.5%, and a modest graphitization. When used as a supercapacitor electrode, a-NC700 offers a high specific capacitance of 296 F g(-1) at a current density of 1 A g(-1), an acceptable rate capability, and a high cycling stability in 1 M H2SO4 electrolyte. As a result, a-NC700 supercapacitor delivers energy densities of 5.0-3.5 Wh kg(-1) under power densities of 83-1609 W kg(-1). Moreover, a-NC700 also demonstrates high electrocatalytic activity for I3- reduction. When employed as a counter electrode (CE) of DSSC, a power conversion efficiency (PCE) of 6.9% is achieved, which is comparable to that of the Pt CE based counterpart (7.1%). The excellent capacitive and photovoltaic performances highlight the potential of a-NCs in sustainable energy devices.

Nanostructured dye-sensitized solar cells

OpenAIRE

Palma, Giuseppina

2014-01-01

2012/2013 Dye-sensitized solar cells (DSSCs) represent a promising alternative to silicon-based technology. From the first publications about DSSCs in the 90s, they are considered an important breakthrough for achieving high efficiency by using relatively inexpensive and abundant materials. Stability and efficiency are two crucial points in the development of this new class of hybrid photovoltaic devices. Most of the DSSC studies carried out over the past twenty years are based on the o...

Radiation sensitivity and EPR dosimetric potential of gallic acid and its esters

International Nuclear Information System (INIS)

Tuner, Hasan; Oktay Bal, M.; Polat, Mustafa

2015-01-01

In the preset work the radiation sensitivities of Gallic Acid anhydrous and monohydrate, Octyl, Lauryl, and Ethyl Gallate (GA, GAm, OG, LG, and EG) were investigated in the intermediate (0.5–20 kGy) and low radiation (<10 Gy) dose range using Electron Paramagnetic Resonance (EPR) spectroscopy. While OG, LG, and EG are presented a singlet EPR spectra, their radiation sensitivity found to be very different in the intermediate dose range. At low radiation dose range (<10 Gy) only LG is found to be present a signal that easily distinguished from the noise signals. The intermediate and low dose range radiation sensitivities are compared using well known EPR dosimeter alanine. The radiation yields (G) of the interested material were found to be 1.34×10 −2 , 1.48×10 −2 , 4.14×10 −2 , and 6.03×10 −2 , 9.44×10 −2 for EG, GA, GAm, OG, and LG, respectively at the intermediate dose range. It is found that the simple EPR spectra and the noticeable EPR signal of LG make it a promising dosimetric material to be used below 10 Gy of radiation dose. - Highlights: • Radiation sensitivity of gallic acid and its esters were studied in intermediate and low radiation dose range using EPR. • While the irradiated samples of GA were presented complex EPR spectra the esters presented singlet ESR spectra. • Samples were compared to alanine in terms of the dosimetric point of view. • The radiation sensitivities of the investigated materials were very low at intermediate doses. • Lauryl ester of gallic acid was found to present a good sensitivity below 10 Gy

Photographic recording material for X-ray and γ-radiation

International Nuclear Information System (INIS)

Elsner, G.; Legler, R.

1976-01-01

It is proposed to increase the sensitivity of photographic recording material to X-ray- and γ-radiation by adding 2-naphthol in a concentration of 0.1 to 10 g per mol silver halogenides as a fluorescent material. (ORU/AK) [de

Novel High Temperature Materials for In-Situ Sensing Devices

Energy Technology Data Exchange (ETDEWEB)

Florian Solzbacher; Anil Virkar; Loren Rieth; Srinivasan Kannan; Xiaoxin Chen; Hannwelm Steinebach

2009-12-31

The overriding goal of this project was to develop gas sensor materials and systems compatible with operation at temperatures from 500 to 700 C. Gas sensors operating at these temperatures would be compatible with placement in fossil-energy exhaust streams close to the combustion chamber, and therefore have advantages for process regulation, and feedback for emissions controls. The three thrusts of our work included investigating thin film gas sensor materials based on metal oxide materials and electroceramic materials, and also development of microhotplate devices to support the gas sensing films. The metal oxide materials NiO, In{sub 2}O{sub 3}, and Ga{sub 2}O{sub 3} were investigated for their sensitivity to H{sub 2}, NO{sub x}, and CO{sub 2}, respectively, at high temperatures (T > 500 C), where the sensing properties of these materials have received little attention. New ground was broken in achieving excellent gas sensor responses (>10) for temperatures up to 600 C for NiO and In{sub 2}O{sub 3} materials. The gas sensitivity of these materials was decreasing as temperatures increased above 500 C, which indicates that achieving strong sensitivities with these materials at very high temperatures (T {ge} 650 C) will be a further challenge. The sensitivity, selectivity, stability, and reliability of these materials were investigated across a wide range of deposition conditions, temperatures, film thickness, as using surface active promoter materials. We also proposed to study the electroceramic materials BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} and BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} for their ability to detect H{sub 2}O and H{sub 2}S, respectively. This report focuses on the properties and gas sensing characteristics of BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} (Y-doped BaZrO{sub 3}), as significant difficulties were encounter in generating BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} sensors. Significant new results were achieved for Y-doped BaZrO{sub 3}, including

Sensitivity of nuclear power plant structural response to aircraft impact

International Nuclear Information System (INIS)

Buchhardt, F.; Magiera, G.; Matthees, W.; Weber, M.

1984-01-01

In this paper a sensitivity study for aircraft impact is performed concerning the excitation of internal components, with particular regard to nonlinear structural material behaviour in the impact area. The nonlinear material values are varied within the bandwidth of suitable material strength, depending on local stiffness pre-calculations. The analyses are then performed on a globally discretized three-dimensional finite element model of a nuclear power plant, using a relatively fine mesh. For specified nodal points results are evaluated by comparing their response spectra. (Author) [pt

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. Raji George. Articles written in Bulletin of Materials Science. Volume 30 Issue 2 April 2007 pp 183-185 Nanomaterials. Synthesis, characterization and gas sensitivity of MoO3 nanoparticles · Arnab Ganguly Raji George · More Details Abstract Fulltext PDF. Nanoparticles of ...

NANOSTRUCTURED TiO2 SENSITIZED WITH PORPHYRINS FOR SOLAR WATER-SPLITTING

Directory of Open Access Journals (Sweden)

MARCELA-CORINA ROŞU

2011-03-01

Full Text Available Nanostructured TiO2 sensitized with porphyrins for Solar water-splitting.The production of hydrogen from water using solar light is very promising for generations of an ecologically pure carrier contributing to a clean, sustainable and renewable energy system. The selection of specific photocatalyst material for hydrogen production in photoelectrochemical cells (PECs is based on some important characteristics of semiconductor, such as photo-corrosion and chemical corrosion stability, photocatalytic potential, high sensitivity for UV-visible light. In the present paper, different nanocrystalline TiO2 photoanodes have been prepared via wet-chemical techniques followed by annealing treatment and sensitized with porphyrins and supramolecular complexes of porphyrins. The so obtained photocatalysts were characterized with UV-VIS absorption spectroscopy and spectrofluorimetry. The purpose of these experiments is to show if the prepared materials possess the necessary photocatalytic characteristics and if they can be used with success in H2 production from water decomposition in PECs.

Temperature- and pH-sensitive wearable materials for monitoring foot ulcers

Directory of Open Access Journals (Sweden)

Salvo P

2017-01-01

Full Text Available Pietro Salvo,1,2 Nicola Calisi,1 Bernardo Melai,1 Valentina Dini,3 Clara Paoletti,1 Tommaso Lomonaco,1 Andrea Pucci,1 Fabio Di Francesco,1 Alberto Piaggesi,4 Marco Romanelli3 1Department of Chemistry and Industrial Chemistry, University of Pisa, 2Institute of Clinical Physiology, National Council of Research, 3Wound Healing Research Unit, Department of Dermatology, University of Pisa, 4Diabetic Foot Section, Department of Medicine, University of Pisa, Pisa, Italy Abstract: Foot ulcers account for 15% of comorbidities associated with diabetes. Presently, no device allows the status of foot ulcers to be continuously monitored when patients are not hospitalized. In this study, we describe a temperature and a pH sensor capable of monitoring diabetic foot and venous leg ulcers developed in the frame of the seventh framework program European Union project SWAN-iCare (smart wearable and autonomous negative pressure device for wound monitoring and therapy. Temperature is measured by exploiting the variations in the electrical resistance of a nanocomposite consisting of multiwalled carbon nanotubes and poly(styrene-b-(ethylene-co-butylene-b-styrene. The pH sensor used a graphene oxide (GO layer that changes its electrical potential when pH changes. The temperature sensor has a sensitivity of ~85 Ω/°C in the range 25°C–50°C and a high repeatability (maximum standard deviation of 0.1% over seven repeated measurements. For a GO concentration of 4 mg/mL, the pH sensor has a sensitivity of ~42 mV/pH and high linearity (R2=0.99. Keywords: diabetic foot ulcer, wearable sensors, wound temperature, wound pH

Highly Sensitive TGA Diagnosis of Thermal Behaviour of Laser-Deposited Materials

Czech Academy of Sciences Publication Activity Database

Galíková, Anna; Pola, Josef

2008-01-01

Roč. 473, 1-2 (2008), s. 54-60 ISSN 0040-6031 R&D Projects: GA AV ČR IAA400720619 Institutional research plan: CEZ:AV0Z40720504 Keywords : thermogravimetry * laser-deposited materials * mass spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.659, year: 2008

Corrosion of container materials for disposal of high-level radioactive wastes

Energy Technology Data Exchange (ETDEWEB)

Chun, K.S.; Park, H.S.; Yeon, J.W.; Ha, Y.K. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-01-01

In the corrosion aspect of container for the deep geological disposal of high-level radioactive waste, disposal concepts and the related container materials, which have been developed by advanced countries, have been reviewed. The disposal circumstances could be divided into the saturated and the unsaturated zones. The candidate materials in the countries, which consider the disposal in the unsaturated zone, are the corrosion resistant materials such as supper alloys and stainless steels, but those in the saturated zone is cupper, one of the corrosion allowable materials. By the results of the pitting corrosion test of sensitized stainless steels (such as 304, 304L, 316 and 316L), pitting potential is decreased with the degree of sensitization and the pitting corrosion resistance of 316L is higher than others. And so, the long-term corrosion experiment with 316L stainless steel specimens, sebsitized and non-sensitized, under the compacted bentonite and synthetic granitic groundwater has been being carried out. The results from the experiment for 12 months indicate that no evidence of pitting corrosion of the specimens has been observed but the crevice corrosion has occurred on the sensitized specimens even for 3 months. (author). 33 refs., 19 figs., 10 tabs.

Effect of Temperature-Sensitive Poloxamer Solution/Gel Material on Pericardial Adhesion Prevention: Supine Rabbit Model Study Mimicking Cardiac Surgery.

Directory of Open Access Journals (Sweden)

Hyun Kang

Full Text Available We investigated the mobility of a temperature-sensitive poloxamer/Alginate/CaCl2 mixture (PACM in relation to gravity and cardiac motion and the efficacy of PACM on the prevention of pericardial adhesion in a supine rabbit model.A total of 50 rabbits were randomly divided into two groups according to materials applied after epicardial abrasion: PACM and dye mixture (group PD; n = 25 and saline as the control group (group CO; n = 25. In group PD, rabbits were maintained in a supine position with appropriate sedation, and location of mixture of PACM and dye was assessed by CT scan at the immediate postoperative period and 12 hours after surgery. The grade of adhesions was evaluated macroscopically and microscopically two weeks after surgery.In group PD, enhancement was localized in the anterior pericardial space, where PACM and dye mixture was applied, on immediate post-surgical CT scans. However, the volume of the enhancement was significantly decreased at the anterior pericardial space 12 hours later (P < .001. Two weeks after surgery, group PD had significantly lower macroscopic adhesion score (P = .002 and fibrosis score (P = .018 than did group CO. Inflammation score and expression of anti-macrophage antibody in group PD were lower than those in group CO, although the differences were not significant.In a supine rabbit model study, the anti-adhesion effect was maintained at the area of PACM application, although PACM shifted with gravity and heart motion. For more potent pericardial adhesion prevention, further research and development on the maintenance of anti-adhesion material position are required.

Non-Celiac Gluten Sensitivity and Autoimmunity. A Case Report.

Directory of Open Access Journals (Sweden)

Carlos Isasi

2014-12-01

Full Text Available Introduction, objective: To present a case report in which the finding of non-coeliac gluten sensitivity was decisive for the treatment of a complex autoimmune disease. Materials and methods: A 43-year-old woman with polyarthritis, psoriatic features, anti-SSA/Ro and anti-cyclic citrullinated peptide antibodies, with refractory course, was evaluated for gluten sensitivity despite negative serology for coeliac disease. Results: The patient carried the HLA DQ2 haplotype and duodenal biopsy showed lymphocytic enteritis. A gluten-free diet resolved the clinical picture and permitted tapering of immunosuppressive therapy. Conclusion: Non-coeliac gluten sensitivity can be associated with autoimmunity despite the absence of the specific autoantibodies of coeliac disease.

Development of radioactive materials inspection system

International Nuclear Information System (INIS)

Yang Lu; Wang Guobao; Chen Yuhua; Li Latu; Zhang Sujing

2005-01-01

Radioactive materials inspection system which is applied to inspect the horror activities of radioactive materials and its illegal transfer. The detector sections are made of highly stable and credible material. It has high sensitivity to radioactive materials. The inspect lowest limit of inspection is the 2-3 times to the background, the energy range is 30 keV-2.5 MeV and the response time is 0.5 s. Inspection message can be transmitted through wired or wireless web to implement remote control. The structure of the system is small, light and convenient. It is ideal for protecting society and public from the harm of the radiation. (authors)

Studies on analytical method and nondestructive measuring method on the sensitization of austenitic stainless steels

International Nuclear Information System (INIS)

Onimura, Kichiro; Arioka, Koji; Horai, Manabu; Noguchi, Shigeru.

1982-03-01

Austenitic stainless steels are widely used as structural materials for the machine and equipment of various kinds of plants, such as thermal power, nuclear power, and chemical plants. The machines and equipment using this kind of material, however, have the possibility of suffering corrosion damage while in service, and these damages are considered to be largely due to the sensitization of the material in sometimes. So, it is necessary to develop an analytical method for grasping the sensitization of the material more in detail and a quantitative nondestructive measuring method which is applicable to various kinds of structures in order to prevent the corrosion damage. From the above viewpoint, studies have been made on the analytical method based on the theory of diffusion of chromium in austenitic stainless steels and on Electro-Potentiokinetics Reactivation Method (EPR Method) as a nondestructive measuring method, using 304 and 316 austenitic stainless steels having different carbon contents in base metals. This paper introduces the results of EPR test on the sensitization of austenitic stainless steels and the correlation between analytical and experimental results. (author)

Implementing of the nuclear materials accounting and control computerized system at JINR

International Nuclear Information System (INIS)

Dobryanskij, V.M.; Kalyakin, N.N.; Koltin, G.P.; Samojlov, V.N.; Cheker, A.V.; Shestakov, B.A.

2000-01-01

The results of the development of the computerized nuclear materials accounting system at the Joint Institute for Nuclear Research (JINR) are submitted. This work was carried out under Russian-American Nuclear Materials Protection, Control and Accounting (MPCandA) Program. The System was implemented at the Institute, it was attested to work with sensitive information. The computerized information nuclear materials accounting and control system, named MTIS (Materials Tracking Information System), is intended for the automated accounting of the nuclear materials used in JINR, tracking their moving, changes of their inventory amounts, preparation of the required documentation, and also for information support of the measures spent in the JINR on MPCandA program. MTIS can prepare reports for federal level and can also generate data to be reported for internal purposes. MTIS includes as one of the subsystems a program module to prepare reporting information to the Federal Information System (FIS). The system MTIS provides control of access to the database (DB), protection of the information against the non-authorized access, division of the data into the sensitive and non-sensitive data. (author)

Modelling of buffer material behaviour

International Nuclear Information System (INIS)

Boergesson, L.

1988-12-01

Some material models of smectite rich buffer material suited for nuclear waste isolation are accounted for in the report. The application of these models in finite element calculations of some scenarios and performance are also shown. The rock shear scenario has been closely studied with comparisons between calculated and measured results. Sensitivity analyses of the effect of changing the density of the clay and the rate of shear have been performed as well as one calculation using a hollow steel cylinder. Material models and finite element calculations of canister settlement, thermomechanical effects and swelling are also accounted for. The report shows the present state of the work to establish material models and calculation tools which can be used at the final design of the repository. (31 illustrations)

Strain sensitivity of carbon nanotube cement-based composites for structural health monitoring

Science.gov (United States)

D'Alessandro, Antonella; Ubertini, Filippo; Laflamme, Simon; Rallini, Marco; Materazzi, Annibale L.; Kenny, Josè M.

2016-04-01

Cement-based smart sensors appear particularly suitable for monitoring applications, due to their self-sensing abilities, their ease of use, and their numerous possible field applications. The addition of conductive carbon nanofillers into a cementitious matrix provides the material with piezoresistive characteristics and enhanced sensitivity to mechanical alterations. The strain-sensing ability is achieved by correlating the variation of external loads or deformations with the variation of specific electrical parameters, such as the electrical resistance. Among conductive nanofillers, carbon nanotubes (CNTs) have shown promise for the fabrication of self-monitoring composites. However, some issues related to the filler dispersion and the mix design of cementitious nanoadded materials need to be further investigated. For instance, a small difference in the added quantity of a specific nanofiller in a cement-matrix composite can substantially change the quality of the dispersion and the strain sensitivity of the resulting material. The present research focuses on the strain sensitivity of concrete, mortar and cement paste sensors fabricated with different amounts of carbon nanotube inclusions. The aim of the work is to investigate the quality of dispersion of the CNTs in the aqueous solutions, the physical properties of the fresh mixtures, the electromechanical properties of the hardened materials, and the sensing properties of the obtained transducers. Results show that cement-based sensors with CNT inclusions, if properly implemented, can be favorably applied to structural health monitoring.

Muon radiography technology for detecting high-Z materials

International Nuclear Information System (INIS)

Ma Lingling; Wang Wenxin; Zhou Jianrong; Sun Shaohua; Liu Zuoye; Li Lu; Du Hongchuan; Zhang Xiaodong; Hu Bitao

2010-01-01

This paper studies the possibility of using the scattering of cosmic muons to identify threatening high-Z materials. Various scenarios of threat material detection are simulated with the Geant4 toolkit. PoCA (Point of Closest Approach) algorithm reconstructing muon track gives 3D radiography images of the target material. Z-discrimination capability, effects of the placement of high-Z materials, shielding materials inside the cargo, and spatial resolution of position sensitive detector for muon radiography are carefully studied. Our results show that a detector position resolution of 50 μm is good enough for shielded materials detection. (authors)

Amazingly resilient Indigenous people! Using transformative learning to facilitate positive student engagement with sensitive material.

Science.gov (United States)

Jackson, Debra; Power, Tamara; Sherwood, Juanita; Geia, Lynore

2013-12-01

If health professionals are to effectively contribute to improving the health of Indigenous people, understanding of the historical, political, and social disadvantage that has lead to health disparity is essential. This paper describes a teaching and learning experience in which four Australian Indigenous academics in collaboration with a non-Indigenous colleague delivered an intensive workshop for masters level post-graduate students. Drawing upon the paedagogy of Transformative Learning, the objectives of the day included facilitating students to explore their existing understandings of Indigenous people, the impact of ongoing colonisation, the diversity of Australia's Indigenous people, and developing respect for alternative worldviews. Drawing on a range of resources including personal stories, autobiography, film and interactive sessions, students were challenged intellectually and emotionally by the content. Students experienced the workshop as a significant educational event, and described feeling transformed by the content, better informed, more appreciative of other worldviews and Indigenous resilience and better equipped to contribute in a more meaningful way to improving the quality of health care for Indigenous people. Where this workshop differs from other Indigenous classes was in the involvement of an Indigenous teaching team. Rather than a lone academic who can often feel vulnerable teaching a large cohort of non-Indigenous students, an Indigenous teaching team reinforced Indigenous authority and created an emotionally and culturally safe space within which students were allowed to confront and explore difficult truths. Findings support the value of multiple teaching strategies underpinned by the theory of transformational learning, and the potential benefits of facilitating emotional as well as intellectual student engagement when presenting sensitive material.

A high sensitivity nanomaterial based SAW humidity sensor

Energy Technology Data Exchange (ETDEWEB)

Wu, T-T; Chou, T-H [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Y-Y [Department of Mechanical Engineering, Tatung University, Taipei 104, Taiwan (China)], E-mail: wutt@ndt.iam.ntu.edu.tw

2008-04-21

In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128{sup 0}YX-LiNbO{sub 3} based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.

Sensitization of Laser-beam Welded Martensitic Stainless Steels

Science.gov (United States)

Dahmen, Martin; Rajendran, Kousika Dhasanur; Lindner, Stefan

Ferritic and martensitic stainless steels are an attractive alternative in vehicle production due to their inherent corrosion resistance. By the opportunity of press hardening, their strength can be increased to up to 2000 MPa, making them competitors for unalloyed ultra-high strength steels. Welding, nevertheless, requires special care, especially when it comes to joining of high strength heat treated materials. With an adopted in-line heat treatment of the welds in as-rolled as well as press hardened condition, materials with sufficient fatigue strength and acceptable structural behavior can be produced. Because of microstructural transformations in the base material such as grain coarsening and forced carbide precipitation, the corrosion resistance of the weld zone may be locally impaired. Typically the material in the heat-affected zone becomes sensitive to intergranular cracking in the form of knife-edge corrosion besides the fusion line. The current study comprises of two text scenarios. By an alternating climate test, general response in a corroding environment is screened. In order to understand the corrosion mechanisms and to localize the sensitive zones, sensitisation tests were undertaken. Furthermore, the applicability of a standard test according to ASTM 763-83 was examined. It was found that the alternative climate test does not reveal any corrosion effects. Testing by the oxalic acid test revealed clearly the effect of welding, weld heat treatment and state of thermal processing. Also application of the standard which originally suited for testing ferritic stainless steels could have been justified.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. KADARKARAI MURUGAN. Articles written in Bulletin of Materials Science. Volume 40 Issue 7 December 2017 pp 1455-1462. A sensitive optical sensor based on DNA-labelled Si@SiO 2 core–shell nanoparticle for the detection of Hg 2 + ions in environmental water samples.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. KANNAIYAN DINAKARAN. Articles written in Bulletin of Materials Science. Volume 40 Issue 7 December 2017 pp 1455-1462. A sensitive optical sensor based on DNA-labelled Si@SiO 2 core–shell nanoparticle for the detection of Hg 2 + ions in environmental water samples.

A study on the sensitivity of self-powered neutron detectors(SPNDs)

International Nuclear Information System (INIS)

Lee, Wan No

1997-02-01

Self-Powered Neutron Detectors(SPND) are currently used to estimate the power generation distribution and fuel burn-up in several nuclear power reactors in Korea. While they have several advantages such as small size, low cost, and relatively simple electronics required in conjunction with those usage, they have some intrinsic problems of the low level of output current, a slow response time, the rapid change of sensitivity which makes it difficult to use for a long term. In this paper, Monte Carlo simulation is accomplished to calculate the escape probability as a function of the birth position of emitted beta particle for a geometry of rhodium-based SPNDs. A simple numerical method calculates the initial generation rate of beta particles and the change of generation rate due to rhodium burn-up. Using the simulation result, the burn-up profile of rhodium number density and the neutron sensitivity are calculated as a function of burn-up time in reactors. The sensitivity of the SPND decreases non-linearly due to the high absorption cross-section and the non-uniform burn-up of rhodium in the emitter rod. In addition, for improvement of some properties of rhodium-based SPNDs which are currently used, this paper presents a new material and modified geometry. From searching nuclear data, Ag 109 is chosen as a replacing material for rhodium. Silver has a low neutron absorption cross-section and a high beta energy and a low density when it is compared with rhodium. The sensitivity and the density change of silver as a function of burn-up are calculated using this method. Also, this paper compares the initial sensitivity of a solid type with its of a tube type. The initial sensitivity is increased with the new material and the tube type. Silver is also found to be used for longer time than rhodium. The method used here can be applied to the analysis of other types of SPNDs and will be useful in the optimum design of new SPNDs for long term usage

Study of the Sensitization on the Grain Boundary in Austenitic Stainless Steel Aisi 316

Directory of Open Access Journals (Sweden)

Kocsisová Edina

2014-12-01

Full Text Available Intergranular corrosion (IGC is one of the major problems in austenitic stainless steels. This type of corrosion is caused by precipitation of secondary phases on grain boundaries (GB. Precipitation of the secondary phases can lead to formation of chromium depleted zones in the vicinity of grain boundaries. Mount of the sensitization of material is characterized by the degree of sensitization (DOS. Austenitic stainless steel AISI 316 as experimental material had been chosen. The samples for the study of sensitization were solution annealed on 1100 °C for 60 min followed by water quenching and then sensitization by isothermal annealing on 700 °C and 650 °C with holding time from 15 to 600 min. Transmission electron microscopy (TEM was used for identification of secondary phases. Electron backscattered diffraction (EBSD was applied for characterization of grain boundary structure as one of the factors which influences on DOS.

A new magnetic nanodiamond/graphene oxide hybrid (Fe3O4@ND@GO) material for pre-concentration and sensitive determination of sildenafil in alleged herbal aphrodisiacs by HPLC-DAD system.

Science.gov (United States)

Yilmaz, Erkan; Ulusoy, Halil İbrahim; Demir, Özge; Soylak, Mustafa

2018-05-01

A sensitive analytical methodology was investigated to concentrate and determine of sildenafil citrate (SLC) present at trace level in herbal supplementary products. The proposed method is based on simple and sensitive pre-concentration of SLC by using magnetic solid phase extraction with new developed magnetic nanodiamond/graphene oxide hybrid (Fe 3 O 4 @ND@GO) material as a sorbent. Experimental variables affecting the extraction efficiency of SLC like; pH, sample volume, eluent type and volume, extraction time and amount of adsorbent were studied and optimized in detail. Determination of sildenafil citrate after magnetic solid phase extraction (MSPE) was carried out by HPLC-DAD system. The morphology, composition, and properties of the synthesized hybrid material was characterized by Fourier transform infrared spectrometry (FT-IR), Raman spectrometry (Raman), X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), mapping photographs, zeta potential analyzer, and BET surface area analysis. Under optimized conditions, linear range was ranged from 5.00 to 250.00 ng mL -1 with R 2 of 0.9952. The limit of detection (LOD) was 1.49 ng mL -1 and the recoveries at two spiked levels were ranged from 94.0 to 104.1% with the relative standard deviation (RSD) < 7.1% (n = 5). The enhancement factor (EF) was 86.9. The results show that the combination MSPE with HPLC-DAD is a suitable and sensitive method for the determination of SLC in real samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Study of the pore filling fraction of carbazole-based hole-transporting materials in solid-state dye-sensitized solar cells

Directory of Open Access Journals (Sweden)

Marwa Ben Manaa

2016-07-01

Full Text Available Carbazole-based molecular glasses have emerged as a promising alternative to the widely used hole-transporting materials (HTM spiro-OMeTAD in solid-state dye-sensitized solar cells (DSSCs. The pore filling fraction (PFF of the mesoporous TiO2 layer by the HTM appears as a key parameter determining the final efficiency of a DSSC. In this work, the pore-filling properties of a family of carbazole-based HTMs are investigated for the first time and the photovoltaic behavior of DSSC devices (fabricated using the D102 dye is discussed in light of the present findings. It is found that N-aryl substituted 3,6-bis(diphenylaminyl-carbazole derivatives exhibit relatively low PFF of ca. 60%. Methoxy groups on the diphenylamine moieties have little influence on the PFF, indicating that the strong enhancement in power conversion efficiency (PCE is not related to an improved filling of the pores by the HTM. N-alkylated HTMs lead to higher PFF, increasing with the alkyl chain length, up to 78%.

Magnetic imaging and its applications to materials

CERN Document Server

De Graef, Marc

2000-01-01

Volume 36 provides an extensive introduction to magnetic imaging,including theory and practice, utilizing a wide range of magnetic sensitive imaging methods. It also illustrates the applications of these modern experimental techniques together with imaging calculations to today's advanced magnetic materials. This book is geared towards the upper-level undergraduate students and entry-level graduate students majoring in physics or materials science who are interested in magnetic structure and magnetic imaging. Researchers involved in studying magnetic materials should alsofind the book usef

Considering the edge-crack sensitivity of a hot-rolled steel in forming simulation

Science.gov (United States)

Gläsner, T.; Schneider, M.; Troitzsch, M.; Westhäuser, S.

2016-11-01

The formability of sheet metal materials is locally reduced by shear cutting operations, and as a result the risk of a crack during further processing is increased at the edge. Materials particularly susceptible to this are described as sensitive to edge-cracking. A procedure for quantitatively determining edge-crack sensitivity and for applying corresponding characteristic values has not been previously established. Below, two test methods and an approach for using the results in an extended forming limit diagram are presented. The producibility of a collar drawn test component as well as a chassis component is reevaluated using this extended forming limit diagram.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. Rani Joseph. Articles written in Bulletin of Materials Science. Volume 26 Issue 3 April 2003 pp 343-348 Thin Films. Optimization of pH and direct imaging conditions of complexed methylene blue sensitized poly(vinyl chloride) films · M Ushamani N G Leenadeenja K Sreekumar ...

Optimizing EFL Learners' Sensitizing Reading Skill: Development of Local Content-Based Textbook

Science.gov (United States)

Arifani, Yudhi

2016-01-01

The development of local wisdom based sensitizing reading material is aimed at penetrating one of the imperishable gaps between authentic and non-authentic reading materials dispute in an EFL teaching context. Promoting EFL learners' needs for the first semester students of English department at university level, who rarely or even never have a…

MICROORGANISMS ANTIBIOTIC SENSITIVITY DETERMINATION IN URINARY TRACT INFECTIONS

Directory of Open Access Journals (Sweden)

Shapovalova O.V.

2016-06-01

Full Text Available Introduction. Nowadays Urinary tract infections (UTI are considered to be the most common bacterial infections. Escherichia coli is the most frequently uropathogen. Other microorganisms of the genera Enterococcus, Klebsiella, Enterobacter, Proteus, Morganella, Citrobacter, Serratia, Pseudomonas, Streptococcus, Staphylococcus, Candida are also isolated with variable frequency. In recent years there has been a decreasing tendency of the causative agents of UTI sensitivity to various antibiotics, which causes growth of an inefficiency treatment risk. In connection with the above the investigations were carried out with the purpose to identify the actual causative agents of bacteriuria and their sensitivity to antibiotics and antifungal drugs. Materials and methods. Bacteriological examination of urine was performed at 42 patients of SI "Sytenko Institute of Spine and Joint Pathology, AMS of Ukraine" clinic. The bacteriological method for determining the number of bacteria in the test material, cultural and bacterioscopic methods for identifying microorganisms and disk-diffusion method for sensitivity of microorganisms to antibiotics determining were used. The clinical material for the study was an average portion of the morning urine or urine collected by catheter. The biological material collection and bacteriological examination was carried by quantitative method, the isolated microorganisms identification and their sensitivity to antibiotics determining was performed by standard methods in accordance with current guidelines. We used the following antibiotics group to determine the microorganisms sensitivity: penicillin, cephalosporin, karbapenems, tetracyclines, aminoglycoside, fluoroquinolones, oxazolidinones, macrolides, lincosamides, glycopeptides, antifungal antibiotics. Results and discussion. During the biological material study 55 isolates of bacterial and fungal pathogens were obtained. The microorganisms’ concentration in urine was in

New applications of photographic materials in science and technique

International Nuclear Information System (INIS)

Buschmann, H.T.; Deml, R.; Duville, R.; Philippaerts, H.; Bollen, R.; Ranz, E.

1976-01-01

In spite of some disatvantages photographic materials based on silver halides possess the outstanding feature of high sensitivity. So again and again special photographic materials have been developed for new techniques including information storage. This contribution reports on some special photographic materials and it briefly discusses some applications. Materials are discussed in detail for holography, carrier-frequency photography, producing masks for integrated circuits, recording equidensities, bubble chamber photography, and for neutron-radiography. (orig.) [de

Influence of Nitrogen Doping on Device Operation for TiO2-Based Solid-State Dye-Sensitized Solar Cells: Photo-Physics from Materials to Devices

Directory of Open Access Journals (Sweden)

Jin Wang

2016-02-01

Full Text Available Solid-state dye-sensitized solar cells (ssDSSC constitute a major approach to photovoltaic energy conversion with efficiencies over 8% reported thanks to the rational design of efficient porous metal oxide electrodes, organic chromophores, and hole transporters. Among the various strategies used to push the performance ahead, doping of the nanocrystalline titanium dioxide (TiO2 electrode is regularly proposed to extend the photo-activity of the materials into the visible range. However, although various beneficial effects for device performance have been observed in the literature, they remain strongly dependent on the method used for the production of the metal oxide, and the influence of nitrogen atoms on charge kinetics remains unclear. To shed light on this open question, we synthesized a set of N-doped TiO2 nanopowders with various nitrogen contents, and exploited them for the fabrication of ssDSSC. Particularly, we carefully analyzed the localization of the dopants using X-ray photo-electron spectroscopy (XPS and monitored their influence on the photo-induced charge kinetics probed both at the material and device levels. We demonstrate a strong correlation between the kinetics of photo-induced charge carriers probed both at the level of the nanopowders and at the level of working solar cells, illustrating a direct transposition of the photo-physic properties from materials to devices.

Signal processors for position-sensitive detectors

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Ken-ichi [Hosei Univ., Koganei, Tokyo (Japan). Coll. of Engineering

1996-07-01

Position-sensitive detectors (PSD) are widely used in following various fields: condensed matter studies, material engineering, medical radiology particle physics, astrophysics and industrial applications. X-ray diffraction analysis is one of the field where PSDs are the most important instruments. In this field, many types of PSAs are employed: position-sensitive proportional counters (PSPC), multi-wire proportional chambers (MWPC), imaging plates, image intensifiers combined CCD cameras and semiconductor array devices. Two readout systems used for PSDs, where one is a charge-division type with high stability and the other is an encoder with multiple delay, line readout circuits useful for fast counting, were reported in this paper. The multiple delay line encoding system can be applicable to high counting rate 1D and 2D gas proportional detectors. (G.K.)

Subthreshold neutron interrogator for detection of radioactive materials

Science.gov (United States)

Evans, Michael L.; Menlove, Howard O.; Baker, Michael P.

1980-01-01

A device for detecting fissionable material such as uranium in low concentrations by interrogating with photoneutrons at energy levels below 500 keV, and typically about 26 keV. Induced fast neutrons having energies above 500 keV by the interrogated fissionable material are detected by a liquid scintillator or recoil proportional counter which is sensitive to the induced fast neutrons. Since the induced fast neutrons are proportional to the concentration of fissionable material, detection of induced fast neutrons indicate concentration of the fissionable material.

Sensitivity of measured steam oxidation kinetics to atmospheric control and impurities

Energy Technology Data Exchange (ETDEWEB)

Sooby Wood, E., E-mail: sooby@lanl.gov [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM (United States); Terrani, K.A. [Nuclear Fuels Materials Group, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Nelson, A.T. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM (United States)

2016-08-15

The most direct means of improving the ability of water cooled reactors to withstand excessive cladding oxidation during a loss of coolant accident is to either modify or replace zirconium cladding. It is important to understand what level of agreement is to be expected as a function of systematic differences in steam oxidation testing techniques and instrumentation among testing facilities. The present study was designed to assess the sensitivities of some of the current and proposed reactor cladding materials. Steam oxidation sensitivity of Zircaloy-2, FeCrAl and Mo to O{sub 2} impurities in steam were examined. It was shown that the effect of O{sub 2} impurities is negligible for the two former materials while significant in the case of Mo.

Sensitization patterns in Compositae-allergic patients with current or past atopic dermatitis

DEFF Research Database (Denmark)

Paulsen, Evy; Andersen, Klaus Ejner

2013-01-01

Background. An association between Compositae sensitization and atopic dermatitis has been suggested on the basis of case reports and clinical studies. Objectives. To describe the characteristics of sensitization in Compositae-allergic patients with current and/or past atopic dermatitis. Patients/materials......-atopics, except that dandelion was an important allergen in children. Cobalt allergy was the most frequent other contact allergy, occurring in 37%. Conclusions. Persons with current or past atopic dermatitis may become sensitized to Compositae at any age, both occupationally and non-occupationally. They should...

Carbon coated stainless steel as counter electrode for dye sensitized solar cells

Science.gov (United States)

Prakash, Shejale Kiran; Sharma, Rakesh K.; Roy, Mahesh S.; Kumar, Mahesh

2014-10-01

A new type of counter electrode for dye sensitized solar cells has been fabricated using a stainless steel sheet as substrate and graphite, graphene and multiwall carbon nanotubes as the catalytic material which applied by screen printing technique. The sheet resistances of the substrates and there influence on the dye sensitized solar cells has been studied. The fabricated counter electrodes i.e. SS-graphite, SS-graphene SS-MWCNT and SS-platinum were tested for their photovoltaic response in the form of dye sensitized solar cells.

Efficient eco-friendly inverted quantum dot sensitized solar cells

NARCIS (Netherlands)

Park, Jinhyung; Sajjad, Muhammad T.; Jouneau, Pierre-Henri; Ruseckas, Arvydas; Faure-Vincent, Jérôme; Samuel, Ifor D. W.; Reiss, Peter; Aldakov, Dmitry

2016-01-01

Recent progress in quantum dot (QD) sensitized solar cells has demonstrated the possibility of low-cost and efficient photovoltaics. However, the standard device structure based on n-type materials often suffers from slow hole injection rate, which may lead to unbalanced charge transport. We have

Generalized tolerance sensitivity and DEA metric sensitivity

OpenAIRE

Neralić, Luka; E. Wendell, Richard

2015-01-01

This paper considers the relationship between Tolerance sensitivity analysis in optimization and metric sensitivity analysis in Data Envelopment Analysis (DEA). Herein, we extend the results on the generalized Tolerance framework proposed by Wendell and Chen and show how this framework includes DEA metric sensitivity as a special case. Further, we note how recent results in Tolerance sensitivity suggest some possible extensions of the results in DEA metric sensitivity.

Generalized tolerance sensitivity and DEA metric sensitivity

Directory of Open Access Journals (Sweden)

Luka Neralić

2015-03-01

Full Text Available This paper considers the relationship between Tolerance sensitivity analysis in optimization and metric sensitivity analysis in Data Envelopment Analysis (DEA. Herein, we extend the results on the generalized Tolerance framework proposed by Wendell and Chen and show how this framework includes DEA metric sensitivity as a special case. Further, we note how recent results in Tolerance sensitivity suggest some possible extensions of the results in DEA metric sensitivity.

New Components for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Stefano Caramori

2010-01-01

Full Text Available Dye-Sensitized Solar Cells (DSSCs are among the most promising solar energy conversion devices of new generation, since coupling ease of fabrication and low cost offer the possibility of building integration in photovoltaic windows and facades. Although in their earliest configuration these systems are close to commercialization, fundamental studies are still required for developing new molecules and materials with more desirable properties as well as improving our understanding of the fundamental processes at the basis of the functioning of photoactive heterogeneous interfaces. In this contribution, some recent advances, made in the effort of improving DSSC devices by finding alternative materials and configurations, are reviewed.

Materials for high temperature reactor vessels

International Nuclear Information System (INIS)

Buenaventura Pouyfaucon, A.

2004-01-01

Within the 5th Euraton Framework Programme, a big effort is being made to promote and consolidate the development of the High Temperature Reactor (HTR). Empresarios Agrupados is participating in this project and among others, also forms part of the HTR-M project Materials for HTRs. This paper summarises the work carried out by Empresarios Agrupados regarding the material selection of the HTR Reactor Pressure Vessel (RPV). The possible candidate materials and the most promising ones are discussed. Design aspects such as the RPV sensitive zones and material damage mechanisms are considered. Finally, the applicability of the existing design Codes and Standards for the design of the HTR RPV is also discussed. (Author)

Influence of annealing time on pH sensitivity of ZnO sensing membrane for EGFET sensor

Science.gov (United States)

Zulkefle, M. A.; Rahman, R. A.; Yusoff, K. A.; Abdullah, W. F. H.; Rusop, M.; Herman, S. H.

2018-05-01

Solid-state materials have becomes essential in recent technological advancements. This study also utilized solid-state material but in form of thin films to sense hydrogen ions in solutions. Fabrication of ZnO thin film was done using sol-gel spin coating technique. In an attempt to increase the pH sensitivity of the produced film, prolonging of annealing time was done. It was found that the increase in annealing time from 15 minutes to 30 minutes had managed to improve the sensitivity by 4.35%. The optimum pH sensitivity and linearity obtained in this study is 50.40 mV/pH and 0.9911 respectively.

Identification of strain-rate and thermal sensitive material model with an inverse method

Directory of Open Access Journals (Sweden)

Peroni M.

2010-06-01

Full Text Available This paper describes a numerical inverse method to extract material strength parameters from the experimental data obtained via mechanical tests at different strainrates and temperatures. It will be shown that this procedure is particularly useful to analyse experimental results when the stress-strain fields in the specimen cannot be correctly described via analytical models. This commonly happens in specimens with no regular shape, in specimens with a regular shape when some instability phenomena occur (for example the necking phenomena in tensile tests that create a strongly heterogeneous stress-strain fields or in dynamic tests (where the strain-rate field is not constant due to wave propagation phenomena. Furthermore the developed procedure is useful to take into account thermal phenomena generally affecting high strain-rate tests due to the adiabatic overheating related to the conversion of plastic work. The method presented requires strong effort both from experimental and numerical point of view, anyway it allows to precisely identify the parameters of different material models. This could provide great advantages when high reliability of the material behaviour is necessary. Applicability of this method is particularly indicated for special applications in the field of aerospace engineering, ballistic, crashworthiness studies or particle accelerator technologies, where materials could be submitted to strong plastic deformations at high-strain rate in a wide range of temperature. Thermal softening effect has been investigated in a temperature range between 20°C and 1000°C.

Novel functional magnetic materials fundamentals and applications

CERN Document Server

2016-01-01

This book presents current research on advanced magnetic materials and multifunctional composites. Recent advances in technology and engineering have resulted from the development of advanced magnetic materials with improved functional magnetic and magneto-transport properties. Certain industrial sectors, such as magnetic sensors, microelectronics, and security, demand cost-effective materials with reduced dimensionality and desirable magnetic properties such as enhanced magnetic softness, giant magnetic field sensitivity, and large magnetocaloric effect.  Expert chapters present the most up-to-date information on the fabrication process, processing, tailoring of properties, and applications of different families of modern functional materials for advanced smart applications. Topics covered include novel magnetic materials and applications; amorphous and nanocrystalline magnetic materials and applications; hard magnetic materials; magnetic shape memory alloys; and magnetic oxides. The book's highly interdis...

High-Sensitivity Measurement of Density by Magnetic Levitation.

Science.gov (United States)

Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

2016-03-01

This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

Potential development in dye-sensitized solar cells for renewable energy

CERN Document Server

Pandikumar, Alagarsamy

2013-01-01

The development of photovoltaic technology is expected to solve problems related to energy shortages and environmental pollution caused by the use of fossil fuels. Dye-sensitizedsolar cells (DSSCs) are promising next-generation alternatives to conventional silicon-based photovoltaic devices owing to their low manufacturing cost and potentially high conversion efficiency. This special topic volume addresses recent advances in the research on dye-sensitized solar cells. The focus of this special topic volume is on materials development (sensitizers, nanostructured oxide films, and electrolyte),

Environmental Sensitivity Index (ESI) Atlas: Upper Texas Coast (NODC Accession 0046089)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This CD-ROM product from the NOAA National Ocean Service Hazardous Materials Response and Assessment Division contains the Environmental Sensitivity Index (ESI) data...

High sensitivity neutron activation analysis of environmental and biological standard reference materials

International Nuclear Information System (INIS)

Greenberg, R.R.; Fleming, R.F.; Zeisler, R.

1984-01-01

Neutron activation analysis is a sensitive method with unique capabilities for the analysis of environmental and biological samples. Since it is based upon the nuclear properties of the elements, it does not suffer from many of the chemical effects that plague other methods of analysis. Analyses can be performed either with no chemical treatment of the sample (instrumentally), or with separations of the elements of interest after neutron irradiation (radiochemically). Typical examples of both types of analysis are discussed, and data obtained for a number of environmental and biological SRMs are presented. (author)

Sensitivity of charge transport measurements to local inhomogeneities

DEFF Research Database (Denmark)

Koon, Daniel; Wang, Fei; Petersen, Dirch Hjorth

an intuitive, visual explanation for experimental misassignment of carrier type in n-type ZnO and agree with published experimental results for holes in a uniform material. These results simplify calculation and plotting of the sensitivities on an N x N grid from a problem of order N5 to one of order N3...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

In contrast to the conventional DSSC systems, where the dye molecules are used as light harvesting material, here a solid-state absorber was used as a sensitizer in conjunction with the dye. The materials like ZnO and Al2O3 : C, which will show optically stimulated luminescence (OSL) upon irradiation were used as ...

Gold Nanoparticles-Coated SU-8 for Sensitive Fluorescence-Based Detections of DNA

DEFF Research Database (Denmark)

Cao, Cuong; Birtwell, Sam W.; Høgberg, Jonas

2012-01-01

SU-8 epoxy-based negative photoresist has been extensively employed as a structural material for fabrication of numerous biological microelectro-mechanical systems (Bio-MEMS) or lab-on-a-chip (LOC) devices. However, SU-8 has a high autofluorescence level that limits sensitivity of microdevices...... for various Bio-MEMs and LOC devices that use SU-8 as a structural material....

The Evaluation of Yellow vs. Blue Color Contrast Sensitivity pre and Post LASIK

Directory of Open Access Journals (Sweden)

S. Heydarian

2007-06-01

Full Text Available Introduction: contrast sensitivity is one of the most important psychophysical tests that may be used for the evaluation of refractive state of eye and retinal image quality. Yellow vs. blue color contrast sensitivity may be more suitable in this regard. Materials and Methods: thirty myopic eyes were considered in this study. Yellow vs. blue color contrast sensitivity was evaluated under the same environment and conditions in these individuals pre and post LASIK. Results: The comparison of yellow vs. blue color contrast sensitivity with glasses pr e and post LASIK shows a significant improvement (p

Measurement techniques for the verification of excess weapons materials

International Nuclear Information System (INIS)

Tape, J.W.; Eccleston, G.W.; Yates, M.A.

1998-01-01

The end of the superpower arms race has resulted in an unprecedented reduction in stockpiles of deployed nuclear weapons. Numerous proposals have been put forward and actions have been taken to ensure the irreversibility of nuclear arms reductions, including unilateral initiatives such as those made by President Clinton in September 1993 to place fissile materials no longer needed for a deterrent under international inspection, and bilateral and multilateral measures currently being negotiated. For the technologist, there is a unique opportunity to develop the technical means to monitor nuclear materials that have been declared excess to nuclear weapons programs, to provide confidence that reductions are taking place and that the released materials are not being used again for nuclear explosive programs. However, because of the sensitive nature of these materials, a fundamental conflict exists between the desire to know that the bulk materials or weapon components in fact represent evidence of warhead reductions, and treaty commitments and national laws that require the protection of weapons design information. This conflict presents a unique challenge to technologists. The flow of excess weapons materials, from deployed warheads through storage, disassembly, component storage, conversion to bulk forms, and disposition, will be described in general terms. Measurement approaches based on the detection of passive or induced radiation will be discussed along with the requirement to protect sensitive information from release to unauthorized parties. Possible uses of measurement methods to assist in the verification of arms reductions will be described. The concept of measuring attributes of items rather than quantitative mass-based inventory verification will be discussed along with associated information-barrier concepts required to protect sensitive information

Raman characterization of high temperature materials using an imaging detector

International Nuclear Information System (INIS)

Rosenblatt, G.M.; Veirs, D.K.

1989-03-01

The characterization of materials by Raman spectroscopy has been advanced by recent technological developments in light detectors. Imaging photomultiplier-tube detectors are now available that impart position information in two dimensions while retaining photon-counting sensitivity, effectively greatly reducing noise. The combination of sensitivity and reduced noise allows smaller amounts of material to be analyzed. The ability to observe small amount of material when coupled with position information makes possible Raman characterization in which many spatial elements are analyzed simultaneously. Raman spectroscopy making use of these capabilities has been used, for instance, to analyze the phases present in carbon films and fibers and to map phase-transformed zones accompanying crack propagation in toughened zirconia ceramics. 16 refs., 6 figs., 2 tabs

Acid-degradable and bioerodible modified polyhydroxylated materials

Energy Technology Data Exchange (ETDEWEB)

Frechet, Jean M. J.; Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.

2017-05-09

Compositions and methods of making a modified polyhydroxylated polymer comprising a polyhydroxylated polymer having reversibly modified hydroxyl groups, whereby the hydroxyl groups are modified by an acid-catalyzed reaction between a polydroxylated polymer and a reagent such as acetals, aldehydes, vinyl ethers and ketones such that the modified polyhydroxylated polymers become insoluble in water but freely soluble in common organic solvents allowing for the facile preparation of acid-sensitive materials. Materials made from these polymers can be made to degrade in a pH-dependent manner. Both hydrophobic and hydrophilic cargoes were successfully loaded into particles made from the present polymers using single and double emulsion techniques, respectively. Due to its ease of preparation, processability, pH-sensitivity, and biocompatibility, of the present modified polyhydroxylated polymers should find use in numerous drug delivery applications.

Dye-Sensitized Approaches to Photovoltaics

Science.gov (United States)

Grätzel, Michael

2008-03-01

Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely

Luminescence sensitivity changes in quartz as a result of annealing

DEFF Research Database (Denmark)

Bøtter-Jensen, L.; Agersnap Larsen, N.; Mejdahl, V.

1995-01-01

archaeological samples show very different OSL sensitivities. In this paper we report on studies of the effect of high temperature annealing on the OSL and phototransferred TL (PTTL) signals from sedimentary and synthetic quartz. A dramatic enhancement of both OSL and PTTL sensitivity was found especially...... in the temperature range 500-800 degrees C. Computer simulations of the possible effects are shown to produce data that agree in all essential details with the experimental observations. It is further demonstrated that the enhanced OSL sensitivity as a function of annealing temperature is not a pre-dose effect....... of magnitude less per unit radiation than that for heated material. The reason these temperature-induced sensitivity changes occur in quartz is presently not well understood. This phenomenon is also seen in the related area of luminescence dating in which sedimentary quartz and quartz from heated...

Tracer techniques in estimating nuclear materials holdup

International Nuclear Information System (INIS)

Pillay, K.K.S.

1987-01-01

Residual inventory of nuclear materials remaining in processing facilities (holdup) is recognized as an insidious problem for safety of plant operations and safeguarding of special nuclear materials (SNM). This paper reports on an experimental study where a well-known method of radioanalytical chemistry, namely tracer technique, was successfully used to improve nondestructive measurements of holdup of nuclear materials in a variety of plant equipment. Such controlled measurements can improve the sensitivity of measurements of residual inventories of nuclear materials in process equipment by several orders of magnitude and the good quality data obtained lend themselves to developing mathematical models of holdup of SNM during stable plant operations

P-polarized surface waves in a slab waveguide with left-handed material for sensing applications

International Nuclear Information System (INIS)

Taya, Sofyan A.

2015-01-01

In this paper, surface waves excited at the interface between left-handed and right-handed materials are employed for sensing applications. The propagation of p-polarized (TM) surface waves in a three-layer slab waveguide structure with air core layer as an analyte and anisotropic left-handed materials as claddings is investigated for detection of any changes in the refractive index of the analyte. The dispersion equations and the sensitivity of the effective refractive index to any change in the air layer index are derived, plotted, and discussed in details. The field profile is also explored. It is found that the sensitivity of the proposed surface wave sensor is almost independent of the wavelength of the propagating wave. A considerable sensitivity improvement can be obtained with the increase of transverse components of the left-handed material permittivity. - Highlights: • P-polarized surface waves in a three-layer slab waveguide are employed for sensing applications. • The structure contains air core layer as an analyte and anisotropic left-handed material in the claddings. • The sensitivity is found to be almost independent of the wavelength of the propagating wave. • Unusual sensitivity enhancement is observed as the transverse components of the LHM permittivity increase. • The asymmetric waveguide structure exhibits much higher sensitivity compared to the symmetric one

Materials characterization by resonant ultrasonic spectroscopy method

International Nuclear Information System (INIS)

Cheong, Yong Moo; Jung, H.K.; Joo, Y.S.; Sim, C.M.

2001-01-01

A high temperature resonant ultrasound spectroscopy(RUS) was developed. The dynamic elastic constant of RPV weld, which has various different microstructure was determined by RUS. It was confirmed the RUS method is very sensitive to the microstructures of the material. RUS can be used to monitor the degradation of nuclear materials including neutron irradiation embrittlement through the measurement of dynamic elastic constants, elastic anisotropy, high temperature elastic constant and Q-factor

Construction materials, monuments and environment

Science.gov (United States)

Prikryl, R.; Siegesmund, S.; Török, A.; Brimblecombe, P.; Gomez-Heras, M.

2012-04-01

Construction materials (natural stone, aggregates, bricks, cement, lime, mortar, etc.) form a wide and heterogeneous group both from the genetic and technological point of view. These materials deserve attention from the scientific community due to their long-term use, importance for society and sensitivity to the environment. Most geomaterials have also been used in important monuments designated as a part of the World Cultural Heritage and/or make part of national monuments. Despite of the wide-ranges of studies and our rapidly increasing understanding of material behaviour, our knowledge is still rather limited in many aspects. This concerns the characterisation of traditional raw materials, the knowledge of their processing and use, and/or durability and compatibility assessment. The exploitation and sustainable use of these materials are also new and emerging challenges in the modern society. The use of local materials for monuments can be considered as a part of our cultural and technological heritage, which has, however, significantly deteriorated during the past several decades. This paper summarizes the general topics related to a modern analysis of traditional construction materials derived from the Earth, and on the characteristic aspects of the behaviour of these materials on selected monuments.

The potential capability of near-real-time materials accountancy

International Nuclear Information System (INIS)

Sellinschegg, D.

1983-01-01

The new approach for the application of materials accountancy, called ''near-real-time materials accountancy'', is described and the practical feasibility as well as the possible improvements are discussed in comparison to the conventional approach. In the case of a reference reprocessing facility with an annual throughput of 1000 t heavy material the application of this procedure is simulated and the resulting improvement in detection sensitivity demonstrated. (author)

Dye-sensitized solar cells using natural dye as light-harvesting materials extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf

Directory of Open Access Journals (Sweden)

Wuletaw Andargie Ayalew

2016-12-01

Full Text Available Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. In this study, dye-sensitized solar cells (DSSCs were fabricated using natural dyes light harvesting materials. The natural dyes were extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf. In the as-prepared DSSC, a quasi-solid state electrolyte was sandwiched between the working electrode (photoanode and counter electrode (PEDOT-coated FTO glass. The photoelectrochemical performance of the as-prepared quasi-solid state DSSCs showed open-circuit voltages (VOC varied from 0.475 to 0.507 V, the short-circuit current densities (JSC ranged from 0.352 to 0.642 mA cm−2 and the fill factors (FF varied from 47 to 60% at 100 mWcm−2 light intensity. The dye extracted from A. sennii chiovenda flower, using acidified ethanol (in 1% HCl as extracting solvent, exhibited best conversion efficiency with a maximum open-circuit voltage (VOC of 0.507 V, short-circuit current density (JSC of 0.491 mA cm−2, fill factor (FF of 0.60 and an overall conversion efficiency (η of 0.15%. On the other hand, the maximum power conversion efficiency of the dye extracted from E. cotinifolia leaf was 0.136%. This is the first study that reports the fabrication of DSSC using natural dye sensitizers extracted from these plants in the presence of quasi-solid state electrolyte and PEDOT as a counter electrode.

Probabilistic analysis of a materially nonlinear structure

Science.gov (United States)

Millwater, H. R.; Wu, Y.-T.; Fossum, A. F.

1990-01-01

A probabilistic finite element program is used to perform probabilistic analysis of a materially nonlinear structure. The program used in this study is NESSUS (Numerical Evaluation of Stochastic Structure Under Stress), under development at Southwest Research Institute. The cumulative distribution function (CDF) of the radial stress of a thick-walled cylinder under internal pressure is computed and compared with the analytical solution. In addition, sensitivity factors showing the relative importance of the input random variables are calculated. Significant plasticity is present in this problem and has a pronounced effect on the probabilistic results. The random input variables are the material yield stress and internal pressure with Weibull and normal distributions, respectively. The results verify the ability of NESSUS to compute the CDF and sensitivity factors of a materially nonlinear structure. In addition, the ability of the Advanced Mean Value (AMV) procedure to assess the probabilistic behavior of structures which exhibit a highly nonlinear response is shown. Thus, the AMV procedure can be applied with confidence to other structures which exhibit nonlinear behavior.

The Effect of Hole Transport Material Pore Filling on Photovoltaic Performance in Solid-State Dye-Sensitized Solar Cells

KAUST Repository

Melas-Kyriazi, John

2011-04-05

A detailed investigation of the effect of hole transport material (HTM) pore filling on the photovoltaic performance of solid-state dye-sensitized solar cells (ss-DSCs) and the specific mechanisms involved is reported. It is demonstrated that the efficiency and photovoltaic characteristics of ss-DSCs improve with the pore filling fraction (PFF) of the HTM, 2,2\\',7,7\\'-tetrakis-(N, N-di-p-methoxyphenylamine)9,9\\'-spirobifluorene(spiro-OMeTAD). The mechanisms through which the improvement of photovoltaic characteristics takes place were studied with transient absorption spectroscopy and transient photovoltage/photocurrent measurements. It is shown that as the spiro-OMeTAD PFF is increased from 26% to 65%, there is a higher hole injection efficiency from dye cations to spiro-OMeTAD because more dye molecules are covered with spiro-OMeTAD, an order-of-magnitude slower recombination rate because holes can diffuse further away from the dye/HTM interface, and a 50% higher ambipolar diffusion coefficient due to an improved percolation network. Device simulations predict that if 100% PFF could be achieved for thicker devices, the efficiency of ss-DSCs using a conventional rutheniumdye would increase by 25% beyond its current value. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Hole Transport Material Pore Filling on Photovoltaic Performance in Solid-State Dye-Sensitized Solar Cells

KAUST Repository

Melas-Kyriazi, John; Ding, I-Kang; Marchioro, Arianna; Punzi, Angela; Hardin, Brian E.; Burkhard, George F.; Té treault, Nicolas; Grä tzel, Michael; Moser, Jacques-E.; McGehee, Michael D.

2011-01-01

A detailed investigation of the effect of hole transport material (HTM) pore filling on the photovoltaic performance of solid-state dye-sensitized solar cells (ss-DSCs) and the specific mechanisms involved is reported. It is demonstrated that the efficiency and photovoltaic characteristics of ss-DSCs improve with the pore filling fraction (PFF) of the HTM, 2,2',7,7'-tetrakis-(N, N-di-p-methoxyphenylamine)9,9'-spirobifluorene(spiro-OMeTAD). The mechanisms through which the improvement of photovoltaic characteristics takes place were studied with transient absorption spectroscopy and transient photovoltage/photocurrent measurements. It is shown that as the spiro-OMeTAD PFF is increased from 26% to 65%, there is a higher hole injection efficiency from dye cations to spiro-OMeTAD because more dye molecules are covered with spiro-OMeTAD, an order-of-magnitude slower recombination rate because holes can diffuse further away from the dye/HTM interface, and a 50% higher ambipolar diffusion coefficient due to an improved percolation network. Device simulations predict that if 100% PFF could be achieved for thicker devices, the efficiency of ss-DSCs using a conventional rutheniumdye would increase by 25% beyond its current value. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viscoplastic Constitutive Theory Demonstrated for Monolithic Ceramic Materials

Science.gov (United States)

Janosik, Lesley A.

1999-01-01

Development of accurate three-dimensional (multiaxial) inelastic stress-strain models is critical in utilizing advanced ceramics for challenging 21st century high-temperature structural applications. The current state of the art uses elastic stress fields as a basis for both subcritical crack growth and creep life prediction efforts aimed at predicting the time dependent reliability response of ceramic components subjected to elevated service temperatures. However, to successfully design components that will meet tomorrow's challenging requirements, design engineers must recognize that elastic predictions are inaccurate for these materials when subjected to high-temperature service conditions such as those encountered in advanced heat engine components. Analytical life prediction methodologies developed for advanced ceramics and other brittle materials must employ accurate constitutive models that capture the inelastic response exhibited by these materials at elevated service temperatures. A constitutive model recently developed at the NASA Lewis Research Center helps address this issue by accounting for the time-dependent (inelastic) material deformation phenomena (e.g., creep, rate sensitivity, and stress relaxation) exhibited by monolithic ceramics exposed to high-temperature service conditions. In addition, the proposed formulation is based on a threshold function that is sensitive to hydrostatic stress and allows different behavior in tension and compression, reflecting experimental observations obtained for these material systems.

The effect of combining a relative-humidity-sensitive ventilation system with the moisture-buffering capacity of materials on indoor climate and energy efficiency of buildings

Energy Technology Data Exchange (ETDEWEB)

Woloszyn, Monika [Universite de Lyon, Lyon F-69003 (France); Universite Lyon1, Villeurbanne F-69622 (France); INSA-Lyon, CETHIL UMR CNRS 5008, bat. Sadi Carnot, F-69621 Villeurbanne cedex (France); Kalamees, Targo [Chair of Building Physics and Architecture, Tallinn University of Technology, Ehiteja tee 5 19086 (Estonia); Olivier Abadie, Marc [Pontifical Catholic University of Parana - PUCPR/CCET-Thermal Systems Laboratory, Rua Imaculada Conceicao, 1155 Curitiba, PR 80215-901 (Brazil); LEPTIAB-University of La Rochelle, Avenue M. Crepeau, 17000 La Rochelle (France); Steeman, Marijke [Department of Architecture and Urban Planning, UGENT-Ghent University, J. Plateaustraat 22, 9000 Ghent (Belgium); Sasic Kalagasidis, Angela [Department of Building Technology, Chalmers University of Technology, Sven Hultins gata 8, 412 96 Gothenburg (Sweden)

2009-03-15

Indoor moisture management, which means keeping the indoor relative humidity (RH) at correct levels, is very important for whole building performance in terms of indoor air quality (IAQ), energy performance and durability of the building. In this study, the effect of combining a relative-humidity-sensitive (RHS) ventilation system with indoor moisture buffering materials was investigated. Four comprehensive heat-air-moisture (HAM) simulation tools were used to analyse the performance of different moisture management strategies in terms of IAQ and of energy efficiency. Despite some differences in results, a good agreement was found and similar trends were detected from the results, using the four different simulation tools. The results from simulations demonstrate that RHS ventilation reduces the spread between the minimum and maximum values of the RH in the indoor air and generates energy savings. Energy savings are achieved while keeping the RH at target level, not allowing for possible risk of condensations. The disadvantage of this type of demand controlled-ventilation is that other pollutants (such as CO{sub 2}) may exceed target values. This study also confirmed that the use of moisture-buffering materials is a very efficient way to reduce the amplitude of daily moisture variations. It was possible, by the combined effect of ventilation and wood as buffering material, to keep the indoor RH at a very stable level. (author)

Microfibres and hydrogels to promote autogenous healing in cementitious materials

OpenAIRE

Snoeck, Didier; Dubruel, Peter; De Belie, Nele

2013-01-01

Cementitious materials are sensitive to crack formation and it would be beneficial if the material could stop the crack propagation, repair the damage and reach again the original liquid-tightness and/or strength. Therefore, a cementitious material with synthetic microfibres and superabsorbent polymers (SAPs) is proposed. Upon crack formation, the microfibres will become active and due to the bridging action, they will stop the opening of a crack, forcing the cementitious material to crack so...

EH AND S ANALYSIS OF DYE-SENSITIZED PHOTOVOLTAIC SOLAR CELL PRODUCTION

International Nuclear Information System (INIS)

BOWERMAN, B.; FTHENAKIS, V.

2001-01-01

Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified

Henna (Lawsonia inermis L.) Dye-Sensitized Nanocrystalline Titania Solar Cell

International Nuclear Information System (INIS)

Jasim, Kh.E.; Al-Dallal, Sh.; Hassan, A.M.

2012-01-01

Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs) emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs) are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed

Henna (Lawsonia inermis L. Dye-Sensitized Nanocrystalline Titania Solar Cell

Directory of Open Access Journals (Sweden)

Khalil Ebrahim Jasim

2012-01-01

Full Text Available Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed.

Tracking Nuclear Material At Proliferation Sensitive Points In The Kazakhstan Fuel Cycle

NARCIS (Netherlands)

Janssens-Maenhout, G.; Delbeke, J.F.A.; Caviglia, M.; Janssens, W.

2006-01-01

Since 1995 with the ratification and enforcement of the Non Proliferation Treaty in the Republic of Kazakhstan, the Kazakhstan Atomic Energy Committee (KAEC) is responsible for the implementation of the State System for Accountancy and Control (SSAC). In the SSAC, data on nuclear material

Nuclear material enrichment identification method based on cross-correlation and high order spectra

International Nuclear Information System (INIS)

Yang Fan; Wei Biao; Feng Peng; Mi Deling; Ren Yong

2013-01-01

In order to enhance the sensitivity of nuclear material identification system (NMIS) against the change of nuclear material enrichment, the principle of high order statistic feature is introduced and applied to traditional NMIS. We present a new enrichment identification method based on cross-correlation and high order spectrum algorithm. By applying the identification method to NMIS, the 3D graphs with nuclear material character are presented and can be used as new signatures to identify the enrichment of nuclear materials. The simulation result shows that the identification method could suppress the background noises, electronic system noises, and improve the sensitivity against enrichment change to exponential order with no system structure modification. (authors)

STRESS MODELING IN COMPOSITE PRODUCTS USING STANDARD OPTICALLY SENSITIVE MATERIAL

Directory of Open Access Journals (Sweden)

Elifkhan K. Agakhanov

2017-01-01

Full Text Available Abstract. Objectives The problem of physically modelling stresses in a compound solid body of revolution having a complex shape and with a complex load distribution is considered. According to the similarity criteria of stress, deformations and displacements from the volume forces decrease proportionally to the scale of similarity of geometric dimensions, which complicates their direct modelling by the photoelasticity method typically using models made from epoxy materials. Methods Based on the principle of the independent action of the forces, the initial problem is represented as the sum of two problems. In the first uniform problem, the stresses in the body of revolution from the centrifugal forces are simulated by the conventional “freezing” method. In order to solve the second nonuniform problem, the stresses in the region of the model, corresponding to the acting centrifugal forces, are “frozen”. The models are glued in a natural state at room temperature, and the compound model is annealed. Results The band patterns in sections as well as components of radial, tangential and axial stresses on contours and in sections of models are obtained by the methods of normal transmission and numerical integration of the equilibrium equation. According to the modelling criteria, the formula for the transition from stresses in models to stresses in the natural structure is established. The results of the analysis of the effect of a body's material density ratio on the stress state of the entire structure are obtained. Conclusion  Axial stresses have insignificant value as compared to radial and tangential stresses; in addition, the ratio of the densities of the compound body has both a quantitative and qualitative influence on the stress state of the structure.

Cultural sensitivity in public health: defined and demystified.

Science.gov (United States)

Resnicow, K; Baranowski, T; Ahluwalia, J S; Braithwaite, R L

1999-01-01

There is consensus that health promotion programs should be culturally sensitive (CS). Yet, despite the ubiquitous nature of CS within public health research and practice, there has been surprisingly little attention given to defining CS or delineating a framework for developing culturally sensitive programs and practitioners. This paper describes a model for understanding CS from a public health perspective; describes a process for applying this model in the development of health promotion and disease prevention interventions; and highlights research priorities. Cultural sensitivity is defined by two dimensions: surface and deep structures. Surface structure involves matching intervention materials and messages to observable, "superficial" characteristics of a target population. This may involve using people, places, language, music, food, locations, and clothing familiar to, and preferred by, the target audience. Surface structure refers to how well interventions fit within a specific culture. Deep structure involves incorporating the cultural, social, historical, environmental and psychological forces that influence the target health behavior in the proposed target population. Whereas surface structure generally increases the "receptivity" or "acceptance" of messages, deep structure conveys salience. Techniques, borrowed from social marketing and health communication theory, for developing culturally sensitive interventions are described. Research is needed to determine the effectiveness of culturally sensitive programs.

EB and EUV lithography using inedible cellulose-based biomass resist material

Science.gov (United States)

Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2016-03-01

The validity of our approach of inedible cellulose-based resist material derived from woody biomass has been confirmed experimentally for the use of pure water in organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques of eco-conscious electron beam (EB) and extreme-ultraviolet (EUV) lithography. The water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB and EUV lithography was developed for environmental affair, safety, easiness of handling, and health of the working people. The inedible cellulose-based biomass resist material was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB and EUV sensitive groups. The 50-100 nm line and space width, and little footing profiles of cellulose-based biomass resist material on hardmask and layer were resolved at the doses of 10-30 μC/cm2. The eco-conscious lithography techniques was referred to as green EB and EUV lithography using inedible cellulose-based biomass resist material.

Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part I. Transmission Holographic Optical Elements

Science.gov (United States)

Kim, Jong Man; Choi, Byung So; Kim, Sun Il; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

2001-02-01

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOE s). The drawback of DCG is its low sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-high-resolution silver halide emulsions. An optimized processing technique for transmission HOE s recorded in these materials is introduced. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOE s.

Bacteriological profile and antibiotic sensitivity pattern in patients with Urinary tract infection

OpenAIRE

N Subedi; S Pudasaini

2017-01-01

Background: Urinary tract infection is one of the common bacterial infections seeking treatment in clinical practice. A variety of organisms are associated with UTI and the most common organisms are Escherichia coli and other coliforms. Bacteriological investigations of UTI are not complete without antibiotic sensitivity test of the isolate. The aim of this study is to determine the bacteriological profile and antibiotic sensitivity patterns and their disease association.Materials and methods...

In vitro assessment of skin sensitization, photosensitization and phototoxicity potential of commercial glyphosate-containing formulations.

Science.gov (United States)

de Ávila, Renato Ivan; Teixeira, Gabriel Campos; Veloso, Danillo Fabrini Maciel Costa; Moreira, Larissa Cleres; Lima, Eliana Martins; Valadares, Marize Campos

2017-12-01

This study evaluated the applicability of a modified Direct Peptide Reactivity Assay (DPRA) (OECD N° 442C, 2015) through the 10-fold reduction of reaction volume (micro-DPRA, mDPRA) for skin sensitization evaluation of six commercial glyphosate-containing formulations. In addition, another modification of DPRA was proposed by adding a UVA (5J/cm 2 ) irradiation step, namely photo-mDPRA, to better characterize (photo)sensitizer materials. The phototoxicity profile of pesticides was also evaluated using the 3T3 Neutral Red Uptake Phototoxicity Test (3T3-NRU-PT) (OECD N° 432, 2004). The mDPRA could represent an environmentally acceptable test approach, since it reduces costs and organic waste. Peptide depletion was greater in photo-mDPRA and changed the reactivity class of each test material, in comparison to mDPRA. Thus, the association of mDPRA with photo-mDPRA was better for correctly characterizing human (photo)sensitizer substances and pesticides. In general, cysteine depletion was greater than that of lysine for all materials tested in both mDPRA and photo-mDPRA. Furthermore, while 3T3-NRU-PT is unable to predict (photo)sensitizers, it was capable of correctly identifying the phototoxic potential of the tested agrochemical formulations. In conclusion, mDPRA plus photo-mDPRA and 3T3-NRU-PT seem to be preliminary non-animal test batteries for skin (photo)sensitization/phototoxicity assessment of chemicals, agrochemical formulations and their ingredients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Report of the Material Control and Material Accounting Task Force: blueprint for the future

International Nuclear Information System (INIS)

1978-03-01

A blueprint is presented for the development of improved material control and material accounting systems by integrating the goals and capabilities of material control and material accounting and recommending specific upgrading actions. An analysis is included of several specific issues and developing recommendations for future actions related to those issues. It is felt that there is a need for a program to define specific quantified goals for an integrated safeguards program, and to monitor safeguards programs in terms of these goals. NRC should give highest priority to developing regulations and guides that will enable material control to make a greater contribution to safeguards by providing greater timeliness and sensitivity in detecting and assessing material losses. It is recommended that a technical study be conducted to determine a quantitative measure or at least a figure of merit for the effectiveness of a security clearance program, based upon full field background investigations, in protecting against malevolent conspiracies involving two or more security cleared individuals. It is also recommended that a specific effort be initiated to formulate an approach to combating collusion. This effort should specifically consider the contribution that material control and material accounting programs can make to safeguards effectiveness in this area

An in vitro human skin test for assessing sensitization potential.

Science.gov (United States)

Ahmed, S S; Wang, X N; Fielding, M; Kerry, A; Dickinson, I; Munuswamy, R; Kimber, I; Dickinson, A M

2016-05-01

Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process. Copyright © 2015 John Wiley & Sons, Ltd.

Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors

Science.gov (United States)

Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura

2018-03-01

We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.

Scientific Structural Changes within Texts of Adapted Reading Materials

Science.gov (United States)

Aziz, Anealka; Fook, Chan Yuen; Alsree, Zubaidah

2010-01-01

ESL instructors generally use ready-made reading materials in commercially published coursebooks. However, it would be more effective for learners if ESL instructors are involved in developing reading materials for them. This is because they are closer, more sensitive and responsive to the needs of their learners and they are also aware of the…

Pressure Sensitive Sensors Based on Carbon Nanotubes, Graphene, and Its Composites

Directory of Open Access Journals (Sweden)

Asar Ali

2018-01-01

Full Text Available Carbon nanotubes (CNTs and graphene have attracted a great deal of interest due to their outstanding mechanical, optical, electrical, and structural properties. Most of the scientists and researchers have investigated the optical and electrical properties of these materials. However, due to unique electromechanical properties of these materials, it is required to explore the piezoresistive properties of bulk nanostructured CNTs, graphene, and CNT-graphene composites. We investigated and compared the sensitivities and piezoresistive properties of sandwich-type pure CNT, pure graphene, and CNT-graphene composite pressure sensors. For all the samples, increase in pressure from 0 to 0.183 kNm−2 results in a decrease in the impedance and direct current (DC resistance. Sensitivity and percentage decrease in resistance and impedance of CNT-graphene composite were lower than pure CNT while being higher than pure graphene based sample. Moreover, under the same external applied pressure, the sensitivity and percentage decrease in impedance for pure CNT, pure graphene, and CNT-graphene composite were smaller than the corresponding sensitivity and percentage decrease in resistance. The achieved experimental results of the composite sample were compared with simulated results which exhibit reasonable agreement with each other. The deviations of simulated resistance-pressure and impedance-pressure curves from experimental graphs were 0.029% and 0.105%, respectively.

Predicting a contact's sensitivity to initial conditions using metrics of frictional coupling

International Nuclear Information System (INIS)

Flicek, Robert C.; Hills, David A.; Brake, Matthew Robert W.

2016-01-01

This paper presents a method for predicting how sensitive a frictional contact’s steady-state behavior is to its initial conditions. Previous research has proven that if a contact is uncoupled, i.e. if slip displacements do not influence the contact pressure distribution, then its steady-state response is independent of initial conditions, but if the contact is coupled, the steady-state response depends on initial conditions. In this paper, two metrics for quantifying coupling in discrete frictional systems are examined. These metrics suggest that coupling is dominated by material dissimilarity due to Dundurs’ composite material parameter β when β ≥ 0.2, but geometric mismatch becomes the dominant source of coupling for smaller values of β. Based on a large set of numerical simulations with different contact geometries, material combinations, and friction coefficients, a contact’s sensitivity to initial conditions is found to be correlated with the product of the coupling metric and the friction coefficient. For cyclic shear loading, this correlation is maintained for simulations with different contact geometries, material combinations, and friction coefficients. Furthermore, for cyclic bulk loading, the correlation is only maintained when the contact edge angle is held constant.

Sensitivity analysis of complex models: Coping with dynamic and static inputs

International Nuclear Information System (INIS)

Anstett-Collin, F.; Goffart, J.; Mara, T.; Denis-Vidal, L.

2015-01-01

In this paper, we address the issue of conducting a sensitivity analysis of complex models with both static and dynamic uncertain inputs. While several approaches have been proposed to compute the sensitivity indices of the static inputs (i.e. parameters), the one of the dynamic inputs (i.e. stochastic fields) have been rarely addressed. For this purpose, we first treat each dynamic as a Gaussian process. Then, the truncated Karhunen–Loève expansion of each dynamic input is performed. Such an expansion allows to generate independent Gaussian processes from a finite number of independent random variables. Given that a dynamic input is represented by a finite number of random variables, its variance-based sensitivity index is defined by the sensitivity index of this group of variables. Besides, an efficient sampling-based strategy is described to estimate the first-order indices of all the input factors by only using two input samples. The approach is applied to a building energy model, in order to assess the impact of the uncertainties of the material properties (static inputs) and the weather data (dynamic inputs) on the energy performance of a real low energy consumption house. - Highlights: • Sensitivity analysis of models with uncertain static and dynamic inputs is performed. • Karhunen–Loève (KL) decomposition of the spatio/temporal inputs is performed. • The influence of the dynamic inputs is studied through the modes of the KL expansion. • The proposed approach is applied to a building energy model. • Impact of weather data and material properties on performance of real house is given

Polarization Sensitive Coherent Raman Measurements of DCVJ

Science.gov (United States)

Anderson, Josiah; Cooper, Nathan; Lawhead, Carlos; Shiver, Tegan; Ujj, Laszlo

2014-03-01

Coherent Raman spectroscopy which recently developed into coherent Raman microscopy has been used to produce label free imaging of thin layers of material and find the spatial distributions of certain chemicals within samples, e.g. cancer cells.(1) Not all aspects of coherent scattering have been used for imaging. Among those for example are special polarization sensitive measurements. Therefore we have investigated the properties of polarization sensitive CARS spectra of a highly fluorescent molecule, DCVJ.(2) Spectra has been recorded by using parallel polarized and perpendicular polarized excitations. A special polarization arrangement was developed to suppress the non-resonant background scattering from the sample. These results can be used to improve the imaging properties of a coherent Raman microscope in the future. This is the first time coherent Raman polarization sensitive measurements have been used to characterize the vibrational modes of DCVJ. 1: K. I. Gutkowski, et al., ``Fluorescence of dicyanovinyl julolidine in a room temperature ionic liquid '' Chemical Physics Letters 426 (2006) 329 - 333 2: Fouad El-Diasty, ``Coherent anti-Stokes Raman scattering: Spectroscopy and microscopy'' Vibrational Spectroscopy 55 (2011) 1-37

On the sensitivity of FPPE - TWRC method in thermal effusivity investigations of solids

International Nuclear Information System (INIS)

Dadarlat, Dorin; Streza, Mihaela; Pop, Mircea N; Tosa, Valer

2009-01-01

The front detection configuration (FPPE) together with the thermal-wave-resonator-cavity (TWRC) method was used for direct measurement of the thermal effusivity of solid materials inserted as backings in the FPPE detection cell. It was demonstrated that the normalized phase of the FPPE signal has an oscillating dependence as a function of sample's thickness. The paper presents experimental results on solid materials, with various values of thermal effusivity (Cu, brass, steel, bakelite, wood). A study of the sensitivity of the technique for different liquid/backing effusivity ratios is performed. The highest sensitivity was obtained when investigating solids with values of thermal effusivity not far from the effusivity of the liquid layer of the detection cell.

Physical nature of strain rate sensitivity of metals and alloys at high strain rates

Science.gov (United States)

Borodin, E. N.; Gruzdkov, A. A.; Mayer, A. E.; Selyutina, N. S.

2018-04-01

The role of instabilities of plastic flow at plastic deformation of various materials is one of the important cross-disciplinary problems which is equally important in physics, mechanics and material science. The strain rate sensitivities under slow and high strain rate conditions of loading have different physical nature. In the case of low strain rate, the sensitivity arising from the inertness of the defect structures evolution can be expressed by a single parameter characterizing the plasticity mechanism. In our approach, this is the value of the characteristic relaxation time. In the dynamic case, there are additional effects of “high-speed sensitivity” associated with the micro-localization of the plastic flow near the stress concentrators. In the frames of mechanical description, this requires to introduce additional strain rate sensitivity parameters, which is realized in numerous modifications of Johnson–Cook and Zerilli–Armstrong models. The consideration of both these factors is fundamental for an adequate description of the problems of dynamic deformation of highly inhomogeneous metallic materials such as steels and alloys. The measurement of the dispersion of particle velocities on the free surface of a shock-loaded material can be regarded as an experimental expression of the effect of micro-localization. This is also confirmed by our results of numerical simulation of the propagation of shock waves in a two-dimensional formulation and analytical estimations.

New Evidences on the Process Sensitivity of Some Renewable Blends Based on Starch considering Their Melt Rheological Properties

Directory of Open Access Journals (Sweden)

Doina Dimonie

2016-01-01

Full Text Available The degradability and processability of new renewable materials based on starch and PVOH were studied using the melt flow index (MFI method by measuring the melt rheological properties which depend not only on the extrusion conditions and material formulation but also on the macromolecule characteristics which can be modified by chemical degradation. These results were correlated with other material properties like color and cross-linking degree. The obtained results show that flowing in the melted state of the studied materials is accompanied by a second process of chains chemical degradation. It was observed that, at the same level of additivation, under identical extrusion conditions, the melted blends with corn starch as main component are highly mechanically sensitive and degrade mostly by chains scission and those with PVOH as major component are highly temperature sensitive and degrade mainly by cross-linking. The obtained results show also that each PVOH-starch blend requires particular formulation and individual windows of melt processing conditions. These results are a good proof that the MFI method is a good path to study the degradability and moldability of process sensitive polymeric materials like those based on starch and PVOH.

Systematic development of new thermoluminescence and optically stimulated luminescence materials

Energy Technology Data Exchange (ETDEWEB)

Yukihara, E.G., E-mail: eduardo.yukihara@okstate.edu [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Milliken, E.D.; Oliveira, L.C. [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Orante-Barron, V.R. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico (Mexico); Jacobsohn, L.G. [Center for Optical Materials Science and Engineering Technologies (COMSET), and School of Materials Science and Engineering, Clemson University, Clemson, SC (United States); Blair, M.W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-01-15

This paper presents an overview of a systematic study to develop new thermoluminescence (TL) and optically stimulated luminescence (OSL) materials using solution combustion synthesis (SCS) for applications such as personal OSL dosimetry, 2D dose mapping, and temperature sensing. A discussion on the material requirements for these applications is included. We present X-ray diffraction (XRD) data on single phase materials obtained with SCS, as well as radioluminescence (RL), TL and OSL data of lanthanide-doped materials. The results demonstrate the possibility of producing TL and OSL materials with sensitivity similar to or approaching those of commercial TL and OSL materials used in dosimetry (e.g., LiF:Mg,Ti and Al{sub 2}O{sub 3}:C) using SCS. The results also show that the luminescence properties can be improved by Li co-doping and annealing. The presence of an atypical TL background and anomalous fading are discussed and deserve attention in future investigations. We hope that these preliminary results on the use of SCS for production of TL and OSL materials are helpful to guide future efforts towards the development of new luminescence materials for different applications. - Highlights: Black-Right-Pointing-Pointer TL and OSL material produced with sensitivity similar to commercial materials. Black-Right-Pointing-Pointer Luminescence properties improved by Li co-doping and annealing. Black-Right-Pointing-Pointer The presence of atypical TL background and anomalous fading observed.

Linear Array Ultrasonic Transducers: Sensitivity and Resolution Study

International Nuclear Information System (INIS)

Kramb, V.A.

2005-01-01

The University of Dayton Research Institute (UDRI) under contract by the US Air Force has designed and integrated a fully automated inspection system for the inspection of turbine engines that incorporates linear phased array ultrasonic transducers. Phased array transducers have been successfully implemented into weld and turbine blade root inspections where the defect types are well known and characterized. Embedded defects in aerospace turbine engine components are less well defined, however. In order to determine the applicability of linear arrays to aerospace inspections the sensitivity of array transducers to embedded defects in engine materials must be characterized. In addition, the implementation of array transducers into legacy inspection procedures must take into account any differences in sensitivity between the array transducer and that of the single element transducer currently used. This paper discusses preliminary results in a study that compares the sensitivity of linear array and conventional single element transducers to synthetic hard alpha defects in a titanium alloy

Sensitivity quantification of remote detection NMR and MRI

Science.gov (United States)

Granwehr, J.; Seeley, J. A.

2006-04-01

A sensitivity analysis is presented of the remote detection NMR technique, which facilitates the spatial separation of encoding and detection of spin magnetization. Three different cases are considered: remote detection of a transient signal that must be encoded point-by-point like a free induction decay, remote detection of an experiment where the transient dimension is reduced to one data point like phase encoding in an imaging experiment, and time-of-flight (TOF) flow visualization. For all cases, the sensitivity enhancement is proportional to the relative sensitivity between the remote detector and the circuit that is used for encoding. It is shown for the case of an encoded transient signal that the sensitivity does not scale unfavorably with the number of encoded points compared to direct detection. Remote enhancement scales as the square root of the ratio of corresponding relaxation times in the two detection environments. Thus, remote detection especially increases the sensitivity of imaging experiments of porous materials with large susceptibility gradients, which cause a rapid dephasing of transverse spin magnetization. Finally, TOF remote detection, in which the detection volume is smaller than the encoded fluid volume, allows partial images corresponding to different time intervals between encoding and detection to be recorded. These partial images, which contain information about the fluid displacement, can be recorded, in an ideal case, with the same sensitivity as the full image detected in a single step with a larger coil.

Dye-sensitized PS-b-P2VP-templated nickel oxide films for photoelectrochemical applications.

Science.gov (United States)

Massin, Julien; Bräutigam, Maximilian; Kaeffer, Nicolas; Queyriaux, Nicolas; Field, Martin J; Schacher, Felix H; Popp, Jürgen; Chavarot-Kerlidou, Murielle; Dietzek, Benjamin; Artero, Vincent

2015-06-06

Moving from homogeneous water-splitting photocatalytic systems to photoelectrochemical devices requires the preparation and evaluation of novel p-type transparent conductive photoelectrode substrates. We report here on the sensitization of polystyrene-block-poly-(2-vinylpyridine) (PS-b-P2VP) diblock copolymer-templated NiO films with an organic push-pull dye. The potential of these new templated NiO film preparations for photoelectrochemical applications is compared with NiO material templated by F108 triblock copolymers. We conclude that NiO films are promising materials for the construction of dye-sensitized photocathodes to be inserted into photoelectrochemical (PEC) cells. However, a combined effort at the interface between materials science and molecular chemistry, ideally funded within a Global Artificial Photosynthesis Project, is still needed to improve the overall performance of the photoelectrodes and progress towards economically viable PEC devices.

The history of permanent magnet materials

International Nuclear Information System (INIS)

Livingston, J.D.

1990-01-01

Permanent-magnet materials play a large and growing, but largely unseen, role in today's technology. Many common devices in the home and elsewhere, including appliances, computers and printers, contain permanent-magnet motors and actuators. The growth of applications for permanent magnets results in large part from the improvements in magnetic properties, which allow the engineer to design smaller, lighter and more efficient devices. The properties of the greatest technological interest are remanence, coercivity and maximum energy product. All are non-equilibrium and high structure-sensitive. Coercivity is particularly sensitive to microstructure, while remanence is sensitive to texture (crystallographic alignment). The energy product depends on both coercivity and remanence. The more than one hundredfold increase in the available energy product in this century, and the corresponding amount of magnet required for a specific application, are shown

Safeguards and security in the face of nonproliferation, material storage and material disposition

International Nuclear Information System (INIS)

Rivers, J.D.; Kohen, M.D.

1996-01-01

Change is everywhere: society, domestic and international business, the US Government. As the world becomes smaller and more interconnected, the task of protecting the US'' most sensitive assets will become more complex. International obligations resulting from treaties and agreements will increasingly impact the Department of Energy (DOE), to include the dismantlement of nuclear weapons, and the safe, secure storage and disposition of special nuclear material that is a product of dismantlement. Two of the most urgent topics facing DOE are the prevention of proliferation of weapons of mass destruction and the future disposition of special nuclear material. This paper discusses how the DOE safeguards and security community is responding to the increasing challenges imposed by these two issues

The sensitizing capacity of multifunctional acrylates in the guinea pig.

Science.gov (United States)

Björkner, B

1984-10-01

The multifunctional acrylates used in ultraviolet (UV) curable resins act as cross-linkers and "diluents". They are usually based on di(meth)acrylate esters of dialcohols or tri- and tetra-acrylate esters of polyalcohols. In UV-curable coatings, the most commonly used are pentaerythritol triacrylate (PETA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA). In other uses, such as dental composite resin materials, the dimethacrylic monomers based on n-ethylene glycol are the most useful. The sensitizing capacity of various multifunctional acrylates and their cross-reactivity pattern have been investigated with the guinea pig maximization test. The tests show that BUDA (1,4-butanediol diacrylate) and HDDA are moderate to strong sensitizers and that they probably cross-react with each other. The n-ethylene glycol diacrylates and methacrylates tested are weak or non-sensitizers. Tripropylene glycol diacrylate (TPGDA) is a moderate and neopentyl glycol diacrylate (NPGDA) a strong sensitizer, whereas neopentyl glycol dimethacrylate is a non-sensitizer. The commercial PETA is a mixture of pentaerythritol tri- and tetra-acrylate (PETA-3 and PETA-4). PETA-3 is a much stronger sensitizer than PETA-4. Simultaneous reactions were seen between PETA-3, PETA-4 and TMPTA. The oligotriacrylate OTA 480 is a moderate sensitizer, but no concomitant reactions were seen with PETA-3, PETA-4 or TMPTA. Of the multifunctional acrylates tested, the di- and triacrylic compounds should be regarded as potent sensitizers. The methacrylated multifunctional acrylic compounds are weak or non-sensitizers.

High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

Notch sensitivity of cast AZ31 magnesium alloy

Czech Academy of Sciences Publication Activity Database

Kunz, Ludvík; Lukáš, Petr; Estrin, Y.; Zúberová, Z.

2005-01-01

Roč. 12, č. 3 (2005), s. 88-91 ISSN 1335-0803. [Degradácia konštrukčných materiálov 2005. Terchová - Biely Potok, 05.09.2005-07.09.2005] R&D Projects: GA MŠk(CZ) 1P05ME804 Institutional research plan: CEZ:AV0Z20410507 Keywords : notch sensitivity * magnesium alloy * fatigue lifetime Subject RIV: JG - Metallurgy

Unique reduced graphene oxide as efficient anode material in Li ion ...

Indian Academy of Sciences (India)

2018-03-29

Mar 29, 2018 ... as an electrode material in dye-sensitized solar cell [1], super- capacitor [2] and Li ion battery ... Ar-filled glove box. In each of the coin cell, ... Li reacts with suitable materials' defects at low potential and as they charge, bonds ...

Guide for use of radiation-sensitive indicators. 2. ed.

International Nuclear Information System (INIS)

2002-01-01

This guide covers the use of radiation-sensitive indicators in radiation processing. These indicators may be labels, papers, inks or packaging materials which undergo a color change or become colored when exposed to ionizing radiation. The purpose of these indicators is to determine visually whether or not a product has been irradiated, rather than to measure different dose levels. Such materials are not dosimeters and should not be used as a substitute for proper dosimetry. Information about dosimetry systems for ionizing radiation is provided in other ASTM and ISO/ASTM documents (see ISO/ASTM Guide 51261

Broadband sensitized photon up-conversion at subsolar irradiance (Conference Presentation)

Science.gov (United States)

Pedrini, Jacopo; Monguzzi, Angelo; Meinardi, Francesco

2016-09-01

A crucial limit of solar devices is their inability to harvest the full solar spectrum. Currently, sensitized up-conversion based on triplet-tripled annihilation (STTA-UC) in bi-component organic systems is the most promising technique to recover sub-bandgap photons, showing good efficiencies also at excitation intensities comparable to the solar irradiance. In STTA-UC, high-energy light is generated through annihilation of metastable triplet states of molecules acting as emitters, which are populated via resonant energy transfer from a light-harvesting sensitizer. However, suitable sensitizers show narrow absorption bands, limiting the fraction of recoverable photons, therefore preventing the application of STTA-UC to real-world devices. Here we demonstrate how to overcome the described limit by using multiple sensitizers that work cooperatively to broaden the overall system absorption band. This is obtained using an additional sensitizer that transfers the extra harvested energy to the main one (sensitization of the sensitizer), or a set of properly designed complementary absorbing sensitizers all able to excite simultaneously the same emitter (multi-sensitizers). In both cases STTA-UC performances result strongly enhanced compared to the corresponding mono-sensitizer system, increasing the up-converted light intensity generated at AM 1.5 up to two times. Remarkably, by coupling our light converters to a DSSC we prove its operation by exploiting exclusively sub-bandgap photons. A detailed modeling of the photophysical processes involved in these complex systems allows us to draw the guidelines for the design of the next generation STTA-UC materials, encouraging their application to photovoltaic technologies.

Antibiotic sensitivity of Enterobacteriaceae at a tertiary care center in India

Directory of Open Access Journals (Sweden)

Summaiya Mulla

2011-01-01

Full Text Available Aims and Objectives: It has been observed that various microorganisms are acquiring resistance to most of the available potent antibiotics; hence, there is a need for every hospital to follow the use of antibiotics according to antibiotic sensitivity pattern in that particular hospital or geographical area. It has been reported that Enterobacteriaceae group of microorganisms are increasingly acquiring resistance to many antibiotics and this resistance varies geographically. As there is a short of recent data with respect to Indian hospital, this particular study was designed with the aim of establishing sensitivity pattern of Enterobacteriaceae group of microorganisms to various antibiotics. Materials and Methods: Data of antibiotic sensitivity from December 2010 to April 2011 of different Enterobacteriaceae was taken from the Department of Microbiology, Govt. Medical College, Surat. Sensitivity of different Enterobacteriaceae was shown as using descriptive statistics. Results: E. coli (55.6% and Klebsiella (31.2% were the most frequent bacteria isolated. Enterobacteriaceae were very less sensitive to amoxicillin + clavulanic acid (13.7%, chloramphenicol (7.6%, cefoperazone (14.4%, cefixime (15.7%, and cefuroxime (17.6. Sensitivity to aztreonam was 32.7%. Sensitivity to carbapenem group of drugs included in this study, i.e., meropenem was 69.8%. Highest sensitivity was shown for ceftazidime (74.1%. E. coli is more sensitive to meropenem as compared with Klebsiella. Conclusion: Sensitivity of Enterobacteriaceae group of microorganisms to known antibiotics is decreasing. Decreased sensitivity to carbapenem group of antibiotics is a matter of concern.

Material characterization of Inconel 718 from free bulging test at high temperature

Energy Technology Data Exchange (ETDEWEB)

Yoo, Joon Tae; Yoon, Jong Hoon; Lee, Ho Sung [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Youn, Sung Kie [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2012-07-15

Macroscopic superplastic behavior of metallic or non metallic materials is usually represented by the strain rate sensitivity, and it can be determined by tensile tests in uniaxial stress state and bulging tests in multi axial stress state, which is the actual hot forming process. And macroscopic behavior of Non SPF grade materials could be described in a similar way as that of superplastic materials, including strain hardening, cavity and so on. In this study, the material characterization of non SPF grade Inconel 718 has been carried out to determine the material parameters for flow stress throughout free bulging test under constant temperature. The measured height of bulged plate during the test was used for estimation of strain rate sensitivity, strain hardening index and cavity volume fraction with the help of numerical analysis. The bulged height obtained from the simulation showed good agreement with the experimental findings. The effects of strain hardening and cavity volume fraction factor for flow stress were also compared.

Near-real-time material accountancy - A technical status report

International Nuclear Information System (INIS)

Lovett, J.; Ikawa, K.; Sellinschegg, D.; Shipley, J.

1983-01-01

Near-Real-time materials accountancy as applied to reprocessing plants involves two major elements, measurement of the in-process physical inventory at frequent intervals, and statistical evaluation of the resulting sequential material balance data. For most reprocessing plants the bulk of the in-process inventory is in measurable intermediate ''buffer'' tanks. The plutonium inventory in the solvent extraction system, which does not appear to be directly measureable, could cause a reduction in sensitivity of the sequential data analysis. Studies are in progress, and it is hoped that an acceptable means for accounting for these variations can be found. Consultants at a meeting in January 1982 agreed that statistical tests for evaluating sequential material balance data will increase both detection timeliness and detection sensitivity. IAEA verification of operator-generated measurement data is an area requiring significantly increased effort, but here too studies are in progress which should help to reduce inspection effort in increased effectiveness

Modeling of Slot Waveguide Sensors Based on Polymeric Materials

Science.gov (United States)

Bettotti, Paolo; Pitanti, Alessandro; Rigo, Eveline; De Leonardis, Francesco; Passaro, Vittorio M. N.; Pavesi, Lorenzo

2011-01-01

Slot waveguides are very promising for optical sensing applications because of their peculiar spatial mode profile. In this paper we have carried out a detailed analysis of mode confinement properties in slot waveguides realized in very low refractive index materials. We show that the sensitivity of a slot waveguide is not directly related to the refractive index contrast of high and low materials forming the waveguide. Thus, a careful design of the structures allows the realization of high sensitivity devices even in very low refractive index materials (e.g., polymers) to be achieved. Advantages of low index dielectrics in terms of cost, functionalization and ease of fabrication are discussed while keeping both CMOS compatibility and integrable design schemes. Finally, applications of low index slot waveguides as substitute of bulky fiber capillary sensors or in ring resonator architectures are addressed. Theoretical results of this work are relevant to well established polymer technologies. PMID:22164020

Modeling of Slot Waveguide Sensors Based on Polymeric Materials

Directory of Open Access Journals (Sweden)

Lorenzo Pavesi

2011-07-01

Full Text Available Slot waveguides are very promising for optical sensing applications because of their peculiar spatial mode profile. In this paper we have carried out a detailed analysis of mode confinement properties in slot waveguides realized in very low refractive index materials. We show that the sensitivity of a slot waveguide is not directly related to the refractive index contrast of high and low materials forming the waveguide. Thus, a careful design of the structures allows the realization of high sensitivity devices even in very low refractive index materials (e.g., polymers to be achieved. Advantages of low index dielectrics in terms of cost, functionalization and ease of fabrication are discussed while keeping both CMOS compatibility and integrable design schemes. Finally, applications of low index slot waveguides as substitute of bulky fiber capillary sensors or in ring resonator architectures are addressed. Theoretical results of this work are relevant to well established polymer technologies.

Development of drying equipment for heat sensitive material : final report

Energy Technology Data Exchange (ETDEWEB)

Schoenau, G.J.; Sokhansanj, S. [Saskatchewan Univ., Saskatoon, SK (Canada)

2003-07-01

This paper described a project in which two types of prototype heat pump dryer systems were designed, constructed and field tested in 2000 to 2002. Performance testing was accomplished through a computer based simulation model for predicting dryer performance. The paper describes the procedures followed and the results obtained. The dryer is used for high value specialty crops such as ginseng, herbs and echinacea which require low temperature drying. The heat pump dryer operates under a closed loop and can dry these crops at low temperatures, independent of ambient conditions. The first prototype was a small fixed bed cabinet dryer suitable for small growers. The other was a full scale prototype moving bed cross flow system suitable for large scale commercial drying of sensitive agricultural crops. The heat pump system is faster and more energy efficient than conventional dryers. The average moisture content of ginseng roots was reduced by 10 per cent in 5 days using 190 kWh of energy. The heat pump dryer is 22 per cent more efficient than a conventional dryer due to its recirculating system. Drying time is reduced by 65 per cent. A computerized simulation validated experimental results. 30 refs., 10 tabs., 29 figs.

Magneto-electro-responsive material based on magnetite nanoparticles/polyurethane composites

International Nuclear Information System (INIS)

Petcharoen, Karat; Sirivat, Anuvat

2016-01-01

Multi-functional materials in actuator applications have been developed toward reversibility and sensitivity under various actuating fields. In this work, magneto-electro-responsive materials consisting of a polyurethane (PU) matrix and its composites embedded with magnetite nanoparticles (MNP) as a dispersed phase were fabricated to tailor the electromechanical properties and bending performance under electric, magnetic, and electromagnetic fields. Due to the superior characteristics of MNP over other magnetic materials, the composites fabricated with electronic polarization were highly responsive under electric field. The highest storage modulus sensitivity belonged to the 1.0% v/v MNP/PU composite which possessed the value of 3.46 at the electric field 2 kV mm"−"1. Moreover, all of the PU composites behaved as an electrostrictive material in which the stress depended quadratically on the electric field. It was demonstrated that the PU composites also possessed very good recoverability, fast response (< 15 s) and large bending angle relative to that of pristine PU under applied electric field. Interestingly, the steady state storage modulus response was attained within the first electrical actuation cycle and the PU composite was a fully reversible material. In addition, it was shown that superparamagnetism was a common characteristic of all fabricated composites under magnetic field. The 3.0%v/v MNP/PU composite provided the largest bending distance up to 23.60 mm, and 14.10 mm under the magnetic field of 5000 G, and the electromagnetic field of 320 G, respectively. In summary, the MNP/PU composite material is a potential candidate to be used as a smart material under the influences of electric and/or magnetic fields over other existing dielectric materials. - Highlights: • MNP/PU composites exhibit a superparamagnetic behavior. • MNP/PU composites show full reversibility under electric field. • 1.0% v/v MNP/PU composite provides the highest sensitivity

Magneto-electro-responsive material based on magnetite nanoparticles/polyurethane composites

Energy Technology Data Exchange (ETDEWEB)

Petcharoen, Karat; Sirivat, Anuvat, E-mail: anuvat.s@chula.ac.th

2016-04-01

Multi-functional materials in actuator applications have been developed toward reversibility and sensitivity under various actuating fields. In this work, magneto-electro-responsive materials consisting of a polyurethane (PU) matrix and its composites embedded with magnetite nanoparticles (MNP) as a dispersed phase were fabricated to tailor the electromechanical properties and bending performance under electric, magnetic, and electromagnetic fields. Due to the superior characteristics of MNP over other magnetic materials, the composites fabricated with electronic polarization were highly responsive under electric field. The highest storage modulus sensitivity belonged to the 1.0% v/v MNP/PU composite which possessed the value of 3.46 at the electric field 2 kV mm{sup −1}. Moreover, all of the PU composites behaved as an electrostrictive material in which the stress depended quadratically on the electric field. It was demonstrated that the PU composites also possessed very good recoverability, fast response (< 15 s) and large bending angle relative to that of pristine PU under applied electric field. Interestingly, the steady state storage modulus response was attained within the first electrical actuation cycle and the PU composite was a fully reversible material. In addition, it was shown that superparamagnetism was a common characteristic of all fabricated composites under magnetic field. The 3.0%v/v MNP/PU composite provided the largest bending distance up to 23.60 mm, and 14.10 mm under the magnetic field of 5000 G, and the electromagnetic field of 320 G, respectively. In summary, the MNP/PU composite material is a potential candidate to be used as a smart material under the influences of electric and/or magnetic fields over other existing dielectric materials. - Highlights: • MNP/PU composites exhibit a superparamagnetic behavior. • MNP/PU composites show full reversibility under electric field. • 1.0% v/v MNP/PU composite provides the highest

Review of ASME-NH Design Materials for Creep-Fatigue

International Nuclear Information System (INIS)

Koo, Gyeong Hoi; Kim, Jong Bum

2010-01-01

To review and recommend the candidate design materials for the Sodium-Cooled Fast Reactor, the material sensitivity evaluations by the comparison of design data between the ASME-NH materials were performed by using the SIE ASME-NH computer program implementing the material database of the ASME-NH. The design material data provided by the ASME-NH code are the elastic modulus and yield Strength, Time-Independent Allowable Stress Intensity value, time-dependent allowable stress intensity value, expected minimum stress-to rupture value, stress rupture Factors for weldment, isochronous stress-strain curves, and design fatigue curves. Among these, the data related with the creep-fatigue evaluation are investigated in this study

Photoelectrochemical characterization of the role of organic sensitizers adsorbed on nanostructured ZnO

Energy Technology Data Exchange (ETDEWEB)

Hastall, Andreas; Loewenstein, Thomas; Schlettwein, Derck [Institut fuer Angewandte Physik, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany)

2008-07-01

Porous sensitized ZnO is a promising material for application as electrode in dye-sensitized solar cells (DSSC) to utilize the intense absorption of organic sensitizers in the visible spectral range. Electrochemical deposition of ZnO from aqueous solutions is a low temperature process (<150 C) which allows the use of various substrates. The process can be performed at low energy input and cost and is therefore promising short pay-back times and high net energy gains. The role of the adsorbed sensitizer dye and resulting charge carrier generation, collection, but also recombination in the interface of ZnO/sensitizer/electrolyte of DSSC were analyzed in detail by transient photocurrent measurements, intensity modulated photocurrent and photovoltage spectroscopy (IMPS/IMVS), photovoltage decay and charge-extraction. Results are discussed for different sensitizers adsorbed to the ZnO surface and for ZnO prepared on various substrates and optimized in structure and morphology.

Sensitivity, Error and Uncertainty Quantification: Interfacing Models at Different Scales

International Nuclear Information System (INIS)

Krstic, Predrag S.

2014-01-01

Discussion on accuracy of AMO data to be used in the plasma modeling codes for astrophysics and nuclear fusion applications, including plasma-material interfaces (PMI), involves many orders of magnitude of energy, spatial and temporal scales. Thus, energies run from tens of K to hundreds of millions of K, temporal and spatial scales go from fs to years and from nm’s to m’s and more, respectively. The key challenge for the theory and simulation in this field is the consistent integration of all processes and scales, i.e. an “integrated AMO science” (IAMO). The principal goal of the IAMO science is to enable accurate studies of interactions of electrons, atoms, molecules, photons, in many-body environment, including complex collision physics of plasma-material interfaces, leading to the best decisions and predictions. However, the accuracy requirement for a particular data strongly depends on the sensitivity of the respective plasma modeling applications to these data, which stresses a need for immediate sensitivity analysis feedback of the plasma modeling and material design communities. Thus, the data provision to the plasma modeling community is a “two-way road” as long as the accuracy of the data is considered, requiring close interactions of the AMO and plasma modeling communities.

Novel D–π–A dye sensitizers of polymeric metal complexes with ...

Indian Academy of Sciences (India)

triphenylamine derivatives as donor for dye-sensitized solar cells: synthesis .... a saturated calomel electrode (SCE) were used as work- ing electrode, auxiliary ..... mechanisms, materials and devices (Boca Raton, FL: CRC). 35. Li X Z, Zeng ...

Effect of sensitization on the mechanical properties of type 304 L stainless steel

International Nuclear Information System (INIS)

Vargas Mendoza, L.F.

1990-01-01

The sensitization is a corrosion cause that it has studied broadly in the austenitic steels; however its relations don't knowed very well, into the sensitization and the steel's mechanical properties. Wherefore, the objectives of this work was to study the mechanical properties, in tension of austenitic steel with different levels of sensitization. The material utilized was a 304 L steel of standard composition AISI. The samples were sensitized at 450, 650 and 850 Centigrade degree, by short expositions, following by a temper in water. After this treatment, the tension test tubes were carried to rupture at low deformation velocity. The sensitization was evaluated by the method of Akashi EPR cyclic polarization. The sensitization distribution was analyzed by optical metallography in color and the fracture surface were studied by sweeping electronic microscopy. The distribution and length of the carbides were the factor that control the mechanic behavior of materials. At 450 Centigrade, the border of the grain its founded free of carbides, also for the longest times of exposition, but the particles are presented as fine precipitates in the grain interior, with this is increased the mechanical properties by the internal interactions of hardness or oldness types. At 650 Centigrade the frontiers show a dense distribution of fine carbides. These precipitates are interacting with the borders grain, increasing lightly the mechanical properties of steel. At 850 Centigrade, were formed discontinued carbides that not affect the mechanical behavior, but whether the fracture; the resistance is reduced and the ductility is increased although to impose the thermic effect of treatment. (Author)

Sensitivity of resistive and Hall measurements to local inhomogeneities

DEFF Research Database (Denmark)

Koon, Daniel W.; Wang, Fei; Petersen, Dirch Hjorth

2013-01-01

We derive exact, analytic expressions for the sensitivity of resistive and Hall measurements to local inhomogeneities in a specimen's material properties in the combined linear limit of a weak perturbation over an infinitesimal area in a small magnetic field. We apply these expressions both to four-point...... probe measurements on an infinite plane and to symmetric, circular van der Pauw discs, obtaining functions consistent with published results. These new expressions speed up calculation of the sensitivity for a specimen of arbitrary shape to little more than the solution of two Laplace equation boundary......-value problems of the order of N3 calculations, rather than N2 problems of total order N5, and in a few cases produces an analytic expression for the sensitivity. These functions provide an intuitive, visual explanation of how, for example, measurements can predict the wrong carrier type in n-type ZnO....

CONCURRENT CONTACT SENSITIZATION TO METALS IN DENTAL EXPOSURES

Directory of Open Access Journals (Sweden)

Maya Lyapina

2018-03-01

Full Text Available Purpose: Sensitization to metals is a significant problem for both dental patients treated with dental materials and for dental professionals in occupational exposures. The purpose of the present study was to evaluate the incidence of concurrent contact sensitization to relevant for dental practice metals among students of dental medicine, students from dental technician school, dental professionals and patients. Material and Methods: A total of 128 participants were included in the study. All of them were patch-tested with nickel, cobalt, copper, potassium dichromate, palladium, aluminium, gold and tin. The results were subject to statistical analysis (p < 0.05. Results: For the whole studied population, potassium dichromate exhibited concomitant reactivity most often; copper and tin also often manifested co-reactivity. For the groups, exposed in dental practice, potassium dichromate and tin were outlined as the most often co-reacting metal allergens, but statistical significance concerning the co-sensitization to copper and the other metals was established only for aluminium. An increased incidence and OR for concomitant sensitization to cobalt and nickel was established in the group of dental students; to copper and nickel - in the control group; to palladium and nickel - in the group of dental professionals, the group of students of dental medicine and in the control group; to potassium dichromate and cobalt - in the group of dental students; to copper and palladium - in the control group of dental patients; to potassium dichromate and copper - in the group of dental professionals; to copper and aluminum - in the groups of students from dental technician school and of dental professionals; to copper and gold - in the groups of dental professionals and in the group of dental patients; to potassium dichromate and aluminum - in the group of dental professionals; to potassium dichromate and gold - in the group of dental professionals, and to

A Sensitive Method Approach for Chromatographic Analysis of Gas Streams in Separation Processes Based on Columns Packed with an Adsorbent Material

Directory of Open Access Journals (Sweden)

I. A. A. C. Esteves

2016-01-01

Full Text Available A sensitive method was developed and experimentally validated for the in-line analysis and quantification of gaseous feed and product streams of separation processes under research and development based on column chromatography. The analysis uses a specific mass spectrometry method coupled to engineering processes, such as Pressure Swing Adsorption (PSA and Simulated Moving Bed (SMB, which are examples of popular continuous separation technologies that can be used in applications such as natural gas and biogas purifications or carbon dioxide sequestration. These processes employ column adsorption equilibria on adsorbent materials, thus requiring real-time gas stream composition quantification. For this assay, an internal standard is assumed and a single-point calibration is used in a simple mixture-specific algorithm. The accuracy of the method was found to be between 0.01% and 0.25% (-mol for mixtures of CO2, CH4, and N2, tested as case-studies. This makes the method feasible for streams with quality control levels that can be used as a standard monitoring and analyzing procedure.

The sensitivity of RTL, RPL and photographic detectors to 14.7MeV neutrons

International Nuclear Information System (INIS)

Spurny, Frantisek; Medioni, Roger; Portal, Guy.

1975-08-01

The sensitivity of various types of γ detectors to neutrons should be known for a better dosimetry of electromagnetic radiations in neutron fields. The sensitivity of various types of detectors to 14.7MeV neutrons was studied using RTL (LiF, 7 LiF, Ca SO 4 : Dy Al 2 O) RPL (C.E.C. glasses) and photographic detectors (Kodak-Pathe dosemeters). The methods used for the determination of the neutron and photon mixed field are described and the effect of containers and packing on the accuracy of results was investigated. For each detector studied the specific sensitivity to neutrons (sensitivity of the product alone) and the apparent sensitivity in usual operating conditions (action of surrounding materials) is given [fr

Study plan for the sensitivity analysis of the Terrain-Responsive Atmospheric Code (TRAC)

International Nuclear Information System (INIS)

Restrepo, L.F.; Deitesfeld, C.A.

1987-01-01

Rocky Flats Plant, Golden, Colorado is presently developing a computer code to model the dispersion of potential or actual releases of radioactive or toxic materials to the environment, along with the public consequences from these releases. The model, the Terrain-Responsive Atmospheric Code (TRAC), considers several complex features which could affect the overall dispersion and consequences. To help validate TRAC, a sensitivity analysis is being planned to determine how sensitive the model's solutions are to input variables. This report contains a brief description of the code, along with a list of tasks and resources needed to complete the sensitivity analysis

The X-ray sensitivity of semi-insulating polycrystalline CdZnTe thick films

International Nuclear Information System (INIS)

Won, Jae Ho; Kim, Ki Hyun; Suh, Jong Hee; Cho, Shin Hang; Cho, Pyong Kon; Hong, Jin Ki; Kim, Sun Ung

2008-01-01

The X-ray sensitivity is one of the important parameters indicating the detector performance. The X-ray sensitivity of semi-insulating polycrystalline CdZnTe:Cl thick films was investigated as a function of electric field, mean photon energy, film thickness, and charge carrier transport parameters and, compared with another promising detector materials. The X-ray sensitivities of the polycrystalline CdZnTe films with 350 μm thickness were about 2.2 and 6.2 μC/cm 2 /R in the ohmic-type and Schottky-type detector at 0.83 V/μm, respectively

Low-cost encapsulation materials for terrestrial solar cell modules

Science.gov (United States)

Cuddihy, E. F.; Baum, B.; Willis, P.

1979-01-01

The paper presents the findings of material surveys intended to identify low cost materials which could be functional as encapsulants (by 1986) for terrestrial solar cell modules. Economic analyses have indicated that in order to meet the low cost goal of $2.70 per sq m, some or all of the following material technologies must be developed or advanced: (1) UV screening outer covers; (2) elastomeric acrylics; (3) weatherproofing and waterproofing of structural wood and paper products; (4) transparent UV stabilizers for the UV-sensitive transparent pottants; and (5) cost-effective utilization of silicone and fluorocarbon materials.

Dual-Wavelength Sensitized Photopolymer for Holographic Data Storage

Science.gov (United States)

Tao, Shiquan; Zhao, Yuxia; Wan, Yuhong; Zhai, Qianli; Liu, Pengfei; Wang, Dayong; Wu, Feipeng

2010-08-01

Novel photopolymers for holographic storage were investigated by combining acrylate monomers and/or vinyl monomers as recording media and liquid epoxy resins plus an amine harder as binder. In order to improve the holographic performances of the material at blue-green wavelength band two novel dyes were used as sensitizer. The methods of evaluating the holographic performances of the material, including the shrinkage and noise characteristics, are described in detail. Preliminary experiments show that samples with optimized composite have good holographic performances, and it is possible to record dual-wavelength hologram simultaneously in this photopolymer by sharing the same optical system, thus the storage density and data rate can be doubly increased.

Development of scintillation materials for PET scanners

CERN Document Server

Korzhik, Mikhail; Annenkov, Alexander N; Borissevitch, Andrei; Dossovitski, Alexei; Missevitch, Oleg; Lecoq, Paul

2007-01-01

The growing demand on PET methodology for a variety of applications ranging from clinical use to fundamental studies triggers research and development of PET scanners providing better spatial resolution and sensitivity. These efforts are primarily focused on the development of advanced PET detector solutions and on the developments of new scintillation materials as well. However Lu containing scintillation materials introduced in the last century such as LSO, LYSO, LuAP, LuYAP crystals still remain the best PET species in spite of the recent developments of bright, fast but relatively low density lanthanum bromide scintillators. At the same time Lu based materials have several drawbacks which are high temperature of crystallization and relatively high cost compared to alkali-halide scintillation materials. Here we describe recent results in the development of new scintillation materials for PET application.

Sensitivity-Enhanced Wearable Active Voiceprint Sensor Based on Cellular Polypropylene Piezoelectret.

Science.gov (United States)

Li, Wenbo; Zhao, Sheng; Wu, Nan; Zhong, Junwen; Wang, Bo; Lin, Shizhe; Chen, Shuwen; Yuan, Fang; Jiang, Hulin; Xiao, Yongjun; Hu, Bin; Zhou, Jun

2017-07-19

Wearable active sensors have extensive applications in mobile biosensing and human-machine interaction but require good flexibility, high sensitivity, excellent stability, and self-powered feature. In this work, cellular polypropylene (PP) piezoelectret was chosen as the core material of a sensitivity-enhanced wearable active voiceprint sensor (SWAVS) to realize voiceprint recognition. By virtue of the dipole orientation control method, the air layers in the piezoelectret were efficiently utilized, and the current sensitivity was enhanced (from 1.98 pA/Hz to 5.81 pA/Hz at 115 dB). The SWAVS exhibited the superiorities of high sensitivity, accurate frequency response, and excellent stability. The voiceprint recognition system could make correct reactions to human voices by judging both the password and speaker. This study presented a voiceprint sensor with potential applications in noncontact biometric recognition and safety guarantee systems, promoting the progress of wearable sensor networks.

High precision laser processing of sensitive materials by Microjet

Science.gov (United States)

Sibailly, Ochelio D.; Wagner, Frank R.; Mayor, Laetitia; Richerzhagen, Bernold

2003-11-01

Material laser cutting is well known and widely used in industrial processes, including micro fabrication. An increasing number of applications require nevertheless a superior machining quality than can be achieved using this method. A possibility to increase the cut quality is to opt for the water-jet guided laser technology. In this technique the laser is conducted to the work piece by total internal reflection in a thin stable water-jet, comparable to the core of an optical fiber. The water jet guided laser technique was developed originally in order to reduce the heat damaged zone near the cut, but in fact many other advantages were observed due to the usage of a water-jet instead of an assist gas stream applied in conventional laser cutting. In brief, the advantages are three-fold: the absence of divergence due to light guiding, the efficient melt expulsion, and optimum work piece cooling. In this presentation we will give an overview on several industrial applications of the water-jet guided laser technique. These applications range from the cutting of CBN or ferrite cores to the dicing of thin wafers and the manufacturing of stencils, each illustrates the important impact of the water-jet usage.

The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

International Nuclear Information System (INIS)

Simonsson, Carl; Stenfeldt, Anna-Lena; Karlberg, Ann-Therese; Ericson, Marica B.; Jonsson, Charlotte A.M.

2012-01-01

Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers. -- Highlights: ► Vehicle effects on sensitization potency were investigated in the LLNA. ► In vivo cutaneous absorption of contact sensitizers was visualized using TPM. ► Sensitizing potency of isothiocyanates depends on the presence of a phthalate. ► Phthalate induced cutaneous absorption via the pilosebaceous units. ► Vehicle-dependent reactivity regulates sensitization potency.

The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

Energy Technology Data Exchange (ETDEWEB)

Simonsson, Carl, E-mail: carl.simonsson@chem.gu.se [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Stenfeldt, Anna-Lena; Karlberg, Ann-Therese [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Ericson, Marica B., E-mail: marica.ericson@physics.gu.se [Department of Physics, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Jonsson, Charlotte A.M. [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden)

2012-10-01

Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers. -- Highlights: ► Vehicle effects on sensitization potency were investigated in the LLNA. ► In vivo cutaneous absorption of contact sensitizers was visualized using TPM. ► Sensitizing potency of isothiocyanates depends on the presence of a phthalate. ► Phthalate induced cutaneous absorption via the pilosebaceous units. ► Vehicle-dependent reactivity regulates sensitization potency.

Laser ultrasonic receivers based on photorefractive materials in non-destructive testing

International Nuclear Information System (INIS)

Zamiri Hosseinzadeh, S.

2014-01-01

The field of laser ultrasonics is one of the most interesting topics in which laser light is used for the generation and the detection of ultrasound waves in materials. This contactless method is extremely useful for materials inspection being nondestructive and contactless, especially for hazardous environments. In this method a pulsed laser with a short pulse length of e.g. nano- or even picoseconds is focused on the surface of a specimen and then ultrasonic waves, nanometer vibrations, such as surface and bulk waves are generated and propagate in all directions on to the material. For contactless detection of ultrasonic waves several interferometers such as confocal Fabry-Perot, Michelson, and long path difference interferometers have been applied. Each of them has its individual advantages and disadvantages concerning, e.g., frequency responses and sensitivity. However, most of these interferometers work best on mirror-like surfaces and exhibit reduced sensitivity on rough surfaces. Also these kinds of interferometer are sensible to external noise as air fluctuations, sample vibrations or thermal deformations, thus requiring relatively complex stabilization techniques. This hinders their applicability in industrial applications with harsh environmental conditions. As an alternative to the before mentioned techniques interferometers based on photorefractive materials (PR) have been established. A typical two wave mixing interferometer (TWMI) configuration enables broadband ultrasonic measurements on rough surfaces. These types of interferometers have a good sensitivity up to 3e-7 nm(W/Hz) 1/2 spatially for samples with a high rough surface unlike the Michelson interferometer. By using ferroelectric photorefractive crystals such as LiNbO:Fe+2, sensitivity even is enhanced to 4e-8 nm(W/Hz) 1/2 but response time in these crystals is slower. In this work, contactless interferometer set ups based on photorefractive materials such as BSO (Bismuth Silicon Oxide: Bi 12

Sensitivity and Awareness: A Guide for Developing Understanding among Children.

Science.gov (United States)

McPhee, Norma H.; Favazza, Paddy C.; Lewis, Eleanore Grater

This guide is designed specifically as a resource for classroom teachers, librarians, or consultants who are concerned with helping children develop an understanding and an ease with people who are different, especially people with disabilities. The book includes materials to be used in sensitivity and awareness discussion sessions based on 12…

Effect of UV on building materials in New Zealand

International Nuclear Information System (INIS)

Bennett, A.F.

1993-01-01

Building materials can be divided into two main classes; organic or polymeric based and inorganic materials. Inorganic materials are in most cases largely unaffected by UV radiation. Many common polymers have bonds sensitive to radiation in the UV region. Absorption of radiation of these wavelengths will lead to excitation of electrons which can lead to isomerisation, chain scissors, cross linking and free radical formation. It is worth noting that the effects of UV radiation are always acting synergistically with other environmental effects. (author). 4 refs., 2 tabs

Solid state photon upconversion utilizing thermally activated delayed fluorescence molecules as triplet sensitizer

Energy Technology Data Exchange (ETDEWEB)

Wu, Tony C.; Congreve, Daniel N.; Baldo, Marc A., E-mail: baldo@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2015-07-20

The ability to upconvert light is useful for a range of applications, from biological imaging to solar cells. But modern technologies have struggled to upconvert incoherent incident light at low intensities. Here, we report solid state photon upconversion employing triplet-triplet exciton annihilation in an organic semiconductor, sensitized by a thermally activated-delayed fluorescence (TADF) dye. Compared to conventional phosphorescent sensitizers, the TADF dye maximizes the wavelength shift in upconversion due to its small singlet-triplet splitting. The efficiency of energy transfer from the TADF dye is 9.1%, and the conversion yield of sensitizer exciton pairs to singlet excitons in the annihilator is 1.1%. Our results demonstrate upconversion in solid state geometries and with non-heavy metal-based sensitizer materials.

Sensitivity, selectivity and stability of tin oxide nanostructures on large area arrays of microhotplates

Science.gov (United States)

Panchapakesan, Balaji; Cavicchi, Richard; Semancik, Steve; DeVoe, Don L.

2006-01-01

In this paper, the sensitivity, stability and selectivity of nanoparticle engineered tin oxide (SnO2) are reported, for microhotplate chemical sensing applications. 16 Å of metals such as nickel, cobalt, iron, copper and silver were selectively evaporated onto each column of the microhotplate array. Following evaporation, the microhotplates were heated to 500 °C and SnO2 was deposited on top of the microhotplates using a self-aligned chemical vapour deposition process. Scanning electron microscopy characterization revealed control of SnO2 nanostructures in the range of 20-121 nm. Gas sensing in seven different hydrocarbons revealed that metal nanoparticles that helped in producing faster nucleation of SnO2 resulted in smaller grain size and higher sensitivity. Sensitivity as a function of concentration and grain size is addressed for tin oxide nanostructures. Smaller grain sizes resulted in higher sensitivity of tin oxide nanostructures. Temperature programmed sensing of the devices yielded shape differences in the response between air and methanol, illustrating selectivity. Spiderweb plots were used to monitor the materials programmed selectivity. The shape differences between different gases in spiderweb plots illustrate materials selectivity as a powerful mapping approach for monitoring selectivity in various gases. Continuous monitoring in 80 ppm methanol yielded stable sensor response for more than 200 h. This comprehensive study illustrates the use of a nanoparticle engineering approach for sensitive, selective and stable gas sensing applications.

Sensitivity Calculation of Vanadium Self-Powered Neutron Detector

International Nuclear Information System (INIS)

Cha, Kyoon Ho

2011-01-01

Self-powered neutron detector (SPND) is being widely used to monitor the reactor core of the nuclear power plants. The SPND contains a neutron-sensitive metallic emitter surrounded by a ceramic insulator. Currently, the rhodium SPND has been used in many nuclear power plants. The lifetime of rhodium is too short (about 3∼5 years) to operate the nuclear power plant economically. The vanadium (V) SPND is also primarily sensitive to neutrons like rhodium, but is a somewhat slower reaction time as that of a rhodium SPND. The benefit of vanadium over rhodium is its low depletion rate, which is a factor of 7 times less than that of rhodium. For this reason, a vanadium SPND has been being developed to replace the rhodium SPND which is used in OPR1000. Some Monte Carlo simulations were accomplished to calculate the initial sensitivity of vanadium emitter material and alumina (Al 2 O 3 ) insulator with a cylindrical geometry. An MCNP-X code was used to simulate some factors (neutron self shielding factor and electron escape probability from the emitter) necessary to calculate the sensitivity of vanadium detector. The simulation results were compared with some theoretical and experimental values. The method presented here can be used to analyze the optimum design of the vanadium SPND

Radiation sensitivity and EPR dosimetric potential of gallic acid and its esters

Science.gov (United States)

Tuner, Hasan; Oktay Bal, M.; Polat, Mustafa

2015-02-01

In the preset work the radiation sensitivities of Gallic Acid anhydrous and monohydrate, Octyl, Lauryl, and Ethyl Gallate (GA, GAm, OG, LG, and EG) were investigated in the intermediate (0.5-20 kGy) and low radiation (<10 Gy) dose range using Electron Paramagnetic Resonance (EPR) spectroscopy. While OG, LG, and EG are presented a singlet EPR spectra, their radiation sensitivity found to be very different in the intermediate dose range. At low radiation dose range (<10 Gy) only LG is found to be present a signal that easily distinguished from the noise signals. The intermediate and low dose range radiation sensitivities are compared using well known EPR dosimeter alanine. The radiation yields (G) of the interested material were found to be 1.34×10-2, 1.48×10-2, 4.14×10-2, and 6.03×10-2, 9.44×10-2 for EG, GA, GAm, OG, and LG, respectively at the intermediate dose range. It is found that the simple EPR spectra and the noticeable EPR signal of LG make it a promising dosimetric material to be used below 10 Gy of radiation dose.

Polarization-sensitive and broadband germanium sulfide photodetectors with excellent high-temperature performance.

Science.gov (United States)

Tan, Dezhi; Zhang, Wenjin; Wang, Xiaofan; Koirala, Sandhaya; Miyauchi, Yuhei; Matsuda, Kazunari

2017-08-31

Layered materials, such as graphene, transition metal dichalcogenides and black phosphorene, have been established rapidly as intriguing building blocks for optoelectronic devices. Here, we introduce highly polarization sensitive, broadband, and high-temperature-operation photodetectors based on multilayer germanium sulfide (GeS). The GeS photodetector shows a high photoresponsivity of about 6.8 × 10 3 A W -1 , an extremely high specific detectivity of 5.6 × 10 14 Jones, and broad spectral response in the wavelength range of 300-800 nm. More importantly, the GeS photodetector has high polarization sensitivity to incident linearly polarized light, which provides another degree of freedom for photodetectors. Tremendously enhanced photoresponsivity is observed with a temperature increase, and high responsivity is achievable at least up to 423 K. The establishment of larger photoinduced reduction of the Schottky barrier height will be significant for the investigation of the photoresponse mechanism of 2D layered material-based photodetectors. These attributes of high photocurrent generation in a wide temperature range, broad spectral response, and polarization sensitivity coupled with environmental stability indicate that the proposed GeS photodetector is very suitable for optoelectronic applications.

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

Science.gov (United States)

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; Wen, Zhenhai; Mao, Shun; Chang, Jingbo; Hersam, Mark C.; Chen, Junhong

2015-01-01

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ∼1015 cm−2 for the 4.8-nm-thick PNS when exposed to 20 p.p.b. NO2 at 300 K. Our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (10 nm). PMID:26486604

Biosmart Materials: Breaking New Ground in Dentistry

Directory of Open Access Journals (Sweden)

Vijetha Badami

2014-01-01

Full Text Available By definition and general agreement, smart materials are materials that have properties which may be altered in a controlled fashion by stimuli, such as stress, temperature, moisture, pH, and electric or magnetic fields. There are numerous types of smart materials, some of which are already common. Examples include piezoelectric materials, which produce a voltage when stress is applied or vice versa, shape memory alloys or shape memory polymers which are thermoresponsive, and pH sensitive polymers which swell or shrink as a response to change in pH. Thus, smart materials respond to stimuli by altering one or more of their properties. Smart behaviour occurs when a material can sense some stimulus from its environment and react to it in a useful, reliable, reproducible, and usually reversible manner. These properties have a beneficial application in various fields including dentistry. Shape memory alloys, zirconia, and smartseal are examples of materials exhibiting a smart behavior in dentistry. There is a strong trend in material science to develop and apply these intelligent materials. These materials would potentially allow new and groundbreaking dental therapies with a significantly enhanced clinical outcome of treatments.

Biosmart Materials: Breaking New Ground in Dentistry

Science.gov (United States)

Badami, Vijetha; Ahuja, Bharat

2014-01-01

By definition and general agreement, smart materials are materials that have properties which may be altered in a controlled fashion by stimuli, such as stress, temperature, moisture, pH, and electric or magnetic fields. There are numerous types of smart materials, some of which are already common. Examples include piezoelectric materials, which produce a voltage when stress is applied or vice versa, shape memory alloys or shape memory polymers which are thermoresponsive, and pH sensitive polymers which swell or shrink as a response to change in pH. Thus, smart materials respond to stimuli by altering one or more of their properties. Smart behaviour occurs when a material can sense some stimulus from its environment and react to it in a useful, reliable, reproducible, and usually reversible manner. These properties have a beneficial application in various fields including dentistry. Shape memory alloys, zirconia, and smartseal are examples of materials exhibiting a smart behavior in dentistry. There is a strong trend in material science to develop and apply these intelligent materials. These materials would potentially allow new and groundbreaking dental therapies with a significantly enhanced clinical outcome of treatments. PMID:24672407

Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

International Nuclear Information System (INIS)

Bero, M A; Abukassem, I

2009-01-01

Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

Science.gov (United States)

Bero, M. A.; Abukassem, I.

2009-05-01

Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

Evaluation of the toxicity of radiosterilized implantable materials

International Nuclear Information System (INIS)

Lewandowska-Szumiel, M.; Kudelska, D.; Mazur, M.; Zimek, Z.

1997-01-01

Autoclave and radiation sterilization modes of selected biomaterials and polymers were studied to evaluate the toxicity, if any, induced in the cells grown in vitro. The materials examined induced: crystalline and amorphous biocarbon, alumina, hydroxyapatite, powdered primary PP (radiation-sensitive), and PP modified with a polypropylene/ethylene or an ethylene/vinyl acetate copolymer to enhance its radiation resistance. Results showed no material to be toxic toward the cell examined. The viability of the cells cultivated in the presence of materials examined was found to remain unaffected regardless of the sterilization mode. (author). 12 refs, 3 figs

Disorder and strain-induced complexity in functional materials

CERN Document Server

Saxena, Avadh; Planes, Antoni; Kakeshita, Tomoyuki

2012-01-01

This book brings together an emerging consensus on our understanding of the complex functional materials including ferroics, perovskites, multiferroics, CMR and high-temperature superconductors. The common theme is the existence of many competing ground states and frustration as a collusion of spin, charge, orbital and lattice degrees of freedom in the presence of disorder and (both dipolar and elastic) long-range forces. An important consequence of the complex unit cell and the competing interactions is that the emergent materials properties are very sensitive to external fields thus rendering these materials with highly desirable, technologically important applications enabled by cross-response.

Influence of Culture and Language Sensitive Physics on Science Attitude Enhancement

Science.gov (United States)

Morales, Marie Paz E.

2015-01-01

The study critically explored how culture and language sensitive curriculum materials in physics improve Pangasinan learners' attitude towards science. Their cultural dimensions, epistemological beliefs, and views on integration of culture and language in the teaching and learning process determined their cultural preference or profile. Design and…

Bio-inspired materials for electrochemical devices

Science.gov (United States)

Pawlicka, A.; Firmino, A.; Sentanin, F.; Sabadini, R. C.; Jimenez, D. E. Q.; Jayme, C. C.; Mindroiu, M.; Zgarian, R. G.; Tihan, G. T.; Rau, I.; Silva, M. M.; Nogueira, A. F.; Kanicki, J.; Kajzar, F.

2015-10-01

Natural macromolecules are very promising row materials to be used in modern technology including security and defense. They are abundant in nature, easy to extract and possess biocompatibility and biodegradability properties. These materials can be modified throughout chemical or physical processes, and can be doped with lithium and rare earth salts, ionic liquids, organic and inorganic acids. In this communication samples of DNA and modified DNA were doped with Prussian Blue (PB), poly(ethylene dioxythiophene) (PEDOT), europium and erbium triflate and organic dyes such as Nile Blue (NB), Disperse Red 1 (DR1) and Disperse Orange 3 (DO3). The colored or colorless membranes were characterized by electrochemical and spectroscopic measurements, and they were applied in electrochromic devices (ECDs) and dye sensitized solar cells (DSSC). ECDs change the color under applied potential, so they can modulate the intensity of transmitted light of 15 to 35%. As the electrochromic materials, WO3 or Prussian blue (PB), are usually blue colored, the color change is from transparent to blue. DNA, and the complexes: DNA-CTMA, DNA-DODA and DNAPEDOT: PSS were also investigated as either hole carrier material (HTM) or polymer electrolyte in dye-sensitized solar cells (DSSC). The DNA-based samples as HTM in small DSSCs revealed a solar energy conversion efficiency of 0.56%. Polymer electrolytes of DNA-CTMA and DNA-DODA, both with 10 wt% of LiI/I2, applied in small DSSC, exhibited the efficiencies of 0.18 and 0.66%, respectively. The obtained results show that natural macromolecules-based membranes are not only environmentally friendly but are also promising materials to be investigated for several electrochemical devices. However, to obtain better performances more research is still needed.

Material operating behaviour of ABB BWR control rods

International Nuclear Information System (INIS)

Rebensdorff, B.; Bart, G.

2000-01-01

The BWR control rods made by ABB use boron carbide (B 4 C and hafnium as absorber material within a cladding of stainless steel. The general behaviour under operation has proven to be very good. ABB and many of their control rod customers have performed extensive inspection programs of control rod behaviour. However, due to changes in the material properties under fast and thermal neutron irradiation defects may occur in the control rods at high neutron fluences. Examinations of irradiated control rod materials have been performed in hot cell laboratories. The examinations have revealed the defect mechanism Irradiation Assisted Stress Corrosion Cracking (IASCC) to appear in the stainless steel cladding. For IASCC to occur three factors have to act simultaneously. Stress, material sensitization and an oxidising environment. Stress may be obtained from boron carbide swelling due to irradiation. Stainless steel may be sensitized to intergranular stress corrosion cracking under irradiation. Normally the reactor environment in a BWR is oxidising. The presentation focuses on findings from hot cell laboratory work on irradiated ABB BWR control rods and studies of irradiated control rod materials in the hot cells at PSI. Apart from physical, mechanical and microstructural examinations, isotope analyses were performed to describe the local isotopic burnup of boron. Consequences (such as possible B 4 C washout) of a under operation in a ABB BWR, after the occurrence of a crack is discussed based on neutron radiographic examinations of control rods operated with cracks. (author)

Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

Directory of Open Access Journals (Sweden)

S. N. F. Mohd-Nasir

2014-01-01

Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

Neutron irradiation effect of thermally-sensitized stainless steels

Energy Technology Data Exchange (ETDEWEB)

Hide, Kouitiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

1998-03-01

Intergranular stress corrosion cracking (IGSCC) susceptibility of irradiated thermally-sensitized Type 304 Stainless Steels (SSs) was studied as a function of neutron fluence and correlated with mechanical responses of the materials. Neutron irradiation was carried out to neutron fluences up to 1.1 x 10{sup 24} n/m{sup 2} (E > 1MeV) at the light water reactor temperature in the Japan Material Test Reactor. The irradiated specimens were examined by slow strain rate stress corrosion cracking tests in 290degC pure water of 0.2 ppm dissolved oxygen concentration and microhardness measurements. The IGSCC susceptibility of the irradiated specimens increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}. From an attempt to correlate the IGSCC susceptibility with the mechanical properties, an excellent correlation was identified between the susceptibility and microhardness increments at the grain boundary relative to the grain center. While intergranular corrosion rate of thermally sensitized SS increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}, that of solution annealed SS did not change. The incremental grain boundary hardening and degradation of intergranular corrosion resistance may presumably be the major factors affecting IGSCC performance. (author)

Study of nano-nitramine explosives: preparation, sensitivity and application

Directory of Open Access Journals (Sweden)

Jie Liu

2014-06-01

Full Text Available Nano-nitramine explosives (RDX, HMX, CL-20 are produced on a bi-directional grinding mill. The scanning electron microscope (SEM observations show that the prepared particles are semi-spherical, and the narrow size distributions are characterized using the laser particle size analyzer. Compared with the micron-sized samples, the nano-products show obvious decrease in friction and impact sensitivities. In the case of shock sensitivities, nano-products have lower values by 59.9% (RDX, 56.4% (HMX, and 58.1% (CL-20, respectively. When nano-RDX and nano-HMX are used in plastic bonded explosives (PBX as alternative materials of micron-sized particles, their shock sensitivities are significantly decreased by 24.5% (RDX and 22.9% (HMX, and their detonation velocities are increased by about 1.7%. Therefore, it is expected to promote the application of nano-nitramine explosives in PBXs and composite modified double-based propellants (CMDBs so that some of their properties would be improved.

AUMGARTEN’S AESTHETICS AS THE SCIENCE OF SENSITIVE COGNITION

Directory of Open Access Journals (Sweden)

Nesrin Erturk

2016-04-01

Full Text Available A. G. Baumgarten grounds the aesthetics of which he was the founder on widely poetic and rhetoric in his ‘Aestetica’ (1750/58. Nevertheless, what is significant here for him is to validate the individualist right of ‘sensitive knowledge.’ The word ‘aesthetics’ (αíσυŋгηικόç here is strictly attached to its basic meaning which is ‘related to sense and perception,’ and ‘sensually understandable.’ The aesthetics of Baumgarten is the philosophy of sensual knowledge and perception, and its sensitivity cannot be perceived as the material of outer stimulation and logic; contrarily, it sincerely sees it as a special genre of the knowledge. Hence, the aesthetics is defined as the ‘science of sensitive knowledge.’ With this study, it has been targeted to draw a general outline of Baumgarten’s aesthetics understanding by discussing the basic chapters of ‘Aestetica.’

A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

International Nuclear Information System (INIS)

Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

2016-01-01

An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y_2O_3NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y_2O_3NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE_p) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y_2O_3NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE_p for ACT at Y_2O_3NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10"−"1"0 to 1.8 × 10"−"8 M with a detection limit of 3.0 × 10"−"1"1 M (based on 3S_b/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

Semiconductor materials for solar photovoltaic cells

CERN Document Server

Wong-Ng, Winnie; Bhattacharya, Raghu

2016-01-01

This book reviews the current status of semiconductor materials for conversion of sunlight to electricity, and highlights advances in both basic science and manufacturing.  Photovoltaic (PV) solar electric technology will be a significant contributor to world energy supplies when reliable, efficient PV power products are manufactured in large volumes at low cost.  Expert chapters cover the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally friendly copper zinc tin sulfide selenides. The latest methods for synthesis and characterization of solar cell materials are described, together with techniques for measuring solar cell efficiency. Semiconductor Materials for Solar Photovoltaic Cells presents the current state of the art as well as key details about future strategies to increase the efficiency and reduce ...

Mannosylated dextran nanoparticles: A pH-sensitive system engineered for immunomodulation through mannose targeting

KAUST Repository

Cui, Lina

2011-05-18

Biotherapeutic delivery is a rapidly growing field in need of new materials that are easy to modify, are biocompatible, and provide for triggered release of their encapsulated cargo. Herein, we report on a particulate system made of a polysaccharide-based pH-sensitive material that can be efficiently modified to display mannose-based ligands of cellsurface receptors. These ligands are beneficial for antigen delivery, as they enhance internalization and activation of APCs, and are thus capable of modulating immune responses. When compared to unmodified particles or particles modified with a nonspecific sugar residue used in the delivery of antigens to dendritic cells (DCs), themannosylated particles exhibited enhanced antigen presentation in the context of major histocompatibility complex (MHC) class I molecules. This represents the first demonstration of a mannosylated particulate system that enables enhancedMHC I antigen presentation by DCs in vitro. Our readily functionalized pH-sensitive material may also open new avenues in the development of optimally modulated vaccine delivery systems. © 2011 American Chemical Society.

Mannosylated dextran nanoparticles: A pH-sensitive system engineered for immunomodulation through mannose targeting

KAUST Repository

Cui, Lina; Cohen, Joel A.; Broaders, Kyle E.; Beaudette, Tristan T.; Frechet, Jean

2011-01-01

Biotherapeutic delivery is a rapidly growing field in need of new materials that are easy to modify, are biocompatible, and provide for triggered release of their encapsulated cargo. Herein, we report on a particulate system made of a polysaccharide-based pH-sensitive material that can be efficiently modified to display mannose-based ligands of cellsurface receptors. These ligands are beneficial for antigen delivery, as they enhance internalization and activation of APCs, and are thus capable of modulating immune responses. When compared to unmodified particles or particles modified with a nonspecific sugar residue used in the delivery of antigens to dendritic cells (DCs), themannosylated particles exhibited enhanced antigen presentation in the context of major histocompatibility complex (MHC) class I molecules. This represents the first demonstration of a mannosylated particulate system that enables enhancedMHC I antigen presentation by DCs in vitro. Our readily functionalized pH-sensitive material may also open new avenues in the development of optimally modulated vaccine delivery systems. © 2011 American Chemical Society.

Angular selectivity asymmetry of holograms recorded in near infrared sensitive liquid crystal photopolymerizable materials

Science.gov (United States)

Harbour, Steven; Galstian, Tigran; Akopyan, Rafik; Galstyan, Artur

2004-08-01

We have experimentally observed and theoretically explained the angular selectivity asymmetry in polymer dispersed liquid crystal holograms. Experiments are conducted in compounds with near infrared sensitivity. The coupled-wave theory is used to describe the diffraction properties of obtained anisotropic holographic gratings. Furthermore, the comparison of theory and experiments provides information about the optical axis direction that is defined by the average molecular orientation of the liquid crystal in the polymer matrix.

Study of thermal sensitivity and thermal explosion violence of energetic materials in the LLNL ODTX system

International Nuclear Information System (INIS)

Hsu, P C; Hust, G; Zhang, M X; Lorenz, T K; Reynolds, J G; Fried, L; Springer, H K; Maienschein, J L

2014-01-01

Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 °C) and the violence from thermal explosion may cause significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. Recent ODTX experimental data are reported in the paper.

Estimating the dimensions of the SEU-sensitive volume

International Nuclear Information System (INIS)

Abdel-Kader, W.G.; McNulty, P.J.; El-Teleaty, S.; Lynch, J.E.; Khondker, A.N.

1987-01-01

Simulations of the diffusion contribution to charge collection in SEU events are carried out under the simple assumption of random walk. The results of the simulation are combined with calculations of the funneling length for the field-assisted drift components to determine the effective thickness of the sensitive volume element to be used in calculations of soft-error rates for heavy-ion-induced and proton-induced upsets in microelectronic circuits. Comparison is made between predicted and measured SEU cross-sections for devices for which the critical charges are known from electrical measurements and the dimensions of the sensitive volume used are determined by the techniques described. The agreement is sufficient to encourage confidence that SEU rates can be calculated from first principles and a knowledge of the material, structural, and electrical characteristics of the device

Optimization of the sample dilution for minimization of the matrix effects and achieving maximal sensitivity in XRFA

International Nuclear Information System (INIS)

Dimov, L.; Benova, M.

1989-01-01

The method of neutral medium dilution can lead to practically full leveling of the matrix but the high degree of dilution at which this effect is achieved will inevitably result in loss of sensitivity. In the XRFA of heavy elements in a light matrix the dependence of the fluorescence intensity upon concentration is characterized by gradually decreasing steepness reacting saturation (as in analysis of Pb in a Pb-concentrate). The dilution by neutral medium can shift the concentration range to a zone of greater steepness but this results in an increase of sensitivity towards the concentration in the initial (undiluted) material only to a certain degree of dilution. This work presents an optimization of the degree of dilution by neutral medium which achieves a sufficient leveling of the matrix when using different materials and also maximal sensitivity towards higher concentrations. Furthermore an original solution is found to the problem of selecting a neutral medium enabling to achieve good homogenization with various materials and particularly - with marble flour. (author)

Dye-Sensitized Solar Cells: The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells (Adv. Mater. 20/2016).

Science.gov (United States)

Briscoe, Joe; Dunn, Steve

2016-05-01

Sustainability is an important concept generating traction in the research community. To be really sustainable the full life cycle of a product needs to be carefully considered. A key aspect of this is using elements that are either readily recycled or accessible in the Earth's biosphere. Jigsawing these materials together in compounds to address our future energy needs represents a great opportunity for the current generation of researchers. On page 3802, S. Dunn and J. Briscoe summarize the performance of a selection of alternative materials to replace platinum in the counter electrodes of dye-sensitized solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Coordinate-sensitive charged particle detector for spectroscopy

Directory of Open Access Journals (Sweden)

Sidorenko V. P.

2016-10-01

Full Text Available The authors have designed, manufactured and tested a coordinate-sensitive detector for charged particle spectroscopy. The detector can be used in the devices for the elemental analysis of materials, providing simultaneous analysis of all the elemental composition with high sensitivity and precision. The designed device is based on an integrated circuit (IC and a microchannel plate (MCP electron multiplier. The IC is mounted on a ceramic substrate. Ions fall on the MCP mounted above the IC. Giving rise to a pulse which typically exceeds 106 electrons, each ion falls on the detector electrodes and these pulses are counted. In this research, a two stage stack of MCPs (Hamamatsu was used. The MCPs have a channel diameter of 12 μm on a 15 μm pitch. The results of tests carried out in a mass spectrometer are presented. The designed detector is small, light, and low-power.

Rheological analysis of fine-grained natural debris-flow material

Science.gov (United States)

Major, Jon J.; Pierson, Thomas C.; ,

1990-01-01

Experiments were conducted on large samples of fine-grained material (???2mm) from a natural debris flow using a wide-gap concentric-cylinder viscometer. The rheological behavior of this material is compatible with a Bingham model at shear rates in excess of 5 sec. At lesser shear rates, rheological behavior of the material deviates from the Bingham model, and when sand concentration of the slurry exceeds 20 percent by volume, particle interaction between sand grains dominates the mechanical behavior. Yield strength and plastic viscosity are extremely sensitive to sediment concentration.

Chemical kinetic functional sensitivity analysis: Elementary sensitivities

International Nuclear Information System (INIS)

Demiralp, M.; Rabitz, H.

1981-01-01

Sensitivity analysis is considered for kinetics problems defined in the space--time domain. This extends an earlier temporal Green's function method to handle calculations of elementary functional sensitivities deltau/sub i//deltaα/sub j/ where u/sub i/ is the ith species concentration and α/sub j/ is the jth system parameter. The system parameters include rate constants, diffusion coefficients, initial conditions, boundary conditions, or any other well-defined variables in the kinetic equations. These parameters are generally considered to be functions of position and/or time. Derivation of the governing equations for the sensitivities and the Green's funciton are presented. The physical interpretation of the Green's function and sensitivities is given along with a discussion of the relation of this work to earlier research

A flexible tactile sensitive sheet using a hetero-core fiber optic sensor

Science.gov (United States)

Fujino, S.; Yamazaki, H.; Hosoki, A.; Watanabe, K.

2014-05-01

In this report, we have designed a tactile sensitive sheet based on a hetero-core fiber-optic sensor, which realize an areal sensing by using single sensor potion in one optical fiber line. Recently, flexible and wide-area tactile sensing technology is expected to applied to acquired biological information in living space and robot achieve long-term care services such as welfare and nursing-care and humanoid technology. A hetero-core fiber-optic sensor has several advantages such as thin and flexible transmission line, immunity to EMI. Additionally this sensor is sensitive to moderate bending actions with optical loss changes and is independent of temperature fluctuation. Thus, the hetero-core fiber-optic sensor can be suitable for areal tactile sensing. We measure pressure characteristic of the proposed sensitive sheet by changing the pressure position and pinching characteristic on the surface. The proposed tactile sensitive sheet shows monotonic responses on the whole sensitive sheet surface although different sensitivity by the position is observed at the sensitive sheet surface. Moreover, the tactile sensitive sheet could sufficiently detect the pinching motion. In addition, in order to realize the discrimination between pressure and pinch, we fabricated a doubled-over sensor using a set of tactile sensitive sheets, which has different kinds of silicon robbers as a sensitive sheet surface. In conclusion, the flexible material could be given to the tactile sensation which is attached under proposed sensitive sheet.

Nonintrusive verification attributes for excess fissile materials

International Nuclear Information System (INIS)

Nicholas, N.J.; Eccleston, G.W.; Fearey, B.L.

1997-10-01

Under US initiatives, over two hundred metric tons of fissile materials have been declared to be excess to national defense needs. These excess materials are in both classified and unclassified forms. The US has expressed the intent to place these materials under international inspections as soon as practicable. To support these commitments, members of the US technical community are examining a variety of nonintrusive approaches (i.e., those that would not reveal classified or sensitive information) for verification of a range of potential declarations for these classified and unclassified materials. The most troublesome and potentially difficult issues involve approaches for international inspection of classified materials. The primary focus of the work to date has been on the measurement of signatures of relevant materials attributes (e.g., element, identification number, isotopic ratios, etc.), especially those related to classified materials and items. The authors are examining potential attributes and related measurement technologies in the context of possible verification approaches. The paper will discuss the current status of these activities, including their development, assessment, and benchmarking status

Dosimetric characterization of a Tl new material of LiF: Mg, Cu, P; Caracterizacion dosimetrica de un nuevo material TL de LiF: Mg, Cu, P

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, P.R.; Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Quiroz, C. [UAEM, Facultad de Medicina, 50180, Toluca, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

2004-07-01

In this work the method of preparation of a new material T L is described of LiF: Mg, Cu, P and the preliminary results of the tests corresponding to their dosimetric characterization are reported. The carried out tests were: detection threshold, sensitivity, dissipation of the sign T L, answer T L in function of the dose of radiation gamma, among others. The results showed that this material when receiving the one thermal treatment of having erased of 280 C by 10 min, followed by 100 C for two hours, he/she has a detection threshold ten times but I lower that that of the TLD-100, is 21 times but sensitive that that of reference and the dissipation of the sign T L during two months was null. This new material T L overcomes in many aspects to the commercial dosemeters of its type. (Author)

Cost-driven materials selection criteria for redox flow battery electrolytes

Science.gov (United States)

Dmello, Rylan; Milshtein, Jarrod D.; Brushett, Fikile R.; Smith, Kyle C.

2016-10-01

Redox flow batteries show promise for grid-scale energy storage applications but are presently too expensive for widespread adoption. Electrolyte material costs constitute a sizeable fraction of the redox flow battery price. As such, this work develops a techno-economic model for redox flow batteries that accounts for redox-active material, salt, and solvent contributions to the electrolyte cost. Benchmark values for electrolyte constituent costs guide identification of design constraints. Nonaqueous battery design is sensitive to all electrolyte component costs, cell voltage, and area-specific resistance. Design challenges for nonaqueous batteries include minimizing salt content and dropping redox-active species concentration requirements. Aqueous battery design is sensitive to only redox-active material cost and cell voltage, due to low area-specific resistance and supporting electrolyte costs. Increasing cell voltage and decreasing redox-active material cost present major materials selection challenges for aqueous batteries. This work minimizes cost-constraining variables by mapping the battery design space with the techno-economic model, through which we highlight pathways towards low price and moderate concentration. Furthermore, the techno-economic model calculates quantitative iterations of battery designs to achieve the Department of Energy battery price target of 100 per kWh and highlights cost cutting strategies to drive battery prices down further.

Sensitivity of the polypropylene to the strain rate: experiments and modeling

International Nuclear Information System (INIS)

Abdul-Latif, A.; Aboura, Z.; Mosleh, L.

2002-01-01

Full text.The main goal of this work is first to evaluate experimentally the strain rate dependent deformation of the polypropylene under tensile load; and secondly is to propose a model capable to appropriately describe the mechanical behavior of this material and especially its sensitivity to the strain rate. Several experimental tensile tests are performed at different quasi-static strain rates in the range of 10 -5 s -1 to 10 -1 s -1 . In addition to some relaxation tests are also conducted introducing the strain rate jumping state during testing. Within the framework of elastoviscoplasticity, a phenomenological model is developed for describing the non-linear mechanical behavior of the material under uniaxial loading paths. With the small strain assumption, the sensitivity of the polypropylene to the strain rate being of particular interest in this work, is accordingly taken into account. As a matter of fact, since this model is based on internal state variables, we assume thus that the material sensitivity to the strain rate is governed by the kinematic hardening variable notably its modulus and the accumulated viscoplastic strain. As far as the elastic behavior is concerned, it is noticed that such a behavior is slightly influenced by the employed strain rate rage. For this reason, the elastic behavior is classically determined, i.e. without coupling with the strain rate dependent deformation. It is obvious that the inelastic behavior of the used material is thoroughly dictated by the applied strain rate. Hence, the model parameters are well calibrated utilizing several experimental databases for different strain rates (10 -5 s -1 to 10 -1 s -1 ). Actually, among these experimental results, some experiments related to the relaxation phenomenon and strain rate jumping during testing (increasing or decreasing) are also used in order to more perfect the model parameters identification. To validate the calibrated model parameters, simulation tests are achieved

Global sensitivity analysis of thermomechanical models in modelling of welding; Analyse de sensibilite globale de modeles thermomecanique de simulation numerique du soudage

Energy Technology Data Exchange (ETDEWEB)

Petelet, M

2008-07-01

Current approach of most welding modellers is to content themselves with available material data, and to chose a mechanical model that seems to be appropriate. Among inputs, those controlling the material properties are one of the key problems of welding simulation: material data are never characterized over a sufficiently wide temperature range. This way to proceed neglect the influence of the uncertainty of input data on the result given by the computer code. In this case, how to assess the credibility of prediction? This thesis represents a step in the direction of implementing an innovative approach in welding simulation in order to bring answers to this question, with an illustration on some concretes welding cases.The global sensitivity analysis is chosen to determine which material properties are the most sensitive in a numerical welding simulation and in which range of temperature. Using this methodology require some developments to sample and explore the input space covering welding of different steel materials. Finally, input data have been divided in two groups according to their influence on the output of the model (residual stress or distortion). In this work, complete methodology of the global sensitivity analysis has been successfully applied to welding simulation and lead to reduce the input space to the only important variables. Sensitivity analysis has provided answers to what can be considered as one of the probable frequently asked questions regarding welding simulation: for a given material which properties must be measured with a good accuracy and which ones can be simply extrapolated or taken from a similar material? (author)

Measuring sensitivity in pharmacoeconomic studies. Refining point sensitivity and range sensitivity by incorporating probability distributions.

Science.gov (United States)

Nuijten, M J

1999-07-01

The aim of the present study is to describe a refinement of a previously presented method, based on the concept of point sensitivity, to deal with uncertainty in economic studies. The original method was refined by the incorporation of probability distributions which allow a more accurate assessment of the level of uncertainty in the model. In addition, a bootstrap method was used to create a probability distribution for a fixed input variable based on a limited number of data points. The original method was limited in that the sensitivity measurement was based on a uniform distribution of the variables and that the overall sensitivity measure was based on a subjectively chosen range which excludes the impact of values outside the range on the overall sensitivity. The concepts of the refined method were illustrated using a Markov model of depression. The application of the refined method substantially changed the ranking of the most sensitive variables compared with the original method. The response rate became the most sensitive variable instead of the 'per diem' for hospitalisation. The refinement of the original method yields sensitivity outcomes, which greater reflect the real uncertainty in economic studies.

Assessing the concept of structure sensitivity or insensitivity for sub-nanometer catalyst materials

Science.gov (United States)

Crampton, Andrew S.; Rötzer, Marian D.; Ridge, Claron J.; Yoon, Bokwon; Schweinberger, Florian F.; Landman, Uzi; Heiz, Ueli

2016-10-01

The nature of the nano-catalyzed hydrogenation of ethylene, yielding benchmark information pertaining to the concept of structure sensitivity/insensitivity and its applicability at the bottom of the catalyst particle size-range, is explored with experiments on size-selected Ptn (n = 7-40) clusters soft-landed on MgO, in conjunction with first-principles simulations. As in the case of larger particles both the direct ethylene hydrogenation channel and the parallel hydrogenation-dehydrogenation ethylidyne-producing route must be considered, with the fundamental uncovering that at the reaction exhibits characteristics consistent with structure sensitivity, in contrast to the structure insensitivity found for larger particles. In this size-regime, the chemical properties can be modulated and tuned by a single atom, reflected by the onset of low temperature hydrogenation at T > 150 K catalyzed by Ptn (n ≥ 10) clusters, with maximum room temperature reactivity observed for Pt13 using a pulsed molecular beam technique. Structure insensitive behavior, inherent for specific cluster sizes at ambient temperatures, can be induced in the more active sizes, e.g. Pt13, by a temperature increase, up to 400 K, which opens dehydrogenation channels leading to ethylidyne formation. This reaction channel was, however found to be attenuated on Pt20, as catalyst activity remained elevated after the 400 K step. Pt30 displayed behavior which can be understood from extrapolating bulk properties to this size range; in particular the calculated d-band center. In the non-scalable sub-nanometer size regime, however, precise control of particle size may be used for atom-by-atom tuning and manipulation of catalyzed hydrogenation activity and selectivity.

Sensitivity-based virtual fields for the non-linear virtual fields method

Science.gov (United States)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2017-09-01

The virtual fields method is an approach to inversely identify material parameters using full-field deformation data. In this manuscript, a new set of automatically-defined virtual fields for non-linear constitutive models has been proposed. These new sensitivity-based virtual fields reduce the influence of noise on the parameter identification. The sensitivity-based virtual fields were applied to a numerical example involving small strain plasticity; however, the general formulation derived for these virtual fields is applicable to any non-linear constitutive model. To quantify the improvement offered by these new virtual fields, they were compared with stiffness-based and manually defined virtual fields. The proposed sensitivity-based virtual fields were consistently able to identify plastic model parameters and outperform the stiffness-based and manually defined virtual fields when the data was corrupted by noise.

Amplification of the Luminescence Response in Organic Materials Exposed to Ionizing Radiation

International Nuclear Information System (INIS)

Michel, M.; Rocha, L.; Hamel, M.; Normand, S.

2013-06-01

Polymer-based scintillators present interesting features for the field of ionizing radiation detection, related to the high sensitivity of fluorescence techniques coupled to the manufacturing advantages of such materials. Organic materials can indeed be manufactured into large sensing areas with different geometrical conformations through low-cost fabrication techniques. While results herein presented focus on liquids, the same phenomena would occur in solid samples. Widely used for sensing applications because of its high sensitivity, fluorescence has yet been further improved using technologies yielded by research in photonics. It has already been shown that the use of nano-structuring for sensing applications enables previously unattained sensitivities. Herein we propose a technique based on the manipulation of light using nano-structuring of the detection medium in order to enable the amplification of the sensitive material emission. This amplification of the luminescence signal is aimed at reducing the detection limit of low-energy beta emitters such as tritium, well-known issue of major importance. The first step of our study, presented here, consists in demonstrating the ability of well-known scintillators to emit in laser regime when optically excited in a Distributed Feedback scheme. They are, to our knowledge, the first of their kind. The technique here presented, being usable whatever the sample maximum emission wavelength, should also enable a simplification of the devices based on scintillators. (authors)

Fracture toughness of fibrous composite materials

Science.gov (United States)

Poe, C. C., Jr.

1984-01-01

Laminates with various proportions of 0 deg, 45 deg, and 90 deg plies were fabricated from T300/5208 and T300/BP-907 graphite/epoxy prepreg tape material. The fracture toughness of each laminate orientation or lay-up was determined by testing center-cracked specimens, and it was also predicted with the general fracture-toughness parameter. The predictions were good except when crack-tip splitting was large, at which time the toughness and strengths tended to be underpredicted. By using predictions, a parametric study was also made of factors that influence fracture toughness. Fiber and matrix properties as well as lay-up were investigated. Without crack-tip splitting, fracture toughness increases in proportion to fiber strength and fiber volume fraction, increases linearly with E(22)/E(11), is largest when the modulus for non-0 deg fibers is greater than that of 0 deg fibers, and is smallest for 0(m)/90(p)(s) lay-ups. (The E(11) and E(22) are Young's moduli of the lamina parallel to and normal to the direction of the fibers, respectively). For a given proportion of 0 deg plies, the most notch-sensitive lay-ups are 0(m)/90(p)(s) and the least sensitive are 0(m)/45(n)(s) and alpha(s). Notch sensitivity increases with the proportion of 0 deg plies and decreases with alpha. Strong, tough matrix materials, which inhibit crack-tip splitting, generally lead to minimum fracture toughness.

Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part 2. Reflection Holographic Optical Elements

Science.gov (United States)

Kim, Jong Man; Choi, Byung So; Choi, Yoon Sun; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

2002-03-01

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-fine-grain silver halide (AgHal) emulsions. In particular, high spatial-frequency fringes associated with HOEs of the reflection type are difficult to construct when SHSG processing methods are employed. Therefore an optimized processing technique for reflection HOEs recorded in the new AgHal materials is introduced. Diffraction efficiencies over 90% can be obtained repeatably for reflection diffraction gratings. Understanding the importance of a selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, also including high-quality display holograms of the reflection type in both monochrome and full color.

Fluence-rate effects on irradiation embrittlement and composition and temperature effects on annealing/reirradiation sensitivity

International Nuclear Information System (INIS)

Hawthorne, J.R.; Hiser, A.L.

1988-01-01

Recent MEA investigation on the effect of neutron fluence rate on radiation-induced embrittlement accrual and the contributions of metallurgical variables to postirradiation annealing and re-irradiation behavior are reviewed. Studies of fluence-rate effects involved experiments in the UBR test reactor and separately, radiation sensitivity determinations for the decommissioned Gundremmingen (KRB-A) vessel material. Annealing-reirradiation studies employed 399 0 C and 454 0 C heat treatments. Material composition is shown to play a major role in postirradiation annealing recovery. Results illustrate effects of variable copper and variable nickel contents on recoveray of steel plate having low phosphorus levels. Composition effects on recovery were also observed for prototypic welds depicting high/low copper and high/low nickel contents and three flux types. The welds, in addition, indicate major differences in re-irradiation sensitivity. The UBR investigations revealed a significant difference in fluence rate sensitivity between the ASTM A 302-B reference plate and a submerged-arc (S/A) Linde 80 weld. Studies of the Gundremmingen reactor vessel, representing a joint USA-FRG-UK undertaking revealed an anomaly in strong vs. weak test orientation radiation sensitivity. (orig./HP)

Superior selectivity and sensitivity of blue phosphorus nanotubes in gas sensing applications

KAUST Repository

Montes Muñoz, Enrique

2017-05-23

On the basis of first principles calculations, we study the adsorption of CO, CO2, NH3, NO, and NO2 molecules on armchair and zigzag blue phosphorus nanotubes. The nanotubes are found to surpass the gas sensing performance of other one-dimensional materials, in particular Si nanowires and carbon nanotubes, and two-dimensional materials, in particular graphene, phosphorene, and MoS2. Investigation of the energetics of the gas adsorption and induced charge transfers indicates that blue phosphorus nanotubes are highly sensitive to N-based molecules, in particular NO2, due to covalent bonding. The current–voltage characteristics of nanotubes connected to Au electrodes are derived by the non-equilibrium Green\\'s function formalism and used to quantitatively evaluate the change in resistivity upon gas adsorption. The observed selectivity and sensitivity properties make blue phosphorus nanotubes superior gas sensors for a wide range of applications.

Recent trends in high spin sensitivity magnetic resonance

Science.gov (United States)

Blank, Aharon; Twig, Ygal; Ishay, Yakir

2017-07-01

Magnetic resonance is a very powerful methodology that has been employed successfully in many applications for about 70 years now, resulting in a wealth of scientific, technological, and diagnostic data. Despite its many advantages, one major drawback of magnetic resonance is its relatively poor sensitivity and, as a consequence, its bad spatial resolution when examining heterogeneous samples. Contemporary science and technology often make use of very small amounts of material and examine heterogeneity on a very small length scale, both of which are well beyond the current capabilities of conventional magnetic resonance. It is therefore very important to significantly improve both the sensitivity and the spatial resolution of magnetic resonance techniques. The quest for higher sensitivity led in recent years to the development of many alternative detection techniques that seem to rival and challenge the conventional ;old-fashioned; induction-detection approach. The aim of this manuscript is to briefly review recent advances in the field, and to provide a quantitative as well as qualitative comparison between various detection methods with an eye to future potential advances and developments. We first offer a common definition of sensitivity in magnetic resonance to enable proper quantitative comparisons between various detection methods. Following that, up-to-date information about the sensitivity capabilities of the leading recently-developed detection approaches in magnetic resonance is provided, accompanied by a critical comparison between them and induction detection. Our conclusion from this comparison is that induction detection is still indispensable, and as such, it is very important to look for ways to significantly improve it. To do so, we provide expressions for the sensitivity of induction-detection, derived from both classical and quantum mechanics, that identify its main limiting factors. Examples from current literature, as well as a description of

Design of a 4D Printing System Using Thermal Sensitive Smart Materials and Photoactivated Shape Changing Polymers

Science.gov (United States)

Leist, Steven Kyle

4D printing is an emerging additive manufacturing technology that combines 3D printing with smart materials. Current 3D printing technology can print objects with a multitude of materials; however, these objects are usually static, geometrically permanent, and not suitable for multi-functional use. The 4D printed objects can change their shape over time when exposed to different external stimuli such as heat, pressure, magnetic fields, or moisture. In this research, heat and light reactive smart materials are explored as a 4D printing materials. Synthetization of a material that actuates when exposed to stimulus can be a very difficult process, and merging that same material with the ability to be 3D printed can be further difficult. A common 3D printing thermoplastic, poly(lactic) acid (PLA), is used as a shape memory material that is 3D printed using a fused deposition machine (FDM) and combined with nylon fabric for the exploration of smart textiles. The research shows that post printed PLA possesses shape memory properties depending on the thickness of the 3D printed material and the activation temperature. PLA can be thermomechanically trained into temporary shapes and return to its original shape when exposed to high temperatures. PLA can be 3D printed onto nylon fabrics for the creation of the smart textiles. Additionally, a photoisomerable shape changing material is explored because light activation is wireless, controllable, focusable, abundant, causes rapid shape change of the smart material, and induces reversible shape change in the material. This study supports the fundamental research to generate knowledge needed for synthesis of a novel azobenzene shape changing polymer (SCP) and integrating this smart material into objects printed with a 4D printing process using syringe printing. Multiple versions of azobenzene SCP are synthesized that actuate when exposed to 365 nm and 455 nm light. Two SCPs, MeOABHx and DR1Hx, are selected for the 4D printing

X-ray Sensitive Material

Science.gov (United States)

2015-12-01

TM 8772 5 Literature reports on BiI3/nylon composites used X-ray sources with a Mo target (Reference 18) or magnesium target (Reference 19). However...1981. Pp. D-155 to D-160. 22. G. Pretzsch, B. Dorschel, and T. Schonmuth. IEEE Transactions on Electrical Insulation, Vol. EI -21, No.3, June 1986

Pressure-Sensitive Resistor Material

Science.gov (United States)

Du Fresne, E. R.

1986-01-01

Low-conductivity particles in rubber offer wide dynamic range. Sensor consists of particles of relatively low conductivity embedded in rubber. Resistance of sensor decreases by about 100 times as pressure on it increases from zero to 0.8 MN/M to the second power. Resistor promising candidate as tactile sensor for robots and remote manipulators.

Government to Government Communication Concerning the Transportation of Radioactive Material: Routine and Crisis

International Nuclear Information System (INIS)

Ludbrook, Julian

2016-01-01

Good communication between Governments about international shipments of nuclear material, including full information sharing, is key to the effective management of the radiological, economic, environmental and political risks associated with such shipments and particularly any accident or incident involving them. In many, if not most, countries public sensitivity about the potential consequences of any accident involving radioactive material generally is high. Recognising this sensitivity, which has been further heightened by the Fukushima accident, rules are already in place regarding advance communication about the shipment of particular nuclear material from one state to or through the land territory of another state. No particular rules exist in relation to shipments of such material passing through or near the waters under the jurisdiction of another state but not being landed in that state. But the same sensitivity exists and there is the same need for the political leadership in the relevant Coastal State to have full information in advance about such shipments in order to ensure effective practical and political management of any accident involving the shipment. In part taking account of such sensitivity, some Shipping States have in practice been willing to communicate information in advance to Coastal States in this situation. There would be value in recognising more systematically the mutual benefit served by Shipping States routinely communicating information relating to these types of shipments in advance to affected Coastal States, while taking into account the shared concern about ensuring that all sensitive information is protected appropriately. This paper identifies the information needed in advance for effective risk management, recognising that this could be supplemented by bilateral arrangements between the relevant Shipping and Coastal State. It also identifies information that should be communicated and exchanged in an emergency situation

Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Yuancheng Qin

2012-01-01

Full Text Available Dye-sensitized solar cells (DSSCs have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.

Sensitivity analysis of longitudinal cracking on asphalt pavement using MEPDG in permafrost region

Directory of Open Access Journals (Sweden)

Chen Zhang

2015-02-01

Full Text Available Longitudinal cracking is one of the most important distresses of asphalt pavement in permafrost regions. The sensitivity analysis of design parameters for asphalt pavement can be used to study the influence of every parameter on longitudinal cracking, which can help optimizing the design of the pavement structure. In this study, 20 test sections of Qinghai–Tibet Highway were selected to conduct the sensitivity analysis of longitudinal cracking on material parameter based on Mechanistic-Empirical Pavement Design Guide (MEPDG and single factorial sensitivity analysis method. Some computer aided engineering (CAE simulation techniques, such as the Latin hypercube sampling (LHS technique and the multiple regression analysis are used as auxiliary means. Finally, the sensitivity spectrum of material parameter on longitudinal cracking was established. The result shows the multiple regression analysis can be used to determine the remarkable influence factor more efficiently and to process the qualitative analysis when applying the MEPDG software in sensitivity analysis of longitudinal cracking in permafrost regions. The effect weights of the three parameters on longitudinal cracking in descending order are air void, effective binder content and PG grade. The influence of air void on top layer is bigger than that on middle layer and bottom layer. The influence of effective asphalt content on top layer is bigger than that on middle layer and bottom layer, and the influence of bottom layer is slightly bigger than middle layer. The accumulated value of longitudinal cracking on middle layer and bottom layer in the design life would begin to increase when the design temperature of PG grade increased.

Performance Modeling of Mimosa pudica Extract as a Sensitizer for Solar Energy Conversion

Directory of Open Access Journals (Sweden)

M. B. Shitta

2016-01-01

Full Text Available An organic material is proposed as a sustainable sensitizer and a replacement for the synthetic sensitizer in a dye-sensitized solar cell technology. Using the liquid extract from the leaf of a plant called Mimosa pudica (M. pudica as a sensitizer, the performance characteristics of the extract of M. pudica are investigated. The photo-anode of each of the solar cell sample is passivated with a self-assembly monolayer (SAM from a set of four materials, including alumina, formic acid, gelatine, and oxidized starch. Three sets of five samples of an M. pudica–based solar cell are produced, with the fifth sample used as the control experiment. Each of the solar cell samples has an active area of 0.3848cm2. A two-dimensional finite volume method (FVM is used to model the transport of ions within the monolayer of the solar cell. The performance of the experimentally fabricated solar cells compares qualitatively with the ones obtained from the literature and the simulated solar cells. The highest efficiency of 3% is obtained from the use of the extract as a sensitizer. It is anticipated that the comparison of the performance characteristics with further research on the concentration of M. pudica extract will enhance the development of a reliable and competitive organic solar cell. It is also recommended that further research should be carried out on the concentration of the extract and electrolyte used in this study for a possible improved performance of the cell.

Sensitivity of NEXT-100 to neutrinoless double beta decay

CERN Document Server

Martín-Albo, J.; Ferrario, P.; Nebot-Guinot, M.; Gómez-Cadenas, J.J.; Álvarez, V.; Azevedo, C.D.R.; Borges, F.I.G.; Cárcel, S.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L.M.P.; Ferreira, A.L.; Freitas, E.D.C.; Gehman, V.M.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R.M.; Henriques, C.A.O.; Hernando Morata, J.A.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Novella, P.; Nygren, D.; Para, A.; Perez, J.; Perez Aparicio, J.L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F.P.; dos Santos, J.M.F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Yepes-Ramírez, H.; Hauptman, J.

2016-01-01

NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta decay of Xe-136. The detector possesses two features of great value in neutrinoless double beta decay searches: very good energy resolution (better than 1% FWHM at the Q value of Xe-136) and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Detailed Monte Carlo detector simulations and material-screening measurements predict a background rate for NEXT-100 of at most 0.0004 counts/(keV kg yr). Accordingly, the detector will reach a sensitivity to the neutrinoless double beta decay half-life of 6.E25 years after running for 3 effective years.

Composite material including nanocrystals and methods of making

Science.gov (United States)

Bawendi, Moungi G.; Sundar, Vikram C.

2010-04-06

Temperature-sensing compositions can include an inorganic material, such as a semiconductor nanocrystal. The nanocrystal can be a dependable and accurate indicator of temperature. The intensity of emission of the nanocrystal varies with temperature and can be highly sensitive to surface temperature. The nanocrystals can be processed with a binder to form a matrix, which can be varied by altering the chemical nature of the surface of the nanocrystal. A nanocrystal with a compatibilizing outer layer can be incorporated into a coating formulation and retain its temperature sensitive emissive properties.

Sensitivity study of the Continuous Release Dispersion Model (CRDM) for radioactive pollutants

International Nuclear Information System (INIS)

Camacho, F.

1987-08-01

The Continuous Release Dispersion Model (CRDM) is used to calculate spatial distribution of pollutants and their radiation doses in the event of accidental releases of radioactive material from Nuclear Generation Stations. A sensitivity analysis of the CRDM was carried out to develop a method for quantifying the expected output uncertainty due to inaccuracies and uncertainties in the input values. A simulation approach was used to explore the behaviour of the sensitivity functions. It was found that the most sensitive variable is wind speed, the least sensitive is the ambient temperature, and that largest values of normalized concentrations are likely to occur for small values of wind speed and highly stable atmospheric conditions. It was also shown that an error between 10% and 25% should be expected in the output values for a 1% overall error in the input values, and this factor could be much larger in certain situations

Moisture buffer capacity of different insulation materials

DEFF Research Database (Denmark)

Peuhkuri, Ruut Hannele; Rode, Carsten; Hansen, Kurt Kielsgaard

2004-01-01

. In the isothermal tests the material samples were exposed to the same change in the relative humidity of the ambient air on both sides, while the samples were exposed to variations in relative humidity only on the cold side in the non-isothermal tests. The results of these rather different measurement principles...... lead to more durable constructions. In this paper, a large range of very different thermal insulation materials have been tested in specially constructed laboratory facilities to determine their moisture buffer capacity. Both isothermal and nonisothermal experimental set-ups have been used...... are discussed, and different ways are presented how to determine the moisture buffer capacity of the materials using partly standard material parameters and partly parameters determined from the actual measurements. The results so far show that the determination of moisture buffer capacity is very sensitive...

Development of high-sensitivity ultrasonic techniques for in-service inspection of nuclear reactors

International Nuclear Information System (INIS)

Linzer, M.

1977-01-01

The principal objective of the program is to develop techniques to enhance the sensitivity of ultrasonic signals which are below the random noise of the system. A secondary objective is to develop instrumentation for improved discrimination of flaw signals from background ''clutter'' and for characterization of failure-related material properties through measurements of ultrasonic parameters such as velocity and attenuation. The improved techniques will be applied to detect flaws in nuclear reactor materials and components

The selectively bred high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats differ in sensitivity to nicotine.

Science.gov (United States)

de Fiebre, NancyEllen C; Dawson, Ralph; de Fiebre, Christopher M

2002-06-01

Studies in rodents selectively bred to differ in alcohol sensitivity have suggested that nicotine and ethanol sensitivities may cosegregate during selective breeding. This suggests that ethanol and nicotine sensitivities may in part be genetically correlated. Male and female high alcohol sensitivity (HAS), control alcohol sensitivity, and low alcohol sensitivity (LAS) rats were tested for nicotine-induced alterations in locomotor activity, body temperature, and seizure activity. Plasma and brain levels of nicotine and its primary metabolite, cotinine, were measured in these animals, as was the binding of [3H]cytisine, [3H]epibatidine, and [125I]alpha-bungarotoxin in eight brain regions. Both replicate HAS lines were more sensitive to nicotine-induced locomotor activity depression than the replicate LAS lines. No consistent HAS/LAS differences were seen on other measures of nicotine sensitivity; however, females were more susceptible to nicotine-induced seizures than males. No HAS/LAS differences in nicotine or cotinine levels were seen, nor were differences seen in the binding of nicotinic ligands. Females had higher levels of plasma cotinine and brain nicotine than males but had lower brain cotinine levels than males. Sensitivity to a specific action of nicotine cosegregates during selective breeding for differential sensitivity to a specific action of ethanol. The differential sensitivity of the HAS/LAS rats is due to differences in central nervous system sensitivity and not to pharmacokinetic differences. The differential central nervous system sensitivity cannot be explained by differences in the numbers of nicotinic receptors labeled in ligand-binding experiments. The apparent genetic correlation between ethanol and nicotine sensitivities suggests that common genes modulate, in part, the actions of both ethanol and nicotine and may explain the frequent coabuse of these agents.

Application of Ammonium Bechromate and Potassium Bechromate as PhotoSensitive Emulsion to Sunlight Irradiation on Printing Screen for Textile

International Nuclear Information System (INIS)

Santoso-Sastrosoeparno

2000-01-01

The paste of photo sensitive emulsion that has been used in thepreparation for producing ready used printing screen contained two materials,namely the paste from monomer solution to be polymerized for strengtheningthe printing screen, and material for photo sensitive emulsion, usingammonium or potassium bichromate as common agent. From the previous studyabout producing printing screen from polyester, by using vinyl alcohol (VA)and polyvinyl acetate (PVAc) as polymeric material, as well as ammoniumbichromate as photo sensitive emulsion, has obtained the best combination forpolymer mixture from 80% of vinyl alcohol and 20% of polyvinyl acetate. Inthis research study, the same activity will be subjected to either ammoniumor potassium bichromate, with assumption that there will be differentproperties between ammonium and potassium cations which might have influenceto the printing screen from polyester. Some various mixture of VA and PVAc aspolymeric materials were carried out in this study, and to each of thepolymeric paste was added the photo sensitive emulsion, either ammoniumbe-chromate or potassium bichromate, stirring to homogeneous condition,coating the surface of flat printing screen, allow to dry in the dark room(no light), apply to sunlight irradiation for few minutes, and followed bycuring process to become ready used as printing screen. The printing screenproduced in this experiment was then subjected to various testing, such asstiffness, strength retention and shearing strength in either length andwidth directions of the screen. It was shown from the testing results thatthe coated screen with potassium bichromate as photo sensitive emulsion willgain better properties in stiffness, strength retention as well as shearingstrength, in all polymeric mixtures, compared to the ones with ammoniumbe-chromate. (author)

Procedures for Sensitive Immunoassay

Energy Technology Data Exchange (ETDEWEB)

Givol, D. [Department of Chemical Immunology, Weizmann Institute of Science, Rehovot (Israel)

1970-02-15

Sensitive immunoassay methods should be applied to small molecules of biological importance, which are non-immunogenic by themselves, such as small peptide hormones (e.g. bradykinin), plant hormones (e.g. indoleacetic acid), nucleotides and other small molecules. Methods of binding these small molecules, as haptens, to immunogenic carriers by various cross-linking agents are described (dicyclohexylcarbodiimide, tolylene-diisocyanate and glutaraldehyde), and the considerations involved in relation to the methods of binding and the specificity of the antibodies formed are discussed. Some uses of antibody bound to bromoacetyl cellulose as an immuno adsorbent convenient for assay of immunoglobulins are described. Finally, the sensitive immunoassay method of chemically modified phage is described. This includes methods of binding small molecules (such as the dinitrophenyl group, penicillin, indoleacetic acid) or proteins (such as insulin, immunoglobulins) to phages. Methods of direct chemical conjugation, or an indirect binding via anti-phage Fab, are described. The phage inactivation method by direct plating and its modifications (such as decision technique and complex inactivation) are compared with the more simple end-point titration method. The inhibition of phage inactivation has some advantages as it does not require radioactive material, or expensive radioactive counters, and avoids the need for separation between bound and unbound antigen. Hence, if developed, it could be used as an alternative to radioimmunoassay. (author)

Feasibility of using microencapsulated phase change materials as filler for improving low temperature performance of rubber sealing materials.

Science.gov (United States)

Tiwari, Avinash; Shubin, Sergey N; Alcock, Ben; Freidin, Alexander B; Thorkildsen, Brede; Echtermeyer, Andreas T

2017-11-01

The feasibility of a novel composite rubber sealing material to improve sealing under transient cooling (in a so-called blowdown scenario) is investigated here. A composite of hydrogenated nitrile butadiene rubber (HNBR) filled with Micro Encapsulated Phase Change Materials (MEPCM) is described. The fillers contain phase change materials that release heat during the phase transformation from liquid to solid while cooling. This exotherm locally heats the rubber and may improve the function of the seal during a blowdown event. A representative HNBR-MEPCM composite was made and the critical thermal and mechanical properties were obtained by simulating the temperature distribution during a blowdown event. Simulations predict that the MEPCM composites can delay the temperature decrease in a region of the seal during the transient blowdown. A sensitivity analysis of material properties is also presented which highlights possible avenues of improvement of the MEPCMs for sealing applications.

Quasi-static crack tip fields in rate-sensitive FCC single crystals

Indian Academy of Sciences (India)

In this work, the effects of loading rate, material rate sensitivity and constraint level on quasi-static crack tip fields in a FCC single crystal are studied. ... Global General Motors R&D, India Science Lab, GM Technical Centre (India), Bangalore 560 066, India; Department of Mechanical Engineering, Indian Institute of Science, ...

Global sensitivity analysis of thermo-mechanical models in numerical weld modelling; Analyse de sensibilite globale de modeles thermomecaniques de simulation numerique du soudage

Energy Technology Data Exchange (ETDEWEB)

Petelet, M

2007-10-15

Current approach of most welding modellers is to content themselves with available material data, and to chose a mechanical model that seems to be appropriate. Among inputs, those controlling the material properties are one of the key problems of welding simulation: material data are never characterized over a sufficiently wide temperature range {exclamation_point} This way to proceed neglect the influence of the uncertainty of input data on the result given by the computer code. In this case, how to assess the credibility of prediction? This thesis represents a step in the direction of implementing an innovative approach in welding simulation in order to bring answers to this question, with an illustration on some concretes welding cases. The global sensitivity analysis is chosen to determine which material properties are the most sensitive in a numerical welding simulation and in which range of temperature. Using this methodology require some developments to sample and explore the input space covering welding of different steel materials. Finally, input data have been divided in two groups according to their influence on the output of the model (residual stress or distortion). In this work, complete methodology of the global sensitivity analysis has been successfully applied to welding simulation and lead to reduce the input space to the only important variables. Sensitivity analysis has provided answers to what can be considered as one of the probable frequently asked questions regarding welding simulation: for a given material which properties must be measured with a good accuracy and which ones can be simply extrapolated or taken from a similar material? (author)

Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

Directory of Open Access Journals (Sweden)

Pavuluri Srinivasu

2011-01-01

Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

Defect creation by swift heavy ions: materials modifications in the electronic stopping power regime

International Nuclear Information System (INIS)

Toulemonde, M.

1994-01-01

The material modifications by swift heavy ions in the electronic stopping power regime are puzzling question: How the energy deposited on the electrons can induced material modifications? In order to answer to this question, the modifications induced in non-radiolytic materials are described and compared to the predictions. In first part the main experimental observations is presented taking into account the irradiation parameters. Then it is shown that the initial phases of the material are very important. Amorphous materials, whatever it is a metal, a semiconductor or an insulator, are till now all sensitive to the high electronic excitation induced by the slowing down of a swift heavy ion. All oxide materials, insulators or conductors, are also sensitive even the MgO, one of most famous exceptions. Crystalline metals or semiconductors are intermediate cases: some are insensitive like Cu and Si respectively while Fe and GeS are sensitive. The main feature is the different values of the electronic stopping power threshold of material modifications. The evolution of the damage creation is described showing that the damage morphology seems to be the same whatever the material is amorphous or crystalline. In second part a try of interpretation of the experimental results will be done on the behalf of the two following models: The Coulomb spike and the thermal spike models. It will be shown that there is some agreement with limited predictions made in the framework of the Coulomb spike model. But it appears that the thermal spike model can account for most of the experimental data using only one free parameter: The electron-phonon strength which is a physical characteristic of the irradiated material. (author). 4 figs., 1 tab., 64 refs

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 35; Issue 3. Property change during nanosecond pulse laser annealing of amorphous NiTi thin film ... amorphous thin films of near equiatomic Ni/Ti composition to produce partially crystallized highly sensitive -phase spots surrounded by amorphous regions. Scanning ...

Introduction to reactor internal materials for pressurized water reactor

Energy Technology Data Exchange (ETDEWEB)

Ryu, Woo Suk; Hong, Joon Hwa; Jee, Se Hwan; Lee, Bong Sang; Kuk, Il Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-06-01

This report reviewed the R and D states of reactor internal materials in order to be a reference for researches and engineers who are concerning on localization of the materials in the field or laboratory. General structure of PWR internals and material specification for YGN 3 and 4 were reviewed. States-of-arts on R and D of stainless steel and Alloy X-750 were reviewed, and degradation mechanisms of the components were analyzed. In order to develop the good domestic materials for reactor internal, following studies would be carried out: microstructure, sensitization behavior, fatigue property, irradiation-induced stress corrosion cracking/radiation-induced segregation, radiation embrittlement. (Author) 7 refs., 14 figs., 5 tabs.,.

Introduction to reactor internal materials for pressurized water reactor

International Nuclear Information System (INIS)

Ryu, Woo Suk; Hong, Joon Hwa; Jee, Se Hwan; Lee, Bong Sang; Kuk, Il Hyun

1994-06-01

This report reviewed the R and D states of reactor internal materials in order to be a reference for researches and engineers who are concerning on localization of the materials in the field or laboratory. General structure of PWR internals and material specification for YGN 3 and 4 were reviewed. States-of-arts on R and D of stainless steel and Alloy X-750 were reviewed, and degradation mechanisms of the components were analyzed. In order to develop the good domestic materials for reactor internal, following studies would be carried out: microstructure, sensitization behavior, fatigue property, irradiation-induced stress corrosion cracking/radiation-induced segregation, radiation embrittlement. (Author) 7 refs., 14 figs., 5 tabs.,

Childhood quality influences genetic sensitivity to environmental influences across adulthood: A life-course Gene × Environment interaction study.

Science.gov (United States)

Keers, Robert; Pluess, Michael

2017-12-01

While environmental adversity has been shown to increase risk for psychopathology, individuals differ in their sensitivity to these effects. Both genes and childhood experiences are thought to influence sensitivity to the environment, and these factors may operate synergistically such that the effects of childhood experiences on later sensitivity are greater in individuals who are more genetically sensitive. In line with this hypothesis, several recent studies have reported a significant three-way interaction (Gene × Environment × Environment) between two candidate genes and childhood and adult environment on adult psychopathology. We aimed to replicate and extend these findings in a large, prospective multiwave longitudinal study using a polygenic score of environmental sensitivity and objectively measured childhood and adult material environmental quality. We found evidence for both Environment × Environment and Gene × Environment × Environment effects on psychological distress. Children with a poor-quality material environment were more sensitive to the negative effects of a poor environment as adults, reporting significantly higher psychological distress scores. These effects were further moderated by a polygenic score of environmental sensitivity. Genetically sensitive children were more vulnerable to adversity as adults, if they had experienced a poor childhood environment but were significantly less vulnerable if their childhood environment was positive. These findings are in line with the differential susceptibility hypothesis and suggest that a life course approach is necessary to elucidate the role of Gene × Environment in the development of mental illnesses.

Determination of carbon-14 in environmental level, solid reference materials

Energy Technology Data Exchange (ETDEWEB)

Blowers, Paul, E-mail: paul.blowers@cefas.co.uk [Cefas Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 0HT (United Kingdom); Caborn, Jane, E-mail: jane.a.caborn@nnl.co.uk [NNL, Springfields, Salwick, Preston, Lancashire, PR4 0XJ (United Kingdom); Dell, Tony [Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT15 3NB (United Kingdom); Gingell, Terry [DSTL, Radiation Protection Services, Crescent Road, Alverstoke, Gosport, Hants, PO12 2DL (United Kingdom); Harms, Arvic [National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Long, Stephanie [Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Clonskeagh Road, Dublin 14, Ireland (United Kingdom); Sleep, Darren [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Stewart, Charlie [UKAEA (Waste Management Group), Chemical Support Services, D1310/14, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom); Walker, Jill [Radiocarbon Dating, The Old Stables, East Lockinge, Wantage, Oxon OX12 8QY (United Kingdom); Warwick, Phil E. [GAU-Radioanalytical, National Oceanography Centre Southampton, European Way, Southampton, SO14 3ZH (United Kingdom)

2011-10-15

An intercomparison exercise to determine the {sup 14}C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing {sup 14}C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

Determination of carbon-14 in environmental level, solid reference materials

International Nuclear Information System (INIS)

Blowers, Paul; Caborn, Jane; Dell, Tony; Gingell, Terry; Harms, Arvic; Long, Stephanie; Sleep, Darren; Stewart, Charlie; Walker, Jill; Warwick, Phil E.

2011-01-01

An intercomparison exercise to determine the 14 C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing 14 C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

D33 mode piezoelectric diaphragm based acoustic transducer with high sensitivity

KAUST Repository

Shen, Zhiyuan; Lu, Jingyu; Tan, Cheewee; Miao, Jianmin; Wang, Zhihong

2013-01-01

This paper presents the design, fabrication, and characterization of an acoustic transducer using a piezoelectric freestanding bulk diaphragm as the sensing element. The diaphragm bearing the spiral electrode operates in d 33 mode, which allows the in-plane deformation of the diaphragm to be converted to the out-of-plane deformation and generates an acoustic wave in the same direction. A finite element code is developed to reorient the material polarization distribution according to the poling field calculated. The first four resonance modes have been simulated and verified by impedance and velocity spectra. The sensitivity and the sound pressure level of the transducer were characterized. The realized sensitivity of 126.21 μV/Pa at 1 kHz is nearly twenty times of the sensitivity of a sandwich d31 mode transducer. © 2012 Elsevier B.V.

Materials data in the nuclear industry. Present and future

International Nuclear Information System (INIS)

Rowe, J.P.

1985-01-01

The database for materials must address the various needs of different participants in industry. The materials producer must use the base to assure that his product meets required specifications and that his operations are under control. The designer will need the ''standard design values'' resulting from the analysis of the data, as well as the ability to examine the raw data, to assess the sensitivity of his design to postulated system conditions. Finally, the assessment of materials following extensive service must rely on this database to indicate the effect of environment on the serviceability of a given material. Encompassing all of these needs is the need to know how the data were taken; e.g., temperature control, specimen fabrication, material orientation, test machine calibration, etc. In short, the materials part of the ''common database'' is complex

Current trends in nuclear material transportation

International Nuclear Information System (INIS)

Ravenscroft, Norman; Oshinowo, Franchone

1997-01-01

The business of radioactive material transportation has evolved considerably in the past 40 years. Current practices reflect extensive international experience in handling radioactive cargo within a mature and tested regulatory framework. Nevertheless, new developments continue to have an impact on how shipments of nuclear material are planned and carried out. Entities involved in the transport of radioactive materials must keep abreast of these developments and work together to find innovative solutions to ensure that safe, smooth transport activities may continue. Several recent trends in the regulatory environment and political atmosphere require attention. There are four key trends that we'll be examining today: 1) the reduction in the pool of available commercial carriers; 2) routing restrictions; 3) package validation issues; and 4) increasing political sensitivities. Careful planning and cooperative measures are necessary to alleviate problems in each of these areas. (author)

Fundamentals and applications of magnetic materials

CERN Document Server

Krishnan, Kannan M

2016-01-01

Students and researchers looking for a comprehensive textbook on magnetism, magnetic materials and related applications will find in this book an excellent explanation of the field. Chapters progress logically from the physics of magnetism, to magnetic phenomena in materials, to size and dimensionality effects, to applications. Beginning with a description of magnetic phenomena and measurements on a macroscopic scale, the book then presents discussions of intrinsic and phenomenological concepts of magnetism such as electronic magnetic moments and classical, quantum, and band theories of magnetic behavior. It then covers ordered magnetic materials (emphasizing their structure-sensitive properties) and magnetic phenomena, including magnetic anisotropy, magnetostriction, and magnetic domain structures and dynamics. What follows is a comprehensive description of imaging methods to resolve magnetic microstructures (domains) along with an introduction to micromagnetic modeling. The book then explores in detail size...

Corrosion and material transfer in a sodium loop

International Nuclear Information System (INIS)

Garcia, A.M.; Espigares, M.M.; Arroyo, J.; Borgstedt, H.U.; Kernforschungszentrum Karlsruhe G.m.b.H.

1984-01-01

The corrosion and material transfer behaviour of the martensitic steel X18 CrMoVNb 12 1 as a function of the temperature and the position is studied in the ML-1 sodium loop. Up to 600 C the material has the same good compatibility with liquid sodium as austenitic stainless steels, as well in the corrosion region of the loop as in the deposition zone in the cooled leg. The steel is not sensitive to carburization or decarburization under the conditions in the sodium rig. (author)

Clearance Laboratory - Capability and measurement sensitivity

Energy Technology Data Exchange (ETDEWEB)

Hedemann Jensen, P.; Lauridsen, B.; Silva, J.; Soegaard-Hansen, J.; Warming, L.

2005-08-01

A new low-level Clearance Laboratory has been built at the Risoe-site. Building materials with a low content of naturally occurring radionuclides have been used. To minimize transport of radon gas from soil into the laboratory the foundation has been supplied with a membrane. The laboratory has been equipped with two high-efficiency germanium detectors. These detectors will be used for clearance measurements on the predicted amount of 15,000 - 18,000 tonnes of non-active or nearly non-active materials, which will originate from the decommissioning of all the nuclear facilities at the Risoe-site. They will be used also for clearance measurements on buildings and land. Objects and materials to be measured for clearance are placed on a rotation table that can carry up to one tonne and can rotate once a minute to simulate some averaging of inhomogeneously distributed activity. Sensitivity and background measurements reveal that measuring times of 20 - 50 minutes would normally be sufficient to detect radionuclide concentrations of only a small fraction of the nuclide-specific clearance levels with a sufficiently low uncertainty. Probability calculations of the measurement capacity of the Clearance Laboratory indicate that the mean value of the total measuring time for all materials that potentially can be cleared would be 13 years with a 95% probability of being less than 25 years. The mean value of the annual amount of materials that can be measured in the laboratory is 600 tonnes with a 95% probability of being less than 1,200 tonnes. If needed, there is room for additional measuring systems to increase the capacity of the laboratory. (au)

Clearance Laboratory - Capability and measurement sensitivity

International Nuclear Information System (INIS)

Hedemann Jensen, P.; Lauridsen, B.; Silva, J.; Soegaard-Hansen, J.; Warming, L.

2005-09-01

A new low-level Clearance Laboratory has been built at the Risoe-site. Building materials with a low content of naturally occurring radionuclides have been used. To minimize transport of radon gas from soil into the laboratory the foundation has been supplied with a membrane. The laboratory has been equipped with two high-efficiency germanium detectors. These detectors will be used for clearance measurements on the predicted amount of 15,000 - 18,000 tonnes of non-active or nearly non-active materials, which will originate from the decommissioning of all the nuclear facilities at the Risoe-site. They will be used also for clearance measurements on buildings and land. Objects and materials to be measured for clearance are placed on a rotation table that can carry up to one tonne and can rotate once a minute to simulate some averaging of inhomogeneously distributed activity. Sensitivity and background measurements reveal that measuring times of 20 - 50 minutes would normally be sufficient to detect radionuclide concentrations of only a small fraction of the nuclide-specific clearance levels with a sufficiently low uncertainty. Probability calculations of the measurement capacity of the Clearance Laboratory indicate that the mean value of the total measuring time for all materials that potentially can be cleared would be 13 years with a 95% probability of being less than 25 years. The mean value of the annual amount of materials that can be measured in the laboratory is 600 tonnes with a 95% probability of being less than 1,200 tonnes. If needed, there is room for additional measuring systems to increase the capacity of the laboratory. (au)

Molecular and Material Approaches to Overcome Kinetic and Energetic Constraints in Dye-Sensitized Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Hamann, Thomas [Michigan State Univ., East Lansing, MI (United States)

2016-08-14

Dye-sensitized solar cells (DSSCs) have attracted a lot of interest as they proffer the possibility of extremely inexpensive and efficient solar energy conversion. The excellent performance of the most efficient DSSCs relies on two main features: 1) a high surface area nanoparticle semiconductor photoanode to allow for excellent light absorption with moderate extinction molecular dyes and 2) slow recombination rates from the photoanode to I₃^- allowing good charge collection. The I₃^-/I^- couple, however, has some disadvantages, notably the redox potential limits the maximum open-circuit voltage, and the dye regeneration requires a large driving force which constrains the light harvesting ability. Thus, the design features that allow DSSCs to perform as well as they do also prevent further significant improvements in performance. As a consequence, the most efficient device configuration, and the maximum efficiency, has remained essentially unchanged over the last 16 years. Significant gains in performance are possible; however it will likely require a substantial paradigm shift. The general goal of this project is to understand the fundamental role of dye-sensitized solar cell, DSSC, components (sensitizer, redox shuttle, and photoanode) involved in key processes in order to overcome the kinetic and energetic constraints of current generation DSSCs. For example, the key to achieving high energy conversion efficiency DSSCs is the realization of a redox shuttle which fulfills the dual requirements of 1) efficient dye regeneration with a minimal driving force and 2) efficient charge collection. In current generation DSSCs, however, only one or the other of these requirements is met. We are currently primarily interested in understanding the physical underpinnings of the regeneration and recombination reactions. Our approach is to systematically vary the components involved in reactions and interrogate them with a

SENSIT: a cross-section and design sensitivity and uncertainty analysis code

International Nuclear Information System (INIS)

Gerstl, S.A.W.

1980-01-01

SENSIT computes the sensitivity and uncertainty of a calculated integral response (such as a dose rate) due to input cross sections and their uncertainties. Sensitivity profiles are computed for neutron and gamma-ray reaction cross sections of standard multigroup cross section sets and for secondary energy distributions (SEDs) of multigroup scattering matrices. In the design sensitivity mode, SENSIT computes changes in an integral response due to design changes and gives the appropriate sensitivity coefficients. Cross section uncertainty analyses are performed for three types of input data uncertainties: cross-section covariance matrices for pairs of multigroup reaction cross sections, spectral shape uncertainty parameters for secondary energy distributions (integral SED uncertainties), and covariance matrices for energy-dependent response functions. For all three types of data uncertainties SENSIT computes the resulting variance and estimated standard deviation in an integral response of interest, on the basis of generalized perturbation theory. SENSIT attempts to be more comprehensive than earlier sensitivity analysis codes, such as SWANLAKE

Influence of culture and language sensitive physics on science attitude enhancement

Science.gov (United States)

Morales, Marie Paz E.

2015-12-01

The study critically explored how culture and language sensitive curriculum materials in physics improve Pangasinan learners' attitude towards science. Their cultural dimensions, epistemological beliefs, and views on integration of culture and language in the teaching and learning process determined their cultural preference or profile. Design and development of culture and language sensitive curriculum materials in physics were heavily influenced by these learners' cultural preference or profile. Pilot-study using interviews and focus group discussions with natives of Pangasinan and document analysis were conducted to identify the culture, practices, and traditions integrated in the lesson development. Comparison of experimental participants' pretest and posttest results on science attitude measure showed significant statistical difference. Appraisal of science attitude enhancement favored the experimental group over the control group. Qualitative data deduced from post implementation interviews, focus group discussions, and journal log entries showed the same trend in favor of the experimental participants. The study revealed that culture and language integration in the teaching and learning process of physics concepts enabled students to develop positive attitude to science, their culture, and native language.

Brittle materials at high-loading rates: an open area of research