A demonstration of NIOSH push-pull ventilation criteria.

PubMed

Klein, M K

1987-03-01

This paper summarizes the results of a study performed on an actual chrome plating tank in order to validate criteria for push-pull ventilation systems developed by Huebener and Hughes at NIOSH. Validation of the criteria was made by taking area industrial hygiene samples for hexavalent and total chrome at ten locations around the plating tank. The sampling was performed during actual production runs or while the tank was operating with a dummy load. The sampling data are summarized. The data show that the push-pull system, operating at Huebener's criteria, could control emissions to below the current standards and guidelines. Conclusions and recommendations are included.

Thermal degradation of a black chrome solar selective absorber coating: short term

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lampert, C.M.

1979-05-01

Both the energy absorption properties and chemical microstructure of CHROM-ONYX were investigated using electron microscopy and X-ray diffraction techniques. Different temperatures for short annealing times were used to evaluate this coating's temperature resistance limitations along with possible degradation mechanisms for various stagnation situations. Samples were tested in both air and vacuum. As a result, each sample regardless of atmosphere was characteristically similar, with air acting to mildly accelerate optical degradation at higher temperatures. Below 300 to 400/sup 0/C black chrome exhibited a structural transformation precipitating Cr/sub 2/O/sub 3/. Above 500/sup 0/C this phase grew considerably, while chromium was depleted. Atmore » 600/sup 0/C and above, a new dominant phase developed corresponding to NiCr/sub 2/O/sub 4/, a cubic spinel. However, for all practical purposes black chrome optically degraded between 500 to 600/sup 0/C during short exposure times.« less

Industrial Processes to Reduce Generation of Hazardous Waste at DoD Facilities. Phase III Report. Appendix B. Workshop Manual Innovative Hard Chrome Plating, Pensacola Naval Air Rework Facility, Pensacola, Florida.

DTIC Science & Technology

1985-12-01

The first cases of occupational health effects from hexa- 1. Chromium metals and alloys valent chromium were reported in 1827(2) by Cumin , who .. This...however, has reported an increase in lung Costa et ap4) in 1916 described chrome ulcers in tanners and other cancers in chrome platers in England. and... cancer risk. With the data 2.8 mg/m 3 (as Cr6). Levels of Cr6 in the form of chromi- available, however, this TLV provides an ade- urn trioxide, were

Chemometrics models for assessment of oxidative stress risk in chrome-electroplating workers.

PubMed

Zendehdel, Rezvan; Shetab-Boushehri, Seyed Vahid; Azari, Mansoor R; Hosseini, Vajihe; Mohammadi, Hamidreza

2015-04-01

Oxidative stress is the main cause of hexavalant chromium-induced damage in chrome electroplating workers. The main goal of this study is toxicity analysis and the possibility of toxicity risk categorizing in the chrome electroplating workers based on oxidative stress parameters as prognostic variables. We assessed blood chromium levels and biomarkers of oxidative stress such as lipid peroxidation, thiol (SH) groups and antioxidant capacity of plasma. Data were subjected to principle component analysis (PCA) and artificial neuronal network (ANN) to obtain oxidative stress pattern for chrome electroplating workers. Blood chromium levels increased from 4.42 ppb to 10.6 ppb. Induction of oxidative stress was observed by increased in lipid peroxidation (22.38 ± 10.47 μM versus 14.74 ± 4.82 μM, p < 0.0008), decreased plasma antioxidant capacity (3.17 ± 1.35 μM versus 7.74 ± 4.45 μM, p < 0.0001) and plasma total thiol (SH groups) (0.21 ± 0.07 μM versus 0.45 ± 0.41 μM, p < 0.0042) in comparison to controls. Based on the oxidative parameters, two groups were identified by PCA methods. One category is workers with the risk of oxidative stress and second group is subjects with probable risk of oxidative stress induction. ANN methods can predict oxidative-risk category for assessment of toxicity induction in chrome electroplaters. The result showed multivariate modeling can be interpreted as the induced biochemical toxicity in the workers exposed to hexavalent chromium. Different occupation groups were assessed on the basis of risk level of oxidative stress which could further justify proceeding engineering control measures.

Occupational exposure to Cr(VI): comparison between chromium levels in lymphocytes, erythrocytes, and urine.

PubMed

Lukanova, A; Toniolo, P; Zhitkovich, A; Nikolova, V; Panev, T; Popov, T; Taioli, E; Costa, M

1996-01-01

The relationships between chromium (Cr) levels in lymphocytes, erythrocytes, urine, and ambient air were compared among 14 chrome-platers from a metallurgic plant in Bulgaria and two groups of local controls, one from the same heavily polluted industrial town as the chrome-platers (n = 11) and one from a seaside resort town 100 km away (n = 6). Among the chrome-platers, the Cr concentration in peripheral lymphocytes was positively correlated with total Cr and Cr(VI) levels in ambient air and with Cr excretion in urine. As compared to the controls, the chrome-platers had mean Cr levels in lymphocytes twice as high, in erythrocytes ninefold higher, and in urine fourfold to eightfold higher. Although Cr levels in urine and lymphocytes were similar between the two control groups, levels in erythrocytes were 3 times higher among subjects from the industrial area than among those from the seaside town. The study suggests that lymphocyte Cr could be a good indicator of the Cr body burden caused by high exposures to Cr(VI), such as in electroplating operations. In these conditions, erythrocyte Cr may be less useful, possibly owing to increased toxicity due to the high affinity of erythrocytes for Cr. However, when exposure is lower, such as in most environmental situations, erythrocyte Cr should provide a better and more sensitive index than lymphocyte Cr. By contrast, urinary Cr, which provides information on total Cr exposure, including Cr(III) from dietary and environmental sources, does not seem to be of value for studying occupational exposure to Cr(VI).

Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, J.P.; Kwong, K.-S.; Powell, C.P.

2007-01-01

Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575º C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed ratemore » and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE’s Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace.« less

Electrospark Deposition for the Repair of Army Main Battle Tank Components

DTIC Science & Technology

2006-07-01

Inconel 718, and Inconel 625 were deposited onto low-alloy carbon steel and Inconel 718 substrates. 6.2 ESD Procedure Development (M1A1... Inconel 625 Inconel 718 Inconel 718 Inconel 718 Electrode diameter (in) 0.125 0.125 0.125 .125 0.125 0.125 Pulse rate (Hz) 400 400 400 400 400 400...coating Chrome plating Chrome plating Chrome plating Chrome plating Chrome plating Chrome plating Electrode alloy Inconel 718 Inconel

Mineralogy and geochemistry of two metamorphosed sedimentary manganese deposits, Sierra Nevada, California, USA

USGS Publications Warehouse

Flohr, M.J.K.; Huebner, J.S.

1992-01-01

Laminated to massive rhodochrosite, hausmannite, and Mn-silicates from the Smith prospect and Manga-Chrome mine, Sierra Nevada, California were deposited as ocean floor sediments associated with chert and shale. The principal lithologies at Smith are chert, argillite, rhodochrosite-, hausmannite- and chlorite-rich layers, and relatively uncommon layers of jacobsite. The Manga-Chrome mine also contains layers rich in manganoan calcite and caryopilite. Tephroite, rhodonite, spessartine, and accessory alleghanyite and sonolite formed during metamorphism. Volcaniclastic components are present at Manga-Chrome as metavolcanic clasts and as Mn-poor, red, garnet- and hematite-rich layers. There is no evidence, such as relict lithologies, that Mn was introduced into Mn-poor lithologies such as chert, limestone or mudstone. Replacement of Mn-poor phases by Mn-rich phases is observed only in the groundmass of volcanic clasts that appear to have fallen into soft Mn-rich mud. Manganiferous samples from the Smith prospect and Manga-Chrome mine have high Mn Fe and low concentrations of Ni, Cu, Zn, Co, U, Th and the rare-earth elements that are similar to concentrations reported from other ancient Mn deposits found in chert-greenstone complexes and from manganiferous sediments and crusts that are forming near modern sea floor vents. The Sierra Nevada deposits formed as precipitates of Mn-rich sediments on the sea floor, probably from mixtures of circulating hydrothermal fluids and seawater. The composition of a metabasalt from the Smith prospect is consistent with those of island-arc tholeiites. Metavolcanic clasts from the Manga-Chrome mine are compositionally distinct from the Smith metabasalt and have alkaline to calc-alkaline affinities. A back-arc basin is considered to be the most likely paleoenvironment for the formation of the Mn-rich lenses at the Manga-Chrome mine and, by association, the Smith prospect. Layers of rhodochrosite, hausmannite and chert preserve the composition and some textures of the sedimentary protoliths at both Sierra Nevada deposits. Jacobsite-rich layers probably represent a Fe-rich protolith. Caryopilite and manganoan calcite represent additional protoliths at the Manga-Chrome mine. The metamorphic assemblage prehnite-chlorite-epidote-calcite in a metabasalt from the Smith prospect constrains regional metamorphic conditions to a maximum temperature of 325??C and a pressure of 2 kbar. Slightly higher temperatures are indicated by the presence of actinolite in another metabasalt. Compositions of Mn-rich minerals in Smith samples are consistent with these metamorphic conditions. ?? 1992.

Lung cancer mortality in nickel/chromium platers, 1946-95.

PubMed

Sorahan, T; Burges, D C; Hamilton, L; Harrington, J M

1998-04-01

To investigate mortality from lung cancer in nickel/chromium platers. The mortality experience of a cohort of 1762 chrome workers (812 men, 950 women) from a large electroplating and light engineering plant in the Midlands, United Kingdom, was investigated for the period 1946-95. All subjects were first employed in chrome work at the plant during the period 1946-75, and had at least six months employment in jobs associated with exposure to chromic acid mist (hexavalent chromium). Detailed job histories were abstracted from original company personnel records and individual cumulative durations of employment in three types of chrome work were derived as time dependent variables (chrome bath work, other chrome work, any chrome work). Two analytical approaches were used--indirect standardisation and Poisson regression. Based on mortalities for the general population of England and Wales, male workers with some period of chrome bath work had higher lung cancer mortalities (observed deaths 40, expected deaths 25.41, standardised mortality ratio (SMR) 157, 95% confidence interval (95% CI) 113 to 214, p < 0.01) than did other male chrome workers (observed 9, expected 13.70, SMR 66, 95% CI 30 to 125). Similar findings were shown for female workers (chrome bath workers: observed 15, expected 8.57, SMR 175, 95% CI 98 to 289, p = 0.06; other chrome workers: observed 1, expected 4.37, SMR 23, 95% CI 1 to 127). Poisson regression was used to investigate risks of lung cancer relative to four categories of cumulative duration of chrome bath work and four categories of cumulative duration of other chrome work (none, < 1 y, 1-4 y, > or = 5 y). After adjusting for sex, age, calendar period, year of starting chrome work, period from first chrome work, and employment status (still employed v left employment), there was a significant positive trend (p < 0.05) between duration of chrome bath work and risks of mortality for lung cancer. Relative to a risk of unity for those chrome workers without any period of chrome bath work, risks were 2.83 (95% CI 1.47 to 5.45), 1.61 (95% CI 0.75 to 3.44), and 4.25 (95% CI 1.83 to 9.87) for the second, third, and fourth exposure categories, respectively. Duration of other chrome work was not a useful predictor of risks of lung cancer. Similar findings for both variables were obtained when adjustment was made for sex and age only. Similar findings for both variables were obtained relative to risk of chrome nasal ulceration. The findings are consistent with the hypothesis that soluble hexavalent chromium compounds are potent human lung carcinogens.

ALTERNATIVE TO CHROME ETCHING PROCESSES FOR METALS

EPA Science Inventory

Several industries, including the National Center for Manufacturing Science have initiated programs for chrome abatement. The programs, however, generally focus on chrome reduction by use of existing technologies and do not address the elimination of chrome in pretreatment proces...

Black chrome on commercially electroplated tin as a solar selecting coating

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1977-01-01

The reflectance properties of black chrome electroplated on commercially electroplated tin were measured for various black chrome plating times for both the solar and infrared spectrum. The values of absorptance and emittance were calculated from the measured reflectance values. The results indicate that the optimum combination of the highest absorptance in the solar region and the lowest emittance in the infrared of the black chrome plated on commercially electroplated tin is obtained for a black chrome plating time of between one and two minutes.

The Record of Meteorite Infall During the Jurassic as Derived from Chrome-Spinel Grains

NASA Astrophysics Data System (ADS)

Caplan, C.; Huss, G. R.; Schmitz, B.; Nagashima, K.

2017-12-01

We study sediment-dispersed chrome-spinels in the stratigraphic record to determine how the types and amounts of meteorites falling to Earth have changed over time. The parent meteorite type of chrome-spinel grains can be determined using characteristic elemental and O-isotope compositions. In this study, we present data on grains from the Jurassic period ( 160 Ma). The Jurassic was chosen because of the possibility of discovering remnants from the breakup of the Baptistina asteroid family estimated to have occurred 160 Ma (+30, -20 Myr) (Bottke et al., 2007). Chrome-spinel grains derived from 400 kg of condensed limestone near Carcabuey, Spain were measured for their chemical compositions by electron microprobe, and their O-isotope compositions were measured by ion microprobe at the University of Hawai'i. Initial results show that 43% of the grains come from ordinary chondrites (OCs) and 18% from known types of achondrites. The remaining grains are extraterrestrial, as shown by their O-isotopes, but have not yet been classified. Some may represent material that is not currently falling on Earth. Meteorites falling on Earth today are 90.6% OCs and 7.1% achondrites. The Jurassic samples show a lower percentage of chrome-spinels from OCs (even though OCs are chrome-spinel rich). Other time periods also show meteorite abundances that are different than today. About 466 Ma there was an overwhelming influx of L-chondritic material (>99% of infalling material), due to the breakup of the L-chondrite parent body (Schmitz et al., 2001). One million years prior to the breakup, 56% of the infalling meteorites were OCs and 44% were achondrites (Heck et al., 2017). A new study suggests that 80% of the material falling in the Early Cretaceous (145-133 Ma) were from OCs and 10% were from achondrites (Schmitz et al., 2017). With just a few windows into Earth's past, we are already seeing significant changes in the mixture of materials that have fallen to Earth throughout time.

Lung cancer in Yorkshire chrome platers, 1972-97.

PubMed

Sorahan, T; Harrington, J M

2000-06-01

To investigate mortality from lung cancer in chrome platers, a group exposed to chromic acid. The mortality of a cohort of 1087 chrome platers (920 men, 167 women) from 54 plants situated in the West Riding of Yorkshire, United Kingdom, was investigated for the period 1972-97. All subjects were employed as chrome platers for >/=3 months and all were alive on 31 May 1972. Mortality data were also available for a cohort of 1163 comparison workers with no known occupational exposure to chrome compounds (989 men, 174 women). Information on duration of chrome work and smoking habits collected for a cross sectional survey carried out in 1969-72 were available for 916 (84.3%) of the chrome platers; smoking habits were available for 1004 (86.3%) comparison workers. Two analytical approaches were used, indirect standardisation and Poisson regression. Based on serial mortality rates for the general population of England and Wales, significantly increased mortality from lung cancer was observed (obs) in male chrome platers (obs 60, expected (exp) 32.5, standardised mortality ratio (SMR) 185, p<0. 001) but not in male comparison workers (obs 47, exp 36.9, SMR 127). Positive trends were not shown for duration of employment exposed to chrome, although data on working after 1972 were not available. Confident interpretation is not possible but occupational exposures to hexavalent chromium may well have been involved in the increased mortality from lung cancer found in this cohort of chrome platers.

Microbial Influenced Corrosion (MIC) Study

DTIC Science & Technology

2012-05-23

DAY 28 Chrome  Conversion Coating  Coupon Type: A    Alodine 1200 (Henkel)  Non‐ Chrome  Treatment  Coupon Type: E    Prekote® (Pantheon Chemical... Chrome  Conversion Coating +  Chrome  Primer  Coupon Type: B    Alodine 1200 (Henkel)  MIL PRF 23377H TY 1 CL 2 (Deft‐ ‐ ,    ,       ‐   02Y040A)  Non... Chrome  Treatment + Non‐ Chrome  Primer  Coupon Type: F BUSINESS SENSITIVE 23         Prekote® (Pantheon Chemical)  MIL‐PRF‐23377H, TY 1, CL N (Deft

Design Architecture of field-effect transistor with back gate electrode for biosensor application

NASA Astrophysics Data System (ADS)

Fathil, M. F. M.; Arshad, M. K. Md.; Hashim, U.; Ruslinda, A. R.; Gopinath, Subash C. B.; M. Nuzaihan M., N.; Ayub, R. M.; Adzhri, R.; Zaki, M.; Azman, A. H.

2016-07-01

This paper presents the preparation method of photolithography chrome mask design used in fabrication process of field-effect transistor with back gate biasing based biosensor. Initially, the chrome masks are designed by studying the process flow of the biosensor fabrication, followed by drawing of the actual chrome mask using the AutoCAD software. The overall width and length of the device is optimized at 16 mm and 16 mm, respectively. Fabrication processes of the biosensor required five chrome masks, which included source and drain formation mask, the back gate area formation mask, electrode formation mask, front gate area formation mask, and passivation area formation mask. The complete chrome masks design will be sent for chrome mask fabrication and for future use in biosensor fabrication.

Electrodeposition of Nanocrystalline Cobalt Phosphorous Coatings as a Hard Chrome Alternative

DTIC Science & Technology

2014-11-01

1 ASETSDefense 2014 Electrodeposition of Nanocrystalline Cobalt Phosphorous Coatings as a Hard Chrome Alternative Ruben A. Prado, CEF...COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Electrodeposition of Nanocrystalline Cobalt Phosphorous Coatings as a Hard Chrome Alternative...coatings as a Hard Chrome (EHC) electroplating alternative for DoD manufacturing and repair. – Fully define deposition parameters and properties

Lung cancer in Yorkshire chrome platers, 1972-97

PubMed Central

Sorahan, T.; Harrington, J

2000-01-01

OBJECTIVES—To investigate mortality from lung cancer in chrome platers, a group exposed to chromic acid.
METHODS—The mortality of a cohort of 1087 chrome platers (920 men, 167 women) from 54 plants situated in the West Riding of Yorkshire, United Kingdom, was investigated for the period 1972-97. All subjects were employed as chrome platers for ⩾3 months and all were alive on 31 May 1972. Mortality data were also available for a cohort of 1163 comparison workers with no known occupational exposure to chrome compounds (989 men, 174 women). Information on duration of chrome work and smoking habits collected for a cross sectional survey carried out in 1969-72 were available for 916 (84.3%) of the chrome platers; smoking habits were available for 1004 (86.3%) comparison workers. Two analytical approaches were used, indirect standardisation and Poisson regression.
RESULTS—Based on serial mortality rates for the general population of England and Wales, significantly increased mortality from lung cancer was observed (obs) in male chrome platers (obs 60, expected (exp) 32.5, standardised mortality ratio (SMR) 185, p<0.001) but not in male comparison workers (obs 47, exp 36.9, SMR 127). Positive trends were not shown for duration of employment exposed to chrome, although data on working after 1972 were not available.
CONCLUSIONS—Confident interpretation is not possible but occupational exposures to hexavalent chromium may well have been involved in the increased mortality from lung cancer found in this cohort of chrome platers.


Keywords: chromium plating; lung cancer PMID:10810127

Ultrasound assisted chrome tanning: Towards a clean leather production technology.

PubMed

Mengistie, Embialle; Smets, Ilse; Van Gerven, Tom

2016-09-01

Nowadays, there is a growing demand for a cleaner, but still effective alternative for production processes like in the leather industry. Ultrasound (US) assisted processing of leather might be promising in this sense. In the present paper, the use of US in the conventional chrome tanning process has been studied at different pH, temperature, tanning time, chrome dose and US exposure time by exposing the skin before tanning and during tanning operation. Both prior exposure of the skin to US and US during tanning improves the chrome uptake and reduces the shrinkage significantly. Prior exposure of the skin to US increase the chrome uptake by 13.8% or reduces the chrome dose from 8% to 5% (% based on skin weight) and shorten the process time by half while US during tanning increases the chrome uptake by 28.5% or reduces the chrome dose from 8% to 4% (half) and the tanning time to one third compared to the control without US. Concomitantly, the resulting leather quality (measured as skin shrinkage) improved from 5.2% to 3.2% shrinkage in the skin exposed to US prior tanning and to 1.3% in the skin exposed to US during the tanning experiment. This study confirms that US chrome tanning is an effective and eco-friendly tanning process which can produce a better quality leather product in a shorter process time with a lower chromium dose. Copyright © 2016 Elsevier B.V. All rights reserved.

AMCOM Hexavalent Chrome Free Initiatives

DTIC Science & Technology

2010-12-01

AMCOM Hexavalent Chrome Free Initiatives 1 December 2010 SERDP-ESTCP Symposium Washington DC Mark Feathers AMCOM G-4 Environmental Division... Hexavalent Chrome Free Initiatives 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...system environmental life cycle sustainability. G-4 is actively engaged in initiatives to reduce the use of hexavalent chrome used in materials and

Study of skin and mucous membrane disorders among workers engaged in the sodium dichromate manufacturing industry and chrome plating industry.

PubMed

Singhal, Vijay Kumar; Deswal, Balbir Singh; Singh, Bachu Narayan

2015-01-01

Inhalation of dusts and fumes arising during the manufacture of sodium dichromate from chrome ore, chromic acid mist emitted during electroplating, and skin contact with chromate produce hazards to workers. (1) To elucidate the prevalence of skin and mucous membrane disorders among the workers engaged in the sodium dichromate manufacturing industry and chrome plating industry. (2) To know the relationship of prevalence with the duration of exposure to chrome mist, dust, and fumes. A cross-sectional study was conducted among all the workers engaged in sodium dichromate manufacturing and chrome plating from several industries situated near the Delhi-Haryana border in the districts of Faridabad and Sonepat of Haryana, India from January 01, 2014 to December 31, 2014. All the workers available from the concerned industries for the study were interviewed and medically examined after obtaining their informed consent. A total of 130 workers comprising 66 workers from the sodium dichromate manufacturing industry and 64 workers from the chrome plating industry were examined on a pretested schedule. Descriptive statistical methods (proportions, relative risk, and Chi-square test of significance with P value analyzed using Epi Info version 7). All the workers were found to be males and of the adult age group. Out of the total examined, 69.69% and 56.22% of the workers had disorders of the nasal mucous membrane in the sodium dichromate manufacturing industry and the chrome plating industry, respectively. 42.42% and 28.22% of the workers had perforation of the nasal septum in the sodium dichromate manufacturing industry and chrome plating industry, respectively. 6.06% and 3.12% workers had skin ulcers in the sodium dichromate manufacturing industry and chrome plating industry, respectively. Nasal irritation and rhinorrhea were the most commonly found symptoms in both the processes. 48.48% and 90.52% of the workers were using hand gloves in the sodium dichromate manufacturing and chrome plating industry, respectively. Only 27.27% and 37.50% of the workers were using masks in the sodium dichromate manufacturing industry and chrome plating industry, respectively. No worker was using protective clothing or barrier cream in the sodium dichromate manufacturing industry. 40.65% and 12.50% workers were using protective clothing and barrier cream in the chrome plating industry. Workers engaged in sodium dichromate manufacturing and chrome plating are at a great risk of skin and mucous membrane disorders including chrome holes and nasal septum perforation. Protective measures and awareness of the management and workers about the exposure hazards and safeguarding against them will be useful public measures to prevent these occupational hazards among workers engaged in these processes.

Study of skin and mucous membrane disorders among workers engaged in the sodium dichromate manufacturing industry and chrome plating industry

PubMed Central

Singhal, Vijay Kumar; Deswal, Balbir Singh; Singh, Bachu Narayan

2015-01-01

Background: Inhalation of dusts and fumes arising during the manufacture of sodium dichromate from chrome ore, chromic acid mist emitted during electroplating, and skin contact with chromate produce hazards to workers. Objectives: (1) To elucidate the prevalence of skin and mucous membrane disorders among the workers engaged in the sodium dichromate manufacturing industry and chrome plating industry. (2) To know the relationship of prevalence with the duration of exposure to chrome mist, dust, and fumes. Settings and Design: A cross-sectional study was conducted among all the workers engaged in sodium dichromate manufacturing and chrome plating from several industries situated near the Delhi-Haryana border in the districts of Faridabad and Sonepat of Haryana, India from January 01, 2014 to December 31, 2014. Materials and Methods: All the workers available from the concerned industries for the study were interviewed and medically examined after obtaining their informed consent. A total of 130 workers comprising 66 workers from the sodium dichromate manufacturing industry and 64 workers from the chrome plating industry were examined on a pretested schedule. Statistical Analysis: Descriptive statistical methods (proportions, relative risk, and Chi-square test of significance with P value analyzed using Epi Info version 7). Results: All the workers were found to be males and of the adult age group. Out of the total examined, 69.69% and 56.22% of the workers had disorders of the nasal mucous membrane in the sodium dichromate manufacturing industry and the chrome plating industry, respectively. 42.42% and 28.22% of the workers had perforation of the nasal septum in the sodium dichromate manufacturing industry and chrome plating industry, respectively. 6.06% and 3.12% workers had skin ulcers in the sodium dichromate manufacturing industry and chrome plating industry, respectively. Nasal irritation and rhinorrhea were the most commonly found symptoms in both the processes. 48.48% and 90.52% of the workers were using hand gloves in the sodium dichromate manufacturing and chrome plating industry, respectively. Only 27.27% and 37.50% of the workers were using masks in the sodium dichromate manufacturing industry and chrome plating industry, respectively. No worker was using protective clothing or barrier cream in the sodium dichromate manufacturing industry. 40.65% and 12.50% workers were using protective clothing and barrier cream in the chrome plating industry. Conclusion: Workers engaged in sodium dichromate manufacturing and chrome plating are at a great risk of skin and mucous membrane disorders including chrome holes and nasal septum perforation. Protective measures and awareness of the management and workers about the exposure hazards and safeguarding against them will be useful public measures to prevent these occupational hazards among workers engaged in these processes. PMID:26957809

Design architecture of double spiral interdigitated electrode with back gate electrode for biosensor application

NASA Astrophysics Data System (ADS)

Fathil, M. F. M.; Arshad, M. K. Md.; Hashim, U.; Ruslinda, A. R.; Gopinath, Subash C. B.; M. Nuzaihan M., N.; Ayub, R. M.; Adzhri, R.; Zaki, M.; Azman, A. H.

2016-07-01

This paper presents the preparation method of photolithography chrome mask design used in fabrication process of double spiral interdigitated electrode with back gate biasing based biosensor. By learning the fabrication process flow of the biosensor, the chrome masks are designed through drawing using the AutoCAD software. The overall width and length of the device is optimized at 7.0 mm and 10.0 mm, respectively. Fabrication processes of the biosensor required three chrome masks, which included back gate opening, spiral IDE formation, and passivation area formation. The complete chrome masks design will be sent for chrome mask fabrication and for future use in biosensor fabrication.

[A case of chrome asthma induced by exposure to the stone cutter dust].

PubMed

Onizuka, Reiko; Tanabe, Kimiko; Nakayama, Yoshihisa; Fukuchi, Tetsuroh; Nakata, Kazunori; Hiki, Toshinobu

2006-12-01

The case of a forty-six year old, male patient with asthma caused by exposure to dust containing chrome is presented. When the patient was nineteen years old, he started working as a stonemason in a factory. He cut and ground stone with a stone-cutter to make statues and tombstones. Three years after staring to work, contact dermatitis was observed on his arms and hands. Within six years of work, he suffered from chronic coughing. After eight years, he experienced bronchial asthma attacks with wheezing and dyspnea. He had been exposed to dust for eight years before developing asthma. The symptoms increased gradually. He fell into severe asthma attacks causing unconsciousness and dyspnea. Several common therapies were not effective. The characteristics of his clinical course and occupational history suggested that the asthma must be caused by exposure to dust containing metal generated in the factory. Skin Patch Tests (SPT) were performed for cobalt, copper, iron, chrome, tin, and manganese salt. The result of the SPT indicated a strong positive result for potassium dichromate and positive for chromium sulfate, but did not show any indications in the control or for other metallic salt. Fluorescent X-ray analysis detected that chrome was present in the powder dust under the stone-cutter machine. However, the fluorescent X-ray analysis did not detect chrome in the stone materials. It was suggested that chrome must be contained in the metal dust generated from the steel cutter used to cut off and grind the stone. The metal component in the used cutter edge and the unused cutter edge were analyzed with electro-probe microanalyzer (EPMA). The result revealed that chrome was contained in the used, dull cutter edge and not in the new sharp cutter edge. Thus, the patient had been exposed to the dust containing chrome generated from part of the stainless steel of cutter. He had sensitized to chrome and this had caused the occupational chrome-asthma.

High Temperature Brush Seal Tuft Testing of Selected Nickel-Chrome and Cobalt-Chrome Superalloys

NASA Technical Reports Server (NTRS)

Fellenstein, James A.; DellaCorte, Christopher; Moore, Kenneth D.; Boyes, Esther

1997-01-01

The tribology of brush seals is of considerable interest to turbine engine designers because bristle wear continues to limit long term seal performance and life. To provide better materials characterization and foster the development of improved seals, NASA Lewis has developed a brush seal tuft tester. In this test, a 'paintbrush' sample tuft is loaded under constant contact pressure against the outside diameter of a rotating journal. With this configuration, load and friction are directly measured and accurate wear measurements are possible. Previously reported research using this facility showed excellent data repeatability and wear morphology similar to published seal data and dynamic rig tests. This paper is an update of the ongoing research into the tribology of brush seals. The effects of wire materials processing on seal wear and the tribological results for three journal coatings are discussed. Included in the materials processing were two nickel-chrome superalloys each processed to two different yield strengths. The results suggest that seal wear is dependent more on material composition than processing conditions.

77 FR 60285 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-03

... the MLG for chicken- wire cracks, corrosion, and chrome plate distress; repetitive magnetic particle... center axles of the MLG for chicken-wire cracks, corrosion, and chrome plate distress; repetitive... the MLG for chicken- wire cracks, corrosion, and chrome plate distress; do a magnetic particle...

Petrology of ultramafic xenoliths from Loihi Seamount, Hawaii

USGS Publications Warehouse

Clague, D.A.

1988-01-01

Ultramafic xenoliths were recovered in four alkalic lava flows from Loihi Seamount at depths between 2200 and 1400 m. No xenolith bearing flows were sampled near the summit despite a concentrated dredge program. The flows, three of alkalic basalt and one of basanite, contain common olivine megacrysts and small xenoliths of dunite, rarer harzburgite, and a single wehrlite. Olivine megacrysts as large as 8 mm are Fo84-88.6 and contain magnesiochromite inclusions with 1.1-3.5 wt.% TiO2. Dunite contains Fo83.5-88.5 olivine, meganesiochromite with 1.5-6.9 wt.% TiO2 (avg. 3.2 wt.), and extremely rare chrome-rich diopside. The wehrlite contains euhedral Fo85.9 olivine and magnesiochromite with 1.9-4.7 wt.% TiO2, poikilitically enclosed in chrome-rich diposide (Wo45.4En48.0s6.6). Most of the olivine megacrysts, dunite, and the wehrlite are cumulates of Loihi alkalic lavas that accumulated in a magma storage zone located at least 16 km below sea level. The rarity of dunite related to tholeiitic magmas supports the interpretation that the alkalic lavas at Loihi generally predate the tholeiitic lavas. -from Author

Minimization of the environmental impact of chrome tanning: a new process with high chrome exhaustion.

PubMed

Morera, Josep M; Bacardit, Anna; Ollé, Lluís; Bartolí, Esther; Borràs, Maria D

2007-11-01

In all tanning technology operations wastes are generated. These reach the environment as residual waters, solid and liquid waste as well as atmospheric emissions and odours. This study tests an alternative method to the traditional tanning method at an industrial level. The new method is based on tanning without float and by significantly increasing the temperature at the end of the tanning process. The properties of the leathers obtained using the two methods have been compared and the results indicate that those leathers have similar physical, chemical, and organoleptic properties. However, the differences existing from the environmental point of view are significant. It is not necessary to use clean water for this tanning. Moreover, there is a 75% reduction of the residual float, a 91% reduction of the chrome discharged, and a 94% reduction of the chlorides discharged. A financial assessment was carried out to demonstrate that the newly proposed system is 32% more economic than the traditional one.

LABORATORY STUDY FOR THE REDUCTION OF CHROME (VI) TO CHROME (III) USING SODIUM METABISULFITE UNDER ACIDIC CONDITIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

DUNCAM JB; GUTHRIE MD; LUECK KJ

2007-07-18

This report describes the results from RPP-PLAN-32738, 'Test Plan for the Effluent Treatment Facility to Reduce Chrome(VI) to Chrome(I1I) in the Secondary Waste Stream', using sodium metabisulfite. Appendix A presents the report as submitted by the Center for Laboratory Sciences (CLS) to CH2M HILL Hanford Group, Inc. The CLS carried out the laboratory effort under Contract Number 21065, release Number 30. This report extracts the more pertinent aspects of the laboratory effort.

FINAL REPORT FOR THE REDUCTION OF CHROME (VI) TO CHROME (III) IN THE SECONDARY WASTE STREAM OF THE EFFLUENT TREATMENT FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

DUNCAN JB; GUTHRIE MD

2008-08-29

This report documents the laboratory results of RPP-PLAN-35958, Test Plan for the Effluent Treatment Facility to Reduce Chrome (VI) to Chrome (III) in the Secondary Waste Stream With the exception of the electrochemical corrosion scans, all work was carried out at the Center for Laboratory Science (CLS) located at the Columbia Basin College. This document summarizes the work carried out at CLS and includes the electrochemical scans and associated corrosion rates for 304 and 316L stainless steel.

Occupational asthma due to chrome and nickel electroplating

PubMed Central

Bright, P.; Burge, P. S.; O'Hickey, S. P.; Gannon, P. F.; Robertson, A. S.; Boran, A.

1997-01-01

BACKGROUND: Exposure to chromium during electroplating is a recognised though poorly characterised cause of occupational asthma. The first series of such patients referred to a specialist occupational lung disease clinic is reported. METHODS: The diagnosis of occupational asthma was made from a history of asthma with rest day improvement and confirmed by specific bronchial provocation testing with potassium dichromate and nickel chloride. RESULTS: Seven workers had been exposed to chrome and nickel fumes from electroplating for eight months to six years before asthma developed. One subject, although exposed for 11 years without symptoms, developed asthma after a single severe exposure during a ventilation failure. This was the only subject who had never smoked. The diagnosis was confirmed by specific bronchial challenges. Two workers had isolated immediate reactions, one a late asthmatic reaction, and four a dual response following exposure to nebulised potassium dichromate at 1-10 mg/ml. Two of the four subjects were also challenged with nebulised nickel chloride at 0.1-10 mg/ml. Two showed isolated late asthmatic reactions, in one at 0.1 mg/ml, where nickel was probably the primary sensitising agent. Four workers carried out two hourly measurements of peak expiratory flow over days at and away from work. All were scored as having occupational asthma using OASYS-2. Breathing zone air monitoring was carried out in 60 workers from four decorative and two hard chrome plating shops from workers with similar jobs to those sensitised. No measurement exceeded the current occupational exposure standard for chromate or nickel, the mean levels of chromate exposure for jobs similar to those of the affected workers were 9-15 micrograms/m3. CONCLUSION: Chrome used in electroplating is a potential cause of occupational asthma. Sensitivity to chrome in electroplaters may occur in situations where exposure levels are likely to be within the current exposure standards. There may be cross reactivity with nickel. Inhalation challenge with nebulised potassium dichromate solution is helpful in making the specific diagnosis where doubt exists. 


 PMID:9039236

Osseointegration and biocompatibility of different metal implants - a comparative experimental investigation in sheep

PubMed Central

2012-01-01

Background In the present study, 4 different metallic implant materials, either partly coated or polished, were tested for their osseointegration and biocompatibility in a pelvic implantation model in sheep. Methods Materials to be evaluated were: Cobalt-Chrome (CC), Cobalt-Chrome/Titanium coating (CCTC), Cobalt-Chrome/Zirconium/Titanium coating (CCZTC), Pure Titanium Standard (PTST), Steel, TAN Standard (TANST) and TAN new finish (TANNEW). Surgery was performed on 7 sheep, with 18 implants per sheep, for a total of 63 implants. After 8 weeks, the specimens were harvested and evaluated macroscopically, radiologically, biomechanically (removal torque), histomorphometrically and histologically. Results Cobalt-Chrome screws showed significantly (p = 0.031) lower removal torque values than pure titanium screws and also a tendency towards lower values compared to the other materials, except for steel. Steel screws showed no significant differences, in comparison to cobalt-chrome and TANST, however also a trend towards lower torque values than the remaining materials. The results of the fluorescence sections agreed with those of the biomechanical test. Histomorphometrically, there were no significant differences of bone area between the groups. The BIC (bone-to-implant-contact), used for the assessment of the osseointegration, was significantly lower for cobalt-chrome, compared to steel (p = 0.001). Steel again showed a lower ratio (p = 0.0001) compared to the other materials. Conclusion This study demonstrated that cobalt-chrome and steel show less osseointegration than the other metals and metal-alloys. However, osseointegration of cobalt-chrome was improved by zirconium and/or titanium based coatings (CCTC, TANST, TAN, TANNEW) being similar as pure titanium in their osseointegrative behavior. PMID:22400715

Performance evaluation of two black nickel and two black chrome solar collectors

NASA Technical Reports Server (NTRS)

Losey, R.

1977-01-01

The test program was based on the evaluation of four unique solar collectors described below: (1) black nickel collector surface with a desiccant drying bed, (2) black nickel collector surface without a desiccant drying bed, (3) black chrome collector surface with a dessicant drying bed, and (4) black chrome collector surface without a desiccant drying bed. The test program included three distinct phases: Initial performance evaluation, natural environmental aging, and post-aging performance evaluation. Results of Phase III testing conclusively indicated a higher normalized efficiency for Black Chrome surfaces when compared to Black Nickel.

No allergic reaction after TKA in a chrome-cobalt-nickel-sensitive patient: case report and review of the literature.

PubMed

Thienpont, Emmanuel; Berger, Yorick

2013-03-01

Hypersensitivity to metallic implants remains relatively unpredictable and poorly understood. Although 20-25 % of total joint arthroplasty patients develop metal sensitivity, only a few highly susceptible persons (<1 %) exhibit symptoms. We present a case report of a fifty-two-year-old woman with a preoperatively documented metal allergy who underwent bilateral total knee arthroplasty using a titanium-niobium-coated implant on one side and a chrome-cobalt implant on the other side because of a logistics problem. At 2-year follow-up, no clinical symptoms of allergy or loosening of the implant were observed. Level of evidence IV.

40 CFR 425.10 - Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. 425.10 Section 425.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome...

40 CFR 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. 425.20 Section 425.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan,...

40 CFR 425.10 - Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory § 425.10 Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. The provisions of this subpart are...

40 CFR 425.10 - Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory § 425.10 Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. The provisions of this subpart are...

40 CFR 425.10 - Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the hair... POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory § 425.10 Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. The provisions of this subpart are...

40 CFR 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet Finish Subcategory § 425.20 Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. The provisions of this subpart are...

40 CFR 425.10 - Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory § 425.10 Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. The provisions of this subpart are...

40 CFR 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the hair... POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet Finish Subcategory § 425.20 Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. The provisions of this subpart are...

40 CFR 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet Finish Subcategory § 425.20 Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. The provisions of this subpart are...

40 CFR 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet Finish Subcategory § 425.20 Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. The provisions of this subpart are...

Hexavalent Chrome Free Coatings for Electronics Applications: Joint Test Report

NASA Technical Reports Server (NTRS)

Rothgeb, Matt; Kessel, Kurt

2013-01-01

The overall objective of the Hexavalent Chrome Free Coatings for Electronics Applications project is to evaluate and test pretreatments not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders.

Hex Chrome Free Coatings for Electronics Overview

NASA Technical Reports Server (NTRS)

Kessel, Kurt

2013-01-01

The overall objective of the Hex Chrome Free Coatings for Electronics project is to evaluate and test pretreatment coating systems not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders.

Molecular spectroscopic study for suggested mechanism of chrome tanned leather

NASA Astrophysics Data System (ADS)

Nashy, Elshahat H. A.; Osman, Osama; Mahmoud, Abdel Aziz; Ibrahim, Medhat

2012-03-01

Collagen represents the structural protein of the extracellular matrix, which gives strength of hides and/or skin under tanning process. Chrome tan is the most important tanning agent all over the world. The methods for production of leather evolved over several centuries as art and engineering with little understanding of the underlying science. The present work is devoted to suggest the most probable mechanistic action of chrome tan on hide proteins. First the affect of Cr upon hide protein is indicated by the studied mechanical properties. Then the spectroscopic characterization of the hide protein as well as chrome tanned leather was carried out with Horizontal Attenuated Total Reflection (HATR) FT-IR. The obtained results indicate how the chromium can attached with the active sites of collagen. Molecular modeling confirms that chromium can react with amino as well as carboxylate groups. Four schemes were obtained to describe the possible interactions of chrome tan with hide proteins.

SUPERFUND TREATABILITY CLEARINGHOUSE: SOIL STABILIZATION PILOT STUDY, UNITED CHROME NPL SITE PILOT STUDY AND HEALTH AND SAFETY PROGRAM, UNITED CHROME NPL SITE PILOT STUDY

EPA Science Inventory

This document is a project plan for a pilot study at the United Chrome NPL site, Corvallis, Oregon and includes the health and safety and quality assurance/quality control plans. The plan reports results of a bench-scale study of the treatment process as iieasured by the ...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory. The...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

Alternatives To Cadmium Plated Military Connectors

DTIC Science & Technology

2011-08-30

from Feb 2011 Asets Defense conference  Amphenol Aerospace Operations report. 9/21/2011 10 Chromate finish  Hexavalent chrome was targeted by DOD...Fluorocarbon Zinc-Nickel Pure Dense Aluminum  Zinc-Nickel and Aluminum currently contain hexavalent chromate. Nickel-Fluorocarbon requires no...to lack of available drop in replacements, but this will change as alternatives become available.  Trivalent chrome and other non- chrome

Novel Chemical Process for Producing Chrome Coated Metal

PubMed Central

Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien

2018-01-01

This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed. PMID:29303977

Novel Chemical Process for Producing Chrome Coated Metal.

PubMed

Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien; Luhrs, Claudia C; Phillips, Jonathan

2018-01-05

This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

CAPSULE REPORT: HARD CHROME FUME ...

EPA Pesticide Factsheets

All existing information which includes the information extrapolated from the Hard Chrome Pollution Prevention Demonstration Project(s) and other sources derived from plating facilities and industry contacts, will be condensed and featured in this document. At least five chromium emission prevention/control devices have been tested covering a wide spectrum of techniques currently in use at small and large-sized chrome metal plating shops. The goal for limiting chromium emissions to levels specified in the MACT Standards are: (1) 0.030 milligrams per dry standard cubic meter of air (mg/dscm) for small facilities with existing tanks, (2) 0.015 mg/dscm for small facilities with new tanks or large facilities with existing or new tanks. It should be emphasized that chemical mist suppressants still have quality issues and work practices that need to be addressed when they are used. Some of the mist suppressants currently in use are: one-, two-, and three-stage mesh pad mist eliminators; composite mesh pad mist eliminators; packed-bed scrubbers and polyballs. This capsule report should, redominantly, emphasize pollution prevention techniques and include, but not be restricted to, the afore-mentioned devices. Information

Selective coating for solar panels. [using black chrome and black nickel

NASA Technical Reports Server (NTRS)

Mcdonald, G. E. (Inventor)

1977-01-01

The energy absorbing properties of solar heating panels are improved by depositing a black chrome coating of controlled thickness on a specially prepared surface of a metal substrate. The surface is prepared by depositing a dull nickel on the substrate, and the black chrome is plated on this low emittance surface to a thickness between 0.5 micron and 2.5 microns.

Ultraviolet Curable Powder Coatings With Robotic Curing for Aerospace Applications

DTIC Science & Technology

2011-02-01

Problem: DoD spends millions of dollars annually on solvent- based coatings Hexavalent chrome primer use still very widespread Many topcoats contain...cure functionality can be added Various advanced non- chrome corrosion inhibitors DISTRIBUTION A. Approved for public release; distribution...chromate), Alodine 8800 (sol-gel) and Alodine 5200 (Zr chemistry) Fair to poor results over Alodine 1200S (chromate), and Alodine 5900 (tri- chrome

SU-E-T-328: Dosimetric Impact of Cobalt-Chrome Stabilization Hardware in Paraspinal Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, G; LoSasso, T; Saleh, Z

2015-06-15

Purpose: Due to saturation, high density materials Result in an apparent density of 3.2 g/cm{sup 3} in CT images. The true density of traditional titanium stabilization rods (∼4.4 g/cm{sup 3}) is typically ignored in treatment planning. This may not be acceptable for new cobalt-chrome rods with a density of 8.5 g/cm{sup 3}. This study reports the dosimetric impact of cobalt-chrome rods in paraspinal radiotherapy. Methods: For titanium and cobalt-chrome rods, two planning studies were done for both IMRT and VMAT in Varian Eclipse using AAA. 1) The effect of planning without assigning the true rod density was assessed by comparingmore » plans generated with the apparent density and recalculated with the true density for titanium and cobalt-chrome. 2) To test if TPS can compensate for high density rods during optimization. Furthermore, TPS calculation accuracy was verified using MapCheck for a single 20 x 10 cm{sup 2} field. The MapCheck was incrementally shifted to achieve measurement resolution of 1 mm. Results: PTV coverage was ∼0.3% and ∼4.7% lower in plans that were recalculated with the true rod density of titanium and cobalt-chrome, respectively. PTV coverage can be maintained if the correct density is used in optimization. Measurements showed that TPS overestimated the dose locally by up to 11% for cobalt-chrome rods and up to 4% for titanium rods if the density is incorrect. With density corrected, maximum local differences of 6% and 3% were seen for cobalt-chrome and titanium rods, respectively. At 2 cm beneath a rod, electrons scattered from the side of the rod increased the lateral dose and diminished as depth increases. TPS was not able to account for this effect properly even with the true rod density assigned. Conclusion: Neglecting the true density of cobalt-chrome rods can cause under coverage to the PTV. Assigning the correct density during treatment planning can minimize unexpected decrease in PTV dose.« less

Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods. 1. Artificially aged model samples.

PubMed

Monico, Letizia; Van der Snickt, Geert; Janssens, Koen; De Nolf, Wout; Miliani, Costanza; Verbeeck, Johan; Tian, He; Tan, Haiyan; Dik, Joris; Radepont, Marie; Cotte, Marine

2011-02-15

On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO(4), PbCrO(4)·xPbSO(4), or PbCrO(4)·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1-3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr(2)O(3)·2H(2)O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr(2)(SO(4))(3)·H(2)O or (CH(3)CO(2))(7)Cr(3)(OH)(2) [chromium(III) acetate hydroxide], is likely.

Trace elements and diabetes: Assessment of levels in tears and serum.

PubMed

Cancarini, A; Fostinelli, J; Napoli, L; Gilberti, M E; Apostoli, P; Semeraro, F

2017-01-01

Tear film is critical for the well-being and homeostasis of the ocular surface. Although the composition of the tear film is well known, the composition of metallic elements have yet to be analysed. Despite trace elements metabolism has been reported to play a role in the pathogenesis of diabetes mellitus, a metabolic disease that affects several aspects of homeostasis, little is known in the literature regarding concentration and possible variation of metallic elements in tear film. We studied the concentrations of several essential and non-essential metallic elements in the tear fluid and serum of patients with type II diabetes mellitus and a group of non-diabetic controls. Serum and tear fluid were collected from 97 patients: 47 type II diabetic patients and 50 non-diabetic controls. Regarding tear film, there were statistically significant differences in Zinc, Chrome, Cobalt, Manganese, Barium, and Lead between groups; the values of all metallic elements were found to be statistically significant higher in patients with mellitus type II diabetes. Regarding serum values there was a statistically significant difference in Chrome, Cobalt, and Selenium values; the concentrations of Chrome and Cobalt were higher in the control group, while Selenium concentration was higher in diabetic patients. In patients with type II diabetes, metal elements with higher concentrations in tears compared to serum were: Lead, Barium, Manganese, Cobalt, and Chrome. In the control group, the metal elements with the highest concentration in tear film compared to serum were Chrome, Manganese, Barium, and Lead. In this study, we attempted to evaluate the possible effect of a disease, such as diabetes, on the metabolism of metallic elements. Although our evidence was very interesting, it is probably limited in its accuracy due to the fact that individuals in the control group harboured ocular pathologies. This work lays the foundation for future studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular spectroscopic study for suggested mechanism of chrome tanned leather.

PubMed

Nashy, Elshahat H A; Osman, Osama; Mahmoud, Abdel Aziz; Ibrahim, Medhat

2012-03-01

Collagen represents the structural protein of the extracellular matrix, which gives strength of hides and/or skin under tanning process. Chrome tan is the most important tanning agent all over the world. The methods for production of leather evolved over several centuries as art and engineering with little understanding of the underlying science. The present work is devoted to suggest the most probable mechanistic action of chrome tan on hide proteins. First the affect of Cr upon hide protein is indicated by the studied mechanical properties. Then the spectroscopic characterization of the hide protein as well as chrome tanned leather was carried out with Horizontal Attenuated Total Reflection (HATR) FT-IR. The obtained results indicate how the chromium can attached with the active sites of collagen. Molecular modeling confirms that chromium can react with amino as well as carboxylate groups. Four schemes were obtained to describe the possible interactions of chrome tan with hide proteins. Copyright © 2011 Elsevier B.V. All rights reserved.

NASA TEERM Hexavalent Chrome Alternatives Projects

NASA Technical Reports Server (NTRS)

Rothgeb, Matt

2009-01-01

This slide presentation reviews the NASA/DOD projects to select an alternative to hexavalent chrome in the aerospace industry. The Phase I process of the project performed: (1) Evaluation and testing of non-chromated coating systems as replacements for hexavalent chrome coatings in aircraft and aerospace applications. (2) Testing of coating systems to DoD and NASA specifications for corrosion resistance and adhesion. (3) Bare corrosion resistance and atmospheric exposure will be focus areas of Phase II Testing. The description includes a chart that summarizes the 3000 hour salt fog test results. The second phase of the project includes (1) Evaluation and testing of coating systems that do not contain hexavalent chrome as replacements for aerospace applications. (2) Evaluation of coatings at Beach Test Site and Launch Complex 39B (3) Evaluation of non-chrome coatings for electronic housings (bare corrosion resistance and electrical impedance) is a part of this round of testing. This project was performed for the Technology Evaluation for Environmental Risk Mitigation (TEERM)

Safety evaluation of traces of nickel and chrome in cosmetics: The case of Dead Sea mud.

PubMed

Ma'or, Ze'evi; Halicz, Ludwik; Portugal-Cohen, Meital; Russo, Matteo Zanotti; Robino, Federica; Vanhaecke, Tamara; Rogiers, Vera

2015-12-01

Metal impurities such as nickel and chrome are present in natural ingredients-containing cosmetic products. These traces are unavoidable due to the ubiquitous nature of these elements. Dead Sea mud is a popular natural ingredient of cosmetic products in which nickel and chrome residues are likely to occur. To analyze the potential systemic and local toxicity of Dead Sea mud taking into consideration Dead Sea muds' natural content of nickel and chrome. The following endpoints were evaluated: (Regulation No. 1223/20, 21/12/2009) systemic and (SCCS's Notes of Guidance) local toxicity of topical application of Dead Sea mud; health reports during the last five years of commercial marketing of Dead Sea mud. Following exposure to Dead Sea mud, MoS (margin of safety) calculations for nickel and chrome indicate no toxicological concern for systemic toxicity. Skin sensitization is also not to be expected by exposure of normal healthy skin to Dead Sea mud. Topical application, however, is not recommended for already nickel-or chrome-sensitized persons. As risk assessment of impurities present in cosmetics may be a difficult exercise, the case of Dead Sea mud is taken here as an example of a natural material that may contain traces of unavoidable metals. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

The Petrogenesis of the Unit 7/8 and 11/12 Chrome-spinel Seams of the Rum Eastern Layered Intrusion (NW Scotland) Re-evaluated

NASA Astrophysics Data System (ADS)

O'Driscoll, B.; Daly, J. S.; Emeleus, C. H.; Donaldson, C. H.

2007-12-01

Laterally extensive (~2 mm thick) chrome-spinel seams in the Rum Layered Suite, NW Scotland, occur at the junctions of several of the coupled peridotite-troctolite macro-rhythmic units that make up the bulk of the eastern part of the intrusion. A detailed petrographic study of the rocks immediately above and below two of these seams suggests that existing models for seam formation involving early crystallisation and gravitational settling of chrome-spinel crystals from a newly emplaced body of picritic magma may be flawed. Instead, the textural relationships between minerals suggest that olivine crystallisation in the peridotite above each of the seams occurred before that of most of the chrome-spinel. Reaction textures between olivine and chrome-spinel crystals are commonly observed, with plagioclase usually occurring as thin rims between both olivine and chrome-spinel where both are in close proximity. The textural evidence suggests a significant degree of olivine crystal-shape change; it seems that many of the olivine crystals immediately above the main seams may initially have had much more complex (harrisitic) crystal shapes before modification to simpler morphologies in a crystal mush. Plagioclase occurs in the peridotite as large oikocrysts up to several cm in size. Additionally, the chrome-spinel seams occur only in those units that display extensive evidence of syn-magmatic deformation of unconsolidated cumulate in the underlying troctolite, and the seams themselves often exhibit small-scale load structures. A model suggesting in-situ crystallisation of the chrome-spinel seams is proposed, whereby mixing of an evolved interstitial liquid with a primitive picritic melt occurred approximately at the crystal mush-magma interface. The former was released from the unconsolidated troctolite mush as a response to re-mobilization and chaotic slumping, possibly triggered by emplacement of some of the hot picrite into the crystal mush pile. Significant undercooling in the picrite due to emplacement-related cooling had already produced a crystal framework comprising complex skeletal olivine crystal morphologies with very fast growth rates. It is envisaged that the significantly modified olivine textures in the peridotite immediately above both seams can be attributed to upward- moving porosity waves of the same 'mixed' interstitial melt that precipitated the chrome-spinel seams. In addition to formation of the seams at the main unit junctions, 'necklace' or 'chain-like' distributions of chrome-spinel crystals around olivine crystals in the peridotite, as well as the large plagioclase oikocrysts, argue for the presence of a mobile interstitial melt with a protracted cooling history.

Installation Restoration Program. Phase 1. Records Search. Air Force Plant Number 3, Tulsa, Oklahoma

DTIC Science & Technology

1983-12-01

treatment plant was designed for cyanide and chromium treat- ment. Wastes are collected in two separate sewer systems; acid-chrome, and alkali cyanide...reduction of hexavalent chrome to trivalent chrome with sulfur dioxide. After the oxidation and reduction are accomplished separately, the wastes are...uses of the water. CCNVEPSI N COATING WASTE: Acidic solution containinq chromium . 0COOLANT: An oil-water mixture used for coolina metal parts durirq

C-130 Corrosion Prevention and Control Program

DTIC Science & Technology

2011-08-01

hexavalent chrome … Warner Robins Air Logistics Center People First…Mission Always SIBR Projects  Back Scatter X-Ray NDI  Detect concealed...Projects Listing Future Projects  Chrome -Free Coating Systems Flight Tests • AkzoNobel (Sep-Oct 2011) – PreKote – Aerodur 2100 magnesium rich...primer (MgRP) – Aerodur 5000 topcoat color #36173 • Deft (June 2012) – Rare earth conversion coating (RECC) 1015/3021 – 02-GN-093 chrome -free

Acquisition Documentation Streamlining, the SEP, and the PESHE

DTIC Science & Technology

2012-05-21

identifying any other ESOH requirements (e.g., ban on use of Ozone Depleting Substances or hexavalent chrome )  "Description/Comments:" Use 2-3...limitations on use of hexavalent chrome )  "Description/Comments:" Use 2-3 paragraphs to describe the strategy for integrating ESOH into SE processes...optional tasks) and identifying any other ESOH requirements (e.g., ban on use of Ozone Depleting Substances or hexavalent chrome )  "Description

Characterization of emission factors related to source activity for trichloroethylene degreasing and chrome plating processes.

PubMed

Wadden, R A; Hawkins, J L; Scheff, P A; Franke, J E

1991-09-01

A study at an automotive parts fabrication plant evaluated four metal surface treatment processes during production conditions. The evaluation provides examples of how to estimate process emission factors from activity and air concentration data. The processes were open tank and enclosed tank degreasing with trichloroethylene (TCE), chromium conversion coating, and chromium electroplating. Area concentrations of TCE and chromium (Cr) were monitored for 1-hr periods at three distances from each process. Source activities at each process were recorded during each sampling interval. Emission rates were determined by applying appropriate mass balance models to the concentration patterns around each source. The emission factors obtained from regression analysis of the emission rate and activity data were 16.9 g TCE/basket of parts for the open-top degreaser; 1.0 g TCE/1000 parts for the enclosed degreaser; 1.48-1.64 mg Cr/1000 parts processed in the hot CrO3/HNO3 tank for the chrome conversion coating; and 5.35-9.17 mg Cr/rack of parts for chrome electroplating. The factors were also used to determine the efficiency of collection for the local exhaust systems serving each process. Although the number of observations were limited, these factors may be useful for providing initial estimates of emissions from similar processes in other settings.

[Spatial distribution of birth defects among children aged 0 to 5 years and its relationship with soil chemical elements in Chongqing].

PubMed

Dong, Yan; Zhong, Zhao-hui; Li, Hong; Li, Jie; Wang, Ying-xiong; Peng, Bin; Zhang, Mao-zhong; Huang, Qiao; Yan, Ju; Xu, Fei-long

2013-10-01

To explore the correlation between the incidence of birth defects and the contents of soil elements so as to provide a scientific basis for screening the related pathogenic factors that inducing birth defects for the development of related preventive and control strategies. MapInfo 7.0 software was used to draw the maps on spatial distribution regarding the incidence rates of birth defects and the contents of 11 chemical elements in soil in the 33 studied areas. Variables on the two maps were superposed for analyzing the spatial correlation. SAS 8.0 software was used to analyze single factor, multi-factors and principal components as well as to comprehensively evaluate the degrees of relevance. Different incidence rates of birth defects showed in the maps of spatial distribution presented certain degrees of negative correlation with anomalies of soil chemical elements, including copper, chrome, iodine, selenium, zinc while positively correlated with the levels of lead. Results from the principal component regression equation indicating that the contents of copper(0.002), arsenic(-0.07), cadmium(0.05), chrome (-0.001), zinc (0.001), iodine(-0.03), lead (0.08), fluorine(-0.002)might serve as important factors that related to the prevalence of birth defects. Through the study on spatial distribution, we noticed that the incidence rates of birth defects were related to the contents of copper, chrome, iodine, selenium, zinc, lead in soil while the contents of chrome, iodine and lead might lead to the occurrence of birth defects.

Poultry feed based on protein hydrolysate derived from chrome-tanned leather solid waste: creating value from waste.

PubMed

Chaudhary, Rubina; Pati, Anupama

2016-04-01

Leather industry generates huge amount of chrome-containing leather solid waste which creates major environment problems to tanners worldwide. Chrome-tanned leather solid waste is primarily chromium complex of collagen protein. The presence of chromium limits its protein application in animal feed industry. The purified protein hydrolysate with zero chromium could be used in poultry feed. In this study, an attempt has been made to assess performance of poultry with purified protein hydrolysate as a feed derived from chrome-tanned leather waste as partial replacement of soyabean meal as a sole source of protein for growing broiler chickens. Growth study was conducted to evaluate the effect of feeding protein hydrolysate on performance and physiochemical characteristics of meat of broiler chickens. Two experimental diets containing various levels of protein hydrolysate (EI-20 % and EII-30 %) were evaluated. The comparative study was performed as control with soyabean meal. Daily feed intake, body weight gain and feed conversion ratio were measured from day 8 to day 35. At the end of the study, birds were randomly selected and slaughtered to evaluate for physiochemical characteristics of meat. Diet had significant effects on feed intake and body weight gain. Birds fed with 20 and 30 % protein hydrolysate consumed 9.5 and 17.5 % higher amount of feed and gained 6.5 and 16.6 % higher than soyabean meal-fed birds. The current study produced evidence that protein hydrolysate can replace up to 75 % of soyabean meal in broiler diets without affecting either growth performance or meat characteristics.

Optical and spectroscopic studies on tannery wastes as a possible source of organic semiconductors

NASA Astrophysics Data System (ADS)

Nashy, El-Shahat H. A.; Al-Ashkar, Emad; Abdel Moez, A.

2012-02-01

Tanning industry produces a large quantity of solid wastes which contain hide proteins in the form of protein shavings containing chromium salts. The chromium wastes are the main concern from an environmental stand point of view, because chrome wastes posses a significant disposal problem. The present work is devoted to investigate the possibility of utilizing these wastes as a source of organic semi-conductors as an alternative method instead of the conventional ones. The chemical characterization of these wastes was determined. In addition, the Horizontal Attenuated Total Reflection (HATR) FT-IR spectroscopic analysis and optical parameters were also carried out for chromated samples. The study showed that the chromated samples had suitable absorbance and transmittance in the wavelength range (500-850 nm). Presence of chromium salt in the collagen samples increases the absorbance which improves the optical properties of the studied samples and leads to decrease the optical energy gap. The obtained optical energy gap gives an impression that the environmentally hazardous chrome shavings wastes can be utilized as a possible source of natural organic semiconductors with direct and indirect energy gap. This work opens the door to use some hazardous wastes in the manufacture of electronic devices such as IR-detectors, solar cells and also as solar cell windows.

Gun Liner Emplacement With an Elastomeric Material

DTIC Science & Technology

2010-04-01

Introduction The U.S. Army uses liners or coatings in many of its guns currently in service. This includes a chrome coating in the M256 main tank...coatings increase the barrel wear life of those guns by protecting them against the effects of hot propellant gasses. Chrome coatings are applied by...CCM is a chrome -cobalt alloy that is used for medical implants. The tube was machined from a solid bar of metal. The load frame was programmed to

Electrodeposition of Nanocrystalline Co-P Coatings as a Hard Chrome Alternative

DTIC Science & Technology

2009-09-02

Electrodeposition  of Nanocrystalline Co‐P  Coatings as a Hard Chrome Alternative Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden...AND SUBTITLE Electrodeposition of Nanocrystalline Co‐P Coatings as a Hard Chrome Alternative 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Defense Conference – 2 September 2009 Conventional  Electrodeposits Polycrystalline (10‐100 µm) Electrodeposited Nanocrystalline Materials Pulsed

Development of CMOS MEMS inductive type tactile sensor with the integration of chrome steel ball force interface

NASA Astrophysics Data System (ADS)

Yeh, Sheng-Kai; Chang, Heng-Chung; Fang, Weileun

2018-04-01

This study presents an inductive tactile sensor with a chrome steel ball sensing interface based on the commercially available standard complementary metal-oxide-semiconductor (CMOS) process (the TSMC 0.18 µm 1P6M CMOS process). The tactile senor has a deformable polymer layer as the spring of the device and no fragile suspended thin film structures are required. As a tactile force is applied on the chrome steel ball, the polymer would deform. The distance between the chrome steel ball and the sensing coil would changed. Thus, the tactile force can be detected by the inductance change of the sensing coil. In short, the chrome steel ball acts as a tactile bump as well as the sensing interface. Experimental results show that the proposed inductive tactile sensor has a sensing range of 0-1.4 N with a sensitivity of 9.22(%/N) and nonlinearity of 2%. Preliminary wireless sensing test is also demonstrated. Moreover, the influence of the process and material issues on the sensor performances have also been investigated.

Biological and chemical removal of Cr(VI) from waste water: cost and benefit analysis.

PubMed

Demir, Aynur; Arisoy, Münevver

2007-08-17

The objective of the present study is cost and benefit analysis of biological and chemical removal of hexavalent chromium [Cr(VI)] ions. Cost and benefit analysis were done with refer to two separate studies on removal of Cr(VI), one of heavy metals with a crucial role concerning increase in environmental pollution and disturbance of ecological balance, through biological adsorption and chemical ion-exchange. Methods of biological and chemical removal were compared with regard to their cost and percentage in chrome removal. According to the result of the comparison, cost per unit in chemical removal was calculated 0.24 euros and the ratio of chrome removal was 99.68%, whereas those of biological removal were 0.14 and 59.3% euros. Therefore, it was seen that cost per unit in chemical removal and chrome removal ratio were higher than those of biological removal method. In the current study where chrome removal is seen as immeasurable benefit in terms of human health and the environment, percentages of chrome removal were taken as measurable benefit and cost per unit of the chemicals as measurable cost.

The effect of platform switching on the levels of metal ion release from different implant–abutment couples

PubMed Central

Alrabeah, Ghada O; Knowles, Jonathan C; Petridis, Haralampos

2016-01-01

The improved peri-implant bone response demonstrated by platform switching may be the result of reduced amounts of metal ions released to the surrounding tissues. The aim of this study was to compare the levels of metal ions released from platform-matched and platform-switched implant–abutment couples as a result of accelerated corrosion. Thirty-six titanium alloy (Ti-6Al-4V) and cobalt–chrome alloy abutments were coupled with titanium cylinders forming either platform-switched or platform-matched groups (n=6). In addition, 18 unconnected samples served as controls. The specimens were subjected to accelerated corrosion by static immersion in 1% lactic acid for 1 week. The amount of metal ions ion of each test tube was measured using inductively coupled plasma mass spectrometry. Scanning electron microscope (SEM) images and energy dispersive spectroscopy X-ray analyses were performed pre- and post-immersion to assess corrosion at the interface. The platform-matched groups demonstrated higher ion release for vanadium, aluminium, cobalt, chrome, and molybdenum compared with the platform-switched groups (P<0.05). Titanium was the highest element to be released regardless of abutment size or connection (P<0.05). SEM images showed pitting corrosion prominent on the outer borders of the implant and abutment platform surfaces. In conclusion, implant–abutment couples underwent an active corrosion process resulting in metal ions release into the surrounding environment. The highest amount of metal ions released was recorded for the platform-matched groups, suggesting that platform-switching concept has a positive effect in reducing the levels of metal ion release from the implant–abutment couples. PMID:27357323

The CHROME Honors Program

NASA Technical Reports Server (NTRS)

Wilson, Eleanor

2002-01-01

The CHROME Honors Program was designed as a two-week residential program for 9th and 1Oth grade students participating in CHROME clubs. The curriculum focused on the health sciences with instruction from: (1) the science and health curriculum of the Dozoretz National Program for Minorities in Applied Sciences (DNIMAS) Program of Norfolk State University (NSU); (2) the humanities curriculum of the NSU Honors Program; (3) NASA-related curriculum in human physiology. An Advisory Committee was formed to work with the Project Coordinator in the design of the summer program.

Electrodeposition of Nanocrystalline Co-P Coatings as a Hard Chrome Alternative (Briefing Charts)

DTIC Science & Technology

2011-02-10

chrome plating utilizes chromium in the hexavalent state (Cr6+) Cr6+ is a known carcinogen and poses a health risk to operators OSHA lowered the Cr6+ PEL...from 52 µg/m3 to 5 µg/m3 8 Apr 09, Memorandum, DoD Directive Hexavalent Chromium Management Policy NAVAIR Cr6+ Authorization Process Hard Chrome...Systems Allocation (ESA) data extrapolated across all FRCs over a 10 yr period Environmental Driver/Benefit (Hexavalent Chromium Plating at Navy

Variation of solar-selective properties of black chrome with plating time

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.; Curtis, H. B.

1975-01-01

The spectral reflectance properties of a commercially prepared black chrome over dull nickel, both plated on steel, for various plating times of the black chrome were measured. The plating current was 180 amperes per square foot. Values of absorptance integrated over the solar spectrum, and of infrared emittance integrated over black-body radiation at 250 F were obtained. It is shown that plating between one and two minutes produces the optimum combination of highest heat absorbed and lowest heat lost by radiation.

Nanocrystalline Cobalt-Phosphorous Electroplating as an Alternative to Hard Chromium Electroplating

DTIC Science & Technology

2012-08-01

Validate pulsed electrodeposition of Nanocrystalline Cobalt-Phosphorous (nCoP) alloy coatings as a Hard Chrome electroplating alternative for DoD...limits Cr+6  Cathode Efficiency Cr Plating *Co PEL is 20 µg/m3  ≈5X faster than Chrome plating  Increased throughput  One nCo-P tank can...replace several hard chrome tanks  Bath is Stable nCoP Plating Approaches 100% Efficiency  Process Comparison CoP Technical Approach

Soybean plant growth study conducted using purified protein hydrolysate-based fertilizer made from chrome-tanned leather waste.

PubMed

Pati, Anupama; Chaudhary, Rubina

2015-12-01

Leather processing discharges enormous amount of chrome containing leather solid waste which creates a major disposal problem. Chrome-tanned leather solid waste is a complex of collagen and chromium. The presence of chromium limits protein application in fertilizer industry. The purified protein hydrolysate with zero chromium could be used as a nitrogen source for fertilizer formulation. In this study, an attempt has been made to employ purified protein hydrolysate derived from chrome-tanned leather shavings (CTLS) in formulation of fertilizer. The formulated fertilizer (1–3 t ha(-1)) is employed as nitrogen source in production of soybean. Plant growth study demonstrates that formulated fertilizer dosage 3 t ha(-1) produced similar effects of commercial fertilizer-treated plants. Application of formulated fertilizer yielded higher seed in plant than commercial fertilizer.

CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY (ETF) CHROME (VI) REDUCTANT SOLUTION USING 304 & 316L STAINLESS STEEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

DUNCAN, J.B.

2007-06-27

The Effluent Treatment Facility has developed a method to regenerate spent resin from the groundwater pump and treat intercepting chrome(VI) plumes (RPP-RPT-32207, Laboratory Study on Regeneration of Spent DOWEX 21K 16-20 Mesh Ion Exchange Resin). Subsequent laboratory studies have shown that the chrome(VI) may be reduced to chrome(III) by titrating with sodium metabisulfite to an oxidation reduction potential (ORP) of +280 mV at a pH of 2. This test plan describes the use of cyclic potentiodynamic polarization and linear polarization techniques to ascertain the electrochemical corrosion and pitting propensity of the 304 and 316L stainless steel in the acidified reducingmore » the solution that will be contained in either the secondary waste receiver tank or concentrate tank.« less

Manufacturing of ArF chromeless hard shifter for 65-nm technology

NASA Astrophysics Data System (ADS)

Park, Keun-Taek; Dieu, Laurent; Hughes, Greg P.; Green, Kent G.; Croffie, Ebo H.; Taravade, Kunal N.

2003-12-01

For logic design, Chrome-less Phase Shift Mask is one of the possible solutions for defining small geometry with low MEF (mask enhancement factor) for the 65nm node. There have been lots of dedicated studies on the PCO (Phase Chrome Off-axis) mask technology and several design approaches have been proposed including grating background, chrome patches (or chrome shield) for applying PCO on line/space and contact pattern. In this paper, we studied the feasibility of grating design for line and contact pattern. The design of the grating pattern was provided from the EM simulation software (TEMPEST) and the aerial image simulation software. AIMS measurements with high NA annular illumination were done. Resist images were taken on designed pattern in different focus. Simulations, AIMS are compared to verify the consistency of the process with wafer printed performance.

Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation.

PubMed

Hansen, A B; Larsen, E; Hansen, L V; Lyngsaae, M; Kunze, H

1991-12-01

During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud.

A hip joint simulator study using new and physiologically scratched femoral heads with ultra-high molecular weight polyethylene acetabular cups.

PubMed

Barbour, P S; Stone, M H; Fisher, J

2000-01-01

This study validates a hip joint simulator configuration as compared with other machines and clinical wear rates using smooth metal and ceramic femoral heads and ultra-high molecular weight polyethylene (UHMWPE) acetabular cups. Secondly the wear rate of UHMWPE cups is measured in the simulator with deliberately scratched cobalt-chrome heads to represent the type of mild and severe scratch damage found on retrieved heads. Finally, the scratching processes are described and the resulting scratches compared with those found in retrieved cobalt-chrome heads. For smooth cobalt-chrome and zirconia heads the wear rates were found to be statistically similar to other simulator machines and within the normal range found from clinical studies. An increased wear rate was found with cobalt-chrome heads scratched using either the diamond stylus or the bead cobalt-chrome but the greatest increase was with the diamond scratched heads which generated scratches of similar dimensions to those on retrieved heads. A greater than twofold increase in wear rate is reported for these heads when compared with smooth heads. This increased wear rate is, however, still within the limits of data from clinical wear studies.

Total control of chromium in tanneries - thermal decomposition of filtration cake from enzymatic hydrolysis of chrome shavings.

PubMed

Kocurek, P; Kolomazník, K; Bařinová, M; Hendrych, J

2017-04-01

This paper deals with the problem of chromium recovery from chrome-tanned waste and thus with reducing the environmental impact of the leather industry. Chrome-tanned waste was transformed by alkaline enzymatic hydrolysis promoted by magnesium oxide into practically chromium-free, commercially applicable collagen hydrolysate and filtration cake containing a high portion of chromium. The crude and magnesium-deprived chromium cakes were subjected to a process of thermal decomposition at 650°C under oxygen-free conditions to reduce the amount of this waste and to study the effect of magnesium removal on the resulting products. Oxygen-free conditions were applied in order to prevent the oxidation of trivalent chromium into the hazardous hexavalent form. Thermal decomposition products from both crude and magnesium-deprived chrome cakes were characterized by high chromium content over 50%, which occurred as eskolaite (Cr 2 O 3 ) and magnesiochromite (MgCr 2 O 4 ) crystal phases, respectively. Thermal decomposition decreased the amount of chrome cake dry feed by 90%. Based on the performed experiments, a scheme for the total control of chromium in the leather industry was designed.

Comparative Study Between Cobalt Chrome and Titanium Alloy Rods for Multilevel Spinal Fusion: Proximal Junctional Kyphosis More Frequently Occurred in Patients Having Cobalt Chrome Rods.

PubMed

Han, Sanghyun; Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

2017-07-01

The use of titanium alloy (Ti) rods is frequently associated with rod fracture after spinal fixation. To address this issue, cobalt chrome (CoCr) rods, which are advantageous because of their greater strength and resistance to fatigue relative to Ti rods, have been introduced. The purpose of the present study was to compare radiographic outcomes after the use of Ti versus CoCr rods in a matched cohort of patients undergoing posterior spinal fusion for treatment of spinal instability. We retrospectively reviewed data from patients who had undergone spinal fusion involving more than 3 levels at a single institution between 2004 and 2015. Patients were matched for age, diagnosis, 3-column osteotomy, levels fused, and T score. Fifty patients with Ti rods were identified and appropriately matched to 50 consecutive patients with CoCr rods. The distributions of age at surgery, sex, diagnosis, 3-column osteotomy, levels fused, number of patients with previous surgical procedures, and T score did not significantly differ between the 2 groups. However, there were significant differences in length of follow-up (CoCr, 25.0 vs. Ti, 28.5 months; P < 0.001), fusion rate (CoCr, 45 [90%] vs. Ti, 33 [66%]; P = 0.004), occurrence of rod breakage (CoCr, 0 vs. T, 8 [16%]; P = 0.006), and junctional kyphosis (CoCr, 24 [46%] vs. Ti, 9 [18%]; P = 0.003). Our findings indicate that the use of CoCr rods is effective in ensuring stability of the posterior spinal construct and accomplishment of spinal fusion. Furthermore, our results indicate that junctional kyphosis may occur more frequently in CoCr systems than in Ti systems. Copyright © 2017 Elsevier Inc. All rights reserved.

NASA and ESA Collaboration on Hexavalent Chrome Free Coatings

NASA Technical Reports Server (NTRS)

Greene, Brian

2017-01-01

Presentation on the NASA and ESA Collaboration on Hexavalent Chrome Free Coatings project. Project is in response to a Memorandum of Understanding between NASA and ESA Concerning Cooperation in the Field of Space Transportation - signed September 11, 2009. The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) have expressed mutual interest in pursuing cooperation in the areas of evaluating hexavalent chrome-free coatings, environmentally-preferable coatings for maintenance of launch facilities and ground support equipment, citric acid as an alternative to nitric acid for passivation of stainless steel alloys.

GSDO Program Hexavalent Chrome Alternatives: Final Pretreatments Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt

2013-01-01

Hexavalent chrome free pretreatments should be considered for use on Ground Support Equipment (OSE) and Electrical Ground Support Equipment (EOSE). Both of the hexavalent chrome free pretreatments (Metalast TCP HF and SurTec 650C) evaluated by this project met, and in some instances exceeded, the requirements ofMIL-DTL-5541 "Chemical Conversion Coatings on Aluminum and Aluminum Alloys". For DC resistance measurements, both Metalast TCP HF and SurTec (!50C met initial requirements following assembly and in many cases continued to maintain passing readings for the duration of testing.

Black chrome solar selective coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pettit, R.B.; Sowell, R.R.

1980-01-01

Electrodeposited black chrome solar selective coatings have frequently experienced thermal stability problems when heated to temperatures above 250/sup 0/C (480/sup 0/F) in air. By reducing the trivalent chromium concentration in the standard black chrome plating bath, coatings on nickel substrates are obtained which are stable for thousands of hours at 350/sup 0/C (660/sup 0/F) and for hundreds of hours at 400/sup 0/C (750/sup 0/F). These results have been obtained consistently on a laboratory scale, but difficulty in reproducing the results has been encountered in a production environment. A current study of the effects of known plating variables on the opticalmore » properties and thermal stability of coatings is aimed at establishing an acceptable range for each plating parameter. A preliminary process specification for electroplating mild steel substrates with a stable black chrome coating is presented.« less

Machine Gun Liner Bond Strength

DTIC Science & Technology

2007-08-01

explosive bonding of pure tantalum, several tantalum alloys, and Stellite 25 (an alloy of cobalt, chrome , nickel, and tungsten) in a liner...smoothly as elastic stresses increase in the plug and liner. At a certain level of displacement, the load reaches a peak and then drops sharply. The

Revision of Articular Surface Replacement (ASR) Total Hip Arthroplasty: Correlation of Perioperative Data and Early Post-Revision Outcome Results.

PubMed

Cip, Johannes; Bach, Christian; Widemschek, Mark; Luegmair, Matthias; Martin, Arno

2015-09-01

The articular surface replacement (ASR) total hip arthroplasty (THA) showed accelerated failure rates due to adverse-reaction to metal debris (ARMD). Literature correlating preoperative with intraoperative revision findings respectively post-revision outcome results are rare. 30 of 99 available ASR THA were revised due to ARMD. Mean post-revision follow-up term was 2.3 years. In part, preoperative data did not correlate with intraoperative revision findings. ARMD was even found in asymptomatic patients with non-elevated ion levels. Postoperative pain and metal ions decreased significantly (P ≤ 0.016). Cobalt decreased faster than chrome. Patients with intraoperative pseudotumors, osteolysis or bilateral THA did not have higher pre- or postoperative ion values (P ≥ 0.053). Females showed higher postoperative chrome levels (P=0.031). One major post-revision complication (femoral nerve palsy) and one re-revision (late onset infection) occurred. Copyright © 2015 Elsevier Inc. All rights reserved.

Optical and spectroscopic studies on tannery wastes as a possible source of organic semiconductors.

PubMed

Nashy, El-Shahat H A; Al-Ashkar, Emad; Moez, A Abdel

2012-02-01

Tanning industry produces a large quantity of solid wastes which contain hide proteins in the form of protein shavings containing chromium salts. The chromium wastes are the main concern from an environmental stand point of view, because chrome wastes posses a significant disposal problem. The present work is devoted to investigate the possibility of utilizing these wastes as a source of organic semi-conductors as an alternative method instead of the conventional ones. The chemical characterization of these wastes was determined. In addition, the Horizontal Attenuated Total Reflection (HATR) FT-IR spectroscopic analysis and optical parameters were also carried out for chromated samples. The study showed that the chromated samples had suitable absorbance and transmittance in the wavelength range (500-850 nm). Presence of chromium salt in the collagen samples increases the absorbance which improves the optical properties of the studied samples and leads to decrease the optical energy gap. The obtained optical energy gap gives an impression that the environmentally hazardous chrome shavings wastes can be utilized as a possible source of natural organic semiconductors with direct and indirect energy gap. This work opens the door to use some hazardous wastes in the manufacture of electronic devices such as IR-detectors, solar cells and also as solar cell windows. Copyright © 2011 Elsevier B.V. All rights reserved.

Primary DNA damage in chrome-plating workers.

PubMed

Gambelunghe, A; Piccinini, R; Ambrogi, M; Villarini, M; Moretti, M; Marchetti, C; Abbritti, G; Muzi, G

2003-06-30

In order to evaluate the primary DNA damage due to occupational exposure to chromium (VI), DNA strand-breaks and apoptosis in peripheral lymphocytes were measured in a group of 19 chrome-plating workers. DNA strand-breaks was assessed by alkaline (pH>13) single-cell microgel electrophoresis ('comet') assay, while apoptosis was measured by flow-cytometry after propidium iodide staining of the cells. Concentrations of chromium in urine, erythrocytes and lymphocytes were investigated as biological indicators of exposure. A group of 18 hospital workers (control group I) and another 20 university personnel (control group II) without exposure to chromium were also studied as controls. The results of the study show that chrome-plating workers have higher levels of chromium in urine, erythrocytes and lymphocytes than unexposed workers. Comet tail moment values, assumed as index of DNA damage, are increased in chromium-exposed workers and results are significantly correlated to chromium lymphocyte concentrations. No difference emerged in the percentage of apoptotic nuclei in exposed and unexposed workers. The study confirms that measurements of chromium in erythrocytes and lymphocytes may provide useful information about recent and past exposure to hexavalent chromium at the workplace. The increase in DNA strand-breaks measured by comet assay suggests this test is valid for the biological monitoring of workers exposed to genotoxic compounds such as chromium (VI).

40 CFR 425.03 - Sulfide analytical methods and applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wastewaters discharged by plants operating in all subcategories except the hair save or pulp, non-chrome tan... operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart C, see § 425.30...

40 CFR 425.03 - Sulfide analytical methods and applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... wastewaters discharged by plants operating in all subcategories except the hair save or pulp, non-chrome tan... operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart C, see § 425.30...

40 CFR 425.50 - Applicability; description of the no beamhouse subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY No... cattle hides, sheepskins, or splits (hair previously removed and pickled) into finished leather by chrome or non-chrome tanning, and retan-wet finishing. ...

CAPSULE REPORT: HARD CHROME FUME SUPPRESSANTS & CONTROL TECHNOLOGIES

EPA Science Inventory

All existing information which includes the information extrapolated from the Hard Chrome Pollution Prevention Demonstration Project(s) and other sources derived from plating facilities and industry contacts, will be condensed and featured in this document. At least five chromium...

Survey of coatings for solar collectors. [ceramic enamels and chromium

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1974-01-01

Ceramic enamel is found to be more solar selective, (i.e., has high solar absorptance in combination with low infrared emittance) than organic enamel, but neither is as solar selective as black chrome, black copper, black zinc, or black nickel. Ceramic enamel is matched only by black chrome in durability and wide availability. Ceramic enamel and organic enamel have approximately the same cost, and both are currently slightly lower in cost than black chrome, black copper, or black zinc. Black nickel is relatively unavailable and, because of that, realistic cost comparisons are not possible.

Status of black chrome coating research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pettit, R.B.; Sowell, R.R.

1983-01-01

Recent results regarding the optimization of electrodeposited black chrome solar selective coatings for operation in solar collectors to temperatures up to 300/sup 0/C are summarized. Careful control of the electroplating-bath composition and special regard for bath contamination are required in order to obtain coatings that will survive daily collector operation for tens of years. An accelerated temperature aging test is presented which can be used both to estimate the coating lifetime and to monitor the coating during production. Finally, the use of sol-gel protective films to extend the lifetime of the black chrome coating is also discussed.

Characterization of Crystallographic Structure and Internal Stress of Chromium Coatings Plated under Current Interruptions.

DTIC Science & Technology

1983-09-01

phase has a preferred orientation as most other electrodeposits, this peak found off the equatorial direction provided a way of measuring...40 (S)IoA) 1IliN3i0d , STANDARD HARD CHROM (KiC) INTERRUPTED PLATED CHROME (tC) -4’? 1001 1000X KC Chrome IC Chrome Bath Temperature *C 55 55 Current...COMMANDER ATTN: DRSNC- LC (D) I US ARMY TANK-AUTMV COWD DRSMC-LCE(D) 1 ATTN: DRSTA-RC DRSC-LCM(D) (BLDG 321) 1 WARREN, MI 48090 DRSMC- LCS (D) 1 DRSNC-LCU

Pathfinder Atomic Power Plant Nozzle Galling Test, Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

1961-12-29

Galling tests of 304, 17-4PH, and chrome-plated 304 stainless-steel nozzles with 304 stainless-steel sleeves were conducted at Pathflnder reactor conditions of 480 deg F, 600 psig. A horizontal force was imposed on the sleeve with the nozzle inserted; and the nozzle was moved axially to determine galling tendencies. Galling was produced on both the 304 and 17-4PH stainless-steel nozzles. The chrome-plated 304-stainless-steel nozzles were cycled numerous times without galling. On the basis of these tests, chrome-plated 304-stainless- steel is the material selected for the Pathfinder boiler fuel-element nozzle.

[New perspectives in biomonitoring of metallic elements: the example of hexavalent chromium].

PubMed

Mutti, A; De Palma, G; Goldoni, M

2012-01-01

Plating industry is an important productive sector in all the national territory, because of its contribution to a high number of industrial products and crafts. In the chrome plating sector there is a specific chemical risk due to the exposure to compounds containing hexavalent Chromium [Cr(VI)]. Exhaled breath condensate (EBC) has been used to study both acute and long term exposure to Cr(VI) in chrome plating workers. Cr-EBC correlates with specific oxidative stress biomarkers. Moreover, both total Cr and its hexavalent fraction can be measured in EBC, which therefore is a promising biological fluid to assess the absorbed dose at the target organ level, the pulmonary reduction kinetics of Cr(VI) and in general its local pneumotoxic effects. EBC collection and analysis could give additional information to the traditional measures performed during biomonitoring.

Mid-term survivorship and clinical outcomes of cobalt-chrome and oxidized zirconium on highly crosslinked polyethylene.

PubMed

Petis, Stephen M; Vasarhelyi, Edward M; Lanting, Brent A; Howard, James L; Naudie, Douglas D R; Somerville, Lyndsay E; McCalden, Richard W

2016-02-01

The choice of bearing articulation for total hip arthroplasty in younger patients is amenable to debate. We compared mid-term patient-reported outcomes and survivorship across 2 different bearing articulations in a young patient cohort. We reviewed patients with cobalt-chrome or oxidized zirconium on highly crosslinked polyethylene who were followed prospectively between 2004 and 2012. Kaplan-Meier analysis was used to determine predicted cumulative survivorship at 5 years with all-cause and aseptic revisions as the outcome. We compared patient-reported outcomes, including the Harris hip score (HHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short-form 12 (SF-12) scores. A total of 622 patients were followed during the study period. Mean follow-up was 8.2 (range 2.0-10.6) years for cobalt-chrome and 7.8 (range 2.1-10.7) years for oxidized zirconium. Mean age was 54.9 ± 10.6 years for cobalt-chrome and 54.8 ± 10.7 years for oxidized zirconium. Implant survivorship was 96.0% (95% confidence interval [CI] 94.9%-97.1%) for cobalt-chrome and 98.7% (95% CI 98.0%-99.4%) for oxidized zirconium on highly crosslinked polyethylene for all-cause revisions, and 97.2% (95% CI 96.2%-98.2%) for cobalt-chrome and 99.0% (95% CI 98.4%-99.6%) for oxidized zirconium for aseptic revisions. An age-, sex- and diagnosis-matched comparison of the HHS, WOMAC and SF-12 scores demonstrated no significant changes in clinical outcomes across the groups. Both bearing surface couples demonstrated excellent mid-term survivorship and outcomes in young patient cohorts. Future analyses on wear and costs are warranted to elicit differences between the groups at long-term follow-up.

Investigation of the Cross-Section Stratifications of Icons Using Micro-Raman and Micro-Fourier Transform Infrared (FT-IR) Spectroscopy.

PubMed

Lazidou, Dimitra; Lampakis, Dimitrios; Karapanagiotis, Ioannis; Panayiotou, Costas

2018-01-01

The cross-section stratifications of samples, which were removed from six icons, are studied using optical microscopy, micro-Raman spectroscopy, and micro-Fourier transform infrared (FT-IR) spectroscopy. The icons, dated from the 14th to 19th centuries, are prominent examples of Byzantine painting art and are attributed to different artistic workshops of ​​northern Greece. The following materials are identified in the cross-sections of the icon samples using micro-Raman spectroscopy: anhydrite; calcite; carbon black; chrome yellow; cinnabar; gypsum; lead white; minium; orpiment; Prussian blue; red ochre; yellow ochre; and a paint of organic origin which can be either indigo ( Indigofera tinctoria L. and others) or woad ( Isatis tinctoria L.). The same samples are investigated using micro-FT-IR which leads to the following identifications: calcite; calcium oxalates; chrome yellow; gypsum; kaolinite; lead carboxylates; lead sulfate (or quartz); lead white; oil; protein; Prussian blue; saponified oil; shellac; silica; and tree resin. The study of the cross-sections of the icon samples reveals the combinations of the aforementioned inorganic and organic materials. Although the icons span over a long period of six centuries, the same stratification comprising gypsum ground layer, paint layers prepared by modified "egg tempera" techniques (proteinaceous materials mixed with oil and resins), and varnish layer is revealed in the investigated samples. Moreover, the presence of three layers of varnishes, one at the top and other two as intermediate layers, in the cross-section analysis of a sample from Virgin and Child provide evidence of later interventions.

Ultraviolet Curable Powder Coatings with Robotic Curing for Aerospace Applications

DTIC Science & Technology

2012-05-01

millions of dollars annually on solvent- based coatings  Hexavalent chrome primer use still very widespread  Contains or requires volatile solvent...functionality can be added  Various advanced non- chrome corrosion inhibitors DISTRIBUTION A. Approved for public release; distribution unlimited. Case

Analysis of Sulfidation Routes for Processing Weathered Ilmenite Concentrates Containing Impurities

NASA Astrophysics Data System (ADS)

Ahmad, Sazzad; Rhamdhani, M. Akbar; Pownceby, Mark I.; Bruckard, Warren J.

Rutile is the preferred feedstock for producing high-grade TiO2 pigment but due to decreasing resources, alternative materials such as ilmenite is now used to produce a synthetic rutile (SR) feedstock. This requires removal of impurities (e.g. Fe, Mg, Mn) which, for a primary ilmenite is straightforward process. Processing of weathered ilmenite however, is complex, especially when chrome-bearing impurities are present since minor chromium downgrades the SR market value as it imparts color to the final TiO2 pigment, Chrome-bearing spinels are a problem in weathered ilmenites from the Murray Basin, Australia as their physical and chemical properties overlap with ilmenite making separation difficult. In this paper, different sulfidation process routes for weathered ilmenites are analyzed for their applicability to Murray Basin deposits as a mean of remove chrome spinel impurities. Thermodynamic and experimental studies indicated that selective sulfidation of chrome-bearing spinel can be achieved under controlled pO2 and pS2 processing conditions thereby making them amenable to separation.

Superfund Record of Decision (EPA Region 5): Better Brite Plating Chrome and Zinc, De Pere, WI. (First remedial action), June 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The 2-acre Better Brite Plating Chrome and Zinc site is composed of two plating facilities in De Pere, Brown County, Wisconsin. The site includes the 1.5-acre Chrome Shop and the 0.5-acre Zinc Shop. Land use in the area is predominantly residential and commercial, with a wetlands located approximately one-quarter mile from the site. The estimated 15,000 area residents use the municipal wells drawing from the deep aquifer as a drinking water supply. The Zinc Shop has a long history of improper operational procedures and spills into the surrounding soil. The selected remedial action for this interim remedy includes continuing andmore » expanding the current operation of the ground water extraction system and pretreatment facility, which will include pretreatment of the additional water collected by the surface water and ground water collection systems, and the Chrome and Zinc shops, with discharge to the De Pere wastewater system.« less

Start-stop testing of two self-acting air-lubricated spiral groove thrust bearing coatings

NASA Technical Reports Server (NTRS)

Dunfee, J. D.; Shapiro, W.

1974-01-01

Start-stop tests were conducted on air-lubricated spiral-groove thrust bearings. Application of a matrix-bonded molybdenum disulfide (MoS2) coating over a porous chrome oxide coating resulted in significantly lower friction, compared to bearings coated with chrome oxide only. The MoS2 coated bearing sustained 15,000 start-stop cycles at a maximum of 3600 rpm. Each cycle was 15 seconds on, 30 seconds off. The chrome oxide coated bearing failed by local welding after 2030 cycles. Both types of coatings exhibited early failures under higher thrust loads when operating films were insufficient to sustain the load without overheating.

Elevated Frequencies of Micronuclei and other Nuclear Abnormalities of Chrome Plating Workers Occupationally Exposed to Hexavalent Chromium.

PubMed

Sudha, S; Kripa, S K; Shibily, P; Shyn, J

2011-01-01

Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to assess the potential cytogenetic damage associated with occupational exposure to hexavalent chromium by using micronuclei (MN) as a biomarker. This was a cross-sectional study and all participants were males. Both the exposed and control individuals were selected from Coimbatore, Southern India. Exfoliated buccal cells from 44 chrome plating workers and 40 age and sex matched control subjects were examined for MN frequency and nuclear abnormalities (NA) other than micronuclei, such as binucleates, broken eggs, karyorrhexis, karyolysis and pyknosis. Results showed statistically significant difference between chrome plating workers and control groups. MN and NA frequencies in chrome plating workers were significantly higher than those in control groups (p < 0.05) and also significantly related to smoking habit (P < 0.05). A significant difference in NA was observed in workers exposed to chromium for longer duration. In addition to this, a higher degree of NA was observed among smokers. MN and other NA reflect genetic changes, events associated with carcinogenesis. Therefore the results of this study indicate that chrome plating workers are under risk of significant cytogenetic damage. Therefore, there is a need to educate those who work with heavy metals about the potential hazard of occupational exposure and the importance of using protective measures.

Introduction to Toxicity and Risk Assessment for Project Chemists

DTIC Science & Technology

2012-03-27

Toxicity of Hexavalent Chromium  External review complete  EPA will wait until studies underway on carcinogenic mode of action are complete to...finalize the assessment  NJ and Cal values for hex chrome 16 Risk-Based Screening Levels Resident Soil (mg/kg) Resident Water Use (µg/L) DRAFT 0.04

Evaluation of TF11 attenuated-PSM mask blanks with DUV laser patterning

NASA Astrophysics Data System (ADS)

Xing, Kezhao; Björnberg, Charles; Karlsson, Henrik; Paulsson, Adisa; Beiming, Peter; Vedenpää, Jukka; Walford, Jonathan

2008-05-01

Tightening requirements on resolution, CD uniformity and positional accuracy push the development of improved photomask blanks. One such blank for 45nm node attenuated phase shift masks (att-PSM) provides a thinner chrome film, TF11, with a higher etch rate compared to previous generation NTAR5 att-PSM blanks from the same supplier. FEP-171, a positive chemically amplified resist, is commonly used in mask manufacturing for both e-beam and DUV laser pattern generators. TF11 chrome allows the FEP-171 resist thickness to be decreased at least down to 2000 Å while maintaining sufficient etch resistance, thereby improving photomask CD performance. The lower stress level in TF11 chrome films also reduces the image placement error induced by the material. In this study, TF11 chrome and FEP-171 resist are evaluated with exposures on a 248 nm DUV laser pattern generator, the Sigma7500. Patterning is first characterized for resist thicknesses of 2000 Å to 2600 Å in steps of 100 Å, assessing the minimum feature resolution, CD linearity, isolated-dense CD bias and dose sensitivity. Swing curve analysis shows a minimum near 2200 Å and a maximum near 2500 Å, corresponding closely to the reflectivity measurements provided by the blank supplier. The best overall patterning performance is obtained when operating near the swing maximum. The patterning performance is then studied in more detail with a resist thickness of 2550 Å that corresponds to the reflectivity maximum. This is compared to the results with 2000 Å resist, a standard thickness for e-beam exposures on TF11. The lithographic performance on NTAR5 att-PSM blanks with 3200 Å resist is also included for reference. This evaluation indicates that TF11 blanks with 2550 Å resist provide the best overall mask patterning performance obtained with the Sigma7500, showing a global CD uniformity below 4 nm (3s) and minimum feature resolution below 100 nm.

Application of molecular simulation to investigate chrome(III)-crosslinked collagen problems

NASA Astrophysics Data System (ADS)

Ding, Yun-Qiao; Chen, Cheng-Lung; Gu, Qi-Rui; Liao, Jun-Min; Chuang, Po-Hsiang

2014-04-01

Molecular dynamics simulation with a modified CHARMM (Chemistry at Harvard Macromolecular Mechanics) force field was carried out to investigate the properties of chrome-tanned collagen in comparison with chrome-free collagen under hydrated and dehydrated conditions. An attempt has been made to explain the microcosmic origins of the various properties of the chromium(III)-crosslinked collagen. The present simulation describes the clear crosslinking topology of polychromiums to peptide chains, identifies the linking site and the capacity of the linkage, explains why the efficiency is not 100% in a practical tanning process and provides a new viewpoint on the crosslinking of the polychromium with the side chains of the collagen.

NASA and ESA Collaboration on Hexavalent Chrome Alternatives: Pretreatments Only Final Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2015-01-01

Hexavalent chromium (hex chrome or CR(VI)) is a widely used element within applied coating systems because of its self-healing and corrosion-resistant properties. The replacement of hex chrome in the processing of aluminum for aviation and aerospace applications remains a goal of great significance. Aluminum is the major manufacturing material of structures and components in the space flight arena. The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are engaged in a collaborative effort to test and evaluate alternatives to hexavalent chromium containing corrosion coating systems. NASA and ESA share common risks related to material obsolescence associated with hexavalent chromium used in corrosion-resistant coatings.

CHROME: An Approach to Teaching the Concept of Inter-Functional Cooperation in Services Organizations

ERIC Educational Resources Information Center

Johnson, Lester W.

2010-01-01

When teaching a services course (e.g., Services Marketing) it is essential that students understand that marketing/management, operations and human resource management within the service organization be fully coordinated. One useful acronym used to remind students of this need is "CHROME", standing for Communications, Human Resources,…

Elevated Frequencies of Micronuclei and other Nuclear Abnormalities of Chrome Plating Workers Occupationally Exposed to Hexavalent Chromium

PubMed Central

Sudha, S; Kripa, SK; Shibily, P; Shyn, J

2011-01-01

Background Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to assess the potential cytogenetic damage associated with occupational exposure to hexavalent chromium by using micronuclei (MN) as a biomarker. Methods This was a cross-sectional study and all participants were males. Both the exposed and control individuals were selected from Coimbatore, Southern India. Exfoliated buccal cells from 44 chrome plating workers and 40 age and sex matched control subjects were examined for MN frequency and nuclear abnormalities (NA) other than micronuclei, such as binucleates, broken eggs, karyorrhexis, karyolysis and pyknosis. Results Results showed statistically significant difference between chrome plating workers and control groups. MN and NA frequencies in chrome plating workers were significantly higher than those in control groups (p < 0.05) and also significantly related to smoking habit (P < 0.05). A significant difference in NA was observed in workers exposed to chromium for longer duration. In addition to this, a higher degree of NA was observed among smokers. Conclusion MN and other NA reflect genetic changes, events associated with carcinogenesis. Therefore the results of this study indicate that chrome plating workers are under risk of significant cytogenetic damage. Therefore, there is a need to educate those who work with heavy metals about the potential hazard of occupational exposure and the importance of using protective measures. PMID:26328050

Mid-term survivorship and clinical outcomes of cobalt-chrome and oxidized zirconium on highly crosslinked polyethylene

PubMed Central

Petis, Stephen M.; Vasarhelyi, Edward M.; Lanting, Brent A.; Howard, James L.; Naudie, Douglas D.R.; Somerville, Lyndsay E.; McCalden, Richard W.

2016-01-01

Background The choice of bearing articulation for total hip arthroplasty in younger patients is amenable to debate. We compared mid-term patient-reported outcomes and survivorship across 2 different bearing articulations in a young patient cohort. Methods We reviewed patients with cobalt-chrome or oxidized zirconium on highly crosslinked polyethylene who were followed prospectively between 2004 and 2012. Kaplan–Meier analysis was used to determine predicted cumulative survivorship at 5 years with all-cause and aseptic revisions as the outcome. We compared patient-reported outcomes, including the Harris hip score (HHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short-form 12 (SF-12) scores. Results A total of 622 patients were followed during the study period. Mean follow-up was 8.2 (range 2.0–10.6) years for cobalt-chrome and 7.8 (range 2.1–10.7) years for oxidized zirconium. Mean age was 54.9 ± 10.6 years for cobalt-chrome and 54.8 ± 10.7 years for oxidized zirconium. Implant survivorship was 96.0% (95% confidence interval [CI] 94.9%–97.1%) for cobalt-chrome and 98.7% (95% CI 98.0%–99.4%) for oxidized zirconium on highly crosslinked polyethylene for all-cause revisions, and 97.2% (95% CI 96.2%–98.2%) for cobalt-chrome and 99.0% (95% CI 98.4%–99.6%) for oxidized zirconium for aseptic revisions. An age-, sex- and diagnosis-matched comparison of the HHS, WOMAC and SF-12 scores demonstrated no significant changes in clinical outcomes across the groups. Conclusion Both bearing surface couples demonstrated excellent mid-term survivorship and outcomes in young patient cohorts. Future analyses on wear and costs are warranted to elicit differences between the groups at long-term follow-up. PMID:26812409

Effects of alpha-tocopherol addition to polymeric coatings on the UV and heat resistance of a fibrous collagen material--chrome-free leather

USDA-ARS?s Scientific Manuscript database

UV and heat resistance are very important qualities of leather because most leather products are constantly exposed to outdoor environments. In recent years, we have focused on using environmentally friendly antioxidants that will improve the UV and heat resistance of chrome-free leather. Tocopher...

Low Temperature Powder Coating

DTIC Science & Technology

2011-02-09

of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) • Legacy primers contain hexavalent chrome • Conventional powder coatings...coatings both in laboratory and field service evaluations • LTCPC allows environmental cost reductions through VOC/HAP elimination and hexavalent ... chrome reduction. • The LTCPC process greatly shortens the coating operation (LTCPC cures much more rapidly then conventional wet coatings) resulting in

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory. 425.30 Section 425.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save...

A useful single-solution polychrome stain for plant material...Brook Cyte-Chrome I.

Treesearch

Stanley L Krugman; Julia F. Littlefield

1968-01-01

Fresh and chemically fixed sectioned plant material can be quickly stained by applying a Brook Cyte Chrome I polychrome stain. Staining time averaged only about 10 minutes. And exact timing of staining and de-staining is not as critical as with most of the commonly used stains. The overall quality is comparable to that of the traditional stains.

Development of advanced thermoelectric materials, phase A

NASA Technical Reports Server (NTRS)

1980-01-01

Work performed on the chemical system characterized by chrome sulfide, chrome selenide, lanthanum selenide, and lanthanum sulfide is described. Most materials within the chemical systems possess the requisites for attractive thermoelectric materials. The preparation of the alloys is discussed. Graphs show the Seebeck coefficient, electrical resistivity, and thermal conductivity of various materials within the chemical systems. The results of selected doping are included.

Changes Found on Run-In and Scuffed Surfaces of Steel Chrome Plate, and Cast Iron

NASA Technical Reports Server (NTRS)

Good, J. N.; Godfrey, Douglas

1947-01-01

A study was made of run-in and scuffed steel, chrome-plate, and cast-iron surfaces. X-ray and electron diffraction techniques, micro-hardness determinations, and microscopy were used. Surface changes varied and were found to include three classes: chemical reaction, hardening, and crystallite-size alteration. The principal chemical reactions were oxidation and carburization.

Fleet Readiness Center - Southeast Technology Development Program (Cadmium & Hexavalent Chromium Reduction)

DTIC Science & Technology

2014-11-01

Industrial Waste Water Treatment  Aircraft & Component Paint Removal (ABM & Chemical)  Chrome Electroplating  Corrosion Treatment  Aircraft...Hex Chrome post treatment )  Energy Use; Electrical (& Steam)  NDI- Florescent Penetrant  Solvent Tank Cleaning  Water (& Sanitary) Use...Engineer Corrosion Science & Engineering NAVAIR Jacksonville Phone: (904) 790-6405 Email: john.benfer@navy.mil ASETS Technical Workshop (NOV

Evaluation of Advanced Solid Lubricant Coatings for Foil Air Bearings Operating at 25 and 500 C

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Fellenstein, James A.; Benoy, Patricia A.

1998-01-01

The tribological properties of one chrome oxide and one chrome carbide based solid lubricant coating were evaluated in a partial-arc foil bearing at 25 and 500 C. Start/stop bearing operation up to 20,000 cycles were run under 10 kPa (1.5 psi) static deadweight load. Bearing friction (torque) was measured during the test. Specimen wear and SEM/EDS surface analyses were conducted after testing to understand and elucidate the tribological characteristics observed. The chrome oxide coating which contains both (Ag) and (BaF2/CaF2) for low and high temperature lubrication, exhibited low friction in sliding against Al2O3 coated foils at 25 and 500 C. The chrome carbide coating, which lacked a low temperature lubricant but contained BaF2/CaF2 as a high temperature lubricant, exhibited high friction at 25 C and low friction at 500 C against both bare and Al2O3 coated superalloy foil surfaces. Post test surface analyses suggest that improved tribological performance is exhibited when a lubricant film from the coating transfers to the foil surface.

Green chemistry approaches to leather tanning process for making chrome-free leather by unnatural amino acids.

PubMed

Krishnamoorthy, G; Sadulla, S; Sehgal, P K; Mandal, Asit Baran

2012-05-15

In the present study, green and sustainable method or eco-friendly approaches to tanning process based on unnatural D-amino acids (D-AA)-aldehyde (Ald) as a substitute for chrome-free tanning has been attempted. The distribution of optically active D-AA in tanned leather, the hydrothermal stability, the mechanical properties and resistance to collagenolytic activity of tanned leather, the evaluation of eco-friendly characteristics were investigated. Scanning electron microscopic (SEM) and Atomic force microscopic (AFM) analyses indicate the surface morphology and roughness, respectively, of the tanned leather collagen matrix. Shrinkage and Differential scanning calorimetric (DSC) analyses shows that the shrinkage temperature (T(s)) and denaturation temperature (T(d)) of tanned leather are related to the content of D-AA+Ald present in the leather matrix. It has been found that the T(s) of D-AA tanned leather is more than that of Ald tanned leather and also more or less equal to chrome tanned leather. Environmental impact assessment (EIA) shows that the developed process results in significant reduction in total solids content (TSC) and improves better biodegradability of organic compound present in the effluent compared to chrome tanning. Copyright © 2012 Elsevier B.V. All rights reserved.

SPANISH PEAKS PRIMITIVE AREA, MONTANA.

USGS Publications Warehouse

Calkins, James A.; Pattee, Eldon C.

1984-01-01

A mineral survey of the Spanish Peaks Primitive Area, Montana, disclosed a small low-grade deposit of demonstrated chromite and asbestos resources. The chances for discovery of additional chrome resources are uncertain and the area has little promise for the occurrence of other mineral or energy resources. A reevaluation, sampling at depth, and testing for possible extensions of the Table Mountain asbestos and chromium deposit should be undertaken in the light of recent interpretations regarding its geologic setting.

Aerospace Non Chrome Corrosion Inhibiting Primer Systems

DTIC Science & Technology

2009-09-01

Meet all HSE specifications, TSCA, REACh, Akzo • Strippable • No weight increase over current system • Meet specification requirements for corrosion, not...Positive and negative controls • Primer only and topcoated samples Aerospace Coatings | Title 9 OEM CF Optimization/ Down Selects •Usual issues...found to be true • Good NSS ≠ Good filiform ≠ Good cure ≠ Good application properties • Down select process is to minimize ≠ and move to a balance of

Speciation of Cr(VI) in environmental samples in the vicinity of the ferrochrome smelter.

PubMed

Sedumedi, Hilda N; Mandiwana, Khakhathi L; Ngobeni, Prince; Panichev, Nikolay

2009-12-30

The impact of ferrochrome smelter on the contamination of its environment with toxic hexavalent chromium, Cr(VI), was assessed by analyzing smelter dusts, soil, grass and tree barks. For the separation of Cr(VI) from Cr(III), solid samples were treated with 0.1M Na(2)CO(3) and filtered through hydrophilic PDVF 0.45 microm filter prior to the determination of Cr(VI) by electrothermal atomic absorption spectrometry (ET-AAS). Ferrochrome smelter dust was found to contain significant levels of Cr(VI), viz. 43.5 microg g(-1) (cyclone dust), 2710 microg g(-1) (fine dust), and 7800 microg g(-1) (slimes dust) which exceeded the maximum acceptable risk concentration (20 microg g(-1)). The concentration of Cr(VI) in environmental samples of grass (3.4+/-0.2), soil (7.7+/-0.2), and tree bark (11.8+/-1.2) collected in the vicinity of the chrome smelter were higher as compared with the same kind of samples collected from uncontaminated area. The results of the investigation show that ferrochrome smelter is a source of environmental pollution with contamination factors of Cr(VI) ranging between 10 and 50.

Low temperature selective absorber research

NASA Astrophysics Data System (ADS)

Herzenberg, S. A.; Silberglitt, R.

1982-04-01

Research carried out since 1979 on selective absorbers is surveyed, with particular attention given to the low-temperature coatings seen as promising for flat plate and evacuated tube applications. The most thoroughly investigated absorber is black chrome, which is highly selective and is the most durable low-temperature absorber. It is believed that other materials, because of their low cost and lower content of strategic materials, may eventually supplant black chrome. Among these candidates are chemically converted black nickel; anodically oxidized nickel, zinc, and copper composites; and nickel or other low-cost multilayer coatings. In reviewing medium and high-temperature research, black chrome, multilayer coatings and black cobalt are seen as best medium-temperature candidates. For high temperatures, an Al2O3/Pt-Al203 multilayer composite or the zirconium diboride coating is preferred.

Implant Failure After Motec Wrist Joint Prosthesis Due to Failure of Ball and Socket-Type Articulation-Two Patients With Adverse Reaction to Metal Debris and Polyether Ether Ketone.

PubMed

Karjalainen, Teemu; Pamilo, Konsta; Reito, Aleksi

2018-04-21

We describe 2 cases of articulation-related failures resulting in revision surgery after a Motec total wrist arthroplasty: one with an adverse reaction to metal debris and the other with an adverse reaction to polyether ether ketone. In the first patient, blood cobalt and chrome levels were elevated and magnetic resonance imaging showed clear signs of a pseudotumor. The other patient had an extensive release of polyether ether ketone particles into the surrounding synovia due to adverse wear conditions in the cup, leading to the formation of a fluid-filled cyst sac with a black lining and diffuse lymphocyte-dominated inflammation in the synovia. We recommend regular follow-up including x-rays, monitoring of cobalt and chrome ion levels, and a low threshold for cross-sectional imaging in patients who have undergone total wrist arthroplasty with a Motec joint prosthesis. Wear-related problems can also develop in implants in which polyether ether ketone is the bulk material. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

STRAWBERRY MOUNTAIN WILDERNESS, OREGON.

USGS Publications Warehouse

Thayer, T.P.; Stotelmeyer, Ronald B.

1984-01-01

The Strawberry Mountain Wilderness extends 18 mi along the crest of the Strawberry Range and comprises about 53 sq mi in the Malheur National Forest, Grant County, Oregon. Systematic geologic mapping, geochemical sampling and detailed sampling of prospect workings was done. A demonstrated copper resource in small quartz veins averaging at most 0. 33 percent copper with traces of silver occurs in shear zones in gabbro. Two small areas with substantiated potential for chrome occur near the northern edge of the wilderness. There is little promise for the occurrence of additional mineral or energy resources in the Strawberry Mountain Wilderness.

Fundamental studies of black chrome for solar collector use

NASA Technical Reports Server (NTRS)

Mcdonald, G.; Buzek, B.; Curtis, H.

1976-01-01

The thicknesses of black chrome plated for various times have been measured from electron photomicrographs and correlated with the solar spectrum absorptance and infrared emittance as calculated from spectral reflectance measurements. The maximum absorptance is reached at an average thickness of 0.5 micrometer. The emittance increases only slightly up to 1.0 micrometer but increases rapidly at thickness above 1.0 micrometer.

Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

NASA Technical Reports Server (NTRS)

Bolgar, A. S.; Verkhoglyadova, T. S.; Samsonov, G. V.

1985-01-01

The vapor pressure and evaporation rate of borides of titanium, zirconium, and chrome; and of strontium and carbides of titanium, zirconium, and chrome, molybdenum silicide; and nitrides of titanium, niobium, and tantalum in a vacuum were studied. It is concluded that all subject compounds evaporate by molecular structures except AlB sub 12' which dissociates, losing the aluminum.

USMC Environmental and Corrosion Control Issues

DTIC Science & Technology

2010-12-01

b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Minimizing Hexavalent Chromium ...cadmium – Use of hexavalent chromium – Potential incompatibilities with alternatives – Use of non-corrosion resistant hardware in harsh...on non-chrome and trivalent -chrome alternatives • Favor non-cadmium hardware • Concern with logistics and supply chain of many alternatives Pre

Clean Metal Finishing Alternatives

DTIC Science & Technology

2006-05-01

Cr, must heat treat for hardness 4 4 Trivalent chrome Trivalent plating chemistry Varying success, some must be brush plate 3 3 Alloy plating...metals. Hard coating deposition unproven. 3 N/A Weld coating Electrospark Deposition/ Alloying (ESD/ ESA) Microarc welding Localized repair of non...Alternatives to chromate conversion coatings Al TriChrome Pretreatment (TCP)* – AnoChem TCP, Aluminescent, TCP-HF Trivalent Cr3+ conversion with Zr

Chromium Elimination and Cannon Life Extension for Gun Tubes

DTIC Science & Technology

2012-08-30

the use of hexavalent chromium (VI) in the production of cannon barrels by developing a cost effective environmentally friendly Explosive Bonding...erosion- resistant chrome cobalt alloy matrix with 15% tungsten. Stellite is used as M60 machine gun barrel liner. Tantalum Cobalt Tungsten...Grounds (YPG) Preliminary proof of principle endurance testing at YPG shows promising results when conducted side by side to a chrome plated

New PVD Technologies for New Ordnance Coatings

DTIC Science & Technology

2012-04-01

characteristics using a Tantalum and a Chrome target; 4) Deposition of Ta coatings and reactive deposition of CrN; 5) Deposition parameters affecting film...Vapor Deposition (PVD); High Power Impulse Magnetron Sputtering (HIPIMS); Modulated Pulsed Power (MPP); Tantalum; Chrome ; Ta coatings; CrN; coating...The pre-production chemicals and acids are hazardous and hexavalent Cr is a known carcinogen. Significant annual expenditures are necessary to

PEEK-OPTIMA™ as an alternative to cobalt chrome in the femoral component of total knee replacement: A preliminary study

PubMed Central

Cowie, Raelene M; Briscoe, Adam; Fisher, John; Jennings, Louise M

2016-01-01

PEEK-OPTIMA™ (Invibio Ltd, UK) has been considered as an alternative joint arthroplasty bearing material due to its favourable mechanical properties and the biocompatibility of its wear debris. In this study, the potential to use injection moulded PEEK-OPTIMA™ as an alternative to cobalt chrome in the femoral component of a total knee replacement was investigated in terms of its wear performance. Experimental wear simulation of three cobalt chrome and three PEEK-OPTIMA™ femoral components articulating against all-polyethylene tibial components was carried out under two kinematic conditions: 3 million cycles under intermediate kinematics (maximum anterior-posterior displacement of 5 mm) followed by 3 million cycles under high kinematic conditions (anterior-posterior displacement 10 mm). The wear of the GUR1020 ultra-high-molecular-weight polyethylene tibial components was assessed by gravimetric analysis; for both material combinations under each kinematic condition, the mean wear rates were low, that is, below 5 mm3/million cycles. Specifically, under intermediate kinematic conditions, the wear rate of the ultra-high-molecular-weight polyethylene tibial components was 0.96 ± 2.26 mm3/million cycles and 2.44 ± 0.78 mm3/million cycle against cobalt chrome and PEEK-OPTIMA™ implants, respectively (p = 0.06); under high kinematic conditions, the wear rates were 2.23 ± 1.85 mm3/million cycles and 4.44 ± 2.35 mm3/million cycles, respectively (p = 0.03). Following wear simulation, scratches were apparent on the surface of the PEEK-OPTIMA™ femoral components. The surface topography of the femoral components was assessed using contacting profilometry and showed a statistically significant increase in measured surface roughness of the PEEK-OPTIMA™ femoral components compared to the cobalt chrome implants. However, this did not appear to influence the wear rate, which remained linear over the duration of the study. These preliminary findings showed that PEEK-OPTIMA™ gives promise as an alternative bearing material to cobalt chrome alloy in the femoral component of a total knee replacement with respect to wear performance. PMID:27637723

Evaluation of attenuated PSM photomask blanks with TF11 chrome and FEP-171 resist on a 248 nm DUV laser pattern generator

NASA Astrophysics Data System (ADS)

Xing, Kezhao; Björnborg, Charles; Karlsson, Henrik; Paulsson, Adisa; Rosendahl, Anna; Beiming, Peter; Vedenpää, Jukka; Walford, Jonathan; Newman, Tom

2007-10-01

Tighter requirements on mask resolution, CD and image positioning accuracy at and beyond the 45 nm technology node push the development of improved photomask blanks. One such blank for attenuated phase-shift masks (att-PSM) provides a thinner chrome film, named TF11, with higher chrome etch rate compared to the previous generation Att- PSM blank (NTAR5 chrome film) from the same supplier. Reduced stress in the chrome film also results in less image placement error induced by the material. FEP-171 is the positive chemically amplified resist (PCAR) that is most commonly used in advanced mask manufacturing with both 50 keV variable shaped e-beam (VSB) and DUV laser pattern generators. TF11 allows an FEP-171 resist film down to about 2000 Å thickness with sufficient etch resistance, while the standard resist thickness for NTAR5 is around 3000 Å. This work has experimentally evaluated the use of TF11 chrome and FEP-171 resist together with a 248 nm DUV laser pattern generator, the Sigma7500. First, patterning performance in resist with thicknesses from 2000 Å to 2600 Å, in steps of 100 Å, was tested with respect to swing curve and basic lithographic parameters including resolution, CD linearity, CD iso-dense bias and dose sensitivity. Patterning results on mask showed a swing minimum at around 2200 Å and a swing maximum at around 2500 Å, which correspond to reflectivity measurements for 248 nm wavelength performed by the blank supplier. It was concluded that the overall patterning performance was best close to the swing maximum. Thereafter the patterning performance using TF11 at two resist thicknesses, 2000 Å and 2550 Å, was studied in more detail and compared to performance using NTAR5 with 3200 Å resist. The evaluation showed that the Sigma7500-II offers good compatibility with TF11, especially using the optimized FEP-171 resist thickness of 2550 Å. It also showed that the patterning capability of the Sigma7500-II using TF11 and 2550 Å resist is improved compared to using NTAR5 and 3200 Å resist.

Microstructure and optical properties of black chrome befor and after exposure to high temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lampert, C.M.; Washburn, J.

1979-01-01

the chemical and microstructural stability of the CHROM-ONYX type of black chrome solar coating was investigated at different temperatures and atmospheres. This was done to give a better understanding of the mechanism of solar energy selectivity and its variability when subjected to short term heat treatments. The as-plated structure was found to consist of a suspension of metallic chromium particles within the size range of 100A in a amorphous oxide matrix. this assembly was in turn formed into larger particles within the size range of 0.05 to 0.30 microns. Short term high temperature heat treatments were used to simulate stagnationmore » conditions. Samples were annealed in both air and vacuum, which resulted in similar characteristics. Annealing in air appeared to mildly accelerate optical degradation at high temperatures. For short term heat treatments below 300/sup 0/C the reflective and microstructural properties appeared to be unchanged. By in situ vacuum annealing of the coating above 400/sup 0/C microscrystalline Cr/sub 2/O/sub 3/ was identified. By observation of diffraction patterns it was concluded that a-Cr/sub 2/O/sub 3/ was transformed into crystalline Cr/sub 2/O/sub 3/. The Cr/sub 2/O/sub 3/ phase continued to grow at higher temperatures at the expense of chromium content. At temperatures above 500/sup 0/C in vacuum, a new phase identified as Cr/sub 3/O/sub 4/ formed. It was found that black chrome failed optically between 500 to 600/sup 0/C for 1 hour heat treatments in both air and vacuum; also the coating heated in air failed mechanically by peeling at 600/sup 0/C.« less

High pressure furnace

DOEpatents

Morris, Donald E.

1993-01-01

A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

Separation of motor oils, oily wastes and hydrocarbons from contaminated water by sorption on chrome shavings.

PubMed

Gammoun, A; Tahiri, S; Albizane, A; Azzi, M; Moros, J; Garrigues, S; de la Guardia, M

2007-06-25

In this paper, the ability of chrome shavings to remove motor oils, oily wastes and hydrocarbons from water has been studied. To determine amount of hydrocarbons sorbed on tanned wastes, a FT-NIR methodology was used and a multivariate calibration based on partial least squares (PLS) was employed for data treatment. The light density, porous tanned waste granules float on the surface of water and remove hydrocarbons and oil films. Wastes fibers from tannery industry have high sorption capacity. These tanned solid wastes are capable of absorbing many times their weight in oil or hydrocarbons (6.5-7.6g of oil and 6.3g of hydrocarbons per gram of chrome shavings). The removal efficiency of the pollutants from water is complete. The sorption of pollutants is a quasi-instantaneous process.

Service Test Plan for A-10 Hydraulic Actuators

DTIC Science & Technology

2014-05-29

utilizes electroplated chrome as a wear coating on the actuator assembly. This actuator will be delta-qualified while two other actuators will be qualified...2730534-1 Similarity to (1) 3 Elevator Actuator Hydraulic Flight Control System 2730551-5 Similarity to (1) The current chrome electroplating ...process has been proven to be a significant health hazard, and it is anticipated that future Government regulation will make the use of electroplated

Laboratory Validation and Demonstrations of Non-Hexavalent Chromium Conversion Coatings for Steel Substrates (Briefing Charts)

DTIC Science & Technology

2011-02-01

UNCLASSIFIED: Approved for public release; distribution unlimited. Laboratory Validation and Demonstrations of Non-Hexavalent Chromium Conversion...00-00-2011 4. TITLE AND SUBTITLE Laboratory Validation and Demonstrations of Non-Hexavalent Chromium Conversion Coatings for Steel Substrates 5a...Coatings for HHA • SurTec 650 - ChromitAL TCP - Trivalent Chrome Pretreatment Developed by NAVAIR for Aluminum. • Chemetall Oxsilan 9810/2 - Non-chrome

Project SQUID. Quarterly Progress Report

DTIC Science & Technology

1948-04-01

connection with temperature measurements we are investigating the infrared emission of the pulse jet. We have a lead sulphide cell which, when...formed on an 11% chrome-iron alloy when oxidized in oxygen at a pressure of one millimeter of mercury (sumnarized in the Annual Report, 1947) show...work has been obtained recently. 36 TABLE I Surface Structures Formed on a 27% Chrome-Iron Oxidized in Dry Oxygen at One Millimeter Mercury

Development of advanced thermoelectric materials

NASA Technical Reports Server (NTRS)

1984-01-01

The development of an advanced thermoelectric material for radioisotope thermoelectric generator (RTG) applications is reported. A number of materials were explored. The bulk of the effort, however, was devoted to improving silicon germanium alloys by the addition of gallium phosphide, the synthesis and evaluation of lanthanum chrome sulfide and the formulation of various mixtures of lanthanum sulfide and chrome sulfide. It is found that each of these materials exhibits promise as a thermoelectric material.

Co-electrodeposition of hard Ni-W/diamond nanocomposite coatings

PubMed Central

Zhang, Xinyu; Qin, Jiaqian; Das, Malay Kumar; Hao, Ruru; Zhong, Hua; Thueploy, Adisak; Limpanart, Sarintorn; Boonyongmaneerat, Yuttanant; Ma, Mingzhen; Liu, Riping

2016-01-01

Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings. PMID:26924136

[Evaluation of bond strength between low fusing porcelain with goldplated cobalt-chromium alloys].

PubMed

Guo, Jing; Zhu, Jia; Zhu, Hong-shui

2014-02-01

To evaluate the bond strength of Vita OMEGA 900 low fusing porcelain fused with the goldplated Wirobond cobalt-chrome metalt ceramic alloy. Low fusing porcelain was fused with the cobalt-chromium alloy strips(group A) and the goldplated cobalt-chromium alloy strips(group B) respectively according to ISO9693 (A:8,B:10). 8 specimens of each group were submitted to three point bending test. Two more test pieces fused with gold plated cobalt-chromium alloys were made (group B'). One test piece of both group B and group B' were observed under scanning electron microscope (SEM) randomly. The data was analyzed with SPSS 16.0 software package. The bond strength (MPa) of group A and group B was 29.92±4.28 and 28.20±5.21, respectively (P>0.05), both higher than 25 MPa required by ISO9693. SEM showed that Vita OMEGA 900 low fusing porcelain and the goldplated Wirobond cobalt-chrome metalt ceramic alloy combined together closely without cracks. Much gold was fused to the cobalt-chrome alloy surface of breaking porcelain specimen after testing. Vita OMEGA 900 low fusing porcelain can match with the goldplated Wirobond cobalt-chrome metalt ceramic alloy. Supported by Foundation of Education Department of Jiangxi Province (GJJ10367).

Co-electrodeposition of hard Ni-W/diamond nanocomposite coatings.

PubMed

Zhang, Xinyu; Qin, Jiaqian; Das, Malay Kumar; Hao, Ruru; Zhong, Hua; Thueploy, Adisak; Limpanart, Sarintorn; Boonyongmaneerat, Yuttanant; Ma, Mingzhen; Liu, Riping

2016-02-29

Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.

Co-electrodeposition of hard Ni-W/diamond nanocomposite coatings

NASA Astrophysics Data System (ADS)

Zhang, Xinyu; Qin, Jiaqian; Das, Malay Kumar; Hao, Ruru; Zhong, Hua; Thueploy, Adisak; Limpanart, Sarintorn; Boonyongmaneerat, Yuttanant; Ma, Mingzhen; Liu, Riping

2016-02-01

Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.

Laboratory scale studies on removal of chromium from industrial wastes.

PubMed

Baig, M A; Mir, Mohsin; Murtaza, Shazad; Bhatti, Zafar I

2003-05-01

Chromium being one of the major toxic pollutants is discharged from electroplating and chrome tanning processes and is also found in the effluents of dyes, paint pigments, manufacturing units etc. Chromium exists in aqueous systems in both trivalent (Cr(3+)) and hexavalent (Cr(6+)) forms. The hexavalent form is carcinogenic and toxic to aquatic life, whereas Cr(3+) is however comparatively less toxic. This study was undertaken to investigate the total chromium removal from industrial effluents by chemical means in order to achieve the Pakistan NEQS level of 1 mg/L by the methods of reduction and precipitation. The study was conducted in four phases. In phase I, the optimum pH and cost effective reducing agent among the four popular commercial chemicals was selected. As a result, pH of 2 was found to be most suitable and sodium meta bisulfate was found to be the most cost effective reducing agent respectively. Phase II showed that lower dose of sodium meta bisulfate was sufficient to obtain 100% efficiency in reducing Cr(6+) to Cr(3+), and it was noted that reaction time had no significance in the whole process. A design curve for reduction process was established which can act as a tool for treatment of industrial effluents. Phase III studies indicated the best pH was 8.5 for precipitation of Cr(3+) to chromium hydroxide by using lime. An efficiency of 100% was achievable and a settling time of 30 minutes produced clear effluent. Finally in Phase IV actual waste samples from chrome tanning and electroplating industries, when precipitated at pH of 12 gave 100% efficiency at a settling time of 30 minutes and confined that chemical means of reduction and precipitation is a feasible and viable solution for treating chromium wastes from industries.

Improvement of the Corrosion Resistance of Turbine Engine Bearings

DTIC Science & Technology

1986-04-01

high chrome martensitic steels . Studies conducted in the past several years (References 6 and 7) have shown that high-chrome stainless steels ...qualification procedures required for production use of powder metallurgy bearings may exceed the 3- to 5-year introduction goal. Another stainless steel ...addition, these alloys are commercially available in wrought form as is the currently used VIM-VAR M50. A common high car!.on stainless steel , AISI 440C is

Chrome - Free Aluminum Coating System

NASA Technical Reports Server (NTRS)

Bailey, John H.; Gugel, Jeffrey D.

2010-01-01

This slide presentation concerns the program to qualify a chrome free coating for aluminum. The program was required due to findings by OSHA and EPA, that hexavalent chromium, used to mitigate corrosion in aerospace aluminum alloys, poses hazards for personnel. This qualification consisted of over 4,000 tests. The tests revealed that a move away from Cr+6, required a system rather than individual components and that the maximum corrosion protection required pretreatment, primer and topcoat.

High pressure oxygen furnace

DOEpatents

Morris, D.E.

1992-07-14

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized, the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 5 figs.

High pressure oxygen furnace

DOEpatents

Morris, Donald E.

1992-01-01

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

High pressure furnace

DOEpatents

Morris, D.E.

1993-09-14

A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum)). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 19 figures.

NASA TEERM Hexavalent Chrome Alternatives Projects

NASA Technical Reports Server (NTRS)

Kessel, Kurt; Rothgeb, Matt

2011-01-01

This slide presentation reviews the NASA project to select an alternative to hexavalent chrome in the aerospace industry. Included is a recent historic testing and research that the Agency has performed on (1) the external tank, (2) the shuttle orbiter, (3) the Shuttle Rocket Booster, and (4) the Space Shuttle Main Engine. Other related Technology Evaluation for Environmental Risk Mitigation (TEERM) projects are reviewed. The Phase I process of the project performed testing of alternatives the results are shown in a chart for different coating systems. International collaboration was also reviewed. Phase II involves further testing of pretreatment and primers for 6 and 12 months of exposure to conditions at Launch Pad and the beach. Further test were performed to characterize the life cycle corrosion of the space vehicles. A new task is described as a joint project with the Department of Defense to identify a Hex Chrome Free Coatings for Electronics.

An Analysis of Army Hazardous Waste Disposal Cost Data

DTIC Science & Technology

1991-04-01

be contaminated with gl EP Toxic (but not limited to) chromium 2133 Sludge, may be contaminated with (but not lb EP Toxic limited to) trivalent ...limited to) trivalent chrome, cadmium, heavy metals and metals continued - ’kg = kilograms 18 Table 6 (Cont’d) CLIN Supplies/Services CLIN (kg) % of...2.0 0600 Compressed gas cylinders, misc. 81,566 1.8 2133 Sludge, may be contaminated with (but not 78,000 1.7 limited to) trivalent chrome, cadmium

Influences of the current density on the performances of the chrome-plated layer in deterministic electroplating repair

NASA Astrophysics Data System (ADS)

Xia, H.; Shen, X. M.; Yang, X. C.; Xiong, Y.; Jiang, G. L.

2018-01-01

Deterministic electroplating repair is a novel method for rapidly repairing the attrited parts. By the qualitative contrast and quantitative comparison, influences of the current density on performances of the chrome-plated layer were concluded in this study. The chrome-plated layers were fabricated under different current densities when the other parameters were kept constant. Hardnesses, thicknesses and components, surface morphologies and roughnesses, and wearability of the chrome-plated layers were detected by the Vickers hardness tester, scanning electron microscope / energy dispersive X-ray detector, digital microscope in the 3D imaging mode, and the ball-milling instrument with profilograph, respectively. In order to scientifically evaluate each factor, the experimental data was normalized. A comprehensive evaluation model was founded to quantitative analyse influence of the current density based on analytic hierarchy process method and the weighted evaluation method. The calculated comprehensive evaluation indexes corresponding to current density of 40A/dm2, 45A/dm2, 50A/dm2, 55A/dm2, 60A/dm2, and 65A/dm2 were 0.2246, 0.4850, 0.4799, 0.4922, 0.8672, and 0.1381, respectively. Experimental results indicate that final optimal option was 60A/dm2, and the priority orders were 60A/dm2, 55A/dm2, 45A/dm2, 50A/dm2, 40A/dm2, and 65A/dm2.

PIXE analysis of mineral matter in thin sections of human lung

NASA Astrophysics Data System (ADS)

Annegarn, H. J.; Pillay, A. E.; Da Vies, J. C. A.; Faure, D.; Sellschop, J. P. F.

1988-12-01

It is postulated that insoluble mineral residues in the lungs of deceased miners may provide a quantitative measure of the integrated lifetime dust exposure. For epidemiological surveys rapid instrumental techniques are required to analyse representative samples of lung tissue. Particle-induced X-ray emission (PIXE) has been evaluated for analysis of microtomed slices of wax-embedded lung and lymph node (Hilar gland) tissue from deceased miners. The 50 μm slices, mounted on Mylar backings and placed in a He atmosphere, were irradiated using 3.2 MeV protons. PIXE analysis provided adequate sensitivity for key mineral elements including Si, Cr and Ti. The porous, nonuniform nature of lung tissue made it impossible to measure the tissue mass in the irradiated area, preventing the calculation of mass concentrations. Instead, biological sulphur was used as an internal standard, assuming that the fraction of S in soft, fat-free tissue is constant. Results are presented for lung and lymph node tissue from gold, chrome, copper, platinum and asbestos miners. Si mineral residues in lymph node tissue were found to be concentrated by a factor 50 relative to lung. Cr residues were clearly observed in the chrome miner's lung, but no excess of Cu was present in the copper miner's lung. There is evidence of preferential Si removal relative to Ti. Results warrant further development of PIXE for scanning of large numbers of lung samples prepared in the above manner.

Strengthening DoD Cyber Security with the Vulnerability Market

DTIC Science & Technology

2014-01-01

50,000 – $100,000 Windows $60,000 – $120,000 Firefox or Safari $60,000 – $150,000 Chrome or Internet Explorer $80,000 – $200,000 iOS $100,000...the CTB metric for the Google Chrome OS at $110,000. Accordingly, this metric could be used by Google to compare its security to other operating...Mozilla Foundation. (n.d.). Mozilla. Retrieved from https://www.mozilla. org/en-US/foundation/ Thomson, I. (2013, March 8). Pwn2Own: IE10, Firefox

Nanoscale investigation of the degradation mechanism of a historical chrome yellow paint by quantitative electron energy loss spectroscopy mapping of chromium species.

PubMed

Tan, Haiyan; Tian, He; Verbeeck, Jo; Monico, Letizia; Janssens, Koen; Van Tendeloo, Gustaaf

2013-10-18

Getting the picture: The investigation of 100 year old chrome yellow paint by transmission electron microscopy and spectroscopy has led to the identification of four types of core-shell particles. This nanoscale investigation has allowed a mechanism to be proposed for the darkening of some bright yellow colors in Van Gogh's paintings (e.g. in Falling leaves (Les Alyscamps), 1888). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Special Advanced Studies for Pollution Prevention. Delivery Order 0046: Advanced Studies in Pollution Prevention Chrome Replacements for Internal and Small Parts

DTIC Science & Technology

1999-01-01

Control Conference Proceedings, Orlando (1997), p 143. 5 US Patent # 5,196,109 (1993): " Trivalent chromium electrolytes and plating processes...Summary -Electroplating 7.1. Introduction 7.2. Process Description 7.2.1 Trivalent chrome plating 7.2.2. Composite electroplating 7.2.3. Alloy...requirements of chromium without the environmental and health hazards associated with chromic acid. Ideally, the process would not use any EPA 17

The influence of activating agents on the performance of rice husk-based carbon for sodium lauryl sulfate and chrome (Cr) metal adsorptions

NASA Astrophysics Data System (ADS)

Arneli; Safitri, Z. F.; Pangestika, A. W.; Fauziah, F.; Wahyuningrum, V. N.; Astuti, Y.

2017-02-01

This research aims to study the influence of activating agents to produce rice husk based-carbon with high adsorption capacity and efficiency for either hazardous organic molecules or heavy metals which are unfriendly for the environment. Firstly, rice husk was burned by pyrolysis at different temperatures to produce rice husk-based carbon. To improve its ability as an adsorbent, carbon was treated with activating agents, namely, H3PO4 and KOH at room and high temperature (420 °C). The performance of carbon was then tested by contacting it with surfactant (SLS). Finally, the surfactant-modified active carbon was applied for chrome metal removal. The result shows that activation of carbon using phosphate acid (H3PO4) was more effective than potassium hydroxide (KOH) conducted at high temperature to adsorb sodium lauryl sulfate (SLS) and chrome metal with the adsorption capacity 1.50 mgg-1 and 0.375 mgg-1, respectively.

Mechanisms of Zn(II) binded to collagen and its effect on the capacity of eco-friendly Zn-Cr combination tanning system.

PubMed

Cao, Shan; Liu, Bing; Cheng, Baozhen; Lu, Fuping; Wang, Yanping; Li, Yu

2017-01-05

The eco-friendly combination tanning process has been developed to reduce chromium in existing researches, which is based on zinc tanning agents. This can be considered as a less-chrome substitute for current tanning process. To gain deeper understanding of the binding mechanisms of zinc-collagen interaction, which are affected by tanning pH, experiments have been carried out. Analysis in this paper reveals how chemical bonds from the collagen's main function groups combine with zinc. XPS and NIR data was analyzed for further understanding of where the zinc binding sites lie on collagen fibers at different pH. The results indicate that high pH is helpful to amino-binding sites while low pH promotes carboxyl-binding sites on collagen fibers. Furthermore, from the effect of Zinc-chrome combination tanning, we can see that the new method reduces the chromium dosage in tanning process compared to the conventional chrome tanning method. Copyright © 2016 Elsevier B.V. All rights reserved.

Metal ion release from silver soldering and laser welding caused by different types of mouthwash.

PubMed

Erdogan, Ayse Tuygun; Nalbantgil, Didem; Ulkur, Feyza; Sahin, Fikrettin

2015-07-01

To compare metal ion release from samples welded with silver soldering and laser welding when immersed into mouthwashes with different ingredients. A total of 72 samples were prepared: 36 laser welded and 36 silver soldered. Four samples were chosen from each subgroup to study the morphologic changes on their surfaces via scanning electron microscopy (SEM). Each group was further divided into four groups where the samples were submerged into mouthwash containing sodium fluoride (NaF), mouthwash containing sodium fluoride + alcohol (NaF + alcohol), mouthwash containing chlorhexidine (CHX), or artificial saliva (AS) for 24 hours and removed thereafter. Subsequently, the metal ion release from the samples was measured with inductively coupled plasma mass spectrometry (ICP-MS). The metal ion release among the solutions and the welding methods were compared. The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for the group comparisons, and post hoc Dunn multiple comparison test was utilized for the two group comparisons. The level of metal ion release from samples of silver soldering was higher than from samples of laser welding. Furthermore, greater amounts of nickel, chrome, and iron were released from silver soldering. With regard to the mouthwash solutions, the lowest amounts of metal ions were released in CHX, and the highest amounts of metal ions were released in NaF + alcohol. SEM images were in accord with these findings. The laser welding should be preferred over silver soldering. CHX can be recommended for patients who have welded appliances for orthodontic reasons.

Edge effects in phase-shifting masks for 0.25-µm lithography

NASA Astrophysics Data System (ADS)

Wong, Alfred K. K.; Neureuther, Andrew R.

1993-03-01

The impact on image quality of scattering from phase-shifter edges and of interactions between phase-shifter and chrome edges is assessed using rigorous electromagnetic simulation. Effects of edge taper in phase-shift masks, spacing between phase-shifter and chrome edges, small outrigger features with a trench phase-shifter, and of the repair of phase defects by etching to 360 degree(s) are considered. Near field distributions and diffraction efficiencies are examined and images are compared with more approximate results from the commonly used Hopkins' theory of imaging.

Monitoring of cellular enzymes in the serum of electroplating workers at Coimbatore.

PubMed

Saraswathy, C P; Usharani, M V

2007-04-01

Chromium compounds are potent toxic and carcinogenic substances. With respect to toxicity, hepatic and renal toxicity have been reported both in workers and in animals exposed to chromium (VI). Chromium (VI) compounds induces DNA damage in vivo and in cultured cells as well as the cytotoxicity evaluated by the leakage of lactate dehydrogenase. The present study reports the cytotoxicity of chrome platers who are employed from 8 to 25 years in electroplating industries at Coimbatore, Tamilnadu. Blood samples were collected and estimated for glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and total protein in the serum. The study revealed that there is a significant elevation in the level of LDH, ALP, CPK and transaminases and a decrease in total protein in serum. The results of the study suggests that chromium (VI), a hepatotoxic chemical may perhaps damage the plasma membrane resulting in leakage of enzymes in to the serum of chromeplaters.

Characterization of cinematographic films by Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Gaspard, S.; Oujja, M.; Rebollar, E.; Abrusci, C.; Catalina, F.; Castillejo, M.

2007-12-01

The emulsion-coated transparent plastic-base film has been the main carrier for production and preservation of motion picture contents since the 19th century. The knowledge of the composition of black and white silver gelatine cinematographic films is of great importance for the characterization of the photographic process and for identifying the optimum conditions for conservation. A cinematographic film is a multi-component system that consists of a layer of photographic emulsion overcoating a polymeric support (plasticized cellulose triacetate) and a protective transparent cross-linked gelatine layer coating the emulsion. In the present work, Laser Induced Breakdown Spectroscopy (LIBS) is used to characterize the composition of the materials of cinematographic films. LIB spectra of film samples and of different individual film components, polymeric support and reference gelatines, were acquired in vacuum by excitation at 266 nm (Q-switched Nd:YAG laser, 6 ns, 10 Hz). In the cinematographic film, silver lines from the light-sensitive silver halide salts of the photographic emulsion are accompanied by iron, lead, chrome and phosphorus lines. Iron and lead are constituents of film developers, chrome is included in the composition of the hardening agents and phosphorus has its origin in the plasticizer used in the polymeric support. By applying successive pulses on the same spot of the film sample, it was possible to observe through stratigraphic analysis the different layers composition. Additionally, the results obtained reveal the analytical capacity of LIBS for the study and classification of the different gelatine types and qualities used for the protecting layer and the photographic emulsion.

[The study of the colorimetric characteristics of the cobalt-chrome alloys abutments covered by four different all-ceramic crowns by using dental spectrophotometer].

PubMed

Chen, Yifan; Liu, Hongchun; Meng, Yukun; Chao, Yonglie; Liu, Changhong

2015-06-01

This study aims to evaluate the optical data of the different sites of the cobalt-chrome (Co-Cr) alloy abutments covered by four different all-ceramic crowns and the color difference between the crowns and target tab using a digital dental spectrophotometer. Ten Co-Cr alloy abutments were made and tried in four different groups of all-ceramic crowns, namely, Procera aluminia, Procera zirconia, Lava zirconia (Lava-Zir), and IPS E.max glass-ceramic lithium disilicate-reinforced monolithic. The color data of the cervical, body, and incisal sites of the samples were recorded and analyzed by dental spectrophotometer. The CIE L*, a*, b* values were again measured after veneering. The color difference between the abutments covered by all-ceramic crowns and A2 dentine shade tab was evaluated. The L* and b* values of the abutments can be increased by all of the four groups of all-ceramic copings, but a* values were decreased in most groups. A statistical difference was observed among four groups. After being veneered, the L* values of all the copings declined slightly, and the values of a*, b* increased significantly. When compared with A2 dentine shade tab, the ΔE of the crowns was below 4. Four ceramic copings were demonstrated to promote the lightness and hue of the alloy abutments effecttively. Though the colorimetric baseline of these copings was uneven, veneer porcelain can efficiently decrease the color difference between the samples and thee target.

Study on Movable gel Profiling/Flooding System Optimization at Boundary Temperature

NASA Astrophysics Data System (ADS)

Gao, Shanshan; Xie, Gang; Zhang, Tiantian; Wang, Zhiqiang; Jiang, Peijun; Wei, Junjie; Gu, Yi; Lei, Xiaoyang; Guo, Suzhen; Lei, Shi

2017-12-01

65-75°C is the boundary temperature of phenol-formaldehyde resin and organic chrome crosslink with HPAM to generate movable gel. Generally speaking, when the reservoir temperature is below 65-75°C, the crosslinking agent is Organic chrome. Phenol-formaldehyde resin is used when the temperature is above 65-75°C. In this paper the gelation properties of phenol-formaldehyde resin and organic chrome were compared at 70°C. The experiment results showed that the crosslinking time of phenol-formaldehyde resin gel was longer and more conducive to field injection. In addition the phenol-formaldehyde resin gel had greater viscosity, adhesion and shearing resistance compared with the organic chrome gel. So the phenol-formaldehyde resin was chosen for further optimization. The crosslinking time was shortened and the gel viscosity increased with the increase of the polymer concentration. As the polymer crosslinker proportion increased The crosslinking time was shortened and the gel viscosity increased first and then decreased. Reinforcer NC and stabilizer WG were added to improve the temperature and salt tolerance of the gel. The gel formula suitable for the boundary temperature was obtained. The optimum polymer concentration is 1200mg/L, the polymer crosslinker proportion is 1:1.1, the best reinforcer concentration is 400mg/L and the concentration of the stabilizer is 150mg/L. The crosslinking time is 31h, the gel viscosity is above 2100mPa·s. The gel did not shrink and no water separation was observed at 70°C for 150 days. The viscosity retention rate was more than 70%.

Halloysite nanotubule clay for efficient water purification.

PubMed

Zhao, Yafei; Abdullayev, Elshad; Vasiliev, Alexandre; Lvov, Yuri

2013-09-15

Halloysite clay has chemical structure similar to kaolinite but it is rolled in tubes with diameter of 50 nm and length of ca. 1000 nm. Halloysite exhibits higher adsorption capacity for both cationic and anionic dyes because it has negative SiO2 outermost and positive Al2O3 inner lumen surface; therefore, these clay nanotubes have efficient bivalent adsorbancy. An adsorption study using cationic Rhodamine 6G and anionic Chrome azurol S has shown approximately two times better dye removal for halloysite as compared to kaolin. Halloysite filters have been effectively regenerated up to 50 times by burning the adsorbed dyes. Overall removal efficiency of anionic Chrome azurol S exceeded 99.9% for 5th regeneration cycle of halloysite. Chrome azurol S adsorption capacity decreases with the increase of ionic strength, temperature and pH. For cationic Rhodamine 6G, higher ionic strength, temperature and initial solution concentration were favorable to enhanced adsorption with optimal pH 8. The equilibrium adsorption data were described by Langmuir and Freundlich isotherms. Copyright © 2013 Elsevier Inc. All rights reserved.

Occupational exposure to chrome VI compounds in French companies: results of a national campaign to measure exposure (2010-2013).

PubMed

Vincent, Raymond; Gillet, Martine; Goutet, Pierre; Guichard, Christine; Hédouin-Langlet, Catherine; Frocaut, Anne Marie; Lambert, Pierre; Leray, Fabrice; Mardelle, Patricia; Dorotte, Michel; Rousset, Davy

2015-01-01

A campaign to measure exposure to hexavalent chromium compounds was carried out in France by the seven CARSAT chemistry laboratories, CRAMIF laboratory, and INRS over the 2010-2013 period. The survey included 99 companies involved in various activity sectors. The inhalable fraction of airborne particles was sampled, and exposure levels were determined using ion chromatography analysis combined with post-column derivatization and UV detection. The quality of the measurement results was guaranteed by an inter-laboratory comparison system involving all the laboratories participating in this study. Exposure levels frequently exceeded the French occupational exposure limit value (OELV) of 1 µg m(-3), in activities such as thermal metallization and manufacturing and application of paint in the aeronautics sector. The results also reveal a general trend for a greater proportion of soluble Chromium VI (Cr VI) compounds compared with insoluble compounds. Qualitative and quantitative information relating to the presence of other metallic compounds in the air of workplaces is also provided, for example for Cr III, Ni, Fe, etc. The sampling strategy used and the measurement method are easy to implement, making it possible to check occupational exposure with a view to comparing it to an 8 h-OELV of 1 µg m(-3). © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Investigation of Plasma Spray Coatings as an Alternative to Hard Chrome Plating on Internal Surfaces

DTIC Science & Technology

2006-06-20

specimens, typically 3 specimens at 5 stress levels, although stresses were chosen to obtain a full curve, with runout defined as 107 cycles. Maximum...measured using the ASTM G-65 method of a rubber wheel with dry sand rubbing against the substrate (see Figure 4-27). 100 120 140 160 180 200 220 240...different finishing methods. Silicon carbide, aluminum oxide and diamond grinding wheels were tested for the finishing trials. It was determined by

REACH Compliant Hexavalent Chrome Replacement for Corrosion Protection (HITEA)

DTIC Science & Technology

2014-11-01

3 The Role of the AAD and Materials KTNs • A joint AAD and Materials KTN workshop in 2011 resulted in: - Definition of the hexavalent chromium ...Alloy Nimonic alloy Hard chrome plating x x x TiN x x CrN x x DLC x WC/C x x x PEO x x Co-P x x x x x x Trivalent Cr x x x x x x Filled ENP x x 8...aims to establish a fast, inexpensive and robust testing methodology for selecting the most promising chromium -free alternatives. • Creation of a

ET Toxic Metals Replacement Review SEA Spring Face to Face

NASA Technical Reports Server (NTRS)

Pratz, Earl

2007-01-01

The information contained in the presentation covers development work carried out under SDS projects. The intent of the effort is to find chrome(VI) free alternates to our current chromated processing solutions. The information presented reports progress in work aimed to replace our alkaline cleaner (Turco 4215), conversion coat (Iridite 14-2) and chrome (VI) compounds used in LOx tank hydrostatic proof test solution. To date we have found candidates for use in the proof test solution and alkaline cleaner. These candidates are in the final stages of testing. Lab data is reported in the presentation.

Tissue Photolithography

NASA Technical Reports Server (NTRS)

Wade, Lawrence A.; Kartalov, Emil; Shibata, Darryl; Taylor, Clive

2011-01-01

Tissue lithography will enable physicians and researchers to obtain macromolecules with high purity (greater than 90 percent) from desired cells in conventionally processed, clinical tissues by simply annotating the desired cells on a computer screen. After identifying the desired cells, a suitable lithography mask will be generated to protect the contents of the desired cells while allowing destruction of all undesired cells by irradiation with ultraviolet light. The DNA from the protected cells can be used in a number of downstream applications including DNA sequencing. The purity (i.e., macromolecules isolated form specific cell types) of such specimens will greatly enhance the value and information of downstream applications. In this method, the specific cells are isolated on a microscope slide using photolithography, which will be faster, more specific, and less expensive than current methods. It relies on the fact that many biological molecules such as DNA are photosensitive and can be destroyed by ultraviolet irradiation. Therefore, it is possible to protect the contents of desired cells, yet destroy undesired cells. This approach leverages the technologies of the microelectronics industry, which can make features smaller than 1 micrometer with photolithography. A variety of ways has been created to achieve identification of the desired cell, and also to designate the other cells for destruction. This can be accomplished through chrome masks, direct laser writing, and also active masking using dynamic arrays. Image recognition is envisioned as one method for identifying cell nuclei and cell membranes. The pathologist can identify the cells of interest using a microscopic computerized image of the slide, and appropriate custom software. In one of the approaches described in this work, the software converts the selection into a digital mask that can be fed into a direct laser writer, e.g. the Heidelberg DWL66. Such a machine uses a metalized glass plate (with chrome metallization) on which there is a thin layer of photoresist. The laser transfers the digital mask onto the photoresist by direct writing, with typical best resolution of 2 micrometers. The plate is then developed to remove the exposed photoresist, which leaves the exposed areas susceptible to chemical chrome etch. The etch removes the unprotected chrome. The rest of the photoresist is then removed, by either ultraviolet organic solvent or over-development. The remaining chrome pattern is quickly oxidized by atmospheric exposure (typically within 30 seconds). The ready chrome mask is now applied to the tissue slide and aligned manually, or using automatic software and pre-designed alignment marks. The slide plate sandwich is then exposed to UV to destroy the DNA of the unwanted cells. The slide and plate are separated and the slide is processed in a standard way to prepare for polymerase chain reaction (PCR) and potential identification of cancer sequences.

Solution of rocks and refractory minerals by acids at high temperatures and pressures. Determination of silica after decomposition with hydrofluoric acid

USGS Publications Warehouse

May, I.; Rowe, J.J.

1965-01-01

A modified Morey bomb was designed which contains a removable nichromecased 3.5-ml platinium crucible. This bomb is particularly useful for decompositions of refractory samples for micro- and semimicro-analysis. Temperatures of 400-450?? and pressures estimated as great as 6000 p.s.i. were maintained in the bomb for periods as long as 24 h. Complete decompositions of rocks, garnet, beryl, chrysoberyl, phenacite, sapphirine, and kyanite were obtained with hydrofluoric acid or a mixture of hydrofluoric and sulfuric acids; the decomposition of chrome refractory was made with hydrochloric acid. Aluminum-rich samples formed difficultly soluble aluminum fluoride precipitates. Because no volatilization losses occur, silica can be determined on sample solutions by a molybdenum-blue procedure using aluminum(III) to complex interfering fluoride. ?? 1965.

Modelling biological Cr(VI) reduction in aquifer microcosm column systems.

PubMed

Molokwane, Pulane E; Chirwa, Evans M N

2013-01-01

Several chrome processing facilities in South Africa release hexavalent chromium (Cr(VI)) into groundwater resources. Pump-and-treat remediation processes have been implemented at some of the sites but have not been successful in reducing contamination levels. The current study is aimed at developing an environmentally friendly, cost-effective and self-sustained biological method to curb the spread of chromium at the contaminated sites. An indigenous Cr(VI)-reducing mixed culture of bacteria was demonstrated to reduce high levels of Cr(VI) in laboratory samples. The effect of Cr(VI) on the removal rate was evaluated at concentrations up to 400 mg/L. Following the detailed evaluation of fundamental processes for biological Cr(VI) reduction, a predictive model for Cr(VI) breakthrough through aquifer microcosm reactors was developed. The reaction rate in batch followed non-competitive rate kinetics with a Cr(VI) inhibition threshold concentration of approximately 99 mg/L. This study evaluates the application of the kinetic parameters determined in the batch reactors to the continuous flow process. The model developed from advection-reaction rate kinetics in a porous media fitted best the effluent Cr(VI) concentration. The model was also used to elucidate the logistic nature of biomass growth in the reactor systems.

Detection of hazardous pollutants in chrome-tanned leather using locally developed laser-induced breakdown spectrometer.

PubMed

Nasr, M M; Gondal, Mohammed Asharf; Seddigi, Z S

2011-04-01

Highly toxic contaminants like Cr, As, and Pb were detected in chrome-tanning process of animal skin to produce leather by applying locally developed laser-induced breakdown spectrometer. An Nd-YAG laser with 1,064 nm wavelength was focused on the surface of leather samples (natural and manufactured) to generate a plasma spark and spectrally resolved spectra were used for identification and quantification of contaminants. The leather samples were collected from a tannery located in industrial cities of Riyadh and Jeddah, Saudi Arabia. The study was carried out on fully, half manufactured (wet blue leather), and natural hide (skin). To the best of our knowledge, this is the first attempt where laser-induced breakdown spectroscopy (LIBS) technique has been applied for the analysis of leather before and after tanning process. The maximum concentration of different elements of environmental significance like chromium, lead, arsenic, sulfur, magnesium were 199, 289, 31, 38, and 39 ppm, respectively, in one of the manufactured leather samples. The limit of detection (LOD) of our LIBS system for chromium, lead, arsenic, sulfur, and magnesium were 2, 3, 1.5,7, and 3 ppm, respectively. The safe permissible limit for tanned leather for highly toxic elements like chromium, lead, and arsenic are 1, 0.5, 0.01 ppm, respectively, as prescribed in Environmental Regulation Standards for Saudi Industries set by Royal Commission Jubail, Saudi Arabia. The LIBS technique is superior to other conventional techniques like ICP or atomic absorption that a little or no sample preparation is required, no chemicals are needed, multi-elemental analysis is possible for all kinds of samples (natural and anthropogenic materials), microgram of sample is essential, and LIBS could be applied for remote analysis. It is highly selective and sensitivity higher than ICP, and as no sample and chemicals are required, it is cost effective for multi-sample analysis per unit time as compared with other conventional techniques. The concentration of some toxic elements (Cr, Pb, As) is much higher than the safe permissible limits set by Occupational Safety and Health Administration in USA or Saudi environmental regulatory agencies. Results obtained with our LIBS systems were in close agreement with the results obtained using other standard analytical technique such as the inductively coupled plasma atomic emission spectroscopy.

Does the Type of Metal Instrumentation Affect the Risk of Surgical Site Infection in Pediatric Scoliosis Surgery?

PubMed

Wright, Margaret L; Skaggs, David L; Matsumoto, Hiroko; Woon, Regina P; Trocle, Ashley; Flynn, John M; Vitale, Michael G

2016-05-01

Retrospective cohort study. To determine the association of implant metal composition with the risk of surgical site infection (SSI) following pediatric spine surgery. SSI is a well-described complication following pediatric spine surgery. Many risk factors have been identified in the literature, but controversy remains regarding metal composition as a risk factor. This was a retrospective study of patients who underwent posterior spinal instrumentation procedures between January 1, 2006, and December 31, 2008, at three large children's hospitals for any etiology of scoliosis and had at least 1 year of postoperative follow-up. Procedures included posterior spinal fusion, growth-friendly instrumentation, and revision of spinal instrumentation. The Centers for Disease Control and Prevention definition of SSI was used. A chi-squared test was performed to determine the relationship between type of metal instrumentation and development of an SSI. The study included 874 patients who underwent 1,156 total procedures. Overall, 752 (65%) procedures used stainless steel instrumentation, 238 (21%) procedures used titanium instrumentation, and the remaining 166 (14%) procedures used cobalt chrome and titanium hybrid instrumentation. The overall risk of infection was 6.1% (70/1,156) per procedure, with 5.9% (44/752) for stainless steel, 6.7% (12/238) for titanium, and 6.0% (10/166) for cobalt chrome. The multiple regression analysis found no significant differences in the metal type used between patients with and without infection (p = .886) adjusting for etiology, instrumentation to pelvis, and type of procedures. When stratified based on etiology, the multiple regression analyses also found no significant difference in SSI between two metal type groups. This study found no difference in risk of infection with stainless steel, titanium, or cobalt chrome/titanium instrumentation and is adequately powered to detect a true difference in risk of SSI. Level II, prognostic. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

In-Service Evaluation of HVOF Coated Main Landing Gear on Navy P-3 Aircraft

NASA Technical Reports Server (NTRS)

Devereaux, jon L.; Forrest, Clint

2008-01-01

Due to the environmental and health concerns with Electroplated Hard Chrome (EHC), the Hard Chrome Alternatives Team (HCAT) has been working to provide an alternative wear coating for EHC. The US Navy selected Tungsten-Carbide Cobalt (WC- 17Co) High Velocity Oxy-Fuel (HVOF) thermal spray coating for this purpose and completed service evaluations on select aircraft components to support the HCAT charter in identifying an alternative wear coating for chrome plating. Other benefits of WC-Co thermal spray coatings over EHC are enhanced corrosion resistance, improved durability, and exceptional wear properties. As part of the HCAT charter and to evaluate HVOF coatings on operational Navy components, the P-3 aircraft was selected for a service evaluation to determine the coating durability as compared to chrome plating. In April 1999, a VP-30 P-3 aircraft was outfitted with a right-hand Main Landing Gear (MLG) shock strut coated with WCCo HYOF thermal spray applied to the piston barrel and four axle journals. The HVOF coating on the piston barrel and axle journals was applied by Southwest United Industries, Inc. This HVOF coated strut assembly has since completed 6,378 landings. Teardown analysis .for this WC-Co HVOF coated MLG asset is significant in assessing the durability of this wear coating in service relative to EHC and to substantiate Life Cycle Cost (LCC) data to support a retrograde transition from EHC to HVOF thermal spray coatings. Findings from this teardown analysis may also benefit future transitions to HVOF thermal spray coatings by identifying enhancements to finishing techniques, mating bearing and liner material improvements, improved seal materials, and improvements in HVOF coating selection.

Rod stiffness as a risk factor of proximal junctional kyphosis after adult spinal deformity surgery: comparative study between cobalt chrome multiple-rod constructs and titanium alloy two-rod constructs.

PubMed

Han, Sanghyun; Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Lee, Subum; Rhim, Seung-Chul

2017-07-01

Little is known about the effect of rod stiffness as a risk factor of proximal junctional kyphosis (PJK) after adult spinal deformity (ASD) surgery. The aim of this study was to compare radiographic outcomes after the use of cobalt chrome multiple-rod constructs (CoCr MRCs) and titanium alloy two-rod constructs (Ti TRCs) for ASD surgery with a minimum 1-year follow-up. Retrospective case-control study in two institutes. We included 54 patients who underwent ASD surgery with fusion to the sacrum in two academic institutes between 2002 and 2015. Radiographic outcomes were measured on the standing lateral radiographs before surgery, 1 month postoperatively, and at ultimate follow-up. The outcome measures were composed of pre- and postoperative sagittal vertical axis (SVA), pre- and postoperative lumbar lordosis (LL), pre- and postoperative thoracic kyphosis (TK)+LL+pelvic incidence (PI), pre- and postoperative PI minus LL, level of uppermost instrumented vertebra (UIV), evaluation of fusion after surgery, the presence of PJK, and the occurrence of rod fracture. We reviewed the medical records of 54 patients who underwent ASD surgery. Of these, 20 patients had CoCr MRC and 34 patients had Ti TRC. Baseline data and radiographic measurements were compared between the two groups. The Mann-Whitney U test, the chi-square test, and the Fisher exact test were used to compare outcomes between the groups. The patients of the groups were similar in terms of age, gender, diagnosis, number of three-column osteotomy, levels fused, bone mineral density, preoperative TK, pre- and postoperative TK+LL+PI, SVA difference, LL change, pre- and postoperative PI minus LL, and location of UIV (upper or lower thoracic level). However, there were significant differences in the occurrence of PJK and rod breakage (PJK: CoCr MRC: 12 [60%] vs. Ti TRC: 9 [26.5%], p=.015; occurrence of rod breakage: CoCr MRC: 0 [0%] vs. Ti TRC: 11 [32.4%], p=.004). The time of PJK was less than 12 months after surgery in the CoCr MRC group. However, 55.5% (5/9) of PJK developed over 12 months after surgery in the Ti TRC group. Increasing the rod stiffness by the use of cobalt chrome rod and can prevent rod breakage but adversely affects the occurrence and the time of PJK. Copyright © 2017 Elsevier Inc. All rights reserved.

Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

PubMed

Przepiórkowska, A; Chrońska, K; Zaborski, M

2007-03-06

The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work.

NASA TEERM Hexavalent Chrome Alternatives Projects

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.; Rothgeb, Matthew

2011-01-01

The overall objective of the Hex Chrome Free Coatings for Electronics project is to evaluate and test pretreatment coating systems not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders. The technical stakeholders have agreed that this protocol will focus specifically on Class 3 coatings. Original Equipment Manufacturers (OEMs), depots, and support contractors have to be prepared to deal with an electronics supply chain that increasingly provides parts with lead-free finishes, some labeled no differently and intermingled with their SnPb counterparts. Allowance of lead-free components presents one of the greatest risks to the reliability of military and aerospace electronics. The introduction of components with lead-free terminations, termination finishes, or circuit boards presents a host of concerns to customers, suppliers, and maintainers of aerospace and military electronic systems such as: 1. Electrical shorting due to tin whiskers 2. Incompatibility of lead-free processes and parameters (including higher melting points of lead-free alloys) with other materials in the system 3. Unknown material properties and incompatibilities that could reduce solder joint reliability

The effect of chrome adhesion layer on quartz resonator aging.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wessendorf, Kurt O.; Ohlhausen, James Anthony

2011-03-01

This SAND report documents a late start LDRD designed to determine the possible aging effects of a quartz resonator gold adhesion layer. Sandia uses quartz resonators for applications. These applications require a very stable frequency source with excellent aging (low drift) characteristics. These parts are manufactured by one of our qualified vendors outside Sandia Laboratories, Statek Corp. Over the years we, Sandia and the vendor, have seen aging variations that have not been completely explained by the typical mechanisms known in the industry. One theory was that the resonator metallization may be contributing to the resonator aging. This LDRD wouldmore » allow us to test and analyze a group of resonators with known differentiating metallization and via accelerated aging determine if a chrome adhesion layer used to accept the final gold plating may contribute to poor aging. We worked with our main vendor to design and manufacture a set of quartz resonators with a wide range of metallization thickness ratios between the chrome and gold that will allow us determine the cause of this aging and which plating thickness ratios provide the best aging performance while not degrading other key characteristics.« less

Kinetic model of the thermal pyrolysis of chrome tanned leather treated with NaOH under different conditions using thermogravimetric analysis.

PubMed

Bañón, E; Marcilla, A; García, A N; Martínez, P; León, M

2016-02-01

The thermal decomposition of chrome tanned leather before and after a soaking treatment with NaOH was studied using thermogravimetric analysis (TGA). The effect of the solution concentration (0.2M and 0.5M) and the soaking time (5min and 15min) was evaluated. TGA experiments at four heating rates (5, 10, 15 and 20°Cmin(-1)) were run in a nitrogen atmosphere for every treatment condition. A kinetic model was developed considering the effect of the three variables studied, i.e.: the NaOH solution concentration, the soaking time and the heating rate. The proposed model for chrome tanned leather pyrolysis involves a set of four reactions, i.e.: three independent nth order reactions, yielding the corresponding products and one of them undergoing a successive cero order reaction. The model was successfully applied simultaneously to all the experimental data obtained. The evaluation of the kinetic parameters obtained (activation energy, pre-exponential factor and reaction order) allowed a better understanding of the effect of the alkali treatment on these wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental study of the complex resistivity and dielectric constant of chrome-contaminated soil

NASA Astrophysics Data System (ADS)

Liu, Haorui; Yang, Heli; Yi, Fengyan

2016-08-01

Heavy metals such as arsenic and chromium often contaminate soils near industrialized areas. Soil samples, made with different water content and chromate pollutant concentrations, are often needed to test soil quality. Because complex resistivity and complex dielectric characteristics of these samples need to be measured, the relationship between these measurement results and chromium concentration as well as water content was studied. Based on soil sample observations, the amplitude of the sample complex resistivity decreased with an increase of contamination concentration and water content. The phase of complex resistivity takes on a tendency of initially decrease, and then increase with the increasing of contamination concentration and water content. For a soil sample with the same resistivity, the higher the amplitude of complex resistivity, the lower the water content and the higher the contamination concentration. The real and imaginary parts of the complex dielectric constant increase with an increase in contamination concentration and water content. Note that resistivity and complex resistivity methods are necessary to adequately evaluate pollution at various sites.

Contaminants in landfill soils - Reliability of prefeasibility studies.

PubMed

Hölzle, Ingo

2017-05-01

Recent landfill mining studies have researched the potential for resource recovery using samples from core drilling or grab cranes. However, most studies used small sample numbers, which may not represent the heterogeneous landfill composition. As a consequence, there exists a high risk of an incorrect economic and/or ecological evaluation. The main objective of this work is to investigate the possibilities and limitations of preliminary investigations concerning the crucial soil composition. The preliminary samples of landfill investigations were compared to the excavation samples from three completely excavated landfills in Germany. In addition, the research compared the reliability of prediction of the two investigation methods, core drilling and grab crane. Sampling using a grab crane led to better results, even for smaller investigations of 10 samples. Analyses of both methods showed sufficiently accurate results to make predictions (standard error 5%, level of confidence 95%) for most heavy metals, cyanide and PAH in the dry substance and for sulphate, barium, Benzo[a]pyrene, pH and the electrical conductivity in leachate analyses of soil type waste. While chrome and nickel showed less accurate results, the concentrations of hydrocarbons, TOC, DOC, PCB and fluorine (leachate) were not predictable even for sample numbers of up to 59. Overestimations of pollutant concentrations were more frequently apparent in drilling, and underestimations when using a grab crane. The dispersion of the element and elemental composition had no direct impact on the reliability of prediction. Thus, an individual consideration of the particular element or elemental composition for dry substance and leachate analyses is recommended to adapt the sample strategy and calculate an optimum sample number. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel co-culture model of murine K12 osteosarcoma cells and S. aureus on common orthopedic implant materials: 'the race to the surface' studied in vitro.

PubMed

McConda, David B; Karnes, Jonathan M; Hamza, Therwa; Lindsey, Brock A

2016-07-01

Infection is a major cause of orthopedic implant failure. There are few studies assessing both tissue cell and bacterial adherence on common orthopedic implant materials in a co-culture environment. An in vitro co-culture model was created using K12 osteosarcoma cells and Staphylococcus aureus in a medium incubated over metal disks for 48 h. The results showed that, in the presence of S. aureus, there were fewer osteosarcoma cells attached to the disks for all substrata tested. There were significantly more osteosarcoma cells adhering to the cobalt chrome than the stainless steel and titanium disks. Overall, in the presence of osteosarcoma cells, there were more bacteria adhering to the disks for all the substrata tested, with significantly more bacteria adhering to the stainless steel disks compared to cobalt chrome and titanium disks. Scanning electron microscopy verified that osteosarcoma cells and bacteria were adherent to the metal disks after incubation for 48 h. Furthermore, the observation that more bacteria were in the co-culture than in the control sample suggests that the osteosarcoma cells serve as a nutrient source for the bacteria. Future models assessing the interaction of osteogenic cells with bacteria on a substratum would be improved if the model accounted for the role of the immune system in secondary bone healing.

[Influence of repeated sintering on the color of two brands of porcelain-fused-to-titanium].

PubMed

Shu, Cheng-jun; Luo, Xiao-ping; Wu, Lie

2007-08-01

To investigate the influence of repeated sintering on the color of two porcelain-fused-to-titanium, and the differences between the two porcelains. Thirty samples were prepared and sintered for 9 times. The color of samples were measured following sintering 1, 3, 5, 7, 9 times by ShadeEye NCC colorimeter according to two brands of porcelains with CIE1976L*a*b* color system, and calculated relevant chrome, chromatism and hue, and statistical analysis. When two brands of porcelains were sintered 5 times, the color parameters had no significant change and sintered continuely, the color parameters of L* and a* had obvious changes, but can't be observed by eyes. The color parameters of titanium-porcelains have no significant change after repeated sintering.

Performance and applications of GaAs:Cr-based Medipix detector in X-ray CT

NASA Astrophysics Data System (ADS)

Kozhevnikov, D.; Chelkov, G.; Demichev, M.; Gridin, A.; Smolyanskiy, P.; Zhemchugov, A.

2017-01-01

In the recent years, the method of single photon counting X-ray μ-CT is being actively developed and applied in various fields. Results of our studies carried out using the MARS μ-CT scanner equipped with GaAs Medipix-based camera are presented. The procedure of mechanical alignment of the scanner is described, including direct and indirect measurements of the spatial resolution. The software chain for data processing and reconstruction has been developed and reported. We demonstrate the possibility to apply the scanner for research in geology and medicine and provide demo images of geological samples (chrome spinellids, titanium magnetite ore) and medical samples (atherosclerotic plaque, abdominal aortic aneurysm). The first results of multi-energy scans using GaAs:Cr-based camera are shown.

Bushfires and tank rainwater quality: a cause for concern?

PubMed

Spinks, Jean; Phillips, Suzanne; Robinson, Priscilla; Van Buynder, Paul

2006-03-01

In early 2003, after a prolonged drought period, extensive bushfires occurred in the east of Victoria affecting 1.5 million hectares of land. At the time, smoke and ash from bushfires, settling on roofs, contained pollutants that could potentially contaminate rainwater collected and stored in tanks for domestic use. The major concerns include polycyclic aromatic hydrocarbons (PAHs) from incomplete combustion of organic matter and arsenic from burnt copper chrome arsenate (CCA) treated wood. An increase in microbial contamination through altered nutrient levels was also hypothesised. A pilot study of 49 rainwater tank owners was undertaken in north-east Victoria. A rainwater tank sample was taken and analysed for a variety of parameters including organic compounds, microbiological indicators, metals, nutrients and physico-chemical parameters. A survey was administered concurrently. A number of results were outside the Australian Drinking Water Guideline (ADWG) values for metals and microbiological indicator organisms, but not for any tested organic compounds. PAHs and arsenic are unlikely to be elevated in rainwater tanks as a result of bushfires, but cadmium may be of concern.

[Clinical evaluation of the ceramic femoral component used for reconstruction of total knee replacement].

PubMed

Vavrík, P; Landor, I; Denk, F

2008-12-01

The study evaluates mid-term results of total knee replacement with a zirconia ceramic (ZrO2) femoral component. The evaluated group comprised 20 knees in 19 patients (4 men and 15 women). In one patient the replacement was performed bilaterally. Two patients had in the contralateral knee the same type of prosthesis with a femoral chrome-cobalt component.The mean age at the time of operation was 65.2 years (range, 38-81 years).The primary indication was 14 times osteoarthritis and 5 times rheumatoid arthritis. The average follow-up period was 6.5 years (range, 2.1-8.5 years). Patients included in the study regardless of age, body mass and the basic diagnosis, agreed with the use of the ceramic femoral component. The evaluation covered a range of motion, mechanical axis, joint stability, pain, swelling, ability to walk on level ground and on stairs, subjective satisfaction (EULAR Knee Chart). Radiograph were assessed at one year intervals in two projections to identify the incidence of radiolucency around the implant. The Kaplan-Meier survival curve was used and compared with the survival curve in identical chrome-cobalt implants. At he final follow-up, 14 knees were evaluated, because 3 patients died without any connection with the implant, in one case the tibial component migrated due to necrosis of the tibial condyle in a patient with RA and two implants had to be revised and replaced due to polyethylene wear. No infection or negative tissue reaction was recorded in the evaluated group. The average flexion range was 109 degrees. All knees were stable and without swelling, in two cases there occurred slight femoropatellar pain. Twelve patients were fully satisfied, 2 patients were satisfied with a certain reservation. The differences in the course of the survival curves of chrome-cobalt and ceramic implants were statistically insignificant. Although the use of zirconia ceramics in vitro reduces the amount of polyethylene wear, the clinical outcomes of total knee replacements as compared to the hip are not convincing. One of the causes may be the substantially different and more complex biomechanics of the knee. Tribology improvement of the femoral ceramic component cannot compensate the deficiencies in the joint balancing in flexion and extension. The economically and technologically demanding production of these implants may be justified in patients with allergies caused by chrome-cobalt components. The results of mid-term follow-up of the use of zirconia ceramic femoral components proved no impact on the improvement of the period of survival of the knee implant. No adverse response to the material or mechanical failure of the ceramic components was encountered. Key words: total knee replacement, zirconia ceramic femoral component, TKR mid-term results, ceramic knee survival curve.

Cobalt Chrome Spinal Constructs Trigger Airport Security Screening in 24% of Pediatric Patients.

PubMed

Woon, Regina P; Andras, Lindsay M; Barrett, Kody K; Skaggs, David L

2015-03-01

Retrospective study. To determine whether pediatric patients undergo additional airport security screening after posterior spinal fusion. Airport security has expanded to include body scanners as well as traditional metal detectors. Families frequently ask whether spinal implants will trigger airport security, but there is limited information on modern implants and screening methods. The researchers conducted a survey of 50 pediatric patients after posterior spinal fusion from 2004 to 2013. Inclusion criteria were posterior instrumentation, pedicle screws for at least 80% of anchors, and at least 1 trip through an American airport after surgery. Charts and radiographs were reviewed for metal type, number of levels fused, number of anchors, and rod diameter. A total of 16% of patients (8 of 50) were detected by body scan or metal detector and all had cobalt chrome (CoCr) rods. No patients with stainless-steel (SS) rods were detected. The CoCr rods triggered additional screening in 24% of children (8 of 33), compared with none of 17 with SS rods (p = .03). For patients with CoCr rods, the detection rate was 18% (5 of 28) by metal detector and 17% (3 of 18) by body scanner. For patients with CoCr rods, there was no significant difference between detection rates and levels fused (p = .30), number of anchors (p = .15), or rod diameter (p = .17). In this series, CoCr constructs were more likely to incur additional airport security compared with more traditional SS constructs. Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Establishment of Wear Resistant HVOF Coatings for 50CrMo4 Chromium Molybdenum Alloy Steel as an Alternative for Hard Chrome Plating

NASA Astrophysics Data System (ADS)

Karuppasamy, S.; Sivan, V.; Natarajan, S.; Kumaresh Babu, S. P.; Duraiselvam, M.; Dhanuskodi, R.

2018-05-01

High cost imported components of seamless steel tube manufacturing plants wear frequently and need replacement to ensure the quality of the product. Hard chrome plating, which is time consuming and hazardous, is conventionally used to restore the original dimension of the worn-out surface of the machine components. High Velocity Oxy-Fuel (HVOF) thermal spray coatings with NiCrBSi super alloy powder and Cr3C2 NiCr75/25 alloy powder applied on a 50CrMo4 (DIN-1.7228) chromium molybdenum alloy steel, the material of the wear prone machine component, were evaluated for use as an alternative for hard chrome plating in this present work. The coating characteristics are evaluated using abrasive wear test, sliding wear test and microscopic analysis, hardness test, etc. The study results revealed that the HVOF based NiCrBSi and Cr3C2NiCr75/25 coatings have hardness in the range of 800-900 HV0.3, sliding wear rate in the range of 50-60 µm and surface finish around 5 microns. Cr3C2 NiCr75/25 coating is observed to be a better option out of the two coatings evaluated for the selected application.

Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

NASA Astrophysics Data System (ADS)

Pietrucha, K.; Pȩkala, W.; Kroh, J.

Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by the irradiation with 60Co ?-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high - ca 90% of monomer converts into copolymer and only 10% is converted into homopolymer. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The results reported seem to indicate that MMA may be used in the production of shoe upper and sole leathers. The mechanism of some of the processes occuring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed.

A numerical investigation into the influence of the properties of cobalt chrome cellular structures on the load transfer to the periprosthetic femur following total hip arthroplasty.

PubMed

Hazlehurst, Kevin Brian; Wang, Chang Jiang; Stanford, Mark

2014-04-01

Stress shielding of the periprosthetic femur following total hip arthroplasty is a problem that can promote the premature loosening of femoral stems. In order to reduce the need for revision surgery it is thought that more flexible implant designs need to be considered. In this work, the mechanical properties of laser melted square pore cobalt chrome molybdenum cellular structures have been incorporated into the design of a traditional monoblock femoral stem. The influence of incorporating the properties of cellular structures on the load transfer to the periprosthetic femur was investigated using a three dimensional finite element model. Eleven different stiffness configurations were investigated by using fully porous and functionally graded approaches. This investigation confirms that the periprosthetic stress values depend on the stiffness configuration of the stem. The numerical results showed that stress shielding is reduced in the periprosthetic Gruen zones when the mechanical properties of cobalt chrome molybdenum cellular structures are used. This work identifies that monoblock femoral stems manufactured using a laser melting process, which are designed for reduced stiffness, have the potential to contribute towards reducing stress shielding. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Decorin content and near infrared spectroscopy analysis of dried collagenous biomaterial samples.

PubMed

Aldema-Ramos, Mila L; Castell, Joan Carles; Muir, Zerlina E; Adzet, Jose Maria; Sabe, Rosa; Schreyer, Suzanne

2012-12-14

The efficient removal of proteoglycans, such as decorin, from the hide when processing it to leather by traditional means is generally acceptable and beneficial for leather quality, especially for softness and flexibility. A patented waterless or acetone dehydration method that can generate a product similar to leather called Dried Collagenous Biomaterial (known as BCD) was developed but has no effect on decorin removal efficiency. The Alcian Blue colorimetric technique was used to assay the sulfated glycosaminoglycan (sGAG) portion of decorin. The corresponding residual decorin content was correlated to the mechanical properties of the BCD samples and was comparable to the control leather made traditionally. The waterless dehydration and instantaneous chrome tanning process is a good eco-friendly alternative to transforming hides to leather because no additional effects were observed after examination using NIR spectroscopy and additional chemometric analysis.

NASA and ESA Collaboration on Hexavalent Chrome Alternatives Pretreatments Only Interim Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2015-01-01

NASA and ESA continue to search for an alternative to hexavalent chromium in coatings applications that meet their performance requirements in corrosion protection, cost, operability, and health and safety, while typically specifying that performance must be equal to or greater than existing systems. The overall objective of the collaborative effort between NASA TEERM and ESA is to test and evaluate coating systems (pretreatments, pretreatments with primer, and pretreatments with primer and topcoat) as replacements for hexavalent chrome coatings in aerospace applications. This objective will be accomplished by testing promising coatings identified from previous NASA, ESA, Department of Defense (DOD), and other project experience. Additionally, several new materials will be analyzed according to ESA-identified specifications.

Nucleotide sequence of Hungarian grapevine chrome mosaic nepovirus RNA1.

PubMed Central

Le Gall, O; Candresse, T; Brault, V; Dunez, J

1989-01-01

The nucleotide sequence of the RNA1 of hungarian grapevine chrome mosaic virus, a nepovirus very closely related to tomato black ring virus, has been determined from cDNA clones. It is 7212 nucleotides in length excluding the 3' terminal poly(A) tail and contains a large open reading frame extending from nucleotides 216 to 6971. The presumably encoded polyprotein is 2252 amino acids in length with a molecular weight of 250 kDa. The primary structure of the polyprotein was compared with that of other viral polyproteins, revealing the same general genetic organization as that of other picorna-like viruses (comoviruses, potyviruses and picornaviruses), except that an additional protein is suspected to occupy the N-terminus of the polyprotein. PMID:2798128

Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses.

PubMed

Kılınç, Halil İbrahim; Kesim, Bülent; Gümüş, Hasan Önder; Dinçel, Mehmet; Erkaya, Selçuk

2014-08-01

This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level. The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P<.05). SBS values of none of the groups differed from those of the control group (P>.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (P<.05). Grinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength.

Hexavalent Chrome Free Coatings for Electronics; Electromagnetic Interference (EMI) Shielding Effectiveness (SE)

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2014-01-01

The purpose of this testing is to determine the suitability of trivalent chromium conversion coatings that meet the requirements of MIL-DTL-5541, Type II, for use in applications where high-frequency electrical performance is important. This project will evaluate the ability of coated aluminum to form adequate EMI seals. Testing will assess performance of the trivalent chromium coatings against the known control hexavalent chromium MIL-DTL-5541 Type I Class 3 before and after they have been exposed to a set of environmental conditions. Performance will be assessed by evaluating shielding effectiveness (SE) test data from a variety of test samples comprised of different aluminum types and/or conversion coatings.

Raman analysis of complex pigment mixtures in 20th century metal knight shields of the Order of the Elephant.

PubMed

Lauridsen, Clara Bratt; Sanyova, Jana; Simonsen, Kim Pilkjær

2015-11-05

The pigment composition of six painted metal knight shields of the Order of the Elephant dating from the second half of the 20th century belonging to the Danish royal collection were studied using Raman microscopy. By focusing a 785 nm laser with a 50× objective on particles in paint cross sections, it was possible to identify the following 20 compounds: hematite, goethite, chrome red/orange, chrome yellow, zinc chrome yellow, carbon black, toluidine red PR3, chlorinated para red PR4, dinitroaniline orange PO5, phthalocyanine blue PB15, indanthrone blue PB60, ultramarine, Prussian blue, lead white, anatase, rutile, calcium carbonate, barium sulphate, gypsum and dolomite. The components were frequently present in complex pigment mixtures. Additional information was obtained by elemental analysis with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) to identify cobalt blue, zinc white and cadmium red, as well as to indicate the presence of zinc white in some pigment mixtures. The study allowed a comparison between the industrially applied preparation layers and the artistic paint layers applied by the heraldic painter. Differences in the choice of paint and pigment types were observed on the earliest knight shields, demonstrating a general delay of industrial materials into artist paints. Copyright © 2015 Elsevier B.V. All rights reserved.

Dry etching of chrome for photomasks for 100-nm technology using chemically amplified resist

NASA Astrophysics Data System (ADS)

Mueller, Mark; Komarov, Serguie; Baik, Ki-Ho

2002-07-01

Photo mask etching for the 100nm technology node places new requirements on dry etching processes. As the minimum-size features on the mask, such as assist bars and optical proximity correction (OPC) patterns, shrink down to 100nm, it is necessary to produce etch CD biases of below 20nm in order to reproduce minimum resist features into chrome with good pattern fidelity. In addition, vertical profiles are necessary. In previous generations of photomask technology, footing and sidewall profile slope were tolerated, since this dry etch profile was an improvement from wet etching. However, as feature sizes shrink, it is extremely important to select etch processes which do not generate a foot, because this will affect etch linearity and also limit the smallest etched feature size. Chemically amplified resist (CAR) from TOK is patterned with a 50keV MEBES eXara e-beam writer, allowing for patterning of small features with vertical resist profiles. This resist is developed for raster scan 50 kV e-beam systems. It has high contrast, good coating characteristics, good dry etch selectivity, and high environmental stability. Chrome etch process development has been performed using Design of Experiments to optimize parameters such as sidewall profile, etch CD bias, etch CD linearity for varying sizes of line/space patterns, etch CD linearity for varying sizes of isolated lines and spaces, loading effects, and application to contact etching.

Use of 2-octyl cyanoacrylate adhesive in rat liver induced lesion.

PubMed

Santos, Orlando José dos; Marques, Giancarlo de Souza; Sauaia Filho, Euler Nicolau; Frota, Gustavo Medeiros; Santos, Rayan Haquim Pinheiro; Santos, Rennan Abud Pinheiro

2012-09-01

To evaluate the healing process of rat traumatic liver lesion corrected with the use of 2-octyl cyanoacrylate adhesive, compared to the use of biologically absorbable chromed catgut thread suture. Thirty mail adult rats were divided into two groups (15 per group) according to the used method for liver lesion correction as follows: adhesive group (AG), and catgut group (CG); each group being divided into three subsets of five animals (7th, 14th, and 21st day), respectively, according to post-surgery evaluation. All animals were submitted to homogeneous lesion applying synthetic bonding to AG and using chromed catgut suture to CG for lesion correction. Macroscopic and microscopic parameters of healing processes were evaluated. Both groups of animals showed excellent abdominal wall healing, with no evidence of infection, and no abdominal cavity peritonitis or abscess. The presence of adherence was observed in both groups with no statistically significant difference. As to macroscopic evaluation, there was statistically significant difference with respect to specific factors of clinical inflammation (ischemic inflammation and giant celular inflammatory reaction) between animals evaluated on the 10th day (ischemic necrosis and giant cellular inflammatory reaction) among animals evaluated on the 14th day (A14 versus C14). Applying 2-octyl-cyanoacrylate adhesive for correcting rat liver lesion does not change healing process when compared to the use of chromed catgut stitch.

A Russian record of a Middle Ordovician meteorite shower: Extraterrestrial chromite at Lynna River, St. Petersburg region

NASA Astrophysics Data System (ADS)

Lindskog, Anders; Schmitz, Birger; Cronholm, Anders; Dronov, Andrei

2012-08-01

Numerous fossil meteorites and high concentrations of sediment-dispersed extraterrestrial chromite (EC) grains with ordinary chondritic composition have previously been documented from 467 ± 1.6 Ma Middle Ordovician (Darriwilian) strata. These finds probably reflect a temporarily enhanced influx of L-chondritic matter, following the disruption of the L-chondrite parent body in the asteroid belt 470 ± 6 Ma. In this study, a Volkhovian-Kundan limestone/marl succession at Lynna River, northwestern Russia, has been searched for EC grains (>63 μm). Eight samples, forming two separate sample sets, were collected. Five samples from strata around the Asaphus expansus-A. raniceps trilobite Zone boundary, in the lower-middle Kundan, yielded a total of 496 EC grains in 65.5 kg of rock (average 7.6 EC grains kg-1, but up to 10.2 grains kg-1). These are extremely high concentrations, three orders of magnitude higher than "background" levels in similar condensed sediment from other periods. EC grains are typically about 50 times more abundant than terrestrial chrome spinel in the samples and about as common as terrestrial ilmenite. Three stratigraphically lower lying samples, close to the A. lepidurus-A. expansus trilobite Zone boundary, at the Volkhov-Kunda boundary, yielded only two EC grains in 38.2 kg of rock (0.05 grains kg-1). The lack of commonly occurring EC grains in the lower interval probably reflects that these strata formed before the disruption of the L-chondrite parent body. The great similarity in EC chemical composition between this and other comparable studies indicates that all or most EC grains in these Russian mid-Ordovician strata share a common source--the L-chondrite parent body.

Finnish wallpaper pigments in the 18th-19th century: Presence of KFe3(CrO4)2(OH)6 and odd pigment mixtures

NASA Astrophysics Data System (ADS)

Castro, Kepa; Knuutinen, Ulla; Vallejuelo, Silvia Fdez-Ortiz de; Irazola, Mireia; Madariaga, Juan Manuel

2013-04-01

Several Finish wallpapers from the 18th and 19th century were analysed by using Raman spectroscopy assisted with EDXRF instrumentation, in an attempt of determine the pigments used in their manufacture process as well as of trying to date some of the samples through pigment composition. All pigments present in samples were determined and surprisingly the unusual and strange iron (III) chromate yellow pigment was found. Besides, unusual mixtures were found to obtain fashionable colours, especially in blue and green areas, where more than one blue pigments were mixed with green and yellow pigments. Blue verditer, ultramarine blue, Prussian blue, chrome yellow, calcite, lead white, red and yellow iron oxide, gypsum and carbon black were identified. The presence of the risky and poisonous emerald green must be highlighted. The results were compared with those found in other wallpapers from Spain and France.

Solid state electro-optic color filter and iris

NASA Technical Reports Server (NTRS)

1974-01-01

The electro-optic properties of lanthanum-modified lead zirconate titanate (PLZT) ferroelectric ceramic material are evaluated when utilized as a variable density and/or spectral filter in conjunction with a television scanning system. Emphasis was placed on the development of techniques and procedures for processing the PLZT disks and for applying efficient electrode structures. A number of samples were processed using different combinations of cleaning, electrode material, and deposition process. Best overall performance resulted from the direct evaporation of gold over chrome electrodes. A ruggedized mounting holder assembly was designed, fabricated, and tested. The assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and permits mounting and optical alignment of the associated polarizers. Operational measurements of a PLZT sample mounted in the holder assembly were performed in conjunction with a television camera and the associated drive circuits. The data verified achievement of the elimination of the observed white-line effect.

Decorin Content and Near Infrared Spectroscopy Analysis of Dried Collagenous Biomaterial Samples

PubMed Central

Aldema-Ramos, Mila L.; Castell, Joan Carles; Muir, Zerlina E.; Adzet, Jose Maria; Sabe, Rosa; Schreyer, Suzanne

2012-01-01

The efficient removal of proteoglycans, such as decorin, from the hide when processing it to leather by traditional means is generally acceptable and beneficial for leather quality, especially for softness and flexibility. A patented waterless or acetone dehydration method that can generate a product similar to leather called Dried Collagenous Biomaterial (known as BCD) was developed but has no effect on decorin removal efficiency. The Alcian Blue colorimetric technique was used to assay the sulfated glycosaminoglycan (sGAG) portion of decorin. The corresponding residual decorin content was correlated to the mechanical properties of the BCD samples and was comparable to the control leather made traditionally. The waterless dehydration and instantaneous chrome tanning process is a good eco-friendly alternative to transforming hides to leather because no additional effects were observed after examination using NIR spectroscopy and additional chemometric analysis. PMID:24970152

The characterization of canvas painting by the Serbian artist Milo Milunović using X-ray fluorescence, micro-Raman and FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Damjanović, Lj.; Gajić-Kvaščev, M.; Đurđević, J.; Andrić, V.; Marić-Stojanović, M.; Lazić, T.; Nikolić, S.

2015-10-01

A canvas painting by Milo Milunović "The Inspiration of the poet" was studied by energy dispersive X-Ray fluorescence (EDXRF), micro-Raman and Fourier transform infrared (FTIR) spectroscopy in order to identify materials used by the artist and his painting technique. Study is perfomed combining in situ non-destructive method with the preparation and study of cross-section samples and raw fragments of the samples. Milo Milunović, an eminent painter from Balkan region, made a copy of the Nicolas Poussin's original painting in Louvre in 1926/27. Obtained results revealed following pigments on the investigated canvas painting: vermilion, minium, cobalt blue, ultramarine, lead white, zinc white, cadmium yellow, chrome-based green pigment and several earth pigments - red and yellow ocher, green earth and umber. Ground layer was made of lead white mixed with calcium carbonate.

Advanced mask cleaning for 0.20-μm technology: an integrated user-supplier approach

NASA Astrophysics Data System (ADS)

Poschenrieder, Rudolf; Hay, Bernd; Beier, Matthias; Hourd, Andrew C.; Stuemer, Harald; Gairing, Thomas M.

1998-12-01

A newly developed photomask final cleaning system, STEAG HamaTech's Advanced Single Substrate Cleaner, ASC 500, was assessed and optimized at the Siemens mask shop in Munich, Germany, under production conditions within the Esprit European Semiconductor Equipment Assessment programme (SEA). The project was carried out together with the active participation of Compugraphics Intl. Ltd. (UK), DuPont Photomasks, Inc. (Germany; Photronics-MZD, Germany). The results of the assessment are presented, focusing on the cleaning performance at the 0.25 micrometer defect level on photomasks, equipment reliability and Cost of Ownership data. A reticle free of soft defects on glass and on chrome down to the 0.25 micrometer level requires an excellent cleaning process and the use of high-end inspection tools like the KLA STARlight. In order to get a full understanding of the nature of the detected features additional investigations on the blank quality have been carried out. These investigations include the questions whether a detection is a hard or a soft defect and whether small defects on chrome are able to move on the reticle surface. Final cleaning recipes have been optimized in respect to cleaning efficiency while maintaining high throughput and low Cost of Ownership. A benchmark comparison against other final cleaning tools at the partner's maskshops showed the leading data of the ASC 500. It was found that a cleaning program which includes several substrate flips and a combination of the available cleaning methods acid- dispense, water pressure jet clean, brush and megasonic clean was best suitable to achieve these goals. In particular the use of the brush unit was shown to improve the yield while not adding damage to the plate.

Chrome-free Samarium-based Protective Coatings for Magnesium Alloys

NASA Astrophysics Data System (ADS)

Hou, Legan; Cui, Xiufang; Yang, Yuyun; Lin, Lili; Xiao, Qiang; Jin, Guo

The microstructure of chrome-free samarium-based conversion coating on magnesium alloy was investigated and the corrosion resistance was evaluated as well. The micro-morphology, transverse section, crystal structure and composition of the coating were observed by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and X- ray photoelectron spectroscopy (XPS), respectively. The corrosion resistance was evaluated by potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS). The results reveal that the morphology of samarium conversion coating is of crack-mud structure. Tiny cracks distribute in the compact coating deposited by samarium oxides. XRD, EDS and XPS results characterize that the coating is made of amorphous and trivalent-samarium oxides. The potentiodynamic polarization curve, EIS and OCP indicate that the samarium conversion coating can improve the corrosion resistance of magnesium alloys.

Quaternized wood as sorbent for hexavalent chromium.

PubMed

Low, K S; Lee, C K; Lee, C Y

2001-01-01

The potential of quaternized wood (QW) chips in removing hexavalent chromium from synthetic solution and chrome waste under both batch and continuous-flow conditions was investigated. Sorption was found to be dependent on pH, metal concentration, and temperature. QW chips provide higher sorption capacity and wider pH range compared with untreated wood chips. The equilibrium data could be fitted into the Langmuir isotherm model, and maximum sorption capacities were calculated to be 27.03 and 25.77 mg/g in synthetic chromate solution and chrome waste, respectively. The presence of sulfate in high concentration appeared to suppress the uptake of chromium by QW chips. Column studies showed that bed depth influenced the breakthrough time greatly whereas flow rate of influent had little effect on its sorption on the column.

Substance use -- inhalants

MedlinePlus

... blast, bold, chroming, discorama, glad, hippie crack, moon gas, oz, poor man's pot, rush, snappers, whippets, and ... computer cleaning spray, freon , helium, nitrous oxide (laughing gas), which is found in whipped cream containers, and ...

Metals concentrations in sediments and oyster Crassostrea gigas from La Pitahaya lagoon, Sinaloa, NW Mexico

NASA Astrophysics Data System (ADS)

Luna Varela, R.; Muñoz Sevilla, N.; Campos Villegas, L.; Rodriguez Espinosa, P.; Gongora Gomez, A.; MP, J.

2013-05-01

This present study was performed in a culture of Crassostrea gigas in La Pitahaya, Sinaloa, México. The main objective is to identify the enrichment pattern of trace elements (Cu, Cd, Cr, Ni, Pb, Zn, Hg, As, V) also was determine concentrations thereof in oyster. Four sampling sites were selected, two smaller channels which connect the lagoon directly , the region of culture and connection with the sea ; and each sampling consisted of 4 sample sediments and 50 oysters of commercial size per mounth . Concentrations of trace metals were determined using atomic absorption spectrophotometry (AAS). The higher concentration of elements in certain samples clearly suggests that they are directly fed by the smaller channels which connect the lagoon directly. These small channels often carry the contaminants which are absorbed and deposited in the sediments. The results were also compared with the Effect Range Low (ERL) and Effect Range Medium (ERM) of NOAA and it indicates that Ni is above the ERL values. Cadmium, lead, chrome and copper concentrations exceeded the limits permissible of bivalbe mollusks established by the sanitary regulations

Fountain Flow cytometry, a new technique for the rapid detection and enumeration of microorganisms in aqueous samples.

PubMed

Johnson, Paul E; Deromedi, Anthony J; Lebaron, Philippe; Catala, Philippe; Cash, Jennifer

2006-12-01

Pathogenic microorganisms are known to cause widespread waterborne disease worldwide. There is an urgent need to develop a technique for the real-time detection of pathogens in environmental samples at low concentrations, <10 microorganisms/ml, in large sample volumes, > or =100 ml. A novel method, Fountain Flowtrade mark cytometry, for the rapid and sensitive detection of individual microorganisms in aqueous samples is presented. Each sample is first incubated with a fluorescent label and then passed as a stream in front of a laser, which excites the label. The fluorescence is detected with a CCD imager as the sample flows toward the imager along its optical axis. The feasibility of Fountain Flow cytometry (FFC) is demonstrated by the detection of Escherichia coli labeled with ChemChrome CV6 and SYBR Gold in buffer and natural river water. Detections of labeled E. coli were made in aqueous suspensions with an efficiency of 96% +/- 14% down to a concentration approximately 200 bacteria/ml. The feasibility of FFC is demonstrated by the detection of E. coli in buffer and natural river water. FFC should apply to the detection of a wide range of pathogenic microorganisms including amoebae.

76 FR 66684 - Foreign-Trade Zone 29-Louisville, KY, Application for Subzone; North American Stainless...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

...) include: fluorospar, molybdenum oxide, ferromanganese, ferrosilicon, ferrosilicon manganese, charge chrome... spent anodes, nickel, unwrought nickel alloys, aluminum, zinc, zinc alloys, manganese metal, titanium...

Influence of third-body particles originating from bone void fillers on the wear of ultra-high-molecular-weight polyethylene

PubMed Central

Cowie, Raelene M; Carbone, Silvia; Aiken, Sean; Cooper, John J; Jennings, Louise M

2016-01-01

Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subsequent wear of ultra-high-molecular-weight polyethylene is unknown. In this study, third-body damage to cobalt chrome counterfaces was simulated using particles of the calcium sulfate bone void fillers Stimulan® (Biocomposites Ltd., Keele, UK) and Osteoset® (Wright Medical Technology, TN, USA) using a bespoke rig. Scratches on the cobalt chrome plates were quantified in terms of their density and mean lip height, and the damage caused by the bone void fillers was compared to that caused by particles of SmartSet GMV PMMA bone cement (DePuy Synthes, IN, USA). The surface damage from Stimulan® was below the resolution of the analysis technique used; SmartSet GMV caused 0.19 scratches/mm with a mean lip height of 0.03 µm; Osteoset® led to a significantly higher number (1.62 scratches/mm) of scratches with a higher mean lip height (0.04 µm). Wear tests of ultra-high-molecular-weight polyethylene were carried out in a six-station multi-axial pin on plate reciprocating rig against the damaged plates and compared to negative (highly polished) and positive control plates damaged with a diamond stylus (2 µm lip height). The wear of ultra-high-molecular-weight polyethylene was shown to be similar against the negative control plates and those damaged with third-body particles; there was a significantly higher (p < 0.001) rate of ultra-high-molecular-weight polyethylene wear against the positive control plates. This study showed that bone void fillers of similar composition can cause varying damage to cobalt chrome counterfaces. However, the lip heights of the scratches were not of sufficient magnitude to increase the wear of ultra-high-molecular-weight polyethylene above that of the negative controls. PMID:27312481

40 CFR 425.80 - Applicability; description of the pigskin subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Pigskin... into finished leather by chemically dissolving or pulping the hair and tanning with chrome, then retan...

40 CFR 425.70 - Applicability; description of the shearling subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Shearling... cured sheep or sheep-like skins with the wool or hair retained into finished leather by chrome tanning...

NASA TEERM Principal Center Non-Chrome Projects

NASA Technical Reports Server (NTRS)

Rothgeb, Matthew

2008-01-01

Technology Evaluation for Environmental Risk Mitigation (TEERM) Principal Center Mission is to identify and validate environmental technologies through joint activities that enhance mission readiness and reduce risk while minimizing duplication and associated costs.

Presidential Green Chemistry Challenge: 2013 Small Business Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2013 award winner, Faraday Technology, Inc., process high-performance chrome coatings to be made from the less toxic, trivalent chromium. Reduce millions of pounds hexavalent chromium without comprising performance.

Raman spectroscopy for the identification of pigments and color measurement in Dugès watercolors

NASA Astrophysics Data System (ADS)

Frausto-Reyes, C.; Ortiz-Morales, M.; Bujdud-Pérez, J. M.; Magaña-Cota, G. E.; Mejía-Falcón, R.

2009-12-01

Spectroscopic and colorimetric analysis of a representative set of Dugès watercolor paintings was performed. These paintings were the result of scientific studies carried out by the zoologist Alfredo Dugès, who recorded the fauna of the Mexican Republic between 1853 and 1910. Micro-Raman spectroscopy, with an excitation wavelength of 830 nm, and colorimetric techniques were employed in order to understand if different colors with the same hue were reproduced using the same pigments. The color coordinates of the measured areas were obtained in the CIE L* a* b* color space. Raman analysis showed that, in some cases, to reproduce colors with the same hue the pigment employed was not the same. Pigments identified in the watercolors were vermilion, carbon-based black, lead white, gamboge and chrome yellow, Prussian and ultramarine blue. Some of these pigments have been used since ancient times, others as Prussian blue, chrome yellow and synthetic ultramarine blue arrived to the market at the beginning of the 18th and 19th centuries, respectively. Furthermore, regarding the white color, instead of left the paper unpainted, lead white was detected in the eye of a bird. The green color was obtained by mixing Prussian blue with chrome yellow. The results of this work show the suitability of using Raman spectroscopy for watercolor pigment analysis and colorimetric techniques to measure the color of small areas (246 μm × 246 μm) that was the case for the lead white pigment.

Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses

PubMed Central

Kesim, Bülent; Gümüş, Hasan Önder; Dinçel, Mehmet; Erkaya, Selçuk

2014-01-01

PURPOSE This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. MATERIALS AND METHODS Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level. RESULTS The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P<.05). SBS values of none of the groups differed from those of the control group (P>.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (P<.05). CONCLUSION Grinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength. PMID:25177476

Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886-1970): The EDXRF, FT-IR and micro Raman spectroscopic studies

NASA Astrophysics Data System (ADS)

Akyuz, Sevim; Akyuz, Tanil; Emre, Gulder; Gulec, Ahmet; Basaran, Sait

2012-04-01

The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm × 136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artist's paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C + Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones.

40 CFR 425.03 - Sulfide analytical methods and applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp... by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart C...

40 CFR 425.03 - Sulfide analytical methods and applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp... by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart C...

40 CFR 425.03 - Sulfide analytical methods and applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp... by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart C...

40 CFR 63.340 - Applicability and designation of sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subject to this subpart. An example of such a tank is a chrome conversion coating tank where no electrical current is applied. (d) Affected sources in which research and laboratory operations are performed are...

40 CFR 63.340 - Applicability and designation of sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... subject to this subpart. An example of such a tank is a chrome conversion coating tank where no electrical current is applied. (d) Affected sources in which research and laboratory operations are performed are...

40 CFR 63.340 - Applicability and designation of sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... subject to this subpart. An example of such a tank is a chrome conversion coating tank where no electrical current is applied. (d) Affected sources in which research and laboratory operations are performed are...

Chemistry and Artists' Colors: Part III. Preparation and Properties of Artists' Pigments.

ERIC Educational Resources Information Center

Orna, Mary Virginia

1980-01-01

Describes laboratory methods for synthesizing chrome yellow, prussian blue, and phthalalocyanine blue; reviews chemical properties of artists' pigments including chemical structure and light-scattering properties; and explains how pigments are classified. (CS)

30 CFR 50.20-6 - Criteria-MSHA Form 7000-1, Section C.

Code of Federal Regulations, 2010 CFR

2010-07-01

... as the first day of illness. (i) Code 21—Occupational Skin Diseases or Disorders. Examples: Contact dermatitis, eczema, or rash caused by primary irritants and sensitizers or poisonous plants; oil acne; chrome...

A sharp knife for high temperatures

NASA Technical Reports Server (NTRS)

Heisman, R. M.; Iceland, W. F.

1978-01-01

Electrically heated nickel-chrome-steel alloy knife may be used to cut heat resistant plastic felt and similar materials with relative ease. Blade made of commercially available alloy RA 330 retains edge at temperatures as high as 927 C.

Enhancing Surface Finish of Additively Manufactured Titanium and Cobalt Chrome Elements Using Laser Based Finishing

NASA Astrophysics Data System (ADS)

Gora, Wojciech S.; Tian, Yingtao; Cabo, Aldara Pan; Ardron, Marcus; Maier, Robert R. J.; Prangnell, Philip; Weston, Nicholas J.; Hand, Duncan P.

Additive manufacturing (AM) offers the possibility of creating a complex free form object as a single element, which is not possible using traditional mechanical machining. Unfortunately the typically rough surface finish of additively manufactured parts is unsuitable for many applications. As a result AM parts must be post-processed; typically mechanically machined and/or and polished using either chemical or mechanical techniques (both of which have their limitations). Laser based polishing is based on remelting of a very thin surface layer and it offers potential as a highly repeatable, higher speed process capable of selective area polishing, and without any waste problems (no abrasives or liquids). In this paper an in-depth investigation of CW laser polishing of titanium and cobalt chrome AM elements is presented. The impact of different scanning strategies, laser parameters and initial surface condition on the achieved surface finish is evaluated.

The Evaluation of a Modified Chrome Oxide Based High Temperature Solid Lubricant Coating for Foil Gas Bearings

NASA Technical Reports Server (NTRS)

DellaCorte, Chris

1998-01-01

This paper describes the friction and wear performance of PS304, a modified chrome oxide based coating, for foil gas bearings. PS304 contains 60 wt% NiCr binder, 20 wt% Cr2O3 hardener, and 10 wt% each Ag, and BaF2/CaF2 lubricants. For evaluation, the coating is plasma spray deposited onto test journals which are slid against a superalloy partial arc foil bearing. The test load was 10 KPa (1.5 psi) and the bearings were run under start/stop cyclic conditions. The data show good wear performance of the bearing, especially at temperatures above 25 deg. C. Bearing friction was moderate (micron approx. or equal to 0.4) over the entire temperature range. Based upon the results obtained, the PS304 coating has promise for high temperature, oil-free turbomachinery applications.

The effect of anticoagulants on the distribution of chromium VI in blood fractions.

PubMed

Afolaranmi, Grace A; Tettey, Justice N A; Murray, Helen M; Meek, R M Dominic; Grant, M Helen

2010-01-01

Metal-on-metal resurfacing arthroplasty is associated with elevated circulating levels of cobalt and chromium ions. To establish the long-term safety of metal-on-metal resurfacing arthroplasty, it has been recommended that during clinical follow-up of these patients, the levels of these metal ions in blood be monitored. In this article, we provide information on the distribution of chromium VI ions (the predominant form of chromium released by cobalt-chrome alloys in vivo and in vitro) in blood fractions. Chromium VI is predominantly partitioned into red blood cells compared with plasma (analysis of variance, P < .05). The extent of accumulation in red blood cells is influenced by the anticoagulant used to collect the blood, with EDTA giving a lower partitioning into red cells compared with sodium citrate and sodium heparin. 2010 Elsevier Inc. All rights reserved.

Metal artifact reduction in CT, a phantom study: subjective and objective evaluation of four commercial metal artifact reduction algorithms when used on three different orthopedic metal implants.

PubMed

Bolstad, Kirsten; Flatabø, Silje; Aadnevik, Daniel; Dalehaug, Ingvild; Vetti, Nils

2018-01-01

Background Metal implants may introduce severe artifacts in computed tomography (CT) images. Over the last few years dedicated algorithms have been developed in order to reduce metal artifacts in CT images. Purpose To investigate and compare metal artifact reduction algorithms (MARs) from four different CT vendors when imaging three different orthopedic metal implants. Material and Methods Three clinical metal implants were attached to the leg of an anthropomorphic phantom: cobalt-chrome; stainless steel; and titanium. Four commercial MARs were investigated: SmartMAR (GE); O-MAR (Philips); iMAR (Siemens); and SEMAR (Toshiba). The images were evaluated subjectively by three observers and analyzed objectively by calculating the fraction of pixels with CT number above 500 HU in a region of interest around the metal. The average CT number and image noise were also measured. Results Both subjective evaluation and objective analysis showed that MARs reduced metal artifacts and improved the image quality for CT images containing metal implants of steel and cobalt-chrome. When using MARs on titanium, all MARs introduced new visible artifacts. Conclusion The effect of MARs varied between CT vendors and different metal implants used in orthopedic surgery. Both in subjective evaluation and objective analysis the effect of applying MARs was most obvious on steel and cobalt-chrome implants when using SEMAR from Toshiba followed by SmartMAR from GE. However, MARs may also introduce new image artifacts especially when used on titanium implants. Therefore, it is important to reconstruct all CT images containing metal with and without MARs.

Groundwater contaminated with hexavalent chromium [Cr (VI)]: a health survey and clinical examination of community inhabitants (Kanpur, India).

PubMed

Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K; Verma, Vipin; Kesavachandran, Chandrasekharan N; Pangtey, Balram S; Mathur, Neeraj; Singh, Kunwar Pal; Srivastava, Mithlesh; Goel, Sudhir K

2012-01-01

We assessed the health effects of hexavalent chromium groundwater contamination (from tanneries and chrome sulfate manufacturing) in Kanpur, India. The health status of residents living in areas with high Cr (VI) groundwater contamination (N = 186) were compared to residents with similar social and demographic features living in communities having no elevated Cr (VI) levels (N = 230). Subjects were recruited at health camps in both the areas. Health status was evaluated with health questionnaires, spirometry and blood hematology measures. Cr (VI) was measured in groundwater samples by diphenylcarbazide reagent method. Residents from communities with known Cr (VI) contamination had more self-reports of digestive and dermatological disorders and hematological abnormalities. GI distress was reported in 39.2% vs. 17.2% males (AOR = 3.1) and 39.3% vs. 21% females (AOR = 2.44); skin abnormalities in 24.5% vs. 9.2% males (AOR = 3.48) and 25% vs. 4.9% females (AOR = 6.57). Residents from affected communities had greater RBCs (among 30.7% males and 46.1% females), lower MCVs (among 62.8% males) and less platelets (among 68% males and 72% females) than matched controls. There were no differences in leucocytes count and spirometry parameters. Living in communities with Cr (VI) groundwater is associated with gastrointestinal and dermatological complaints and abnormal hematological function. Limitations of this study include small sample size and the lack of long term follow-up.

Groundwater Contaminated with Hexavalent Chromium [Cr (VI)]: A Health Survey and Clinical Examination of Community Inhabitants (Kanpur, India)

PubMed Central

Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K.; Verma, Vipin; Kesavachandran, Chandrasekharan N.; Pangtey, Balram S.; Mathur, Neeraj; Singh, Kunwar Pal; Srivastava, Mithlesh; Goel, Sudhir K.

2012-01-01

Background We assessed the health effects of hexavalent chromium groundwater contamination (from tanneries and chrome sulfate manufacturing) in Kanpur, India. Methods The health status of residents living in areas with high Cr (VI) groundwater contamination (N = 186) were compared to residents with similar social and demographic features living in communities having no elevated Cr (VI) levels (N = 230). Subjects were recruited at health camps in both the areas. Health status was evaluated with health questionnaires, spirometry and blood hematology measures. Cr (VI) was measured in groundwater samples by diphenylcarbazide reagent method. Results Residents from communities with known Cr (VI) contamination had more self-reports of digestive and dermatological disorders and hematological abnormalities. GI distress was reported in 39.2% vs. 17.2% males (AOR = 3.1) and 39.3% vs. 21% females (AOR = 2.44); skin abnormalities in 24.5% vs. 9.2% males (AOR = 3.48) and 25% vs. 4.9% females (AOR = 6.57). Residents from affected communities had greater RBCs (among 30.7% males and 46.1% females), lower MCVs (among 62.8% males) and less platelets (among 68% males and 72% females) than matched controls. There were no differences in leucocytes count and spirometry parameters. Conclusions Living in communities with Cr (VI) groundwater is associated with gastrointestinal and dermatological complaints and abnormal hematological function. Limitations of this study include small sample size and the lack of long term follow-up. PMID:23112863

TRAY MOUNTAIN ROADLESS AREA, GEORGIA.

USGS Publications Warehouse

Nelson, Arthur E.; Chatman, Mark L.

1984-01-01

A mineral survey indicates that the Tray Mountain Roadless Area, Georgia has little promise for the occurrence of metallic mineral resources. Rocks underlying the Tray Mountain Roadless Area are suitable for crushed rock or aggregate; however, other sources for these materials are available closer to present markets. There is a possibility for the occurrence of hydrocarbon resources underlying the area at great depth, but no hydrocarbon potential was identified. Detailed studies are needed to establish the presence or absence and mineral-resource potential of olivine, nickel, cobalt, and chrome in the two mafic-ultramafic bodies in the Hayesville thrust sheet. The cause of the lead anomaly in pan concentrate samples taken from the southwest part of the roadless area has not been established; the mineral residence and source of the anomaly remain to be determined.

NASA and ESA Collaboration on Hexavalent Chrome Alternatives - Pretreatments with Primers Screening Final Test Report

NASA Technical Reports Server (NTRS)

Rothgeb, Matthew J.; Kessel, Kurt R.

2015-01-01

Hexavalent chromium (hex chrome or Cr(VI)) is a widely used element within applied coating systems because of its self-healing and corrosion-resistant properties. The replacement of hex chrome in the processing of aluminum for aviation and aerospace applications remains a goal of great significance. Aluminum is the major manufacturing material of structures and components in the space flight arena. The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are engaged in a collaborative effort to test and evaluate alternatives to hexavalent chromium containing corrosion coating systems. NASA and ESA share common risks related to material obsolescence associated with hexavalent chromium used in corrosion-resistant coatings. In the United States, Occupational Safety and Health Administration (OSHA) studies have concluded that hexavalent chromium is carcinogenic and poses significant risk to human health. On May 5, 2011, amendments to the Defense Federal Acquisition Regulation Supplement (DFARS) were issued in the Federal Register. Subpart 223.73 prohibits contracts from requiring hexavalent chromium in deliverables unless certain exceptions apply. Subpart 252.223-7008 provides the contract clause prohibiting contractors and subcontractors from using or delivering hexavalent chromium in a concentration greater than 0.1 percent by weight for all new contracts associated with supplies, maintenance and repair services, and construction materials. ESA faces its own increasingly stringent regulations within European directives such as Registration, Evaluation, Authorization and Restriction of Chemical (REACH) substances and the Restriction of Hazardous Substances Directive (RoHS) which have set a mid-2017 sunset date for hexavalent chromium. NASA and ESA continue to search for an alternative to hexavalent chromium in coatings applications that meet their performance requirements in corrosion protection, cost, operability, and health and safety, while typically specifying that performance must be equal to or greater than existing systems. The overall objective of the collaborative effort between NASA TEERM and ESA is to test and evaluate coating systems (pretreatments, pretreatments with primer, and pretreatments with primer and topcoat) as replacements for hexavalent chrome coatings in aerospace applications. This objective will be accomplished by testing promising coatings identified from previous NASA, ESA, Department of Defense (DOD), and other project experience. Additionally, several new materials will be analyzed according to ESA-identified specifications.

Laser-Induced Breakdown Spectroscopy of Cinematographic Film

NASA Astrophysics Data System (ADS)

Oujja, M.; Abrusci, C.; Gaspard, S.; Rebollar, E.; Amo, A. del; Catalina, F.; Castillejo, M.

Laser-induced breakdown spectroscopy (LIBS) was used to characterize the composition of black-and-white, silver-gelatine photographic films. LIB spectra of samples and reference gelatine (of various gel strengths, Bloom values 225 and 75 and crosslinking degrees) were acquired in vacuum by excitation at 266 nm. The elemental composition of the gelatine used in the upper protective layer and in the underlying emulsion is revealed by the stratigraphic analysis carried out by delivering successive pulses on the same spot of the sample. Silver (Ag) lines from the light-sensitive silver halide salts are accompanied by iron, lead and chrome lines. Fe and Pb are constituents of film developers and Cr is included in the hardening agent. The results demonstrate the analytical capacity of LIBS for study and classification of different gelatine types and the sensitivity of the technique to minor changes in gelatine composition. In addition LIBS analysis allows extracting important information on the chemicals used as developers and hardeners of archival cinematographic films.

Numerical correction of distorted images in full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Min, Gihyeon; Kim, Ju Wan; Choi, Woo June; Lee, Byeong Ha

2012-03-01

We propose a numerical method which can numerically correct the distorted en face images obtained with a full field optical coherence tomography (FF-OCT) system. It is shown that the FF-OCT image of the deep region of a biological sample is easily blurred or degraded because the sample has a refractive index (RI) much higher than its surrounding medium in general. It is analyzed that the focal plane of the imaging system is segregated from the imaging plane of the coherence-gated system due to the RI mismatch. This image-blurring phenomenon is experimentally confirmed by imaging the chrome pattern of a resolution test target through its glass substrate in water. Moreover, we demonstrate that the blurred image can be appreciably corrected by using the numerical correction process based on the Fresnel-Kirchhoff diffraction theory. The proposed correction method is applied to enhance the image of a human hair, which permits the distinct identification of the melanin granules inside the cortex layer of the hair shaft.

High sensitivity electric field monitoring system for control of field-induced CD degradation in reticles (EFM)

NASA Astrophysics Data System (ADS)

Sebald, Thomas; Rider, Gavin

2009-04-01

It has recently been reported [1] that production reticles are subject to progressive CD degradation during use and intense study is under way to try and identify the causes of it. One damage mechanism which has already been identified and quantified [2] is electric field induced migration of chrome (EFM). This can be caused by electric fields that are more than 100x weaker than those that cause ESD. Such low level electric fields can be experienced by a reticle during normal handling and processing steps, as well as coming from external sources during transportation and storage. The field strength of concern is lower than most electrostatic field meters are designed to measure and it can be difficult or impossible to measure such fields inside the cramped environment of equipment. To measure this risk a new sensor device ("E-Reticle") has been developed having the same materials of construction and form factor as a standard chrome-on-quartz reticle. It allows the electric field that a reticle would experience during normal use and handling to be measured and recorded. Results from testing of this device in a semiconductor production facility are reported, showing that certain processes like reticle washing are inherently hazardous. It also enables identification of problems with electrostatic protection measures inside equipment, such as unbalanced ionizers or poor load port grounding. The device is shown to be capable of recording electric fields in the reticle handling environment that are below the recommended maximum that is being proposed for the 2009 ITRS guidelines.

Analysis of Content Legibility for Smartphones of Websites of the Korean Urological Association and Other Urological Societies in Korea

PubMed Central

Lee, Joo Yong; Kang, Dong Hyuk; Moon, Hong Sang; Kim, Yong Tae; Yoo, Tag Keun; Choi, Hong Yong; Lee, Tchun Yong

2011-01-01

Purpose We performed an analysis of the smartphone legibility of the websites of the Korean Urological Association (KUA) and other urological societies. Materials and Methods This study was conducted on the websites of the KUA and nine other urological societies. Each website was accessed via iPhone Safari and Android Chrome, respectively, to evaluate the establishment and readability of the mobile web pages. The provision of Really Simple Syndication (RSS) feeds by the websites and whether the websites had Twitter and Facebook accounts were evaluated. In addition, a validation test on the web standards was performed by using the World Wide Web Consortium (W3C®) Markup Validation Service, and subsequently the numbers of errors and warnings that occurred were analyzed. Results When accessed via Safari, two websites were legible, four were somewhat legible, and four were somewhat illegible. When accessed via Chrome, two websites were legible, six were somewhat legible, and two were somewhat illegible. One website provided an RSS feed and two websites managed members via separate Twitter accounts. No website supported mobile web pages. The result of the W3C® Markup Validation test on 10 websites showed a mean error rate of 221.6 (range, 13-1,477) and a mean warning rate of 127.13 (range, 0-655). Conclusions The smartphone legibility level of the websites of urological societies was relatively low. Improved smartphone legibility and web standard compliance of the websites of urological societies are required to keep up with the popularity of smartphones. PMID:21379433

Absorptive coating for aluminum solar panels

NASA Technical Reports Server (NTRS)

Desmet, D.; Jason, A.; Parr, A.

1979-01-01

Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

40 CFR 60.260 - Applicability and designation of affected facility.

Code of Federal Regulations, 2011 CFR

2011-07-01

... affected facility. 60.260 Section 60.260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Performance for Ferroalloy Production Facilities § 60.260 Applicability and designation of affected facility..., ferrochrome silicon, silvery iron, high-carbon ferrochrome, charge chrome, standard ferromanganese...

40 CFR 60.260 - Applicability and designation of affected facility.

Code of Federal Regulations, 2012 CFR

2012-07-01

... affected facility. 60.260 Section 60.260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Performance for Ferroalloy Production Facilities § 60.260 Applicability and designation of affected facility..., ferrochrome silicon, silvery iron, high-carbon ferrochrome, charge chrome, standard ferromanganese...

Heavy metal contaminants in tissues of the garfish, Belone belone L., 1761, and the bluefish, Pomatomus saltatrix L., 1766, from Turkey waters.

PubMed

Türkmen, Aysun; Tepe, Yalçin; Türkmen, Mustafa; Mutlu, Ekrem

2009-01-01

Levels of contaminants in fish are of particular interest because of the potential risk to humans who consume them. Fish samples were collected through the coastal waters of Turkey and the contents of cadmium, cobalt, chrome, copper, iron, manganese, nickel, zinc and lead in the liver and muscle tissues were determined. Among the metals analyzed, copper, zinc and iron were the most abundant in the different tissues while cadmium and lead were the least abundant both in Belone belone and Pomatomus saltatrix. Metal concentrations in muscles of fish species were found 0.01-0.38 mg kg(-1) for cadmium, 0.01-0.53 mg kg(-1) for cobalt, 0.05-1.87 mg kg(-1) for chromium, 0.21-5.89 mg kg(-1) for copper, 9.99-43.3 mg kg(-1) for iron, 0.14-1.33 mg kg(-1) for manganese, 0.06-4.70 mg kg(-1) for nickel, 0.09-0.81 mg kg(-1) for lead, 3.85-15.9 mg kg(-1) for zinc, respectively. Regional changes in metal concentration were observed in the tissues of both species, but these variations may not influence consumption advisories.

USE OF FUME SUPPRESSANTS IN HARD CHROMIUM BATHS - EMISSION TESTING

EPA Science Inventory

The EPA Common Sense Initiative (CSI) is a cooperative effort of government, industry, environmental, and other stakeholder groups to find "cleaner, cheaper, smarter" approaches to environmental management in industrial sectors. The purpose of the project is to assist hard chrome...

TACOM LCMC Industrial Base Engineering Support - Board of Directors

DTIC Science & Technology

2011-07-01

Hex Chrome Replacement (High Purity Aluminum) Capability o Advanced Aviation Forward Area Refueling System (AAFARS)Tech Data Development o Common...SIAD (As needed) Example Issues: • Hexavalent Chromium/Cadmium (RRAD) • Common Adhesive (ANAD) • AVLB Pressure Plate (ANAD) • Paladin Corrosion

Trace elements in oceanic pelagic communities in the western Indian Ocean.

PubMed

Bodin, Nathalie; Lesperance, Dora; Albert, Rona; Hollanda, Stephanie; Michaud, Philippe; Degroote, Maxime; Churlaud, Carine; Bustamante, Paco

2017-05-01

The mineral composition of target and non-target pelagic fish caught by purse-seiners and longliners in the western-central Indian Ocean was determined. From the 10 essential elements analysed, selenium and zinc showed the highest concentrations in swordfish and blue marlin while Indian mackerel appeared as a good source of copper, iron and chrome. All catch had levels of lead and cadmium, two toxic elements, below the maximum sanitary limits. Although some concerns were raised regarding mercury concentrations in the largest species (wahoo, swordfish and blue marlin), molar ratios of mercury and selenium indicate that all oceanic pelagic fish from the western-central Indian Ocean are safe for human consumption. This study also gives insights on the relationships between the levels of essential and toxic elements in fish muscle and the size, trophic position and diet sources of the studied pelagic species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microstructure and optical properties of black chrome before and after exposure to high temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lampert, C.M.; Washburn, J.

1979-01-01

The chemical and microstructural stability of the CHROM-ONYX type of black chrome solar coating was investigated at different temperatures and atmospheres. This was done to give a better understanding of the mechanism of solar energy selectivity and its variability when subjected to short term heat treatments. The as-plated structure was found to consist of a suspension of metallic chromium particles within the size range of 100A in an amorphous oxide matrix. This assembly was in turn formed into larger particles within the size range of 0.05-0.30 microns. Short term high temperature heat treatments were used to simulate stagnation conditions. Samplesmore » were annealed in both air and vacuum, which resulted in similar characteristics. Annealing in air appeared to mildly accelerate optical degradation at high temperatures. For short term heat treatments below 300/sup 0/C the reflective and microstructural properties appeared to be unchanged. By in situ vacuum annealing of the coating above 400/sup 0/C microcrystalline Cr/sub 2/O/sub 3/ was identified. By observation of diffraction patterns it was concluded that a-Cr/sub 2/O/sub 3/ was transformed into crystalline Cr/sub 2/O/sub 3/. The Cr/sub 2/O/sub 3/ phase continued to grow at higher temperatures at the expense of chromium content. At temperatures above 500/sup 0/C in vacuum, a new phase identified as NiCr/sub 2/O/sub 4/ formed. It was found that black chrome failed optically between 500-600/sup 0/C for 1 hour heat treatments in both air and vacuum; also the coating heated in air failed mechanically by peeling at 600/sup 0/C.« less

Hazardous effects of effluent from the chrome plating industry: 70 kDa heat shock protein expression as a marker of cellular damage in transgenic Drosophila melanogaster (hsp70-lacZ).

PubMed Central

Mukhopadhyay, Indranil; Saxena, Daya Krishna; Chowdhuri, Debapratim Kar

2003-01-01

Hazardous effects of an effluent from the chrome plating industry were examined by exposing transgenic Drosophila melanogaster (hsp70-lacZ) to various concentrations (0.05, 0.1, 1.0, 10.0, and 100.0 micro L/mL) of the effluent through diet. The emergence pattern of adult flies was affected, along with impaired reproductive performance at the higher dietary concentrations of the effluent. Interestingly, the effect of the effluent was more pronounced in male than in female flies. The effect of the effluent on development of adult flies was concurrent with the expression pattern of the heat shock protein 70 gene (hsp70), both in larval tissues and in the reproductive organs of adult flies. We observed a dose- and time-dependent expression of hsp70 in third instar larvae exposed for different time intervals. Absence of hsp70 expression in larvae exposed to 0.1 micro L/mL of the effluent indicated that this is the highest nontoxic concentration for Drosophila. The stress gene assay in the reproductive organs of adult flies revealed hsp70 expression in the testis of male flies only. However, trypan blue dye exclusion tests in these tissues indicate tissue damage in the male accessory gland of adult flies, which was further confirmed by ultrastructural observations. In the present study we demonstrate the utility of transgenic Drosophila as an alternative animal model for evaluating hazardous effects of the effluent from the chrome plating industry and further reveal the cytoprotective role of hsp70 and its expression as an early marker in environmental risk assessment. PMID:14644668

Hexavalent Chrome Free Coatings for Electronics Applications: Joint Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt

2012-01-01

Regardless of the corrosivity of the environment, all metals require periodic maintenance activity to guard against the insidious effects of corrosion and thus ensure that alloys meet or exceed design or performance life. The standard practice for protecting metallic substrates is the application of a coating system. Applied coating systems work via a variety of methods (barrier, galvanic, and/or inhibitor) and adhere to the substrate through a combination of chemical and physical bonds. For years hexavalent chromium has been a widely used element within applied coating systems because of its self healing and corrosion resistant properties. Occupational Safety and Health Administration (OSHA) studies have concluded that hexavalent chromium (hex chrome) is carcinogenic and poses significant risk to human health. On May 5, 2011 amendments to the Defense Federal Acquisition Regulation Supplement (DFARS) were issued in the Federal Register. Subpart 223.73 prohibits contracts from requiring hexavalent chromium in deliverables unless certain exceptions apply. These exceptions include authorization from a general or flag officer and members of the Senior Executive Service from a Program Executive Office, and unmodified legacy systems. Otherwise, Subpart 252.223-7008 provides the contract clause prohibiting contractors from using or delivering hexavalent chromium in a concentration greater than 0.1 percent by weight for all new contracts and to be included down to subcontractors for supplies, maintenance and repair services, and construction materials. National Aeronautics and Space Administration (NASA), Department of Defense (DoD), and industry stakeholders continue to search for alternatives to hex chrome in coatings applications that meet their performance requirements in corrosion protection, cost, operability, and health and safety, while typically specifying that performance must be equal to or greater than existing systems.

Biointervention makes leather processing greener: an integrated cleansing and tanning system.

PubMed

Thanikaivelan, Palanisamy; Rao, Jonnalagadda Raghava; Nair, Balachandran Unni; Ramasami, Thirumalachari

2003-06-01

The do-undo methods adopted in conventional leather processing generate huge amounts of pollutants. In other words, conventional methods employed in leather processing subject the skin/hide to wide variations in pH. Pretanning and tanning processes alone contribute more than 90% of the total pollution from leather processing. Included in this is a great deal of solid wastes such as lime and chrome sludge. In the approach described here, the hair and flesh removal as well as fiber opening have been achieved using biocatalysts at pH 8.0 for cow hides. This was followed by a pickle-free chrome tanning, which does not require a basification step. Hence, this tanning technique involves primarily three steps, namely, dehairing, fiber opening, and tanning. It has been found that the extent of hair removal, opening up of fiber bundles, and penetration and distribution of chromium are comparable to that produced by traditional methods. This has been substantiated through scanning electron microscopic, stratigraphic chrome distribution analysis, and softness measurements. Performance of the leathers is shown to be on par with conventionally processed leathers through physical and hand evaluation. Importantly, softness of the leathers is numerically proven to be comparable with that of control. The process also demonstrates reduction in chemical oxygen demand load by 80%, total solids load by 85%, and chromium load by 80% as compared to the conventional process, thereby leading toward zero discharge. The input-output audit shows that the biocatalytic three-step tanning process employs a very low amount of chemicals, thereby reducing the discharge by 90% as compared to the conventional multistep processing. Furthermore, it is also demonstrated that the process is technoeconomically viable.

40 CFR 425.60 - Applicability; description of the through-the-blue subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY... processes raw or cured cattle or cattle-like hides through the blue tanned state by hair pulp unhairing and chrome tanning; no retan-wet finishing is performed. ...

HARD CHROME POLLUTION PREVENTION DEMONSTRATION PROJECT - INTERIM REPORT

EPA Science Inventory

In the project, five chromium emission prevention/control devices were tested tha cover the spectrum of prevention/control techniques currently in use in small- and large-size hard chromium electroplating job shops. The Project results show that some of the tested devices had ch...

40 CFR 425.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards (NSPS). 425.24 Section 425.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome...

40 CFR 425.14 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards (NSPS). 425.14 Section 425.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome...

40 CFR 425.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards (NSPS). 425.24 Section 425.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome...

40 CFR 425.14 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards (NSPS). 425.14 Section 425.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome...

40 CFR 425.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards (NSPS). 425.24 Section 425.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome...

40 CFR 425.14 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards (NSPS). 425.14 Section 425.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome...

40 CFR 415.344 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Pretreatment standards for existing... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Chrome Pigments Production Subcategory § 415.344 Pretreatment standards for existing sources (PSES). (a) Existing...

Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber

NASA Astrophysics Data System (ADS)

El-Sabbagh, Salwa H.; Mohamed, Ola A.

2010-06-01

Concerns on environmental waste problem caused by chrome tanned leather wastes in huge amount have caused an increasing interest in developing this wastes in many composite formation. This leather dust was used as filler in acrylonitrile butadiene rubber (NBR) before treatment and after treatment with ammonia solution and sod. formate. Different formulations of NBR/ leather dust (untreated-treated with ammonia solution—treated with sod. formate) composites are prepared. The formed composite exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather dust. Tensile strength, modulus at 100% elongation, hardness and youngs modulus were improved then by further loading start to be steady or decrease. Cross linking density in toluene were increased by incorporation of leather dust treated or untreated resulting in decreases in equilibrium swelling. Distinct increase in the ageing coefficient of both treated and untreated leather with drop in NBR vulcanizates without leather dust. Addition of leather dust treated or untreated exhibit better thermal stability.

Tribological evaluation of PS300: A new chrome oxide based solid lubricant coating sliding against Al2O3 From 25 to 650 C

NASA Technical Reports Server (NTRS)

DellaCorte, C.; Laskowski, J. A.

1996-01-01

This paper presents the tribological characteristics of Al203 sliding against PS300; a chrome oxide based self lubricating coating. Al203 pins were slid against PS300 coated superalloy disks in air, under a 4.9 N load at velocities of 1 to 8 m/s. At a sliding velocity of 1 m/s, friction ranged from 0.6 at 25 C to 0.2 at 650 C. Wear factors for the Al203 pins were in the 10(exp -7) mm(exp 3)/N-m range and for the PS300 coating was in the 10(exp -5) mm(exp 3)/N-m range. The test results suggest that increased surface temperature resulting from either frictional heating, generated by increased sliding velocity, or ambient heating caused a reduction in friction and wear of the sliding couple. Based upon these results, the tested material combination is a promising candidate for high temperature wear applications.

Development of thermal model to analyze thermal flux distribution in thermally enhanced machining of high chrome white cast iron

NASA Astrophysics Data System (ADS)

Ravi, A. M.; Murigendrappa, S. M.

2018-04-01

In recent times, thermally enhanced machining (TEM) slowly gearing up to cut hard metals like high chrome white cast iron (HCWCI) which were impossible in conventional procedures. Also setting up of suitable cutting parameters and positioning of the heat source against the work appears to be critical in order to enhance the machinability characteristics of the work material. In this research work, the Oxy - LPG flame was used as the heat source and HCWCI as the workpiece. ANSYS-CFD-Flow software was used to develop the transient thermal model to analyze the thermal flux distribution on the work surface during TEM of HCWCI using Cubic boron nitride (CBN) tools. Non-contact type Infrared thermo sensor was used to measure the surface temperature continuously at different positions, and is validated with the thermal model results. The result confirms thermal model is a better predictive tool for thermal flux distribution analysis in TEM process.

Reducing chromium losses from a chromium plating bath. 1987 summer intern report. Project conducted at New Dimension Plating, Hutchinson, Minnesota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achman, D.

1987-12-31

The company employs about forty people and operates for one or two eight hour shifts with an average of 315 racks of chrome plating per eight hour day. They plate a variety of metals including copper, nickel, gold, brass and chromium. Chromium is the major metal plated and is usually the last step in plating cycle. Most parts are copper plated and then nickel plated in preparation for chrome plating. The main difference between New Dimension Plating and other plating shops is the variety of parts plated. As New Dimension Plating is a job shop, a wide range of partsmore » such as motorcycle accessories, stove parts, and custom items are metal finished. The plating lines are manual, meaning employees dip the racks into the tanks by hand. This fact along with the fact that parts vary greatly in size and shape accounts for the significant drag-out on the chromium plating line.« less

A novel detection approach based on chromophore-decolorizing with free radical and application to photometric determination of copper with acid chrome dark blue.

PubMed

Gao, Hong-Wen; Chen, Fang-Fang; Chen, Ling; Zeng, Teng; Pan, Lu-Ting; Li, Jian-Hua; Luo, Hua-Fei

2007-03-21

A novel detection approach named chromophore-decolorizing with free radicals is developed for determination of trace heavy metal. The hydroxyl radicals (HO) generated from Fe(III) and hydrogen peroxide will oxidize the free chromophore into almost colorless products. The copper-acid chrome dark blue (ACDB) complexation was investigated at pH 5.07. In the presence of Fe(III) and hydrogen peroxide, the excess ACDB was decolorized in the Cu-ACDB reaction solution, and the final solution contained only one color compound, the Cu-ACDB complex. After oxidation of free hydroxyl radicals, the complexation becomes sensitive and selective and it has been used for the quantitation of trace amounts of Cu(II) dissolved in natural water. Beer's law is obeyed in the range from 0 to 0.500 microg mL(-1) Cu(II) and the limit of detection is only 6 microg L(-1) Cu(II). Besides, the Cu-ACDB complex formed was characterized.

[Study on hydrothermal stability of the collagen].

PubMed

Wang, Yajuan; Chen, Hui; Shan, Zhihua

2009-02-01

The low hydrothermal stability of the raw collagen restricts its usage. To improve the hydrothermal stability of collagen, two kinds of materials with weak astringency were used by experts. The research proved that the synergistic effect was formed during the process. In this study, by using UV, FT-IR, 13CNMR spectra and elemental analysis on the salicylic acid and metal-salicylic complexes, we could get the structural formula of every compound. And then, the hide powder was treated with the compounds. At last, the treated hide powder was tested by DSC. It could be presumed that the Rigid Matrix formed between the collagen doses can increase the hydrothermal stability of raw collagen, The result indicated that salicylic-chrome with large stable constant was better than others in improving the heat resistance of raw collagen, and the denaturalization temperature of hide powder treated with salicylic-chrome was 146.7 degrees C. Salicylic-aluminum was in the second place, the relevant temperature being 145.7 degrees C.

A new shock wave assisted wood preservative injection system

NASA Astrophysics Data System (ADS)

Rao, K. S.; Ravikumar, G.; Lai, Ram; Jagadeesh, G.

Preservative treatment of many tropical hard woods and bamboo pose severe problem. A number of wood preservatives (chemical formulations toxic to wood decay/ destroying organisms like fungi, wood destroying termites, marine borers etc.) and wood impregnating techniques are currently in use for improving bio resistance of timber and bamboo and thereby enhancing service life for different end uses. How ever, some species of tropical hardwoods and many species of bamboo are difficult to treat, posing technical problems. In this paper we report preliminary results of treatment of bamboo with a novel Shockwave assisted injection treatment. Samples (30×2.5×1.00 cm) of an Indian species of bamboo Dendrocalamus strictus prepared from defect free culms of dry bamboo are placed in the driven section of a vertical shock tube filled with the 4Coppepr-Chrome-Arsenic(CCA) preservative solution.The bamboo samples are subjected to repeated shock wave loading (3 shots) with typical over pressures of 30 bar. The results from the study indicate excellent penetration and retention of CCA preservative in bamboo samples. The method itself is much faster compared to the conventional methods like pressure treatment or hot and cold process.

40 CFR 261.32 - Hazardous wastes from specific sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

.../or pigments production is defined to include manufacture of the following product classes: dyes... pentachlorophenol (T) Inorganic pigments: K002 Wastewater treatment sludge from the production of chrome yellow and orange pigments (T) K003 Wastewater treatment sludge from the production of molybdate orange pigments (T...

Molecular modeling approach to vegetable tanning: preliminary results for gallotannin interactions with the collagen microfibril

USDA-ARS?s Scientific Manuscript database

Tanning of animal hides produces leather, a durable, flexible material that is stabilized against putrefaction. Chrome-tanned wet blue, aldehyde crosslinked wet white, and vegetable tanned hides are major contributors to current leather production. Although the chemistries involved are significant...

40 CFR 425.25 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for existing sources (PSES). 425.25 Section 425.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan...

40 CFR 425.14 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards (NSPS). 425.14 Section 425.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet...

40 CFR 425.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 425.24 Section 425.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet...

40 CFR 425.15 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for existing sources (PSES). 425.15 Section 425.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan...

40 CFR 425.25 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for existing sources (PSES). 425.25 Section 425.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan...

40 CFR 425.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards (NSPS). 425.24 Section 425.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan, Retan-Wet...

40 CFR 425.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards (NSPS). 425.34 Section 425.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome...

40 CFR 425.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 425.34 Section 425.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome...

40 CFR 425.14 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 425.14 Section 425.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan, Retan-Wet...

40 CFR 425.15 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for existing sources (PSES). 425.15 Section 425.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan...

40 CFR 425.16 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for new sources (PSNS). 425.16 Section 425.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan...

40 CFR 425.16 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for new sources (PSNS). 425.16 Section 425.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Pulp, Chrome Tan...

40 CFR 425.26 - Pretreatment standards for new sources (PSNS)

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for new sources (PSNS) 425.26 Section 425.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan...

40 CFR 425.26 - Pretreatment standards for new sources (PSNS)

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for new sources (PSNS) 425.26 Section 425.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save, Chrome Tan...

Environmentally Friendly Pretreatment for Department of Defense Applications

DTIC Science & Technology

2012-08-29

Develop an environmentally friendly pretreatment system for multi-material Department of Defense applications ― Free of hexavalent chromium (Cr6...Zn phosphate and chrome wash primer •Two Zirconium pretreatment variations passed the 336 hr and 1000 hr B-117 outlined per MIL-DTL-53022 or MIL

Lessons Learned in Technology Transition (Briefing Charts)

DTIC Science & Technology

2011-02-01

recertification • Environmental regulations • Federal clean air act • OSHA and EPA requirements – Cadmium, hexavalent chromium, VOC reduction • ReaCH Copyright...Efforts • Non-Chromated Exterior System Non-chromated conversion coat and primer • Non- Chrome for other areas • Chemical topcoat reactivation Future

CHARACTERIZATION OF CHROMIUM-CONTAMINATED SOILS USING FIELD-PORTABLE X-RAY FLUORESCENCE

EPA Science Inventory

A detailed characterization of the underlying and adjacent soils near a chrome plating shop utilized field-portable X- ray fluorescence (XRF) as a screening tool. XRF permitted real-time acquisition of estimates for total metal content of soils. A trailer-mounted soil coring unit...

Serpentinite slices within a tectonic zone at the base of the Juvavic nappe system in the Northern Calcareous Alps (Austria): characterization and origin

NASA Astrophysics Data System (ADS)

Boehm, Katharina; Schuster, Ralf; Wagreich, Michael; Koller, Friedrich; Wimmer-Frey, Ingeborg

2014-05-01

The investigated serpentinites are present in an ENE-WSW orientated tectonic zone at the base of Juvavic nappes (Northern Calcareous Alps), situated at the eastern margin of the Eastern Alps (Lower Austria). They form small tectonically squeezed slices, which are embedded in Permotriassic schists and Middle to Upper Triassic limestones. These serpentinites play an important, but not yet understood role in reconstructing Neotethys evolution, Alpine Orogeny and the correlation of Dinarides and Alps. The largest serpentinite body near to Unterhöflein is 400 to 100 meters in size and was investigated by mineralogical (XRD) and petrological/geochemical (XRF) methods. The primary mineral composition is olivine + orthopyroxene + clinopyroxene + chrome spinel. Pseudomorphs of pyroxenes are visible macroscopically, but almost all primary minerals are replaced by serpentine minerals. Former olivine is converted to chrysotile minerals, which show typical reticulate textures, orthopyroxene turned into lizardite pseudomorphs and chrome spinel is almost completely altered to magnetite. Major contents of chrysotile-α, chrysotile-γ and lizardite and minor antigorite, as well as secondary minerals like talc, chlorite and hydrogrossular were identified with XRD. Results from whole rock geochemistry indicate harzburgitic precursor rocks for the serpentinites. According to the low antigorite content, the rocks have only a weak metamorphic imprint and therefore an obduction rather than a subduction history is likely. This leads to the assumption that these serpentinites possibly originate from the Neotethys and not from the Penninic oceanic realm. Further, the tectonic position of the serpentinite slices is in close vicinity to sediments of the Meliata unit which also occur between Juvavic and underlying Tirolic nappe system (Mandl & Ondrejickova, 1993). Additionally, remnants from ophiolite nappes are found reworked into the surrounding Upper Cretaceous Gosau Group. In the latter also chrome spinel detritus is present. In contrast to the altered chrome spinels in the investigated serpentinites, the spinels from Gosau Group are well preserved and they show similarities to those of Dinaric Cretaceous basins, concerning their harzburgitic and lherzolitic sources (Stern & Wagreich, 2013). If the investigated serpentinites belong to obducted material from Neothetys oceanic realm, a tectonic model of a slab-tearing induced sinistral strike-slip zone could explain the position in the Eastern Alps. However, the relationship to other basic magmatic rocks from several other localities in similar positions, mostly occurring within evaporitic sediments of Permian Haselgebirge (Schorn et al., 2013), has to be clarified.

Survey of coatings for solar collectors

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1975-01-01

Optimum solar selective properties of black chrome require some tailoring of current and time for plating solution being used. Black zinc is produced from high zinc electroplate by subsequent conversion with chromate dip. Measurements have also been made of reflectance of previously known solar selective coatings of black copper and electroplated black nickel.

IN-SITU TREATMENT OF CHROMIUM SOURCE AREA USING REDOX MANIPULATION

EPA Science Inventory

Sodium dithionite was used to treat a chromium source zone in soils beneath an old chrome plating shop. The sodium dithionite was injected as a buffered solution into the soils to transform the chromium from the oxidized (+6) state to the reduced (+3) state. Once reduced the chro...

REDUCTIVE DETOXIFICATION AND IMMOBILIZATION OF CHROMATE PRESENT IN SOILS

EPA Science Inventory

Sodium dithionite was used to treat a chromium source zone in soils beneath an old chrome plating shop. The sodium dithionite was injected as a buffered solution into the soils to transform the chromium from the oxidized (+6) state to the reduced (+3) state. Once reduced the chro...

77 FR 26739 - High Pressure Steel Cylinders From the People's Republic of China: Final Determination of Sales...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-07

.... Department of Transportation, Pipeline and Hazardous Materials Safety Administration (``DOT'') approved high.... International Trading Corporation (``Shanghai J.S.X.''), and Shijiazhuang Enric Gas Equipment Co., Ltd. (``Enric... liquefied gas (``high pressure steel cylinders''). High pressure steel cylinders are fabricated of chrome...

Vulnerability Assessment of Open Source Wireshark and Chrome Browser

DTIC Science & Technology

2013-08-01

UNLIMITED 5 We spent much of the initial time learning about the logical model that modern HTML5 web browsers support, including how users interact with...are supposed to protect users of that site against cross-site scripting) and the new powerful an all-encompassing HTML5 standard. This vulnerability

CERAL 3450 Chrome-Free Aluminum Ceramic Coating

DTIC Science & Technology

2008-02-27

expected and provided good corrosion protection • No service difficulties or warranties related to the coating Rolls Royce T56 • Powers the Lockheed C-130...version of T56 • Inlet air filters typically reduce dust ingestion, but the operating environments can be very corrosive • Borescope photo at ~25,000

IN-SITU REDUCTION OF CHROMIUM-CONTAMINATED GROUNDWATER, SOILS, AND SEDIMENTS BY SODIUM DITHIONITE

EPA Science Inventory

Laboratory studies were conducted to characterize the extent of chromium contamination in the groundwater and underlying soils and sediments of a chrome-plating shop at the USCG Support Center near Elizabeth City, NC. Most of the mobile Cr(VI) is present in the capillary zone ...

IN-SITU REMEDIATION OF CHROMIUM-CONTAMINATED SOILS AND SEDIMENTS USING SODIUM DITHIONITE

EPA Science Inventory

Soil cores were collected from beneath an old chrome plating shop at the USCG Support Center near Elizabeth City, NC in order to determine the extent of chromium contamination in the soils and ground water. Selective extractions were used to assess the chemical speciation and di...

RESPONSE OF TALL FESCUE, BUSH BEAN, AND MAIZE TO CHROME TANNERY SLUDGE IN SOILS

EPA Science Inventory

Tannery sludge was compared with commercial nitrogen fertiliser to investigate its potential use as an alternative to commercial fertiliser. Soils containing 38% and 7% organic carbon and with nitrogen contents of 1-3% and 0-2%, respectively, were amended with either commercial N...

TRANSPORT AND TRANSFORMATION OF HEXAVALENT CHROMIUM THROUGH SOILS AND INTO GROUND WATER

EPA Science Inventory

A detailed characterization of the underlying and adjacent soils of a chrome-plating shop was performed to provide information on the extent of soil and aquifer contamination at the site and on the potential for off-site migration and environmental impact. Intact, moist cores wer...

PHYSICAL VAPOR DEPOSITION OF TANTALUM ON GUN BARREL STEEL (SYSTEMS ANLAYSIS BRANCH, SUSTAINABLE TECHNOLOGY DIVISION, NRMRL)

EPA Science Inventory

This project entails the development of an alternative technology for plating gun barrel steel to replace the process electroplating of chrome (Cr-electroplate) with physical vapor deposition of tantalum (Ta-PVD). Developed by Benet Laboratory at Watervliet Arsenal, this project'...

LETTUCE AND BROCCOLI RESPONSE AND SOIL PROPERTIES RESULTING FROM TANNERY WASTE APPLICATIONS

EPA Science Inventory

Broccoli (Brassica oleracea L. var. italica) and lettuce (Lactuca sativa L.) were grown on Willamette sil (Pachic Ultic Argixerolls) amended 1 and 2 yr earlier with chrome tannery wastes at rates up to 192 Mg ha to determine nutrient and trace element availability. Soils were sam...

IN-SITU REMEDIATION OF CHROMIUM-CONTAMINATED SOILS AND SEDIMENTS

EPA Science Inventory

The objectives of this study were to characterize the extent of total chromium and Cr(VI)contamination in the underlying soils and sediments of a chrome-plating shop at the USCG Support Center near Elizabeth City, NC and to evaluate the use of liquid reductants for in situ treatm...

Risk Report on Perfluorooctanesulfonate (PFOS) as a Component of Mist Suppressants in Chrome-Plating Tanks

DTIC Science & Technology

2003-02-01

Perfluorooctanesulfonate ( PFOS ) is a synthetic perfluorinated surfactant recently discovered to be ubiquitous in the environment. Animal data suggest...a high tolerance for PFOS , as does epidemiological analysis of workers in PFOS manufacturing plants. A suggested reference dose of 0.02 mg$kg/day is

High throughput, real-time detection of Naegleria lovaniensis in natural river water using LED-illuminated Fountain Flow Cytometry.

PubMed

Johnson, P E; Deromedi, A J; Lebaron, P; Catala, P; Havens, C; Pougnard, C

2007-09-01

To test Fountain Flow Cytometry (FFC) for the rapid and sensitive detection of Naegleria lovaniensis amoebae (an analogue for Naegleria fowleri) in natural river waters. Samples were incubated with one of two fluorescent labels to facilitate detection: ChemChrome V6, a viability indicator, and an R-phycoerytherin (RPE) immunolabel to detect N. lovaniensis specifically. The resulting aqueous sample was passed as a stream in front of a light-emitting diode, which excited the fluorescent labels. The fluorescence was detected with a digital camera as the sample flowed toward the imager. Detections of N. lovaniensis were made in inoculated samples of natural water from eight rivers in France and the United States. FFC enumeration yielded results that are consistent with other counting methods: solid-phase cytometry, flow cytometry, and hemocytometry, down to concentrations of 0.06 amoebae ml(-1), using a flow rate of 15 ml min(-1). This study supports the efficacy of using FFC for the detection of viable protozoa in natural waters and indicates that use of RPE illuminated at 530 nm and detected at 585 nm provides a satisfactory means of attenuating background. Because of the severe global public health issues with drinking water and sanitation, there is an urgent need to develop a technique for the real-time detection of viable pathogens in environmental samples at low concentrations. FFC addresses this need.

Characterization of Mesoamerican jade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishop, R.L.; Sayre, E.V.; van Zelst, L.

1983-11-23

Jadeite occurring in the Motague River Valley of Guatemala has been characterized by neutron activation analysis and forms two district, phase-related groups. Comparison of the compositional profiles of Mayan jadeite artifacts reveals many specimens having profiles matching those of the Montagua source. Of particular interest are the large number of jadeite artifacts which show internal similarity yet have compositional patterns which are significantly different from the Montagua samples and Montagua-related artifacts. A few of the analyzed Costa Rican artifacts show patterns similar to those of the Motagua yet the vast majority fall within one of the two Costa Rican compositionalmore » groups. When considering the non-Motagua related Mayan artifacts, the analytical approach appears to be sufficiently sensitive so as to distinguish differences between the Chrome-green and Chichen-green material. Even two Honduran site specific groups of albite - cultural jade - form distinct groups.« less

Experimental studies and performance analyses on polyurethane and nitrile rubber rod seals

NASA Astrophysics Data System (ADS)

Mirza, M.; Temiz, V.; Kamburoǧlu, E.

2012-09-01

The aim of this study is to determine the friction and leakage properties of rod seals made of polyethylene and nitrile rubber with different design geometries, under various pressure and lubricating oil viscosity conditions, in order to make assumptions about their general sealing characteristics and their pros and cons under certain working conditions that involve a range of fluid pressures. The test specimens consist of commercial rod seals of various designs and materials and were mounted on a hard chrome coated shaft subject to reciprocating motion. The test rig is capable of measuring friction force by means of strain measurements on a load cell transmitting the linear motion of a screw shaft to the test shaft. The test results of the reciprocating rod seal samples were evaluated according to leakage amount and friction resistance as a function of materials, design geometries and fluid pressures as well as the lubricating oil viscosity.

Characterization of Sorolla's gouache pigments by means of spectroscopic techniques

NASA Astrophysics Data System (ADS)

Roldán, Clodoaldo; Juanes, David; Ferrazza, Livio; Carballo, Jorgelina

2016-02-01

This paper presents the characterization of the Joaquín Sorolla's gouache sketches for the oil on canvas series "Vision of Spain" commissioned by A. M. Huntington to decorate the library of the Hispanic Society of America in New York. The analyses were focused on the identification of the elemental composition of the gouache pigments by means of portable EDXRF spectrometry in a non-destructive mode. Additionally, SEM-EDX and FTIR analyses of a selected set of micro-samples were carried out to identify completely the pigments, the paint technique and the binding media. The obtained results have confirmed the identification of lead and zinc white, vermillion, earth pigments, ochre, zinc yellow, chrome yellow, ultramarine, Prussian blue, chromium based and copper-arsenic based green pigments, bone black and carbon based black pigments, and the use of gum arabic as binding media in the gouache pigments.

[Comparison of in vivo characteristics of polyethylene wear particles produced by a metal and a ceramic femoral component in total knee replacement].

PubMed

Veigl, D; Vavřík, P; Pokorný, D; Slouf, M; Pavlova, E; Landor, I

2011-01-01

The aim of the study was to evaluate in vivo and compare, in terms of the quality and number of ultra high-molecular polyethylene (UHMWPE) wear particles, total knee replacements of identical construction differing only in the material used for femoral component production, i.e., CoCrMo alloy or ZrO2 ceramics. Samples of peri-prosthetic granuloma tissue were collected in two patients with total knee replacement suffering from implant migration, who were matched in relevant characteristics. The primary knee replacement in Patient 1 with a CoCrMo femoral component was done 7.2 years and in Patient 2 with a ZrO2 implant 6.8 years before this assessment. The polyethylene wear-induced granuloma was analysed by the MORF method enabling us to assess the shape and size of wear debris and the IRc method for assessment of particle concentration. In the granuloma tissue samples of Patient 1, on the average, particles were 0.30 mm in size and their relative volume was 0.19. In the Patient 2 tissue samples, the average size of particles was 0.33 mm and their relative volume was 0.26. There was no significant difference in either particle morphology or their concentration in the granuloma tissue between the two patients. One of the options of how to reduce the production of polyethylene wear particles is to improve the tribological properties of contacting surfaces in total knee replacement by substituting a cobalt-chrome femoral component with a zirconia ceramic femoral component. The previous in vitro testing carried out with a mechanical simulator under conditions approaching real weight-bearing in the human body did show a nearly three-fold decrease in the number of UHMWPE wear particles in zirconia components. The evaluation of granuloma tissue induced by the activity of a real prosthetic joint for nearly seven years, however, did not reveal any great difference in either quality or quantity of polyethylene debris between the two replacements. The difference of surface roughness between CoCrMo (Ra = 0.05) and ZrO2 (Ra = 0.02) components did not play any role in in vivo conditions. CONCLUSIONS In accordance with a previous clinical study, this evaluation of the quality and quantity of UHMWPE wear particles produced by a ceramic femoral component in vivo failed to demonstrate any advantage of zirconia ceramic components over the cobalt-chrome femoral components so far used.

Modeling of Cr contamination in the agricultural lands of three villages near the leather industry in Kasur, Pakistan, using statistical and GIS techniques.

PubMed

Shafiq, Muhammad; Shaukat, Tahira; Nazir, Aisha; Bareen, Firdaus-E-

2017-08-01

Kasur is one of the hubs of leather industry in the Punjab, Pakistan, where chrome tanning method of leather processing is extensively being used. Chromium (Cr) accumulation levels in the irrigation water, soil, and seasonal vegetables were studied in three villages located in the vicinity of wastewater treatment plant and solid waste dumping site operated by the Kasur Tanneries Waste Management Agency (KTWMA). The data was interpreted using analysis of variance (ANOVA), clustering analysis (CA), and principal component analysis (PCA). Interpolated surface maps for Cr were generated using the actual data obtained for the 30 sampling sites in each of the three villages for irrigation water, soil, and seasonal vegetables. The level of contamination in the three villages was directly proportional to their distance from KTWMA wastewater treatment plant and the direction of water runoff. The highest level of Cr contamination in soil (mg kg -1 ) was observed at Faqeeria Wala (37.67), intermediate at Dollay Wala (30.33), and the least in Maan (25.16). A gradational variation in Cr accumulation was observed in the three villages from contaminated wastewater having the least contamination level (2.02-4.40 mg L -1 ), to soil (25.16-37.67 mg kg -1 ), and ultimately in the seasonal vegetable crops (156.67-248.33 mg kg -1 ) cultivated in the region, having the highest level of Cr contamination above the permissible limit. The model used not only predicted the current situation of Cr contamination in the three villages but also indicated the trend of magnification of Cr contamination from irrigation water to soil and to the base of the food chain. Among the multiple causes of Cr contamination of vegetables, soil irrigation with contaminated groundwater was observed to be the dominant one.

78 FR 60876 - Advisory Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Advisory... by teleconference. Please dial (877) 930-8819 and enter code 1579739. Web links: Windows Connection-2: http://wm.onlinevideoservice.com/CDC2 Flash Connection-4 (For Safari and Google Chrome Users): http...

78 FR 60876 - Advisory Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Advisory... by teleconference. Please dial (877) 930-8819 and enter code 1579739. Web Links Windows Connection-2: http://wm.onlinevideoservice.com/CDC2 . Flash Connection-4 (For Safari and Google Chrome Users): http...

SITE CHARACTERIZATION OF A CHROMIUM SOURCE AREA AT THE USCG SUPPORT CENTER, ELIZABETH CITY, NC

EPA Science Inventory

The chrome source area is located beneath an old electroplating shop at the United States Coast Guard Support Center near Elizabeth City, NC . This electroplating shop was in
use for approximately 30 years until 1984 and was the source of discharges of chromic and sulfuric...

77 FR 25647 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

... inspections of the outer diameter chrome on the center axles of the MLG for cracks; and related investigative... MLG for cracks; and related investigative and corrective actions if necessary. The related... operators Lubrication of MLG pivot joints.. 4 work-hours x $85 $0 $340 per $54,400 per per hour = $340...

SITE CHARACTERIZATION OF A CHROMIUM SOURCE AREA AT THE USGS SUPPORT CENTER, ELIZABETH CITY, NC

EPA Science Inventory

Chromic and sulfuric acid wastes had discharged through a hole in the concrete floor of a chrome-plating shop located within a hangar at the U.S. Coast Guard Support Center near Elizabeth City, North Carolina and infiltrated the soils and groundwater beneath the shop. Following i...

Using Web Speech Technology with Language Learning Applications

ERIC Educational Resources Information Center

Daniels, Paul

2015-01-01

In this article, the author presents the history of human-to-computer interaction based upon the design of sophisticated computerized speech recognition algorithms. Advancements such as the arrival of cloud-based computing and software like Google's Web Speech API allows anyone with an Internet connection and Chrome browser to take advantage of…

62P-165

NASA Image and Video Library

1962-10-18

The Atlas-Agena B space Vehicle waits on the launch pad to launch the National Aeronautics and Space Administration’s Ranger V Spacecraft on a 66 – 62 hour journey to the moon. Ranger V is a 735-pound gold and chrome Plated payload designed to perform a series of complicated tasks, including taking television pictures of the lunar surface.

Voice-Recognition Augmented Performance Tools in Performance Poetry Pedagogy

ERIC Educational Resources Information Center

Devanny, David; McGowan, Jack

2016-01-01

This provocation shares findings from the use of bespoke voice-recognition performance software in a number of seminars (which took place in the 2014-2016 academic years at Glasgow School of Art, University of Warwick, and Falmouth University). The software, made available through this publication, is a web-app which uses Google Chrome's native…

DoD Metal Finishing Workshop: Chromate Alternatives for Metal Treatment and Sealing

DTIC Science & Technology

2007-05-17

always) contain Co inhibitors and nanophase SiO2 to fill scratches. For many materials trivalent processes are now as good as (and in some cases better...6 2.4. Trivalent and non-chrome technology ..................................................... 6 3...5 Figure 3. Trivalent passivate market (1000 gals).................................................. 6 Figure 4. Protection

77 FR 3281 - High Pressure Steel Cylinders From China; Scheduling of the Final Phase of Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

...)] High Pressure Steel Cylinders From China; Scheduling of the Final Phase of Countervailing Duty and... retarded, by reason of subsidized and less-than-fair-value imports from China of high pressure steel... (``high pressure steel cylinders''). High pressure steel cylinders are fabricated of chrome alloy steel...

COMPARISON OF RAPID METHODS TO EVALUATE CHLORINE INACTIVATION OF THE BIOLOGICAL AGENT E. COLI 0157:H7

EPA Science Inventory

Rapid viability tests of the Catagory B agent Escherichia coli O157:H7 were evaluated after disinfection with chlorine. The metabolic activity dyes ChemChrome V6, a modified fluorescein diacetate (FDA) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) were compared to standard ...

Maxillary overdentures supported by four splinted direct metal laser sintering implants: a 3-year prospective clinical study.

PubMed

Mangano, Francesco; Luongo, Fabrizia; Shibli, Jamil Awad; Anil, Sukumaran; Mangano, Carlo

2014-01-01

Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

Maxillary Overdentures Supported by Four Splinted Direct Metal Laser Sintering Implants: A 3-Year Prospective Clinical Study

PubMed Central

Mangano, Francesco; Shibli, Jamil Awad; Anil, Sukumaran

2014-01-01

Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results. PMID:25580124

Optical properties and crystallinity of silver mirrors under a 35 krad cobalt-60 radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, Po-Kai, E-mail: pkchiu@itrc.narl.org.tw; Chiang, Donyau; Lee, Chao-Te

2015-09-15

This study addresses the effects of thin film optical design and environmental radiation on the optical properties of silver mirrors. Different experimental thin film optical designs are selected, and the film stack is built using Macleod's approach. Mirror elements are exposed to the same dose of radiation and their properties are characterized using a spectrophotometer equipped with an integration sphere and an x-ray diffractometer. Spectrophotometric analyses of mirrors exposed to about 35 krad of {sup 60}Co radiations overall show that the B270 glass substrates coated with titanium oxide (TiO{sub 2}), silicon dioxide (SiO{sub 2}), pure chrome, and pure silver effectivelymore » reduces radiation damage. The absorption spectrum of the TiO{sub 2} film in the visible region decreases after radiation and displays drifting. As thin metal films comparison, the silver thin film exhibits higher radiation resistance than the chrome thin film. The x-ray diffraction analysis on metal film layers reveals that crystallinity slightly increases when the silver thin film is irradiated.« less

Bioremoval of trivalent chromium using Bacillus biofilms through continuous flow reactor.

PubMed

Sundar, K; Sadiq, I Mohammed; Mukherjee, Amitava; Chandrasekaran, N

2011-11-30

Present study deals with the applicability of bacterial biofilms for the bioremoval of trivalent chromium from tannery effluents. A continuous flow reactor was designed for the development of biofilms on different substrates like glass beads, pebbles and coarse sand. The parameters for the continuous flow reactor were 20 ml/min flow rate at 30°C, pH4. Biofilm biomass on the substrates was in the following sequence: coarse sand>pebbles>glass beads (4.8 × 10(7), 4.5 × 10(7) and 3.5 × 10(5)CFU/cm(2)), which was confirmed by CLSM. Biofilms developed using consortium of Bacillus subtilis and Bacillus cereus on coarse sand had more surface area and was able to remove 98% of Cr(III), SEM-EDX proved 92.60% Cr(III) adsorption on biofilms supported by coarse sand. Utilization of Bacillus biofilms for effective bioremoval of Cr(III) from chrome tanning effluent could be a better option for tannery industry, especially during post chrome tanning operation. Copyright © 2011 Elsevier B.V. All rights reserved.

A review on management of chrome-tanned leather shavings: a holistic paradigm to combat the environmental issues.

PubMed

Pati, Anupama; Chaudhary, Rubina; Subramani, Saravanabhavan

2014-10-01

Raw hide/skins come to the tanners as a by-product of meat industry which is converted into value-added leather as product for fashion market. Leather manufacturing is a chemical process of natural biological matrix. It employs a huge quantity of water and inorganic and organic chemicals for processing and thereby discharges solid and liquid wastes into the environment. One of the potential solid wastes generated from leather industry is chrome-tanned leather shavings (CTLSs), and its disposal is increasingly becoming a huge challenge on disposal to tanners due to presence of heavy metal chromium. Hence, finding a sustainable solution to the CTLS disposal problem is a prime challenge for global tanners and researchers. This paper aims to the deeper review of various disposal methods on CTLS such as protein, chromium, and energy recovery processes and its utilization methodologies. Sustainable technologies have been developed to overcome CTLS solid wastes emanating from leather processing operations. Further, this review paper brings a broader classification of developed methodologies for treatment of CTLSs.

Waterborne carboxyl-terminated hyperbranched oligomer polyester ligand: Synthesis, characterization and chelation with chromium(III)

NASA Astrophysics Data System (ADS)

Yao, Qi; Li, Chenying; Huang, Henghui; Chen, Hualin; Liu, Bailing

2017-09-01

A series of carboxyl-terminated hyperbranched oligomer polyester (HBP) with different degree of branching (DB) and number average molar mass (Mbarn) have been prepared. The molecular structure, degree of branching, molecular mass and its distribution of HBP were investigated by FTIR, 1H NMR, and GPC, respectively. And the coordination number, stability constant and degree of dissociation (α) between HBP and chromium(Ⅲ) were measured via continuous variation method (Job's plot). Experimental results show that the coordination capability between HBP and chromium(Ⅲ) affected by both DB and molecular mass, and the latter plays a decisive role. Moreover HBP outperforms low molecular weight of organic acids (citric acid, acetic acid) and linear polyacrylic acid with similar molecular mass. The coordination number and stability constants of HBP-3 (Mbarn = 1713 Da, Mbarw /Mbarn (PDI) = 1.11 and DB = 0.72) can reach 4 and 6.55e+008, which demonstrated it can be selected as a good ligand to coordination with chromium(Ⅲ). Therefore HBP can be used as chrome auxiliary in chrome tanning to improve the absorption of chromium.

Hardening parts by chrome plating in manufacture and repair

NASA Astrophysics Data System (ADS)

Astanin, V. K.; Pukhov, E. V.; Stekolnikov, Y. A.; Emtsev, V. V.; Golikova, O. A.

2018-03-01

In the engineering industry, galvanic coatings are widely used to prolong the service life of the machines, which contribute to the increase in the strength of the parts and their resistance to environmental influences, temperature and pressure drops, wear and fretting corrosion. Galvanic coatings have been widely applied in engineering, including agriculture, aircraft building, mining, construction, and electronics. The article focuses on the manufacturing methods of new agricultural machinery parts and the repair techniques of worn parts by chrome plating. The main attention is paid to the unstable methods of chromium deposition (in pulsed and reversing modes) in low-concentration electrolytes, which makes it possible to increase the reliability and durability of the hardened parts operation by changing the conditions of electrocrystallization, that is, directed formation of the structure and texture, thickness, roughness and microhardness of chromium plating. The practical recommendations are given on the current and temperature regimes of chromium deposition and composition of baths used for the restoration and hardening of the machine parts. Moreover, the basic methods of machining allowances removal are analysed.

Useful surface parameters for biomaterial discrimination.

PubMed

Etxeberria, Marina; Escuin, Tomas; Vinas, Miquel; Ascaso, Carlos

2015-01-01

Topographical features of biomaterials' surfaces are determinant when addressing their application site. Unfortunately up to date there has not been an agreement regarding which surface parameters are more representative in discriminating between materials. Discs (n = 16) of different currently used materials for implant prostheses fabrication, such as cast cobalt-chrome, direct laser metal soldered (DLMS) cobalt-chrome, titanium grade V, zirconia (Y-TZP), E-glass fiber-reinforced composite and polyetheretherketone (PEEK) were manufactured. Nanoscale topographical surface roughness parameters generated by atomic force microscopy (AFM), microscale surface roughness parameters obtained by white light interferometry (WLI) and water angle values obtained by the sessile-water-drop method were analyzed in order to assess which parameter provides the best optimum surface characterization method. Correlations between nanoroughness, microroughness, and hydrophobicity data were performed to achieve the best parameters giving the highest discriminatory power. A subset of six parameters for surface characterization were proposed. AFM and WLI techniques gave complementary information. Wettability did not correlate with any of the nanoroughness parameters while it however showed a weak correlation with microroughness parameters. © Wiley Periodicals, Inc.

Lipid peroxidation in workers exposed to hexavalent chromium.

PubMed

Huang, Y L; Chen, C Y; Sheu, J Y; Chuang, I C; Pan, J H; Lin, T H

1999-02-26

The aim of this study was to investigate whether exposure to hexavalent chromium induces lipid peroxidation in human. This study involved 25 chrome-plating factory workers and a reference group of 28 control subjects. The whole-blood and urinary chromium concentrations were determined by graphite furnace atomic absorption spectrophotometry. Malondialdehyde (MDA), the product of lipid peroxidation, was determined by high-performance liquid chromatography, and the activities of protective enzymes were measured by ultraviolet-visible spectrophotometry. In the chrome-plating workers, the mean concentrations of chromium in blood and urine were 5.98 microg/L and 5.25 microg/g creatinine, respectively; the mean concentrations of MDA in blood and urine were 1.7 micromol/L and 2.24 micromol/g creatinine. The concentrations of both chromium and MDA in blood and urine were significantly higher in the chromium-exposed workers. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) were not markedly different between control and exposed workers. Data suggest that MDA may be used as a biomarker for occupational chromium exposure. Antioxidant enzymic activities are not a suitable marker for chromium exposure.

PMF and PSCF based source apportionment of PM2.5 at a regional background site in North China

NASA Astrophysics Data System (ADS)

Zong, Zheng; Wang, Xiaoping; Tian, Chongguo; Chen, Yingjun; Fu, Shanfei; Qu, Lin; Ji, Ling; Li, Jun; Zhang, Gan

2018-05-01

To apportion regional PM2.5 (atmospheric particles with aerodynamic diameter < 2.5 μm) source types and their geographic pattern in North China, 120 daily PM2.5 samples on Beihuangcheng Island (BH, a regional background site in North China) were collected from August 20th, 2014 to September 15th, 2015 showing one-year period. After the chemical analyses on carbonaceous species, water-soluble ions and inorganic elements, various approaches, such as Mann-Kendall test, chemical mass closure, ISORROPIA II model, Positive Matrix Factorization (PMF) linked with Potential Source Contribution Function (PSCF), were used to explore the PM2.5 speciation, sources, and source regions. Consequently, distinct seasonal variations of PM2.5 and its main species were found and could be explained by varying emission source characteristics. Based on PMF model, seven source factors for PM2.5 were identified, which were coal combustion + biomass burning, vehicle emission, mineral dust, ship emission, sea salt, industry source, refined chrome industry with the contribution of 48.21%, 30.33%, 7.24%, 6.63%, 3.51%, 3.2%, and 0.88%, respectively. In addition, PSCF analysis using the daily contribution of each factor from PMF result suggested that Shandong peninsula and Hebei province were identified as the high potential region for coal combustion + biomass burning; Beijing-Tianjin-Hebei (BTH) region was the main source region for industry source; Bohai Sea and East China Sea were found to be of high source potential for ship emission; Geographical region located northwest of BH Island was possessed of high probability for sea salt; Mineral dust presumably came from the region of Mongolia; Refined chrome industry mostly came from Liaoning, Jilin province; The vehicle emission was primarily of BTH region origin, centring on metropolises, such as Beijing and Tianjin. These results provided precious implications for PM2.5 control strategies in North China.

Wear Analysis in THA Utilizing Oxidized Zirconium and Crosslinked Polyethylene

PubMed Central

Garvin, Kevin L.; Mangla, Jimmi; Murdoch, Nathan; Martell, John M.

2008-01-01

Oxidized zirconium, a material with a ceramic surface on a metal substrate, and highly cross-linked polyethylene are two materials developed to reduce wear. We measured in vivo femoral head penetration in patients with these advanced bearings. We hypothesized the linear wear rates would be lower than those published for cobalt-chrome and standard polyethylene. We retrospectively reviewed a select series of 56 THAs in a relatively young, active patient population utilizing oxidized zirconium femoral heads and highly cross-linked polyethylene acetabular liners. Femoral head penetration was determined using the Martell computerized edge-detection method. All patients were available for 2-year clinical and radiographic followup. True linear wear was 4 μm/year (95% confidence intervals, ± 59 μm/year). The early wear rates in this cohort of relatively young, active patients were low and we believe justify the continued study of these alternative bearing surfaces. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18946711

Reduction of hexavalent chromium collected on PVC filters.

PubMed

Shin, Y C; Paik, N W

2000-01-01

Chromium exists at various valences, including elemental, trivalent, and hexavalent chromium, and undergoes reduction-oxidation reactions in the environment. Since hexavalent chromium is known as a human carcinogen, it is most important to evaluate the oxidation-reduction characteristics of the hexavalent chromium species. Although hexavalent chromium can be reduced to trivalent state, the detailed information on this in workplace environments is limited. The purpose of this study was to investigate hexavalent chromium reduction in time in various conditions. A pilot chrome plating operation was prepared and operated in a laboratory for this study. There was evidence that the hexavalent chromium was reduced by time after mist generation. The percentage ratio (with 95% confidence intervals in parentheses) of hexavalent chromium to total chromium was almost 100% (99.1 approximately 102.3) immediately after mist generation, and was reduced to 87.4% (84.8 approximately 89.9) at 1 hour and 81.0% (78.3 approximately 83.5) at 2 hours, respectively. Another test indicated that hexavalent chromium collected on PVC filters was also reduced by time after sampling. Hexavalent chromium was reduced to 90.8% (88.2 approximately 93.3) at 2 hours after sampling. It also was found that hexavalent chromium was reduced during storage in air. It is recommended that air samples of hexavalent chromium be protected against reduction during storage.

Influence of substrate metal alloy type on the properties of hydroxyapatite coatings deposited using a novel ambient temperature deposition technique.

PubMed

Barry, J N; Cowley, A; McNally, P J; Dowling, D P

2014-03-01

Hydroxyapatite (HA) coatings are applied widely to enhance the level of osteointegration onto orthopedic implants. Atmospheric plasma spray (APS) is typically used for the deposition of these coatings; however, HA crystalline changes regularly occur during this high-thermal process. This article reports on the evaluation of a novel low-temperature (<47°C) HA deposition technique, called CoBlast, for the application of crystalline HA coatings. To-date, reports on the CoBlast technique have been limited to titanium alloy substrates. This study addresses the suitability of the CoBlast technique for the deposition of HA coatings on a number of alternative metal alloys utilized in the fabrication of orthopedic devices. In addition to titanium grade 5, both cobalt chromium and stainless steel 316 were investigated. In this study, HA coatings were deposited using both the CoBlast and the plasma sprayed techniques, and the resultant HA coating and substrate properties were evaluated and compared. The CoBlast-deposited HA coatings were found to present similar surface morphologies, interfacial properties, and composition irrespective of the substrate alloy type. Coating thickness however displayed some variation with the substrate alloy, ranging from 2.0 to 3.0 μm. This perhaps is associated with the electronegativity of the metal alloys. The APS-treated samples exhibited evidence of both coating, and significantly, substrate phase alterations for two metal alloys; titanium grade 5 and cobalt chrome. Conversely, the CoBlast-processed samples exhibited no phase changes in the substrates after depositions. The APS alterations were attributed to the brief, but high-intensity temperatures experienced during processing. Copyright © 2013 Wiley Periodicals, Inc.

nStudy: A System for Researching Information Problem Solving

ERIC Educational Resources Information Center

Winne, Philip H.; Nesbit, John C.; Popowich, Fred

2017-01-01

A bottleneck in gathering big data about learning is instrumentation designed to record data about processes students use to learn and information on which those processes operate. The software system nStudy fills this gap. nStudy is an extension to the Chrome web browser plus a server side database for logged trace data plus peripheral modules…

IN-SITU REDUCTION OF CHROMATE-CONTAMINATED SOILS AND SEDIMENTS BY SODIUM DITHIONITE: A FIELD-SCALE STUDY

EPA Science Inventory

A chrome-plating shop had been the source of discharges of acidic chromium wastes into the soils and groundwater beneath the shop at the USCG Support Center near Elizabeth City, NC. An initial characterization of the site was conducted in 1990 and 1991 to determine the extent of...

Environmentally Friendly Zirconium Oxide Pretreatment

DTIC Science & Technology

2013-05-01

during the conversion of the highly soluble hexavalent chromate ions to an inert and relatively insoluble trivalent chromium oxide layer. Depletion of...are being used commercially in automotive and other industrial operations as replacements to hexavalent chromium -based and zinc phosphate...Society for Testing and Materials AVCRAD Aviation Classification Repair Activity Depot Chrome (VI) Hexavalent Chromium CRS Cold Rolled Steel

78 FR 24426 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-25

... application for the Kineflex/C Cervical Artificial Disc sponsored by SpinalMotion. The Kineflex/C is a metal-on-metal (cobalt chrome molybdenum alloy) cervical total disc replacement device. The Kineflex/C is... degenerative disc disease (DDD) where DDD is defined as discogenic back pain with degeneration of the disc as...

Electrodeposited Nano Co-P: Coating Development and Technology Insertion at NADEP-JAX

DTIC Science & Technology

2008-02-27

Properties nCoP Hard Chrome Hardness 530-580 VHN 800-1200 VHN Ductility Elongation 2-7% < 1% Abrasive Wear (Taber) CS-17 wheels 17-20 mg/1000 cycles 3 mg...gage) - Due to high stress concentration (no runout ) Prior fatigue data invalid – testing to be repeated Gage Failure Transition region failure SERDP

Late Eocene 3He and Ir anomalies associated with ordinary chondritic spinels

NASA Astrophysics Data System (ADS)

Boschi, Samuele; Schmitz, Birger; Heck, Philipp R.; Cronholm, Anders; Defouilloy, Céline; Kita, Noriko T.; Monechi, Simonetta; Montanari, Alessandro; Rout, Surya S.; Terfelt, Fredrik

2017-05-01

During the late Eocene there was an enigmatic enhancement in the flux of extraterrestrial material to Earth. Evidence comes from sedimentary 3He records indicating an increased flux of interplanetary dust during ca. 2 Myr, as well as two very large impact structures, Popigai (100 km diameter) and Chesapeake Bay (40-85 km), that formed within 10-20 kyr at the peak of the 3He delivery. The Massignano section in Italy has one of the best sedimentary records of these events, including a well-defined 3He record, an Ir-rich ejecta bed related to the Popigai impact event, and two smaller Ir anomalies. Recently we showed that the Popigai ejecta is associated with a significant enrichment of chromite grains (>63 μm) with an H-chondritic elemental composition (17 grains in 100 kg of rock). Most likely these grains are unmelted fragments from the impactor. Slightly higher up (ca. 20 cm) in the section, where a small Ir anomaly possibly related to the Chesapeake Bay impact has been measured, we found a weak enrichment in L-chondritic grains (8 grains in 208 kg of rock). Here we report an extended data set increasing the total amount of sediment dissolved in acid and searched for extraterrestrial chromite grains from 658 to 1168 kg. In altogether 760 kg of background sediment from 17 levels over 14 m of strata outside the interval corresponding to the Popigai and Chesapeake Bay impacts, we only found 2 extraterrestrial chromite grains. Both grains have L-chondritic compositions and were found in a 100 kg sample from the ca. 10.25 m level in the section where the second of the smaller Ir anomalies has been reported. A correlation appears to exist between Ir, 3He and chromite from ordinary chondrites. We also report oxygen three-isotope measurements of the extraterrestrial chromite grains associated with the Popigai ejecta and confirm an H-chondritic composition. The new results strengthen our scenario that the upper Eocene 3He and Ir enrichments originate from the asteroid belt rather than the Oort cloud as originally proposed when the 3He anomaly was discovered. The generally low background concentrations of extraterrestrial chromite through the section speak against any major single asteroid breakup event such as in the mid-Ordovician after the break-up of the L-chondrite parent body. Instead the data reconcile with a small, possibly a factor of 2-3, increase in the flux of extraterrestrial material to Earth, but of both H- and L-chondritic composition. We also report the composition of all the 2310 terrestrial chrome spinel grains recovered, and show that their chemical composition indicates a dominantly regional ophiolitic source. Four anomalous chrome spinel grains with high Ti and V concentrations were found in the Popigai ejecta. These grains originate from Siberian Traps basalts in the Popigai crater at the time of impact.

Total and Viable Legionella pneumophila Cells in Hot and Natural Waters as Measured by Immunofluorescence-Based Assays and Solid-Phase Cytometry ▿†

PubMed Central

Parthuisot, N.; Binet, M.; Touron-Bodilis, A.; Pougnard, C.; Lebaron, P.; Baudart, J.

2011-01-01

A new method was developed for the rapid and sensitive detection of viable Legionella pneumophila. The method combines specific immunofluorescence (IF) staining using monoclonal antibodies with a bacterial viability marker (ChemChrome V6 cellular esterase activity marker) by means of solid-phase cytometry (SPC). IF methods were applied to the detection and enumeration of both the total and viable L. pneumophila cells in water samples. The sensitivity of the IF methods coupled to SPC was 34 cells liter−1, and the reproducibility was good, with the coefficient of variation generally falling below 30%. IF methods were applied to the enumeration of total and viable L. pneumophila cells in 46 domestic hot water samples as well as in cooling tower water and natural water samples, such as thermal spring water and freshwater samples. Comparison with standard plate counts showed that (i) the total direct counts were always higher than the plate counts and (ii) the viable counts were higher than or close to the plate counts. With domestic hot waters, when the IF assay was combined with the viability test, SPC detected up to 3.4 × 103 viable but nonculturable L. pneumophila cells per liter. These direct IF methods could be a powerful tool for high-frequency monitoring of domestic hot waters or for investigating the occurrence of viable L. pneumophila in both man-made water systems and environmental water samples. PMID:21742913

Speciation studies of nickel and chromium in wastewater from an electroplating plant.

PubMed

Kiptoo, Jackson K; Ngila, J Catherine; Sawula, Gerald M

2004-09-08

A speciation scheme involving the use of flame atomic absorption spectrometry (FAAS) and differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) techniques was applied to studies of nickel and chromium in wastewater from a nickel-chrome electroplating plant. Dimethylglyoxime (DMG) and diethylenetriaminepentaacetic acid (DTPA) were employed as complexing agents for adsorptive voltammetric determination of Ni and Cr, respectively. Cr(III) and Cr(VI) were determined by exploiting differences in their reactivity towards DTPA at HMDE. Total dissolved metal content was in the range 2906-3141 and 30.7-31.2mgl(-1) for Ni and Cr, respectively. A higher percentage of the metal was present as labile species (mean value of 67.9% for Ni and 79.8% for Cr) suggesting that strongly binding ligands are not ubiquitous in the sample. About 77.8% of Cr was found to exist in the higher oxidization state, Cr(IV). Results on effect of dilution on lability of the metal forms in the sample using DPAdCSV showed slight peak shifts to a more negative (cathodic) value by -0.036V for Ni and -0.180V for Cr with a dilution factor of 100, while peak intensity (cathodic current) remained fairly constant.

Pigment Synthesis for the Exploration of Binding Media Using a Lead-Free Alternative to Chrome Yellow

ERIC Educational Resources Information Center

Gaquere-Parker, Anne C.; Hill, Patricia S.; Haaf, Michael P.; Parker, Cass D.; Doles, N. Allie; Yi, Amanda K.; Kaminski, Todd A.

2017-01-01

Generating enthusiasm among nonscience majors in a laboratory course is a difficult task. Often, students are asked to perform a precipitation reaction, only to collect and then safely dispose of the solid without detailing composition, properties, or uses. In an effort to keep the students engaged, this laboratory exercise presents an innovative…

Engineering Design Handbook: Maintenance Engineering Techniques

DTIC Science & Technology

1975-06-30

resistance and lustrous appearance. Relatively expensive. Spec- ify hard chrome plate for exceptionally hard abrasion-resistant surface . Has low...36 Bearing Seals 3-36 Derating 3-37 Lubrication 3-37 Fixed Joints 3-37 Self-adjusting Components ." 3-38 Corrosion Aspects 3-38 Material...Troubleshooting Considerations by Army Command Category •■■ Fixed Plant/Defense Communications and USASA Equipment Army Aircraft Automotive and

Evaluation of Microcomposite Coatings for Chrome Replacement

DTIC Science & Technology

2009-09-02

Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time...of information . Send comments regarding this burden estimate or any other aspect of this collection of information , including suggestions for reducing...this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204

Hexavalent Chromium Free Coatings Projects for Aerospace Applications

DTIC Science & Technology

2012-08-01

1-Evaluate trivalent chromium pretreatment (TCP) for use on aluminum  2-Evaluate three hexavalent chrome free alternatives to DoD-P-15328 wash...UNCLASSIFIED UNCLASSIFIED Hexavalent Chromium Free Coatings Projects for Aerospace Applications Report Documentation Page Form...COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Hexavalent Chromium Free Coatings Projects for Aerospace Applications 5a. CONTRACT NUMBER

46 CFR 160.061-2 - Requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Leader, wire, 0.011-inch diameter, 27-pound test (with No. 3 snap on one end and No. 7 swivel on the other end) 6-inch length 2 ea. 6 Leader, wire, 0.016-inch diameter, 58-pound test (with No. 3 snap on... shank, blade length 23/16 inches, width 13/16 inch, weight 1/4 ounce, stainless steel or chrome plated...

46 CFR 160.061-2 - Requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Leader, wire, 0.011-inch diameter, 27-pound test (with No. 3 snap on one end and No. 7 swivel on the other end) 6-inch length 2 ea. 6 Leader, wire, 0.016-inch diameter, 58-pound test (with No. 3 snap on... shank, blade length 23/16 inches, width 13/16 inch, weight 1/4 ounce, stainless steel or chrome plated...

Affinities of the Boletus chromapes group to Royoungia and the description of two new genera, Harrya and Australopilus

Treesearch

Roy E. Halling; Mitchell Nuhn; Todd Osmundson; Nigel Fechner; James M. Trappe; Kasem Soytong; David Arora; David S. Hibbett; Manfred Binder

2012-01-01

Harrya is described as a new genus of Boletaceae to accommodate Boletus chromapes, a pink-capped bolete with a finely scabrous stipe adorned with pink scabers, a chrome yellow base and a reddish-brown spore deposit. Harrya is a unique generic lineage with two species, one of which is newly described (

"A Chrome Yellow Blackboard with Blue Chalk": New Education and the New Architecture--Modernism at Koornong School

ERIC Educational Resources Information Center

Goad, Philip

2010-01-01

This paper examines, through one school's location in Australia, the international reach and nature of the networks associated with New Education; the aims and ideals of Clive and Janet Nield, the main protagonists behind the venture of Koornong School; what transformations they brought to progressive education; and the deliberate assembling of a…

Supplier Perspective: Paints & Finishes for Corrosion Protection of Military Vehicles

DTIC Science & Technology

2010-06-15

Systems , Oshkosh Truck, General Dynamics, AM General. Automotive approvals include Honda , Toyota , General Motors, Ford, Chrysler, BMW, Subaru, Nissan...Military Compliance EXAMPLE OF AN INFERIOR PROCESS MIL-DTL-5541 Aluminum pretreatment conveyor system using a trivalent chrome pretreatment...Automotive has become a leader in corrosion prevention. Vehicles last much longer due to improved paint systems . Much of this is attributed to

THE APPLICATION OF IN SITU PERMEABLE REACTIVE (ZERO-VALENT IRON) BARRIER TECHNOLOGY FOR THE REMEDIATION OF CHROMATE-CONTAMINATED GROUNDWATER: A FIELD TEST

EPA Science Inventory

A small-scale field test was initiated in September 1994 to evaluate the in situ remediation of groundwater contaminated with chromate using a permeable reactive barrier composed of a mixture of zero-valent Fe, sand and aquifer sediment. The site used was an old chrome-plating f...

Lexicon Sextant: Modeling a Mnemonic System for Customizable Browser Information Organization and Management

ERIC Educational Resources Information Center

Shen, Siu-Tsen

2016-01-01

This paper presents an ongoing study of the development of a customizable web browser information organization and management system, which the author has named Lexicon Sextant (LS). LS is a user friendly, graphical web based add-on to the latest generation of web browsers, such as Google Chrome, making it easier and more intuitive to store and…

Acquisition Environment, Safety, and Occupational Health: Lessons Learned From DoD Acquisition Systems Engineering Program Support Reviews

DTIC Science & Technology

2011-05-01

not integrated Lack of emphasis on implementing ESOH mitigations Failure to address USD (AT&L) hexavalent chrome policy 12 ODUSD(I&E) / CMRM Value of...4.1, Design Considerations Factor 4.1.4, ESOH Factor 4.1.7, Corrosion ( Hexavalent Chromium) 6 ODUSD(I&E) / CMRM 1. Mission Capabilities – Clarity and

Low Temperature Cure Powder Coatings

DTIC Science & Technology

2013-05-01

operations Minimize worker exposure to VOCs, HAPs, and hexavalent chrome Passed objective AF Engr Qual Plan = Air Force Engineer Quality Plan MIL-PRF...Inconclusive • Inconclusive • Not applicable (N/A) • Passed criteria Reduction of hexavalent chromium use • Passed objective Reduction of hazardous...compliance. The implementation of the OSHA Final Rule designating the permissible exposure limit (PEL) for hexavalent chromium is a significant

Managing Chemical & Material Risks

DTIC Science & Technology

2011-12-01

Certification Program Acquisition, Technology and Logistics 9 DoD Hexavalent Chromium Risk Reduction Non- Chrome Primer II EXAVAJ ENT CHROM lrUMI...Royal Demolition eXplosive (RDX) • Cyclotrimethylenetrinitramine  Hexavalent Chromium (Cr6+) Naphthalene …pending downgrade to watch list Beryllium...T1me (secondo) 700 Acquisition, Technology and Logistics 10 Hexavalent Chromium Risk Management Actions • DoD minimization policy signed April

NAVAIR Progress in Assessing, Validating and Implementing Non-Chromate Primers (Briefing charts)

DTIC Science & Technology

2011-02-09

logistics for any new coating or coating system NAVAIR Application Areas for Hexavalent Chromium Alternatives: Status Components/ Structure... Hexavalent chromium alternatives Sacrificial Coating Post Treatment MIL-A-8625 Anodize Avionics/ Electronics Magnesium/Titanium Conversion Aluminum Anodizing...Aluminum Pretreatment Type IC Seal Type IIB Seal Type II Seal Phosphating Rinse (Aluminum)Rinse (Steel) Cadmium Zinc-Nickel Aluminum Bonding Chrome

Treatment of chrome plating wastewater (Cr+6) using activated alumina.

PubMed

Sarkar, Sudipta; Gupta, Anirban

2003-01-01

Suitability of activated alumina for removal of hexavalent chromium from electroplating wastewater has been investigated. Activated alumina exhibited good sorption capacity for hexavalent chromium and pH has no pronounced effect on the sorption capacity. Both batch and column adsorption studies have been carried out and an adsorption column design indicated reasonable depth of column for practical application.

Effects of Nonadecafluorodecanoic Acid on Tissue Fatty Acids of the Rat.

DTIC Science & Technology

1982-01-01

REVIEW Perfluorinated compounds have wide application. Perfluorocarboxylic and perfluorosulfonic acids have found commercial utilization in plating...readily obtainable in crystalline form. 1 Perfluorocarboxylic and perfluorosulfonic acids are used commercially in plating systems and as wetting agents...are generally considered to be metaboli- cally inert, but perfluorohexane causes reduction of microsomal cyto- chrome P-450 in vitro and perfluoro -n

Biosorption of trivalent chromium by free and immobilized blue green algae: kinetics and equilibrium studies.

PubMed

Shashirekha, V; Sridharan, M R; Swamy, Mahadeswara

2008-03-01

The process of biosorption of trivalent chromium (Cr(3+)) by live culture of Spirulina platensis and the sorption potential by the dried biomass, in both free and immobilized states have been investigated for a simulated chrome liquor in the concentration range of 100-4500 ppm. Both live and dried biomass were very good biosorbents as they could remove high amounts of chromium from tannery wastewater. Polyurethane foam and sodium alginate were used as immobilizing agents and their performances compared. Biosorption kinetic data on Cr(3+) sorption onto dried biomass were analyzed using pseudo-first-and pseudo-second-order kinetic models in batch column experiments. The second-order equation was more appropriate to predict the rate of biosorption. Subsequently, the effects of height of packing & diameter of the column, concentration of blue-green algae (BGA) in varying amounts of sodium alginate, chromium concentration were studied. The results fit into both Langmuir & Freundlich isotherm models with very high regression coefficients. Furthermore, equilibrium studies using retan chrome liquor (RCL), with a chromium concentration of 1660 ppm, obtained from a tannery also showed promising results. In general, our studies indicate the efficacy of the algal species in removal of chromium from tannery wastewater.

A new critical dimension metrology for chrome-on-glass substrates based on s-parameter measurements extracted from coplanar waveguide test structures

NASA Astrophysics Data System (ADS)

Nwokoye, Chidubem A.; Zaghloul, Mona; Cresswell, Michael W.; Allen, Richard A.; Murabito, Christine E.

2006-10-01

The technical objective of the work reported here is to assess whether radio-frequency (RF) measurements made on coplanar waveguide (CPW) test structures, which are replicated in conducting material on insulating substrates, could be employed to extract the critical dimension (CD) of the signal line using its center-to-center separation from the groundlines as a reference. The specific near-term objective is to assess whether this CPW-based CD-metrology has sensitivity and repeatability competitive with the other metrology techniques that are now used for chrome-on-glass (COG) photomasks. An affirmative answer is encouraging because advancing to a non-contact and non-vacuum implementation would then seem possible for this application. Our modeling of specific cases shows that, when the pitch of the replicated lines of the CPW is maintained constant, the sensitivity of its characteristic impedance to the CDs of the signal and ground lines is approximately 60 Ω/μm. This is a potentially useful result. For the same implementation, the quantity ∂C/∂w has a value of approximately 45 (pF/m)/μm, which appears to be large enough to provide acceptable accuracy.

Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tahiri, S.; Albizane, A.; Messaoudi, A.

2007-07-01

The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH){sub 2} was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 deg. C are Cr{sub 2}O{sub 3} and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 deg. C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographsmore » show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 deg. C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 deg. C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO{sub 4} and CaCO{sub 3}.« less

In the year 2525, if x ray is still alive, if lithography can survive, they may find...

NASA Astrophysics Data System (ADS)

Nistler, John L.; Michael, Mark; Hause, Fred N.; Edwards, Richard D.

1998-12-01

Data and discussions will be presented on the NTRM, National Technology Roadmap, for reticles based on a Process Integration perception. Specifically two layers are considered for this paper, the gate layer which is primarily a chrome geometry mask with a lot of open glass and a local interconnect layer which is primarily a chrome plate using clear geometries. Information from other sources is used where appropriate and actual in-house data is used to illustrate specific points. Realizing that demands from different customers for specific types of features tend to drive specific mask makers and their decisions on equipment purchases and processes. We attempt to help predict where Integration approaches have either caused a lag in technology pushes or have actually speeded up certain requirements. Discussions of integration requirements, which tend to push maskmakers, will be presented. Along with typical design approaches in OPC and PSM which either will push technology or actually slow down the trend towards smaller geometries. In addition, data will be presented showing how specific stepper characteristics may actually drive the customer's criteria, thus changing the requirements from customer to customer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant, C.; Dobbs, A.J.

Salts of copper, chromium and arsenic are used together in water soluble formulations for the preservation of wood against insect and fungal attack. Copper/chrome/arsenic (CCA) preservatives are of proven efficacy and, used correctly, ensure a useful service life for timber for 30 years or more with little, if any, attendant threat to the environment from the treated wood itself. The preservative treatment site can, however, provide a point of entry for the preservative into the general environment by way of spills and leaks of the treating fluid and run-off from treated wood, with resultant contamination of the surrounding soil. Themore » possible effects of the CCA salts on plant growth and metals uptake are the subject of this paper. In a series of greenhouse pot experiments the effects of varying concentrations of CCA in soil on the germination, growth and cropping of beans, carrots and tomatoes was studied. Crops produced by the plants were analyzed for their copper, chromium and arsenic contents. Additionally, grasses were grown to assess possible land reclamation difficulties. It was found that soil having a combined copper, chromium and arsenic concentration of approximately 7000 ppM completely inhibited the growth of all the plants tested, while certain concentrations below this inhibited or retarded growth to some degree. Carrots grown in soil containing approximately 1000 ppM Cu, Cr, As (200 ppM As) produced crops containing nearly twice the current recommended limit for arsenic in food. Relating the levels of CCA used in the experimentallydosed soil with the amounts found in soil samples taken from preservative treatment sites, it is apparent that many contaminated areas would not support plant life. Less heavily contaminated soil will support growth and may give rise to crops with arsenic levels higher than those deemed to be safe.« less

Internal Diameter HVAF Spraying for Wear and Corrosion Applications

NASA Astrophysics Data System (ADS)

Lyphout, C.; Björklund, S.

2015-01-01

Electrolytic hard chrome (EHC) methods are still widely utilized in the printing, automotive and off-shore industries. Alternative methods to EHC have been widely developed in the past decade by conventional HVOF processes and more recently HVAF systems, which are processing at higher kinetic energy and more particularly at lower temperature, significantly increasing wear and corrosion resistance properties. A dedicated internal diameter HVAF system is here presented, and coatings characteristics are compared to the one obtained by standard HVAF coatings. Specially R&D designed fixtures with inside bore of 200 mm have been manufactured for this purpose, with a possibility to spray samples at increasing depth up to 400 mm while simulating closed bottom bore spraying. WC-based and Cr3C2-based powder feedstock materials have been deposited onto high-strength steel substrates. Respective coating microstructures, thermally induced stresses and corrosion resistance are discussed for further optimization of coating performances. The fact that the ID-HVAF system is utilized both for spraying and gritblasting procedures is also given a particular interest.

A shape memory polymer concrete crack closure system activated by electrical current

NASA Astrophysics Data System (ADS)

Teall, Oliver; Pilegis, Martins; Davies, Robert; Sweeney, John; Jefferson, Tony; Lark, Robert; Gardner, Diane

2018-07-01

The presence of cracks has a negative impact on the durability of concrete by providing paths for corrosive materials to the embedded steel reinforcement. Cracks in concrete can be closed using shape memory polymers (SMP) which produce a compressive stress across the crack faces. This stress has been previously found to enhance the load recovery associated with autogenous self-healing. This paper details the experiments undertaken to incorporate SMP tendons containing polyethylene terephthalate (PET) filaments into reinforced and unreinforced 500 × 100 × 100 mm structural concrete beam samples. These tendons are activated via an electrical supply using a nickel-chrome resistance wire heating system. The set-up, methodology and results of restrained shrinkage stress and crack closure experiments are explained. Crack closure of up to 85% in unreinforced beams and 26%–39% in reinforced beams is measured using crack-mouth opening displacement, microscope and digital image correlation equipment. Conclusions are made as to the effectiveness of the system and its potential for application within industry.

Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill

NASA Astrophysics Data System (ADS)

Pasko, O. A.; Mochalova, T. N.

2014-08-01

The paper delivers the analysis of an 18-year dynamic pattern of land pollutants concentration in the soils of a solid domestic waste landfill. It also presents the composition of the contaminated soils from different areas of the waste landfill during its operating period. The authors calculate the concentrations of the following pollutants: chrome, nickel, tin, vanadium, lead, cuprum, zinc, cobalt, beryllium, barium, yttrium, cadmium, arsenic, germanium, nitrate ions and petrochemicals and determine a consistent pattern of their spatial distribution within the waste landfill area as well as the dynamic pattern of their concentration. Test-objects are used in experiments to make an integral assessment of the polluted soil's impact on living organisms. It was discovered that the soil samples of an animal burial site are characterized by acute toxicity while the area of open waste dumping is the most dangerous in terms of a number of pollutants. This contradiction can be attributed to the synergetic effect of the polluted soil, which accounts for the regularities described by other researchers.

Investigation of mechanical properties for open cellular structure CoCrMo alloy fabricated by selective laser melting process

NASA Astrophysics Data System (ADS)

Azidin, A.; Taib, Z. A. M.; Harun, W. S. W.; Che Ghani, S. A.; Faisae, M. F.; Omar, M. A.; Ramli, H.

2015-12-01

Orthodontic implants have been a major focus through mechanical and biological performance in advance to fabricate shape of complex anatomical. Designing the part with a complex mechanism is one of the challenging process and addition to achieve the balance and desired mechanical performance brought to the right manufacture technique to fabricate. Metal additive manufacturing (MAM) is brought forward to the newest fabrication technology in this field. In this study, selective laser melting (SLM) process was utilized on a medical grade cobalt-chrome molybdenum (CoCrMo) alloy. The work has focused on mechanical properties of the CoCrMo open cellular structures samples with 60%, 70%, and 80% designed volume porosity that could potentially emulate the properties of human bone. It was observed that hardness values decreased as the soaking time increases except for bottom face. For compression test, 60% designed volume porosity demonstrated highest ultimate compressive strength compared to 70% and 80%.

Removal of hexavalent chromium from wastewater using a new composite chitosan biosorbent.

PubMed

Boddu, Veera M; Abburi, Krishnaiah; Talbott, Jonathan L; Smith, Edgar D

2003-10-01

A new composite chitosan biosorbent was prepared by coating chitosan, a glucosamine biopolymer, onto ceramic alumina. The composite bioadsorbent was characterized by high-temperature pyrolysis, porosimetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Batch isothermal equilibrium and continuous column adsorption experiments were conducted at 25 degrees C to evaluate the biosorbent for the removal of hexavalent chromium from synthetic as well as field samples obtained from chrome plating facilities. The effect of pH, sulfate, and chloride ion on adsorption was also investigated. The biosorbent loaded with Cr(VI) was regenerated using 0.1 M sodium hydroxide solution. A comparison of the results of the present investigation with those reported in the literature showed that chitosan coated on alumina exhibits greater adsorption capacity for chromium(VI). Further, experimental equilibrium data were fitted to Langmuir and Freundlich adsorption isotherms, and values of the parameters of the isotherms are reported. The ultimate capacity obtained from the Langmuir model is 153.85 mg/g chitosan.

Two fold modified chitosan for enhanced adsorption of hexavalent chromium from simulated wastewater and industrial effluents.

PubMed

Kahu, S S; Shekhawat, A; Saravanan, D; Jugade, R M

2016-08-01

Ionic solid (Ethylhexadecyldimethylammoniumbromide) impregnated phosphated chitosan (ISPC) was synthesized and applied for enhanced adsorption of hexavalent chromium from industrial effluent. The compound obtained was extensively characterized using instrumental techniques like FT-IR, TGA-DTA, XRD, SEM, BET and EDX. ISPC showed high adsorption capacity of 266.67mg/g in accordance with Langmuir isotherm model at pH 3.0 due to the presence of multiple sites which contribute for ion pair and electrostatic interactions with Cr(VI) species. The sorption kinetics and thermodynamic studies revealed that adsorption of Cr(VI) followed pseudo-second-order kinetics with exothermic and spontaneous behaviour. Applicability of ISPC for higher sample volumes was discerned through column studies. The real chrome plating industry effluent was effectively treated with total chromium recovery of 94%. The used ISPC was regenerated simply by dilute ammonium hydroxide treatment and tested for ten adsorption-desorption cycles with marginal decrease in adsorption efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Problems of Determining the Content of Cr(VI) in Raw Materials and Materials Containing Chromite Ore.

PubMed

Stec, Katarzyna

2017-11-02

Materials made with chromite ore are widely applied in the industry metallurgy as well as in the foundry industry. The oxidation number of chromium in these materials is both (III) and (VI). Currently there are no procedures allowing proper determination of chrome in chromite ores and ore-containing materials. The analytical methods applied, which are dedicated to a very narrow range of materials, e.g., cement, and cannot be applied in the case of materials which, apart from trace amounts of Cr(VI), contain mainly compounds of Cr(III), Fe(III) as well as trace compounds of Cu(II), Ni(II) and V(V). In the work particular attention has been paid to the preparation of test samples and creating measurement conditions in which interferences from Cr(III) and Fe(III) spectral lines could be minimized. Two separate instrumental measurement techniques have been applied: Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP AES) and the spectrophotometric method using diphenylcarbazide.

Photomask linewidth comparison by PTB and NIST

NASA Astrophysics Data System (ADS)

Bergmann, D.; Bodermann, B.; Bosse, H.; Buhr, E.; Dai, G.; Dixson, R.; Häßler-Grohne, W.; Hahm, K.; Wurm, M.

2015-10-01

We report the initial results of a recent bilateral comparison of linewidth or critical dimension (CD) calibrations on photomask line features between two national metrology institutes (NMIs): the National Institute of Standards and Technology (NIST) in the United States and the Physikalisch-Technische Bundesanstalt (PTB) in Germany. For the comparison, a chrome on glass (CoG) photomask was used which has a layout of line features down to 100 nm nominal size. Different measurement methods were used at both institutes. These included: critical dimension atomic force microscopy (CD-AFM), CD scanning electron microscopy (CD-SEM) and ultraviolet (UV) transmission optical microscopy. The measurands are CD at 50 % height of the features as well as sidewall angle and line width roughness (LWR) of the features. On the isolated opaque features, we found agreement of the CD measurements at the 3 nm to 5 nm level on most features - usually within the combined expanded uncertainties of the measurements.

Material Perception.

PubMed

Fleming, Roland W

2017-09-15

Under typical viewing conditions, human observers effortlessly recognize materials and infer their physical, functional, and multisensory properties at a glance. Without touching materials, we can usually tell whether they would feel hard or soft, rough or smooth, wet or dry. We have vivid visual intuitions about how deformable materials like liquids or textiles respond to external forces and how surfaces like chrome, wax, or leather change appearance when formed into different shapes or viewed under different lighting. These achievements are impressive because the retinal image results from complex optical interactions between lighting, shape, and material, which cannot easily be disentangled. Here I argue that because of the diversity, mutability, and complexity of materials, they pose enormous challenges to vision science: What is material appearance, and how do we measure it? How are material properties estimated and represented? Resolving these questions causes us to scrutinize the basic assumptions of mid-level vision.

Maxillary overlay removable partial dentures for the restoration of worn teeth.

PubMed

Fonseca, Júlio; Nicolau, Pedro; Daher, Tony

2011-04-01

Prolonged tooth maintenance by a more aged population considerably increases the probability of dentists having to treat patients with high levels of tooth wear. Pathological tooth wear, caused primarily by parafunction, seems to be a growing problem that affects a large number of adult patients. The clinical report presents a case of a partially edentulous patient with an elevated degree of wear in the upper jaw caused by attrition and erosion, rehabilitated with a maxillary overlay removable partial denture (ORPD) consisting of a chrome-cobalt (Cr-Co) framework with anterior acrylic resin veneers, posterior cast overlays, and acrylic resin denture bases. Removable partial prosthesis is a treatment alternative when teeth are found to be severely worn or when the patient needs a simple and economical option. Because economics is a conditional factor of the treatment, the clinician should present different treatment alternatives to the patient, in which the overlay prosthesis can be considered.

NTIAC Handbook. Revision/Supplement Number 1

DTIC Science & Technology

1982-06-01

Engi- neering, Ceramics Bldg., 22-17, 2-Chrome, Hyakunincho, Shinjiku-ku, Tokyo, Japan NTIAC-023416 4 Yamanouchi, Kazuhiko; Sachse, Wolfgang "Shear...tional Bureau of Standards, Washington, DC 20234 NTIAC-022425M Sachse, Wolfgang ; Pao, Yih-Hsing "Ultrasonic Nondestructive Testing of Materials...burg, MD, NBS SP 596, 395-406; National Bureau of Standards, Washington, DC 29234 Pao, Yih-Hsing; Sachse, Wolfgang "Ultrasonic Nondestructive Testing of

High Temperature Hot Corrosion Control by Fuel Additives (Contaminated Fuels).

DTIC Science & Technology

1987-06-01

ABSTRACT The potential of fuel additives to minimize corrosion of blade material in gas turbine engines has been analyzed by the following series of steps...INTRODUCTION High chrome steels and superalloys, which are used extensively for high temperature boilers and gas turbine (GT) engines and related...combustion gases onto turbine blades and other hot components. Among the factors expected to affect the corrosion resis

Transect studies on pine litter organic matter: decomposition and chemical properties of upper soil layers in Polish forests

Treesearch

Alicja Breymeyer; Marek Degorski; David Reed

1998-01-01

The relationship between litter decomposition rate, some chemical properties of upper soil layers (iron, manganese, zinc, copper, lead, mercury, nickel, chrome in humus-mineral horizon-A), and litter (the same eight elements in needle litter fraction) in pine forests of Poland was studied. Heavy metal content in organic-mineral horizon of soils was highly correlated...

Evaluation of the Possibility of Obtaining Tube-to-Tube Sheet Welded Joints of 15Cr5Mo Steel by Alternative Technological Process

NASA Astrophysics Data System (ADS)

Rizvanov, R. G.; Mulikov, D. Sh.; Karetnikov, D. V.; Fairushin, A. M.; Tokarev, A. S.

2018-03-01

This paper presents the results of the tests of joints of chrome-molybdenum steel, obtained by rotary friction welding. On their basis, conclusions were drawn about the weldability of this type of steel by friction welding, and also the applicability of this welding technology in the manufacture of heat exchange equipment.

UNICOAT. Development Laboratory Characterization and Field Evaluation

DTIC Science & Technology

1990-03-30

flexibility of the coatlig system and prevent cracking of the paint, especially around fasteners. Although the current paint system performs well, the...topcoat formulation that non-lead, non-chroaate, corrosion preventive coatings for aluminum can be develped. Currently, there are two military...specifications, Mil-P-52995 and Mil-P-53030, for lead and chrome free corrogion preventive primers for ferrous and non-ferrous substrates. The pigment system

Corrosion Behavior of Sacrificial Coatings on Grade 10.9 Fasteners for Multimetal Armor Applications

DTIC Science & Technology

2013-08-01

hexavalent chromium , immersion, magniplate, trivalent chromium (TCP), bolts nonchromate, hexavalent chrome, grade 10.9 fasteners, bolt-on armor...for Testing and Materials (ASTM) B633 (4) electroplated zinc with hexavalent chromium conversion coating 2. Trivalent Chromium Process (TCP): ASTM...B633 (4) electroplated zinc with trivalent chromium conversion coating 3. AlumiPlate: Process details, entire surface electroplated with aluminum (Al

An Electron-Diffraction Examination of Cast-Iron Piston Rings from Single-Cylinder Aircraft-Engine Tests

DTIC Science & Technology

1945-02-01

found t; a great extent on thn ueed cylinder barrel ( SAE 4140 steel) and to a lesser extent on the top ohrmne- plated ring of the aesembl.yafter it had...on the used cylinder barrel (W 4140 steel) used in the tests and, to a lesser extent, on the used top chrome-platedring of the piston assembly. The

Chrome-Free Paint Primer for Zn/Ni Plated High-Strength Steel (Briefing Charts)

DTIC Science & Technology

2014-11-19

restrictions on use of chromates and Cd  Strontium chromate sunset in EU - REACH: 2017  LHE ZnNi replacing LHE Cd in military and commercial...Interaction Plot for Corrosion score Data Means 10001001010.10.01 99 95 90 80 70 60 50 40 30 20 10 5 1 Corrosion score P e rc e n t 1 2 Metal Base Lognormal

Nasal manifestations in chromium industry workers.

PubMed

Aiyer, R G; Kumar, Gaurav

2003-04-01

People working in mines, plating factories, cement industries are mainly exposed to chrome substances, IIexavalent chromium has been implicated for its toxic effect on the nasal mucosa. Hereby we present a rare study of 28 patients who attended out patient department of Otorhinolaryngology at SSG Hospital, Baroda from a nearby chromium industry. This study aims to present various nasal manifestations of toxic effects of prolonged chromium exposure.

Hexavalent Chromium Minimization Strategy

DTIC Science & Technology

2011-05-01

Logistics 4 Initiative - DoD Hexavalent Chromium Minimization Non- Chrome Primer IIEXAVAJ ENT CHRO:M I~UMI CHROMIUM (VII Oil CrfVli.J CANCEfl HAnRD CD...Management Office of the Secretary of Defense Hexavalent Chromium Minimization Strategy Report Documentation Page Form ApprovedOMB No. 0704-0188...00-2011 4. TITLE AND SUBTITLE Hexavalent Chromium Minimization Strategy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Chromate dermatitis from a boiler lining.

PubMed

Rycroft, R J; Calnan, C D

1977-08-01

Chromate dermatitis is described in a mechanical fitter working inside boiler combustion chambers. A source of hexavalent chromate is traced to the action of the heat and alkaline fuel ash on trivalent chrome ore in parts of the refractory lining. Removal of the patient from this contact has resulted in almost complete clearing of his dermatitis, without any relapse, during a 9-month follow-up period.

Advanced Powder Coating Systems for Military Applications

DTIC Science & Technology

2011-05-01

UVCPC • Conclusions • DoD spends billions of dollars annually on protective organic coatings – Hexavalent chrome primer use still widespread – Contains...Elimination of Hazardous Air Pollutants (HAP) • Reduction/Elimination of ESOH Concerns – Elimination of hexavalent chromium – Elimination of free...production and release; hexavalent chromium; free isocyanates; up to 72 hrs “dry to fly” time Longer cure times than traditional primers and

Perceptions on use of home telemonitoring in patients with long term conditions - concordance with the Health Information Technology Acceptance Model: a qualitative collective case study.

PubMed

Middlemass, Jo B; Vos, Jolien; Siriwardena, A Niroshan

2017-06-26

Health information technology (HIT) may be used to improve care for increasing numbers of older people with long term conditions (LTCs) who make high demands on health and social care services. Despite its potential benefits for reducing disease exacerbations and hospitalisations, HIT home monitoring is not always accepted by patients. Using the Health Information Technology Acceptance Model (HITAM) this qualitative study examined the usefulness of the model for understanding acceptance of HIT in older people (≥60 years) participating in a RCT for older people with Chronic Obstructive Pulmonary Disease (COPD) and associated heart diseases (CHROMED). An instrumental, collective case study design was used with qualitative interviews of patients in the intervention arm of CHROMED. These were conducted at two time points, one shortly after installation of equipment and again at the end of (or withdrawal from) the study. We used Framework Analysis to examine how well the HITAM accounted for the data. Participants included 21 patients aged between 60-99 years and their partners or relatives where applicable. Additional concepts for the HITAM for older people included: concerns regarding health professional access and attachment; heightened illness anxiety and desire to avoid continuation of the 'sick-role'. In the technology zone, HIT self-efficacy was associated with good organisational processes and informal support; while ease of use was connected to equipment design being suitable for older people. HIT perceived usefulness was related to establishing trends in health status, detecting early signs of infection and potential to self-manage. Due to limited feedback to users opportunities to self-manage were reduced. HITAM helped understand the likelihood that older people with LTCs would use HIT, but did not explain how this might result in improved self-management. In order to increase HIT acceptance among older people, equipment design and organisational factors need to be considered. ClinicalTrials.gov Identifier: NCT01960907 October 9 2013 (retrospectively registered) Clinical tRials fOr elderly patients with MultiplE Disease (CHROMED). Start date October 2012, end date March 2016. Date of enrolment of the first participant was February 2013.

Treatment of highly concentrated tannery wastewater using electrocoagulation: Influence of the quality of aluminium used for the electrode.

PubMed

Elabbas, S; Ouazzani, N; Mandi, L; Berrekhis, F; Perdicakis, M; Pontvianne, S; Pons, M-N; Lapicque, F; Leclerc, J-P

2016-12-05

This paper deals with the ability of electrocoagulation (EC) to remove simultaneously COD and chromium from a real chrome tanning wastewater in a batch stirred electro-coagulation cell provided with two aluminium-based electrodes (aluminium/copper/magnesium alloy and pure aluminium). Effects of operating time, current density and initial concentration of Cr(III) and COD have been investigated. The concentrations of pollutants have been successfully reduced to environmentally acceptable levels even if the concentrated effluent requires a long time of treatment of around 6h with a 400A/m(2) current density. The aluminium alloy was found to be more efficient than pure aluminium for removal of COD and chromium. Dilution of the waste has been tested for treatment: high abatement levels could be obtained with shorter time of treatment and lower current densities. Energy consumption of the electrocoagulation process was also discussed. The dilution by half of the concentrated waste leads to a higher abatement performance of both COD and chromium with the best energy efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of subsoil and Soil Volume on the accumulation of nickel by Alyssum corsicum grown on a serpentine soil

USDA-ARS?s Scientific Manuscript database

Aims: Test the effect of soil volume and presence of subsoil on Ni hyperaccumulation. Methods: A. corsicum Duby was grown for 3 months on Chrome loam topsoil and subsoil from near Reistertown, MD, in a test of growth and Ni accumulation with varied soil masses (2.8 and 5.6 kg pot-1) to study the im...

The Labour Welfare Fund Laws (Amendment) Act, 1987 (No. 15 of 1987), 22 May 1987.

PubMed

1987-01-01

This Act authorizes funds constituted under the Mica Mines Labour Welfare Fund Act, 1946, the Limestone and Dolomite Mines Labour Welfare Fund Act, 1972, the Iron Ore Mines, Manganese Ore Mines and Chrome Mines Labour Welfare Fund Act, 1976, and the Beedi Workers Welfare Fund Act, 1976, to be applied for the provision of family welfare, including family planning education and services. full text

Challenges in the Development and Evolution of Secure Open Architecture Command and Control Systems (Briefing Charts)

DTIC Science & Technology

2013-06-01

widgets for an OA system Design-time architecture: Browser, email, widget, DB, OS Go ogle Instance architecture: Chrome, Gmail, Google...provides functionally similar components or applications compatible with an OA system design Firefox Browser, WP, calendar Opera Instance...architecture: Firefox , AbiWord, Evolution, Fedora GPL Ab1Word Google Docs Instance ardlitecture: Fire fox, OR Google cal., Google Docs, Fedora

A Miniature Stem Thermocouple Hygrometer 1

PubMed Central

Michel, Burlyn E.

1977-01-01

An unprotected chromel-constantan thermocouple was mounted in a cavity (4 × 2 × 1 mm) with rounded corners in a chrome-plated brass block (10 × 6 × 4 mm). When installed against a soybean (Glycine max [L.] Merr.) xylem face, sealed with caulking gum, and insulated with polyurethane foam and aluminum foil, even rapidly changing stem water potentials could be followed accurately. Temperature gradients can be a problem. PMID:16660155

QuEST: Qualifying Environmentally Sustainable Technologies. Volume 6

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2011-01-01

QuEST is a publication of the NASA Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM). This issue contains brief articles on: Risk Identification and Mitigation, Material Management and Substitution Efforts--Hexavalent Chrome-free Coatings and Low volatile organic compounds (VOCs) Coatings, Lead-Free Electronics, Corn-Based Depainting Media; Alternative Energy Efforts Hydrogen Sensors and Solar Air Conditioning. Other TEERM Efforts include: Energy and Water Management and Remediation Technology Collaboration.

Electroformed Nanocrystalline Coatings: An Advanced Alternative to Hard Chrome Electroplating

DTIC Science & Technology

2003-11-21

hypo/ phosphorous acid was included in the estimate. The cost analysis is given in Table 2-3. The relative consumable cost for the nanocrystalline...concentrations and phosphorous acid concentrations. While the internal stress of the Co- P deposit was affected by changes in the above-mentioned...may be occurring which consumes the phosphorous acid in solution (see Section 2.2). Table 5-1 Hardness at distance from deposit/substrate

A Comparison of Gravimetric and Photometric Aerosol Samplers

DTIC Science & Technology

2009-03-24

the potential to cause disease (Vincent, 2007; Meldrum , 1996; and ATSDR, 2001). f) Fog – discernible mist that floats in air and usually settles to...atomization, such as spraying or arising from acid baths in chrome plating. The droplets are homogenous with the parent material and range from xvi...Contaminant Control. Boston, Butterworth Publishers. Meldrum , M. (1996). Review of fibre toxicology. H.S.E. Report, London, UK, Health and Safety

USAF Corrosion Prevention and Control Enterprise - Sustainability Links

DTIC Science & Technology

2014-11-18

projects and $84M  Example of potential synergy: From FY05-14, the DoD Corrosion Program funded 21 projects on hexavalent chromium reduction  OSD...coatings, effects on structural integrity, environmental effects, etc  Some topics of interest  Inhibitor mechanisms for mg-rich primer (non- chrome ...approach  Financial and engineering resources are limited  Potential costs of corrosion are significant  Supporting replacements for hexavalent

Improving global CD uniformity by optimizing post-exposure bake and develop sequences

NASA Astrophysics Data System (ADS)

Osborne, Stephen P.; Mueller, Mark; Lem, Homer; Reyland, David; Baik, KiHo

2003-12-01

Improvements in the final uniformity of masks can be shrouded by error contributions from many sources. The final Global CD Uniformity (GCDU) of a mask is degraded by individual contributions of the writing tool, the Post Applied Bake (PAB), the Post Exposure Bake (PEB), the Develop sequence and the Etch step. Final global uniformity will improve by isolating and minimizing the variability of the PEB and Develop. We achieved this de-coupling of the PEB and Develop process from the whole process stream by using "dark loss" which is the loss of unexposed resist during the develop process. We confirmed a correspondence between Angstroms of dark loss and nanometer sized deviations in the chrome CD. A plate with a distinctive dark loss pattern was related to a nearly identical pattern in the chrome CD. This pattern was verified to have originated during the PEB process and displayed a [Δ(Final CD)/Δ(Dark Loss)] ratio of 6 for TOK REAP200 resist. Previous papers have reported a sensitive linkage between Angstroms of dark loss and nanometers in the final uniformity of the written plate. These initial studies reported using this method to improve the PAB of resists for greater uniformity of sensitivity and contrast. Similarly, this paper demonstrates an outstanding optimization of PEB and Develop processes.

Safe disposal of toxic chrome buffing dust generated from leather industries.

PubMed

Swarnalatha, S; Srinivasulu, T; Srimurali, M; Sekaran, G

2008-01-31

The high concentration of trivalent chromium along with organic/inorganic compounds in chrome buffing dust (CBD), the solid waste discharged from leather industries, causes severe groundwater contamination on land co-disposal and chronic air pollution during thermal incineration. In the present investigation, CBD was subjected to starved air incineration (SAI) at 800 degrees C in a thermal incinerator under different flow rates of oxygen to optimize the oxygen required to incinerate the organic compounds and simultaneously preventing the conversion of Cr(3+) to Cr(6+). The energy audit of SAI of buffing dust under the external supply of oxygen was carried out under different incineration conditions. The bottom ash from SAI was effectively solidified/stabilized using Portland cement and fine aggregate. The solidified blocks were tested for unconfined compressive strength and heavy metal leaching. Unconfined compressive strength of the blocks was in the range of 120-180 kg/cm(2). The stabilization of chromium(III) in the cement gel matrix was confirmed using Scanning Electron Microscopy SEM, Electron Paramagnetic Resonance spectroscopy (EPR) and X-ray diffraction spectroscopy (XRD). Leachability studies through TCLP on solidified blocks were carried out to determine the degree of leaching of chromium and organic compounds (expressed as COD) under standard conditions.

HVOF repair of steering rams for the USS Saipan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwyer, A.L.; Jones, S.A.; Wykle, R.J.

1995-12-31

The steering rams aboard the USS Saipan (LHA-2) were badly corroded after 18 years of service. These rams are hydraulically operated and change the angle of the ship`s rudder. This corrosion allowed excessive leaking of hydraulic fluid into the machinery space. Permanent repairs were required as the ship has more than 20 years of service life remaining. Two methods of repair were considered, chrome plating and a HVOF applied coating. The size, 13 in. diameter and 15 ft in length, posed a significant problem for either process. The cost of the repair was similar but the time for completion wasmore » better with the HVOF process since chrome plating would have to be accomplished off yard. The HVOF process was not available within the shipyard at the time and the process and material to be used had not been approved. Extensive testing was required to get approval to proceed, a facility to accomplish the work had to be built, and the operators and HVOF procedure had to be qualified. After completion of spraying, single point machining and honing was used to obtain the required surface finish. This was the largest single HVOF coating applied by the Navy and great interest to all concerned.« less

Size of metallic and polyethylene debris particles in failed cemented total hip replacements

NASA Technical Reports Server (NTRS)

Lee, J. M.; Salvati, E. A.; Betts, F.; DiCarlo, E. F.; Doty, S. B.; Bullough, P. G.

1992-01-01

Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements.

[Exposure to metal compounds in occupational galvanic processes].

PubMed

Surgiewicz, Jolanta; Domański, Wojciech

2006-01-01

Occupational galvanic processes are provided in more than 600 small and medium enterprises in Poland. Workers who deal with galvanic coating are exposed to heavy metal compounds: tin, silver, copper and zinc. Some of them are carcinogenic, for example, hexavalent chromium compounds, nickel and cadmium compounds. Research covered several tens of workstations involved in chrome, nickel, zinc, tin, silver, copper and cadmium plating. Compounds of metals present in the air were determined: Cr, Ni, Cd, Sn, Ag--by atomic absorption spectrometry with electrothermal atomization (ET-AAS) and Zn--by atomic absorption spectrometry with flame atomization (F-AAS). The biggest metal concentrations--of silver and copper--were found at workstations of copper, brass, cadmium, nickel and chrome plating, conducted at the same time. Significant concentrations of copper were found at workstations of maintenance bathing and neutralizing of sewage. The concentrations of metals did not exceed Polish MAC values. MAC values were not exceeded for carcinogenic chromium(VI), nickel or cadmium, either. In galvanic processes there was no hazard related to single metals or their compounds, even carcinogenic ones. Combined exposure indicators for metals at each workstation did not exceed 1, either. However, if there are even small quantities of carcinogenic agents, health results should always be taken into consideration.

Bacterial communities in pigmented biofilms formed on the sandstone bas-relief walls of the Bayon Temple, Angkor Thom, Cambodia.

PubMed

Kusumi, Asako; Li, Xianshu; Osuga, Yu; Kawashima, Arata; Gu, Ji-Dong; Nasu, Masao; Katayama, Yoko

2013-01-01

The Bayon temple in Angkor Thom, Cambodia has shown serious deterioration and is subject to the formation of various pigmented biofilms. Because biofilms are damaging the bas-reliefs, low reliefs engraved on the surface of sandstone, information about the microbial community within them is indispensable to control biofilm colonization. PCR-denaturing gradient gel electrophoresis (DGGE) analysis of biofilm samples from the pigmented sandstone surfaces showed that the bacterial community members in the biofilms differed clearly from those in the air and had low sequence similarity to database sequences. Non-destructive sampling of biofilm revealed novel bacterial groups of predominantly Rubrobacter in salmon pink biofilm, Cyanobacteria in chrome green biofilm, Cyanobacteria and Chloroflexi in signal violet biofilm, Chloroflexi in black gray biofilm, and Deinococcus-Thermus, Cyanobacteria, and Rubrobacter in blue green biofilm. Serial peeling-off of a thick biofilm by layers with adhesive sheets revealed a stratified structure: the blue-green biofilm, around which there was serious deterioration, was very rich in Cyanobacteria near the surface and Chloroflexi in deep layer below. Nitrate ion concentrations were high in the blue-green biofilm. The characteristic distribution of bacteria at different biofilm depths provides valuable information on not only the biofilm formation process but also the sandstone weathering process in the tropics.

Exploratory Visual Analytics of a Dynamically Built Network of Nodes in a WebGL-Enabled Browser

DTIC Science & Technology

2014-01-01

dimensionality reduction, feature extraction, high-dimensional data, t-distributed stochastic neighbor embedding, neighbor retrieval visualizer, visual...WebGL-enabled rendering is supported natively by browsers such as the latest Mozilla Firefox , Google Chrome, and Microsoft Internet Explorer 11. At the...appropriate names. The resultant 26-node network is displayed in a Mozilla Firefox browser in figure 2 (also see appendix B). 3 Figure 1. The

MOUNT ZIRKEL WILDERNESS AND VICINITY, COLORADO.

USGS Publications Warehouse

Snyder, George L.; Patten, Lowell L.

1984-01-01

Several areas of metallic and nonmetallic mineralization have been identified from surface occurrences within the Mount Zirkel Wilderness and vicinity, Colorado. Three areas of probable copper-lead-zinc-silver-gold resource potential, two areas of probable chrome-platinum resource potential, four areas of probable uranium-thorium resource potential, two areas of probable molybdenum resource potential, and one area of probable fluorspar potential were identified. No potential for fossil fuel or geothermal resources was identified.

Silicon-on-Sapphire Waveguides for Widely Tunable Coherent Mid-IR Sources

DTIC Science & Technology

2013-09-01

fabricated using a chrome mask. .......................................... 10 1 1. BACKGROUND The mid- infrared (IR) range between 3 m...leveraging existing sources in telecom and short-wave infrared (SWIR) bands. It has been demonstrated using silicon waveguides on silicon-on-silicon...reported [3]. The approach proposed under this project involves the four-wave mixing of a pump at a SWIR wavelength around 2 m and signals in the near

Gram-Negative Bacterial Wound Infections

DTIC Science & Technology

2013-05-01

chelator 2,2’ dipyridyl (DIP), while the production and secretion of iron chelating compounds, known as siderophores, was tested using the Chrome Azurol S...identical to that of 19606, which includes distinct peaks for DHBA and acinetobactin (Fig. 1, profile 1), while three others (3927, 4498 and 5197) make...17978 antibodies to bacteria cultured under iron-rich or iron-limiting conditions (right peaks on top panels of Fig. 2B). On the other hand, low

Studies of Lanthanide Transport in Metallic Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jinsuo; Taylor, Christopher

Metallic nuclear fuels were tested in fast reactor programs and performed well. However, metallic fuels have shown the phenomenon of FCCI that are due to deleterious reactions between lanthanide fission products and cladding material. As the burnup is increased, lanthanide fission products that contact with the cladding could react with cladding constituents such as iron and chrome. These reactions produce higher-melting intermetallic compounds and low-melting alloys, and weaken the mechanical integrity.

Manufacturing Methods and Technology Project Summary Reports.

DTIC Science & Technology

1980-12-01

deposition of chrome-copper (Cr- Cu ), dry-film photoresist application, photolithographic masking, spray etching, die bonding, ultrasonic...4) cold roll forging. Of these, the cold roll forging process is the most widely used for the pro- duction of steel and low alloy blades. It provides... sprayed Mo- Al -Ni both provide relatively good wear resistance, see Figure 1. The powder -flame sprayed aluminum bronze did not perform as well. 147 -S t. I

Integrated Printed Circuit Board (PCB) Active Cooling With Piezoelectric Actuator

DTIC Science & Technology

2012-09-01

The cooler substrate is a laminated multilayer FR-4 substrate. Individual layers are patterned to support the active element, form a resonant...prepreg epoxy. Individual FR-4 lamina were mechanically machined to pattern each layer. The layers were aligned, stacked, and laminated to form the... laminated with 70/30 copper-nickel alloy or 80/20 nickel-chrome alloy and patterned by means of photolithographic techniques and wet etching in a ferric

S8DR shield examination

NASA Technical Reports Server (NTRS)

Mason, D. G.; Mccurnin, W. R.

1973-01-01

The SNAP 8 developmental reactor lithium hydride shield was examined after being irradiated for over 7000 hours at relatively low temperature. A crack was located in the seam weld of the containment vessel, probably the result of hot short cracking under thermal stress. The LiH was visually examined at two locations and its appearance was typical of low temperature irradiated LiH. The adherence of the chrome oxide emittance coating was found to be excellent.

The National Shipbuilding Research Program. Shipyard Welding Emission Factor Development

DTIC Science & Technology

1999-09-01

percent composition in the rod/wire. Three specific HAPs of concern were identified: 1. Chrome and chromium compounds; 2. Nickel and nickel compounds...welding processes. These are: 1. Those rod/wires reported to be used in the largest amounts (> 10,000 pounds annually) did not contain chromium or...amounts ranging from less than 1,000 to greater than 10,000 pounds annually contained chromium and chromium compounds in concentrations ranging from

The United States’ National Interests in Central Asia

DTIC Science & Technology

2000-03-23

Street Journal, 16 September 1997. 49 Ibid. 50 McHugh , Jane; Elfers, Steve. “Showtime for Sergeants.” Army Times, Vol 59, Issue 17 (23 November...petroleum, coal, manganese,chrome cant deposits of gold some petroleum, coal, sulfur, gold, uranium, ore, nickel , cobalt, and rare earth metals; uranium...Management Review, April 1999. McHugh , Jane; Elfers, Steve. “Showtime for Sergeants.” Army Times, Vol 59, Issue 17 (23 November 1998. Mikhailov

Navy Successes and Challenges in Cr6+ Minimization

DTIC Science & Technology

2011-05-12

Authorization to Use Hexavalent Chromium. YES NO • Approval of alternatives by W/S PM and Corrosion SME designee. • Change technical/maintenance...Inorganic Coatings and Processes – Alternatives authorized for • Aluminum and magnesium anodizing • Hard Chrome Plating • Type II, Class 1A conversion...savings due to use of aluminum cathodes – Allows for consolidation of anodizing processes – Elimination of Hexavalent Chromium 80% 5% 14% 1% Type II

Chemical & Material Risk Management Initiatives: Reach & Cr6+ Strategies (Briefing Charts)

DTIC Science & Technology

2011-02-01

Definition Acquisition, Technology and Logistics 17 DoD Hexavalent Chromium Minimization Strategy Non‐ Chrome  Primer Acquisition, Technology and...Logistics 18 Hexavalent Chromium (Cr6+) - Some Facts • Cr6+ compounds are wonderful corrosion inhibitors • Cr6+ compounds are highly toxic – We’ve learned...and Logistics 21 DoD Hexavalent Chromium Minimization Policy Acquisition, Technology and Logistics 22 Myth-busters • The DoD policy does not ban the

The Nature of Surface Oxides on Corrosion-Resistant Nickel Alloy Covered by Alkaline Water

PubMed Central

2010-01-01

A nickel alloy with high chrome and molybdenum content was found to form a highly resistive and passive oxide layer. The donor density and mobility of ions in the oxide layer has been determined as a function of the electrical potential when alkaline water layers are on the alloy surface in order to account for the relative inertness of the nickel alloy in corrosive environments. PMID:20672134

Brush seal shaft wear resistant coatings

NASA Astrophysics Data System (ADS)

Howe, Harold

1995-03-01

Brush seals suffer from high wear, which reduces their effectiveness. This work sought to reduce brush seal wear by identifying and testing several industry standard coatings. One of the coatings was developed for this work. It was a co-sprayed PSZ with boron-nitride added for a high temperature dry lubricant. Other coatings tested were a PSZ, chrome carbide and a bare rotor. Testing of these coatings included thermal shocking, tensile testing and wear/coefficient of friction testing. Wear testing consisted of applying a coating to a rotor and then running a sample tuft of SiC ceramic fiber against the coating. Surface speeds at point of contact were slightly over 1000 ft/sec. Rotor wear was noted, as well as coefficient of friction data. Results from the testing indicates that the oxide ceramic coatings cannot withstand the given set of conditions. Carbide coatings will not work because of the need for a metallic binder, which oxidizes in the high heat produced by friction. All work indicated a need for a coating that has a lubricant contained within itself and the coating must be resistant to an oxidizing environment.

Evaluation on the Corrosion of the Three Ni-Cr Alloys with Different Composition

PubMed Central

Rao, Srinivasa B.; Chowdhary, Ramesh

2011-01-01

Dental casting alloys are widely used in contact with oral tissue for many years now. With the development of new dental alloys over the past 15 years, many questions remain unanswered about their biologic safety. Concepts and current issues concerning the response to the biologic effects of dental casting alloys are presented. In this paper, samples of three commercially available nickel-chrome (Ni-cr) casting alloys (Dentaurum, Bego, Sankin) were taken to assess their corrosion behavior, using potentiodynamic polarization method (electrochemical method) with fusayama artificial saliva as an electrolyte medium to check for their biocompatibility. The parameters for corrosion rate and corrosion resistance were obtained from computer-controlled corrosion schematic instrument, namely, potentiostat through corrosion software (power CV). The results obtained were analyzed by classic Tafel analysis. Statistical analysis was done by Student's t-test and ANOVA test. It was concluded that Dentarum and Bego showed satisfactory corrosive behavior, with exception of Sankin which depicted higher corrosion rate and least resistance to corrosion. Thus, the selection of an alloy should be made on the basis of corrosion resistance and biologic data from dental manufactures. PMID:21461232

History of the Colorado-Wyoming state line diatremes.

USGS Publications Warehouse

Collins, D.S.; Heyl, A.V.

1984-01-01

Although >90 kimberlite diatremes have been found in the area, it was not until after 1963 that these bodies were correctly identified. The presence of large inclusions of sedimentary rocks had hindered their recognition. In 1975 a diamond crystal 3.5 carats). They are usually colourless, but light-brown, blue-white, pale orange, pale to bright yellow and nearly black crystals occur. Associated minerals, including chrome-diopside, chromite, magnesian ilmenite, pyrope and omphacite, are described.-R.S.M.

Survey of Cyber Moving Target Techniques

DTIC Science & Technology

2013-09-25

Description: Details: The authors propose a very simple form of multivariant execution with two replicas where one replica runs with the stack growing ...upwards and the other runs with the stack growing down. Normally any single architecture only supports the stack growing in one direction, but the...April 2012. 8. “The NX Bit and ASLR,” Tom’s Hardware, 25 March 2009. 9. “Pwn2Own day 2: iPhone, BlackBerry beaten; Chrome, Firefox no-shows,” Ars

Studies on Rheomelanins. VI. The Apparent Lipofuscin Characteristics of Rheomelanins,

DTIC Science & Technology

1980-05-01

of aldchydes formed by the action of periodic acid on non carbohydrate conit-tining unsaturated phosphatides . At present we know only that in the o...A ’mV -5 1. Periodic Acid -Schiff Test 2. Long Ziehl-Neelsen Test for Acid Fast lilpofuscii 3. Alternative Nile Blue Method 4. Schmorl Test 5. Sudan...Black B in Alcohol 6. Chrome Alum Hematoxylin Test 7. Protein Determination 8. Specific Miucoprotein Test 9. Phosphoric Acid -Vanillin Lipid

RDT&E Progress and Plansfor Hexavalent Chromium (Cr6+)

DTIC Science & Technology

2011-05-12

RDT&E Progress and Plans for Hexavalent Chromium (Cr6+) Bruce Sartwell Weapons Systems and Platforms Program Manager E2S2 Conference May 12, 2011...2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE RDT&E Progress and Plansfor Hexavalent Chromium (Cr6+) 5a...Tasks/Projects Surface treatments and soluble inhibitors: 1. Fundamental studies of the Trivalent Chrome Process (TCP) 2. Mechanisms of selected

Demonstrating Nonhexavelent Chrome Steel Conversion Coatings on Stryker High Hard Armor Steel Hatches

DTIC Science & Technology

2014-01-01

29 Draft Joint Test Protocol – Validation of Pretreatments for Steel Armor 68 4.4.7 Rising Step Load (Stress Corrosion Cracking) 4.4.7.1...Cost Assessment 27 9. Schedule of Activities 29 10. Management and Staffing 29 11. References 30 Appendix A. Joint Test Protocol 33 Appendix B...in accordance with the tests delineated in the joint test protocol (JTP) provided in appendix A. The functional performance objectives are

Industrial Processes to Reduce Generation of Hazardous Waste at DoD facilities. Phase 3 Report. Summary of Projects of Excellence Workshops

DTIC Science & Technology

1985-12-01

cation impurities from the plating solution and anodes to oxidize trivalent chromium to hexavalent chromium . Hexa- . valent chromium ions remain on the...corrosion, or to improve its engineering properties (harlness, durability, solderability, or frictional characteristics). Chromium ic used principally...facturing consists of machining the worn part or stripping a portion of the old plate, overplating it with a thick layer of chromium (hard chrome plating

Validation of HVOF Thermal Spray Coatings as a Replacement for Hard Chrome Plating on Hydraulic/Pneumatic Actuators

DTIC Science & Technology

2007-12-01

Projects Agency (DARPA). The program evaluated HVOF, physical vapor deposition (PVD) and laser cladding , and concluded that HVOF was the best overall...components such as titanium flap tracks. 5 2.0 TECHNOLOGY DESCRIPTION 2.1 TECHNOLOGY DEVELOPMENT AND APPLICATION Technology background and...theory of operation: High-velocity oxygen-fuel (HVOF) is a standard commercial thermal spray process in which a powder of the material to be sprayed

Energy Partitioning and Impulse Dispersion in the Decorated, Tapered, Strongly Nonlinear Granular Alignment: A System with Many Potential Applications

DTIC Science & Technology

2010-03-01

finally discuss some preliminary experimental results using systems with chrome spheres and small Nitinol interstitial grains to present the... Nitinol interstitial grains to present the underlying nonlinear dynamics of this so-called decorated tapered granular alignment. We are specifically...second was the DTC setup. In this case, small Nitinol 2.38 mm diameter particles were in- troduced between the main STC particles so that NDTC=9. 53 The

Implementing New Non-Chromate Coatings Systems (Briefing Charts)

DTIC Science & Technology

2011-02-09

Initiate Cr6+ authorization process for continued Cr6+ use using the form, Authorization to Use Hexavalent Chromium. YES NO • Approval of...Aluminum and magnesium anodizing • Hard Chrome Plating • Type II conversion coating on aluminum alloys under chromated primer • Type II conversion coating...Elimination of Hexavalent Chromium 80% 5% 14% 1% Type II Type III Type IC Type IC Fatigue Critical 50% 50% Type II Type IC FRC-SE (JAX) Fully Integrated FRC

Enhancement of chromium uptake in tanning using oxazolidine.

PubMed

Sundarapandiyan, S; Brutto, Patrick E; Siddhartha, G; Ramesh, R; Ramanaiah, B; Saravanan, P; Mandal, A B

2011-06-15

Monocyclic and bicyclic oxazolidines were offered at three different junctures of chrome tanning process viz. prior to BCS offer, along with BCS and after basification. It was found that oxazolidine when offered after basification brought about better chromium uptake and reduction of chromium load in the wastewater. Offer of oxazolidine was also varied. Increase in offer of oxazolidine from 0.25% to 1% was found to enhance the chromium uptake and decrease the chromium load in wastewater. But the increase in uptake was not proportionate to the increase in oxazolidine offer more than 0.75%. Offer of 1% Zoldine ZA 78 (monocyclic oxazolidine) and Zoldine ZE (bicyclic oxazolidine) after basification brought about 63.4% and 73.1% enhancement in chrome content in leather compared to control where oxazolidine was not offered. The tone of the wetblue was found to be altered moderately. However this did not call for any process adjustments in wet-finishing. The oxazolidine treated leathers were found to be immensely fuller and tighter. It was found experimentally that offer of 1% of oxazolidine facilitated reduction in the offer of syntans administered for filling and grain tightening by around 46%. Oxazolidine could bring about significant reduction in cost of chemicals apart from resulting environmental benefits due to enhancement of chromium uptake during tanning. Copyright © 2011 Elsevier B.V. All rights reserved.

Occurrences, uses, and properties of chromium.

PubMed

Barnhart, J

1997-08-01

Chromium is the 21st most abundant element in the Earth's crust with a mean concentration in United States soils of about 40 mg/kg. Although it exists in several oxidation states, the zero, trivalent, and hexavalent states are the most important in commercial products and the environment. Nearly all naturally occurring chromium is in the trivalent state, usually in combination with iron or other metal oxides. Although only about 15% of the chromium mined is used in the manufacture of chemicals, most applications of chromium utilize the chemistry of chromium. For instance, the "stainless" nature of stainless steel is due to the chemical properties of the chromium oxides which form on the surface of the alloy. Similarly, the protective properties of chrome plating of metals, chromated copper arsenate (CCA) treatment of wood, and chrome tanning of leather are all dependent on chromium chemistry. The key to these uses is that under typical environmental and biological conditions of pH and oxidation-reduction potential, the most stable form of chromium is the trivalent oxide. This form has very low solubility and low reactivity resulting in low mobility in the environment and low toxicity in living organisms. In this paper the chemical properties of chromium are discussed for the major commercial products in the context of the Eh-pH diagram for chromium. Copyright 1997 Academic Press.

Comparison of three sampling and analytical methods for the determination of airborne hexavalent chromium.

PubMed

Boiano, J M; Wallace, M E; Sieber, W K; Groff, J H; Wang, J; Ashley, K

2000-08-01

A field study was conducted with the goal of comparing the performance of three recently developed or modified sampling and analytical methods for the determination of airborne hexavalent chromium (Cr(VI)). The study was carried out in a hard chrome electroplating facility and in a jet engine manufacturing facility where airborne Cr(VI) was expected to be present. The analytical methods evaluated included two laboratory-based procedures (OSHA Method ID-215 and NIOSH Method 7605) and a field-portable method (NIOSH Method 7703). These three methods employ an identical sampling methodology: collection of Cr(VI)-containing aerosol on a polyvinyl chloride (PVC) filter housed in a sampling cassette, which is connected to a personal sampling pump calibrated at an appropriate flow rate. The basis of the analytical methods for all three methods involves extraction of the PVC filter in alkaline buffer solution, chemical isolation of the Cr(VI) ion, complexation of the Cr(VI) ion with 1,5-diphenylcarbazide, and spectrometric measurement of the violet chromium diphenylcarbazone complex at 540 nm. However, there are notable specific differences within the sample preparation procedures used in three methods. To assess the comparability of the three measurement protocols, a total of 20 side-by-side air samples were collected, equally divided between a chromic acid electroplating operation and a spray paint operation where water soluble forms of Cr(VI) were used. A range of Cr(VI) concentrations from 0.6 to 960 microg m(-3), with Cr(VI) mass loadings ranging from 0.4 to 32 microg, was measured at the two operations. The equivalence of the means of the log-transformed Cr(VI) concentrations obtained from the different analytical methods was compared. Based on analysis of variance (ANOVA) results, no statistically significant differences were observed between mean values measured using each of the three methods. Small but statistically significant differences were observed between results obtained from performance evaluation samples for the NIOSH field method and the OSHA laboratory method.

Porous titanium particles for acetabular reconstruction in total hip replacement show extensive bony armoring after 15 weeks

PubMed Central

Walschot, Lucas H B; Aquarius, René; Verdonschot, Nico; Buma, Pieter

2014-01-01

Background and purpose — The bone impaction grafting technique restores bone defects in total hip replacement. Porous titanium particles (TiPs) are deformable, like bone particles, and offer better primary stability. We addressed the following questions in this animal study: are impacted TiPs osteoconductive under loaded conditions; do released micro-particles accelerate wear; and are systemic titanium blood levels elevated after implantation of TiPs? Animals and methods — An AAOS type-III defect was created in the right acetabulum of 10 goats weighing 63 (SD 6) kg, and reconstructed with calcium phosphate-coated TiPs and a cemented polyethylene cup. A stem with a cobalt chrome head was cemented in the femur. The goats were killed after 15 weeks. Blood samples were taken pre- and postoperatively. Results — The TiP-graft layer measured 5.6 (SD 0.8) mm with a mean bone ingrowth distance of 2.8 (SD 0.8) mm. Cement penetrated 0.9 (0.3–1.9) mm into the TiPs. 1 reconstruction showed minimal cement penetration (0.3 mm) and failed at the cement-TiP interface. There were no signs of accelerated wear, metallic particle debris, or osteolysis. Median systemic titanium concentrations increased on a log-linear scale from 0.5 (0.3–1.1) parts per billion (ppb) to 0.9 (0.5–2.8) ppb (p = 0.01). Interpretation — Adequate cement pressurization is advocated for impaction grafting with TiPs. After implantation, calcium phosphate-coated TiPs were osteoconductive under loaded conditions and caused an increase in systemic titanium concentrations. However, absolute levels remained low. There were no signs of accelerated wear. A clinical pilot study should be performed to prove that application in humans is safe in the long term. PMID:25238431

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reno, J.; Dalrymple, D.

Before implementing a crosslinked polymer water-control treatment, a Phillips well was producing 33 b/d of oil and 318 b/d of water. After the treatment, oil production reached 40 b/d of oil and water production decreased to 130 b/d. Water disposal costs decreased by 60% and lifting and maintenance costs were also reduced. The technological key to the improvement was a dry polymer developed for use in hostile well environments. The polymer was crosslinked with chrome (III) propionate, a crosslinker with low toxicity that produces strong, rigid gels.

Single-Cylinder Oil-Control Tests of Porous Chrome-Plated Cylinder Barrels for Radial Air-Cooled Engines

DTIC Science & Technology

1946-01-01

plating, it will affect a choke as desired in the cylinder. When the clearance between the anode and the cathode (cylinder barrel) is decreased, an...National Advisory Commltteo for Aeronautics, Cltivel« oid , Ohio. RSFEFKICE3 1. Johnson, Robert L., wad Anderson, Roy I.: S.’.nglo-Cylindor Engine Tests...plating a choke in the bore. Choice la obtained by decreasing the clear- ance between the anode and the cylinder barrel ( cathode ). Taper on anode la

Installation Restoration Program Records Search for Air Force Plant 4, Texas.

DTIC Science & Technology

1984-08-01

treatment, landfills, waste oil pits, chrome and die yard pits, disposal and spill sites. A total of 20 sites were ranked using the HARM (Hazard...Meteorology Iii-i B. Physical Geography 111-3 C. Hydrology 111-24 D. Ecology 111-44 1. Habitat 111-44 2. Threatened or Endangered Species 111-45 IV. FINDINGS A...ASSESSMENT RATING METHODOLOGY K. SITE RATING FORMS L. GLOSSARY OF TERMS M. LIST OF ACRONYMS, ABBREVIATIONS, AND SYMBOLS USED IN THE TEXT N. REFERENCES 0

Phase control of austenitic chrome-nickel steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korkh, M. K., E-mail: KorkhMK@imp.uran.ru; Davidov, D. I., E-mail: davidov@imp.uran.ru; Korkh, J. V., E-mail: Korkh@imp.uran.ru

2015-10-27

The paper presents the results of the comparative study of the possibilities of different structural and magnetic methods for detection and visualization of the strain-induced martensitic phase in low carbon austenitic chromium-nickel steel. Results of TEM, SEM, optical microscopy, atomic and magnetic force microscopy, and magnetic measurements are presented. Amount of the magnetic strain-induced martensite was estimated. We pioneered magnetic force microscopic images of the single domain cluster distribution of the strain-induced martensite in austenite-ferrite materials.

Detailed Analysis and Design Review of the MARK IX (Modified) Underwater Breathing Apparatus

DTIC Science & Technology

1969-07-30

hard- chrome plated, and the purge-valve assembly and regulator piston . electroless-nickel plated. Manufacturing/Assembly Controls and Tests The control...high a flow through the orifice, peak pressures of 4500 psi have been applied repeatedly with- out failure or damage to any component. (7) Orifice...c) Proved In use. (d) "Functional" test by stpplkir. (5)J (e) Peak pressure of only 4500 jsi reached. (1) (f) Leak test at 1-1/2 •is. (g) Predive

A Highly Functional Decision Paradigm Based on Nonlinear Adaptive Genetic Algorithm

DTIC Science & Technology

1997-10-07

significant speedup. p£ lC <$jALTnimm SCTED & 14. SUBJECT TERMS Network Topology Optimization, Mathlink, Mathematica Plug-In, GA Route Optimizer, DSP...operations per second 2.4 Gbytes/second sustainable on-chip data transfer rate 400 Mb/s off-chip peak transfer rate Layer-to-layer interconnection...SecondHighestDist# = DistanceArray%(IndexList%(ChromeGene%(i%, 1) -1), IndexList%( Chrom eGene%(i%, 2) - 1)) For j% = 1 To StrandLength% - 1 ’If highest distance

Examination of Spray-Applied Oxsilan 9810/2 Steel Pretreatment on a Mine Resistant Ambush Protected (MRAP) Vehicle

DTIC Science & Technology

2013-10-01

2 Omitting this pretreatment/conversion coating step was justified because hexavalent chromium - based pretreatments, such as DOD-P-15328 (8...along with the fact that it does not contain chrome (hex or trivalent ), were the criteria for selecting Oxsilan 9310/2 for demonstrating on the...Hexavalent Chromium -Based DOD-P-15328D Wash Primer for MIL-A-46100D High Hard Steel Armor; ARL-TR-3393; U.S. Army Research Laboratory: Aberdeen Proving

Heat Setting Procedures for Helical Coiled Springs

DTIC Science & Technology

1976-12-01

Springs, M -aw-Hill Book Company, Inc., New York, New York, 1963. 1 - 1i) Music Wire, QQ-9-JM7 •r ’Wire diameter = 0.043 iALCh Stress relieve: Heat at... music wire and chrome vanadium materials c) 100,000 psi corresponds to 1.580 inches b) 150,0O0 psi corresponds to 1.020 inches For stainless steel...frequency which would produce spring set with the minimun amount of sprirg breakage. It was determined that the music wire springs should be cycled

Hex-Chrome Free Hardware - BAE Experience

DTIC Science & Technology

2010-06-01

plating, freedom from hydrogen embrittlement Cost is comparable to Type II chromate zinc • But much better corrosion performance Wide use by automotive...Fiat 9.57513/ Tipo IV • Ford S439 (WSS-M21P37-A1) • General Motors GM7114M, GMW3359 • Int’l Truck TMS-4518, Type I • ISO 10683 • JLG 4150701 • John...salt spray) to meet customer requirements (uses Geomet) • Fastener supplier provides similar dip-spin coatings • Cost virtually same as zinc plate • No

Evaluation of Solidification/Stabilization for Treating Contaminates Soils from the Frontier Hard Chrome Site

DTIC Science & Technology

1992-05-01

replicates were ɘ.020 mg/L. The chromium present was in the trivalent form. 139. Vendor 2. The replicate total chromium TCLP concentrations in the...criterion. The chromium present in the leachates was in the trivalent form, shown by concentrations of Cr(VI) of ɘ.020, ɘ.020, and 0.042 mg/L. 142...concentrations of total chromium were 4.7, 3.7, and 4.1 mg/L. Chromium is present in the trivalent form. The total chromium concentrations were below

Chromium-Makes stainless steel stainless

USGS Publications Warehouse

Kropschot, S.J.; Doebrich, Jeff

2010-01-01

Chromium, a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point, is a silvery white, hard, and bright metal plating on steel and other material. Commonly known as chrome, it is one of the most important and indispensable industrial metals because of its hardness and resistance to corrosion. But it is used for more than the production of stainless steel and nonferrous alloys; it is also used to create pigments and chemicals used to process leather.

Hexavalent Chromium Substitution Projects

DTIC Science & Technology

2011-05-12

Hexavalent Chromium Substitution Projects Date (12 May 2011) Gene McKinley ASC/WNV (937) 255-3596 Gene.McKinley@wpafb.af.mil Aeronautical Systems...valid OMB control number. 1. REPORT DATE 12 MAY 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Hexavalent ...A-10) – AETC (T-6, T-38 and T1A) • Both Cr Primers & Non-Cr primers as well as Cr Surface Treatment – F-22 8 Non- Chrome Tie-coat & touch-up

Tensile properties of chrome tanned leather waste short fibre filled unsaturated polyester composite

NASA Astrophysics Data System (ADS)

Talib, Satariah; Romli, Ahmad Zafir; Saad, Siti Zaleha

2017-12-01

Waste leather from industries was commonly disposed via land filling or incineration where the oxidation of Cr III to Cr VI by oxidants (such as peroxides and hypohalide) can easily occur. Cr VI is well known as carcinogenic and mutagenic element where the excessive exposure to this element can be very harmful. As an alternative way, the leather waste from footwear industry was utilised as filler in unsaturated polyester composite (UPC). The leather waste was ground using 0.25 mm mesh size and used without any chemical treatment. The sample was fabricated via castingtechnique and the study was carried out at 1 wt%, 2 wt% and 3 wt% filler loading. The leather waste filled composites showed lower tensile strength and Young's modulus than the unfilled composite. The increasing loading amount of leather waste led to the decreased in tensile strength and Young's modulus. The tensile results was supported by the decreasing pattern of density result which indicates the increasing of void content as the filler loading increased. The results of glass transition temperature are also parallel to the tensile properties where the increasing filler loading had decreased the glass transition temperature. Based on the morphological observation on the fractured tensile sample, much severe filler agglomerations and higher amount of voids was observed at higher filler loading compared to the lower filler loading.

[Distribution of soil heavy metal and pollution evaluation on the different sampling scales in farmland on Yellow River irrigation area of Ningxia: a case study in Xingqing County of Yinchuan City].

PubMed

Wang, You-Qi; Bai, Yi-Ru; Wang, Jian-Yu

2014-07-01

Determining spatial distributions and analyses contamination condition of soil heavy metals play an important role in evaluation of the quality of agricultural ecological environment and the protection of food safety and human health. Topsoil samples (0-20 cm) from 223 sites in farmland were collected at two scales of sampling grid (1 m x 1 m, 10 m x 10 m) in the Yellow River irrigation area of Ningxia. The objectives of this study were to investigate the spatial variability of total copper (Cu), total zinc (Zn), total chrome (Cr), total cadmium (Cd) and total lead (Pb) on the two sampling scales by the classical and geostatistical analyses. The single pollution index (P(i)) and the Nemerow pollution index (P) were used to evaluate the soil heavy metal pollution. The classical statistical analyses showed that all soil heavy metals demonstrated moderate variability, the coefficient of variation (CV) changed in the following sequence: Cd > Pb > Cr > Zn > Cu. Geostatistical analyses showed that the nugget coefficient of Cd on the 10 m x 10 m scale and Pb on the 1 m x 1 m scale were 100% with pure nugget variograms, which showed weak variability affected by random factors. The nugget coefficient of the other indexes was less than 25%, which showed a strong variability affected by structural factors. The results combined with P(i) and P indicated that most soil heavy metals have slight pollution except total copper, and in general there were the trend of heavy metal accumulation in the study area.

Groundwater quality appraisal and its hydrochemical characterization in Ghaziabad (a region of indo-gangetic plain), Uttar Pradesh, India

NASA Astrophysics Data System (ADS)

Singh, Uday Veer; Abhishek, Amar; Singh, Kunwar P.; Dhakate, Ratnakar; Singh, Netra Pal

2014-06-01

India's growing population enhances great pressure on groundwater resources. The Ghaziabad region is located in the northern Indo-Gangetic alluvium plain of India. Increased population and industrial activities make it imperative to appraise the quality of groundwater system to ensure long-term sustainability of resources. A total number of 250 groundwater samples were collected in two different seasons, viz., pre-monsoon and post monsoon and analyzed for major physico-chemical parameters. Broad range and great standard deviation occurs for most parameters, indicating chemical composition of groundwater affected by process, including water-rock interaction and anthropogenic effect. Iron was found as predominant heavy metal in groundwater samples followed by copper and lead. An exceptional high concentration of Chromium was found in some locations. Industrial activities as chrome plating and wood preservative are the key source to metal pollution in Ghaziabad region. On the basis of classification the area water shows normal sulfate, chloride and bi-carbonate type, respectively. Base-exchange indices classified 76 % of the groundwater sources was the sodium-bicarbonate type. The meteoric genesis indices demonstrated that 80 % of groundwater sources belong to a shallow meteoric water percolation type. Chadha's diagram suggested that the hydro-chemical faces belong to the HCO3 - dominant Ca2+-Mg2+ type along with Cl--dominant Ca2+-Mg2+-type. There was no significant change in pollution parameters in the selected seasons. Comparison of groundwater quality with Indian standards proves that majority of water samples are suitable for irrigation purposes but not for drinking.

Modification of Bushing Test Rig and Research of Variable Inlet Guide Vane Bushings For Further Development of PM304 Bushings

NASA Technical Reports Server (NTRS)

Yanke, Anne

2004-01-01

PS304 is a high temperature solid lubricant coating comprised of a nickel-chrome binder, chrome oxide hardener, barium-calcium fluoride high temperature lubricant, and silver as the low temperature lubricant. This coating is used to lubricate Oil-Free Foil Air Bearings as they experience friction and wear during start up and shut down. The coating deposition process begins with undercutting the shaft. This area is then sandblasted to provide a rough surface for the coating to adhere to. The coating powder is then sent through the plasma spray gun and a reasonably thick layer is applied to the undercut area of the shaft. The coating is then ground down even with the surface of the shaft and gets a nice polished finish. The foil air bearings use the solid lubricant, as mentioned above, during start up and shut down. During normal operating conditions, generally above 2000RPM, the bearings utilize air as their lubricant. Foil air bearings are comprised of a thin top foil and a corrugated bump foil. They have an interference fit with the shaft before operation. As the air gets "trapped" between the top foil and the shaft, it presses the top foil against the bump foil, in turn compressing the bumps. As the bumps compress, it allows for the air to separate the top foil from the shaft, therefore, utilizing the trapped air as its lubricant.

The Performance of Chrome-Coated Copper as Metallic Catalytic Converter to Reduce Exhaust Gas Emissions from Spark-Ignition Engine

NASA Astrophysics Data System (ADS)

Warju; Harto, S. P.; Soenarto

2018-01-01

One of the automotive technologies to reduce exhaust gas emissions from the spark-ignition engine (SIE) is by using a catalytic converter. The aims of this research are firstly to conduct a metallic catalytic converter, secondly to find out to what extend chrome-coated copper plate (Cu+Cr) as a catalyst is efficient. To measure the concentration of carbon monoxide (CO) and hydrocarbon (HC) on the frame there are two conditions required. First is when the standard condition, and second is when Cu+Cr metallic catalytic converter is applied using exhaust gas analyzer. Exhaust gas emissions from SIE are measured by using SNI 19-7118.1-2005. The testing of CO and HC emissions were conducted with variable speed to find the trend of exhaust gas emissions from idle speed to high speed. This experiment results in the fact that the use of Cu+Cr metallic catalytic converter can reduce the production of CO and HC of a four-stroke gasoline engine. The reduction of CO and HC emission are 95,35% and 79,28%. Using active metal catalyst in form of metallic catalytic converter, it is gained an optimum effective surface of a catalyst which finally is able to decrease the amount of CO and HC emission significantly in every spinning happened in the engine. Finally, this technology can be applied to the spark ignition engine both car and motorcycle to support blue sky program in Indonesia.

New NIST Photomask Linewidth Standard

NASA Astrophysics Data System (ADS)

Potzick, James E.; Pedulla, J. Marc; Stocker, Michael T.

2002-12-01

NIST is preparing to issue the next generation in its line of binary photomask linewidth standards. Called SRM 2059, it was developed for calibrating microscopes used to measure linewidths on photomasks, and consists of antireflecting chrome line and space patterns on a 6 inch quartz substrate ( 6 × 6 × 0.25 inches, or 15.2 × 15.2 × 0.635 cm). Certified line- and space-widths range from nominal 0.250 μm to 32 μm, and pitches from 0.5 μm to 250 μm, and are traceable to the definition of the meter. NIST's reference value, the definition of the meter, is well defined and unconditionally stable. Any replacement or duplicate NIST linewidth standard will be traceable to this same reference, and thus traceable to any other NIST length standard. Such measurement traceability can be achieved only by evaluating the measurement uncertainty (not just the repeatability) of each length comparison in the metrology chain between the definition of the meter and the NIST linewidth standard. This process results in a confidence interval about the calibration result that has a 95% probability of containing the true value. While the meter (and the μm) are well-defined, the geometrical width of a chrome line with nonrectangular cross section is not, and so the "true value" linewidth must be carefully defined to best meet users' needs. The paper and presentation will describe how these mask features are measured at NIST and how their measurement traceability is accomplished.

Evaluation of marginal/internal fit of chrome-cobalt crowns: Direct laser metal sintering versus computer-aided design and computer-aided manufacturing.

PubMed

Gunsoy, S; Ulusoy, M

2016-01-01

The purpose of this study was to evaluate the internal and marginal fit of chrome cobalt (Co-Cr) crowns were fabricated with laser sintering, computer-aided design (CAD) and computer-aided manufacturing, and conventional methods. Polyamide master and working models were designed and fabricated. The models were initially designed with a software application for three-dimensional (3D) CAD (Maya, Autodesk Inc.). All models were fabricated models were produced by a 3D printer (EOSINT P380 SLS, EOS). 128 1-unit Co-Cr fixed dental prostheses were fabricated with four different techniques: Conventional lost wax method, milled wax with lost-wax method (MWLW), direct laser metal sintering (DLMS), and milled Co-Cr (MCo-Cr). The cement film thickness of the marginal and internal gaps was measured by an observer using a stereomicroscope after taking digital photos in ×24. Best fit rates according to mean and standard deviations of all measurements was in DLMS both in premolar (65.84) and molar (58.38) models in μm. A significant difference was found DLMS and the rest of fabrication techniques (P < 0.05). No significant difference was found between MCo-CR and MWLW in all fabrication techniques both in premolar and molar models (P > 0.05). DMLS was best fitting fabrication techniques for single crown based on the results.The best fit was found in marginal; the larger gap was found in occlusal.All groups were within the clinically acceptable misfit range.

Prevention of Thyroidectomy Scars in Asian Adults With Low-Level Light Therapy.

PubMed

Park, Young Joon; Kim, Sang Jin; Song, Hyo Sang; Kim, Sue Kyoung; Lee, Jeonghun; Soh, Euy Young; Kim, You Chan

2016-04-01

Abnormal wound-healing after thyroidectomy with a resulting scar is a common dermatologic consultation. Despite many medical and surgical approaches, prevention of postoperative scars is challenging. This study validated the efficacy and safety of low-level light therapy (LLLT) using an 830/590 nm light-emitting diode (LED)-based device for prevention of thyroidectomy scars. Thirty-five patients with linear surgical suture lines after thyroidectomy were treated with 830/590 nm LED-LLLT. Daily application of 60 J/cm (11 minutes) for 1 week starting on postoperative day 1 was followed by treatment 3 times per week for 3 additional weeks. The control group (n = 15) remained untreated. Scar-prevention effects were evaluated 1 and 3 months after thyroidectomy with colorimetric evaluation using a tristimulus-color analyzer. The Vancouver Scar Scale (VSS) score, global assessment, and a subjective satisfaction score (range: 1-4) were also determined. Lightness (L*) and chrome values (a*) decreased significantly at the 3-month follow-up visit in the treatment group compared with those of controls. The average VSS and GAS scores were lower in the treatment group, whereas the subjective score was not significantly different. Light-emitting diode based LLLT treatment suppressed the formation of scars after thyroidectomy and could be safely used without noticeable adverse effects.

Microwave Measurement of Refractory Materials at High-Temperature

NASA Astrophysics Data System (ADS)

Kharkovsky, S.; Zoughi, R.; Smith, J.; Davis, B.; Limmer, R.

2009-03-01

Knowledge of the electrical behavior of refractory materials may enable the development and optimization of microwave nondestructive techniques to detect and evaluate changes in their physical properties while the materials are in service. This paper presents the results of a limited and preliminary investigation in which two refractory materials (dense chrome and dense zircon) were subjected to increasing temperature in a furnace and in which a frequency-modulated continuous-wave radar operating in the frequency range of 8-18 GHz radar was used to evaluate their attenuation properties.

QuEST: Qualifying Environmentally Sustainable Technologies. Volume 4

NASA Technical Reports Server (NTRS)

Lewis, Pattie L.

2009-01-01

In 2004, in one of their first collaborative efforts, Centro Para Prevencao da Poluicao (Portuguese Center for Pollution Prevention or C3P). teamed with Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) and two Portuguese entities, TAP Portugal (Portuguese National Airline) and OGMA Indtistria Aeron utica de Portugal (Portuguese Aeronautics Industry), to target the reduction of hexavalent chromium, cadmium, and volatile organic compounds (VOCs) in aircraft maintenance operations. This project focused on two coating systems that utilize non-chrome pretreatments and low-VOC primers and topcoats.

Interrelationship of mechanical and corrosion-mechanical characteristics of type 12KhN4MF steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voronin, V.P.; Goncharov, A.F.; Maslov, V.A.

1985-11-01

Investigations presented include a comparative evaluation of the corrosionmechanical characteristics of specimens of high-strength chrome-nickelmolybdenum steel taking into consideration the different methods of melting of the original metal. A comparison of the corrosion-mechanical test results obtained with the results of acceptance tests are presented. A study of the fracture surfaces and the specimen material with the use of fractographic, macroscopic, and microscopic analyses is given. The systematization of the corrosion-mechanical test results with the use of methods of mathematical statistics are presented.

Investigation of Plasma Spray Coatings as an Alternative to Hard Chrome Plating on Internal Surfaces

DTIC Science & Technology

2006-09-14

low fracture strength, making it prone to cracking. It may be the best option for utility actuators that experience side loads or excessive ID wear...material than WC-12Co, but had the lowest porosity of the plasma spray coatings in initial process development tests, as well as higher fracture ...grind Adhesion Pull 0.013-0.015" 0.008-0.010" 8 microinch Residual stress Almen 0.013-0.015" no grind Strain-to- fracture 4-pt Almen 0.013-0.015

Calibration of Breech Erosion Gage for 5.56mm Chrome-Plated Bores

DTIC Science & Technology

1975-12-01

34 tft.. CantoiIlate Olft.) Ill TEUIy CLASS. (of ffile .oepot) Unclassified ISO . DECL ASSi VIC ATION’DOW94GRADING 16. DISTRIOUTION STATEMENT (of Wit9...6.3 8.9 13.4 7.6 7.3 6.3 6.2 7.1 26000 16.1 9.1 10.9 13.9 8.9 6.4 6.3 3.1 4.9 27000 12.4 8.4 11.2 13.1 8.3 6.5 7.3 3.4 4.3 28000 12.1 6.9 19.3 11.4

Exposure to Sodium Dichromate at Qarmat Ali Iraq in 2003: Part 2 -- Evaluation of Army and Contractor Actions Related to Hazardous Industrial Exposure

DTIC Science & Technology

2011-09-28

hexavalent chromium (chromium VI), a known carcinogen. USACE and the Army command in Iraq were made aware of the exposure in 2003 and took a series of...occupational and environmental health risks to U.S. personnel from potential exposure to hexavalent chromium [Cr(VI)] and other hazards prior to...chromium, or stigmata such as chrome ulcers. It was assumed by the 12 USACHPPM identified members of the West Virginia Army National Guard as part of the

Heavy metals in liquid pig manure in light of bacterial antimicrobial resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoelzel, Christina S., E-mail: Christina.Hoelzel@wzw.tum.de; Mueller, Christa; Harms, Katrin S.

Heavy metals are regularly found in liquid pig manure, and might interact with bacterial antimicrobial resistance. Concentrations of heavy metals were determined by atomic spectroscopic methods in 305 pig manure samples and were connected to the phenotypic resistance of Escherichia coli (n=613) against 29 antimicrobial drugs. Concentrations of heavy metals (/kg dry matter) were 0.08-5.30 mg cadmium, 1.1-32.0 mg chrome, 22.4-3387.6 mg copper, <2.0-26.7 mg lead, <0.01-0.11 mg mercury, 3.1-97.3 mg nickel and 93.0-8239.0 mg zinc. Associated with the detection of copper and zinc, resistance rates against {beta}-lactams were significantly elevated. By contrast, the presence of mercury was significantly associatedmore » with low antimicrobial resistance rates of Escherichia coli against {beta}-lactams, aminoglycosides and other antibiotics. Effects of subinhibitory concentrations of mercury on bacterial resistance against penicillins, cephalosporins, aminoglycosides and doxycycline were also demonstrated in a laboratory trial. Antimicrobial resistance in the porcine microflora might be increased by copper and zinc. By contrast, the occurrence of mercury in the environment might, due to co-toxicity, act counter-selective against antimicrobial resistant strains.« less

[Analysis and Evaluation of Inorganic Elements in Euryale Semen from Different Habitats by Microwave Digestion-ICP-OES].

PubMed

Wang, Hong; Wu, Qi-nan; Wu, Cheng-ying; Fan, Xiu-he; Jiang, Zheng; Gu, Wei; Yue, Wei

2015-01-01

To establish a simple, rapid and efficient method for determination of different inorganic elements in Euryale Semen from different habitats. Inductively coupled plasma-optical emission spectrometry(ICP-OES) was applied to determine inorganic elements in Euryale Semen, and the results were analyzed by principal component analysis. Euryale Semen from different habitats contained the kind of inorganic elements ranging from 22 to 26, including micronutrient elements like Iron, Zinc, Selenium, Copper, Molybdenum, Chrome and Cobalt, as well as macronutrient elements such as Potassium, Calcium, Sodium, Magnesium and Phosphorus. Five factors were extracted and used to comprehensively evaluate Euryale Semen from 20 different habitats covered almost China. The comprehensive function was F = 0. 38828F1 + 0. 25603F2 + 0. 07617F3 + 0. 06860F4 + 0. 04868F5, which resulted in the top three samples coming from Jiangsu Gaoyou, Hunan Xiangxi and Jiangsu Suzhou respectively. The study indicates that ICP-OES is a quick, accurate and sensitive method to determine the contents of inorganic elements in Euryale Semen,which provides scientific and reliable reference for its quality control and safety assessment.

Effect of cloric acid concentration on corrosion behavior of Ni/Cr coated on carbon steel

NASA Astrophysics Data System (ADS)

Desiati, Resetiana Dwi; Sugiarti, Eni; Thosin, K. A. Zaini

2018-05-01

Corrosion is one of the causes of metal degradation. Carbon steel (Fe) is easy to corrode in the extreme environment. Coating on carbon steel is required to improve corrosion resistance owing to protection or hindrance to extreme environmental conditions. In this present work, carbon steel was coated by electroplating techniques for nickel and pack cementation for chrome. The corrosion rate test was performed by Weight Loss method on FeNiCr, FeNi, FeCr and uncoated Fe as comparator which was dyed in 37% HCl and 25% HCl which had previously been measured dimension and mass. The immersion test result of FeNiCr and FeNi specimen were better than FeCr and uncoated Fe in terms of increasing corrosion resistance. The corrosion rate for 56 hours in 37% HCl for FeNiCr was 1.592 mm/y and FeNi was 3.208 mm/y, FeCr only lasted within 32 hours with corrosion rate was 6.494 mm/y. Surface of the sample after the corrosion test there was pitting, crevice corrosion and alloy cracking caused by chloride. The higher the concentration of HCl the faster the corrosion rate.

[Nose disease caused by occupational exposure to chromium in the electroplating industry: cytomorphological aspects].

PubMed

Bolla, I; Gariboldi, L M; Gabrielli, M; Baldo, D; Romanelli, A; Tuberti, E; Magnani, F

1990-01-01

Twenty-six workers were studied (9 chrome-platers exposed to chromium dioxide and 17 workers exposed to metallic chromium dust) in order to investigate the macroscopic and cytological changes of the nasal mucosa due to exposure to water-soluble hexavalent chromium or to metallic chromium dust in the electroplating industry and the role of different valencies in the onset of nasal disease. Experimental and epidemiological data have shown that hexavalent chromium, which has strong oxidative power, induces more noticeable toxic effects on tissues and mucous membranes than other compounds. The correlation between the degree of local toxic effects and the chemical state of chromium was demonstrated in both the macro- and the microscopic investigations and in particular in the cytological examinations: cases of atypia were found only in workers exposed to hexavalent chromium. Evidence of atypia raises the question of whether hexavalent chromium may act as a carcinogenic agent on the rhinosinusal mucosa. For this reason, the introduction of cytological nasal examination in health surveillance programmes for this category of workers acquires considerable importance. Sample collection from the nasal mucosa by brushing is the method of choice since it is simple, non-invasive and gives good diagnostic results.

Chromium carcinogenicity: California strategies.

PubMed

Alexeeff, G V; Satin, K; Painter, P; Zeise, L; Popejoy, C; Murchison, G

1989-10-01

Hexavalent chromium was identified by California as a toxic air contaminant (TAC) in January 1986. The California Department of Health Services (CDHS) concurred with the findings of the International Agency for Research on Cancer that there is sufficient evidence to demonstrate the carcinogenicity of chromium in both animals and humans. CDHS did not find any compelling evidence demonstrating the existence of a threshold with respect to chromium carcinogenesis. Experimental data was judged inadequate to assess potential human reproductive risks from ambient exposures. Other health effects were not expected to occur at ambient levels. The theoretically increased lifetime carcinogenic risk from a continuous lifetime exposure to hexavalent chromium fell within the range 12-146 cancer cases per nanogram hexavalent chromium per cubic meter of air per million people exposed, depending on the potency estimate used. The primary sources found to contribute significantly to the risk of exposure were chrome platers, chromic acid anodizing facilities and cooling towers utilizing hexavalent chromium as a corrosion inhibitor. Evaluation of genotoxicity data, animal studies and epidemiological studies indicates that further consideration should be given to the potential carcinogenicity of hexavalent chromium via the oral route.

Role of functional groups on Aspergillus niger biomass in the detoxification of hexavalent chromium.

PubMed

Narvekar, Sneha; Vaidya, Varsha K

2009-10-01

Chromium (VI) contamination is not uncommon, especially near industries involved in leather tanning, chrome painting, metal cleaning and processing, wood preservation and alloy preparation. The mutagenic and carcinogenic properties of Chromium (VI) necessitate effective remedial processes. Difficulties associated with chemical and physical techniques to remediate a Chromium (VI) contaminated site to EPA recommended level (50 ppm), in addition to higher costs involved, assert the need for bioremedial measures. Biosorption can be one such solution to clean up heavy metal contamination. The objective of this study was to examine the main aspects of a possible strategy for the removal of Chromium (VI), employing Aspergillus niger biomass. The roles played by amines, carboxylic acids, phosphates, in Chromium (VI) biosorption were studied. Amino and the carboxy groups on the fungal cell wall play an important role in sorption. However, the role of carboxy group was far less than amino group. Surface adsorption of Chromium (VI) was also seen by scanning electron microscopy (SEM) thus indicating involvement of ion-exchange and surface adsorption mechanism in removal of Chromium (VI) ions.

Combined biodegradation and ozonation for removal of tannins and dyes for the reduction of pollution loads.

PubMed

Kanagaraj, James; Mandal, Asit Baran

2012-01-01

Tannins and dyes pose major threat to the environment by generating huge pollution problem. Biodegradation of wattle extract, chrome tannin and dye compounds using suitable fungal culture namely Aspergillus niger, Penicillium sp. were carried out. In addition to these, ozone treatment was carried out to get higher degradation rate. The results were monitored by carrying out chemical oxygen demand (COD), total organic carbon (TOC), and UV-Vis analysis. The results showed that wattle extract (vegetable tannin) gave better biodegradation rate than dye and chromium compounds. Biodegradation plus ozone showed degradation rates of 92-95%, 94-95%, and 85-87% for the wattle extract, dyes, chromium compounds, respectively. UV-Vis showed that there were no peaks observed for biodegraded samples indicating better degradation rates as compared to the control samples. FT-IR spectra analysis suggested that the formation of flavanoid derivatives, chromic oxide and NH(2) compounds during degradation of wattle extract, chromium and dye compounds, respectively, at the peaks of 1,601-1,629 cm(-1), 1,647 cm(-1), and 1,610-1,680 cm(-1). The present investigation shows that combination of biodegradation with ozone is the effective method for the removal of dyes and tannins. The biodegradation of the said compounds in combination with ozonation showed better rate of degradation than by chemical methods. The combination of biodegradation with ozone helps to reduce pollution problems in terms of COD, TOC, total dissolved solids and total suspended solids.

Comparison of early-phase arterial repair following cobalt-chrome everolimus-eluting stent and slow-release zotarolimus-eluting stent: an angioscopic study.

PubMed

Ishihara, Takayuki; Iida, Osamu; Fujita, Masashi; Masuda, Masaharu; Okamoto, Shin; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Sunaga, Akihiro; Awata, Masaki; Nanto, Shinsuke; Uematsu, Masaaki

2018-04-01

Whether arterial repair following implantation of drug-eluting stents (DES) of the second generation differs among stent types remains unknown. We examined 41 DES placed in 28 patients (age 72 ± 7 years, male 89%) presenting with stable angina pectoris due to de novo lesions in native coronary arteries. Coronary angioscopy was performed 4 ± 1 months after stent implantation. Patients were divided into two groups based on the DES types: 22 cobalt-chrome everolimus-eluting stents (CoCr-EES) in 13 patients and 19 slow-release zotarolimus-eluting stents (R-ZES) in 15 patients. Neointimal coverage (NIC) was graded as: grade 0, stent struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded in the neointima, but translucent; grade 3, struts fully embedded and invisible. NIC was defined as heterogeneous when the NIC grade variation was ≥1. Presence of thrombus was also investigated. Distribution of dominant NIC grade (CoCr-EES: grade 0, 9%; grade 1, 77%; grade 2, 9%; grade 3, 5%; R-ZES: grade 0, 16%; grade 1: 47%; grade 2, 37%; grade 3, 0%, P = 0.38) and heterogeneity of NIC (P = 0.43) were similar between CoCr-EES and R-ZES groups. Existence of thrombus was not significantly different in CoCr-EES and R-ZES (18 versus 42%, P = 0.17). Arterial repair occurred without significant differences between CoCr-EES and R-ZES 4 months after implantation.

The interobserver-validated relevance of intervertebral spacer materials in MRI artifacting

PubMed Central

Heidrich, G.; Bruening, T.; Krefft, S.; Buchhorn, G.; Klinger, H.M.

2006-01-01

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium, carbon or cobalt-chrome, which can affect the post-fusion MRI scans. Implant-related susceptibility artifacts can decrease the quality of MRI scans, thwarting proper evaluation. This cadaver study aimed to demonstrate the extent that implant-related MRI artifacting affects the post-fusion evaluation of intervertebral spacers. In a cadaveric porcine spine, we evaluated the post-implantation MRI scans of three intervertebral spacers that differed in shape, material, surface qualities and implantation technique. A spacer made of human cortical bone was used as a control. The median sagittal MRI slice was divided into 12 regions of interest (ROI). No significant differences were found on 15 different MRI sequences read independently by an interobserver-validated team of specialists (P>0.05). Artifact-affected image quality was rated on a score of 0-1-2. A maximum score of 24 points (100%) was possible. Turbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. The carbon, titanium and cobalt-chrome spacers scored 83.3, 62.5 and 50%, respectively. Our scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the control that was independent of artifact dimensions. The carbon spacer had the lowest percentage of susceptibility artifacts. Even with turbo spin echo sequences, the susceptibility artifacts produced by the metallic spacers showed a high degree of variability. Despite optimum sequencing, implant design and material are relevant factors in MRI artifacting. PMID:16463200

Reconstructing the colour palette of the Konstantinos Parthenis' burnt paintings.

PubMed

Antonopoulou-Athera, N; Chatzitheodoridis, E; Terlixi, A; Doulgerides, M; Serafetinides, A A

2018-05-09

This case study focuses on the reconstruction of the colour palette and the possibility of laser cleaning of burnt paintings. The paintings ORPHEUS IN THE UNDERWORLD and CONCORDIA, composed by the Greek artist Konstantinos Parthenis (1878-1967), have been severely damaged by fire. The colour palette of Parthenis is thoroughly investigated for the first time, and to perform this, a multi-analytical spectroscopic approach was employed. Non-destructive in situ analysis was performed on multiple areas of the paintings by portable XRF. SEM-EDS and Raman, supported by reflected visible light optical microscopy, and ultraviolet light microscopy, as well as structural XRD and molecular FTIR were performed for identifying the pigments, the binder and the substrate of the paintings. This work also unveiled new aspects of the painting technique used by the artist, such as the uncommon use of multiple pigments of red hue in the upper paint layers, comparatively with the rest of Parthenis' paintings. Molecular spectroscopic techniques (i.e., Raman and FTIR) were effective in identifying pigments like chrome yellow (crocoite mineral), chrome orange (phoenicochroite mineral) and viridian green (hydrated chromium oxide). The spectroscopic analyses were also essential in the laser cleaning restoration because of the detection of pigments (i.e., lead white, vermilion etc.) prone to phase transformations due to photothermal and/or photochemical effects. Our investigation establishes the basis on the application of non-conventional cleaning methods on damaged paintings, such as laser irradiation, in order to remove the damaged layer and/or the superficial accretions, while preserving the hues of the original painting. Copyright © 2018 Elsevier B.V. All rights reserved.

[Evaluation of Artificial Hip Joint with Radiofrequency Heating Issues during MRI Examination: A Comparison between 1.5 T and 3 T].

PubMed

Yamazaki, Masaru; Ideta, Takahiro; Kudo, Sadahiro; Nakazawa, Masami

2016-06-01

In magnetic resonance imaging (MRI), when radiofrequency (RF) is irradiated to a subject with metallic implant, it can generate heat by RF irradiation. Recently 3 T MRI scanner has spread widely and imaging for any regions of whole body has been conducted. However specific absorption rate (SAR) of 3 T MRI becomes approximately four times as much as the 1.5 T, which can significantly affect the heat generation of metallic implants. So, we evaluated RF heating of artificial hip joints in different shapes and materials in 1.5 T and 3 T MRI. Three types of artificial hip joints made of stainless alloy, titanium alloy and cobalt chrome alloy were embedded in the human body-equivalent phantom respectively and their temperature change were measured for twenty minutes by 1.5 T and 3 T MRI. The maximum temperature rise was observed at the bottom head in all of three types of artificial hip joints, the rise being 12°C for stainless alloy, 11.9°C for titanium alloy and 6.1°C for cobalt chrome alloy in 1.5 T. The temperature rise depended on SAR and the increase of SAR had a good linear relationship with the temperature rise. It was found from the result that the RF heating of metallic implants can take place in various kinds of material and the increase of SAR has a good linear relationship with the temperature rise. This experience shows that reduction of SAR can decrease temperature of metallic implants.

Articulation of Native Cartilage Against Different Femoral Component Materials. Oxidized Zirconium Damages Cartilage Less Than Cobalt-Chrome.

PubMed

Vanlommel, Jan; De Corte, Ronny; Luyckx, Jean Philippe; Anderson, Melissa; Labey, Luc; Bellemans, Johan

2017-01-01

Oxidized zirconium (OxZr) is produced by thermally driven oxidization creating an oxidized surface with the properties of a ceramic at the top of the Zr metal substrate. OxZr is much harder and has a lower coefficient of friction than cobalt-chrome (CoCr), both leading to better wear characteristics. We evaluated and compared damage to the cartilage of porcine patella plugs, articulating against OxZr vs CoCr. Our hypothesis was that, owing to its better wear properties, OxZr would damage cartilage less than CoCr. If this is true, OxZr might be a better material for the femoral component during total knee arthroplasty if the patella is not resurfaced. Twenty-one plugs from porcine patellae were prepared and tested in a reciprocating pin-on-disk machine while lubricated with bovine serum and under a constant load. Three different configurations were tested: cartilage-cartilage as the control group, cartilage-OxZr, and cartilage-CoCr. Macroscopic appearance, cartilage thickness, and the modified Mankin score were evaluated after 400,000 wear cycles. The control group showed statistically significant less damage than plugs articulating against both other materials. Cartilage plugs articulating against OxZr were statistically significantly less damaged than those articulating against CoCr. Although replacing cartilage by an implant always leads to deterioration of the cartilage counterface, OxZr results in less damage than CoCr. The use of OxZr might thus be preferable to CoCr in case of total knee arthroplasty without patella resurfacing. Copyright © 2016 Elsevier Inc. All rights reserved.

Portsmouth Atmospheric Science School (PASS) Project

NASA Technical Reports Server (NTRS)

Coleman, Clarence D.; Hathaway, Roger (Technical Monitor)

2002-01-01

The Portsmouth Atmospheric Science School Project (PASS) Project was granted a one-year no cost extension for 2001-2002. In year three of the project, objectives and strategies were modified based on the previous year-end evaluation. The recommendations were incorporated and the program was replicated within most of the remaining elementary schools in Portsmouth, Virginia and continued in the four middle schools. The Portsmouth Atmospheric Science School Project is a partnership, which includes Norfolk State University, Cooperating Hampton Roads Organizations for Minorities in Engineering (CHROME), NASA Langley Research Center, and the City of Portsmouth, Virginia Public Schools. The project seeks to strengthen the knowledge of Portsmouth Public Schools students in the field of atmospheric sciences and enhance teacher awareness of hands on activities in the atmospheric sciences. The project specifically seeks to: 1) increase the interest and participation of elementary and middle school students in science and mathematics; 2) strengthen existing science programs; and 3) facilitate greater achievement in core subjects, which are necessary for math, science, and technical careers. Emphasis was placed on providing training activities, materials and resources for elementary students (grades 3 - 5) and middle school students (grades 6 - 8), and teachers through a CHROME club structure. The first year of the project focused on introducing elementary students to concepts and activities in atmospheric science. Year two of the project built on the first year's activities and utilizes advanced topics and activities appropriate for middle school students. During the third year of the project, in addition to the approaches used in years one and two, emphasis was placed on activities that enhanced the Virginia Standards of Learning (SOL).

Comparison of hospital room surface disinfection using a novel ultraviolet germicidal irradiation (UVGI) generator.

PubMed

Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

2016-09-01

The estimated 721,800 hospital acquired infections per year in the United States have necessitated development of novel environmental decontamination technologies such as ultraviolet germicidal irradiation (UVGI). This study evaluated the efficacy of a novel, portable UVGI generator (the TORCH, ChlorDiSys Solutions, Inc., Lebanon, NJ) to disinfect surface coupons composed of plastic from a bedrail, stainless steel, chrome-plated light switch cover, and a porcelain tile that were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE). Each surface type was placed at 6 different sites within a hospital room and treated by 10-min ultraviolet-C (UVC) exposures using the TORCH with doses ranging from 0-688 mJ/cm(2) between sites. Organism reductions were compared with untreated surface coupons as controls. Overall, UVGI significantly reduced MRSA by an average of 4.6 log10 (GSD: 1.7 log10, 77% inactivation, p < 0.0001) and VRE by an average of 3.9 log10 (GSD: 1.7 log10, 65% inactivation, p < 0.0001). MRSA on bedrail was reduced significantly (p < 0.0001) less than on other surfaces, while VRE was reduced significantly less on chrome (p = 0.0004) and stainless steel (p = 0.0012) than porcelain tile. Organisms out of direct line of sight of the UVC generator were reduced significantly less (p < 0.0001) than those directly in line of sight. UVGI was found an effective method to inactivate nosocomial pathogens on surfaces evaluated within the hospital environment in direct line of sight of UVGI treatment with variation between organism and surface types.

MR scanning, tattoo inks, and risk of thermal burn: An experimental study of iron oxide and organic pigments: Effect on temperature and magnetic behavior referenced to chemical analysis.

PubMed

Alsing, K K; Johannesen, H H; Hvass Hansen, R; Dirks, M; Olsen, O; Serup, J

2018-05-01

Tattooed persons examined with magnetic resonance imaging (MRI) can develop burning sensation suggested in the literature to be thermal burn from the procedure. MRI-induced thermal effect and magnetic behavior of known tattoo pigments were examined ex vivo. Magnetic resonance imaging effects on 3 commonly used commercial ink stock products marketed for cosmetic tattooing was studied. A main study tested 22 formulations based on 11 pigment raw materials, for example, one line of 11 called pastes and another called dispersions. Samples were spread in petri dishes and tested with a 0.97 T neodymium solid magnet to observe visual magnetic behavior. Before MRI, the surface temperature of the ink was measured using an infrared probe. Samples were placed in a clinical 3T scanner. Two scans were performed, that is, one in the isocenter and one 30 cm away from the center. After scanning, the surface temperature was measured again. Chemical analysis of samples was performed by mass spectroscopy. Mean temperature increase measured in the isocenter ranged between 0.14 and 0.26°C (P < .01) and in the off-center position from -0.16 to 0.21°C (P < .01). Such low increase of temperature is clinically irrelevant. Chemical analysis showed high concentrations of iron, but also nickel and chrome were found as contaminants. High concentration of iron was not associated with any increase of temperature or any physical draw or move of ink. The study could not confirm any clinically relevant temperature increase of tattoo pigments after MRI. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Petrology and geochemistry of Patuxent Range 91501, a clast-poor impact-melt from the L chondrite parent body, and Lewis Cliff 88663, an L7 chondrite

NASA Astrophysics Data System (ADS)

Mittlefehldt, David W.; Lindstrom, Marilyn M.

2001-03-01

We have performed petrologic and geochemical studies of Patuxent Range 91501 and Lewis Cliff 88663. PAT 91501, originally classified as an L7 chondrite, is rather a unique, near total impact-melt from the L chondrite parent body. Lewis Cliff 88663 was originally classified as an "achondrite (?)," but we find that it is a very weakly shocked L7 chondrite. PAT 91501 is an unshocked, homogeneous, igneous-textured ultramafic rock composed of euhedral to subhedral olivine, low-Ca pyroxene, augite and chrome-rich spinels with interstitial albitic plagioclase and minor silica-alumina-alkali-rich glass. Only ~10% relict chondritic material is present. Olivine grains are homogeneous (Fa25.2-26.8). Low-Ca pyroxene (Wo1.9-7.2En71.9-78.2Fs19.9-20.9) and augite (Wo29.8-39.0En49.2-55.3Fs11.8-14.9) display a strong linear TiO2-Al2O3 correlations resulting from igneous fractionation. Plagioclase is variable in composition; Or3.0-7.7Ab79.8-84.1An8.2-17.2. Chrome-rich spinels are variable in composition and zoned from Cr-rich cores to Ti-Al-rich rims. Some have evolved compositions with up to 7.9 wt% TiO2. PAT 91501 bulk silicate has an L chondrite lithophile element composition except for depletions in Zn and Br. Siderophile and chalcophile elements are highly depleted due to sequestration in cm-size metal-troilite nodules. The minerals in LEW 88663 are more uniform in composition than those in PAT 91501. Olivine grains have low CaO and Cr2O3 contents similar to those in L5-6 chondrites. Pyroxenes have high TiO2 contents with only a diffuse TiO2-Al2O3 correlations. Low-Ca pyroxenes are less calcic (Wo1.6-3.1En76.5-77.0Fs20.4-21.4), while augites (Wo39.5-45.6En46.8-51.1Fs7.6-9.4) and plagioclases (Or2.6-5.7Ab74.1-83.1An11.2-23.3) are more calcic. Spinels are homogeneous and compositionally similar to those in L6 chondrites. LEW 88663 has an L chondrite bulk composition for lithophile elements, and only slight depletions in siderophile and chalcophile elements that are plausibly due to weathering and/or sample heterogeneity.

Web Apollo: a web-based genomic annotation editing platform.

PubMed

Lee, Eduardo; Helt, Gregg A; Reese, Justin T; Munoz-Torres, Monica C; Childers, Chris P; Buels, Robert M; Stein, Lincoln; Holmes, Ian H; Elsik, Christine G; Lewis, Suzanna E

2013-08-30

Web Apollo is the first instantaneous, collaborative genomic annotation editor available on the web. One of the natural consequences following from current advances in sequencing technology is that there are more and more researchers sequencing new genomes. These researchers require tools to describe the functional features of their newly sequenced genomes. With Web Apollo researchers can use any of the common browsers (for example, Chrome or Firefox) to jointly analyze and precisely describe the features of a genome in real time, whether they are in the same room or working from opposite sides of the world.

QuEST: Qualifying Environmentally Sustainable Technologies, Volume 5

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2010-01-01

This edition of the QuEST newsletter contains brief articles that discuss the NASA Technology Evaluation for Environmental Risk Mitigation (TEERM) program, and the importance of collaboration, efforts in materials management and substitution for coatings for launch structures, Low volatile organic compound (VOC) Coatings Field Testing, Non-Chrome Coating Systems, Life Cycle Corrosion Testing, Lead-Free Electronics Testing and Corn Based Depainting and efforts in Pollution Control in the area of Hypergolic Propellant Destruction Evaluation, efforts in development of alternative energy in particular Hydrogen Sensors, Energy and Water Management, and efforts in remediation in the removal of Polychlorinated Biphenyl (PCB) contamination

Cemented fixation with PMMA or Bis-GMA resin hydroxyapatite cement: effect of implant surface roughness.

PubMed

Walsh, W R; Svehla, M J; Russell, J; Saito, M; Nakashima, T; Gillies, R M; Bruce, W; Hori, R

2004-09-01

Implant surface roughness is an important parameter governing the overall mechanical properties at the implant-cement interface. This study investigated the influence of surface roughness using polymethylmethcrylate (PMMA) and a Bisphenol-a-glycidylmethacyrlate resin-hydroxyapatite cement (CAP). Mechanical fixation at the implant-cement interface was evaluated in vitro using static shear and fatigue loading with cobalt chrome alloy (CoCr) dowels with different surface roughness preparations. Increasing surface roughness improved the mechanical properties at the implant-cement interface for both types of cement. CAP cement fixation was superior to PMMA under static and dynamic loading.