Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

Directory of Open Access Journals (Sweden)

Marie Pospíšilová

2015-09-01

Full Text Available This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS and biosensors (FOBS. Fiber optic sensor (FOS systems use the ability of optical fibers (OF to guide the light in the spectral range from ultraviolet (UV (180 nm up to middle infrared (IR (10 μm and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors.

Chemical and Physical Sensing in the Petroleum Industry

Science.gov (United States)

Disko, Mark

2008-03-01

World-scale oil, gas and petrochemical production relies on a myriad of advanced technologies for discovering, producing, transporting, processing and distributing hydrocarbons. Sensing systems provide rapid and targeted information that can be used for expanding resources, improving product quality, and assuring environmentally sound operations. For example, equipment such as reactors and pipelines can be operated with high efficiency and safety with improved chemical and physical sensors for corrosion and hydrocarbon detection. At the interface between chemical engineering and multiphase flow physics, ``multi-scale'' phenomena such as catalysis and heat flow benefit from new approaches to sensing and data modeling. We are combining chemically selective micro-cantilevers, fiber optic sensing, and acoustic monitoring with statistical data fusion approaches to maximize control information. Miniaturized analyzers represent a special opportunity, including the nanotech-based quantum cascade laser systems for mid-infrared spectroscopy. Specific examples for use of these new micro-systems include rapid monocyclic aromatic molecule identification and measurement under ambient conditions at weight ppb levels. We see promise from emerging materials and devices based on nanotechnology, which can one day be available at modest cost for impact in existing operations. Controlled surface energies and emerging chemical probes hold the promise for reduction in greenhouse gas emissions for current fuels and future transportation and energy technologies.

Aerosol chemical physics

International Nuclear Information System (INIS)

Marlow, W.H.

1982-01-01

A classification of the research fields in the chemical physics of aerosol microparticles is given. The emphasis lies on the microphysics of isolated particles and clusters and on physical transformations and thermodynamics. (LDN)

Chemical Abundances and Physical Parameters of H II Regions in the Magellanic Clouds

Science.gov (United States)

Reyes, R. E. C.

The chemical abundances and physical parameters of H II regions are important pa rameters to determine in order to understand how stars and galaxies evolve. The Magellanic Clouds offer us a unique oportunity to persue such studies in low metallicity galaxies. In this contribution we present the results of the photoionization modeling of 5 H II regions in each of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) sys tems. Optical data were collected from the literature, complemented by our own observa tions (Carlos Reyes et al. 1998), including UV spectra from the new IUE data ban k and infrared fluxes from the IRAS satellite. The chemical abundances of He, C, N, O, Ne, S, Ar and physical parameters like the densities, the ionized masses, the luminosities, the ionization temperatures , the filling factor and optical depth are determined. A comparison of the abundances of these HII regions with those of typical planetary nebulae and supergiants stars is also presented.

Toxic effects of the interaction of titanium dioxide nanoparticles with chemicals or physical factors

Science.gov (United States)

Liu, Kui; Lin, Xialu; Zhao, Jinshun

2013-01-01

Due to their chemical stability and nonallergic, nonirritant, and ultraviolet protective properties, titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in industries such as electronics, optics, and material sciences, as well as architecture, medicine, and pharmacology. However, increasing concerns have been raised in regards to its ecotoxicity and toxicity on the aquatic environment as well as to humans. Although insights have been gained into the effects of TiO2 NPs on susceptible biological systems, there is still much ground to be covered, particularly in respect of our knowledge of the effects of the interaction of TiO2 NPs with other chemicals or physical factors. Studies suggest that interactions of TiO2 NPs with other chemicals or physical factors may result in an increase in toxicity or adverse effects. This review highlights recent progress in the study of the interactive effects of TiO2 NPs with other chemicals or physical factors. PMID:23901269

Synthesis and optical spectroscopy of (hetero)-nanocrystals: An exciting interplay between Chemistry and Physics

NARCIS (Netherlands)

Groeneveld, E.

2012-01-01

This thesis describes the synthesis and study of the optical properties of various colloidal semiconductor (hetero)nanocrystals ((H)NCs). Before the experimental results are discussed in detail, the essential theoretical background on the chemical and physical aspects of this work is provided in

Size dependent optical characteristics of chemically deposited

Indian Academy of Sciences (India)

Keywords. Thin film; ZnS; CBD method; optical properties. Abstract. ZnS thin films of different thicknesses were prepared by chemical bath deposition using thiourea and zinc acetate as S2- and Zn2+ source. The effect of film thickness on the optical and structural properties was studied. The optical absorption studies in the ...

Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

Czech Academy of Sciences Publication Activity Database

Pospíšilová, M.; Kuncová, Gabriela; Trögl, J.

2015-01-01

Roč. 15, č. 10 (2015), s. 25208-25259 ISSN 1424-8220 Institutional support: RVO:67985858 Keywords : fiber-optic sensor * chemical sensors * enzymatic sensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 2.033, year: 2015

LIDAR Measurements of the Vertical Distribution of Aerosol Optical and Physical Properties over Central Asia

Science.gov (United States)

The vertical structure of aerosol optical and physical properties was measured by Lidar in Eastern Kyrgyzstan, Central Asia, from June 2008 to May 2009. Lidar measurements were supplemented with surface-based measurements of PM2.5 and PM10 mass and chemical ...

Structural, optical and electrical properties of chemically deposited ...

Indian Academy of Sciences (India)

Structural, optical and electrical properties of chemically deposited nonstoichiometric copper ... One of these compounds, CuInSe2, with its optical absorption .... is clear from SEM images that the number of grains goes on increasing with the ...

Optical fiber cable chemical stripping fixture

Science.gov (United States)

Kolasinski, John R. (Inventor); Coleman, Alexander M. (Inventor)

1995-01-01

An elongated fixture handle member is connected to a fixture body member with both members having interconnecting longitudinal central axial bores for the passage of an optical cable therethrough. The axial bore of the fixture body member, however, terminates in a shoulder stop for the outer end of a jacket of the optical cable covering both an optical fiber and a coating therefor, with an axial bore of reduced diameter continuing from the shoulder stop forward for a predetermined desired length to the outer end of the fixture body member. A subsequent insertion of the fixture body member including the above optical fiber elements into a chemical stripping solution results in a softening of the exposed external coating thereat which permits easy removal thereof from the optical fiber while leaving a desired length coated fiber intact within the fixture body member.

Laboratory of Chemical Physics

Data.gov (United States)

Federal Laboratory Consortium — Current research in the Laboratory of Chemical Physics is primarily concerned with experimental, theoretical, and computational problems in the structure, dynamics,...

The optical model in atomic physics

International Nuclear Information System (INIS)

McCarthy, I.E.

1978-01-01

The optical model for electron scattering on atoms has quite a short history in comparison with nuclear physics. The main reason for this is that there were insufficient data. Angular distribution for elastic and some inelastic scattering have now been measured for the atoms which exist in gaseous form at reasonable temperatures, inert gases, hydrogen, alkalies and mercury being the main ones out in. The author shows that the optical model makes sense in atomic physics by considering its theory and recent history. (orig./AH) [de

Physics through the 1990s: Atomic, molecular, and optical physics

International Nuclear Information System (INIS)

1986-01-01

This report was prepared by the Panel on Atomic, Molecular, and Optical Physics of the Physics Survey Committee in response to its charge to describe the field, to characterize the recent advances, and to identify the current frontiers of research. Some of the areas discussed are: atomic structure, atomic dynamics, accelerator-based atomic physics, molecular photoionization and electron-molecule scattering, astrophysics, laser spectroscopy, atmospheric physics, plasma physics, and applications

Characterizing physical properties and heterogeneous chemistry of single particles in air using optical trapping-Raman spectroscopy

Science.gov (United States)

Gong, Z.; Wang, C.; Pan, Y. L.; Videen, G.

2017-12-01

Heterogeneous reactions of solid particles in a gaseous environment are of increasing interest; however, most of the heterogeneous chemistry studies of airborne solids were conducted on particle ensembles. A close examination on the heterogeneous chemistry between single particles and gaseous-environment species is the key to elucidate the fundamental mechanisms of hydroscopic growth, cloud nuclei condensation, secondary aerosol formation, etc., and reduce the uncertainty of models in radiative forcing, climate change, and atmospheric chemistry. We demonstrate an optical trapping-Raman spectroscopy (OT-RS) system to study the heterogeneous chemistry of the solid particles in air at single-particle level. Compared to other single-particle techniques, optical trapping offers a non-invasive, flexible, and stable method to isolate single solid particle from substrates. Benefited from two counter-propagating hollow beams, the optical trapping configuration is adaptive to trap a variety of particles with different materials from inorganic substitution (carbon nanotubes, silica, etc.) to organic, dye-doped polymers and bioaerosols (spores, pollen, etc.), with different optical properties from transparent to strongly absorbing, with different sizes from sub-micrometers to tens of microns, or with distinct morphologies from loosely packed nanotubes to microspheres and irregular pollen grains. The particles in the optical trap may stay unchanged, surface degraded, or optically fragmented according to different laser intensity, and their physical and chemical properties are characterized by the Raman spectra and imaging system simultaneously. The Raman spectra is able to distinguish the chemical compositions of different particles, while the synchronized imaging system can resolve their physical properties (sizes, shapes, morphologies, etc.). The temporal behavior of the trapped particles also can be monitored by the OT-RS system at an indefinite time with a resolution from

Optical investigation of niobium properties: Electrical- and physical constants

Science.gov (United States)

Singh, Nageshwar; Deo, M. N.; Roy, S. B.

2017-08-01

In this paper, we report optical (reflectance) measurements and investigations of optical properties of electropolished (EP), buffered chemical polished (BCP), and as-received (AR) from vendor niobium (Nb) samples typically used for fabrication of superconducting radio frequency (SCRF) cavities. Optical conductivity (σ(0), approximated near zero frequency) of EP (σ(0) ∼ 9 × 103 Ω-1 cm-1) sample is one order of magnitude higher than that of BCP (σ(0) ∼ 7 × 102 Ω-1 cm-1) and AR (σ(0) ∼ 3 × 102 Ω-1 cm-1) niobium samples. Furthermore, physical constants of electropolished Nb-SCRF materials such as concentration of conduction electrons (∼ 1.8 × 1022 electrons/cm3), average velocity (∼ 5.9 × 107 cm/s) of the electrons on the Fermi surface, and mean free path (∼ 0.53 nm) were also found to be considerably higher than that of the BCP and the AR samples. The depth of electric field penetration (in low frequency region) in the electropolished Nb sample (∼ 80 nm) is appreciably lesser than the BCP (∼ 450 nm) and the AR (∼ 400 nm) samples.

International Conference on Laser Physics and Quantum Optics

CERN Document Server

Xie, Shengwu; Zhu, Shi-Yao; Scully, Marlan

2000-01-01

Since the advent of the laser about 40 years ago, the field of laser physics and quantum optics have evolved into a major discipline. The early studies included the optical coherence theory and the semiclassical and quantum mechanical theories of the laser. More recently many new and interesting effects have been predicted. These include the role of coherent atomic effects in lasing without inversion and electromagnetically induced transparency, atom optics, laser cooling and trapping, teleportation, the single-atom micromaser and its role in quantum measurement theory, to name a few. The International Conference on Laser Physics and Quantum Optics was held in Shanghai from August 25 to August 28, 1999, to discuss these and many other exciting developments in laser physics and quantum optics. The international character of the conference was manifested by the fact that scientists from over 13 countries participated and lectured at the conference. There were four keynote lectures delivered by Nobel laureate Wi...

Applications of fiber optics in physical protection

International Nuclear Information System (INIS)

Buckle, T.H.

1994-03-01

The purpose of this NUREG is to provide technical information useful for the development of fiber-optic communications and intrusion detection subsystems relevant to physical protection. There are major sections on fiber-optic technology and applications. Other topics include fiber-optic system components and systems engineering. This document also contains a glossary, a list of standards and specifications, and a list of fiber-optic equipment vendors

Physically Unclonable Cryptographic Primitives by Chemical Vapor Deposition of Layered MoS2.

Science.gov (United States)

Alharbi, Abdullah; Armstrong, Darren; Alharbi, Somayah; Shahrjerdi, Davood

2017-12-26

Physically unclonable cryptographic primitives are promising for securing the rapidly growing number of electronic devices. Here, we introduce physically unclonable primitives from layered molybdenum disulfide (MoS 2 ) by leveraging the natural randomness of their island growth during chemical vapor deposition (CVD). We synthesize a MoS 2 monolayer film covered with speckles of multilayer islands, where the growth process is engineered for an optimal speckle density. Using the Clark-Evans test, we confirm that the distribution of islands on the film exhibits complete spatial randomness, hence indicating the growth of multilayer speckles is a spatial Poisson process. Such a property is highly desirable for constructing unpredictable cryptographic primitives. The security primitive is an array of 2048 pixels fabricated from this film. The complex structure of the pixels makes the physical duplication of the array impossible (i.e., physically unclonable). A unique optical response is generated by applying an optical stimulus to the structure. The basis for this unique response is the dependence of the photoemission on the number of MoS 2 layers, which by design is random throughout the film. Using a threshold value for the photoemission, we convert the optical response into binary cryptographic keys. We show that the proper selection of this threshold is crucial for maximizing combination randomness and that the optimal value of the threshold is linked directly to the growth process. This study reveals an opportunity for generating robust and versatile security primitives from layered transition metal dichalcogenides.

Physical meaning of the optical reference geometry

International Nuclear Information System (INIS)

Abramowicz, M.A.

1990-09-01

I show that contrary to a popular misconception the optical reference geometry, introduced a few years ago as a formally possible metric of a 3-space corresponding to a static spacetime, is quite satisfactory also from the physical point of view. The optical reference geometry has a clear physical meaning, as it may be constructed experimentally by measuring light round travel time between static observers. Distances and directions in the optical reference geometry are more strongly connected to experiment than distances and directions in the widely used directly projected metric (discussed e.g. in Landau and Lifshitz textbook. In addition, the optical reference geometry is more natural and convenient than the directly projected one in application to dynamics. In the optical geometry dynamical behaviour of matter is described by concepts and formulae identical to those well known in Newtonian dynamics on a given two dimensional (curved) surface. (author). 22 refs

Optical MEMS for chemical analysis and biomedicine

CERN Document Server

Jiang, Hongrui

2016-01-01

This book describes the current state of optical MEMS in chemical and biomedical analysis and brings together current trends and highlights topics representing the most exciting progress in recent years in the field.

Optical, physical and chemical properties of aerosols transported to a coastal site in the western Mediterranean: a focus on primary marine aerosols

Directory of Open Access Journals (Sweden)

M. Claeys

2017-06-01

Full Text Available As part of the ChArMEx-ADRIMED campaign (summer 2013, ground-based in situ observations were conducted at the Ersa site (northern tip of Corsica; 533 m a.s.l. to characterise the optical, physical and chemical properties of aerosols. During the observation period, a major influence of primary marine aerosols was detected (22–26 June, with a mass concentration reaching up to 6.5 µg m−3 and representing more than 40 % of the total PM10 mass concentration. Its relatively low ratio of chloride to sodium (average of 0.57 indicates a fairly aged sea salt aerosol at Ersa. In this work, an original data set, obtained from online real-time instruments (ATOFMS, PILS-IC has been used to characterise the ageing of primary marine aerosols (PMAs. During this PMA period, the mixing of fresh and aged PMAs was found to originate from both local and regional (Gulf of Lion emissions, according to local wind measurements and FLEXPART back trajectories. Two different aerosol regimes have been identified: a dust outbreak (dust originating from Algeria/Tunisia, and a pollution period with aerosols originating from eastern Europe, which includes anthropogenic and biomass burning sources (BBP. The optical, physical and chemical properties of the observed aerosols, as well as their local shortwave (SW direct radiative effect (DRE in clear-sky conditions, are compared for these three periods in order to assess the importance of the direct radiative impact of PMAs compared to other sources above the western Mediterranean Basin. As expected, AERONET retrievals indicate a relatively low local SW DRF during the PMA period with mean values of −11 ± 4 at the surface and −8 ± 3 W m−2 at the top of the atmosphere (TOA. In comparison, our results indicate that the dust outbreak observed at our site during the campaign, although of moderate intensity (AOD of 0.3–0.4 at 440 nm and column-integrated SSA of 0.90–0.95, induced a local

A decade of optical physics in a small liberal arts college.

Science.gov (United States)

Taylor, J H

1969-01-01

The development of a program of optical physics research involving undergraduates is described. Some of the problems encountered by college teachers trying to maintain a research program are discussed. A Physics Tower that has been uniquely designed for work in optical physics is discussed in considerable detail. The optical physics facilities include two domes for housing telescopes, one dome housing an optical tracker, two domes housing a coelostat system, dark tunnel, sun telescope, and spectroscopic and radiometric laboratories. Radiation from the sun can be directed throughout the Physics Tower.

Optical, physical and chemical characteristics of Australian continental aerosols: results from a field experiment

Directory of Open Access Journals (Sweden)

M. Radhi

2010-07-01

Full Text Available Mineral dust is one of the major components of the world's aerosol mix, having a number of impacts within the Earth system. However, the climate forcing impact of mineral dust is currently poorly constrained, with even its sign uncertain. As Australian deserts are more reddish than those in the Northern Hemisphere, it is important to better understand the physical, chemical and optical properties of this important aerosol. We have investigated the properties of Australian desert dust at a site in SW Queensland, which is strongly influenced by both dust and biomass burning aerosol.

Three years of ground-based monitoring of spectral optical thickness has provided a statistical picture of gross aerosol properties. The aerosol optical depth data showed a clear though moderate seasonal cycle with an annual mean of 0.06 ± 0.03. The Angstrom coefficient showed a stronger cycle, indicating the influence of the winter-spring burning season in Australia's north. AERONET size distributions showed a generally bimodal character, with the coarse mode assumed to be mineral dust, and the fine mode a mixture of fine dust, biomass burning and marine biogenic material.

In November 2006 we undertook a field campaign which collected 4 sets of size-resolved aerosol samples for laboratory analysis – ion beam analysis and ion chromatography. Ion beam analysis was used to determine the elemental composition of all filter samples, although elemental ratios were considered the most reliable output. Scatter plots showed that Fe, Al and Ti were well correlated with Si, and Co reasonably well correlated with Si, with the Fe/Al ratio somewhat higher than values reported from Northern Hemisphere sites (as expected. Scatter plots for Ca, Mn and K against Si showed clear evidence of a second population, which in some cases could be identified with a particular sample day or size fraction. These data may be used to attempt to build a signature of soil in this

Fiber Optic Sensors for Health Monitoring of Morphing Airframes. Part 2; Chemical Sensing Using Optical Fibers with Bragg Gratings

Science.gov (United States)

Wood, Karen; Brown, Timothy; Rogowski, Robert; Jensen, Brian

2000-01-01

Part 1 of this two part series described the fabrication and calibration of Bragg gratings written into a single mode optical fiber for use in strain and temperature monitoring. Part 2 of the series describes the use of identical fibers and additional multimode fibers, both with and without Bragg gratings, to perform near infrared spectroscopy. The demodulation system being developed at NASA Langley Research Center currently requires the use of a single mode optical fiber. Attempts to use this single mode fiber for spectroscopic analysis are problematic given its small core diameter, resulting in low signal intensity. Nonetheless, we have conducted a preliminary investigation using a single mode fiber in conjunction with an infrared spectrometer to obtain spectra of a high-performance epoxy resin system. Spectra were obtained using single mode fibers that contained Bragg gratings; however, the peaks of interest were barely discernible above the noise. The goal of this research is to provide a multipurpose sensor in a single optical fiber capable of measuring a variety of chemical and physical properties.

Perspective: Reaches of chemical physics in biology

Science.gov (United States)

Gruebele, Martin; Thirumalai, D.

2013-01-01

Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry. PMID:24089712

Perspective: Reaches of chemical physics in biology.

Science.gov (United States)

Gruebele, Martin; Thirumalai, D

2013-09-28

Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry.

Increased Surface Roughness in Polydimethylsiloxane Films by Physical and Chemical Methods

Directory of Open Access Journals (Sweden)

Jorge Nicolás Cabrera

2017-08-01

Full Text Available Two methods, the first physical and the other chemical, were investigated to modify the surface roughness of polydimethylsiloxane (PDMS films. The physical method consisted of dispersing multi-walled carbon nanotubes (MWCNTs and magnetic cobalt ferrites (CoFe2O4 prior to thermal cross-linking, and curing the composite system in the presence of a uniform magnetic field H. The chemical method was based on exposing the films to bromine vapours and then UV-irradiating. The characterizing techniques included scanning electron microscopy (SEM, energy-dispersive spectroscopy (EDS, Fourier transform infrared (FTIR spectroscopy, optical microscopy, atomic force microscopy (AFM and magnetic force microscopy (MFM. The surface roughness was quantitatively analyzed by AFM. In the physical method, the random dispersion of MWCNTs (1% w/w and magnetic nanoparticles (2% w/w generated a roughness increase of about 200% (with respect to PDMS films without any treatment, but that change was 400% for films cured in the presence of H perpendicular to the surface. SEM, AFM and MFM showed that the magnetic particles always remained attached to the carbon nanotubes, and the effect on the roughness was interpreted as being due to a rupture of dispersion randomness and a possible induction of structuring in the direction of H. In the chemical method, the increase in roughness was even greater (1000%. Wells were generated with surface areas that were close to 100 μm2 and depths of up to 500 nm. The observations of AFM images and FTIR spectra were in agreement with the hypothesis of etching by Br radicals generated by UV on the polymer chains. Both methods induced important changes in the surface roughness (the chemical method generated the greatest changes due to the formation of surface wells, which are of great importance in superficial technological processes.

Quantum mechanical tunneling in chemical physics

CERN Document Server

Nakamura, Hiroki

2016-01-01

Quantum mechanical tunneling plays important roles in a wide range of natural sciences, from nuclear and solid-state physics to proton transfer and chemical reactions in chemistry and biology. Responding to the need for further understanding of multidimensional tunneling, the authors have recently developed practical methods that can be applied to multidimensional systems. Quantum Mechanical Tunneling in Chemical Physics presents basic theories, as well as original ones developed by the authors. It also provides methodologies and numerical applications to real molecular systems. The book offers information so readers can understand the basic concepts and dynamics of multidimensional tunneling phenomena and use the described methods for various molecular spectroscopy and chemical dynamics problems. The text focuses on three tunneling phenomena: (1) energy splitting, or tunneling splitting, in symmetric double well potential, (2) decay of metastable state through tunneling, and (3) tunneling effects in chemical...

Advances in atomic, molecular, and optical physics

CERN Document Server

Bederson, Benjamin

1993-01-01

Advances in Atomic, Molecular, and Optical Physics, established in 1965, continues its tradition of excellence with Volume 32, published in honor of Founding Editor Sir David Bates upon his retirement as editorof the series. This volume presents reviews of topics related to the applications of atomic and molecular physics to atmospheric physics and astrophysics.

The physics of thin film optical spectra an introduction

CERN Document Server

Stenzel, Olaf

2016-01-01

The book bridges the gap between fundamental physics courses (such as optics, electrodynamics, quantum mechanics and solid state physics) and highly specialized literature on the spectroscopy, design, and application of optical thin film coatings. Basic knowledge from the above-mentioned courses is therefore presumed. Starting from fundamental physics, the book enables the reader derive the theory of optical coatings and to apply it to practically important spectroscopic problems. Both classical and semiclassical approaches are included. Examples describe the full range of classical optical coatings in various spectral regions as well as highly specialized new topics such as rugate filters and resonant grating waveguide structures.The second edition has been updated and extended with respect to probing matter in different spectral regions, homogenous and inhomogeneous line broadening mechanisms and the Fresnel formula for the effect of planar interfaces.

Comparison of Chemical and Physical-chemical Wastewater Discoloring Methods

Directory of Open Access Journals (Sweden)

Durašević, V.

2007-11-01

Full Text Available Today's chemical and physical-chemical wastewater discoloration methods do not completely meet demands regarding degree of discoloration. In this paper discoloration was performed using Fenton (FeSO4 . 7 H2O + H2O2 + H2SO4 and Fenton-like (FeCl3 . 6 H2O + H2O2 + HCOOH chemical methods and physical-chemical method of coagulation/flocculation (using poly-electrolyte (POEL combining anion active coagulant (modified poly-acrylamides and cationic flocculant (product of nitrogen compounds in combination with adsorption on activated carbon. Suitability of aforementioned methods was investigated on reactive and acid dyes, regarding their most common use in the textile industry. Also, investigations on dyes of different chromogen (anthraquinone, phthalocyanine, azo and xanthene were carried out in order to determine the importance of molecular spatial structure. Oxidative effect of Fenton and Fenton-like reagents resulted in decomposition of colored chromogen and high degree of discoloration. However, the problem is the inability of adding POEL in stechiometrical ratio (also present in physical-chemical methods, when the phenomenon of overdosing coagulants occurs in order to obtain a higher degree of discoloration, creating a potential danger of burdening water with POEL. Input and output water quality was controlled through spectrophotometric measurements and standard biological parameters. In addition, part of the investigations concerned industrial wastewaters obtained from dyeing cotton materials using reactive dye (C. I. Reactive Blue 19, a process that demands the use of vast amounts of electrolytes. Also, investigations of industrial wastewaters was labeled as a crucial step carried out in order to avoid serious misassumptions and false conclusions, which may arise if dyeing processes are only simulated in the laboratory.

Physical-chemical property based sequence motifs and methods regarding same

Science.gov (United States)

Braun, Werner [Friendswood, TX; Mathura, Venkatarajan S [Sarasota, FL; Schein, Catherine H [Friendswood, TX

2008-09-09

A data analysis system, program, and/or method, e.g., a data mining/data exploration method, using physical-chemical property motifs. For example, a sequence database may be searched for identifying segments thereof having physical-chemical properties similar to the physical-chemical property motifs.

40 CFR 716.50 - Reporting physical and chemical properties.

Science.gov (United States)

2010-07-01

... chemical properties. Studies of physical and chemical properties must be reported under this subpart if... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reporting physical and chemical...

Integrated optical sensors for the chemical domain

NARCIS (Netherlands)

Lambeck, Paul

2006-01-01

During the last decade there has been a rapidly growing interest in integrated optical (IO) sensors, expecially because many of them principally allow for sensitive, real time, label-free-on-site measurements of the concentration of (bio-)chemical species. This review aims at giving an overview of

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

1999-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics.

Optical and magneto-optical properties of zinc-oxide nanostructures grown by the low-temperature chemical route

Science.gov (United States)

Willander, M.; Alnoor, H.; Savoyant, A.; Adam, Rania E.; Nur, O.

2018-02-01

We demonstrate that the low temperature synthesis chemical route can be utilized to control the functionality of zinc oxide (ZnO) nanoparticles (NPs) and nanorods (NRs) for optical and magneto-optical performance. Different structural, optical, electro- and magneto-optical results will be displayed and analyzed. In the first part, we show how high quality ZnO NPs can be efficient for photodegradation using ultra-violet radiation. In the second part we will present our recent results on the control of the core defects in cobalt doped ZnO NR. Here and by using electron paramagnetic resonance (EPR) measurements, the substitution of Co2+ ions in the ZnO NRs crystal is shown. The relation between the incorporation and core defects concentration will be discussed. The findings give access to the magnetic anisotropy of ZnO NRs grown by the low temperature chemical route and can lead to demonstrate room temperature ferromagnetism in nanostructures with potential for different device applications.

Engineered Barrier System: Physical and Chemical Environment

International Nuclear Information System (INIS)

Dixon, P.

2004-01-01

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

Optical and Physical Properties of ONP Deinked Pulp

Directory of Open Access Journals (Sweden)

Iman Akbarpoor

2012-01-01

Full Text Available Enzymes are protein molecules with complex structures that accelerate the biochemical reactions. Activity of these chemical compounds is accomplished at limited range of pH, temperature and concentration. In this study, the effects of different concentrations of cellulose enzyme were investigated on deinking of old newsprint. Old newsprint (ONP was repulped at 5% consistency for 10 minutes in disintegrator with total revolution number of 26500. Enzymatic treatments of recycled ONP pulp were done under constant conditions (10% consistency,treatment time of 15 minutes, pH range of 5-5.5 at different cellulose concentrations of 0.025, 0.05, 0.1 and 0.2% (based on oven-dry waste paper. The optical and physical properties of the standard paper (60g/m2 made at different concentrations of cellulose were evaluated in comparison with control pulp (untreated ONP pulp with cellulase. Overall, the results achieved by comparison the optical properties of the paper produced indicated that using cellulase in deinking of ONP led to increase the brightness and the yellowness and decrease the opacity. The brightness was improved to a maximum level of 47.5 ISO %, but the yellowness was decreased to a minimum level of 11.3 ISO %, while the brightness reduced and the yellowness increased at higher concentrations than 0.05% cellulase. The highest opacity of 99.3 ISO % was achieved using 0.1% cellulase even higher than control pulp. The results gained by comparison the physical properties of the paper showed that using cellulase resulted in decrease of paper calliper, air resistance and density and improve the freeness of pulp

Advances in chemical physics advances in liquid crystals

CERN Document Server

Prigogine, Ilya; Vij, Jagdish K

2009-01-01

Prigogine and Rice's highly acclaimed series, Advances in Chemical Physics, provides a forum for critical, authoritative reviews of current topics in every area of chemical physics. Edited by J.K. Vij, this volume focuses on recent advances in liquid crystals with significant, up-to-date chapters authored by internationally recognized researchers in the field.

Atomic, molecular and optical physics

International Nuclear Information System (INIS)

1990-01-01

This is related to the actual situation and perspectives of atomic, molecular and optical physics in Brazil. It gives a general overview of the most important research groups in the above mentioned areas. It discusses as well, the future trends of Brazilian universities and the financing of these groups. (A.C.A.S.)

Quantum Dot Semiconductor Optical Amplifiers - Physics and Applications

DEFF Research Database (Denmark)

Berg, Tommy Winther

2004-01-01

This thesis describes the physics and applications of quantum dot semiconductor optical amplifiers based on numerical simulations. These devices possess a number of unique properties compared with other types of semiconductor amplifiers, which should allow enhanced performance of semiconductor...... respects is comparable to those of fiber amplifiers. The possibility of inverting the optically active states to a large degree is essential in order to achieve this performance. Optical signal processing through cross gain modulation and four wave mixing is modeled and described. For both approaches...... and QW devices and to experiments on quantum dot amplifiers. These comparisons outline the qualitative differences between the different types of amplifiers. In all cases focus is put on the physical processes responsible the differences....

Engineered Barrier System: Physical and Chemical Environment

Energy Technology Data Exchange (ETDEWEB)

P. Dixon

2004-04-26

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

Atomic physics and quantum optics using superconducting circuits.

Science.gov (United States)

You, J Q; Nori, Franco

2011-06-29

Superconducting circuits based on Josephson junctions exhibit macroscopic quantum coherence and can behave like artificial atoms. Recent technological advances have made it possible to implement atomic-physics and quantum-optics experiments on a chip using these artificial atoms. This Review presents a brief overview of the progress achieved so far in this rapidly advancing field. We not only discuss phenomena analogous to those in atomic physics and quantum optics with natural atoms, but also highlight those not occurring in natural atoms. In addition, we summarize several prospective directions in this emerging interdisciplinary field.

Physical and chemical characteristics of fibrous peat

Science.gov (United States)

Sutejo, Yulindasari; Saggaff, Anis; Rahayu, Wiwik; Hanafiah

2017-11-01

Banyuasin is one of the regency in South Sumatera which has an area of 200.000 Ha of peat land. Peat soil are characterized by high compressibility parameters and low initial shear strength. Block sampling method was used to obtain undisturbed sample. The results of this paper describe the characteristics of peat soil from physical and chemical testing. The physical and chemical characteristics of peat include water content (ω), specific gravity (Gs), Acidity (pH), unit weight (γ), and ignition loss tests. SEM and EDS test was done to determine the differences in fiber content and to analyze chemical elements of the specimen. The average results ω, Gs, and pH are 263.538 %, 1.847, and 3.353. Peat is classified in H4 (by Von Post). The results of organic content (OC), ash content (AC), and fiber content (FC) are found 78.693 %, 21.310 %, and 73.703 %. From the results of physical and chemical tests, the peat in Banyuasin is classified as fibrous peat. All the results of the characteristics and classification of fibrous peat compared with published data were close.

Atoms, molecules and optical physics

CERN Document Server

Hertel, Ingolf V

2015-01-01

This is the first volume of textbooks on atomic, molecular and optical physics, aiming at a comprehensive presentation of this highly productive branch of modern physics as an indispensable basis for many areas in physics and chemistry as well as in state of the art bio- and material-sciences. It primarily addresses advanced students (including PhD students), but in a number of selected subject areas the reader is lead up to the frontiers of present research. Thus even the active scientist is addressed. This volume 1 provides the canonical knowledge in atomic physics together with basics of modern spectroscopy. Starting from the fundamentals of quantum physics, the reader is familiarized in well structured chapters step by step with the most important phenomena, models and measuring techniques. The emphasis is always on the experiment and its interpretation, while the necessary theory is introduced from this perspective in a compact and occasionally somewhat heuristic manner, easy to follow even for beginner...

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

International Nuclear Information System (INIS)

Jarek, R.

2004-01-01

The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

International Nuclear Information System (INIS)

G.H. Nieder-Westermann

2005-01-01

The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports

Physical-layer network coding in coherent optical OFDM systems.

Science.gov (United States)

Guan, Xun; Chan, Chun-Kit

2015-04-20

We present the first experimental demonstration and characterization of the application of optical physical-layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share the same link so as to enhance system throughput, while individual OFDM frames can be recovered with digital signal processing at the destined node.

Progress in Nano-Electro-Optics VII Chemical, Biological, and Nanophotonic Technologies for Nano-Optical Devices and Systems

CERN Document Server

Ohtsu, Motoichi

2010-01-01

This book focuses on chemical and nanophotonic technology to be used to develop novel nano-optical devices and systems. It begins with temperature- and photo-induced phase transition of ferromagnetic materials. Further topics include: energy transfer in artificial photosynthesis, homoepitaxial multiple quantum wells in ZnO, near-field photochemical etching and nanophotonic devices based on a nonadiabatic process and optical near-field energy transfer, respectively and polarization control in the optical near-field for optical information security. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

The physical-optics approximation and its application to light backscattering by hexagonal ice crystals

International Nuclear Information System (INIS)

Borovoi, A.; Konoshonkin, A.; Kustova, N.

2014-01-01

The physical-optics approximation in the problem of light scattering by large particles is so defined that it includes the classical physical optics concerning the problem of light penetration through a large aperture in an opaque screen. In the second part of the paper, the problem of light backscattering by quasi-horizontally oriented atmospheric ice crystals is considered where conformity between the physical-optics and geometric-optics approximations is discussed. The differential scattering cross section as well as the polarization elements of the Mueller matrix for quasi-horizontally oriented hexagonal ice plates has been calculated in the physical-optics approximation for the case of vertically pointing lidars. - Highlights: • The physical-optics Mueller matrix is a smoothed geometric-optics counterpart. • Backscatter by partially oriented hexagonal ice plates has been calculated. • Depolarization ratio for partially oriented hexagonal ice plates is negligible

Chemical and physical structures of proteinoids and related polyamino acids

Science.gov (United States)

Mita, Hajime; Kuwahara, Yusuke; Nomoto, Shinya

Studies of polyamino acid formation pathways in the prebiotic condition are important for the study of the origins of life. Several pathways of prebiotic polyamino acid formation have been reported. Heating of monoammonium malate [1] and heating of amino acids in molten urea [2] are important pathways of the prebiotic peptide formation. The former case, globular structure called proteinoid microsphere is formed in aqueous conditions. The later case, polyamino acids are formed from unrestricted amino acid species. Heating of aqueous aspargine is also interesting pathway for the prebiotic polyamino acid formation, because polyamino acid formation proceeds in aqueous condition [3]. In this study, we analyzed the chemical structure of the proteinoids and related polyamino acids formed in the above three pathways using with mass spectrometer. In addition, their physical structures are analyzed by the electron and optical microscopes, in order to determine the self-organization abilities. We discuss the relation between the chemical and the physical structures for the origins of life. References [1] Harada, K., J. Org. Chem., 24, 1662 (1959), Fox, S. W., Harada, K., and Kendrick, J., Science, 129, 1221 (1959). [2] Terasaki, M., Nomoto, S., Mita, H., and Shimoyama, A., Chem. Lett., 480 (2002), Mita, H., Nomoto, S., Terasaki, M., Shimoyama, A., and Yamamoto, Y., Int. J. Astrobiol., 4, 145 (2005). [3] Kovacs, K and Nagy, H., Nature, 190, 531 (1961), Munegumi, T., Tanikawa, N., Mita, H. and Harada, K., Viva Origino, 22, 109 (1994).

Life Science-Related Physics Laboratory on Geometrical Optics

Science.gov (United States)

Edwards, T. H.; And Others

1975-01-01

Describes a laboratory experiment on geometrical optics designed for life science majors in a noncalculus introductory physics course. The thin lens equation is used by the students to calculate the focal length of the lens necessary to correct a myopic condition in an optical bench simulation of a human eye. (Author/MLH)

XXI symposium Modern chemical physics. Tuapse 2009. Summaries of reports

International Nuclear Information System (INIS)

2009-01-01

The materials of the XXI symposium Modern chemical physics, Tuapse 2009 (25 September - 6 October, 2009) are presented. Scientific program includes lectures, presentations and poster sessions on photochemistry and radiation chemistry, elementary processes, homogeneous and heterogeneous catalysis. The problems of chemical reaction kinetics, quantum chemistry, chemical spectroscopy, macromolecular chemistry are discussed. Topics of chemical physics of surface, nanochemistry, nanophysics and nanotechnology are treated [ru

Quantum Optics, Diffraction Theory, and Elementary Particle Physics

CERN Multimedia

CERN. Geneva

2009-01-01

Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

Physical Chemistry Chemical Kinetics and Reaction Mechanism

CERN Document Server

Trimm, Harold H

2011-01-01

Physical chemistry covers diverse topics, from biochemistry to materials properties to the development of quantum computers. Physical chemistry applies physics and math to problems that interest chemists, biologists, and engineers. Physical chemists use theoretical constructs and mathematical computations to understand chemical properties and describe the behavior of molecular and condensed matter. Their work involves manipulations of data as well as materials. Physical chemistry entails extensive work with sophisticated instrumentation and equipment as well as state-of-the-art computers. This

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

R. Jarek

2004-11-23

The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

G.H. Nieder-Westermann

2005-04-07

The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

Engineered Barrier System: Physical and Chemical Environment Model

International Nuclear Information System (INIS)

Jolley, D. M.; Jarek, R.; Mariner, P.

2004-01-01

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2001-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2000-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2002-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered include related applied areas, such as atmospheric science, astrophysics, surface physics and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Optical system to study temperature influenced chemical and mechanical changes to the PCD structure

CSIR Research Space (South Africa)

Masina, B

2010-09-01

Full Text Available .csir.co.za An optical system to study temperature influenced chemical and mechanical changes to the PCD structure Bathusile Masina and Andrew Forbes SAIP 2010: Applied and Industrial Physics 1 October 2010 © CSIR 2010 Slide 2 It is acknowledged that temperature... re (K el vi n) Minutes © CSIR 2010 Slide 15 -0.008 -0.006 -0.004 -0.002 0.000 0.002 0.004 0.006 0.008 0.4 0.5 0.6 0.7 0.8 0.9 1.0 N or m al iz ed T em pe ra tu re r (m) At steady state we predict a gradient temperature...

Physical and chemical stability of proflavine contrast agent solutions for early detection of oral cancer.

Science.gov (United States)

Kawedia, Jitesh D; Zhang, Yan-Ping; Myers, Alan L; Richards-Kortum, Rebecca R; Kramer, Mark A; Gillenwater, Ann M; Culotta, Kirk S

2016-02-01

Proflavine hemisulfate solution is a fluorescence contrast agent to visualize cell nuclei using high-resolution optical imaging devices such as the high-resolution microendoscope. These devices provide real-time imaging to distinguish between normal versus neoplastic tissue. These images could be helpful for early screening of oral cancer and its precursors and to determine accurate margins of malignant tissue for ablative surgery. Extemporaneous preparation of proflavine solution for these diagnostic procedures requires preparation in batches and long-term storage to improve compounding efficiency in the pharmacy. However, there is a paucity of long-term stability data for proflavine contrast solutions. The physical and chemical stability of 0.01% (10 mg/100 ml) proflavine hemisulfate solutions prepared in sterile water was determined following storage at refrigeration (4-8℃) and room temperature (23℃). Concentrations of proflavine were measured at predetermined time points up to 12 months using a validated stability-indicating high-performance liquid chromatography method. Proflavine solutions stored under refrigeration were physically and chemically stable for at least 12 months with concentrations ranging from 95% to 105% compared to initial concentration. However, in solutions stored at room temperature increased turbidity and particulates were observed in some of the tested vials at 9 months and 12 months with peak particle count reaching 17-fold increase compared to baseline. Solutions stored at room temperature were chemically stable up to six months (94-105%). Proflavine solutions at concentration of 0.01% were chemically and physically stable for at least 12 months under refrigeration. The solution was chemically stable for six months when stored at room temperature. We recommend long-term storage of proflavine solutions under refrigeration prior to diagnostic procedure. © The Author(s) 2014.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

1998-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material as well as detailed descriptions of important recent developments.

Chemical analysis of steel by optical emission spectrometry

International Nuclear Information System (INIS)

Hayakawa, M.O.; Kajita, T.; Jeszensky, G.

1981-01-01

The development of the chemical analysis for special steels by optical emission spectrometry direct reading method with computer, at the Siderurgica N.S. Aparecida S.A. is presented. Results are presented for the low alloy steels and high speed steel. Also, the contribution of this method to the special steel preparation is commented. (Author) [pt

Engineered Barrier System: Physical and Chemical Environment Model

Energy Technology Data Exchange (ETDEWEB)

D. M. Jolley; R. Jarek; P. Mariner

2004-02-09

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

Chemical physics of electroactive materials: concluding remarks.

Science.gov (United States)

Rutland, Mark W

2017-07-01

It is an honour to be charged with providing the concluding remarks for a Faraday Discussion. As many have remarked before, it is nonetheless a prodigious task, and what follows is necessarily a personal, and probably perverse, view of a watershed event in the Chemical Physics of Electroactive materials. The spirit of the conference was captured in a single sentence during the meeting itself."It is the nexus between rheology, electrochemistry, colloid science and energy storage". The current scientific climate is increasingly dominated by a limited number of global challenges, and there is thus a tendency for research to resemble a football match played by 6 year olds, where everyone on the field chases the (funding) ball instead of playing to their "discipline". It is thus reassuring to see how the application of rigorous chemical physics is leading to ingenious new solutions for both energy storage and harvesting, via, for example, nanoactuation, electrowetting, ionic materials and nanoplasmonics. In fact, the same language of chemical physics allows seamless transition between applications as diverse as mechano-electric energy generation, active moisture transport and plasmonic shutters - even the origins of life were addressed in the context of electro-autocatalysis!

Chemical and Physical Interactions of Martian Surface Material

Science.gov (United States)

Bishop, J. L.

1999-09-01

A model of alteration and maturation of the Martian surface material is described involving both chemical and physical interactions. Physical processes involve distribution and mixing of the fine-grained soil particles across the surface and into the atmosphere. Chemical processes include reaction of sulfate, salt and oxidizing components of the soil particles; these agents in the soils deposited on rocks will chew through the rock minerals forming coatings and will bind surface soils together to form duricrust deposits. Formation of crystalline iron oxide/oxyhydroxide minerals through hydrothermal processes and of poorly crystalline and amorphous phases through palagonitic processes both contribute to formation of the soil particles. Chemical and physical alteration of these soil minerals and phases contribute to producing the chemical, magnetic and spectroscopic character of the Martian soil as observed by Mars Pathfinder and Mars Global Surveyor. Minerals such as maghemite/magnetite and jarosite/alunite have been observed in terrestrial volcanic soils near steam vents and may be important components of the Martian surface material. The spectroscopic properties of several terrestrial volcanic soils containing these minerals have been analyzed and evaluated in terms of the spectroscopic character of the surface material on Mars.

Chemical and Physical Soil Restoration in Mining Areas

Science.gov (United States)

Teresinha Gonçalves Bizuti, Denise; de Marchi Soares, Thaís; Roberti Alves de Almeida, Danilo; Sartorio, Simone Daniela; Casagrande, José Carlos; Santin Brancalion, Pedro Henrique

2017-04-01

The current trend of ecological restoration is to address the recovery of degraded areas by ecosystemic way, overcoming the rehabilitation process. In this sense, the topsoil and other complementary techniques in mining areas plays an important role in soil recovery. The aim of this study was to contextualize the soil improvement, with the use of topsoil through chemical and physical attributes, relative to secondary succession areas in restoration, as well as in reference ecosystems (natural forest). Eighteen areas were evaluated, six in forest restoration process, six native forests and six just mining areas. The areas were sampled in the depths of 0-5, 5-10, 10-20, 20-40 and 40-60 cm. Chemical indicators measured were parameters of soil fertility and texture, macroporosity, microporosity, density and total porosity as physical parameters. The forest restoration using topsoil was effective in triggering a process of soil recovery, promoting, in seven years, chemical and physical characteristics similar to those of the reference ecosystem.

Optical and Chemical Characterization of Aerosols Produced from Cooked Meats

Science.gov (United States)

Niedziela, R. F.; Foreman, E.; Blanc, L. E.

2011-12-01

Cooking processes can release a variety compounds into the air immediately above a cooking surface. The distribution of compounds will largely depend on the type of food that is being processed and the temperatures at which the food is prepared. High temperatures release compounds from foods like meats and carry them away from the preparation surface into cooler regions where condensation into particles can occur. Aerosols formed in this manner can impact air quality, particularly in urban areas where the amount of food preparation is high. Reported here are the results of laboratory experiments designed to optically and chemically characterize aerosols derived from cooking several types of meats including ground beef, salmon, chicken, and pork both in an inert atmosphere and in synthetic air. The laboratory-generated aerosols are studied using a laminar flow cell that is configured to accommodate simultaneous optical characterization in the mid-infrared and collection of particles for subsequent chemical analysis by gas chromatography. Preliminary optical results in the visible and ultra-violet will also be presented.

Chemical/Light-Powered Hybrid Micromotors with "On-the-Fly" Optical Brakes.

Science.gov (United States)

Chen, Chuanrui; Tang, Songsong; Teymourian, Hazhir; Karshalev, Emil; Zhang, Fangyu; Li, Jinxing; Mou, Fangzhi; Liang, Yuyan; Guan, Jianguo; Wang, Joseph

2018-07-02

Hybrid micromotors capable of both chemically powered propulsion and fuel-free light-driven actuation and offering built-in optical brakes for chemical propulsion are described. The new hybrid micromotors are designed by combining photocatalytic TiO 2 and catalytic Pt surfaces into a Janus microparticle. The chemical reactions on the different surfaces of the Janus particle hybrid micromotor can be tailored by using chemical or light stimuli that generate counteracting propulsion forces on the catalytic Pt and photocatalytic TiO 2 sides. Such modulation of the surface chemistry on a single micromotor leads to switchable propulsion modes and reversal of the direction of motion that reflect the tuning of the local ion concentration and hence the dominant propulsion force. An intermediate Au layer (under the Pt surface) plays an important role in determining the propulsion mechanism and operation of the hybrid motor. The built-in optical braking system allows "on-the-fly" control of the chemical propulsion through a photocatalytic reaction on the TiO 2 side to counterbalance the chemical propulsion force generated on the Pt side. The adaptive dual operation of these chemical/light hybrid micromotors, associated with such control of the surface chemistry, holds considerable promise for designing smart nanomachines that autonomously reconfigure their propulsion mode for various on-demand operations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of ozone gas processing on physical and chemical properties ...

African Journals Online (AJOL)

Purpose: To investigate the effects of ozone treatment on chemical and physical properties of wheat (Triticum aestivum L.) gluten, glutenin and gliadin. Methods: Wheat proteins isolated from wheat flour were treated with ozone gas. The physical and chemical properties of gluten proteins were investigated after treatment ...

Biological, chemical and medical physics

International Nuclear Information System (INIS)

1990-01-01

This is an overview of the actual situation in Brazil, concerning three important areas of physics: biological, chemical and medical. It gives a brief historical of research in these areas. It talks as well, about perspectives and financing. It contains many tables with the main research groups in activity in Brazilian institutions. (A.C.A.S.)

Mimicking Bone - Chemical and Physical Challenges

Directory of Open Access Journals (Sweden)

Sophie C Cox

2014-08-01

Full Text Available It is known that chemical and physical features of bone contribute to its functionality, reactivity and mechanical performance. This fundamental rationale underpins the author’s research strategy. This paper presents a summary of efforts to fabricate a synthetic structure, referred to as a scaffold, that both chemically and physical emulates the intricate structure of bone. An understanding of key features of bone tissue that contribute to its remarkable properties is presented as a background to this work. Novel work aimed at improving the understanding of the synthesis of a ceramic biomaterial, namely hydroxyapatite, that is chemically similar to bone mineral is discussed. A case study involving the manufacture of porous scaffolds by 3D printing is also presented. In summary, this article highlights a number of on-going challenges that multidisciplinary tissue engineers aim to solve to get one step closer to mimicking bone, which clinically could improve the quality of life for millions of people worldwide.    Photo credit: By Doc. RNDr. Josef Reischig, CSc. (Author's archive [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0], via Wikimedia Commons

Optically pumped semiconductor lasers for atomic and molecular physics

Science.gov (United States)

Burd, S.; Leibfried, D.; Wilson, A. C.; Wineland, D. J.

2015-03-01

Experiments in atomic, molecular and optical (AMO) physics rely on lasers at many different wavelengths and with varying requirements on spectral linewidth, power and intensity stability. Optically pumped semiconductor lasers (OPSLs), when combined with nonlinear frequency conversion, can potentially replace many of the laser systems currently in use. We are developing a source for laser cooling and spectroscopy of Mg+ ions at 280 nm, based on a frequency quadrupled OPSL with the gain chip fabricated at the ORC at Tampere Univ. of Technology, Finland. This OPSL system could serve as a prototype for many other sources used in atomic and molecular physics.

Springer handbook of atomic, molecular, and optical physics

CERN Document Server

Cassar, Mark M

2006-01-01

This Springer Handbook of Atomic, Molecular, and Optical Physics comprises a comprehensive reference source that unifies the entire fields of atomic, molecular, and optical (AMO) physics, assembling the principal ideas, techniques and results of the field from atomic spectroscopy to applications in comets. Its 92 chapters are written by over 100 authors, all leaders in their respective disciplines. Carefully edited to ensure uniform coverage and style, with extensive cross references, and acting as a guide to the primary research literature, it is both a source of information and an inspiration for graduate students and other researchers new to the field. Relevant diagrams, graphs, and tables of data are provided throughout the text. Substantially updated and expanded since the 1996 edition and published in conjunction with the 2005 World Year of Physics (commemorating Einstein’s 1905 "miracle year"), it contains several entirely new chapters covering current areas of great research interest, such as Bose �...

Impact of Rangeland Degradation on Soil Physical, Chemical

African Journals Online (AJOL)

major threats to enhance a sustainable pastoral-livestock production in Ethiopia. ... overall negative impact on the soil physical and chemical characteristics, demanding ... chemical properties (Gemedo et al., 2006) as well as the rangeland .... parameters such as life forms (annuals and perennials), plant forms (woody plant,.

Chemical tapering of polymer optical fiber

Directory of Open Access Journals (Sweden)

Abdul Rashid Affa Rozana

2017-01-01

Full Text Available Polymer optical fibers (POFs have significant advantages over numerous sensing applications. The key element in developing sensor is by removing the cladding of the fiber. The use of organic solvent is one of the methods to create tapered POF in order to expose the core region. In this study, the etching chemicals involved is acetone, methyl isobutyl ketone (MIBK, and acetone-methanol mixture. The POF is immersed in 100%, 80%, and 50% of acetone and MIBK dilution. In addition, the mixture of acetone and methanol is also used for POF etching by the ratio 2:1 of the volume. Acetone has shown to be the most reactive solvent towards POF due to its fastest etching rate compared to MIBK and acetone-methanol mixture. The POF is immersed and lifted from the solution for a specific time, depending on the power loss properties for the purpose of producing unclad POF. In comparison to silica fiber optic, the advantages of POF in terms of its simple technique and easy handling enable it to produce unclad POF without damaging the core region. The surface roughness of the POF is investigated under the microscope after being immersed into different solvent. This method of chemical tapering of POF can be used as the fundamental technique for sensor development. Next, the unclad fiber is immersed into ethanol solutions in order to determine the reaction of unclad POF towards its surrounding. The findings show that this particular sensor is sensitive towards concentration changes ranging between 10 wt% to 50 wt%.

Chemical tapering of polymer optical fiber

Science.gov (United States)

Rashid, Affa Rozana Abdul; Afiqah Nasution, Amna; Hanim Suranin, Aisyah; Athirah Taib, Nur; Maisarah Mukhtar, Wan; Dasuki, Karsono Ahmad; Annuar Ehsan, Abang

2017-11-01

Polymer optical fibers (POFs) have significant advantages over numerous sensing applications. The key element in developing sensor is by removing the cladding of the fiber. The use of organic solvent is one of the methods to create tapered POF in order to expose the core region. In this study, the etching chemicals involved is acetone, methyl isobutyl ketone (MIBK), and acetone-methanol mixture. The POF is immersed in 100%, 80%, and 50% of acetone and MIBK dilution. In addition, the mixture of acetone and methanol is also used for POF etching by the ratio 2:1 of the volume. Acetone has shown to be the most reactive solvent towards POF due to its fastest etching rate compared to MIBK and acetone-methanol mixture. The POF is immersed and lifted from the solution for a specific time, depending on the power loss properties for the purpose of producing unclad POF. In comparison to silica fiber optic, the advantages of POF in terms of its simple technique and easy handling enable it to produce unclad POF without damaging the core region. The surface roughness of the POF is investigated under the microscope after being immersed into different solvent. This method of chemical tapering of POF can be used as the fundamental technique for sensor development. Next, the unclad fiber is immersed into ethanol solutions in order to determine the reaction of unclad POF towards its surrounding. The findings show that this particular sensor is sensitive towards concentration changes ranging between 10 wt% to 50 wt%.

Radon: Chemical and physical states of radon progeny. Final technical report

International Nuclear Information System (INIS)

Castleman, A.W. Jr.

1996-01-01

The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

Generalized statistical criterion for distinguishing random optical groupings from physical multiple systems

International Nuclear Information System (INIS)

Anosova, Z.P.

1988-01-01

A statistical criterion is proposed for distinguishing between random and physical groupings of stars and galaxies. The criterion is applied to nearby wide multiple stars, triplets of galaxies in the list of Karachentsev, Karachentseva, and Shcherbanovskii, and double galaxies in the list of Dahari, in which the principal components are Seyfert galaxies. Systems that are almost certainly physical, probably physical, probably optical, and almost certainly optical are identified. The limiting difference between the radial velocities of the components of physical multiple galaxies is estimated

Optical fibers and their instrumentation applications

International Nuclear Information System (INIS)

Boisde, Gilbert.

1982-09-01

The use of optical fibers in instrumentation requires a knowledge of their properties as ''photon carriers'' and ''sensors''. New instrumentation design implies a satisfactory evaluation of the entire measurement circuit, including the emitter, optical coupling, optical fiber with its physical, spectral and physico-chemical properties, the connector, receiver, signal amplifier and data processing system. An example, is provided of the development of a new technique in physico-chemical instrumentation: remote spectrophotometry. Three aspects are discussed: 1) industrial measurement in ''process control'' using the Telephot (R), 2) remote spectral measurement, 3) opical multiplexing. This is followed by a review of various optical fiber based instrumental techniques used in the fields of medicine (endoscopy, fluorothermy, laser surgery), solar energy industrial applications subject to electrical disturbances (position sensors, strain measurements), and in physico-chemical analysis (fluorescence, redox potentials) [fr

Advances in imaging and electron physics optics of charged particle analyzers

CERN Document Server

Hawkes, Peter W

2011-01-01

Advances in Imaging and Electron Physics merges two long-running serials--Advances in Electronics and Electron Physics and Advances in Optical and Electron Microscopy. This series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. * Contributions from leading international scholars and industry experts * Discusses hot topic areas and presents current and future research trends * Invaluable reference and guide for physicists, engineers and mathematicians.

Advances in imaging and electron physics optics of charged particle analyzers

CERN Document Server

Hawkes, Peter W

2011-01-01

Advances in Imaging and Electron Physics merges two long-running serials--Advances in Electronics and Electron Physics and Advances in Optical and Electron Microscopy. This series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Contributions from leading international scholars and industry experts Discusses hot topic areas and presents current and future research trends Invaluable reference and guide for physicists, engineers and mathematicians.

[Construction of chemical information database based on optical structure recognition technique].

Science.gov (United States)

Lv, C Y; Li, M N; Zhang, L R; Liu, Z M

2018-04-18

To create a protocol that could be used to construct chemical information database from scientific literature quickly and automatically. Scientific literature, patents and technical reports from different chemical disciplines were collected and stored in PDF format as fundamental datasets. Chemical structures were transformed from published documents and images to machine-readable data by using the name conversion technology and optical structure recognition tool CLiDE. In the process of molecular structure information extraction, Markush structures were enumerated into well-defined monomer molecules by means of QueryTools in molecule editor ChemDraw. Document management software EndNote X8 was applied to acquire bibliographical references involving title, author, journal and year of publication. Text mining toolkit ChemDataExtractor was adopted to retrieve information that could be used to populate structured chemical database from figures, tables, and textual paragraphs. After this step, detailed manual revision and annotation were conducted in order to ensure the accuracy and completeness of the data. In addition to the literature data, computing simulation platform Pipeline Pilot 7.5 was utilized to calculate the physical and chemical properties and predict molecular attributes. Furthermore, open database ChEMBL was linked to fetch known bioactivities, such as indications and targets. After information extraction and data expansion, five separate metadata files were generated, including molecular structure data file, molecular information, bibliographical references, predictable attributes and known bioactivities. Canonical simplified molecular input line entry specification as primary key, metadata files were associated through common key nodes including molecular number and PDF number to construct an integrated chemical information database. A reasonable construction protocol of chemical information database was created successfully. A total of 174 research

Optically transparent glass micro-actuator fabricated by femtosecond laser exposure and chemical etching

NARCIS (Netherlands)

Lenssen, B.L.K.; Bellouard, Y.

2012-01-01

Femtosecond laser manufacturing combined with chemical etching has recently emerged as a flexible platform for fabricating three-dimensional devices and integrated optical elements in glass substrates. Here, we demonstrate an optically transparent micro-actuator fabricated out of a single piece of

Evaluation of physical and chemical characteristics of xanthan gums

Directory of Open Access Journals (Sweden)

Claire Tondo Vendruscolo

2007-03-01

Full Text Available This work aimed at evaluating the physical and chemical characteristics of the xanthan produced by Xanthomonas arboricola pv pruni strain 115, and at comparing it with two xanthans obtained from commercial sources – Kelzan e Roeper. The analyzed xanthans showed specified patterns mentioned in the literature, except for low pyruvic acid content in the xanthan produced by strain 115, low monovalent salt content in the Roeper sample and high divalent salt content in both commercial samples. The low pyruvic acid content in the xanthan produced by X. arboricola pv pruni 115 did not affect the aqueous solution viscosity. Thus, the xanthan produced by strain 115 show physical and chemical characteristics that allow its use by the petroleum industry, as well as, in food, pharmaceutical and cosmetics products. Xanthomonas arboricola pv pruni. Xanthan. Physical and chemical characteristics.

Plasma flow reactor for steady state monitoring of physical and chemical processes at high temperatures.

Science.gov (United States)

Koroglu, Batikan; Mehl, Marco; Armstrong, Michael R; Crowhurst, Jonathan C; Weisz, David G; Zaug, Joseph M; Dai, Zurong; Radousky, Harry B; Chernov, Alex; Ramon, Erick; Stavrou, Elissaios; Knight, Kim; Fabris, Andrea L; Cappelli, Mark A; Rose, Timothy P

2017-09-01

We present the development of a steady state plasma flow reactor to investigate gas phase physical and chemical processes that occur at high temperature (1000 flow injector). We have modeled the system using computational fluid dynamics simulations that are bounded by measured temperatures. In situ line-of-sight optical emission and absorption spectroscopy have been used to determine the structures and concentrations of molecules formed during rapid cooling of reactants after they pass through the plasma. Emission spectroscopy also enables us to determine the temperatures at which these dynamic processes occur. A sample collection probe inserted from the open end of the reactor is used to collect condensed materials and analyze them ex situ using electron microscopy. The preliminary results of two separate investigations involving the condensation of metal oxides and chemical kinetics of high-temperature gas reactions are discussed.

XIII symposium. Modern chemical physics. Theses of reports

International Nuclear Information System (INIS)

2001-01-01

Materials of the thirteenth symposium on modern chemical physics are presented. They represent different directions of development of this field of knowledge, such as synthesis, structure, properties of metal-polymer compositions, radiation-chemical investigations in nanotechnology, problems of supercritical chemistry, calculations of kinetic parameters of catalytic systems [ru

Reflector antenna analysis using physical optics on Graphics Processing Units

DEFF Research Database (Denmark)

Borries, Oscar Peter; Sørensen, Hans Henrik Brandenborg; Dammann, Bernd

2014-01-01

The Physical Optics approximation is a widely used asymptotic method for calculating the scattering from electrically large bodies. It requires significant computational work and little memory, and is thus well suited for application on a Graphics Processing Unit. Here, we investigate the perform......The Physical Optics approximation is a widely used asymptotic method for calculating the scattering from electrically large bodies. It requires significant computational work and little memory, and is thus well suited for application on a Graphics Processing Unit. Here, we investigate...

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2005-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered include related applied areas, such as atmospheric science, astrophysics, surface physics and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments. · Reviews timely fields of atomic physics · Articles written by world leaders in those fields · In depth review of the subject with relevant literature · Suitable for researchers in other fields · Only book series of this kind.

RADIANCE AND PHOTON NOISE: Imaging in geometrical optics, physical optics, quantum optics and radiology.

Science.gov (United States)

Barrett, Harrison H; Myers, Kyle J; Caucci, Luca

2014-08-17

A fundamental way of describing a photon-limited imaging system is in terms of a Poisson random process in spatial, angular and wavelength variables. The mean of this random process is the spectral radiance. The principle of conservation of radiance then allows a full characterization of the noise in the image (conditional on viewing a specified object). To elucidate these connections, we first review the definitions and basic properties of radiance as defined in terms of geometrical optics, radiology, physical optics and quantum optics. The propagation and conservation laws for radiance in each of these domains are reviewed. Then we distinguish four categories of imaging detectors that all respond in some way to the incident radiance, including the new category of photon-processing detectors. The relation between the radiance and the statistical properties of the detector output is discussed and related to task-based measures of image quality and the information content of a single detected photon.

Nonlinear optical and atomic systems at the interface of physics and mathematics

CERN Document Server

Garreau, Jean-Claude

2015-01-01

Focusing on the interface between mathematics and physics, this book offers an introduction to the physics, the mathematics, and the numerical simulation of nonlinear systems in optics and atomic physics. The text covers a wide spectrum of current research on the subject, which is  an extremely active field in physics and mathematical physics, with a very broad range of implications, both for fundamental science and technological applications: light propagation in microstructured optical fibers, Bose-Einstein condensates, disordered systems, and the newly emerging field of nonlinear quantum mechanics.   Accessible to PhD students, this book will also be of interest to post-doctoral researchers and seasoned academics.

Monitoring remediation of trichloroethylene using a chemical fiber optic sensor: Field studies

International Nuclear Information System (INIS)

Colston, B.W.; Brown, S.B.; Langry, K.; Daley, P.; Milanovich, F.P.

1994-06-01

Current US Department of Energy (DOE) policy requires characterization and subsequent remediation of areas where trichloroethylene (TCE) has been discharged into the soil and groundwater. Technology that allows trace quantities of this contaminant to be measured in situ on a continuous basis is needed. Fiber optic chemical sensors offer a promising low cost solution. Field tests of such a fiber optic chemical sensor for TCE have recently been completed. Sensors have been used to measure TCE contamination at Savannah River Site (SRS) and Lawrence Livermore National Laboratory Site 300 (S300) in the groundwater and vadose zones. Both sites are currently undergoing remediation processes

A fibre optic chemical sensor for the detection of cocaine

Science.gov (United States)

Nguyen, T. Hien; Sun, Tong; Grattan, Kenneth T. V.; Hardwick, S. A.

2010-09-01

A fibre-optic chemical sensor for the detection of cocaine has been developed, based on a molecularly imprinted polymer (MIP) containing a fluorescein moiety as the signalling group. The fluorescent MIP was formed and covalently attached to the distal end of an optical fibre. The sensor exhibited an increase in fluorescence intensity in response to cocaine in the concentration range of 0 - 500 μM in aqueous acetonitrile mixtures with good reproducibility over 24 h. Selectivity for cocaine over others drugs has also been demonstrated.

Frontiers in Chemical Physics

Energy Technology Data Exchange (ETDEWEB)

Bowlan, Pamela Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-02

These are slides dealing with frontiers in chemical physics. The following topics are covered: Time resolving chemistry with ultrashort pulses in the 0.1-40 THz spectral range; Example: Mid-infrared absorption spectrum of the intermediate state CH₂OO; Tracking reaction dynamics through changes in the spectra; Single-shot measurement of the mid-IR absorption dynamics; Applying 2D coherent mid-IR spectroscopy to learn more about transition states; Time resolving chemical reactions at a catalysis using mid-IR and THz pulses; Studying topological insulators requires a surface sensitive probe; Nonlinear phonon dynamics in Bi₂Se₃; THz-pump, SHG-probe as a surface sensitive coherent 2D spectroscopy; Nanometer and femtosecond spatiotemporal resolution mid-IR spectroscopy; Coherent two-dimensional THz/mid-IR spectroscopy with 10nm spatial resolution; Pervoskite oxides as catalysts; Functionalized graphene for catalysis; Single-shot spatiotemporal measurements; Spatiotemporal pulse measurement; Intense, broad-band THz/mid-IR generation with organic crystals.

Physical and Chemical Properties of Soils under Contrasting Land ...

African Journals Online (AJOL)

Physical and Chemical Properties of Soils under Contrasting Land Use ... the aim of understanding the response of the soil to different management practices over time. ... The soil chemical properties studied were soil pH, organic carbon, total ...

Study on Physical Properties and Chemical Composition of Some Myanmar Gems

International Nuclear Information System (INIS)

Kyaw Myint Htoo; Tun Khin; Sein Htoon

2004-05-01

Physical properties of some Myanmar gems were studied by using refractometer, dichroscope, polariscope, SG test, UV test and microscope. Then, chemical composition were investigated by XRF-technique. After that, gem identification, evaluation, colour improvement were studied according to these physical properties and chemical composition

Optical characterization of In{sub 2}S{sub 3} solar cell buffer layers grown by chemical bath and physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Trigo, J.F.; Asenjo, B.; Herrero, J.; Gutierrez, M.T. [Department of Energy, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain)

2008-09-15

In this paper, we study the optical properties of indium sulfide thin films to establish the best conditions to obtain a good solar cell buffer layer. The In{sub 2}S{sub 3} buffer layers have been prepared by chemical bath deposition (CBD) and thermal evaporation (PVD). Optical behavior differences have been found between CBD and PVD In{sub 2}S{sub 3} thin films that have been explained as due to structural, morphological and compositional differences observed in the films prepared by both methods. The resultant refractive index difference has to be attributed to the lower density of the CBD films, which can be related to the presence of oxygen. Its higher refractive index makes PVD film better suited to reduce overall reflectance in a typical CIGS solar cell. (author)

Chemical and physical quality examination: Chapter 4

Science.gov (United States)

Lamar, William

1953-01-01

In a balanced study of water pollution or water utilization a thorough chemical and physical examination is essential. This provides a basis for evaluation of stream conditions, their effects and remedies. Such information is of value to the general public who are interested in clean water and in recreation, hunting, fishing, and wildlife; to the chemist, engineer, hydrologist, and industrialist who are interested in the domestic and industrial use of water both as raw material and as a vehicle for the removal of waste materials; to the sanitarian who is interested in healthful conditions; and to the biologist who is interested in maintaining a favorable biological balance. For every living plant and animal there are optimum physical and chemical conditions and these characteristics are determining factors in the aquatic life of any body of water.

Optical sensors and their applications for probing biological systems

DEFF Research Database (Denmark)

Palanco, Marta Espina

There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant and mammal......There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant...... of a trapped cell. The project could provide new insights into the desired biosensor for future membrane-protein cell studies....

Atomic, molecular, and optical physics charged particles

CERN Document Server

Dunning, F B

1995-01-01

With this volume, Methods of Experimental Physics becomes Experimental Methods in the Physical Sciences, a name change which reflects the evolution of todays science. This volume is the first of three which will provide a comprehensive treatment of the key experimental methods of atomic, molecular, and optical physics; the three volumes as a set will form an excellent experimental handbook for the field. The wide availability of tunable lasers in the pastseveral years has revolutionized the field and lead to the introduction of many new experimental methods that are covered in these volumes. Traditional methods are also included to ensure that the volumes will be a complete reference source for the field.

Physical and chemical characterization of bioaerosols - Implications for nucleation processes

Science.gov (United States)

Ariya, P. A.; Sun, J.; Eltouny, N. A.; Hudson, E. D.; Hayes, C. T.; Kos, G.

The importance of organic compounds in the oxidative capacity of the atmosphere, and as cloud condensation and ice-forming nuclei, has been recognized for several decades. Organic compounds comprise a significant fraction of the suspended matter mass, leading to local (e.g. toxicity, health hazards) and global (e.g. climate change) impacts. The state of knowledge of the physical chemistry of organic aerosols has increased during the last few decades. However, due to their complex chemistry and the multifaceted processes in which they are involved, the importance of organic aerosols, particularly bioaerosols, in driving physical and chemical atmospheric processes is still very uncertain and poorly understood. Factors such as solubility, surface tension, chemical impurities, volatility, morphology, contact angle, deliquescence, wettability, and the oxidation process are pivotal in the understanding of the activation processes of cloud droplets, and their chemical structures, solubilities and even the molecular configuration of the microbial outer membrane, all impact ice and cloud nucleation processes in the atmosphere. The aim of this review paper is to assess the current state of knowledge regarding chemical and physical characterization of bioaerosols with a focus on those properties important in nucleation processes. We herein discuss the potential importance (or lack thereof) of physical and chemical properties of bioaerosols and illustrate how the knowledge of these properties can be employed to study nucleation processes using a modeling exercise. We also outline a list of major uncertainties due to a lack of understanding of the processes involved or lack of available data. We will also discuss key issues of atmospheric significance deserving future physical chemistry research in the fields of bioaerosol characterization and microphysics, as well as bioaerosol modeling. These fundamental questions are to be addressed prior to any definite conclusions on the

Can disorder act as a chemical pressure? An optical study of the Hubbard model

Science.gov (United States)

Barman, H.; Laad, M. S.; Hassan, S. R.

2018-05-01

The optical properties have been studied using the dynamical mean-field theory on a disordered Hubbard model. Despite the fact that disorder turns a metal to an insulator in high dimensional correlated materials, we notice that it can enhance certain metallic behavior as if a chemical pressure is applied to the system resulting in an increase of the effective lattice bandwidth (BW). We study optical properties in such a scenario and compare results with experiments where the BW is changed through isovalent chemical substitution (keeping electron filling unaltered) and obtain remarkable similarities vindicating our claim. We also make the point that these similarities differ from some other forms of BW tuned optical effects.

Physical- chemical changes in irradiated sodium alginate algimar

International Nuclear Information System (INIS)

Rapado Paneque, Manuel; Alazanes, Sonia; Sainz Vidal, Dianelys; Wandrey, Christine

2003-01-01

The effect of gamma radiation on the physical-chemical properties of sodium alginate Algimar has been investigated. dilution viscometric, densitometry FTIR spectroscopy served to identify modifications. Decreasing intrinsic, viscosities clearly revealed chain cleavage for both solid alginate indicate that chain degradation occurs without significant change of the chemical structure, The obtained results have practical implication change of the chemical structure. The obtained results have practical implication in the field of radiation modification and sterilization of sodium alginate used for microcapsule formation

Physical and chemical changes induced by 70 MeV carbon ions in polyvinylidene difluoride (PVDF) polymer

International Nuclear Information System (INIS)

Virk, H.S.; Chandi, P.S.; Srivastava, A.K.

2001-01-01

Physical and chemical changes induced by 70 MeV carbon ions ( 12 C 5+ ) have been investigated in bulk polyvinylidene fluoride (PVDF) polymer. The induced changes have been studied with respect to their optical, chemical and structural response using UV-visible, FTIR and XRD techniques. The ion fluences ranging from 2.5x10 11 to 9x10 13 ions cm -2 have been used to study the irradiation effects. It has been observed that at the fluence of 9x10 13 ions cm -2 the PVDF sample became brittle and practically it was not possible to handle it for any further measurements. The recorded UV-visible spectra show that the optical absorption increases with increasing fluence, indicating maximum absorption at 200 nm. An interesting feature of UV-visible spectra is that dips change into peaks and vice versa with increase of fluence. In the FTIR spectra, development of new peaks at 1714 and 3692 cm -1 along with disappearance of peaks at 2363 and 3025 cm -1 and shifting of peak at 2984-2974 cm -1 have been observed due to high energy irradiation, indicating the chemical changes induced by 12 C 5+ . The diffraction pattern of PVDF indicates that this polymer is semi-crystalline in nature; a large decrease in the diffraction intensity indicates decrease in crystallinity. Increase in crystallite size has also been observed due to heavy ion irradiation

Physical and Chemical Factors Affecting Contaminant Hydrology in Cold Environments

National Research Council Canada - National Science Library

Grant, Steven

2000-01-01

.... The chemical thermodynamics of geochemical solutions below 0 deg C is then reviewed. Particular attention is placed on the physical-chemical properties of ice and liquid water at subzero temperatures...

Applications of Ionic Liquids for the Development of Optical Chemical Sensors and Biosensors.

Science.gov (United States)

Muginova, Svetlana V; Myasnikova, Dina A; Kazarian, Sergei G; Shekhovtsova, Tatiana N

2017-01-01

This paper reviews the primary literature reporting the use of ionic liquids (ILs) in optical sensing technologies. The optical chemical sensors that have been developed with the assistance of ILs are classified according to the type of resultant material. Key aspects of applying ILs in such sensors are revealed and discussed. They include using ILs as solvents for the synthesis of sensor matrix materials; additives in polymer matrices; matrix materials; modifiers of the surfaces; and multifunctional sensor components. The operational principles, design, texture, and analytical characteristics of the offered sensors for determining CO 2 , O 2 , metal ions, CN - , and various organic compounds are critically discussed. The key advantages and disadvantages of using ILs in optical sensing technologies are defined. Finally, the applicability of the described materials for chemical analysis is evaluated, and possibilities for their further modernization are outlined.

IOTA (Integrable Optics Test Accelerator): facility and experimental beam physics program

Science.gov (United States)

Antipov, S.; Broemmelsiek, D.; Bruhwiler, D.; Edstrom, D.; Harms, E.; Lebedev, V.; Leibfritz, J.; Nagaitsev, S.; Park, C. S.; Piekarz, H.; Piot, P.; Prebys, E.; Romanov, A.; Ruan, J.; Sen, T.; Stancari, G.; Thangaraj, C.; Thurman-Keup, R.; Valishev, A.; Shiltsev, V.

2017-03-01

The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. The physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

IOTA (Integrable Optics Test Accelerator): Facility and experimental beam physics program

International Nuclear Information System (INIS)

Antipov, Sergei; Broemmelsiek, Daniel; Bruhwiler, David; Edstrom, Dean; Harms, Elvin

2017-01-01

The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. Finally, the physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

Physical and chemical stability of pemetrexed in infusion solutions.

Science.gov (United States)

Zhang, Yanping; Trissel, Lawrence A

2006-06-01

Pemetrexed is a multitargeted, antifolate, antineoplastic agent that is indicated for single-agent use in locally advanced or metastatic non-small-cell lung cancer after prior chemotherapy and in combination with cisplatin for the treatment of malignant pleural mesothelioma not treatable by surgery. Currently, there is no information on the long-term stability of pemetrexed beyond 24 hours. To evaluate the longer-term physical and chemical stability of pemetrexed 2, 10, and 20 mg/mL in polyvinyl chloride (PVC) bags of dextrose 5% injection and NaCl 0.9% injection. Triplicate samples of pemetrexed were prepared in the concentrations and infusion solutions required. Evaluations for physical and chemical stability were performed initially and over 2 days at 23 degrees C protected from light and exposed to fluorescent light, and over 31 days of storage at 4 degrees C protected from light. Physical stability was assessed using turbidimetric and particulate measurement as well as visual observation. Chemical stability was evaluated by HPLC. All pemetrexed solutions remained chemically stable, with little or no loss of pemetrexed over 2 days at 23 degrees C, protected from light and exposed to fluorescent light, and over 31 days of storage at 4 degrees C, protected from light. The room temperature samples were physically stable throughout the 48 hour test period. However, pemetrexed admixtures developed large numbers of microparticulates during refrigerated storage exceeding 24 hours. Pemetrexed is chemically stable for 2 days at room temperature and 31 days refrigerated in dextrose 5% injection and NaCl 0.9% injection. However, substantial numbers of microparticulates may form in pemetrexed diluted in the infusion solutions in PVC bags, especially during longer periods of refrigerated storage. Limiting the refrigerated storage period to the manufacturer-recommended 24 hours will limit particulate formation.

Photobiology of Symbiodinium revisited: bio-physical and bio-optical signatures

Science.gov (United States)

Hennige, S. J.; Suggett, D. J.; Warner, M. E.; McDougall, K. E.; Smith, D. J.

2009-03-01

Light is often the most abundant resource within the nutrient-poor waters surrounding coral reefs. Consequently, zooxanthellae ( Symbiodinium spp.) must continually photoacclimate to optimise productivity and ensure coral success. In situ coral photobiology is becoming dominated by routine assessments using state-of-the-art non-invasive bio-optical or chlorophyll a fluorescence (bio-physical) techniques. Multiple genetic types of Symbiodinium are now known to exist; however, little focus has been given as to how these types differ in terms of characteristics that are observable using these techniques. Therefore, this investigation aimed to revisit and expand upon a pivotal study by Iglesias-Prieto and Trench (1994) by comparing the photoacclimation characteristics of different Symbiodinium types based on their bio-physical (chlorophyll a fluorescence, reaction centre counts) and bio-optical (optical absorption, pigment concentrations) ‘signatures’. Signatures described here are unique to Symbiodinium type and describe phenotypic responses to set conditions, and hence are not suitable to describe taxonomic structure of in hospite Symbiodinium communities. In this study, eight Symbiodinium types from clades and sub-clades (A-B, F) were grown under two PFDs (Photon Flux Density) and examined. The photoacclimation response by Symbiodinium was highly variable between algal types for all bio-physical and for many bio-optical measurements; however, a general preference to modifying reaction centre content over effective antennae-absorption was observed. Certain bio-optically derived patterns, such as light absorption, were independent of algal type and, when considered per photosystem, were matched by reaction centre stoichiometry. Only by better understanding genotypic and phenotypic variability between Symbiodinium types can future studies account for the relative taxonomic and physiological contribution by Symbiodinium to coral acclimation.

Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

International Nuclear Information System (INIS)

Gonzalez, G.; Krishnan, B.; Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K.; Shaji, S.

2011-01-01

Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

2011-08-31

Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

Electron Optics for Biologists: Physical Origins of Spherical Aberrations

Science.gov (United States)

Geissler, Peter; Zadunaisky, Jose

1974-01-01

Reports on the physical origins of spherical aberrations in axially symmetric electrostatic lenses to convey the essentials of electon optics to those who must think critically about the resolution of the electron microscope. (GS)

Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications.

Science.gov (United States)

Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W; Dokmeci, Mehmet Remzi; Boyden, Edward S; Khademhosseini, Ali

2016-03-15

To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such "hybrid microscopy" methods--combining physical and optical magnifications--can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes ("mini-microscopes"), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics--a process we refer to as Expansion Mini-Microscopy (ExMM)--is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

Measured Mass-Normalized Optical Cross Sections For Aerosolized Organophosphorus Chemical Warfare Simulants

National Research Council Canada - National Science Library

Gurton, Kristan P; Felton, Melvin; Dahmani, Rachid; Ligon, David

2007-01-01

We present newly measured results of an ongoing experimental program established to measure optical cross sections in the mid and long wave infrared for a variety of chemical and biologically based aerosols...

Microbiology and atmospheric processes: biological, physical and chemical characterization of aerosol particles

Directory of Open Access Journals (Sweden)

D. G. Georgakopoulos

2009-04-01

Full Text Available The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e.g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques required prior to comprehensive understanding of chemical and physical characterization of bioaerosols.

Physical layer impairments tolerance based lightpath provision in software defined optical network

Institute of Scientific and Technical Information of China (English)

Zhao Xianlong; Xu Xianze; Bai Huifeng

2017-01-01

As all-optical networks grow with ever increasing ultra-high speed, the communication quality suffers seriously from physical layer impairments ( PLIs) .The same problem still exists in software defined optical network ( SDON) controlled by OpenFlow.Aimed to solve this problem, a PLIs tol-erance based lightpath provision scheme is proposed for OpenFlow controlled optical networks.This proposed approach not only takes the OSNR model to represent those linear PLIs factors, but also in-troduces those nonlinear factors into the OSNR model.Thus, the proposed scheme is able to cover most PLIs factors of each optical link and conduct optical lightpath provison with better communica-tion quality.Moreover, PLIs tolerance model is also set up and considered in this work with some necessary extension to OpenFlow protocols to achieve better compatibility between physical layer im-pairments factors and various services connections.Simulation results show that the proposed scheme is able to get better performance in terms of packet loss rate and connection setup time.

Working sketch of an anatomically and optically equivalent physical model eye

Science.gov (United States)

Bakaraju, Ravi Chandra; Ehrmann, Klaus; Falk, Darrin; Papas, Eric B.; Ho, Arthur

2009-02-01

Our aim was to fabricate a bench-top physical model eye that closely replicates anatomical and optical properties of the average human eye, and to calibrate and standardize this model to suit normal viewing conditions and subsequently utilize it to understand the optical performance of corrective lens designs; especially multifocal soft contact lenses. Using available normative data on ocular biometrics and Zemax ray-tracing software as a tool, we modeled 25, 45 and 55 year-old average adult human eyes with discrete accommodation levels and pupil sizes. Specifications for the components were established following manufacturing tolerance analyses. The cornea was lathed from an optical material with refractive index of 1.376 @ 589 nm and the crystalline lenses were made of Boston RGP polymers with refractive indices of 1.423 (45 & 55yr) and 1.429 (25yr) @ 589 nm. These two materials served to model the equivalent crystalline lens of the different age-groups. A camera, the acting retina, was hosted on the motor-base having translatory and rotary functions to facilitate the simulation of different states of ametropia and peripheral refraction respectively. We report on the implementation of the first prototype and present some simulations of the optical performance of certain contact lenses with specific levels of ametropia, to demonstrate the potential use of such a physical model eye. On completion of development, calibration and standardization, optical quality assessment and performance predictions of different ophthalmic lenses can be studied in great detail. Optical performance with corrective lenses may be reliably simulated and predicted by customized combined computational and physical models giving insight into the merits and pitfalls of their designs

[INVITED] Recent advances in surface plasmon resonance based fiber optic chemical and biosensors utilizing bulk and nanostructures

Science.gov (United States)

Gupta, Banshi D.; Kant, Ravi

2018-05-01

Surface plasmon resonance has established itself as an immensely acclaimed and influential optical sensing tool with quintessential applications in life sciences, environmental monitoring, clinical diagnostics, pharmaceutical developments and ensuring food safety. The implementation of sensing principle of surface plasmon resonance employing an optical fiber as a substrate has concomitantly resulted in the evolution of fiber optic surface plasmon resonance as an exceptionally lucrative scaffold for chemical and biosensing applications. This perspective article outlines the contemporary studies on fiber optic sensors founded on the sensing architecture of propagating as well as localized surface plasmon resonance. An in-depth review of the prevalent analytical and surface chemical tactics involved in configuring the sensing layer over an optical fiber for the detection of various chemical and biological entities is presented. The involvement of nanomaterials as a strategic approach to enhance the sensor sensitivity is furnished concurrently providing an insight into the diverse geometrical blueprints for designing fiber optic sensing probes. Representative examples from the literature are discussed to appreciate the latest advancements in this potentially valuable research avenue. The article concludes by identifying some of the key challenges and exploring the opportunities for expanding the scope and impact of surface plasmon resonance based fiber optic sensors.

Three-Dimensional Optical Trapping for Cell Isolation Using Tapered Fiber Probe by Dynamic Chemical Etching

International Nuclear Information System (INIS)

Taguchi, K; Okada, J; Nomura, Y; Tamura, K

2012-01-01

In this paper, chemically etched fiber probe was proposed for laser trapping and manipulation of cells. We fabricated tapered fiber probe by dynamic chemical etching technique. Three-Dimensional optical trap of a yeast cell dispersed in water solution could be formed by the fiber tip with 17deg tip. Optical forces were sufficient to move the yeast cell for trapping and manipulation. From these experimental results, it was found that our proposed tapered fiber tip was a promising tool for cell isolation.

Fundamental aspects of plasma chemical physics Thermodynamics

CERN Document Server

Capitelli, Mario; D'Angola, Antonio

2012-01-01

Fundamental Aspects of Plasma Chemical Physics - Thermodynamics develops basic and advanced concepts of plasma thermodynamics from both classical and statistical points of view. After a refreshment of classical thermodynamics applied to the dissociation and ionization regimes, the book invites the reader to discover the role of electronic excitation in affecting the properties of plasmas, a topic often overlooked by the thermal plasma community. Particular attention is devoted to the problem of the divergence of the partition function of atomic species and the state-to-state approach for calculating the partition function of diatomic and polyatomic molecules. The limit of ideal gas approximation is also discussed, by introducing Debye-Huckel and virial corrections. Throughout the book, worked examples are given in order to clarify concepts and mathematical approaches. This book is a first of a series of three books to be published by the authors on fundamental aspects of plasma chemical physics.  The next bo...

Chemical and Physical Properties of Hi-Cal-2

Science.gov (United States)

Spakowski, A. E.; Allen, Harrison, Jr.; Caves, Robert M.

1955-01-01

As part of the Navy Project Zip to consider various boron-containing materials as possible high-energy fuels, the chemical and physical properties of Hi-Cal-2 prepared by the Callery Chemical Company were evaluated at the NACA Lewis laboratory. Elemental chemical analysis, heat of combustion, vapor pressure and decomposition, freezing point, density, self ignition temperature, flash point, and blow-out velocity were determined for the fuel. Although the precision of measurement of these properties was not equal to that obtained for hydrocarbons, this special release research memorandum was prepared to make the data available as soon as possible.

Physical, optical and structural studies of copper-doped lead ...

Indian Academy of Sciences (India)

2018-05-23

May 23, 2018 ... Physical, optical and structural studies of copper-doped lead oxychloro ... to the borate glass system increases the Raman scattering cross-section by ..... equations (6) and (7), molar refraction and electronic polariz- ability are ...

Variation in the chemical composition, physical characteristics and ...

African Journals Online (AJOL)

Variation in the chemical composition, physical characteristics and energy values of cereal grains produced in the Western Cape area of South Africa. TS Brand, CW Cruywagen, DA Brandt, M Viljoen, WW Burger ...

International physical protection self-assessment tool for chemical facilities.

Energy Technology Data Exchange (ETDEWEB)

Tewell, Craig R.; Burdick, Brent A.; Stiles, Linda L.; Lindgren, Eric Richard

2010-09-01

This report is the final report for Laboratory Directed Research and Development (LDRD) Project No.130746, International Physical Protection Self-Assessment Tool for Chemical Facilities. The goal of the project was to develop an exportable, low-cost, computer-based risk assessment tool for small to medium size chemical facilities. The tool would assist facilities in improving their physical protection posture, while protecting their proprietary information. In FY2009, the project team proposed a comprehensive evaluation of safety and security regulations in the target geographical area, Southeast Asia. This approach was later modified and the team worked instead on developing a methodology for identifying potential targets at chemical facilities. Milestones proposed for FY2010 included characterizing the international/regional regulatory framework, finalizing the target identification and consequence analysis methodology, and developing, reviewing, and piloting the software tool. The project team accomplished the initial goal of developing potential target categories for chemical facilities; however, the additional milestones proposed for FY2010 were not pursued and the LDRD funding therefore was redirected.

Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport

Science.gov (United States)

Rod, Kenton; Um, Wooyong; Chun, Jaehun; Wu, Ning; Yin, Xialong; Wang, Guohui; Neeves, Keith

2018-06-01

A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d-1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500-600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500-600 μm and 300-400 μm). A chemical heterogeneity was created using 25% of the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500-600 μm). Input solution with 0.5 mM CsI and 50 mg L-1 colloids (1-μm diameter SiO2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.

The Main Physical-Chemical Characteristics of Smoked Sausage

Directory of Open Access Journals (Sweden)

Corina Iuliana Costescu

2015-05-01

Full Text Available The paper presents the organoleptic and physical-chemical quality of smoked sausage, produced by a manufacturer in the western part of Romania. The organoleptic examination highlighted: product shape, exterior and in section aspect, consistency, color, taste and flavor. The physical-chemical examination highlighted the content of moisture, fat, sodium chloride, nitrites and easy hydrolyzed nitrogen. Water content was under the maximum admitted limit of 58%. Medium fat value was 32.24%, by 5.76% under the 38% maximum limit. Medium sodium chloride content was 2.1%, under the maximum admitted limit of 3%. Easy hydrolyzed nitrogen registered a medium value of 26.71 mg NH3/100g product under the 45% maximum admitted limit. Nitrites content was 5.18 ppm, under the 7 ppm imposed limit.

Physical impairment aware transparent optical networks

Science.gov (United States)

Antona, Jean-Christophe; Morea, Annalisa; Zami, Thierry; Leplingard, Florence

2009-11-01

As illustrated by optical fiber and optical amplification, optical telecommunications have appeared for the last ten years as one of the most promising candidates to increase the transmission capacities. More recently, the concept of optical transparency has been investigated and introduced: it consists of the optical routing of Wavelength Division Multiplexed (WDM) channels without systematic optoelectronic processing at nodes, as long as propagation impairments remain acceptable [1]. This allows achieving less power-consuming, more scalable and flexible networks, and today partial optical transparency has become a reality in deployed systems. However, because of the evolution of traffic features, optical networks are facing new challenges such as demand for higher transmitted capacity, further upgradeability, and more automation. Making all these evolutions compliant on the same current network infrastructure with a minimum of upgrades is one of the main issues for equipment vendors and operators. Hence, an automatic and efficient management of the network needs a control plan aware of the expected Quality of Transmission (QoT) of the connections to set-up with respect to numerous parameters such as: the services demanded by the customers in terms of protection/restoration; the modulation rate and format of the connection under test and also of its adjacent WDM channels; the engineering rules of the network elements traversed with an accurate knowledge of the associated physical impairments. Whatever the method and/or the technology used to collect this information, the issue about its accuracy is one of the main concerns of the network system vendors, because an inaccurate knowledge could yield a sub-optimal dimensioning and so additional costs when installing the network in the field. Previous studies [1], [2] illustrated the impact of this knowledge accuracy on the ability to predict the connection feasibility. After describing usual methods to build

Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

International Nuclear Information System (INIS)

Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone; Kelecom, Alphonse; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova; Dores, Luis Augusto de Carvalho Bresser

2011-01-01

The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

Energy Technology Data Exchange (ETDEWEB)

Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone, E-mail: wspereira@inb.gov.br [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Protecao Radiologica. Grupo Multidisciplinar de Radioprotecao; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Desenvolvimento de Processos; Dores, Luis Augusto de Carvalho Bresser [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Gerencia de Descomissionamento

2011-07-01

The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

Physical and Chemical Environmental Abstraction Model

International Nuclear Information System (INIS)

Nowak, E.

2000-01-01

As directed by a written development plan (CRWMS M and O 1999a), Task 1, an overall conceptualization of the physical and chemical environment (P/CE) in the emplacement drift is documented in this Analysis/Model Report (AMR). Included are the physical components of the engineered barrier system (EBS). The intended use of this descriptive conceptualization is to assist the Performance Assessment Department (PAD) in modeling the physical and chemical environment within a repository drift. It is also intended to assist PAD in providing a more integrated and complete in-drift geochemical model abstraction and to answer the key technical issues raised in the U.S. Nuclear Regulatory Commission (NRC) Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE) Revision 2 (NRC 1999). EBS-related features, events, and processes (FEPs) have been assembled and discussed in ''EBS FEPs/Degradation Modes Abstraction'' (CRWMS M and O 2000a). Reference AMRs listed in Section 6 address FEPs that have not been screened out. This conceptualization does not directly address those FEPs. Additional tasks described in the written development plan are recommended for future work in Section 7.3. To achieve the stated purpose, the scope of this document includes: (1) the role of in-drift physical and chemical environments in the Total System Performance Assessment (TSPA) (Section 6.1); (2) the configuration of engineered components (features) and critical locations in drifts (Sections 6.2.1 and 6.3, portions taken from EBS Radionuclide Transport Abstraction (CRWMS M and O 2000b)); (3) overview and critical locations of processes that can affect P/CE (Section 6.3); (4) couplings and relationships among features and processes in the drifts (Section 6.4); and (5) identities and uses of parameters transmitted to TSPA by some of the reference AMRs (Section 6.5). This AMR originally considered a design with backfill, and is now being updated (REV 00 ICN1) to address

Experimental display of Fourier analysis through the optical physics and its didatical utilization

International Nuclear Information System (INIS)

Oliveira, S.M.M. de.

1983-01-01

The properties of Fourier analysis through physical optics are displayed experimentally. Within physical optics topics that illustrate didactically Fourier analysis, a subject usually considered purely mathematical are selected. The most important properties of Fourier transform and their utilization in cleaning up images through spatial filtering are presented, in this way the properties of convolution to analyse image formation and characterize some diffraction patterns are also used. (Author) [pt

Advances in hybrid optics physical sensors for extreme environments

Science.gov (United States)

Riza, Nabeel A.

2010-04-01

Highlighted are novel innovations in hybrid optical design physical sensors for extreme environments. Various hybrid design compositions are proposed that are suited for a particular sensor application. Examples includes combining freespace (wireless) and fiber-optics (wired) for gas turbine sensing and combining single crystal and sintered Silicon Carbide (SiC) materials for robust extreme environment Coefficent of Thermal Expansion (CTE) matched frontend probe design. Sensor signal processing also includes the hybrid theme where for example Black-Body radiation thermometry (pyrometry) is combined with laser interferometry to provide extreme temperature measurements. The hybrid theme also operates on the optical device level where a digital optical device such as a Digital Micromirror Device (DMD) is combined with an analog optical device such as an Electronically Controlled Variable Focal Length Lens (ECVFL) to deliver a smart and compressive Three Dimensional (3-D) imaging sensor for remote scene and object shape capture including both ambient light (passive) mode and active laser targeting and receive processing. Within a device level, the hybrid theme also operates via combined analog and digital control such as within a wavelength-coded variable optical delay line. These powerful hybrid design optical sensors have numerous applications in engineering and science applications from the military to the commercial/industrial sectors.

Fundamentals of physics II electromagnetism, optics, and quantum mechanics

CERN Document Server

Shankar, R

2016-01-01

R. Shankar, a well-known physicist and contagiously enthusiastic educator, was among the first to offer a course through the innovative Open Yale Course program. His popular online video lectures on introductory physics have been viewed over a million times. In this second book based on his online Yale course, Shankar explains essential concepts, including electromagnetism, optics, and quantum mechanics. The book begins at the simplest level, develops the basics, and reinforces fundamentals, ensuring a solid foundation in the principles and methods of physics. It provides an ideal introduction for college-level students of physics, chemistry, and engineering; for motivated AP Physics students; and for general readers interested in advances in the sciences.

Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

International Nuclear Information System (INIS)

Sierra-Sosa, Daniel-Esteban; Angel-Toro, Luciano

2011-01-01

Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB (registered) software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

Energy Technology Data Exchange (ETDEWEB)

Sierra-Sosa, Daniel-Esteban; Angel-Toro, Luciano, E-mail: dsierras@eafit.edu.co, E-mail: langel@eafit.edu.co [Grupo de Optica Aplicada, Universidad EAFIT, 1 Medellin (Colombia)

2011-01-01

Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB (registered) software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

Science.gov (United States)

Sierra-Sosa, Daniel-Esteban; Ángel-Toro, Luciano

2011-01-01

Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB® software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

Optical, physical and structural studies of boro-zinc tellurite glasses

International Nuclear Information System (INIS)

Gayathri Pavani, P.; Sadhana, K.; Chandra Mouli, V.

2011-01-01

To investigate the modification effect of the modifier ZnO on boro-tellurite glass, a series of glasses with compositions 50B 2 O 3 -(50-x)ZnO-xTeO 2 have been prepared by conventional melt quenching technique. Amorphous nature of the samples was confirmed through X-ray diffraction technique. Optical absorption and IR structural studies are carried out on the glass system. The optical absorption studies revealed that the cutoff wavelength increases while optical band gap (E opt ) and Urbach energy decreases with an increase of ZnO content. Refractive index evaluated from E opt was found to increase with an increase of ZnO content. The compositional dependence of different physical parameters such as density, molar volume, oxygen packing density, optical basicity, have been analyzed and discussed. The IR studies showed that the structure of glass consists of TeO 4 , TeO 3 /TeO 3+1 , BO 3 , BO 4 and ZnO 4 units. -- Research highlights: → Novel boro-zinc tellurite ternary glasses that can compete with boro-tellurite and zinc tellurite glasses are successfully prepared. → Boro-zinc tellurite ternary glasses are of higher refractive index compared with zinc tellurite glasses. → Optical, physical and structural properties of the novel ternary glass system are explained.→ At 30 mol% of ZnO, TeO 4 is replaced by ZnO 4 indicating the presence of ZnO 4 network.

CHEMICAL AND PHYSICAL CHARACTERIZATION OF COLLAPSING LOW-MASS PRESTELLAR DENSE CORES

Energy Technology Data Exchange (ETDEWEB)

Hincelin, U. [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Commerçon, B. [Ecole Normale Supérieure de Lyon, CRAL, UMR 5574 du CNRS, Université Lyon I, 46 Allée d’Italie, F-69364 Lyon cedex 07 (France); Wakelam, V.; Hersant, F.; Guilloteau, S. [Univ. Bordeaux, LAB, UMR 5804, F-33270, Floirac (France); Herbst, E., E-mail: ugo.hincelin@gmail.com [Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)

2016-05-01

The first hydrostatic core, also called the first Larson core, is one of the first steps in low-mass star formation as predicted by theory. With recent and future high-performance telescopes, the details of these first phases are becoming accessible, and observations may confirm theory and even present new challenges for theoreticians. In this context, from a theoretical point of view, we study the chemical and physical evolution of the collapse of prestellar cores until the formation of the first Larson core, in order to better characterize this early phase in the star formation process. We couple a state-of-the-art hydrodynamical model with full gas-grain chemistry, using different assumptions for the magnetic field strength and orientation. We extract the different components of each collapsing core (i.e., the central core, the outflow, the disk, the pseudodisk, and the envelope) to highlight their specific physical and chemical characteristics. Each component often presents a specific physical history, as well as a specific chemical evolution. From some species, the components can clearly be differentiated. The different core models can also be chemically differentiated. Our simulation suggests that some chemical species act as tracers of the different components of a collapsing prestellar dense core, and as tracers of the magnetic field characteristics of the core. From this result, we pinpoint promising key chemical species to be observed.

Tuning the nonlinear optical absorption of reduced graphene oxide by chemical reduction.

Science.gov (United States)

Shi, Hongfei; Wang, Can; Sun, Zhipei; Zhou, Yueliang; Jin, Kuijuan; Redfern, Simon A T; Yang, Guozhen

2014-08-11

Reduced graphene oxides with varying degrees of reduction have been produced by hydrazine reduction of graphene oxide. The linear and nonlinear optical properties of both graphene oxide as well as the reduced graphene oxides have been measured by single beam Z-scan measurement in the picosecond region. The results reveal both saturable absorption and two-photon absorption, strongly dependent on the intensity of the pump pulse: saturable absorption occurs at lower pump pulse intensity (~1.5 GW/cm2 saturation intensity) whereas two-photon absorption dominates at higher intensities (≥5.7 GW/cm2). Intriguingly, we find that the two-photon absorption coefficient (from 1.5 cm/GW to 4.5cm/GW) and the saturation intensity (from 1 GW/cm2 to 2 GW/cm2) vary with chemical reduction, which is ascribed to the varying concentrations of sp2 domains and sp2 clusters in the reduced graphene oxides. Our results not only provide an insight into the evolution of the nonlinear optical coefficient in reduced graphene oxide, but also suggest that chemical engineering techniques may usefully be applied to tune the nonlinear optical properties of various nano-materials, including atomically thick graphene sheets.

BOOK REVIEW: Introductory Nanoscience: Physical and Chemical Concepts Introductory Nanoscience: Physical and Chemical Concepts

Science.gov (United States)

Bich Ha, Nguyen

2011-12-01

Having grown rapidly during the last two decades, and successfully synthesized the achievements of physics, chemistry, life science as well as information and computational science and technology, nanoscience and nanotechnology have emerged as interdisciplinary fields of modern science and technology with various prospective applications towards environmental protection and the sustainable development of industry, agriculture, public health etc. At the present time, there exist many textbooks, monographs and encyclopedias on nanoscience and nanotechnology. They present to readers the whole process of development from the emergence of new scientific ideas to comprehensive studies of concrete subjects. They are useful for experienced scientists in nanoscience and nanotechnology as well as related scientific disciplines. However, there are very few textbooks on nanoscience and nanotechnology for beginners—senior undergraduate and junior graduate students. Published by Garland Science in August 2011, Introductory Nanoscience: Physical and Chemical Concepts by Masaru Kuno is one of these rare textbooks. The purpose of this book is twofold. In a pedagogical manner the author presents the basic physical and chemical concepts of nanoscience and nanotechnology. Students with a background knowledge in general chemistry and semiclassical quantum physics can easily understand these concepts. On the other hand, by carefully studying the content of this textbook, readers can learn how to derive a large number of formulae and expressions which they will often use in their study as well as in their future research work. A distinguishing feature of the book is the inclusion of a large number of thought problems at the end of each chapter for demonstrating how to calculate the numerical values of almost all physical quantities involved in the theoretical and experimental studies of all subjects of nanoscience and nanotechnology. The author has successfully achieved both of the

A study of the effects of physical dermabrasion combined with chemical peeling in porcine skin.

Science.gov (United States)

Kang, Boo Kyoung; Choi, Jeong Hwee; Jeong, Ki Heon; Park, Jong Min; Suh, Dong Hye; Lee, Sang Jun; Shin, Min Kyung

2015-02-01

Many comparative studies of chemical peeling and dermabrasion have been reported. However, rare basic scientific data about the immediate effects after combined treatment with chemical peeling and dermabrasion have been confirmed. The aim of this study is to evaluate the effect of the application of physical abrasion in combination with chemical peels. Three pigs were treated with physical abrasion using a water jet device in combination with an α-hydroxy acid solution, and the skin samples of the control received chemical peeling solution alone. The levels of growth factors and neuropeptides were measured with a multiplex immunoassay. Skin treated with physical dermabrasion combined with chemical peeling showed prominent detachment and swelling of the stratum corneum (SC), and fluid collection in the hair follicles. The mean cell count of CD34 positive fibroblasts and mast cells, levels of epidermal growth factor, fibroblast growth factor-2, vascular endothelial growth factor, and neurotensin, were significantly increased in the tissue treated with physical abrasion combined with a chemical peeling agent, compared to the skin in the control. We concluded that physical dermabrasion combined with chemical peeling can be more effective than chemical peeling alone, for the approach through transfollicular routes.

PROPERTIES AND OPTICAL APPLICATION OF POLYCRYSTALLINE ZINC SELENIDE OBTAINED BY PHYSICAL VAPOR DEPOSITION

Directory of Open Access Journals (Sweden)

A. A. Dunaev

2015-05-01

Full Text Available Findings on production technology, mechanical and optical properties of polycrystalline zinc selenide are presented. The combination of its physicochemical properties provides wide application of ZnSe in IR optics. Production technology is based on the method of physical vapor deposition on a heated substrate (Physical Vapor Deposition - PVD. The structural features and heterogeneity of elemental composition for the growth surfaces of ZnSe polycrystalline blanks were investigated using CAMEBAX X-ray micro-analyzer. Characteristic pyramid-shaped crystallites were recorded for all growth surfaces. The measurements of the ratio for major elements concentrations show their compliance with the stoichiometry of the ZnSe compounds. Birefringence, optical homogeneity, thermal conductivity, mechanical and optical properties were measured. It is established that regardless of polycrystalline condensate columnar and texturing, the optical material is photomechanically isotropic and homogeneous. The actual performance of parts made of polycrystalline optical zinc selenide in the thermal spectral ranges from 3 to 5 μm and from 8 to 14 μm and in the CO2 laser processing plants with a power density of 500 W/cm2 is shown. The developed technology gives the possibility to produce polycrystalline optical material on an industrial scale.

Sputtered titanium oxynitride coatings for endosseous applications: Physical and chemical evaluation and first bioactivity assays

Energy Technology Data Exchange (ETDEWEB)

Banakh, Oksana, E-mail: oksana.banakh@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Moussa, Mira, E-mail: mira.moussa@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Matthey, Joel, E-mail: joel.matthey@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Pontearso, Alessandro, E-mail: alessandro.pontearso@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Cattani-Lorente, Maria, E-mail: maria.cattani-lorente@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Sanjines, Rosendo, E-mail: rosendo.sanjines@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Condensed Matter Physics, Station 3, CH-1015 Lausanne (Switzerland); Fontana, Pierre, E-mail: Pierre.Fontana@hcuge.ch [Haemostasis laboratory, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH-1205 Geneva (Switzerland); Wiskott, Anselm, E-mail: anselm.wiskott@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Durual, Stephane, E-mail: stephane.durual@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland)

2014-10-30

Highlights: • Titanium oxynitride coatings (TiN{sub x}O{sub y}) with chemical composition ranging from TiN to TiO{sub 2} were deposited by magnetron sputtering from a metallic Ti target using a mixture of O{sub 2} + N{sub 2}. • The coatings structure as well as physical, chemical and mechanical properties progressively changes as a function of oxygen content in the TiN{sub x}O{sub y.} • All TiN{sub x}O{sub y} coatings show a significantly higher level of bioactivity as compared to bare Ti substrates (1.2 to 1.4 fold increase in cell proliferation). Despite variations in surface chemistry, topography and surface tension observed on films as a function of chemical composition, no significant differences in the films’ biological activity were observed after 3 days of testing. - Abstract: Titanium oxynitride coatings (TiN{sub x}O{sub y}) are considered a promising material for applications in dental implantology due to their high corrosion resistance, their biocompatibility and their superior hardness. Using the sputtering technique, TiN{sub x}O{sub y} films with variable chemical compositions can be deposited. These films may then be set to a desired value by varying the process parameters, that is, the oxygen and nitrogen gas flows. To improve the control of the sputtering process with two reactive gases and to achieve a variable and controllable coating composition, the plasma characteristics were monitored in-situ by optical emission spectroscopy. TiN{sub x}O{sub y} films were deposited onto commercially pure (ASTM 67) microroughened titanium plates by reactive magnetron sputtering. The nitrogen gas flow was kept constant while the oxygen gas flow was adjusted for each deposition run to obtain films with different oxygen and nitrogen contents. The physical and chemical properties of the deposited films were analyzed as a function of oxygen content in the titanium oxynitride. The potential application of the coatings in dental implantology was assessed by

Fiber-optical sensor with intensity compensation model in college teaching of physics experiment

Science.gov (United States)

Su, Liping; Zhang, Yang; Li, Kun; Zhang, Yu

2017-08-01

Optical fiber sensor technology is one of the main contents of modern information technology, which has a very important position in modern science and technology. Fiber optic sensor experiment can improve students' enthusiasm and broaden their horizons in college physics experiment. In this paper the main structure and working principle of fiberoptical sensor with intensity compensation model are introduced. And thus fiber-optical sensor with intensity compensation model is applied to measure micro displacement of Young's modulus measurement experiment and metal linear expansion coefficient measurement experiment in the college physics experiment. Results indicate that the measurement accuracy of micro displacement is higher than that of the traditional methods using fiber-optical sensor with intensity compensation model. Meanwhile this measurement method makes the students understand on the optical fiber, sensor and nature of micro displacement measurement method and makes each experiment strengthen relationship and compatibility, which provides a new idea for the reform of experimental teaching.

Methodology for completing Hanford 200 Area tank waste physical/chemical profile estimations

International Nuclear Information System (INIS)

Kruger, A.A.

1996-01-01

The purpose of the Methodology for Completing Hanford 200 Area Tank Waste Physical/Chemical Profile Estimations is to capture the logic inherent to completing 200 Area waste tank physical and chemical profile estimates. Since there has been good correlation between the estimate profiles and actual conditions during sampling and sub-segment analysis, it is worthwhile to document the current estimate methodology

Analysis of Electrically Large Antennas using Fast Physical Optics

DEFF Research Database (Denmark)

Borries, Oscar Peter; Viskum, Hans-Henrik; Meincke, Peter

2015-01-01

accelerated Physical Optics (Fast-PO) and show that this approach allows for a timely and accurate solution of realistic designs. Several examples, ranging from canonical tests of the scaling of the method against the wavelength to real-life applications, illustrate the performance of the approach in practice....

A quantum-chemical perspective into low optical-gap polymers for highly-efficient organic solar cells

KAUST Repository

Risko, Chad

2011-03-15

The recent and rapid enhancement in power conversion efficiencies of organic-based, bulk heterojunction solar cells has been a consequence of both improved materials design and better understanding of the underlying physical processes involved in photocurrent generation. In this Perspective, we first present an overview of the application of quantum-chemical techniques to study the intrinsic material properties and molecular- and nano-scale processes involved in device operation. In the second part, these quantum-chemical tools are applied to an oligomer-based study on a collection of donor-acceptor copolymers that have been used in the highest-efficiency solar cell devices reported to date. The quantum-chemical results are found to be in good agreement with the empirical data related to the electronic and optical properties. In particular, they provide insight into the natures of the electronic excitations responsible for the near-infrared/visible absorption profiles, as well as into the energetics of the low-lying singlet and triplet states. These results lead to a better understanding of the inherent differences among the materials, and highlight the usefulness of quantum chemistry as an instrument for material design. Importantly, the results also point to the need to continue the development of integrated, multi scale modeling approaches to provide a thorough understanding of the materials properties. © The Royal Society of Chemistry 2011.

Conceptual Integration of Chemical Equilibrium by Prospective Physical Sciences Teachers

Science.gov (United States)

Ganaras, Kostas; Dumon, Alain; Larcher, Claudine

2008-01-01

This article describes an empirical study concerning the mastering of the chemical equilibrium concept by prospective physical sciences teachers. The main objective was to check whether the concept of chemical equilibrium had become an integrating and unifying concept for them, that is to say an operational and functional knowledge to explain and…

Fiber Optic Chemical Nanosensors Based on Engineered Single-Walled Carbon Nanotubes

Directory of Open Access Journals (Sweden)

M. Consales

2008-01-01

Full Text Available In this contribution, a review of the development of high-performance optochemical nanosensors based on the integration of carbon nanotubes with the optical fiber technology is presented. The paper first provide an overview of the amazing features of carbon nanotubes and their exploitation as highly adsorbent nanoscale materials for gas sensing applications. Successively, the attention is focused on the operating principle, fabrication, and characterization of fiber optic chemosensors in the Fabry-Perot type reflectometric configuration, realized by means of the deposition of a thin layer of single-walled carbon nanotubes (SWCNTs upon the distal end of standard silica optical fibers. This is followed by an extensive review of the excellent sensing capabilities of the realized SWCNTs-based chemical nanosensors against volatile organic compounds and other pollutants in different environments (air and water and operating conditions (room temperature and cryogenic temperatures. The experimental results reported here reveal that ppm and sub-ppm chemical detection limits, low response times, as well as fast and complete recovery of the sensor responses have been obtained in most of the investigated cases. This evidences the great potentialities of the proposed photonic nanosensors based on SWCNTs to be successfully employed for practical environmental monitoring applications both in liquid and vapor phase as well as for space. Furthermore, the use of novel SWCNTs-based composites as sensitive fiber coatings is proposed to enhance the sensing performance and to improve the adhesion of carbon nanotubes to the fiber surface. Finally, new advanced sensing configurations based on the use of hollow-core optical fibers coated and partially filled by carbon nanotubes are also presented.

Controlled optical properties via chemical composition tuning in molybdenum-incorporated β-Ga2O3 nanocrystalline films

Science.gov (United States)

Battu, Anil K.; Manandhar, S.; Shutthanandan, V.; Ramana, C. V.

2017-09-01

An approach is presented to design refractory-metal incorporated Ga2O3-based materials with controlled structural and optical properties. The molybdenum (Mo)-content in Ga2O3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo-content (≤4 at%) results in the formation of single-phase (β-Ga2O3), higher Mo-content results in amorphization. Chemically-induced band gap variability (Eg ∼ 1 eV) coupled with structure-modification indicates the electronic-structure changes in Ga-Mo-O. The linear relationship between chemical-composition and optical properties suggests that tailoring the optical-quality and performance of Ga-Mo-O films is possible by tuning the Mo-content.

Investigating the effects of different physical and chemical stress ...

African Journals Online (AJOL)

2018-04-09

Apr 9, 2018 ... bacteria from extreme physical and chemical stress conditions. Additionally .... by inducing stress response genes, become more tolerant phenotypes ..... biofilm, monochloramine is more effective than free chlorine over long ...

Development of activated carbon pore structure via physical and chemical activation of biomass fibre waste

International Nuclear Information System (INIS)

Williams, Paul T.; Reed, Anton R.

2006-01-01

Biomass waste in the form of biomass flax fibre, produced as a by-product of the textile industry was processed via both physical and chemical activation to produce activated carbons. The surface area of the physically activated carbons were up to 840 m 2 g -1 and the carbons were of mesoporous structure. Chemical activation using zinc chloride produced high surface area activated carbons up to 2400 m 2 g -1 and the pore size distribution was mainly microporous. However, the process conditions of temperature and zinc chloride concentration could be used to manipulate the surface area and porosity of the carbons to produce microporous, mesoporous and mixed microporous/mesoporous activated carbons. The physically activated carbons were found to be a mixture of Type I and Type IV carbons and the chemically activated carbons were found to be mainly Type I carbons. The development of surface morphology of physically and chemically activated carbons observed via scanning electron microscopy showed that physical activation produced activated carbons with a nodular and pitted surface morphology whereas activated carbons produced through chemical activation had a smooth surface morphology. Transmission electron microscopy analysis could identify mesopore structures in the physically activated carbon and microporous structures in the chemically activated carbons

Optical fiber sensors: Systems and applications. Volume 2

Science.gov (United States)

Culshaw, Brian; Dakin, John

State-of-the-art fiber-optic (FO) sensors and their applications are described in chapters contributed by leading experts. Consideration is given to interferometers, FO gyros, intensity- and wavelength-based sensors and optical actuators, Si in FO sensors, point-sensor multiplexing principles, and distributed FO sensor systems. Also examined are chemical, biochemical, and medical sensors; physical and chemical sensors for process control; FO-sensor applications in the marine and aerospace industries; FO-sensor monitoring systems for security and safety, structural integrity, NDE, and the electric-power industry; and the market situation for FO-sensor technology. Diagrams, drawings, graphs, and photographs are provided.

Atoms, molecules and optical physics 2. Molecules and photons - Spectroscopy and collisions

Energy Technology Data Exchange (ETDEWEB)

Hertel, Ingolf V.; Schulz, Claus-Peter [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie im Forschungsverbund Berlin e.V. (Germany)

2015-09-01

This is the second volume of textbooks on atomic, molecular and optical physics, aiming at a comprehensive presentation of this highly productive branch of modern physics as an indispensable basis for many areas in physics and chemistry as well as in state of the art bio- and material-sciences. It primarily addresses advanced students (including PhD students), but in a number of selected subject areas the reader is lead up to the frontiers of present research. Thus even the active scientist is addressed. This volume 2 introduces lasers and quantum optics, while the main focus is on the structure of molecules and their spectroscopy, as well as on collision physics as the continuum counterpart to bound molecular states. The emphasis is always on the experiment and its interpretation, while the necessary theory is introduced from this perspective in a compact and occasionally somewhat heuristic manner, easy to follow even for beginners.

Chemically deposited Sb2S3 thin films for optical recording

International Nuclear Information System (INIS)

Shaji, S; Arato, A; Castillo, G Alan; Palma, M I Mendivil; Roy, T K Das; Krishnan, B; O'Brien, J J; Liu, J

2010-01-01

Laser induced changes in the properties of Sb 2 S 3 thin films prepared by chemical bath deposition are described in this paper. Sb 2 S 3 thin films of thickness 550 nm were deposited from a solution containing SbCl 3 and Na 2 S 2 O 3 at 27 0 C for 5 h. These thin films were irradiated by a 532 nm continuous wave laser beam under different conditions at ambient atmosphere. X-ray diffraction analysis showed amorphous to polycrystalline transformation due to laser exposure of these thin films. Morphology and composition of these films were described. Optical properties of these films before and after laser irradiation were analysed. The optical band gap of the material was decreased due to laser induced crystallization. The results obtained confirm that there is further scope for developing this material as an optical recording media.

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

International Nuclear Information System (INIS)

R. Jarek

2005-01-01

The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The resulting seepage evaporation and gas abstraction models are used in the total system performance assessment for the license application (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2005 [DIRS 173782], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports. To be consistent with other project documents that address features, events, and processes (FEPs), Table 6.14.1 of the current report includes updates to FEP numbers and FEP subjects for two FEPs identified in the technical work plan (TWP) governing this report (BSC 2005 [DIRS 173782]). FEP 2.1.09.06.0A (Reduction-oxidation potential in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.06.0B (Reduction-oxidation potential in Drifts; see Table 6.14-1). FEP 2.1.09.07.0A (Reaction kinetics in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.07.0B (Reaction kinetics in Drifts; see Table 6.14-1). These deviations from the TWP are justified because they improve integration with FEPs documents. The updates

Fiber optic chemical sensors: The evolution of high- density fiber-optic DNA microarrays

Science.gov (United States)

Ferguson, Jane A.

2001-06-01

Sensors were developed for multianalyte monitoring, fermentation monitoring, lactate analysis, remote oxygen detection for use in bioremediation monitoring and in a fuel spill clean-up project, heavy metal analysis, and high density DNA microarrays. The major focus of this thesis involved creating and improving high-density DNA gene arrays. Fiber optic sensors are created using fluorescent indicators, polymeric supports, and optical fiber substrates. The fluorescent indicator is entrapped in a polymer layer and attached to the tip of the optical fiber. The tip of the fiber bearing the sensing layer (the distal end) is placed in the sample of interest while the other end of the fiber (the proximal end) is connected to an analysis system. Any length of fiber can be used without compromising the integrity or sensitivity of the system. A fiber optic oxygen sensor was designed incorporating an oxygen sensitive fluorescent dye and a gas permeable polymer attached to an optical fiber. The construction simplicity and ruggedness of the sensor enabled its deployment for in situ chemical oxidation and bioremediation studies. Optical fibers were also used as the substrate to detect biomolecules in solution. To monitor bioprocesses, the production of the analyte of interest must be coupled with a species that is optically measurable. For example, oxygen is consumed in many metabolic functions. The fiber optic oxygen sensor is equipped with an additional sensing layer. Upon contact with a specific biochemical in the sample, a reaction occurs in the additional sensing layer that either consumes or produces oxygen. This dual layer system was used to monitor the presence of lactate, an important metabolite for clinical and bioprocess analysis. In many biological and environmental systems, the generation of one species occurs coincidentally with the generation or consumption of another species. A multianalyte sensor was prepared that can monitor the simultaneous activity of pH, CO2

Physical and Chemical Interactions between Mg:Al Layered Double Hydroxide and Hexacyanoferrate

Science.gov (United States)

Boclair, Joseph W.; Braterman, Paul S.; Brister, Brian D.; Wang, Zhiming; Yarberry, Faith

2001-11-01

The physical and chemical interactions of ferrocyanide (potassium and ammonium salts) and ferricyanide (potassium salt) with Mg:Al layered double hydroxides (LDH) (having Mg:Al ratios of 2 and 3) are investigated using powder XRD and FTIR spectroscopy. Physically, the potassium ferricyanide is shown to intercalate with a small local field deformation similar to that seen for hexacyanocobaltate (III) in similar materials. Chemically, the reduction of ferricyanide to ferrocyanide upon intercalation is confirmed. Physical interactions of ferrocyanide with 3:1 LDH are shown spectroscopically to include the possible generation of anions in differing environments. Chemically, ferrocyanide is shown to generate cubic ferrocyanides (of the type M2MgFe(CN)6, where M=K+ or NH+4) under conditions where free Mg2+ is likely present in solution, namely, solutions with a pH lower than ∼7.5. It is shown that the reported 2112-cm-1 band found in some chemically altered LDH ferrocyanide is indeed due to interlayer ferricyanide, but that the 2080 cm-1 band is due to the cubic material.

Integrated optics ring-resonator chemical sensor with polymer transduction layer

Science.gov (United States)

Ksendzov, A.; Homer, M. L.; Manfreda, A. M.

2004-01-01

An integrated optics chemical sensor based on a ring resonator with an ethyl cellulose polymer coating has been demonstrated. The measured sensitivity to isopropanol in air is 50 ppm-the level immediately useful for health-related air quality monitoring. The resonator was fabricated using SiO2 and SixNy materials. The signal readout is based on tracking the wavelength of a resonance peak. The resonator layout optimisation for sensing applications is discussed.

Chemical physics of decomposition of energetic materials. Problems and prospects

International Nuclear Information System (INIS)

Smirnov, Lev P

2004-01-01

The review is concerned with analysis of the results obtained in the kinetic and mechanistic studies on decomposition of energetic materials (explosives, powders and solid propellants). It is shown that the state-of-the art in this field is inadequate to the potential of modern chemical kinetics and chemical physics. Unsolved problems are outlined and ways of their solution are proposed.

Optical sensing method to analyze germination rate of Capsicum annum seeds treated with growth-promoting chemical compounds using optical coherence tomography

Science.gov (United States)

Wijesinghe, Ruchire Eranga; Lee, Seung-Yeol; Kim, Pilun; Jung, Hee-Young; Jeon, Mansik; Kim, Jeehyun

2017-09-01

Seed germination rate differs based on chemical treatments, and nondestructive measurements of germination rate have become an essential requirement in the field of agriculture. Seed scientists and other biologists are interested in optical sensing technologies-based biological discoveries due to nondestructive detection capability. Optical coherence tomography (OCT) has recently emerged as a powerful method for biological and plant material discoveries. We report an extended application of OCT by monitoring the germination rate acceleration of chemically primed seeds. To validate the versatility of the method, Capsicum annum seeds were primed using three chemical compounds: sterile distilled water (SDW), butandiol, and 1-hexadecene. Monitoring was performed using a 1310-nm swept source OCT system. The results confirmed more rapid morphological variations in the seeds treated with 1-hexadecene medium than the seeds treated with SDW and butandiol within 8 consecutive days. In addition, fresh weight measurements (gold standard) of seeds were monitored for 15 days, and the obtained results were correlated with the OCT results. Thus, such a method can be used in various agricultural fields, and OCT shows potential as a rigorous sensing method for selecting the optimal plant growth-promoting chemical compounds rapidly, when compared with the gold standard methods.

Atomic, molecular, and optical physics electromagnetic radiation

CERN Document Server

Dunning, F B; Lucatorto, Thomas

1997-01-01

Combined with Volumes 29A and 29B, this volume is a comprehensive treatment of the key experimental methods of atomic, molecular, and optical physics, as well as an excellent experimental handbook for the field. Thewide availability of tunable lasers in the past several years has revolutionized the field and lead to the introduction of many new experimental methods that are covered in these volumes. Traditional methods are also included to ensure that the volumes will be a complete reference source for the field.

Cloud Physics Lidar Optical Measurements During the SAFARI-2000 Field Campaign

Science.gov (United States)

Hlavka, Dennis L.; McGill, Matt; Hart, William D.; Spinhirne, James D.; Starr, David OC. (Technical Monitor)

2002-01-01

In this presentation, we will show new optical data processing results from the Cloud Physics War during SAFARI-2000. Retrieved products include aerosol and cloud layer location and identification, layer optical depths, vertical extinction profiles, and extinction-to-backscatter (S) ratios for 532 and 1064 nm. The retrievals will focus on the persistent and smoky planetary boundary layer and occasional elevated aerosol layers found in southern Africa during August and September 2000.

Production of nanomaterials: physical and chemical technologies

International Nuclear Information System (INIS)

Giorgi, Leonardo; Salernitano, Elena

2015-01-01

Are define nanomaterials those materials which have at least one dimension in the range between 1 and 100 nm. By the term nanotechnology refers, instead, to the study of phenomena and manipulation of materials at the atomic and molecular level. The materials brought to the nanometric dimensions take particular chemical-physical properties different from the corresponding conventional macro materials. Speaking about the structure of nanoscale, you can check some basic properties materials (eg. Melting temperature, magnetic and electrical properties) without changing its chemical composition. In this perspective are crucial knowledge and control of production processes in order to design and get the nanomaterial more suitable for a specific application. For this purpose, it describes a series of processes of production of nanomaterials with application examples. [it

Atoms, molecules and optical physics 1. Atoms and spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Hertel, Ingolf V.; Schulz, Claus-Peter

2015-09-01

This is the first volume of textbooks on atomic, molecular and optical physics, aiming at a comprehensive presentation of this highly productive branch of modern physics as an indispensable basis for many areas in physics and chemistry as well as in state of the art bio- and material-sciences. It primarily addresses advanced students (including PhD students), but in a number of selected subject areas the reader is lead up to the frontiers of present research. Thus even the active scientist is addressed. This volume 1 provides the canonical knowledge in atomic physics together with basics of modern spectroscopy. Starting from the fundamentals of quantum physics, the reader is familiarized in well structured chapters step by step with the most important phenomena, models and measuring techniques. The emphasis is always on the experiment and its interpretation, while the necessary theory is introduced from this perspective in a compact and occasionally somewhat heuristic manner, easy to follow even for beginners.

Physical-chemical structure of VIPRO

International Nuclear Information System (INIS)

Lauri, L.

1986-01-01

PELF is a manufacturer of rigid expanded PVC in the form of panels of different density. There are only three manufacturers of this product in the world. This material is used in self-supporting structures of forms of transport, refrigerator trucks, busses, in the naval industry, for the construction of boats up to 40-50 meters in length, in the aeronautical and military industries. The research was developed in the two following phases: 1st phase: construction of a PVC panel with the density of approximately 1.000 Kg/cm. doped with extremely pure Boron using the base formula of rigid expanded PVC 2nd phase: construction of a completely new panel using for the first time in the world in the sector of plastic matters, the formula 'in alloy' where the absorbing material Boron or Lead become part of the chemical link. Only a simple and at the same time extremely resistant physical-chemical structure, a determined increase of resistance to temperatures, a considerable increase also of the number of Hydrogen atoms/c.m. could give the hoped for results. This is how VIPRO was born

Structural and optical characterization of self-assembled Ge nanocrystal layers grown by plasma-enhanced chemical vapor deposition

NARCIS (Netherlands)

Saeed, S.; Buters, F.; Dohnalova, K.; Wosinski, L.; Gregorkiewicz, T.

2014-01-01

We present a structural and optical study of solid-state dispersions of Ge nanocrystals prepared by plasma-enhanced chemical vapor deposition. Structural analysis shows the presence of nanocrystalline germanium inclusions embedded in an amorphous matrix of Si-rich SiO2. Optical characterization

Physical and optical characterisation of carbon-silicon layers produced by rapid thermal chemical vapour deposition

International Nuclear Information System (INIS)

McBride, G.M.

1994-04-01

The Quplas II reactor is a novel chemical vapour deposition (CVD) system, which was recently designed and built at The Queen's University of Belfast. The system was intended to produce layers of Silicon (Si) for application in advanced bipolar transistor manufacture. It became clear that the system was capable of depositing novel materials such as Silicon-Carbon (Si-C) films which could have application as the emitter material in heterojunction bipolar transistors (HBT's) formed on silicon substrates. This work focuses mainly on the development of analytical techniques to allow characterisation of the deposited layers of Si-C and permit optimisation of both the process conditions and the deposition system. The techniques that were developed to characterise the Si-C films in terms of their physical and optical properties included: Secondary Ion Mass Spectroscopy (SIMS), X-Ray Diffractometry (XRD), Transmission and Scanning Electron Microscopy (TEM and SEM), Near Infrared (NIR) and Ultraviolet/Visible/Near Infrared (UV/VIS/NIR) Spectroscopy. From assessing the data obtained from the analysis of the samples using the techniques mentioned above, it was possible to characterise the Si-C films in terms of: stoichiometry, crystallinity, degree of oxygen contamination, thickness, optical roughness of the film/air and film/substrate interfaces, and energy bandgap. In the fabrication of Si-C films it was found to be necessary to use low process pressures in order to ensure that the film deposition was slow enough to allow for a more ordered growth process. This led to the formation of polycrystalline Si-C films which had greatly reduced levels of oxygen compared to earlier amorphous films. In addition the polycrystalline Si-C films tended to have optically rough film/air and film/substrate interfaces. For most samples it was possible to obtain the thickness of their Si-C films from their SIMS profiles. Based on the method of interferometry, the thickness of the Si-C films

Scintillating plastic optical fiber radiation detectors in high energy particle physics

International Nuclear Information System (INIS)

Bross, A.D.

1991-01-01

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs

Synthesis of chiral polyaniline films via chemical vapor phase polymerization

DEFF Research Database (Denmark)

Chen, J.; Winther-Jensen, B.; Pornputtkul, Y.

2006-01-01

Electrically and optically active polyaniline films doped with (1)-(-)-10- camphorsulfonic acid were successfully deposited on nonconductive substrates via chemical vapor phase polymerization. The above polyaniline/ R- camphorsulfonate films were characterized by electrochemical and physical...

Physical and Chemical Properties of Some Selected Rice Varieties

African Journals Online (AJOL)

User

Physical and chemical properties of nine rice varieties grown and processed in Ebonyi .... Therefore, one tonne of a slender variety of rice will need more storage space than the ..... during washing and boiling of milled rice Starch 36:386-390.

Physical, chemical and texture characteristics of Aro cheese

Directory of Open Access Journals (Sweden)

González, M.L.

2017-10-01

Full Text Available In 2016, Mexico’s total annual production of cheese was 375,181 tons. Cheese is widely consumed among all socioeconomic groups, and the decision to purchase this product is based on income, with a wide variety of cheeses, brands, and styles available. The fresco cheese is the most popular type and is mostly produced according to traditional or artisanal methods in small family businesses, and small and medium-sized enterprises. It is made with the milk of the producers' livestock, giving it an added value. In Mexico, however, there is not enough scientific information related to the characterization of various dairy products of artisanal production, for example, Aro cheese. The aim of the present study was to define the physical, chemical, and rheological characteristics of the Aro cheese that is commercialized in Teotitlán de Flores Magón, Oaxaca, Mexico. Twenty-four samples of Aro cheese were collected in four establishments with high sales in Teotitlán de Flores Magón, Oaxaca, for analysis physical (Diameter, weight, height and color, chemical (pH, acidity, aw, chlorides, moisture, ashes, protein and fat, and texture (hardness, springiness, adhesiveness and cohesiveness. No difference was found in weight, diameter, height, and color (L* and b*. However, differences in hardness and cohesiveness were found. Although Aro cheese is characterized as an enzymatically coagulated cheese, pH values of 5.82 to 6.08 were recorded, and the data relating to moisture, protein, fat, and chlorides are similar to other Mexican fresh cheeses. The cheese of Aro that is commercialized in Teotitlán de Flores Magón, presents similar physical, chemical and texture characteristics to other fresh cheeses of artisanal production.

Advances in atomic, molecular, and optical physics

CERN Document Server

Berman, Paul R; Arimondo, Ennio

2006-01-01

Volume 54 of the Advances Series contains ten contributions, covering a diversity of subject areas in atomic, molecular and optical physics. The article by Regal and Jin reviews the properties of a Fermi degenerate gas of cold potassium atoms in the crossover regime between the Bose-Einstein condensation of molecules and the condensation of fermionic atom pairs. The transition between the two regions can be probed by varying an external magnetic field. Sherson, Julsgaard and Polzik explore the manner in which light and atoms can be entangled, with applications to quantum information processing

Analysis and classification of physical and chemical methods of fuel activation

Directory of Open Access Journals (Sweden)

Fedorchak Viktoriya

2015-12-01

Full Text Available The offered article explores various research studies, developed patents in terms of physical and chemical approaches to the activation of fuel. In this regard, national and foreign researches in the field of fuels activators with different principles of action were analysed, evaluating their pros and cons. The article also intends to classify these methods and compare them regarding diverse desired results and types of fuels used. In terms of physical and chemical influences on fuels and the necessity of making constructive changes in the fuel system of internal combustion engines, an optimal approach was outlined.

Physical and chemical properties of ice residuals during the 2013 and 2014 CLACE campaigns

Science.gov (United States)

Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Hammer, Emanuel; Gysel, Martin; Färber, Raphael; Fuchs, Claudia; Schnaiter, Martin; Baltensperger, Urs; Schmidt, Susan; Schneider, Johannes; Bigi, Alessandro; Toprak, Emre; Linke, Claudia; Klimach, Thomas

2014-05-01

The shortcomings in our understanding and, thus, representation of aerosol-cloud interactions are one of the major sources of uncertainty in climate model projections. Among the poorly understood processes is mixed-phase cloud formation via heterogeneous nucleation, and the subsequent spatial and temporal evolution of such clouds. Cloud glaciation augments precipitation formation, resulting in decreased cloud cover and lifetime, and affects cloud radiative properties. Meanwhile, the physical and chemical properties of atmospherically relevant ice nuclei (IN), the sub-population of aerosol particles which enable heterogeneous nucleation, are not well known. Extraction of ice residuals (IR) in mixed-phase clouds is a difficult task, requiring separation of the few small, freshly formed ice crystals (the IR within such crystals can be deemed representative of the original IN) not only from interstitial particles, but also from the numerous supercooled droplets which have aerodynamic diameters similar to those of the ice crystals. In order to address the difficulties with ice crystal sampling and IR extraction in mixed-phase clouds, the new Ice Selective Inlet (ISI) has been designed and deployed at the Jungfraujoch field site. Small ice crystals are selectively sampled via the inlet with simultaneous counting, sizing and imaging of hydrometeors contained in the cloud by a set of optical particle spectrometers, namely Welas optical particle counters (OPC) and a Particle Phase Discriminator (PPD). The heart of the ISI is a droplet evaporation unit with ice-covered inner walls, resulting in removal of droplets using the Wegener-Bergeron-Findeisen process, while transmitting a relatively high fraction of small ice crystals. The ISI was deployed in the winters of 2013 and 2014 at the high alpine Jungfraujoch site (3580 m.a.s.l) during the intensive CLACE field campaigns. The measurements focused on analysis of the physical and chemical characteristics of IR and the

Physical and chemical events that follow the passage of a charged particle in liquid water

International Nuclear Information System (INIS)

Wright, H.A.; Hamm, R.N.; Turner, J.E.; Magee, J.L.; Chatterjee, A.

1985-01-01

Biological effects of radiation are the result of a complicated sequence of events that begins with initial physical interactions that are complete by approx. 10 -15 s, followed by chemical interactions that begin at approx. 10 -11 s and are complete by approx. 10 -6 s, and followed by later biochemical and biological events, some of which may not occur for years. A central problem in radiation physics and radiation chemistry is to understand the details of the physical and chemical events that occur during that first microsecond following the passage of a charged particle. Significant progress has been made recently at linking early physical events with later chemical events. We have developed a Monte Carlo computer code to calculate the position and identity of each physical event that a charged particle (electron, proton, alpha) and all of its secondaries undergoes in traversing liquid water. The code then calculates the position and identity of each reactive chemical species (ion or radical) that is produced from these physical events and is present at 10 -11 s, and then follows each reactant through the diffusion and chemical reaction stage of track development. This work will be discussed and examples of ''pictures'' of charged-particle tracks at various times will be shown. 11 refs., 9 figs

Impact of Simulator-Based Instruction on Diagramming in Geometrical Optics by Introductory Physics Students.

Science.gov (United States)

Reiner, Miriam; And Others

1995-01-01

Observations of high school physics students in an instructional experiment with an interactive learning environment in geometrical optics indicated that students in the Optics Dynagrams Project went through major conceptual developments as reflected in the diagrams they constructed. (Author/MKR)

Perspective: Fifty years of density-functional theory in chemical physics

International Nuclear Information System (INIS)

Becke, Axel D.

2014-01-01

Since its formal inception in 1964–1965, Kohn-Sham density-functional theory (KS-DFT) has become the most popular electronic structure method in computational physics and chemistry. Its popularity stems from its beautifully simple conceptual framework and computational elegance. The rise of KS-DFT in chemical physics began in earnest in the mid 1980s, when crucial developments in its exchange-correlation term gave the theory predictive power competitive with well-developed wave-function methods. Today KS-DFT finds itself under increasing pressure to deliver higher and higher accuracy and to adapt to ever more challenging problems. If we are not mindful, however, these pressures may submerge the theory in the wave-function sea. KS-DFT might be lost. I am hopeful the Kohn-Sham philosophical, theoretical, and computational framework can be preserved. This Perspective outlines the history, basic concepts, and present status of KS-DFT in chemical physics, and offers suggestions for its future development

Perspective: Fifty years of density-functional theory in chemical physics

Energy Technology Data Exchange (ETDEWEB)

Becke, Axel D., E-mail: axel.becke@dal.ca [Department of Chemistry, Dalhousie University, 6274 Coburg Rd., P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada)

2014-05-14

Since its formal inception in 1964–1965, Kohn-Sham density-functional theory (KS-DFT) has become the most popular electronic structure method in computational physics and chemistry. Its popularity stems from its beautifully simple conceptual framework and computational elegance. The rise of KS-DFT in chemical physics began in earnest in the mid 1980s, when crucial developments in its exchange-correlation term gave the theory predictive power competitive with well-developed wave-function methods. Today KS-DFT finds itself under increasing pressure to deliver higher and higher accuracy and to adapt to ever more challenging problems. If we are not mindful, however, these pressures may submerge the theory in the wave-function sea. KS-DFT might be lost. I am hopeful the Kohn-Sham philosophical, theoretical, and computational framework can be preserved. This Perspective outlines the history, basic concepts, and present status of KS-DFT in chemical physics, and offers suggestions for its future development.

Effect of temperature on the morphology and electro-optical properties of liquid crystal physical gel

International Nuclear Information System (INIS)

Leaw, W.L.; Mamat, C.R.; Triwahyono, S.; Jalil, A.A.; Bidin, N.

2016-01-01

Liquid crystal physical gels were (thermally) prepared with cholesteryl stearate as a gelator in nematic liquid crystal, 4-cyano-4′-pentylbiphenyl. The electro-optical performance of liquid crystal physical gels is almost entirely dependent on the gels' inherent morphology. This study involved an empirical investigation of the relationships among all of the gelation temperature, morphology, and electro-optical properties. Besides continuous cooling at room temperature, isothermal cooling was also performed at both 18 and 0 °C, corresponding to near-solid and solid phases of 4-cyano-4′-pentylbiphenyl respectively. Nevertheless, the liquid crystal physical gel was also isothermally rapidly cooled using liquid nitrogen. Polarizing optical microscopy showed that the gel structure became thinner when isothermal cooling was carried out. These thinner gel aggregates then interconnected to form larger liquid crystal domains. Moreover, it was also revealed that the gel networks were randomized. Electron spin resonance results showed that the liquid crystal director orientation was severely randomized in the presence of gel networks. Conversely, isothermal cooling using liquid nitrogen generated a higher liquid crystal director orientation order. The 6.0 wt% cholesteryl stearate/4-cyano-4′-pentylbiphenyl physical gel that was isothermally cooled using liquid nitrogen showed the lowest response time in a twisted nematic mode optical cell. - Graphical abstract: Liquid crystal physical gel was prepared using nematic liquid crystal, 4-cyano-4′-pentylbiphenyl and cholesteryl stearate as gelator. Isothermal cooling at lower temperature produced thinner gel network and larger liquid crystal domain. - Highlights: • 5CB nematic liquid crystal was successfully gelled by cholesteryl stearate gelator. • The morphology of gel network was controlled by different cooling conditions. • Thinner gel network was formed by the rapid cooling using liquid nitrogen. • Enhanced

Effect of temperature on the morphology and electro-optical properties of liquid crystal physical gel

Energy Technology Data Exchange (ETDEWEB)

Leaw, W.L. [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Mamat, C.R., E-mail: che@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Triwahyono, S. [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Jalil, A.A. [Department of Chemical Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Centre of Hydrogen Energy, Institute of Future Energy, Univerisiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Bidin, N. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia)

2016-12-01

Liquid crystal physical gels were (thermally) prepared with cholesteryl stearate as a gelator in nematic liquid crystal, 4-cyano-4′-pentylbiphenyl. The electro-optical performance of liquid crystal physical gels is almost entirely dependent on the gels' inherent morphology. This study involved an empirical investigation of the relationships among all of the gelation temperature, morphology, and electro-optical properties. Besides continuous cooling at room temperature, isothermal cooling was also performed at both 18 and 0 °C, corresponding to near-solid and solid phases of 4-cyano-4′-pentylbiphenyl respectively. Nevertheless, the liquid crystal physical gel was also isothermally rapidly cooled using liquid nitrogen. Polarizing optical microscopy showed that the gel structure became thinner when isothermal cooling was carried out. These thinner gel aggregates then interconnected to form larger liquid crystal domains. Moreover, it was also revealed that the gel networks were randomized. Electron spin resonance results showed that the liquid crystal director orientation was severely randomized in the presence of gel networks. Conversely, isothermal cooling using liquid nitrogen generated a higher liquid crystal director orientation order. The 6.0 wt% cholesteryl stearate/4-cyano-4′-pentylbiphenyl physical gel that was isothermally cooled using liquid nitrogen showed the lowest response time in a twisted nematic mode optical cell. - Graphical abstract: Liquid crystal physical gel was prepared using nematic liquid crystal, 4-cyano-4′-pentylbiphenyl and cholesteryl stearate as gelator. Isothermal cooling at lower temperature produced thinner gel network and larger liquid crystal domain. - Highlights: • 5CB nematic liquid crystal was successfully gelled by cholesteryl stearate gelator. • The morphology of gel network was controlled by different cooling conditions. • Thinner gel network was formed by the rapid cooling using liquid nitrogen. �

Irradiation of 'minas frescal' cheese: physical-chemical aspects

International Nuclear Information System (INIS)

Gurgel, Maria Sylvia de C.C. do Amaral; Spoto, Marta H.F.; Domardo, Raquel E.; Gutierrez, Erica Maria Roel

2000-01-01

The present work studied the viability of gamma radiation as alternative method of conservation 'minas frescal' cheese through by determining its effect on the physical-chemical properties of this product after irradiation. Cheese elaborated in the Laboratory of Food Irradiation CENA/USP, were exposed to doses of 0 (it controls); 1; 2; 3 and 4 kGy and stored under refrigeration (±5 deg C). The analysis were accomplished in the 1st, 7th and 14th day of storage considered the following parameters: acidity, pH, moisture and level of proteolysis according to methodology of Association of Official Analytical Chemists (A.O.A.C.),1995. The results revealed that the dose of 2 kGy was the most indicated for irradiation of that type of cheese, because after this treatment, the product maintained in good conditions for consumption after 14 days of storage. It was concluded that gamma radiation can be used as a method of conservation of 'minas frescal' cheese, without causing alterations in its physical-chemical characteristics. (author)

Physical and dispersive optical characteristics of ZrON/Si thin-film system

Energy Technology Data Exchange (ETDEWEB)

Wong, Yew Hoong [University of Malaya, Centre of Advanced Materials, Department of Mechanical Engineering, Faculty of Engineering, Kuala Lumpur (Malaysia); University of Malaya, Centre of Advanced Manufacturing and Material Processing, Kuala Lumpur (Malaysia); Atuchin, V.V. [Institute of Semiconductor Physics, SB RAS, Laboratory of Optical Materials and Structures, Novosibirsk (Russian Federation); Kruchinin, V.N. [Institute of Semiconductor Physics, SB RAS, Laboratory for Ellipsometry of Semiconductor Materials and Structures, Novosibirsk (Russian Federation); Cheong, Kuan Yew [Universiti Sains Malaysia, Electronic Materials Research Group, School of Materials and Mineral Resources Engineering, Engineering Campus, Seberang Perai Selatan, Penang (Malaysia)

2014-06-15

To date, the complex evaluation of physical and dispersive optical characteristics of the ZrON/Si film system has yet been reported. Hence, ZrON thin films have been formed on Si(100) substrates through oxidation/nitridation of sputtered metallic Zr in N{sub 2}O environment at 500, 700, and 900 C. Physical properties of the deposited films have been characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, reflection high-energy electron diffraction (RHEED), and spectroscopic ellipsometry (SE). It has been shown that ZrON/Si thin films without optical absorption can be prepared by oxidation/nitridation reaction in N{sub 2}O environment at 700-900 C. (orig.)

Directional radiometry and radiative transfer: The convoluted path from centuries-old phenomenology to physical optics

International Nuclear Information System (INIS)

Mishchenko, Michael I.

2014-01-01

This Essay traces the centuries-long history of the phenomenological disciplines of directional radiometry and radiative transfer in turbid media, discusses their fundamental weaknesses, and outlines the convoluted process of their conversion into legitimate branches of physical optics. - Highlights: • History of phenomenological radiometry and radiative transfer is described. • Fundamental weaknesses of these disciplines are discussed. • The process of their conversion into legitimate branches of physical optics is summarized

Spring Blooms Observed with Biochemical Profiling Floats from a Chemical and Biological Perspective

Science.gov (United States)

Plant, J. N.; Johnson, K. S.; Sakamoto, C.; Jannasch, H. W.; Coletti, L. J.; Elrod, V.

2015-12-01

Recently there has been renewed interest in the mechanisms which control the seasonal increases in plankton biomass (spring blooms). Changes in physical and chemical forcing (light, wind, heat and nutrients) may increase the specific growth rate of phytoplankton. These changes may also shift the predator - prey relationships within the food web structure, which can alter the balance between plankton growth and loss rates. Biogeochemical profiling floats provide a means to observe the seasonal evolution of spring blooms from a physical, chemical and biological perspective in near real time. Floats equipped with optical sensors to measure nitrate, oxygen, chlorophyll fluorescence, and optical backscatter now have a presence in many ocean regions including the North Pacific, Subarctic Pacific, North Atlantic, South Atlantic and the Southern Ocean. Data from these regions are used to compare and contrast the evolution of spring blooms. The evolution of the bloom is examined using both chemical (oxygen, nitrate) and biooptical (phytoplankton from chlorophyll fluorescence and particulate organic carbon from optical backscatter) sensors under vastly different environmental conditions.

Chemical, physical and tribological investigation of polymercaptanized soybean oil

Science.gov (United States)

Polymercaptanized soybean oil (PMSO) was investigated for its chemical, physical and tribological properties relative to soybean oil (SO) and also as a potential multi-functional lubricant additive in high oleic sunflower oil (HOSuO). Analytical investigations showed that PMSO is obtained by convers...

Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

Science.gov (United States)

Taguchi, K.; Hirota, S.; Nakayama, H.; Kunugihara, D.; Mihara, Y.

2012-03-01

In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

International Nuclear Information System (INIS)

Taguchi, K; Hirota, S; Nakayama, H; Kunugihara, D; Mihara, Y

2012-01-01

In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

[Chemical, physical and biological risks in law enforcement].

Science.gov (United States)

Magrini, Andrea; Grana, Mario; Vicentini, Laura

2014-01-01

Chemical, physical and biological risks among public safety and security forces. Law enforcement personnel, involved in routine tasks and in emergency situations, are exposed to numerous and several occupational hazards (chemical, physical and biological) whith likely health and security consequences. These risks are particularly high when the organization and preparation are inadequate, there is a lacking or insufficient coordination, information, education and communication and safety and personal protective equipment are inadequate or insufficient. Despite the objective difficulties, caused by the actual special needs related to the service performed or the organizational peculiarities, the risk identification and assessment is essential for worker health and safety of personnel, as provided for by Legislative Decree no. 81/2008. Chemical risks include airborne pollutants due to vehicular traffic (carbon monoxide, ultrafine particles, benzene, polycyclic aromatic hydrocarbons, aldehydes, nitrogen and sulfur oxides, lead), toxic gases generated by combustion process following fires (aromatic hydrocarbons, PAHs, dioxins and furans, biphenyls, formaldehyde, metals and cyanides), substances emitted in case of chemical accidents (solvents, pesticides, toxic gases, caustics), drugs (methylamphetamine), riot control agents and self-defence spray, lead at firing ranges, and several materials and reagents used in forensic laboratory. The physical hazards are often caused by activities that induce biomechanical overload aid the onset of musculoskeletal disorders, the use of visual display terminals and work environments that may expose to heat stress and discomfort, high and low pressure, noise, vibrations, ionizing and non-ionizing radiation. The main biological risks are blood-borne diseases (viral hepatitis, AIDS), airborne diseases (eg, tuberculosis, meningitis, SARS, anthrax), MRSA, and vector-borne diseases. Many of these risk factors are unavoidable or are not

Elaboration of colloidal silica sols in aqueous medium: functionalities, optical properties and chemical detection of coating

International Nuclear Information System (INIS)

Le Guevel, X.

2006-03-01

The aim of this work was to study surface reactivity of silica nanoparticles through physical and chemical properties of sols and coatings. Applications are numerous and they are illustrated in this work by optical coating preparation for laser components and chemical gas sensor development for nitroaromatics detection. On one hand, protocol synthesis of colloidal silica sols has been developed in water medium using sol-gel process (0 to 100 w%). These sols, so-called BLUESIL, are time-stable during at least one year. Homogeneous coatings having thickness fixed to 200 nm, have been prepared on silica substrate and show high porosity and high transparence. Original films have been developed using catalytic curing in gas atmosphere (ammonia curing) conferring good abrasive resistance to the coating without significant properties modification. In order to reduce film sensitivity to molecular adsorption (water, polluting agents... ), specific BLUESIL coatings have been prepared showing hydrophobic property due to apolar species grafting onto silica nanoparticles. Using this route, coatings having several functional properties such as transparence, hydrophobicity, high porosity and good abrasive resistance have been elaborated. On the other hand, we show that colloidal silica is a material specifically adapted to the detection of nitro aromatic vapors (NAC). Indeed, the use of colloidal silica as chemical gas sensor reveals very high sensitivity, selectivity to NAC compared to Volatile Organic Compound (V.O.C) and good detection performances during one year. Moreover, chemical sensors using functionalized colloidal silica have exhibited good results of detection, even in high humidity medium (≥70 %RH). (author)

Micro- and nanostructured sol-gel-based materials for optical chemical sensing (2005–2015)

International Nuclear Information System (INIS)

Barczak, Mariusz; McDonagh, Colette; Wencel, Dorota

2016-01-01

This review (with 172 references) highlights the progress made in the past 10 years in silica sol-gel-based materials for use in optical chemical sensing. Following an introduction, the processes leading to the sol-gel-based and ormosil materials, their printability and methods for characterisation are discussed. Then various classes of optical sensors, with a focus on sensors for pH values, oxygen, carbon dioxide, ammonia (also in dissolved form), and heavy metal ions are described. A further section covers nanoparticle-based optical sensors mainly for use in intracellular sensing of the above species. Recent developments in this area are also emphasised and future trends discussed. (author)

Optical bio-chemical sensors on SNOW ring resonators

Science.gov (United States)

Khorasaninejad, Mohammadreza; Clarke, Nigel; Anantram, M. P.; Singh Saini, Simarjeet

2011-08-01

In this paper, we propose and analyze novel ring resonator based bio-chemical sensors on silicon nanowire optical waveguide (SNOW) and show that the sensitivity of the sensors can be increased by an order of magnitude as compared to silicon-on-insulator based ring resonators while maintaining high index contrast and compact devices. The core of the waveguide is hollow and allows for introduction of biomaterial in the center of the mode, thereby increasing the sensitivity of detection. A sensitivity of 243 nm/refractive index unit (RIU) is achieved for a change in bulk refractive index. For surface attachment, the sensor is able to detect monolayer attachments as small as 1 Å on the surface of the silicon nanowires.

Technical aspects of the use of optical fibers for data transmission in particle physics

International Nuclear Information System (INIS)

Petrolo, E.

1991-01-01

This presentation will discuss the major technical aspects related to the use of optical fibers for data transmission in particle physics. The different possibilities of use of optical links for different experimental applications and environments will be presented with an overview of the technical problems in the use of optical transmission components, such as fibers and their radiation damage, emitters, detectors, cables, transmission systems, etc. (orig.)

Microspectroscopic imaging of solution plasma: How do its physical properties and chemical species evolve in atmospheric-pressure water vapor bubbles?

Science.gov (United States)

Yui, Hiroharu; Banno, Motohiro

2018-01-01

In this article, we review the development of scientific instruments for obtaining information on the evolution of physical properties and chemical species of solution plasma (SP). When a pulsed high voltage is applied between electrodes immersed in an aqueous solution, SP is formed in water vapor bubbles transiently generated in the solution under atmospheric pressure. To clarify how SP emerges in water vapor bubbles and is sustained in solutions, an instrument with micrometer spatial resolution and nanosecond temporal resolution is required. To meet these requirements, a microscopic system with a custom-made optical discharge cell was newly developed, where the working distance between the SP and the microscopic objective lens was minimized. A hollow electrode equipped in the discharge cell also enabled us to control the chemical composition in water vapor bubbles. To study the spatial and temporal evolutions of chemical species in micrometer and nano- to microsecond regions, a streak camera with a spectrometer and a CCD detector with a time-gated electronic device were combined with the microscope system. The developed instrument is expected to contribute to providing a new means of developing new schemes for chemical reactions and material syntheses.

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

Directory of Open Access Journals (Sweden)

Sérgio Paulo Hilgenberg

2011-08-01

Full Text Available This in vitro study evaluated the physical-chemical characteristics of whitening toothpastes and their effect on bovine enamel after application of a bleaching agent (16% carbamide peroxide. Physical-chemical analysis was made considering mass loss by desiccation, ash content and pH of the toothpastes. Thirty bovine dental enamel fragments were prepared for roughness measurements. The samples were subjected to bleaching treatments and simulated brushing: G1. Sorriso Dentes Brancos (Conventional toothpaste, G2. Close-UP Whitening (Whitening toothpaste, and G3. Sensodyne Branqueador (Whitening toothpaste. The average roughness (Ra was evaluated prior to the bleaching treatment and after brushing. The results revealed differences in the physical-chemical characteristics of the toothpastes (p < 0.0001. The final Ra had higher values (p < 0.05 following the procedures. The mean of the Ra did not show significant differences, considering toothpaste groups and bleaching treatment. Interaction (toothpaste and bleaching treatment showed significant difference (p < 0.0001. The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the enamel surface, probably by the use of a bleaching agent.

Development of absorption fiber optic sensor for distributed measurement of ammonia gas

Science.gov (United States)

Aubrecht, J.; Kalvoda, L.

2013-05-01

Polymer-clad silica optical fibers are employed for development of different absorption optic fiber sensors of gaseous analytes. In our case, the physical principles of the detection are combined with a chemical reaction between analyte and suitable opto-chemical absorption reagents. Selected organometallic complex reagents with different lengths of lateral aliphatic chains are studied with respect to the type of central ions and their coordinative conditions to surrounding ligands. The effect of solvent type on solubility and the long-term stability of the prepared reagents in solid matrix are presented and discussed. Various methods are also tested in order to achieve an effective reagent immobilization into the polymer matrix, which creates optical fiber cladding. The chemical reaction of the reagents with ammonia based on ligand exchange process is accompanied by changes of visible-near-infrared optical absorption influencing via evanescent field on the guided light intensity. Experimental results suggest that the selected reagents provide optical properties suitable for practical sensing applications and that the sensitized PCS optical fibers could be used for detection of ammonia gas.

ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

R. Jarek

2005-08-29

The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The resulting seepage evaporation and gas abstraction models are used in the total system performance assessment for the license application (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2005 [DIRS 173782], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports. To be consistent with other project documents that address features, events, and processes (FEPs), Table 6.14.1 of the current report includes updates to FEP numbers and FEP subjects for two FEPs identified in the technical work plan (TWP) governing this report (BSC 2005 [DIRS 173782]). FEP 2.1.09.06.0A (Reduction-oxidation potential in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.06.0B (Reduction-oxidation potential in Drifts; see Table 6.14-1). FEP 2.1.09.07.0A (Reaction kinetics in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.07.0B (Reaction kinetics in Drifts; see Table 6.14-1). These deviations from the TWP are justified because they improve integration with FEPs

Reducing uncertainties associated with filter-based optical measurements of light absorbing carbon particles with chemical information

Science.gov (United States)

Engström, J. E.; Leck, C.

2011-08-01

The presented filter-based optical method for determination of soot (light absorbing carbon or Black Carbon, BC) can be implemented in the field under primitive conditions and at low cost. This enables researchers with small economical means to perform monitoring at remote locations, especially in the Asia where it is much needed. One concern when applying filter-based optical measurements of BC is that they suffer from systematic errors due to the light scattering of non-absorbing particles co-deposited on the filter, such as inorganic salts and mineral dust. In addition to an optical correction of the non-absorbing material this study provides a protocol for correction of light scattering based on the chemical quantification of the material, which is a novelty. A newly designed photometer was implemented to measure light transmission on particle accumulating filters, which includes an additional sensor recording backscattered light. The choice of polycarbonate membrane filters avoided high chemical blank values and reduced errors associated with length of the light path through the filter. Two protocols for corrections were applied to aerosol samples collected at the Maldives Climate Observatory Hanimaadhoo during episodes with either continentally influenced air from the Indian/Arabian subcontinents (winter season) or pristine air from the Southern Indian Ocean (summer monsoon). The two ways of correction (optical and chemical) lowered the particle light absorption of BC by 63 to 61 %, respectively, for data from the Arabian Sea sourced group, resulting in median BC absorption coefficients of 4.2 and 3.5 Mm-1. Corresponding values for the South Indian Ocean data were 69 and 97 % (0.38 and 0.02 Mm-1). A comparison with other studies in the area indicated an overestimation of their BC levels, by up to two orders of magnitude. This raises the necessity for chemical correction protocols on optical filter-based determinations of BC, before even the sign on the

Reducing uncertainties associated with filter-based optical measurements of light absorbing carbon particles with chemical information

Directory of Open Access Journals (Sweden)

J. E. Engström

2011-08-01

Full Text Available The presented filter-based optical method for determination of soot (light absorbing carbon or Black Carbon, BC can be implemented in the field under primitive conditions and at low cost. This enables researchers with small economical means to perform monitoring at remote locations, especially in the Asia where it is much needed.

One concern when applying filter-based optical measurements of BC is that they suffer from systematic errors due to the light scattering of non-absorbing particles co-deposited on the filter, such as inorganic salts and mineral dust. In addition to an optical correction of the non-absorbing material this study provides a protocol for correction of light scattering based on the chemical quantification of the material, which is a novelty. A newly designed photometer was implemented to measure light transmission on particle accumulating filters, which includes an additional sensor recording backscattered light. The choice of polycarbonate membrane filters avoided high chemical blank values and reduced errors associated with length of the light path through the filter.

Two protocols for corrections were applied to aerosol samples collected at the Maldives Climate Observatory Hanimaadhoo during episodes with either continentally influenced air from the Indian/Arabian subcontinents (winter season or pristine air from the Southern Indian Ocean (summer monsoon. The two ways of correction (optical and chemical lowered the particle light absorption of BC by 63 to 61 %, respectively, for data from the Arabian Sea sourced group, resulting in median BC absorption coefficients of 4.2 and 3.5 Mm⁻¹. Corresponding values for the South Indian Ocean data were 69 and 97 % (0.38 and 0.02 Mm⁻¹. A comparison with other studies in the area indicated an overestimation of their BC levels, by up to two orders of magnitude. This raises the necessity for chemical correction protocols on optical filter

Physical and chemical events that follow the passage of a charged particle in liquid water

International Nuclear Information System (INIS)

Wright, H.A.; Hamm, R.N.; Turner, J.E.; Magee, J.L.; Chatterjee, A.

1986-01-01

Biological effects of radiation are the result of a complicated sequence of events that begins with initial physical interactions that are complete by ∼10 -15 s, followed by chemical interactions that begin at ∼10 -11 s and are completed by ∼10 -15 s, and followed by later biochemical and biological events, some of which may not occur for years. A central problem in radiation physics and radiation chemistry is to understand the details of the physical and chemical events that occur during that first microsecond following the passage of a charged particle. Significant progress has been made recently at linking early physical events with later chemical events. The authors have developed a Monte Carlo computer code to calculate the position and identity of each physical event that a charged particle (electron, proton, alpha) and all of its secondaries undergoes in traversing liquid water. The code then calculates the position and identity of each reactive chemical species (ion or radical) that is produced from these physical events and is present at 10 -11 s, and then follows each reactant through the diffusion and chemical reaction stage of track development. This work will be discussed and examples of pictures of charged-particle tracks at various times will be shown. 11 references, 9 figures, 4 tables

QUERCETIN PHYSICAL-CHEMICAL CHARACTERISTICS’ DEFINITION

Directory of Open Access Journals (Sweden)

I. V. Kovalevska

2014-04-01

dissolubility raise of this substance. Quercetin soaking research exposed that the substance does not get wet with hydrofoil dissolutions. Melting temperature determination showed that quercetin refers to thermostable powders (Тmelt. – 302 0С, that is why there are no physical-chemical changes while mechanic and physical affect. Thickness meaning (1,478 gives a chance to predict the creation of substance particles conglomeration which is being investigated. Conclusion. Thus, received experimental data allows to come to conclusion about the necessity to carry out the researches of the physical-chemical quercetin substance features to improve biopharmaceutic indices.

Calculations of physical and chemical reactions with DNA in aqueous solution from Auger cascades

International Nuclear Information System (INIS)

Wright, H.A.; Hamm, R.N.; Turner, J.E.; Howell, R.W.; Rao, D.V.; Sastry, K.S.R.

1989-01-01

Monte Carlo calculations are performed of the physical and chemical interactions in liquid water by electrons produced during Auger cascades resulting from the decay of various radionuclides. Estimates are also made of the number of direct physical and indirect chemical interactions that would be produced on DNA located near the decay site. 13 refs., 8 figs

Optimization of the sampling scheme for maps of physical and chemical properties estimated by kriging

Directory of Open Access Journals (Sweden)

Gener Tadeu Pereira

2013-10-01

Full Text Available The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.

Cyclotrons at the Institute of Physical and Chemical Research

International Nuclear Information System (INIS)

Imamura, Masashi.

1989-01-01

In this article the destruction by American forces, during World War II, of the Japanese cyclotrons and the subsequent construction of new cyclotrons at the Institute of Physical and Chemical Research, Japan is described. Their use for biological and medical radiation chemistry studies is summarized. (UK)

Statistical physics inspired energy-efficient coded-modulation for optical communications.

Science.gov (United States)

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2012-04-15

Because Shannon's entropy can be obtained by Stirling's approximation of thermodynamics entropy, the statistical physics energy minimization methods are directly applicable to the signal constellation design. We demonstrate that statistical physics inspired energy-efficient (EE) signal constellation designs, in combination with large-girth low-density parity-check (LDPC) codes, significantly outperform conventional LDPC-coded polarization-division multiplexed quadrature amplitude modulation schemes. We also describe an EE signal constellation design algorithm. Finally, we propose the discrete-time implementation of D-dimensional transceiver and corresponding EE polarization-division multiplexed system. © 2012 Optical Society of America

Quantum simulation of 2D topological physics in a 1D array of optical cavities.

Science.gov (United States)

Luo, Xi-Wang; Zhou, Xingxiang; Li, Chuan-Feng; Xu, Jin-Shi; Guo, Guang-Can; Zhou, Zheng-Wei

2015-07-06

Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration.

Chemically etched fiber tips for near-field optical microscopy: a process for smoother tips.

Science.gov (United States)

Lambelet, P; Sayah, A; Pfeffer, M; Philipona, C; Marquis-Weible, F

1998-11-01

An improved method for producing fiber tips for scanning near-field optical microscopy is presented. The improvement consists of chemically etching quartz optical fibers through their acrylate jacket. This new method is compared with the previous one in which bare fibers were etched. With the new process the meniscus formed by the acid along the fiber does not move during etching, leading to a much smoother surface of the tip cone. Subsequent metallization is thus improved, resulting in better coverage of the tip with an aluminum opaque layer. Our results show that leakage can be avoided along the cone, and light transmission through the tip is spatially limited to an optical aperture of a 100-nm dimension.

Physical and chemical characteristics of off vine ripened mango ...

African Journals Online (AJOL)

The need to develop the best off vine mango ripening technique for both consumption and processing was investigated. Some physical and chemical measurements were performed on mature Green Dodo mangoes before and during a 3-day and 6-day ripening period by smoked pit ripening (SPR), ethylene (fruit ...

Fabrication and characterization of a nanometer-sized optical fiber electrode based on selective chemical etching for scanning electrochemical/optical microscopy.

Science.gov (United States)

Maruyama, Kenichi; Ohkawa, Hiroyuki; Ogawa, Sho; Ueda, Akio; Niwa, Osamu; Suzuki, Koji

2006-03-15

We have already reported a method for fabricating ultramicroelectrodes (Suzuki, K. JP Patent, 2004-45394, 2004). This method is based on the selective chemical etching of optical fibers. In this work, we undertake a detailed investigation involving a combination of etched optical fibers with various types of tapered tip (protruding-shape, double- (or pencil-) shape and triple-tapered electrode) and insulation with electrophoretic paint. Our goal is to establish a method for fabricating nanometer-sized optical fiber electrodes with high reproducibility. As a result, we realized pencil-shaped and triple-tapered electrodes that had radii in the nanometer range with high reproducibility. These nanometer-sized electrodes showed well-defined sigmoidal curves and stable diffusion-limited responses with cyclic voltammetry. The pencil-shaped optical fiber, which has a conical tip with a cone angle of 20 degrees , was effective for controlling the electrode radius. The pencil-shaped electrodes had higher reproducibility and smaller electrode radii (r(app) etched optical fiber electrodes. By using a pencil-shaped electrode with a 105-nm radius as a probe, we obtained simultaneous electrochemical and optical images of an implantable interdigitated array electrode. We achieved nanometer-scale resolution with a combination of scanning electrochemical microscopy SECM and optical microscopy. The resolution of the electrochemical and optical images indicated sizes of 300 and 930 nm, respectively. The neurites of living PC12 cells were also successfully imaged on a 1.6-microm scale by using the negative feedback mode of an SECM.

Group Theory with Applications in Chemical Physics

Science.gov (United States)

Jacobs, Patrick

2005-10-01

Group Theory is an indispensable mathematical tool in many branches of chemistry and physics. This book provides a self-contained and rigorous account on the fundamentals and applications of the subject to chemical physics, assuming no prior knowledge of group theory. The first half of the book focuses on elementary topics, such as molecular and crystal symmetry, whilst the latter half is more advanced in nature. Discussions on more complex material such as space groups, projective representations, magnetic crystals and spinor bases, often omitted from introductory texts, are expertly dealt with. With the inclusion of numerous exercises and worked examples, this book will appeal to advanced undergraduates and beginning graduate students studying physical sciences and is an ideal text for use on a two-semester course. An introductory and advanced text that comprehensively covers fundamentals and applications of group theory in detail Suitable for a two-semester course with numerous worked examples and problems Includes several topics often omitted from introductory texts, such as rotation group, space groups and spinor bases

Starnet, a high-speed fiber optical network for particle physics application

International Nuclear Information System (INIS)

Bacilieri, P.; Ghiselli, A.; Caccia, B.; Valentini, S.; Ciaffoni, O.; Di Pirro, G.; Ferrer, M.L.; Martini, A.; Pace, E.; Trasatti, L.

1990-01-01

An asynchronous data transmission optical network using single-mode fibers and capable of transmitting frequencies of a few Gbit/s at distances of tens of kilometers is presented. This network (or part of it) is of interest for application in particle physics. (orig.)

Reverse engineering life: physical and chemical mimetics for controlled stem cell differentiation into cardiomyocytes.

Science.gov (United States)

Skuse, Gary R; Lamkin-Kennard, Kathleen A

2013-01-01

Our ability to manipulate stem cells in order to induce differentiation along a desired developmental pathway has improved immeasurably in recent years. That is in part because we have a better understanding of the intracellular and extracellular signals that regulate differentiation. However, there has also been a realization that stem cell differentiation is not regulated only by chemical signals but also by the physical milieu in which a particular stem cell exists. In this regard we are challenged to mimic both chemical and physical environments. Herein we describe a method to induce stem cell differentiation into cardiomyocytes using a combination of chemical and physical cues. This method can be applied to produce differentiated cells for research and potentially for cell-based therapy of cardiomyopathies.

Chemical and physical soil attributes in integrated crop-livestock system under no-tillage

OpenAIRE

Silva,Hernani Alves da; Moraes,Anibal de; Carvalho,Paulo César de Faccio; Fonseca,Adriel Ferreira da; Caires,Eduardo Fávero; Dias,Carlos Tadeu dos Santos

2014-01-01

Although integrated crop-livestock system (ICLS) under no-tillage (NT) is an attractive practice for intensify agricultural production, little regional information is available on the effects of animal grazing and trampling, particularly dairy heifers, on the soil chemical and physical attributes. The objective of this study was to evaluate the effects of animal grazing on the chemical and physical attributes of the soil after 21 months of ICLS under NT in a succession of annual winter pastur...

Understanding the physical and chemical changes on the three levels of the presentation of chemical concepts in students primary education

OpenAIRE

Bregar, Anja

2017-01-01

Physical and chemical changes are learning contents that address the essential chemical concepts in processes at particle level. When explaining chemical concepts at particle level, it is necessary to use various and appropriate visualization elements, such as (1) pictures, (2) photographs, (3) film excerpts (4) 2D or 3D stationary submicroscopic representations, (5) 2D and 3D dynamic contamination schemes, etc. This way, teachers can explain and interpret a chemical concept on three presenta...

Physical optics-based diffraction coefficient for a wedge with different face impedances.

Science.gov (United States)

Umul, Yusuf Ziya

2018-03-20

A new diffraction field expression is introduced with the aid of the modified theory of physical optics for a wedge with different face impedances. First, the scattered geometrical optics fields are determined when both faces of the wedge are illuminated by the incident wave. The geometrical optics waves are then expressed in terms of the sum of two different fields that occur for different impedance wedges. The diffracted fields are determined for the two cases separately, and the total diffracted field is obtained as a sum of these waves. Lastly, the uniform field expressions are obtained, and the resultant fields are numerically compared with the solution of Maliuzhinets.

Optical and electrical properties of chemical bath deposited cobalt sulphide thin films

Energy Technology Data Exchange (ETDEWEB)

Govindasamy, Geetha [R& D Centre, Bharathiar University, Coimbatore (India); Murugasen, Priya, E-mail: priyamurugasen15@gmail.com [Department of Physics, Saveetha Engineering, Chennai, Tamil Nadu (India); Sagadevan, Suresh [Department of Physics, AMET University, Chennai, Tamil Nadu (India)

2017-01-15

Cobalt sulphide (CoS) thin films were synthesized using the Chemical Bath Deposition (CBD) technique. X-ray diffraction (XRD) analysis was used to study the structure and the crystallite size of CoS thin film. Scanning Electron Microscope (SEM) studies reveal the surface morphology of these films. The optical properties of the CoS thin films were determined using UV-Visible absorption spectrum. The optical band gap of the thin films was found to be 1.6 eV. Optical constants such as the refractive index, the extinction coefficient and the electric susceptibility were determined. The dielectric studies were carried out at different frequencies and at different temperatures for the prepared CoS thin films. In addition, the plasma energy of the valence electron, Penn gap or average energy gap, the Fermi energy and electronic polarizability of the thin films were determined. The AC electrical conductivity measurement was also carried out for the thin films. The activation energy was determined by using DC electrical conductivity measurement. (author)

Optical orientation of atoms in plasma

Energy Technology Data Exchange (ETDEWEB)

Zhitnikov, R

1979-06-01

The results are summed up of experimental work on the optical orientation of atoms in a plasma conducted by the Atomic Radiospectroscopy Group at the AN SSSR Physical Technology Institute. The main methods of forming and observing the optical orientation of atoms in a helium plasma and an alkali metal plasma are described in detail. A quantum mechanical explanation is given of all observed phenomena. The most significant results include the discovery of the effect of the optical orientation of atoms in a plasma on the plasma optical and electrical properties, such as electric conductivity, emitted light intensity, ionization degree, and electron density. The phenomenon applies generally and is inherent to plasmas of different chemical compositions, at the optical orientation of atoms of different elements. The methods are indicated of the practical application of the phenomenon in designing principally new precision quantum magnetometers.

Aligned carbon nanotubes. Physics, concepts, fabrication and devices

Energy Technology Data Exchange (ETDEWEB)

Ren, Zhifeng; Lan, Yucheng [Boston College, Chestnut Hill, MA (United States). Dept. of Physics; Wang, Yang [South China Normal Univ. Guangzhou (China). Inst. for Advanced Materials

2013-07-01

This book gives a survey of the physics and fabrication of carbon nanotubes and their applications in optics, electronics, chemistry and biotechnology. It focuses on the structural characterization of various carbon nanotubes, fabrication of vertically or parallel aligned carbon nanotubes on substrates or in composites, physical properties for their alignment, and applications of aligned carbon nanotubes in field emission, optical antennas, light transmission, solar cells, chemical devices, bio-devices, and many others. Major fabrication methods are illustrated in detail, particularly the most widely used PECVD growth technique on which various device integration schemes are based, followed by applications such as electrical interconnects, nanodiodes, optical antennas, and nanocoax solar cells, whereas current limitations and challenges are also be discussed to lay the foundation for future developments.

Responses of soil physical and chemical properties to karst rocky desertification evolution in typical karst valley area

Science.gov (United States)

Chen, Fei; Zhou, Dequan; Bai, Xiaoyong; zeng, Cheng; Xiao, Jianyong; Qian, Qinghuan; Luo, Guangjie

2018-01-01

In order to reveal the differences of soil physical and chemical properties and their response mechanism to the evolution of KRD. The characteristics of soil physical and chemical properties of different grades of KRD were studied by field sampling method to research different types of KRD in the typical karst valley of southern China. Instead of using space of time, to explore the response and the mechanisms of the soil physical and chemical properties at the different evolution process. The results showed that: (1) There were significant differences in organic matter, pH, total nitrogen, total phosphorus, total potassium, sediment concentration, clay content and AWHC in different levels of KRD environment. However, these indicators are not with increasing desertification degree has been degraded, but improved after a first degradation trends; (2) The correlation analysis showed that soil organic matter, acid, alkali, total nitrogen, total phosphorus, total potassium and clay contents were significantly correlated with other physical and chemical factors. They are the key factors of soil physical and chemical properties, play a key role in improving soil physical and chemical properties and promoting nutrient cycling; (3) The principal component analysis showed that the cumulative contribution rate of organic matter, pH, total nitrogen, total phosphorus, total potassium and sediment concentration was 80.26%, which was the key index to evaluate rocky desertification degree based on soil physical and chemical properties. The results have important theoretical and practical significance for the protection and restoration of rocky desertification ecosystem in southwest China.

Physical, sensory and chemical properties of bread prepared from ...

African Journals Online (AJOL)

Physical, sensory and chemical properties of bread prepared from wheat and ... Different levels (0, 1, 2 and 3% w/w) of cissus gum powder was added to ... flours for bread making where 100% wheat bread without cissus gum served as control. ... serve as a gluten substitute in preparing acceptable wheat bread substituted ...

Optical closure experiments for biomass smoke aerosols

Science.gov (United States)

L. A. Mack; E. J. T. Levin; S. M. Kreidenweis; D. Obrist; H. Moosmuller; K. A. Lewis; W. P. Arnott; G. R. McMeeking; A. P. Sullivan; C. E. Wold; W.-M. Hao; J. L. Collett; W. C. Malm

2010-01-01

A series of laboratory experiments at the Fire Laboratory at Missoula (FLAME) investigated chemical, physical, and optical properties of fresh smoke samples from combustion of wildland fuels that are burned annually in the western and southeastern US The burns were conducted in the combustion chamber of the US Forest Service Fire Sciences Laboratory in Missoula,...

Connections between physical, optical and biogeochemical processes in the Pacific Ocean

Science.gov (United States)

Xiu, Peng; Chai, Fei

2014-03-01

A new biogeochemical model has been developed and coupled to a three-dimensional physical model in the Pacific Ocean. With the explicitly represented dissolved organic pools, this new model is able to link key biogeochemical processes with optical processes. Model validation against satellite and in situ data indicates the model is robust in reproducing general biogeochemical and optical features. Colored dissolved organic matter (CDOM) has been suggested to play an important role in regulating underwater light field. With the coupled model, physical and biological regulations of CDOM in the euphotic zone are analyzed. Model results indicate seasonal variability of CDOM is mostly determined by biological processes, while the importance of physical regulation manifests in the annual mean terms. Without CDOM attenuating light, modeled depth-integrated primary production is about 10% higher than the control run when averaged over the entire basin, while this discrepancy is highly variable in space with magnitudes reaching higher than 100% in some locations. With CDOM dynamics integrated in physical-biological interactions, a new mechanism by which physical processes affect biological processes is suggested, namely, physical transport of CDOM changes water optical properties, which can further modify underwater light field and subsequently affect the distribution of phytoplankton chlorophyll. This mechanism tends to occur in the entire Pacific basin but with strong spatial variability, implying the importance of including optical processes in the coupled physical-biogeochemical model. If ammonium uptake is sufficient to permit utilization of DOM, that is, UB∗⩾-U{U}/{U}-{(1-r_b)}/{RB}, then bacteria uptake of DOM has the form of FB=(1-r_b){U}/{RB}, bacteria respiration, SB=r_b×U, remineralization by bacteria, EB=UC{UN}/{UC}-{(1-r_b)}/{RB}. If EB > 0, then UB = 0; otherwise, UB = -EB. If there is insufficient ammonium, that is, UB∗CO2 is calculated using the

Photo-physics of third-order nonlinear optical processes in organic dyes

International Nuclear Information System (INIS)

Delysse, Stephane

1997-01-01

We study some aspects of the nonlinear picosecond photo-physics in organic dyes using Kerr ellipsometry. The aim is to establish link between the photo-physics and nonlinear optics in these compounds. First, we study coherent processes directly linked to the third-order susceptibility. Thus, we measure two-photon absorption spectra of large internal charge transfer dyes. We take into account all coupling between three electronic states which can interfere to explain the particular response of some stilbene dyes. On the second hand, we expose a more photophysical approach to determine the S 1 → S n transition energies and moments using the measurement of excited state absorption cross sections. These results allow the prediction of the susceptibilities relevant to alternative nonlinear optical methods. Nevertheless, the stationary approach hides the complex relaxation processes which can take place in organic dyes. As an illustration, we study the formation and disappearance of a TICT (Twisted intramolecular charge transfer) in a pyrylium salt in solvents of increasing viscosity. (author) [fr

Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

Directory of Open Access Journals (Sweden)

Fuensanta Sánchez Rojas

2006-10-01

Full Text Available Optical techniques for chemical analysis are well established and sensors based on thesetechniques are now attracting considerable attention because of their importance in applications suchas environmental monitoring, biomedical sensing, and industrial process control. On the other hand,flow injection analysis (FIA is advisable for the rapid analysis of microliter volume samples and canbe interfaced directly to the chemical process. The FIA has become a widespread automatic analyticalmethod for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, andease of assembling. In this paper, an overview of flow injection determinations by using opticalchemical sensors is provided, and instrumentation, sensor design, and applications are discussed. Thiswork summarizes the most relevant manuscripts from 1980 to date referred to analysis using opticalchemical sensors in FIA.

Chemical and physical effects of crowding on growth and survival of Penaeus monodon Fabricius post-larvae

NARCIS (Netherlands)

Nga, B.T.; Lürling, M.F.L.L.W.; Peeters, E.T.H.M.; Roijackers, R.M.M.; Scheffer, M.; Nghia, T.T.

2005-01-01

The hypothesis that crowding effects through physical and/or chemical interference may be an important factor in lowering the chance of survival and reducing growth of Penaeus monodon post-larvae under high stocking densities was tested. To separate physical interference from chemically-exerted

Physical and chemical characterization of waste wood derived biochars.

Science.gov (United States)

Yargicoglu, Erin N; Sadasivam, Bala Yamini; Reddy, Krishna R; Spokas, Kurt

2015-02-01

Biochar, a solid byproduct generated during waste biomass pyrolysis or gasification in the absence (or near-absence) of oxygen, has recently garnered interest for both agricultural and environmental management purposes owing to its unique physicochemical properties. Favorable properties of biochar include its high surface area and porosity, and ability to adsorb a variety of compounds, including nutrients, organic contaminants, and some gases. Physical and chemical properties of biochars are dictated by the feedstock and production processes (pyrolysis or gasification temperature, conversion technology and pre- and post-treatment processes, if any), which vary widely across commercially produced biochars. In this study, several commercially available biochars derived from waste wood are characterized for physical and chemical properties that can signify their relevant environmental applications. Parameters characterized include: physical properties (particle size distribution, specific gravity, density, porosity, surface area), hydraulic properties (hydraulic conductivity and water holding capacity), and chemical and electrochemical properties (organic matter and organic carbon contents, pH, oxidation-reduction potential and electrical conductivity, zeta potential, carbon, nitrogen and hydrogen (CHN) elemental composition, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and leachable PAHs and heavy metals). A wide range of fixed carbon (0-47.8%), volatile matter (28-74.1%), and ash contents (1.5-65.7%) were observed among tested biochars. A high variability in surface area (0.1-155.1g/m(2)) and PAH and heavy metal contents of the solid phase among commercially available biochars was also observed (0.7-83 mg kg(-1)), underscoring the importance of pre-screening biochars prior to application. Production conditions appear to dictate PAH content--with the highest PAHs observed in biochar produced via fast pyrolysis and lowest among the gasification

Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

Directory of Open Access Journals (Sweden)

J. P. Engelbrecht

2016-08-01

Full Text Available This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The  <  38 µm sieved fraction of each sample was re-suspended in a chamber, from which the airborne mineral dust could be extracted, sampled, and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size analyzer, and a three-wavelength (405, 532, 781 nm photoacoustic instrument with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sampling media included Teflon® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM. The  <  38 µm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the  >  75,  <  125 µm soil fractions were mineralogically assessed by optical microscopy. Presented here are results of the optical measurements, showing the interdependency of single-scattering albedos (SSA at three different wavelengths and mineralogical content of the entrained dust samples. To explain the elevated concentrations of iron (Fe and Fe ∕ Al ratios in the soil re-suspensions, we propose that dust particles are to a large extent composed of nano-sized particles of micas, clays, metal oxides, and ions of potassium (K+, calcium (Ca2+, and sodium (Na+ evenly dispersed as a colloid or adsorbed in amorphous

ANTIMICROBIAL, PHYSICAL AND CHEMICAL QUALITIES OF MEDICINAL ANTISEPTIC DRUGS

Directory of Open Access Journals (Sweden)

Paliy D. V.

2014-12-01

Full Text Available In our research results of the study of antimicrobial, physical and chemical qualities of antiseptic medicines of decamethoxin (DCM. Antimicrobial activity of DCM, palisan, decasan, deseptol against srains of S.aureus (n 56, S.epidermidis (n 26, E.coli (n 24, P.mirabilis (n 11, P.vulgaris (n 8 was studied by means of method of serial dilutions. Obtained data of mass spectrometry study of antimicrobial compositions with constant concentrations of DCM have shown that medicinal forms of DCM are complex physical and chemical systems, because of different origin and number of adjuvant ingredients used during their fabrication. Among synthetic quaternary ammonium agents there have been found the substance (commercial name of medicine is decamethoxin to have high antimicrobial activity against strains of grampositive and gram-negative microorganisms, an also C.albicans. There was found that antimicrobial activity of antiseptic palisan had been higher comparably to DCM in equivalent concentration. The composition and concentrations of acting agents and the methodology of preparation of palisan have been substantiated on the basis of microbiological, mass spectrometry characteristics of antiseptics DCM, palisan.

The development and characterization of sol-gel substrates for chemical and optical applications

Science.gov (United States)

Powers, Kevin William

1998-12-01

The sol gel process can be used to make monolithic porous glass for various scientific and engineering uses. The porosity of the material imparts a large surface area which is advantageous in applications such as catalyst supports or in the study of surface mediated chemical reactions. The chemical stability and transparency of the porous glass also make it suitable for use in the emerging field of optical sensors. In this study fluoride catalysis is used to produce sol gel monoliths with pore radii of up to 400 Angstroms, four times larger than any previously reported using conventional drying techniques. Gel monoliths with pore radii of 200 Angstroms were found to have the best combination of surface area, pore volume and optical transparency. Typical monoliths have surface areas of 150 m2/g and pore volumes of 1.60 cm3/g with good transparency. The monoliths are chemically stable, have good mechanical strength and can be easily rehydrated without cracking. The substrates are also suitable for sintering into dense high purity silica glass with little tendency towards foaming. An in-depth study of the catalytic effect of fluoride on the sol gel process is also included. It has been theorized that fluoride serves to expand the coordination sphere of the silicon center making it more subject to nucleophilic attack. In this work an ion-specific fluoride electrode is used to monitor free fluoride concentrations in HF catalyzed sols while silicic acid is added in the form of tetramethoxysilane (TMOS). It is found that fluoride is rapidly bound by the silicic acid in a ratio of four to one, indicating the formation of silicon tetrafluoride. A concurrent decrease in pH suggests that a pentacoordinate species is formed that is more stable than previously thought. A polymerization mechanism is proposed that explains the hydrophobicity of fluoride catalyzed gels and the difficulty in retaining structural fluoride in fluoride catalyzed sol gel glasses. Finally, several

Investigations of Physical-Chemical and Microbiological Deterioration of Chocolate Pralines

DEFF Research Database (Denmark)

Nielsen, Cecilie Lykke Marvig

Chocolate pralines, defined as soft fruit, sugar or fat based fillings covered with a chocolate shell, are multidomain, complex food products. The chocolate shell consists of a continuous fat phase in which sugar and cocoa particles are dispersed. The fillings can vary in composition and texture...... of the sugar and cocoa particles plays a role in the sensorial assessment of the chocolate. Fillings for chocolate pralines varies a lot and no common quality parameters can be set for these, but needs to be defined for the individual filling. The shelf life of chocolate pralines is determined by numerous...... and complex interactions between intrinsic and external parameters, and spoilage can be of either microbial or physical-chemical character or a combination of the two. Chocolate belong to the group of low moisture food products and is only susceptible to physical-chemical spoilage, while the fillings has...

Summer Research Institute Interfacial and Condensed Phase Chemical Physics

Energy Technology Data Exchange (ETDEWEB)

Barlow, Stephan E.

2004-10-01

Pacific Northwest National Laboratory (PNNL) hosted its first annual Summer Research Institute in Interfacial and Condensed Phase Chemical Physics from May through September 2004. During this period, fourteen PNNL scientists hosted sixteen young scientists from eleven different universities. Of the sixteen participants, fourteen were graduate students; one was transitioning to graduate school; and one was a university faculty member.

Surface treatments for biological, chemical and physical applications

CERN Document Server

Karaman, Mustafa

2017-01-01

A step-by-step guide to the topic with a mix of theory and practice in the fields of biology, chemistry and physics. Straightforward and well-structured, the first chapter introduces fundamental aspects of surface treatments, after which examples from nature are given. Subsequent chapters discuss various methods to surface modification, including chemical and physical approaches, followed by the characterization of the functionalized surfaces. Applications discussed include the lotus effect, diffusion barriers, enzyme immobilization and catalysis. Finally, the book concludes with a look at future technology advances. Throughout the text, tutorials and case studies are used for training purposes to grant a deeper understanding of the topic, resulting in an essential reference for students as well as for experienced engineers in R&D.

Physical and chemical stability of palonosetron HCl in 4 infusion solutions.

Science.gov (United States)

Trissel, Lawrence A; Xu, Quanyun A

2004-10-01

Palonosetron HCl is a selective 5-HT(3) receptor antagonist used for the prevention of chemotherapy-induced nausea and vomiting. Palonosetron HCl may be diluted in an infusion solution for administraton. Consequently, stability information is needed for palonosetron HCl admixed in common infusion solutions. To evaluate the physical and chemical stability of palonosetron HCl in concentrations of 5 and 30 microg/mL in dextrose 5% injection, NaCl 0.9% injection, dextrose 5% in NaCl 0.45% injection, and dextrose 5% in lactated Ringer's injection. Triplicate test samples of palonosetron HCl at each concentration in each diluent were tested. Samples were stored and evaluated at appropriate intervals for up to 48 hours at room temperature ( approximately 23 degrees C) and 14 days under refrigeration (4 degrees C). Physical stability was assessed using turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed by HPLC. All of the admixtures were initially clear and colorless when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and remained low throughout the study. The drug concentration was unchanged in any of the samples at either temperature throughout the study. Palonosetron HCl is physically and chemically stable in all 4 common infusion solutions for at least 48 hours at room temperature and 14 days under refrigeration.

Physical-chemical pretreatment as an option for increased sustainability of municipal wastewater treatment plants

NARCIS (Netherlands)

Mels, A.

2001-01-01

Keywords : municipal wastewater treatment, physical-chemical pretreatment, chemically enhanced primary treatment, organic polymers, environmental sustainability

Most of the currently applied municipal wastewater treatment plants in The Netherlands are

Denaturation of collagen structures and their transformation under the physical and chemical effects

Science.gov (United States)

Ivankin, A.; Boldirev, V.; Fadeev, G.; Baburina, M.; Kulikovskii, A.; Vostrikova, N.

2017-11-01

The process of denaturation of collagen structures under the influence of physical and chemical factors play an important role in the manufacture of food technology and the production of drugs for medicine and cosmetology. The paper discussed the problem of the combined effects of heat treatment, mechanical dispersion and ultrasonic action on the structural changes of the animal collagen in the presence of weak protonated organic acids. Algorithm combined effects of physical and chemical factors as a result of the formation of the technological properties of products containing collagen has been shown.

Chemical vapor deposition. Volume 2. 1975--July, 1978 (a bibliography with abstracts). Report for 1975--July 1978

International Nuclear Information System (INIS)

Smith, M.F.

1978-07-01

Research on chemical vapor deposition of carbon, carbides, ceramics, metals, and glasses are cited. Applications of this process include optical coatings, semiconducting films, laser materials, solar cells, composite fabrication, and nuclear reactor material fabrication. The physical, mechanical, and chemical properties of these coatings are covered

Optical orientation of atoms in plasma

International Nuclear Information System (INIS)

Zhitnikov, R.

1979-01-01

The results are summed up of experimental work on the optical orientation of atoms in a plasma conducted by the Atomic Radiospectroscopy Group at the AN SSSR Physical Technology Institute. The main methods of forming and observing the optical orientation of atoms in a helium plasma and an alkali metal plasma are described in detail. A quantum mechanical explanation is given of all observed phenomena. The most significant results include the discovery of the effect of the optical orientation of atoms in a plasma on the plasma optical and electrical properties, such as electric conductivity, emitted light intensity, ionization degree, and electron density. The phenomenon applies generally and is inherent to plasmas of different chemical compositions, at the optical orientation of atoms of different elements. The methods are indicated of the practical application of the phenomenon in designing principally new precision quantum magnetometers. (J.U.)

Physical and chemical properties of gels. Application to protein nucleation control in the gel acupuncture technique

Science.gov (United States)

Moreno, Abel; Juárez-Martínez, Gabriela; Hernández-Pérez, Tomás; Batina, Nikola; Mundo, Manuel; McPherson, Alexander

1999-09-01

In this work, we present a new approach using analytical and optical techniques in order to determine the physical and chemical properties of silica gel, as well as the measurement of the pore size in the network of the gel by scanning electron microscopy. The gel acupuncture technique developed by García-Ruiz et al. (Mater. Res. Bull 28 (1993) 541) García-Ruiz and Moreno (Acta Crystallogr. D 50 (1994) 484) was used throughout the history of crystal growth. Several experiments were done in order to evaluate the nucleation control of model proteins (thaumatin I from Thaumatococcus daniellii, lysozyme from hen egg white and catalase from bovine liver) by the porous network of the gel. Finally, it is shown how the number and the size of the crystals obtained inside X-ray capillaries is controlled by the size of the porous structure of the gel.

Physical optics modeling of modal patterns in a crossed porro prism resonator

CSIR Research Space (South Africa)

Litvin, IA

2006-07-01

Full Text Available A physical optics model is proposed to describe the transverse modal patterns in crossed Porro prism resonators. The model departs from earlier attempts in that the prisms are modeled as non-classical rotating elements with amplitude and phase...

The Magnetic Physical Optics Scattered Field in Terms of a Line Integral

DEFF Research Database (Denmark)

Meincke, Peter; Breinbjerg, Olav; Jørgensen, Erik

2000-01-01

An exact line integral representation Is derived for the magnetic physical optics field scattered by a perfectly electrically conducting planar plate illuminated by a magnetic Hertzian dipole. A numerical example is presented to illustrate the exactness of the line integral representation...

Effects of anticaking agents and relative humidity on the physical and chemical stability of powdered vitamin C.

Science.gov (United States)

Lipasek, Rebecca A; Taylor, Lynne S; Mauer, Lisa J

2011-09-01

Vitamin C is an essential nutrient that is widely used by the food industry in the powder form for both its nutritional and functional properties. However, vitamin C is deliquescent, and deliquescence has been linked to physical and chemical instabilities. Anticaking agents are often added to powder systems to delay or prevent caking, but little is known about their effect on the chemical stability of powders. In this study, various anticaking agents (calcium phosphate, calcium silicate, calcium stearate, corn starch, and silicon dioxide) were combined with sodium ascorbate at 2% and 50% w/w ratios and stored at various relative humidities (23%, 43%, 64%, 75%, 85%, and 98% RHs). Chemical and physical stability and moisture sorption were monitored over time. Additionally, saturated solution samples were stored at various pHs to determine the effect of surface pH and dissolution on the vitamin degradation rate. Storage RH, time, and anticaking agent type and ratio all significantly affected (P vitamin C stability. Silicon dioxide and calcium silicate (50% w/w) and calcium stearate (at both ratios) were the only anticaking agents to improve the physical stability of powdered sodium ascorbate while none of the anticaking agents improved its chemical stability. However, corn starch and calcium stearate had the least adverse effect on chemical stability. Dissolution rate and pH were also important factors affecting the chemical and physical stability of the powders. Therefore, monitoring storage environmental conditions and anticaking agent usage are important for understanding the stability of vitamin C. Anticaking agent type and ratio significantly affected the physical and chemical stability of vitamin C over time and over a range of RHs. No anticaking agent improved the chemical stability of the vitamin, and most caused an increase in chemical degradation even if physical stability was improved. It is possible that anticaking agents would greatly affect other

Do it yourself: optical spectrometer for physics undergraduate instruction in nanomaterial characterization

International Nuclear Information System (INIS)

Nuryantini, Ade Yeti; Mahen, Ea Cahya Septia; Sawitri, Asti; Nuryadin, Bebeh Wahid

2017-01-01

In this paper, we report on a homemade optical spectrometer using diffraction grating and image processing techniques. This device was designed to produce spectral images that could then be processed by measuring signal strength (pixel intensity) to obtain the light source, transmittance, and absorbance spectra of the liquid sample. The homemade optical spectrometer consisted of: (i) a white LED as a light source, (ii) a cuvette or sample holder, (iii) a slit, (iv) a diffraction grating, and (v) a CMOS camera (webcam). In this study, various concentrations of a carbon nanoparticle (CNP) colloid were used in the particle size sample test. Additionally, a commercial optical spectrometer and tunneling electron microscope (TEM) were used to characterize the optical properties and morphology of the CNPs, respectively. The data obtained using the homemade optical spectrometer, commercial optical spectrometer, and TEM showed similar results and trends. Lastly, the calculation and measurement of CNP size were performed using the effective mass approximation (EMA) and TEM. These data showed that the average nanoparticle sizes were approximately 2.4 nm and 2.5 ± 0.3 nm, respectively. This research provides new insights into the development of a portable, simple, and low-cost optical spectrometer that can be used in nanomaterial characterization for physics undergraduate instruction. (paper)

Chemically functionalized ZnS quantum dots as new optical nanosensor of herbicides

Science.gov (United States)

Masteri-Farahani, M.; Mahdavi, S.; Khanmohammadi, H.

2018-03-01

Surface chemical functionalization of ZnS quantum dots (ZnS-QDs) with cysteamine hydrochloride resulted in the preparation of an optical nanosensor for detection of herbicides. Characterization of the functionalized ZnS-QDs was performed with physicochemical methods such as x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive x-ray (EDX) analysis, ultraviolet-visible (UV–vis) and photoluminescence (PL) spectroscopies. The optical band gap of the functionalized ZnS-QDs was determined by using Tauc plot as 4.1 eV. Addition of various herbicides resulted in the linearly fluorescence quenching of the functionalized ZnS-QDs according to the Stern-Volmer equation. The functionalized ZnS-QDs can be used as simple, rapid, and inexpensive nanosensor for practical detection and measurement of various herbicides.

Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

Directory of Open Access Journals (Sweden)

Hong Chen

Full Text Available The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS, play vital roles in the normal operation of wastewater treatment plants (WWTPs. The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm, but different observation were made at higher CuNPs concentrations (30 and 50 ppm. At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

The influence of mineralogical, chemical and physical properties on grindability of commercial clinkers with high MgO level

International Nuclear Information System (INIS)

Souza, Vladia Cristina G. de; Koppe, Jair Carlos; Costa, Joao F.C.L.; Vargas, Andre Luis Marin; Blando, Eduardo; Huebler, Roberto

2008-01-01

This research investigates various methods able to identify possible mineralogical, physical and chemical influences on the grindability of commercial clinkers with high MgO level. The aim of the study is to evaluate the hardness and elastic modulus of the clinker mineral phases and their fracture strength during the comminution processes, comparing samples from clinkers with low MgO level (0.5%) and clinkers with elevated MgO levels (> 5.0%). The study of the influence of mineralogical, chemical and physical properties was carried out using several analytical techniques, such as: optical microscopy, X-ray diffraction with Rietveld refinement (XRD) and X-ray fluorescence (XRF). These techniques were useful in qualifying the different clinker samples. The drop weight test (DWT) and the Bond ball mill grindability test were performed to characterize the mechanical properties of clinkers. Nanoindentation tests were also carried out. Results from the Bond ball mill grindability test were found to be related to the hardness of the mineral phase and to mineralogical characteristics, such as type and amount of inclusions in silicates, belite and alite crystals shape, or microcracked alites. In contrast, the results obtained by the DWT were associated to the macro characteristics of clinkers, such as porosity, as well as to the hardness and mineralogical characteristics of belite crystals in clusters. Hardness instrumented tests helped to determine the Vickers hardness and elastic modulus from the mineral phases in commercial clinkers and produced different values for the pure phases compared to previous publications

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review.

Science.gov (United States)

Ding, Zhenyang; Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

2018-04-03

Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

Nanoporous Anodic Alumina: A Versatile Platform for Optical Biosensors

Directory of Open Access Journals (Sweden)

Abel Santos

2014-05-01

Full Text Available Nanoporous anodic alumina (NAA has become one of the most promising nanomaterials in optical biosensing as a result of its unique physical and chemical properties. Many studies have demonstrated the outstanding capabilities of NAA for developing optical biosensors in combination with different optical techniques. These results reveal that NAA is a promising alternative to other widely explored nanoporous platforms, such as porous silicon. This review is aimed at reporting on the recent advances and current stage of development of NAA-based optical biosensing devices. The different optical detection techniques, principles and concepts are described in detail along with relevant examples of optical biosensing devices using NAA sensing platforms. Furthermore, we summarise the performance of these devices and provide a future perspective on this promising research field.

Miniaturised wireless smart tag for optical chemical analysis applications.

Science.gov (United States)

Steinberg, Matthew D; Kassal, Petar; Tkalčec, Biserka; Murković Steinberg, Ivana

2014-01-01

A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction. RFID is set to become a key enabling technology of the Internet-of-Things (IoT), hence devices such as the photometer described here will enable numerous mobile, wearable and vanguard chemical sensing applications in the emerging connected world. In the work presented here, we demonstrate the characterisation of a low-power RFID wireless sensor tag with an LED/photodiode-based photometric input. The performance of the wireless photometer has been tested through two different model analytical applications. The first is photometry in solution, where colour intensity as a function of dye concentration was measured. The second is an ion-selective optode system in which potassium ion concentrations were determined by using previously well characterised bulk optode membranes. The analytical performance of the wireless photometer smart tag is clearly demonstrated by these optical absorption-based analytical experiments, with excellent data agreement to a reference laboratory instrument. © 2013 Elsevier B.V. All rights reserved.

The effects of physical and chemical changes on the optimum ...

African Journals Online (AJOL)

The aim of this study was to determine physical and chemical changes during fruit development and their relationship with optimum harvest maturity for Bacon, Fuerte and Zutano avocado cultivars grown under Dörtyol ecological condition. Fruits cv. Bacon, Fuerte and Zutano were obtained trees grafted on seedlings and ...

The physical and chemical stability of suspensions of sustained-release diclofenac microspheres.

Science.gov (United States)

Lewis, L; Boni, R L; Adeyeye, C M

1998-01-01

The major challenge in liquid sustained-release oral suspensions is to minimize drug diffusion into the suspending medium and to retain the original properties of the microparticles during storage. Diclofenac wax microspheres prepared by the hydrophobic congealable disperse phase method were formulated as a sustained release suspension and stored at three different temperatures (25, 37 and 45 degrees C) for 3 months, to evaluate the physical and chemical stability of the suspended microspheres. Suspensions of microspheres stored at ambient temperatures were both physically and chemically stable, but at higher temperatures, up to 45 degrees C, there was a decrease in drug release due to scaling and melting on the microsphere surface as observed by scanning electron microscopy. However, on prolonged storage, up to 90 days, especially at 45 degrees C, temperature became a dominant factor causing an increase in drug release. The suspension of diclofenac microspheres was chemically stable for 3 months, while the plain drug suspension exhibited slight degradation.

Physical and chemical stability of different formulations with superoxide dismutase.

Science.gov (United States)

Di Mambro, V M; Campos, P M B G Maia; Fonseca, M J V

2004-10-01

Topical formulations with superoxide dismutase (SOD), a scavenger of superoxide radicals, have proved to be effective against some skin diseases. Nevertheless, formulations with proteins are susceptible to both chemical and physical instability. Three different formulations (anionic and non-ionic gel and emulsion) were developed and supplemented with SOD in order to determine the most stable formulation that would maintain SOD activity. Physical stability was evaluated by assessing the rheological behavior of the formulations stored at room temperature, 37 and 45 degrees C. Chemical stability was evaluated by the measurement of enzymatic activity in the formulations stored at room temperature and at 45 degrees C. Formulations showed a flow index less than one, characterizing pseudoplastic behavior. There was no significant difference in initial values of flow index, tixotropy or minimum apparent viscosity. Neither gel showed significant changes in minimum apparent viscosity concerning storage time or temperature, as well, SOD presence and its activity. The emulsion showed decreased viscosity by the 28th day, but no significant changes concerning storage temperature or SOD presence, although it showed a decreased activity. The addition of SOD to the formulations studied did not affect their physical stability but gel formulations seem to be better bases for enzyme addition.

The plutonium: brief presentation of its nuclear, physical and chemical properties

International Nuclear Information System (INIS)

Madic, C.

1993-01-01

In this text we give a brief presentation of the nuclear properties (isotopes, isotopic composition of spent fuels, decay), of the physical properties (phase diagrams, alloys) and of the chemical properties (complexes, solvent extraction) of the plutonium

Chemically deposited Sb{sub 2}S{sub 3} thin films for optical recording

Energy Technology Data Exchange (ETDEWEB)

Shaji, S; Arato, A; Castillo, G Alan; Palma, M I Mendivil; Roy, T K Das; Krishnan, B [Facultad de IngenierIa Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P- 66450 (Mexico); O' Brien, J J; Liu, J, E-mail: bkrishnan@fime.uanl.m [Center for Nanoscience and Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One Univ. Blvd., St. Louis, MO - 63121 (United States)

2010-02-24

Laser induced changes in the properties of Sb{sub 2}S{sub 3} thin films prepared by chemical bath deposition are described in this paper. Sb{sub 2}S{sub 3} thin films of thickness 550 nm were deposited from a solution containing SbCl{sub 3} and Na{sub 2}S{sub 2}O{sub 3} at 27 {sup 0}C for 5 h. These thin films were irradiated by a 532 nm continuous wave laser beam under different conditions at ambient atmosphere. X-ray diffraction analysis showed amorphous to polycrystalline transformation due to laser exposure of these thin films. Morphology and composition of these films were described. Optical properties of these films before and after laser irradiation were analysed. The optical band gap of the material was decreased due to laser induced crystallization. The results obtained confirm that there is further scope for developing this material as an optical recording media.

Monitoring soil chemical and physical parameters under Douglas fir in the Netherlands

Energy Technology Data Exchange (ETDEWEB)

Konsten, C.J.M.; Tiktak, A.; Bouten, W.

1987-01-01

In march 1987 a monitoring program started in two Douglas fir stands of different vitality in the Netherlands. Aim of the study is to provide insight in the chemical and physical rooting conditions of the vegetation and to quantify the contributions of atmospheric deposition to soil acidification. The hydrological part of the monitoring progam consists of automated measurements of precipitation, throughfall, soil water pressure head and soil water content; in addition soil water content is determined by neutron sonde measurements and gravimetry. These data are used as input data for simulation models which calculate water fluxes through the vegetation and soil. For the soil chemical part of the program precipitation (bulk and wet-only), throughfall and litter fall are sampled. The soil solution is sampled by suction from porous cups and from porous plates by a new, continous technique. Combination of soil chemical and soil physical data will result in chemical fluxes through the vegetation and through various soil compartments. Element budgets for the ecosystem will also be calculated. The program forms part of an interdisciplinary monitoring project within the Dutch Priority Programme on Acidification. 2 figs., 1 tab., 19 refs.

Preliminary study on rotary ultrasonic machining of Bk-7 optical glass rod

International Nuclear Information System (INIS)

Hamzah, E.; Izman, S.; Khoo, C.Y.; Zainal Abidin, N.N.

2007-01-01

This paper presents an experimental observation on rotary ultrasonic machining (RUM) of BK7 optical glass rod. BK7 is a common technical optical glass for high quality optical components due to its high linear optical transmission in the visible range and is chemically stable. RUM is a hybrid machining process that combines the material removal mechanisms of diamond grinding and ultrasonic machining (USM) and it is non-thermal, non-chemical, creates no change in the microstructure, chemical or physical properties of the work piece. In the RUM, a controlled static load is applied to the rotating core drill with metal bonded diamond abrasive and is ultrasonically vibrated in the axial direction. A water-soluble coolant was used to cool the tool and sample during machining processes. By using DOE (Design of Experiment) approach, the effect of spindle speed and feed rate to the ultrasonic machinability had been developed. The main effects and two-factor interactions of process parameters (spindle speed) and feed rate) on output variables (MRR, surface roughness, opaqueness, chipping thickness and chipping size) are studied. (author)

Construction of a Chemical Sensor/Instrumentation Package Using Fiber Optic and Miniaturization Technology

Science.gov (United States)

Newton, R. L.

1999-01-01

The objective of this research was to construct a chemical sensor/instrumentation package that was smaller in weight and volume than conventional instrumentation. This reduction in weight and volume is needed to assist in further reducing the cost of launching payloads into space. To accomplish this, fiber optic sensors, miniaturized spectrometers, and wireless modems were employed. The system was evaluated using iodine as a calibration analyte.

Aspects of optical fibers and spectrometric sensors in chemical process and industrial environments

International Nuclear Information System (INIS)

Boisde, G.; Perez, J.J.

1988-01-01

For on-line control, the two alternatives of automatic sample transfer and in situ remote analysis are discussed. New concepts are emerging from the possibilities offered by optical fibers. Absorption in the visible, UV and IR, fluorescence and Raman spectrometric techniques are examined. The state of the art of optodes and devices in chemical process control are given, with some examples of applications in nuclear plants

Molybdenum and technetium cycle in the environment. Physical chemical evolution and mobility in soils and plants

International Nuclear Information System (INIS)

Saas, A.; Denardi, J.L.; Colle, C.; Quinault, J.M.

1980-01-01

Molybdenum 99 and technetium 99 from liquid discharges of base nuclear installations (reactors, reprocessing plants, UF 6 treatment, etc.) can reach the environment via irrigation waters and atmospheric deposits. The contribution to the soil by irrigation results in a physical-chemical transformation, the results of which, in the case of technetium 99, could be volatilization via microbes. The changes in the physical-chemical forms of technetium in different soils reveals the preponderant effect of the initial amount deposited. The determination of the rate of technetium and molybdenum assimilation shows a certain similarity in behaviour; yet the localization of these isotopes is not the same. The transfer of molybdenum and technetium via the root system is different in its intensity; this is mainly due to different physical-chemical forms. Finally, each isotope has an optimum assimilation threshold and a toxicity threshold. The study of the physical-chemical evolution and the mobility in the soil-plant-water table system of these two isotopes shows a new aspect with respect to certain transfer channels to the human being [fr

Physical and chemical characteristics of cheese bread, using fermented broken rice

Directory of Open Access Journals (Sweden)

Andressa CORADO

2017-10-01

Full Text Available Abstract Development of new food products, taking as raw material the subproducts obtained during industrial process become an economic and nutritious alternative, since these are usually discarded, caning be a significant nutritional source good. This research aimed to develop cheese bread using fermented broken rice instead of sour starch in four different concentrations (0%, 25%, 50%, 75% and 100%. After the development of formulations, was performed physics and chemicals characterization of products obtained, performing analysis of: proximate composition, dietary fiber, acidity, pH, ºBrix, total soluble sugars, reducing and sucrose. The increased formulations didn’t present significant differences, highlighting the average values of protein 7%, dietary fiber 9% and ash 1.9%. Broken rice, after fermentation process, becomes a profitable alternative instead of the sour starch on cheese breads, saving all the physical and chemical characteristics and being inexpensive.

International School of Physics Enrico Fermi : Course 190 : Frontiers in Modern Optics

CERN Document Server

Dudley, J; Clerici, M

2016-01-01

The year 2015 was designated by the United Nations General Assembly as the Year of Light and Light-based Technologies, and also marks the anniversaries of a number of significant historical events related to light. In 1015, Ibn Al-Haytham published his book of optics; in 1815, Fresnel first proposed the notion that light is actually a wave; James Clerk Maxwell then firmly established this concept with his electromagnetic theory of light propagation; and Einstein announced his discovery of the photoelectric effect, demonstrating that light is made of photons in 1905, followed in 1915 by his general theory of relativity, in which light plays a central role. This book presents lectures from the International School of Physics Enrico Fermi summer school: Frontiers in Modern Optics, held in Varenna, Italy, in June and July 2014. The school attempted to give a broad and modern overview of the field of optics in a series of lectures addressing ongoing topics of research. Subject areas include: nonlinear optics; lig...

A Review on Homogeneous Charge Compression Ignition and Low Temperature Combustion by Optical Diagnostics

Directory of Open Access Journals (Sweden)

Chao Jin

2015-01-01

Full Text Available Optical diagnostics is an effective method to understand the physical and chemical reaction processes in homogeneous charge compression ignition (HCCI and low temperature combustion (LTC modes. Based on optical diagnostics, the true process on mixing, combustion, and emissions can be seen directly. In this paper, the mixing process by port-injection and direct-injection are reviewed firstly. Then, the combustion chemical reaction mechanism is reviewed based on chemiluminescence, natural-luminosity, and laser diagnostics. After, the evolution of pollutant emissions measured by different laser diagnostic methods is reviewed and the measured species including NO, soot, UHC, and CO. Finally, a summary and the future directions on HCCI and LTC used optical diagnostics are presented.

Comparisons of physical and chemical sputtering in high density divertor plasmas with the Monte Carlo Impurity (MCI) transport model

International Nuclear Information System (INIS)

Evans, T.E.; Loh, Y.S.; West, W.P.; Finkenthal, D.F.

1997-11-01

The MCI transport model was used to compare chemical and physical sputtering for a DIII-D divertor plasma near detachment. With physical sputtering alone the integrated carbon influx was 8.4 x 10 19 neutral/s while physical plus chemical sputtering produced an integrated carbon influx of 1.7 x 10 21 neutrals/s. The average carbon concentration in the computational volume increased from 0.012% with only physical sputtering to 0.182% with both chemical and physical sputtering. This increase in the carbon inventory produced more radiated power which is in better agreement with experimental measurements

The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled.

Science.gov (United States)

Göppel, Tobias; Palyulin, Vladimir V; Gerland, Ulrich

2016-07-27

An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a drift-diffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.

Chemical and optical changes in freshwater dissolved organic matter exposed to solar radiation

Science.gov (United States)

Osburn, C.L.; Morris, D.P.; Thorn, K.A.; Moeller, R.E.

2001-01-01

We studied the chemical and optical changes in the dissolved organic matter (DOM) from two freshwater lakes and a Sphagnum bog after exposure to solar radiation. Stable carbon isotopes and solid-state 13C-NMR spectra of DOM were used together with optical and chemical data to interpret results from experimental exposures of DOM to sunlight and from seasonal observations of two lakes in northeastern Pennsylvania. Solar photochemical oxidation of humic-rich bog DOM to smaller LMW compounds and to DIC was inferred from losses of UV absorbance, optical indices of molecular weight and changes in DOM chemistry. Experimentally, we observed a 1.2??? enrichment in ??13C and a 47% loss in aromatic C functionality in bog DOM samples exposed to solar UVR. Similar results were observed in the surface waters of both lakes. In late summer hypolimnetic water in humic Lake Lacawac, we observed 3 to 4.5??? enrichments in ??13C and a 30% increase in aromatic C relative to early spring values during spring mixing. These changes coincided with increases in molecular weight and UV absorbance. Anaerobic conditions of the hypolimnion in Lake Lacawac suggest that microbial metabolism may be turning over allochthonous C introduced during spring mixing, as well as autochthonous C. This metabolic activity produces HMW DOM during the summer, which is photochemically labile and isotopically distinct from allochthonous DOM or autochthonous DOM. These results suggest both photooxidation of allochthonous DOM in the epilimnion and autotrophic production of DOM by bacteria in the hypolimnion cause seasonal trends in the UV absorbance of lakes.

Optics in the physics degree at the USC: the use of the Moodle platform

Science.gov (United States)

Flores-Arias, M. Teresa

2014-07-01

The unification of the new European studies under the Bologna process creates a new adaptation within the field of Physics. An adjustment to the programs is required to migrate to the new European Credit Transfer (ECTS). According to the article 12.2 of the R.D. 1393/2007, the Physics Degree at the University of Santiago de Compostela (USC), Spain, has 240 ECTS distributed in 4 years with 60 ECTS each. In particular, the subject of Optics is imparted in the third year of the degree and it is divided in two courses, Optics I and Optics II, both belonging to the Module "Fundamentals of Physics". Both courses are mandatory and are composed by 6 ECTS, distributed in 30 hours of theory, 15 hours of seminars and 15 hours of particular tutorials. Besides, the work developed by the students is supposed to be 75 hours of dedication for learning the theoretical lectures contents and 15 hours for the development of exercises and other homework. The reduction of the number of hours devoted to the theoretical lesson respect to the older syllabus has made necessary the use of virtual platforms for helping the teacher and the student to be more connected and to share the academic materials needed to the good developing of the course. This work is devoted to the analysis of this kind of virtual tools, in particular, to the Moodle platform, in the course Optics I, focusing on the satisfaction degree of the student with it.

Effects of high neutron doses and duration of the chemical etching on the optical properties of CR-39

International Nuclear Information System (INIS)

Sahoo, G.S.; Tripathy, S.P.; Paul, S.; Sharma, S.C.; Joshi, D.S.; Gupta, A.K.; Bandyopadhyay, T.

2015-01-01

Effects of the duration of chemical etching on the transmittance, absorbance and optical band gap width of the CR-39 (Polyallyl diglycol carbonate) detectors irradiated to high neutron doses (12.7, 22.1, 36.0 and 43.5 Sv) were studied. The neutrons were produced by bombardment of a thick Be target with 12 MeV protons of different fluences. The unirradiated and neutron-irradiated CR-39 detectors were subjected to a stepwise chemical etching at 1 h intervals. After each step, the transmission spectra of the detectors were recorded in the range from 200 to 900 nm, and the absorbances and optical band gap widths were determined. The effect of the etching on the light transmittance of unirradiated detectors was insignificant, whereas it was very significant in the case of the irradiated detectors. The dependence of the optical absorbance on the neutron dose is linear at short etching periods, but exponential at longer ones. The optical band gap narrows with increasing etching time. It is more significant for the irradiated dosimeters than for the unirradiated ones. The rate of the narrowing of the optical band gap with increasing neutron dose increases with increasing duration of the etching. - Highlights: • The variation of optical properties of CR-39 at very high neutron dose is analyzed. Etching process is found to play a crucial role for change in optical properties of neutron-irradiated CR-39. • The optical absorbance varies linearly at lower dose, at very high dose absorbance saturation occurs. The dose at which saturation absorbance is observed shifts towards lower neutron dose with increase in etching time. • The rate of decrease in optical band gap with respect to neutron dose is found to be more at higher etching durations

Device physics vis-à-vis fundamental physics in Cold War America: the case of quantum optics.

Science.gov (United States)

Bromberg, Joan Lisa

2006-06-01

Historians have convincingly shown the close ties U.S. physicists had with the military during the Cold War and have raised the question of whether this alliance affected the content of physics. Some have asserted that it distorted physics, shifting attention from fundamental problems to devices. Yet the papers of physicists in quantum electronics and quantum optics, fields that have been exemplary for those who hold the distortion thesis, show that the same scientists who worked on military devices simultaneously pursued fundamental and foundational topics. This essay examines one such physicist, Marlan O. Scully, with attention to both his extensive foundational studies and the way in which his applied and basic researches played off each other.

The Physical, Chemical and Physiological Limits of Life

Directory of Open Access Journals (Sweden)

Dirk Schulze-Makuch

2015-07-01

Full Text Available Life on Earth displays an incredible diversity in form and function, which allows it to survive not only physical extremes, but also periods of time when it is exposed to non-habitable conditions. Extreme physiological adaptations to bridge non-habitable conditions include various dormant states, such as spores or tuns. Here, we advance the hypothesis that if the environmental conditions are different on some other planetary body, a deviating biochemistry would evolve with types of adaptations that would manifest themselves with different physical and chemical limits of life. In this paper, we discuss two specific examples: putative life on a Mars-type planet with a hydrogen peroxide-water solvent and putative life on a Titan-type planetary body with liquid hydrocarbons as a solvent. Both examples would have the result of extending the habitable envelope of life in the universe.

Optical and Electrical Performance of ZnO Films Textured by Chemical Etching

Directory of Open Access Journals (Sweden)

Shiuh-Chuan HER

2015-11-01

Full Text Available Zinc oxide (ZnO films were prepared by radio frequency (RF magnetron sputtering on the glass substrate as transparent conductive oxide films. For silicon solar cells, a proper surface texture is essential to introduce light scattering and subsequent light trapping to enhance the current generation. In this study, the magnetron-sputtered ZnO films were textured by wet-chemical etching in diluted hydrochloric acid (HCl for better light scattering. The diffuse transmittance of the surface textured ZnO films was measured to evaluate the light scattering. The influence of hydrochloric acid concentration on the morphology, optical and electrical properties of the surface-textured ZnO film was investigated. The ZnO film etched in 0.05M HCl solution for 30 s exhibited average diffuse transmittance in the visible wavelength range of 9.52 % and good resistivity of 1.10 x 10-3 W×cm while the as-deposited ZnO film had average diffuse transmittance of 0.51 % and relatively high resistivity of 5.84 x 10-2 W×cm. Experimental results illustrated that the optical and electrical performance of ZnO films can be significantly improved by introducing the surface texture through the wet-chemical etching process.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9624

Efficient Regeneration of Physical and Chemical Solvents for CO₂ Capture

Energy Technology Data Exchange (ETDEWEB)

Tande, Brian [Univ. of North Dakota, Grand Forks, ND (United States); Seames, Wayne [Univ. of North Dakota, Grand Forks, ND (United States); Benson, Steve [Univ. of North Dakota, Grand Forks, ND (United States)

2013-12-01

The objective of this project was to evaluate the use of composite polymer membranes and porous membrane contactors to regenerate physical and chemical solvents for capture of carbon dioxide (CO₂) from synthesis gas or flue gas, with the goal of improving the energy efficiency of carbon capture. Both a chemical solvent (typical for a post-combustion capture of CO₂ from flue gas) and a physical solvent (typical for pre- combustion capture of CO₂ from syngas) were evaluated using two bench-scale test systems constructed for this project. For chemical solvents, polytetrafluoroethylene and polypropylene membranes were found to be able to strip CO₂ from a monoethanolamine (MEA) solution with high selectivity without significant degradation of the material. As expected, the regeneration temperature was the most significant parameter affecting the CO₂ flux through the membrane. Pore size was also found to be important, as pores larger than 5 microns lead to excessive pore wetting. For physical solvents, polydimethyl-siloxane (PDMS)-based membranes were found to have a higher CO₂ permeability than polyvinylalcohol (PVOH) based membranes, while also minimizing solvent loss. Overall, however, the recovery of CO₂ in these systems is low – less than 2% for both chemical and physical solvents – primarily due to the small surface area of the membrane test apparatus. To obtain the higher regeneration rates needed for this application, a much larger surface area would be needed. Further experiments using, for example, a hollow fiber membrane module could determine if this process could be commercially viable.

Effect of Lepidium meyenii (maca) on testicular function of mice with chemically and physically induced subfertility.

Science.gov (United States)

Valdivia Cuya, M; Yarasca De La Vega, K; Lévano Sánchez, G; Vásquez Cavero, J; Temoche García, H; Torres Torres, L; Cruz Ornetta, V

2016-10-01

The aim of this study was to evaluate the effect of Lepidium meyenii (maca) in chemically and physically subfertile mice. After 35 days, the following groups of mice were evaluated: control, sham, chemical subfertility, chemical subfertility-maca-supplemented, physical subfertility, physical subfertility-maca-supplemented and maca-supplemented only. Motility (32.36% ± 5.34%) and sperm count (44.4 ± 5.37 × 10(6) /ml) in the chemically and physically subfertile mice (11.81% ± 4.06%, 17.34 ± 13.07 × 10(6) /ml) decreased compared to the control (75.53% ± 2.97% and 57.4 ± 19.6 10(6) /ml) and sham (53.5% ± 7.86% and 58.4 ± 14.10 10(6) /ml). Maca was able to reverse the deleterious effect of motility (76.36 ± 1.97) as well as sperm count (53.5 ± 9.18 × 10(6) /ml) on chemical subfertility. In contrast, maca did not reverse the effects of induced physical subfertility nor motility (18.78% ± 14.41%) or sperm count (20.17 ± 11.20 × 10(6) /ml). The percentage of sperm DNA fragmentation in the physically subfertile mice increased (11.1% ± 19.29%) compared to the control (0.84% ± 0.85%). However, in the physically subfertile group, maca decreased sperm DNA fragmentation (2.29% ± 2.30%) closer to the sham (1.04% ± 0.62%) and the control (0.84% ± 0.85%). The group supplemented only with maca showed 0.54% ± 0.50% of spermatozoa with DNA fragmentation. Yet, the differences observed were statistically not significant. In conclusion, it appears that maca activates the cytochrome P450 system after chemically induced subfertility. However, it does not reverse the low mitochondrial membrane potential in spermatozoa compromised in the physical subfertility group. © 2016 Blackwell Verlag GmbH.

Physical optics simulations with PHASE for SwissFEL beamlines

Energy Technology Data Exchange (ETDEWEB)

Flechsig, U.; Follath, R.; Reiche, S. [Paul Scherrer Institut, Swiss Light Source, 5232 Villigen PSI (Switzerland); Bahrdt, J. [Helmholtz Zentrum Berlin (Germany)

2016-07-27

PHASE is a software tool for physical optics simulation based on the stationary phase approximation method. The code is under continuous development since about 20 years and has been used for instance for fundamental studies and ray tracing of various beamlines at the Swiss Light Source. Along with the planning for SwissFEL a new hard X-ray free electron laser under construction, new features have been added to permit practical performance predictions including diffraction effects which emerge with the fully coherent source. We present the application of the package on the example of the ARAMIS 1 beamline at SwissFEL. The X-ray pulse calculated with GENESIS and given as an electrical field distribution has been propagated through the beamline to the sample position. We demonstrate the new features of PHASE like the treatment of measured figure errors, apertures and coatings of the mirrors and the application of Fourier optics propagators for free space propagation.

Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.

Science.gov (United States)

Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T; Ohodnicki, Paul R

2018-02-23

Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2 , N 2 , O 2 , and CO) with rapid (optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.

Technical area status report for chemical/physical treatment

International Nuclear Information System (INIS)

Brown, C.H. Jr.; Schwinkendorf, W.E.

1993-08-01

These Appendices describe various technologies that may be applicable to the Mixed Waste Treatment Plant (MWTP) Chemical/Physical Treatment System (CPTS). These technologies were identified by the CPTS Technical Support Group (TSG) as potentially applicable to a variety of separation, volume reduction, and decontamination requirements. The purpose was to identify all available and developing technologies, and their characteristics, for subsequent evaluation for specific requirements identified for the CPTS. However, the technologies described herein are not necessarily all inclusive, nor are they necessarily all applicable

Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

CERN Document Server

Berruti, Gaia Maria; Cusano, Andrea

This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

SIFAT FISIK, KIMIA, DAN FUNGSIONAL DAMAR [Brief Review on: Physical, Chemical and Functional Properties of Dammar

Directory of Open Access Journals (Sweden)

Noryawati Mulyono1

2004-12-01

Full Text Available Dammar is one of Indonesian forestry products which is abundant. It has unique physical, chemical and functional properties. The important physical properties of dammar include its solubility in some organic solvents, softening temperature, viscosity and its absorbance. The important chemical properties reviewed here include its properties as resin, composition of terpenoid compounds present in dammar, and essential oil yielded from distillation of fresh dammar. Physical and chemical properties of dammar need to be studied further in order to optimize its functional properties. So far, dammar is widely used as weighting agent and source of essential oil. However, now, some species of dammar are being explored and developed for sal flour, fat source, triacylglycerol substituent for cocoa butter and wood preservatives.

PHYSICAL AND CHEMICAL DEGRADATION OF AGRICULTURAL SOILS AT SAN PEDRO LAGUNILLAS, NAYARIT

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Gelacio Alejo Santiago

2012-08-01

Full Text Available The objective of this study was to evaluate the degradation to propose strategies for remediation and recovery of agricultural soils of San Pedro Lagunillas, Nayarit, Mexico; considering physical and chemical properties. Soils maintained with natural vegetation but slightly grazed and agricultural soils used for more than 20 years for the production of several crops, were compared. Eight sites were studied (four cultivated and four uncultivated, each agricultural lands (cultivated was located at a distance of 30 to 80 m from its counterpart or soil with natural vegetation (uncultivated. Samples were obtained from the following layers: 0 to 10, 10 to 20 and 20 to 30 cm. The variables evaluated were: particles smaller than 2 mm, pH, organic matter, extractable phosphorus, exchangeable potassium, calcium and magnesium; soil texture and water infiltration rate. An analysis of variance and Tukey means test (α = 0.05 was applied. It was concluded that traditional farming practices led to adverse changes in soil chemical properties, in the upper 20 cm soil layer. Physical properties were also affected because infiltration film and water infiltration rate decreased about 50% in cultivated soils. The overall results in this work evident the need to take appropriate measures to prevent the physical and chemical degradation of cultivated soils in order to preserve this resource and maintain their productivity.

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

Directory of Open Access Journals (Sweden)

Zhenyang Ding

2018-04-01

Full Text Available Distributed optical fiber sensors (DOFS offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

Science.gov (United States)

Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

2018-01-01

Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on. PMID:29614024

Dominance of physical and chemical gases properties on kinetics of gassing in NPP's circulation contours

International Nuclear Information System (INIS)

Piontkovskij, A.I.

2001-01-01

Is seen out a dominance analysis of physical and chemical matter properties on gases solubility in circulation contour NPP's heat-transfer. Is represented a concentration computation methods of gas dissolved in heat-transfer with use of in lying pressure in matter. Are analysed the computation results for diverse gases in wide range of operating parameters, and also dominance of physical and chemical gas properties on intensity of heat-exchange processes in heat-transfer with dissolved gase

Improving the Database for Physical and Chemical Sputtering. Summary Report of an IAEA Technical Meeting

International Nuclear Information System (INIS)

Braams, B. J.

2013-02-01

Seven experts and IAEA staff convened in Vienna to review the existing database for physical and chemical sputtering of fusion wall materials and to make recommendations about priorities for further work. Recommendations were made about database needs for pure and mixed Be, C and W wall material for the processes of physical and chemical sputtering, reflection, penetration and trapping and also for effects of surface and material microstructure. The proceedings and recommendations of the meeting are summarized here. (author)

Optical fibre sensor coated with porous silica layers for gas and chemical vapour detection

Czech Academy of Sciences Publication Activity Database

Abdelghani, A.; Chovelon, J. M.; Jaffrezic-Renault, N.; Lacroix, M.; Gagnaire, H.; Veillas, C.; Berková, Daniela; Chomát, Miroslav; Matějec, Vlastimil

B44, l/3 (1997), s. 495-498 ISSN 0925-4005 R&D Projects: GA ČR GA102/95/0871; GA ČR GA102/96/0939 Grant - others:EU COPERNICUS(XE) CIPA-CT94-0140 Keywords : nonelectric sensing devices * optical fibres * chemical sensors * sol-gel processing Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 0.858, year: 1997

Influence of culture media on the physical and chemical properties of Ag-TiCN coatings

Science.gov (United States)

Carvalho, I.; Escobar Galindo, R.; Henriques, M.; Palacio, C.; Carvalho, S.

2014-08-01

The aim of this study was to verify the possible physical and chemical changes that may occur on the surface of Ag-TiCN coatings after exposure to the culture media used in microbiological and cytotoxic assays, respectively tryptic soy broth (TSB) and Dulbecco's modified eagle's medium (DMEM). After sample immersion for 24 h in the media, analyses were performed by glow discharge optical emission spectroscopy discharge radiation (GDOES), Rutherford backscattering spectroscopy (RBS) and x-ray photoelectron spectroscopy (XPS). The results of GDOES profile, RBS and XPS spectra, of samples immersed in TSB, demonstrated the formation of a thin layer of carbon, oxygen and nitrogen that could be due to the presence of proteins in TSB. After 24 h of immersion in DMEM, the results showed the formation of a thin layer of calcium phosphates on the surface, since the coatings displayed a highly oxidized surface in which calcium and phosphorus were detected. All these results suggested that the formation of a layer on the coating surface prevented the release of silver ions in concentrations that allow antibacterial activity.

Integrated modelling of physical, chemical and biological weather

DEFF Research Database (Denmark)

Kurganskiy, Alexander

. This is an online-coupled meteorology-chemistry model where chemical constituents and different types of aerosols are an integrated part of the dynamical model, i.e., these constituents are transported in the same way as, e.g., water vapor and cloud water, and, at the same time, the aerosols can interactively...... impact radiation and cloud micro-physics. The birch pollen modelling study has been performed for domains covering Europe and western Russia. Verification of the simulated birch pollen concentrations against in-situ observations showed good agreement obtaining the best score for two Danish sites...

X-ray excited optical luminescence studies on the system BaXY (X ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 65; Issue 2. X-ray excited optical luminescence studies on the system Ba (, =F, Cl, Br, I) ... India; Department of Chemical Engineering, National Taiwan University, Republic of China ... Proceedings of the International Workshop/Conference on Computational ...

On the relation between chemical composition and optical properties of detonation nanodiamonds

KAUST Repository

Kirmani, Ahmad R.

2015-06-23

The morphology and presence of impurities strongly influence mechanical, optical, electrical, and thermal properties of detonation nanodiamonds (DNDs). Here we report insights on the chemical composition and its effect on the optical properties of the DNDs obtained by rate-zonal density gradient ultracentrifugation. Herein, for the first time, a detailed valence band structure of as-prepared and oxidized DNDs is reported. Photoemission spectroscopy (PES) measurements demonstrate that the defects, originating from fullerene-like C bonding in the sp2 shells of the DNDs, are governing the literature-reported loss of the emission spectral features arising from the nitrogen-vacancy (NV) center excitations. X-ray photoelectron spectroscopy (XPS) measurements reveal that nitrogen is present in the DNDs in the form of N–O bonded species located at the surface region/sp2 shells, while in core of the DND it is in the form of N–C/N=C species.

An Exact Line Integral Representation of the Magnetic Physical Optics Scattered Field

DEFF Research Database (Denmark)

Meincke, Peter; Breinbjerg, Olav; Jørgensen, Erik

2003-01-01

An exact line integral representation is derived for the magnetic physical optics field scattered by a perfectly electrically conducting planar plate illuminated by electric or magnetic Hertzian dipoles. The positions of source and observation points can be almost arbitrary. Numerical examples...... are presented to illustrate the exactness of the line integral representation....

Fiber optic sensors for environmental applications: A brief review

International Nuclear Information System (INIS)

Rossabi, J.

1992-04-01

Understanding the flow a groundwater quality. This understanding is achieved by measurement of the appropriate chemical and physical subsurface parameters. The ideal measurement would accurately assess a parameter without affecting the parameter or its environment. Fiber optic spectroscopy offers some of the most promising techniques for accurate, non-invasive measurements of environmental parameters. Fiber optic sensors for subsurface applications are currently being developed by several Department of Energy laboratories. Some of these sensors have been successfully deployed in the field and are attaining the goals of accurate, noninvasive, real time measurements in the subsurface

Heterogeneity in physical, chemical and plankton-community structures in Lake Tanganyika

NARCIS (Netherlands)

Langenberg, V.T.; Tumba, J.M.; Tshibangu, K.; Lukwesa, C.; Chitamwebwa, D.; Bwebwa, D.; Makasa, L.; Roijackers, R.M.M.

2008-01-01

From 28 August to 6 September 1995, we monitored the lake-wide physical, chemical and biological properties of the pelagic waters in Lake Tanganyika. The aim of this study was to examine the spatial environmental variability and its relation to fluctuations in plankton abundance and community

Sensorial, physical and chemical evaluation of bio-fortified Ipomoea batatas

Directory of Open Access Journals (Sweden)

Mara N.G. Santos

2014-08-01

Full Text Available Context: Bio-fortified sweet potato, Ipomoea batatas (L. Lamarck beta-carotene rich, has been included in the most vulnerable population’s diet with the purpose of reducing health disturbances associated with hipovitaminosis. Aims:To evaluate a physical and chemical analysis of total carotenes and beta-carotene and to determine the antioxidant potential as well as to carry out a sensorial analysis of the bio-fortified Ipomoea batatas (L. Lamarck (BDB in nature and processed. Methods: BDB was processed as sweet (in natura, paste and syrup and physicochemical characteristics were compared, total carotenoids, beta-carotene, antioxidant activity (DPPH and microbiological and sensory analyses were performed. Results:The analysis of total carotenoids, beta-carotene and anti-oxidant potential showed the following results: BDB in nature – 11.81 mg/100 g/440.5 mg/100 g/26.30%; sweet paste – 0.61 mg/100 g/53.5 mg/100 g/53.40% and savored syrup – 0.85 mg/100 g/46.0 mg/100 g/14.30%. The methods of conservation avoided the coliforms growth at 35 and 45°C, Staphylococcus coagulasa positivo, Bacillus cereus and Salmonella in all elaborated candies. The sensorial analysis didn’t detect significant differences among the syrup or paste. Conclusions: The conservation methods have an important function keeping the physical, chemical characteristics and sensorial of BDB, although they can influence in their chemical and nutritional composition, mainly in relation to the quantity of total carotenoids and beta-carotene.

Chemical, physical-chemical, and sensory characteristics of lychee (Litchi chinensis Sonn) wines.

Science.gov (United States)

Alves, Juliana Alvarenga; de Oliveira Lima, Luiz Carlos; Nunes, Cleiton Antônio; Dias, Disney Ribeiro; Schwan, Rosane Freitas

2011-01-01

Four lychee (Litchi chinensis Sonn) wines (prepared with 3 yeast strains [UFLA CA11, UFLA CA1183, and UFLA CA1174]) and a spontaneous fermentation (SPON) were done in order to add value to the fruit while preventing waste arising from the short shelf life of lychee. The fermentation was monitored daily by analyzing the soluble solids, pH, acidity, ethanol, and sugar. At the end of fermentation, the wines were subjected to chemical, physical-chemical, and sensory analysis. The wines prepared showed greater variations in the qualitative than in the quantitative analysis of their constituents. The sensory analysis indicated that the wines fermented by yeast UFLA CA1183 and UFLA CA11 had rates of acceptance above 75%. The principal components analysis separated the wines into 2 groups according to the analyzed compounds. Based on these analyses, the wine produced by inoculation with UFLA CA1183 proved to be the most suitable for the production of lychee wines. Development of new products and adding value to fruits. Importance of selection of specific yeasts for production of fruit wine. © 2011 Institute of Food Technologists®

Chemical and Biological Sensing with a Fiber Optic Surface Plasmon Resonance Device

Science.gov (United States)

Shevchenko, Yanina

Fiber biosensors have emerged as an alternative to other optical sensor platforms which utilize bulkier optical elements. Sensors manufactured using optical fiber offer considerable advantages over traditional platforms, such as simple manufacturing process, small size and possibility for in situ and remote measurements. The possibility to manufacture a compact sensor with very few optical elements and package it into a portable hand-held device makes it particularly useful in many biomedical applications. Such applications generate a growing demand for an improved understanding of how fiber sensors function as well as for sensor optimization techniques so later these devices can suit the needs of the applications they are developed for. Research presented in this thesis is focused on a development of a plasmonic fiber biosensor and its application towards biochemical sensing. The fiber sensor used in this study integrates plasmonics with tilted Bragg grating technology, creating a versatile sensing solution. Plasmonics alone is an established phenomenon that is widely employed in many sensing applications. The Bragg grating is also a well-researched optical component that has been extensively applied in telecommunication. By combining both plasmonics and Bragg gratings, it is possible to design a compact and very sensitive chemical sensor. The presented work focuses on the characterization and optimization of the fiber sensor so later it could be applied in biochemical sensing. It also explores several applications including real-time monitoring of polymer adsorption, detection of thrombin and cellular sensing. All applications are focused on studying processes that are very different in their nature and thus the various strengths of the developed sensing platform were leveraged to suit the requirements of these applications.

Structural and optical properties of nano-structured CdS thin films prepared by chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Bai, Rekha, E-mail: rekha.mittal07@gmail.com; Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K. [Thin Film Laboratory, Physics Department, Indian Institute of Technology Delhi, New Delhi-110016 (India)

2016-05-06

Cadmium sulfide (CdS) thin films have been deposited on conducting glass substrates by chemical bath deposition (CBD) technique. The effect of precursor concentration on the structural, morphological, compositional, and optical properties of the CdS films has been studied. Crystal structure of these CdS films is characterized by X-ray diffraction (XRD) and it reveals polycrystalline structure with mixture of cubic and wurtzite phases with grain size decreasing as precursor concentration is increased. Optical studies reveal that the CdS thin films have high transmittance in visible spectral region reaching 90% and the films possess direct optical band gap that decreases from 2.46 to 2.39 eV with decreasing bath concentration. Our study suggests that growth is nucleation controlled.

Structural and optical properties of nano-structured CdS thin films prepared by chemical bath deposition

International Nuclear Information System (INIS)

Bai, Rekha; Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K.

2016-01-01

Cadmium sulfide (CdS) thin films have been deposited on conducting glass substrates by chemical bath deposition (CBD) technique. The effect of precursor concentration on the structural, morphological, compositional, and optical properties of the CdS films has been studied. Crystal structure of these CdS films is characterized by X-ray diffraction (XRD) and it reveals polycrystalline structure with mixture of cubic and wurtzite phases with grain size decreasing as precursor concentration is increased. Optical studies reveal that the CdS thin films have high transmittance in visible spectral region reaching 90% and the films possess direct optical band gap that decreases from 2.46 to 2.39 eV with decreasing bath concentration. Our study suggests that growth is nucleation controlled.

Optically stimulated luminescence of ZnO obtained by thermal treatment of ZnS chemically synthesized

International Nuclear Information System (INIS)

Cruz V, C.; Burruel I, S.E.; Orante B, V.R.; Grijalva M, H.; Perez S, R.; Bernal, R.

2005-01-01

In this work, we report the optically stimulated luminescence (OSL) dosimetry of new nano phosphors of ZnO obtained by thermal annealing of chemically synthesized ZnS powder. The synthesized ZnS nano powder was compressed in order to form pellet shaped pellets, which were afterwards subjected to a thermal annealing at 700 C during 24 h under air atmosphere. X-ray diffraction (XRD) patterns and energy-disperse X-ray Spectrometry (EDS) analyses confirmed the transformation of ZnS to ZnO. Samples were exposed to several doses of beta radiation up to 600 Gy, and the optically stimulated luminescence with 470 nm wavelength light was recorded as a function of dose. The intensity of the OSL signal increases by increasing dose, for what it is concluded that these new phosphor materials are suitable to be used in optically stimulated luminescence dosimetry. (Author)

Economic Aspects of the Chemical Industry

Science.gov (United States)

Koleske, Joseph V.

Within the formal disciplines of science at traditional universities, through the years, chemistry has grown to have a unique status because of its close correspondence with an industry and with a branch of engineering—the chemical industry and chemical engineering. There is no biology industry, but aspects of biology have closely related disciplines such as fish raising and other aquaculture, animal cloning and other facets of agriculture, ethical drugs of pharmaceutical manufacture, genomics, water quality and conservation, and the like. Although there is no physics industry, there are power generation, electricity, computers, optics, magnetic media, and electronics that exist as industries. However, in the case of chemistry, there is a named industry. This unusual correspondence no doubt came about because in the chemical industry one makes things from raw materials—chemicals—and the science, manufacture, and use of chemicals grew up together during the past century or so.

Thermotropic and optical properties of chiral nematic polymers

International Nuclear Information System (INIS)

Tsai, M.L.; Chen, S.H.; Marshall, K.L.; Jacobs, S.D.

1988-09-01

The thermotropic and optical properties of methacrylate copolymers and chemically modified poly(γ-benzyl L-glutamate) were investigated as part of our effort to explore the optical applications of these materials. It was found that besides the commonly cited comonomer ratio, physical blending and annealing followed by quenching represent a new and more flexible means to tune the selective reflection wavelength. In the poly (γ-benzyl L-glutamate) systems, it appears that the relatively high melt viscosity is capable of sustaining the cholesteric mesophase, generated by annealing and quenching, up to 100/degree/C. 22 refs., 8 figs

Archival-grade optical disc design and international standards

Science.gov (United States)

Fujii, Toru; Kojyo, Shinichi; Endo, Akihisa; Kodaira, Takuo; Mori, Fumi; Shimizu, Atsuo

2015-09-01

Optical discs currently on the market exhibit large variations in life span among discs, making them unsuitable for certain business applications. To assess and potentially mitigate this problem, we performed accelerated degradation testing under standard ISO conditions, determined the probable disc failure mechanisms, and identified the essential criteria necessary for a stable disc composition. With these criteria as necessary conditions, we analyzed the physical and chemical changes that occur in the disc components, on the basis of which we determined technological measures to reduce these degradation processes. By applying these measures to disc fabrication, we were able to develop highly stable optical discs.

Effect of textured soy protein and tomato pulp on chemical, physical ...

African Journals Online (AJOL)

Yomi

2012-03-27

Mar 27, 2012 ... chemical, physical and sensory properties of ground chicken döner kebab ... foods with health-enhancing activity. Soy proteins ... vascular disease, cancer and osteoporosis (Anderson et al., 1995). Thus ... antioxidant content is associated with a reduced risk of lung and other .... Ease of fracture. Juiciness.

Coupling of physical erosion and chemical weathering after phases of intense human activity

Science.gov (United States)

Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Ameijeiras-Mariño, Yolanda; Kubik, Peter W.

2014-05-01

Anthropogenic disturbance of natural vegetation profoundly alters the lateral and vertical fluxes of soil nutrients and particles at the land surface. Human-induced acceleration of soil erosion can thereby result in an imbalance between physical erosion, soil production and chemical weathering. The (de-)coupling between physical erosion and chemical weathering in ecosystems with strong anthropogenic disturbances is not yet fully understood, as earlier studies mostly focused on natural ecosystems. In this study, we explore the chemical weathering intensity for four study sites located in the Internal Zone of the Spanish Betic Cordillera. Most of the sites belong to the Nevado-Filabres complex, but are characterized by different rates of long-term exhumation, 10Be catchment-wide denudation and hill slope morphology. Denudation rates are generally low, but show large variation between the three sites (from 23 to 246 mm kyr-1). The magnitude of denudation rates is consistent with longer-term uplift rates derived from marine deposits, fission-track measurements and vertical fault slip rates. Two to three soil profiles were sampled per study site at exposed ridge tops. All soils overly fractured mica schist, and are very thin (< 60cm). In each soil profile, we sampled 5 depth slices, rock fragments and the (weathered) bedrock. In total, 38 soil and 20 rock samples were analyzed for their chemical composition. The chemical weathering intensity is constrained by the Chemical Depletion Fraction that is based on a chemical mass balance approach using Zr as an immobile element. Chemical weathering accounts for 5 to 35% of the total mass lost due to denudation. We observe systematically higher chemical weathering intensities (CDFs) in sites with lower denudation rates (and vice versa), suggesting that weathering is supply-limited. Our measurements of soil elemental losses from 10 soil profiles suggest that the observed variation in chemical weathering is strongly associated

Calibration of optical cantilever deflection readers

International Nuclear Information System (INIS)

Hu Zhiyu; Seeley, Tim; Kossek, Sebastian; Thundat, Thomas

2004-01-01

Because of its ultrahigh sensitivity, the optical lever detection method similar to that used in the atomic force microscope (AFM) has been widely employed as a standard technique for measuring microcantilever deflection. Along with the increasing interest in using the microcantilever as a sensing platform, there is also a requirement for a reliable calibration technique. Many researchers have used the concept of optical lever detection to construct microcantilever deflection readout instruments for chemical, physical, and biological detection. However, without an AFM piezo z scanner, it is very difficult to precisely calibrate these instruments. Here, we present a step-by-step method to conveniently calibrate an instrument using commercially available piezoresistive cantilevers. The experimental results closely match the theoretical calculation. Following this procedure, one can easily calibrate any optical cantilever deflection detection system with high reproducibility, precision, and reliability. A detailed discussion of the optical lever readout system design has been addressed in this article

A new insight into black blooms: Synergies between optical and chemical factors

Science.gov (United States)

Duan, Hongtao; Loiselle, Steven Arthur; Li, Zuochen; Shen, Qiushi; Du, Yingxun; Ma, Ronghua

2016-06-01

Black blooms have been associated with fish-kills and the loss of benthic fauna as well as closure of potable water supplies. Their frequency and duration has increased in recent decades in rivers, inland lakes and reservoirs, and has often been associated with the decay and release of organic matter (planktonic algae, aquatic macrophytes, sediment release, etc.). However, the interactions between microbial, chemical, hydrodynamic and optical conditions necessary for black blooms are poorly understood. The present study combines field investigations and laboratory mesocosm studies to show that black blooms are caused by a combination of high CDOM (chromophoric dissolved organic matter) absorption, the formation of CDOM-Fe complexes and low backscattering. Mesocosm experiments showed that black bloom conditions occur after 4 days, with a significant increase in the concentrations of Fe2+ and ∑S2-. Total absorption (excluding absorption due to water) at 440 nm increased by 30% over this time to 7.3 m-1. In addition, the relative contribution of CDOM absorption to the non-water total absorption increased from 18% to 50%. Regression analyses between chemical and bio-optical data in both field and mesocosm experiments indicated that the concentrations of Fe2+ co-varied positively with CDOM absorption ag(440) (R2 > 0.70), and the specific CDOM absorption (ag(440)/DOC). Conditions that favored the development of black blooms were elevated algal or macrophyte biomass and limited water column mixing.

Physical and chemical trigger factors in environmental intolerance.

Science.gov (United States)

Claeson, Anna-Sara; Palmquist, Eva; Nordin, Steven

2018-04-01

Individuals with environmental intolerance (EI) react to exposure from different environmental sources at levels tolerated by most people and that are below established toxicological and hazardous thresholds. The main aim of this study was to determine the prevalence of attributing symptoms to chemical and physical sources in the environment among individuals with different forms of self-reported EI and in referents. Cross-sectional data from a population-based study, the Västerbotten Environmental Health Study (n = 3406), were used and individuals with self-reported EI to chemicals, buildings, electromagnetic fields and sounds as well as a group with multiple EIs were identified. The Environmental-Symptom Attribution Scale was used to quantify degree to which health symptoms are attributed to 40 specific environmental exposures and sources, with subscales referring to the four types of EI. All EI groups, except the group with building related intolerance (BRI), reported more symptoms from the expected sources compared to the referents. In addition, individuals with chemical and sound intolerance reported symptoms from building related trigger factors, and individuals with electromagnetic hypersensitivity reported symptoms from chemical trigger factors. The study suggests that individuals with BRI react to fewer and more specific trigger factors than do individuals with other EIs, and that it is important to ask about different sources since three of the EI groups attribute their symptoms to a wide variety of sources in addition to the sources to which their EI implicates. Copyright © 2018 Elsevier GmbH. All rights reserved.

High speed optical wireless data transmission system for particle sensors in high energy physics

Science.gov (United States)

Ali, W.; Corsini, R.; Ciaramella, E.; Dell'Orso, R.; Messineo, A.; Palla, F.

2015-08-01

High speed optical fiber or copper wire communication systems are frequently deployed for readout data links used in particle physics detectors. Future detector upgrades will need more bandwidth for data transfer, but routing requirements for new cables or optical fiber will be challenging due to space limitations. Optical wireless communication (OWC) can provide high bandwidth connectivity with an advantage of reduced material budget and complexity of cable installation and management. In a collaborative effort, Scuola Superiore Sant'Anna and INFN Pisa are pursuing the development of a free-space optical link that could be installed in a future particle physics detector or upgrade. We describe initial studies of an OWC link using the inner tracker of the Compact Muon Solenoid (CMS) detector as a reference architecture. The results of two experiments are described: the first to verify that the laser source transmission wavelength of 1550 nm will not introduce fake signals in silicon strip sensors while the second was to study the source beam diameter and its tolerance to misalignment. For data rates of 2.5 Gb/s and 10 Gb/s over a 10 cm working distance it was observed that a tolerance limit of ±0.25 mm to ±0.8 mm can be obtained for misaligned systems with source beam diameters of 0.38 mm to 3.5 mm, respectively.

Lepidopteran defence droplets - A composite physical and chemical weapon against potential predators

DEFF Research Database (Denmark)

Pentzold, S.; Zagrobelny, Mika; Khakimov, Bekzod

2016-01-01

Insects often release noxious substances for their defence. Larvae of Zygaena filipendulae (Lepidoptera) secrete viscous and cyanogenic glucoside-containing droplets, whose effectiveness was associated with their physical and chemical properties. The droplets glued mandibles and legs of potential...

Double-Layer Structured CO2 Adsorbent Functionalized with Modified Polyethyleneimine for High Physical and Chemical Stability.

Science.gov (United States)

Jeon, Sunbin; Jung, Hyunchul; Kim, Sung Hyun; Lee, Ki Bong

2018-06-18

CO 2 capture using polyethyleneimine (PEI)-impregnated silica adsorbents has been receiving a lot of attention. However, the absence of physical stability (evaporation and leaching of amine) and chemical stability (urea formation) of the PEI-impregnated silica adsorbent has been generally established. Therefore, in this study, a double-layer impregnated structure, developed using modified PEI, is newly proposed to enhance the physical and chemical stabilities of the adsorbent. Epoxy-modified PEI and diepoxide-cross-linked PEI were impregnated via a dry impregnation method in the first and second layers, respectively. The physical stability of the double-layer structured adsorbent was noticeably enhanced when compared to the conventional adsorbents with a single layer. In addition to the enhanced physical stability, the result of simulated temperature swing adsorption cycles revealed that the double-layer structured adsorbent presented a high potential working capacity (3.5 mmol/g) and less urea formation under CO 2 -rich regeneration conditions. The enhanced physical and chemical stabilities as well as the high CO 2 working capacity of the double-layer structured adsorbent were mainly attributed to the second layer consisting of diepoxide-cross-linked PEI.

Optical and physical properties of samarium doped lithium diborate glasses

Science.gov (United States)

Hanumantharaju, N.; Sardarpasha, K. R.; Gowda, V. C. Veeranna

2018-05-01

Sm3+ doped lithium di-borate glasses with composition 30Li2O-60B2O3-(10-x) PbO, (where 0 molar volume with samarium ion content indicates the openness of the glass structure. The gradual increase in average separation of boron-boron atoms with VmB clearly indicates deterioration of borate glass network, which in turn leads to decrease in the oxygen packing density. The replacements of Sm2O3 for PbO depolymerise the chain structure and that would increase the concentration of non-bridging oxygens. The marginal increase of optical band gap energy after 1.0 mol.% of Sm2O3 is explained by considering the structural modification in lead-borate. The influence of Sm3+ ion on physical and optical properties in lithium-lead-borate glasses is investigated and the results were discussed in view of the structure of borate glass network.

Nonlinear optics

CERN Document Server

Boyd, Robert W

2013-01-01

Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

Chemical and physical characteristics of phosphate rock materials of varying reactivity

International Nuclear Information System (INIS)

Syers, J.K.; Currie, L.D.

1986-01-01

Several chemical and physical properties of 10 phosphate rock (PR) materials of varying reactivity were evaluated. The highest concentrations of As and Cd were noted. Because Cd and U can accumulate in biological systems, it may be necessary to direct more attention towards the likely implications of Cd and U concentrations when evaluating a PR for direct application. Three sequential extractions with 2% citric acid may be more useful for comparing the chemical solubility of PR materials, particularly for those containing appreciable CaC0 3 . The poor relationship obtained between surface area and the solubility of the PR materials suggests that surface area plays a secondary role to chemical reactivity in controlling the solubility of a PR in a chemical extractant. A Promesh plot provided an effective method for describing the particle-size characteristics of those PR materials which occurred as sands. Fundamental characteristics, such as mean particle size and uniformity, can readily be determined from a Promesh plot. (author)

Colloquium on Atomic, Molecular and Optical Physics of the French Physics Society. Days of Molecular Spectroscopy, Lille, 7-10 July 2008

International Nuclear Information System (INIS)

Balcou, Philippe; Aspect, Alain; Merkt, Frederic; Haroche, Serge; Hendecourt, Louis d'; Dereux, Alain; Bloch, Daniel; Courty, Jean-Michel; Demaison, Jean; Hynes, James T.; Lievin, Jacky; Billy, J.; Josse, V.; Zuo, Z.; Bernard, A.; Hambrecht, B.; Lugan, P.; Clement, D.; Sanchez-Palencia, L.; Bouyer, P.; Aspect, A.; Garreau, Jean-Claude; Chabe, Julien; Szriftgiser, Pascal; Lemarie, Gabriel; Gremaud, Benoit; Delande, Dominique; Simoni, Andrea; Browaeys, Antoine; Kasparian, Jerome; Boutou, Veronique; Guyon, Laurent; Courvoisier, Francois; Roth, Matthias; Roslund, Jon; Rabitz, Herschel; Bonacina, Luigi; Rondi, Ariana; Extermann, Jerome; Wolf, Jean-Pierre; Maitre, Philippe; Zehnacker, Anne; Le Barbu-Debus, Katia; Sidis, Victor; Aguillon, Francois; Sizun, Muriel; Rougeau, Nathalie; Teillet-Billy, Dominique; Bachellerie, Damien; Jeloaica, Leonard; Morisset, Sabine; Picaud, Sylvain; Cacciani, Patrice; Grosliere, Marie-Christine; Joly, Gilles; Joly, Nicolas; Kudlinsky, Alexandre; Martinelli, Gilbert; Buchard, Virginie; Tudorie, Marcela; Khelkhal, Mohamed; Cosleou, Jean; Hennequin, Daniel; Beaugeois, Maxime; Lebrun, Nathalie; Droz, Daniel; El Aydam, Mohamed; Gama, Marie-Jose; Ferri, Sandrine; Schyns, Bernadette; Courty, Jean Michel

2008-07-01

This colloquium of the French Physics Society on atomic, molecular and optical physics (and more particularly on molecular spectroscopy) comprised several mini-colloquia: methane and its applications in planetology, moving mirrors and Casimir, atoms and molecules in interaction with surfaces, electronic properties of small molecules, molecular spectroscopy for atmospheric applications, quantum memories in atomic sets, methods and applications of reaction dynamics, dynamics of super-excited molecular statuses, mass spectrometry, quantum spectroscopy and chemistry, spectroscopy and reactivity of of confined molecules, electronic and molecular dynamics, dipolar quantum gases. It also comprised plenary sessions: atto-second optics, the atomic Hanbury-Brown-Twiss effect with fermions and bosons, atom and molecule slowing down by Zeeman effect and by Stark effect on Rydberg levels, non destructive counting of photons trapped in a cavity, interstellar chemistry, atom-surface van der Waals interaction noticed in the exotic regime of short distances, communication, vulgarisation and education (the multiple lives of a scientific result), the actual precision of molecular parameters, towards the formation of an amine acid precursor in the interstellar medium via proton transfer, prediction of the ionized and excited molecular electronic structure by Quantum Chemistry (from bi-atomic to bio-molecules), direct observation of Anderson location of matter waves in a controlled disordered potential, experimental observation of the Anderson transition of cold atoms, ultra-cold collisions as a key towards the quantum world, Quantum physics with a single atom, Teramobile or plasma filaments to study the atmosphere, optimal control or how to discriminate two almost identical bio-molecules, infrared spectroscopy as a new dimension for mass spectrometry, chiral recognition in gaseous phase, interactions and reactions between H atoms and graphite surfaces, modelling of gas

Physical-chemical processes of astrophysical interest: nitrogen chemistry

International Nuclear Information System (INIS)

Loison, Jean-Christophe; Hickson, Kevin; Hily-Blant, Pierre; Faure, Alexandre; Vuitton, Veronique; Bacmann, A.; Maret, Sebastien; Legal, Romane; Rist, Claire; Roncero, Octavio; Larregaray, Pascal; Hochlaf, Majdi; Senent, M. L.; Capron, Michael; Biennier, Ludovic; Carles, Sophie; Bourgalais, Jeremy; Le Picard, Sebastien; Cordier, Daniel; Guillemin, Jean-Claude; Trolez, Yann; Bertin, M.; Poderoso, H.A.M.; Michaut, X.; Jeseck, P.; Philippe, L.; Fillion, J.H.; Fayolle, E.C.; Linnartz, H.; Romanzin, C.; Oeberg, K.I.; Roueff, Evelyne; Pagani, Laurent; Padovani, Marco; Wakelam, Veronique; Honvault, Beatrice; Zvereva-Loete, Natalia; Ouk, Chanda-Malis; Scribano, Yohann; Hartmann, J.M.; Pineau des Forets, Guillaume; Hernandez, Mario; Lique, Francois; Kalugina, Yulia N.; Stoecklin, T.; Hochlaf, M.; Crespos, C.; Larregaray, P.; Martin-Gondre, L.; Petuya, R.; Quintas Sanchez, E.L.; Zanchet, Alexandre; Rodriguez-Lazcano, Yamilet; Mate, Belen

2013-06-01

This document contains the programme and abstracts of contributions to a workshop on nitrogen chemistry within an astrophysical perspective. These contributions have been presented in sessions: Introduction (opening lecture, experimental approaches to molecular astrophysics, theoretical approaches to astrophysics, observations in molecular astrophysics), Physical-chemical theory of the gas phase (time-dependent approach in elementary activity, statistic approach in elementary activity in the case of the N+H_2 reaction, potential energy surfaces for inelastic and reactive collisions, collision rate for N_2H"+, ortho/para selection rules in the chemistry of nitrogen hydrides, cyanides/iso-cyanides excitation in the ISM, CN excitation, radiative association with N_2H as new interstellar anion, ro-vibratory excitation of HCN) Laboratory astrophysics (measurement of reaction products in the CRESUSOL project, reactivity of the CN- anion, N_2 photo-desorption in ices, CRESU study of nitrogen chemistry, chemistry of nitrogen complex molecules), Observations and chemistry of astrophysical media (the problem of interstellar nitrogen fractioning, abundance of N_2 in proto-stellar cores, HNC in Titan atmosphere and nitrogen-related mechanisms in hot Jupiters, HCN and HNC in dark clouds or how theoretical modelling helps in interpreting observations, nitrogen chemistry in cold clouds, deuteration of nitrogen hydrides, nitrogen in interstellar ices, biochemical molecules on Titan, coupling between excitation and chemistry, radiative transfer of nitrogen hydrides, ortho/para chemistry of nitrogen hydrides), Physical-chemical theory of gas-grain interactions (nitrogen reactivity on surfaces, IR spectra of ices of NH_3 and NH_3/N_2 mixtures)

Numerical tables on physical and chemical analyses of Rhine water 1983

International Nuclear Information System (INIS)

1984-01-01

The numerical tables contain the measuring results of the physical-chemical studies on the Rhine water for the year 1983. The tables are arranged by general parameters, organic matter, eutrophicating substances, anorganic matter, metals, organic micropollution as well as by radioactivity (total alpha- or beta- and T-activity). (MM) [de

Nonequilibrium thermodynamics transport and rate processes in physical, chemical and biological systems

CERN Document Server

Demirel, Yasar

2014-01-01

Natural phenomena consist of simultaneously occurring transport processes and chemical reactions. These processes may interact with each other and may lead to self-organized structures, fluctuations, instabilities, and evolutionary systems. Nonequilibrium Thermodynamics, 3rd edition emphasizes the unifying role of thermodynamics in analyzing the natural phenomena. This third edition updates and expands on the first and second editions by focusing on the general balance equations for coupled processes of physical, chemical, and biological systems. The new edition contains a new chapte

South African EUCAARI measurements: Seasonal variation of trace gases and aerosol optical properties

NARCIS (Netherlands)

Laakso, L.; Vakkari, V.; Virkkula, A.; Laakso, H.; Backman, J.; Kulmala, M.; Beukes, J.P.; Zyl, P.G. van; Tiitta, P.; Josipovic, M.; Pienaar, J.J.; Chiloane, K.; Gilardoni, S.; Vignati, E.; Wiedensohler, A.; Tuch, T.; Birmili, W.; Piketh, S.; Collett, K.; Fourie, G.D.; Komppula, M.; Lihavainen, H.; Leeuw, G. de; Kerminen, V.-M.

2012-01-01

In this paper we introduce new in situ observations of atmospheric aerosols, especially chemical composition, physical and optical properties, on the eastern brink of the heavily polluted Highveld area in South Africa. During the observation period between 11 February 2009 and 31 January 2011, the

Physical and chemical properties of pyrethroids.

Science.gov (United States)

Laskowski, Dennis A

2002-01-01

The physical and chemical properties of the pyrethroids bifenthrin, cyfluthrin, cypermethrin (also zetacypermethrin), deltamethrin, esfenvalerate (also fenvalerate), fenpropathrin, lambda-cyhalothrin (also cyhalothrin), permethrin, and tralomethrin have been reviewed and summarized in this paper. Physical properties included molecular weight, octanol-water partition coefficient, vapor pressure, water solubility, Henry's law constant, fish biocencentration factor, and soil sorption, desorption, and Freundlich coefficients. Chemical properties included rates of degradation in water as a result of hydrolysis, photodecomposition, aerobic or anaerobic degradation by microorganisms in the absence of light, and also rates of degradation in soil incubated under aerobic or anaerobic conditions. Collectively, the pyrethroids display a highly nonpolar nature of low water solubility, low volatility, high octanol-water partition coefficients, and have high affinity for soil and sediment particulate matter. Pyrethroids have low mobility in soil and are sorbed strongly to the sediments of natural water systems. Although attracted to living organisms because of their nonpolar nature, their capability to bioconcentrate is mitigated by their metabolism and subsequent elimination by the organisms. In fish, bioconcentration factors (BCF) ranged from 360 and 6000. Pyrethroids in water solution tend to be stable at acid and neutral pH but [table: see text] become increasingly susceptible to hydrolysis at pH values beyond neutral. Exceptions at higher pH are bifenthrin (stable), esfenvalerate (stable), and permethrin (half-life, 240 d). Pyrethroids vary in susceptibility to sunlight. Cyfluthrin and tralomethrin in water had half-lives of 0.67 and 2.5 d; lambda-cyhalothrin, esfenvalerate, deltamethrin, permethrin, and cypermethrin were intermediate with a range of 17-110 d; and bifenthrin and fenpropathrin showed the least susceptibility with half-lives of 400 and 600 d, respectively

Physical and Chemical Properties of Coal Bottom Ash (CBA) from Tanjung Bin Power Plant

Science.gov (United States)

Izzati Raihan Ramzi, Nurul; Shahidan, Shahiron; Zulkhairi Maarof, Mohamad; Ali, Noorwirdawati

2016-11-01

The objective of this study is to determine the physical and chemical characteristics of Coal Bottom Ash (CBA) obtained from Tanjung Bin Power Plant Station and compare them with the characteristics of natural river sand (as a replacement of fine aggregates). Bottom ash is the by-product of coal combustion during the electricity generating process. However, excess bottom ash production due to the high production of electricity in Malaysia has caused several environmental problems. Therefore, several tests have been conducted in order to determine the physical and chemical properties of bottom ash such as specific gravity, density, particle size distribution, Scanning Electron Microscopic (SEM) and X- Ray Fluorescence (XRF) in the attempt to produce sustainable material from waste. The results indicated that the natural fine aggregate and coal bottom ash have very different physical and chemical properties. Bottom ash was classified as Class C ash. The porous structure, angular and rough texture of bottom ash affected its specific gravity and particle density. From the tests, it was found that bottom ash is recommended to be used in concrete as a replacement for fine aggregates.

Optical fibre sensing of plasmas

International Nuclear Information System (INIS)

Woolsey, G.A.; Scelsi, G.B.

2000-01-01

The progress of optical fiber technology for communications has induced an interest in, among others, the sensing of a wide range of physical, and chemical quantities. Any application of optical fibers that are crucial for communication are significant for sensing, e.g. small dimension, insulating materials, immunity to high voltage field etc. In the present paper basic points of optical fiber sensing are summarized. It is noted optical fiber sensors come in two forms, intrinsic and extrinsic. In the former the fiber itself works as sensing element, in addition to data transmission lines. In an intrinsic sensor, a single fiber transmits the light from the source to the detector and the light is modulated while it is in the fiber. On the other hand, in the extrinsic sensor, the light leaves the input fiber to be modulated before being collected by the second output fiber. Characteristic of the light that can be modulated are amplitude, phase, polarization, and wavelength. The paper describes the modulation in some details. (author)

Optical fibre sensing of plasmas

Energy Technology Data Exchange (ETDEWEB)

Woolsey, G.A.; Scelsi, G.B. [School of Physical Sciences and Engineering, Univ. of New England, Armidale, NSW (Australia)

2000-03-01

The progress of optical fiber technology for communications has induced an interest in, among others, the sensing of a wide range of physical, and chemical quantities. Any application of optical fibers that are crucial for communication are significant for sensing, e.g. small dimension, insulating materials, immunity to high voltage field etc. In the present paper basic points of optical fiber sensing are summarized. It is noted optical fiber sensors come in two forms, intrinsic and extrinsic. In the former the fiber itself works as sensing element, in addition to data transmission lines. In an intrinsic sensor, a single fiber transmits the light from the source to the detector and the light is modulated while it is in the fiber. On the other hand, in the extrinsic sensor, the light leaves the input fiber to be modulated before being collected by the second output fiber. Characteristic of the light that can be modulated are amplitude, phase, polarization, and wavelength. The paper describes the modulation in some details. (author)

Optical micro-bubble resonators as promising biosensors

Science.gov (United States)

Giannetti, A.; Barucci, A.; Berneschi, S.; Cosci, A.; Cosi, F.; Farnesi, D.; Nunzi Conti, G.; Pelli, S.; Soria, S.; Tombelli, S.; Trono, C.; Righini, G. C.; Baldini, F.

2015-05-01

Recently, optical micro-bubble resonators (OMBRs) have gained an increasing interest in many fields of photonics thanks to their particular properties. These hollow microstructures can be suitable for the realization of label - free optical biosensors by combining the whispering gallery mode (WGM) resonator properties with the intrinsic capability of integrated microfluidics. In fact, the WGMs are morphology-dependent modes: any change on the OMBR inner surface (due to chemical and/or biochemical binding) causes a shift of the resonance position and reduces the Q factor value of the cavity. By measuring this shift, it is possible to obtain information on the concentration of the analyte to be detected. A crucial step for the development of an OMBR-based biosensor is constituted by the functionalization of its inner surface. In this work we report on the development of a physical and chemical process able to guarantee a good homogeneity of the deposed bio-layer and, contemporary, to preserve a high quality factor Q of the cavity. The OMBR capability of working as bioassay was proved by different optical techniques, such as the real time measurement of the resonance broadening after each functionalization step and fluorescence microscopy.

Photo-physical characterization of fluorophore Ru(bpy32+ for optical biosensing applications

Directory of Open Access Journals (Sweden)

E.L. Sciuto

2015-12-01

Full Text Available We studied absorption, emission and lifetime of the coordination compound tris(2,2′-bipyridylruthenium(II fluorophore (Ru(bpy32+ both dissolved in water solutions and dried. Lifetime measurements were carried out using a new detector, the Silicon Photomultiplier (SiPM, which is more sensitive and physically much smaller than conventional optical detectors, such as imager and scanner. Through these analyses and a morphological characterization with transmission electron microscopy, revealed its usability for sensor applications, in particular, as dye in optical DNA-chip technology, a viable alternative to the conventional CY5 fluorophore. The use of Ru(bpy32+ would solve some of the typical disadvantages related to Cy5’s application, such as self-absorption of fluorescence and photobleaching. In addition, the Ru(bpy32+ longer lifetime may play a key role in the definition of new optical DNA-chip. Keywords: Tris(2,2′-bipyridylruthenium(II, Fluorophore, Spectroscopy, Lifetime measurements, SiPM, TEM

Combustion physics

Science.gov (United States)

Jones, A. R.

1985-11-01

Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

Physical and chemical effects of low octane gasoline fuels on compression ignition combustion

KAUST Repository

Badra, Jihad; Viollet, Yoann; Elwardani, Ahmed Elsaid; Im, Hong G.; Chang, Junseok

2016-01-01

Gasoline compression ignition (GCI) engines running on low octane gasoline fuels are considered an attractive alternative to traditional spark ignition engines. In this study, three fuels with different chemical and physical characteristics have

Physical, chemical and sensory characteristics of red guava (Psidium guajava) velva at different fruit ripening time

Science.gov (United States)

Ishartani, D.; Rahman, F. L. F.; Hartanto, R.; Utami, R.; Khasanah, L. U.

2018-01-01

This study purposed to determine the effect of red guava fruit ripening time on the physical (overrun and melting rate), chemical (vitamin C, pH, total dissolved solid) and sensory (color, taste, aroma, texture, and overall compare to control (without ripening) velva) characteristic of red guava velva. Red guava fruits were harvested at 90 days after flowering, ripened and then processed into velva. This research used Completely Randomized Design with fruit ripening time (without ripening, 4 days, and 6 days) as single factor. The research was conducted in triplicate. Chemical and physical characteristic data was analysed using One Way Analysis of Varian whether sensory characteristic data was analyzed using Independent Sample T-test. The result showed that fruit ripening time significantly affected the physical, chemical and sensory characteristic of the velva. Vitamin C, pH, and total solid of the velva were increased as the ripening time prolonged. In other hand, increasing of fruit ripening time decreased the overrun and melting rate of the velva. Red guava velva made from 6 days ripening had better sensory characteristics compared to velva made from red guava fruit without ripening or 4 day ripening. This research conclude that 6 days ripening time gives better chemical, physical and sensory characteristics of the velva compare to 4 days ripening time. Red guava fruits ripened for 6 days were recommended as raw material in velva making.

Applied optics

International Nuclear Information System (INIS)

Orszag, A.; Antonetti, A.

1988-01-01

The 1988 progress report, of the Applied Optics laboratory, of the (Polytechnic School, France), is presented. The optical fiber activities are focused on the development of an optical gyrometer, containing a resonance cavity. The following domains are included, in the research program: the infrared laser physics, the laser sources, the semiconductor physics, the multiple-photon ionization and the nonlinear optics. Investigations on the biomedical, the biological and biophysical domains are carried out. The published papers and the congress communications are listed [fr

Polymer optical fiber tapering using chemical solvent and polishing

Science.gov (United States)

Supian, L. S.; Syuhaimi Ab-Rahman, Mohd; Arsad, Norhana

2017-11-01

A method for developing polymer optical fiber (POF) directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

Polymer optical fiber tapering using chemical solvent and polishing

Directory of Open Access Journals (Sweden)

Supian L. S.

2017-01-01

Full Text Available A method for developing polymer optical fiber (POF directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

Quantum optics and nuclear clocks: a look at the 2012 physics nobel prize

International Nuclear Information System (INIS)

Herrera-Sancho, Oscar-Andrey

2013-01-01

Pioneering researches in the field of quantum optics are presented. These have laid the foundation for photonics research, that has grasped the particle properties of light to create new technologies and deepen the understanding of the physical laws. The quantum computation and quantum clocks have been highlighted. Individual particles have managed to manipulate without losing its properties in quantum, using photons to immobilize atoms with electric charges (ions) and study their properties. Researches conducted by the French scientist Serge Haroche and American David Wineland nobel prize winners for Physics 2012, have been commented [es

Self-organization of grafted polyelectrolyte layers via the coupling of chemical equilibrium and physical interactions.

Science.gov (United States)

Tagliazucchi, Mario; de la Cruz, Mónica Olvera; Szleifer, Igal

2010-03-23

The competition between chemical equilibrium, for example protonation, and physical interactions determines the molecular organization and functionality of biological and synthetic systems. Charge regulation by displacement of acid-base equilibrium induced by changes in the local environment provides a feedback mechanism that controls the balance between electrostatic, van der Waals, steric interactions and molecular organization. Which strategies do responsive systems follow to globally optimize chemical equilibrium and physical interactions? We address this question by theoretically studying model layers of end-grafted polyacids. These layers spontaneously form self-assembled aggregates, presenting domains of controlled local pH and whose morphologies can be manipulated by the composition of the solution in contact with the film. Charge regulation stabilizes micellar domains over a wide range of pH by reducing the local charge in the aggregate at the cost of chemical free energy and gaining in hydrophobic interactions. This balance determines the boundaries between different aggregate morphologies. We show that a qualitatively new form of organization arises from the coupling between physical interactions and protonation equilibrium. This optimization strategy presents itself with polyelectrolytes coexisting in two different and well-defined protonation states. Our results underline the need of considering the coupling between chemical equilibrium and physical interactions due to their highly nonadditive behavior. The predictions provide guidelines for the creation of responsive polymer layers presenting self-organized patterns with functional properties and they give insights for the understanding of competing interactions in highly inhomogeneous and constrained environments such as those relevant in nanotechnology and those responsible for biological cells function.

Radioactive isotopes in solid-state physics

CERN Document Server

Deicher, M

2002-01-01

Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as M\\"ossbauer spectroscopy, perturbed angular correlation, $\\beta$-NMR, and emission channelling have used nuclear properties (via hyperfine interactions or emitted particles) to gain microscopical information on the structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as a clean ion beam at ISOL facilities such as ISOLDE at CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Extremely sensitive spectroscopic techniques like deep-level transient spectroscopy (DLTS), photoluminescence (PL), and Hall effect have gained a new quality by using radioactive isotopes. Because of their decay the chemical origin of an observed electronic and optical b...

STUDYING THE STRUCTURAL, OPTICAL, CHEMICAL AND ELECTROCHEMICAL ETCHING CHANGES OF CR-39 FOR DOSEMETRIC APPLICATIONS.

Science.gov (United States)

Zaki, M F; Elshaer, Y H; Taha, Doaa H

2017-12-01

The present work shows the induced modification of the structural, optical, chemical etching and electrochemical etching parameters of CR-39 irradiated with alpha-particles. CR-39 polymer track detectors were irradiated with different fluences (1.62 × 106, 2.72 × 106, 3.82 × 106 and 5.21 × 106 particles/cm2) of alpha-particles using 241Am source. The structural and optical properties were measured by FT-IR spectroscopy, X-ray diffraction and UV/Vis spectroscopy, respectively. The FT-IR spectra reveal that no major changes in the typical functional groups of irradiated polymer detectors. The X-ray diffraction patterns show that a broad band in the region of 12° 27°, which refers to the presence of the combination of amorphous and crystalline phases. UV/Vis responses of irradiated polymer track detectors exhibit a single absorption band in the range of 254-352 nm that is correlated to the occurrence of electronic transition. Also, the changes in the chemical and electrochemical parameters due to alpha-irradiation are examined and thoroughly discussed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Optical and magnetic properties of a transparent garnet film for atomic physics experiments

Directory of Open Access Journals (Sweden)

Mari Saito

2016-12-01

Full Text Available We investigated the optical and magnetic properties of a transparent magnetic garnet with a particular focus on its applications to atomic physics experiments. The garnet film used in this study was a magnetically soft material that was originally designed for a Faraday rotator at optical communication wavelengths in the near infrared region. The film had a thickness of 2.1 μm and a small optical loss at a wavelength of λ=780 nm resonant with Rb atoms. The Faraday effect was also small and, thus, barely affected the polarization of light at λ=780 nm. In contrast, large Faraday rotation angles at shorter wavelengths enabled us to visualize magnetic domains, which were perpendicularly magnetized in alternate directions with a period of 3.6 μm. We confirmed the generation of an evanescent wave on the garnet film, which can be used for the optical observation and manipulation of atoms on the surface of the film. Finally, we demonstrated a magnetic mirror for laser-cooled Rb atoms using the garnet film.

Plasma-enhanced chemical vapor deposited silicon oxynitride films for optical waveguide bridges for use in mechanical sensors

DEFF Research Database (Denmark)

Storgaard-Larsen, Torben; Leistiko, Otto

1997-01-01

In this paper the influence of RF power, ammonia flow, annealing temperature, and annealing time on the optical and mechanical properties of plasma-enhanced chemically vapor deposited silicon oxynitride films, is presented. A low refractive index (1.47 to 1.48) film having tensile stress has been...

Physical and chemical assessment of MSF distillate and SWRO product for drinking purpose

KAUST Repository

Gacem, Yasmine; Taleb, Safia; Ramdani, Amina; Senadjki, Samia; Ghaffour, NorEddine

2012-01-01

The objective of this study was to evaluate the physical and chemical proprieties of desalinated seawater produced by Multi Stage Flash (MSF) and Reverse Osmosis (RO) processes for drinking purpose. The final products, after post

Determination of physicochemical and optical parameters of xerogel layers for chemical sensing

Czech Academy of Sciences Publication Activity Database

Matějec, Vlastimil; Mrázek, Jan; Chomát, Miroslav; Skokánková, Jana; Raileanu, M.; Zaharescu, M.

2003-01-01

Roč. 12,3 P.IVSup.(2003), s. 1545-1554 ISSN 1224-9513. [Physical Chemistry Conference ROMPHYSCHEM /11./. Timisoara, 02.09.2003-05.09.2003] R&D Projects: GA ČR(CZ) GA102/02/0779; GA AV ČR(CZ) KSK2067107 Keywords : chemical sensor s * sol-gel processing * aerogels * gases Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Effects of chemical-physical pre-treatment processes on hemp fibres for reinforcement of composites and textiles

DEFF Research Database (Denmark)

Thomsen, Anne Belinda; Thygesen, Anders; Bohn, Vibeke

2006-01-01

Retted hemp fibres were treated using chemical-physical pre-treatments and the material was characterised chemically in order to evaluate the effect of the pre-treatments, respectively, wet oxidation (WO), hydrothermal treatment (HT) and steam explosion (STEX). Process variables were addition...

Physical and Chemical Changes of Polystyrene Nanospheres Irradiated with Laser

International Nuclear Information System (INIS)

Mustafa, Mohd Ubaidillah; Juremi, Nor Rashidah Md.; Mohamad, Farizan; Wibawa, Pratama Jujur; Agam, Mohd Arif; Ali, Ahmad Hadi

2011-01-01

It has been reported that polymer resist such as PMMA (Poly(methyl methacrylate) which is a well known and commonly used polymer resist for fabrication of electronic devices can show zwitter characteristic due to over exposure to electron beam radiation. Overexposed PMMA tend to changes their molecular structure to either become negative or positive resist corresponded to electron beam irradiation doses. These characteristic was due to crosslinking and scissors of the PMMA molecular structures, but till now the understanding of crosslinking and scissors of the polymer resist molecular structure due to electron beam exposure were still unknown to researchers. Previously we have over exposed polystyrene nanospheres to various radiation sources, such as electron beam, solar radiation and laser, which is another compound that can act as polymer resist. We investigated the physical and chemical structures of the irradiated polystyrene nanospheres with FTIR analysis. It is found that the physical and chemical changes of the irradiated polystyrene were found to be corresponded with the radiation dosages. Later, combining Laser irradiation and Reactive Ion Etching manipulation, created a facile technique that we called as LARIEA NSL (Laser and Reactive Ion Etching Assisted Nanosphere Lithography) which can be a facile technique to fabricate controllable carbonaceous nanoparticles for applications such as lithographic mask, catalysts and heavy metal absorbers.

Mechanical, electronic, chemical bonding and optical properties of cubic BaHfO3: First-principles calculations

International Nuclear Information System (INIS)

Liu Qijun; Liu Zhengtang; Feng Liping; Tian Hao

2010-01-01

We have performed ab-initio total energy calculations using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT) to study structural parameters, mechanical, electronic, chemical bonding and optical properties of cubic BaHfO 3 . The calculated lattice parameter and independent elastic constants are in good agreement with previous theoretical and experimental work. The bulk, shear and Young's modulus, Poisson coefficient, compressibility and Lame constants are obtained using Voigt-Reuss-Hill method and the Debye temperature is estimated using Debye-Grueneisen model, which are consistent with previous results. Electronic and chemical bonding properties have been studied from the calculations of band structure, density of states and charge densities. Furthermore, in order to clarify the mechanism of optical transitions of cubic BaHfO 3 , the complex dielectric function, refractive index, extinction coefficient, reflectivity, absorption efficient, loss function and complex conductivity function are calculated. Then, we have explained the origins of spectral peaks on the basis of the theory of crystal-field and molecular-orbital bonding.

Physical, chemical, and biological properties of radiocerium relevant to radiation protection guidelines

International Nuclear Information System (INIS)

Anon.

1978-01-01

Present knowledge of the relevant physical, chemical, and biological properties of radiocerium as a basis for establishing radiation protection guidelines is summarized. The first section of the report reviews the chemical and physical properties of radiocerium relative to the biological behavior of internally-deposited cerium and other lanthanides. The second section of the report gives the sources of radiocerium in the environment and the pathways to man. The third section of the report describes the metabolic fate of cerium in several mammalian species as a basis for predicting its metabolic fate in man. The fourth section of the report considers the biomedical effects of radiocerium in light of extensive animal experimentation. The last two sections of the report describe the history of radiation protection guidelines for radiocerium and summarize data required for evaluating the adequacy of current radiation protection guidelines. Each section begins with a summary of the most important findings that follow

High-Resolution Integrated Optical System

Science.gov (United States)

Prakapenka, V. B.; Goncharov, A. F.; Holtgrewe, N.; Greenberg, E.

2017-12-01

Raman and optical spectroscopy in-situ at extreme high pressure and temperature conditions relevant to the planets' deep interior is a versatile tool for characterization of wide range of properties of minerals essential for understanding the structure, composition, and evolution of terrestrial and giant planets. Optical methods, greatly complementing X-ray diffraction and spectroscopy techniques, become crucial when dealing with light elements. Study of vibrational and optical properties of minerals and volatiles, was a topic of many research efforts in past decades. A great deal of information on the materials properties under extreme pressure and temperature has been acquired including that related to structural phase changes, electronic transitions, and chemical transformations. These provide an important insight into physical and chemical states of planetary interiors (e.g. nature of deep reservoirs) and their dynamics including heat and mass transport (e.g. deep carbon cycle). Optical and vibrational spectroscopy can be also very instrumental for elucidating the nature of the materials molten states such as those related to the Earth's volatiles (CO2, CH4, H2O), aqueous fluids and silicate melts, planetary ices (H2O, CH4, NH3), noble gases, and H2. The optical spectroscopy study performed concomitantly with X-ray diffraction and spectroscopy measurements at the GSECARS beamlines on the same sample and at the same P-T conditions would greatly enhance the quality of this research and, moreover, will provide unique new information on chemical state of matter. The advanced high-resolution user-friendly integrated optical system is currently under construction and expected to be completed by 2018. In our conceptual design we have implemented Raman spectroscopy with five excitation wavelengths (266, 473, 532, 660, 946 nm), confocal imaging, double sided IR laser heating combined with high temperature Raman (including coherent anti-Stokes Raman scattering) and

Quantum and semiclassical physics behind ultrafast optical nonlinearity in the midinfrared: the role of ionization dynamics within the field half cycle.

Science.gov (United States)

Serebryannikov, E E; Zheltikov, A M

2014-07-25

Ultrafast ionization dynamics within the field half cycle is shown to be the key physical factor that controls the properties of optical nonlinearity as a function of the carrier wavelength and intensity of a driving laser field. The Schrödinger-equation analysis of a generic hydrogen quantum system reveals universal tendencies in the wavelength dependence of optical nonlinearity, shedding light on unusual properties of optical nonlinearities in the midinfrared. For high-intensity low-frequency fields, free-state electrons are shown to dominate over bound electrons in the overall nonlinear response of a quantum system. In this regime, semiclassical models are shown to offer useful insights into the physics behind optical nonlinearity.

Gold processing residue from Jacobina Basin: chemical and physical properties

OpenAIRE

Lima, Luiz Rogério Pinho de Andrade; Bernardez, Letícia Alonso; Barbosa, Luís Alberto Dantas

2007-01-01

p. 848-852 Gold processing residues or tailings are found in several areas in the Itapicuru River region (Bahia, Brazil), and previous studies indicated significant heavy metals content in the river sediments. The present work focused on an artisanal gold processing residue found in a site from this region. Samples were taken from the processing residue heaps and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron...

Sensorial, physical and chemical evaluation of bio-fortified Ipomoea batatas

OpenAIRE

Mara N.G. Santos; Joice V.C. Orsine; Alexandre I. de A. Pereira; Roberto Cañete; María R.C.G. Novaes

2014-01-01

Context: Bio-fortified sweet potato, Ipomoea batatas (L.) Lamarck beta-carotene rich, has been included in the most vulnerable population’s diet with the purpose of reducing health disturbances associated with hipovitaminosis. Aims:To evaluate a physical and chemical analysis of total carotenes and beta-carotene and to determine the antioxidant potential as well as to carry out a sensorial analysis of the bio-fortified Ipomoea batatas (L.) Lamarck (BDB) in nature and processed. Method...

Nonlinear optical systems

CERN Document Server

Lugiato, Luigi; Brambilla, Massimo

2015-01-01

Guiding graduate students and researchers through the complex world of laser physics and nonlinear optics, this book provides an in-depth exploration of the dynamics of lasers and other relevant optical systems, under the umbrella of a unitary spatio-temporal vision. Adopting a balanced approach, the book covers traditional as well as special topics in laser physics, quantum electronics and nonlinear optics, treating them from the viewpoint of nonlinear dynamical systems. These include laser emission, frequency generation, solitons, optically bistable systems, pulsations and chaos and optical pattern formation. It also provides a coherent and up-to-date treatment of the hierarchy of nonlinear optical models and of the rich variety of phenomena they describe, helping readers to understand the limits of validity of each model and the connections among the phenomena. It is ideal for graduate students and researchers in nonlinear optics, quantum electronics, laser physics and photonics.

Introduction to Stochastic Simulations for Chemical and Physical Processes: Principles and Applications

Science.gov (United States)

Weiss, Charles J.

2017-01-01

An introduction to digital stochastic simulations for modeling a variety of physical and chemical processes is presented. Despite the importance of stochastic simulations in chemistry, the prevalence of turn-key software solutions can impose a layer of abstraction between the user and the underlying approach obscuring the methodology being…

Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 2000

International Nuclear Information System (INIS)

Lebech, B.

2001-03-01

The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 2000 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 1999

Energy Technology Data Exchange (ETDEWEB)

Lebech, B [ed.

2000-02-01

The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scalestructures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 1999

International Nuclear Information System (INIS)

Lebech, B.

2000-02-01

The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1997

International Nuclear Information System (INIS)

Nielsen, M.; Bechgaard, K.; Clausen, K.N.; Feidenhans'l, R.; Johannsen, I.

1998-01-01

The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1997 are presented in this progress report. The research in physics in concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems in undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

Uncertainty of inhalation dose coefficients for representative physical and chemical forms of iodine-131

Science.gov (United States)

Harvey, Richard Paul, III

Releases of radioactive material have occurred at various Department of Energy (DOE) weapons facilities and facilities associated with the nuclear fuel cycle in the generation of electricity. Many different radionuclides have been released to the environment with resulting exposure of the population to these various sources of radioactivity. Radioiodine has been released from a number of these facilities and is a potential public health concern due to its physical and biological characteristics. Iodine exists as various isotopes, but our focus is on 131I due to its relatively long half-life, its prevalence in atmospheric releases and its contribution to offsite dose. The assumption of physical and chemical form is speculated to have a profound impact on the deposition of radioactive material within the respiratory tract. In the case of iodine, it has been shown that more than one type of physical and chemical form may be released to, or exist in, the environment; iodine can exist as a particle or as a gas. The gaseous species can be further segregated based on chemical form: elemental, inorganic, and organic iodides. Chemical compounds in each class are assumed to behave similarly with respect to biochemistry. Studies at Oak Ridge National Laboratories have demonstrated that 131I is released as a particulate, as well as in elemental, inorganic and organic chemical form. The internal dose estimate from 131I may be very different depending on the effect that chemical form has on fractional deposition, gas uptake, and clearance in the respiratory tract. There are many sources of uncertainty in the estimation of environmental dose including source term, airborne transport of radionuclides, and internal dosimetry. Knowledge of uncertainty in internal dosimetry is essential for estimating dose to members of the public and for determining total uncertainty in dose estimation. Important calculational steps in any lung model is regional estimation of deposition fractions

Applied optics and optical design

CERN Document Server

Conrady, Alexander Eugen

1957-01-01

""For the optical engineer it is an indispensable work."" - Journal, Optical Society of America""As a practical guide this book has no rival."" - Transactions, Optical Society""A noteworthy contribution,"" - Nature (London)Part I covers all ordinary ray-tracing methods, together with the complete theory of primary aberrations and as much of higher aberration as is needed for the design of telescopes, low-power microscopes and simple optical systems. Chapters: Fundamental Equations, Spherical Aberration, Physical Aspect of Optical Images, Chromatic Aberration, Design of Achromatic Object-Glass

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.

Directional Radiometry and Radiative Transfer: the Convoluted Path From Centuries-old Phenomenology to Physical Optics

Science.gov (United States)

Mishchenko, Michael I.

2014-01-01

This Essay traces the centuries-long history of the phenomenological disciplines of directional radiometry and radiative transfer in turbid media, discusses their fundamental weaknesses, and outlines the convoluted process of their conversion into legitimate branches of physical optics.

Effect of sintering temperature on physical, structural and optical properties of wollastonite based glass-ceramic derived from waste soda lime silica glasses

Directory of Open Access Journals (Sweden)

Karima Amer Almasri

Full Text Available The impact of different sintering temperatures on physical, optical and structural properties of wollastonite (CaSiO3 based glass-ceramics were investigated for its potential application as a building material. Wollastonite based glass-ceramics was provided by a conventional melt-quenching method and followed by a controlled sintering process. In this work, soda lime silica glass waste was utilized as a source of silicon. The chemical composition and physical properties of glass were characterized by using Energy Dispersive X-ray Fluorescence (EDXRF and Archimedes principle. The Archimedes measurement results show that the density increased with the increasing of sintering temperature. The generation of CaSiO3, morphology, size and crystal phase with increasing the heat-treatment temperature were examined by field emission scanning electron microscopy (FESEM, Fourier transforms infrared reflection spectroscopy (FTIR, and X-ray diffraction (XRD. The average calculated crystal size gained from XRD was found to be in the range 60 nm. The FESEM results show a uniform distribution of particles and the morphology of the wollastonite crystal is in relict shapes. The appearance of CaO, SiO2, and Ca-O-Si bands disclosed from FTIR which showed the formation of CaSiO3 crystal phase. In addition to the calculation of the energy band gap which found to be increased with increasing sintering temperature. Keywords: Soda lime silica glass, Wollastonite, Sintering, Structural properties, Optical properties

Launching partnership in optics and photonics education between University of Rochester and Moscow Engineering Physics Institute NRNU MEPhI

Science.gov (United States)

Lukishova, Svetlana G.; Zavestovskaya, Irina N.; Zhang, Xi-Cheng; Aleshchenko, Yury A.; Konov, Vitaly I.

2017-08-01

A collaboration in education between the oldest and one of the most comprehensive Optics schools in U.S., the Institute of Optics (IO), University of Rochester (UR), and one of the most recognized Russian university, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) was started in 2015 by signing an agreement on a double-Master's degree program in optics. It was based on earlier collaboration between research groups in both universities. In summer of 2016, nine UR Optics undergraduate students participated with MEPhI students at the International School on Optics and Laser Physics in MEPhI. During five days they were immersed into the world of cutting edge research, technologies and ideas that Russian, European and U.S. scientists offered them. This School also included tours of MEPhI Nanotechnologies and Lasers Centers and Nano-bioengineering Laboratory as well as of scientific laboratories of the leading institutes in optics, photonics and laser physics of the Russian Academy of Sciences. In December of 2015, one MEPhI Master student visited IO UR for one month for a research project with results presented later at a MEPhI conference. Samples prepared by MEPhI researchers are used in IO students teaching laboratories. One Master student from MEPhI is working now towards the Master's degree at the IO UR. In this paper benefits and pitfalls of a cross-border collaboration are discussed as well as different directions of such a collaboration to provide a high-quality specialization for the students of the 21 century which includes international cooperation.

Chemical sensors

International Nuclear Information System (INIS)

Hubbard, C.W.; Gordon, R.L.

1987-05-01

The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

Physical-chemical characterization of quinoa (Chenopodium quinoa Willd., amaranth (Amaranthus caudatus L., and chia (Salvia hispanica L. flours and seeds

Directory of Open Access Journals (Sweden)

Olga Lucía Torres Vargas

2018-04-01

Full Text Available Quinoa, amaranth, and chia flours have considerable amounts of protein, starch, dietary fiber, lipids, minerals, vitamins, and bioactive components, which provide in them exceptional properties for human nutrition. The aim of this research was the physical-chemical characterization of quinoa, amaranth, and chia flours and seeds through proximal, optical, functional, thermal, and structural analyses. From the results obtained during the proximal analysis, considerable proportions were determined of protein and fiber for the three flours, with the highest values in chia flour at 28.56% and 39.8%, respectively. These results were corroborated by optical microscopy analysis performed on longitudinal cuts in the three types of seeds. Thermal parameters indicated that the three flours presented irreversible thermal degradation processes and glass transition change for amaranth and chia flours at temperatures above 100ºC. Structural characterization of the flours via FTIR have allowed detecting differences in protein and lipid characteristic absorption bands. Diffraction patterns of type A starch were identified for quinoa and amaranth flours, while the chia flour had two crystalline peaks corresponding to calcium and magnesium. Scanning electron microscopy images showed starch aggregates in the quinoa flour, a complex structure composed of spherical proteins that surround the starches in amaranth flour and fibrous structures and spherical proteins in chia flour.

Technical area status report for chemical/physical treatment

International Nuclear Information System (INIS)

Brown, C.H. Jr.; Schwinkendorf, W.E.

1993-08-01

The Office of Environmental Restoration and Waste Management (EM) was established by the Department of Energy (DOE) to direct and coordinate waste management and site remediation programs and activities throughout the DOE Complex. The Mixed Waste Integrated Program (MWIP) was created by the DOE Office of Technology Development (OTD) to develop, deploy, and complete appropriate technologies for the treatment of an DOE low-level mixed waste (LLMW). The MWIP mission includes development of strategies related to enhanced waste form production, improvements to and testing of the EM-30 baseline flowsheet for mixed waste treatment, programmatic oversight for ongoing technical projects, and specific technical tasks related to the site specific Federal Facilities Compliance Agreement (FFCA). The MWIP has established five Technical Support Groups (TSGs) based on primary functional areas of the Mixed Waste Treatment Plant) identified by EM-30. These TSGs are: (1) Front-End Waste Handling, (2) Chemical/Physical Treatment, (3) Waste Destruction and Stabilization, (4) Second-stage Destruction and Offgas Treatment, and (5) Final Waste Forms. The focus of this document is the Chemical/Physical Treatment System (CPTS). The CPTS performs the required pretreatment and/or separations on the waste streams passing through the system for discharge to the environment or efficient downstream processing. Downstream processing can include all system components except Front-End Waste Handling. The primary separations to be considered by the CPTS are: (1) removal of suspended and dissolved solids from aqueous and liquid organic streams, (2) separation of water from organic liquids, (3) treatment of wet and dry solids, including separation into constituents as required, for subsequent thermal treatment and final form processing, (4) mercury removal and control, and (5) decontamination of equipment and waste classified as debris

Physical and chemical effects of low octane gasoline fuels on compression ignition combustion

KAUST Repository

Badra, Jihad

2016-09-30

Gasoline compression ignition (GCI) engines running on low octane gasoline fuels are considered an attractive alternative to traditional spark ignition engines. In this study, three fuels with different chemical and physical characteristics have been investigated in single cylinder engine running in GCI combustion mode at part-load conditions both experimentally and numerically. The studied fuels are: Saudi Aramco light naphtha (SALN) (Research octane number (RON) = 62 and final boiling point (FBP) = 91 °C), Haltermann straight run naphtha (HSRN) (RON = 60 and FBP = 140 °C) and a primary reference fuel (PRF65) (RON = 65 and FBP = 99 °C). Injection sweeps, where the start of injection (SOI) is changed between −60 and −11 CAD aTDC, have been performed for the three fuels. Full cycle computational fluid dynamics (CFD) simulations were executed using PRFs as chemical surrogates for the naphtha fuels. Physical surrogates based on the evaporation characteristics of the naphtha streams have been developed and their properties have been implemented in the engine simulations. It was found that the three fuels have similar combustion phasings and emissions at the conditions tested in this work with minor differences at SOI earlier than −30 CAD aTDC. These trends were successfully reproduced by the CFD calculations. The chemical and physical effects were further investigated numerically. It was found that the physical characteristics of the fuel significantly affect the combustion for injections earlier than −30 CAD aTDC because of the low evaporation rates of the fuel because of the higher boiling temperature of the fuel and the colder in-cylinder air during injection. © 2016 Elsevier Ltd

Fiber optics spectrochemical emission sensors

Science.gov (United States)

Griffin, Jeffrey W.; Olsen, Khris B.

1992-01-01

A method of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species uses a probe insertable into the well or tank via a cable and having electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited the fluid in alignment with the light guide axis and optical emissions are received from the excited chemical species along such axis.

Chemical Processing effects on the radiation doses measured by Film Dosimeter System

International Nuclear Information System (INIS)

Mihai, F.

2009-01-01

Halide film dosimetry is a quantitative method of measurement of the radiation doses. The fog density and chemical processing of the dosimeter film affect the radiation dose measurement accuracy. This work presents the effect of the developer solution concentration on the response of the dosimetric film which different fog densities. Thus, three batches of film, dosimeters with following fog density 0.312 ± 1.31 %, 0.71 ± 0.59% and 0.77 ± 0.81 %, were irradiated to 137 Cs standard source to dose value of 1mSv. The halide films have been chemical processed at different concentrations of the developer solution: 20 %; 14.29 %; 11.11%; all other physics-chemical conditions in baths of development have been kept constants. Concentration of 20% is considered to be chemical processed standard conditions of the films. In case of the films exposed to 1 mSv dose, optical density recorded on the low fog films processed at 20% developer solution is rather closed of high fog film optical densities processed at 11.11% developer solution concentration. Also, the chemical processing effect on the image contrast was taken into consideration

Challenges in paper-based fluorogenic optical sensing with smartphones

Science.gov (United States)

Ulep, Tiffany-Heather; Yoon, Jeong-Yeol

2018-05-01

Application of optically superior, tunable fluorescent nanotechnologies have long been demonstrated throughout many chemical and biological sensing applications. Combined with microfluidics technologies, i.e. on lab-on-a-chip platforms, such fluorescent nanotechnologies have often enabled extreme sensitivity, sometimes down to single molecule level. Within recent years there has been a peak interest in translating fluorescent nanotechnology onto paper-based platforms for chemical and biological sensing, as a simple, low-cost, disposable alternative to conventional silicone-based microfluidic substrates. On the other hand, smartphone integration as an optical detection system as well as user interface and data processing component has been widely attempted, serving as a gateway to on-board quantitative processing, enhanced mobility, and interconnectivity with informational networks. Smartphone sensing can be integrated to these paper-based fluorogenic assays towards demonstrating extreme sensitivity as well as ease-of-use and low-cost. However, with these emerging technologies there are always technical limitations that must be addressed; for example, paper's autofluorescence that perturbs fluorogenic sensing; smartphone flash's limitations in fluorescent excitation; smartphone camera's limitations in detecting narrow-band fluorescent emission, etc. In this review, physical optical setups, digital enhancement algorithms, and various fluorescent measurement techniques are discussed and pinpointed as areas of opportunities to further improve paper-based fluorogenic optical sensing with smartphones.

Laser chemical analysis: the recent developments

International Nuclear Information System (INIS)

Mauchien, P.

1997-01-01

This paper gives a general overview and describes the principles of the main laser-based techniques for physical and chemical analysis, and of their recent developments. Analytical techniques using laser radiations were actually developed at the end of the 1970's. The recent evolutions concern the 3 principal techniques of laser spectroscopy currently used: Raman, fluorescence (atomic and molecular) and ablation (ICP laser ablation-plasma coupling, optical emission spectroscopy on laser-induced plasma). The description of these different techniques is illustrated with some examples of applications. (J.S.)

Uniform surface-to-line integral reduction of physical optics for curved surfaces by modified edge representation with higher-order correction

Science.gov (United States)

Lyu, Pengfei; Ando, Makoto

2017-09-01

The modified edge representation is one of the equivalent edge currents approximation methods for calculating the physical optics surface radiation integrals in diffraction analysis. The Stokes' theorem is used in the derivation of the modified edge representation from the physical optics for the planar scatterer case, which implies that the surface integral is rigorously reduced into the line integral of the modified edge representation equivalent edge currents, defined in terms of the local shape of the edge. On the contrary, for curved surfaces, the results of radiation integrals depend upon the global shape of the scatterer. The physical optics surface integral consists of two components, from the inner stationary phase point and the edge. The modified edge representation is defined independently from the orientation of the actual edge, and therefore, it could be available not only at the edge but also at the arbitrary points on the scatterer except the stationary phase point where the modified edge representation equivalent edge currents becomes infinite. If stationary phase point exists inside the illuminated region, the physical optics surface integration is reduced into two kinds of the modified edge representation line integrations, along the edge and infinitesimally small integration around the inner stationary phase point, the former and the latter give the diffraction and reflection components, respectively. The accuracy of the latter has been discussed for the curved surfaces and published. This paper focuses on the errors of the former and discusses its correction. It has been numerically observed that the modified edge representation works well for the physical optics diffraction in flat and concave surfaces; errors appear especially for the observer near the reflection shadow boundary if the frequency is low for the convex scatterer. This paper gives the explicit expression of the higher-order correction for the modified edge representation.

Physical optics far field inverse scattering in the time domain

International Nuclear Information System (INIS)

Bleistein, N.

1976-01-01

The physical optics far field inverse scattering (POFFIS) identity relates the phase and range normalized far field back scattering amplitude to the spatial Fourier transform of the characteristic function of the scattering obstacle. The characteristic function is equal to unity in the region occupied by the obstacle and zero elsewhere. The original identity was derived by Bojarski for impulsive point sources. The result is extended to sources of arbitrary time dependence. One obtains an alternative form of Bojarski's POFFIS identity. One also derives a POFFIS identity in the time domain. Numerically synthesized checks on the method are provided

An open source digital servo for atomic, molecular, and optical physics experiments

Energy Technology Data Exchange (ETDEWEB)

Leibrandt, D. R., E-mail: david.leibrandt@nist.gov; Heidecker, J. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2015-12-15

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of {sup 27}Al{sup +} in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

An open source digital servo for atomic, molecular, and optical physics experiments

International Nuclear Information System (INIS)

Leibrandt, D. R.; Heidecker, J.

2015-01-01

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27 Al + in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser

An open source digital servo for atomic, molecular, and optical physics experiments

Science.gov (United States)

Leibrandt, D. R.; Heidecker, J.

2015-12-01

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27Al+ in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

PHYSICAL AND CHEMICAL CHARACTERIZATION OF NEUROLOGICAL INJURY IN AN AVIAN MODEL OF PRIMARY GENERALIZED EPILEPSY

Directory of Open Access Journals (Sweden)

Edward Kendall

2011-05-01

Full Text Available Purpose This study was undertaken to determine if the epileptic chicken phenotype exhibited unique physical and chemical neurological changes. Methods Quantitative 1H-MRI/MRS measurements were performed on adult control (Rr and epileptic (rr chickens. The metrics included nuclear relaxation rate, diffusion rate and concentration of metabolites associated with neuronal cells. Comparisons were performed using Students t or Mann-Whitney tests according to the data distribution. Results Proton density measurements detected no significant difference in density among the cerebral hemispheres and optic lobes within the control and epi birds, nor between bird phenotypes. Thus, within experimental error it appears that brain tissue density is similar in adult control and epi birds. Volume calculation from images spanning the entire brain confirmed that a consistent feature of the epi genotype was megalencephaly. Nuclear relaxation (T2 values obtained for the control bird were within the normal variant range for neuronal tissue. However, T2's of the epi birds were significantly higher than that of the controls ((158 ms versus 123 ms. Similarly, in the diffusion data there was no apparent hemispheric bias. The optic lobes of the control animals exhibited an apparent diffusion coefficient significantly lower than that found for the cerebrum (Table 2. Interestingly, this differential was not apparent in the epi birds. The control birds across all regions of interest exhibited an ADC significantly less than that of the epi birds. Quantitative 1Hspectroscopy using tissue extracts collected immediately after sacrifice revealed phenotypic differences in lactate, glutamate, creatine and NAA but not GABA. A reduction in NAA was detected in the cerebrum of epi birds. This is in agreement with the generally held view that seizure activity causes loss of neurones, thus the loss of N-acetyl aspartate. HPLC data corroborated the spectroscopic NAA findings but also

Physical properties and chemical composition of Segamat Kaolin, Johor, Malaysia

International Nuclear Information System (INIS)

Umar Hamzah; Learn, K.K.; Sahibin Rahim

2010-01-01

Kaolin is a source of secondary mineral as a product of a weathering process of primary minerals. Its main component is fine grain kaolinite (< 2 μm) and it also contains other elements such as aluminium and iron phyllosilicate as the pigment. Aluminium rich kaolin is light in colour with high plasticity and is normally used in the ceramic, plastic, paint, paper, pesticide, pharmacology and cosmetic industries. The physical and chemical characteristics of kaolins are important for its potential application. In this study, about 25 kaolin samples were hand-augered from depths of 1-2 m at Buloh Kasap Segamat, Johor, Malaysia. Chemical analysis carried out included determination of oxides and types of minerals by X-ray diffraction and X-ray fluorescence. Shrinkage rate, rupture modulus and water absorption rate tests were carried out in the physical properties analysis. Plastic and liquid limits of the kaolin were also measured for plastic index. The Segamat kaolin was light in colour due to its high silicate composition. The highest mineral content in the kaolin was kaolinite and quartz occurred as impurities. The low shrinkage rate showed that the kaolin was dense with little voids, hence very suitable for use in the ceramic industry. This kaolin has low water absorption, plasticity and durable according to the rupture modulus test. (author)

Broadband optical properties of biomass-burning aerosol and identification of brown carbon chromophores: OPTICAL AND CHEMICAL PROPERTIES OF BROWN CARBON AEROSOLS

Energy Technology Data Exchange (ETDEWEB)

Bluvshtein, Nir [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Lin, Peng [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Flores, J. Michel [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Segev, Lior [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Mazar, Yinon [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Tas, Eran [The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot Israel; Snider, Graydon [Department of Physics and Atmospheric Science, Dalhousie University, Halifax Nova Scotia Canada; Weagle, Crystal [Department of Chemistry, Dalhousie University, Halifax Nova Scotia Canada; Brown, Steven S. [Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder Colorado USA; Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder Colorado USA; Laskin, Alexander [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Rudich, Yinon [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel

2017-05-23

The radiative effects of biomass burning aerosols on regional and global scale is substantial. Accurate modeling of the radiative effects of smoke aerosols require wavelength-dependent measurements and parameterizations of their optical properties in the UV and visible spectral ranges along with improved description of their chemical composition. To address this issue, we used a recently developed approach to retrieve the time- and spectral-dependent optical properties of ambient biomass burning aerosols between 300 and 650 nm wavelength during a regional bonfire festival in Israel. During the biomass burning event, the overall absorption at 400 nm increased by about two orders of magnitude, changing the size-weighted single scattering albedo from a background level of 0.95 to 0.7. Based on the new retrieval method, we provide parameterizations of the wavelength-dependent effective complex refractive index from 350 to 650 nm for freshly emitted and aged biomass burning aerosols. In addition, PM2.5 filter samples were collected for detailed off-line chemical analysis of the water soluble organics that contribute to light absorption. Nitrophenols were identified as the main organic species responsible for the increased absorption at 400-500 nm. These include species such as 4- nitrocatechol, 4-nitrophenol, nitro-syringol and nitro-guaiacol; oxidation-nitration products of methoxyphenols, known products of lignin pyrolysis. Our findings emphasize the importance of both primary and secondary organic aerosol from biomass burning in absorption of solar radiation and in effective radiative forcing.

Nanostructure and optical properties of CeO{sub 2} thin films obtained by plasma-enhanced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Barreca, D.; Bruno, G.; Gasparotto, A.; Losurdo, M.; Tondello, E

2003-12-15

In the present study, Spectroscopic Ellipsometry (SE) is used to investigate the interrelations between nanostructure and optical properties of CeO{sub 2} thin films deposited by Plasma-Enhanced Chemical Vapor Deposition (PE-CVD). The layers were synthesized in Ar and Ar-O{sub 2} plasmas on Si(100) substrates at temperatures lower than 300 deg. C. Both the real and imaginary parts of the complex dielectric functions and, subsequently, the optical constants of the films are derived up to 6.0 eV photon energy. Particular attention is devoted to the influence of synthesis conditions and sample properties on the optical response, taking into account the effects of surface roughness and SiO{sub 2} interface layer on Si.

Physical-chemical, caloric and sensory characterization of light jambolan (Syzygium cumini Lamarck jelly

Directory of Open Access Journals (Sweden)

Ellen Silva Lago-Vanzela

2011-09-01

Full Text Available In Brazil, several little economically explored fruits have good potential as raw material for the agro-industry. This study aimed to produce and determine the physical-chemical and sensory characteristics of light jambolan jelly. This fruit has intense purple color, which gave the jellies - both standard and light - a quite attractive visual aspect. The light jellies exhibited similar physical-chemical characteristics to the ones developed through the conventional method and; with the proportion of sweeteners used, the caloric values of the formulations were reduced to the range of 41 to 53%, attending the requirements of the Brazilian legislation for this type of product. The sensory profile obtained for the 4 light formulations developed, clearly showed the tasters' preference for the jelly elaborated with the association of cyclamate and saccharin. Thus, the results revealed good perspectives for the application of this fruit in the food industry.

Optical network democratization.

Science.gov (United States)

Nejabati, Reza; Peng, Shuping; Simeonidou, Dimitra

2016-03-06

The current Internet infrastructure is not able to support independent evolution and innovation at physical and network layer functionalities, protocols and services, while at same time supporting the increasing bandwidth demands of evolving and heterogeneous applications. This paper addresses this problem by proposing a completely democratized optical network infrastructure. It introduces the novel concepts of the optical white box and bare metal optical switch as key technology enablers for democratizing optical networks. These are programmable optical switches whose hardware is loosely connected internally and is completely separated from their control software. To alleviate their complexity, a multi-dimensional abstraction mechanism using software-defined network technology is proposed. It creates a universal model of the proposed switches without exposing their technological details. It also enables a conventional network programmer to develop network applications for control of the optical network without specific technical knowledge of the physical layer. Furthermore, a novel optical network virtualization mechanism is proposed, enabling the composition and operation of multiple coexisting and application-specific virtual optical networks sharing the same physical infrastructure. Finally, the optical white box and the abstraction mechanism are experimentally evaluated, while the virtualization mechanism is evaluated with simulation. © 2016 The Author(s).

Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

Directory of Open Access Journals (Sweden)

Daniela Aparecida de Oliveira

2014-10-01

Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

RCOP: Research Center for Optical Physics

Science.gov (United States)

Tabibi, Bagher M. (Principal Investigator)

1996-01-01

During the five years since its inception, Research Center for Optical Physics (RCOP) has excelled in the goals stated in the original proposal: 1) training of the scientists and engineers needed for the twenty-first century with special emphasis on underrepresented citizens and 2) research and technological development in areas of relevance to NASA. In the category of research training, there have been 16 Bachelors degrees and 9 Masters degrees awarded to African American students working in RCOP during the last five years. RCOP has also provided research experience to undergraduate and high school students through a number of outreach programs held during the summer and the academic year. RCOP has also been instrumental in the development of the Ph.D. program in physics which is in its fourth year at Hampton. There are currently over 40 graduate students in the program and 9 African American graduate students, working in RCOP, that have satisfied all of the requirements for Ph.D. candidancy and are working on their dissertation research. At least three of these students will be awarded their doctoral degrees during 1997. RCOP has also excelled in research and technological development. During the first five years of existence, RCOP researchers have generated well over $3 M in research funding that directly supports the Center. Close ties with NASA Langley and NASA Lewis have been established, and collaborations with NASA scientists, URC's and other universities as well as with industry have been developed. This success is evidenced by the rate of publishing research results in refereed journals, which now exceeds that of the goals in the original proposal (approx. 2 publications per faculty per year). Also, two patents have been awarded to RCOP scientists.

Chemical and physical soil attributes in integrated crop-livestock system under no-tillage

Directory of Open Access Journals (Sweden)

Hernani Alves da Silva

Full Text Available Although integrated crop-livestock system (ICLS under no-tillage (NT is an attractive practice for intensify agricultural production, little regional information is available on the effects of animal grazing and trampling, particularly dairy heifers, on the soil chemical and physical attributes. The objective of this study was to evaluate the effects of animal grazing on the chemical and physical attributes of the soil after 21 months of ICLS under NT in a succession of annual winter pastures (2008, soybeans (2008/2009, annual winter pastures (2009, and maize (2009/10. The experiment was performed in the municipality of Castro (PR in a dystrophic Humic Rhodic Hapludox with a clay texture. The treatments included a combination of two pasture (annual ryegrass monoculture and multicropping - annual ryegrass, black oat, white clover and red clover with animal grazing during the fall-winter period with two animal weight categories (light and heavy, in a completely randomized block experimental design with 12 replications. After the maize harvest (21 months after beginning, soil samples were collected at 0-10 and 10-20 cm layers to measure soil chemical and physical attributes. The different combinations of pasture and animal weight did not alter the total organic carbon and nitrogen in the soil, but they influence the attributes of soil acidity and exchangeable cations. The monoculture pasture of ryegrass showed greater soil acidification process compared to the multicropping pasture. When using heavier animals, the multicropping pasture showed lesser increase in soil bulk density and greater macroporosity.

Adsorption and Pore of Physical-Chemical Activated Coconut Shell Charcoal Carbon

Science.gov (United States)

Budi, E.; Umiatin, U.; Nasbey, H.; Bintoro, R. A.; Wulandari, Fi; Erlina, E.

2018-04-01

The adsorption of activated carbon of coconut shell charcoal on heavy metals (Cu and Fe) of the wastewater and its relation with the carbon pore structure was investigated. The coconut shell was pyrolized in kiln at temperature about 75 - 150 °C for about 6 hours to produce charcoal and then shieved into milimeter sized granule particles. Chemical activation was done by immersing the charcoal into chemical solution of KOH, NaOH, HCl and H3PO4, with various concentration. The activation was followed by physical activation using horizontal furnace at 400°C for 1 hours in argon gas environment with flow rate of 200 kg/m3. The surface morphology of activated carbon were characterized by using Scanning Electron Microscopy (SEM). Wastewater was made by dissolving CuSO4.5H2O and FeSO4.7H2O into aquades. The metal adsorption was analized by using Atomic Absorption Spectroscopy (AAS). The result shows that in general, the increase of chemical concentration cause the increase of pore number of activated carbon due to an excessive chemical attack and lead the increase of adsorption. However it tend to decrease as further increasing in chemical activator concentration due to carbon collapsing. In general, the adsorption of Cu and Fe metal from wastewater by activated carbon increased as the activator concentration was increased.

Physics of a ballistic missile defense - The chemical laser boost-phase defense

Science.gov (United States)

Grabbe, Crockett L.

1988-01-01

The basic physics involved in proposals to use a chemical laser based on satellites for a boost-phase defense are investigated. After a brief consideration of simple physical conditions for the defense, a calculation of an equation for the number of satellites needed for the defense is made along with some typical values of this for possible future conditions for the defense. Basic energy and power requirements for the defense are determined. A sumary is made of probable minimum conditions that must be achieved for laser power, targeting accuracy, number of satellites, and total sources for power needed.

Review: Physical, physical chemistries, chemical and sensorial characteristics of the several fruits and vegetables chips by low-temperature vacuum frying machine

Directory of Open Access Journals (Sweden)

AHMAD DWI SETYAWAN

2013-11-01

Full Text Available Setyawan AD, Sugiyarto, Solichatun, Susilowati A. 2013. Review: Physical, physical chemistries, chemical and sensorial characteristics of the several fruits and vegetables chips by low-temperature vacuum frying machine. Nusantara Bioscience 5: 84-100. Frying process is one of the oldest cooking methods and most widely practiced in the world. Frying process is considered as a dry cooking method because the process does not involve water. In frying process, oil conduction occurs at high temperature pressing water out of food in the form of bubbles. Fried foods last longer due to reduced water levels lead less decomposition by microbes, even fried foods can be enhanced nutritional value and quality of appearance. Food frying technology can extend the shelf life of fruits and vegetables and frying oil enhances the flavors of the products, however, improper frying oil can have harmful effects on human health. Vacuum frying is a promising technology that may be an option for the production of novel snacks such as fruit and vegetable crisps that present the desired quality and respond to new health trends. This technique fry food at a low temperature and pressure so that the nutritional quality of the food is maintained and the quality of the used oil does not quickly declined and became saturated oils that are harmful to human health. This technique produces chips that have physical, physico-chemical, chemical, and sensory generally better than conventional deep-fat frying methods.

Physical--chemical studies of transuranium elements. Progress report, April 1, 1977--March 31, 1978

International Nuclear Information System (INIS)

Peterson, J.R.

1978-01-01

Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized for the period April 1, 1977, through March 31, 1978. CfCl 2 , EsCl 2 , EsBr 2 , and EsI 2 were synthesized and characterized spectrophotometrically, as were several mixed-valence lanthanide-actinide halides (e.g., GdCf 4 Cl 11 ) and CmF 4 , CfF 4 , and EsF 3 . All samples not containing einsteinium were also examined by X rays. Studies of the chemical consequences of the radioactive decay series 253 Es alpha decaying to 249 Bk beta decaying to 249 Cf have continued and expanded. Elemental Cm-248 has been prepared on the one-half milligram scale and used to synthesize CmP and CmSb. Single crystals of AmTe 2 and AmSe 2 have been grown from a Te melt and by iodine transport, respectively. Our SQUID magnetometer was tested successfully in a preliminary configuration, and the expected sensitivity of the device was confirmed. A new design for the flux sensing coils was incorporated prior to an apparatus calibration experiment with lead. A porous vitreous carbon material was found to make a useful optically transparent electrode for simultaneous electrochemical and absorption spectroscopic investigations. Cyclic voltammograms of UO 2 2+ were obtained prior to a spectroelectrochemical study of the radiation of UO 2 2+ . The major obstacle in our solution microcalorimetry program was overcome by the realization of a leak-free sample container. Calorimeter performance now warrants experiments with transuranium element samples. The electrochemical reductions of Cf(III) and Es(III) have been studied by polarography and/or cyclic voltammetry. The results suggest that both are reduced to the divalent state before being reduced to the amalgam

THE PHYSICAL AND CHEMICAL CHARACTERIZATION OF THE EMISSIONS FROM A RESIDENTIAL OIL BOILER

Science.gov (United States)

The toxicity of emissions from the combustion of home heating oil and the use of residential oil boilers (ROB) is an important health concern. Yet scant physical and chemical information about the emissions from this source are available for dispersion, climate, and source-recep...

Application of Optical Imaging Techniques for Quantification of pH and O2 Dynamicsin Porous Media

Science.gov (United States)

Li, B.; Seliman, A. F.; Pales, A. R.; Liang, W.; Sams, A.; Darnault, C. J. G.; DeVol, T. A.

2016-12-01

Understanding the spatial and temporal distribution of physical and chemical parameters (e.g. pH, O2) is imperative to characterize the behavior of contaminants in a natural environment. The objectives of this research are to calibrate pH and O2 sensor foils, to develop a dual pH/O2 sensor foil, and to apply them into flow and transport experiments, in order to understand the physical and chemical parameters that control contaminant fate and transport in an unsaturated sandy porous medium. In addition, demonstration of a sensor foil that quantifies aqueous uranium concentration will be presented. Optical imaging techniques will be conducted with 2D tanks to investigate the influence of microbial exudates and plant roots on pH and O2 parameters and radionuclides transport. As a non-invasive method, the optical imaging technique utilizes optical chemical sensor films and either a digital camera or a spectrometer to capture the changes with high temporal and spatial resolutions. Sensor foils are made for different parameters by applying dyes to generate favorable fluorescence that is proportional to the parameter of interest. Preliminary results suggested that this method could detect pH ranging from 4.5 to 7.5. The result from uranium foil test with different concentrations in the range of 2 to 8 ppm indicated that a higher concentration of uranium resulted in a greater color intensity.

Chemical, optical and radiative characteristics of aerosols during haze episodes of winter in the North China Plain

Science.gov (United States)

Ding, Jing; Zhang, Yufen; Han, Suqin; Xiao, Zhimei; Wang, Jiao; Feng, Yinchang

2018-05-01

Aerosol and water vapor radiative forcings, shortwave atmospheric heating rates and longwave atmospheric cooling rates were determined based on in situ physical and chemical measurements of aerosol, associated with the Mie theory and a radiative transfer model, LOWTRAN7, during the two haze episodes in the winter of 2013 in Tianjin, China. The aerosol types considered in LOWTRAN7 included rural, urban, marine, desert and custom aerosols. The default ratio of the absorption coefficient to the extinction coefficient for urban aerosol in LOWTRAN7 was approximately double of those found in this work, implying the weaker absorption ability of aerosols in the North China Plain (NCP). Moreover, the aerosol is assumed to be evenly distributed below 1 km of planetary boundary layer (PBL) on hazy days in LOWTRAN7. If the default urban aerosol optical properties and extinction profile in LOWTRAN7 is employed directly, a larger energy imbalance between the atmosphere and surface is generated and the warming effect of the aerosol is magnified. Hence, modified urban aerosol optical properties were established to replace the corresponding parameters' database in LOWTRAN7. The aerosol extinction profiles were obtained based on a 255-m meteorological tower and observed results from the studies about Tianjin. In the NCP, the aerosol had little impact on atmospheric counter radiation. The water vapor is the crucial factor that affects atmospheric counter radiation. Both modified high shortwave heating rates and longwave cooling rates occur near the surface due to the abundance of aerosol and water vapor. The modified net atmospheric heating rate near the surface is 1.2 K d-1 on hazy days and 0.3 K d-1 on non-hazy days. Compared with the default urban aerosol optical properties and its vertical distribution in LOWTRAN7, the feedback effect of the modified urban aerosol on the boundary layer may not necessarily result in a stable lower atmosphere, but depends on the aerosol light

Fiber-Optic U-Shaped Detection Elements for the Investigation of Photocatalytic Activity of Optical Fibers Coated with Layer of TiO2

Czech Academy of Sciences Publication Activity Database

Matějec, Vlastimil; Mrázek, Jan; Podrazký, Ondřej; Hayer, Miloš; Pospíšilová, Marie

2009-01-01

Roč. 7, č. 5 (2009), s. 900-904 ISSN 1546-198X. [6th Maghreb-Europe Meeting on Materials and Their Applications for Devices and Physical, Chemical and Biological Sensors. Rabat, 30.10.2008-01.11.2008] R&D Projects: GA MŠk OC08023 Institutional research plan: CEZ:AV0Z20670512 Keywords : photocatalysis * anatase laayer * fiber - optic sensor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.626, year: 2009

Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1997

Energy Technology Data Exchange (ETDEWEB)

Nielsen, M; Bechgaard, K; Clausen, K N; Feidenhans` l, R; Johannsen, I [eds.

1998-01-01

The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1997 are presented in this progress report. The research in physics in concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems in undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au). 129 ills., 213 refs.

Different physical and chemical pretreatments of wheat straw for enhanced biobutanol production in simultaneous saccharification and fermentation

Energy Technology Data Exchange (ETDEWEB)

Thirmal, Chumangalah; Dahman, Yaser [Department of Chemical Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

2011-07-01

The objective of this study is to increase butanol product yields using wheat straw as the biomass. First this study examined different pretreatment and saccharification processes to obtain the maximum sugar concentration. Three different physical and chemical pretreatment methods for the wheat straws were examined in the present work in comparison with physical pretreatment alone as a reference. This included water, acidic, and alkaline pretreatment. For all cases, physical pretreatment represented by 1 mm size reduction of the straws was applied prior to each pretreatment. Results showed that 13.91 g/L glucose concentration was produced from saccharification with just the physical pretreatment (i.e., no chemical pretreatment). This represented {approx}5-20 % lower sugar release in saccharification compared to the other three pretreatment processes. Saccharification with acid pretreatment obtained the highest sugar concentrations, which were 18.77 g/L glucose and 12.19 g/L xylose. Second this study produced butanol from simultaneous saccharification and fermentation (SSF) using wheat straw hydrolysate and Clostridium beijerinckii BA101. Water pretreatment was applied to separate lignin and polysaccharides from the wheat straw. Physical pretreatment was applied prior to water pretreatment where, wheat straw was grounded into fine particles less than 1 mm size. Another experiment was conducted where physical pretreatment was applied alone prior to SSF (i.e. no chemical pretreatment was applied). Both processes converted more than 10% of wheat straw into butanol product. This was 2% higher than previous studies. The results illustrated that SSF with physical pretreatment alone obtained 2.61 g/L butanol.

Perspective: Quantum Hamiltonians for optical interactions

Science.gov (United States)

Andrews, David L.; Jones, Garth A.; Salam, A.; Woolley, R. Guy

2018-01-01

The multipolar Hamiltonian of quantum electrodynamics is extensively employed in chemical and optical physics to treat rigorously the interaction of electromagnetic fields with matter. It is also widely used to evaluate intermolecular interactions. The multipolar version of the Hamiltonian is commonly obtained by carrying out a unitary transformation of the Coulomb gauge Hamiltonian that goes by the name of Power-Zienau-Woolley (PZW). Not only does the formulation provide excellent agreement with experiment, and versatility in its predictive ability, but also superior physical insight. Recently, the foundations and validity of the PZW Hamiltonian have been questioned, raising a concern over issues of gauge transformation and invariance, and whether observable quantities obtained from unitarily equivalent Hamiltonians are identical. Here, an in-depth analysis of theoretical foundations clarifies the issues and enables misconceptions to be identified. Claims of non-physicality are refuted: the PZW transformation and ensuing Hamiltonian are shown to rest on solid physical principles and secure theoretical ground.

Optical and passivating properties of hydrogenated amorphous silicon nitride deposited by plasma enhanced chemical vapour deposition for application on silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Wight, Daniel Nilsen

2008-07-01

Within this thesis, several important subjects related to the use of amorphous silicon nitride made by plasma enhanced chemical vapour deposition as an anti-reflective coating on silicon solar cells are presented. The first part of the thesis covers optical simulations to optimise single and double layer anti-reflective coatings with respect to optical performance when situated on a silicon solar cell. The second part investigates the relationship between important physical properties of silicon nitride films when deposited under different conditions. The optical simulations were either based on minimising the reflectance off a silicon nitride/silicon wafer stack or maximising the transmittance through the silicon nitride into the silicon wafer. The former method allowed consideration of the reflectance off the back surface of the wafer, which occurs typically at wavelengths above 1000 nm due to the transparency of silicon at these wavelengths. However, this method does not take into consideration the absorption occurring in the silicon nitride, which is negligible at low refractive indexes but quite significant when the refractive index increases above 2.1. For high-index silicon nitride films, the latter method is more accurate as it considers both reflectance and absorbance in the film to calculate the transmittance into the Si wafer. Both methods reach similar values for film thickness and refractive index for optimised single layer anti-reflective coatings, due to the negligible absorption occurring in these films. For double layer coatings, though, the reflectance based simulations overestimated the optimum refractive index for the bottom layer, which would have lead to excessive absorption if applied to real anti-reflective coatings. The experimental study on physical properties for silicon nitride films deposited under varying conditions concentrated on the estimation of properties important for its applications, such as optical properties, passivation

A development optical course based on optical fiber white light interference

Science.gov (United States)

Jiang, Haili; Sun, Qiuhua; Zhao, Yancheng; Li, Qingbo

2017-08-01

The Michelson interferometer is a very important instrument in optical part for college physics teaching. But most students only know the instrument itself and don't know how to use it in practical engineering problems. A case about optical fiber white light interference based on engineering practice was introduced in the optical teaching of college physics and then designed a development course of university physical optics part. This system based on low-coherence white light interferometric technology can be used to measure distribution strain or temperature. It also could be used in the case of temperature compensation mode.This teaching design can use the knowledge transfer rule to enable students to apply the basic knowledge in the university physics to the new knowledge domain, which can promote the students' ability of using scientific methods to solve complex engineering problems.

2005 Annual Report Summer Research Institute Interfacial and Condensed Phase Chemical Physics

Energy Technology Data Exchange (ETDEWEB)

Barlow, Stephan E.

2005-11-15

The Pacific Northwest National Laboratory (PNNL) hosted its second annual Summer Research Institute in Interfacial and Condensed Phase Chemical Physics from May through September 2005. During this period, sixteen PNNL scientists hosted fourteen young scientists from eleven different universities. Of the fourteen participants, twelve were graduate students; one was a postdoctoral fellow; and one was a university faculty member.

Compound Tension Control of an Optical-Fiber Coil System: A Cyber-Physical System View

Directory of Open Access Journals (Sweden)

Zhang Peng

2014-03-01

Full Text Available The full-automatic optical-fiber coil winding equipment is a complex electromechanical system which contains signal acquisition, data processing, communications, and motor control. In the complex electromechanical system, the subsystems rely on wired or wireless network technology to complete the real-time perception, coordinate, accurate, and dynamitic control, and information exchange services. The paper points to the full-automatic optical-fiber coil winding equipment with the characteristics of cyber-physical system to research its numerical design. We present a novel compound tension control system based on the experimental platform dSPACE to achieve semiphysical simulation of compound tension control system and examine the functions of control system.

Fundamental aspects of plasma chemical physics transport

CERN Document Server

Capitelli, Mario; Laricchiuta, Annarita

2013-01-01

Fundamental Aspects of Plasma Chemical Physics: Tranpsort develops basic and advanced concepts of plasma transport to the modern treatment of the Chapman-Enskog method for the solution of the Boltzmann transport equation. The book invites the reader to consider actual problems of the transport of thermal plasmas with particular attention to the derivation of diffusion- and viscosity-type transport cross sections, stressing the role of resonant charge-exchange processes in affecting the diffusion-type collision calculation of viscosity-type collision integrals. A wide range of topics is then discussed including (1) the effect of non-equilibrium vibrational distributions on the transport of vibrational energy, (2) the role of electronically excited states in the transport properties of thermal plasmas, (3) the dependence of transport properties on the multitude of Saha equations for multi-temperature plasmas, and (4) the effect of the magnetic field on transport properties. Throughout the book, worked examples ...

Fundamental aspects of plasma chemical physics kinetics

CERN Document Server

Capitelli, Mario; Colonna, Gianpiero; Esposito, Fabrizio; Gorse, Claudine; Hassouni, Khaled; Laricchiuta, Annarita; Longo, Savino

2016-01-01

Describing non-equilibrium "cold" plasmas through a chemical physics approach, this book uses the state-to-state plasma kinetics, which considers each internal state as a new species with its own cross sections. Extended atomic and molecular master equations are coupled with Boltzmann and Monte Carlo methods to solve the electron energy distribution function. Selected examples in different applied fields, such as microelectronics, fusion, and aerospace, are presented and discussed including the self-consistent kinetics in RF parallel plate reactors, the optimization of negative ion sources and the expansion of high enthalpy flows through nozzles of different geometries. The book will cover the main aspects of the state-to-state kinetic approach for the description of nonequilibrium cold plasmas, illustrating the more recent achievements in the development of kinetic models including the self-consistent coupling of master equations and Boltzmann equation for electron dynamics. To give a complete portrayal, the...

The physical and chemical environment and radionuclide migration in a low level radioactive waste repository

International Nuclear Information System (INIS)

Torok, J.; Buckley, L.P.

1988-01-01

The expected physical and chemical environment within the low-level radioactive waste repository to be sited at Chalk River is being studied to establish the rate of radionuclide migration. Chemical conditions in the repository are being assessed for their effect on buffer performance and the degradiation of the concrete structure. Experimental programs include the effect of changes in solution chemistry on radionuclide distribution between buffer/backfill materials and the aqueous phase; the chemical stability of the buffer materials and the determination of the controlling mechanism for radionuclide transport during infiltration

Physical-layer network coding for passive optical interconnect in datacenter networks.

Science.gov (United States)

Lin, Rui; Cheng, Yuxin; Guan, Xun; Tang, Ming; Liu, Deming; Chan, Chun-Kit; Chen, Jiajia

2017-07-24

We introduce physical-layer network coding (PLNC) technique in a passive optical interconnect (POI) architecture for datacenter networks. The implementation of the PLNC in the POI at 2.5 Gb/s and 10Gb/s have been experimentally validated while the gains in terms of network layer performances have been investigated by simulation. The results reveal that in order to realize negligible packet drop, the wavelengths usage can be reduced by half while a significant improvement in packet delay especially under high traffic load can be achieved by employing PLNC over POI.

Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

FIBER OPTICS: Fibre optics: Forty years later

Science.gov (United States)

Dianov, Evgenii M.

2010-01-01

This paper presents a brief overview of the state of the art in fibre optics and its main applications: optical fibre communications, fibre lasers and fibre sensors for various physical property measurements. The future of fibre optics and the status of this important area of the modern technology in Russia are discussed.

Feasibility of using fiber optics for monitoring ground water contaminants

International Nuclear Information System (INIS)

Hirschfeld, T.; Deaton, T.; Milanovich, F.; Klainer, S.M.

1984-06-01

The report contains the results of the initial feasibility study for a research program undertaken to develop the technology needed to use fiber optics for monitoring groundwater contaminants. The technology appears especially well suited to the requirements of detection monitoring where a few indicator parameters can be measured continuously by sensors placed down small-diameter monitoring wells. Data are generated at a remote, centrally located fluorimeter, connected to the sampling sites by inexpensive optical fibers. The analytical method is laser-induced fluorescence which gives the desired sensitivity. The optrode, a chemical system and/or a mechanical device at the distal end of a fiber optic, furnishes the needed specificity. Various fiber and optrode configurations have been evaluated and their applications to groundwater monitoring are discussed. Feasibility is shown for physical measurements such as temperature, pressure and pH. Chemical detection and quantification of the actinides, inorganic and organic chlorides, sulfates, alcohols, aldehydes, pesticides and tracer materials are presented. Finally, it is shown that the need for smaller diameter wells (as compared to conventional sampling methods), and the ability to make up to 50 unattended in situ measurements, using a reasonably priced centralized fluorometer system connected to the sampling sites by inexpensive optical fibers, results in acceptable economy

Physical and optical properties of size-selective CdTe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Fok, Alice [Department of Chemistry, The City College of New York, CUNY New York, NY 10031 (United States); Morales, Jorge [Department of Biology, City College of New York, CUNY New York, NY 10031 (United States); Sohel, Mohammad [Natural Sciences Department, Hostos College, CUNY Bronx, NY 10451 (United States)

2010-06-15

Physical and optical properties of colloidal cadmium telluride nanocrystals (CdTe NCs) were investigated. The CdTe NCs were synthesized by reacting elemental tellurium dissolved in tributylphosphine with a mixture of cadmium oxide, octadecene, and oleic acid. These NCs, which were characterized by transmission electron microscopy (TEM) are spherical and ranged from 5 to 7 nm in diameter. The identity of the compound post-synthesis was confirmed by X-Ray diffraction (XRD) patterns. UV-Vis and photoluminescence (PL) properties as grown and pure CdTe samples were investigated. Bright excitonic photoluminescence emission was observed (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Allocation of fossil and nuclear fuels. Heat production from chemically and physically bound energy

International Nuclear Information System (INIS)

Wagner, U.

2008-01-01

The first part of the book presents the broad field of allocation, transformation, transport and distribution of the most important energy carriers in the modern power industry. The following chapters cover solid fossil fuel, liquid fuel, gaseous fuel and nuclear fuel. The final chapters concern the heat production from chemically and physically bound energy, including elementary analysis, combustion calculations, energy balance considerations in fossil fuel fired systems, and fundamentals of nuclear physics

Efficient On-chip Optical Microresonator for Optical Comb Generation: Design and Fabrication

Science.gov (United States)

Han, Kyunghun

An optical frequency comb is a series of equally spaced frequency components. It has gained much attention since Nobel physics prize was awarded John L. Hall and Theodor W. Hansch for their contribution to the optical frequency comb technique in 2005. The optical frequency comb has been extensively studied because of its precision as a tool for spectroscopy, and is now widely used in bio- and chemical sensors, optical clocks, mode-locked dark pulse generation, soliton generation, and optical communication. Recently, thanks to the developments in nanotechnology, the optical frequency comb generation is made possible at a chip-scale level with microresonators. However, because the threshold power of the optical frequency comb generation is beyond the capability of the on-chip laser source, efficient microresonator is required. Here, we demonstrate an ultra-compact and highly efficient strip-slot direct mode coupler, aiming to achieve slotted silicon microresonator cladded with nonlinear polymer Poly-DDMEBT in SOI platform. As an application of the strip-slot direct mode coupling, a double slot fiber-to-chip edge coupler is demonstrated showing 2 dB insertion loss reduction compared to the conventional single tip edge coupler. For silicon nitride platform, we investigated evanescent wave coupling of microresonator, focusing on bus waveguide geometry optimization. The optimized waveguide width offers an efficient excitation of a fundamental mode in the resonator waveguide. This investigation can benefit low threshold comb generation by enhancing the extinction ratio. We experimentally demonstrated the high Q-factor micro-ring resonator with intrinsic Q of 12.6 million as well as the single FSR comb generation with 63 mW.

Triple modifier effect on physical, optical and structural properties of boro tellurite zinc lithium glasses

Science.gov (United States)

Naresh, P.; Srinivasu, D.; Narsimlu, N.; Ch. Srinivas, Kavitha, B.; Deshpandhe, Uday; Kumar, K. Siva

2018-05-01

To investigate physical, optical and structural properties of glass samples of the Quaternary system (60-x)B2O3-xTeO2-10ZnO-30Li2O with x=0,5,10,15, and 20 mol% were prepared by conventional melt quenching technique. XRD confirmed the amorphous nature of all samples. Physical parameters like density, molar volume, Oxygen packing density and etc. calculated. Density of glass samples increased with the increase of TeO2 concentration due to the replacement of lighter B2O3 with heavier TeO2. Optical properties has studied with the help of UV-Visible spectra. Cut off wavelength is increases whereas Eopt and Urbache energies is decreased except intermediate mole fraction of TeO2 at which the triple modifier effect can be observed. Fourier Transform Infrared spectroscopy reveals that the network consists of TeO3 and TeO6 structural units along with BO3 and BO4 units.

Scattering and absorption of light by ice particles: Solution by a new physical-geometric optics hybrid method

International Nuclear Information System (INIS)

Bi Lei; Yang Ping; Kattawar, George W.; Hu Yongxiang; Baum, Bryan A.

2011-01-01

A new physical-geometric optics hybrid (PGOH) method is developed to compute the scattering and absorption properties of ice particles. This method is suitable for studying the optical properties of ice particles with arbitrary orientations, complex refractive indices (i.e., particles with significant absorption), and size parameters (proportional to the ratio of particle size to incident wavelength) larger than ∼20, and includes consideration of the edge effects necessary for accurate determination of the extinction and absorption efficiencies. Light beams with polygon-shaped cross sections propagate within a particle and are traced by using a beam-splitting technique. The electric field associated with a beam is calculated using a beam-tracing process in which the amplitude and phase variations over the wavefront of the localized wave associated with the beam are considered analytically. The geometric-optics near field for each ray is obtained, and the single-scattering properties of particles are calculated from electromagnetic integral equations. The present method does not assume additional physical simplifications and approximations, except for geometric optics principles, and may be regarded as a 'benchmark' within the framework of the geometric optics approach. The computational time is on the order of seconds for a single-orientation simulation and is essentially independent of the size parameter. The single-scattering properties of oriented hexagonal ice particles (ice plates and hexagons) are presented. The numerical results are compared with those computed from the discrete-dipole-approximation (DDA) method.

Physical model of optical inhomogeneities of water

Science.gov (United States)

Shybanov, E. B.

2017-11-01

The paper is devoted to theoretical aspects of the light scattering of water that does not contain suspended particles. To be consistent with current physical point of view the water as far as any liquid is regarded as a complex unstable nonergodic media. It was proposed that at fixed time the water as a condensed medium had global inhomogeneities similar to linear and planar defects in a solid. Anticipated own global inhomogeneities of water have been approximated by the system randomly distributed spherical clusters filling the entire water bulk. An analytical expression for the single scattered light has been derived. The formula simultaneously describes both the high anisotropy of light scattering and the high degree of polarization which one close to those for molecular scattering. It is shown that at general angles there is a qualitative coincidence with the two-component Kopelevich's model for the light scattering by marine particles. On the contrary towards to forwards angles the spectral law becomes much more prominent i.e. it corresponds to results for model of optically soft particles.

Effects of physical and chemical heterogeneity on water-quality samples obtained from wells

Science.gov (United States)

Reilly, Thomas E.; Gibs, Jacob

1993-01-01

Factors that affect the mass of chemical constituents entering a well include the distributions of flow rate and chemical concentrations along and near the screened or open section of the well. Assuming a layered porous medium (with each layer being characterized by a uniform hydraulic conductivity and chemical concentration), a knowledge of the flow from each layer along the screened zone and of the chemical concentrations in each layer enables the total mass entering the well to be determined. Analyses of hypothetical systems and a site at Galloway, NJ, provide insight into the temporal variation of water-quality data observed when withdrawing water from screened wells in heterogeneous ground-water systems.The analyses of hypothetical systems quantitatively indicate the cause-and-effect relations that cause temporal variability in water samples obtained from wells. Chemical constituents that have relatively uniform concentrations with depth may not show variations in concentrations in the water discharged from a well after the well is purged (evacuation of standing water in the well casing). However, chemical constituents that do not have uniform concentrations near the screened interval of the well may show variations in concentrations in the well discharge water after purging because of the physics of ground-water flow in the vicinity of the screen.Water-quality samples were obtained through time over a 30 minute period from a site at Galloway, NJ. The water samples were analyzed for aromatic hydrocarbons, and the data for benzene, toluene, and meta+para xylene were evaluated for temporal variations. Samples were taken from seven discrete zones, and the flow-weighted concentrations of benzene, toluene, and meta+para xylene all indicate an increase in concentration over time during pumping. These observed trends in time were reproduced numerically based on the estimated concentration distribution in the aquifer and the flow rates from each zone.The results of

Chemical and physical analyses of selected plants and soils from Puerto Rico (1981-1990)

Science.gov (United States)

M. J. Sanchez; E. Lopez; A. E. Lugo

1997-01-01

This report contains the result of many analyses conducted at the laboratory of the IITF of Puerto Rico between 1981 and 1990. our objective was to make available the chemical and physical data developed for tropical forest ecosystems.

Environmental parameters of the Tennessee River in Alabama. 2: Physical, chemical, and biological parameters. [biological and chemical effects of thermal pollution from nuclear power plants on water quality

Science.gov (United States)

Rosing, L. M.

1976-01-01

Physical, chemical and biological water quality data from five sites in the Tennessee River, two in Guntersville Reservoir and three in Wheeler Reservoir were correlated with climatological data for three annual cycles. Two of the annual cycles are for the years prior to the Browns Ferry Nuclear Power Plant operations and one is for the first 14 months of Plant operations. A comparison of the results of the annual cycles indicates that two distinct physical conditions in the reservoirs occur, one during the warm months when the reservoirs are at capacity and one during the colder winter months when the reservoirs have been drawn-down for water storage during the rainy months and for weed control. The wide variations of physical and chemical parameters to which the biological organisms are subjected on an annual basis control the biological organisms and their population levels. A comparison of the parameters of the site below the Power plant indicates that the heated effluent from the plant operating with two of the three reactors has not had any effect on the organisms at this site. Recommendations given include the development of prediction mathematical models (statistical analysis) for the physical and chemical parameters under specific climatological conditions which affect biological organisms. Tabulated data of chemical analysis of water and organism populations studied is given.

Performance of the sol-gel method for the preparation of optical fibers

Czech Academy of Sciences Publication Activity Database

Matějec, Vlastimil; Hayer, Miloš; Mrázek, Jan; Kašík, Ivan; Podrazký, Ondřej; Pospíšilová, Marie

2007-01-01

Roč. 52, č. 10 (2007), s. 991-998 ISSN 0035-3930. [Physical Chemistry Conference ROMPHYSCHEM /12./. Bucharest, 06.09.2006-08.09.2006] R&D Projects: GA ČR GA102/05/0956 Institutional research plan: CEZ:AV0Z20670512 Keywords : sol-gel processing * optical fibres * chemical sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.262, year: 2007

Research on physical and chemical parameters of coolant in Light-Water Reactors

Energy Technology Data Exchange (ETDEWEB)

Reis, Isabela C.; Mesquita, Amir Z., E-mail: icr@cdtn.br, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEM-MG), Belo Horizonte, MG (Brazil)

2015-07-01

The coolant radiochemical monitoring of light-water reactors, both power reactor as research reactors is one most important tasks of the system safe operation. The last years have increased the interest in the coolant chemical studying to optimize the process, to minimize the corrosion, to ensure the primary system materials integrity, and to reduce the workers exposure radiation. This paper has the objective to present the development project in Nuclear Technology Development Center (CDTN), which aims to simulate the primary water physical-chemical parameters of light-water-reactors (LWR). Among these parameters may be cited: the temperature, the pressure, the pH, the electric conductivity, and the boron concentration. It is also being studied the adverse effects that these parameters can result in the reactor integrity. The project also aims the mounting of a system to control and monitoring of temperature, electric conductivity, and pH of water in the Installation of Test in Accident Conditions (ITCA), located in the Thermal-Hydraulic Laboratory at CDTN. This facility was widely used in the years 80/90 for commissioning of several components that were installed in Angra 2 containment. In the test, the coolant must reproduce the physical and chemical conditions of the primary. It is therefore fundamental knowledge of the main control parameters of the primary cooling water from PWR reactors. Therefore, this work is contributing, with the knowledge and the reproduction with larger faithfulness of the reactors coolant in the experimental circuits. (author)

Ultradense, Deep Subwavelength Nanowire Array Photovoltaics As Engineered Optical Thin Films

KAUST Repository

Tham, Douglas

2010-11-10

A photovoltaic device comprised of an array of 20 nm wide, 32 nm pitch array of silicon nanowires is modeled as an optical material. The nanowire array (NWA) has characteristic device features that are deep in the subwavelength regime for light, which permits a number of simplifying approximations. Using photocurrent measurements as a probe of the absorptance, we show that the NWA optical properties can be accurately modeled with rigorous coupled-wave analysis. The densely structured NWAs behave as homogeneous birefringent materials into the ultraviolet with effective optical properties that are accurately modeled using the dielectric functions of bulk Si and SiO 2, coupled with a physical model for the NWA derived from ellipsometry and transmission electron microscopy. © 2010 American Chemical Society.

Monostatic Radar Cross Section Estimation of Missile Shaped Object Using Physical Optics Method

Science.gov (United States)

Sasi Bhushana Rao, G.; Nambari, Swathi; Kota, Srikanth; Ranga Rao, K. S.

2017-08-01

Stealth Technology manages many signatures for a target in which most radar systems use radar cross section (RCS) for discriminating targets and classifying them with regard to Stealth. During a war target’s RCS has to be very small to make target invisible to enemy radar. In this study, Radar Cross Section of perfectly conducting objects like cylinder, truncated cone (frustum) and circular flat plate is estimated with respect to parameters like size, frequency and aspect angle. Due to the difficulties in exactly predicting the RCS, approximate methods become the alternative. Majority of approximate methods are valid in optical region and where optical region has its own strengths and weaknesses. Therefore, the analysis given in this study is purely based on far field monostatic RCS measurements in the optical region. Computation is done using Physical Optics (PO) method for determining RCS of simple models. In this study not only the RCS of simple models but also missile shaped and rocket shaped models obtained from the cascaded objects with backscatter has been computed using Matlab simulation. Rectangular plots are obtained for RCS in dbsm versus aspect angle for simple and missile shaped objects using Matlab simulation. Treatment of RCS, in this study is based on Narrow Band.

FORMULATION OF MATHEMATICAL PROBLEM DESCRIBING PHYSICAL AND CHEMICAL PROCESSES AT CONCRETE CORROSION

Directory of Open Access Journals (Sweden)

Sergey V. Fedosov

2017-06-01

Full Text Available The article deals with the relevance of new scientific research focused on modeling of physical and chemical processes occurring in the cement concrete at their exploitation. The basic types of concrete corrosion are described. The problem of mass transfer processes in a flat reinforced concrete wall at concrete corrosion of the first and the second types has been mathematically formulated.

Disruption of the ‘disease triangle’ by chemical and physical environmental change

Science.gov (United States)

A. H. Chappelka; N. E. Grulke; L. De Kok

2015-01-01

The physical and chemical environment of the Earth has changed rapidly over the last 100 years and is predicted to continue to change into the foreseeable future. One of the main concerns with potential alterations in climate is the propensity for increases in the magnitude and frequency of extremes to occur. Even though precipitation is predicted to increase in some...

Physical and chemical properties for sandstone and bentonites

International Nuclear Information System (INIS)

Sato, Haruo

2004-01-01

Physical and chemical properties such as porosity, pore-size distribution, dry density, solid density, mineralogy and chemical composition, which are important parameters for the understanding and analysis of the diffusion phenomena of radionuclides and ions in bentonite and in the geosphere, were measured. The measurements were performed for sandstone, of which fundamental data and information are limited. For bentonite, 3 kinds of bentonites with different smectite contents (Kunigel-V1, Kunipia-F, MX80) were used. In the measurements of the physical and chemical properties of rock, the measurements of solid density by pychnometer, the measurements of porosity, dry density and solid density by water saturation method, the measurements of porosity, dry density, solid density, pore-size distribution and specific surface area of pores by Hg porosimetry, the identifications of constituent minerals by X-ray Diffractometry (XRD), the measurement of chemical composition by whole rock analysis, the observations of micropore structure by Laser Confocal Microscope (LCM), the measurements of water vaporization curves and the measurements of the homogeneity of the rock by penetration of KMnO 4 were performed. While, in the measurements of the physical and chemical properties for bentonite, water basis water content, water content, porosity, dry density, solid density and their distributions in samples were measured, and the degree of inhomogeneity was quantitatively evaluated by comparing with data and information reported up to date. The porosities of sandstone are 15.6±0.21% for water saturation method and 15.5±0.2% for Hg porosimetry, and similar values were obtained in both methods. The solid densities ranged 2.65-2.69 Mg/m 3 for 3 methods, and the average value was 2.668±0.012 Mg/m 3 . The average pore size was 88.8±0.5nm, and pore sizes ≤10μm shared 80% of total pore volume and pore sizes ≤1μm shared 40%. The specific surface area of the pores is 4.09±0.017 m

Real-time optical diagnostics of graphene growth induced by pulsed chemical vapor deposition

Science.gov (United States)

Puretzky, Alexander A.; Geohegan, David B.; Pannala, Sreekanth; Rouleau, Christopher M.; Regmi, Murari; Thonnard, Norbert; Eres, Gyula

2013-06-01

The kinetics and mechanisms of graphene growth on Ni films at 720-880 °C have been measured using fast pulses of acetylene and real-time optical diagnostics. In situ UV-Raman spectroscopy was used to unambiguously detect isothermal graphene growth at high temperatures, measure the growth kinetics with ~1 s temporal resolution, and estimate the fractional precipitation upon cooldown. Optical reflectivity and videography provided much faster temporal resolution. Both the growth kinetics and the fractional isothermal precipitation were found to be governed by the C2H2 partial pressure in the CVD pulse for a given film thickness and temperature, with up to ~94% of graphene growth occurring isothermally within 1 second at 800 °C at high partial pressures. At lower partial pressures, isothermal graphene growth is shown to continue 10 seconds after the gas pulse. These flux-dependent growth kinetics are described in the context of a dissolution/precipitation model, where carbon rapidly dissolves into the Ni film and later precipitates driven by gradients in the chemical potential. The combination of pulsed-CVD and real-time optical diagnostics opens new opportunities to understand and control the fast, sub-second growth of graphene on various substrates at high temperatures.The kinetics and mechanisms of graphene growth on Ni films at 720-880 °C have been measured using fast pulses of acetylene and real-time optical diagnostics. In situ UV-Raman spectroscopy was used to unambiguously detect isothermal graphene growth at high temperatures, measure the growth kinetics with ~1 s temporal resolution, and estimate the fractional precipitation upon cooldown. Optical reflectivity and videography provided much faster temporal resolution. Both the growth kinetics and the fractional isothermal precipitation were found to be governed by the C2H2 partial pressure in the CVD pulse for a given film thickness and temperature, with up to ~94% of graphene growth occurring isothermally

Structural, Chemical and Physical Properties of Mn12

Science.gov (United States)

Sessoli, Roberta

1997-03-01

Recent investigations on the physical properties of the first molecular nanomagnet, Mn12ac, will be reported. Among them very high field EPR spectra (up to 25 T) (A. L. Barra, D. Gatteschi, R. Sessoli Phys. Rev. B. submitted) have provided precise information on the spin hamiltonian up to the fourth order terms. These new findings justify the irregularities in the step separations in the quantum hysteresis that we have observed performing the measurements on a single crystal (L. Thomas et al, Nature.383, 145 (1996)), and confirm that we are observing resonant quantum tunneling of the magnetization. The magnetic hysteresis has been also optically detected in collaboration with Prof. A. Thomson of the University of East Anglia, UK. Possible modifications to the Mn12 cluster as well as an iron cluster showing MQT of the magnetization (C. Sangregorio, T. Ohm, C. Paulsen, R. Sessoli, D. Gatteschi, submitted) will be briefly presented.