Enforcement actions: Significant actions resolved material licensees. Semiannual progress report, July--December 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-04-01

This compilation summarizes significant enforcement actions that have been resolved during the period and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

Enforcement actions: Significant actions resolved material licensees. Semiannual progress report, July--December 1996

International Nuclear Information System (INIS)

1997-04-01

This compilation summarizes significant enforcement actions that have been resolved during the period and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Motivationally Significant Stimuli Show Visual Prior Entry: Evidence for Attentional Capture

Science.gov (United States)

West, Greg L.; Anderson, Adam A. K.; Pratt, Jay

2009-01-01

Previous studies that have found attentional capture effects for stimuli of motivational significance do not directly measure initial attentional deployment, leaving it unclear to what extent these items produce attentional capture. Visual prior entry, as measured by temporal order judgments (TOJs), rests on the premise that allocated attention…

Significance of tests and properties of concrete and concrete-making materials

CERN Document Server

Pielert, James H

2006-01-01

Reflects a decade of technological changes in concrete industry! The newest edition of this popular ASTM publication reflects the latest technology in concrete and concrete-making materials. Six sections cover: (1) General information on the nature of concrete, sampling, variability, and testing laboratories. A new chapter deals with modeling cement and concrete properties. (2) Properties of freshly mixed concrete. (3) Properties of hardened concrete. (4) Concrete aggregates—this section has been revised and the chapters are presented in the order that most concerns concrete users: grading, density, soundness, degradation resistance, petrographic examination, reactivity, and thermal properties. (5) Materials other than aggregates—the chapter on curing materials now reflects the current technology of materials applied to new concrete surfaces. The chapter on mineral admixtures has been separated into two chapters: supplementary cementitious materials and ground slag. (6) Specialized concretes—contains a ...

Hyperspectral surface materials map of quadrangle 3266, Uruzgan (519) and Moqur (520) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3464, Shahrak (411) and Kasi (412) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3470, Jalalabad (511) and Chaghasaray (512) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3368, Ghazni (515) and Gardez (516) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3162, Chakhansur (603) and Kotalak (604) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3362, Shindand (415) and Tulak (416) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3366, Gizab (513) and Nawer (514) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3770, Faizabad (217) and Parkhaw (218) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3564, Jowand (405) and Gurziwan (406) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

The significance of cladding material on the integrity of nuclear pressure vessels with cracks

International Nuclear Information System (INIS)

Sattari-Far, Iradj.

1989-05-01

The significance of the austenitic cladding layer is reviewed in this literature study. The cladding induced stresses are generally not considered when evaluating the severity of flaws in reactor pressure vessels. It has been shown that this emission may be misleading. The necessity to consider the cladding induced stresses is also emphasized in the latest edition of ASME XI. Contrary to what is commonly assumed, the austenitic cladding displays a charpy V transition region with a low ductility. The interface material (HAZ) is the most influenced region by irradiation, and a transition shift of over 100 degree C may be expected. Because of the significant difference in the thermal expansion coefficients of the cladding and the base metal, cladding induced stresses can be set up. Even after PWHT, residual stresses of yield magnitude remain in the cladding and the HAZ at ambient temperature. The cladding induced stresses are temperature dependent and decrease as the temperature increases. The cladding induced stresses have a significant influence on small defects near the inside surface of a pressure vessel. For semielliptical surface cracks, the maximum CTOD-value along the crack front is not found at the deepest point, but in the cladding/base metal interface, having a magnitude three times higher than the value in the deepest point. It implies that this type of crack would propagate along the clad/base material interface. At some point in time, the crack will reach a geometry which may cause such a severe condition at the deepest point that it will start to grow in the depth direction as well. The initiation and growth behaviour of such cracks need to be investigated to be able to assess the significance of cladding on the integrity of nuclear pressure vessels. (author) (50 figs., 33 refs.)

10 CFR 74.31 - Nuclear material control and accounting for special nuclear material of low strategic significance.

Science.gov (United States)

2010-01-01

... and maintain a measurement system which assures that all quantities in the material accounting records...) In each inventory period, control total material control and accounting measurement uncertainty so... 10 Energy 2 2010-01-01 2010-01-01 false Nuclear material control and accounting for special...

Fungal communities in wheat grain show significant co-existence patterns among species

DEFF Research Database (Denmark)

Nicolaisen, M.; Justesen, A. F.; Knorr, K.

2014-01-01

identified as ‘core’ OTUs as they were found in all or almost all samples and accounted for almost 99 % of all sequences. The remaining OTUs were only sporadically found and only in small amounts. Cluster and factor analyses showed patterns of co-existence among the core species. Cluster analysis grouped...... the 21 core OTUs into three clusters: cluster 1 consisting of saprotrophs, cluster 2 consisting mainly of yeasts and saprotrophs and cluster 3 consisting of wheat pathogens. Principal component extraction showed that the Fusarium graminearum group was inversely related to OTUs of clusters 1 and 2....

Hyperspectral surface materials map of quadrangle 3462, Herat (409) and Chishti Sharif (410) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3166, Jaldak (701) and Maruf-Nawa (702) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3670, Jurm-Kishim (223) and Zebak (224) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3164, Lashkar Gah (605) and Kandahar (606) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3562, Khawja-Jir (403) and Murghab (404) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral Surface Materials Map of Quadrangle 3268, Khayr Kot (521) and Urgun (522) Quadrangles, Afghanistan, Showing Iron-bearing Minerals and Other Materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Enforcement actions: Significant actions resolved material licensees. Quarterly progress report, April 1995--June 1995

International Nuclear Information System (INIS)

1995-08-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April-June 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Double polymer sheathed carbon nanotube supercapacitors show enhanced cycling stability

Science.gov (United States)

Zhao, Wenqi; Wang, Shanshan; Wang, Chunhui; Wu, Shiting; Xu, Wenjing; Zou, Mingchu; Ouyang, An; Cao, Anyuan; Li, Yibin

2015-12-01

Pseudo-materials are effective in boosting the specific capacitance of supercapacitors, but during service their degradation may also be very strong, causing reduced cycling stability. Here, we show that a carbon nanotube sponge grafted by two conventional pseudo-polymer layers in sequence can serve as a porous supercapacitor electrode with significantly enhanced cycling stability compared with single polymer grafting. Creating conformal polymer coatings on the nanotube surface and the resulting double-sheath configuration are important structural factors leading to the enhanced performance. Combining different polymers as double sheaths as reported here might be a potential route to circumvent the dilemma of pseudo-materials, and to simultaneously improve the capacitance and stability for various energy storage devices.Pseudo-materials are effective in boosting the specific capacitance of supercapacitors, but during service their degradation may also be very strong, causing reduced cycling stability. Here, we show that a carbon nanotube sponge grafted by two conventional pseudo-polymer layers in sequence can serve as a porous supercapacitor electrode with significantly enhanced cycling stability compared with single polymer grafting. Creating conformal polymer coatings on the nanotube surface and the resulting double-sheath configuration are important structural factors leading to the enhanced performance. Combining different polymers as double sheaths as reported here might be a potential route to circumvent the dilemma of pseudo-materials, and to simultaneously improve the capacitance and stability for various energy storage devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05978j

The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials.

Directory of Open Access Journals (Sweden)

Carmel McDougall

Full Text Available In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the

Material flows accounting for Scotland shows the merits of a circular economy and the folly of territorial carbon reporting

Directory of Open Access Journals (Sweden)

Kimberley Pratt

2016-09-01

boundaries, as well as territorial boundaries, if carbon savings are to be maximised. This is because imports and recyclate sent abroad can have significant effect on the carbon emissions from material consumption. We demonstrate that the more circular an economy is, the smaller the difference between global and territorial carbon emissions, and therefore that climate change targets based solely on territorial carbon emissions create perverse incentives. The study also found that there could be areas of economic development which are compatible with environmental aims, based around encouraging reprocessing activities in developed nations.

Material flows accounting for Scotland shows the merits of a circular economy and the folly of territorial carbon reporting.

Science.gov (United States)

Pratt, Kimberley; Lenaghan, Michael; Mitchard, Edward T A

2016-12-01

maximised. This is because imports and recyclate sent abroad can have significant effect on the carbon emissions from material consumption. We demonstrate that the more circular an economy is, the smaller the difference between global and territorial carbon emissions, and therefore that climate change targets based solely on territorial carbon emissions create perverse incentives. The study also found that there could be areas of economic development which are compatible with environmental aims, based around encouraging reprocessing activities in developed nations.

Hyperspectral surface materials map of quadrangle 3564, Jowand (405) and Gurziwan (406) quadrangles, Afghanistan, showing carbonates, phyllosilicates, sulfates, altered minerals, and other materials

Science.gov (United States)

Kokaly, Raymond F.; King, Trude V.V.; Hoefen, Todd M.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected carbonates, phyllosilicates, sulfates, altered minerals, and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. The map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Epidote or chlorite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3364, Pasaband (417) and Markaz-e Kajiran (418) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3566, Sangcharak (501) and Sayghan-o-Kamard (502) quadrangles, Afghanistan, showing iron-bearing minerals and other material

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3568, Pul-e Khumri (503) and Charikar (504) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Roofing Materials Assessment: Investigation of Five Metals in Runoff from Roofing Materials.

Science.gov (United States)

Winters, Nancy; Granuke, Kyle; McCall, Melissa

2015-09-01

To assess the contribution of five toxic metals from new roofing materials to stormwater, runoff was collected from 14 types of roofing materials and controls during 20 rain events and analyzed for metals. Many of the new roofing materials evaluated did not show elevated metals concentrations in the runoff. Runoff from several other roofing materials was significantly higher than the controls for arsenic, copper, and zinc. Notably, treated wood shakes released arsenic and copper, copper roofing released copper, PVC roofing released arsenic, and Zincalume® and EPDM roofing released zinc. For the runoff from some of the roofing materials, metals concentrations decreased significantly over an approximately one-year period of aging. Metals concentrations in runoff were demonstrated to depend on a number of factors, such as roofing materials, age of the materials, and climatic conditions. Thus, application of runoff concentrations from roofing materials to estimate basin-wide releases should be undertaken cautiously.

Hyperspectral surface materials map of quadrangle 3264, Naw Zad-Musa Qala (423) and Dihrawud (424) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3570, Tagab-e-Munjan (505) and Asmar-Kamdesh (506) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3468, Chak-e Wardak-Siyahgird (509) and Kabul (510) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3262, Farah (421) and Hokumat-e-pur-Chaman (422) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Material Rhetoric: Spreading Stones and Showing Bones in the Study of Prehistory

NARCIS (Netherlands)

Van Reybrouck, D.; de Bont, R.; Rock, J.

2009-01-01

Since the linguistic turn, the role of rhetoric in the circulation and the popular representation of knowledge has been widely accepted in science studies. This article aims to analyze not a textual form of scientific rhetoric, but the crucial role of materiality in scientific debates. It introduces

Spectrophotometric Evaluation of Polyetheretherketone (PEEK as a Core Material and a Comparison with Gold Standard Core Materials

Directory of Open Access Journals (Sweden)

Bogna Stawarczyk

2016-06-01

Full Text Available This study investigated the colorimetric properties of different veneering materials on core materials. Standardized specimens (10 mm × 10 mm × 1.5 mm reflecting four core (polyetheretherketone (PEEK, zirconia (ZrO2, cobalt–chromium–molybdenum alloy (CoCrMo, and titanium oxide (TiO2; thickness: 1.5 mm and veneering materials (VITA Mark II, IPS e.max CAD, LAVA Ultimate and VITA Enamic, all in shade A3; thickness: 0.5, 1.0, 1.5 and 2 mm, respectively were fabricated. Specimens were superimposed to assemblies, and the color was determined with a spectrophotometer (CieLab-System or a chair-side color measurement device (VITA EasyShade, respectively. Data were analyzed using three-, two-, and one-way ANOVA, a Chi2-test, and a Wilson approach (p < 0.05. The measurements with EasyShade showed A2 for VITA Mark II, A3.5 for VITA Enamic, B2 for LAVA Ultimate, and B3 for IPS e.max CAD. LabE-values showed significant differences between the tested veneering materials (p < 0.001. CieLab-System and VITA EasyShade parameters of the different assemblies showed a significant impact of core (p < 0.001, veneering material (p < 0.001, and thickness of the veneering material (p < 0.001. PEEK as core material showed comparable outcomes as compared to ZrO2 and CoCrMo, with respect to CieLab-System parameters for each veneering material. The relative frequency of the measured VITA EasyShade parameters regarding PEEK cores also showed comparable results as compared to the gold standard CoCrMo, regardless of the veneering material used.

Enforcement actions: Significant actions resolved material licensees (non-medical). Quarterly progress report, October 1994--December 1994

International Nuclear Information System (INIS)

1995-02-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October - December 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees (non-medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Enforcement actions: Significant actions resolved material licensees (non-medical). Quarterly progress report, October 1994--December 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-02-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October - December 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees (non-medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

Hyperspectral surface materials map of quadrangle 3466, La`l wa Sar Jangal (507) and Bamyan (508) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Polypyridylruthenium(II complexes exert in vitro and in vivo nematocidal activity and show significant inhibition of parasite acetylcholinesterases

Directory of Open Access Journals (Sweden)

Madhu Sundaraneedi

2018-04-01

Full Text Available Over 4.5 billion people are at risk of infection with soil transmitted helminths and there are concerns about the development of resistance to the handful of frontline nematocides in endemic populations. We investigated the anti-nematode efficacy of a series of polypyridylruthenium(II complexes and showed they were active against L3 and adult stages of Trichuris muris, the rodent homologue of the causative agent of human trichuriasis, T. trichiura. One of the compounds, Rubb12-mono, which was among the most potent in its ability to kill L3 (IC50 = 3.1 ± 0.4 μM and adult (IC50 = 5.2 ± 0.3 μM stage worms was assessed for efficacy in a mouse model of trichuriasis by administering 3 consecutive daily oral doses of the drug 3 weeks post infection with the murine whipworm Trichuris muris. Mice treated with Rubb12-mono showed an average 66% reduction (P = 0.015 in faecal egg count over two independent trials. The drugs partially exerted their activity through inhibition of acetylcholinesterases, as worms treated in vitro and in vivo showed significant decreases in the activity of this class of enzymes. Our data show that ruthenium complexes are effective against T. muris, a model gastro-intestinal nematode and soil-transmitted helminth. Further, knowledge of the target of ruthenium drugs can facilitate modification of current compounds to identify analogues which are even more effective and selective against Trichuris and other helminths of human and veterinary importance. Keywords: Acetylcholinesterase, Trichuris muris, Ruthenium complex, Anthelmintic

Costs of disposable material in the operating room do not show high correlation with surgical time: Implications for hospital payment.

Science.gov (United States)

Delo, Caroline; Leclercq, Pol; Martins, Dimitri; Pirson, Magali

2015-08-01

The objectives of this study are to analyze the variation of the surgical time and of disposable costs per surgical procedure and to analyze the association between disposable costs and the surgical time. The registration of data was done in an operating room of a 419 bed general hospital, over a period of three months (n = 1556 surgical procedures). Disposable material per procedure used was recorded through a barcode scanning method. The average cost (standard deviation) of disposable material is €183.66 (€183.44). The mean surgical time (standard deviation) is 96 min (63). Results have shown that the homogeneity of operating time and DM costs was quite good per surgical procedure. The correlation between the surgical time and DM costs is not high (r = 0.65). In a context of Diagnosis Related Group (DRG) based hospital payment, it is important that costs information systems are able to precisely calculate costs per case. Our results show that the correlation between surgical time and costs of disposable materials is not good. Therefore, empirical data or itemized lists should be used instead of surgical time as a cost driver for the allocation of costs of disposable materials to patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

An active principle of Nigella sativa L., thymoquinone, showing significant antimicrobial activity against anaerobic bacteria.

Science.gov (United States)

Randhawa, Mohammad Akram; Alenazy, Awwad Khalaf; Alrowaili, Majed Gorayan; Basha, Jamith

2017-01-01

Thymoquinone (TQ) is the major active principle of Nigella sativa seed (black seed) and is known to control many fungi, bacteria, and some viruses. However, the activity of TQ against anaerobic bacteria is not well demonstrated. Anaerobic bacteria can cause severe infections, including diarrhea, aspiration pneumonia, and brain abscess, particularly in immunodeficient individuals. The present study aimed to investigate the in vitro antimicrobial activity of TQ against some anaerobic pathogens in comparison to metronidazole. Standard, ATCC, strains of four anaerobic bacteria ( Clostridium difficile , Clostridium perfringens , Bacteroides fragilis , and Bacteroides thetaiotaomicron ), were initially isolated on special Brucella agar base (with hemin and vitamin K). Then, minimum inhibitory concentrations (MICs) of TQ and metronidazole were determined against these anaerobes when grown in Brucella agar, using serial agar dilution method according to the recommended guidelines for anaerobic organisms instructed by the Clinical and Laboratory Standards Institute. TQ showed a significant antimicrobial activity against anaerobic bacteria although much weaker than metronidazole. MICs of TQ and metronidazole against various anaerobic human pathogens tested were found to be between 10-160 mg/L and 0.19-6.25 mg/L, respectively. TQ controlled the anaerobic human pathogenic bacteria, which supports the use of N. sativa in the treatment of diarrhea in folk medicine. Further investigations are in need for determination of the synergistic effect of TQ in combination with metronidazole and the activity of derivatives of TQ against anaerobic infections.

Impact studies of five ceramic materials and pyrex

International Nuclear Information System (INIS)

Cunningham, B.J.; Holt, A.C.; Hord, B.L.; Kusubov, A.S.; Reaugh, J.E.; Wilkins, M.L.

1998-01-01

We measured the ballistic performance of five ceramic materials (alumina, silicon carbide, boron carbide, aluminum nitride, and titanium diboride) and Pyrex, when they are backed by thick steel plates. The projectile for all tests was a right-circular cylinder of tungsten sinter-alloy W2 with length 25.4 mm and diameter 6.35 mm, fired at velocities from 1.35 to 2.65 km/s. For this threat we determined the minimum areal density of each material that is needed to keep the projectile from penetrating the backup steel. For all of the facing materials studied here, this performance measure increases approximately linearly with projectile velocity. However, the rate of increase is significantly lower for aluminum nitride than for the other materials studied. Indeed, aluminum nitride is a poor performer at the lowest velocity tested, but is clearly the best at the highest velocity. Our computer simulations show the significant influence of the backing material on ceramic performance, manifested by a transition region extending two projectile diameters upstream from the material interface. Experiments with multiple material layers show that this influence also manifests itself through a significant dependence of ballistic performance on the ordering of the material

The energy show

International Nuclear Information System (INIS)

1988-01-01

The Energy Show is a new look at the problems of world energy, where our supplies come from, now and in the future. The programme looks at how we need energy to maintain our standards of living. Energy supply is shown as the complicated set of problems it is - that Fossil Fuels are both raw materials and energy sources, that some 'alternatives' so readily suggested as practical options are in reality a long way from being effective. (author)

Hyperspectral surface materials map of quadrangle 3260, Dasht-e-Chah-e-Mazar (419) and Anar Darah (420) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Advanced Industrial Materials (AIM) Program: Compilation of project summaries and significant accomplishments, FY 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-04-01

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This report contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Subject areas covered are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes.

Photosensitive chiral self-assembling materials: significant effects of small lateral substituents

Czech Academy of Sciences Publication Activity Database

Cigl, Martin; Bubnov, Alexej; Kašpar, Miroslav; Hampl, F.; Hamplová, Věra; Pacherová, Oliva; Svoboda, J.

2016-01-01

Roč. 4, č. 23 (2016), 5326-5333 ISSN 2050-7526 R&D Projects: GA ČR GA16-12150S; GA MŠk(CZ) LH15305 Institutional support: RVO:68378271 Keywords : liquid crystals * lateral substitution * azo group * isomerization Subject RIV: JJ - Other Materials Impact factor: 5.256, year: 2016

Color stability of esthetic restorative materials: a spectrophotometric analysis.

Science.gov (United States)

Poggio, Claudio; Ceci, Matteo; Beltrami, Riccardo; Mirando, Maria; Wassim, Jaffal; Colombo, Marco

2016-12-01

Objective: The aim of this in vitro study was to evaluate the color stability of different restorative materials (one microfilled composite, one nanofilled composite, one nanohybrid composite and one Ormocer-based composite) after exposure to different staining solutions (coffee, coca-cola and red wine). Material and methods: All materials were polymerized into silicon rings (2 mm ×6 mm ×8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. They were immersed in staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro-Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. The paired t -test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. Results: All restorative materials showed clinically perceptible color differences after immersion in coffee. L* and b* values showed the highest variability. Coca cola and red wine did not influence the color stability for all restorative materials except for Filtek Supreme XTE. Conclusions: Coffee caused a significant color change in all types of tested composite resins. Filtek Supreme XTE demonstrated alone a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials' different composition.

Different histopathological subtypes of Hodgkin lymphoma show significantly different levels of FDG uptake

DEFF Research Database (Denmark)

Hutchings, Martin; Loft, Annika; Hansen, Mads

2006-01-01

) patients, 20.8 g/ml in 11 mixed cellularity (MC) patients, and 19.5 g/ml in four patients with unclassified classical HL (CHL-NOS), (ANOVA, p = 0.011). Out of 780 sites (600 lymph node regions plus 180 organs), 208 sites were found to be affected with HL. Mean SUV(max) was 8.3 g/ml in the 12 sites with NLP......, 11.2 g/ml in the 147 sites affected with NS, 14.6 g/ml in the 36 sites with MC, and 13.1 g/ml in the 13 sites with CHL-NOS (ANOVA, p = 0.002). There is a significant difference in FDG/glucose uptake between the different histopathological subtypes of HL....

Optimisation of integrated energy and materials systems

International Nuclear Information System (INIS)

Gielen, D.J.; Okken, P.A.

1994-06-01

To define cost-effective long term CO2 reduction strategies an integrated energy and materials system model for the Netherlands for the period 2000-2040 is developed. The model is based upon the energy system model MARKAL, which configures an optimal mix of technologies to satisfy the specified energy and product/materials service demands. This study concentrates on CO 2 emission reduction in the materials system. For this purpose, the energy system model is enlarged with a materials system model including all steps 'from cradle to grave'. The materials system model includes 29 materials, 20 product groups and 30 waste materials. The system is divided into seven types of technologies; 250 technologies are modeled. The results show that the integrated optimisation of the energy system and the materials system can significantly reduce the emission reduction costs, especially at higher reduction percentages. The reduction is achieved through shifts in materials production and waste handling and through materials substitution in products. Shifts in materials production and waste management seem cost-effective, while the cost-effectiveness of shifts in product composition is sensitive due to the cost structure of products. For the building sector, transportation applications and packaging, CO 2 policies show a significant impact on prices, and shifts in product composition could occur. For other products, the reduction through materials substitution seems less promising. The impact on materials consumption seems most significant for cement (reduced), timber and aluminium (both increased). For steel and plastics, the net effect is balanced, but shifts between applications do occur. The MARKAL-approach is feasible to study integrated energy and materials systems. The progress compared to other environmental system analysis instruments is much more insight in the interaction of technologies on a national scale and in time

Mandatory special or dedicated trains for radioactive materials shipments evidence shows they're not needed

International Nuclear Information System (INIS)

Goodman, L.S.; Garrison, R.F.; Harmon, L.H.

1988-01-01

The rejection of mandatory special or dedicated trains by all responsible Federal agencies for transportation of radioactive materials in shielded casks has a long history. Working with the railroads and the National Academy of Sciences, the ICC adopted standards for transporting radioactive materials in regular freight trains in the mid 1940's. The standards rested primarily on ensuring the integrity of the radioactive materials packaging. AEC, then NRC and DOT, followed the ICC lead, supplementing the licensing rules for casks with a series of performance or stress tests. At no time did these agencies require special trains or special routing for rail casks. Mandatory special trains have too many disadvantages without any proven safety benefit to be worth their high cost to the shipper. The ICC, in a series of litigated cases, found that given the strength of the casks, mandatory special trains were wasteful transportation and an unreasonable railroad practice

A method for determination of X-ray elastic constants of materials showing non-linear sin2ψ diagrams and its application to Zn-Ni-alloy electroplate

International Nuclear Information System (INIS)

Sasaki, Toshihiko; Kuramoto, Makoto; Yoshioka, Yasuo.

1990-01-01

This paper describes the method and the experiment for the determination of the x-ray elastic constants of Zn-Ni-alloy electroplate. For this material, the sin 2 ψ method is not adequate to use because this material shows severely curved sin 2 ψ diagrams. Therefore, a new method developed by the authors was explained first. This new method is effective for materials showing nonlinear sin 2 ψ diagrams. Secondly, the experiment was made on the application of this method to the Zn-Ni-alloy electroplate. And it was found out that the experimental data agreed well to the theory of this method. As a result, the following values were obtained as the x-ray elastic constants of the sample measured: (1+ν)/E=8.44 TPa -1 ν/E=2.02 TPa -1 (author)

Evaluation of materials and design modifications for aircraft brakes

Science.gov (United States)

Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

1975-01-01

A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

In Vitro Investigation of Wear of CAD/CAM Polymeric Materials Against Primary Teeth

Directory of Open Access Journals (Sweden)

Jae-Won Choi

2017-12-01

Full Text Available The aim of the study was to evaluate the effects of polymeric computer-aided design/computer-aided manufacturing CAD/CAM materials on antagonistic primary tooth wear. Five CAD/CAM polymeric materials were examined: Vipi Block Monocolor (VBM, Yamahachi polymethylmethacrylate (PMMA (YAP, Mazic Duro (MZD, Vita Enamic (ENA, and Pekkton (PEK. All of the specimens were tested in a thermomechanical loading machine with the primary canine as the antagonist (50 N, 1.2 × 105 cycles, 1.7 Hz, 5/55 °C. The wear losses of the antagonist tooth and the restorative materials were calculated using reverse modelling software and an electronic scale. VBM and ENA showed significantly higher antagonist tooth wear than PEK (p < 0.05, but there was no significant difference observed among VBM, YAP, MZD, and ENA (p > 0.05. PEK showed the largest value in both material volumetric and weight losses. In terms of material volumetric losses, there was no significant difference between all of the groups (p > 0.05. In terms of material weight losses, PEK was significantly larger than ENA (p < 0.05, but there was no significant difference between VBM, YAP, MZD, and ENA (p > 0.05. Volumetric and weight losses of materials showed similar wear behaviour. However, the wear patterns of antagonists and materials were different, especially in PEK.

Hyperspectral surface materials map of quadrangles 3668 and 3768, Baghlan (221), Taluqan (222), Imam Sahib (215), and Rustaq (216) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Effect of different sizes of planting material on the growth and yield ...

African Journals Online (AJOL)

However, a significant (P<0.05) effect was recorded in cap diameter (3.68cm) from the 20g weight planting material. Stipe height and girth did not show any significant difference amongst the treatments. The 60g planting material weight recorded more shoots than the 20g and 40g planting material sizes. The 60g planting ...

The social in scene in significant materiality = O social em cena na materialidade significante

Directory of Open Access Journals (Sweden)

Suzy Lagazzi

2010-07-01

Full Text Available This paper analyses the movies: Tropa de Elite, Tereza and Boca de Lixo, with the aim of providing visibility, in the imbrication of different significant materialities, for the discursive work of textualizing social differences. In the theoretical and methodologicalperspective of the materialistic Discourse Analysis, this text allows us to observe the functioning of the contradiction during the oppositional naturalization that structures most of the relations which organize our society, presenting the resistance as a process of possible displacement.Este artigo reúne análises de Tropa de Elite, Tereza e Boca de Lixo com o objetivo de dar visibilidade, na imbricação de distintas materialidades significantes, ao trabalho discursivo de textualização da diferença no social. Na perspectiva teórico-metodológica da Análise do Discurso materialista, este texto permite-nos observar o funcionamento da contradição em meio à naturalização opositiva que estrutura grande parte das relações que organizam nossa sociedade atual, apresentando a resistência como um processo de deslocamento possível.

Technological significances to reduce the material problems. Feasibility of heat flux reduction

International Nuclear Information System (INIS)

Yamazaki, Seiichiro; Shimada, Michiya.

1994-01-01

For a divertor plate in a fusion power reactor, a high temperature coolant must be used for heat removal to keep thermal efficiency high. It makes the temperature and thermal stress of wall materials higher than the design limits. Issues of the coolant itself, e.g. burnout of high temperature water, will also become a serious problem. Sputtering erosion of the surface material will be a great concern of its lifetime. Therefore, it is necessary to reduce the heat and particle loads to the divertor plate technologically. The feasibility of some technological methods of heat reduction, such as separatrix sweeping, is discussed. As one of the most promising ideas, the methods of radiative cooling of the divertor plasma are summarized based on the recent results of large tokamaks. The feasibility of remote radiative cooling and gas divertor is discussed. The ideas are considered in recent design studies of tokamak power reactors and experimental reactors. By way of example, conceptual designs of divertor plate for the steady state tokamak power reactor are described. (author)

The cosmopolitan maternal heritage of the Thoroughbred racehorse breed shows a significant contribution from British and Irish native mares.

Science.gov (United States)

Bower, M A; Campana, M G; Whitten, M; Edwards, C J; Jones, H; Barrett, E; Cassidy, R; Nisbet, R E R; Hill, E W; Howe, C J; Binns, M

2011-04-23

The paternal origins of Thoroughbred racehorses trace back to a handful of Middle Eastern stallions, imported to the British Isles during the seventeenth century. Yet, few details of the foundation mares were recorded, in many cases not even their names (several different maternal lineages trace back to 'A Royal Mare'). This has fuelled intense speculation over their origins. We examined mitochondrial DNA from 1929 horses to determine the origin of Thoroughbred foundation mares. There is no evidence to support exclusive Arab maternal origins as some historical records have suggested, or a significant importation of Oriental mares (the term used in historic records to refer to Middle East and western Asian breeds including Arab, Akhal-Teke, Barb and Caspian). Instead, we show that Thoroughbred foundation mares had a cosmopolitan European heritage with a far greater contribution from British and Irish Native mares than previously recognized.

The cosmopolitan maternal heritage of the Thoroughbred racehorse breed shows a significant contribution from British and Irish native mares

Science.gov (United States)

Bower, M. A.; Campana, M. G.; Whitten, M.; Edwards, C. J.; Jones, H.; Barrett, E.; Cassidy, R.; Nisbet, R. E. R.; Hill, E. W.; Howe, C. J.; Binns, M.

2011-01-01

The paternal origins of Thoroughbred racehorses trace back to a handful of Middle Eastern stallions, imported to the British Isles during the seventeenth century. Yet, few details of the foundation mares were recorded, in many cases not even their names (several different maternal lineages trace back to ‘A Royal Mare’). This has fuelled intense speculation over their origins. We examined mitochondrial DNA from 1929 horses to determine the origin of Thoroughbred foundation mares. There is no evidence to support exclusive Arab maternal origins as some historical records have suggested, or a significant importation of Oriental mares (the term used in historic records to refer to Middle East and western Asian breeds including Arab, Akhal-Teke, Barb and Caspian). Instead, we show that Thoroughbred foundation mares had a cosmopolitan European heritage with a far greater contribution from British and Irish Native mares than previously recognized. PMID:20926431

Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 3

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 3

International Nuclear Information System (INIS)

1998-04-01

This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Guide to the declaration procedure and coding system for criteria concerning significant events related to safety, radiation protection or the environment, applicable to basic nuclear installations and the transport of radioactive materials

International Nuclear Information System (INIS)

Lacoste, Andre-Claude

2005-01-01

This guide notably contains various forms associated with the declaration of significant events, and explanations to fill them in: significant event declaration form for a basic nuclear installation, significant event declaration form for radioactive material transport, significant event report for a basic nuclear installation, significant event report for radioactive material transport, declaration criteria for significant events related to the safety of non-PWR basic nuclear installations, declaration criteria for significant events related to PWR safety, significant events declared further to events resulting in group 1 unavailability and non-compliance with technical operating specifications, declaration criteria for significant events concerning radiation protection for basic nuclear installations, declaration criteria for significant events concerning environmental protection, applicable to basic nuclear installations, and declaration criteria for significant events concerning radioactive material transport

Building Investigation: Material or Structural Performance

Directory of Open Access Journals (Sweden)

Yusof M.Z.

2014-03-01

Full Text Available Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

Hyperspectral surface materials map of quadrangles 3664 and 3764, Char Shengo (123), Shibirghan (124), Jalajin (117), and Kham-Ab (118) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangles 2962 and 3062, Gawdezereh (615), Galachah (616), Chahar Burjak (609), and Khan Neshin (610) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

Hoefen, Todd M.; King, Trude V.V.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Laser additive manufacturing of high-performance materials

CERN Document Server

Gu, Dongdong

2015-01-01

This book entitled “Laser Additive Manufacturing of High-Performance Materials” covers the specific aspects of laser additive manufacturing of high-performance new materials components based on an unconventional materials incremental manufacturing philosophy, in terms of materials design and preparation, process control and optimization, and theories of physical and chemical metallurgy. This book describes the capabilities and characteristics of the development of new metallic materials components by laser additive manufacturing process, including nanostructured materials, in situ composite materials, particle reinforced metal matrix composites, etc. The topics presented in this book, similar as laser additive manufacturing technology itself, show a significant interdisciplinary feature, integrating laser technology, materials science, metallurgical engineering, and mechanical engineering. This is a book for researchers, students, practicing engineers, and manufacturing industry professionals interested i...

Presence and leaching of bisphenol a (BPA) from dental materials

Science.gov (United States)

Becher, Rune; Wellendorf, Hanne; Sakhi, Amrit Kaur; Samuelsen, Jan Tore; Thomsen, Cathrine; Bølling, Anette Kocbach; Kopperud, Hilde Molvig

2018-01-01

Abstract BPA has been reported to leach from some resin based dental restorative materials and materials used for orthodontic treatment. To confirm and update previous findings, especially in light of the new temporary lower threshold value for tolerable daily BPA intake, we have investigated the leaching of BPA from 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials. The materials were either uncured and dissolved in methanol or cured. The cured materials were kept in deionized water for 24 hours or 2 weeks. Samples were subsequently analyzed by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS-MS). The composite filling material Tetric EvoFlow® and the fissure sealant DELTON® showed significantly higher levels of BPA leaching compared to control samples for all test conditions (uncured, 24 h leaching and 2 weeks leaching). There were no significant differences in amount of leached BPA for any of the tested materials after 24 hours compared to 2 weeks. These results show that BPA is still released from some dental materials despite the general concern about potential adverse effects of BPA. However, the amounts of BPA were relatively low and most likely represent a very small contribution to the total BPA exposure. PMID:29868625

Non-declarative sequence learning does not show savings in relearning.

Science.gov (United States)

Keisler, Aysha; Willingham, Daniel T

2007-04-01

Researchers have utilized the savings in relearning paradigm in a variety of settings since Ebbinghaus developed the tool over a century ago. In spite of its widespread use, we do not yet understand what type(s) of memory are measurable by savings. Specifically, can savings measure both declarative and non-declarative memories? The lack of conscious recollection of the encoded material in some studies indicates that non-declarative memories may show savings effects, but as all studies to date have used declarative tasks, we cannot be certain. Here, we administer a non-declarative task and then measure savings in relearning the material declaratively. Our results show that while material outside of awareness may show savings effects, non-declarative sequence memory does not. These data highlight the important distinction between memory without awareness and non-declarative memory.

Properties of nanoclay PVA composites materials

Directory of Open Access Journals (Sweden)

Mohamed H. M. Ali

2012-03-01

Full Text Available Polyvinyl alcohol (PVA/ Na-rich Montmorillonite (MMT nanocomposites were prepared using solution method to create polymer-clay nanocomposite (PCN material. The PCN material was studied using X-ray diffraction (XRD, demonstrating polymer-clay intercalation that has a high d-spacing (lower diffraction angles in the PCN XRD pattern, compared to the pure MMT clay XRD pattern, which has a low d-spacing (high diffraction angles. The nano-scanning electron microscope (NSEM was used to study the morphological image of the PVA, MMT and PCN materials. The results showed that intercalation that took place between the PVA and MMT produced the PCN material. The mechanical properties of the pure PVA and the intercalated polymer material were studied. It was found that the small amount of MMT clay made the tensile modulus and percentage of the total elongation of the nano-composite significantly higher than the pure PVA polymer value, due to polymer-clay intercalation. The thermal stability of the intercalated polymer has been studied using thermal analytical techniques such as thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The results showed that the PCN material is more thermally stable than the pure PVA polymer.

Hyperspectral surface materials map of quadrangles 3666 and 3766, Balkh (219), Mazar-e Sharif (220), Qarqin (213), and Hazara Toghai (214) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Materials Characterization and Microelectronic Implementation of Metal-insulator Transition Materials and Phase Change Materials

Science.gov (United States)

2015-03-26

materials like crystalline semiconductors, graphene , and composites, the materials discussed here could have a significant impact. This thesis investigates...diagnosis [124], crystallinity of pharmaceutical materials [125], materials diagnosis for restoration of paintings [126], and materials research [127...temperature dots and paint were placed on samples on the substrate. Temperature dots are typically used in the transportation of goods such as food in order

Memory for biopsychology material presented in comic book format.

OpenAIRE

Aleixo, Paul; Sumner, Krystina

2017-01-01

This study investigated the influence of format of presentation on memory for undergraduate level Biopsychology material. Ninety participants read either seven comic book pages from Aleixo and Baillon (2008) explaining the rudiments of sleep, the same material presented in text only format or seven pages where the original images were replaced with random incongruous images. Participants were tested on the material using ten multiple-choice questions. Results showed significantly higher memor...

Four-phonon scattering significantly reduces intrinsic thermal conductivity of solids

Science.gov (United States)

Feng, Tianli; Lindsay, Lucas; Ruan, Xiulin

2017-10-01

For decades, the three-phonon scattering process has been considered to govern thermal transport in solids, while the role of higher-order four-phonon scattering has been persistently unclear and so ignored. However, recent quantitative calculations of three-phonon scattering have often shown a significant overestimation of thermal conductivity as compared to experimental values. In this Rapid Communication we show that four-phonon scattering is generally important in solids and can remedy such discrepancies. For silicon and diamond, the predicted thermal conductivity is reduced by 30% at 1000 K after including four-phonon scattering, bringing predictions in excellent agreement with measurements. For the projected ultrahigh-thermal conductivity material, zinc-blende BAs, a competitor of diamond as a heat sink material, four-phonon scattering is found to be strikingly strong as three-phonon processes have an extremely limited phase space for scattering. The four-phonon scattering reduces the predicted thermal conductivity from 2200 to 1400 W/m K at room temperature. The reduction at 1000 K is 60%. We also find that optical phonon scattering rates are largely affected, being important in applications such as phonon bottlenecks in equilibrating electronic excitations. Recognizing that four-phonon scattering is expensive to calculate, in the end we provide some guidelines on how to quickly assess the significance of four-phonon scattering, based on energy surface anharmonicity and the scattering phase space. Our work clears the decades-long fundamental question of the significance of higher-order scattering, and points out ways to improve thermoelectrics, thermal barrier coatings, nuclear materials, and radiative heat transfer.

75 FR 69138 - Environmental Assessment and Finding of No Significant Impact Related to Exemption of Material...

Science.gov (United States)

2010-11-10

... Installation was completed, and the decontamination and dismantlement phase of HBPP Unit 3 decommissioning..., building materials, and soil debris from Unit 3. The waste would be transported by truck from HBPP in... concrete, steel, insulation, roofing material, gravel and other metal, wood and soil debris generated...

Apparent diffusion coefficient ratio correlates significantly with prostate cancer gleason score at final pathology

DEFF Research Database (Denmark)

Boesen, Lars; Chabanova, Elizaveta; Løgager, Vibeke

2015-01-01

PURPOSE: To evaluate the correlation between apparent diffusion coefficient measurements (ADCtumor and ADCratio ) and the Gleason score from radical prostatectomy specimens. MATERIALS AND METHODS: Seventy-one patients with clinically localized prostate cancer scheduled for radical prostatectomy...... correlated with the Gleason score from the prostatectomy specimens. RESULTS: The association between ADC measurements and Gleason score showed a significant negative correlation (P ... ) and 0.90 (ADCratio ) when discriminating Gleason score ≤7(3+4) from Gleason score ≥7(4+3). CONCLUSION: ADC measurements showed a significant correlation with tumor Gleason score at final pathology. The ADCratio demonstrated the best correlation compared to the ADCtumor value and radically improved...

Toxicity Testing of Restorative Dental Materials Using Brine Shrimp Larvae (Artemia salina

Directory of Open Access Journals (Sweden)

Manar M. Milhem

2008-08-01

Full Text Available This study investigated the effect of extracts of different composites, glass ionomer cement (GICs and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy, a conventional GIC (Ketac-Fil, a resin-modified glass ionomer cement (Vitremer, two compomers (F2000; Dyract AP, and a flowable compomer (Dyract Flow were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively. One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001. Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (α =0.05 showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100% lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001. Follow-up comparison between the groups by Tukey's test (α = 0.05 showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.

The first F-ring modified ciguatoxin analogue showing significant toxicity.

Science.gov (United States)

Ishihara, Yuuki; Lee, Nayoung; Oshiro, Naomasa; Matsuoka, Shigeru; Yamashita, Shuji; Inoue, Masayuki; Hirama, Masahiro

2010-05-07

Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are potent neurotoxic polycyclic ethers. We report herein the total synthesis of a 10-membered F-ring analogue of 51-hydroxyCTX3C, which constitutes the first example of an F-ring modified ciguatoxin that exhibits potent cytotoxicity as well as mouse acute toxicity.

Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1995: Volume 14, Numbers 3 and 4, Part 3

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1995: Volume 14, Numbers 3 and 4, Part 3

International Nuclear Information System (INIS)

1996-02-01

This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Effect of phase change material on the heat transfer rate of different building materials

Science.gov (United States)

Hasan, Mushfiq; Alam, Shahnur; Ahmed, Dewan Hasan

2017-12-01

Phase change material (PCM) is widely known as latent heat storage. A comprehensive study is carried out to investigate the effect of PCM on heat transfer rate of building materials. Paraffin is used as PCM along with different conventional building materials to investigate the heat transfer rate from the heated region to the cold region. PCM is placed along with the three different types of building materials like plaster which is well know building material in urban areas and wood and straw which are commonly used in rural areas for roofing as well as wall panel material and investigated the heat transfer rate. An experimental setup was constructed with number of rectangular shape aluminum detachable casing (as cavity) and placed side by side. Series of rectangular cavity filled with convent ional building materials and PCM and these were placed in between two chambers filled with water at different temperature. Building materials and PCM were placed in different cavities with different combinations and investigated the heat transfer rate. The results show that using the PCM along with other building materials can be used to maintain lower temperature at the inner wall and chamber of the cold region. Moreover, the placement or orientation of the building materials and PCM make significant contribution to heat transfer rate from the heated zone to the cold zone.

Proceedings of DAE-BRNS national workshop on materials chemistry: functional materials

International Nuclear Information System (INIS)

2011-12-01

Design and development of materials with tailored properties assumes great significance in our everyday life and are crucial to modern technologies. Chemistry has had a tremendous Convener role in developing several need based materials by integrating multiple functionalities. The year 2011, being recognised as the International Year of Chemistry by the UNESCO, assumes further significance for material chemists. In view of the renowned interest in advanced functional materials, the Society for Materials Chemistry, India together with Chemistry Division, BARC has taken an initiative to organise this National Workshop on Materials Chemistry (NWMC-2011) under the theme 'Functional Materials (FUN-MAT)'. NWMC- 2011 aims to provide a forum for young researchers to interact with experts involved in synthesis, processing and applications of various advanced functional materials. In particular, recent developments and future prospects of magnetic, electronic and optical materials, glasses, ceramics, soft materials, materials for sensors, materials for hydrogen production and storage etc. will be addressed in this workshop. Papers relevant to INIS are indexed separately

Significance of Shrinkage Induced Clamping Pressure in Fiber-Matrix Bonding in Cementitious Composite Materials

DEFF Research Database (Denmark)

Stang, Henrik

1996-01-01

used in high performance cementitious composite materials.Assuming a Coulomb type of friction on the fiber/matrix interface andusing typical values for the frictional coefficient it is shownthat the shrinkage induced clamping pressure could be one of the mostimportant factors determining the frictional...

Enforcement actions: Significant actions resolved, material licensees (non-medical). Quarterly progress report, July--September 1994: Volume 13, Number 3, Part 3

International Nuclear Information System (INIS)

1994-12-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees (non-medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated the managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Enforcement actions: Significant actions resolved material licensees (non-medical). Volume 14, No. 1, Part 3, Quarterly progress report, January--March 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to Material Licensees (non-Medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

Enforcement actions: Significant actions resolved material licensees (non-medical). Volume 14, No. 1, Part 3, Quarterly progress report, January--March 1995

International Nuclear Information System (INIS)

1995-05-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to Material Licensees (non-Medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

Demineralized dentin matrix composite collagen material for bone tissue regeneration.

Science.gov (United States)

Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

2013-01-01

Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

Natural radioactivity in building materials in the European Union: a database and an estimate of radiological significance.

Science.gov (United States)

Trevisi, R; Risica, S; D'Alessandro, M; Paradiso, D; Nuccetelli, C

2012-02-01

The authors set up a database of activity concentration measurements of natural radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) in building material. It contains about 10,000 samples of both bulk material (bricks, concrete, cement, natural- and phosphogypsum, sedimentary and igneous bulk stones) and superficial material (igneous and metamorphic stones) used in the construction industry in most European Union Member States. The database allowed the authors to calculate the activity concentration index I--suggested by a European technical guidance document and recently used as a basis for elaborating the draft Euratom Basic Safety Standards Directive--for bricks, concrete and phosphogypsum used in the European Union. Moreover, the percentage could be assessed of materials possibly subject to restrictions, if either of the two dose criteria proposed by the technical guidance were to be adopted. Copyright © 2011 Elsevier Ltd. All rights reserved.

Consumption of pornographic materials among Hong Kong early adolescents: a replication.

Science.gov (United States)

Shek, Daniel T L; Ma, Cecilia M S

2012-01-01

Consumption of pornographic materials was examined in 3,638 secondary 2 students in Hong Kong. Results showed that over 80% of the respondents had never consumed pornographic materials in the past year. Internet pornography was the most common medium that adolescents used when viewing pornographic materials. Males reported a higher level of pornography consumption than did females. Participants who were born in mainland China were more likely to consume pornographic materials than their Hong Kong counterparts. Regardless of the types of pornographic materials, the levels of pornography consumption significantly increased over time. Results also showed that higher levels of positive youth development and better family functioning were concurrently related to a lower level of pornography consumption at secondary 2. The relative contribution of positive youth development and family factors to pornographic material consumption was also explored.

Analyses of significant features of L-Prolinium Picrate single crystal: An excellent material for non linear optical applications

Energy Technology Data Exchange (ETDEWEB)

Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi, 110012 (India); CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vij, Mahak [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Nagaraja, C.M. [Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, 140001, Punjab (India); Jayaramakrishnan, V. [Centro De Investigations En Optica, Loma del Bosque 115, Colonia Lomas del Campestre, León, Guanajuato, Código Postal, 37150 (Mexico); Jayalakshmy, M.S. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, 686560 (India); Kant, Rajni [Department of Physics and Electronics, University of Jammu, Jammu Tawi, 180006 (India)

2017-06-15

Today the fundamental aspect of the researchers is to explore maximum physical properties of the material for device fabrication. In the present article, single crystal X-ray diffraction has been carried out to verify the formation of the synthesized compound. In addition to that, powder X-ray diffraction has been performed to obtain diffraction pattern of L-Prolinium Picrate single crystal. The strain present inside the single crystal was measured using Hall-Williamson equation from PXRD measurements. The dark current and photon current was obtained from photoconductivity technique whose plot depicted that the sample was negative photoconducting material. Optical homogeneity of the single crystal was analyzed using birefringence technique. Its resistance towards Nd: YAG laser was scrutinized for L-Prolinium Picrate single crystal by applying 1 pulse per second. Different thermal parameters like thermal conductivity, thermal diffusivity, thermal effusivity and specific heat were computed using photo-pyroelectric technique. Solid state parameters were calculated from Clausius Mossotti relation by taking structural information of the title compound. Also, optical parameters like refractive index, reflectance etc were calculated through UV–Vis–NIR analysis. - Highlights: • An optically transparent L-Prolinium Picrate single crystal was harvested from slow evaporation solution growth technique. • The compound shows negative photoconducting nature. • Its optical homogeneity was analyzed using birefringence. • Single shot of laser was applied to sample to measure laser damage threshold value. • The thermal parameters were computed from Photopyroelectric technique.

76 FR 34273 - Environmental Assessment and Finding of No Significant Impact for Special Nuclear Material...

Science.gov (United States)

2011-06-13

... Nuclear Material, TVA applied for an SNM license by application dated November 12, 2009 (ML100120487). The..., including site geography, demographics, meteorology, hydrology, and geology. The proposed activity is...

Automated material interface (AMI) for mini-environment technology

International Nuclear Information System (INIS)

Wolf, M.; Fleming, J.; Mueller, R.; Pulaski, L.

1993-01-01

The Automated Material Inter-face or AMI presented here is a new method of automating the input/output of materials or products into mini-environments. The AMI concept and hardware, and preliminary data are presented to show that neither the automation hardware nor the product isolation carrier contribute any significant contamination to the product during the I/O process. Budgetary estimates are presented which support the AMI concept for cost effective manufacturing of advanced semiconductors and disk media

Biofertilizers for the revegetation of coal overburden dumps top materials

Energy Technology Data Exchange (ETDEWEB)

Nikhil, K. [Central Mining Research Institute, Dhanbad (India). Environmental Management Group

2001-07-01

Adding and improving nutrient status of overburden dump top material through biofertilizer for supporting vegetation and for sustainable spoil development, a pot experiment was conducted. In this, two bio-fertilizers namely bactin and phosphin in three doses were applied on overburden dump top material kept in pots growing two grass species. The growths were compared with control on dump and soil both. Results shows that overburden dump amended with bio-fertilizer at lowest dose have significant increase in growth over the control of dump material and soil in vetiver grass but failed to shows the same result in lemon grass. This may be due to different growth behaviour of the grasses. 14 refs., 2 tabs.

Characterization of temperature-dependent optical material properties of polymer powders

Energy Technology Data Exchange (ETDEWEB)

Laumer, Tobias [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); SAOT Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany); Stichel, Thomas; Bock, Thomas; Amend, Philipp [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany); Schmidt, Michael [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); University of Erlangen-Nürnberg, Institute of Photonic Technologies, 91052 Erlangen (Germany); SAOT Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany)

2015-05-22

In former works, the optical material properties of different polymer powders used for Laser Beam Melting (LBM) at room temperature have been analyzed. With a measurement setup using two integration spheres, it was shown that the optical material properties of polymer powders differ significantly due to multiple reflections within the powder compared to solid bodies of the same material. Additionally, the absorption behavior of the single particles shows an important influence on the overall optical material properties, especially the reflectance of the powder bed. Now the setup is modified to allow measurements at higher temperatures. Because crystalline areas of semi-crystalline thermoplastics are mainly responsible for the absorption of the laser radiation, the influence of the temperature increase on the overall optical material properties is analyzed. As material, conventional polyamide 12 and polypropylene as new polymer powder material, is used. By comparing results at room temperature and at higher temperatures towards the melting point, the temperature-dependent optical material properties and their influence on the beam-matter interaction during the process are discussed. It is shown that the phase transition during melting leads to significant changes of the optical material properties of the analyzed powders.

Hyperspectral surface materials map of quadrangles 3360 and 3460, Kawir-e Naizar (413), Kohe-Mahmudo-Esmailjan (414), Kol-e Namaksar (407), and Ghoriyan (408) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan.Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines.The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Nanostructured composite reinforced material

Science.gov (United States)

Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

2012-07-31

A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

Functional Biomass Carbons with Hierarchical Porous Structure for Supercapacitor Electrode Materials

International Nuclear Information System (INIS)

Chen, Hao; Liu, Duo; Shen, Zhehong; Bao, Binfu; Zhao, Shuyan; Wu, Limin

2015-01-01

Highlights: • We successfully prepared bamboo-derived porous carbon with B and N co-doping. • This novel carbon exhibits significantly enhanced specific capacitance and energy density. • The highest specific capacitance exceeds those of most similar carbon materials. • Asymmetric supercapacitor based on this carbon shows satisfactory capacitive performance. - Abstract: This paper presents nitrogen and boron co-doped KOH-activated bamboo-derived carbon as a porous biomass carbon with utility as a supercapacitor electrode material. Owing to the high electrochemical activity promoted by the hierarchical porous structure and further endowed by boron and nitrogen co-doping, electrodes based on the as-obtained material exhibit significantly enhanced specific capacitance and energy density relative to those based on most similar materials. An asymmetric supercapacitor based on this novel carbon material demonstrated satisfactory energy density and electrochemical cycling stability.

Radiological dose assessment of naturally occurring radioactive materials in concrete building materials

International Nuclear Information System (INIS)

Amran AB Majid; Aznan Fazli Ismail; Muhamad Samudi Yasir; Redzuwan Yahaya; Ismail Bahari

2013-01-01

Previous studies have shown that the natural radioactivity contained in building materials have significantly influenced the dose rates in dwelling. Exposure to natural radiation in building has been of concerned since almost 80 % of our daily live are spend indoor. Thus, the aim of the study is to assess the radiological risk associated by natural radioactivity in soil based building materials to dwellers. A total of 13 Portland cement, 46 sand and 43 gravel samples obtained from manufacturers or bought directly from local hardware stores in Peninsular of Malaysia were analysed for their radioactivity concentrations. The activity concentrations of 226 Ra, 232 Th and 40 K in the studied building materials samples were found to be in the range of 3.7-359.3, 2.0-370.8 and 10.3-1,949.5 Bq kg -1 respectively. The annual radiation dose rates (μSv year -1 ) received by dwellers were evaluated for 1 to 50 years of exposure using Resrad-Build Computer Code based on the activity concentration of 226 Ra, 232 Th and 40 K found in the studied building material samples. The rooms modelling were based on the changing parameters of concrete wall thickness and the room dimensions. The annual radiation dose rates to dwellers were found to increase annually over a period of 50 years. The concrete thicknesses were found to have significantly influenced the dose rates in building. The self-absorption occurred when the concrete thickness was thicker than 0.4 m. Results of this study shows that the dose rates received by the dwellers of the building are proportional to the size of the room. In general the study concludes that concrete building materials; Portland cements, sands, and gravels in Peninsular of Malaysia does not pose radiological hazard to the building dwellers. (author)

Important physical properties of peat materials

Science.gov (United States)

D.H. Boelter

1968-01-01

Peat materials from 12 bogs in northern Minnesota, U.S.A., showed significant differences in physical properties. It is pointed out that 1) these properties can be related to the hydrology of organic soils only if the soils represent undisturbed field conditions, and 2) volumetric expressions of water content are necessary to correctly evaluate the amount of water in a...

COMPARATIVE ANALYSIS OF WATER SORPTION BY DIFFERENT ACRYLIC MATERIALS

Directory of Open Access Journals (Sweden)

Milena Kostić

2014-06-01

Full Text Available Acrylic materials are used daily for the production of mobile dental restorations and orthodontic appliances. The presence of residual monomer, as a product of incomplete polymerisation of material, results in more porous structure of the material, which greatly reduces the mechanical and physical quality of the acrylic restorations and increases the absorption of liquids. The aim of this study was to examine the water absorption of different types of resin material. In the study it was assumed that the cold polymerized acrylates show a greater potential for absorbing fluid from the environment in relation to the hot polymerized acrylic. The study included two hot and two cold polymerized acrylates, and cold polymerized acrylate impregnated with aesthetic pearls. In order to determine the degree of water absorption, the mass of the samples was measured before and after one day, seven days and thirty days of immersion in a water bath of body temperature. The tested hot and cold polymerized acrylates after immersion in water bath showed standard values of water absorption. The degree of water absorption was not significantly influenced by the type and manner of polymerisation. Water absorption values were significantly higher after seven days and thirty days of water storage relative to the observational period of one day.

Human microRNA oncogenes and tumor suppressors show significantly different biological patterns: from functions to targets.

Directory of Open Access Journals (Sweden)

Dong Wang

Full Text Available MicroRNAs (miRNAs are small noncoding RNAs which play essential roles in many important biological processes. Therefore, their dysfunction is associated with a variety of human diseases, including cancer. Increasing evidence shows that miRNAs can act as oncogenes or tumor suppressors, and although there is great interest in research into these cancer-associated miRNAs, little is known about them. In this study, we performed a comprehensive analysis of putative human miRNA oncogenes and tumor suppressors. We found that miRNA oncogenes and tumor suppressors clearly show different patterns in function, evolutionary rate, expression, chromosome distribution, molecule size, free energy, transcription factors, and targets. For example, miRNA oncogenes are located mainly in the amplified regions in human cancers, whereas miRNA tumor suppressors are located mainly in the deleted regions. miRNA oncogenes tend to cleave target mRNAs more frequently than miRNA tumor suppressors. These results indicate that these two types of cancer-associated miRNAs play different roles in cancer formation and development. Moreover, the patterns identified here can discriminate novel miRNA oncogenes and tumor suppressors with a high degree of accuracy. This study represents the first large-scale bioinformatic analysis of human miRNA oncogenes and tumor suppressors. Our findings provide help for not only understanding of miRNAs in cancer but also for the specific identification of novel miRNAs as miRNA oncogenes and tumor suppressors. In addition, the data presented in this study will be valuable for the study of both miRNAs and cancer.

Plasma-wall interaction of advanced materials

Directory of Open Access Journals (Sweden)

J.W. Coenen

2017-08-01

Full Text Available DEMO is the name for the first stage prototype fusion reactor considered to be the next step after ITER. For the realization of fusion energy especially materials questions pose a significant challenge already today. Advanced materials solution are under discussion in order to allow operation under reactor conditions [1] and are already under development used in the next step devices. Apart from issues related to material properties such as strength, ductility, resistance against melting and cracking one of the major issues to be tackled is the interaction with the fusion plasma. Advanced tungsten (W materials as discussed below do not necessarily add additional lifetime issues, they will, however, add concerns related to erosion or surface morphology changes due to preferential sputtering. Retention of fuel and exhaust species are one of the main concerns. Retention of hydrogen will be one of the major issues to be solved in advanced materials as especially composites and alloys will introduce new hydrogen interactions mechanisms. Initial calculations show these mechanisms. Especially for Helium as the main impurity species material issues arise related to surfaces modification and embrittlement. Solutions are proposed to mitigate effects on material properties and introduce new release mechanisms.

Scaling and universality in magnetocaloric materials

DEFF Research Database (Denmark)

Smith, Anders; Nielsen, Kaspar Kirstein; Bahl, Christian R. H.

2014-01-01

-order phase transition within the context of the theory of critical phenomena. Sufficiently close to the critical temperature of a second-order material, the scaling of the isothermal entropy change will be determined by the critical exponents and will be the same as that of the singular part of the entropy......The magnetocaloric effect of a magnetic material is characterized by two quantities, the isothermal entropy change and the adiabatic temperature change, both of which are functions of temperature and applied magnetic field. We discuss the scaling properties of these quantities close to a second...... fields are not universal, showing significant variation for models in the same universality class. As regards the adiabatic temperature change, it is not determined exclusively by the singular part of the free energy and its derivatives. We show that the field dependence of the adiabatic temperature...

CT classification and clinical significance of rupture globe

International Nuclear Information System (INIS)

Diao Jinzhong; Zhang Guixiang

1998-01-01

Purpose: To discuss CT appearances of the rupture globe, and CT classifications and their clinical significance. Materials and methods: Forty-nine rupture globes were verified; 79% patents were scanned within 24 hours. Axial plane scanning were done with 3 mm slice and 256 x 256 matrix. Bone and soft tissue conditions were adjusted to analyse the bone and globe structures. Results: CT showed that globe circle rupture in one point of 32%, two points of 20%, and multiple points of 28%. Thickening of globe circle was as follows: 5 mm in 10 globes, 6 mm in 24, and 7 mm in 9.20% injured globes were enlarged and 32% were contracted. 14 anterior chambers deepened more than 4 mm. 83% rupture globes also had intraglobe hemorrhage and 48% foreign bodies. 28% injured globes had exophthalmus, and 75% had injured parasinuses or orbits, or brain trauma. Conclusion: The authors classified the rupture globe into three types. Type III showed unrepaired that should ablate the injured globes, whereas type I and II had to repair and to debride

Materials Science | NREL

Science.gov (United States)

microscopy and imaging science, interfacial and surface science, materials discovery, and thin-film material Science Materials Science Illustration with bottom row showing a ball-and-stick model and top row dense black band. State-of-the-art advances in materials science come from a combination of experiments

Educational Outreach: The Space Science Road Show

Science.gov (United States)

Cox, N. L. J.

2002-01-01

The poster presented will give an overview of a study towards a "Space Road Show". The topic of this show is space science. The target group is adolescents, aged 12 to 15, at Dutch high schools. The show and its accompanying experiments would be supported with suitable educational material. Science teachers at schools can decide for themselves if they want to use this material in advance, afterwards or not at all. The aims of this outreach effort are: to motivate students for space science and engineering, to help them understand the importance of (space) research, to give them a positive feeling about the possibilities offered by space and in the process give them useful knowledge on space basics. The show revolves around three main themes: applications, science and society. First the students will get some historical background on the importance of space/astronomy to civilization. Secondly they will learn more about novel uses of space. On the one hand they will learn of "Views on Earth" involving technologies like Remote Sensing (or Spying), Communication, Broadcasting, GPS and Telemedicine. On the other hand they will experience "Views on Space" illustrated by past, present and future space research missions, like the space exploration missions (Cassini/Huygens, Mars Express and Rosetta) and the astronomy missions (Soho and XMM). Meanwhile, the students will learn more about the technology of launchers and satellites needed to accomplish these space missions. Throughout the show and especially towards the end attention will be paid to the third theme "Why go to space"? Other reasons for people to get into space will be explored. An important question in this is the commercial (manned) exploration of space. Thus, the questions of benefit of space to society are integrated in the entire show. It raises some fundamental questions about the effects of space travel on our environment, poverty and other moral issues. The show attempts to connect scientific with

Novel antibacterial mouthguard material manufactured using silver-nanoparticleembedded ethylene-vinyl acetate copolymer masterbatch.

Science.gov (United States)

Yoshida, Yuriko; Churei, Hiroshi; Takeuchi, Yasuo; Wada, Takahiro; Uo, Motohiro; Izumi, Yuichi; Ueno, Toshiaki

2018-01-26

The purpose of the present study was to develop an antibacterial mouthguard (MG) material using a masterbatch of silvernanoparticle-embedded ethylene-vinyl acetate (EVA) copolymers. In order to verify that the testing material was clinically applicable as an antibacterial MG material, we conducted an antibacterial test, a shock absorption test, and analysis of in vitro silver release. The colony-forming activity of Streptococcus sobrinus, Porphyromonas gingivalis, and Escherichia coli were significantly inhibited on the testing materials compared with the commercial EVA sheet (p<0.05). The shock absorption capability of the testing material was not significantly different from that of the commercial EVA sheet. Cumulative silver release (in pure water) from the testing materials were infinitesimal after soaking for 20 days, which implied that there could be no harm in wearing the MG during exercise. These results showed that this testing material could be clinically applicable as an antibacterial MG material.

Flexible-CMOS and biocompatible piezoelectric AlN material for MEMS applications

International Nuclear Information System (INIS)

Jackson, Nathan; Keeney, Lynette; Mathewson, Alan

2013-01-01

The development of a CMOS compatible flexible piezoelectric material is desired for numerous applications and in particular for biomedical MEMS devices. Aluminum nitride (AlN) is the most commonly used CMOS compatible piezoelectric material, which is typically deposited on Si in order to enhance the c-axis (002) crystal orientation which gives AlN its high piezoelectric properties. This paper reports on the successful deposition of AlN on polyimide (PI-2611) material. The AlN deposited has a FWHM (002) value of 5.1° and a piezoelectric d 33 value of 1.12 pm V −1 , and SEM images show high quality columnar grains. The highly crystalline AlN material is due to the semi-crystalline properties of the polyimide film used. Cytotoxicity testing showed the AlN/polyimide material to be non-toxic to 3T3 cells and primary neurons. Surface properties of the AlN/polyimide film were evaluated as they have a significant effect on the adhesion of cells to the film. The results show neurons adhering to the AlN surface. The results of this paper show the characterization of a new flexible-CMOS and biocompatible AlN/polyimide material for MEMS devices with improved crystallinity and piezoelectric properties. (paper)

Effect of the raw materials processing on their dustiness

International Nuclear Information System (INIS)

López Lilaoa, A.; Juárezb, M.; Sanfelix Fornera, V.; Mallol Gascha, G.; Monfort Gimeno, E.

2017-01-01

During the handling and/or processing of powdered materials in the CERAMICS INDUSTRY, one of the most important risks regarding the environmental and occupational health is the potential generation of dust. In this regard, a parameter of great interest is the dustiness of the processed materials; this parameter quantifies the tendency of the powdered materials to generate dust when handled. In this study, to determine the dustiness of a ceramic raw material composition (mixture of the body raw materials), the continuous drop method has been used. This test apparatus was selected because it is considered to better simulate how ceramic materials are handled in the CERAMICS INDUSTRY. The obtained results show that the dustiness of the same ceramic composition exhibits significant changes during the manufacturing process, depending on the presentation form. In this regard, the dry milling sample presents the highest dustiness, which can be significantly reduced (>75%) applying the the moisturization and agglomeration. The obtained results also shown that the best presentation form, regarding the minimization of the dust generation, is achieved in the spray-drying process, where the dustiness is reduced by 95%. [es

Intracerebral metastasis showing restricted diffusion: Correlation with histopathologic findings

Energy Technology Data Exchange (ETDEWEB)

Duygulu, G. [Radiology Department, Ege University Medicine School, Izmir (Turkey); Ovali, G. Yilmaz [Radiology Department, Celal Bayar University Medicine School, Manisa (Turkey)], E-mail: gulgun.yilmaz@bayar.edu.tr; Calli, C.; Kitis, O.; Yuenten, N. [Radiology Department, Ege University Medicine School, Izmir (Turkey); Akalin, T. [Pathology Department, Ege University Medicine School, Izmir (Turkey); Islekel, S. [Neurosurgery Department, Ege University Medicine School, Izmir (Turkey)

2010-04-15

Objective: We aimed to detect the frequency of restricted diffusion in intracerebral metastases and to find whether there is correlation between the primary tumor pathology and diffusion-weighted MR imaging (DWI) findings of these metastases. Material and methods: 87 patients with intracerebral metastases were examined with routine MR imaging and DWI. 11 hemorrhagic metastatic lesions were excluded. The routine MR imaging included three plans before and after contrast enhancement. The DWI was performed with spin-echo EPI sequence with three b values (0, 500 and 1000), and ADC maps were calculated. 76 patients with metastases were grouped according to primary tumor histology and the ratios of restricted diffusion were calculated according to these groups. ADCmin values were measured within the solid components of the tumors and the ratio of metastases with restricted diffusion to that which do not show restricted diffusion were calculated. Fisher's exact and Mann-Whitney U tests were used for the statistical analysis. Results: Restricted diffusion was observed in a total of 15 metastatic lesions (19, 7%). Primary malignancy was lung carcinoma in 10 of these cases (66, 6%) (5 small cell carcinoma, 5 non-small cell carcinoma), and breast carcinoma in three cases (20%). Colon carcinoma and testicular teratocarcinoma were the other two primary tumors in which restricted diffusion in metastasis was detected. There was no statistical significant difference between the primary pathology groups which showed restricted diffusion (p > 0.05). ADCmin values of solid components of the metastasis with restricted diffusion and other metastasis without restricted diffusion also showed no significant statistical difference (0.72 {+-} 0.16 x 10{sup -3} mm{sup 2}/s and 0.78 {+-} 21 x 10{sup -3} mm{sup 2}/s respectively) (p = 0.325). Conclusion: Detection of restricted diffusion on DWI in intracerebral metastasis is not rare, particularly if the primary tumor is lung or breast

Brazing of special metallic materials and material combinations using a special material

International Nuclear Information System (INIS)

Lison, R.

1981-01-01

The special materials include metals of groups IVa, Va and VIa of the periodic tables and their alloys. Their particular properties have won them applications in many highly specialized industries. For these materials to be used, mastery of thermal joining methods appropriate to their characteristics is necessary. High-temperature brazing is one such method for joining special materials. This paper presents variants of this technique suitable for each individual special material. Compatibility tests between various brazing metals and various special materials have been carried out by simulating the temperature/time cycle involved in brazing procedures. Special materials are relatively expensive, and their special properties are not required at every point in a structure: elsewhere they can be replaced by a different special material or by other metals or alloys. This means that joints must be made between two special materials or between a special material and a conventional material. When certain conditions are fulfilled, such joins can be made by high-temperature brazing. This paper also shows the extent to which the geometry of the join determines the choice of process. Example of applications are also given. (orig.)

Edge strength of CAD/CAM materials.

Science.gov (United States)

Pfeilschifter, Maria; Preis, Verena; Behr, Michael; Rosentritt, Martin

2018-05-16

To investigate the edge force of CAD/CAM materials as a function of (a) material, (b) thickness, and (c) distance from the margin. Materials intended for processing with CAD/CAM were investigated: eight resin composites, one resin-infiltrated ceramic, and a clinically proven lithiumdisilicate ceramic (reference). To measure edge force (that is, load to failure/crack), plates (d = 1 mm) were fixed and loaded with a Vickers diamond indenter (1 mm/min, Zwick 1446) at a distance of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm from the edge. Edge force was defined as a loading force at a distance of 0.5 mm. The type of failure was determined. To investigate the influence of the thickness, all data were determined on 1-mm and 2-mm plates. To test the influence of bonding and an underlying dentin, individual 1-mm plates were bonded to a 1-mm-thick dentin-like (concerning modulus of elasticity) resin composite. For the 1-mm plates, edge force varied between 64.4 ± 24.2 N (Shofu Block HC) and 183.2 ± 63.3 N (ceramic reference), with significant (p ≤ 0.001) differences between the materials. For the 2-mm plates, values between 129.2 ± 32.5 N (Lava Ultimate) and 230.3 ± 67.5 N (Cerasmart) were found. Statistical comparison revealed no significant differences (p > 0.109) between the materials. Brilliant Crios (p = 0.023), Enamic (p = 0.000), Shofu Blocks HC (p = 0.009), and Grandio Bloc (p = 0.002) showed significantly different edge force between the 1-mm- and 2-mm-thick plates. The failure pattern was either cracking, (severe) chipping, or fracture. Material, material thickness, and distance from the edge impact the edge force of CAD/CAM materials. CAD/CAM materials should be carefully selected on the basis of their individual edge force and performance during milling. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthetic bone substitute material comparable with xenogeneic material for bone tissue regeneration in oral cancer patients: First and preliminary histological, histomorphometrical and clinical results.

Science.gov (United States)

Ghanaati, Shahram; Barbeck, Mike; Lorenz, Jonas; Stuebinger, Stefan; Seitz, Oliver; Landes, Constantin; Kovács, Adorján F; Kirkpatrick, Charles J; Sader, Robert A

2013-07-01

The present study was first to evaluate the material-specific cellular tissue response of patients with head and neck cancer to a nanocrystalline hydroxyapatite bone substitute NanoBone (NB) in comparison with a deproteinized bovine bone matrix Bio-Oss (BO) after implantation into the sinus cavity. Eight patients with tumor resection for oral cancer and severely resorbed maxillary bone received materials according to a split mouth design for 6 months. Bone cores were harvested prior to implantation and analyzed histologically and histomorphometrically. Implant survival was followed-up to 2 years after placement. Histologically, NB underwent a higher vascularization and induced significantly more tartrate-resistant acid phosphatase-positive (TRAP-positive) multinucleated giant cells when compared with BO, which induced mainly mononuclear cells. No significant difference was observed in the extent of new bone formation between both groups. The clinical follow-up showed undisturbed healing of all implants in the BO-group, whereas the loss of one implant was observed in the NB-group. Within its limits, the present study showed for the first time that both material classes evaluated, despite their induction of different cellular tissue reactions, may be useful as augmentation materials for dental and maxillofacial surgical applications, particularly in patients who previously had oral cancer.

Influence of training and competitive sessions on peripheral β-endorphin levels in training show jumping horses

Directory of Open Access Journals (Sweden)

Cristina Cravana

2017-01-01

Full Text Available Aim: To investigate the effects of training sessions on circulating β-endorphin changes in sport horses before and after competition and to ascertain whether competition would affect this response. Materials and Methods: A total of 24 trained jumping horses were randomly assigned to one of two training groups: Group A (competing and Group B (not competing. To determined plasma β-endorphin concentrations, two pre- and postcompetition training weeks at aerobic workout and two competitive show jumping event days at anaerobic workout were measured before, 5 and 30 min after exercise. Exercise intensity is described using lactate concentrations and heart rate. The circuit design, intensity, and duration of training sessions were the same for both groups. Results: In Group A, one-way analysis of variance for repeated measures (RM-ANOVA showed significant effects of exercise on β-endorphin changes (F=14.41; p<0.001, only in the post-competition training sessions, while in Group B showed no significant effects. Two-way RM-ANOVA showed, after post-competition training sessions, a significant difference between Group A and Group B (F=6.235; p=0.023, with higher β-endorphin changes in Group A, compared to Group B. During the competitive show jumping sessions, one-way RM ANOVA showed significant effects of exercise on β-endorphin changes (F=51.10; p<0.001. The statistical analysis, in Group A, showed a significant difference between postcompetition training and competitive exercise (F=6.32; p=0.024 with higher β-endorphin values in competitive sessions compared to those of post-competition training. Conclusion: Lactate concentrations seem to be the main factors being correlated with the raise of β-endorphin during anaerobic exercise of competitive events. Exercise of low intensity, as well as that one of training sessions, does not appear to stimulate a significant increased release of β-endorphin and it may depend on the duration of the exercise

Wear characteristics of current aesthetic dental restorative CAD/CAM materials: two-body wear, gloss retention, roughness and Martens hardness.

Science.gov (United States)

Mörmann, Werner H; Stawarczyk, Bogna; Ender, Andreas; Sener, Beatrice; Attin, Thomas; Mehl, Albert

2013-04-01

This study determined the two-body wear and toothbrushing wear parameters, including gloss and roughness measurements and additionally Martens hardness, of nine aesthetic CAD/CAM materials, one direct resin-based nanocomposite plus that of human enamel as a control group. Two-body wear was investigated in a computer-controlled chewing simulator (1.2 million loadings, 49N at 1.7Hz; 3000 thermocycles 5/50°C). Each of the 11 groups consisted of 12 specimens and 12 enamel antagonists. Quantitative analysis of wear was carried out with a 3D-surface analyser. Gloss and roughness measurements were evaluated using a glossmeter and an inductive surface profilometer before and after abrasive toothbrushing of machine-polished specimens. Additionally Martens hardness was measured. Statistically significant differences were calculated with one-way ANOVA (analysis of variance). Statistically significant differences were found for two-body wear, gloss, surface roughness and hardness. Zirconium dioxide ceramics showed no material wear and low wear of the enamel antagonist. Two-body wear of CAD/CAM-silicate and -lithium disilicate ceramics, -hybrid ceramics and -nanocomposite as well as direct nanocomposite did not differ significantly from that of human enamel. Temporary polymers showed significantly higher material wear than permanent materials. Abrasive toothbrushing significantly reduced gloss and increased roughness of all materials except zirconium dioxide ceramics. Gloss retention was highest with zirconium dioxide ceramics, silicate ceramics, hybrid ceramics and nanocomposites. Temporary polymers showed least gloss retention. Martens hardness differed significantly among ceramics, between ceramics and composites, and between resin composites and acrylic block materials as well. All permanent aesthetic CAD/CAM block materials tested behave similarly or better with respect to two-body wear and toothbrushing wear than human enamel, which is not true for temporary polymer CAD

Electron microscopy of fine-grained extraterrestrial materials

International Nuclear Information System (INIS)

Mackinnon, I.D.R.; McKay, D.S.; Isaacs, A.M.; Nace, G.

1982-01-01

Electron micrographs are shown of (a) Mighei C2 carbonaceous chondrite (variety of matrix phases present; micro-diffraction patterns of a region showing small, discrete intergrowths of planar serpentine and an ordered mixed-layer material; figures showing examples of textures which may be interpreted in terms of alteration processes, and inclusions); and (b) a typical cosmic dust particle collected by high-flying aircraft in the Earth's stratosphere. The composition and morphology of the samples are discussed and their significance. (U.K.)

The material system beryllium-nitrogen-deuterium: review of recent results

Energy Technology Data Exchange (ETDEWEB)

Dittmar, Timo; Koeppen, M.; Kreter, A.; Linsmeier, C. [Institut fuer Energie- und Klimaforschung - Plasmaphysik, Forschungszentrum Juelich (Germany); Doerner, R.P. [Center for Energy Research, UC San Diego, CA (United States); Oberkofler, M.; Schwarz-Selinger, T. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

2014-07-01

Beryllium has been chosen as first-wall amour material in JET-ILW and ITER. Due to the usage of N seeding in current tokamaks and a possible use of N in ITER, the properties of the Be-N-D material system became of greater interest: Ion beam experiments showed the formation of thermally stable Be{sub 3}N{sub 2}. Beryllium samples exposed to D-plasma in the linear plasma device PISCES-B showed a significant reduction in Be erosion rate with N seeding. Measured N/Be and D/Be ratios in codeposits were independent of the N seeding rate (0.8% - 10% N seeding). Gas balance measurements for N seeded L-mode discharges in JET indicate strong N retention and show a potential increase in D retention, possibly due to ND{sub 3} formation. This paper will re-visit and evaluate the available data from the different experiments in order to build a consistent model of the processes relevant for plasma-material interactions in the Be-N-D material system.

Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

International Nuclear Information System (INIS)

Alyoshina, Nonna A.; Parfenyuk, Elena V.

2013-01-01

A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N 2 adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica

Pulmonary spheral tuberculosis: features and clinical significance of spiral dynamic CT

International Nuclear Information System (INIS)

Xie Ruming; Ma Daqing; Li Tieyi; Chen Yi; Lu Fudong; Zhou Xinhua

2001-01-01

Objective: To assess the features and clinical significance of spiral dynamic CT in patients with pulmonary spheral tuberculosis. Methods: The 54 foci in 42 patients with pulmonary spheral tuberculosis were studied. Thin-sections at 2 mm thickness and 2 mm interval through the nodular center were obtained before and after administration of contrast material. Results: In 54 pulmonary spheral tuberculosis, maximum enhanced CT value in 51 (94.4%, 51/54) foci was less than 20 HU, and more than 20 HU in the other 3(5.6%, 3/54) foci. 27(50.0%, 27/54) foci showed no any enhancement, 24, (44%, 24/54) foci showed capsular enhancement, 1(1.9%, 1/54) focus showed peripheral enhancement and 2(3.7%, 2/54) foci showed extensive enhancement. The accuracy of the correct diagnosis was 25.9% in terms of plain CT and 94.4% in terms of enhanced CT scanning. The difference was significant (x 2 = 50.1, P < 0.05). The curative effect of extensive enhanced foci and peripheral enhanced foci was optimal, capsular enhanced foci was second, and non-enhanced foci was barely satisfactory. Conclusion: Spiral dynamic CT technique may improve the accuracy of diagnosing pulmonary spheral tuberculosis. No enhancement and/or capsular enhancement were suggestive of tuberculosis. The enhancing character of foci might contribute to assess the curative effect of anti-tuberculosis

Big data integration shows Australian bush-fire frequency is increasing significantly.

Science.gov (United States)

Dutta, Ritaban; Das, Aruneema; Aryal, Jagannath

2016-02-01

Increasing Australian bush-fire frequencies over the last decade has indicated a major climatic change in coming future. Understanding such climatic change for Australian bush-fire is limited and there is an urgent need of scientific research, which is capable enough to contribute to Australian society. Frequency of bush-fire carries information on spatial, temporal and climatic aspects of bush-fire events and provides contextual information to model various climate data for accurately predicting future bush-fire hot spots. In this study, we develop an ensemble method based on a two-layered machine learning model to establish relationship between fire incidence and climatic data. In a 336 week data trial, we demonstrate that the model provides highly accurate bush-fire incidence hot-spot estimation (91% global accuracy) from the weekly climatic surfaces. Our analysis also indicates that Australian weekly bush-fire frequencies increased by 40% over the last 5 years, particularly during summer months, implicating a serious climatic shift.

Creating Significant Learning Experiences across Disciplines

Science.gov (United States)

Levine, Laura E.; Fallahi, Carolyn R.; Nicoll-Senft, Joan M.; Tessier, Jack T.; Watson, Cheryl L.; Wood, Rebecca M.

2008-01-01

The purpose of this study was to use Fink's (2003) taxonomy of significant learning to redesign courses and assess student learning. Significant improvements were found across the semester for students in the six courses, but there were differences in which taxa showed improvement in each course. The meta-analysis showed significant, positive…

Spirobifluorene Core-Based Novel Hole Transporting Materials for Red Phosphorescence OLEDs

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Ramanaskanda Braveenth

2017-03-01

Full Text Available Two new hole transporting materials, named HTM 1A and HTM 1B, were designed and synthesized in significant yields using the well-known Buchwald Hartwig and Suzuki cross- coupling reactions. Both materials showed higher decomposition temperatures (over 450 °C at 5% weight reduction and HTM 1B exhibited a higher glass transition temperature of 180 °C. Red phosphorescence-based OLED devices were fabricated to analyze the device performances compared to Spiro-NPB and NPB as reference hole transporting materials. Devices consist of hole transporting material as HTM 1B showed better maximum current and power efficiencies of 16.16 cd/A and 11.17 lm/W, at the same time it revealed an improved external quantum efficiency of 13.64%. This efficiency is considerably higher than that of Spiro-NPB and NPB-based reference devices.

Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency.

Science.gov (United States)

Yu, Qilin; Zhang, Bing; Li, Jianrong; Du, Tingting; Yi, Xiao; Li, Mingchun; Chen, Wei; Alvarez, Pedro J J

Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. Saccharomyces cerevisiae, Candida albicans, and Komagataella pastoris) and prokaryotes (Pseudomonas fluorescens). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate-an iron chelating agent-to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.

Using Task-based Materials in Teaching Writing for EFL Classes in Indonesia

Directory of Open Access Journals (Sweden)

Hanna Sundari

2018-05-01

Full Text Available Task-based language teaching has been widely used for language classroom. Using tasks as main activities, task-based materials was developed particularly for writing class. This article is intended to present the study of effectiveness of task-based materials in improving writing class for university. To accommodate the research purposes, mixed method approach was carried out by using quasi experimental research and content analysis of sentence complexity. The respondents were 210 students from writing classes as experiment and control with writing test as instrument. The results of data analysis showed that there were significant differences of writing skill to those who taught using developed task-based materials. Despite the fact that the score did not significantly differ on the aspect of writing mechanics, a developed task-based material has been proved to improve students’ writing skill in the aspect of format, content, organization and grammar. Moreover, the levels of lexical complexity and accuracy from the students whose materials use task-based design are higher than those who do not use it. Then, it can be drawn a conclusion that the use of developed task-based materials brings significant effects toward writing performance.

Meta-analysis of the antecedent and consequent constructs of materialism

Directory of Open Access Journals (Sweden)

Fernando de Oliveira Santini

2017-10-01

Full Text Available Purpose – Materialism has been gaining ground in the academic field, especially from the 1980s on, given the relevance of understanding sentiments connected to possessing and acquiring goods. Thus, this meta-analysis was carried out to assess the antecedents and consequents of materialism. Design/methodology/approach – Based on a systematic review, we gathered a total 77 articles that examined those aspects, generating 99 effects-sizes and a cumulative sample of 40,288 studied individuals. Findings – The antecedents of materialism that showed a significant relationship with this construct were: perceived hedonic value, interpersonal influence, life satisfaction, and income. As for the consequents, we observed significance for purchase intention, impulsive buying, compulsive buying, conspicuous consumption, status consumption, and consumer involvement. Regarding the moderating effect, we observed that small samples produce greater effects. Furthermore, for the relationship between materialism and purchase intention, there are stronger effects for surveys conducted in Western countries. Originality/value – Based on the methodology applied in this study, we expected a solid and generalizable contribution regarding construct materialism.

DNA Methylation Profiling of Human Prefrontal Cortex Neurons in Heroin Users Shows Significant Difference between Genomic Contexts of Hyper- and Hypomethylation and a Younger Epigenetic Age

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Alexey Kozlenkov

2017-05-01

Full Text Available We employed Illumina 450 K Infinium microarrays to profile DNA methylation (DNAm in neuronal nuclei separated by fluorescence-activated sorting from the postmortem orbitofrontal cortex (OFC of heroin users who died from heroin overdose (N = 37, suicide completers (N = 22 with no evidence of heroin use and from control subjects who did not abuse illicit drugs and died of non-suicide causes (N = 28. We identified 1298 differentially methylated CpG sites (DMSs between heroin users and controls, and 454 DMSs between suicide completers and controls (p < 0.001. DMSs and corresponding genes (DMGs in heroin users showed significant differences in the preferential context of hyper and hypo DM. HyperDMSs were enriched in gene bodies and exons but depleted in promoters, whereas hypoDMSs were enriched in promoters and enhancers. In addition, hyperDMGs showed preference for genes expressed specifically by glutamatergic as opposed to GABAergic neurons and enrichment for axonogenesis- and synaptic-related gene ontology categories, whereas hypoDMGs were enriched for transcription factor activity- and gene expression regulation-related terms. Finally, we found that the DNAm-based “epigenetic age” of neurons from heroin users was younger than that in controls. Suicide-related results were more difficult to interpret. Collectively, these findings suggest that the observed DNAm differences could represent functionally significant marks of heroin-associated plasticity in the OFC.

The materiality of materials and artefacts used in science classrooms

DEFF Research Database (Denmark)

Cowie, Bronwen; Otrel-Cass, Kathrin; Moreland, Judy

Material objects and artefacts receive limited attention in science education (Roehl, 2012) though they shape emerging interactions. This is surprising given science has material and a social dimensions (Pickering, 1995) whereby new knowledge develops as a consensus explanation of natural phenomena...... that is mediated significantly through materials and instruments used. Here we outline the ways teachers deployed material objects and artefacts by identifying their materiality to provide scenarios and resources (Roth, 2005) for interactions. Theoretical framework We use Ingold's (2011) distinction between...... materials as natural objects in this world and artefacts as manmade objects. We are aware that in a classroom material objects and artefacts shape, and are shaped by classroom practice through the way they selectively present scientific explanations. However, materials and artefacts have no intrinsic...

Radiation Effects on Spacecraft Structural Materials

International Nuclear Information System (INIS)

Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

2002-01-01

Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

New materials for polymer electrolyte membrane fuel cell current collectors

Science.gov (United States)

Hentall, Philip L.; Lakeman, J. Barry; Mepsted, Gary O.; Adcock, Paul L.; Moore, Jon M.

Polymer Electrolyte Membrane Fuel cells for automotive applications need to have high power density, and be inexpensive and robust to compete effectively with the internal combustion engine. Development of membranes and new electrodes and catalysts have increased power significantly, but further improvements may be achieved by the use of new materials and construction techniques in the manufacture of the bipolar plates. To show this, a variety of materials have been fabricated into flow field plates, both metallic and graphitic, and single fuel cell tests were conducted to determine the performance of each material. Maximum power was obtained with materials which had lowest contact resistance and good electrical conductivity. The performance of the best material was characterised as a function of cell compression and flow field geometry.

Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis

Science.gov (United States)

Roll, Stephanie; Müller-Nordhorn, Jacqueline; Keil, Thomas; Scholz, Hans; Eidt, Daniela; Greiner, Wolfgang; Willich, Stefan N

2008-01-01

Background In peripheral vascular bypass surgery different synthetic materials are available for bypass grafting. It is unclear which of the two commonly used materials, polytetrafluoroethylene (PTFE) or polyester (Dacron®) grafts, is to be preferred. Thus, the aim of this meta-analysis and systematic review was to compare the effectiveness of these two prosthetic bypass materials (Dacron® and PTFE). Methods We performed a systematic literature search in MEDLINE, Cochrane-Library – CENTRAL, EMBASE and other databases for relevant publications in English and German published between 1999 and 2008. Only randomized controlled trials were considered for inclusion. We assessed the methodological quality by means of standardized checklists. Primary patency was used as the main endpoint. Random-effect meta-analysis as well as pooling data in life table format was performed to combine study results. Results Nine randomized controlled trials (RCT) were included. Two trials showed statistically significant differences in primary patency, one favouring Dacron® and one favouring PTFE grafts, while 7 trials did not show statistically significant differences between the two materials. Meta-analysis on the comparison of PTFE vs. Dacron® grafts yielded no differences with regard to primary patency rates (hazard ratio 1.04 (95% confidence interval [0.85;1.28]), no significant heterogeneity (p = 0.32, I2 = 14%)). Similarly, there were no significant differences with regard to secondary patency rates. Conclusion Systematic evaluation and meta-analysis of randomized controlled trials comparing Dacron® and PTFE as bypass materials for peripheral vascular surgery showed no evidence of an advantage of one synthetic material over the other. PMID:19099583

Standard format and content for a licensee physical security plan for the protection of special nuclear material of moderate or low strategic significance - January 1980

International Nuclear Information System (INIS)

Anon.

1981-01-01

This guide describes the information required in the physical security plan submitted as part of an application for a license to possess, use, or transport special nuclear material (SNM) of moderate strategic significance or 10 kg or more of SNM of low strategic significance and recommends a standard format for presenting the information in an orderly arrangement. This standards format will thus serve as an aid to uniformity and completeness in the preparation and review of the physical protection plan of the license application. This document can also be used as guidance by licensees possessing or transporting less than 10 kg of SNM of low strategic significance in understanding the intent and implementing the requirements of paragraphs 73.67(a), 73.67(f), and 73.67(g) of 10 CRF Part 73

Drag reduction through self-texturing compliant bionic materials

Science.gov (United States)

Liu, Eryong; Li, Longyang; Wang, Gang; Zeng, Zhixiang; Zhao, Wenjie; Xue, Qunji

2017-01-01

Compliant fish skin is effectively in reducing drag, thus the design and application of compliant bionic materials may be a good choice for drag reduction. Here we consider the drag reduction of compliant bionic materials. First, ZnO and PDMS mesh modified with n-octadecane were prepared, the drag reduction of self-texturing compliant n-octadecane were studied. The results show that the mesh modified by ZnO and PDMS possess excellent lipophilic and hydrophobic, thus n-octadecane at solid, semisolid and liquid state all have good adhesion with modified mesh. The states of n-octadecane changed with temperature, thus, the surface contact angle and adhesive force all varies obviously at different state. The contact angle decreases with temperature, the adhesive force shows a lower value at semisolid state. Furthermore, the drag testing results show that the compliant n-octadecane film is more effectively in drag reduction than superhydrophobic ZnO/PDMS film, indicating that the drag reduction mechanism of n-octadecane is significantly different with superhydrophobic film. Further research shows that the water flow leads to self-texturing of semisolid state n-octadecane, which is similar with compliant fish skin. Therefore, the compliant bionic materials of semisolid state n-octadecane with regular bulge plays a major role in the drag reduction.

Raw material consumption of the European Union--concept, calculation method, and results.

Science.gov (United States)

Schoer, Karl; Weinzettel, Jan; Kovanda, Jan; Giegrich, Jürgen; Lauwigi, Christoph

2012-08-21

This article presents the concept, calculation method, and first results of the "Raw Material Consumption" (RMC) economy-wide material flow indicator for the European Union (EU). The RMC measures the final domestic consumption of products in terms of raw material equivalents (RME), i.e. raw materials used in the complete production chain of consumed products. We employed the hybrid input-output life cycle assessment method to calculate RMC. We first developed a highly disaggregated environmentally extended mixed unit input output table and then applied life cycle inventory data for imported products without appropriate representation of production within the domestic economy. Lastly, we treated capital formation as intermediate consumption. Our results show that services, often considered as a solution for dematerialization, account for a significant part of EU raw material consumption, which emphasizes the need to focus on the full production chains and dematerialization of services. Comparison of the EU's RMC with its domestic extraction shows that the EU is nearly self-sufficient in biomass and nonmetallic minerals but extremely dependent on direct and indirect imports of fossil energy carriers and metal ores. This implies an export of environmental burden related to extraction and primary processing of these materials to the rest of the world. Our results demonstrate that internalizing capital formation has significant influence on the calculated RMC.

Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Alyoshina, Nonna A.; Parfenyuk, Elena V., E-mail: evp@iscras.ru

2013-09-15

A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N{sub 2} adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica.

Volta-Based Cells Materials Chemical Multiple Representation to Improve Ability of Student Representation

Science.gov (United States)

Helsy, I.; Maryamah; Farida, I.; Ramdhani, M. A.

2017-09-01

This study aimed to describe the application of teaching materials, analyze the increase in the ability of students to connect the three levels of representation and student responses after application of multiple representations based teaching materials chemistry. The method used quasi one-group pretest-posttest design to 71 students. The results showed the application of teaching materials carried 88% with very good category. A significant increase ability to connect the three levels of representation of students after the application of multiple representations based teaching materials chemistry with t-value > t-crit (11.402 > 1.991). Recapitulation N-gain pretest and posttest showed relatively similar for all groups is 0.6 criterion being achievement. Students gave a positive response to the application of multiple representations based teaching materials chemistry. Students agree teaching materials used in teaching chemistry (88%), and agrees teaching materials to provide convenience in connecting the three levels of representation (95%).

Analysis of the Mechanical Behavior and Surface Rugosity of Different Dental Die Materials.

Science.gov (United States)

Niekawa, Ciro T; Kreve, Simone; A'vila, Gisseli Bertozzi; Godoy, Gilmar Gil; Eduardo Vieira da Silva, J R; Dias, Sergio Candido

2017-01-01

This work evaluated the mechanical and surface behavior of different die materials. The studied materials are polyurethane resin Exakto-Form (Bredent), Gypsum type IV, Fuji Rock EP (Gc), and Durone (Dentsply). Two metallic matrices molded in polyvinyl siloxane provided 30 cylindrical test specimens for the diametral compression test and 30 hemispherical test specimens for the surface rugosity test. The cylindrical test specimens were submitted to tests of diametral compression strength using a DL2000 universal assay machine, with a load cell of 2000 Kgf and constant speed of 1 mm/min connected to the software. Kruskal-Wallis and Dunn's nonparametric tests were used to analyze the results. The hemispheres were submitted to the surface rugosity assay using a SJ201-P rugosimeter with a sensitivity of 300 μm, speed of 0.5 mm/s, and cut-off of 0.8 mm, and the readings were taken on the convex surface of the test specimens and metallic matrix. Results were analyzed using with Fisher's least significant differences test (LSD) and Dunnett's test. Kruskal-Wallis test showed significant difference between die materials for diametral compression strength ( P = 0.002). Dunn's test showed significantly higher values for modified polyurethane resin (Exakto-Form). The gypsum type IV, which did not significantly differ regarding diametral compression strength, showed 34.0% (Durone) and 42.7% (Fuji Rock) lower values in comparison to Exakto-Form. Within the parameters adopted in this study, it is possible to conclude that Exakto-Form polyurethane resin showed higher resistance to compression and was closer to the metallic matrix rugosity, and, along with the gypsum type IV Durone, showed better reproducibility of details relative to the Fuji Rock.

The central nervous system of sea cucumbers (Echinodermata: Holothuroidea shows positive immunostaining for a chordate glial secretion

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Grondona Jesus M

2009-06-01

Full Text Available Abstract Background Echinoderms and chordates belong to the same monophyletic taxon, the Deuterostomia. In spite of significant differences in body plan organization, the two phyla may share more common traits than was thought previously. Of particular interest are the common features in the organization of the central nervous system. The present study employs two polyclonal antisera raised against bovine Reissner's substance (RS, a secretory product produced by glial cells of the subcomissural organ, to study RS-like immunoreactivity in the central nervous system of sea cucumbers. Results In the ectoneural division of the nervous system, both antisera recognize the content of secretory vacuoles in the apical cytoplasm of the radial glia-like cells of the neuroepithelium and in the flattened glial cells of the non-neural epineural roof epithelium. The secreted immunopositive material seems to form a thin layer covering the cell apices. There is no accumulation of the immunoreactive material on the apical surface of the hyponeural neuroepithelium or the hyponeural roof epithelium. Besides labelling the supporting cells and flattened glial cells of the epineural roof epithelium, both anti-RS antisera reveal a previously unknown putative glial cell type within the neural parenchyma of the holothurian nervous system. Conclusion Our results show that: a the glial cells of the holothurian tubular nervous system produce a material similar to Reissner's substance known to be synthesized by secretory glial cells in all chordates studied so far; b the nervous system of sea cucumbers shows a previously unrealized complexity of glial organization. Our findings also provide significant clues for interpretation of the evolution of the nervous system in the Deuterostomia. It is suggested that echinoderms and chordates might have inherited the RS-producing radial glial cell type from the central nervous system of their common ancestor, i.e., the last common

Performance of dental impression materials: Benchmarking of materials and techniques by three-dimensional analysis.

Science.gov (United States)

Rudolph, Heike; Graf, Michael R S; Kuhn, Katharina; Rupf-Köhler, Stephanie; Eirich, Alfred; Edelmann, Cornelia; Quaas, Sebastian; Luthardt, Ralph G

2015-01-01

Among other factors, the precision of dental impressions is an important and determining factor for the fit of dental restorations. The aim of this study was to examine the three-dimensional (3D) precision of gypsum dies made using a range of impression techniques and materials. Ten impressions of a steel canine were fabricated for each of the 24 material-method-combinations and poured with type 4 die stone. The dies were optically digitized, aligned to the CAD model of the steel canine, and 3D differences were calculated. The results were statistically analyzed using one-way analysis of variance. Depending on material and impression technique, the mean values had a range between +10.9/-10.0 µm (SD 2.8/2.3) and +16.5/-23.5 µm (SD 11.8/18.8). Qualitative analysis using colorcoded graphs showed a characteristic location of deviations for different impression techniques. Three-dimensional analysis provided a comprehensive picture of the achievable precision. Processing aspects and impression technique were of significant influence.

Report of the Material Control and Material Accounting Task Force

International Nuclear Information System (INIS)

1978-03-01

In September 1977 a Task Force was formed to complete a study of the role of material control and material accounting in NRC's safeguards program. The Task Force's assignment was to: define the roles and objectives of material control and material accounting in the NRC safeguards program; recommend goals for the material control and material accounting systems based on their roles and objectives; assess the extent to which the existing safeguards regulatory base meets or provides the capability to meet the recommended goals; and provide direction for material control and material accounting development, including both near-term and long-term upgrades. The study was limited to domestic nuclear facilities possessing significant amounts of plutonium, uranium-233 or highly enriched uranium in unsealed form. The Task Force findings are reported

Nanometer scale materials - characterization and fabrication

International Nuclear Information System (INIS)

Murday, J.S.; Colton, R.J.; Rath, B.B.

1993-01-01

Materials and solid state scientists have made excellent progress in understanding material behavior in length scales from microns to meters. Below a micron, the lack of analytical prowess has been a deterrent. At the atomic scale, chemistry and atomic/molecular physics have also contributed significant understanding of matter. The maturity of these three communities, materials, solid state physics, atomic/molecular physics/chemistry, coupled with the development of analytical capability for nanometer-sized structures, promises to broaden our grasp of materials behavior into the last realm of unexplored size scales-nanometer. The motivation for this effort is driven both by the expectation of novel properties as well as by the potential solution to long standing technological issues. Critical scale lengths for many material properties fall in the nanometer range, examples include superconductor coherence lengths, electron inelastic mean free paths, electron wavelengths in solids, critical lengths for dislocation generation. Structures of nanometer size will undoubtedly show behavior unexpected from experience at the larger and smaller scales. Many technological problems such as adhesion, friction, corrosion, elasticity and fracture are believed to depend critically on nanometer scale phenomena. The millennia-old efforts to improve materials behavior have undoubtedly been slowed by our inability to 'observe' in this size range. (orig.)

Special purpose materials. Annual progress report, October 1, 1979

International Nuclear Information System (INIS)

1980-04-01

Fusion reactor materials problems other than the first-wall and blanket structural materials are investigated. Components that are considered as special purpose materials include breeding materials, coolants, neutron multipliers, barriers for tritium control, materials for compression and OH coils and waveguides, grahite and SiC, heat-sink materials, ceramics, and materials for high-field (>10-T) superconducting magnets. Radiation-induced conductivity of three forms of Al 2 O 3 was measured as a function of ionizing dose rate and temperature. Increases observed are large enough to affect performance of insulators under some fusion reactor operating conditions. Single-crystal MgAl 2 O 4 was shown to exhibit zero swelling when irradiated to approx. 2 x 10 26 n/m 2 at 925 and 1100 K. This ceramic is resistant to nucleation and growth of defect aggregates, and is not characterized by those microstructural conditions which lead to void formation and swelling in Al 2 O 3 . Fracture toughness of single-crystal Al 2 O 3 was significantly increased by elevated-temperature irradiation to approx. 2 x 10 26 n/m 2 , while that for MgAl 2 O 4 and Y 3 Al 5 O 12 showed little or no change. These results show that ceramics can retain their original resistance to crack propagation after high-dose neutron irradiation

Endovascular management for significant iatrogenic portal vein bleeding.

Science.gov (United States)

Kim, Jong Woo; Shin, Ji Hoon; Park, Jonathan K; Yoon, Hyun-Ki; Ko, Gi-Young; Gwon, Dong Il; Kim, Jin Hyoung; Sung, Kyu-Bo

2017-11-01

Background Despite conservative treatment, hemorrhage from an intrahepatic branch of the portal vein can cause hemodynamic instability requiring urgent intervention. Purpose To retrospectively report the outcomes of hemodynamically significant portal vein bleeding after endovascular management. Material and Methods During a period of 15 years, four patients (2 men, 2 women; median age, 70.5 years) underwent angiography and embolization for iatrogenic portal vein bleeding. Causes of hemorrhage, angiographic findings, endovascular treatment, and complications were reported. Results Portal vein bleeding occurred after percutaneous liver biopsy (n = 2), percutaneous radiofrequency ablation (n = 1), and percutaneous cholecystostomy (n = 1). The median time interval between angiography and percutaneous procedure was 5 h (range, 4-240 h). Common hepatic angiograms including indirect mesenteric portograms showed active portal vein bleeding into the peritoneal cavity with (n = 1) or without (n = 2) an arterioportal (AP) fistula, and portal vein pseudoaneurysm alone with an AP fistula (n = 1). Successful transcatheter arterial embolization (n = 2) or percutaneous transhepatic portal vein embolization (n = 2) was performed. Embolic materials were n-butyl cyanoacrylate alone (n = 2) or in combination with gelatin sponge particles and coils (n = 2). There were no major treatment-related complications or patient mortality within 30 days. Conclusion Patients with symptomatic or life-threatening portal vein bleeding following liver-penetrating procedures can successfully be managed with embolization.

Friction Material Composites Materials Perspective

CERN Document Server

Sundarkrishnaa, K L

2012-01-01

Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

Thin-Film Material Science and Processing | Materials Science | NREL

Science.gov (United States)

Thin-Film Material Science and Processing Thin-Film Material Science and Processing Photo of a , a prime example of this research is thin-film photovoltaics (PV). Thin films are important because cadmium telluride thin film, showing from top to bottom: glass, transparent conducting oxide (thin layer

Material and energy productivity.

Science.gov (United States)

Steinberger, Julia K; Krausmann, Fridolin

2011-02-15

Resource productivity, measured as GDP output per resource input, is a widespread sustainability indicator combining economic and environmental information. Resource productivity is ubiquitous, from the IPAT identity to the analysis of dematerialization trends and policy goals. High resource productivity is interpreted as the sign of a resource-efficient, and hence more sustainable, economy. Its inverse, resource intensity (resource per GDP) has the reverse behavior, with higher values indicating environmentally inefficient economies. In this study, we investigate the global systematic relationship between material, energy and carbon productivities, and economic activity. We demonstrate that different types of materials and energy exhibit fundamentally different behaviors, depending on their international income elasticities of consumption. Biomass is completely inelastic, whereas fossil fuels tend to scale proportionally with income. Total materials or energy, as aggregates, have intermediate behavior, depending on the share of fossil fuels and other elastic resources. We show that a small inelastic share is sufficient for the total resource productivity to be significantly correlated with income. Our analysis calls into question the interpretation of resource productivity as a sustainability indicator. We conclude with suggestions for potential alternatives.

Application of common packaging materials in the probiotic fresh cheese production

Directory of Open Access Journals (Sweden)

Mirela Iličić

2016-03-01

Full Text Available The aim of this work was to investigate the application of common packaging materials polypropylene (PP and polystyrene (PS in the probiotic fresh cheese production packaging. Probiotic and traditional cheeses were produced from milk with standardized milk fat content of 2.3 g/100 g including the application of two cultures (probiotic and traditional. The samples were packed in the PP and PS cups and stored at 4 ºC for 30 days. The observed permeability of gases through the two applied packaging materials was significantly different. Cheese samples were analysed for microbiological properties whereby lactic acid bacteria, Bifidobacterium sp. and aerobic mesophilic bacteria (AMB were determined. Packaging materials showed no significant effect on the content of ascorbic acid which is known to be sensitive to the presence of oxygen.

Obesity in show cats.

Science.gov (United States)

Corbee, R J

2014-12-01

Obesity is an important disease with a high prevalence in cats. Because obesity is related to several other diseases, it is important to identify the population at risk. Several risk factors for obesity have been described in the literature. A higher incidence of obesity in certain cat breeds has been suggested. The aim of this study was to determine whether obesity occurs more often in certain breeds. The second aim was to relate the increased prevalence of obesity in certain breeds to the official standards of that breed. To this end, 268 cats of 22 different breeds investigated by determining their body condition score (BCS) on a nine-point scale by inspection and palpation, at two different cat shows. Overall, 45.5% of the show cats had a BCS > 5, and 4.5% of the show cats had a BCS > 7. There were significant differences between breeds, which could be related to the breed standards. Most overweight and obese cats were in the neutered group. It warrants firm discussions with breeders and cat show judges to come to different interpretations of the standards in order to prevent overweight conditions in certain breeds from being the standard of beauty. Neutering predisposes for obesity and requires early nutritional intervention to prevent obese conditions. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Materials by design

International Nuclear Information System (INIS)

Eberhardt, J.; Hay, P.J.; Carpenter, J.A. Jr.

1986-01-01

Major developments in materials characterization instrumentation over the past decade have helped significantly to elucidate complex processes and phenomena connected with the microstructure of materials and interfacial interactions. Equally remarkable advances in theoretical models and computer technology also have been taking place during this period. These latter now permit, for example, in selected cases the computation of material structures and bonding and the prediction of some material properties. Two assessments of the state of the art of instrumental techniques and theoretical methods for the study of material structures and properties have recently been conducted. This paper discusses aspects from these assessments of computational theoretical methods apply to materials

Effect of Different Irrigation Solutions on the Colour Stability of Three Calcium Silicate-Based Materials

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Sobhnamayan F

2017-06-01

Full Text Available Abstract: Statement of Problem: Previous studies have shown discoloration of mineral trioxide aggregate (MTA in contact with root canal irrigation solutions. However, there are limited data on colour stability of other calcium silicate–based materials (CSMs. Objectives: This in vitro study aimed to evaluate the colour stability of three CSMs in contact with different irrigation solutions. Materials and Methods: Three CSMs including White MTA (wMTA Angelus, calcium enriched mixture (CEM, and Biodentine were assessed in this study. Forty five samples of each material were mixed according to the manufactures’ instructions and then placed in silicone tubes. After 24 hours, the materials were removed from the moulds and 9 samples of each material left dry or immersed in normal saline, 5% sodium hypochlorite (NaOCL, 2% chlorhexidinegluconate (CHX, or 17%EDTA for 24 hours. Colour changes were measured with a spectrophotometer. Data were evaluated with 2-way analysis of variance, one way analysis of variance and Tukey post hoc tests. Results: The highest discoloration of all materials was observed after contact with CHX. In the MTA Angelus and CEM cement groups, significant differences were observed between CHX and NaOCl and also between these two irrigants with the other three irrigants (p < 0.05. In the Biodentine group, CHX created statistically significant discoloration compared to other irrigants (p < 0.05. Only wMTA Angelus showed a significantly higher discoloration in contact with EDTA compared to normal saline and dry condition (p < 0.05. wMTA Angelus showed a significantly higher colour change compared with CEM cement and Biodentine after contact with NaOCl, CHX, and EDTA (p < 0.05. Conclusions: The contact of wMTA, CEM cement, and Biodentine with CHX should be avoided because this leads to severe discoloration. Contact with sodium hypochlorite also leads to discoloration of wMTA and CEM cements. Among of the three tested materials, w

Absorbent material for type a radioactive materials packaging containing liquids

International Nuclear Information System (INIS)

Saunders, G.A.

1989-11-01

The application of absorbent materials to the packaging and transport of liquid radioactive materials in Type A packages has not been reported in the literature. However, a significant body of research exists on absorbent materials for personal hygiene products such as diapers. Absorption capacity is dependent on both the absorbent material and the liquid being absorbed. Theoretical principles for capillary absorption in both the horizontal and the vertical plane indicate that small contact angle between the absorbent fibre and the liquid, and a small inter-fibre pore size are important. Some fluid parameters such as viscosity affect the rate of absorption but not the final absorption capacity. There appears to be little comparability between results obtained for the same absorbent and fluid using different test procedures. Test samples of materials from several classes of potential absorbents have been evaluated in this study, and shown to have a wide range of absorbent capacities. Foams, natural fibres, artificial fibres and granular materials are all potentially useful absorbents, with capacities ranging from as little as 0.86 to as much as 40.6 grams of distilled water per gram of absorbent. Two experimental procedures for evaluating the absorbent capacity of these materials have been detailed in this report, and found suitable for evaluating granular, fibrous or foam materials. Compression of the absorbent material reduces its capacity, but parameters such as relative humidity, pH, temperature, and viscosity appear to have little significant influence on capacity. When the materials were loaded to 50% of their one-minute absorbency, subsequent loss of the absorbed liquid was generally minimal. All of the absorbent materials rapidly lost their absorbed water through evaporation within twenty-four hours in still air at 21 degrees C and 50% relative humidity

Evaluation of mechanical and thermal properties of insulation materials for HTS power devices at liquid nitrogen temperature

Energy Technology Data Exchange (ETDEWEB)

Shin, Hyung Seop; Diaz, Mark Angelo [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of)

2017-06-15

In superconducting power devices including power cables in which high temperature superconducting (HTS) tapes are utilized, a reliable electrical insulation should be achieved for its maximum performance. For an efficient design of HTS superconducting devices, a comparative evaluation of the mechanical and thermal propperties for various insulation materials at cryogenic temperatures is required. Especially, in the process of the property evaluation of the sheet-shaped insulation materials, anisotropy according to the machining direction should be considered because the mechanical and thermal properties are significantly influenced by the sample orientation. In this study, the cryogenic thermal and mechanical properties of various insulation material sheets such as PPLP, Cryoflex, Teflon, and Kapton were determined considering sample orientation. All samples tested at cryogenic temperature showed significantly higher tensile strength as compared with that of room temperature. The ultimate tensile strength at both temperature conditions significantly depended upon the sample orientation. The thermal properties of the insulation materials exhibited a slight difference among samples depending on the orientation: for the PPLP and Cryoflex, the CD orientation showed larger thermal contraction up to 77 K as compared to the MD one. MD samples in PPLP and Cryoflex showed a lower CTE and thermal contraction which made it more promising as an insulation material due to its comparable CTE with HTS CC tapes.

Fusion of protegrin-1 and plectasin to MAP30 shows significant inhibition activity against dengue virus replication.

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Hussin A Rothan

Full Text Available Dengue virus (DENV broadly disseminates in tropical and sub-tropical countries and there are no vaccine or anti-dengue drugs available. DENV outbreaks cause serious economic burden due to infection complications that requires special medical care and hospitalization. This study presents a new strategy for inexpensive production of anti-DENV peptide-fusion protein to prevent and/or treat DENV infection. Antiviral cationic peptides protegrin-1 (PG1 and plectasin (PLSN were fused with MAP30 protein to produce recombinant antiviral peptide-fusion protein (PG1-MAP30-PLSN as inclusion bodies in E. coli. High yield production of PG1-MAP30-PLSN protein was achieved by solubilization of inclusion bodies in alkaline buffer followed by the application of appropriate refolding techniques. Antiviral PG1-MAP30-PLSN protein considerably inhibited DENV protease (NS2B-NS3pro with half-maximal inhibitory concentration (IC50 0.5±0.1 μM. The real-time proliferation assay (RTCA and the end-point proliferation assay (MTT assay showed that the maximal-nontoxic dose of the peptide-fusion protein against Vero cells is approximately 0.67±0.2 μM. The cell-based assays showed considerable inhibition of the peptide-fusion protein against binding and proliferating stages of DENV2 into the target cells. The peptide-fusion protein protected DENV2-challeged mice with 100% of survival at the dose of 50 mg/kg. In conclusion, producing recombinant antiviral peptide-fusion protein by combining short antiviral peptide with a central protein owning similar activity could be useful to minimize the overall cost of short peptide production and take advantage of its synergistic antiviral activities.

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

Science.gov (United States)

Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis

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Eidt Daniela

2008-12-01

Full Text Available Abstract Background In peripheral vascular bypass surgery different synthetic materials are available for bypass grafting. It is unclear which of the two commonly used materials, polytetrafluoroethylene (PTFE or polyester (Dacron® grafts, is to be preferred. Thus, the aim of this meta-analysis and systematic review was to compare the effectiveness of these two prosthetic bypass materials (Dacron® and PTFE. Methods We performed a systematic literature search in MEDLINE, Cochrane-Library – CENTRAL, EMBASE and other databases for relevant publications in English and German published between 1999 and 2008. Only randomized controlled trials were considered for inclusion. We assessed the methodological quality by means of standardized checklists. Primary patency was used as the main endpoint. Random-effect meta-analysis as well as pooling data in life table format was performed to combine study results. Results Nine randomized controlled trials (RCT were included. Two trials showed statistically significant differences in primary patency, one favouring Dacron® and one favouring PTFE grafts, while 7 trials did not show statistically significant differences between the two materials. Meta-analysis on the comparison of PTFE vs. Dacron® grafts yielded no differences with regard to primary patency rates (hazard ratio 1.04 (95% confidence interval [0.85;1.28], no significant heterogeneity (p = 0.32, I2 = 14%. Similarly, there were no significant differences with regard to secondary patency rates. Conclusion Systematic evaluation and meta-analysis of randomized controlled trials comparing Dacron® and PTFE as bypass materials for peripheral vascular surgery showed no evidence of an advantage of one synthetic material over the other.

Simple and effective method of determining multiplicity distribution law of neutrons emitted by fissionable material with significant self -multiplication effect

International Nuclear Information System (INIS)

Yanjushkin, V.A.

1991-01-01

At developing new methods of non-destructive determination of plutonium full mass in nuclear materials and products being involved in uranium -plutonium fuel cycle by its intrinsic neutron radiation, it may be useful to know not only separate moments but the multiplicity distribution law itself of neutron leaving this material surface using the following as parameters - firstly, unconditional multiplicity distribution laws of neutrons formed in spontaneous and induced fission acts of the given fissionable material corresponding nuclei and unconditional multiplicity distribution law of neutrons caused by (α,n) reactions at light nuclei of some elements which compose this material chemical structure; -secondly, probability of induced fission of this material nuclei by an incident neutron of any nature formed during the previous fissions or(α,n) reactions. An attempt to develop similar theory has been undertaken. Here the author proposes his approach to this problem. The main advantage of this approach, to our mind, consists in its mathematical simplicity and easy realization at the computer. In principle, the given model guarantees any good accuracy at any real value of induced fission probability without limitations dealing with physico-chemical composition of nuclear material

A human intervention study with foods containing natural Ah-receptor agonists does not significantly show AhR-mediated effects as measured in blood cells and urine.

Science.gov (United States)

de Waard, Pim W J; Peijnenburg, Ad A C M; Baykus, Hakan; Aarts, Jac M M J G; Hoogenboom, Ron L A P; van Schooten, Frederik J; de Kok, Theo M C M

2008-10-22

Binding and activation of the aryl hydrocarbon receptor (AhR) is thought to be an essential step in the toxicity of the environmental pollutants dioxins and dioxin-like PCBs. However, also a number of natural compounds, referred to as NAhRAs (natural Ah-receptor agonists), which are present in, for example, fruits and vegetables, can bind and activate this receptor. To study their potential effects in humans, we first investigated the effect of the prototypical AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gene expression in ex vivo exposed freshly isolated human lymphocytes, and compared the resulting gene expression profile with those caused by the well-known NAhRA indolo[3,2-b]carbazole (ICZ), originating from cruciferous vegetables, and by a hexane extract of NAhRA-containing grapefruit juice (GJE). Only ICZ induced a gene expression profile similar to TCDD in the lymphocytes, and both significantly up-regulated CYP1B1 and TIPARP (TCDD-inducible poly (ADP-ribose) polymerase) mRNA. Next, we performed a human intervention study with NAhRA-containing cruciferous vegetables and grapefruit juice. The expression of the prototypical AhR-responsive genes CYP1A1, CYP1B1 and NQO1 in whole blood cells and in freshly isolated lymphocytes was not significantly affected. Also enzyme activities of CYP1A2, CYP2A6, N-acetyltransferase 2 (NAT2) and xanthine oxidase (XO), as judged by caffeine metabolites in urine, were unaffected, except for a small down-regulation of NAT2 activity by grapefruit juice. Examination of blood plasma with DR CALUX showed a 12% increased AhR agonist activity 3 and 24 h after consumption of cruciferous vegetables, but did not show a significant effect of grapefruit juice consumption. We conclude that intake of NAhRAs from food may result in minor AhR-related effects measurable in human blood and urine.

EFFECTS OF DIFFERENT SUTURE MATERIALS ON TISSUE HEALING

Directory of Open Access Journals (Sweden)

Fırat SELVİ

2016-01-01

Full Text Available Purpose: The purpose of this study was to investigate the healing differences in between four different widely used suture materials in the oral surgery practice, including silk (Perma- Hand; Ethicon, INC., Somerville, NJ, USA, polypropylene (Prolene; Ethicon, INC., Somerville, NJ, USA, coated polyglactin 910 (Ethicon, INC., Somerville, NJ, USA. and polyglecaprone 25 (Ethicon, INC., Somerville, NJ, USA . Materials and Methods: 20 male rats were randomly allocated into two groups depending on their sacrification days (post-operative 1st and the 7th days. Four longitudinal incision wounds, each 1cm in size, were created on the dorsum of each animal which were then primarily closed with four different types of sutures. Results: The effects of these suture materials on soft tissue healing were compared histopathologically, by means of density of the cells, necrosis, fibrosis, foreign body reaction, the presence of cells of acute and chronic infection. No statistically significant difference was observed between the groups regarding the density of the cells, necrosis, fibrosis, foreign body reaction, and the presence of the cells of acute & chronic infections. Of note, propylene showed slightly less tissue reaction among the other materials. Conclusion: The results of our study showed that there is no only one ideal suture material for surgical practice. The factors related to the patient, the type of the surgery and the quality of the tissue are important to decide an appropriate suture material.

Representation of Glossy Material Surface in Ventral Superior Temporal Sulcal Area of Common Marmosets.

Science.gov (United States)

Miyakawa, Naohisa; Banno, Taku; Abe, Hiroshi; Tani, Toshiki; Suzuki, Wataru; Ichinohe, Noritaka

2017-01-01

The common marmoset ( Callithrix jacchus ) is one of the smallest species of primates, with high visual recognition abilities that allow them to judge the identity and quality of food and objects in their environment. To address the cortical processing of visual information related to material surface features in marmosets, we presented a set of stimuli that have identical three-dimensional shapes (bone, torus or amorphous) but different material appearances (ceramic, glass, fur, leather, metal, stone, wood, or matte) to anesthetized marmoset, and recorded multiunit activities from an area ventral to the superior temporal sulcus (STS) using multi-shanked, and depth resolved multi-electrode array. Out of 143 visually responsive multiunits recorded from four animals, 29% had significant main effect only of the material, 3% only of the shape and 43% of both the material and the shape. Furthermore, we found neuronal cluster(s), in which most cells: (1) showed a significant main effect in material appearance; (2) the best stimulus was a glossy material (glass or metal); and (3) had reduced response to the pixel-shuffled version of the glossy material images. The location of the gloss-selective area was in agreement with previous macaque studies, showing activation in the ventral bank of STS. Our results suggest that perception of gloss is an important ability preserved across wide range of primate species.

The significance of appearance in physician-nurse collaboration

DEFF Research Database (Denmark)

Konradsen, H.; Christensen, O.M.; Berthelsen, C.

2009-01-01

INTRODUCTION: According to nurses' assessment, physician-nurse collaboration is problematic. The aim of the study was to investigate whether nurses believe physicians' appearances is significant for their ability to collaborate. MATERIAL AND METHODS: This is a single-blinded, quasi-experimental i......-depth interviews to achieve harmonic interaction leading to a prolific and close future collaboration Udgivelsesdato: 2009/12/14......INTRODUCTION: According to nurses' assessment, physician-nurse collaboration is problematic. The aim of the study was to investigate whether nurses believe physicians' appearances is significant for their ability to collaborate. MATERIAL AND METHODS: This is a single-blinded, quasi....... The Jefferson Scale of Attitudes Toward Physician-Nurse Collaboration will be used for baseline and follow-up study of the nurses' assessment. RESULTS: Due to ethical considerations, researchers had difficulties finding surgeons prepared to perform procedures aiming at weakening the physicians' physical...

[The body as source of significance. Interdisciplinary perspectives].

Science.gov (United States)

Tofan, I A; Crumpei, Irina

2010-01-01

This paper concerns a general theoretical aspect, followed by different examples which discusses the thesis in relation to major connected domains of research: psychology and philosophy. The thesis which we are arguing for is that the body represents a source of significance in the definitions of he self used as theoretical background in moral problems (philosophical aspect) and the explanations of the way the image of the self is constituted (psychological aspect). The philosophical "conclusion" is that the body, in its materiality, cannot be judged by the metaphysical dualism scheme, which assigns it a secondary role in the hierarchy of categories. From a psychological point of view, this paper tends to show that the body does not represent an accident of personality or a "prison of the soul" as Plato refers to it, but rather an element through which personality is built on and develops and similarly, the mental and personality structures are those which allow the forming of corporeality and then the person's reference to it.

O significado do acidente de trabalho com material biológico para os profissionais de enfermagem El significado del accidente de trabajo con material biológico para los profesionales de enfermería The significance of accidents involving biological material to nursing professionals

Directory of Open Access Journals (Sweden)

Maristela Aparecida Magri Magagnini

2011-06-01

Full Text Available O objetivo deste estudo foi compreender o significado dos acidentes de trabalho com exposição a material biológico na perspectiva dos profissionais de enfermagem. De caráter exploratório com abordagem qualitativa pela análise de conteúdo de Bardin. No período de 2001 a 2006 ocorreram 87 acidentes com material biológico, sendo que destes, oito eram soropositivos para hepatite B e C e Síndrome da Imunodeficiência Adquirida/Vírus da Imunodeficiência Humana. Para coleta de dados utilizou-se entrevista com perguntas norteadoras. Ao indagar esses profissionais sobre o significado dos acidentes, emergiram quatro categorias: situação de risco; percepção de perigo; fatalidade e sentimentos. Embora não seja estratégia de esclarecimento, mas é fato que organização de trabalho e ações educativas tem impacto considerável para diminuir esse tipo de acidente, diminuindo prejuízos na vida dos acidentados.El objetivo de este estudio ha sido comprender el significado de accidentes de trabajo con exposición a material biológico, desde la perspectiva de los profesionales de enfermería. De carácter exploratorio con enfoque cualitativo por el análisis de contenido de Bardin. En el período de 2001 a 2006 ocurrieron 87 accidentes con material biológico, de estos, ocho eran seropositivos para hepatitis B y C y Síndrome de la Inmunodeficiencia Adquirida/Virus de la Inmunodeficiencia Humana. Para recoger datos se ha utilizado entrevista con preguntas. Al preguntar a esos profesionales sobre el significado de los accidentes, han surgido cuatro categorías: situación de riesgo, percepción de peligro, fatalidad y sentimientos. Aunque no sea estrategia de aclaración, pero es un hecho que la organización de trabajo y acciones educativas tienen impacto considerable para disminuir ese tipo de accidente, disminuyendo perjuicios en la vida de los accidentados.The objective of this present study was to understand the significance of

Glass material oxidation and dissolution system: Converting miscellaneous fissile materials to glass

International Nuclear Information System (INIS)

Forsberg, C.W.; Ferrada, J.J.

1996-01-01

The cold war and the development of nuclear energy have resulted in significant inventories of miscellaneous fissile materials (MFMs). MFMs include (1) plutonium scrap and residue, (2) miscellaneous spent nuclear fuel (SNF), (3) certain hot cell wastes, and (4) many one-of-a-kind materials. Major concerns associated with the long-term management of these materials include: safeguards and nonproliferation issues; health, environment, and safety concerns. waste management requirements; and high storage costs. These issues can be addressed by converting the MFMs to glass for secure, long-term storage or repository disposal; however, conventional glass-making processes require oxide-like feed materials. Converting MFMs to oxide-like materials with subsequent vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS), which directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride (NaCl) stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium, Zircaloy, stainless steel, multiple oxides, and other materials to glass. However, significant work is required to develop GMODS further for applications at an industrial scale. If implemented, GMODS will provide a new approach to manage these materials

Wear Resistance of 3D Printing Resin Material Opposing Zirconia and Metal Antagonists.

Science.gov (United States)

Park, Ji-Man; Ahn, Jin-Soo; Cha, Hyun-Suk; Lee, Joo-Hee

2018-06-20

3D printing offers many advantages in dental prosthesis manufacturing. This study evaluated the wear resistance of 3D printing resin material compared with milling and conventional resin materials. Sixty substrate specimens were prepared with three types of resin materials: 3D printed resin, milled resin, and self-cured resin. The 3D printed specimens were printed at a build angle of 0° and 100 μm layer thickness by digital light processing 3D printing. Two kinds of abraders were made of zirconia and CoCr alloy. The specimens were loaded at 5 kg for 30,000 chewing cycles with vertical and horizontal movements under thermocycling condition. The 3D printed resin did not show significant difference in the maximal depth loss or the volume loss of wear compared to the milled and the self-cured resins. No significant difference was revealed depending on the abraders in the maximal depth loss or the volume loss of wear. In SEM views, the 3D printed resin showed cracks and separation of inter-layer bonds when opposing the metal abrader. The results suggest that the 3D printing using resin materials provides adequate wear resistance for dental use.

10 CFR 74.41 - Nuclear material control and accounting for special nuclear material of moderate strategic...

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Nuclear material control and accounting for special nuclear material of moderate strategic significance. 74.41 Section 74.41 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL NUCLEAR MATERIAL Special Nuclear Material...

Machinability of CAD-CAM materials.

Science.gov (United States)

Chavali, Ramakiran; Nejat, Amir H; Lawson, Nathaniel C

2017-08-01

Although new materials are available for computer-aided design and computer-aided manufacturing (CAD-CAM) fabrication, limited information is available regarding their machinability. The depth of penetration of a milling tool into a material during a timed milling cycle may indicate its machinability. The purpose of this in vitro study was to compare the tool penetration rate for 2 polymer-containing CAD-CAM materials (Lava Ultimate and Enamic) and 2 ceramic-based CAD-CAM materials (e.max CAD and Celtra Duo). The materials were sectioned into 4-mm-thick specimens (n=5/material) and polished with 320-grit SiC paper. Each specimen was loaded into a custom milling apparatus. The apparatus pushed the specimens against a milling tool (E4D Tapered 2016000) rotating at 40 000 RPM with a constant force of 0.98 N. After a 6-minute timed milling cycle, the length of each milling cut was measured with image analysis software under a digital light microscope. Representative specimens and milling tools were examined with scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy. The penetration rate of Lava Ultimate (3.21 ±0.46 mm/min) and Enamic (2.53 ±0.57 mm/min) was significantly greater than that of e.max CAD (1.12 ±0.32 mm/min) or Celtra Duo (0.80 ±0.21 mm/min) materials. SEM observations showed little tool damage, regardless of material type. Residual material was found on the tools used with polymer-containing materials, and wear of the embedding medium was seen on the tools used with the ceramic-based materials. Edge chipping was noted on cuts made in the ceramic-based materials. Lava Ultimate and Enamic have greater machinability and less edge chipping than e.max CAD and Celtra Duo. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Processes for fabricating composite reinforced material

Science.gov (United States)

Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

2015-11-24

A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

Isotopically enriched structural materials in nuclear devices

Energy Technology Data Exchange (ETDEWEB)

Morgan, L.W.G., E-mail: Lee.Morgan@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Shimwell, J. [CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Gilbert, M.R. [CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)

2015-01-15

Highlights: • C-B analysis of isotopic enrichment of structural materials is presented. • Some, previously, prohibited elements could be used as alloying elements in LAM's. • Adding enriched molybdenum and nickel, to EUROFER, could increase availability. • Isotope enrichment for EUROFER could be cost-effective. • Isotopically enriching copper, in CuCrZr, can reduce helium production by 50%. - Abstract: A large number of materials exist which have been labeled as low activation structural materials (LAM). Most often, these materials have been designed in order to substitute-out or completely remove elements that become activated and contribute significantly to shut-down activity after being irradiated by neutrons in a reactor environment. To date, one of the fundamental principles from which LAMs have been developed is that natural elemental compositions are the building blocks of LAMs. Thus, elements such as Co, Al, Ni, Mo, Nb, N and Cu that produce long-lived decay products are significantly reduced or removed from the LAM composition. These elements have an important part to play in the composition of steels and the removal/substitution can have a negative impact on materials properties such as yield stress and fracture toughness. This paper looks in more detail at whether using isotopic selection of the more mechanically desirable, but prohibited due to activation, elements can improve matters. In particular, this paper focuses on the activation of Eurofer. Carefully chosen isotopically enriched elements, which are normally considered to be on the prohibited element list, are added to EUROFER steel as potential alloying elements. The EUROFER activation results show that some prohibited elements can be used as alloying elements in LAM steels, providing the selected isotopes do not have a significant impact on waste disposal rating or shut-down dose. The economic implications of isotopically enriching elements and the potential implications for

New technologies for monitoring nuclear materials

International Nuclear Information System (INIS)

Moran, B.W.

1993-01-01

This paper describes new technologies for monitoring the continued presence of nuclear materials that are being evaluated in Oak Ridge, Tennessee, to reduce the effort, cost, and employee exposures associated with conducting nuclear material inventories. These technologies also show promise for the international safeguarding of process systems and nuclear materials in storage, including spent fuels. The identified systems are based on innovative technologies that were not developed for safeguards applications. These advanced technologies include passive and active sensor systems based on optical materials, inexpensive solid-state radiation detectors, dimensional surface characterization, and digital color imagery. The passive sensor systems use specialized scintillator materials coupled to optical-fiber technologies that not only are capable of measuring radioactive emissions but also are capable of measuring or monitoring pressure, weight, temperature, and source location. Small, durable solid-state gamma-ray detection devices, whose components are estimated to cost less than $25 per unit, can be implemented in a variety of configurations and can be adapted to enhance existing monitoring systems. Variations in detector design have produced significantly different system capabilities. Dimensional surface characterization and digital color imaging are applications of developed technologies that are capable of motion detection, item surveillance, and unique identification of items

Multicriteria Decision Analysis of Material Selection of High Energy Performance Residential Building

Science.gov (United States)

Čuláková, Monika; Vilčeková, Silvia; Katunská, Jana; Krídlová Burdová, Eva

2013-11-01

In world with limited amount of energy sources and with serious environmental pollution, interest in comparing the environmental embodied impacts of buildings using different structure systems and alternative building materials will be increased. This paper shows the significance of life cycle energy and carbon perspective and the material selection in reducing energy consumption and emissions production in the built environment. The study evaluates embodied environmental impacts of nearly zero energy residential structures. The environmental assessment uses framework of LCA within boundary: cradle to gate. Designed alternative scenarios of material compositions are also assessed in terms of energy effectiveness through selected thermal-physical parameters. This study uses multi-criteria decision analysis for making clearer selection between alternative scenarios. The results of MCDA show that alternative E from materials on nature plant base (wood, straw bales, massive wood panel) present possible way to sustainable perspective of nearly zero energy houses in Slovak republic

Low-cost synthesis of pure ZnO nanowalls showing three-fold symmetry

Science.gov (United States)

Scuderi, Mario; Strano, Vincenzina; Spinella, Corrado; Nicotra, Giuseppe; Mirabella, Salvo

2018-04-01

ZnO nanowalls (NWLs) represent a non-toxic, Earth abundant, high surface-to-volume ratio, semiconducting nanostructure which has already showed potential applications in biosensing, environmental monitoring and energy. Low-cost synthesis of these nanostructures is extremely appealing for large scale upgrading of laboratory results, and its implementation has to be tested at the nanoscale, at least in terms of chemical purity and crystallographic orientation. Here, we have produced pure and texturized ZnO NWLs by using chemical bath deposition (CBD) synthesis followed by a thermal treatment at 300 °C. We examined the NWL formation process and the new obtained structure at the nanoscale, by means of scanning and transmission electron microscopy in combination with x-ray diffraction and Rutherford backscattering spectrometry. We have shown that only after annealing at 300 °C in nitrogen does the as-grown material, composed of a mixture of Zn compounds NWLs, show its peculiar crystal arrangement. The resulting ZnO sheets are in fact made by ZnO wurtzite domains (4-5 nm) that show a particular kind of texturization; indeed, they are aligned with their own c-axis always perpendicular to the sheets forming the wall and rotated (around the c-axis) by multiples of 20° from each other. The presented data show that low-cost CBD, followed by an annealing process, gives pure ZnO with a peculiarly ordered nanostructure that shows three-fold symmetry. Such evidence at the nanoscale will have significant implications for realizing sensing or catalyst devices based on ZnO NWLs.

High temperature material characterization and advanced materials development

International Nuclear Information System (INIS)

Ryu, Woo Seog; Kim, D. H.; Kim, S. H. and others

2005-03-01

The study is to characterize the structural materials under the high temperature, one of the most significant environmental factors in nuclear systems. And advanced materials are developed for high temperature and/or low activation in neutron irradiation. Tensile, fatigue and creep properties have been carried out at high temperature to evaluate the mechanical degradation. Irradiation tests were performed using the HANARO. The optimum chemical composition and heat treatment condition were determined for nuclear grade 316NG stainless steel. Nitrogen, aluminum, and tungsten were added for increasing the creep rupture strength of FMS steel. The new heat treatment method was developed to form more stable precipitates. By applying the novel whiskering process, high density SiC/SiC composites with relative density above 90% could be obtained even in a shorter processing time than the conventional CVI process. Material integrated databases are established using data sheets. The databases of 6 kinds of material properties are accessible through the home page of KAERI material division

Five dangers of materialism.

Science.gov (United States)

Mills, Jon

2002-02-01

Amidst the boon of medical, scientific, and technological progress, materialism has gained increasing explanatory power in deciphering the enigma of mind. But with the proliferation and acceptance of cognitive science, psychic reality has been largely reduced to a physical ontology. In this article, the author explores the ground, scope, and limits to the materialist framework and shows that although biological-neurochemical physiology is a necessary condition for mental functioning, it is far from a sufficient condition to adequately explain the human being. This situation becomes especially significant when one examines the issues of selfhood, freedom, personal autonomy, and the phenomenal quality of the lived experience.

The first word in material control is material

International Nuclear Information System (INIS)

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

1989-01-01

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

Composite Materials

DEFF Research Database (Denmark)

Nielsen, Lauge Fuglsang

This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry......, viscoelastic behavior, and internal stress states. Other physical properties considered are thermal and electrical conductivities, diffusion coefficients, dielectric constants and magnetic permeability. Special attention is given to the effect of pore shape on the mechanical and physical behavior of porous....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro-thermal behavior...

Various Effects of Sandblasting of Dental Restorative Materials.

Directory of Open Access Journals (Sweden)

Goro Nishigawa

Full Text Available Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC group and non-ultrasonic cleaning (NUSC group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.

Naturally radioactivity in common building materials used in Thiruvannamalai city, Tamilnadu, India

International Nuclear Information System (INIS)

Ravisankar, R.; Vanasundari, K.; Suganya, M.; Sivakumar, S.; Senthilkumar, G.; Chandramohan, J.; Vijayagopal, P.; Venkatraman, B.

2012-01-01

The radioactivity of some building materials used in Thiruvannamalai city has been measured using a NaI(Tl) detector based gamma ray spectrometer. The distribution of natural occurring radionuclides ( 226 Ra, 232 Th and 40 K) in the building materials was studied. The radium equivalent activity (Ra eq ), external hazard index (H ex ) internal radiation hazard index (H in ) and the activity utilization index (I) associated with the natural radionuclide are calculated to assess the radiation hazard of the natural radioactivity in the building materials. The present work shows that the natural radioactivity levels in the building construction materials used in Thiruvannamalai city is well below the acceptable limits. From the analysis, it was found that these materials may be safely used as construction materials and do not pose significant radiation hazards. (author)

Cavity nonlinear optics with layered materials

Directory of Open Access Journals (Sweden)

Fryett Taylor

2017-12-01

Full Text Available Unprecedented material compatibility and ease of integration, in addition to the unique and diverse optoelectronic properties of layered materials, have generated significant interest in their utilization in nanophotonic devices. While initial nanophotonic experiments with layered materials primarily focused on light sources, modulators, and detectors, recent efforts have included nonlinear optical devices. In this paper, we review the current state of cavity-enhanced nonlinear optics with layered materials. Along with conventional nonlinear optics related to harmonic generation, we report on emerging directions of nonlinear optics, where layered materials can potentially play a significant role.

Study of Material Compatibility for a Thermal Energy Storage System with Phase Change Material

Directory of Open Access Journals (Sweden)

Songgang Qiu

2018-03-01

Full Text Available The suitability of stainless steel 316L and Inconel 625 for use in a latent heat thermal energy storage (TES system was investigated. A NaCl–NaF eutectic mixture with a melting temperature of 680 °C was used as the phase change material (PCM. Containers were filled with the PCM prior to heating to 750 °C, then examined after 100 and 2500 h of high-temperature exposure by analyzing the material surface and cross-section areas. A small amount of corrosion was present in both samples after 100 h. Neither sample suffered significant damage after 2500 h. The undesirable inter-granular grain boundary attack found in SS316L samples was in the order of 1–2 µm in depth. On Inconel 625 sample surface, an oxide complex formed, resisting material dissolution into the PCM. The surface morphology of tested samples remained largely unchanged after 2500 h, but the corrosion pattern changed from an initially localized corrosion penetration to a more uniform type. After 2500 h, the corrosion depth of Inconel 625 remained at roughly 1–2 µm, indicating that the corrosion rate decelerated. Both materials demonstrated good compatibility with the chosen NaF–NaCl eutectic salt, but the low corrosion activity in Inconel 625 samples shows a performance advantage for long term operation.

Novel kaolin/polysiloxane based organic-inorganic hybrid materials: Sol-gel synthesis, characterization and photocatalytic properties

Science.gov (United States)

dos Reis, Glaydson Simões; Lima, Eder Cláudio; Sampaio, Carlos Hoffmann; Rodembusch, Fabiano Severo; Petter, Carlos Otávio; Cazacliu, Bogdan Grigore; Dotto, Guillherme Luiz; Hidalgo, Gelsa Edith Navarro

2018-04-01

New hybrid materials using kaolin and the organosilicas methyl-polysiloxane (MK), methyl-phenyl-polysiloxane (H44), tetraethyl-ortho-silicate (TEOS) and 3-amino-propyl-triethoxysilane (APTES) were obtained by sol-gel process. These materials presented specific surfaces areas (SBET) in the range of 20-530 m2 g-1. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed remarkable differences between the kaolin and hybrid structures. Thermogravimetric analysis (TGA) revealed that the hybrid materials presented higher thermal stability when compared with their precursors. The electronic properties of the materials were also studied by Ultraviolet-Visible Diffuse Reflectance Absorption (DRUV) and Diffuse Reflectance spectroscopy (DR), where a new absorption band was observed located around 400-660 nm. In addition, these materials exhibit a decrease in DR from 30% to 70% in the blue-cyan green region and are significantly more transparent in the UV region than the kaolin, which could be useful for photocatalysis applications. These results show that the electronic structure of the final material was changed, indicating a significant interaction between the kaolin and the respective silica derivative. These findings support the main idea of the hybridization afforded by pyrolysis between kaolin and organosilica precursors. In addition, as a proof of concept, these hybrid materials were successfully employed as photocatalyst in the photoreduction of Cr(VI) to Cr(III).

Theory of Mind, Material Altruism and Family Context in Preschoolers

Science.gov (United States)

Keskin, Burhanettin; Jones, Ithel

2011-01-01

The relationship between theory of mind, material altruism, and family context was examined. Forty-one preschool children (16 females and 25 males) enrolled in a private school participated in the study. Results of this study showed no relationship between theory of mind and altruism. There were no significant correlations between theory of mind…

Basis material decomposition method for material discrimination with a new spectrometric X-ray imaging detector

Science.gov (United States)

Brambilla, A.; Gorecki, A.; Potop, A.; Paulus, C.; Verger, L.

2017-08-01

Energy sensitive photon counting X-ray detectors provide energy dependent information which can be exploited for material identification. The attenuation of an X-ray beam as a function of energy depends on the effective atomic number Zeff and the density. However, the measured attenuation is degraded by the imperfections of the detector response such as charge sharing or pile-up. These imperfections lead to non-linearities that limit the benefits of energy resolved imaging. This work aims to implement a basis material decomposition method which overcomes these problems. Basis material decomposition is based on the fact that the attenuation of any material or complex object can be accurately reproduced by a combination of equivalent thicknesses of basis materials. Our method is based on a calibration phase to learn the response of the detector for different combinations of thicknesses of the basis materials. The decomposition algorithm finds the thicknesses of basis material whose spectrum is closest to the measurement, using a maximum likelihood criterion assuming a Poisson law distribution of photon counts for each energy bin. The method was used with a ME100 linear array spectrometric X-ray imager to decompose different plastic materials on a Polyethylene and Polyvinyl Chloride base. The resulting equivalent thicknesses were used to estimate the effective atomic number Zeff. The results are in good agreement with the theoretical Zeff, regardless of the plastic sample thickness. The linear behaviour of the equivalent lengths makes it possible to process overlapped materials. Moreover, the method was tested with a 3 materials base by adding gadolinium, whose K-edge is not taken into account by the other two materials. The proposed method has the advantage that it can be used with any number of energy channels, taking full advantage of the high energy resolution of the ME100 detector. Although in principle two channels are sufficient, experimental measurements show

Environmental impacts of construction materials. A report on the contribution of construction materials to greenhouse gas emissions of construction; Rakennusmateriaalien ympaeristoevaikutukset. Selvitys rakennusmateriaalien vaikutuksesta rakentamisen kasvihuonekaasupaeaestoeihin, tiivistelmaeraportti

Energy Technology Data Exchange (ETDEWEB)

Ruuska, A.; Haekkinen, T.; Vares, S.; Korhonen, M.-R.; Myllymaa, T.

2013-05-15

As the energy performance of new construction improves and the related greenhouse gas (GHG) emissions diminish the carbon footprint of construction materials becomes more important. One objective in the current government's programme is to take into account construction materials and products in the energy performance assessment of buildings. At the request of the Ministry of the Environment, VTT Technical Research Centre of Finland and the Finnish Environment Institute analysed, through a case study, the significance of the environmental impacts of construction materials. The aim was to develop preliminary recommendations for guiding construction. The case study calculated the overall GHG emissions from the materials used in an apartment building over its life cycle and estimated the range of emissions. In addition, the amount of construction waste was assessed, as was the effects of waste management and waste utilisation processes on GHG emissions. This report presents a summary of the results. According to this case study, GHG emissions can vary in typical multi-storey residential buildings within the range of 1 to 2.2 or 1 to 3.9 when the site foundation work also taken into account. The study shows that the construction materials and related processes contribute significantly to the GHG emissions of a building over its life cycle. In fact the level of significance is of the same order as the heating of spaces in an A-class energy performance building. The efficient recycling of materials can contribute to reductions in GHG emissions. The study showed that the estimated benefit was 9 % of the total life-cycle emissions. In the future, specific assessments of different types of waste could look at opportunities for the recycling and reuse of critical materials. Plastics and wood are especially important waste components. Future research topics include improving the use of recycled materials, collecting information on user experiences and enhancing quality

Characterization of sialon-type materials

Energy Technology Data Exchange (ETDEWEB)

Spencer, Paul Newman [Univ. of California, Berkeley, CA (United States)

1977-06-01

Four sialon-type materials using volcanic ash as a raw material were characterized and some of their properties were determined. The M3 and M4 materials were identified as β¹--Si₃N₄ sialons; their principal constituent is silicon. The M2 material was identified as a 15R-A1N polytype sialon whose principal constituent is aluminum. The M1 material is a mixture of the two types. An overview of results showing the general structural formulae and the relative order of the materials with respect to various properties as determined by the investigation is presented. It is concluded that of the materials tested, the M2 material shows the most promise as a candidate for meeting some of the current needs for high-temperature materials. It is also concluded that more research is needed in order to explain the low resistance of these materials to thermal shock since their coefficients of thermal expansion are relatively low.

Basic Thermal Parameters of Selected Foods and Food Raw Materials

Directory of Open Access Journals (Sweden)

Monika Božiková

2017-01-01

Full Text Available In general, processing and manipulation with foods and food raw materials have significant influence on their physical properties. The article is focused on thermophysical parameters measurement of selected foods and food raw materials. There were examined thermal conductivity and thermal diffusivity of selected materials. For detection of thermal parameters was used instrument Isomet 2104, which principle of measurement is based on transient methods. In text are presented summary results of thermal parameters measurement for various foods and food raw materials as: granular materials – corn flour and wheat flour; fruits, vegetables and fruit products – grated apple, dried apple and apple juice; liquid materials – milk, beer etc. Measurements were performed in two temperature ranges according to the character of examined material. From graphical relations of thermophysical parameter is evident, that thermal conductivity and diffusivity increases with temperature and moisture content linearly, only for granular materials were obtained non‑linear dependencies. Results shows, that foods and food raw materials have different thermal properties, which are influenced by their type, structure, chemical and physical properties. From presented results is evident, that basic thermal parameters are important for material quality detection in food industry.

Assessment of the significance of organically-bound tritium in environmental materials

International Nuclear Information System (INIS)

Brown, R.M.

1988-09-01

The present state of knowledge of the significance, with respect to dose, or organically-bound tritium (OBT) in diet items has been reviewed. Ratios of the specific activity of the OBT to that of the free water (HTO) in foodstuffs have been commonly reported in the range of 1 to 4. A metabolism model of Etnier, Travis and Hetrick that takes direct assimilation of food OBT into account indicates that such levels result in a dose two to three times greater than that calculated solely on the basis of body water tritium content. Very high OBT/HTO values reported by Italian studies on food items are discounted. It is recommended that OBT/HTO measurements be done on Canadian diet items and that tritium metabolism models be more thoroughly evaluated. 71 refs

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

Directory of Open Access Journals (Sweden)

Wenning Shen

Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

Evaluation of color stability of different temporary restorative materials

Directory of Open Access Journals (Sweden)

José Vitor Quinelli Mazaro

Full Text Available AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG and 30 test specimens (15 mm in diameter and 2 mm thick per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee and storage time intervals (2, 5, 7 and 15 days. Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767. As regards solutions tested, coffee showed the highest color change values (p<0.001, and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001.ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

Surface Characteristics and Biofilm Development on Selected Dental Ceramic Materials

Directory of Open Access Journals (Sweden)

Kyoung H. Kim

2017-01-01

Full Text Available Background. Intraoral adjustment and polishing of dental ceramics often affect their surface characteristics, promoting increased roughness and consequent biofilm growth. This study correlated surface roughness to biofilm development with four commercially available ceramic materials. Methods. Four ceramic materials (Vita Enamic®, Lava™ Ultimate, Vitablocs Mark II, and Wieland Reflex® were prepared as per manufacturer instructions. Seventeen specimens of each material were adjusted and polished to simulate clinical intraoral procedures and another seventeen remained unaltered. Specimens were analysed by SEM imaging, confocal microscopy, and crystal violet assay. Results. SEM images showed more irregular surface topography in adjusted specimens than their respective controls. Surface roughness (Ra values were greater in all materials following adjustments. All adjusted materials with the exception of Vitablocs Mark II promoted significantly greater biofilm growth relative to controls. Conclusion. Simulated intraoral polishing methods resulted in greater surface roughness and increased biofilm accumulation.

Laser Materials Processing for NASA's Aerospace Structural Materials

Science.gov (United States)

Nagarathnam, Karthik; Hunyady, Thomas A.

2001-01-01

Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, and surface treatment. Due to the multifunctional nature of a single tool and the variety of materials that can be processed, these attributes are attractive in order to support long-term missions in space. However, current laser technology also has drawbacks for space-based applications. Specifically, size, power efficiency, lack of robustness, and problems processing highly reflective materials are all concerns. With the advent of recent breakthroughs in solidstate laser (e.g., diode-pumped lasers) and fiber optic technologies, the potential to perform multiple processing techniques in space has increased significantly. A review of the historical development of lasers from their infancy to the present will be used to show how these issues may be addressed. The review will also indicate where further development is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. Both short- and long-term space missions will benefit from the development of a universal laser-based tool with low power consumption, improved process flexibility, compactness (e.g., miniaturization), robustness, and automation for maximum utility with a minimum of human interaction. The potential advantages of using lasers with suitable wavelength and beam properties for future space missions to the moon, Mars and beyond will be discussed. The laser processing experiments in the present report were performed using a diode pumped, pulsed/continuous wave Nd:YAG laser (50 W max average laser power), with a 1064 nm wavelength. The processed materials included Ti-6AI-4V, Al-2219 and Al-2090. For Phase I of this project, the laser process conditions were varied and optimized

Human and Animal Isolates of Yersinia enterocolitica Show Significant Serotype-Specific Colonization and Host-Specific Immune Defense Properties

Science.gov (United States)

Schaake, Julia; Kronshage, Malte; Uliczka, Frank; Rohde, Manfred; Knuuti, Tobias; Strauch, Eckhard; Fruth, Angelika; Wos-Oxley, Melissa

2013-01-01

Yersinia enterocolitica is a human pathogen that is ubiquitous in livestock, especially pigs. The bacteria are able to colonize the intestinal tract of a variety of mammalian hosts, but the severity of induced gut-associated diseases (yersiniosis) differs significantly between hosts. To gain more information about the individual virulence determinants that contribute to colonization and induction of immune responses in different hosts, we analyzed and compared the interactions of different human- and animal-derived isolates of serotypes O:3, O:5,27, O:8, and O:9 with murine, porcine, and human intestinal cells and macrophages. The examined strains exhibited significant serotype-specific cell binding and entry characteristics, but adhesion and uptake into different host cells were not host specific and were independent of the source of the isolate. In contrast, survival and replication within macrophages and the induced proinflammatory response differed between murine, porcine, and human macrophages, suggesting a host-specific immune response. In fact, similar levels of the proinflammatory cytokine macrophage inflammatory protein 2 (MIP-2) were secreted by murine bone marrow-derived macrophages with all tested isolates, but the equivalent interleukin-8 (IL-8) response of porcine bone marrow-derived macrophages was strongly serotype specific and considerably lower in O:3 than in O:8 strains. In addition, all tested Y. enterocolitica strains caused a considerably higher level of secretion of the anti-inflammatory cytokine IL-10 by porcine than by murine macrophages. This could contribute to limiting the severity of the infection (in particular of serotype O:3 strains) in pigs, which are the primary reservoir of Y. enterocolitica strains pathogenic to humans. PMID:23959720

Effects of packaging materials on storage quality of peanut kernels

Science.gov (United States)

Fu, Xiaoji; Xing, Shengping; Xiong, Huiwei; Min, Hua; Zhu, Xuejing; He, Jialin; Mu, Honglei

2018-01-01

In order to obtain optimum packaging materials for peanut kernels, the effects of four types of packaging materials on peanut storage quality (coat color, acid value, germination rate, relative damage, and prevention of aflatoxin contamination) were examined. The results showed that packaging materials had a major influence on peanut storage quality indexes. The color of the peanut seed coat packaged in the polyester/aluminum/polyamide/polyethylene (PET/AL/PA/PE) composite film bag did not change significantly during the storage period. Color deterioration was slower with polyamide/polyethylene (PA/PE) packaging materials than with polyethylene (PE) film bags and was slower in PE bags than in the woven bags. The use of PET/AL/PA/PE and PA/PE bags maintained peanut quality and freshness for more than one year and both package types resulted in better germination rates. There were significant differences between the four types of packaging materials in terms of controlling insect pests. The peanuts packaged in the highly permeable woven bags suffered serious invasion from insect pests, while both PET/AL/PA/PE and PA/PE bags effectively prevented insect infection. Peanuts stored in PET/AL/PA/PE and PA/PE bags were also better at preventing and controlling aflatoxin contamination. PMID:29518085

Investigation of Kevlar fabric based materials for use with inflatable structures

Science.gov (United States)

Niccum, R. J.; Munson, J. B.

1974-01-01

Design, manufacture and testing of laminated and coated composite materials incorporating a structural matrix of Kevlar are reported in detail. The practicality of using Kevlar in aerostat materials is demonstrated and data are provided on practical weaves, lamination and coating particulars, rigidity, strength, weight, elastic coefficients, abrasion resistance, crease effects, peel strength, blocking tendencies, helium permeability, and fabrication techniques. Properties of the Kevlar based materials are compared with conventional, Dacron reinforced counterparts. A comprehensive test and qualification program is discussed and quantitative biaxial tensile and shear test data are provided. The investigation shows that single ply laminates of Kevlar and plastic films offer significant strength to weight improvements, are less permeable than two ply coated materials, but have a lower flex life.

Reference materials and representative test materials: the nanotechnology case

International Nuclear Information System (INIS)

Roebben, G.; Rasmussen, K.; Kestens, V.; Linsinger, T. P. J.; Rauscher, H.; Emons, H.; Stamm, H.

2013-01-01

An increasing number of chemical, physical and biological tests are performed on manufactured nanomaterials for scientific and regulatory purposes. Existing test guidelines and measurement methods are not always directly applicable to or relevant for nanomaterials. Therefore, it is necessary to verify the use of the existing methods with nanomaterials, thereby identifying where modifications are needed, and where new methods need to be developed and validated. Efforts for verification, development and validation of methods as well as quality assurance of (routine) test results significantly benefit from the availability of suitable test and reference materials. This paper provides an overview of the existing types of reference materials and introduces a new class of test materials for which the term ‘representative test material’ is proposed. The three generic concepts of certified reference material, reference material(non-certified) and representative test material constitute a comprehensive system of benchmarks that can be used by all measurement and testing communities, regardless of their specific discipline. This paper illustrates this system with examples from the field of nanomaterials, including reference materials and representative test materials developed at the European Commission’s Joint Research Centre, in particular at the Institute for Reference Materials and Measurements (IRMM), and at the Institute for Health and Consumer Protection (IHCP).

Standard format and content for a licensee physical security plan for the protection of special nuclear material of moderate or low strategic significance (Revision 1, Feb. 1983)

International Nuclear Information System (INIS)

Anon.

1983-01-01

This regulatory guide describes the information required in the physical security plan submitted as part of an application for a license to possess, use, or transport Special Nuclear Materials (SNM) of moderate strategic significance or 10 kg or more of SNM of low strategic significance and recommends a standard format for presenting the information in an orderly arrangement. This standard format will thus serve as an aid to uniformity and completeness in the preparation and review of the physical security plan of the license application. This document can also be used as guidance by licensees possessing or transporting less than 10 kg of SNM of low strategic significance in understanding the intent and implementing the requirements of paragraphs 73.67(a), 73.67(f), and 73.67(g) of 10 CFR Part 73

[Biomimetic nanohydroxyapatite/gelatin composite material preparation and in vitro study].

Science.gov (United States)

Li, Siriguleng; Hu, Xiaowen

2014-09-01

To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility. We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit. Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3. Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.

Evaluation Of Gas Diffusion Through Plastic Materials Used In Experimental And Sampling Equipment

DEFF Research Database (Denmark)

Kjeldsen, Peter

1993-01-01

. Calculations show that diffusion of oxygen through plastic tubing and reactors into anoxic water can be a serious problem for a series of plastic materials. Comparison of the method for turbulent and laminar flow in tubings shows that the difference is insignificant for most cases. Calculations show also......Plastic materials are often used in experimental and sampling equipment. Plastics are not gas tight, since gases are able to diffuse through the walls of tubing and containers made of plastic. Methods for calculating the significance of gas diffusion through the walls of containers and the walls...... of tubings for both turbulent and laminar flow conditions is presented. A more complex model for diffusion under laminar flow conditions is developed. A comprehensive review on gas diffusion coefficients for the main gases (O2, N2, CO2, CH4 etc.) and for a long range of plastic materials is also presented...

Composite Material Suitable for Use as Electrode Material in a SOC

DEFF Research Database (Denmark)

2010-01-01

The present invention relates to composite material suitable for use as an electrode material in a solid oxide cell, said composite material consist of at least two non-miscible mixed ionic and electronic conductors. Further provided is a composite material suitable for use as an electrode material...... in a solid oxide cell, said composite material being based on (Gd1-xSrx)1-sFe1-yCoyO3-[delta] or (Ln1-xSrx)1-sFe1-yCioyO3-[delta](s equal to 0.05 or larger) wherein Ln is a lanthanide element, Sc or Y, said composite material comprising at least two phases which are non-miscible, said composite material...... being obtainable by the glycine nitrate combustion method. Said composite material may be used for proving an electrode material in the form of at least a two-phase system showing a very low area specific resistance of around 0.1 [Omega]cm2 at around 600 DEG C....

Durability of Selected Membrane Materials when Exposed to Chlorine Gas

Energy Technology Data Exchange (ETDEWEB)

Eikeland, Marianne Soerflaten

2001-03-01

This thesis is focusing on the durability of selected membrane materials when exposed to chlorine gas in the temperature range 30-100{sup o}C. Studies of the changes of membrane separation properties and the mechanisms promoting these changes have been studied. The selected membrane materials were poly(dimethylsioxane) (PDMS), Fluorel, fluorosilicone, and blends of PDMS and Fluorel. The thesis is organised in seven chapters. The first chapter gives an introduction to the background of the work. The second chapter presents the theory for gas separation using dense rubbery membranes. The properties of the selected membrane materials are presented in chapter three. The fourth chapter describes degradation mechanisms for polymeric materials in general and for the selected membrane materials in particular. Presentation of the experimental work is given in chapter five, while the results with discussions are presented in chapter six. The conclusions and recommendations for further studies are given in chapter seven. Five appendixes are attached: Appendix A describes the calculations of permeability and solubility coefficients and the accuracy of the experimental measurements. Appendix B summarises the measured values in tables and Appendix C describes the analytical methods. Appendix D gives the properties of the gases used in the experiments. Appendix E is the article ''Durability of Poly(dimethylsiloxane) when Exposed to Chlorine Gas'', submitted to the Journal of Applied Polymer Science. Highly crosslinked PDMS was found to have an initial high permeability for chlorine gas and a high Cl{sub 2}/O{sub 2} selectivity. However when exposed to chlorine gas the permeability decreased significantly. Crosslinking of the PDMS polymer chain and chlorination of the polymer gave a denser polymer structure and thus lower permeability. Fluorel showed very low permeabilities and selectivities for the gases in question and was thus not interesting for this

Age distribution of human gene families shows significant roles of both large- and small-scale duplications in vertebrate evolution.

Science.gov (United States)

Gu, Xun; Wang, Yufeng; Gu, Jianying

2002-06-01

The classical (two-round) hypothesis of vertebrate genome duplication proposes two successive whole-genome duplication(s) (polyploidizations) predating the origin of fishes, a view now being seriously challenged. As the debate largely concerns the relative merits of the 'big-bang mode' theory (large-scale duplication) and the 'continuous mode' theory (constant creation by small-scale duplications), we tested whether a significant proportion of paralogous genes in the contemporary human genome was indeed generated in the early stage of vertebrate evolution. After an extensive search of major databases, we dated 1,739 gene duplication events from the phylogenetic analysis of 749 vertebrate gene families. We found a pattern characterized by two waves (I, II) and an ancient component. Wave I represents a recent gene family expansion by tandem or segmental duplications, whereas wave II, a rapid paralogous gene increase in the early stage of vertebrate evolution, supports the idea of genome duplication(s) (the big-bang mode). Further analysis indicated that large- and small-scale gene duplications both make a significant contribution during the early stage of vertebrate evolution to build the current hierarchy of the human proteome.

Final environmental assessment and Finding-of-No-Significant-Impact - drum storage facility for interim storage of materials generated by environmental restoration operations

International Nuclear Information System (INIS)

1994-09-01

The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-0995, for the construction and operation of a drum storage facility at Rocky Flats Environmental Technology Site, Golden, Colorado. The proposal for construction of the facility was generated in response to current and anticipated future needs for interim storage of waste materials generated by environmental restoration operations. A public meeting was held on July 20, 1994, at which the scope and analyses of the EA were presented. The scope of the EA included evaluation of alternative methods of storage, including no action. A comment period from July 5, 1994 through August 4, 1994, was provided to the public and the State of Colorado to submit written comment on the EA. No written comments were received regarding this proposed action, therefore no comment response is included in the Final EA. Based on the analyses in the EA, DOE has determined that the proposed action would not significantly affect the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, preparation of an Environmental Impact Statement is not required and the Department is issuing this Finding of No Significant Impact

Color stability evaluation of aesthetic restorative materials

Directory of Open Access Journals (Sweden)

Adriana Postiglione Bührer Samra

2008-09-01

Full Text Available Color match is one of the most important characteristics of aesthetic restorative materials. Maintenance of color throughout the functional lifetime of restorations is important for the durability of treatment. This characteristic is not constant among dental materials. The purpose of this research was to assess the color stability of five aesthetic restorative materials when immersed in a coffee solution. Seventy-one 17 mm x 1 mm specimens, divided into five groups, were made using one direct composite resin (Tetric Ceram®, Ivoclar/Vivadent - G1, three indirect composite resins (Targis, Ivoclar/Vivadent - G2; Resilab Master, Wilcos - G3; belleGlassTM HP, Kerr - G4 and one porcelain (IPS Empress® 2, Ivoclar/Vivadent - G5. The specimens were immersed in a coffee staining media for 15 days and stored under a controlled temperature of 37°C ± 1°C in the dark. The evaluations were made after 1, 7 and 15 days by means of reflectance spectrophotometry. The data was submitted to two-way ANOVA (p < 0.005 and post hoc tests. Statistical difference was observed between G1 / G3 and the other groups; G2 / G4 and the other groups; and G5 and all the other groups. It was concluded that G1 and G3 showed significantly higher discoloration than the other groups. G2 and G4 showed intermediary pigmentation, while G5 showed the smallest changes.

Application of Glow Discharge Plasma to Alter Surface Properties of Materials

Science.gov (United States)

Trigwell, Steve; Buhler, Charles R.; Calle, Carlos I.

2005-01-01

Some polymer materials that are considered important for spaceport operations are rendered noncompliant when subjected to the Kennedy Space Center (KSC) Standard electrostatic testing. These materials operate in stringent environmental conditions, such as high humidity. Treating materials that fail electrostatic testing and altering their surface properties so that they become compliant would result in considerable cost savings. Significant improvement in electrostatic dissipation of Saf-T-Vu PVC after treatment with air Atmospheric Plasma Glow Discharge (APGD) was observed and the material now passed the KSC electrostatic test. The O:C ratio on the surface, as monitored by X-ray Photoelectron Spectroscopy, increased from 0.165 tO 0.275 indicating enhanced oxidation, and surface contact angle measurements decreased from 107.5 to 72.6 showing increased hydrophilicity that accounted for the increased conductivity. Monitoring of the aging showed that the materials hydrophobic recovery resulted in it failing the electrostatic test 30 hours after treatment. This was probably due to the out-diffusion of the added Zn, Ba, and Cd salt stabilizers detected on the surface and/or diffusion of low molecular weight oligomers. On going work includes improving the long term hydrophilicity by optimizing the APGD process with different gas mixtures. Treatment of other spaceport materials is also presented.

Synthesis, properties and applications of 2D non-graphene materials

International Nuclear Information System (INIS)

Wang, Feng; Wang, Zhenxing; Wang, Qisheng; Wang, Fengmei; Yin, Lei; Xu, Kai; Huang, Yun; He, Jun

2015-01-01

As an emerging class of new materials, two-dimensional (2D) non-graphene materials, including layered and non-layered, and their heterostructures are currently attracting increasing interest due to their promising applications in electronics, optoelectronics and clean energy. In contrast to traditional semiconductors, such as Si, Ge and III–V group materials, 2D materials show significant merits of ultrathin thickness, very high surface-to-volume ratio, and high compatibility with flexible devices. Owing to these unique properties, while scaling down to ultrathin thickness, devices based on these materials as well as artificially synthetic heterostructures exhibit novel and surprising functions and performances. In this review, we aim to provide a summary on the state-of-the-art research activities on 2D non-graphene materials. The scope of the review will cover the preparation of layered and non-layered 2D materials, construction of 2D vertical van der Waals and lateral ultrathin heterostructures, and especially focus on the applications in electronics, optoelectronics and clean energy. Moreover, the review is concluded with some perspectives on the future developments in this field. (topical review)

SIMS studies of low-K materials

International Nuclear Information System (INIS)

Lin Xuefeng; Smith, Stephen P.

2006-01-01

We report progress in conducting quantitative SIMS analyses of low-K materials. Electron-beam (e-beam) pre-irradiation of SIMS measurement sites was used to study the e-beam-induced effects on SIMS depth profiling of a porous organosilicate low-K material. Pre-irradiation of the sample surface using the e-beam causes a reduction in the thickness of the low-K film. SIMS profiling was used to sputter to identifiable marker positions within the pre-irradiated film. Physical measurement of the thickness of the remaining film was used to show that the e-beam-induced reduction in thickness occurs uniformly throughout the pre-irradiated film. Exposure of the film to the e-beam prior to SIMS analysis also resulted in minor changes in the composition of the film. However, pre-irradiation of the film is not part of the normal SIMS measurement procedure. We conclude that when the e-beam irradiation is used only for charge compensation during SIMS depth profiling, the SIMS analysis of the low-K material will not be significantly affected

Powder Materials and Energy Efficiency in Transportation: Opportunities and Challenges

Science.gov (United States)

Marquis, Fernand D. S.

2012-03-01

The transportation industry accounts for one quarter of global energy use and has by far the largest share of global oil consumption. It used 51.5% of the oil worldwide in 2003. Mobility projections show that it is expected to triple by 2050 with associated energy use. Considerable achievements recently have been obtained in the development of powder and powder-processed metallic alloys, metal matrix composites, intermetallics, and carbon fiber composites. These achievements have resulted in their introduction to the transportation industry in a wide variety of transportation components with significant impact on energy efficiency. A significant number of nano, nanostructured, and nanohybrid materials systems have been deployed. Others, some of them incorporating carbon nanotubes and graphene, are under research and development and exhibit considerable potential. Airplane redesign using a materials and functional systems integration approach was used resulting in considerable system improvements and energy efficiency. It is expected that this materials and functional systems integration soon will be adopted in the design and manufacture of other advanced aircrafts and extended to the automotive industry and then to the marine transportation industry. The opportunities for the development and application of new powder materials in the transportation industry are extensive, with considerable potential to impact energy utilization. However, significant challenges need to be overcome in several critical areas.

Measurement of natural radioactivity in building materials used in Urumqi, China.

Science.gov (United States)

Ding, Xiang; Lu, Xinwei; Zhao, Caifeng; Yang, Guang; Li, Nan

2013-07-01

Building materials contain natural radionuclides (226)Ra, (232)Th and (40)K, which cause direct radiation exposure of the public. The concentrations of (226)Ra, (232)Th and (40)K in commonly used building materials of Urumqi, China have been analysed using gamma-ray spectrometry. The concentrations of (226)Ra, (40)K and (232)Th in the studied building materials range from 19.8 to 87.4, from 273.3 to 981.2 and from 11.6 to 47.7 Bq kg(-1), respectively. The radium equivalent activity (Raeq), gamma index (Iγ) and alpha index (Iα) were calculated to assess the radiation hazards to people living in dwellings made of the materials studied. The calculated Raeq values of all the building materials are lower than the limit of 370 Bq kg(-1) for building materials. The values of Iγ and Iα of all the building materials are less than unity. The study shows that these materials may be safely used as construction materials and do not pose significant radiation hazards.

Linear Dimensional Stability of Irreversible Hydrocolloid Materials Over Time.

Science.gov (United States)

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

2015-12-01

The aim of this study was to evaluate the linear dimensional stability of different irreversible hydrocolloid materials over time. A metal mold was designed with custom trays made of thermoplastic sheets (Sabilex, sheets 0.125 mm thick). Perforations were made in order to improve retention of the material. Five impressions were taken with each of the following: Kromopan 100 (LASCOD) [AlKr], which has dimensional stability of 100 hours, and Phase Plus (ZHERMACK) [AlPh], which has dimensional stability of 48 hours. Standardized digital photographs were taken at different time intervals (0, 15, 30, 45, 60, 120 minutes; 12, 24 and 96 hours), using an "ad-hoc" device. The images were analyzed with software (UTHSCSA Image Tool) by measuring the distance between intersection of the lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. Initial and final values were (mean and standard deviation): AlKr: 16.44 (0.22) and 16.34 (0.11), AlPh: 16.40 (0.06) and 16.18 (0.06). Statistical evaluation showed significant effect of material and time factors. Under the conditions in this study, time significantly affects the linear dimensional stability of irreversible hydrocolloid materials. Sociedad Argentina de Investigación Odontológica.

The Computational Materials Repository

DEFF Research Database (Denmark)

Landis, David D.; Hummelshøj, Jens S.; Nestorov, Svetlozar

2012-01-01

The possibilities for designing new materials based on quantum physics calculations are rapidly growing, but these design efforts lead to a significant increase in the amount of computational data created. The Computational Materials Repository (CMR) addresses this data challenge and provides...

Removable thermoplastic appliances modified by incisal cuts show altered biomechanical properties during tipping of a maxillary central incisor.

Science.gov (United States)

Brockmeyer, Phillipp; Kramer, Katharina; Böhrnsen, Florian; Gruber, Rudolf Matthias; Batschkus, Sarah; Rödig, Tina; Hahn, Wolfram

2017-08-28

The present study aimed to evaluate the force delivery of removable thermoplastic appliances (RTAs), modified by different sized incisal cuts, during tipping of a maxillary central incisor in palatal and vestibular direction. Forty-five RTAs from three different materials (Biolon®, Erkodur®, Ideal Clear®) of the same thickness (1 mm) were used. Analysis was performed on a separated maxillary central incisor which was part of a resin model with a complete dentition. In 15 RTAs, of different material, a cut was inserted at the incisal edge of tooth 11. In 15 other appliances, the cut was extended to teeth 12 and 21. Fifteen aligners remained uncut. The experimental tooth was tipped starting from the zero position in 0.05° steps to a maximal deflection of ± 0.42° of the incisal edge in vestibular and palatal direction, after positioning the RTA onto the model. The horizontal (Fx) and the vertical (Fz) force components were decreased by approximately half with increasing cut size. Fz values changed during palatal tipping from a weak intrusive force, for aligners without cut, to an extrusive force with increasing cut size. Compared to both other materials used (Erkodur® and Ideal Clear®), the Biolon® aligners showed significantly higher Fx and Fz values (p < 0.0001, respectively). RTAs modified by different sized incisal cuts show altered biomechanical properties and an inversion of the vertical force component, during tipping of a maxillary central incisor.

Wear Resistance of 3D Printing Resin Material Opposing Zirconia and Metal Antagonists

Directory of Open Access Journals (Sweden)

Ji-Man Park

2018-06-01

Full Text Available 3D printing offers many advantages in dental prosthesis manufacturing. This study evaluated the wear resistance of 3D printing resin material compared with milling and conventional resin materials. Sixty substrate specimens were prepared with three types of resin materials: 3D printed resin, milled resin, and self-cured resin. The 3D printed specimens were printed at a build angle of 0° and 100 μm layer thickness by digital light processing 3D printing. Two kinds of abraders were made of zirconia and CoCr alloy. The specimens were loaded at 5 kg for 30,000 chewing cycles with vertical and horizontal movements under thermocycling condition. The 3D printed resin did not show significant difference in the maximal depth loss or the volume loss of wear compared to the milled and the self-cured resins. No significant difference was revealed depending on the abraders in the maximal depth loss or the volume loss of wear. In SEM views, the 3D printed resin showed cracks and separation of inter-layer bonds when opposing the metal abrader. The results suggest that the 3D printing using resin materials provides adequate wear resistance for dental use.

Magnetism reflectometer study shows LiF layers improve efficiency in spin valve devices

Energy Technology Data Exchange (ETDEWEB)

Bardoel, Agatha A [ORNL; Lauter, Valeria [ORNL; Szulczewski, Greg J [ORNL

2012-01-01

New, more efficient materials for spin valves - a device used in magnetic sensors, random access memories, and hard disk drives - may be on the way based on research using the magnetism reflectometer at Oak Ridge National Laboratory (ORNL). Spin valve devices work by means of two or more conducting magnetic material layers that alternate their electrical resistance depending on the layers alignment. Giant magnetoresistance is a quantum mechanical effect first observed in thin film structures about 20 years ago. The effect is observed as a significant change in electrical resistance, depending on whether the magnetization of adjacent ferromagnetic layers is in a parallel or an antiparallel magnetic alignment. 'What we are doing here is developing new materials. The search for new materials suitable for injecting and transferring carriers with a preferential spin orientation is most important for the development of spintronics,' said Valeria Lauter, lead instrument scientist on the magnetism reflectometer at the Spallation Neutron Source (SNS), who collaborated on the experiment. The researchers discovered that the conductivity of such materials is improved when an organic polymer semiconductor layer is placed between the magnetic materials. Organic semiconductors are now the material of choice for future spin valve devices because they preserve spin coherence over longer times and distances than conventional semiconductors. While research into spin valves has been ongoing, research into organic semiconductors is recent. Previous research has shown that a 'conductivity mismatch' exists in spin valve systems in which ferromagnetic metal electrodes interface with such organic semiconductors as Alq3 ({pi}-conjugated molecule tris(8-hydroxy-quinoline) aluminium). This mismatch limits the efficient injection of the electrons from the electrodes at the interface with the semiconductor material. However, lithium fluoride (LiF), commonly used in light

Moderate running and plyometric training during off-season did not show a significant difference on soccer-related high-intensity performances compared with no-training controls.

Science.gov (United States)

Nakamura, Daisuke; Suzuki, Tomohiro; Yasumatsu, Mikinobu; Akimoto, Takayuki

2012-12-01

Several investigators have reported the effects of reduced training and interrupted training on athletic performance, but few reports are available for soccer players. The purpose of this study was to examine, using the Yo-Yo intermittent recovery level 2 (YoYoIR2) test and sprint performance, the effects on soccer players of a reduced training program consisting of either moderate running training, plyometric training. After the completion of a competitive season, 29 male soccer players were divided into 3 groups: the running group (n = 13), the plyometric group (n = 11), and the control group (n = 5). Both training groups completed either running or plyometric training sessions 2 d·wk(-1) for 3 weeks, whereas the control group was not allowed to perform any training. The subjects performed YoYoIR2 and 20-m sprint tests before (pre) and after (post) the experimental period. Neither training group showed any significant training effects on the YoYoIR2 performance or 20-m sprint times compared with the control group. This study suggests that neither endurance running nor plyometric training 2 d·wk(-1) for 3 weeks has a significant effect on high-intensity performance compared with a nontraining regimen. However, our results do not support complete inactivity. These results may have important implications for the management of training cessation for a few weeks.

Piezoelectric materials as stimulatory biomedical materials and scaffolds for bone repair.

Science.gov (United States)

Tandon, Biranche; Blaker, Jonny J; Cartmell, Sarah H

2018-04-16

The process of bone repair and regeneration requires multiple physiological cues including biochemical, electrical and mechanical - that act together to ensure functional recovery. Myriad materials have been explored as bioactive scaffolds to deliver these cues locally to the damage site, amongst these piezoelectric materials have demonstrated significant potential for tissue engineering and regeneration, especially for bone repair. Piezoelectric materials have been widely explored for power generation and harvesting, structural health monitoring, and use in biomedical devices. They have the ability to deform with physiological movements and consequently deliver electrical stimulation to cells or damaged tissue without the need of an external power source. Bone itself is piezoelectric and the charges/potentials it generates in response to mechanical activity are capable of enhancing bone growth. Piezoelectric materials are capable of stimulating the physiological electrical microenvironment, and can play a vital role to stimulate regeneration and repair. This review gives an overview of the association of piezoelectric effect with bone repair, and focuses on state-of-the-art piezoelectric materials (polymers, ceramics and their composites), the fabrication routes to produce piezoelectric scaffolds, and their application in bone repair. Important characteristics of these materials from the perspective of bone tissue engineering are highlighted. Promising upcoming strategies and new piezoelectric materials for this application are presented. Electrical stimulation/electrical microenvironment are known effect the process of bone regeneration by altering the cellular response and are crucial in maintaining tissue functionality. Piezoelectric materials, owing to their capability of generating charges/potentials in response to mechanical deformations, have displayed great potential for fabricating smart stimulatory scaffolds for bone tissue engineering. The growing

Limonene hydroperoxide analogues show specific patch test reactions.

Science.gov (United States)

Christensson, Johanna Bråred; Hellsén, Staffan; Börje, Anna; Karlberg, Ann-Therese

2014-05-01

The fragrance terpene R-limonene is a very weak sensitizer, but forms allergenic oxidation products upon contact with air. The primary oxidation products of oxidized limonene, the hydroperoxides, have an important impact on the sensitizing potency of the oxidation mixture. One analogue, limonene-1-hydroperoxide, was experimentally shown to be a significantly more potent sensitizer than limonene-2-hydroperoxide in the local lymph node assay with non-pooled lymph nodes. To investigate the pattern of reactivity among consecutive dermatitis patients to two structurally closely related limonene hydroperoxides, limonene-1-hydroperoxide and limonene-2-hydroperoxide. Limonene-1-hydroperoxide, limonene-2-hydroperoxide, at 0.5% in petrolatum, and oxidized limonene 3.0% pet. were tested in 763 consecutive dermatitis patients. Of the tested materials, limonene-1-hydroperoxide gave most reactions, with 2.4% of the patients showing positive patch test reactions. Limonene-2-hydroperoxide and oxidized R-limonene gave 1.7% and 1.2% positive patch test reactions, respectively. Concomitant positive patch test reactions to other fragrance markers in the baseline series were frequently noted. The results are in accordance with the experimental studies, as limonene-1-hydroperoxide gave more positive patch test reactions in the tested patients than limonene-2-hydroperoxide. Furthermore, the results support the specificity of the allergenic activity of the limonene hydroperoxide analogues and the importance of oxidized limonene as a cause of contact allergy. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Radioisotopes present in building materials of workplaces

Science.gov (United States)

Del Claro, F.; Paschuk, S. A.; Corrêa, J. N.; Denyak, V.; Kappke, J.; Perna, A. F. N.; Martins, M. R.; Santos, T. O.; Rocha, Z.; Schelin, H. R.

2017-11-01

The isotope 222Rn is responsible for approximately half of the effective annual dose received by the world population. The decay products of 222Rn interacting with the cells of biological tissue of lungs have very high probability to induce cancer. The present survey was focused in the evaluation of activity concentration of 222Rn and other radioisotopes related to the building materials at workplaces at Curitiba - Paraná State. For this purpose, the instant radon detector AlphaGUARD (Saphymo GmbH) was used to measure the average concentrations of 222Rn in building materials, which were also submitted to gamma spectrometry analysis for qualitative and quantitative evaluation of the radionuclides present in samples of sand, mortar, blue crushed stone (Gneissic rock), red crushed stone (Granite), concrete and red bricks. The main radionuclides evaluated by gamma spectrometry in building material samples were 238U/226Ra, 232Th and 40K. These measurements were performed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology - Paraná in collaboration with the Center of Nuclear Technology Development (CDTN - CNEN). The results of the survey present the concentration values of 222Rn related to construction materials in a range from 427±40.52 Bq/m³ to 2053±90.06 Bq/m³. The results of gamma spectroscopy analysis show that specific activity values for the mentioned isotopes are similar to the results indicated by the literature. Nevertheless, the present survey is showing the need of further studies and indicates that building materials can contribute significantly to indoor concentration of 222Rn.

Ultrathin Shape Change Smart Materials.

Science.gov (United States)

Xu, Weinan; Kwok, Kam Sang; Gracias, David H

2018-02-20

With the discovery of graphene, significant research has focused on the synthesis, characterization, and applications of ultrathin materials. Graphene has also brought into focus other ultrathin materials composed of organics, polymers, inorganics, and their hybrids. Together, these ultrathin materials have unique properties of broad significance. For example, ultrathin materials have a large surface area and high flexibility which can enhance conformal contact in wearables and sensors leading to improved sensitivity. When porous, the short transverse diffusion length in these materials allows rapid mass transport. Alternatively, when impermeable, these materials behave as an ultrathin barrier. Such controlled permeability is critical in the design of encapsulation and drug delivery systems. Finally, ultrathin materials often feature defect-free and single-crystal-like two-dimensional atomic structures resulting in superior mechanical, optical, and electrical properties. A unique property of ultrathin materials is their low bending rigidity, which suggests that they could easily be bent, curved, or folded into 3D shapes. In this Account, we review the emerging field of 2D to 3D shape transformations of ultrathin materials. We broadly define ultrathin to include materials with a thickness below 100 nm and composed of a range of organic, inorganic, and hybrid compositions. This topic is important for both fundamental and applied reasons. Fundamentally, bending and curving of ultrathin films can cause atomistic and molecular strain which can alter their physical and chemical properties and lead to new 3D forms of matter which behave very differently from their planar precursors. Shape change can also lead to new 3D architectures with significantly smaller form factors. For example, 3D ultrathin materials would occupy a smaller space in on-chip devices or could permeate through tortuous media which is important for miniaturized robots and smart dust applications. Our

Dielectric characterization of high-performance spaceflight materials

Science.gov (United States)

Kleppe, Nathan; Nurge, Mark A.; Bowler, Nicola

2015-03-01

As commercial space travel increases, the need for reliable structural health monitoring to predict possible weaknesses or failures of structural materials also increases. Monitoring of these materials can be done through the use of dielectric spectroscopy by comparing permittivity or conductivity measurements performed on a sample in use to that of a pristine sample from 100 μHz to 3 GHz. Fluctuations in these measured values or of the relaxation frequencies, if present, can indicate chemical or physical changes occurring within the material and the possible need for maintenance/replacement. In this work, we establish indicative trends that occur due to changes in dielectric spectra during accelerated aging of various high-performance polymeric materials: ethylene vinyl alcohol (EVOH), Poly (ether ether ketone) (PEEK), polyphenylene sulfide (PPS), and ultra-high molecular weight polyethylene (UHMWPE). Uses for these materials range from electrical insulation and protective coatings to windows and air- or space-craft parts that may be subject to environmental damage over long-term operation. Samples were prepared by thermal exposure and, separately, by ultraviolet/water-spray cyclic aging. The aged samples showed statistically-significant trends of either increasing or decreasing real or imaginary permittivity values, relaxation frequencies, conduction or the appearance of new relaxation modes. These results suggest that dielectric testing offers the possibility of nondestructive evaluation of the extent of age-related degradation in these materials.

Prognostic significance of cytosolic pS2 content in ovarian tumors

International Nuclear Information System (INIS)

Raigoso, P.; Allende, T.; Zeidan, N.; Llana, B.; Bernardo, L.; Roiz, C.; Tejuca, S.; Vazquez, J.; Lamelas, M.L.

2002-01-01

Aim: pS2 is an estrogen regulated peptide which has been associated with a good prognosis an with a more favorable response to treatment in breast cancer patients. In ovarian tumors, the expression of pS2 was demonstrated at both mRNA and protein levels. In addition, it has been showed significant association of pS2 with mucinous differentiation or well differentiation grade of the tumors. However, it is little know about the prognostic significance of the pS2 content in ovarian carcinomas. The aims of the present work were to analyze the cytosolic pS2 content in benign and malignant ovarian tumors, its relationship with clinico-pathologic parameters, steroid receptor status, and prognostic significance. Material and Methods: We analysed the cytosolic concentrations of pS2 in 91 specimen ovarian tissues by an immunoradiometric assay (ELSA-pS2, CIS, France). The tissues were 8 normal ovaries, 43 benign tumors and 40 malignant ovarian tumors. The same ovarian tissues processed to pS2 were analyzed to Estrogen (ER) and Progesterone (PgR) Receptor status. These steroid receptors were quantified biochemically following commercial ELISA method (ABBOTT Diagnostics, Germany). The relationship between cytosolic content and clinico-pathologic factors was examined by the Mann-Whitney or Kruskall-Wallis test. Correlation between steroid receptors and pS2 content was calculated with the Spearman test. Survival curves were calculated using the Kaplan-Meier method and compared by the log-rank test. Differences were considered significant at 5% probability level. Results: pS2 could be detected in 30 cases (32.9%) with values ranged from 0.04 to 89 ng/mg prt. Only one normal ovary showed detectable levels of pS2 and there were not differences in cytosolic content between benign and malignant ovarian tumors. The pS2 levels were only associated to mucinous differentiation in both benign and malignant ovarian tumors (p=0.029 and p=0.015, respectively). Significantly higher

Superconducting cavity material for the European XFEL

Science.gov (United States)

Singer, W.; Singer, X.; Brinkmann, A.; Iversen, J.; Matheisen, A.; Navitski, A.; Tamashevich, Y.; Michelato, P.; Monaco, L.

2015-08-01

Analysis of the strategy for superconducting cavity material procurement and quality management is done on the basis of the experience with the cavity production for the European x-ray free electron laser (EXFEL) facility. An adjustment of the material specification to EXFEL requirements, procurement of material, quality control (QC), documentation, and shipment to cavity producers have been worked out and carried out by DESY. A multistep process of qualification of the material suppliers included detailed material testing, single- and nine-cell cavity fabrication, and cryogenic radiofrequency tests. Production of about 25 000 semi-finished parts of high purity niobium and niobium-titanium alloy in a period of three years has been divided finally between companies Heraeus, Tokyo Denkai, Ningxia OTIC, and PLANSEE. Consideration of large-grain (LG) material as a possible option for the EXFEL has resulted in the production of one cryogenic module consisting of seven (out of eight) LG cavities. LG materials fulfilled the EXFEL requirements and showed even 25% to 30% higher unloaded quality factor. A possible shortage of the required quantity of LG material on the market led, however, to the choice of conventional fine-grain (FG) material. Eddy-current scanning (ECS) has been applied as an additional QC tool for the niobium sheets and contributed significantly to the material qualification and sorting. Two percent of the sheets have been rejected, which potentially could affect up to one-third of the cavities. The main imperfections and defects in the rejected sheets have been analyzed. Samples containing foreign material inclusions have been extracted from the sheets and electrochemically polished. Some inclusions remained even after 150 μm surface layer removal. Indications of foreign material inclusions have been found in the industrially fabricated and treated cavities and a deeper analysis of the defects has been performed.

High-entropy alloys as high-temperature thermoelectric materials

Energy Technology Data Exchange (ETDEWEB)

Shafeie, Samrand [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Guo, Sheng, E-mail: sheng.guo@chalmers.se [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Hu, Qiang [Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330029 (China); Fahlquist, Henrik [Bruker AXS Nordic AB, 17067 Solna (Sweden); Erhart, Paul [Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Palmqvist, Anders, E-mail: anders.palmqvist@chalmers.se [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden)

2015-11-14

Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

Material attractiveness of plutonium composition on doping minor actinide of large FBR

International Nuclear Information System (INIS)

Permana, Sidik; Suzuki, Mitsutoshi; Kuno, Yusuke

2011-01-01

Material attractiveness analysis on isotopic plutonium compositions of fast breeder reactors (FBR) has been investigated based on figure of merit (FOM) formulas as key parameters as well as decay heat (DH) and spontaneous fission neutron (SFN) compositions. Increasing minor actinide (MA) doping gives the significant effect to increase Pu-238 composition. However, the compositions of Pu-240 and Pu-242 become less with increasing MA doping. DH and SFN compositions in the core regions similar to the DH and SFN compositions of MOX-grade. Material attractiveness based on FOM1 formula shows all isotopic plutonium compositions in the blanket regions as well as in the core regions are categorized as high attractive material. Adopted FOM2 formula can distinguishes the material attractiveness levels which show the plutonium compositions in blanket regions as high attractiveness level and its composition in the core regions as low level of material attractiveness. MA doping is effective to reduce the material attractiveness level of blanket regions from high to medium and it requires much more MA doping rate to achieve low level of attractiveness (FOM<1) based on adopted FOM1 formula. Low material attractiveness level can be obtained by 4 % or more doping MA based on adopted FOM2 formula which considers not only DH composition effect, but also SFN composition effect that gives relatively higher contribution to material barrier of plutonium isotopes. (author)

Oxidation and creep behaviour of dense silicon nitride materials with different compositions

International Nuclear Information System (INIS)

Ernstberger, U.

1985-09-01

The study was intended to yield information on the oxidation and creep behaviour of Si 3 N 4 materials of different composition and microstructure, and produced by different processes. The experiments carried out in a vast temperature and load range showed that the chemical grain boundary composition is the key parameter affecting the materials' high-temperature properties. Significant correlations could be established between oxidation and creep behaviour on the one hand, and between microstructure and the behaviour on the other. (orig./IHOE) [de

Microleakage of Different Self-Adhesive Materials for Lithium Disilicate CAD/CAM Crowns

Directory of Open Access Journals (Sweden)

Ella A. Naumova

2015-06-01

Full Text Available Objectives: To evaluate the microleakage and marginal gap of various luting materials after cementing ceramic crowns. Methods: Cervical margins of human molars were designed as circular chamfers. Cementation of full-contour ceramic crowns was conducted with zinc-phosphate cement (Harvard cement, resin cement (Panavia F 2.0 and self-adhesive resin cements (RelyX Unicem, BifixSE, MaxCem Elite, PermaCem2.0, G-Cem. Aging of specimens was performed in artificial saliva, at 37 °C for four weeks and thermocycling. The marginal gap was measured with a scanning electron microscope and silver precipitation within the microleakage. All data were compared statistically. Results: Independent of the margin preparation, the highest median value for microleakage was 320.2 μm (Harvard cement, and the lowest was 0 μm (Panavia F 2.0. The median value for enamel was 0 µm and for dentin 270.9 μm (p < 0.001, which was independent of the luting material. The marginal and absolute marginal gaps were not significantly different between the tested materials. There was no correlation between microleakage and the marginal gaps. Conclusion: Significant differences in microleakage were found between the tested luting materials (p < 0.05. Independent from the luting materials, the microleakage in dentin showed significantly higher values than in enamel.

Composite materials for protection against electromagnetic microwave radiation

International Nuclear Information System (INIS)

Senyk, IV; Barsukov, VZ; Savchenko, BM; Shevchenko, KL; Plavan, VP; Shpak, Yu V; Kruykova, OA

2016-01-01

A fairly wide range of carbon-polymer composite materials was synthesized and studied in terms of their potential to protect people and electronic equipment from exposure to electromagnetic radiation (EMR). The materials studied included three main groups: (1) PVC polymer composites filled with various carbon-containing fillers (colloidal graphite, thermally expanded graphite, acetylene black, graphitized carbon black, carbon nanotubes, graphene) at concentrations ranging from 5 to 20%; (2) carbon cloth - commercial and modified with nanometal additives (e.g., nanoparticles of Cu, TiN, etc.); (3) highly-filled polymer-carbon composites in the form of paint. The transmission rate a of electromagnetic radiation was investigated for such materials in the frequency range of 10 GHz as well as their electrical conductivity. The results showed that the shielding ability of the materials of group (2) is significantly higher than that of the materials of group (1), which is probably due to the presence of strong internal skeleton of conductivity. Nevertheless, some highly-filled mixed polymer-carbon composites in the form of paint demonstrate even more shielding ability than carbon cloth and could be used for the defense against EMR. (paper)

Development of starch-based materials

NARCIS (Netherlands)

Habeych Narvaez, E.A.

2009-01-01

Starch-based materials show potential as fully degradable plastics. However, the current
applicability of these materials is limited due to their poor moisture tolerance and
mechanical properties. Starch is therefore frequently blended with other polymers to make
the material more

Dielectric Characteristics of Microstructural Changes and Property Evolution in Engineered Materials

Science.gov (United States)

Clifford, Jallisa Janet

quantitatively using BbDS. These materials are typically used in solid oxide fuel cells (SOFC). Results show significant effect of microstructural design on material properties at multiple temperatures (up to 800 °C). In the later part of the thesis, we will focus on microstructural changes of fiber reinforced composite materials due to impact and static loading. The changes in dielectric response can then be linked to the bulk mechanical properties of the material and various damage modes. Observing trends in dielectric response enables us to further determine local mechanisms and distribution of properties throughout the damaged specimens. A 3D X-ray microscope and a digital microscope have been used to visualize these changes in material microstructure and validate experimental observations. The increase in damage observed in the material microstructure can then also be linked to the changes in dielectric response. Results show that BbDS is an extremely useful tool for identifying microstructural changes within a heterogeneous material and particularly useful in relating remaining properties. Dielectric material variables can be used directly in property degradation laws and help develop a framework for future predictive modeling methodologies.

Process Design and Techno-economic Analysis for Materials to Treat Produced Waters.

Energy Technology Data Exchange (ETDEWEB)

Heimer, Brandon Walter [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Paap, Scott M [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sasan, Koroush [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Brady, Patrick Vane. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Nenoff, Tina M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2017-09-01

Significant quantities of water are produced during enhanced oil recovery making these “produced water” streams attractive candidates for treatment and reuse. However, high concentrations of dissolved silica raise the propensity for fouling. In this paper, we report the design and economic analysis for a new ion exchange process using calcined hydrotalcite (HTC) to remove silica from water. This process improves upon known technologies by minimizing sludge product, reducing process fouling, and lowering energy use. Process modeling outputs included raw material requirements, energy use, and the minimum water treatment price (MWTP). Monte Carlo simulations quantified the impact of uncertainty and variability in process inputs on MWTP. These analyses showed that cost can be significantly reduced if the HTC materials are optimized. Specifically, R&D improving HTC reusability, silica binding capacity, and raw material price can reduce MWTP by 40%, 13%, and 20%, respectively. Optimizing geographic deployment further improves cost competitiveness.

Influence of material anisotropy on the hydroelastic response of composite plates in water

Science.gov (United States)

Akcabay, Deniz Tolga; Young, Yin Lu

2018-03-01

Flexible lightweight plate-like lifting surfaces in external flows have a diverse range of use from propelling and controlling marine and aerospace vehicles to converting wind and ocean energy to electrical energy. Design and analysis of such structures are complex for underwater applications where the water density is much higher than air. The hydrodynamic loads, which vary with the inflow speed, can significantly alter the dynamic response and stability. This paper focuses on the hydroelastic response of composite plates in water. The results show that the dynamics and stability of the structure can be significantly modified by taking advantage of the material anisotropic; on the contrary, careless composite material designs may lead to unwanted dynamic instability failures. The resonance frequencies, divergence speeds, and fluid loss coefficients change with material anisotropy and hydrodynamic loads. The resonance frequencies are much lower in water than in air. The critical divergence speed increases, if the principal fiber direction is oriented towards the inflow. Hydrodynamic damping is shown to be much higher than the material damping, and tend to increase with flow speed and to decrease with increasing modal frequency. The paper derives Response Amplitude Operators (RAOs) for sample composite plates in water and use them to predict the motion response when subject to stochastic flow excitations. We show how material anisotropy can be used to passively tailor the plate vibration response spectrum to limit or enhance flow-induced vibrations of the plate depending on the desired applications.

Smuggling special nuclear materials

International Nuclear Information System (INIS)

Lazaroiu, Gheorghe

1999-01-01

Ever since the collapse of the former Soviet Union reports have circulated with increasing frequency concerning attempts to smuggle materials from that country's civil and military nuclear programs. Such an increase obviously raises a number of concerns (outlined in the author's introduction), chief among which is the possibility that these materials might eventually fall into the hands of proliferant states or terrorist groups. The following issues are presented: significance of materials being smuggled; sources and smuggling routes; potential customers; international efforts to reduce nuclear smuggling; long-term disposition of fissile materials. (author)

Superconducting composites materials

International Nuclear Information System (INIS)

Kerjouan, P.; Boterel, F.; Lostec, J.; Bertot, J.P.; Haussonne, J.M.

1991-01-01

The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa 2 Cu 3 O 7-δ material. We first realized a composite material glass/YBa 2 Cu 3 O 7-δ , by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa 2 Cu 3 O 7-δ material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs [fr

Templated assembly of photoswitches significantly increases the energy-storage capacity of solar thermal fuels.

Science.gov (United States)

Kucharski, Timothy J; Ferralis, Nicola; Kolpak, Alexie M; Zheng, Jennie O; Nocera, Daniel G; Grossman, Jeffrey C

2014-05-01

Large-scale utilization of solar-energy resources will require considerable advances in energy-storage technologies to meet ever-increasing global energy demands. Other than liquid fuels, existing energy-storage materials do not provide the requisite combination of high energy density, high stability, easy handling, transportability and low cost. New hybrid solar thermal fuels, composed of photoswitchable molecules on rigid, low-mass nanostructures, transcend the physical limitations of molecular solar thermal fuels by introducing local sterically constrained environments in which interactions between chromophores can be tuned. We demonstrate this principle of a hybrid solar thermal fuel using azobenzene-functionalized carbon nanotubes. We show that, on composite bundling, the amount of energy stored per azobenzene more than doubles from 58 to 120 kJ mol(-1), and the material also maintains robust cyclability and stability. Our results demonstrate that solar thermal fuels composed of molecule-nanostructure hybrids can exhibit significantly enhanced energy-storage capabilities through the generation of template-enforced steric strain.

New Design Concept for a Lifting Platform Made of Composite Material

Science.gov (United States)

Solazzi, L.; Scalmana, R.

2013-08-01

Elevating work platforms are hoists equipment that are increasingly used in many applications, like in the construction industry and in the maintenance field. The maintenance of the hub of the wind turbines, for example, can be done through the use of a working platform; these structures have to reach great heights and obviously they have to satisfy the constraints induced by the highway standards, like the maximum axle load and the maximum overall dimensions. To satisfy these requests the material of the structures changed from the classic structural steel (S235 JR, S275 JR or S355JR) to high strength steel (S700 to S1100 or more), characterized by a significantly higher specific resistance. The idea of this paper is to use a composite material for the construction of the arms of an elevating platform in order to reduce the global weight of the machine. The analyses on the new kind of platform show the technical possibility to change the material of the arms with composite materials and this produces a significant reduction of the weight of the machine components, about 50 %. Being a feasibility study, still remain open some problems such as the mechanical behavior of the used composite materials (fatigue, environment effects, etc.).

Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties

Directory of Open Access Journals (Sweden)

Almudena Díaz-García

2017-01-01

Full Text Available Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values.

Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties.

Science.gov (United States)

Díaz-García, Almudena; Martínez-García, Carmen; Cotes-Palomino, Teresa

2017-01-25

Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values.

Show-Bix &

DEFF Research Database (Denmark)

2014-01-01

The anti-reenactment 'Show-Bix &' consists of 5 dias projectors, a dial phone, quintophonic sound, and interactive elements. A responsive interface will enable the Dias projectors to show copies of original dias slides from the Show-Bix piece ”March på Stedet”, 265 images in total. The copies are...

Significant blockade of multiple receptor tyrosine kinases by MGCD516 (Sitravatinib), a novel small molecule inhibitor, shows potent anti-tumor activity in preclinical models of sarcoma.

Science.gov (United States)

Patwardhan, Parag P; Ivy, Kathryn S; Musi, Elgilda; de Stanchina, Elisa; Schwartz, Gary K

2016-01-26

Sarcomas are rare but highly aggressive mesenchymal tumors with a median survival of 10-18 months for metastatic disease. Mutation and/or overexpression of many receptor tyrosine kinases (RTKs) including c-Met, PDGFR, c-Kit and IGF1-R drive defective signaling pathways in sarcomas. MGCD516 (Sitravatinib) is a novel small molecule inhibitor targeting multiple RTKs involved in driving sarcoma cell growth. In the present study, we evaluated the efficacy of MGCD516 both in vitro and in mouse xenograft models in vivo. MGCD516 treatment resulted in significant blockade of phosphorylation of potential driver RTKs and induced potent anti-proliferative effects in vitro. Furthermore, MGCD516 treatment of tumor xenografts in vivo resulted in significant suppression of tumor growth. Efficacy of MGCD516 was superior to imatinib and crizotinib, two other well-studied multi-kinase inhibitors with overlapping target specificities, both in vitro and in vivo. This is the first report describing MGCD516 as a potent multi-kinase inhibitor in different models of sarcoma, superior to imatinib and crizotinib. Results from this study showing blockade of multiple driver signaling pathways provides a rationale for further clinical development of MGCD516 for the treatment of patients with soft-tissue sarcoma.

Dolphin shows and interaction programs: benefits for conservation education?

Science.gov (United States)

Miller, L J; Zeigler-Hill, V; Mellen, J; Koeppel, J; Greer, T; Kuczaj, S

2013-01-01

Dolphin shows and dolphin interaction programs are two types of education programs within zoological institutions used to educate visitors about dolphins and the marine environment. The current study examined the short- and long-term effects of these programs on visitors' conservation-related knowledge, attitude, and behavior. Participants of both dolphin shows and interaction programs demonstrated a significant short-term increase in knowledge, attitudes, and behavioral intentions. Three months following the experience, participants of both dolphin shows and interaction programs retained the knowledge learned during their experience and reported engaging in more conservation-related behaviors. Additionally, the number of dolphin shows attended in the past was a significant predictor of recent conservation-related behavior suggesting that repetition of these types of experiences may be important in inspiring people to conservation action. These results suggest that both dolphin shows and dolphin interaction programs can be an important part of a conservation education program for visitors of zoological facilities. © 2012 Wiley Periodicals, Inc.

The EBR-II materials-surveillance program. 5: Results of SURV-5

International Nuclear Information System (INIS)

Ruther, W.E.; Staffon, J.D.; Carlson, B.G.; Allen, T.R.

1998-01-01

In March of 1965, a set of surveillance (SURV) samples was placed in the EBR-II reactor to determine the effect of irradiation, thermal aging, and sodium corrosion on reactor materials. Eight subassemblies were placed into row 12 positions of EBR-II to determine the effect of irradiation at 370 C. Two subassemblies were placed into the primary sodium basket to determine the effect of thermal aging at 370 C. One half of all samples were exposed to primary system sodium while one half were sealed in capsules with a helium atmosphere. Fifteen different structural materials were tested in the SURV program. In this work, the properties of these materials irradiated at 370 C to a total fluence of 3.2 x 10 22 n/cm 2 were determined. These materials are the fifth set of irradiated subassemblies to be examined as part of the SURV program (SURV-5). The properties analyzed were weight, density, microstructure, hardness, tensile and yield strength, and fracture resistance. Of all the alloys examined in SURV-5, only Berylco-25 showed any significant weight loss. Stainless steel (both 304 and 347) had the largest density decrease, although the density decrease from irradiation for all alloys was less than 0.4 percent. The microstructure of both Berylco-25 and the aluminum-bronze alloy was altered significantly. Iron- and nickel-base alloys showed little change in microstructure. Austenitic steels (304 and 347) harden with irradiation. The hardness of Inconel X750 did not change significantly with irradiation. The ultimate tensile strength of Inconel X750, 304 stainless steel, 420 stainless steel and welded 304 changed little due to a fluence increase from 2.2 x 10 22 n/cm 2 (the maximum fluence of the SURV-4 samples) to 3.2 x 10 22 n/cm 2

[Correlation research of photosynthetic characteristics and medicinal materials production with 4 Uncariae Cum Uncis].

Science.gov (United States)

Luo, Min; Song, Zhi-Qin; Yang, Ping-Fei; Liu, Hai; Yang, Zai-Gang; Wu, Ming-Kai

2017-01-01

Using four Uncariae Cum Uncis materials including Uncaria sinensis (HGT), U. hirsutea (MGT), Jianhe U. rhynchophylla (JHGT) and U. rhynchophylla(GT) as the research objects, the correlations between medicinal materials' yield and photosynthetic ecophysiology-factors in the plant exuberant growth period were studied. Results showed that the Uncaria plants net photosynthetic rate (Pn) changed by unimodal curve. There was not "midday depression" phenomenon. There was a different relationship among the photosynthetic ecophysiology-factors and between photosynthetic ecophysiology-factors and medicinal materials' yield. Pn,Tl,Gs had a significant correlation with medicinal materials' yield（M）and were the most important factors of growth. Copyright© by the Chinese Pharmaceutical Association.

Safe transport of radioactive materials

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-12-31

The film shows the widespread use of radioactive materials in industry, medicine and research and explains the need for transporting nuclear material from producer to user. It shows the way in which packages containing radioactive materials are handled during transport and explains the most important provisions of the IAEA transport regulations, safety series no. 6, such as packaging design criteria and testing requirements, illustrated by various tests carried out, specimen packages and package and freight container labelling. Also illustrated are practical measures to be taken in case of an accident

Color change of CAD-CAM materials and composite resin cements after thermocycling.

Science.gov (United States)

Gürdal, Isil; Atay, Ayse; Eichberger, Marlis; Cal, Ebru; Üsümez, Aslihan; Stawarczyk, Bogna

2018-04-24

The color of resin cements and computer-aided-design and computer-aided-manufacturing (CAD-CAM) restorations may change with aging. The purpose of this in vitro study was to analyze the influence of thermocycling on the color of CAD-CAM materials with underlying resin cement. Seven different CAD-CAM materials, composite resins and glass-ceramics were cut into 0.7-mm and 1.2-mm thicknesses (n=10) and cemented with a dual-polymerizing resin cement, a light-polymerizing resin cement, and a preheated composite resin (N=420). Color values were measured by using spectrophotometry. Specimens were subjected to thermocycling (5°C and 55°C; 5000 cycles). The measured color difference (ΔE) data were analyzed by using descriptive statistics. Normality of data distribution was tested by using the Kolmogorov-Smirnov test. Three-way and 1-way ANOVA followed by the Scheffé post-hoc test and unpaired 2-sample Student t test were computed to determine the significant differences among the tested parameters (α=.05). ΔE values were significantly influenced by the CAD-CAM material (η p 2 =0.85, Pcement (η P 2 =0.03, P=.003) but were not influenced by thickness (P=.179). Significant interactions were present among thickness, cement, and CAD-CAM materials (Pcement showed significantly lower ΔE values than the preheated composite resin (P=.003). Restoration materials and composite resin cement types used for cementation influence the amount of color change due to aging. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A systematic concept of assuring structural integrity of components and parts for applying to highly ductile materials through brittle material

International Nuclear Information System (INIS)

Suzuki, Kazuhiko

2007-09-01

Concepts of assuring structural integrity of plant components have been developed under limited conditions of either highly ductile or brittle materials. There are some cases where operation in more and more severe conditions causes a significant reduction in ductility for materials with a high ductility before service. Use of high strength steels with relatively reduced ductility is increasing as industry applications. Current concepts of structural integrity assurance under the limited conditions of material properties or on the requirement of no significant changes in material properties even after long service will fail to incorporate expected technological innovations. A systematic concept of assuring the structural integrity should be developed for applying to highly ductile materials through brittle materials. Objectives of the on-going research are to propose a detail of the systematic concept by considering how we can develop the concept without restricting materials and for systematic considerations on a broad range of material properties from highly ductile materials through brittle materials. First, background of concepts of existing structural codes for components of highly ductile materials or for structural parts of brittle materials are discussed. Next, issues of existing code for parts of brittle materials are identified, and then resolutions to the issues are proposed. Based on the above-mentioned discussions and proposals, a systematic concept is proposed for application to components with reduced ductility materials and for applying to components of materials with significantly changing material properties due to long service. (author)

Hyperspectral surface materials map of quadrangles 2964, 2966, 3064, and 3066, Shah-Esmail (617), Reg-Alaqadari (618), Samandkhan-Karez (713), Laki-Bander (611), Jahangir-Naweran (612), and Sreh-Chena (707) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

Science.gov (United States)

Hoefen, Todd M.; King, Trude V.V.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Comparison of Two Xenograft Materials Used in Sinus Lift Procedures: Material Characterization and In Vivo Behavior

Directory of Open Access Journals (Sweden)

María Piedad Ramírez Fernández

2017-06-01

Full Text Available Detailed information about graft material characteristic is crucial to evaluate their clinical outcomes. The present study evaluates the physico-chemical characteristics of two xenografts manufactured on an industrial scale deproteinized at different temperatures (non-sintered and sintered in accordance with a protocol previously used in sinus lift procedures. It compares how the physico-chemical properties influence the material’s performance in vivo by a histomorphometric study in retrieved bone biopsies following maxillary sinus augmentation in 10 clinical cases. An X-ray diffraction analysis revealed the typical structure of hydroxyapatite (HA for both materials. Both xenografts were porous and exhibited intraparticle pores. Strong differences were observed in terms of porosity, crystallinity, and calcium/phosphate. Histomorphometric measurements on the bone biopsies showed statistically significant differences. The physic-chemical assessment of both xenografts, made in accordance with the protocol developed on an industrial scale, confirmed that these products present excellent biocompatibilitity, with similar characteristics to natural bone. The sintered HA xenografts exhibited greater osteoconductivity, but were not completely resorbable (30.80 ± 0.88% residual material. The non-sintered HA xenografts induced about 25.92 ± 1.61% of new bone and a high level of degradation after six months of implantation. Differences in the physico-chemical characteristics found between the two HA xenografts determined a different behavior for this material.

Preparation and characterization of hybrid materials based on polypyrrole and silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Nguyen Duc Nghia; Ngo Trinh Tung [Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam)], E-mail: ducnghia264@fpt.vn

2009-09-01

Hybrid material is one of the most promising materials classed in the 21st century because of its unique properties and its advanced applications. In this work, hybrid materials based on polypyrrole (Ppy) and silver nanoparicles were prepared and characterized. The preparation of the hybrid material was performed by the chemical polymerization method. The structure, electrical and thermal properties of Ppy/Ag hybrid materials were characterized by XRD, SEM, and TGA and the conventional four probe method. The results showed that the Ag particles of 4-8 nm were agglomerated during the in-situ polymerization of PPy and formed some clusters with the diameter of 25 -150 nm. By the addition of Ag particles, the electrical conductivity of Ppy increased with increasing Ag concentration. The thermal stability of Ppy was significantly improved by modification with Ag particles.

Preparation and characterization of hybrid materials based on polypyrrole and silver nanoparticles

International Nuclear Information System (INIS)

Nguyen Duc Nghia; Ngo Trinh Tung

2009-01-01

Hybrid material is one of the most promising materials classed in the 21st century because of its unique properties and its advanced applications. In this work, hybrid materials based on polypyrrole (Ppy) and silver nanoparicles were prepared and characterized. The preparation of the hybrid material was performed by the chemical polymerization method. The structure, electrical and thermal properties of Ppy/Ag hybrid materials were characterized by XRD, SEM, and TGA and the conventional four probe method. The results showed that the Ag particles of 4-8 nm were agglomerated during the in-situ polymerization of PPy and formed some clusters with the diameter of 25 -150 nm. By the addition of Ag particles, the electrical conductivity of Ppy increased with increasing Ag concentration. The thermal stability of Ppy was significantly improved by modification with Ag particles.

Evaluation of radiation effects on dental enamel hardness and dental restorative materials

International Nuclear Information System (INIS)

Adachi, Lena Katekawa; Saiki, Mitiko; Campos, Tomie Nakakuki

2000-01-01

This research presents the results of the microhardness of human dental enamel and of the following dental restorative materials: three dental porcelains - Ceramco II, Finesse and Noritake, and two resin restorative materials - Artglass and Targis, for materials submitted to different times of irradiation at the IEA-R1m nuclear reactor under a thermal neutron flux of 10 12 n cm -2 .s -1 . The results obtained indicated that there is a decrease of the surface microhardness when the enamel is irradiated for 1 h and when dental materials are irradiated for 3 h. However, enamels irradiated for 30 min. did not show significant change of their surface hardness. Therefore, the selection of irradiation time is an important factor to be considered when irradiated teeth or dental materials are used in the investigations of their properties. (author)

Effects of Surface Morphology ZnAl2O4 of Ceramic Materials on Osteoblastic Cells Responses

International Nuclear Information System (INIS)

Suarez-Franco, J.L.; Fernandez-Pedrero, J.A.; Ivarez-Perez, M.A.; Garcia-Hipolito, M.; Surarez-Rosales, M.; Fregoso, O.; Juarez-Islas, J.A.; Ivarez-Perez, M.A.

2013-01-01

Ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. The purpose of this study was to investigate the effect of surface morphology of nano structure thin films of ZnAl 2 O 4 prepared by spray pyrolysis and bulk pellets of polycrystalline ZnAl 2 O 4 prepared by chemical coprecipitation reaction on the in vitro cell adhesion, viability, and cell-material interactions of osteoblastic cells. Our result showed that cell attachment was significantly enhanced from 60 to 80% on the ZnAl 2 O 4 nano structured material surface when compared with bulk ceramic surfaces. Moreover, our results showed that the balance of morphological properties of the thin film nano structure ceramic improves cell-material interaction with enhanced spreading and filopodia with multiple cellular extensions on the surface of the ceramic and enhancing cell viability/proliferation in comparison with bulk ceramic surfaces used as control. Altogether, these results suggest that zinc aluminate nano structured materials have a great potential to be used in dental implant and bone substitute applications.Ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. The purpose of this study was to investigate the effect of surface morphology of nano structure thin films of ZnAl 2 O 4 prepared by spray pyrolysis and bulk pellets of polycrystalline ZnAl 2 O 4 prepared by chemical coprecipitation reaction on the in vitro cell adhesion, viability, and cell-material interactions of osteoblastic cells. Our result showed that cell attachment was significantly enhanced from 60 to 80% on the ZnAl 2 O 4 nano structured material surface when compared with bulk ceramic surfaces. Moreover, our results showed that the balance of morphological properties of the thin film nano structure ceramic improves

Significance of rice sheath photosynthesis: Yield determination by ...

African Journals Online (AJOL)

Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these ...

Effect of a self-adhesive coating on the load-bearing capacity of tooth-coloured restorative materials.

Science.gov (United States)

Bagheri, R; Palamara, Jea; Mese, A; Manton, D J

2017-03-01

The aim of this study was to compare the flexural strength and Vickers hardness of tooth-coloured restorative materials with and without applying a self-adhesive coating for up to 6 months. Specimens were prepared from three resin composites (RC), two resin-modified glass-ionomer cements (RM-GIC) and two conventional glass-ionomer cements (CGIC). All materials were tested both with and without applying G-Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four-point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope. Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent. The load-bearing capacity of the restorative materials was affected by applying self-adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM-GIC and RC. © 2016 Australian Dental Association.

Theoretical backgrounds of non-tempered materials production based on new raw materials

Science.gov (United States)

Lesovik, V. S.; Volodchenko, A. A.; Glagolev, E. S.; Chernysheva, N. V.; Lashina, I. V.; Feduk, R. S.

2018-03-01

One of the trends in construction material science is development and implementation of highly effective finish materials which improve architectural exterior of cities. Silicate materials widely-used in the construction today have rather low decorative properties. Different coloring agents are used in order to produce competitive materials, but due to the peculiarities of the production, process very strict specifications are applied to them. The use of industrial wastes or variety of rock materials as coloring agents is of great interest nowadays. The article shows that clay rock can be used as raw material in production of finish materials of non-autoclaved solidification. This raw material due to its material composition actively interacts with cementing component in steam treatment at 90–95 °C with formation of cementing joints that form a firm coagulative-cristalized and crystallization structure of material providing high physic-mechanical properties of silicate goods. It is determined that energy-saving, colored finish materials with compression strength up to 16 MPa can be produced from clay rocks.

The influence of surface treatment on mass transfer between air and building material

DEFF Research Database (Denmark)

Kwiatkowski, Jerzy; Rode, Carsten; Hansen, Kurt Kielsgaard

2008-01-01

for the experiments: gypsum board and calcium silicate. The wallpaper and paint were used as finishing materials. Impact of the following parameters for changes of RH was studied: coating, temperature and air movement. The measurements showed that acryl paint (diffusion open) can significantly decrease mass uptake......The processes of mass transfer between air and building structure and in the material influence not only the conditions within the material but also inside the connected air spaces. The material which absorbs and desorbs water vapour can be used to moderate the amplitude of indoor relative humidity...... and therefore to participate in the improvement of the indoor air quality and energy saving. Many parameters influence water vapour exchange between indoor air and building material. The aim of this work is to present the change of mass transfer under different climatic and material conditions. The measurements...

Measurement of naturally occurring radioactive materials in commonly used building materials in Hyderabad, India

International Nuclear Information System (INIS)

Balbudhe, A.Y.; Vishwa Prasad, K.; Vidya Sagar, D.; Jha, S.K.; Tripathi, R.M.

2018-01-01

Building materials can cause significant gamma dose indoors, due to their natural radioactivity content. The knowledge of the natural radioactivity level of building materials is important for determination of population exposure, as most people spend 80-90% of their time indoors furthermore, it is useful in setting the standards and national guidelines for the use and management of these materials. The concentrations of natural radionuclides in building materials vary depending on the local geological and geographical conditions as well as geochemical characteristics of those materials. The aim of the study is to determine levels of natural radionuclide in the commonly used building materials in Hyderabad, India

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

Directory of Open Access Journals (Sweden)

Sang-Mi Yun

2012-02-01

Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Biological evaluation of a new pulp capping material developed from Portland cement.

Science.gov (United States)

Negm, Ahmed M; Hassanien, Ehab E; Abu-Seida, Ashraf M; Nagy, Mohamed M

2017-03-02

This study evaluates the biological properties of a new pulp capping material developed from Portland cement. This study was conducted on 48 teeth in 4 dogs (12 teeth/dog). The dogs were classified into two equal groups (n=24 teeth) according to the evaluation period including: group A (3 weeks) and group B (3 months). Each group was further subdivided into three equal subgroups (n=8 teeth) according to the capping material including: subgroup 1: mineral trioxide aggregate (MTA), subgroup2: Portland cement+10% calcium hydroxide+20% bismuth oxide (Port Cal) and subgroup 3: Portland cement+bismuth oxide. After general anesthesia, a class V buccal cavity was prepared coronal to the gingival margin. After pulp exposure and hemostasis,the capping materials and glass ionomer filling were placed on the exposure sites. All histopathological findings, inflammatory cell count and dentin bridge formation were recorded. Data were analyzed statistically. After 3 months, the histopathological picture of the pulp in subgroup 1 showed normal pulp, continuous odontoblastic layer and complete dentin bridge formation while subgroup 2 showed partial and complete dentin bridge over a normal and necrotic pulps. Subgroup 3 showed loss of normal architecture, areas of necrosis, complete, or incomplete dentin bridge formation, attached and detached pulp stones and fatty degeneration in group B. For group A, MTA subgroup showed the least number of inflammatory cell infiltrate followed by Port Cal subgroup. While subgroup 3 showed the highest number of inflammatory cell infiltrate. For group B, the mean inflammatory cell count increased with the three tested materials with no statistical difference. Regarding dentin bridge formation at group A, no significant differences was found between subgroups, while at group B, MTA subgroup exhibited significantly higher scores than other subgroups. In conclusion, addition of calcium hydroxide to Portland cement improves the dentin bridge formation

Removable thermoplastic appliances modified by incisal cuts show altered biomechanical properties during tipping of a maxillary central incisor

Directory of Open Access Journals (Sweden)

Phillipp Brockmeyer

2017-08-01

Full Text Available Abstract Background The present study aimed to evaluate the force delivery of removable thermoplastic appliances (RTAs, modified by different sized incisal cuts, during tipping of a maxillary central incisor in palatal and vestibular direction. Methods Forty-five RTAs from three different materials (Biolon®, Erkodur®, Ideal Clear® of the same thickness (1 mm were used. Analysis was performed on a separated maxillary central incisor which was part of a resin model with a complete dentition. In 15 RTAs, of different material, a cut was inserted at the incisal edge of tooth 11. In 15 other appliances, the cut was extended to teeth 12 and 21. Fifteen aligners remained uncut. The experimental tooth was tipped starting from the zero position in 0.05° steps to a maximal deflection of ± 0.42° of the incisal edge in vestibular and palatal direction, after positioning the RTA onto the model. Results The horizontal (Fx and the vertical (Fz force components were decreased by approximately half with increasing cut size. Fz values changed during palatal tipping from a weak intrusive force, for aligners without cut, to an extrusive force with increasing cut size. Compared to both other materials used (Erkodur® and Ideal Clear®, the Biolon® aligners showed significantly higher Fx and Fz values (p < 0.0001, respectively. Conclusions RTAs modified by different sized incisal cuts show altered biomechanical properties and an inversion of the vertical force component, during tipping of a maxillary central incisor.

The clinical significance of brain microbleeds in patients with Alzheimer′s disease: Preliminary study

Directory of Open Access Journals (Sweden)

Jae-Hyeok Heo

2016-01-01

Full Text Available Background: Microbleeds (MBs are observed frequently in Alzheimer′s disease (AD and suggested to play a crucial role in the pathophysiology, but their clinical significance remains unclear. Materials and Methods: The study recruited 100 patients with AD who were diagnosed at the memory clinic in Seoul Medical Center in 2014. For each patient, baseline characteristics, neuropsychological tests, cerebrovascular risk factors, medial temporal lobe atrophy (MTLA, and severity of small vessel disease (SVD according to the existence of MBs were evaluated. Results: The prevalence of MBs in patients with AD was 33%. The percentage of male gender, the severity of SVD and MTLA were significantly increased in MB(+ group. The MB(+ group showed more severe MTLA and SVD than MB(− group. Conclusions: These results suggested that MBs might reflect the burden of amyloid and ischemic vascular pathology.

Effect of thermal annealing on property changes of neutron-irradiated non-graphitized carbon materials and nuclear graphite

International Nuclear Information System (INIS)

Matsuo, Hideto

1991-06-01

Changes in dimension of non-graphitized carbon materials and nuclear graphite, and the bulk density, electrical resistivity, Young's modulus and thermal expansivity of nuclear graphite were studied after neutron irradiation at 1128-1483 K and the successive thermal annealing up to 2573 K. Carbon materials showed larger and anisotropic dimensional shrinkage than that of nuclear graphite after the irradiation. The irradiation-induced dimensional shrinkage of carbon materials decreased during annealing at temperatures from 1773 to 2023 K, followed by a slight increase at higher temperatures. On the other hand, the irradiated nuclear graphite hardly showed the changes in length, density and thermal expansivity under the thermal annealing, but the electrical resistivity and Young's modulus showed a gradual decrease with annealing temperature. It has been clarified that there exists significant difference in the effect of thermal annealing on irradiation-induced dimensional shrinkage between graphitized nuclear graphite and non-graphitized carbon materials. (author)

A Comparison of implant impression precision: Different materials and techniques

Science.gov (United States)

Tabesh, Mahtab; Alikhasi, Marzieh

2018-01-01

Background Precision of implant impressions is a prerequisite for long-term success of implant supported prostheses. Impression materials and impression techniques are two important factors that impression precision relies on. Material and Methods A model of edentulous maxilla containing four implants inserted by All-on-4 guide was constructed. Seventy two impressions using polyether (PE), polyvinyl siloxane (PVS), and vinyl siloxanether (VSE) materials with direct and indirect techniques were made (n=12). Coordinates of implants in casts were measured using coordinate measuring machine (CMM). Data were analyzed with ANOVA; t-test and Tukey test were used for post hoc. Results With two-way ANOVA, mean values of linear displacements of implants were significantly different among materials and techniques. One-way ANOVA and Tukey showed significant difference between PE and VSE (P=0.019), PE and PVS (P=0.002) in direct technique, and between PVS and PE (Pimpression of implants, PE is recommended for direct technique while PE and VSE are recommended for indirect technique. Recommended technique for VSE is either direct or indirect; and for PE and PVS is direct. Key words:Polyvinyl siloxane, polyether, vinyl siloxanether, direct technique, indirect technique, All-on-4, coordinate measuring machine. PMID:29670733

Radiopacity and microhardness changes and effect of X-ray operating voltage in resin-based materials before and after the expiration date

Directory of Open Access Journals (Sweden)

Tirapelli Camila

2004-01-01

Full Text Available This study observed alteration in the radiopacity and microhardness of expired resin-based materials compared to non-expired materials and the operating characteristics of the X-ray source used. Five 2 mm-thick cured specimens were prepared for each material: composite resins (P60®, Z100®, and a compomer (Dyract AP®. Radiopacity of the specimens was evaluated comparing the density of the resin-based material to an equivalent (mm density of a 99.5% pure aluminum step wedge using a transmission densitometer. Surface microhardness measurements were carried out using a calibrated Vickers indenter on three different points of the same surface. ANOVA and Tukey tests (pre-set alpha = 0.05 revealed that expired materials showed no significant change in radiopacity. One material (Filtek P60 demonstrated lower radiopacity with lower KVp. Change in microhardness wa s statistically significant for Z100: for this material, the microhardness after expiration was significantly lower than before the expiration date.

Scanning Capacitance Microscopy | Materials Science | NREL

Science.gov (United States)

obtained using scanning capacitance microscopy. Top Right: Image of p-type and n-type material, obtained 'fingers' of light-colored n-type material on a yellow and blue background representing p-type material material, obtained using scanning capacitance microscopy, in a sample semiconductor device; the image shows

Atomistic Simulations of Small-scale Materials Tests of Nuclear Materials

International Nuclear Information System (INIS)

Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun

2012-01-01

Degradation of materials properties under neutron irradiation is one of the key issues affecting the lifetime of nuclear reactors. Evaluating the property changes of materials due to irradiations and understanding the role of microstructural changes on mechanical properties are required for ensuring reliable and safe operation of a nuclear reactor. However, high dose of neuron irradiation capabilities are rather limited and it is difficult to discriminate various factors affecting the property changes of materials. Ion beam irradiation can be used to investigate radiation damage to materials in a controlled way, but has the main limitation of small penetration depth in the length scale of micro meters. Over the past decade, the interest in the investigations of size-dependent mechanical properties has promoted the development of various small-scale materials tests, e.g. nanoindentation and micro/nano-pillar compression tests. Small-scale materials tests can address the issue of the limitation of small penetration depth of ion irradiation. In this paper, we present small-scale materials tests (experiments and simulation) which are applied to study the size and irradiation effects on mechanical properties. We have performed molecular dynamics simulations of nanoindentation and nanopillar compression tests. These atomistic simulations are expected to significantly contribute to the investigation of the fundamental deformation mechanism of small scale irradiated materials

Early detection of materials degradation

Science.gov (United States)

Meyendorf, Norbert

2017-02-01

Lightweight components for transportation and aerospace applications are designed for an estimated lifecycle, taking expected mechanical and environmental loads into account. The main reason for catastrophic failure of components within the expected lifecycle are material inhomogeneities, like pores and inclusions as origin for fatigue cracks, that have not been detected by NDE. However, material degradation by designed or unexpected loading conditions or environmental impacts can accelerate the crack initiation or growth. Conventional NDE methods are usually able to detect cracks that are formed at the end of the degradation process, but methods for early detection of fatigue, creep, and corrosion are still a matter of research. For conventional materials ultrasonic, electromagnetic, or thermographic methods have been demonstrated as promising. Other approaches are focused to surface damage by using optical methods or characterization of the residual surface stresses that can significantly affect the creation of fatigue cracks. For conventional metallic materials, material models for nucleation and propagation of damage have been successfully applied for several years. Material microstructure/property relations are well established and the effect of loading conditions on the component life can be simulated. For advanced materials, for example carbon matrix composites or ceramic matrix composites, the processes of nucleation and propagation of damage is still not fully understood. For these materials NDE methods can not only be used for the periodic inspections, but can significantly contribute to the material scientific knowledge to understand and model the behavior of composite materials.

Development of porous materials for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Shinji Oshima; Osamu Kato; Takeshi Kataoka; Yoshihiro Kobori; Michiaki Adachi [Hydrogen and New Energy Research Laboratory Nippon Oil Corporation 8, Chidoricho, Naka-ku, Yokohama, 231-0815 (Japan)

2006-07-01

To achieve hydrogen storage of more than 5 mass%, we are focusing on porous materials that consist of light elements. At WHEC 15, we reported that KOH-activated bamboo charcoal showed 0.79 mass% hydrogen uptake at 9.5 MPa and 303 K. After examining various carbon materials, we found that carbonized and KOH-activated polyacrylonitrile fibers showed 1.0 mass% hydrogen uptake at 9.5 MPa and 303 K. When the pressure was raised to 35 MPa, this material showed 1.5 mass% hydrogen uptake at 303 K. Besides porous carbon, other materials, such as coordination polymers, were examined. Since these materials contain elements other than carbon, different adsorption phenomena may be expected. Although the values of their hydrogen uptakes are still lower than those of carbon materials, a coordination polymer which showed 0.38 mass% hydrogen uptake at 9.5 MPa and 303 K was revealed to give an adsorption density of 47 kg/m{sup 3} at 0.1 MPa and 77 K, the highest value reported for a coordination polymer. (authors)

The thresholds for statistical and clinical significance

DEFF Research Database (Denmark)

Jakobsen, Janus Christian; Gluud, Christian; Winkel, Per

2014-01-01

BACKGROUND: Thresholds for statistical significance are insufficiently demonstrated by 95% confidence intervals or P-values when assessing results from randomised clinical trials. First, a P-value only shows the probability of getting a result assuming that the null hypothesis is true and does...... not reflect the probability of getting a result assuming an alternative hypothesis to the null hypothesis is true. Second, a confidence interval or a P-value showing significance may be caused by multiplicity. Third, statistical significance does not necessarily result in clinical significance. Therefore...... of the probability that a given trial result is compatible with a 'null' effect (corresponding to the P-value) divided by the probability that the trial result is compatible with the intervention effect hypothesised in the sample size calculation; (3) adjust the confidence intervals and the statistical significance...

CPR in medical TV shows: non-health care student perspective.

Science.gov (United States)

Alismail, Abdullah; Meyer, Nicole C; Almutairi, Waleed; Daher, Noha S

2018-01-01

There are over a dozen medical shows airing on television, many of which are during prime time. Researchers have recently become more interested in the role of these shows, and the awareness on cardiopulmonary resuscitation. Several cases have been reported where a lay person resuscitated a family member using medical TV shows as a reference. The purpose of this study is to examine and evaluate college students' perception on cardiopulmonary resuscitation and when to shock using an automated external defibrillator based on their experience of watching medical TV shows. A total of 170 students (nonmedical major) were surveyed in four different colleges in the United States. The survey consisted of questions that reflect their perception and knowledge acquired from watching medical TV shows. A stepwise regression was used to determine the significant predictors of "How often do you watch medical drama TV shows" in addition to chi-square analysis for nominal variables. Regression model showed significant effect that TV shows did change students' perception positively ( p <0.001), and they would select shock on asystole as the frequency of watching increases ( p =0.023). The findings of this study show that high percentage of nonmedical college students are influenced significantly by medical shows. One particular influence is the false belief about when a shock using the automated external defibrillator (AED) is appropriate as it is portrayed falsely in most medical shows. This finding raises a concern about how these shows portray basic life support, especially when not following American Heart Association (AHA) guidelines. We recommend the medical advisors in these shows to use AHA guidelines and AHA to expand its expenditures to include medical shows to educate the public on the appropriate action to rescue an out-of-hospital cardiac arrest patient.

Shear bond strength of brackets on restorative materials: Comparison on various dental restorative materials using the universal primer Monobond® Plus.

Science.gov (United States)

Ebert, Thomas; Elsner, Laura; Hirschfelder, Ursula; Hanke, Sebastian

2016-03-01

The purpose of this work was to analyze surfaces consisting of different restorative materials for shear bond strength (SBS) and failure patterns of metal and ceramic brackets. Bonding involved the use of a universal primer (Monobond® Plus, Ivoclar Vivadent). Six restorative materials were tested, including one composite resin (Clearfil Majesty™ Posterior, Kuraray Noritake Dental), one glass-ceramic material (IPS Empress® Esthetic, Ivoclar Vivadent), one oxide-ceramic material (CORiTEC Zr transpa Disc, imes-icore), two base-metal alloys (remanium® star, Dentaurum; Colado® CC, Ivoclar Vivadent), and one palladium-based alloy (Callisto® 75 Pd, Ivoclar Vivadent). Bovine incisors served as controls. Both metal and ceramic brackets (discovery®/discovery® pearl; Dentaurum) were bonded to the restorative surfaces after sandblasting and pretreatment with Monobond® Plus. A setup modified from DIN 13990-2 was used for SBS testing and adhesive remnant index (ARI)-based analysis of failure patterns. The metal brackets showed the highest mean SBS values on the glass-ceramic material (68.61 N/mm(2)) and the composite resin (67.58 N/mm(2)) and the lowest mean SBS on one of the base-metal alloys (Colado® CC; 14.01 N/mm(2)). The ceramic brackets showed the highest mean SBS on the glass-ceramic material (63.36 N/mm(2)) and the lowest mean SBS on the palladium-based alloy (38.48 N/mm(2)). Significant differences between the metal and ceramic brackets were observed in terms of both SBS values and ARI scores (p bracket types, fractures of the composite-resin and the glass-ceramic samples were observed upon debonding. Opaque restorative materials under metal brackets were found to involve undercuring of the adhesive. Monobond® Plus succeeded in generating high bond strengths of both bracket types on all restorative surfaces. Given our observations of cohesive fracture (including cases of surface avulsion) of the composite-resin and the glass-ceramic samples, we recommend

Probabilistic analysis of a materially nonlinear structure

Science.gov (United States)

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

1990-01-01

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

Tribological comparison of materials

Science.gov (United States)

Shi, Bing

Approximately 600,000 total joint replacement surgeries are performed each year in the United States. Current artificial joint implants are mainly metal-on-plastic. The synthetic biomaterials undergo degradation through fatigue and corrosive wear from load-bearing and the aqueous ionic environment of the human body. Deposits of inorganic salts can scratch weight-bearing surfaces, making artificial joints stiff and awkward. The excessive wear debris from polyethylene leads to osteolysis and potential loosening of the prosthesis. The lifetime for well-designed artificial joints is at most 10 to 15 years. A patient can usually have two total joint replacements during her/his lifetime. Durability is limited by the body's reaction to wear debris of the artificial joints. Wear of the artificial joints should be reduced. A focus of this thesis is the tribological performance of bearing materials for Total Replacement Artificial Joints (TRAJ). An additional focus is the scaffolds for cell growth from both a tissue engineering and tribological perspective. The tribological properties of materials including Diamond-like Carbon (DLC) coated materials were tested for TRAJ implants. The DLC coatings are chemically inert, impervious to acid and saline media, and are mechanically hard. Carbon-based materials are highly biocompatible. A new alternative to total joints implantation is tissue engineering. Tissue engineering is the replacement of living tissue with tissue that is designed and constructed to meet the needs of the individual patient. Cells were cultured onto the artificial materials, including metals, ceramics, and polymers, and the frictional properties of these materials were investigated to develop a synthetic alternative to orthopedic transplants. Results showed that DLC coated materials had low friction and wear, which are desirable tribological properties for artificial joint material. Cells grew on some of the artificial matrix materials, depending on the

Radiation-Induced Fluidity and Glass-Liquid Transition in Irradiated Amorphous Materials

International Nuclear Information System (INIS)

Ojovan, M.I.

2009-01-01

This paper describes the fluidity behaviour of continuously irradiated glasses using the Congruent Bond Lattice model in which broken bonds 'configurons' facilitate the flow. Irradiation breaks the bonds creating configurons which at high concentrations provide the transition of material from the glassy to liquid state. An explicit equation of viscosity has been derived which gives results in agreement with experimental data. This equation provides correct viscosity data for non-irradiated materials and shows a significant increase of fluidity in radiation fields. It demonstrates a decrease of activation energy of flow for irradiated glasses. A simple equation for glass-transition temperature was also obtained which shows that irradiated glasses have lower glass transition temperatures and are readily transformed from glassy to liquid state e.g. fluidized in strong radiation fields. (authors)

The effect of disinfectant agents on dimensional stability and surface roughness of a tissue conditioner material

Directory of Open Access Journals (Sweden)

Amiralireza Khaledi

2011-01-01

Conclusion: The results showed that the disinfectant solutions used in this study did not have a significant effect on the surface quality and dimensional accuracy of Visco-gel as a functional impression material.

Natural radioactivity of building materials used in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Omar, M. [Malaysian Inst. for Nuclear Technology Research (MINT), Bangi, Kajang, Selangor D.E. (Malaysia)

2002-03-01

A study has been carried out to determine the natural radioactive content of building materials used in Malaysia. The materials analysed include both old and new clay bricks, cement bricks, mortar, cement, sands, ceramic tiles and gypsum. Samples of the first three materials were collected from the 12 states of the Malay Peninsula. Radium-226 (from the U-238 series) and Ra-228 (from the Th-232 series), these both representing naturally occurring radionuclides, were analysed using high-resolution HpGe gamma spectrometers. The results of our investigations showed that some old clay bricks contain high levels (at more than 5 times the normal soil concentration) of natural radionuclides, with maximum concentrations of 590 Bq/kg and 480 Bq/kg for respectively Ra-226 and Ra-228. The reasons behind this finding were not clearly understood. As there are people living in old buildings, i.e. built using old clay bricks, there is a possibility that they are being exposed to significant radiation doses. However, there proved to be no significant overall difference between old and new clay bricks in terms of the natural radioactivity levels determined, at a 95% confidence level. The overall mean concentrations of Ra-226 and Ra-228 observed in Malaysian clay bricks were respectively 118 {+-} 58 Bq/kg and 120 {+-} 42 Bq/kg. The radioactive content of other materials was found to be not much different from that to be determined in normal soil from Malaysia. The data obtained can be used as a basis for reaching decisions on the regulatory limits for radioactivity levels in building materials in Malaysia. (orig.)

Elementary Students' Learning of Materials Science Practices Through Instruction Based on Engineering Design Tasks

Science.gov (United States)

Wendell, Kristen Bethke; Lee, Hee-Sun

2010-12-01

Materials science, which entails the practices of selecting, testing, and characterizing materials, is an important discipline within the study of matter. This paper examines how third grade students' materials science performance changes over the course of instruction based on an engineering design challenge. We conducted a case study of nine students who participated in engineering design-based science instruction with the goal of constructing a stable, quiet, thermally comfortable model house. The learning outcome of materials science practices was assessed by clinical interviews conducted before and after the instruction, and the learning process was assessed by students' workbooks completed during the instruction. The interviews included two materials selection tasks for designing a sturdy stepstool and an insulated pet habitat. Results indicate that: (1) students significantly improved on both materials selection tasks, (2) their gains were significantly positively associated with the degree of completion of their workbooks, and (3) students who were highly engaged with the workbook's reflective record-keeping tasks showed the greatest improvement on the interviews. These findings suggest the important role workbooks can play in facilitating elementary students' learning of science through authentic activity such as engineering design.

Experimental studies on a new bioactive material: HAIonomer cements.

Science.gov (United States)

Yap, A U J; Pek, Y S; Kumar, R A; Cheang, P; Khor, K A

2002-02-01

The lack of exotherm during setting, absence of monomer and improved release of incorporated therapeutic agents has resulted in the development of glass ionomer cements (GICs) for biomedical applications. In order to improve biocompatibility and biomechanically match GICs to bone, hydroxyapatite-ionomer (HAIonomer) hybrid cements were developed. Ultra-fine hydroxyapatite (HA) powders were produced using a new induction spraying technique that utilizes a radio-frequency source to spheriodize an atomized suspension containing HA crystallites. The spheriodized particulates were then held at 800 degrees C for 4 h in a carbolite furnace using a heating and cooling rate of 25 degrees C/min to obtain almost fully crystalline HA powders. The heat-treated particles were characterized and introduced into a commercial glass ionomer cement. 4 (H4), 12 (H12) and 28 (H28) vol% of fluoroalumino silicate were substituted by crystalline HA particles that were dispersed using a high-speed dispersion technique. The HAIonomer cements were subjected to hardness, compressive and diametral tensile strength testing based upon BS6039:1981. The storage time were extended to one week to investigate the effects of cement maturation on mechanical properties. Commercially available capsulated GIC (GC) and GIC at maximum powder:liquid ratio (GM) served as comparisons. Results were analyzed using factorial ANOVA/Scheffe's post-hoc tests and independent samples t-test at significance level 0.05. The effect of time on hardness was material dependent. With the exception of H12, a significant increase in hardness was observed for all materials at one week. A significant increase in compressive strength was, however, observed for H12 over time. At 1 day and 1 week, the hardness of H28 was significantly lower than for GM, H4, and H12. No significant difference in compression and diametral tensile strengths were observed between materials at both time intervals. Results show that HAIonomers is a

Materials development for TESOL

CERN Document Server

Mishan, Freda

2015-01-01

Materials development has become much more important in the field of TESOL in the last twenty years: modules on materials development are now commonplace on MA TESOL courses around the world. The overall aim of the book is to introduce readers to a wide range of theoretical and practical issues in materials development to enable them to make informed and principled choices in the selection, evaluation, adaptation and production of materials. The book aims to show how these choices need to be informed by an awareness of culture, context and purpose.

Effects of CTR irradiation on the mechanical properties of structural materials

International Nuclear Information System (INIS)

Wiffen, F.W.

1976-11-01

Mechanical properties of CTR structural materials are important in determining the reliability and economics of fusion power. Furthermore, these properties are significantly affected by the high neutron flux experienced by components in the regions near the plasma of the fusion reactor. In general, irradiation hardens the material and leads to a reduction in ductility. An exception to this is in some complex engineering alloys where either hardening or softening can be observed depending on the alloy and the irradiation conditions. Regardless of this restriction, irradiation usually leads to a reduction in ductility. Available tensile data examined in this paper show that significant ductility reduction can be found for irradiation conditions typical of CTR operation. Consideration of these effects show that extensive work will be needed to fully establish the in-service properties of CTR structures. This information will be used by designers to develop conditions and design philosophies adapted to avoid the most deleterious conditions and minimize stresses on structures on reactor design. The information will also be used as input to alloy development programs with goals of producing materials more resistant to property degradation during irradiation. It is clear that a great deal of additional work will be required both to understand the effect of CTR irradiation on properties and to develop optimal alloys for this application

Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling.

Science.gov (United States)

Fafenrot, Susanna; Grimmelsmann, Nils; Wortmann, Martin; Ehrmann, Andrea

2017-10-19

Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

Material investigation for manufacturing of reference step gauges for CT scanning verification

DEFF Research Database (Denmark)

Cantatore, Angela; Angel, Jais Andreas Breusch; De Chiffre, Leonardo

2012-01-01

This work deals with the study of stability and material investigation for manufacturing of step gauges for CT scanning verification. Four replica step gauges were fabricated using a bisacryl material for dental applications and the stability over five months was monitored using a tactile CMM....... The material was unstable, probably due to a modification of the chemical composition which lowered the hardness. New step gauges were manufactured through milling. Polyetheretherketone (PEEK) and Polyp-phenylenesulphide (PPS with 40% glass) fulfil the requirements regarding hardness and mechanical properties...... and two series of five step gauges (one series for each material) were manufactured by milling. Results show a significant improvement in terms of form stability and surface geometry quality of the new step gauges with respect to the replica step gauges in Luxabite, as reported below....

Mechanics for materials and technologies

CERN Document Server

Goldstein, Robert; Murashkin, Evgenii

2017-01-01

This book shows impressively how complex mathematical modeling of materials can be applied to technological problems. Top-class researchers present the theoretical approaches in modern mechanics and apply them to real-world problems in solid mechanics, creep, plasticity, fracture, impact, and friction. They show how they can be applied to technological challenges in various fields like aerospace technology, biological sciences and modern engineering materials.

Nano-CL-20/HMX Cocrystal Explosive for Significantly Reduced Mechanical Sensitivity

Directory of Open Access Journals (Sweden)

Chongwei An

2017-01-01

Full Text Available Spray drying method was used to prepare cocrystals of hexanitrohexaazaisowurtzitane (CL-20 and cyclotetramethylene tetranitramine (HMX. Raw materials and cocrystals were characterized using scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, Raman spectroscopy, and Fourier transform infrared spectroscopy. Impact and friction sensitivity of cocrystals were tested and analyzed. Results show that, after preparation by spray drying method, microparticles were spherical in shape and 0.5–5 µm in size. Particles formed aggregates of numerous tiny plate-like cocrystals, whereas CL-20/HMX cocrystals had thicknesses of below 100 nm. Cocrystals were formed by C–H⋯O bonding between –NO2 (CL-20 and –CH2– (HMX. Nanococrystal explosives exhibited drop height of 47.3 cm, and friction demonstrated explosion probability of 64%. Compared with raw HMX, cocrystals displayed significantly reduced mechanical sensitivity.

Material civilization: things and society.

Science.gov (United States)

Dant, Tim

2006-06-01

This paper argues that although classical sociology has largely overlooked the importance of social relations with the material world in shaping the form of society, Braudel's concept of 'material civilization' is a useful way to begin to understand the sociological significance of this relationship. The limitations of Braudel's historical and general concept can be partially overcome with Elias's analysis of the connection between 'technization' and 'civilization' that allows for both a civilizing and a de-civilizing impact of emergent forms of material relation that both lengthen and shorten the chains of interdependence between the members of a society. It is suggested that the concept of the 'morality of things' employed by a number of commentators is useful in summarizing the civilizing effects of material objects and addressing their sociological significance. From the sociology of consumption the idea of materiality as a sign of social relationships can be drawn, and from the sociology of technology the idea of socio-technical systems and actor-networks can contribute to the understanding of material civilization. It is argued that the concept of 'material capital' can usefully summarize the variable social value of objects but to understand the complexity of material civilization as it unfolds in everyday life, an analysis of 'material interaction' is needed. Finally the paper suggests some initial themes and issues apparent in contemporary society that the sociological study of material civilization might address; the increased volume, functional complexity and material specificity of objects and the increased social complexity, autonomy and substitutability that is entailed. A theory of 'material civilization' is the first step in establishing a sociology of objects.

How Materials Support Conceptual Blending in Ideation

DEFF Research Database (Denmark)

Biskjaer, Michael Mose; Fischel, Aron Daniel; Dove, Graham

2018-01-01

as an explanatory model to pry open the complexity of this activity, showing how research on design materials improves insight into how a design concept emerges. We show this empirically in a second-by- second analysis of a card-based design ideation episode using a multi-touch surface table. We offer process......-analytical evidence for the case that manipulation of design materials helps stabilize an emerging concept, as conceptual blending research has shown by analyzing artifacts, and extend this work by showing the dynamic interplay between the emerging conceptual blend and participants’ collaborative interaction...... with the materials. Our study advances understanding of interaction with materials in design ideation and aims to facilitate future research on how materials support conceptual blending as a useful model of how design concepts emerge....

Ti-doped isotropic graphite: A promising armour material for plasma-facing components

Science.gov (United States)

García-Rosales, C.; López-Galilea, I.; Ordás, N.; Adelhelm, C.; Balden, M.; Pintsuk, G.; Grattarola, M.; Gualco, C.

2009-04-01

Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of ˜200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

Ti-doped isotropic graphite: A promising armour material for plasma-facing components

Energy Technology Data Exchange (ETDEWEB)

Garcia-Rosales, C. [CEIT and Tecnun (University of Navarra), Paseo de Manuel Lardizabal, 15, E-20018 San Sebastian (Spain)], E-mail: cgrosales@ceit.es; Lopez-Galilea, I.; Ordas, N. [CEIT and Tecnun (University of Navarra), Paseo de Manuel Lardizabal, 15, E-20018 San Sebastian (Spain); Adelhelm, C.; Balden, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Pintsuk, G. [Forschungszentrum Juelich GmbH, EURATOM Association, D-52425 Juelich (Germany); Grattarola, M.; Gualco, C. [Ansaldo Ricerche S.p.A., I-16152 Genoa (Italy)

2009-04-30

Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of {approx}200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

Ti-doped isotropic graphite: A promising armour material for plasma-facing components

International Nuclear Information System (INIS)

Garcia-Rosales, C.; Lopez-Galilea, I.; Ordas, N.; Adelhelm, C.; Balden, M.; Pintsuk, G.; Grattarola, M.; Gualco, C.

2009-01-01

Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of ∼200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

Applications: Accelerators for new materials

International Nuclear Information System (INIS)

Andersen, H.H.

1990-01-01

Ion beams bring important benefits to material processing, and the Seventh International Conference on Ion Beam Modification of Materials (IBMM 90), held in Knoxville, Tennessee, in September showed the promising progress being made

Applications: Accelerators for new materials

Energy Technology Data Exchange (ETDEWEB)

Andersen, H. H. [Copenhagen (Denmark)

1990-12-15

Ion beams bring important benefits to material processing, and the Seventh International Conference on Ion Beam Modification of Materials (IBMM 90), held in Knoxville, Tennessee, in September showed the promising progress being made.

Cutting of nonmetallic materials using Nd:YAG laser beam

Institute of Scientific and Technical Information of China (English)

Bashir Ahmed Tahir; Rashid Ahmed; M. G. B. Ashiq; Afaq Ahmed; M. A. Saeed

2012-01-01

This study deals with Nd:YAG laser cutting nonmetallic materials,which is one of the most important and popular industrial applications of laser.The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed.For approximate cutting depth,a theoretical study is conducted in terms of material property and cutting speed.Results show a nonlinear relation between the cutting depth and input energy.There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s.An extra energy is utilized in the deep cutting.It is inferred that as the laser power increases,cutting depth increases.The experimental outcomes are in good agreement with theoretical results.This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting,scribing,trimming,engraving,and marking nonmetallic materials.

Viscoelastic characterization of soft biological materials

Science.gov (United States)

Nayar, Vinod Timothy

Progressive and irreversible retinal diseases are among the primary causes of blindness in the United States, attacking the cells in the eye that transform environmental light into neural signals for the optic pathway. Medical implants designed to restore visual function to afflicted patients can cause mechanical stress and ultimately damage to the host tissues. Research shows that an accurate understanding of the mechanical properties of the biological tissues can reduce damage and lead to designs with improved safety and efficacy. Prior studies on the mechanical properties of biological tissues show characterization of these materials can be affected by environmental, length-scale, time, mounting, stiffness, size, viscoelastic, and methodological conditions. Using porcine sclera tissue, the effects of environmental, time, and mounting conditions are evaluated when using nanoindentation. Quasi-static tests are used to measure reduced modulus during extended exposure to phosphate-buffered saline (PBS), as well as the chemical and mechanical analysis of mounting the sample to a solid substrate using cyanoacrylate. The less destructive nature of nanoindentation tests allows for variance of tests within a single sample to be compared to the variance between samples. The results indicate that the environmental, time, and mounting conditions can be controlled for using modified nanoindentation procedures for biological samples and are in line with averages modulus values from previous studies but with increased precision. By using the quasi-static and dynamic characterization capabilities of the nanoindentation setup, the additional stiffness and viscoelastic variables are measured. Different quasi-static control methods were evaluated along with maximum load parameters and produced no significant difference in reported reduced modulus values. Dynamic characterization tests varied frequency and quasi-static load, showing that the agar could be modeled as a linearly

Quality indicators for woodwind reed material

International Nuclear Information System (INIS)

Glave, Stefan; Pallon, Jan; Bornman, Chris; Bjoern, Lars Olof; Wallen, Rita; Raastam, Jacob; Kristiansson, Per; Elfman, Mikael; Malmqvist, Klas

1999-01-01

For the generation of sound, some woodwind musical instruments, e.g. oboe, bassoon, clarinet and saxophone, are provided with mouthpieces made from reeds. These reeds are the culms of Arundo donax, a tall, cane-like perennial grass. A general problem is that the material is of varying quality, yet externally differences cannot be observed. Hence, large proportions of the prepared reeds are unusable. One hypothesis is that the changes in quality are correlated with differences in the chemical and anatomical structure of the tissue. Therefore, a comparison of superior and inferior mouthpieces, used by professional musicians, was undertaken to determinate potential indicators of quality. Nuclear microprobe analysis of reeds was carried out and complemented by scanning electron and light microscopy. The elemental levels of Si, P, S, Cl, K and Ca were compared between good and poor mouthpieces using appropriate statistical tests. No statistically significant differences could be identified. Microscopical observations showed that partial occlusion of vessels by tylose formation was associated with material deemed unusable

Can you see what you feel? Color and folding properties affect visual-tactile material discrimination of fabrics.

Science.gov (United States)

Xiao, Bei; Bi, Wenyan; Jia, Xiaodan; Wei, Hanhan; Adelson, Edward H

2016-01-01

Humans can often estimate tactile properties of objects from vision alone. For example, during online shopping, we can often infer material properties of clothing from images and judge how the material would feel against our skin. What visual information is important for tactile perception? Previous studies in material perception have focused on measuring surface appearance, such as gloss and roughness, and using verbal reports of material attributes and categories. However, in real life, predicting tactile properties of an object might not require accurate verbal descriptions of its surface attributes or categories. In this paper, we use tactile perception as ground truth to measure visual material perception. Using fabrics as our stimuli, we measure how observers match what they see (photographs of fabric samples) with what they feel (physical fabric samples). The data shows that color has a significant main effect in that removing color significantly reduces accuracy, especially when the images contain 3-D folds. We also find that images of draped fabrics, which revealed 3-D shape information, achieved better matching accuracy than images with flattened fabrics. The data shows a strong interaction between color and folding conditions on matching accuracy, suggesting that, in 3-D folding conditions, the visual system takes advantage of chromatic gradients to infer tactile properties but not in flattened conditions. Together, using a visual-tactile matching task, we show that humans use folding and color information in matching the visual and tactile properties of fabrics.

Regional and global significance of nuclear energy

International Nuclear Information System (INIS)

Schilling, H.D.

1995-01-01

Measures to combat poverty and improve the standard of living in countries of the Third World will inevitably boost global demand for energy, and energy conservation measures will not be able to offset this increase. Nuclear energy will regain significance in the framework of approaches adopted to resolve the energy problem, which primarily is an ecologic problem created by an extremely large flow of materials. The extraordinarily high energy density of nuclear fuels can contribute to markedly reduce the flow of materials; and at that, electric energy is an efficient substitute for primary energy forms. Thus nuclear electricity generation is of double benefit to the ecology. Engineering goals in nuclear technology thus gain a service aspect, with progress in power plant engineering and design aiming not only at enhanced engineered safety, but also at regaining public acceptance of and confidence in nuclear power plant technology. (orig./UA) [de

Accuracy of five implant impression technique: effect of splinting materials and methods

Science.gov (United States)

Cho, Sung-Bum

2011-01-01

PURPOSE The aim of this study was to evaluate the effect of dimensional stability of splinting material on the accuracy of master casts. MATERIALS AND METHODS A stainless steel metal model with 6 implants embedded was used as a master model. Implant level impressions were made after square impression copings were splinted using 5 different techniques as follows. (1) Splinted with autopolymerizing resin and sectioned, reconnected to compensate polymerization shrinkage before the impression procedure. (2) Splinted with autopolymerizing resin just before impression procedure. (3) Primary impression made with impression plaster and secondary impression were made over with polyether impression material. (4) Splinted with impression plaster. (5) Splinted with VPS bite registration material. From master model, 5 impressions and 5 experimental casts, total 25 casts were made for each of 5 splinting methods. The distortion values of each splinting methods were measured using coordinate measuring machine, capable of recordings in the x-, y-, z-axes. A one-way analysis of variance (ANOVA) at a confidence level of 95% was used to evaluate the data and Tukey's studentized range test was used to determine significant differences between the groups. RESULTS Group 1 showed best accuracy followed by Group 3 & 4. Group 2 and 5 showed relatively larger distortion value than other groups. No significant difference was found between group 3, 4, 5 in x-axis, group 2, 3, 4 in y-axis and group 1, 3, 4, 5 in z-axis (Pimpression copings with autopolymerizing resin following compensation of polymerization shrinkage and splinting method with impression plaster can enhance the accuracy of master cast and impression plaster can be used simple and effective splinting material for implant impression procedure. PMID:22259700

Thermomechanics of solid materials with application to the Gurson-Tvergaard material model

Energy Technology Data Exchange (ETDEWEB)

Santaoja, K. [VTT Manufacturing Technology, Espoo (Finland). Materials and Structural Integrity

1997-12-31

The elastic-plastic material model for porous material proposed by Gurson and Tvergaard is evaluated. First a general description is given of constitutive equations for solid materials by thermomechanics with internal variables. The role and definition of internal variables are briefly discussed and the following definition is given: The independent variables present (possibly hidden) in the basic laws for thermomechanics are called controllable variables. The other independent variables are called internal variables. An internal variable is shown always to be a state variable. This work shows that if the specific dissipation function is a homogeneous function of degree one in the fluxes, a description for a time-independent process is obtained. When damage to materials is evaluated, usually a scalar-valued or tensorial variable called damage is introduced in the set of internal variables. A problem arises when determining the relationship between physically observable weakening of the material and the value for damage. Here a more feasible approach is used. Instead of damage, the void volume fraction is inserted into the set of internal variables. This allows use of an analytical equation for description of the mechanical weakening of the material. An extension to the material model proposed by Gurson and modified by Tvergaard is derived. The derivation is based on results obtained by thermomechanics and damage mechanics. The main difference between the original Gurson-Tvergaard material model and the extended one lies in the definition of the internal variable `equivalent tensile flow stress in the matrix material` denoted by {sigma}{sup M}. Using classical plasticity theory, Tvergaard elegantly derived an evolution equation for {sigma}{sup M}. This is not necessary in the present model, since damage mechanics gives an analytical equation between the stress tensor {sigma} and {sigma}M. Investigation of the Clausius-Duhem inequality shows that in compression

Thermomechanics of solid materials with application to the Gurson-Tvergaard material model

International Nuclear Information System (INIS)

Santaoja, K.

1997-01-01

The elastic-plastic material model for porous material proposed by Gurson and Tvergaard is evaluated. First a general description is given of constitutive equations for solid materials by thermomechanics with internal variables. The role and definition of internal variables are briefly discussed and the following definition is given: The independent variables present (possibly hidden) in the basic laws for thermomechanics are called controllable variables. The other independent variables are called internal variables. An internal variable is shown always to be a state variable. This work shows that if the specific dissipation function is a homogeneous function of degree one in the fluxes, a description for a time-independent process is obtained. When damage to materials is evaluated, usually a scalar-valued or tensorial variable called damage is introduced in the set of internal variables. A problem arises when determining the relationship between physically observable weakening of the material and the value for damage. Here a more feasible approach is used. Instead of damage, the void volume fraction is inserted into the set of internal variables. This allows use of an analytical equation for description of the mechanical weakening of the material. An extension to the material model proposed by Gurson and modified by Tvergaard is derived. The derivation is based on results obtained by thermomechanics and damage mechanics. The main difference between the original Gurson-Tvergaard material model and the extended one lies in the definition of the internal variable 'equivalent tensile flow stress in the matrix material' denoted by σ M . Using classical plasticity theory, Tvergaard elegantly derived an evolution equation for σ M . This is not necessary in the present model, since damage mechanics gives an analytical equation between the stress tensor σ and σM. Investigation of the Clausius-Duhem inequality shows that in compression, states occur which are not

Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability

Directory of Open Access Journals (Sweden)

Nick POLYCHRONAKIS

2018-06-01

Full Text Available Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm from polyamide (Valplast and PMMA (Vertex Rapid Simplified denture base materials were made. Eight specimens from each material were immersed in distilled water (control and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE* and translucency parameter (TP were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p0.05. TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001. Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.

Enhancing the Performance of the Microwave Absorbing Materials by Using Dielectric Resonator Arrays

Directory of Open Access Journals (Sweden)

Omar H. Al-Zoubi

2017-01-01

Full Text Available We present a technique for enhancing the performance of microwave absorbing materials in terms of weight, thickness, and bandwidth. The introduced technique is based on fabricating the microwave absorbing (MA material in a structure comprised of an array of circular cylinder dielectric resonators (CDR backed by a perfect electric conductor (PEC ground plane. Numerical electromagnetic methods are employed to study the properties of the proposed MA array structures, where 3D full wave simulation using finite-element method is implemented. The obtained results show that the performance of the MA-CDR arrays significantly outperforms that of a flat layer composed of the same material and having equivalent thickness. A flat layer of MA material with thickness of 5 mm backed by perfect electric conductor (PEC shows as low as -50 dB reflection loss (RL peak and ~3 GHz 10-dB bandwidth, whereas an MA-CDR array, composed of the same MA material, of height of 4 mm can achieve as low as ~−50 dB RL peak and ~12 GHz 10-dB RL bandwidth.

Wettability changes in polyether impression materials subjected to immersion disinfection.

Science.gov (United States)

Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

2013-07-01

Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P polyether material. Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

Safety of the Transport of Radioactive Materials for Civilian Use in France. Lessons learned by IRSN from analysis of significant events reported in 2012 and 2013

International Nuclear Information System (INIS)

2015-01-01

Every two years since 2008, IRSN has published in a report the lessons learnt from its analysis of significant events involving the transport of radioactive materials for civilian purposes in France. Each year in France, some 770,000 shipments of radioactive materials for civilian use are done by road, railway, inland waterway, sea and air. For 2012 and 2013, the report did not find evidence of degradation compared with previous years, particularly for industrial activities in the nuclear power industry, which raise the most significant safety issues. Since 1999, approximately a hundred events are reported each year, which represents, on average, one event per 10,000 packages transported. IRSN notes that none of the events that occurred over the two years had an impact on public health or environmental protection. Events involving a defect in the closure of spent fuel shipping packages and deviations concerning the content of the packages, which had increased in 2010 and 2011, are now down. It would seem to confirm that the organizational measures implemented by those sending the packages have had a positive impact. Previous trends which brought to light failures in the preparation of packages and their handling, in particular in the medical sector, have been confirmed. Even if most of the packages concerned contain low levels of radioactivity, recurrence of these events confirms the value of implementing appropriate preventive actions on the part of the companies involved. Lastly, descriptions of several typical events that occurred in 2012 and 2013 provide illustrations of the analyses that were performed on actual cases

Anthropogenic materials and products containing natural radionuclides. Pt. 1a. Radiation properties of raw materials and waste materials. A literature study

International Nuclear Information System (INIS)

Reichelt, A.; Roehrer, J.; Lehmann, K.H.

1995-12-01

Cased on the literature study, the publication presents relevant data on raw materials and wastes containing natural radionuclides. The study is part 1a of the project on ''Anthropogenic materials and waste materials containing natural radionuclides''. Part 1 of the project gives data and information on about 100 different materials and wastes or products for household or industrial applications which contain significant amounts of natural radioactivity. In addition, part 1 presents for some of these materials information on their applications, consumption, radioactivity and resulting radiation doses. The raw materials and waste materials on the list in part 1 are characterised in this 1a report. Wherever appropriate, two or more materials are dealt with in one chapter, as e.g. felspar and felspar sands (pegmatite), talcum, and soapstone. The wastes are dealt with in the chapters discussing the relevant raw materials. The information given is as derived from the literature and does not include comments or evaluation by the authors of this report. Whenever the literature study did not yield information on radiological aspects of a material on the list, an appropriate notice is given. (Orig./DG) [de

Molecular dynamics simulations of interactions between hydrogen and fusion-relevant materials

International Nuclear Information System (INIS)

Rooij, Dagmar de

2010-01-01

sticking probability of small hydrocarbons is highest on material previously subjected to the highest hydrogen flux. This result suggests that redeposition is more effective under high than under low hydrogen fluxes, partly explaining the experimentally observed reduction in the carbon erosion yield. Lastly, we studied amorphous tungsten carbide. Amorphous material with three different carbon percentages (15, 50 and 95%) was subjected to deuterium bombardment and the resulting erosion and deuterium retention was analyzed. The 95% carbon sample behaves like doped carbon, the carbon erosion yield is reduced and no tungsten is eroded. Segregation was of the materials was observed, resulting in an accumulation of tungsten at the surface. The hydrogen retention was similar to a-C:H. The 15% carbon sample showed no significant erosion or retention. The most interesting was the 50% sample. Here deuterium bubbles formed that burst open after sufficiently long bombardment, thereby removing both carbon and tungsten from the surface. In the context of ITER our MD simulations suggest that tungsten is the better suited material since both the erosion and the hydrogen retention are significantly lower than for carbon.

The Physics Show--Inexpensively.

Science.gov (United States)

Hultsch, Roland A.

1982-01-01

Describes five physics demonstrations using inexpensive and easily obtainable materials. Demonstrations include: (1) sinking ice cubes and diffusion; (2) returnable can; (3) persistent currents in a liquid; (4) light scattering by milk particles; and (5) rotation of a plane of polarization. (JN)

Study of tertiary creep instability in several elevated-temperature structural materials

International Nuclear Information System (INIS)

Booker, M.K.; Sikka, V.K.

1978-01-01

Data for a number of common elevated temperature structural materials have been analyzed to yield mathematical predictions for the time and strain to tertiary creep at various rupture lives and temperatures. Materials examined include types 304 and 316 stainless steel, 2 1/4 Cr-1 Mo steel, alloy 800H, alloy 718, Hastelloy alloy X, and ERNiCr--3 weld metal. Data were typically examined over a range of creep temperatures for rupture lives ranging from less than 100 to greater than 10,000 hours. Within a given material, trends in these quantities can be consistently described, but it is difficult to directly relate the onset of tertiary creep to failure-inducing instabilities. A series of discontinued tests for alloy 718 at 649 and 620 0 C showed that the material fails by intergranular cracking but that no significant intergranular cracking occurs until well after the onset of tertiary creep

Ultrasonic imaging of material flaws exploiting multipath information

Science.gov (United States)

Shen, Xizhong; Zhang, Yimin D.; Demirli, Ramazan; Amin, Moeness G.

2011-05-01

In this paper, we consider ultrasonic imaging for the visualization of flaws in a material. Ultrasonic imaging is a powerful nondestructive testing (NDT) tool which assesses material conditions via the detection, localization, and classification of flaws inside a structure. Multipath exploitations provide extended virtual array apertures and, in turn, enhance imaging capability beyond the limitation of traditional multisensor approaches. We utilize reflections of ultrasonic signals which occur when encountering different media and interior discontinuities. The waveforms observed at the physical as well as virtual sensors yield additional measurements corresponding to different aspect angles. Exploitation of multipath information addresses unique issues observed in ultrasonic imaging. (1) Utilization of physical and virtual sensors significantly extends the array aperture for image enhancement. (2) Multipath signals extend the angle of view of the narrow beamwidth of the ultrasound transducers, allowing improved visibility and array design flexibility. (3) Ultrasonic signals experience difficulty in penetrating a flaw, thus the aspect angle of the observation is limited unless access to other sides is available. The significant extension of the aperture makes it possible to yield flaw observation from multiple aspect angles. We show that data fusion of physical and virtual sensor data significantly improves the detection and localization performance. The effectiveness of the proposed multipath exploitation approach is demonstrated through experimental studies.

Characterization of ureasil-polyethylene oxide/chitosan hybrid materials

Energy Technology Data Exchange (ETDEWEB)

Paredes Zaldivar, M.; Pulcinelli, S.H.; Peniche Covas, C.; Santilli, C.V. [Universidad de la Habana, Havana (Cuba); Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica

2016-07-01

Full text: Siloxane-polyether hybrids are an interesting and versatile family of multifunctional organic-inorganic hybrid materials, also named ureasils. Ureasils have been the object of intensive studies in the last years due to their versatility and wide range of applications. Polyethylene oxide (PEO) and chitosan are biocompatible and low toxicity polymers that were used as organic phase while the inorganic phase was siloxane. Therefore, the aim of this work was the characterization of these hybrids that were prepared by the sol–gel route. Hydrochloric and acetic acids were used as catalysts. Due to the insolubility of chitosan in ethanol and organic solvents, water was used in the hydrolysis solution as the main component or alone. The obtained materials were transparent, rubbery, flexible and water-insoluble. They were characterized by different physicochemical techniques such as FTIR (Fourier Transform Infrared Spectroscopy), DSC (Differential Scanning Calorimetry), TG (Thermogravimetric Analysis), XRD (X-Ray Diffraction), SAXS (Small Angle X-ray Scattering) and NMR (Nuclear Magnetic Resonance Spectroscopy). Results showed that chitosan addition did not provoke appreciable changes in the thermal properties but modifies the polycondensation degree and the nanoscopic structure of the materials. Significant changes were not found neither by the hydrolysis solution nor by the type of acid, except in the thermal stability. It depended on the type of acid catalyst, being higher in hybrids prepared with HCl. We can conclude that these materials can be synthesized just with water as the hydrolysis solution and that any of the two acids can be used as catalyst without significantly affect its final properties. (author)

Cytotoxicity of newly developed pozzolan cement and other root-end filling materials on human periodontal ligament cell

Directory of Open Access Journals (Sweden)

Minju Song

2014-02-01

Full Text Available Objectives The purpose of this study was to evaluate in vitro cytotoxicity of the pozzolan cement and other root-end filling materials using human periodontal ligament cell. Materials and Methods Endocem (Maruchi, white ProRoot MTA (Dentsply, white Angelus MTA (Angelus, and Super EBA (Bosworth Co. were tested after set completely in an incubator at 37℃ for 7 days, Endocem was tested in two ways: 1 immediately after mixing (fresh specimens and 2 after setting completely like other experimental materials. The methods for assessment included light microscopic examination, cell counting and WST-1 assay on human periodontal ligament cell. Results In the results of microscopic examination and cell counting, Super EBA showed significantly lower viable cell than any other groups (p < 0.05. As the results of WST-1 assay, compared with untreated control group, there was no significant cell viability of the Endocem group. However, the fresh mixed Endocem group had significantly less cell viability. The cells exposed to ProRoot MTA and Angelus MTA showed the highest viability, whereas the cells exposed to Super EBA displayed the lowest viability (p < 0.05. Conclusions The cytotoxicity of the pozzolan cement (Endocem was comparable with ProRoot MTA and Angelus MTA. Considering the difficult manipulation and long setting time of ProRoot MTA and Angelus MTA, Endocem can be used as the alternative of retrofilling material.

Crystallization kinetics of phase change materials

Energy Technology Data Exchange (ETDEWEB)

Klein, Michael; Sontheimer, Tobias; Wuttig, Matthias [I. Physikalisches Institut (1A), RWTH Aachen (Germany)

2008-07-01

Phase change materials are fascinating materials. They can be rapidly switched between two metastable states, the amorphous and crystalline phase, which show pronounced contrast in their optical and electrical properties. They are already widely used as the active layer in rewritable optical media and are expected to be used in the upcoming phase change random access memory (PRAM). Here we show measurements of the crystallization kinetics of chalcogenide materials that lead to a deeper understanding of these processes. This work focuses mainly on the Ge-Sb-Te system but also includes Ag-In-Te materials. The crystallization behaviour of these materials was investigated with an ex-situ annealing method employing the precise oven of a differential scanning calorimeter and imaging techniques employing atomic force microscopy and optical microscopy.

Ultrasonic grinding of optical materials

Science.gov (United States)

Cahill, Michael; Bechtold, Michael; Fess, Edward; Stephan, Thomas; Bechtold, Rob

2017-10-01

Hard ceramic optical materials such as sapphire, ALON, Spinel, PCA, or Silicon Carbide can present a significant challenge in manufacturing precision optical components due to their tough mechanical properties. These are also the same mechanical properties that make them desirable materials when used in harsh environments. Slow processing speeds, premature tool wear, and poor surface quality are common results of the tough mechanical properties of these materials. Often, as a preparatory stage for polishing, the finish of the ground surface greatly influences the polishing process and the resulting finished product. To overcome these challenges, OptiPro Systems has developed an ultrasonic assisted grinding technology, OptiSonic, which has been designed for the precision optics and ceramics industry. OptiSonic utilizes a custom tool holder designed to produce oscillations, in microns of amplitude, in line with the rotating spindle. A software package, IntelliSonic, is integral to the function of this platform. IntelliSonic can automatically characterize tooling during setup to identify and select the ideal resonant peak which to operate at. Then, while grinding, IntelliSonic continuously adjusts the output frequency for optimal grinding efficiency while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more precise surface. Utilizing a variety of instruments, tests have proven to show a reduction in force between tool and part by up to 50%, while increasing the surface quality and reducing tool wear. This paper will present the challenges associated with these materials and solutions created to overcome them.

Natural radioactivity and radiological hazards of building materials in Xianyang, China

International Nuclear Information System (INIS)

Lu Xinwei; Yang Guang; Ren Chunhui

2012-01-01

Common building materials collected from Xianyang, China were analyzed for the natural radioactivity of 226 Ra, 232 Th and 40 K using γ-ray spectroscopy. The average activity concentration of 226 Ra, 232 Th and 40 K in the studied building materials ranges from 13.4 to 69.9, 13.1–99.1 and 124.7–915.1 Bq kg −1 , respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and with the worldwide average activity of soil. To assess the radiation hazard of the natural radioactivity in all samples to the people, the radium equivalent activity, external hazard index, internal hazard index, indoor absorbed dose rate and total annual effective dose were estimated. The radium equivalent activities of the studied samples are below the internationally accepted values. The external hazard index and internal hazard index of all analyzed building materials are less than unity. The mean values of indoor absorbed dose rate for all building materials except for lime are higher than the world population-weighted average of 84 nGy h −1 and the total annual effective dose values of building materials are lower than 1 mSv y −1 except for some cyan brick samples. The study shows the measured building materials do not pose significant source of radiation hazard and are safe for use in the construction of dwellings. - Highlights: ► Natural radioactivity in building materials was determined by gamma ray spectrometry. ► The radiological hazard of studied building materials is within the recommended safety limit. ► Most of the studied building materials do not pose significant radiation risk to residents.

Biomedical composites materials, manufacturing and engineering

CERN Document Server

Davim, J Paulo

2013-01-01

Composite materials are engineered materials, made from two or more constituents with significantly different physical or chemical properties which remain separate on a macroscopic level within the finished structure. Due to their special mechanical and physical properties they have the potential to replace conventional materials in various fields such as the biomedical industry.

The Effectiveness of Scaffolding Design in Training Writing Skills Physics Teaching Materials

Directory of Open Access Journals (Sweden)

Parlindungan Sinaga

2015-01-01

Full Text Available Result of field studies showed low writing skill of teachers in teaching material. The root of the problem lies in their inability on translating description of teaching material into writing. This research focused on the effectiveness of scaffolding design. The scaffolding design was tested in the selected topics of physics courses for pre-service teachers through learning to write activity approach. The treatment effectiveness was determined by considering the effect size and normalized gain percentage, while the hypothesis was tested using “the Kruskal-Wallis test”. The research results showed that scaffolding between the stages of planning and translating plans into text was effective in improving pre-service physics teachers’ ability of writing physics teaching materials and was similarly effective in improving their conceptual understanding of the topics of electromagnetism, waves, and optics. Learning to write activity implemented in the course of physics with selected topics was effective in improving the ability of pre-service teachers in translating among different modes of representation and making multiple concept representations. The hypothesis test demonstrated that there was a significant difference in the abilities of writing teaching materials and conceptual understanding between experimental and control classes.

Modeling of AA5083 Material-Microstructure Evolution During Butt Friction-Stir Welding

Science.gov (United States)

Grujicic, M.; Arakere, G.; Yalavarthy, H. V.; He, T.; Yen, C.-F.; Cheeseman, B. A.

2010-07-01

A concise yet a fairly comprehensive overview of the friction stir welding (FSW) process is provided. This is followed by a computational investigation in which FSW behavior of a prototypical solution-strengthened and strain-hardened aluminum alloy, AA5083-H131, is modeled using a fully coupled thermo-mechanical finite-element procedure developed in our prior study. Particular attention is given to proper modeling of the welding work-piece material behavior during the FSW process. Specifically, competition and interactions between plastic-deformation and dynamic-recrystallization processes are considered to properly account for the material-microstructure evolution in the weld nugget zone. The results showed that with proper modeling of the material behavior under high-temperature/severe-plastic-deformation conditions, significantly improved agreement can be attained between the computed and measured post-FSW residual-stress and material-strength distribution results.

Materials for High-Temperature Catalytic Combustion

Energy Technology Data Exchange (ETDEWEB)

Ersson, Anders

2003-04-01

Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

Supercapacitors specialities - Materials review

Science.gov (United States)

Obreja, Vasile V. N.

2014-06-01

The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

Supercapacitors specialities - Materials review

Energy Technology Data Exchange (ETDEWEB)

Obreja, Vasile V. N. [National Research and Development Institute for Microtechnologies (IMT-Bucuresti), Bucharest, 126A Erou Iancu Nicolae Street, 077190 (Romania)

2014-06-16

The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

Supercapacitors specialities - Materials review

International Nuclear Information System (INIS)

Obreja, Vasile V. N.

2014-01-01

The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

The Tools of Teacher Education: Preservice Teachers' Use of Technology To Create Instructional Materials.

Science.gov (United States)

Roberts, Sherron Killingsworth; Hsu, Ying-Shao

2000-01-01

Examines the effectiveness/efficiency of preservice teachers' use of technology to create instructional materials developed in an undergraduate reading/language arts course. Results showed no significant difference between measures of overall quality of the technology assistance as compared to handmade prompts. Eighty-five percent of the teachers…

Reversible switching in phase-change materials

OpenAIRE

Wojciech Wełnic; Matthias Wuttig

2008-01-01

Phase-change materials are successfully employed in optical data storage and are becoming a promising candidate for future electronic storage applications. Despite the increasing technological interest, many fundamental properties of these materials remain poorly understood. However, in the last few years the understanding of the material properties of phase-change materials has increased significantly. At the same time, great advances have been achieved in technological applications in elect...

Corrosion of metal materials embedded in concrete

International Nuclear Information System (INIS)

Duffo, G.S.; Farina, S.B.; Schulz, F.M.

2010-01-01

Carbon steel is the material most frequently used to strengthen reinforced concrete structures; however, stainless steel and galvanized steel reinforcements are also used in construction concretes; and they are not often used in Latin America. Meanwhile, there are other metals that are embedded in the concrete forming part of the openings (aluminum) or in tubing systems (copper and lead). The use of concrete as a cementing material is also useful for immobilizing wastes, such as for example those generated by the nuclear industry. There is a great deal of research and development on the corrosion of steel reinforcements, but the same is not true for the behavior of other metals embedded in concrete and that also undergo corrosive processes. This work aims to study the corrosion of different metals: copper, lead, aluminum, zinc, stainless steel and carbon steel; embedded in concrete with and without the presence of aggressive species for the metal materials. Test pieces were made of mortar containing rods of different materials for testing, and with chlorides added in concentrations of 0; 0.3 % and 1% (mass of chloride per mass of cement). The test pieces were exposed to different conditions; laboratory environment with a relative humidity (RH) of 45%, a controlled atmosphere with 98% RH and submerged in a solution of 3.5% NaCl. The susceptibility to corrosion of the different metals was evaluated using techniques to monitor the corrosion potential, the resistivity of the mortar and the polarization resistance (PR). The rods were weighed before being placed inside the test pieces to later determine the loss of weight generated by the corrosion process. Polarization curves for the metals were also traced in a simulated pore solution (SPS) and in SPS with added chloride. The results obtained to date show that, of all the metals analyzed, aluminum is the most susceptible to corrosion, and that the test specimens with 0% and 1% of chloride exposed to the laboratory

Non-Declarative Sequence Learning does not Show Savings in Relearning

OpenAIRE

Keisler, Aysha; Willingham, Daniel T.

2007-01-01

Researchers have utilized the savings in relearning paradigm in a variety of settings since Ebbinghaus developed the tool over a century ago. In spite of its widespread use, we do not yet understand what type(s) of memory are measurable by savings. Specifically, can savings measure both declarative and non-declarative memories? The lack of conscious recollection of the encoded material in some studies indicates that non-declarative memories may show savings effects, but as all studies to date...

Nanostructural Materials for Energy Storage Systems

Directory of Open Access Journals (Sweden)

Bronislaw Buczek

2011-01-01

Full Text Available The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

Survival of Spoilage and Pathogenic Microorganisms on Cardboard and Plastic Packaging Materials

Directory of Open Access Journals (Sweden)

Lorenzo Siroli

2017-12-01

Full Text Available The aim of this work was to study the interaction of corrugated and plastic materials with pathogenic and spoiling microorganisms frequently associated to fresh produce. The effect of the two packaging materials on the survival during the storage of microorganisms belonging to the species Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Saccharomyces cerevisiae, Lactobacillus plantarum, Pseudomonas fluorescens, and Aspergillus flavus was studied through traditional plate counting and scanning electron microscopy (SEM. The results obtained showed that cardboard materials, if correctly stored, reduced the potential of packaging to cross-contaminate food due to a faster viability loss by spoilage and pathogenic microorganisms compared to the plastic ones. In fact, the cell loads of the pathogenic species considered decreased over time independently on the inoculation level and packaging material used. However, the superficial viability losses were significantly faster in cardboard compared to plastic materials. The same behavior was observed for the spoilage microorganisms considered. The SEM microphotographs indicate that the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this material. In addition, SEM data showed that the entrapped cells were subjected to more or less rapid lyses, depending on the species, due to the absence of water and nutrients, with the exception of molds. The latter spoilers were able to proliferate inside the cardboard fibers only when the absorption of water was not prevented during the storage. In conclusion, the findings of this work showed the reduction of cross-contamination potential of corrugated compared to plastic packaging materials used in fruit and vegetable sector. However, the findings outlined the importance of hygiene and low humidity during cardboard storage to prevent the mold growth on

Analysis of interfacial crack propagation under asymmetric loading in anisotropic materials

International Nuclear Information System (INIS)

Pryce, L; Mishuris, G; Morini, L

2013-01-01

This paper considers a steady-state crack propagating along an interface between dissimilar orthotropic materials under an asymmetric load. Although most of the known results so far deal with symmetric loading, it has been shown recently that a significant asymmetry in the applied loading may lead to a pronounced effect in terms of the values of the SIFs. The aim of the paper is to extend these results from the static case to a moving crack. In particular, we show the significance of the asymmetry of the loading for computing the energy release rate

Cutting of nonmetallic materials using Nd:YAG laser beam

International Nuclear Information System (INIS)

Tahir, Bashir Ahmed; Ashiq, M.G. B.; Saeed, M.A.; Ahmed, Rashid; Ahmed, Afaq

2012-01-01

This study deals with Nd:YAG laser cutting nonmetallic materials, which is one of the most important and popular industrial applications of laser. The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed. For approximate cutting depth, a theoretical study is conducted in terms of material property and cutting speed. Results show a nonlinear relation between the cutting depth and input energy. There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s. An extra energy is utilized in the deep cutting. It is inferred that as the laser power increases, cutting depth increases. The experimental outcomes are in good agreement with theoretical results. This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting, scribing, trimming, engraving, and marking nonmetallic materials. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Sintesis dan Karakterisasi Material Nanokomposit CNT/MnO2 Untuk Aplikasi Material Superkapasitor

Directory of Open Access Journals (Sweden)

A. Subagio

2014-01-01

diameter of 1 cm and thickness of 2 mm with variations addition of binder polyvinylidene difluoride (PVDF of 10, 20 and 30%. Pellets of the material were then heated at a temperature of 70 oC for 1 hour. Resistance measurement results showed that the ratio of the mass of material CNT/MnO2 by 75% and additions by 20% PVDF binder showed the lowest resistance value. Furthermore, CNT/MnO2 supercapacitor prototype using PVDF of 20% measured with electrochemical impedance spectroscopy method showed specific capacitance of 7.86 F/gr.

Significant incidents in nuclear fuel cycle facilities

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

In contrast to nuclear power plants, events in nuclear fuel cycle facilities are not well documented. The INES database covers all the nuclear fuel cycle facilities; however, it was developed in the early 1990s and does not contain information on events prior to that. The purpose of the present report is to collect significant events and analyze them in order to give a safety related overview of nuclear fuel cycle facilities. Significant incidents were selected using the following criteria: release of radioactive material or exposure to radiation; degradation of items important to safety; and deficiencies in design, quality assurance, etc. which include criticality incidents, fire, explosion, radioactive release and contamination. This report includes an explanation, where possible, of root causes, lessons learned and action taken. 4 refs, 4 tabs.

Significant incidents in nuclear fuel cycle facilities

International Nuclear Information System (INIS)

1996-03-01

In contrast to nuclear power plants, events in nuclear fuel cycle facilities are not well documented. The INES database covers all the nuclear fuel cycle facilities; however, it was developed in the early 1990s and does not contain information on events prior to that. The purpose of the present report is to collect significant events and analyze them in order to give a safety related overview of nuclear fuel cycle facilities. Significant incidents were selected using the following criteria: release of radioactive material or exposure to radiation; degradation of items important to safety; and deficiencies in design, quality assurance, etc. which include criticality incidents, fire, explosion, radioactive release and contamination. This report includes an explanation, where possible, of root causes, lessons learned and action taken. 4 refs, 4 tabs

Neutron shielding material

International Nuclear Information System (INIS)

Nodaka, M.; Iida, T.; Taniuchi, H.; Yosimura, K.; Nagahama, H.

1993-01-01

From among the neutron shielding materials of the 'kobesh' series developed by Kobe Steel, Ltd. for transport and storage packagings, silicon rubber base type material has been tested for several items with a view to practical application and official authorization, and in order to determine its adaptability to actual vessels. Silicon rubber base type 'kobesh SR-T01' is a material in which, from among the silicone rubber based neutron shielding materials, the hydrogen content is highest and the boron content is most optimized. Its neutron shielding capability has been already described in the previous report (Taniuchi, 1986). The following tests were carried out to determine suitability for practical application; 1) Long-term thermal stability test 2) Pouring test on an actual-scale model 3) Fire test The experimental results showed that the silicone rubber based neutron shielding material has good neutron shielding capability and high long-term fire resistance, and that it can be applied to the advanced transport packaging. (author)

Clinical significance of the fabella

International Nuclear Information System (INIS)

Dodevski, A.; Lazarova-Tosovska, D.; Zhivadinovik, J.; Lazareska, M.

2012-01-01

Full text: Introduction: There is variable number of sesamoid bones in the human body; one of them is fabella, located in the tendon of the gastrocnemius muscle. Aim of this study was to investigate the frequency of occurrence of fabella in the Macedonian population and to discuss about clinical importance of this bone. Materials and methods: We retrospectively examined radiographs of 53 patients who had knee exams undertaken for a variety of clinical reasons, performed as a part of their medical treatment. Over a time span of six months, 53 patients (38 males and 15 females, age range 19-60 years, mean age of 36.7±12.3 years) were examined. Results: In seven (13.2%) patients of 53 analyzed reports, fabella was found in the lateral tendon of gastrocnemius muscle. We did not find a significant gender or side difference in the appearance of fabella. Conclusion: Although anatomic studies emphasized a lack of significance of the fabella, this bone has been associated with a spectrum of pathology affecting the knee as fabellar syndrome, perineal nerve injury and fracture. We should think of this sesamoid bone while performing diagnostic and surgical procedures

Preparation and Properties of Moisture-absorbing Film Impregnated with Polyacrylic Acid Partial Sodium Salt Material

International Nuclear Information System (INIS)

Lee, Youn Suk; Park, Insik; Choi, Hong Yeol

2014-01-01

Moisture is a major factor causing the deteriorative physical change, microbial growth, and chemical reaction of the products. In this study, the moisture absorbing composite films have been prepared with moisture absorbing material of polyacrylic acid partial sodium salt (PAPSS) impregnated on LLDPE polymer for the functional packaging applications. The results showed that PAPSS impregnated film illustrated uniformly dispersed PAPSS particles in the LLDPE polymer matrix. The transparency of the PAPSS impregnated film decreased slightly at higher PAPSS concentrations. An increase in the PAPSS content for moisture-absorbing films showed a similar decrease in tensile strength, percent elongation at break, and tear strength. Their values of films impregnated with PAPSS of 0.5, 1, and 2% showed no significant difference. Meanwhile, 4% PAPSS films significantly decreased the values of mechanical properties compared to the films impregnated with different PAPSS levels. Values of the oxygen permeability and water vapor permeability for PAPSS impregnated films decreased significantly with greater PAPSS. The results indicate that 4% PAPSS impregnated in LLDPE films had high affinity of moisture absorbencies compared to the other films. The mathematical equation that best described the moisture sorption isotherm of each film sample was the GAB equation at 25 .deg. C. The crystallization and melting temperatures of PAPSS films were influenced by the addition of PAPSS material, but showed good thermal stability

Preparation and Properties of Moisture-absorbing Film Impregnated with Polyacrylic Acid Partial Sodium Salt Material

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Suk; Park, Insik [Yonsei University, Wonju (Korea, Republic of); Choi, Hong Yeol [CJ Cheiljedang, Seoul (Korea, Republic of)

2014-08-15

Moisture is a major factor causing the deteriorative physical change, microbial growth, and chemical reaction of the products. In this study, the moisture absorbing composite films have been prepared with moisture absorbing material of polyacrylic acid partial sodium salt (PAPSS) impregnated on LLDPE polymer for the functional packaging applications. The results showed that PAPSS impregnated film illustrated uniformly dispersed PAPSS particles in the LLDPE polymer matrix. The transparency of the PAPSS impregnated film decreased slightly at higher PAPSS concentrations. An increase in the PAPSS content for moisture-absorbing films showed a similar decrease in tensile strength, percent elongation at break, and tear strength. Their values of films impregnated with PAPSS of 0.5, 1, and 2% showed no significant difference. Meanwhile, 4% PAPSS films significantly decreased the values of mechanical properties compared to the films impregnated with different PAPSS levels. Values of the oxygen permeability and water vapor permeability for PAPSS impregnated films decreased significantly with greater PAPSS. The results indicate that 4% PAPSS impregnated in LLDPE films had high affinity of moisture absorbencies compared to the other films. The mathematical equation that best described the moisture sorption isotherm of each film sample was the GAB equation at 25 .deg. C. The crystallization and melting temperatures of PAPSS films were influenced by the addition of PAPSS material, but showed good thermal stability.

Machinability Study on Milling Kenaf Fiber Reinforced Plastic Composite Materials using Design of Experiments

Science.gov (United States)

Azmi, H.; Haron, C. H. C.; Ghani, J. A.; Suhaily, M.; Yuzairi, A. R.

2018-04-01

The surface roughness (Ra) and delamination factor (Fd) of a milled kenaf reinforced plastic composite materials are depending on the milling parameters (spindle speed, feed rate and depth of cut). Therefore, a study was carried out to investigate the relationship between the milling parameters and their effects on a kenaf reinforced plastic composite materials. The composite panels were fabricated using vacuum assisted resin transfer moulding (VARTM) method. A full factorial design of experiments was use as an initial step to screen the significance of the parameters on the defects using Analysis of Variance (ANOVA). If the curvature of the collected data shows significant, Response Surface Methodology (RSM) is then applied for obtaining a quadratic modelling equation that has more reliable in expressing the optimization. Thus, the objective of this research is obtaining an optimum setting of milling parameters and modelling equations to minimize the surface roughness (Ra) and delamination factor (Fd) of milled kenaf reinforced plastic composite materials. The spindle speed and feed rate contributed the most in affecting the surface roughness and the delamination factor of the kenaf composite materials.

Histopathological changes by the use of soft reline materials: a rat model study.

Science.gov (United States)

Bail, Michele; Meister, Lissandra Matos Brol; Campagnoli, Eduardo Bauml; Jorge, Janaina Habib; Ban, Manuella de Cassia Iglesias; Sanchez-Ayala, Alfonso; Campanha, Nara Hellen

2014-01-01

To assess the histopathological changes of rat palatal mucosa exposed to soft reline materials. Forty-five adult female Wistar rats with controlled living conditions and fed ad libitum were employed. Palatal appliances of heat-polymerized acrylic resin Lucitone 550 were manufactured and worn by forty animals during 14 days. Five animals did not use the appliances (G1) and were used to control the appliance influence. One experimental group (n = 10) used the appliances without any relining material (G2) to control the material effect. Three experimental groups (n = 10) received the following soft reline materials below appliances: Dentusoft (G3), Dentuflex (G4), and Trusoft (G5). Appliances from half of each experimental group(n = 5) was immersed in water bath at 55°C for 10 min before use. Animals were slaughtered and the palates were fixed in 10% buffered formalin. Hematoxylin and eosin stained sections of 5 µm were analyzed by computerized planimetry. Cellular compartment, keratin and total epithelial thickness, and basement membrane length were measured to histopathological description.Analysis of variance and Tukey post-hoc test were used to data examination(α = 0.05). For heat-treatment groups, G4 showed less elongated ridges at the basal layer interface (p = 0.037) than G2. When comparing the conditions with and without heat-treatment, only G2 showed a significant decrease in the cellular compartment, keratin layer and total epithelium thickness (p<0.05). The post-polymerization for Lucitone 550 was an effective method to reduce the changes in the rat palatal mucosa. The soft reline materials tested did not cause significant histopathological changes in the rat palatal mucosa.

Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions.

Science.gov (United States)

Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N Suman; Tadi, Durga Prasad

2016-01-01

This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In

Minimizing residues and strain in 2D materials transferred from PDMS

Science.gov (United States)

Jain, Achint; Bharadwaj, Palash; Heeg, Sebastian; Parzefall, Markus; Taniguchi, Takashi; Watanabe, Kenji; Novotny, Lukas

2018-06-01

Integrating layered two-dimensional (2D) materials into 3D heterostructures offers opportunities for novel material functionalities and applications in electronics and photonics. In order to build the highest quality heterostructures, it is crucial to preserve the cleanliness and morphology of 2D material surfaces that come in contact with polymers such as PDMS during transfer. Here we report that substantial residues and up to ∼0.22% compressive strain can be present in monolayer MoS2 transferred using PDMS. We show that a UV-ozone pre-cleaning of the PDMS surface before exfoliation significantly reduces organic residues on transferred MoS2 flakes. An additional 200 ◦C vacuum anneal after transfer efficiently removes interfacial bubbles and wrinkles as well as accumulated strain, thereby restoring the surface morphology of transferred flakes to their native state. Our recipe is important for building clean heterostructures of 2D materials and increasing the reproducibility and reliability of devices based on them.

Influence of Handling Practices on Material Recovery from Residential Solid Waste

Directory of Open Access Journals (Sweden)

Jairo F. Pereira

2010-07-01

Full Text Available Material recovery from municipal solid waste (MSW is becoming widely adopted in several developing countries. Residential solid waste is one of the most important components of MSW and the handling practices of the MSW by the generators have a major impact on the quality and quantity of the materials for recovery. This article analyzes the generation and composition of residential solid waste and the handling practices by users in three municipalities in Colombia that have a solid waste management plant (SWMP. The findings show that, although there are significant amounts of useful materials, their handling of the materials as “garbage”, the low recognition of recovery work, and the inadequate storage and source management practices, affect material recovery and the operation of SWMPs. These results may be taken as a reference for this type of municipality, because the solid waste management system and the type of operation of the SWMPs analyzed is similar to all of the SWMPs in the country as well as in other countries in the region.

Superamphiphobic overhang structured coating on a biobased material

Energy Technology Data Exchange (ETDEWEB)

Tuominen, Mikko, E-mail: mikko.tuominen@sp.se [SP Technical Research Institute of Sweden—Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm (Sweden); Teisala, Hannu [Tampere University of Technology, Paper Converting and Packaging Technology, Department of Materials Science, P.O. Box 589, FI-33101 Tampere (Finland); Haapanen, Janne; Mäkelä, Jyrki M. [Tampere University of Technology, Aerosol Physics Laboratory, Department of Physics, P.O. Box 692, FI-33101 Tampere (Finland); Honkanen, Mari; Vippola, Minnamari [Tampere University of Technology, Material Characterization, Department of Materials Science, P.O. Box 589, FI-33101 Tampere (Finland); Bardage, Stig [SP Technical Research Institute of Sweden, Sustainable Built Environment, Biobased Materials and Products, Box 5609, SE-114 86 Stockholm (Sweden); Wålinder, Magnus E.P. [KTH Royal Institute of Technology, Department of Civil and Architectural Engineering, Building Materials, SE-100 44 Stockholm (Sweden); Swerin, Agne [SP Technical Research Institute of Sweden—Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm (Sweden); KTH Royal Institute of Technology, Department of Chemistry, Surface and Corrosion Science, SE-100 44 Stockholm (Sweden)

2016-12-15

Highlights: • A superamphiphobic coating on a wood shows extreme liquid repellence against water, ethylene glycol, diiodomethane and olive oil. • The coated wood sample can have the required geometrical homogeneity to establish superamphiphobic properties. • To our knowledge, this is the first time superamphiphobicity based on overhang structures has been shown for a renewable bio-based material.A superamphiphobic coating on a wood shows extreme liquid repellence with static contact angles (CA) greater than 150° and roll-off angles less than 10° against water, ethylene glycol, diiodomethane and olive oil. - Abstract: A superamphiphobic coating on a biobased material shows extreme liquid repellency with static contact angles (CA) greater than 150° and roll-off angles less than 10° against water, ethylene glycol, diiodomethane and olive oil, and a CA for hexadecane greater than 130°. The coating consisting of titania nanoparticles deposited by liquid flame spray (LFS) and hydrophobized using plasma-polymerized perfluorohexane was applied to a birch hardwood. Scanning electron microscopy (SEM) imaging after sample preparation by UV laser ablation of coated areas revealed that capped structures were formed and this, together with the geometrically homogeneous wood structure, fulfilled the criteria for overhang structures to occur. The coating showed high hydrophobic durability by still being non-wetted after 500 000 water drop impacts, and this is discussed in relation to geometrical factors and wetting forces. The coating was semi-transparent with no significant coloration. A self-cleaning effect was demonstrated with both water and oil droplets. A self-cleanable, durable and highly transparent superamphiphobic coating based on a capped overhang structure has a great potential for commercial feasibility in a variety of applications, here exemplified for a biobased material.

Mesoporous materials for clean energy technologies.

Science.gov (United States)

Linares, Noemi; Silvestre-Albero, Ana M; Serrano, Elena; Silvestre-Albero, Joaquín; García-Martínez, Javier

2014-11-21

Alternative energy technologies are greatly hindered by significant limitations in materials science. From low activity to poor stability, and from mineral scarcity to high cost, the current materials are not able to cope with the significant challenges of clean energy technologies. However, recent advances in the preparation of nanomaterials, porous solids, and nanostructured solids are providing hope in the race for a better, cleaner energy production. The present contribution critically reviews the development and role of mesoporosity in a wide range of technologies, as this provides for critical improvements in accessibility, the dispersion of the active phase and a higher surface area. Relevant examples of the development of mesoporosity by a wide range of techniques are provided, including the preparation of hierarchical structures with pore systems in different scale ranges. Mesoporosity plays a significant role in catalysis, especially in the most challenging processes where bulky molecules, like those obtained from biomass or highly unreactive species, such as CO2 should be transformed into most valuable products. Furthermore, mesoporous materials also play a significant role as electrodes in fuel and solar cells and in thermoelectric devices, technologies which are benefiting from improved accessibility and a better dispersion of materials with controlled porosity.

Matcom 86: Engineering materials in South Africa

International Nuclear Information System (INIS)

1986-01-01

The Symposium MATCOM '86 represents a significant departure from the usual format of scientific and engineering conferences. It provides a unique opportunity for industrialists, economists, the engineering and scientific communities, and research and development establishments to be briefed on critical issues relating to engineering materials and the effect of these materials on the manufacturing, service, health, strategic and minerals industries. Profitability and productivity in industry can often be linked to engineering materials and their in-service performance. Major surveys conducted in South Africa and developed countries have revealed the significance of losses to industry due to materials degradation problems such as fracture, wear, corrosion etc. One of the papers delivered at this symposium focus on the nuclear engineering industry, namely the application of materials in the field of uranium enrichment

Heat transfer in multi-phase materials

CERN Document Server

Öchsner, Andreas

2011-01-01

This book provides a profound understanding, which physical processes and mechanisms cause the heat transfer in composite and cellular materials. It shows models for all important classes of composite materials and introduces into the latest advances. In three parts, the book covers Composite Materials (Part A), Porous and Cellular Materials (Part B) and the appearance of a conjoint solid phase and fluid aggregate (Part C).

Significance of pH-value for meat quality of broilers: Influence of breed lines

Directory of Open Access Journals (Sweden)

Ristic M.

2013-01-01

Full Text Available For determination of poultry quality shortly after slaughtering, physical criteria (pH-value, conductivity, colour, juice retention are of importance. However, they are affected by breeding, transport, cooling and the storage period. PH-values of breast meat (genetically structured material were recorded shortly after slaughtering (15 min p.m. and differences between breeding line and gender were found (n=5109. The pH1-values ranged from 5.50 to 6.79. Male broilers showed significantly lower pH1-values than female ones (6.02:6.10. There were also significant differences concerning breeding line and gender. Meat quality (PSE, DFD of broilers can be recorded quickly and accurately determining the pH1-value of breast meat. Threshold ranges to be considered are ≤ 5.8 (PSE, 5.9-6.2 (standard meat properties and ≥ 6.3 (DFD. This classification is not to be compared to the deviation of pork.

The use of differential scanning calorimetry for the evaluation of dental materials. I. Cements, cavity lining materials and anterior restorative materials.

Science.gov (United States)

McCabe, J F; Wilson, H J

1980-03-01

Thermal changes occurring during the setting of restorative materials have been measured accurately using a differential scanning calorimeter. The results were used to evaluate setting characteristics. The heat of reaction and rate of heat output may be significant in determining thermal damage to the pulp. The heat capacity is related to thermal insulation properties. These properties have been determined and their effect on the efficacy of restorative materials discussed.

Three-Dimensional (3D Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling

Directory of Open Access Journals (Sweden)

Susanna Fafenrot

2017-10-01

Full Text Available Fused deposition modeling (FDM is a three-dimensional (3D printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid (PLA printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

Materials Science with Ion Beams

CERN Document Server

Bernas, Harry

2010-01-01

This book introduces materials scientists and designers, physicists and chemists to the properties of materials that can be modified by ion irradiation or implantation. These techniques can help design new materials or to test modified properties; novel applications already show that ion-beam techniques are complementary to others, yielding previously unattainable properties. Also, ion-beam interactions modify materials at the nanoscale, avoiding the often detrimental results of lithographic or chemical techniques. Here, the effects are related to better-known quasi-equilibrium thermodynamics, and the consequences to materials are discussed with concepts that are familiar to materials science. Examples addressed concern semiconductor physics, crystal and nanocluster growth, optics, magnetism, and applications to geology and biology.

Localization of self-generated synthetic footstep sounds on different walked-upon materials through headphones

DEFF Research Database (Denmark)

Turchet, Luca; Spagnol, Simone; Geronazzo, Michele

2016-01-01

typologies of surface materials: solid (e.g., wood) and aggregate (e.g., gravel). Different sound delivery methods (mono, stereo, binaural) as well as several surface materials, in presence or absence of concurrent contextual auditory information provided as soundscapes, were evaluated in a vertical...... localization task. Results showed that solid surfaces were localized significantly farther from the walker's feet than the aggregate ones. This effect was independent of the used rendering technique, of the presence of soundscapes, and of merely temporal or spectral attributes of sound. The effect...

The effect of orthodontic bonding materials on dental plaque accumulation and composition in vitro.

Science.gov (United States)

Badawi, H; Evans, R D; Wilson, M; Ready, D; Noar, J H; Pratten, J

2003-08-01

The aim of this study was to investigate the accumulation and composition of microcosm dental plaque on different orthodontic bonding materials using an in vitro model. Microcosm plaques were grown on discs of a range of bonding materials in a constant depth film fermentor. The biofilms were derived from human saliva and supplied with artificial saliva as a source of nutrients. The number of viable bacteria in the biofilms was determined and the streptococci present were identified to species level. The results showed that there was no significant difference in bacterial accumulation between different bonding materials, however, biofilms grown on materials which were fluoride releasing, did not contain Streptococcus mutans. This in vitro study has shown that the use of fluoride-releasing bonding materials may support the growth of supragingival plaque, which does not contain S. mutans.

Ceramic breeder materials

International Nuclear Information System (INIS)

Johnson, C.E.

1990-01-01

The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 32 refs., 1 fig., 1 tab

External exposure model for various geometries of contaminated materials

International Nuclear Information System (INIS)

LePoire, D.; Kamboj, S.; Yu, C.

1996-01-01

A computational model for external exposure was developed for the U.S. Department of Energy's residual radioactive material guideline computer code (RESRAD) on the basis of dose coefficients from Federal Guidance Report No. 12 and the point-kernel method. This model includes the effects of different materials and exposure distances, as well as source geometry (cover thickness, source depth, area, and shape). A material factor is calculated on the basis of the point-kernel method using material-specific photon cross-section data and buildup factors. This present model was incorporated into RESRAD-RECYCLE (a RESRAD family code used for computing radiological impacts of metal recycling) and is being incorporated into RESRAD-BUILD (a DOE recommended code for computing impacts of building decontamination). The model was compared with calculations performed with the Monte Carlo N-Particle Code (MCNP) and the Microshield code for three different source geometries, three different radionuclides ( 234 U, 238 U, and 60 Co, representing low, medium, and high energy, respectively), and five different source materials (iron, copper, aluminum, water, and soil). The comparison shows that results of this model are in very good agreement with MCNP calculations (within 5% for 60 Co and within 30% for 238 U and 234 U for all materials and source geometries). Significant differences (greater than 100%) were observed with Microshield for thin 234 U sources

2D materials in electro-optic modulation: energy efficiency, electrostatics, mode overlap, material transfer and integration

Science.gov (United States)

Ma, Zhizhen; Hemnani, Rohit; Bartels, Ludwig; Agarwal, Ritesh; Sorger, Volker J.

2018-02-01

Here we discuss the physics of electro-optic modulators deploying 2D materials. We include a scaling laws analysis and show how energy-efficiency and speed change for three underlying cavity systems as a function of critical device length scaling. A key result is that the energy-per-bit of the modulator is proportional to the volume of the device, thus making the case for submicron-scale modulators possible deploying a plasmonic optical mode. We then show how Graphene's Pauli-blocking modulation mechanism is sensitive to the device operation temperature, whereby a reduction of the temperature enables a 10× reduction in modulator energy efficiency. Furthermore, we show how the high-index tunability of graphene is able to compensate for the small optical overlap factor of 2D-based material modulators, which is unlike classical silicon-based dispersion devices. Lastly, we demonstrate a novel method towards a 2D material printer suitable for cross-contamination free and on-demand printing. The latter paves the way to integrate 2D materials seamlessly into taped-out photonic chips.

Heterogeneous Materials I and Heterogeneous Materials II

International Nuclear Information System (INIS)

Knowles, K M

2004-01-01

In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field of materials science interested in comparing predictions of properties with experimental results may well find the mathematical level quite daunting initially, as it is apparent that the author assumes a level of mathematics consistent with that taught in final year undergraduate and graduate theoretical physics courses. However, for such readers it is well worth persevering because of the in-depth coverage to which the various models are subjected, and also because of the extensive reference lists at the back of both volumes which direct readers to the various source references in the scientific literature. Thus, for the wider materials science scientific community the two volumes will be a valuable library resource. While I would have liked to see more comparison with experimental data on both ideal and 'real' heterogeneous materials than is provided by the author and a discussion of how to model strong nonlinear current--voltage behaviour in systems such as zinc oxide varistors, my overall

The use of radiation for the study of material of cultural heritage significance

Energy Technology Data Exchange (ETDEWEB)

Creagh, D.C. E-mail: dcreagh@bigpond.net.aududleyc@ise.canberra.edu.au; Otieno-Alego, V

2004-01-01

For the indigenous people of Northern Australia the expression of their experience of life, their 'dreaming', is in the form of painting, usually on the bark stripped from trees growing in their tribal lands. These are often works of great beauty and the major collecting institutions in Australia and elsewhere have significant holdings of Aboriginal bark paintings. A wide range of analytical techniques (optical microscopy, FTIR microscopy, Raman microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, and synchrotron radiation X-ray diffraction) has been used in a project to determine how best to conserve Aboriginal bark paintings.

The use of radiation for the study of material of cultural heritage significance

International Nuclear Information System (INIS)

Creagh, D.C.; Otieno-Alego, V.

2004-01-01

For the indigenous people of Northern Australia the expression of their experience of life, their 'dreaming', is in the form of painting, usually on the bark stripped from trees growing in their tribal lands. These are often works of great beauty and the major collecting institutions in Australia and elsewhere have significant holdings of Aboriginal bark paintings. A wide range of analytical techniques (optical microscopy, FTIR microscopy, Raman microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, and synchrotron radiation X-ray diffraction) has been used in a project to determine how best to conserve Aboriginal bark paintings

EU-policy and smart materials; EU-beleid en smart materials

Energy Technology Data Exchange (ETDEWEB)

Pieters, D.; Van der Beek, M.

2012-09-15

Netherlands will focus on large-scale production of smart materials. Several examples from Dutch universities show that the Netherlands is very active in this sector. Nanotechnology and the development of advanced materials are considered as 'key technologies'. To realize these applications EU funding will be made available both for research projects and to support market introduction [Dutch] Nederland zet in de toekomst in op grootschalige productie van smart materials. Verschillende voorbeelden van Nederlandse universiteiten laten zien dat Nederland tot op heden zeer actief is in deze veelzijdige sector. Nanotechnologie en de ontwikkeling van geavanceerde materialen worden in dit licht beschouwd als zogenoemde 'sleuteltechnologieen'. Om deze toepassingen te realiseren komt zowel EU-geld beschikbaar voor onderzoeksprojecten als ter ondersteuning van marktintroductie.

Experimental Study on the Interaction Between Contacting Barrier Materials for Containment of Radioactive Wastes

Science.gov (United States)

Huang, W. H.; Chang, H. C.

2017-12-01

The disposal of low- and intermediate-level radioactive wastes requires use of multi-barriers for isolation of the wastes from the biosphere. Typically, the engineered barriers are composed of a concrete vault, buffer and backfill materials. Zhishin clay and Black Hill bentonite were used as raw clay material in making buffer and backfill materials in this study. These clays were compacted to make buffer material, or mixed with Taitung area argillite to produce backfill material for potential application as barriers for the disposal of low- and intermediate-level radioactive wastes. The interaction between concrete barrier and the buffer/backfill material is simulated by an accelerated migration test to investigate the effect of contacting concrete on the expected functions of buffer/backfill material. The results show buffer material close to the contact with concrete exhibits significant change in the ratio of calcium/sodium exchange capacity, due to the move of calcium ions released from the concrete. The shorter the distance from the contacting interface, the ratio of the calcium/sodium concentration in buffer/backfill materials increases. The longer the distance from the interface, the effect of the contact on alteration in clays become less significant. Also, some decreases in swelling capacity in the buffer/backfill material near the concrete-backfill interface are noted. Finally, a comparison is made between Zhisin clay and Balck Hill bentonite on the interaction between concrete and the two clays. Black Hill bentonite was found to be influenced more by the interaction, because of the higher content of montmorillonite. On the other hand, being a mixture of clay and sand, backfill material is less affected by the decalsification of concrete at the contact than buffer material.

Significant exposures to isoeugenol derivaties in perfumes

DEFF Research Database (Denmark)

Rastogi, Suresh Chandra; Johansen, Jeanne Duus

2008-01-01

in perfumes/aftershaves. MATERIALS AND METHODS: 29 international brand perfumes/aftershaves were analysed for the target fragrance ingredient by gas chromatography-mass spectrometry. All samples were analysed in duplicate at detection levels of 1-5 p.p.m. RESULTS: 16 products (55%) contained isoeugenol...... was not detected in any of the investigated products. CONCLUSIONS: Isoeugenyl acetate is present in perfumes/aftershaves, in some products in significant amounts. This may lead to elicitation of contact allergy in isoeugenol-sensitized individuals and may contribute to unchanged levels of isoeugenol sensitization....

Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin.

Science.gov (United States)

Kim, Haseog; Park, Sangki; Lee, Seahyun

2016-07-19

There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance.

Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin

Directory of Open Access Journals (Sweden)

Haseog Kim

2016-07-01

Full Text Available There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance.

Advanced Materials for Automotive Application

International Nuclear Information System (INIS)

Tisza, M

2013-01-01

In this paper some recent material developments will be overviewed mainly from the point of view of automotive industry. In car industry, metal forming is one of the most important manufacturing processes imposing severe restrictions on materials; these are often contradictory requirements, e.g. high strength simultaneously with good formability, etc. Due to these challenges and the ever increasing demand new material classes have been developed; however, the more and more wide application of high strength materials meeting the requirements stated by the mass reduction lead to increasing difficulties concerning the formability which requires significant technological developments as well. In this paper, the recent materials developments will be overviewed from the point of view of the automotive industry

BOOK REVIEW: Heterogeneous Materials I and Heterogeneous Materials II

Science.gov (United States)

Knowles, K. M.

2004-02-01

In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field\

[Digital educational materials in nursing: assessment by professors from an undergraduate course].

Science.gov (United States)

Cogo, Ana Luísa Petersen; Pedro, Eva Néri Rubim; da Silva, Ana Paula Scheffer Schell; Schatkoski, Aline Modelski; Catalan, Vanessa Menezes; Alves, Rosa Helena Kreutz

2009-06-01

This study addresses the use of digital learning materials in the format of hypertext, educational games and simulations about oxygen therapy with professors of an Undergraduate Nursing Course. It is a cross-sectional exploratory study that was carried out at the Federal University of Rio Grande do Sul in 2006 with 10 intentionally selected professors. Data collection was performed by means of a questionnaire, using a Likert scale to assess the suitability of the content, visual presentation and use of learning materials. Descriptive statistics was used to organize and process the data. Results showed that the professors approved of the presentation of educational materials, they agreed with the suitability of the contents presented and with using the materials with the content regarding oxygen therapy. There was no significant relation between the professors' opinion and their age group, nor with their computer technology knowledge, their time in teaching and the addressed contents.

Methodology for categorization of nuclear material in pyroprocessing facility

Energy Technology Data Exchange (ETDEWEB)

Lee, Chanki; Choi, Sungyeol [UNIST, Ulsan (Korea, Republic of); Kim, Woo Jin; Kim, Min Su; Jeong, Yon Hong [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2016-10-15

For the pyroprocessing facility to be commercialized in future, current regulations should be evaluated and developed in advance, based on the new types of nuclear materials in the facility. Physical protection system, especially, requires reasonable and reliable categorization of nuclear materials, to prevent from the theft of nuclear materials. In this paper, therefore, current categorization methods of nuclear material are investigated and applied to the pyroprocessing facility. After inconsistencies and gaps are found among methods, they are compared and discussed based on eight considering points (i.e, degrees of attractiveness, levels of category, discount factor, physical barriers, chemical barriers, isotopic barriers, radiological barriers, and capabilities of adversaries), to roughly suggest a new method for categorization. Current categorization methods of nuclear material, including IAEA's INFCIRC/225, U.S. DOE's method, newly expected U.S. NRC's method, FOM, and Bunn's approach, are different and can bring inconsistencies of physical protection requirements. The gap among methods will be significant if advanced fuel cycles are applied to them for the future. For example, the categorization results of 5 target materials in pyroprocessing facility show clear inconsistencies, while TRU ingot is considered the most attractive material. To resolve inconsistencies, it is necessary to determine new method suitable to pyroproessing facility, by considering the effects of eight points (i.e, degrees of attractiveness, levels of category, discount factor, physical barriers, chemical barriers, isotopic barriers, radiological barriers, and capabilities of adversaries)

Methodology for categorization of nuclear material in pyroprocessing facility

International Nuclear Information System (INIS)

Lee, Chanki; Choi, Sungyeol; Kim, Woo Jin; Kim, Min Su; Jeong, Yon Hong

2016-01-01

For the pyroprocessing facility to be commercialized in future, current regulations should be evaluated and developed in advance, based on the new types of nuclear materials in the facility. Physical protection system, especially, requires reasonable and reliable categorization of nuclear materials, to prevent from the theft of nuclear materials. In this paper, therefore, current categorization methods of nuclear material are investigated and applied to the pyroprocessing facility. After inconsistencies and gaps are found among methods, they are compared and discussed based on eight considering points (i.e, degrees of attractiveness, levels of category, discount factor, physical barriers, chemical barriers, isotopic barriers, radiological barriers, and capabilities of adversaries), to roughly suggest a new method for categorization. Current categorization methods of nuclear material, including IAEA's INFCIRC/225, U.S. DOE's method, newly expected U.S. NRC's method, FOM, and Bunn's approach, are different and can bring inconsistencies of physical protection requirements. The gap among methods will be significant if advanced fuel cycles are applied to them for the future. For example, the categorization results of 5 target materials in pyroprocessing facility show clear inconsistencies, while TRU ingot is considered the most attractive material. To resolve inconsistencies, it is necessary to determine new method suitable to pyroproessing facility, by considering the effects of eight points (i.e, degrees of attractiveness, levels of category, discount factor, physical barriers, chemical barriers, isotopic barriers, radiological barriers, and capabilities of adversaries)

Polyhexamethylene guanidine hydrochloride shows bactericidal advantages over chlorhexidine digluconate against ESKAPE bacteria.

Science.gov (United States)

Zhou, Zhongxin; Wei, Dafu; Lu, Yanhua

2015-01-01

More information regarding the bactericidal properties of polyhexamethylene guanidine hydrochloride (PHMG) against clinically important antibiotic-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens needs to be provided for its uses in infection control. The bactericidal properties of PHMG and chlorhexidine digluconate (CHG) were compared based on their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, and time-course-killing curves against clinically important antibiotic-susceptible and antibiotic-resistant ESKAPE pathogens. Results showed that PHMG exhibited significantly higher bactericidal activities against methicillin-resistant Staphylococcus aureus, carbapenem-resistant Klebsiella pneumoniae, and ceftazidime-resistant Enterobacter spp. than CHG. A slight bactericidal advantage over CHG was obtained against vancomycin-resistant Enterococcus faecium, ciprofloxacin- and levofloxacin-resistant Acinetobacter spp., and multidrug-resistant Pseudomonas aeruginosa. In previous reports, PHMG had higher antimicrobial activity against almost all tested Gram-negative bacteria and several Gram-positive bacteria than CHG using MIC test. These studies support the further development of covalently bound PHMG in sterile-surface materials and the incorporation of PHMG in novel disinfectant formulas. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Simulated Aging and Characterization of Phase Change Materials for Thermal Management of Building Envelopes

Science.gov (United States)

2015-09-01

materials of a PCM wall or ceiling panel. BioPCMat™ absorbs heat in the daytime and releases that heat during the night. The dimension of the typical...micrographs of Energain PCM samples showed evidence of melting and re- ERDC/CERL TR-15-23 32 crystallization ; however, there was no significant

Dimensional Stability of Two Polyvinyl Siloxane Impression Materials in Different Time Intervals

Directory of Open Access Journals (Sweden)

Aalaei Sh

2015-12-01

Full Text Available Statement of the Problem: Dental prosthesis is usually made indirectly; there- fore dimensional stability of the impression material is very important. Every few years, new impression materials with different manufacturers’ claims regarding their better properties are introduced to the dental markets which require more research to evaluate their true dimensional changes. Objectives: The aim of this study was to evaluate dimensional stability of additional silicone impression material (Panasil® and Affinis® in different time intervals. Materials and Methods: In this experimental study, using two additional silicones (Panasil® and Affinis®, we made sixty impressions of standard die in similar conditions of 23 °C and 59% relative humidity by a special tray. The die included three horizontal and two vertical lines that were parallel. The vertical line crossed the horizontal ones at a point that served as reference for measurement. All impressions were poured with high strength dental stone. The dimensions were measured by stereo-microscope by two examiners in three interval storage times (1, 24 and 168 hours.The data were statistically analyzed using t-test and ANOVA. Results: All of the stone casts were larger than the standard die. Dimensional changes of Panasil and Affinis were 0.07%, 0.24%, 0.27% and 0.02%, 0.07%, 0.16% after 1, 24 and 168 hours, respectively. Dimensional change for two impression materials wasn’t significant in the interval time, expect for Panasil after one week (p = 0.004. Conclusions: According to the limitations of this study, Affinis impressions were dimensionally more stable than Panasil ones, but it was not significant. Dimensional change of Panasil impression showed a statistically significant difference after one week. Dimensional changes of both impression materials were based on ADA standard limitation in all time intervals (< 0.5%; therefore, dimensional stability of this impression was accepted at least

2D materials: Graphene and others

Energy Technology Data Exchange (ETDEWEB)

Bansal, Suneev Anil, E-mail: suneev@gmail.com; Singh, Amrinder Pal [Deptt. of Mech Engg, UIET, Panjab University, Chandigarh (India); Kumar, Suresh [Deptt. of Applied Sciences, UIET, Panjab University, Chandigarh (India)

2016-05-06

Present report reviews the recent advancements in new atomically thick 2D materials. Materials covered in this review are Graphene, Silicene, Germanene, Boron Nitride (BN) and Transition metal chalcogenides (TMC). These materials show extraordinary mechanical, electronic and optical properties which make them suitable candidates for future applications. Apart from unique properties, tune-ability of highly desirable properties of these materials is also an important area to be emphasized on.

Damage mechanisms and metallic materials development in multiphase flow

International Nuclear Information System (INIS)

Zheng, Yugui; Liu, Wei; Yao, Zhiming; Ke, Wei

2002-01-01

The investigation on the synergistic effects among corrosion, slurry erosion and cavitation erosion has special significance for hydraulic turbines operated in Yangtze River and Yellow River where the high concentration solid particles exist in water. Two typical metallic materials i.e. Cr-Mn-N stainless steel and Ni-Ti shapememory-alloy, and two typical materials used for hydraulic turbines 20SiMn and 0Cr13Ni5Mo as compared materials were selected in order to investigate the roles of work-hardening ability and martensitic transformation as well as pseudoelastics in damage mechanism in multiphase flow. Both modified rotating disk rig and ultrasonic vibration facility were used to simulate the possible damage mechanism of materials in multiphase flow. The effects of corrosion on cavitation erosion were investigated through adding 3wt% NaCl. The degradation mechanism was analyzed by electrochemical test, SEM observation, hardness and roughness measurement. The results showed that there was a strong synergistic interaction among electrochemical corrosion, slurry erosion and cavitation erosion for 20SiMn in liquid-solid two-phase medium. In contrast, corrosion played little role for 0Cr13Ni5Mo. Cr-Mn-N stainless steel with high Mn content showed better resistance to cavitation erosion and slurry erosion than 0Cr13Ni5Mo, which was mainly due to its good work-hardening ability as well as strain-induced martensite transformation. The cavitation micro-cracks for Cr-Mn-N stainless steel were parallel to the specimen surface in contrast with 0Cr13Ni5Mo whose micro-cracks were perpendicular to the surface. Ni-Ti alloy with pseudoelasticity showed excellent resistance to combined interaction of cavitation erosion and slurry erosion

Materials Frontiers to Empower Quantum Computing

Energy Technology Data Exchange (ETDEWEB)

Taylor, Antoinette Jane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sarrao, John Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Richardson, Christopher [Laboratory for Physical Sciences, College Park, MD (United States)

2015-06-11

This is an exciting time at the nexus of quantum computing and materials research. The materials frontiers described in this report represent a significant advance in electronic materials and our understanding of the interactions between the local material and a manufactured quantum state. Simultaneously, directed efforts to solve materials issues related to quantum computing provide an opportunity to control and probe the fundamental arrangement of matter that will impact all electronic materials. An opportunity exists to extend our understanding of materials functionality from electronic-grade to quantum-grade by achieving a predictive understanding of noise and decoherence in qubits and their origins in materials defects and environmental coupling. Realizing this vision systematically and predictively will be transformative for quantum computing and will represent a qualitative step forward in materials prediction and control.

SuperFormLab: showing SuperFormLab

DEFF Research Database (Denmark)

2013-01-01

bachelor program, followed by two years of master studies. The courses are offered equally to students from other design disciplines, e.g. industrial design. Teaching is mainly in English as the program is attended by a relatively large group of non-Danish students, who seek exactly this combination......3D-printing in clay and ceramic objects shaped by your own sounds and movements! Digital form transferred via CNC-milling to ornamental ceramic wall-cladding. Brave New World… Students and their teacher at SuperFormLab, the new ceramic workshop of the School of Design at the Royal Danish Academy...... of Fine Arts in Copenhagen, will be showing results of their investigations into the potential of combining digital technologies with ceramic materials. It is now possible to shape the most complex mathematical, virtual 3D objects through the use of advanced software-programs. And more than that – you can...

Risk assessment during transport of radioactive materials through the Suez Canal

Science.gov (United States)

Sabek, M. G.; El-Shinawy, R. M. K.; Gomaa, M.

1997-03-01

In this paper a study for risk assessment of the impact of transporting radioactive materials, during the period 1986-1992, through the Suez Canal of Egypt is given. The code RADTRAN-IV was used for this study. The results of the code, for a normal case, show that the transportation of low activity materials such as uranium (U 3O 8) represent the main items that contribute significantly to the collective dose within the Suez Canal area (Port-Said, Ismailia and Suez). The values of the annual collective dose due to transportation of all radionuclide materials was found to be at a maximum in Suez town and is equal to 5.04 × 10 -8 Man-Sv for the whole populations. If we only consider the workder at the harbour (estimated to be 50 persons), the value of the annual collective dose is about 3.33 × 10 -4 Man-Sv. These values are less than the exemption value of 1 Man-Sv recommended by the IAEA. For the accident case, the following pathways are considered by the code: ground-shine, direct inhalation, inhalation of resuspended material and cloud-shine. The total values of the estimated risks for each radionuclide material are presented in table form and, in addition, health effects (genetic effects, GE, and latent cancer fatality), LCF) are discussed. The calculated values of the radiological risks are very low for the three towns, showing that no radiation-induced early deaths are to be expected.

Economically Significant Sites - OSPR [ds356

Data.gov (United States)

California Natural Resource Agency — This point data set shows locations of Economically Significant Sites along the California coast from Del Norte to San Diego counties. Data for locating these points...

Radon exhalation from building materials for decorative use

Energy Technology Data Exchange (ETDEWEB)

Chen Jing, E-mail: jing.chen@hc-sc.gc.c [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada); Rahman, Naureen M.; Atiya, Ibrahim Abu [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada)

2010-04-15

Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m{sup -2} d{sup -1}. Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m{sup -2} d{sup -1} for slate tiles and 42 Bq m{sup -2} d{sup -1} for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m{sup -2} d{sup -1}, it would contribute only 18 Bq m{sup -3} to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.

"Tormenta Espacial" - Exploring The Sun-earth Connection With A Spanish-language Planetarium Show

Science.gov (United States)

Elteto, Attila; Salas, F.; Duncan, D.; Traub-Metlay, S.

2007-10-01

Reaching out to Spanish speakers is increasingly vital to workforce development and public support of space science projects. Building on a successful partnership with NASA's TIMED mission, LASP and Space Science Institute, Fiske Planetarium has translated its original planetarium show - "Space Storm” - into "Tormenta Espacial". This show explores the Sun-Earth connection and explains how solar activity affects technology and life on Earth. Solar scientists from NOAA's Space Environment Center and the University of Colorado at Boulder contributed to provide scientific accuracy. Show content and accompanying educational materials are aligned with state and national science standards. While designed for students in grades 6-8, this show has been positively evaluated by students from grades 4-10 and shown to the general public with favorable responses. Curricular materials extend the planetarium experience into the K-12 classroom so that students inspired and engaged by the show continue to see real-life applications and workplace opportunities. Fiske Planetarium offers both "Space Storm” and "Tormenta Espacial” to other planetariums at a minimal rate, including technical support for the life of the show. Thanks to a request from a planetarium in Belgium, a version of "Space Storm” is available with no spoken dialogue so that languages other than English or Spanish may be accommodated. Collaborative projects among planetariums, NASA missions (planned as well as active), research scientists and other parties keep EPO activities healthy and well-funded. Fiske Planetarium staff strive to develop and maintain partnerships throughout the EPO and informal education communities.

Technology Assessment of Laser-Assisted Materials Processing in Space

Science.gov (United States)

Nagarathnam, Karthik; Taminger, Karen M. B.

2001-01-01

Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, shock processing, and surface treatments. These attributes are attractive for the supportability of longer-term missions in space due to the multi-functionality of a single tool and the variety of materials that can be processed. However, current laser technology also has drawbacks for space-based applications, specifically size, power efficiency, lack of robustness, and problems processing highly reflective materials. A review of recent laser developments will be used to show how these issues may be reduced and indicate where further improvement is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. With the advent of recent breakthroughs in diode-pumped solid-state lasers and fiber optic technologies, the potential to perform multiple processing techniques is increasing significantly. Lasers with suitable wavelengths and beam properties have tremendous potential for supporting future space missions to the moon, Mars and beyond.

Interaction of Water with Cement Based Repository Materials - Application of Neutron Imaging

International Nuclear Information System (INIS)

Mcglinn, P.J.; Brew, D.R.M.; Beer, F.C. De; Radebe, M.J.; Nshimirimana, R.

2013-01-01

Cementitious materials are conventionally used in conditioning intermediate and low level radioactive waste. In this study, a candidate cement-based wasteform and a series of barrier materials have been investigated using neutron imaging to: 1) characterise the wasteform for disposal in a repository for radioactive materials, and 2) characterise the compositon of the barrier materials in assessing their potential to transmit water. Imaging showed both the pore size distribution and the extent of the cracking that had occurred in the wasteform samples. The rate of the water penetration measured both by conventional sorptivity measurements and neutron imaging was greater than in pastes made from Ordinary Portland Cement. The ability of the cracks to distribute the water through the sample in a very short time was also evident. Macro-pore volume distributions of barrier samples, also acquired using neutron tomography, are shown to relate to water/cement ratio, composition and sorptivity data. The study highlights the significant potential of neutron imaging in the investigation of cementitious materials. The technique has the advantage of visualising and measuring, non-destructively, material distribution within macroscopic samples and is particularly useful in defining movement of water through the cementitious materials. (author)

Preparation process and properties of LiCoO2/PANI/dodecylbenzenesulfonate composite electrode materials

International Nuclear Information System (INIS)

Ferchichi, Karima; Hbaieb, Souhaira; Amdouni, Noureddine; Kalfat, Rafik; Chevalier, Yves

2013-01-01

Composite materials that combine the lithium exchanging material LiCoO 2 and the conductive polymer poly(aniline) (PANI) have been investigated regarding their possible application to electrode materials of lithium batteries. Such composite materials have been prepared by means of polymerization of aniline in acidic suspensions of LiCoO 2 particles. PANI was synthesized by oxidative polymerization of aniline by ammonium persulfate in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant. The composite material consisted in LiCoO 2 particles dispersed in a continuous matrix of PANI. The ribbon-like morphology of the powdered material was distinctly different of the morphologies of the parent materials. The conductive material had conductivity close to that of PANI because the LiCoO 2 content of the composite material was low. The presence of the poorly conductive inorganic phase caused a significant loss of conductivity, showing that LiCoO 2 blocked electronic transfers between PANI crystallites. Ammonium persulfate caused the loss of lithium from LiCoO 2 when it was used at high concentration in the polymerization recipe. In this case a new phase made of Co 3 O 4 formed by chemical decomposition of Li x CoO 2 . Thin films prepared from stable suspensions of composite materials in water show comparable electrical performance to that measured for bulk materials. - Highlights: • LiCoO 2 was incorporated in a conductive polymer matrix made of PANI. • The hybrid material retained the high conductive properties of PANI. • Loss of lithium by persulfate oxidation caused conversion of LiCoO 2 into Co 3 O 4

Effect of Time on Gypsum-Impression Material Compatibility

Science.gov (United States)

Won, John Boram

The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix ® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

Effect of material parameters on the compactibility of backfill materials

International Nuclear Information System (INIS)

Keto, P.; Kuula-Vaeisaenen, P.; Ruuskanen, J.

2006-05-01

The effect of different parameters on compactibility of mixture of bentonite and ballast as well as Friedland-clay was studied in laboratory with two different types of compaction tests. The material parameters varied were grain size distribution of the ballast material, grain shape, water ratio and bentonite content (15/30%). The other parameters varied were salinity of the mixing water, mixing process and compaction method and energy. Ballast materials with varying grain size distributions were produced from Olkiluoto mica-gneiss with different type of crushing processes. In addition, sand was chosen for ballast material due to its uniform grain size distribution and rounded grain shape. The maximum grain size of the ballast materials was between 5-10 mm. When comparing the compactibility of ballast materials, the highest dry densities were gained for ballast materials with graded grain size distribution. The compaction behaviour of the tested bentonite ballast mixtures is dominated by the bentonite content. The other parameters varied did not have significant effect on the compactibility of the mixtures with bentonite content of 30%. This can be explained with the amount of bentonite that is higher than what is needed to fill up the volume between the ballast grains. The results gained with the two different compaction tests are comparable. Both the bentonite/ballast mixtures and the Friedland clay behaved similarly when compacted with three different compaction pressures (180, 540 and 980 kPa). (orig.)

3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching

Directory of Open Access Journals (Sweden)

Bryant Anthony Irawan

2015-01-01

Full Text Available This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n=30 measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n=10: subgroup A (Opalescence PF, subgroup B (Opalescence Boost in-office bleaching, and subgroup C (distilled water serving as control. Samples were bleached according to the manufacturer’s instructions for a period of two weeks. The Commission Internationale de L’Eclairage (CIE L*, a*, b* system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM. Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤0.05. The three restorative materials showed significant color changes (ΔE; P≤0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6 > Ketac Nano (2.97 ± 1.2 > Filtek Z350 XT (2.25 ± 1.0. However, none of the tested materials showed statistically significant changes in surface roughness; P>0.05.

Impact-limiting materials characterization

International Nuclear Information System (INIS)

Glass, R.E.; Duffey, T.A.; McConnell, P.

1993-01-01

Three types of impact-limiting materials have been characterized which have applications in packages for the transport of radioactive materials. These materials are aluminum honeycombs, polyurethane foams, and aluminum foams. The results of the materials characterization have indicated strengths and weaknesses for each type of material. The polyurethane foams provide good impact limiting ability and excellent thermal insulation. However, they burn when subjected to the regulatory thermal event in the presence of air. The aluminum honeycombs provide excellent impact resistance in specific impact orientations. However, they provide relatively poor resistance to thermal assault. Finally, the aluminum foams exhibit relatively poor impact energy absorption capacities, significant variability in energy absorption, and limited thermal insulation. The development of the figures of merit examined the response of the materials to the impact event with the intent of maximizing the energy absorption of the materials with respect to either the volume or mass of the materials. Three figures of merit will be presented for the structural response. The figure of merit for the thermal event is based on minimizing the heat flux to the containment boundary. The paper presents a discussion of the test methods, a summary of the data and the figures of merit for each material. (J.P.N.)

Material synergism fusion-fission

International Nuclear Information System (INIS)

Sankara Rao, K.B.; Raj, B.; Cook, I.; Kohyama, A.; Dudarev, S.

2007-01-01

In fission and fusion reactors the common features such as operating temperatures and neutron exposures will have the greatest impact on materials performance and component lifetimes. Developing fast neutron irradiation resisting materials is a common issue for both fission and fusion reactors. The high neutron flux levels in both these systems lead to unique materials problems like void swelling, irradiation creep and helium embitterment. Both fission and fusion rely on ferritic-martensitic steels based on 9%Cr compositions for achieving the highest swelling resistance but their creep strength sharply decreases above ∝ 823K. The use of oxide dispersion strengthened (ODS) alloys is envisaged to increase the operating temperature of blanket systems in the fusion reactors and fuel clad tubes in fast breeder reactors. In view of high operating temperatures, cyclic and steady load conditions and the long service life, properties like creep, low cycle fatigue,fracture toughness and creepfatigue interaction are major considerations in the selection of structural materials and design of components for fission and fusion reactors. Currently, materials selection for fusion systems has to be based upon incomplete experimental database on mechanical properties. The usage of fairly well developed databases, in fission programmes on similar materials, is of great help in the initial design of fusion reactor components. Significant opportunities exist for sharing information on technology of irradiation testing, specimen miniaturization, advanced methods of property measurement, safe windows for metal forming, and development of common materials property data base system. Both fusion and fission programs are being directed to development of clean steels with very low trace and tramp elements, characterization of microstructure and phase stability under irradiation, assessment of irradiation creep and swelling behaviour, studies on compatibility with helium and developing

Heat conductivity of buffer materials

International Nuclear Information System (INIS)

Boergesson, L.; Fredrikson, Anders; Johannesson, L.E.

1994-11-01

The report deals with the thermal conductivity of bentonite based buffer materials. An improved technique for measuring the thermal conductivity of buffer materials is described. Measurements of FLAC calculations applying this technique have led to a proposal of how standardized tests should be conducted and evaluated. The thermal conductivity of bentonite with different void ratio and degree of water saturation has been determined in the following different ways: * Theoretically according to three different investigations by other researchers. * Laboratory measurements with the proposed method. * Results from back-calculated field tests. Comparison and evaluation showed that these results agreed very well, when the buffer material was almost water saturated. However, the influence of the degree of saturation was not very well predicted with the theoretical methods. Furthermore, the field tests showed that the average thermal conductivity in situ of buffer material (compacted to blocks) with low degree of water saturation was lower than expected from laboratory tests. 12 refs, 29 figs, 11 tabs

Tailored Materials for High Efficiency CIDI Engines

Energy Technology Data Exchange (ETDEWEB)

Grant, G.J.; Jana, S.

2012-03-30

The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

Captopril 25 mg tablets stability assessment in different primary packing materials

Directory of Open Access Journals (Sweden)

Flávia Costa Mendes Paiva

2017-11-01

Full Text Available Introduction: Packaging is used to provide protection and information, from the production to the administration of a formulation. It is essential to define the primary packaging, for keeping the therapeutic efficacy of drugs, safety of users and for protecting drugs from instability. Objectives: The main objective of this study was to assess the stability of captopril 25 mg tablets in different primary packaging materials. Method: The characterization (IR, DSC and physical tests of the packaging materials used for captopril was carried out prior to the manufacture of tablets. Tablets were also characterized by physical-chemical analysis, comparative dissolution profile and stability studies. Results: The characterization of packaging materials was crucial for understanding the behavior of captopril when packed in each material. Materials with significant barrier, as blisters PVC/PVdC 90 g.m-² and hard aluminum and PVC/PE/PVdC and hard aluminum showed satisfactory results in a second stage, S2. On the contrary, lower barrier materials as blisters PVC/PVdC 40 g.m-² and hard aluminum did not present dissolution analysis S2. Conclusions: The aluminum strip presented the best results. And the batch in glass bottle, although packaged in excellent material, was disapproved in accelerated stability.

Reclamation of waste rock material at the Summitville Mine Superfund site using organic matter and topsoil treatments

Energy Technology Data Exchange (ETDEWEB)

Winter, M.E.; Redente, E.F.

1999-07-01

The Summitville Mine was a high elevation (3,500 m) open-pit gold mine located in southwestern Colorado. The mine was abandoned in 1992 leaving approximately 200 ha of disturbed area comprised partially of two large waste rock piles. Reclamation of waste rock material is challenging due to extreme climatic conditions in conjunction with a high acid-production potential and low organic matter concentration of the material. In addition, stockpiled topsoil at the site is acidic and may be biologically inactive due to long-term storage, and therefore sufficient plant growth medium may be limited. The purpose of this study was to determine the effect of organic amendments (mushroom compost vs. biosolids) and topsoil (stockpiled vs. nonstockpiled) on aboveground biomass, herbaceous cover, and trace element uptake. An on-site field study was established in 1995 to identify the most effective combination of treatments for successful reclamation of waste rock material. Incorporation of organic matter increased total aboveground production and cover, with mushroom compost being more effective than biosolids, but did not show significant trends relative to trace element uptake. The use of topsoil did not show a significant response relative to aboveground production, cover, and trace element uptake. This study shows that waste rock materials can be directly revegetated if properly neutralized, fertilized, and amended with organic matter. Additionally, stockpiled topsoil was equivalent in plant growth to non-stockpiled topsoil when neutralized with lime.

X-Ray and UV Photoelectron Spectroscopy | Materials Science | NREL

Science.gov (United States)

backsheet material, showing excellent quantitative agreement between measured and predicted peak area ratios XPS spectra of carbon 1s from polyethylene terephthalate backsheet material, showing excellent

Linear dimensional stability of elastomeric impression materials over time.

Science.gov (United States)

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

2011-01-01

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

Experimental investigation on material migration phenomena in micro-EDM of reaction-bonded silicon carbide

Energy Technology Data Exchange (ETDEWEB)

Liew, Pay Jun [Department of Mechanical Systems and Design, Tohoku University, Aramaki Aoba 6-6-01, Aoba-ku, Sendai, 980-8579 (Japan); Manufacturing Process Department, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100, Durian Tunggal, Melaka (Malaysia); Yan, Jiwang, E-mail: yan@mech.keio.ac.jp [Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Kohoku-ku, Yokohama, 223-8522 (Japan); Kuriyagawa, Tsunemoto [Department of Mechanical Systems and Design, Tohoku University, Aramaki Aoba 6-6-01, Aoba-ku, Sendai, 980-8579 (Japan)

2013-07-01

Material migration between tool electrode and workpiece material in micro electrical discharge machining of reaction-bonded silicon carbide was experimentally investigated. The microstructural changes of workpiece and tungsten tool electrode were examined using scanning electron microscopy, cross sectional transmission electron microscopy and energy dispersive X-ray under various voltage, capacitance and carbon nanofibre concentration in the dielectric fluid. Results show that tungsten is deposited intensively inside the discharge-induced craters on the RB-SiC surface as amorphous structure forming micro particles, and on flat surface region as a thin interdiffusion layer of poly-crystalline structure. Deposition of carbon element on tool electrode was detected, indicating possible material migration to the tool electrode from workpiece material, carbon nanofibres and dielectric oil. Material deposition rate was found to be strongly affected by workpiece surface roughness, voltage and capacitance of the electrical discharge circuit. Carbon nanofibre addition in the dielectric at a suitable concentration significantly reduced the material deposition rate.

Experimental investigation on material migration phenomena in micro-EDM of reaction-bonded silicon carbide

International Nuclear Information System (INIS)

Liew, Pay Jun; Yan, Jiwang; Kuriyagawa, Tsunemoto

2013-01-01

Material migration between tool electrode and workpiece material in micro electrical discharge machining of reaction-bonded silicon carbide was experimentally investigated. The microstructural changes of workpiece and tungsten tool electrode were examined using scanning electron microscopy, cross sectional transmission electron microscopy and energy dispersive X-ray under various voltage, capacitance and carbon nanofibre concentration in the dielectric fluid. Results show that tungsten is deposited intensively inside the discharge-induced craters on the RB-SiC surface as amorphous structure forming micro particles, and on flat surface region as a thin interdiffusion layer of poly-crystalline structure. Deposition of carbon element on tool electrode was detected, indicating possible material migration to the tool electrode from workpiece material, carbon nanofibres and dielectric oil. Material deposition rate was found to be strongly affected by workpiece surface roughness, voltage and capacitance of the electrical discharge circuit. Carbon nanofibre addition in the dielectric at a suitable concentration significantly reduced the material deposition rate.

Genetic similarity among commercial oil palm materials based on microsatellite markers

Directory of Open Access Journals (Sweden)

Diana Arias

2012-08-01

Full Text Available Microsatellite markers are used to determine genetic similarities among individuals and might be used in various applications in breeding programs. For example, knowing the genetic similarity relationships of commercial planting materials helps to better understand their responses to environmental, agronomic and plant health factors. This study assessed 17 microsatellite markers in 9 crosses (D x P of Elaeis guineensis Jacq. from various commercial companies in Malaysia, France, Costa Rica and Colombia, in order to find possible genetic differences and/or similarities. Seventy-seven alleles were obtained, with an average of 4.5 alleles per primer and a range of 2-8 amplified alleles. The results show a significant reduction of alleles, compared to the number of alleles reported for wild oil palm populations. The obtained dendrogram shows the formation of two groups based on their genetic similarity. Group A, with ~76% similarity, contains the commercial material of 3 codes of Deli x La Mé crosses produced in France and Colombia, and group B, with ~66% genetic similarity, includes all the materials produced by commercial companies in Malaysia, France, Costa Rica and Colombia

Mechanisms of material removal and mass transport in focused ion beam nanopore formation

Energy Technology Data Exchange (ETDEWEB)

Das, Kallol, E-mail: das7@illinois.edu; Johnson, Harley T., E-mail: htj@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, MC-244, Urbana, Illinois 61801 (United States); Freund, Jonathan B., E-mail: jbfreund@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, MC-244, Urbana, Illinois 61801 (United States); Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, 306 Talbot Laboratory, MC-236, 104 South Wright Street Urbana, Illinois 61801 (United States)

2015-02-28

Despite the widespread use of focused ion beam (FIB) processing as a material removal method for applications ranging from electron microscope sample preparation to nanopore processing for DNA sequencing, the basic material removal mechanisms of FIB processing are not well understood. We present the first complete atomistic simulation of high-flux FIB using large-scale parallel molecular dynamics (MD) simulations of nanopore fabrication in freestanding thin films. We focus on the root mechanisms of material removal and rearrangement and describe the role of explosive boiling in forming nanopores. FIB nanopore fabrication is typically understood to occur via sputter erosion. This can be shown to be the case in low flux systems, where individual ion impacts are sufficiently separated in time that they may be considered as independent events. But our detailed MD simulations show that in high flux FIB processing, above a threshold level at which thermal effects become significant, the primary mechanism of material removal changes to a significantly accelerated, thermally dominated process. Under these conditions, the target is heated by the ion beam faster than heat is conducted away by the material, leading quickly to melting, and then continued heating to nearly the material critical temperature. This leads to explosive boiling of the target material with spontaneous bubble formation and coalescence. Mass is rapidly rearranged at the atomistic scale, and material removal occurs orders of magnitude faster than would occur by simple sputtering. While the phenomenology is demonstrated computationally in silicon, it can be expected to occur at lower beam fluxes in other cases where thermal conduction is suppressed due to material properties, geometry, or ambient thermal conditions.

Assessment of significance of features acquired from thyroid ultrasonograms in Hashimoto's disease

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Koprowski Robert

2012-08-01

Full Text Available Abstract Introduction This paper concerns the analysis of the features obtained from thyroid ultrasound images in left and right transverse and longitudinal sections. In the image analysis, the thyroid lobe is treated as a texture for healthy subjects and patients with Hashimoto’s disease. The applied methods of analysis and image processing were profiled to obtain 10 features of the image. Then, their significance in the classification was shown. Material In this study, the examined group consisted of 29 healthy subjects aged 18 to 60 and 65 patients with Hashimoto's disease. For each subject, four ultrasound images were taken. They were all in transverse and longitudinal sections of the right and left lobe of the thyroid, which gave 376 images in total. Method 10 different features obtained from each ultrasound image were suggested. The analyzed thyroid lobe was marked automatically or manually with a rectangular element. Results The analysis of 10 features and the creation for each one of them their own decision tree configuration resulted in distinguishing 3 most significant features. The results of the quality of classification show accuracy above 94% for a non-trimmed decision tree.

A Market Model for Evaluating Technologies That Impact Critical-Material Intensity

Science.gov (United States)

Iyer, Ananth V.; Vedantam, Aditya

2016-07-01

A recent Critical Materials Strategy report highlighted the supply chain risk associated with neodymium and dysprosium, which are used in the manufacturing of neodymium-iron-boron permanent magnets (PM). In response, the Critical Materials Institute is developing innovative strategies to increase and diversify primary production, develop substitutes, reduce material intensity and recycle critical materials. Our goal in this paper is to propose an economic model to quantify the impact of one of these strategies, material intensity reduction. Technologies that reduce material intensity impact the economics of magnet manufacturing in multiple ways because of: (1) the lower quantity of critical material required per unit PM, (2) more efficient use of limited supply, and (3) the potential impact on manufacturing cost. However, the net benefit of these technologies to a magnet manufacturer is an outcome of an internal production decision subject to market demand characteristics, availability and resource constraints. Our contribution in this paper shows how a manufacturer's production economics moves from a region of being supply-constrained, to a region enabling the market optimal production quantity, to a region being constrained by resources other than critical materials, as the critical material intensity changes. Key insights for engineers and material scientists are: (1) material intensity reduction can have a significant market impact, (2) benefits to manufacturers are non-linear in the material intensity reduction, (3) there exists a threshold value for material intensity reduction that can be calculated for any target PM application, and (4) there is value for new intellectual property (IP) when existing manufacturing technology is IP-protected.

The influence of mechanical properties of workpiece material on the main cutting force in face milling

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M. Sekulić

2010-10-01

Full Text Available The paper presents the research into cutting forces in face milling of three different materials: steel Č 4732 (EN42CrMo4, nodular cast iron NL500 (EN-GJS-500-7 and silumine AlSi10Mg (EN AC-AlSi10Mg. Obtained results show that hardness and tensile strength values of workpiece material have a significant influence on the main cutting force, and thereby on the cutting energy in machining.

Composite Materials for Low-Temperature Applications

Science.gov (United States)

2008-01-01

Composite materials with improved thermal conductivity and good mechanical strength properties should allow for the design and construction of more thermally efficient components (such as pipes and valves) for use in fluid-processing systems. These materials should have wide application in any number of systems, including ground support equipment (GSE), lunar systems, and flight hardware that need reduced heat transfer. Researchers from the Polymer Science and Technology Laboratory and the Cryogenics Laboratory at Kennedy Space Center were able to develop a new series of composite materials that can meet NASA's needs for lightweight materials/composites for use in fluid systems and also expand the plastic-additive markets. With respect to thermal conductivity and physical properties, these materials are excellent alternatives to prior composite materials and can be used in the aerospace, automotive, military, electronics, food-packaging, and textile markets. One specific application of the polymeric composition is for use in tanks, pipes, valves, structural supports, and components for hot or cold fluid-processing systems where heat flow through materials is a problem to be avoided. These materials can also substitute for metals in cryogenic and other low-temperature applications. These organic/inorganic polymeric composite materials were invented with significant reduction in heat transfer properties. Decreases of 20 to 50 percent in thermal conductivity versus that of the unmodified polymer matrix were measured. These novel composite materials also maintain mechanical properties of the unmodified polymer matrix. These composite materials consist of an inorganic additive combined with a thermoplastic polymer material. The intrinsic, low thermal conductivity of the additive is imparted into the thermoplastic, resulting in a significant reduction in heat transfer over that of the base polymer itself, yet maintaining most of the polymer's original properties. Normal

Materials processing using supercritical fluids

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Orlović Aleksandar M.

2005-01-01

Full Text Available One of the most interesting areas of supercritical fluids applications is the processing of novel materials. These new materials are designed to meet specific requirements and to make possible new applications in Pharmaceuticals design, heterogeneous catalysis, micro- and nano-particles with unique structures, special insulating materials, super capacitors and other special technical materials. Two distinct possibilities to apply supercritical fluids in processing of materials: synthesis of materials in supercritical fluid environment and/or further processing of already obtained materials with the help of supercritical fluids. By adjusting synthesis parameters the properties of supercritical fluids can be significantly altered which further results in the materials with different structures. Unique materials can be also obtained by conducting synthesis in quite specific environments like reversed micelles. This paper is mainly devoted to processing of previously synthesized materials which are further processed using supercritical fluids. Several new methods have been developed to produce micro- and nano-particles with the use of supercritical fluids. The following methods: rapid expansion of supercritical solutions (RESS supercritical anti-solvent (SAS, materials synthesis under supercritical conditions and encapsulation and coating using supercritical fluids were recently developed.