Packed bed carburization of tantalum and tantalum alloy

DOEpatents

Lopez, P.C.; Rodriguez, P.J.; Pereyra, R.A.

1999-06-29

Packed bed carburization of a tantalum or tantalum alloy object is disclosed. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum carbide along the grain boundaries, and etching the surface of the carburized object. This latter step removes tantalum carbides from the surface of the carburized tantalum object while leaving the tantalum carbide along the grain boundaries. 4 figs.

Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

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

Wan, Yimao, E-mail: yimao.wan@anu.edu.au; Bullock, James; Cuevas, Andres

2015-05-18

This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negativemore » fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.« less

METHOD OF FORMING TANTALUM SILICIDE ON TANTALUM SURFACES

DOEpatents

Bowman, M.G.; Krikorian, N.H.

1961-10-01

A method is described for forming a non-corrosive silicide coating on tantalum. The coating is made through the heating of trirhenium silicides in contact with the tantalum object to approximately 1400 deg C at which temperature trirhenium silicide decomposes into rhenium and gaseous silicons. The silicon vapor reacts with the tantalum surface to form a tantalum silicide layer approximately 10 microns thick. (AEC)

Hot carrier dynamics in plasmonic transition metal nitrides

NASA Astrophysics Data System (ADS)

Habib, Adela; Florio, Fred; Sundararaman, Ravishankar

2018-06-01

Extraction of non-equilibrium hot carriers generated by plasmon decay in metallic nano-structures is an increasingly exciting prospect for utilizing plasmonic losses, but the search for optimum plasmonic materials with long-lived carriers is ongoing. Transition metal nitrides are an exciting class of new plasmonic materials with superior thermal and mechanical properties compared to conventional noble metals, but their suitability for plasmonic hot carrier applications remains unknown. Here, we present fully first principles calculations of the plasmonic response, hot carrier generation and subsequent thermalization of all group IV, V and VI transition metal nitrides, fully accounting for direct and phonon-assisted transitions as well as electron–electron and electron–phonon scattering. We find the largest frequency ranges for plasmonic response in ZrN, HfN and WN, between those of gold and silver, while we predict strongest absorption in the visible spectrum for the VN, NbN and TaN. Hot carrier generation is dominated by direct transitions for most of the relevant energy range in all these nitrides, while phonon-assisted processes dominate only below 1 eV plasmon energies primarily for the group IV nitrides. Finally, we predict the maximum hot carrier lifetimes to be around 10 fs for group IV and VI nitrides, a factor of 3–4 smaller than noble metals, due to strong electron–phonon scattering. However, we find longer carrier lifetimes for group V nitrides, comparable to silver for NbN and TaN, while exceeding 100 fs (twice that of silver) for VN, making them promising candidates for efficient hot carrier extraction.

Hot pressing of nanocrystalline tantalum using high frequency induction heating and pulse plasma sintering

NASA Astrophysics Data System (ADS)

Jakubowicz, J.; Adamek, G.; Sopata, M.; Koper, J. K.; Siwak, P.

2017-12-01

The paper presents the results of nanocrystalline powder tantalum consolidation using hot pressing. The authors used two different heating techniques during hot pressing: high-frequency induction heating (HFIH) and pulse plasma sintering (PPS). A comparison of the structure, microstructure, mechanical properties and corrosion resistance of the bulk nanocrystalline tantalum obtained in both techniques was performed. The nanocrystalline powder was made to start from the microcrystalline one using the high-energy ball milling process. The nanocrystalline powder was hot-pressed at 1000 °C, whereas, for comparison, the microcrystalline powder was hot pressed up to 1500 °C for proper consolidation. The authors found that during hot pressing, the powder partially reacts with the graphite die covered by boron nitride, which facilitated punches and powder displacement in the die during densification. Tantalum carbide and boride in the nanocrystalline material was found, which can improve the mechanical properties. The hardness of the HFIH and PPS nanocrystalline tantalum was as high as 625 and 615 HV, respectively. The microstructure was more uniform in the PPS nanomaterial. The corrosion resistance in both cases deteriorated, in comparison to the microcrystalline material, while the PPS material corrosion resistance was slightly better than that of the HFIH one.

Diffusion barrier properties of single- and multilayered quasi-amorphous tantalum nitride thin films against copper penetration

NASA Astrophysics Data System (ADS)

Chen, G. S.; Chen, S. T.

2000-06-01

Tantalum-related thin films containing different amounts of nitrogen are sputter deposited at different argon-to-nitrogen flow rate ratios on (100) silicon substrates. Using x-ray diffractometry, transmission electron microscopy, composition and resistivity analyses, and bending-beam stress measurement technique, this work examines the impact of varying the nitrogen flow rate, particularly on the crystal structure, composition, resistivity, and residual intrinsic stress of the deposited Ta2N thin films. With an adequate amount of controlled, reactive nitrogen in the sputtering gas, thin films of the tantalum nitride of nominal formula Ta2N are predominantly amorphous and can exist over a range of nitrogen concentrations slightly deviated from stoichiometry. The single-layered quasi-amorphous Ta2N (a-Ta2N) thin films yield intrinsic compressive stresses in the range 3-5 GPa. In addition, the use of the 40-nm-thick a-Ta2N thin films with different nitrogen atomic concentrations (33% and 36%) and layering designs as diffusion barriers between silicon and copper are also evaluated. When subjected to high-temperature annealing, the single-layered a-Ta2N barrier layers degrade primarily by an amorphous-to-crystalline transition of the barrier layers. Crystallization of the single-layered stoichiometric a-Ta2N (Ta67N33) diffusion barriers occurs at temperatures as low as 450 °C. Doing so allows copper to preferentially penetrate through the grain boundaries or thermal-induced microcracks of the crystallized barriers and react with silicon, sequentially forming {111}-facetted pyramidal Cu3Si precipitates and TaSi2 Overdoping nitrogen into the amorphous matrix can dramatically increase the crystallization temperature to 600 °C. This temperature increase slows down the inward diffusion of copper and delays the formation of both silicides. The nitrogen overdoped Ta2N (Ta64N36) diffusion barriers can thus be significantly enhanced so as to yield a failure temperature 100 �

Tungsten-reinforced tantalum

NASA Technical Reports Server (NTRS)

Bacigalupi, R. J.; Breitwieser, R.

1972-01-01

Method is described for producing tungsten-reinforced tantalum, a material possessing the high temperature strength of tungsten and room temperature ductility and weldability of tantalum. This material is produced by bonding together and overlaying structure of tungsten wires with chemical vapor deposited tantalum.

Copper-tantalum alloy

DOEpatents

Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

1986-07-15

A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

All-tantalum electrolytic capacitor

NASA Technical Reports Server (NTRS)

Green, G. E., Jr.

1977-01-01

Device uses single-compression tantalum-to-tantalum seal. Single-compression seal allows better utilization of volume within device. As result of all-tantalum case and lengthened cathode, electrical parameters, particularly equivalent series resistance and capacitance stability, improved over silver-cased capacitor.

Niobium and tantalum

USGS Publications Warehouse

Schulz, Klaus J.; Piatak, Nadine M.; Papp, John F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Niobium and tantalum are transition metals that are almost always found together in nature because they have very similar physical and chemical properties. Their properties of hardness, conductivity, and resistance to corrosion largely determine their primary uses today. The leading use of niobium (about 75 percent) is in the production of high-strength steel alloys used in pipelines, transportation infrastructure, and structural applications. Electronic capacitors are the leading use of tantalum for high-end applications, including cell phones, computer hard drives, and such implantable medical devices as pacemakers. Niobium and tantalum are considered critical and strategic metals based on the potential risks to their supply (because current production is restricted to only a few countries) and the significant effects that a restriction in supply would have on the defense, energy, high-tech industrial, and medical sectors.The average abundance of niobium and tantalum in bulk continental crust is relatively low—8.0 parts per million (ppm) niobium and 0.7 ppm tantalum. Their chemical characteristics, such as small ionic size and high electronic field strength, significantly reduce the potential for these elements to substitute for more common elements in rock-forming minerals and make niobium and tantalum essentially immobile in most aqueous solutions. Niobium and tantalum do not occur naturally as pure metals but are concentrated in a variety of relatively rare oxide and hydroxide minerals, as well as in a few rare silicate minerals. Niobium is primarily derived from the complex oxide minerals of the pyrochlore group ((Na,Ca,Ce)2(Nb,Ti,Ta)2(O,OH,F)7), which are found in some alkaline granite-syenite complexes (that is, igneous rocks containing sodium- or potassium-rich minerals and little or no quartz) and carbonatites (that is, igneous rocks that are more than 50 percent composed of primary carbonate minerals, by volume). Tantalum is derived mostly from the

Electrodeposition of Tantalum and Tantalum-Chromium Alloys

DTIC Science & Technology

1980-05-01

Electrochem Soc, 112, 840 (1965). 7Ibid, 113,60 (1966). 8Ibid, 113.66 (1966). J. Wurm, "European Conference on the Development of Molten Salts Applica...Chem. 35, 161-3 (1887). 16. J. Wurm, "European Conference on the Development of Molten Salts Applica- tions," Extended Abstracts and Proceedings, pp...Metals Tantalum Tantalum-Chromium Alloys Chromium Coating Fused Salt Electrolyte Electrodeposition FLINAK 20. ABSTRACT (Continue on reverse

Metastable tantalum oxide formation during the devitrification of amorphous tantalum thin films

DOE PAGES

Donaldson, Olivia K.; Hattar, Khalid; Trelewicz, Jason R.

2016-07-04

Microstructural evolution during the devitrification of amorphous tantalum thin films synthesized via pulsed laser deposition was investigated using in situ transmission electron microscopy (TEM) combined with ex situ isothermal annealing, bright-field imaging, and electron-diffraction analysis. The phases formed during crystallization and their stability were characterized as a function of the chamber pressure during deposition, devitrification temperature, and annealing time. A range of metastable nanocrystalline tantalum oxides were identified following devitrification including multiple orthorhombic oxide phases, which often were present with, or evolved to, the tetragonal TaO 2 phase. While the appearance of these phases indicated the films were evolving tomore » the stable form of tantalum oxide—monoclinic tantalum pentoxide—it was likely not achieved for the conditions considered due to an insufficient amount of oxygen present in the films following deposition. Nevertheless, the collective in situ and ex situ TEM analysis applied to thin film samples enabled the isolation of a number of metastable tantalum oxides. As a result, new insights were gained into the transformation sequence and stability of these nanocrystalline phases, which presents opportunities for the development of advanced tantalum oxide-based dielectric materials for novel memristor designs.« less

High density hexagonal boron nitride prepared by hot isostatic pressing in refractory metal containers

DOEpatents

Hoenig, Clarence L.

1992-01-01

Boron nitride powder with less than or equal to the oxygen content of starting powder (down to 0.5% or less) is hot isostatically pressed in a refractory metal container to produce hexagonal boron nitride with a bulk density greater than 2.0 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800.degree. C. and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.21 g/cc. Complex shapes can be made.

Magazine Exposure, Tanned Women Stereotypes, and Tanning Attitudes

PubMed Central

Lee, Seungyoon; Wilson, Kari

2010-01-01

This study investigated whether magazine exposure is related to stereotypical beliefs about tanned women. A survey of White college women (n = 205) assessed their exposure to beauty/fashion and health/fitness magazines. Outcome variables were the beliefs that tanned women are fashionable, fit, and shallow. Attention to the tanned women’s images in health magazines positively predicted the belief that tanned women are fit and that tanned women are shallow; in contrast, attention to the images in beauty magazine negatively predicted the belief that tanned women are fit. Number of beauty magazines women read negatively predicted the belief that tanned women are shallow. The belief that tanned women are fit was unrelated, but the belief that tanned women are shallow was negatively related, with tanning attitudes. PMID:20573553

Magazine exposure, tanned women stereotypes, and tanning attitudes.

PubMed

Cho, Hyunyi; Lee, Seungyoon; Wilson, Kari

2010-09-01

This study investigated whether magazine exposure is related to stereotypical beliefs about tanned women. A survey of White college women (n=205) assessed their exposure to beauty/fashion and health/fitness magazines. Outcome variables were the beliefs that tanned women are fashionable, fit, and shallow. Attention to the tanned women's images in health magazines positively predicted the belief that tanned women are fit and that tanned women are shallow; in contrast, attention to the images in beauty magazine negatively predicted the belief that tanned women are fit. Number of beauty magazines women read negatively predicted the belief that tanned women are shallow. The belief that tanned women are fit was unrelated, but the belief that tanned women are shallow was negatively related, with tanning attitudes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Tantalum recycling in the United States in 1998

USGS Publications Warehouse

Cunningham, Larry D.

2001-01-01

This report describes the flow of tantalum in the United States in 1998 with emphasis on the extent to which tantalum was recycled/reused. Tantalum was mostly recycled from new scrap that was generated during the manufacture of tantalum-related electronic components and new and old scrap products of tantalum-containing cemented carbides and superalloys. In 1998, about 210 metric tons of tantalum was recycled/reused, with about 43% derived from old scrap. The tantalum recycling rate was calculated to be 21%, and tantalum scrap recycling efficiency, 35%.

Semimicrodetermination of tantalum with selenous acid

USGS Publications Warehouse

Grimaldi, F.S.; Schnepfe, M.M.

1958-01-01

Tantalum is separated and determined gravimetrically by precipitation with selenous acid from a highly acidic solution containing oxalic and tartaric acids. The method is selective for the determination of up to 30 mg. of tantalum pentoxide, and tolerates relatively large amounts of scandium, yttrium, cerium, titanium, zirconium, thorium, vanadium, niobium, molybdenum, tungsten, uranium, iron, aluminum, gallium, tin, lead, antimony, and bismuth. The separation of tantalum from niobium and titanium is not strictly quantitative, and correction is made colorimetrically for the small amounts of niobium and titanium co-precipitating with the tantalum. The method was applied to the determination of tantalum in tantaloniobate ores.

Method of making tantalum capacitors

DOEpatents

McMillan, April D.; Clausing, Robert E.; Vierow, William F.

1998-01-01

A method for manufacturing tantalum capacitors includes preparing a tantalum compact by cold pressing tantalum powder, placing the compact, along with loose refractory metal powder, in a microwave-transparent casket to form an assembly, and heating the assembly for a time sufficient to effect at least partial sintering of the compact and the product made by the method.

Measuring nonsolar tanning behavior: indoor and sunless tanning.

PubMed

Lazovich, Deann; Stryker, Jo Ellen; Mayer, Joni A; Hillhouse, Joel; Dennis, Leslie K; Pichon, Latrice; Pagoto, Sherry; Heckman, Carolyn; Olson, Ardis; Cokkinides, Vilma; Thompson, Kevin

2008-02-01

To develop items to measure indoor tanning and sunless tanning that can be used to monitor trends in population surveys or to assess changes in behavior in intervention studies. A group of experts on indoor tanning convened in December 2005, as part of a national workshop to review the state of the evidence, define measurement issues, and develop items for ever tanned indoors, lifetime frequency, and past-year frequency for both indoor tanning and sunless tanning. Each item was subsequently assessed via in-person interviews for clarity, specificity, recall, and appropriateness of wording. Universities in Tennessee and Virginia, a medical center in Massachusetts, and a high school in New Hampshire. The study population comprised 24 adults and 7 adolescents. Participants understood indoor tanning to represent tanning from beds, booths, and lamps that emit artificial UV radiation, rather than sunless tanning, even though both can be obtained from a booth. Two items were required to distinguish manually applied from booth-applied sunless tanning products. Frequency of use was easier for participants to recall in the past year than for a lifetime. While indoor tanning items may be recommended with confidence for clarity, sunless tanning items require additional testing. Memory aids may be necessary to facilitate recall of lifetime use of nonsolar tanning. In addition, studies that assess reliability and validity of these measures are needed. Since study participants were primarily young and female, testing in other populations should also be considered.

Process for manufacturing tantalum capacitors

DOEpatents

Lauf, Robert J.; Holcombe, Cressie E.; Dykes, Norman L.

1993-01-01

A process for manufacturing tantalum capacitors in which microwave energy is used to sinter a tantalum powder compact in order to achieve higher surface area and improved dielectric strength. The process comprises cold pressing tantalum powder with organic binders and lubricants to form a porous compact. After removal of the organics, the tantalum compact is heated to 1300.degree. to 2000.degree. C. by applying microwave radiation. Said compact is then anodized to form a dielectric oxide layer and infiltrated with a conductive material such as MnO.sub.2. Wire leads are then attached to form a capacitor to said capacitor is hermetically packaged to form the finished product.

Process for manufacturing tantalum capacitors

DOEpatents

Lauf, R.J.; Holcombe, C.E.; Dykes, N.L.

1993-02-02

A process for manufacturing tantalum capacitors in which microwave energy is used to sinter a tantalum powder compact in order to achieve higher surface area and improved dielectric strength. The process comprises cold pressing tantalum powder with organic binders and lubricants to form a porous compact. After removal of the organics, the tantalum compact is heated to 1,300 to 2,000 C by applying microwave radiation. Said compact is then anodized to form a dielectric oxide layer and infiltrated with a conductive material such as MnO[sub 2]. Wire leads are then attached to form a capacitor to said capacitor is hermetically packaged to form the finished product.

Ceramic material suitable for repair of a space vehicle component in a microgravity and vacuum environment, method of making same, and method of repairing a space vehicle component

NASA Technical Reports Server (NTRS)

Riedell, James A. (Inventor); Easler, Timothy E. (Inventor)

2009-01-01

A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium diboride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Methods of repairing a substrate

NASA Technical Reports Server (NTRS)

Riedell, James A. (Inventor); Easler, Timothy E. (Inventor)

2011-01-01

A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium boride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Additively manufactured porous tantalum implants.

PubMed

Wauthle, Ruben; van der Stok, Johan; Amin Yavari, Saber; Van Humbeeck, Jan; Kruth, Jean-Pierre; Zadpoor, Amir Abbas; Weinans, Harrie; Mulier, Michiel; Schrooten, Jan

2015-03-01

The medical device industry's interest in open porous, metallic biomaterials has increased in response to additive manufacturing techniques enabling the production of complex shapes that cannot be produced with conventional techniques. Tantalum is an important metal for medical devices because of its good biocompatibility. In this study selective laser melting technology was used for the first time to manufacture highly porous pure tantalum implants with fully interconnected open pores. The architecture of the porous structure in combination with the material properties of tantalum result in mechanical properties close to those of human bone and allow for bone ingrowth. The bone regeneration performance of the porous tantalum was evaluated in vivo using an orthotopic load-bearing bone defect model in the rat femur. After 12 weeks, substantial bone ingrowth, good quality of the regenerated bone and a strong, functional implant-bone interface connection were observed. Compared to identical porous Ti-6Al-4V structures, laser-melted tantalum shows excellent osteoconductive properties, has a higher normalized fatigue strength and allows for more plastic deformation due to its high ductility. It is therefore concluded that this is a first step towards a new generation of open porous tantalum implants manufactured using selective laser melting. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

State Indoor Tanning Laws and Adolescent Indoor Tanning

PubMed Central

Guy, Gery P.; Berkowitz, Zahava; Jones, Sherry Everett; O’Malley Olsen, Emily; Miyamoto, Justin N.; Michael, Shannon L.; Saraiya, Mona

2014-01-01

Objectives. Recently, several state indoor tanning laws, including age restrictions, were promulgated to reduce indoor tanning among minors. We examined the effects of these laws on adolescent indoor tanning. Methods. We used nationally representative data from the 2009 and 2011 national Youth Risk Behavior Surveys (n = 31 835). Using multivariable logistic regression, we examined the association between state indoor tanning laws and indoor tanning among US high school students. Results. Female students in states with indoor tanning laws were less likely to engage in indoor tanning than those in states without any laws. We observed a stronger association among female students in states with systems access, parental permission, and age restriction laws than among those in states without any laws. We found no significant association among female students in states with only systems access and parental permission laws or among male students. Conclusions. Indoor tanning laws, particularly those including age restrictions, may be effective in reducing indoor tanning among female high school students, for whom rates are the highest. Such reductions have the potential to reduce the health and economic burden of skin cancer. PMID:24524515

Radiopharmaceutical composition containing tantalum-178 and process therefor

DOEpatents

Neirinckx, Rudi D.; Holman, B. Leonard; Davis, Michael A.; Harris, Gale I.

1989-05-16

A physiologically acceptable solution of tantalum-178 having an activity of 0.1 to 200 millicuries per milliliter of tantalum-178 solution is provided. The solution is obtained from tungsten-178 bound to a column of an anion exchange resin which forms tantalum-178 in situ by eluting the column with a hydrochloric acid solution containing hydrogen peroxide to form an acidic solution of tantalum-178. The acidic solution of tantalum-178 then is neutralized.

Friendly tanning: young adults' engagement with friends around indoor tanning.

PubMed

Rodríguez, Vivian M; Daniel, Casey L; Welles, Brooke Foucault; Geller, Alan C; Hay, Jennifer L

2017-08-01

Indoor tanning (IT), particularly during early adulthood, increases risk for melanoma and is exceedingly common among youth. Social influence, including social norms, promotes IT but little is known about young adults' engagement with friends around tanning. We examined IT behaviors and tanning-related communication with friends at three universities. Of 837 participants, 261 (31%) reported ever tanning (90% female, 85% White). Of those, 113 (43%) were former tanners and 148 (57%) current tanners. Current tanners reported more social tanning and discussions with friends about tanning, more frequent outdoor tanning, high propensity to tan, and greater lifetime IT exposure than former tanners. Risks-to-benefits discussion ratios were greater for former tanners. In adjusted analyses, current tanners were more likely to make plans to tan and to talk about tanning benefits with friends. Findings confirm IT is a social experience. Future work should examine social tanning's role in the promotion and reduction of IT among youth.

Indoor Tanning

MedlinePlus

... proof that indoor tanning is safer than tanning outdoors. Indoor tanning systems give concentrated UV exposure regardless ... For example, it’s essential for promoting good bone health. While UV ... a tan to get that benefit. According to the Surgeon General, fair and light- ...

Phase Transformation Synthesis of Strontium Tantalum Oxynitride-based Heterojunction for Improved Visible Light-Driven Hydrogen Evolution.

PubMed

Zeng, Weixuan; Bian, Yuan; Cao, Sheng; Ma, Yongjin; Liu, Yi; Zhu, Anquan; Tan, Pengfei; Pan, Jun

2018-06-07

Tantalum oxynitride-based materials, which possess narrow bandgaps and sufficient band energy potentials, have been of immense interest for water splitting. However, the efficiency of photocatalytic reactions is still low due to the fast electron-hole recombination. Here, a Sr2Ta2O7-xNx/SrTaO2N heterostructured photocatalyst with well-matched band structure was in situ constructed by nitridation of hydrothermal-prepared Sr2Ta2O7 nanosheets. Compared to Sr2Ta2O7-xNx and pure SrTaO2N, the Sr2Ta2O7-xNx/SrTaO2N heterostructured photocatalyst exhibited highest rate of hydrogen evolution, which is ca. 2.0 and 76.4 times of Sr2Ta2O7-xNx and pure SrTaO2N under the similar reaction condition, respectively. The enhanced performance arises from the formation of suitable band matched heterojunction accelerated charge separation. This work provides a promising strategy for the construction of tantalum oxynitride-based heterojunction photocatalysts.

Mineral resource of the month: tantalum

USGS Publications Warehouse

,

2011-01-01

The article offers information on a rare transition metal called tantalum. It says that the blue-gray mineral resource was discovered in 1801 or 1802 and was used for capacitors in 1940. It adds that the tantalite ore and other minerals in the ore should be separated in order to generate concentrates of tantalum. The use of tantalum are also cited.

Contextual Factors, Indoor Tanning, and Tanning Dependence in Young Women

PubMed Central

Heckman, Carolyn J.; Darlow, Susan D.; Kloss, Jacqueline D.; Munshi, Teja; Manne, Sharon L.

2015-01-01

Objectives The study's purpose was to investigate the association of contextual factors such as cost, tanning accessibility, regulations, or marketing and indoor tanning or tanning dependence. Methods One hundred thirty-nine college-aged female indoor tanners completed a questionnaire between 2009 and 2011. Results Higher scores on tanning dependence and assessment in the spring/summer (versus the fall/winter) were associated with more frequent indoor tanning in the last 30 days (ps < .05). More frequent indoor tanning, greater session length, and more trouble paying for tanning were associated with higher scores on tanning dependence (ps < .05). Conclusions Public health research and practice could benefit from attention to such contextual factors as tanning cost and regulations regarding session length. PMID:25741682

Tan and thin? Associations between attitudes toward thinness, motives to tan and tanning behaviors in adolescent girls.

PubMed

Darlow, Susan D; Heckman, Carolyn J; Munshi, Teja

2016-07-01

Tanning during adolescence increases skin cancer risk. Relatively few studies have examined the association between thinness attitudes and tanning attitudes and behaviors. The purpose of the current study was to examine psychosocial predictors of sunbathing and tanning bed use, specifically thin ideal internalization (TII) and motives for tanning among high school girls. Adolescent girls (N = 229) completed a 10-minute questionnaire designed to assess sunbathing and indoor tanning, TII and motives to tan (appearance, social and well-being). Hierarchical regression analyses showed that TII, β = .05, p < .05, appearance motives, β = .11, p < .01 and well-being motives, β = .11, p < .01 were all independently positively associated with sunbathing. Social motives were negatively associated with sunbathing, β = -.07, p < .05. A three-way interaction was found between the three types of motives on indoor tanning, in that appearance and well-being motives interacted to increase indoor tanning levels, especially among those who strongly endorsed social motives for tanning, β = .22, p < .05. Motives for tanning, specifically those associated with appearance and well-being, can interact to increase tanning bed use. When designing tailored interventions for skin cancer prevention in young people, researchers should consider tailoring based on motivation. Researchers and healthcare professionals who work with adolescents should attend to tanners who are motivated for both appearance and mood-related reasons, as they may be most at risk for tanning dependence and skin cancer.

Performance comparison: Aluminum electrolytic and solid tantalum capacitor

NASA Technical Reports Server (NTRS)

Hawthornthwaite, B. G.; Piper, J.; Holland, H. W.

1981-01-01

Several key electrical and environmental parameters of latest technology aluminum electrolytic and solid tantalum capacitors were evaluated in terms of price fluctuations of tantalum metal. Performance differences between solid tantalums and aluminum electrolytics are examined.

High strength forgeable tantalum base alloy

NASA Technical Reports Server (NTRS)

Buckman, R. W., Jr.

1975-01-01

Increasing tungsten content of tantalum base alloy to 12-15% level will improve high temperature creep properties of existing tantalum base alloys while retaining their excellent fabrication and welding characteristics.

Tantalum-copper alloy and method for making

DOEpatents

Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

1984-11-06

A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

Tantalum-copper alloy and method for making

DOEpatents

Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

1983-06-01

A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

Purification of tantalum by plasma arc melting

DOEpatents

Dunn, Paul S.; Korzekwa, Deniece R.

1999-01-01

Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

Support for indoor tanning policies among young adult women who indoor tan.

PubMed

Mays, Darren; Murphy, Sarah E; Bubly, Rachel; Atkins, Michael B; Tercyak, Kenneth P

2016-12-01

The purpose of this study to examine support for indoor tanning policies and correlates of policy support among young adult women who indoor tan. Non-Hispanic white women ages 18-30 who indoor tanned in the past year (n = 356, M 23.3 age, SD 3.1) recruited in the Washington, DC area from 2013 to 2016 completed measures of indoor tanning behaviors, attitudes, perceptions, beliefs, and policy support. Most women in the sample supported policies to prevent children under the age of 18 from indoor tanning (74.0 %) and stronger warnings about the risks of indoor tanning on tanning devices (77.6 %); only 10.1 % supported a total ban. In multivariable analyses, support for individual indoor tanning policies varied by demographics (e.g., age), frequent indoor tanning behavior, indoor tanning beliefs, and risk perceptions. Non-Hispanic white young adult women who indoor tan, the primary consumers of indoor tanning, and a high-risk population, largely support indoor tanning prevention policies implemented by many state governments and those currently under review for national enactment. Given low levels of support for a total indoor tanning ban, support for other potential policies (e.g., increasing the minimum age to 21) should be investigated to inform future steps to reduce indoor tanning and the associated health risks.

Ultraviolet spectrophotometric determination of tantalum with pyrogallol

USGS Publications Warehouse

Dinnin, J.I.

1953-01-01

In a search for a more rapid method for the determination of tantalum in rocks and minerals, an intensive study was made of the tantalum-pyrogallol reaction recommended by Platanov and Krivoshlikov, and a better modified spectrophotometric procedure is given. The improved method consists in measuring the absorbancy of the tantalum-pyrogallol complex at 325 m?? in 4N hydrochloric acid and a fixed concentration (0.0175M) of ammonium oxalate. Beer's law is followed for the concentration range up to 40 ?? per ml. Sensitivity in terms of molar absorbancy index is 4775. Most interferences are additive in character and readily correctable. Separations or major corrections are required in the presence of significant amounts of molybdenum, tungsten, antimony, and uranium. The method has been successfully applied to three ores previously analyzed by gravimetric techniques. The method affords greater speed, sensitivity, and reproducibility in the determination of tantalum in rocks and minerals. A more reliable technique for preparing standard solutions of tantalum has been developed.

Study of constitution diagram aluminum-tantalum

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

Glazov, V.M.; Mal'tsev, M.V.; Chistyakov, Y.D.

1988-10-20

Alloys of aluminum with tantalum were for the first time obtained by aluminothermic method in 1868 by Moriniak. Later these alloys were studied in the works of Schirmeister (1915) and Brouwer (1938), moreover Brouwer established that tantalum with aluminum forms the chemical compound TaA1, which has tetragonal crystal lattice with parameters a=5.422 angstroms and c=8.536 angstroms (1). However despite the fact that alloys of aluminum with tantalum long ago are obtained already, constitution diagram of this system is not studied until recently. In connection with the application of tantalum as the modifying additive in aluminum alloys an emergency in themore » construction of this diagram, without the knowledge by which it is not possible to give the correct explanation of the mechanism of the very process of the modification of primary grain. For this purpose was undertaken this work. Russian translations.« less

Tanning

MedlinePlus

... Spray tans, lotions, or gels use a color additive that makes your skin look tan called DHA. DHA is considered safe for use on the outside of your body by the U.S. Food and Drug Administration. You need to make sure ...

Fabrication of Ta2O5/GeNx gate insulator stack for Ge metal-insulator-semiconductor structures by electron-cyclotron-resonance plasma nitridation and sputtering deposition techniques

NASA Astrophysics Data System (ADS)

Otani, Yohei; Itayama, Yasuhiro; Tanaka, Takuo; Fukuda, Yukio; Toyota, Hiroshi; Ono, Toshiro; Mitsui, Minoru; Nakagawa, Kiyokazu

2007-04-01

The authors have fabricated germanium (Ge) metal-insulator-semiconductor (MIS) structures with a 7-nm-thick tantalum pentaoxide (Ta2O5)/2-nm-thick germanium nitride (GeNx) gate insulator stack by electron-cyclotron-resonance plasma nitridation and sputtering deposition. They found that pure GeNx ultrathin layers can be formed by the direct plasma nitridation of the Ge surface without substrate heating. X-ray photoelectron spectroscopy revealed no oxidation of the GeNx layer after the Ta2O5 sputtering deposition. The fabricated MIS capacitor with a capacitance equivalent thickness of 4.3nm showed excellent leakage current characteristics. The interface trap density obtained by the modified conductance method was 4×1011cm-2eV-1 at the midgap.

Niobium and tantalum: indispensable twins

USGS Publications Warehouse

Schulz, Klaus; Papp, John

2014-01-01

Niobium and tantalum are transition metals almost always paired together in nature. These “twins” are difficult to separate because of their shared physical and chemical properties. In 1801, English chemist Charles Hatchett uncovered an unknown element in a mineral sample of columbite; John Winthrop found the sample in a Massachusetts mine and sent it to the British Museum in London in 1734. The name columbium, which Hatchet named the new element, came from the poetic name for North America—Columbia—and was used interchangeably for niobium until 1949, when the name niobium became official. Swedish scientist Anders Ekberg discovered tantalum in 1802, but it was confused with niobium, because of their twinned properties, until 1864, when it was recognized as a separate element. Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine their primary uses and make niobium and tantalum indispensable.

Spray-on tanning.

PubMed

Rogers, Cindy J

2005-01-01

The modern formulation of dihydroxyacetone (DHA), the only sunless tanning solution approved by the Food and Drug Administration (FDA), is combined with bronzers and moisturizers to deliver a cosmetically acceptable skin color and a natural-looking tan without ultraviolet (UV) exposure. Spray-on tanning products, which deliver this formulation evenly to achieve a full body tan, may be applied in a tanning booth, airbrushed on by a technician, or sprayed on at home, and they appear to offer a generally safe alternative for patients who seek a suntanned appearance.

Tanning

MedlinePlus

... be dangerous and are not approved by the Food and Drug Administration (FDA). Sunless tanners have no known risk for skin cancer, but you do have to be careful. Most spray tans, lotions, and gels use DHA, a color additive that makes your skin look tan. DHA is ...

Killer tans: state, feds crack down on indoor tanning.

PubMed

Conde, Crystal

2010-05-01

The American Cancer Society says that using a tanning bed before age 35 increases a person's risk of developing melanoma by 75 percent. Physicians hope that recent actions by the FTC, along with TMA-supported state legislation placing age restrictions on minors' use of tanning beds, will spur the tanning industry to operate more responsibly and stop spreading false information to the public.

Bone response to a titanium aluminium nitride coating on metallic implants.

PubMed

Freeman, C O; Brook, I M

2006-05-01

The design, surface characteristics and strength of metallic implants are dependant on their intended use and clinical application. Surface modifications of materials may enable reduction of the time taken for osseointegration and improve the biological response of bio-mechanically favourable metals and alloys. The influence of a titanium aluminium nitride (TAN) coating on the response of bone to commercially pure titanium and austenitic 18/8 stainless steel wire is reported. TAN coated and plain rods of stainless steel and commercially pure titanium were implanted into the mid-shaft of the femur of Wistar rats. The femurs were harvested at four weeks and processed for scanning electron and light microscopy. All implants exhibited a favourable response in bone with no evidence of fibrous encapsulation. There was no significant difference in the amount of new bone formed around the different rods (osseoconduction), however, there was a greater degree of shrinkage separation of bone from the coated rods than from the plain rods (p = 0.017 stainless steel and p = 0.0085 titanium). TAN coating may result in reduced osseointegration between bone and implant.

Perceptions of tanning risk among melanoma patients with a history of indoor tanning.

PubMed

Nergard-Martin, Jennifer; Caldwell, Chauncey; Barr, Morgan; Dellavalle, Robert P; Solomon, James A

2018-01-01

A new US Food and Drug Administration (FDA) regulation classified tanning beds as class II, requiring indoor tanning facilities to inform users of the risk of skin cancer in efforts to reverse the growing trend in indoor tanning. However, little is known from the patient's perspective on whether knowledge of the risk of skin cancer development is a deterrent to indoor tanning. There also is conflicting literature regarding the relationship among frequency of indoor tanning, age at onset of melanoma diagnosis, and characteristics of diagnosis in melanoma patients with a history of indoor tanning. An international survey was conducted in patients 18 years and older who self-reported being diagnosed with melanoma after indoor tanning. The purpose of this study was to investigate the patients' perspective on indoor-tanning behaviors as associated with the severity of their melanomas and the time frame in which they were diagnosed as well as their perceived views on the safety of indoor tanning and the frequency in which they continue to tan indoors.

Indoor tanning and problem behavior.

PubMed

Bagdasarov, Zhanna; Banerjee, Smita; Greene, Kathryn; Campo, Shelly

2008-01-01

The authors examined factors predicting college students' use of tanning beds. Undergraduate students (N = 745) at a large Northeastern university participated in the study by answering a survey measuring tanning behavior and other psychosocial variables, including sensation seeking, self-esteem, tanning image beliefs, and friends' tanning bed use. All 3 systems from problem behavior theory predicted past tanning bed use and intention to use tanning beds. The authors observed a positive association between sensation seeking and intention to use tanning beds. Tanning image beliefs were positively associated with both past tanning behavior and intention to use tanning beds. Interventions focusing on friend and acquaintance social network influences may be more effective than health-risk campaigns in reducing tanning bed use.

French teenagers and artificial tanning.

PubMed

Tella, E; Beauchet, A; Vouldoukis, I; Séi, J-F; Beaulieu, P; Sigal, M-L; Mahé, E

2013-03-01

Exposure to solar and artificial ultraviolet (UV) radiations is a major risk factor for skin cancers. France has enacted one of the strictest laws that, notably, restrict tanning-bed access to adults ≥18 years old. We evaluated artificial tanning behaviours of French teenagers (11-17 years old): sunless-tanning products, sunlamps and artificial tanning beds. An anonymous questionnaire evaluating sunburn history, skin phototype, behaviours with sunless-tanning products and indoor tanning, and parents' behaviours was distributed to students enrolled in two middle and high schools in Antony, a typical city of the middle class French population, located in the Paris suburbs. RESULTS Among 713 teenagers (mean age: 13.5 years: male/female: 1.1) responding, more than half declared that it was important to be tanned during the summer, 1% reported having already used tanning pills, 9.9% tanning creams and 1.4% indoor tanning. Female teenagers significantly more frequently resorted to indoor tanning (P = 0.02), cited the importance of being tanned all year long (P < 0.0001), used tanning pills (P < 0.0001) or tanning creams (P < 0.006), and their parents relied on indoor tanning (P < 0.0001). Profiles of tanning-pill and -cream users were similar. Mean ages for the two groups were comparable. French regulations for indoor tanning seem quite effective. Our analyses revealed a typical teenager profile with sun-exposure risk behaviours, for example, indoor tanning, and use of tanning pills or creams. They could be a selective target for sun-protection information campaigns. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

Measurement of Tanning Dependence

PubMed Central

Heckman, C.J.; Darlow, S.; Kloss, J.D.; Cohen-Filipic, J.; Manne, S.L.; Munshi, T.; Yaroch, A.L.; Perlis, C.

2014-01-01

Background Indoor tanning has been found to be addictive. However, the most commonly-used tanning dependence measures have not been well-validated. Objective The study’s purpose was to explore the psychometric characteristics of and compare the mCAGE (modified Cut-down, Annoyed, Guilty, Eye-opener Scale), mDSM-IV-TR (modified Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition - Text Revised), and TAPS (Tanning Pathology Scale) measures of tanning dependence and provide recommendations for research and practice. Methods This study was a cross-sectional online survey with 18–25 year old female university students. The main outcome variable was tanning dependence measured by the mCAGE, mDSM-IV-TR, and TAPS. Results Internal consistency of the TAPS subscales was good but was poor for the mCAGE and mDSM-IV-TR, except when their items were combined. Agreement between the mCAGE and mDSM-IV-TR was fair. Factor analysis of the TAPS confirmed the current four-factor structure. All of the tanning dependence scales were significantly correlated with one another. Likewise, most of the tanning dependence scales were significantly correlated with other measures of tanning attitudes and behaviors. However, the tolerance to tanning TAPS subscale was not significantly correlated with any measure of tanning attitudes or behaviors and had the lowest subscale internal reliability and eigenvalues. Conclusion Based on the data and existing literature, we make recommendations for the continued use of tanning dependence measures. Intervention may be needed for the approximately 5% of college women who tend to be classified as tanning dependent across measures. Monitoring of individuals reporting tanning dependence symptoms is warranted. PMID:23980870

Tanning Bed Perception Survey

PubMed Central

Mcquinn, Donna; Lohse, Christine; Hassani, John

2015-01-01

Objective: This study was intended to investigate the perception of tanning bed use among college students. Design: A 15-question survey was given to young adults regarding tanning perceptions. Setting: Rochester Community College in Rochester, Minnesota. Participants: Forty-four respondents between 18 and 51 years of age. Measurements: Data was collected via a self-reported questionnaire. Results: In this study, 50 percent of participants were not educated on the risks of melanoma, and 68 percent were not interested in receiving information on melanoma and completing a follow-up survey. More specifically, 63 percent versus 89 percent of participants with no tanning bed versus some tanning bed use did not want information regarding melanoma, respectively. This study also shows that more tanning bed users believe tanning helps prevent burning than non-tanning bed users. Fifty-seven percent of the 35 participants who had never used a tanning bed thought that they never prevent sunburn, while only 11 percent of the nine participants who had used a tanning bed in the past thought that they never prevent sunburn, which was statistically significant. PMID:25852811

Scintillation Breakdowns in Chip Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2008-01-01

Scintillations in solid tantalum capacitors are momentarily local breakdowns terminated by a self-healing or conversion to a high-resistive state of the manganese oxide cathode. This conversion effectively caps the defective area of the tantalum pentoxide dielectric and prevents short-circuit failures. Typically, this type of breakdown has no immediate catastrophic consequences and is often considered as nuisance rather than a failure. Scintillation breakdowns likely do not affect failures of parts under surge current conditions, and so-called "proofing" of tantalum chip capacitors, which is a controllable exposure of the part after soldering to voltages slightly higher than the operating voltage to verify that possible scintillations are self-healed, has been shown to improve the quality of the parts. However, no in-depth studies of the effect of scintillations on reliability of tantalum capacitors have been performed so far. KEMET is using scintillation breakdown testing as a tool for assessing process improvements and to compare quality of different manufacturing lots. Nevertheless, the relationship between failures and scintillation breakdowns is not clear, and this test is not considered as suitable for lot acceptance testing. In this work, scintillation breakdowns in different military-graded and commercial tantalum capacitors were characterized and related to the rated voltages and to life test failures. A model for assessment of times to failure, based on distributions of breakdown voltages, and accelerating factors of life testing are discussed.

Indoor tanning promotions on social media in six US cities #UVTanning #tanning.

PubMed

Ricklefs, Christine A; Asdigian, Nancy L; Kalra, Heidi L; Mayer, Joni A; Dellavalle, Robert P; Holman, Dawn M; Crane, Lori A

2016-06-01

There is no research investigating indoor tanning advertising on social media. We assessed the use of social media to promote indoor tanning. We subscribed to social media platforms in six US cities and content-analyzed promotional messages received. We captured 662 messages on Twitter and Facebook, through salon emails, and in daily deal coupons. Salon postings were most frequent on Twitter and Facebook, with an average of 2-3 postings per week. National chains posted more frequently than local businesses. Forty percent of messages were devoid of tanning content and included photos, jokes, or popular references. Thirty percent mentioned price reductions, and 28 % referenced an upcoming holiday. Sunless tanning (17 %) was promoted more often than ultraviolet tanning (9 %). Tanning salons actively use social media as a strategy for maintaining relationships with customers and offer pricing deals that promote loyalty and high-frequency tanning.

21 CFR 886.3100 - Ophthalmic tantalum clip.

Code of Federal Regulations, 2010 CFR

2010-04-01

... blood vessels in the eye. (b) Classification. Class II (special controls). The device is exempt from the...) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3100 Ophthalmic tantalum clip. (a) Identification. An ophthalmic tantalum clip is a malleable metallic device intended to be implanted permanently...

Efficacy of Tantalum Tungsten Alloys for Diffusion Barrier Applications

NASA Astrophysics Data System (ADS)

Smathers, D. B.; Aimone, P. R.

2017-12-01

Traditionally either Niobium, Tantalum or a combination of both have been used as diffusion barriers in Nb3Sn Multi-filament wire. Vanadium has also been used successfully but the ultimate RRR of the copper is limited unless an external shell of Niobium is included. Niobium is preferred over Tantalum when alternating current losses are not an issue as the Niobium will react to form Nb3Sn. Pure Tantalum tends to deform irregularly requiring extra starting thickness to ensure good barrier qualities. Our evaluations showed Tantalum lightly alloyed with 3 wt% Tungsten is compatible with the wire drawing process while deforming as well as or better than pure Niobium. Ta3wt%W has been processed as a single barrier and as a distributed barrier to fine dimensions. In addition, the higher modulus and strength of the Tantalum Tungsten alloy improves the overall tensile properties of the wire.

'My friends love to tan': examining sensation seeking and the mediating role of association with friends who use tanning beds on tanning bed use intentions.

PubMed

Banerjee, Smita C; Greene, Kathryn; Bagdasarov, Zhanna; Campo, Shelly

2009-12-01

This paper explored how sensation seeking contributes to the likelihood of tanning bed use intentions both directly and indirectly through the way it shapes interaction with peers who use tanning beds and attitudes toward tanning bed. Eight hundred and ninety six (n = 896) male and female college students were recruited for the study. Measured variables included sensation seeking, association with friends who use tanning beds, attitudes toward tanning and tanning bed use intentions. Structural equation modeling was performed to test the hypotheses. In general, results supported the proposed hypotheses and documented that sensation seeking is indirectly associated with tanning bed use intentions through the mediation of association with peers who use tanning beds and attitudes toward tanning. The article discusses theoretical and methodological implications of the findings demonstrating the pathways of influence of sensation seeking on tanning bed use intentions.

A cross-sectional study examining the correlation between sunless tanning product use and tanning beliefs and behaviors.

PubMed

Sahn, Rachel E; McIlwain, Mary Jayne; Magee, Kristin H; Veledar, Emir; Chen, Suephy C

2012-04-01

To establish the effect of sunless tanning products on tanning behaviors and to determine characteristics of sunless tanning product users. A cross-sectional survey study conducted between May 30, 2007, and December 4, 2007. The Emory University campus and surrounding locations in Atlanta, Georgia. Four hundred fifteen community and university-affiliated women. Self-reported use of sunless tanning products and UV radiation tanning methods. Forty-eight percent of participants had used sunless tanning products, 70.6% had tanned in the sun, and 26.0% had used tanning beds at least once in the past year. Most participants (92.7%) believed that tanned skin is more attractive than untanned skin, and 79.2% reported feeling better about themselves when tan. Many sunless tanning product users reported decreased frequency of tanning in the sun (36.8%) or in tanning beds (38%) because of product use. Frequent users were more likely to have decreased their UV radiation exposure. Lighter complexion, frequent use of UV radiation tanning methods, feeling better about oneself when tan, and having a history of skin cancer were independently associated with sunless tanning product use. The desire for tanned skin remains strong despite growing awareness of the dangers of UV radiation exposure. In some women, sunless tanning product use is associated with decreased UV radiation tanning frequency, especially in women who use them repeatedly. Improvements in the appearance of sunless tanning product tans may allow wider acceptance by the public and further decreases in UV radiation tanning practices.

Hafnium radioisotope recovery from irradiated tantalum

DOEpatents

Taylor, Wayne A.; Jamriska, David J.

2001-01-01

Hafnium is recovered from irradiated tantalum by: (a) contacting the irradiated tantalum with at least one acid to obtain a solution of dissolved tantalum; (b) combining an aqueous solution of a calcium compound with the solution of dissolved tantalum to obtain a third combined solution; (c) precipitating hafnium, lanthanide, and insoluble calcium complexes from the third combined solution to obtain a first precipitate; (d) contacting the first precipitate of hafnium, lanthanide and calcium complexes with at least one fluoride ion complexing agent to form a fourth solution; (e) selectively adsorbing lanthanides and calcium from the fourth solution by cationic exchange; (f) separating fluoride ion complexing agent product from hafnium in the fourth solution by adding an aqueous solution of ferric chloride to obtain a second precipitate containing the hafnium and iron; (g) dissolving the second precipitate containing the hafnium and iron in acid to obtain an acid solution of hafnium and iron; (h) selectively adsorbing the iron from the acid solution of hafnium and iron by anionic exchange; (i) drying the ion exchanged hafnium solution to obtain hafnium isotopes. Additionally, if needed to remove residue remaining after the product is dried, dissolution in acid followed by cation exchange, then anion exchange, is performed.

Tanning Salon Compliance Rates in States With Legislation to Protect Youth Access to UV Tanning.

PubMed

Williams, Melissa S; Buhalog, Brittany; Blumenthal, Laura; Stratman, Erik J

2018-01-01

The US Food and Drug Administration has classified tanning beds as carcinogenic. Most states have enacted legislation to prevent or create barriers for minors accessing tanning establishments. Determining tanning salon compliance with legislation would provide an indication of the influence of legislation at preventing exposure to the carcinogen in minors. To investigate compliance rates in the 42 states and the District of Columbia with legislation restricting tanning bed use in minors and to identify differences in compliance based on population, regional location, salon ownership, age group being regulated, and time since the law was enacted. This investigation was a cross-sectional telephone survey conducted between February 1, 2015, and April 30, 2016, by callers posing as minors attempting to schedule a tanning appointment. The setting was tanning salons in the 42 states and the District of Columbia that currently have legislation restricting tanning bed use in minors. Included in the study were 427 tanning salons, 10 randomly selected from each state or territory with tanning legislation. Overall compliance of tanning salons with state tanning legislation and differences in compliance based on community population, regional location, independent vs chain tanning salon, age group being regulated, and time since the law was enacted. Of the 427 tanning salons surveyed, overall noncompliance with state legislation was 37.2% (n = 159). There were more noncompliant tanning salons in rural locations (45.5%; 95% CI, 37.5%-53.7%; P = .009), southern regions of the United States (49.4%; 95% CI, 41.4%-57.4%; P = .001), independently owned salons (43.9%; 95% CI, 37.3%-50.6%; P = .003), states with younger age groups being regulated (53.5%; 95% CI, 45.7%-61.2%; P < .001), and states with more than one tanning regulation (50.0%; 95% CI, 42.0%-58.0%; P < .001). No difference was found based on time since the law was enacted. Compliance with state

Intense photoluminescence from amorphous tantalum oxide films

NASA Astrophysics Data System (ADS)

Zhu, Minmin; Zhang, Zhengjun; Miao, Wei

2006-07-01

Tantalum oxide films were deposited on silicon substrates at a temperature of ˜450°C by heating a pure tantalum foil in a rough vacuum. The films were amorphous in structure and consisted of fully oxidized Ta2O5 and (TaOx, x <2.5) suboxides. This feature resulted in strong visible light emission from the films further oxidized in the air at temperatures of 200-300°C. The mechanism for this photoluminescence behavior of the amorphous tantalum oxide films was also investigated and discussed. This study suggests that wide-band-gap materials could act as effective visible light emitters and provides a simple route to synthesize such materials.

Toward quantifying the abuse liability of ultraviolet tanning: A behavioral economic approach to tanning addiction.

PubMed

Reed, Derek D; Kaplan, Brent A; Becirevic, Amel; Roma, Peter G; Hursh, Steven R

2016-07-01

Many adults engage in ultraviolet indoor tanning despite evidence of its association with skin cancer. The constellation of behaviors associated with ultraviolet indoor tanning is analogous to that in other behavioral addictions. Despite a growing literature on ultraviolet indoor tanning as an addiction, there remains no consensus on how to identify ultraviolet indoor tanning addictive tendencies. The purpose of the present study was to translate a behavioral economic task more commonly used in substance abuse to quantify the "abuse liability" of ultraviolet indoor tanning, establish construct validity, and determine convergent validity with the most commonly used diagnostic tools for ultraviolet indoor tanning addiction (i.e., mCAGE and mDSM-IV-TR). We conducted a between-groups study using a novel hypothetical Tanning Purchase Task to quantify intensity and elasticity of ultraviolet indoor tanning demand and permit statistical comparisons with the mCAGE and mDSM-IV-TR. Results suggest that behavioral economic demand is related to ultraviolet indoor tanning addiction status and adequately discriminates between potential addicted individuals from nonaddicted individuals. Moreover, we provide evidence that the Tanning Purchase Task renders behavioral economic indicators that are relevant to public health research. The present findings are limited to two ultraviolet indoor tanning addiction tools and a relatively small sample of high-risk ultraviolet indoor tanning users; however, these pilot data demonstrate the potential for behavioral economic assessment tools as diagnostic and research aids in ultraviolet indoor tanning addiction studies. © 2016 Society for the Experimental Analysis of Behavior.

Electronic structure and charge transport in nonstoichiometric tantalum oxide

NASA Astrophysics Data System (ADS)

Perevalov, T. V.; Gritsenko, V. A.; Gismatulin, A. A.; Voronkovskii, V. A.; Gerasimova, A. K.; Aliev, V. Sh; Prosvirin, I. A.

2018-06-01

The atomic and electronic structure of nonstoichiometric oxygen-deficient tantalum oxide TaO x<2.5 grown by ion beam sputtering deposition was studied. The TaO x film content was analyzed by x-ray photoelectron spectroscopy and by quantum-chemistry simulation. TaO x is composed of Ta2O5, metallic tantalum clusters and tantalum suboxides. A method for evaluating the stoichiometry parameter of TaO x from the comparison of experimental and theoretical photoelectron valence band spectra is proposed. The charge transport properties of TaO x were experimentally studied and the transport mechanism was quantitatively analyzed with four theoretical dielectric conductivity models. It was found that the charge transport in almost stoichiometric and nonstoichiometric tantalum oxide can be consistently described by the phonon-assisted tunneling between traps.

High Temperature Evaluation of Tantalum Capacitors - Test 1

DOE Data Explorer

Cieslewski, Grzegorz

2014-09-28

Tantalum capacitors can provide much higher capacitance at high-temperatures than the ceramic capacitors. This study evaluates selected tantalum capacitors at high temperatures to determine their suitability for you in geothermal field. This data set contains results of the first test where three different types of capacitors were evaluated at 260C.

Review of interventions to reduce ultraviolet tanning: Need for treatments targeting excessive tanning, an emerging addictive behavior.

PubMed

Stapleton, Jerod L; Hillhouse, Joel; Levonyan-Radloff, Kristine; Manne, Sharon L

2017-12-01

Millions of Americans engage in tanning each year, defined as intentional ultraviolet radiation (UVR) exposure in the form of sunbathing or the use of indoor tanning beds. An emerging body of research suggests that UVR has addictive properties and some tanners engage in excessive tanning. This article provides an overview of the evidence of tanning addiction and a systematic review of existing tanning interventions with the goal of evaluating their potential to impact addicted tanners. Our search identified 24 intervention studies that were summarized and discussed according to 3 primary themes. First, there is a dearth of tanning interventions that target excessive tanning or are designed as treatments for tanning addiction. Second, tanning interventions are primarily educational interventions designed to increase knowledge of the risks of tanning. Third, there are notable aspects of existing tanning interventions that are relevant to addiction science, including the use of brief motivational and cognitive-behavioral-based interventions. Future directions are considered including recommendations for utilizing the existing evidence base to formulate interventions targeting excessive tanners. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

2017 NEPP Tasks Update for Ceramic and Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2017-01-01

This presentation gives an overview of current NEPP tasks on ceramic and tantalum capacitors and plans for the future. It includes tasks on leakage currents, gas generation and case deformation in wet tantalum capacitors; ESR degradation and acceleration factors in MnO2 and polymer cathode capacitors. Preliminary results on the effect of moisture on degradation of reverse currents in MnO2 tantalum capacitors are discussed. Latest results on mechanical characteristics of MLCCs and modeling of degradation of leakage currents in BME capacitors with defects are also presented.

METHOD OF PROTECTING TANTALUM CRUCIBLES AGAINST REACTION WITH MOLTEN URANIUM

DOEpatents

Feder, H.M.; Chellew, N.R.

1960-08-16

Tantalum crucibles against reaction with molten uranium by contacting the surfaces to be protected with metallic boron (as powder, vapor, or suspension in a liquid-volatilenonreacting medium, such as acetone and petroleum oil) at about 1800 deg C in vacuum, discontinuing contact with the boron, and heating the crucibles to a temperature of between 1800 aad 2000 deg C, whereby the tantalum boride formed in the first heating step is converted to tantalum monoboride.

Fabrication of a Tantalum-Based Josephson Junction for an X-Ray Detector

NASA Astrophysics Data System (ADS)

Morohashi, Shin'ichi; Gotoh, Kohtaroh; Yokoyama, Naoki

2000-06-01

We have fabricated a tantalum-based Josephson junction for an X-ray detector. The tantalum layer was selected for the junction electrode because of its long quasiparticle lifetime, large X-ray absorption efficiency and stability against thermal cycling. We have developed a buffer layer to fabricate the tantalum layer with a body-centered cubic structure. Based on careful consideration of their superconductivity, we have selected a niobium thin layer as the buffer layer for fabricating the tantalum base electrode, and a tungsten thin layer for the tantalum counter electrode. Fabricated Nb/AlOx-Al/Ta/Nb and Nb/Ta/W/AlOx-Al/Ta/Nb Josephson junctions exhibited current-voltage characteristics with a low subgap leakage current.

Tanning preparations.

PubMed

Levy, S B

2000-10-01

Increasing consumer awareness as to the hazards of UV light should fuel ongoing interest in self-tanning products. As a result of the benign toxicologic profile of DHA, products containing DHA represent a safe alternative to UV-induced tanning. The results obtained with these products depend on the final formulation, the individual application technique, and the consumer's complexion type. Greater experience in formulation combined with increasing sophistication on the part of the consumer should lead to continuing growth in interest and satisfaction with the use of DHA-containing sunless or self-tanning products. Individuals need to be informed that these products do not offer significant protection against UV-B. If formulated with standard sunscreens, consumers should be cautioned that the duration of UV protection is more short-lived than the color change.

Extreme Response in Tension and Compression of Tantalum

NASA Astrophysics Data System (ADS)

Remington, Tane Perry

This research on a model bcc metal, tantalum, has three components: the study of tensile failure; defects generated under a nanoindenter; and dislocation velocities in an extreme regime generated by pulsed lasers. The processes of dynamic failure by spalling were established in nano, poly, and mono crystalline tantalum in recovery experiments following laser compression and release. The process of spall was characterized by different techniques: optical microscopy, scanning electron microscopy, microcomputerized tomography and electron backscatter diffraction. Additionally, the pull back signal was measured by VISAR and the pressure decay was compared with HYADES simulations. There are clear differences in the microscopic fracture mechanisms, dictated by the grain sizes. In the nano and poly crystals, spalling occurred by ductile fracture favoring grain boundaries. In the monocrystals, grain boundaries are absent, and the process was of ductile failure by void initiation, growth and coalescence. The spall strength of single crystalline tantalum was higher than the poly and nano crystals. It was experimentally confirmed that spall strength in tantalum increases with strain rate. In order to generate dislocations close to the surface, single crystalline tantalum with orientations (100), (110) and (111) was nanoindented with a Berkovich tip. Atomic force microscopy showed pile-ups of dislocations around the perimeter of the nanoindentations. Sections of nanoindentations were focused ion beam cut into transmission electron microscope foils. The mechanisms of deformation under a nanoindentation in tantalum were identified and quantified. Molecular dynamics simulations were conducted and the simulated plastic deformation proceeds by the formation of nanotwins, which rapidly evolve into shear dislocation loops. Dislocation densities under the indenter were estimated experimentally (~1.2 x 1015 m-2), by MD (~7 x1015 m-2) and through an analytical calculation (2.6--19 x10

Does the portrayal of tanning in Australian women's magazines relate to real women's tanning beliefs and behavior?

PubMed

Dixon, Helen G; Warne, Charles D; Scully, Maree L; Wakefield, Melanie A; Dobbinson, Suzanne J

2011-04-01

Content analysis data on the tans of 4,422 female Caucasian models sampled from spring and summer magazine issues were combined with readership data to generate indices of potential exposure to social modeling of tanning via popular women's magazines over a 15-year period (1987 to 2002). Associations between these indices and cross-sectional telephone survey data from the same period on 5,675 female teenagers' and adults' tanning attitudes, beliefs, and behavior were examined using logistic regression models. Among young women, greater exposure to tanning in young women's magazines was associated with increased likelihood of endorsing pro-tan attitudes and beliefs. Among women of all ages, greater exposure to tanned models via the most popular women's magazines was associated with increased likelihood of attempting to get a tan but lower likelihood of endorsing pro-tan attitudes. Popular women's magazines may promote and reflect real women's tanning beliefs and behavior.

Fabrication of a tantalum-clad tungsten target for LANSCE

NASA Astrophysics Data System (ADS)

Nelson, A. T.; O'Toole, J. A.; Valicenti, R. A.; Maloy, S. A.

2012-12-01

Development of a solid state bonding technique suitable to clad tungsten targets with tantalum was completed to improve operation of the Los Alamos Neutron Science Centers spallation target. Significant deterioration of conventional bare tungsten targets has historically resulted in transfer of tungsten into the cooling system through corrosion resulting in increased radioactivity outside the target and reduction of delivered neutron flux. The fabrication method chosen to join the tantalum cladding to the tungsten was hot isostatic pressing (HIP) given the geometry constraints of a cylindrical assembly and previous success demonstrated at KENS. Nominal HIP parameters of 1500 °C, 200 MPa, and 3 h were selected based upon previous work. Development of the process included significant surface engineering controls and characterization given tantalums propensity for oxide and carbide formation at high temperatures. In addition to rigorous acid cleaning implemented at each step of the fabrication process, a three layer tantalum foil gettering system was devised such that any free oxygen and carbon impurities contained in the argon gas within the HIP vessel was mitigated to the extent possible before coming into contact with the tantalum cladding. The result of the numerous controls and refined techniques was negligible coarsening of the native Ta2O5 surface oxide, no measureable oxygen diffusion into the tantalum bulk, and no detectable carburization despite use of argon containing up to 5 ppm oxygen and up to 40 ppm total CO, CO2, or organic contaminants. Post bond characterization of the interface revealed continuous bonding with a few microns of species interdiffusion.

Is initiating tanning bed use as a minor associated with increased risky tanning behaviors and burning? An exploratory study.

PubMed

Seidenberg, Andrew B; Noar, Seth M; Sontag, Jennah M

2017-12-01

Tanning bed use is most common among youth and young adults, and is associated with an increased risk of skin cancer. Recently, numerous states have adopted restrictions on minors' access to tanning beds; however, little has been reported on how such policies may impact tanning behaviors and burning. The purpose of this study was to examine the associations between age of indoor tanning initiation and risky tanning behaviors and burning. Female students (n=567) attending a large southeastern public university completed a questionnaire (spring of 2015) assessing tanning bed use history, including age of initiation. The analytic sample was limited to participants reporting past year indoor tanning (n=134). Multivariable logistic regression was used to compare the odds of risky tanning behaviors and burning among those initiating indoor tanning before and after their 18th birthday. Participants initiating indoor tanning as a minor had significantly (ps<0.05) greater odds of using a tanning bed 10 or more times in the previous year, typically indoor tanning for ≥10min, ever indoor tanning without wearing goggles, and ever fallen asleep inside a tanning bed. Further, those that initiated as a minor had significantly greater odds of ever burning from indoor tanning (p<0.05). Indoor tanning initiation as a minor was associated with several risky tanning behaviors and burning. Youth access restrictions may help reduce the harms caused by tanning beds. Copyright © 2017. Published by Elsevier Inc.

The mathematics of tanning

PubMed Central

Thingnes, Josef; Øyehaug, Leiv; Hovig, Eivind; Omholt, Stig W

2009-01-01

Background The pigment melanin is produced by specialized cells, called melanocytes. In healthy skin, melanocytes are sparsely spread among the other cell types in the basal layer of the epidermis. Sun tanning results from an UV-induced increase in the release of melanin to neighbouring keratinocytes, the major cell type component of the epidermis as well as redistribution of melanin among these cells. Here we provide a mathematical conceptualization of our current knowledge of the tanning response, in terms of a dynamic model. The resolution level of the model is tuned to available data, and its primary focus is to describe the tanning response following UV exposure. Results The model appears capable of accounting for available experimental data on the tanning response in different skin and photo types. It predicts that the thickness of the epidermal layer and how far the melanocyte dendrites grow out in the epidermal layers after UV exposure influence the tanning response substantially. Conclusion Despite the paucity of experimental validation data the model is constrained enough to serve as a foundation for the establishment of a theoretical-experimental research programme aimed at elucidating the more fine-grained regulatory anatomy underlying the tanning response. PMID:19505344

ON THE GEOCHEMISTRY OF NIOBIUM AND TANTALUM IN CLAYS (in Russian)

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

Pachadzhanov, D.N.

1963-10-01

With the aid of the spectral method with a preliminary enrichment in tannin, the niobium and tantalum content was determined in some humid and arid clays of the Russian platform. The investigated samples were composed of 354 specimens. The average content of niobium in humid clays is 0.0020%, of tantalum 0.00024% (the Nb/Ta ratio is 8.4) and in arid clays is respectively the content of niobium 0.00133% and the content of tantalum 0.00009% (the Nb/Ta ratio is 14.8). The average value of the content of niobium content for all studied clays is 0.00183% and of the tantalum content 0.00020%, themore » Nb/Ta ratio being 9.1. In clays an interconnection of niobium with tantalum, as well as with aluminium, titanium, zirconium, and hafnium was observed. However, on the background of this connection some separation of the named elements is noted. A tendency for the Nb/Ta ratio shift from the region of matter removal towards the center of the marine basin was observed. The study of niobium and tantalum distribution over different clay fractions showed that one part of elements is connected with zircon and titanium minerals in aleuosand fraction (0.1-- 0.01 mm). Another, approximately similar part is contained in the proper clay fraction (<0. 01 mm), the tantalum somewhat more concentrating in the aleurosand fraction and niobium in the clay fraction. (P.C.H.)« less

Multi-scale Modeling of Plasticity in Tantalum.

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

Lim, Hojun; Battaile, Corbett Chandler.; Carroll, Jay

In this report, we present a multi-scale computational model to simulate plastic deformation of tantalum and validating experiments. In atomistic/ dislocation level, dislocation kink- pair theory is used to formulate temperature and strain rate dependent constitutive equations. The kink-pair theory is calibrated to available data from single crystal experiments to produce accurate and convenient constitutive laws. The model is then implemented into a BCC crystal plasticity finite element method (CP-FEM) model to predict temperature and strain rate dependent yield stresses of single and polycrystalline tantalum and compared with existing experimental data from the literature. Furthermore, classical continuum constitutive models describingmore » temperature and strain rate dependent flow behaviors are fit to the yield stresses obtained from the CP-FEM polycrystal predictions. The model is then used to conduct hydro- dynamic simulations of Taylor cylinder impact test and compared with experiments. In order to validate the proposed tantalum CP-FEM model with experiments, we introduce a method for quantitative comparison of CP-FEM models with various experimental techniques. To mitigate the effects of unknown subsurface microstructure, tantalum tensile specimens with a pseudo-two-dimensional grain structure and grain sizes on the order of millimeters are used. A technique combining an electron back scatter diffraction (EBSD) and high resolution digital image correlation (HR-DIC) is used to measure the texture and sub-grain strain fields upon uniaxial tensile loading at various applied strains. Deformed specimens are also analyzed with optical profilometry measurements to obtain out-of- plane strain fields. These high resolution measurements are directly compared with large-scale CP-FEM predictions. This computational method directly links fundamental dislocation physics to plastic deformations in the grain-scale and to the engineering-scale applications. Furthermore

Development and Applications of Porous Tantalum Trabecular Metal Enhanced Titanium Dental Implants

PubMed Central

Bencharit, Sompop; Byrd, Warren C.; Altarawneh, Sandra; Hosseini, Bashir; Leong, Austin; Reside, Glenn; Morelli, Thiago; Offenbacher, Steven

2013-01-01

Statement of Problem Porous tantalum trabecular metal has recently been incorporated in titanium dental implants as a new form of implant surface enhancement. However, there is little information on the applications of this material in implant dentistry. Methods We, therefore review the current literature on the basic science and clinical uses of this material. Results Porous tantalum metal is used to improve the contact between osseous structure and dental implants; and therefore presumably facilitate osseointegration. Success of porous tantalum metal in orthopedic implants led to the incorporation of porous tantalum metal in the design of root-from endosseous titanium implants. The porous tantalum three-dimensional enhancement of titanium dental implant surface allows for combining bone ongrowth together with bone ingrowth, or osseoincorporation. While little is known about the biological aspect of the porous tantalum in the oral cavity, there seems to be several possible advantages of this implant design. This article reviews the biological aspects of porous tantalum enhanced titanium dental implants, in particular the effects of anatomical consideration and oral environment to implant designs. Conclusions We propose here possible clinical situations and applications for this type of dental implant. Advantages and disadvantages of the implants as well as needed future clinical studies are discussed. PMID:23527899

Watching reality television beauty shows is associated with tanning lamp use and outdoor tanning among college students.

PubMed

Fogel, Joshua; Krausz, Faye

2013-05-01

Ultraviolet radiation exposure through natural sunlight or tanning lamps is a risk factor for skin cancer. As the media can influence behavior, we studied whether watching reality television (TV) beauty shows is associated with tanning lamp use or outdoor tanning. College students (n = 576) were surveyed on their reality TV beauty show watching, their use of tanning lamps, and outdoor tanning behavior. We asked media attitude questions about connectivity with reality TV shows and Internet use of Facebook to discuss reality TV shows. Those who did versus did not watch reality TV beauty shows used tanning lamps (12.9% vs 3.7%, P < .001) and tanned outdoors (43.3% vs 28.7%, P < .001) at significantly greater percentages. Significant predictors of tanning lamp use included watching reality TV beauty shows (odds ratio [OR] 2.58, 95% confidence interval [CI] 1.11-6.00), increasing age (OR 1.17, 95% CI 1.04-1.32), and female sex (OR 10.16, 95% CI 3.29-31.41). Significant predictors of outdoor tanning included watching reality TV beauty shows (OR 2.11, 95% CI 1.33-3.34). The specific names of the reality TV beauty shows watched were not obtained and therefore we cannot determine if particular shows were more or less associated with this behavior. Watching reality TV beauty shows is associated with both tanning lamp use and outdoor tanning. Dermatologists should consider discussing the potential harmful aspects of tanning beds and outdoor tanning, especially with their patients who watch reality TV beauty shows. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

World War II, tantalum, and the evolution of modern cranioplasty technique.

PubMed

Flanigan, Patrick; Kshettry, Varun R; Benzel, Edward C

2014-04-01

Cranioplasty is a unique procedure with a rich history. Since ancient times, a diverse array of materials from coconut shells to gold plates has been used for the repair of cranial defects. More recently, World War II greatly increased the demand for cranioplasty procedures and renewed interest in the search for a suitable synthetic material for cranioprostheses. Experimental evidence revealed that tantalum was biologically inert to acid and oxidative stresses. In fact, the observation that tantalum did not absorb acid resulted in the metal being named after Tantalus, the Greek mythological figure who was condemned to a pool of water in the Underworld that would recede when he tried to take a drink. In clinical use, malleability facilitated a single-stage cosmetic repair of cranial defects. Tantalum became the preferred cranioplasty material for more than 1000 procedures performed during World War II. In fact, its use was rapidly adopted in the civilian population. During World War II and the heyday of tantalum cranioplasty, there was a rapid evolution in prosthesis implantation and fixation techniques significantly shaping how cranioplasties are performed today. Several years after the war, acrylic emerged as the cranioplasty material of choice. It had several clear advantages over its metallic counterparts. Titanium, which was less radiopaque and had a more optimal thermal conductivity profile (less thermally conductive), eventually supplanted tantalum as the most common metallic cranioplasty material. While tantalum cranioplasty was popular for only a decade, it represented a significant breakthrough in synthetic cranioplasty. The experiences of wartime neurosurgeons with tantalum cranioplasty played a pivotal role in the evolution of modern cranioplasty techniques and ultimately led to a heightened understanding of the necessary attributes of an ideal synthetic cranioplasty material. Indeed, the history of tantalum cranioplasty serves as a model for innovative

Thermal shock and erosion resistant tantalum carbide ceramic material

NASA Technical Reports Server (NTRS)

Honeycutt, L., III; Manning, C. R. (Inventor)

1978-01-01

Ceramic tantalum carbide artifacts with high thermal shock and mechanical erosion resistance are provided by incorporating tungsten-rhenium and carbon particles in a tantalum carbide matrix. The mix is sintered by hot pressing to form the ceramic article which has a high fracture strength relative to its elastic modulus and thus has an improved thermal shock and mechanical erosion resistance. The tantalum carbide is preferable less than minus 100 mesh, the carbon particles are preferable less than minus 100 mesh, and the tungsten-rhenium particles are preferable elongate, having a length to thickness ratio of at least 2/1. Tungsten-rhenium wire pieces are suitable as well as graphite particles.

International strategic minerals inventory summary report; niobium (columbium) and tantalum

USGS Publications Warehouse

Crockett, R.N.; Sutphin, D.M.

1993-01-01

Major world resources of niobium and tantalum are described in this summary report of information in the International Strategic Minerals Inventory (ISMI). ISMI is a cooperative data-collection effort of earth-science and mineral-resource agencies in Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, the United Kingdom, and the United States of America. Part I of this report presents an overview of the resources and potential supply of niobium and tantalum based on inventory information; Part II contains tables of both geologic and mineral-resource information and includes production data collected by ISMI participants. Niobium is used principally as an alloying element in special steels and superalloys, and tantalum is used mainly in electronics. Minerals in the columbite-tantalite series are principal ore minerals of niobium and tantalum. Pyrochlore is a principal source of niobium. These minerals are found in carbonatite, certain rocks in alkaline igneous complexes, pegmatite, and placer deposits. ISMI estimates show that there are over 7 million metric tons of niobium and almost 0.5 million metric tons of tantalum in known deposits, outside of China and the former Soviet Union, for which reliable estimates have been made. Brazilian deposits, followed by Canadian deposits, contain by far the largest source of niobium. Tantalum production is spread widely among several countries, and Brazil and Canada are the most significant of these producers. Brazil's position is further strengthened by potential byproduct columbite from tin mining. Present economically exploitable resources of niobium appear to be sufficient for the near future, but Brazil will continue to be the predominant world supplier of ferrocolumbium. Tantalum, a byproduct of tin production, has been captive to the fluctuations of that market, but resources in pegmatite in Canada and Australia make it likely that future increases in the present modest demand will be met.

Indoor Tanning and Problem Behavior

ERIC Educational Resources Information Center

Bagdasarov, Zhanna; Banerjee, Smita; Greene, Kathryn; Campo, Shelly

2008-01-01

Objective: The authors examined factors predicting college students' use of tanning beds. Participants and Methods: Undergraduate students (N = 745) at a large Northeastern university participated in the study by answering a survey measuring tanning behavior and other psychosocial variables, including sensation seeking, self-esteem, tanning image…

State Indoor Tanning Laws and Prevalence of Indoor Tanning Among US High School Students, 2009-2015.

PubMed

Qin, Jin; Holman, Dawn M; Jones, Sherry Everett; Berkowitz, Zahava; Guy, Gery P

2018-07-01

To examine the association between state indoor tanning laws and indoor tanning behavior using nationally representative samples of US high school students younger than 18 years. We combined data from the 2009, 2011, 2013, and 2015 national Youth Risk Behavior Surveys (n = 41 313) to analyze the association between 2 types of state indoor tanning laws (age restriction and parental permission) and the prevalence of indoor tanning during the 12 months before the survey, adjusting for age, race/ethnicity, and survey year, and stratified by gender. Age restriction laws were associated with a 47% (P < .001) lower indoor tanning prevalence among female high school students. Parental permission laws were not found to be associated with indoor tanning prevalence among either female or male high school students. Age restriction laws could contribute to less indoor tanning, particularly among female high school students. Such reductions may reduce the health and economic burden of skin cancer.

Appearance motives to tan and not tan: evidence for validity and reliability of a new scale.

PubMed

Cafri, Guy; Thompson, J Kevin; Roehrig, Megan; Rojas, Ariz; Sperry, Steffanie; Jacobsen, Paul B; Hillhouse, Joel

2008-04-01

Risk for skin cancer is increased by UV exposure and decreased by sun protection. Appearance reasons to tan and not tan have consistently been shown to be related to intentions and behaviors to UV exposure and protection. This study was designed to determine the factor structure of appearance motives to tan and not tan, evaluate the extent to which this factor structure is gender invariant, test for mean differences in the identified factors, and evaluate internal consistency, temporal stability, and criterion-related validity. Five-hundred eighty-nine females and 335 male college students were used to test confirmatory factor analysis models within and across gender groups, estimate latent mean differences, and use the correlation coefficient and Cronbach's alpha to further evaluate the reliability and validity of the identified factors. A measurement invariant (i.e., factor-loading invariant) model was identified with three higher-order factors: sociocultural influences to tan (lower order factors: media, friends, family, significant others), appearance reasons to tan (general, acne, body shape), and appearance reasons not to tan (skin aging, immediate skin damage). Females had significantly higher means than males on all higher-order factors. All subscales had evidence of internal consistency, temporal stability, and criterion-related validity. This study offers a framework and measurement instrument that has evidence of validity and reliability for evaluating appearance-based motives to tan and not tan.

Teens and Tanning Knowledge and Attitudes

PubMed Central

Levine, Vicki J.; Steuer, Alexa B.; Sedwick, Carly

2009-01-01

Background: The incidence of skin cancer, including melanoma, continues to increase. Teenagers are especially vulnerable, as are young females. The incidence of melanoma among young women in their twenties and thirties has begun to increase again. These young people are also the population that frequent tanning salons. Objective: This voluntary, anonymous, New York University, Institutional Review Board-approved survey was given to students in grades 9 through 12 to ascertain their understanding of what causes skin cancers and the dangers of excessive sun exposure and tanning salons. Methods and materials: An Institutional Review Board-approved, 22-question survey was administered anonymously to more than 450 students with 368 returned responses. The survey was administered to students in grades 9 through 12 at two high schools in New York and New Jersey. Results: More than 80 percent of students view movie stars as tan and almost 60 percent see “tan” people as better looking. In addition, more than 90 percent believe that a tan does not prevent further damage to the skin (as opposed to the customary belief that a “base” tan can protect against extreme sun exposures, such as when on a tropical vacation). There appears to be a disconnect between knowledge and sun tanning behaviors. Most teenagers still believe that tans are attractive and teenage girls continue to use tanning salons and tan naturally. We need to address the connection between sun tanning in youth and skin cancers years later. Legislation to limit access of tanning salons to teenagers needs to be enacted. PMID:20967182

Internet advertising of artificial tanning in Australia.

PubMed

Team, Victoria; Markovic, Milica

2006-08-01

Artificial tanning, defined as deliberate exposure to ultraviolet rays produced by artificial tanning devices, is a new and emerging public health issue in Australia and globally. Epidemiological research suggests that artificial tanning may contribute to the incidence of melanoma, nonmelanoma skin cancer as well as other health problems. Given that Australia has a high incidence of skin cancer, we have undertaken a study to explore how artificial tanning has been promoted to its users. The aim was to analyze the completeness and accuracy of information about artificial tanning. A content analysis of web sites of tanning salons and distributors of tanning equipment in Australia was conducted. A total of 22 web sites were analyzed. None of the solarium operators or distributors of equipment provided full information about the risks of artificial tanning. Fifty-nine percent of web advertisements had no information and 41% provided only partial information regarding the risks of artificial tanning. Pictures with the image of bronze-tanned bodies, predominantly women, were used by all web advertisers. In light of the success of sun-safety campaigns in Australia, the findings of future epidemiological research on the prevalence of artificial tanning and sociological and anthropological research on why people utilize artificial tanning should be a basis for developing effective targeted health promotion on the elimination of artificial tanning in the country.

Adolescent attitudes towards tanning: does age matter?

PubMed Central

Dennis, Leslie K.; Kancherla, Vijaya; Snetselaar, Linda G

2012-01-01

Adolescents seem to be obsessed with tanning. One third of both adolescents and adults report sunbathing. On average, about 20% of adolescents report ever-using of artificial UV tanning devices with 15% currently using them. Tanning attitudes appear similar for adolescents and adults. The top three reasons for tanning included beliefs that a tan makes them more comfortable socializing with friends, looks better and is attractive. The top reason for using artificial UV tanning devices is also aesthetics, followed by relaxation. Other reasons for using artificial UV tanning devices include vacation preparation and to gain a protective base. Attitudes related to appearance that result in more frequent tanning may be difficult to change. PMID:22707979

Adolescent attitudes towards tanning: does age matter?

PubMed

Dennis, Leslie K; Kancherla, Vijaya; Snetselaar, Linda G

2009-12-01

Adolescents seem to be obsessed with tanning. One third of both adolescents and adults report sunbathing. On average, about 20% of adolescents report ever-using of artificial UV tanning devices with 15% currently using them. Tanning attitudes appear similar for adolescents and adults. The top three reasons for tanning included beliefs that a tan makes them more comfortable socializing with friends, looks better and is attractive. The top reason for using artificial UV tanning devices is also aesthetics, followed by relaxation. Other reasons for using artificial UV tanning devices include vacation preparation and to gain a protective base. Attitudes related to appearance that result in more frequent tanning may be difficult to change.

Radiofrequency characteristics of ionized sputtered tantalum nitride thin-film resistor in CMOS device

NASA Astrophysics Data System (ADS)

Sul, Woo Suk; Kwon, Soon Hyeong; Choi, Eunmi; Cui, Yinhua; Lee, Kang Won; Shim, Ho Jae; Gao, Yuan; Hahn, Sang June; Pyo, Sung Gyu

2017-05-01

We report the analysis of the radiofrequency (RF) characteristics according to the size, area, and shape of TaN thin-film resistor (TFR) layers. As the TFR size increased, its characteristics were degraded with increasing frequency owing to the increased capacitive parasitic components. As the frequency increased from 1 MHz to 10 GHz, the effective resistance decreased by approximately 12.5%, 16.4%, and 37.8% when the resistor widths and lengths were 0.5 × 20, 1 × 40, and 2 × 80 μm, respectively. To optimize the performance of the high-frequency TFR, ensuring RF isolation via sufficient separation from the silicon substrates was crucial. To realize this RF isolation, methods for minimizing the effect of lossy Si substrates by using TFRs with a smaller area or by forming a patterned ground shield should be introduced. [Figure not available: see fulltext.

Thermochemistry of tantalum-wall cooling system with lithium and sodium working fluids

NASA Technical Reports Server (NTRS)

Tower, L. K.

1972-01-01

Plots are presented which show the distribution of oxygen between liquid lithium and tantalum or niobium, and between liquid sodium and tantalum at elevated temperatures. Additional plots showing the composition of the gas phase above the solutions of oxygen and alkali metal are presented. The use of the plots is illustrated by an example tantalum heat pipe filled with lithium.

Tantalum coatings for inertial confinement fusion dry wall designs

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

Taylor, L.H.; Green, L.

1996-12-31

The coating on a dry first wall inertial confinement fusion reactor must survive the target explosion and be ductile, inexpensive, and compatible with the materials in the target, i.e. have a high atomic number Z. Calculations indicate that tantalum is the best choice for the coating material. As a test of this design 1 mm tantalum coatings were plasma sprayed onto ferrite steel tubes. They were then subjected to 100 heating-cooling cycles which simulated the stressful thermal cycling which would be encountered during five years of plant startups and shutdowns. The coatings were undamaged and continued to bond well tomore » the steel. Furthermore, chemical reactions should not degrade tantalum coatings.« less

Constitutive behavior of tantalum and tantalum-tungsten alloys

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

Chen, S.R.; Gray, G.T. III

1996-10-01

The effects of strain rate, temperature, and tungsten alloying on the yield stress and the strain-hardening behavior of tantalum were investigated. The yield and flow stresses of unalloyed Ta and tantalum-tungsten alloys were found to exhibit very high rate sensitivities, while the hardening rates in Ta and Ta-W alloys were found to be insensitive to strain rate and temperature at lower temperatures or at higher strain rates. This behavior is consistent with the observation that overcoming the intrinsic Peierls stress is shown to be the rate-controlling mechanism in these materials at low temperatures. The dependence of yield stress on temperaturemore » and strain rate was found to decrease, while the strain-hardening rate increased with tungsten alloying content. The mechanical threshold stress (MTS) model was adopted to model the stress-strain behavior of unalloyed Ta and the Ta-W alloys. Parameters for the constitutive relations for Ta and the Ta-W alloys were derived for the MTS model, the Johnson-Cook (JC), and the Zerilli-Armstrong (ZA) models. The results of this study substantiate the applicability of these models for describing the high strain-rate deformation of Ta and Ta-W alloys. The JC and ZA models, however, due to their use of a power strain-hardening law, were found to yield constitutive relations for Ta and Ta-W alloys that are strongly dependent on the range of strains for which the models were optimized.« less

UV tanning advertisements in high school newspapers.

PubMed

Freeman, Scott; Francis, Shayla; Lundahl, Kristy; Bowland, Terri; Dellavalle, Robert P

2006-04-01

To examine the increasing use of UV tanning parlors by adolescents, despite the World Health Organization recommendation that no one under the age of 18 years use UV tanning devices. We examined tanning advertisements in a sample of public high school newspapers published between 2001 and 2005 in 3 Colorado counties encompassing the Denver metropolitan area. Tanning advertisements appeared in newspapers from 11 (48%) of 23 schools. Newspaper issues (N = 131) contained 40 advertisements placed by 18 tanning parlors. Advertisements commonly offered discounts (19 of 40) including unlimited tanning offers (15 of 40). Thirteen advertisements featured non-UV tanning treatments, and 2 advertisements mentioned parental consent or accompaniment for UV tanning. UV radiation, a classified carcinogen, is commonly and specifically marketed to adolescents through high school newspaper advertising. Public health skin cancer prevention policies should include the prohibition of UV tanning advertising to minors.

Indoor Tanning Dependence in Young Adult Women.

PubMed

Mays, Darren; Atkins, Michael B; Ahn, Jaeil; Tercyak, Kenneth P

2017-11-01

Background: There is mounting evidence that young people can develop a dependence on indoor tanning, but research on factors associated with indoor tanning dependence remains limited. Methods: This cross-sectional study investigated factors associated with indoor tanning dependence in a community sample of 389 non-Hispanic white young adult women ages 18 to 30 who had indoor tanned ≥1 time in the past year. Participants completed measures of indoor tanning dependence, including the modified CAGE and modified Diagnostic and Statistical Manual for Mental Disorders-IV psychiatric screening assessments, indoor tanning behavior and beliefs, and behavioral and psychiatric comorbidity. Results: Overall, 22.6% of the sample screened positive for indoor tanning dependence. In multivariable analyses, indoor tanning dependence was associated with younger age of indoor tanning initiation [adjusted odds ratio (aOR) = 0.79; P = 0.017], indoor tanning ≥20 times in the past year (aOR = 3.03; P = 0.015), stronger beliefs about the benefits of tanning (aOR = 2.15; P = 0.004), greater perceived susceptibility to indoor tanning risks (aOR = 2.72; P < 0.001), stronger beliefs about physical appearance (aOR = 1.73; P = 0.037), and depressive symptoms (aOR = 3.79; P < 0.001). Conclusions: Indoor tanning dependence among young, non-Hispanic white women is associated with behaviors that increase the risk of skin cancer, beliefs favoring the perceived benefits of tanning, and comorbid risks such as stronger beliefs about physical appearance and depressed mood. Impact: Comprehensive skin cancer prevention efforts should address indoor tanning dependence among young women and its leading risk factors. Cancer Epidemiol Biomarkers Prev; 26(11); 1636-43. ©2017 AACR . ©2017 American Association for Cancer Research.

Superconducting structure with layers of niobium nitride and aluminum nitride

DOEpatents

Murduck, James M.; Lepetre, Yves J.; Schuller, Ivan K.; Ketterson, John B.

1989-01-01

A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources.

Mineral-deposit model for lithium-cesium-tantalum pegmatites

USGS Publications Warehouse

Bradley, Dwight C.; McCauley, Andrew D.; Stillings, Lisa L.

2017-06-20

Lithium-cesium-tantalum (LCT) pegmatites comprise a compositionally defined subset of granitic pegmatites. The major minerals are quartz, potassium feldspar, albite, and muscovite; typical accessory minerals include biotite, garnet, tourmaline, and apatite. The principal lithium ore minerals are spodumene, petalite, and lepidolite; cesium mostly comes from pollucite; and tantalum mostly comes from columbite-tantalite. Tin ore as cassiterite and beryllium ore as beryl also occur in LCT pegmatites, as do a number of gemstones and high-value museum specimens of rare minerals. Individual crystals in LCT pegmatites can be enormous: the largest spodumene was 14 meters long, the largest beryl was 18 meters long, and the largest potassium feldspar was 49 meters long.Lithium-cesium-tantalum pegmatites account for about one-fourth of the world’s lithium production, most of the tantalum production, and all of the cesium production. Giant deposits include Tanco in Canada, Greenbushes in Australia, and Bikita in Zimbabwe. The largest lithium pegmatite in the United States, at King’s Mountain, North Carolina, is no longer being mined although large reserves of lithium remain. Depending on size and attitude of the pegmatite, a variety of mining techniques are used, including artisanal surface mining, open-pit surface mining, small underground workings, and large underground operations using room-and-pillar design. In favorable circumstances, what would otherwise be gangue minerals (quartz, potassium feldspar, albite, and muscovite) can be mined along with lithium and (or) tantalum as coproducts.Most LCT pegmatites are hosted in metamorphosed supracrustal rocks in the upper greenschist to lower amphibolite facies. Lithium-cesium-tantalum pegmatite intrusions generally are emplaced late during orogeny, with emplacement being controlled by pre-existing structures. Typically, they crop out near evolved, peraluminous granites and leucogranites from which they are inferred to be

Superconducting structure with layers of niobium nitride and aluminum nitride

DOEpatents

Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

1989-07-04

A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs.

[What nosographic framework for excessive tanning?].

PubMed

Petit, A; Karila, L; Lejoyeux, M

2014-04-01

Socially valorised tanning, like other forms of behaviour, can take on an addictive aspect. Excessive tanning, defined by the presence of impulsivity and repetition of tanning that leads to personal distress, is a psychiatric disorder that has only recently been recognized. This finding is based on the observations of many dermatologists who report an addictive relationship in their patients with tanning cabins despite announcement of the diagnosis of malignant melanoma. This article attempts to synthesize the existing literature on excessive tanning and addiction to investigate possible associations. This review focuses on the prevalence, clinical features, aetiology, and treatment of this disorder. The literature review was conducted from 1983 to 2012, using PubMed, Google Scholar, EMBASE, and PsycInfo, using the following keywords alone or combined: Tanning, Addiction, Sunbeds, Skin cancer prevention, and Treatment. We investigated different models to determine how excessive tanning met these criteria. Excessive Tanning was described in the 2000s by an American dermatologist, Carolyn Heckman. Wartham et al. were the first to have proposed a theoretical framework for addiction to sunbathing, as well as two scales (m CAGE and m DSM IV) for the diagnosis and to assess the degree of addiction. These diagnostic criteria describe the craving like-symptoms, the feeling of losing control, or the continuation of the behavior despite knowledge of negative consequences. Excessive Tanning is not present in the classifications of the DSM or ICD, but may be related to Addiction, Obsessive-Compulsive Disorder, Impulse control disorders, Anorexia, or Body Dysmorphic Disorder. Excessive tanning can be included in the spectrum of behavioural addictions due its clinical characteristics in common with classics addictive disorders. They are a variety of other models, which may offer an explanation for or insight into tanning behaviour. Further studies must be controlled, notably on

A longitudinal test of the Comprehensive Indoor Tanning Expectations Scale: The importance of affective beliefs in predicting indoor tanning behavior.

PubMed

Myrick, Jessica Gall; Noar, Seth M; Kelley, Dannielle; Zeitany, Alexandra E; Morales-Pico, Brenda M; Thomas, Nancy E

2017-01-01

In order to better understand drivers of dangerous indoor tanning behaviors, researchers developed the Comprehensive Indoor Tanning Expectations scale. To examine the longitudinal effectiveness of Comprehensive Indoor Tanning Expectations, we surveyed young women in the Southeastern United States at two time points ( N = 553). The scale demonstrated strong test-retest reliability. Participants who believed indoor tanning would improve their mood and afford social approval were significantly more likely to tan 6 months later, while participants who believed indoor tanning leads to psychological/physical discomfort were significantly less likely to tan 6 months later. Knowing the psychological bases for indoor tanning can inform intervention and message design.

Psychometric assessment of the craving to tan questionnaire.

PubMed

Ashrafioun, Lisham; Bonar, Erin E

2015-01-01

Researchers and clinicians suggest that excessive tanning may be a behavioral addiction. Given the significance of craving in substance use, craving may be a useful construct to assess in those who tan. We designed this study to assess the psychometric properties of an alcohol craving measure adapted to measure past-week craving to tan. Undergraduate students (n = 421) who reported past-month tanning completed a battery of questionnaires that assessed demographics, tanning-related characteristics, and psychopathology, in addition to the Craving to Tan Questionnaire (CTQ). Analyses provided support for a single factor CTQ with good internal consistency, construct validity and convergent validity. CTQ scores were significantly higher among problematic versus non-problematic and dependent versus non-dependent tanners. CTQ scores were also associated with several tanning-related characteristics, such money spent on tanning in a typical month, frequency of tanning, and frequency of tanning-related problems. Additional analyses found that past-week craving to tan was significantly associated with greater obsessive compulsive and body dysmorphic symptoms. It may be useful in clinical settings to identify those experiencing problems with tanning and in research to further clarify the conceptualization of addiction-like tanning. However, the CTQ needs further evaluation.

Strategies to Reduce Indoor Tanning

PubMed Central

Holman, Dawn M.; Fox, Kathleen A.; Glenn, Jeffrey D.; Guy, Gery P.; Watson, Meg; Baker, Katie; Cokkinides, Vilma; Gottlieb, Mark; Lazovich, DeAnn; Perna, Frank M.; Sampson, Blake P.; Seidenberg, Andrew B.; Sinclair, Craig; Geller, Alan C.

2015-01-01

Exposure to ultraviolet radiation from indoor tanning device use is associated with an increased risk of skin cancer, including risk of malignant melanoma, and is an urgent public health problem. By reducing indoor tanning, future cases of skin cancer could be prevented, along with the associated morbidity, mortality, and healthcare costs. On August 20, 2012, the CDC hosted a meeting to discuss the current body of evidence on strategies to reduce indoor tanning as well as research gaps. Using the Action Model to Achieve Healthy People 2020 Overarching Goals as a framework, the current paper provides highlights on the topics that were discussed, including (1) the state of the evidence on strategies to reduce indoor tanning; (2) the tools necessary to effectively assess, monitor, and evaluate the short- and long-term impact of interventions designed to reduce indoor tanning; and (3) strategies to align efforts at the national, state, and local levels through transdisciplinary collaboration and coordination across multiple sectors. Although many challenges and barriers exist, a coordinated, multilevel, transdisciplinary approach has the potential to reduce indoor tanning and prevent future cases of skin cancer. PMID:23683986

UV tanning advertisements in national high school newspapers.

PubMed

Lofgreen, Seth J; Domozych, Renee; Doctor, Monica; Reimer, Christine; Self, Alyssa; Dellavalle, Robert P

2017-04-15

Many young adults have utilized indoor ultraviolet(UV) tanning, putting them at higher risk for development of skin cancers. Prior to the increased regulations on indoor tanning for minors, indoor tanning businesses marketed to teens through modalities such as advertisements in high school newspapers. The purpose of this study was to quantify tanning advertisements in high school newspapers published across the United States between August 2014 and July 2015. Online versions of the newspaper issues were available on issuu.com. Tanning advertisements appeared in 3 of 23 high school newspapers with advertisements of any kind(13%). Among all newspapers with advertisements, 10% were indoor tanning advertisements. One newspaper in Colorado contained advertisements of any kind and had 0 tanning advertisements. A prior study of Colorado high schools showed 11 of 23 schools (48%) to contain tanning advertisements. This suggests that there may be a decrease in indoor UV tanning advertisements owing to increased tanning regulation by state legislatures, national attention to UV tanning, or a general decrease in high school tanning advertisements.

40 CFR 421.110 - Applicability: Description of the primary columbium-tantalum subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE... the production of columbium or tantalum by primary columbium-tantalum facilities. [49 FR 8817, Mar. 8...

Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan.

PubMed

Lim, Henry W; James, William D; Rigel, Darrell S; Maloney, Mary E; Spencer, James M; Bhushan, Reva

2011-04-01

The incidence of melanoma skin cancer is increasing rapidly, particularly among young women in the United States. Numerous studies have documented an association between the use of indoor tanning devices and an increased risk of skin cancer, especially in young women. Studies have shown that ultraviolet exposure, even in the absence of erythema or burn, results in DNA damage. Countries and regulatory bodies worldwide have recognized the health risks associated with indoor tanning. In the United States, 32 states have passed legislation to regulate the indoor tanning industry, but there is an urgent need to restrict the use of indoor tanning devices at the federal level. The Food and Drug Administration is currently reviewing the classification of these devices. For all of these reasons, the Food and Drug Administration should prohibit the use of tanning devices by minors and reclassify tanning devices to at least class II to protect the public from the preventable cancers and other adverse effects caused by ultraviolet radiation from indoor tanning. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Reliability Effects of Surge Current Testing of Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2007-01-01

Solid tantalum capacitors are widely used in space applications to filter low-frequency ripple currents in power supply circuits and stabilize DC voltages in the system. Tantalum capacitors manufactured per military specifications (MIL-PRF-55365) are established reliability components and have less than 0.001% of failures per 1000 hours (the failure rate is less than 10 FIT) for grades D or S, thus positioning these parts among electronic components with the highest reliability characteristics. Still, failures of tantalum capacitors do happen and when it occurs it might have catastrophic consequences for the system. This is due to a short-circuit failure mode, which might be damaging to a power supply, and also to the capability of tantalum capacitors with manganese cathodes to self-ignite when a failure occurs in low-impedance applications. During such a failure, a substantial amount of energy is released by exothermic reaction of the tantalum pellet with oxygen generated by the overheated manganese oxide cathode, resulting not only in destruction of the part, but also in damage of the board and surrounding components. A specific feature of tantalum capacitors, compared to ceramic parts, is a relatively large value of capacitance, which in contemporary low-size chip capacitors reaches dozens and hundreds of microfarads. This might result in so-called surge current or turn-on failures in the parts when the board is first powered up. Such a failure, which is considered as the most prevalent type of failures in tantalum capacitors [I], is due to fast changes of the voltage in the circuit, dV/dt, producing high surge current spikes, I(sub sp) = Cx(dV/dt), when current in the circuit is unrestricted. These spikes can reach hundreds of amperes and cause catastrophic failures in the system. The mechanism of surge current failures has not been understood completely yet, and different hypotheses were discussed in relevant literature. These include a sustained scintillation

Topical Report Tantalum – 2.5% Tungsten Machinability Testing

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

L. J. Lazarus

2009-09-02

Protection Association (NFPA). NFPA 484, Standard for Combustible Metals, Chapter 9 Tantalum and Annex E, supplemental Information on Tantalum require cutting oil be used when machining tantalum because it burns at such a high temperature that it breaks down the water in a water-based metalworking fluid (MWF). The NFPA guide devotes approximately 20 pages to this material. The Kansas City Plant (KCP) uses Fuchs Lubricants Ecocut Base 44 LVC as a MWF. This is a highly chlorinated oil with a high flash point (above 200° F). The chlorine is very helpful in preventing BUE (Built Up Edge) that occurs frequentlymore » with this very gummy material. The Ecocut is really a MWF additive that Fuchs uses to add chlorinated fats to other non-chlorinated MWF.« less

Content analysis of Twitter chatter about indoor tanning.

PubMed

Waring, Molly E; Baker, Katie; Peluso, Anthony; May, Christine N; Pagoto, Sherry L

2018-02-21

Twitter may be useful for learning about indoor tanning behavior and attitudes. The objective of this study was to analyze the content of tweets about indoor tanning to determine the extent to which tweets are posted by people who tan, and to characterize the topics of tweets. We extracted 4,691 unique tweets from Twitter using the terms "tanning bed" or "tanning salon" over 7 days in March 2016. We content analyzed a random selection of 1,000 tweets, double-coding 20% of tweets (κ = 0.74, 81% agreement). Most tweets (71%) were by tanners (n = 699 individuals) and included tweets expressing positive sentiment about tanning (57%), and reports of a negative tanning experience (17%), burning (15%), or sleeping in a tanning bed (9%). Four percent of tweets were by tanning salon employees. Tweets posted by people unlikely to be tanners (15%) included tweets mocking tanners (71%) and health warnings (29%). The term "tanning bed" had higher precision for identifying individuals who engage in indoor tanning than "tanning salon"; 77% versus 45% of tweets captured by these search terms were by individuals who engaged in indoor tanning, respectively. Extrapolating to the full data set of 4,691 tweets, findings suggest that an average of 468 individuals who engage in indoor tanning can be identified by their tweets per day. The majority of tweets were from tanners and included reports of especially risky habits (e.g., burning, falling asleep). Twitter provides opportunity to identify indoor tanners and examine conversations about indoor tanning.

Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2016-01-01

Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2017-01-01

Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

Tribological performance of polycrystalline tantalum-carbide-incorporated diamond films on silicon substrates

NASA Astrophysics Data System (ADS)

Ullah, Mahtab; Rana, Anwar Manzoor; Ahmed, E.; Malik, Abdul Sattar; Shah, Z. A.; Ahmad, Naseeb; Mehtab, Ujala; Raza, Rizwan

2018-05-01

Polycrystalline tantalum-carbide-incorporated diamond coatings have been made on unpolished side of Si (100) wafer by hot filament chemical vapor deposition process. Morphology of the coatings has been found to vary from (111) triangular-facetted to predominantly (111) square-faceted by increasing the concentration of tantalum carbide. The results have been compared to those of a diamond reference coating with no tantalum content. An increase in roughness has been observed with the increase of tantalum carbide (TaC) due to change in morphology of the diamond films. It is noticed that roughness of the coatings increases as grains become more square-faceted. It is found that diamond coatings involving tantalum carbide are not as resistant as diamond films with no TaC content and the coefficient of friction for such coatings with microcrystalline grains can be manipulated to 0·33 under high vacuum of 10-7 Torr. Such a low friction coefficient value enhances tribological behavior of unpolished Si substrates and can possibly be used in sliding applications.

Are tanning beds "safe"? Human studies of melanoma.

PubMed

Berwick, Marianne

2008-10-01

Controversy continues over the carcinogenic properties of tanning beds. The tanning industry "sells" tanning beds as a safe alternative to UV exposure for both tanning as well as vitamin D biosynthesis. But, how safe are tanning beds? Epidemiologic data - incomplete and unsatisfactory - suggests that tanning beds are not safer than solar ultraviolet radiation and that they may have independent effects from solar exposure that increase risk for melanoma.

ADM. Water well pump houses (TAN612 and TAN613). Plans, elevations, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ADM. Water well pump houses (TAN-612 and TAN-613). Plans, elevations, floor and other details. Ralph M. Parsons 902-2-ANP-612-613-A S & P 82. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0612-00-693-106743 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Anomalous softening of yield strength in tantalum at high pressures

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

Jing, Qiumin, E-mail: j-qm@163.com; Wu, Qiang; Xu, Ji-an

2015-02-07

The pressure dependence of the yield strength of tantalum was investigated experimentally up to 101 GPa at room temperature using a diamond anvil cell. A yield strength softening is observed between 52 and 84 GPa, whereas a normal trend is observed below 52 GPa and above 84 GPa. The onset pressure of the softening is in agreement with previous results obtained by the pressure gradient method and shock wave experiments. This unusual strength softening in tantalum is not related with structural transformation, preferred orientation, or material damage. Our measurements indicate that microscopic deviatoric strain is the major reason for the observed strength softening inmore » tantalum.« less

Ultrasonic effects on titanium tanning of leather.

PubMed

Peng, Biyu; Shi, Bi; Sun, Danhong; Chen, Yaowen; Shelly, Dennis C

2007-03-01

The effects of ultrasound on titanium tanning of leather were investigated. Either 20 or 40 kHz ultrasound was applied to the titanium tanning of pigskins. Five different treatment conditions were carried out and the effects were examined, such as leather shrinkage temperature (T(s)), titanium content and titanium distribution in the leather. Overall heat loading was carefully controlled. Results showed that 20 kHz ultrasound effectively improves titanium agent penetration into the hide and increases the leather's shrinkage temperature. Doubling the frequency to 40 kHz produced negligible enhancements. An impressive 105.6 degrees C T(s) was achieved using 20 kHz ultrasound pretreatment of the tanning liquor followed by 20 kHz ultrasound in the tanning mixture (liquor plus pigskins) in a special salt-free medium. Finally, using a unique ultrasonic tanning drum with 26.5 kHz ultrasound, the T(s) reached a record level of 106.5 degrees C, a value not achieved in conventional (no ultrasound) titanium tanning. The ultrasonic effects on titanium tanning of leather are judged to make a superior mineral tanned leather.

Investigating the oxidation mechanism of tantalum nanoparticles at high heating rates

NASA Astrophysics Data System (ADS)

DeLisio, Jeffery B.; Wang, Xizheng; Wu, Tao; Egan, Garth C.; Jacob, Rohit J.; Zachariah, Michael R.

2017-12-01

Reduced diffusion length scales and increased specific surface areas of nanosized metal fuels have recently demonstrated increased reaction rates for these systems, increasing their relevance in a wide variety of applications. The most commonly employed metal fuel, aluminum, tends to oxidize rapidly near its melting point (660 °C) in addition to undergoing a phase change of the nascent oxide shell. To further expand on the understanding of nanosized metal fuel oxidation, tantalum nanoparticles were studied due to their high melting point (3017 °C) in comparison to aluminum. Both traditional slow heating rate and in-situ high heating rate techniques were used to probe the oxidation of tantalum nanoparticles in oxygen containing environments in addition to nanothermite mixtures. When oxidized by gas phase oxygen, the oxide shell of the tantalum nanoparticles rapidly crystallized creating cracks that may attribute to enhanced oxygen diffusion into the particle. In the case of tantalum based nanothermites, oxide shell crystallization was shown to induce reactive sintering with the metal oxide resulting in a narrow range of ignition temperatures independent of the metal oxide used. The oxidation mechanism was modeled using the Deal-Grove model to extract rate parameters, and theoretical burn times for tantalum based nanocomposites were calculated.

IET. Exclusion guard house (TAN621) and unit substation (TAN622). Elevations ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

IET. Exclusion guard house (TAN-621) and unit substation (TAN-622). Elevations and floor plan. Also show concrete pad for substation. Ralph M. Parsons 902-4-ANP-621-622-A&S 411. Date: February 1954. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0621-60-693-106968 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

LPT. Chlorination building (TAN643) and water well pumphouse (TAN644). Plans, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LPT. Chlorination building (TAN-643) and water well pumphouse (TAN-644). Plans, elevations, sections, and details. Ralph M. Parsons 1229-12 ANP/GE-7-643-A-S-H&V-1. November 1956. Approved by INEEL Classification Office for public release. INEEL index code no. 038-0643/0644-00-693-107307 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

High efficiency tantalum-based ceramic composite structures

NASA Technical Reports Server (NTRS)

Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor); DiFiore, Robert R. (Inventor); Katvala, Victor W. (Inventor)

2010-01-01

Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000.degree. F. and above.

Boron nitride composites

DOEpatents

Kuntz, Joshua D.; Ellsworth, German F.; Swenson, Fritz J.; Allen, Patrick G.

2017-02-21

According to one embodiment, a composite product includes: a matrix material including hexagonal boron nitride and one or more borate binders; and a plurality of cubic boron nitride particles dispersed in the matrix material. According to another embodiment, a composite product includes: a matrix material including hexagonal boron nitride and amorphous boron nitride; and a plurality of cubic boron nitride particles dispersed in the matrix material.

Tanning and beauty: Mother and teenage daughters in discussion.

PubMed

Hay, Jennifer L; Geller, Alan C; Schoenhammer, Maria; Gordon, Mallorie; Bishop, Marilyn; Shuk, Elyse; Oliveria, Susan; Halpern, Allan C

2016-07-01

Tanning increases dramatically through the teenage years, but the family context of this health risk behavior is relatively unstudied. We conducted videotaped conversations between teenage girls (10th and 11th grade) and their mothers. We developed a coding system for discussion content and highlight findings including inadequate knowledge concerning the harms of tanning and positive views of outdoor tanning over indoor tanning, yet agreement that all tans are attractive. Many teens believed that indoor tanning is sometimes necessary to achieve the tanned look. These findings can usefully guide intervention development regarding the harms of all tanning, rather than indoor or outdoor tanning specifically. © The Author(s) 2014.

Tanning and beauty: Mother and teenage daughters in discussion

PubMed Central

Hay, Jennifer L.; Geller, Alan C.; Schoenhammer, Maria; Gordon, Mallorie; Bishop, Marilyn; Shuk, Elyse; Oliveria, Susan; Halpern, Allan C.

2017-01-01

Tanning increases dramatically through the teenage years, but the family context of this health risk behavior is relatively unstudied. We conducted videotaped conversations between teenage girls (10th and 11th grade) and their mothers. We developed a coding system for discussion content, and highlight findings including inadequate knowledge concerning the harms of tanning, positive views of outdoor tanning over indoor tanning, yet agreement that all tans are attractive. Many teens believed that indoor tanning is sometimes necessary to achieve the tanned look. These findings can usefully guide intervention development regarding the harms of all tanning, rather than indoor or outdoor tanning specifically. PMID:25318997

The impact of indoor tanning legislation: newspaper coverage of the risks of indoor tanning before and after the California indoor tanning ban for minors.

PubMed

Mayer, Jonathan E; Swetter, Susan M; Guild, Samantha; Geller, Alan C

2015-03-01

On June 1, 2011, the California Senate passed a bill banning minors from indoor tanning. We aimed to determine whether the bill's passage was associated with longer-term media coverage regarding skin protection and the risks associated with indoor tanning. Articles from 31 English-language California newspapers between June 2010-May 2011 (PRE) and June 2011-May 2012 (POST) were searched using terms related to skin protection. Ninety articles were found for in-depth coding and analysis. There were more skin protection articles in the POST period than in the PRE period (57 vs 33; p < .05). In addition, there were more POST articles mentioning the risks of indoor tanning (33 vs 10; p < .001), and a POST article was more likely to mention the risks (58 vs 30%; p < .05). The higher number of POST articles mentioning the risks persisted throughout all quarters. Therefore, the California indoor tanning ban was associated with increased longer-term news coverage of skin protection and the risks associated with indoor tanning. This finding has potential influence on the many states that are considering comparable legislation.

A Review of Common Tanning Methods

PubMed Central

Garone, Michael; Fabrikant, Jordan

2015-01-01

Tanning in the United States has become an increasingly popular activity in our culture. Tanning methods have evolved through the years to become more readily accessible and easier to use for all consumers, regardless of geographic location. With the rising incidence of skin cancer, the demand for safe and efficient tanning methods remains high. There are currently many different tanning methods being utilized, and still more are being researched. This article serves to summarize some of the most common tarining methods used in the United States today as well as some potential methods currently under study. PMID:25741402

Availability of tanning beds on US college campuses.

PubMed

Pagoto, Sherry L; Lemon, Stephenie C; Oleski, Jessica L; Scully, Jonathan M; Olendzki, Gin-Fei; Evans, Martinus M; Li, Wenjun; Florence, L Carter; Kirkland, Brittany; Hillhouse, Joel J

2015-01-01

Indoor tanning is widespread among young adults in the United States despite evidence establishing it as a risk factor for skin cancer. The availability of tanning salons on or near college campuses has not been formally evaluated. To evaluate the availability of indoor tanning facilities on US college and university campuses (colleges) and in off-campus housing surrounding but not owned by the college. This observational study sampled the top 125 US colleges and universities listed in US News and World Report. Investigators searched websites of the colleges and nearby housing and contacted them by telephone inquiring about tanning services. Frequency of indoor tanning facilities on college campus and in off-campus housing facilities, as well as payment options for tanning. Of the 125 colleges, 48.0% had indoor tanning facilities either on campus or in off-campus housing, and 14.4% of colleges allow campus cash cards to be used to pay for tanning. Indoor tanning was available on campus in 12.0% of colleges and in off-campus housing in 42.4% of colleges. Most off-campus housing facilities with indoor tanning (96%) provide it free to tenants. Midwestern colleges had the highest prevalence of indoor tanning on campus (26.9%), whereas Southern colleges had the highest prevalence of indoor tanning in off-campus housing facilities (67.7%). Presence of on-campus tanning facilities was significantly associated with enrollment (P = .01), region (P = .02), and presence of a school of public health (P = .01) but not private vs public status (P = .18) or presence of a tobacco policy (P = .16). Presence of tanning facilities in off-campus housing was significantly associated with region (P = .002) and private vs public status (P = .01) but not enrollment (P = .38), tobacco policy (P = .80), or presence of a school of public health (P = .69). Reducing the availability of indoor tanning on and around college campuses is an important public

Getting a Base Tan: Does it Prevent Sunburn?

MedlinePlus

Tanning: Does a base tan prevent sunburn? Should I go to a tanning salon before a sunny vacation to help prevent sunburn? Answers ... little evidence to support the idea that a base tan protects you against sunburn. A few sessions ...

A niobium oxide-tantalum oxide selector-memristor self-aligned nanostack

NASA Astrophysics Data System (ADS)

Diaz Leon, Juan J.; Norris, Kate J.; Yang, J. Joshua; Sevic, John F.; Kobayashi, Nobuhiko P.

2017-03-01

The integration of nonlinear current-voltage selectors and bi-stable memristors is a paramount step for reliable operation of crossbar arrays. In this paper, the self-aligned assembly of a single nanometer-scale device that contains both a selector and a memristor is presented. The two components (i.e., selector and memristor) are vertically assembled via a self-aligned fabrication process combined with electroforming. In designing the device, niobium oxide and tantalum oxide are chosen as materials for selector and memristor, respectively. The formation of niobium oxide is visualized by exploiting the self-limiting reaction between niobium and tantalum oxide; crystalline niobium (di)oxide forms at the interface between metallic niobium and tantalum oxide via electrothermal heating, resulting in a niobium oxide selector self-aligned to a tantalum oxide memristor. A steady-state finite element analysis is used to assess the electrothermal heating expected to occur in the device. Current-voltage measurements and structural/chemical analyses conducted for the virgin device, the electroforming process, and the functional selector-memristor device are presented. The demonstration of a self-aligned, monolithically integrated selector-memristor device would pave a practical pathway to various circuits based on memristors attainable at manufacturing scales.

Analysis of Weibull Grading Test for Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2010-01-01

Weibull grading test is a powerful technique that allows selection and reliability rating of solid tantalum capacitors for military and space applications. However, inaccuracies in the existing method and non-adequate acceleration factors can result in significant, up to three orders of magnitude, errors in the calculated failure rate of capacitors. This paper analyzes deficiencies of the existing technique and recommends more accurate method of calculations. A physical model presenting failures of tantalum capacitors as time-dependent-dielectric-breakdown is used to determine voltage and temperature acceleration factors and select adequate Weibull grading test conditions. This, model is verified by highly accelerated life testing (HALT) at different temperature and voltage conditions for three types of solid chip tantalum capacitors. It is shown that parameters of the model and acceleration factors can be calculated using a general log-linear relationship for the characteristic life with two stress levels.

Tanning among Ontario adolescents pre-legislation: Prevalence and beliefs.

PubMed

Nadalin, V; Marrett, L; Atkinson, J; Tenkate, T; Rosen, C F

2016-10-01

To establish adolescent tanning beliefs and behaviors, prevalence and location of UV tanning device (beds/lamps) use, awareness of risk and restriction signage, and frequency of tanning service refusal, noting differences by grade and sex, prior to a ban on UV tanning device use among those under 18 in Ontario, Canada. Data were collected May 5 to 20 of 2014. Children in grades 7 to 12, and under age 18 completed an on-line questionnaire that asked their age, sex, grade, methods used to tan, frequency, length and location of UV tanning device use, if services were refused and why, awareness and content of signs/warning labels, tanning beliefs and knowledge, and use of eye protection. Of 1561 participants (10% response rate), 49% were male, 51% female. There were significant differences between the sexes regarding tanning behaviors (e.g. not tanning, tanning outside). Seven percent (108) had 'ever' used UV tanning devices, females more than males (p=0.0026). Over half (57%) of the 104 using UV tanning devices in the past 12months noticed warning signs/labels, of which most noticed that UV tanning devices can cause cancer (65%), and that UV exposure can contribute to premature aging (67%). While most (66%) tanned at tanning salons/studios and beauty salons/studios, gyms/fitness clubs (35%) and home use were common (25%). A relatively low proportion of adolescents used UV tanning devices prior to the ban, with use more common among females and those in higher grades. Copyright © 2016 Elsevier Inc. All rights reserved.

ASSOCIATIONS BETWEEN SEASONAL SLEEP CHANGE AND INDOOR TANNING1,2

PubMed Central

CULNAN, ELIZABETH; KLOSS, JACQUELINE D.; DARLOW, SUSAN; HECKMAN, CAROLYN J.

2015-01-01

Summary Identification of risk factors for indoor tanning may ultimately aid the development of better indoor tanning prevention strategies, which is pertinent given the association between indoor tanning and skin cancer. This study aimed to examine the relationship between seasonal sleep change and indoor tanning. Women tanners (N= 139) completed self-report measures including items relating to seasonal sleep changes, seasonal affective disorder (SAD), reasons for tanning, tanning during the winter months, and the Tanning Pathology Scale (TAPS), which measures problematic tanning motives and symptoms of tanning dependence. It was hypothesized that seasonal sleep change and SAD would be associated with greater indoor tanning during the winter, more tanning to improve mood and to relax, and higher scores on the TAPS. Findings indicated that more seasonal sleep change was associated with tanning to improve mood and higher scores on the TAPS. Similarly, the presence of SAD was related to tanning to improve mood, tanning to relax, and more problematic tanning. PMID:25730744

Use of artificial tanning products among young adults.

PubMed

Brooks, Katie; Brooks, Daniel; Dajani, Zeina; Swetter, Susan M; Powers, Erin; Pagoto, Sherry; Geller, Alan C

2006-06-01

Neither the prevalence of sunless tanner use nor its impact on sunburning and tanning bed use has been evaluated in the United States. We surveyed young adults in greater Boston to measure use of artificial tanning products, as well as recent history of sunburns and tanning bed use. In July 2004, 448 individuals 18 to 30 years of age completed a brief questionnaire at universities, shopping venues, and parks. Twenty-two percent of respondents used sunless tanning lotions in the preceding 12 months, and another 22% had not used them but would consider doing so in the coming year. Sunless tanning users were more likely to be female, younger, and more likely to report being severe burners. Both users and potential users were more likely to have sunburned during the summer and to have used tanning beds than those who neither used nor intended to use sunless tanning lotions, even after controlling for skin type. The study was based on a non-randomly selected sample in one city and was cross-sectional in nature. Our study raises the possibility that sunless tanning products do not decrease rates of sunburning or use of tanning beds. While safe alternatives to ultraviolet exposure are desirable, the potential risks of widely endorsing artificial tanning products must be considered.

Identification of a mutation that is associated with the saddle tan and black-and-tan phenotypes in Basset Hounds and Pembroke Welsh Corgis.

PubMed

Dreger, Dayna L; Parker, Heidi G; Ostrander, Elaine A; Schmutz, Sheila M

2013-01-01

The causative mutation for the black-and-tan (a (t) ) phenotype in dogs was previously shown to be a SINE insertion in the 5' region of Agouti Signaling Protein (ASIP). Dogs with the black-and-tan phenotype, as well as dogs with the saddle tan phenotype, genotype as a (t) /_ at this locus. We have identified a 16-bp duplication (g.1875_1890dupCCCCAGGTCAGAGTTT) in an intron of hnRNP associated with lethal yellow (RALY), which segregates with the black-and-tan phenotype in a group of 99 saddle tan and black-and-tan Basset Hounds and Pembroke Welsh Corgis. In these breeds, all dogs with the saddle tan phenotype had RALY genotypes of +/+ or +/dup, whereas dogs with the black-and-tan phenotype were homozygous for the duplication. The presence of an a (y) /_ fawn or e/e red genotype is epistatic to the +/_ saddle tan genotype. Genotypes from 10 wolves and 1 coyote indicated that the saddle tan (+) allele is the ancestral allele, suggesting that black-and-tan is a modification of saddle tan. An additional 95 dogs from breeds that never have the saddle tan phenotype have all three of the possible RALY genotypes. We suggest that a multi-gene interaction involving ASIP, RALY, MC1R, DEFB103, and a yet-unidentified modifier gene is required for expression of saddle tan.

Nitride alloy layer formation of duplex stainless steel using nitriding process

NASA Astrophysics Data System (ADS)

Maleque, M. A.; Lailatul, P. H.; Fathaen, A. A.; Norinsan, K.; Haider, J.

2018-01-01

Duplex stainless steel (DSS) shows a good corrosion resistance as well as the mechanical properties. However, DSS performance decrease as it works under aggressive environment and at high temperature. At the mentioned environment, the DSS become susceptible to wear failure. Surface modification is the favourable technique to widen the application of duplex stainless steel and improve the wear resistance and its hardness properties. Therefore, the main aim of this work is to nitride alloy layer on the surface of duplex stainless steel by the nitriding process temperature of 400°C and 450°C at different time and ammonia composition using a horizontal tube furnace. The scanning electron microscopy and x-ray diffraction analyzer are used to analyse the morphology, composition and the nitrided alloy layer for treated DSS. The micro hardnesss Vickers tester was used to measure hardness on cross-sectional area of nitrided DSS. After nitriding, it was observed that the hardness performance increased until 1100 Hv0.5kgf compared to substrate material of 250 Hv0.5kgf. The thickness layer of nitride alloy also increased from 5μm until 100μm due to diffusion of nitrogen on the surface of DSS. The x-ray diffraction results showed that the nitride layer consists of iron nitride, expanded austenite and chromium nitride. It can be concluded that nitride alloy layer can be produced via nitriding process using tube furnace with significant improvement of microstructural and hardness properties.

Measurement of total acid number (TAN) and TAN boiling point distribution in petroleum products by electrospray ionization mass spectrometry.

PubMed

Qian, Kuangnan; Edwards, Kathleen E; Dechert, Gary J; Jaffe, Stephen B; Green, Larry A; Olmstead, William N

2008-02-01

We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (<200 mg) and higher throughput (20 samples/h) measurement. Naphthenic acid structures were assigned based on nominal masses of a set of predefined acid structures. Stearic acid is used as an internal standard to calibrate ESI-MS response factors for quantification purposes. With the use of structure-property correlations, boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

Cognitive Rationalizations for Tanning-Bed Use: A Preliminary Exploration

PubMed Central

Banerjee, Smita C.; Hay, Jennifer L.; Greene, Kathryn

2016-01-01

Objectives To examine construct and predictive utility of an adapted cognitive rationalization scale for tanning-bed use. Methods Current/former tanning-bed-using undergraduate students (N = 216; 87.6% females; 78.4% white) at a large northeastern university participated in a survey. A cognitive rationalization for tanning-bed use scale was adapted. Standardized self-report measures of past tanning-bed use, advantages of tanning, perceived vulnerability to photoaging, tanning-bed use dependence, and tanning- bed use intention were also administered. Results The cognitive rationalization scale exhibited strong construct and predictive validity. Current tanners and tanning-bed-use-dependent participants endorsed rationalizations more strongly than did former tanners and not-tanning-bed-use-dependent participants respectively. Conclusions Findings indicate that cognitive rationalizations help explain discrepancy between inconsistent cognitions. PMID:23985280

Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth

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

Nakamura, Daisuke; Suzumura, Akitoshi; Shigetoh, Keisuke

2015-02-23

Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysismore » also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs.« less

A&M. Radioactive parts security storage area, TAN647 and TAN648. Plot ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Radioactive parts security storage area, TAN-647 and TAN-648. Plot plan, fencing details. Relationship to hot shop and railroad turntable. Ralph M. Parsons 1480-7-ANP/GE-3-102. Date: November 19958. Approved by INEEL Classification Office for public release. INEEL index no. 034-0100-00-693-107447 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Is a tan really beautiful?

PubMed

Salpietro, B J; Del Campo, D V

1995-12-01

History has demonstrated many dangerous beauty fads, including tanning, which have evolved into a false concept of beauty. A teaching tool, which emphasizes tanning as just a fashion trend rather than a beauty enhancer, can help discourage people from suntanning their skin.

The Tri-lab Tantalum Strength Consortium

NASA Astrophysics Data System (ADS)

Flicker, Dawn G.; Arsenlis, Thomas A.; Austin, Ryan; Barton, Nathan R.; Benage, John F.; Bronkhorst, Curt A.; Brown, Justin L.; Brown, Staci L.; Buttler, William T.; Shen, Shuh-Rong; Dattelbaum, Dana M.; Fensin, Sayu J.; Gray, George T., III; Lane, J. Matthew D.; Lim, Hojun; Luscher, D. J.; Mattsson, Thomas R.; McNabb, Dennis P.; Remington, Bruce A.; Park, Hye-Sook; Prisbrey, Shon T.; Prime, Michael B.; Scharff, Robert J.; Schraad, Mark W.; Sun, Amy C.

2017-06-01

A Tri-lab consortium of experimentalists and theorists at SNL, LLNL, and LANL is joining forces to better understand tantalum strength across an unprecedented range of loading conditions. The team is collecting and comparing tantalum strength data from Hopkinson bar, Taylor cylinder, guns, Z, Omega and the NIF. These experiments, all using Ta from a single lot, span pressures from tenths to hundreds of GPa and strain rates from 103 to 107. New experiments are underway to provide more overlap between the platforms. The experiments are being simulated with a variety of models in order to determine which processes are important under which conditions. The presentation will show results to date. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

Observation of oxide particles below the apparent oxygen solubility limit in tantalum

NASA Technical Reports Server (NTRS)

Stecura, S.

1973-01-01

The apparent solubility of oxygen in polycrystalline tantalum as determined by the X-ray diffraction lattice parameter technique is about 1.63 atomic percent at 820 C. However, oxide particles were identified in samples containing as low as 0.5 atomic percent of oxygen. These oxide particles were present at the grain boundaries and within the grains. The number of oxide particles increased with increasing oxygen concentration in tantalum. The presence of oxide particles suggests that the true solubility of oxygen in the polycrystalline tantalum metal is probably significantly lower than that reported in the literature.

Simultaneous determination of tantalum and hafnium in silicates by neutron activation analysis

USGS Publications Warehouse

Greenland, L.P.

1968-01-01

A neutron activation procedure suitable for the routine determination of tantalum and hafnium in silicates is described. The irradiated sample is fused with sodium peroxide and leached, and the insoluble hydroxides are dissolved in dilute hydrofluoric acid-hydrochloric acid. After LaF3 and AgCl scavenges, tantalum and hafnium are separated by anion exchange. Tantalum is obtained radiochemically pure; 233Pa and 95Zr contaminants in the hafnium fraction are resolved by ??-ray spectrometry. The chemical yield of the procedure is detemined after counting by re-irradiation. Values for the 8 U.S. Geological Survey standard rocks are reported. ?? 1968.

Synthesis of Coral-Like Tantalum Oxide Films via Anodization in Mixed Organic-Inorganic Electrolytes

PubMed Central

Yu, Hongbin; Zhu, Suiyi; Yang, Xia; Wang, Xinhong; Sun, Hongwei; Huo, Mingxin

2013-01-01

We report a simple method to fabricate nano-porous tantalum oxide films via anodization with Ta foils as the anode at room temperature. A mixture of ethylene glycol, phosphoric acid, NH4F and H2O was used as the electrolyte where the nano-porous tantalum oxide could be synthesized by anodizing a tantalum foil for 1 h at 20 V in a two–electrode configuration. The as-prepared porous film exhibited a continuous, uniform and coral-like morphology. The diameters of pores ranged from 30 nm to 50 nm. The pores interlaced each other and the depth was about 150 nm. After calcination, the as-synthesized amorphous tantalum oxide could be crystallized to the orthorhombic crystal system. As observed in photocatalytic experiments, the coral-like tantalum oxide exhibited a higher photocatalytic activity for the degradation of phenol than that with a compact surface morphology, and the elimination rate of phenol increased by 66.7%. PMID:23799106

Biological Response of Human Bone Marrow-Derived Mesenchymal Stem Cells to Commercial Tantalum Coatings with Microscale and Nanoscale Surface Topographies

NASA Astrophysics Data System (ADS)

Skoog, Shelby A.; Kumar, Girish; Goering, Peter L.; Williams, Brian; Stiglich, Jack; Narayan, Roger J.

2016-06-01

Tantalum is a promising orthopaedic implant coating material due to its robust mechanical properties, corrosion resistance, and excellent biocompatibility. Previous studies have demonstrated improved biocompatibility and tissue integration of surface-treated tantalum coatings compared to untreated tantalum. Surface modification of tantalum coatings with biologically inspired microscale and nanoscale features may be used to evoke optimal tissue responses. The goal of this study was to evaluate commercial tantalum coatings with nanoscale, sub-microscale, and microscale surface topographies for orthopaedic and dental applications using human bone marrow-derived mesenchymal stem cells (hBMSCs). Tantalum coatings with different microscale and nanoscale surface topographies were fabricated using a diffusion process or chemical vapor deposition. Biological evaluation of the tantalum coatings using hBMSCs showed that tantalum coatings promote cellular adhesion and growth. Furthermore, hBMSC adhesion to the tantalum coatings was dependent on surface feature characteristics, with enhanced cell adhesion on sub-micrometer- and micrometer-sized surface topographies compared to hybrid nano-/microstructures. Nanostructured and microstructured tantalum coatings should be further evaluated to optimize the surface coating features to promote osteogenesis and enhance osseointegration of tantalum-based orthopaedic implants.

Dermatology Residents are Prescribing Tanning Bed Treatment.

PubMed

Anderson, Kathryn L; Huang, Karen E; Huang, William W; Feldman, Steven R

2016-07-15

Although 90% of dermatologists discourage the use of tanning beds, about half of psoriasis patients report using tanning beds and most of these note improvement. The purpose of this investigation was to determine if dermatology residents are advocating the tanning bed use to their patients.

Tanning Addiction: Conceptualisation, Assessment, and Correlates.

PubMed

Andreassen, C S; Pallesen, S; Torsheim, T; Demetrovics, Z; Griffiths, M D

2018-02-25

Research into problematic tanning (or 'tanning addiction') has markedly increased over the past few years. Although several excessive tanning instruments exist, most of these are psychometrically poor, not theoretically anchored, and have mainly been used on small samples. Against this background, a new tanning addiction scale was developed based on a specific theoretical approach utilising core addiction criteria. A scale comprising seven items (i.e. salience/craving, mood modification, tolerance, withdrawal, conflict, relapse/loss of control, and problems) was administered online to a cross-sectional convenience sample of 23,537 adults (M age =35.8 years, SD=13.3), together with an assessment of demographic factors, the five-factor model of personality, and symptoms of obsessive-compulsive disorder, anxiety and depression. A confirmatory factor analysis showed that a one-factor model showed an optimal fit with the data collected (RMSEA=.050 [90% CI=.047-.053], CFI=.99, TLI=.99). High factor loadings (.781-.905, all p<.001) and coefficient omega indicator of reliability (ω=.941 [95% CI=.939-.944]) were also found using the new scale. In a multiple linear regression analysis, tanning addiction was positively associated with being female, not being in a relationship, extroversion, neuroticism, anxiety and obsessive-compulsiveness. It was also found that educational level, intellect/openness and depression were inversely associated with tanning addiction. The new scale, Bergen Tanning Addiction Scale (BTAS), showed good psychometric properties, and is the first scale to fully conceptualise tanning addiciton within a contemporary addiction framework. Given this, the BTAS may potentially assist future clinical practice in providing appropriate patient care, prevention and disease management. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pediatricians' perspectives on indoor tanning.

PubMed

Hession, Meghan T; Campbell, Shannon M; Balk, Sophie J; Cummins, Deborah L

2013-01-01

This report presents results from an online survey of New York State pediatricians regarding their counseling habits and attitudes toward indoor tanning among adolescents, as well as their awareness of current legislation that restricts youth access to tanning beds. © 2013 Wiley Periodicals, Inc.

Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) Nanorods Superlattice (SL)

DTIC Science & Technology

2006-03-29

Final Report (Technical) 3. DATES COVERED 29-03-2005 to 29-05-2006 4. TITLE AND SUBTITLE Indium Gallium Nitride/ Gallium Nitride (InGaN/GaN...Institution: Quantum functional Semiconductor Research Center (QSRC), Dongguk University - Title of project: Indium Gallium Nitride/ Gallium Nitride...Accepted with minor revision Indium Gallium Nitride / Gallium Nitride (InGaN/ GaN) Nanorods Superlattice (SL) Abstract The growth condition, electrical

Effect of Post-HALT Annealing on Leakage Currents in Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2010-01-01

Degradation of leakage currents is often observed during life testing of tantalum capacitors and is sometimes attributed to the field-induced crystallization in amorphous anodic tantalum pentoxide dielectrics. However, degradation of leakage currents and the possibility of annealing of degraded capacitors have not been investigated yet. In this work the effect of annealing after highly accelerated life testing (HALT) on leakage currents in various types of solid tantalum capacitors was analyzed. Variations of leakage currents with time during annealing at temperatures from 125 oC to 180 oC, thermally stimulated depolarization (TSD) currents, and I-V characteristics were measured to understand the conduction mechanism and the reason for current degradation. Annealing resulted in a gradual decrease of leakage currents and restored their initial values. Repeat HALT after annealing resulted in reproducible degradation of leakage currents. The observed results are explained based on ionic charge instability (drift/diffusion of oxygen vacancies) in the tantalum pentoxide dielectrics using a modified Schottky conduction mechanism.

The Evaluation of Hydroxyapatite (HA) Coated and Uncoated Porous Tantalum for Biomedical Material Applications

NASA Astrophysics Data System (ADS)

Safuan, Nadia; Sukmana, Irza; Kadir, Mohammed Rafiq Abdul; Noviana, Deni

2014-04-01

Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

21 CFR 878.4635 - Ultraviolet lamp for tanning.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878... tanning. (a) Identification. An ultraviolet lamp for tanning is a device that is a lamp (including a fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b...

Tanning as an addictive behavior: a literature review.

PubMed

Nolan, Bridgit V; Taylor, Sarah L; Liguori, Anthony; Feldman, Steven R

2009-02-01

Recent studies have identified reinforcing properties associated with tanning and suggest a possible physiologic mechanism and addiction driving tanning behavior. This article attempts to synthesize the existing literature on tanning and addiction to investigate possible associations. We investigated a variety of substance dependence models to define what constitutes dependence/addiction and to determine how current studies on tanning meet these criteria. In some individuals, tanning has met Diagnostic and Statistical Manual criteria for a substance-related disorder or tanning-modified Cut Down, Annoyed, Guilt, Eye-opener criteria. Trial studies have demonstrated the induction of withdrawal symptoms in frequent tanners. Additional studies are needed to investigate the associated dependency and addiction more fully and to elucidate its similarities to other better-known addictive syndromes. Tanning is a problem behavior, both as a health risk and as a possible dependency. Future studies, especially in the area of cognitive mapping and cue-related stimuli are needed. Imaging studies may be important in elucidating whether the same areas of the brain are involved in tanning addiction as in other addictive syndromes.

NIOBIUM-TANTALUM SEPARATION

DOEpatents

Wilhelm, H.A.; Foos, R.A.

1959-01-27

The usual method for the separation of tantalum and niobium consists of a selective solvent extraction from an aqueous hydrofluoric acid solution of the metals. A difficulty encountered in this process is the fact that the corrosion problems associated with hydrofluoric acid are serious. It has been found that the corrosion caused by the hydrofluoric acid may be substantially reduced by adding to the acidic solution an amine, such as phenyl diethanolamine or aniline, and adjusting pH value to between 4 and 6.

A&M. TAN633. Utilities plan and profiles. Layout of TAN633 in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. TAN-633. Utilities plan and profiles. Layout of TAN-633 in relation to neighboring buildings: actuator building, pool building, water filter building, liquid waste treatment plant, and buried storage tanks. Ralph M. Parsons 1229-13-ANP/GE-3-301-U-1. Date: December 1956. INEEL index code no. 034-0301-00-693-107311 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

GCN/TAN: A Status Report

NASA Astrophysics Data System (ADS)

Barthelmy, Scott

2015-04-01

The Gamma-ray Coordinates Network / Transient Astronomy Network (GCN/TAN) is your one-stop shopping place for all transient astronomy. It collects nearly all the astrophysical transients from the missions (space-based and ground-based), puts them into a standard format, and distributes them to whomever wishes to receive them. This is all done autonomously (completely autonomous within GCN/TAN, and almost always autonomously within the producer end of operations). This automation means minimal time delays (<0.1 sec within GCN for socket-based distribution methods, and up to 30 sec for email-based which is dependant on the internet email protocol and the number of hops (both of which are out of the control of GCN/TAN). A status report on the current set of sources of transient information, plus recently-added and soon-to-be-added source will be given. Also, a standing request for GCN/TAN to incorporate your transient data stream; plus instruction for customers to receive GCN/TAAN Notice and Circular information.

NUCLEAR REACTOR ELEMENT

DOEpatents

Sanz, M.C.; Scully, C.N.

1961-06-27

The patented fuel element is a hexagonal graphite body having an axial channel therethrough. The graphite is impregnated with uranium which is concentrated near the axial channel. Layers of tantalum nitride and tantalum carbide are disposed on the surface of the body confronting the channel.

Tantalum modified ferritic iron base alloys

NASA Technical Reports Server (NTRS)

Oldrieve, R. E.; Blankenship, C. P. (Inventor)

1977-01-01

Strong ferritic alloys of the Fe-CR-Al type containing 0.4% to 2% tantalum were developed. These alloys have improved fabricability without sacrificing high temperature strength and oxidation resistance in the 800 C (1475 F) to 1040 C (1900 F) range.

The deceptive nature of UVA tanning versus the modest protective effects of UVB tanning on human skin.

PubMed

Miyamura, Yoshinori; Coelho, Sergio G; Schlenz, Kathrin; Batzer, Jan; Smuda, Christoph; Choi, Wonseon; Brenner, Michaela; Passeron, Thierry; Zhang, Guofeng; Kolbe, Ludger; Wolber, Rainer; Hearing, Vincent J

2011-02-01

The relationship between human skin pigmentation and protection from ultraviolet (UV) radiation is an important element underlying differences in skin carcinogenesis rates. The association between UV damage and the risk of skin cancer is clear, yet a strategic balance in exposure to UV needs to be met. Dark skin is protected from UV-induced DNA damage significantly more than light skin owing to the constitutively higher pigmentation, but an as yet unresolved and important question is what photoprotective benefit, if any, is afforded by facultative pigmentation (i.e. a tan induced by UV exposure). To address that and to compare the effects of various wavelengths of UV, we repetitively exposed human skin to suberythemal doses of UVA and/or UVB over 2 weeks after which a challenge dose of UVA and UVB was given. Although visual skin pigmentation (tanning) elicited by different UV exposure protocols was similar, the melanin content and UV-protective effects against DNA damage in UVB-tanned skin (but not in UVA-tanned skin) were significantly higher. UVA-induced tans seem to result from the photooxidation of existing melanin and its precursors with some redistribution of pigment granules, while UVB stimulates melanocytes to up-regulate melanin synthesis and increases pigmentation coverage, effects that are synergistically stimulated in UVA and UVB-exposed skin. Thus, UVA tanning contributes essentially no photoprotection, although all types of UV-induced tanning result in DNA and cellular damage, which can eventually lead to photocarcinogenesis. 2010 John Wiley & Sons A/S. This article is a US Government work and is in the public domain in the USA.

Effect of Compressive Stresses on Leakage Currents in Microchip Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2012-01-01

Microchip tantalum capacitors are manufactured using new technologies that allow for production of small size capacitors (down to EIA case size 0402) with volumetric efficiency much greater than for regular chip capacitors. Due to a small size of the parts and leadless design they might be more sensitive to mechanical stresses that develop after soldering onto printed wiring boards (PWB) compared to standard chip capacitors. In this work, the effect of compressive stresses on leakage currents in capacitors has been investigated in the range of stresses up to 200 MPa. Significant, up to three orders of magnitude, variations of currents were observed after the stress exceeds a certain critical level that varied from 10 MPa to 180 MPa for capacitors used in this study. A stress-induced generation of electron traps in tantalum pentoxide dielectric is suggested to explain reversible variations of leakage currents in tantalum capacitors. Thermo-mechanical characteristics of microchip capacitors have been studied to estimate the level of stresses caused by assembly onto PWB and assess the risk of stress-related degradation and failures. Keywords: tantalum capacitors, leakage current, soldering, reliability, mechanical stress.

The preparation of tantalum powder using a MR-EMR combination process

NASA Astrophysics Data System (ADS)

Yoon, Jae Sik; Kim, Byung Il

2007-04-01

In the conventional metallothermic reduction (MR) process used to obtain tantalum powder in batch-type operation, it is difficult to control the morphology and location of the tantalum deposits. In contrast, an electronically mediated reaction (EMR) process is capable of overcoming this difficulty. It has the advantage of being a continuous process, but has the disadvantage of a poor reduction yield. A process known as the MR-EMR combination process is able to overcome the shortcomings of the MR and EMR processes. In this study, an MR-EMR combination process is applied to the production of tantalum powder via sodium reduction of K2TaF7. In the MR-EMR combination process, the total charge passed through an external circuit and the average particle size (FSSS) increase as the reduction temperature increases. In addition, the proportion of fine particles (-325 mesh) decreases as the reduction temperature increasess. The tantalum yield improved from 65 to 74% as the reduction temperature increased. Taking into account the charge, impurities, morphology, particle size and yield, a reduction temperature of 1123 K was found to be optimum for the MR-EMR combination process.

Preventing Skin Cancer Through Reduction of Indoor Tanning

PubMed Central

Watson, Meg; Holman, Dawn M.; Fox, Kathleen A.; Guy, Gery P.; Seidenberg, Andrew B.; Sampson, Blake P.; Sinclair, Craig; Lazovich, DeAnn

2015-01-01

Exposure to ultraviolet radiation from indoor tanning devices (tanning beds, booths, and sun lamps) or from the sun contributes to the risk of skin cancer, including melanoma, which is the type of skin cancer responsible for most deaths. Indoor tanning is common among certain groups, especially among older adolescents and young adults, adolescent girls and young women, and non-Hispanic whites. Increased understanding of the health risks associated with indoor tanning has led to many efforts to reduce use. Most environmental and systems efforts in the U.S. (e.g., age limits or requiring parental consent/accompaniment) have occurred at the state level. At the national level, the U.S. Food and Drug Administration and the Federal Trade Commission regulate indoor tanning devices and advertising, respectively. The current paper provides a brief review of (1) the evidence on indoor tanning as a risk factor for skin cancer; (2) factors that may influence use of indoor tanning devices at the population level; and (3) various environmental and systems options available for consideration when developing strategies to reduce indoor tanning. This information provides the context and background for the companion paper in this issue of the American Journal of Preventive Medicine, which summarizes highlights from an informal expert meeting convened by the CDC in August 2012 to identify opportunities to prevent skin cancer by reducing use of indoor tanning devices. PMID:23683987

Indoor tanning by adolescents: prevalence, practices and policies.

PubMed

Lazovich, DeAnn; Forster, Jean

2005-01-01

Despite known acute and chronic health effects from the use of indoor tanning, including the potential for all forms of skin cancer, the practice is popular in the United States (US) and Europe. A review of the scientific literature that examines adolescents and indoor tanning use was undertaken, summarising what is known about prevalence and practices among adolescents, characteristics associated with adolescent use, and policies that regulate adolescent access to indoor tanning facilities. The prevalence of indoor tanning is consistently found to be higher among girls than boys and to increase with age in both Europe and the US. An examination of other demographic characteristics, skin cancer risk factors, knowledge, attitudes and social factors points to higher prevalence of the behaviour among adolescents with positive attitudes towards tans and whose friends or parents also tan indoors. Adolescent access to indoor tanning is rarely regulated in the US or Europe, and where regulations exist, business compliance is low. In addition, businesses actively market their product to adolescents as they organise to limit further regulations prohibiting adolescent access. Pricing, licensure, advertising restrictions and media campaigns, in combination with adolescent-targeted interventions, are possible strategies that could be tested for their effectiveness to reduce adolescent indoor tanning use. Harm reduction policies, such as eye protection, that reduce risk for adolescents who choose to tan indoors, are also important.

Tanning and teens: Is indoor exposure the tip of the iceberg?

PubMed Central

Hay, Jennifer L.; Riley, Kristen E.; Geller, Alan C.

2017-01-01

Due to recent state regulations and the reduced availability of free-standing tanning salons, indoor tanning prevalence is beginning to decline. This may lead to unintended consequences – increases in outdoor intentional tanning. We advance a series of research directions to track and intervene to address all forms of intentional tanning. First, we advocate for enforcement of indoor tanning regulation and encourage collection of data on tanning salon compliance and alternative indoor tanning strategies. Second, we suggest questions about outdoor and indoor tanning should be included in national surveys. Third, we need to understand the potentially complex patterns of indoor and outdoor tanning that may exist among those who tan. Fourth, research examining changing motivations for intentional tanning is needed. Finally, indoor tanning intervention studies should include outdoor tanning as an outcome to examine the effect of interventions on these related risk behaviors. These advances will ensure the development of novel interventions to address intentional tanning through multiple routes, and to avoid any unintended negative consequence of indoor tanning regulation. The promising downward direction of indoor tanning use in the United States should now lead the public health field to sharpen its focus on outdoor tanning. PMID:28765337

Aqua vs TanSat: A Long-Term Analysis

NASA Technical Reports Server (NTRS)

Pharr, James; Patano, Scott

2017-01-01

A six-year analysis between Aqua and TanSat was conducted in order to assess whether or not TanSat would be a continued threat to Aqua. It is predicted that TanSat will cross Aqua seven times prior to Aqua's predicted constellation exit and lowering in February 2022. The predicted crossing geometry is generally favorable at any of the crossings due to TanSat's orbit eccentricity.

Reliability of High-Voltage Tantalum Capacitors. Parts 3 and 4)

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2010-01-01

Weibull grading test is a powerful technique that allows selection and reliability rating of solid tantalum capacitors for military and space applications. However, inaccuracies in the existing method and non-adequate acceleration factors can result in significant, up to three orders of magnitude, errors in the calculated failure rate of capacitors. This paper analyzes deficiencies of the existing technique and recommends more accurate method of calculations. A physical model presenting failures of tantalum capacitors as time-dependent-dielectric-breakdown is used to determine voltage and temperature acceleration factors and select adequate Weibull grading test conditions. This model is verified by highly accelerated life testing (HALT) at different temperature and voltage conditions for three types of solid chip tantalum capacitors. It is shown that parameters of the model and acceleration factors can be calculated using a general log-linear relationship for the characteristic life with two stress levels.

Brain intrinsic network connectivity in individuals with frequent tanning behavior.

PubMed

Ketcherside, Ariel; Filbey, Francesca M; Aubert, Pamela M; Seibyl, John P; Price, Julianne L; Adinoff, Bryon

2018-05-01

Emergent studies suggest a bidirectional relationship between brain functioning and the skin. This neurocutaneous connection may be responsible for the reward response to tanning and, thus, may contribute to excessive tanning behavior. To date, however, this association has not yet been examined. To explore whether intrinsic brain functional connectivity within the default mode network (DMN) is related to indoor tanning behavior. Resting state functional connectivity (rsFC) was obtained in twenty adults (16 females) with a history of indoor tanning. Using a seed-based [(posterior cingulate cortex (PCC)] approach, the relationship between tanning severity and FC strength was assessed. Tanning severity was measured with symptom count from the Structured Clinical Interview for Tanning Abuse and Dependence (SITAD) and tanning intensity (lifetime indoor tanning episodes/years tanning). rsFC strength between the PCC and other DMN regions (left globus pallidus, left medial frontal gyrus, left superior frontal gyrus) is positively correlated with tanning symptom count. rsFC strength between the PCC and salience network regions (right anterior cingulate cortex, left inferior parietal lobe, left inferior temporal gyrus) is correlated with tanning intensity. Greater connectivity between tanning severity and DMN and salience network connectivity suggests that heightened self-awareness of salient stimuli may be a mechanism that underlies frequent tanning behavior. These findings add to the growing evidence of brain-skin connection and reflect dysregulation in the reward processing networks in those with frequent tanning.

Methods of forming boron nitride

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

Trowbridge, Tammy L; Wertsching, Alan K; Pinhero, Patrick J

A method of forming a boron nitride. The method comprises contacting a metal article with a monomeric boron-nitrogen compound and converting the monomeric boron-nitrogen compound to a boron nitride. The boron nitride is formed on the same or a different metal article. The monomeric boron-nitrogen compound is borazine, cycloborazane, trimethylcycloborazane, polyborazylene, B-vinylborazine, poly(B-vinylborazine), or combinations thereof. The monomeric boron-nitrogen compound is polymerized to form the boron nitride by exposure to a temperature greater than approximately 100.degree. C. The boron nitride is amorphous boron nitride, hexagonal boron nitride, rhombohedral boron nitride, turbostratic boron nitride, wurzite boron nitride, combinations thereof, or boronmore » nitride and carbon. A method of conditioning a ballistic weapon and a metal article coated with the monomeric boron-nitrogen compound are also disclosed.« less

Surface nanotexturing of tantalum by laser ablation in water

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

Barmina, E V; Simakin, Aleksandr V; Shafeev, Georgii A

2009-01-31

Surface nanotexturing of tantalum by ablation with short laser pulses in water has been studied experimentally using three ablation sources: a neodymium laser with a pulse duration of 350 ps, an excimer laser (248 nm) with a pulse duration of 5 ps and a Ti:sapphire laser with a pulse duration of 180 fs. The morphology of the nanotextured surfaces has been examined using a nanoprofilometer and field emission scanning electron microscope. The results demonstrate that the average size of the hillocks produced on the target surface depends on the laser energy density and is {approx}200 nm at an energy densitymore » approaching the laser-melting threshold of tantalum and a pulse duration of 350 ps. Their surface density reaches 10{sup 6} cm{sup -2}. At a pulse duration of 5 ps, the average hillock size is 60-70 nm. Nanotexturing is accompanied by changes in the absorption spectrum of the tantalum surface in the UV and visible spectral regions. The possible mechanisms of surface nanotexturing and potential applications of this effect are discussed. (nanostructures)« less

Semimicrodetermination of combined tantalum and niobium with selenous acid

USGS Publications Warehouse

Grimaldi, F.S.; Schnepfe, M.

1959-01-01

Tantalum and niobium are separated and determined gravimetrically by precipitation with selenous acid from highly acidic solutions in the absence of complexing agents. Hydrogen peroxide is used in the preparation of the solution and later catalytically destroyed during digestion of the precipitate. From 0.2 to 30 mg., separately or in mixtures, of niobium or tantalum pentoxide can be separated from mixtures containing 100 mg. each of the oxides of scandium, yttrium, cerium, vanadium, molybdenum, iron, aluminum, tin, lead, and bismuth with a single precipitation; and from 30 mg. of titanium dioxide, and 50 mg. each of the oxides of antimony and thorium, when present separately, with three precipitations. At least 50 mg. of uranium(VI) oxide can be separated with a single precipitation when present alone; otherwise, three precipitations may be needed. Zirconium does not interfere when the tantalum and niobium contents of the sample are small, but in general, zirconium as well as tungsten interfere. The method is applied to the determination of the earth acids in tantaloniobate ores.

Tantalum protective coatings for fusion reactor applications

NASA Astrophysics Data System (ADS)

Brossa, Francesco; Piatti, Giovanni; Bardy, Michel

Tantalum has a very low sputtering yield, high melting point, low vapour pressure and good mechanical properties at low and high temperatures, so it is a very interesting candidate for the first wall and blanket structural components. Tantalum coatings overcome the problems of fabrication and joining bulk Ta, thus reducing also dead weight and cost. Ta coatings were produced by chemical vapour deposition and plasma spraying on four conventional structural materials: Al, Cu, AISI 316 L and Inconel 600. The conditions which improve adherence have been studied. The composition of the films was determined by chemical means and by X-ray analysis. Metallographie examination was employed to define the morphological structure of the deposits. The adherence of the coatings was determined by subjecting the samples to bend tests and to thermal shocks.

Effects of severe stressing on tantalum capacitors

NASA Technical Reports Server (NTRS)

Shakar, J. F.; Fairfield, E. H.

1981-01-01

The ultimate capabilities of an all tantalum capacitor were determined and evaluated. The evaluation included: 175 C life; 100 cycle thermal shock; 70 g random vibration; 3000 g shock; and 90 C ase ripple current.

Micro/Nano Structural Tantalum Coating for Enhanced Osteogenic Differentiation of Human Bone Marrow Stem Cells

PubMed Central

Ding, Ding; Xie, Youtao; Li, Kai; Huang, Liping; Zheng, Xuebin

2018-01-01

Recently, tantalum has been attracting much attention for its anticorrosion resistance and biocompatibility, and it has been widely used in surface modification for implant applications. To improve its osteogenic differentiation of human bone marrow stem cells (hBMSCs), a micro/nano structure has been fabricated on the tantalum coating surface through the combination of anodic oxidation and plasma spraying method. The morphology, composition, and microstructure of the modified coating were comprehensively studied by employing scanning electron microscopy (SEM), X-ray diffraction (XRD) as well as transmission electron microscopy (TEM). The effects of hierarchical structures as well as micro-porous structure of tantalum coating on the behavior for human bone marrow stem cells (hBMSCs) were evaluated and compared at both cellular and molecular levels in vitro. The experimental results show that a hierarchical micro/nano structure with Ta2O5 nanotubes spread onto a micro-scale tantalum coating has been fabricated successfully, which is confirmed to promote cell adhesion and spreading. Besides, the hierarchical micro/nano tantalum coating can provide 1.5~2.1 times improvement in gene expression, compared with the micro-porous tantalum coating. It demonstrates that it can effectively enhance the proliferation and differentiation of hBMSCs in vitro. PMID:29614022

Micro/Nano Structural Tantalum Coating for Enhanced Osteogenic Differentiation of Human Bone Marrow Stem Cells.

PubMed

Ding, Ding; Xie, Youtao; Li, Kai; Huang, Liping; Zheng, Xuebin

2018-04-03

Recently, tantalum has been attracting much attention for its anticorrosion resistance and biocompatibility, and it has been widely used in surface modification for implant applications. To improve its osteogenic differentiation of human bone marrow stem cells (hBMSCs), a micro/nano structure has been fabricated on the tantalum coating surface through the combination of anodic oxidation and plasma spraying method. The morphology, composition, and microstructure of the modified coating were comprehensively studied by employing scanning electron microscopy (SEM), X-ray diffraction (XRD) as well as transmission electron microscopy (TEM). The effects of hierarchical structures as well as micro-porous structure of tantalum coating on the behavior for human bone marrow stem cells (hBMSCs) were evaluated and compared at both cellular and molecular levels in vitro. The experimental results show that a hierarchical micro/nano structure with Ta₂O₅ nanotubes spread onto a micro-scale tantalum coating has been fabricated successfully, which is confirmed to promote cell adhesion and spreading. Besides, the hierarchical micro/nano tantalum coating can provide 1.5~2.1 times improvement in gene expression, compared with the micro-porous tantalum coating. It demonstrates that it can effectively enhance the proliferation and differentiation of hBMSCs in vitro.

Integration of amorphous tantalum silicon nitride (TaSiN) films as diffusion barriers in a Cu/SiLK(TM) metallization scheme

NASA Astrophysics Data System (ADS)

Padiyar, Sumant Devdas

2003-09-01

Current and future performance requirements for high- speed integrated circuit (IC) devices have placed great emphasis on the introduction of novel materials, deposition techniques and improved metrology techniques. The introduction of copper interconnects and more currently low-k dielectric materials in IC fabrication are two such examples. This introduction necessitates research on the compatibility of these materials and process techniques with adjacent diffusion barrier materials. One candidate, which has attracted significant attention is tantalum-silicon-nitride (TaSiN) on account of its superior diffusion barrier performance and high recrystallization temperature1. The subject of this dissertation is an investigation of the integration compatibility and performance of TaSiN barrier layers with a low-k dielectric polymer (SiLK ®2). A plasma- enhanced chemical vapor deposition (PECVD) approach is taken for growth of TaSiN films in this work due to potential advantages in conformal film coverage compared to more conventional physical vapor deposition methods. A Design of Experiment (DOE) methodology was introduced for PECVD of TaSiN on SiLK to optimize film properties such as film composition, resistivity, growth rate and film roughness with respect to the predictors viz. substrate temperature, precursor gas flow and plasma power. The first pass study determined the response window for optimized TaSiN film composition, growth rate and low halide contamination and the compatibility of the process with an organic polymer substrate, i.e. SiLK. Second-pass studies were carried out to deposit ultra- thin (10nm) films on: (a)blanket SiLK to investigate the performance of TaSiN films against copper diffusion, and (b)patterned SiLK to evaluate step coverage and conformality. All TaSiN depositions were carried out on SiO2 substrates for baseline comparisons. A second purpose of the diffusion barrier in IC processing is to improve interfacial adhesion between the

Test-retest of self-reported exposure to artificial tanning devices, self-tanning creams, and sun sensitivity showed consistency.

PubMed

Beane Freeman, Laura E; Dennis, Leslie K; Lynch, Charles F; Lowe, John B; Clarke, William R

2005-04-01

Exposure to ultraviolet radiation has consistently been linked to an increased risk of melanoma. Epidemiologic studies are susceptible to measurement error, which can distort the magnitude of observed effects. Although the reliability of self-report of many sun exposure factors has been previously described in several studies, self-report of use of artificial tanning devices and self-tanning creams has been less well characterized. A mailed survey was re-administered 2-4 weeks after completion of the initial survey to 76 randomly selected participants in a case-control study of melanoma. Cases and controls were individuals diagnosed in 1999 and 2000 who were ascertained from the Iowa Cancer Registry in 2002. We assessed the consistency of self-reported use of sunlamps and self-tanning creams, sun sensitivity, and history of sunburns. There was substantial reliability in reporting the use of sunlamps or self-tanning creams (cases: Kappa (kappa)=1.0 for both exposures; controls: kappa=0.71 and 0.87, respectively). kappa estimates of 0.62-0.78 were found for overall reliability of several sun sensitivity factors. Overall, the survey instrument demonstrated substantial reproducibility for factors related to the use of sunlamps or tanning beds, self-tanning creams, and sun sensitivity factors.

Examination of T-111 clad uranium nitride fuel pins irradiated up to 13,000 hours at a clad temperature of 990 C

NASA Technical Reports Server (NTRS)

Slaby, J. G.; Siegel, B. L.

1973-01-01

The examination of 27 fuel pins irradiated for up to 13,000 hours at 990 C is described. The fuel pin clad was a tantalum alloy with uranium nitride as the nuclear fuel. Two nominal fuel pin diameters were tested with a maximum burnup of 2.34 atom percent. Twenty-two fuel pins were tested for fission gas leaks; thirteen pins leaked. Clad ductility tests indicated clad embrittlement. The embrittlement is attributed to hydrogen from an n,p reaction in the fuel. Fuel swelling was burnup dependent, and the amount of fission gas release was low, generally less than 0.5 percent. No incompatibilities between fuel, liner, and clad were in evidence.

Random Vibration Testing of Advanced Wet Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2015-01-01

Advanced wet tantalum capacitors allow for improved performance of power supply systems along with substantial reduction of size and weight of the systems that is especially beneficial for space electronics. Due to launch-related stresses, acceptance testing of all space systems includes random vibration test (RVT). However, many types of advanced wet tantalum capacitors cannot pass consistently RVT at conditions specified in MIL-PRF-39006, which impedes their use in space projects. This requires a closer look at the existing requirements, modes and mechanisms of failures, specifics of test conditions, and acceptance criteria. In this work, different lots of advanced wet tantalum capacitors from four manufacturers have been tested at step stress random vibration conditions while their currents were monitored before, during, and after the testing. It has been shown that the robustness of the parts and their reliability are mostly due to effective self-healing processes and limited current spiking or minor scintillations caused by RVT do not increase the risk of failures during operation. A simple model for scintillations events has been used to simulate current spiking during RVT and optimize test conditions. The significance of scintillations and possible effects of gas generation have been discussed and test acceptance criteria for limited current spiking have been suggested.

Effects of substrate temperature on properties of pulsed dc reactively sputtered tantalum oxide films

NASA Astrophysics Data System (ADS)

Jain, Pushkar; Juneja, Jasbir S.; Bhagwat, Vinay; Rymaszewski, Eugene J.; Lu, Toh-Ming; Cale, Timothy S.

2005-05-01

The effects of substrate heating on the stoichiometry and the electrical properties of pulsed dc reactively sputtered tantalum oxide films over a range of film thickness (0.14 to 5.4 μm) are discussed. The film stoichiometry, and hence the electrical properties, of tantalum oxide films; e.g., breakdown field, leakage current density, dielectric constant, and dielectric loss are compared for two different cases: (a) when no intentional substrate/film cooling is provided, and (b) when the substrate is water cooled during deposition. All other operating conditions are the same, and the film thickness is directly related to deposition time. The tantalum oxide films deposited on the water-cooled substrates are stoichiometric, and exhibit excellent electrical properties over the entire range of film thickness. ``Noncooled'' tantalum oxide films are stoichiometric up to ~1 μm film thickness, beyond that the deposited oxide is increasingly nonstoichiometric. The presence of partially oxidized Ta in thicker (>~1 μm) noncooled tantalum oxide films causes a lower breakdown field, higher leakage current density, higher apparent dielectric constant, and dielectric loss. The growth of nonstoichiometric tantalum oxide in thicker noncooled films is attributed to decreased surface oxygen concentration due to oxygen recombination and desorption at higher film temperatures (>~100 °C). The quantitative results presented reflect experience with a specific piece of equipment; however, the procedures presented can be used to characterize deposition processes in which film stoichiometry can change.

Tanning equipment use: 2014 Canadian Community Health Survey.

PubMed

Qutob, Sami Q; O'Brien, Michelle; Feder, Katya; McNamee, James; Guay, Mireille; Than, John

2017-01-18

Tanning equipment use is related to the early onset of cancer, with the risk increasing as the duration and repetition of exposure increase. In 2009, the International Agency for Research on Cancer classified tanning equipment use as carcinogenic to humans, and according to the World Health Organization, the risk of skin melanoma increases significantly when use begins before age 35. The rapid response component of the 2014 Canadian Community Health Survey collected data on the use of tanning equipment in the previous 12 months, including reasons for use, frequency/duration of use, precautions taken, and adverse reactions or injuries. This analysis examines the prevalence of self-reported indoor tanning in a nationally representative sample of Canadians aged 12 or older in the 10 provinces. In 2014, 4.5% of Canadians (an estimated 1.35 million) reported that they had used tanning equipment in the past year; 70.3% of them were female, and just over half of female users were aged 18 to 34. The prevalence of indoor tanning was highest among people with some postsecondary education and among those in higher income households (trend p-value ⟨ 0.0001). Most users reported fewer than 10 sessions in the past year. The most common reason (62.0%) was to develop a "protective" base tan. Females made up the majority of tanning equipment users, particularly at ages 18 to 34. Efforts to increase awareness of the risks may be beneficial, given the high percentage of users who believed that indoor tanning offers some level of skin protection from future sun exposure.

Tannin fingerprinting in vegetable tanned leather by solid state NMR spectroscopy and comparison with leathers tanned by other processes.

PubMed

Romer, Frederik H; Underwood, Andrew P; Senekal, Nadine D; Bonnet, Susan L; Duer, Melinda J; Reid, David G; van der Westhuizen, Jan H

2011-01-28

Solid state ¹³C-NMR spectra of pure tannin powders from four different sources--mimosa, quebracho, chestnut and tara--are readily distinguishable from each other, both in pure commercial powder form, and in leather which they have been used to tan. Groups of signals indicative of the source, and type (condensed vs. hydrolyzable) of tannin used in the manufacture are well resolved in the spectra of the finished leathers. These fingerprints are compared with those arising from leathers tanned with other common tanning agents. Paramagnetic chromium (III) tanning causes widespread but selective disappearance of signals from the spectrum of leather collagen, including resonances from acidic aspartyl and glutamyl residues, likely bound to Cr (III) structures. Aluminium (III) and glutaraldehyde tanning both cause considerable leather collagen signal sharpening suggesting some increase in molecular structural ordering. The ²⁷Al-NMR signal from the former material is consistent with an octahedral coordination by oxygen ligands. Solid state NMR thus provides easily recognisable reagent specific spectral fingerprints of the products of vegetable and some other common tanning processes. Because spectra are related to molecular properties, NMR is potentially a powerful tool in leather process enhancement and quality or provenance assurance.

Guidelines for the selection and application of tantalum electrolytic capacitors in highly reliable equipment

NASA Technical Reports Server (NTRS)

Holladay, A. M.

1978-01-01

Guidelines are given for the selection and application of three types of tantalum electrolytic capacitors in current use in the design of electrical and electronic circuits for space flight missions. In addition, the guidelines supplement requirements of existing military specifications used in the procurement of capacitors. A need exists for these guidelines to assist designers in preventing some of the recurring, serious problems experienced with tantalum electrolytic capacitors in the recent past. The three types of capacitors covered by these guidelines are; solid, wet foil, and tantalum cased wet slug.

Electronic transitions of tantalum monofluoride

NASA Astrophysics Data System (ADS)

Ng, K. F.; Zou, Wenli; Liu, Wenjian; Cheung, A. S.-C.

2017-03-01

The electronic transition spectrum of the tantalum monofluoride (TaF) molecule in the spectral region between 448 and 560 nm has been studied using the technique of laser-ablation/reaction free jet expansion and laser induced fluorescence spectroscopy. The TaF molecule was produced by reacting laser-ablated tantalum atoms with sulfur hexafluoride gas seeded in argon. Twenty-two vibrational bands with resolved rotational structure have been recorded and analyzed, which were organized into seven electronic transitions. The X3Σ-(0+) state has been identified to be the ground state and the determined equilibrium bond length, re, and vibrational frequency, ωe, are 1.8184 Å and 700.1 cm-1, respectively. The low-lying Λ-S states and Ω sub-states of TaF were also theoretically studied at the MRCISD+Q level of theory with spin-orbit coupling. The Ω = 0+ and 2 sub-states from the -3Σ and 3Φ state have been found to be the ground and the first excited states, respectively, which agrees well with our experimental determinations. This work represents the first experimental investigation of the molecular structure of the TaF molecule.

Invited Commentary: Indoor Tanning-A Melanoma Accelerator?

PubMed

Berwick, Marianne; Doré, Jean-François

2017-02-01

In this issue of the Journal, Ghiasvand et al. (Am J Epidemiol. 2017;185(3):147-156) present results from a longitudinal study of the association between indoor tanning and melanoma in a large cohort of Norwegian women. These new data further support previous findings on the damaging effects of tanning bed exposure on women, particularly young women. The authors present compelling evidence that early exposure to tanning beds advances the date of diagnosis of melanoma by at least 2 years. With a strong design and a large cohort followed for a mean of 13.7 years, this study lends additional support to previous evidence of the negative effects of tanning beds and provides further justification for stronger policy initiatives designed to reduce tanning bed use among young women. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Performance and Reliability of Solid Tantalum Capacitors at Cryogenic Conditions

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2006-01-01

Performance of different types of solid tantalum capacitors was evaluated at room and low temperatures, down to 15 K. The effect of temperature on frequency dependencies of capacitance, effective series resistances (ESR), leakage currents, and breakdown voltages has been investigated and analyzed. To assess thermo-mechanical robustness of the parts, several groups of loose capacitors and those soldered on FR4 boards were subjected to multiple (up to 500) temperature cycles between room temperature and 77 K. Experiments and mathematical modeling have shown that degradation in tantalum capacitors at low temperatures is mostly due to increasing resistance of the manganese cathode layer, resulting in substantial decrease of the roll-off frequency. Absorption currents follow a power law, I approximately t(sup -m), with the exponent m varying from 0.8 to 1.1. These currents do not change significantly at cryogenic conditions and the value of the exponent remains the same down to 15 K. Variations of leakage currents with voltage can be described by Pool-Frenkel and Schottky mechanisms of conductivity, with the Schottky mechanism prevailing at cryogenic conditions. Breakdown voltages of tantalum capacitors increase and the probability of scintillations decreases at cryogenic temperatures. However, breakdown voltages measured during surge current testing decrease at liquid nitrogen (LN) compared to room-temperature conditions. Results of temperature cycling suggest that tantalum capacitors are capable of withstanding multiple exposures to cryogenic conditions, but the probability of failures varies for different part types.

Adolescents' reasons for tanning and appearance motives: a preliminary study.

PubMed

Prior, Suzanne M; Fenwick, Kimberley D; Peterson, Jasmine C

2014-01-01

We examined adolescents' reasons for tanning and how these relate to appearance evaluation and orientation. Two hundred and sixty-four Canadian adolescents (age range 15-19 years) in grades 10, 11, and 12 completed a survey that included scales measuring their reasons for tanning, appearance evaluation, and appearance orientation. It was found that girls and boys differed on four of nine subscales measuring reasons for tanning. Girls believed more strongly than boys that tanning improved their general appearance and that friends influenced their decision to tan. Girls also expressed less concern than boys that tanning caused immediate skin damage or premature aging. The pattern of correlations between the reasons for tanning and appearance orientation was similar for girls and boys. For both, appearance reasons for tanning and sociocultural influences on tanning were positively associated with appearance orientation. Suggestions for future research with adolescents and a proposal for a guiding model are provided. Copyright © 2013 Elsevier Ltd. All rights reserved.

Trending on Pinterest: an examination of pins about skin tanning.

PubMed

Banerjee, Smita C; Rodríguez, Vivian M; Greene, Kathryn; Hay, Jennifer L

2018-04-10

Rates of melanoma and nonmelanoma skin cancers are on the rise in the USA with data revealing disproportionate increase in female young adults. The popularity of intentional skin tanning among U.S. adolescents is attributed to several factors, including prioritization of physical appearance, media images of tanned celebrities, ease of availability of artificial tanning facilities, and more recently, the prevalence and celebration of tanned skin on social media. Pinterest, as the third most popular social media platform, was searched for "pins" about skin tanning. The resultant "pins" were examined to understand the extent and characteristics of skin tanning portrayed on Pinterest. We analyzed pins on Pinterest about skin tanning (n = 501) through a quantitative content analysis. Overall, results indicated an overwhelmingly protanning characteristic of pins about skin tanning on Pinterest, with over 85% of pins promoting tanning behavior. The pins were generally characterized by the portrayal of a female subject (61%) and provided positive reinforcement for tanning (49%). Use of tanning for enhancing appearance was the main positive outcome expectancy portrayed in the pins (35%), and nudity or exposure of skin on arms (32%) and legs (31%) was evident in about a third of pins. With overwhelmingly positive pins promoting tanning, use of female subjects, exhibiting nudity, and appearance enhancement, there seems be to a consistent targeting of female users to accept tanning as a socially acceptable and popular behavior. The findings indicate a need for developing sun protection messages and the leveraging of social media for dissemination of skin cancer prevention and detection messages.

Tantalum-based thin film coatings for wear resistant arthroprostheses.

PubMed

Balagna, C; Faga, M G; Spriano, S

2011-10-01

Cobalt-chromium-molybdenum alloys with high carbon content (HC-CoCrMo) are widely used as materials for arthroprosthesis, in particular in metal-on-metal (MoM) hip joints. In spite of their good wear and corrosion resistance, production of metallic wear particles and metal ion release will occur on a large time-scale. An enhancement of the metal ion level in the patient's blood and urine is often reported in clinical data. Hypersensitivity, inflammatory response and cell necrosis can occur as consequence. So implants on young patients and women on childbearing age are not so widespread. The aim of this research is the realization of a thin film coating in order to improve the biocompatibility of Co-based alloys and to reduce debris production, ion release and citotoxicity. The innovative process consists of a thermal treatment in molten salts, in order to obtain a tantalum enriched thin film coating. Tantalum is chosen because it is considered a biocompatible metal with high corrosion resistance and low ion release. Three HC-CoCrMo alloys, produced by different manufacturing processes, are tested as substrates. The coating is a thin film of TaC or it can be composed by a multilayer of two tantalum carbides and metallic tantalum, depending on the temperature of the treatment and on the carbon content of the substrate. The thin films as well the substrates are characterized from the structural, chemical and morphological point of view. Moreover mechanical behaviour of treated and untreated materials is analyzed by means of nanohardness, scratch and ball-on-disc wear tests. The coating increases the mechanical and tribological properties of HC-CoCrMo.

Development and validation of the Comprehensive Indoor Tanning Expectations Scale.

PubMed

Noar, Seth M; Myrick, Jessica Gall; Morales-Pico, Brenda; Thomas, Nancy E

2014-05-01

Strong links between indoor tanning behavior and skin cancer have been demonstrated across several studies. Understanding the complex belief systems that underlie indoor tanning in young women is a crucial first step in developing interventions to deter this behavior. To develop and validate a comprehensive, multidimensional, theory-based outcome expectations measure to advance an understanding of the sets of beliefs that underlie indoor tanning behavior among young women. Cross-sectional study comprising a web-based survey of 11 sororities at a large university in the southeastern United States. Study participants (n = 706) were aged 18 to 25 years; 45.3% had tanned indoors in their lifetime and 30.3% in the past year. Intention to tan indoors, frequency of indoor tanning behavior in the past year, and indoor tanner type (nontanner, former tanner, or current tanner). A comprehensive scale assessing indoor tanning outcome expectations was developed. In total, 6 positive outcome expectations factors and 5 negative outcome expectations factors were identified. These subscales were reliable (coefficient α range, 0.86-0.95) and were significantly (mostly at P < .001) correlated with a set of established measures, including appearance motivation, indoor tanning attitudes and norms, and intention to tan indoors. Examination of subscales across the 3 indoor tanning groups also revealed significant (P < .001) differences on all 11 subscales. Current tanners had the most positive and least negative perceptions about indoor tanning, while nontanners had the most negative and least positive perceptions. Former tanners tended to fall in between these 2 groups. The 2 subscales with the largest differences across the groups were mood enhancement (positive outcome expectation) and psychological/physical discomfort (negative outcome expectation). Multiple linear regression analyses demonstrated several outcome expectations subscales to be significantly associated with

Crystalline boron nitride aerogels

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

Zettl, Alexander K.; Rousseas, Michael; Goldstein, Anna P.

This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxidemore » and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.« less

A preliminary deposit model for lithium-cesium-tantalum (LCT) pegmatites

USGS Publications Warehouse

Bradley, Dwight; McCauley, Andrew

2013-01-01

This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. We emphasize practical aspects of pegmatite geology that might directly or indirectly help in exploration for lithium-cesium-tantalum (LCT) pegmatites, or for assessing regions for pegmatite-related mineral resource potential. These deposits are an important link in the world’s supply chain of rare and strategic elements, accounting for about one-third of world lithium production, most of the tantalum, and all of the cesium.

Tanning addiction and psychopathology: Further evaluation of anxiety disorders and substance abuse

PubMed Central

Ashrafioun, Lisham; Bonar, Erin E.

2014-01-01

Background Little research has investigated the correlates of problematic tanning and tanning dependence. Objective To identify characteristics associated with problematic tanning and tanning dependence, and to evaluate simultaneously the associations of variables as correlates of problematic tanning and tanning dependence. Method To assess tanning-related characteristics, psychopathology, and demographics, we administered questionnaires to 533 tanning university students; 31% met criteria for tanning dependence, 12% for problematic tanning. Results Both problematic tanning and tanning dependence were significantly associated with being female (p < .001; p < .001, respectively) and with higher scores on screening measures of obsessive-compulsive (p < .001, p = .005, respectively) and body dysmorphic disorders (p = .019, p < .001, respectively). Frequency of tanning in the past month was the strongest correlate of problematic tanning (p < .001) and tanning dependence (p < .001) when included in a model that controlled for shared variance among demographics and psychopathology. Limitations The sample was recruited from one university and contained only self-report measures. Conclusion Results suggest that those who engage in excessive tanning may also have significant psychiatric distress. Additional research is needed to characterize compulsive, problematic tanning as well as its rates, correlates, and risk factors among diverse samples. PMID:24373775

Adolescent egocentrism and indoor tanning: is the relationship direct or mediated?

PubMed Central

Banerjee, Smita C.; Greene, Kathryn; Yanovitzky, Itzhak; Bagdasarov, Zhanna; Choi, Soe Yoon; Magsamen-Conrad, Kate

2016-01-01

This paper explored how imaginary audience and personal fable ideations contribute to adolescent indoor tanning intentions directly and indirectly through the way they shape pro-tanning attitude and association with peers who use tanning beds. Five hundred and ninety-five male (n = 207) and female (n = 387) adolescents, ranging in age from 11 to 19 (M = 16.87; SD = 1.34) years completed a cross-sectional survey. Measures included imaginary audience, personal fable (three dimensions: invulnerability, uniqueness, and omnipotence), pro-tanning attitude, association with peers who use tanning beds, and tanning bed use intentions. Bootstrapping analyses documented that imaginary audience ideations are indirectly associated with indoor tanning intentions through the mediation of pro-tanning attitude and association with peers who use tanning beds. Of the personal fable ideations, only invulnerability ideation is indirectly associated with indoor tanning intentions through the mediation of association with peers who use tanning beds. Design and evaluation of interventions and campaigns to reduce indoor tanning must be targeted to adolescents varying in imaginary audience ideations differently. PMID:28042281

Adolescent egocentrism and indoor tanning: is the relationship direct or mediated?

PubMed

Banerjee, Smita C; Greene, Kathryn; Yanovitzky, Itzhak; Bagdasarov, Zhanna; Choi, Soe Yoon; Magsamen-Conrad, Kate

2015-01-01

This paper explored how imaginary audience and personal fable ideations contribute to adolescent indoor tanning intentions directly and indirectly through the way they shape pro-tanning attitude and association with peers who use tanning beds. Five hundred and ninety-five male ( n = 207) and female ( n = 387) adolescents, ranging in age from 11 to 19 ( M = 16.87; SD = 1.34) years completed a cross-sectional survey. Measures included imaginary audience, personal fable (three dimensions: invulnerability, uniqueness, and omnipotence), pro-tanning attitude, association with peers who use tanning beds, and tanning bed use intentions. Bootstrapping analyses documented that imaginary audience ideations are indirectly associated with indoor tanning intentions through the mediation of pro-tanning attitude and association with peers who use tanning beds. Of the personal fable ideations, only invulnerability ideation is indirectly associated with indoor tanning intentions through the mediation of association with peers who use tanning beds. Design and evaluation of interventions and campaigns to reduce indoor tanning must be targeted to adolescents varying in imaginary audience ideations differently.

Tanning Products

MedlinePlus

... the FDA. Some tanning pills contain the color additive canthaxanthin. When large amounts of canthaxanthin are ingested, it can turn the skin a range of colors from orange to brown. It can also cause serious health problems including liver damage; hives; and an eye ...

Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.

PubMed

Coelho, Sergio G; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Hearing, Vincent J

2015-03-01

Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive. Published 2014. This article is a US Government work and is in the public domain in the USA.

A population-based survey on tanning bed use in Germany.

PubMed

Börner, Franziska U; Schütz, Holger; Wiedemann, Peter

2009-07-20

The suntanning industry has grown up over the last decade in Europe, mainly because tanned skin is considered socially desirable and attractive. Because of the potential negative impact of artificial tanning on public health, this study was to investigate tanning bed use behaviour, UV related risk perception and beliefs about tanning in the German population. In 2007, a representative telephone survey was carried out among 1501 German residents aged 14 years and older. More than one fourth (28%) of the German population have used tanning beds at least once before in their lifetime. High-frequency tanning behaviour, i.e. using tanning beds more than 10 times per year, were recorded for 11%. Men and women aged 18 to 44 years and young women under the age of 18 used tanning beds more frequently (>10 times per year). Tanning bed use was positively related to appearance and lifestyle related beliefs as well as to the perception that tanned skin is healthy. This analysis indicates that tanning bed use is common in Germany. The positive relationships of appearance and health related beliefs with tanning bed use are of great concern. The results indicate underlying misconceptions about the positive effect of artificial UV radiation compared to natural UV radiation particular for high-frequency tanners. The data shows the importance as well as the limitations for risk communication in its current effort to inform effectively about the dangers of artificial UV radiation.

Teens and Indoor Tanning: A Cancer Prevention Opportunity for Pediatricians

PubMed Central

Fisher, David E.; Geller, Alan C.

2013-01-01

In October 2011, California became the first US state to ban indoor tanning for minors under age 18 years. Vermont followed in May 2012. Increasingly, scientific evidence shows that artificial tanning raises the risk of skin cancer, including melanoma, a common cancer in adolescents and young adults and the type most likely to result in death. The World Health Organization, the American Academy of Pediatrics, the American Academy of Dermatology, the American Medical Association, and other organizations strongly recommend legislation to ban minors under age 18 from indoor tanning. Several nations have banned teen tanning. Yet, tanning in salons is still a prevalent practice in the United States, especially among teen girls, where rates for the oldest teens approach 40%. There is no federal legislation to restrict minors from salon tanning. More than 60% of states have some kind of legislation regarding minors’ use of tanning salons, but only California and Vermont have passed complete bans of indoor tanning for minors. The Indoor Tanning Association, an industry advocacy group, has vigorously opposed legislative efforts. Pediatricians can play key roles in counseling families and with legislative efforts. In this update, we review the prevalence of salon tanning, association with skin cancer risk, tanning addiction, the roles of the federal and state governments in regulation and legislation, and responses to arguments created by industry to oppose legislation. Preventing exposure to artificial tanning may save lives, including young lives, and is a key cancer prevention opportunity for pediatricians. PMID:23509165

Teens and indoor tanning: a cancer prevention opportunity for pediatricians.

PubMed

Balk, Sophie J; Fisher, David E; Geller, Alan C

2013-04-01

In October 2011, California became the first US state to ban indoor tanning for minors under age 18 years. Vermont followed in May 2012. Increasingly, scientific evidence shows that artificial tanning raises the risk of skin cancer, including melanoma, a common cancer in adolescents and young adults and the type most likely to result in death. The World Health Organization, the American Academy of Pediatrics, the American Academy of Dermatology, the American Medical Association, and other organizations strongly recommend legislation to ban minors under age 18 from indoor tanning. Several nations have banned teen tanning. Yet, tanning in salons is still a prevalent practice in the United States, especially among teen girls, where rates for the oldest teens approach 40%. There is no federal legislation to restrict minors from salon tanning. More than 60% of states have some kind of legislation regarding minors' use of tanning salons, but only California and Vermont have passed complete bans of indoor tanning for minors. The Indoor Tanning Association, an industry advocacy group, has vigorously opposed legislative efforts. Pediatricians can play key roles in counseling families and with legislative efforts. In this update, we review the prevalence of salon tanning, association with skin cancer risk, tanning addiction, the roles of the federal and state governments in regulation and legislation, and responses to arguments created by industry to oppose legislation. Preventing exposure to artificial tanning may save lives, including young lives, and is a key cancer prevention opportunity for pediatricians.

A population-based survey on tanning bed use in Germany

PubMed Central

Börner, Franziska U; Schütz, Holger; Wiedemann, Peter

2009-01-01

Background The suntanning industry has grown up over the last decade in Europe, mainly because tanned skin is considered socially desirable and attractive. Because of the potential negative impact of artificial tanning on public health, this study was to investigate tanning bed use behaviour, UV related risk perception and beliefs about tanning in the German population. Methods In 2007, a representative telephone survey was carried out among 1501 German residents aged 14 years and older. Results More than one fourth (28%) of the German population have used tanning beds at least once before in their lifetime. High-frequency tanning behaviour, i.e. using tanning beds more than 10 times per year, were recorded for 11%. Men and women aged 18 to 44 years and young women under the age of 18 used tanning beds more frequently (>10 times per year). Tanning bed use was positively related to appearance and lifestyle related beliefs as well as to the perception that tanned skin is healthy. Conclusion This analysis indicates that tanning bed use is common in Germany. The positive relationships of appearance and health related beliefs with tanning bed use are of great concern. The results indicate underlying misconceptions about the positive effect of artificial UV radiation compared to natural UV radiation particular for high-frequency tanners. The data shows the importance as well as the limitations for risk communication in its current effort to inform effectively about the dangers of artificial UV radiation. PMID:19619281

Tanning accelerators: prevalence, predictors of use, and adverse effects.

PubMed

Herrmann, Jennifer L; Cunningham, Rachel; Cantor, Alan; Elewski, Boni E; Elmets, Craig A

2015-01-01

Tanning accelerators are topical products used by indoor tanners to augment and hasten the tanning process. These products contain tyrosine, psoralens, and/or other chemicals. We sought to better define the population using accelerators, identify predictors of their use, and describe any related adverse effects. This cross-sectional study surveyed 200 indoor tanners about their tanning practices and accelerator use. Primary analysis compared accelerator users with nonusers with respect to questionnaire variables. Descriptive statistics and χ(2) contingency tables were applied to identify statistically significant variables. Of respondents, 53% used accelerators; 97% were female and 3% were male with a median age of 22 years (range: 19-67). Users were more likely to spray tan, tan frequently, and be addicted to tanning. Acne and rashes were more common in accelerator users. Adverse reactions to accelerators prevented their further use 31% of the time. A limited adult population was evaluated; exact accelerator ingredients were not examined. Tanning accelerator users are high-risk indoor tanners who tan more frequently and who are more likely addicted to tanning. Acne and rashes are more common with these products and act as only mild deterrents to continued use. Additional research should investigate accelerators' longer-term health effects. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Deformation of Cases in High Capacitance Value Wet Tantalum Capacitors under Environmental Stresses

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2016-01-01

Internal gas pressure in hermetic wet tantalum capacitors is created by air, electrolyte vapor, and gas generated by electrochemical reactions at the electrodes. This pressure increases substantially with temperature and time of operation due to excessive leakage currents. Deformation of the case occurs when the internal pressure exceeds pressure of the environments and can raise significantly when a part operates in space. Contrary to the cylinder case wet tantalum capacitors that have external sealing by welding and internal sealing provided by the Teflon bushing and crimping of the case, no reliable internal sealing exists in the button case capacitors. Single seal design capacitors are used for high capacitance value wet tantalum capacitors manufactured per DLA L&M drawings #04003, 04005, and 10011, and require additional analysis to assure their reliable application in space systems. In this work, leakage currents and case deformation of button case capacitors were measured during different environmental test conditions. Recommendations for derating, screening and qualification testing are given. This work is a continuation of a series of NEPP reports related to quality and reliability of wet tantalum capacitors.

Commercial Tanning Bed Use as a Medical Therapy.

PubMed

Acosta, K Alexandra; Hunter-Ellul, Lindsey; Wilkerson, Michael G

2015-06-01

An anonymous 9-question survey was composed and distributed to members of the Texas Dermatological Society to evaluate dermatologists' prescription of commercial tanning beds for treatment of certain dermatologic and other medical conditions and to seek opinions on whether commercial tanning beds are a legitimate medical therapy. Results show that although dermatologists agree recreational tanning should always be discouraged, some Texas dermatologists do occasionally recommend commercial tanning bed use for some conditions in patients who cannot afford traditional in-office phototherapy because they lack insurance or have high copays or for those patients who live in regions with limited access to in-office phototherapy or have significant barriers to coming into the clinic. Conditions for which patients are referred to commercial tanning beds include psoriasis, renal prurigo, atopic dermatitis, and mycosis fungoides.

A Preliminary Investigation of the Predictors of Tanning Dependence

PubMed Central

Heckman, Carolyn J.; Egleston, Brian L.; Wilson, Diane B.; Ingersoll, Karen S.

2014-01-01

Objectives To investigate possible predictors of tanning dependence including demographic variables, exposure and protective behaviors, and other health-related behaviors. Methods This study consisted of an online survey of 400 students and other volunteers from a university community. Results Twenty-seven percent of the sample was classified as tanning dependent. Tanning dependence was predicted by ethnicity and skin type, indoor and outdoor tanning and burning, and lower skin protective behaviors, as well as smoking and body mass index. Conclusions Young adults are at risk for tanning dependence, which can be predicted by specific demographic and behavioral variables. PMID:18241130

Powdered hide model for vegetable tanning

USDA-ARS?s Scientific Manuscript database

Powdered hide samples for this initial study of vegetable tanning were prepared from hides that were dehaired by a typical sulfide or oxidative process, and carried through the delime/bate step of a tanning process. In this study, we report on interactions of the vegetable tannin, quebracho with th...

Indoor Tanning Legislation: Shaping Policy and Nursing Practice.

PubMed

Driscoll, Donna W; Darcy, Jennifer

2015-01-01

Legislation exists regulating adolescents' use of tanning beds; however, the rate at which adolescents use these devices has not been reduced. The purpose of this study was to provide an analysis of indoor tanning bed legislation in the United States specifically related to legal issues and parental consent along with enforcement of current laws. The investigators collected data via review of state health department websites or telephone interviews of identified contacts for all 50 states. Findings reveal wide variation in legislation related to adolescents' access to tanning devices and enforcement of violation of legal statutes. Nurses and other health care professionals can play key roles in educating families and adolescents to the dangers from the use of tanning beds along with being role models for proper skin protective behaviors. In addition, nurses should become advocates by supporting legislative efforts that ban tanning salons for all minors, with the long-term goal of reducing skin cancer caused by ultraviolet radiation (UVR) exposure from the use of tanning salons today.

Crystalline boron nitride aerogels

DOEpatents

Zettl, Alexander K.; Rousseas, Michael; Goldstein, Anna P.; Mickelson, William; Worsley, Marcus A.; Woo, Leta

2017-04-04

This disclosure provides methods and materials related to boron nitride aerogels. In one aspect, a material comprises an aerogel comprising boron nitride. The boron nitride has an ordered crystalline structure. The ordered crystalline structure may include atomic layers of hexagonal boron nitride lying on top of one another, with atoms contained in a first layer being superimposed on atoms contained in a second layer.

Sociocultural experiences, body image, and indoor tanning among young adult women.

PubMed

Stapleton, Jerod L; Manne, Sharon L; Greene, Kathryn; Darabos, Katie; Carpenter, Amanda; Hudson, Shawna V; Coups, Elliot J

2017-10-01

The purpose of this survey study was to evaluate a model of body image influences on indoor tanning behavior. Participants were 823 young adult women recruited from a probability-based web panel in the United States. Consistent with our hypothesized model, tanning-related sociocultural experiences were indirectly associated with lifetime indoor tanning use and intentions to tan as mediated through tan surveillance and tan dissatisfaction. Findings suggest the need for targeting body image constructs as mechanisms of behavior change in indoor tanning behavioral interventions.

Superconducting characteristics in purified tantalum-foils

NASA Astrophysics Data System (ADS)

Hu, Qinghua; Wang, Zhihe

2018-07-01

We have conducted extensive investigations on the electrical transport and magnetization on a purified tantalum foil with extremely sharp resistive transition (transition width ΔTc < 0.02 K) at 0 T and residual resistivity ratio ρ290K/ρ5K= 16.75. Many effects, such as anisotropic field-induced resistive broadening and second peak of the magnetization-hysteresis loop, are observed in the sample. The maximum upper critical field determined by criteria of R/Rn = 0.9 is about 1.08 T rather weak compared to that in cuprate and/or iron-based superconductors. Although the value of upper critical field Hc2(0) and the field dependence of effective pinning energy U show that the flux pinning potential is weaker, the critical current density Jc(2 K, 0 T) = 1.145 × 105 A/cm2 and the effect of second peak indicate that there should be higher collective vortex pinning potential in the tantalum foil. The carriers are dominated by holes with the density n = 6.6 × 1022/cm3.

Catalytic Hydroamination of Alkynes and Norbornene with Neutral and Cationic Tantalum Imido Complexes

PubMed Central

Anderson, Laura L.; Arnold, John; Bergman, Robert G.

2005-01-01

Several tantalum imido complexes have been synthesized and shown to efficiently catalyze the hydroamination of internal and terminal alkynes. An unusual hydroamination/hydroarylation reaction of norbornene catalyzed by a highly electrophilic cationic tantalum imido complex is also reported. Factors affecting catalyst activity and selectivity are discussed along with mechanistic insights gained from stoichiometric reactions. PMID:15255680

Tanning bed use and melanoma: Establishing risk and improving prevention interventions.

PubMed

Le Clair, Marie Z; Cockburn, Myles G

2016-06-01

Exposure to ultraviolet radiation (UVR) from indoor tanning devices is thought to cause melanoma and other negative health consequences. Despite these findings, the practice of indoor tanning in the United States remains prevalent. In this paper we aim to present a clear discussion of the relationship between indoor tanning and melanoma risk, and to identify potential strategies for effective melanoma prevention by addressing indoor tanning device use. We reviewed relevant literature on the risks of indoor tanning, current indoor tanning legislation, and trends in indoor tanning and melanoma incidence. Study was conducted at the University of Southern California, Los Angeles, CA between the years of 2014 and 2015. Our findings reaffirm the relationship between indoor tanning and melanoma risk, and suggest a widespread public misunderstanding of the negative effects of indoor tanning. This review argues for an aggressive initiative to reduce indoor tanning in the United States, to design prevention efforts tailored towards specific high risk groups, and the need to better inform the public of the risks of indoor tanning.

Characterization of Tantalum Polymer Capacitors

NASA Technical Reports Server (NTRS)

Spence, Penelope

2012-01-01

Overview Reviewed data Caution must be taken when accelerating test conditions Data not useful to establish an acceleration model Introduction of new failure mechanism skewing results Evidence of Anti-Wear-Out De-doping of polymer Decreased capacitance Increased ESR Not dielectric breakdown Needs further investigation Further investigation into tantalum polymer capacitor technology Promising acceleration model for Manufacturer A Possibility for use in high-reliability space applications with suitable voltage derating.

Physically-based strength model of tantalum incorporating effects of temperature, strain rate and pressure

DOE PAGES

Lim, Hojun; Battaile, Corbett C.; Brown, Justin L.; ...

2016-06-14

In this work, we develop a tantalum strength model that incorporates e ects of temperature, strain rate and pressure. Dislocation kink-pair theory is used to incorporate temperature and strain rate e ects while the pressure dependent yield is obtained through the pressure dependent shear modulus. Material constants used in the model are parameterized from tantalum single crystal tests and polycrystalline ramp compression experiments. It is shown that the proposed strength model agrees well with the temperature and strain rate dependent yield obtained from polycrystalline tantalum experiments. Furthermore, the model accurately reproduces the pressure dependent yield stresses up to 250 GPa.more » The proposed strength model is then used to conduct simulations of a Taylor cylinder impact test and validated with experiments. This approach provides a physically-based multi-scale strength model that is able to predict the plastic deformation of polycrystalline tantalum through a wide range of temperature, strain and pressure regimes.« less

Vacuum pyrolysis characteristics and parameter optimization of recycling organic materials from waste tantalum capacitors.

PubMed

Chen, Zhenyang; Niu, Bo; Zhang, Lingen; Xu, Zhenming

2018-01-15

Recycling rare metal tantalum from waste tantalum capacitors (WTCs) is significant to alleviate the shortage of tantalum resource. However, environmental problems will be caused if the organic materials from WTCs are improperly disposed. This study presented a promising vacuum pyrolysis technology to recycle the organic materials from WTCs. The organics removal rate could reach 94.32wt% according to TG results. The optimal parameters were determined as 425°C, 50Pa and 30min on the basis of response surface methodology (RSM). The oil yield and residual rate was 18.09wt% and 74.94wt%, respectively. All pyrolysis products can be recycled through a reasonable route. Besides, to deeply understand the pyrolysis process, the pyrolysis mechanism was also proposed based on the product and free radical theory. This paper provides an efficient process for recycling the organic material from WTCs, which can facilitate the following tantalum recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

7 CFR 29.3066 - Tan color.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Tan color. A light red-yellow. [24 FR 8771, Oct. 29, 1959. Redesignated at 47 FR 51722, Nov. 17, 1982... 7 Agriculture 2 2014-01-01 2014-01-01 false Tan color. 29.3066 Section 29.3066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...

7 CFR 29.3066 - Tan color.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Tan color. A light red-yellow. [24 FR 8771, Oct. 29, 1959. Redesignated at 47 FR 51722, Nov. 17, 1982... 7 Agriculture 2 2012-01-01 2012-01-01 false Tan color. 29.3066 Section 29.3066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...

7 CFR 29.3066 - Tan color.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Tan color. A light red-yellow. [24 FR 8771, Oct. 29, 1959. Redesignated at 47 FR 51722, Nov. 17, 1982... 7 Agriculture 2 2013-01-01 2013-01-01 false Tan color. 29.3066 Section 29.3066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...

7 CFR 29.3066 - Tan color.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Tan color. 29.3066 Section 29.3066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Tan color. A light red-yellow. [24 FR 8771, Oct. 29, 1959. Redesignated at 47 FR 51722, Nov. 17, 1982...

7 CFR 29.3066 - Tan color.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Tan color. 29.3066 Section 29.3066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Tan color. A light red-yellow. [24 FR 8771, Oct. 29, 1959. Redesignated at 47 FR 51722, Nov. 17, 1982...

Corrosion resistance of porous binary tantalum and titanium carbides of various composition

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

Artyunina, N.P.; Komratov, G.N.; Bolonova, E.A.

1993-12-20

Resistance of porous binary tantalum and titanium carbides in solutions of mineral acids and their mixtures, of several organic acids, and of ammonium and potassium hydroxide was studied. It has been shown that as the content of tantalum in a material increases its resistance in solutions of oxidizing acids is improved, but it is reduced in solutions of sulfuric and hydrofluoric acids and also in solutions of potassium hydroxide.

Tanning facility use: are we exceeding Food and Drug Administration limits?

PubMed

Hornung, Robin L; Magee, Kristin H; Lee, Willie J; Hansen, Lori A; Hsieh, Yi-Ching

2003-10-01

The US Food and Drug Administration (FDA) recommends exposure limits for tanning bed use. Tanning patrons may not be following these recommendations and may be overexposed to damaging ultraviolet radiation (UV). This study was conducted to assess tanning patrons' adherence to FDA-recommended exposure limits and to measure the amount of UVA and UVB radiation emitted by tanning beds. A community-based survey was administered during routine state inspections of North Carolina tanning facilities (n = 50). At each facility, patron records were randomly selected (n = 483) for a survey of exposure records, and UVA and UVB outputs were measured for each tanning bed. The recommended limits were exceeded by 95% of patrons, and 33% of patrons began tanning at the maximum doses recommended for maintenance tanning. Average tanning bed output was 192.1 W/m(2) UVA and 0.35 W/m(2) erythemally weighted UVB. Interventions for tanning bed operators and patrons are needed to increase compliance with federally recommended exposure limits.

Tanning bed burns reported on Twitter: over 15,000 in 2013.

PubMed

Seidenberg, Andrew B; Pagoto, Sherry L; Vickey, Theodore A; Linos, Eleni; Wehner, Mackenzie R; Costa, Renata Dalla; Geller, Alan C

2016-06-01

Few surveillance tools exist for monitoring tanning bed injuries. Twitter data were examined to identify and describe reports of tanning bed-caused burns. Tweets sent in 2013 containing keywords for tanning bed use and burning were content analyzed to determine whether a burn caused by a tanning bed was described, and additional data on tanning behavior and burn characteristics were extracted. After content assessment, 15,178 (64 %) tweets were found to describe a tanning bed-caused burn. Sites most reportedly burnt were buttocks (n = 3117), face/head (n = 1020), and chest/breast (n = 546). Alarmingly, 200 burns to the eyes/eyelids were mentioned. A total of 456 tweets described burning >1 time from a tanning bed. A total of 211 tweets mentioned falling asleep inside the tanning bed. In 2013, over 15,000 tweets reported tanning bed-caused burns. Twitter data provides unique insight into tanning behaviors and injuries not captured through traditional public health surveillance.

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.

Sunless Tanning: A Safe Alternative to Sunbathing

MedlinePlus

... in most sunless tanning products is the color additive, dihydroxyacetone (DHA). When applied, dihydroxyacetone reacts with dead ... Sunless tanning pills, which typically contain the color additive canthaxanthin, aren't safe. When taken in large ...

[Short-term curative effects of Tantalum rod treatment in early avascular necrosis].

PubMed

Ye, Fu-Sheng; Ni, Zhe-Ji; Chu, Xiao-Bing; He, Bang-Jian; Li, Ju; Tong, Pei-Jian

2013-08-01

To explore the recent clinical curative effect of Tantalum rod in treating the early avascular necrosis. From January 2008 to November 2008, the 25 patients (39 hips) with early avascular necrosis accepted tantalum rod placement and included 9 males (11 hips) and 16 females (28 hips) with an average age of 37 years old ranging from 18 to 74 years old. Four patients (6 hips) caused by Alcoholic, 6 patients (8 hips) by hormone, 2 cases (2 hips) by traumatic, 13 cases (23 hips) by idiopathic. Steinberg preoperative stage involved 7 hips in period I, 24 hips in period II, 8 hips in period III. Curative effect analysis included preoperative and postoperative Harris score, radiographic changes and hip replacement for follow-up to accept the end of the femoral head survival rate. All patients were followed up for 6 to 47 months (averaged 37.4 months). All 12 hips imaging appeard progress,including tantalum rod exit in 1 hip, hip hemiarthroplasty collapse in 3 hips, the area increased to avascular necrosis in 8 hips. Six hips accepted total hip replacement, including imaging progress in 5 hips (41.7%, 5/12), no imaging progress in 1 hip (3.7%,1/27). All hips' Kaplan-Meier survival curves showed 6-month survival rate was (97.4 +/- 2.5)% after tantalum stick insertion, 1-year survival rate was (94.7 +/- 3.6), and 2-year survival rate was (88.6 +/- 5.4)%, 3-year survival rate was (72.5 +/- 11.2). It is effective for treatment of avascular necrosis of femoral head in Steinberg I and II by Tantalum rod, and it can effectively relieve femoral head replacement time.

Addition of oxygen to and distribution of oxides in tantalum alloy T-111 at low concentrations

NASA Technical Reports Server (NTRS)

Stecura, S.

1975-01-01

Oxygen was added at 820 and 990 C at an oxygen pressure of about .0003 torr. The technique permitted predetermined and reproducible oxygen doping of the tantalum alloy (T-111). Based on the temperature dependency of the doping reaction, it was concluded that the initial rates of oxygen pickup are probably controlled by solution of oxygen into the T-111 lattice. Although hafnium oxides are more stable than those of tantalum or tungsten, analyses of extracted residues indicate that the tantalum and tungsten oxides predominate in the as-doped specimens, presumably because of the higher concentrations of tantalum and tungsten in the alloy. However, high-temperature annealing promotes gettering of dissolved oxygen and oxygen from other oxides to form hafnium oxides. Small amounts of tantalum and tungsten oxides were still present after high temperature annealing. Tungsten oxide (WO3) volatilizes slightly from the surface of T-111 at 990 C but not at 820 C. The vaporization of WO3 has no apparent effect on the doping reaction.

The effects of argon ion bombardment on the corrosion resistance of tantalum

NASA Astrophysics Data System (ADS)

Ramezani, A. H.; Sari, A. H.; Shokouhy, A.

2017-02-01

Application of ion beam has been widely used as a surface modification method to improve surface properties. This paper investigates the effect of argon ion implantation on surface structure as well as resistance against tantalum corrosion. In this experiment, argon ions with energy of 30 keV and in doses of 1 × 1017-10 × 1017 ions/cm2 were used. The surface bombardment with inert gases mainly produces modified topography and morphology of the surface. Atomic Force Microscopy was also used to patterned the roughness variations prior to and after the implantation phase. Additionally, the corrosion investigation apparatus wear was applied to compare resistance against tantalum corrosion both before and after ion implantation. The results show that argon ion implantation has a substantial impact on increasing resistance against tantalum corrosion. After the corrosion test, scanning electron microscopy (SEM) analyzed the samples' surface morphologies. In addition, the elemental composition is characterized by energy-dispersive X-ray (EDX) analysis. The purpose of this paper was to obtain the perfect condition for the formation of tantalum corrosion resistance. In order to evaluate the effect of the ion implantation on the corrosion behavior, potentiodynamic tests were performed. The results show that the corrosion resistance of the samples strongly depends on the implantation doses.

Implications of lessons learned from tobacco control for tanning bed reform.

PubMed

Sinclair, Craig; Makin, Jennifer K

2013-01-01

Tanning beds used according to the manufacturer's instructions expose the user to health risks, including melanoma and other skin cancers. Applying the MPOWER model (monitor, protect, offer alternatives, warn, enforce, and raise taxes), which has been used in tobacco control, to tanning bed reform could reduce the number of people at risk of diseases associated with tanning bed use. Among the tactics available to government are restricting the use of tanning beds by people under age 18 and those with fair skin, increasing the price of tanning bed services through taxation, licensing tanning bed operators, and banning unsupervised tanning bed operations.

An exploration in mineral supply chain mapping using tantalum as an example

USGS Publications Warehouse

Soto-Viruet, Yadira; Menzie, W. David; Papp, John F.; Yager, Thomas R.

2013-01-01

This report uses the supply chain of tantalum (Ta) to investigate the complexity of mineral and metal supply chains in general and show how they can be mapped. A supply chain is made up of all the manufacturers, suppliers, information networks, and so forth, that provide the materials and parts that go into making up a final product. The mineral portion of the supply chain begins with mineral material in the ground (the ore deposit); extends through a series of processes that include mining, beneficiation, processing (smelting and refining), semimanufacture, and manufacture; and continues through transformation of the mineral ore into concentrates, refined mineral commodities, intermediate forms (such as metals and alloys), component parts, and, finally, complex products. This study analyses the supply chain of tantalum beginning with minerals in the ground to many of the final goods that contain tantalum.

STUDIES ON ANALYTICAL METHODS FOR TRACE ELEMENTS IN METALS BY USING RADIOACTIVE ISOTOPE. III. DETERMINATION OF TANTALUM BY MEANS OF ISOTOPE DILUTION METHOD

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

Amano, H.

1959-10-01

The determination of tantalum by the isotope dilution method in the presence of niobium was investigated by the use of the radioisotope Ta/sup 185/. Tantalum was separated from niobium as tantalum-tannin precipitate under the optimum conditions of a pH of 1.9 to 2.5 and a tantalum/niobium ratio of up to 1/ 50. If niobium was present in amounts 100 times or more that of tantalum, reprecipitation was needed. The reciprocal of the specific activity of tanthlum pentoxide precipitate was in a linear relation to the change in the amount of tantalum added. The recommended method gave an accurate result inmore » the determination of tantalum in steal. (auth)« less

Intentional tanning behaviors among undergraduates on the United States' Gulf Coast.

PubMed

Daniel, Casey L; Gassman, Natalie R; Fernandez, Alyssa M; Bae, Sejong; Tan, Marcus C B

2018-04-03

Rates of melanoma have dramatically increased among adolescents and young adults in recent years, particularly among young women. Exposure to ultraviolet radiation from intentional tanning practices is likely a major contributor to this epidemic. Southern and coastal regions have higher melanoma mortality rates among non-Hispanic whites in other parts of the U.S., yet little is known about tanning practices of adolescents and young adults in these regions. This study determines the prevalence and methods of intentional tanning utilized by an undergraduate population located on the United States' Gulf Coast. Undergraduate students enrolled at a university on the Gulf Coast completed an online survey from March-April 2016, self-reporting their engagement, knowledge, and attitudes regarding outdoor tanning (OT), indoor tanning (IT) and spray tanning (ST). Univariate and multivariate analyses were performed to identify factors associated with tanning behaviors. 2668 undergraduates completed the survey. Of these, 64.9% reported OT tanning, 50.7% reported ever IT, and 21.2% reported ever ST. In the largest study to date of intentional tanning behaviors of adolescents and young adults from coastal regions, we found high rates of intentional tanning behaviors. There was also significant engagement in spray tanning by this population, not previously reported for adolescents and young adults in a sample of this size. We also identified a high association between different tanning methods, indicating this population engages in multiple tanning behaviors, a phenomenon whose health consequences are not yet known.

Thermocouples of tantalum and rhenium alloys for more stable vacuum-high temperature performance

NASA Technical Reports Server (NTRS)

Morris, J. F. (Inventor)

1977-01-01

Thermocouples of the present invention provide stability and performance reliability in systems involving high temperatures and vacuums by employing a bimetallic thermocouple sensor wherein each metal of the sensor is selected from a group of metals comprising tantalum and rhenium and alloys containing only those two metals. The tantalum, rhenium thermocouple sensor alloys provide bare metal thermocouple sensors having advantageous vapor pressure compatibilities and performance characteristics. The compatibility and physical characteristics of the thermocouple sensor alloys of the present invention result in improved emf, temperature properties and thermocouple hot junction performance. The thermocouples formed of the tantalum, rhenium alloys exhibit reliability and performance stability in systems involving high temperatures and vacuums and are adaptable to space propulsion and power systems and nuclear environments.

Nitride stabilized core/shell nanoparticles

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

Kuttiyiel, Kurian Abraham; Sasaki, Kotaro; Adzic, Radoslav R.

Nitride stabilized metal nanoparticles and methods for their manufacture are disclosed. In one embodiment the metal nanoparticles have a continuous and nonporous noble metal shell with a nitride-stabilized non-noble metal core. The nitride-stabilized core provides a stabilizing effect under high oxidizing conditions suppressing the noble metal dissolution during potential cycling. The nitride stabilized nanoparticles may be fabricated by a process in which a core is coated with a shell layer that encapsulates the entire core. Introduction of nitrogen into the core by annealing produces metal nitride(s) that are less susceptible to dissolution during potential cycling under high oxidizing conditions.

Tantalum capacitor behavior under fast transient overvoltages. [circuit protection against lightning

NASA Technical Reports Server (NTRS)

Zill, J. A.; Castle, K. D.

1974-01-01

Tantalum capacitors were tested to determine failure time when subjected to short-duration, high-voltage surges caused by lightning strikes. Lightning is of concern to NASA because of possible damage to critical spacecraft circuits. The test was designed to determine the minimum time for tantalum capacitor failure and the amount of overvoltage a capacitor could survive, without permanent damage, in 100 microseconds. All tested exhibited good recovery from the transient one-shot pulses with no failure at any voltage, forward or reverse, in less than 25 microseconds.

SU-E-J-201: Position Verification in Breast Cancer Radiotherapy Using Tantalum Clips in the Lumpectomy Cavity

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

Santvoort, J van; Van der Drift, M; Kuipers, J

2014-06-01

Purpose: To find out whether tantalum surgical clips can be used for online position verification in treatment of the lumpectomy cavity (LC) in breast cancer patients. Tantalum is a high density metal that could be visible on Electronic Portal Images (EPIs) and be an affordable alternative to gold markers. Clips are considered more representative for the LC position than nearby bony structures. Methods: In twelve patients the surgeon had placed 2 to 5 tantalum clips in the LC. The AP and lateral fields used for portal imaging, were adapted. In doing so, both bony structures and tantalum clips were visiblemore » on EPIs. The following analyses were performed:1. Image degradation, with respect to delineating the CTV, of the axial CT slices by artefacts because of the tantalum clips was evaluated by a radiation oncologist;2. The visibility of the tantalum clips on the EPIs was evaluated by four radiation therapists (RTTs);3. Bony anatomy and tantalum clip matches were performed on the same images independently by two observers. Results: 1. Delineation of the CTV by the radiation oncologist was not hampered by CT image artefacts because of the clips.2. The mean score for visibility of the clips on the EPIs, analysed by the four RTTs, was 5.6 on a scale of 10 (range 3.9 – 8.0).3. In total 12 patients with 16 fractions each were analysed. The differences between clip match and bone match are significant with a mean vector length of 5.2 mm (SD 1.9 mm) for the difference. Conclusion: Results of matches on tantalum clips as compared to matches on bony structures differ substantially. Therefore clip matches can result in smaller CTV to PTV margins than bone matches. Visibility of the clips on EPIs is sufficient, so they can be an alternative to gold markers.« less

Decrease in artificial tanning by French teenagers: 2011-2016.

PubMed

Say, Matthieu; Beauchet, Alain; Vouldoukis, Ioannis; Beauchet, Pascale; Boudet, Monique; Tella, Emilie; Mahé, Emmanuel

2018-03-13

The major risk factor for skin cancers is exposure to solar and artificial ultraviolet radiation, in particular during childhood and adolescence. In France, a law was restricted for tanning-bed access to adults (≥18 years) since 1997. To evaluate teenagers' artificial tanning behaviour in 2016 and to compare results with those obtained in a similar survey performed in 2011. The SOLADO 2011 and 2016 surveys were conducted in a general school in Antony and a technical school in Fontenay-aux-Roses (Paris suburb). In 2016, 630 teenagers (mean age: 14.2 ± 1.9 y: Males/Females: 301/329) completed the questionnaire, 1.3% of teenagers reported using tanning beds, 1.1% tanning pills and 8.9% tanning creams. Between 2011 and 2016, the use of tanning beds decreased from 1.4% to 0.7% in Antony (P = .26) and from 9.5% to 4.8% in Fontenay-aux-Roses (P = .01), and the use of tanning creams from 39.8% to 17.6% in Fontenay-aux-Rose (P = .0007). The incidence of sunburn decreased from 60.5% to 54.0% in Antony (P = .02) and from 55.4% to 42.4% in Fontenay-aux-Roses (P = .05). As compared to 2011, teenagers used artificial tanning methods less frequently in 2016. In particular, they used tanning beds less frequently, suggesting that the new stricter legislation has been effective. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Indoor tanning and risk of early-onset basal cell carcinoma

PubMed Central

Ferrucci, Leah M.; Cartmel, Brenda; Molinaro, Annette M.; Leffell, David J.; Bale, Allen E.; Mayne, Susan T.

2011-01-01

Background Despite a rise in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship. Objective Evaluate the association between indoor tanning and early-onset BCC. Methods BCC cases (n=376) and controls with minor benign skin conditions (n=390) under age 40 were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group. Results Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI=1.15-2.48). This association was stronger among women (OR=2.14, 95% CI=1.31-3.47), for multiple BCCs (OR=2.16, 95% CI=1.26-3.70), and for BCCs on the trunk and extremities (OR=2.81, 95% CI=1.57-5.02). Risk increased dose-dependently with years used regular indoor tanning devices (p-trend=0.003), number of overall burns (p-trend=<0.001) and burns to biopsy site (p-trend=<0.001) from indoor tanning. Approximately one-quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors. Limitations Potential recall bias of indoor tanning by cases and generalizability of the control population suggest replication in other studies is warranted. Conclusions Indoor tanning was a strong risk factor for early-onset BCC, particularly among women. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial. PMID:22153793

Implications of Lessons Learned From Tobacco Control for Tanning Bed Reform

PubMed Central

Sinclair, Craig

2013-01-01

Tanning beds used according to the manufacturer’s instructions expose the user to health risks, including melanoma and other skin cancers. Applying the MPOWER model (monitor, protect, offer alternatives, warn, enforce, and raise taxes), which has been used in tobacco control, to tanning bed reform could reduce the number of people at risk of diseases associated with tanning bed use. Among the tactics available to government are restricting the use of tanning beds by people under age 18 and those with fair skin, increasing the price of tanning bed services through taxation, licensing tanning bed operators, and banning unsupervised tanning bed operations. PMID:23449282

Does the Portrayal of Tanning in Australian Women's Magazines Relate to Real Women's Tanning Beliefs and Behavior?

ERIC Educational Resources Information Center

Dixon, Helen G.; Warne, Charles D.; Scully, Maree L.; Wakefield, Melanie A.; Dobbinson, Suzanne J.

2011-01-01

Content analysis data on the tans of 4,422 female Caucasian models sampled from spring and summer magazine issues were combined with readership data to generate indices of potential exposure to social modeling of tanning via popular women's magazines over a 15-year period (1987 to 2002). Associations between these indices and cross-sectional…

The application of porous tantalum cylinder to the repair of comminuted bone defects: a study of rabbit firearm injuries

PubMed Central

Ren, Bo; Zhai, Zhenbo; Guo, Kai; Liu, Yanpu; Hou, Weihuan; Zhu, Qingsheng; Zhu, Jinyu

2015-01-01

The aim of this study is to investigate the effect of porous tantalum material in repair tibial defects caused by firearm injuries in a rabbit model. A multifunctional biological impact machine was used to establish a rabbit tibial defect model of firearm injury. Porous tantalum rods were processed into a hollow cylinder. Kirschner wires were used for intramedullary fixation. We compared the differences of the bone ingrowth of the porous tantalum material by gross observations, X-rays and histological evaluations. The radiographic observations revealed that fibrous tissue covered the material surface after 4 weeks, and periosteal reactions and new bone callus extending materials appeared after 8 weeks. After 16 weeks, the calluses of the firearm injury group were completely wrapped around a porous tantalum material. The group with the highest Lane-Sandhu X-rays cores was the firearm injury and tantalum implant group, and the blank control group exhibited the lowest scores. The histological evaluations revealed that the presence of new bone around the biomaterial had grown into the porous tantalum. By the 16th week, the areas of bone tissue of the firearm injury group was significant higher than that of non-firearm injury group (P<0.05). The comminuted fractures treated with tantalum cylinders exhibited greater bone ingrowth in the firearm injury group. In conditions of firearm injuries, the porous tantalum biomaterial exhibited bone ingrowth that was beneficial to the treatment of bone defects. PMID:26131078

Tanning and Teens: Is Indoor Exposure the Tip of the Iceberg?

PubMed

Hay, Jennifer L; Riley, Kristen E; Geller, Alan C

2017-08-01

Because of recent state regulations and the reduced availability of free-standing tanning salons, indoor tanning (IT) prevalence is beginning to decline. This may lead to unintended consequences, such as increases in outdoor intentional tanning. We advance a series of research directions to track and intervene to address all forms of intentional tanning. First, we advocate for enforcement of IT regulation and encourage collection of data on tanning salon compliance and alternative IT strategies. Second, we suggest questions about outdoor and IT should be included in national surveys. Third, we need to understand the potentially complex patterns of indoor and outdoor tanning that may exist among those who tan. Fourth, research examining changing motivations for intentional tanning is needed. Finally, IT intervention studies should include outdoor tanning as an outcome to examine the effect of interventions on these related risk behaviors. These advances will ensure the development of novel interventions to address intentional tanning through multiple routes, and to avoid any unintended negative consequence of IT regulation. The promising downward direction of IT use in the United States should now lead the public health field to sharpen its focus on outdoor tanning. Cancer Epidemiol Biomarkers Prev; 26(8); 1170-4. ©2017 AACR . ©2017 American Association for Cancer Research.

PECVD silicon-rich nitride and low stress nitride films mechanical characterization using membrane point load deflection

NASA Astrophysics Data System (ADS)

Bagolini, Alvise; Picciotto, Antonino; Crivellari, Michele; Conci, Paolo; Bellutti, Pierluigi

2016-02-01

An analysis of the mechanical properties of plasma enhanced chemical vapor (PECVD) silicon nitrides is presented, using micro fabricated silicon nitride membranes under point load deflection. The membranes are made of PECVD silicon-rich nitride and low stress nitride films. The mechanical performance of the bended membranes is examined both with analytical models and finite element simulation in order to extract the elastic modulus and residual stress values. The elastic modulus of low stress silicon nitride is calculated using stress free analytical models, while for silicon-rich silicon nitride and annealed low stress silicon nitride it is estimated with a pre-stressed model of point-load deflection. The effect of annealing both in nitrogen and hydrogen atmosphere is evaluated in terms of residual stress, refractive index and thickness variation. It is demonstrated that a hydrogen rich annealing atmosphere induces very little change in low stress silicon nitride. Nitrogen annealing effects are measured and shown to be much higher in silicon-rich nitride than in low stress silicon nitride. An estimate of PECVD silicon-rich nitride elastic modulus is obtained in the range between 240-320 GPa for deposited samples and 390 GPa for samples annealed in nitrogen atmosphere. PECVD low stress silicon nitride elastic modulus is estimated to be 88 GPa as deposited and 320 GPa after nitrogen annealing.

Risks of Tanning

MedlinePlus

... it Email Print Sunburn Sun Tan Premature Aging/Photoaging Skin Cancer Actinic or Solar Keratoses Eye Damage ... Aging What it is: Sometimes referred to as “photoaging,” premature aging is the result of unprotected UV ...

Study on leaching of pollutants from vegetable tanning residue.

PubMed

Mazumder, Debabrata; Biswas, Santosh; Bandyopadhyay, Pratip

2006-07-01

The processing of heavy leather employs the vegetable tanning method involving use of tan liquor. The solid residue of this vegetable tanning process aggravates the water pollution by means of leaching of tannin and other associatedpollutants. Tannin is a biologically resistant compound causing several problems in animal body. The present study dealt with the pollution hazard arising out of leaching of pollutants from the open dumped vegetable tanning residue by rainfall washing. The concerned pollutants were pH, Chemical Oxygen Demand (COD), tannin,sulfate and chloride concentration. To explore the possible extent of contamination of these pollutants in the leached water, two different masses (2 kg and 3 kg) of tanning residue were employed. The results of the study showed that there was a continuous release of pollutants from the vegetable tanning residue. Moreover, there was no regular variation in various pollutant concentrations in both the cases solely due to non-homogeneity of the residue.

The window of opportunity for indoor tanning legislation.

PubMed

Mayer, Jonathan E

2014-12-01

As of August 2014, 11 states in the USA have passed under-age-18 bans on indoor tanning. The Society of Behavioral Medicine, the American Academy of Dermatology, and the American Academy of Pediatrics have all issued statements in support of an under-age-18 ban. The World Health Organization and the Food and Drug Administration have both declared indoor tanning devices as carcinogenic, and this year, the Surgeon General for the first time issued a warning on the dangers of UV radiation and indoor tanning. This essay highlights how the awareness of the risks of indoor tanning, effective policies, and a conducive political atmosphere have aligned to create a window of opportunity for further under-age-18 indoor tanning legislation. The rising number of preventable skin cancers and mortalities is an issue that transcends political party lines, and now, there is a need for support from health professionals and advocates to motivate legislators to push new under-age-18 bills past their sticking points.

Tanning beds: Impact on health, and recent regulations.

PubMed

Madigan, Lauren M; Lim, Henry W

2016-01-01

As the use of indoor tanning beds gained popularity in the decades after their appearance in the market in the early 1970s, concerns arose regarding their use. Clinical research has revealed an association between indoor tanning and several health risks, including the subsequent occurrence of melanoma and nonmelanoma skin cancers, the development of psychologic dependence, and a tendency toward other high-risk health behaviors. In the face of mounting evidence, legislation has been passed, which includes the restriction of access to tanning beds by minors in 42 states and the District of Columbia, and the recent reclassification by the Food and Drug Administration, which now categorizes tanning beds as class II devices and worthy of restrictions and oversight. Early evidence suggests that these labors are resulting in cultural change, although continued efforts are necessary to limit further exposure and better inform the public of the dangers associated with indoor tanning use. Copyright © 2016 Elsevier Inc. All rights reserved.

Transition of dislocation glide to shear transformation in shocked tantalum

DOE PAGES

Hsiung, Luke L.; Campbell, Geoffrey H.

2017-02-28

A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa (strain rate: ~1 x 10 4 sec -1) is presented. While no ω (hexagonal) phase was found in shock-recovered pure Ta and Ta-5W that contain mainly a low-energy cellular dislocation structure, shock-induced ω phase was found to form in Ta-10W that contains evenly distributed dislocations with a stored dislocation density higher than 1 x 10 12 cm -2. The TEM results clearly reveal that shock-induced α (bcc) → ω (hexagonal) shear transformation occurs when dynamic recovery reactions which lead the formation low-energymore » cellular dislocation structure become largely suppressed in Ta-10W shocked under dynamic (i.e., high strain-rate and high-pressure) conditions. A novel dislocation-based mechanism is proposed to rationalize the transition of dislocation glide to twinning and/or shear transformation in shock-deformed tantalum. Lastly, twinning and/or shear transformation take place as an alternative deformation mechanism to accommodate high-strain-rate straining when the shear stress required for dislocation multiplication exceeds the threshold shear stresses for twinning and/or shear transformation.« less

Valorization of titanium metal wastes as tanning agent used in leather industry

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

Crudu, Marian, E-mail: mariancrudu@yahoo.com; Deselnicu, Viorica, E-mail: viorica.deselnicu@icpi.ro; Deselnicu, Dana Corina, E-mail: d_deselnicu@yahoo.com

2014-10-15

Highlights: • Valorization of titanium wastes which cannot be recycled in metallurgical industry. • Transferring Ti waste into raw materials for obtaining Ti based tanning agent. • Characterization of new Ti based tanning agents and leather tanned with them. • Characterization of sewage waste water and sludge resulted from leather manufacture. • Analysis of the impact of main metal component of Ti waste. - Abstract: The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromiummore » salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77 °C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome

Prevalence and Correlates of Indoor Tanning among U.S. Adults

PubMed Central

Heckman, Carolyn J.; Coups, Elliot J.; Manne, Sharon L.

2008-01-01

Background Little is known about the prevalence of indoor tanning among the U.S. general adult population. Objectives This study sought to (1) describe the prevalence of indoor tanning throughout adulthood, (2) identify demographic and psychosocial correlates of indoor tanning, and (3) determine whether these correlates vary by age group. Methods This study used data from the 2005 National Health Interview Survey, an annual health survey of the U.S. adult population. Results Indoor tanning rates were higher among individuals who were young, white, and female. Rates of indoor tanning in the last year varied from 20.4% for 18−29 year-olds to 7.8% for those 65 years and older. A variety of demographic, health, and behavioral health risk factors correlated with indoor tanning. Limitations The study design was cross-sectional and all data were self-reported. Conclusions Health care providers should address indoor tanning as a health risk factor across the lifespan. PMID:18328594

Practices of Unregulated Tanning Facilities in Missouri: Implications for Statewide Legislation

PubMed Central

Biesbroeck, Lauren K.; Lickerman, Stephanie H.; Cornelius, Lynn A.; Jeffe, Donna B.

2013-01-01

BACKGROUND: The incidence of skin cancer has increased in the United States, concomitant with increased UV radiation (UVR) exposure among young adults. We examined whether tanning facilities in Missouri, a state without indoor-tanning regulations, acted in accordance with the Food and Drug Administration’s recommendations and consistently imparted information to potential clients about the known risks of UVR. METHODS: We conducted a statewide telephone survey of randomly selected tanning facilities in Missouri. Each tanning facility was surveyed twice, in the morning (7 am–3 pm) and evening (3–10 pm), on different days, to determine intrasalon consistency of information provided to potential clients at different times. RESULTS: On average, 65% of 243 tanning-facility operators would allow children as young as 10 or 12 years old to use indoor-tanning devices, 80% claimed that indoor tanning would prevent future sunburns, and 43% claimed that there were no risks associated with indoor tanning. Intrasalon inconsistencies involved allowable age of use, and UVR exposure type and duration. Morning tanning-facility employees were more likely to allow consumers to start with maximum exposure times and UV-A–emitting devices (P < .001), whereas evening employees were more likely to allow 10- or 12-year-old children to use indoor-tanning devices (P = .008). CONCLUSIONS: Despite increasing evidence that UVR exposure in indoor-tanning devices is associated with skin cancer, ocular damage, and premature photoaging, tanning facilities in Missouri often misinformed consumers regarding these risks and lack of health benefits and inconsistently provided information about the Food and Drug Administration’s guidelines for tanning devices. PMID:23439910

High-acoustic-impedance tantalum oxide layers for insulating acoustic reflectors.

PubMed

Capilla, Jose; Olivares, Jimena; Clement, Marta; Sangrador, Jesús; Iborra, Enrique; Devos, Arnaud

2012-03-01

This work describes the assessment of the acoustic properties of sputtered tantalum oxide films intended for use as high-impedance films of acoustic reflectors for solidly mounted resonators operating in the gigahertz frequency range. The films are grown by sputtering a metallic tantalum target under different oxygen and argon gas mixtures, total pressures, pulsed dc powers, and substrate biases. The structural properties of the films are assessed through infrared absorption spectroscopy and X-ray diffraction measurements. Their acoustic impedance is assessed by deriving the mass density from X-ray reflectometry measurements and the acoustic velocity from picosecond acoustic spectroscopy and the analysis of the frequency response of the test resonators.

Compliance with youth access regulations for indoor UV tanning.

PubMed

Hester, Eric J; Heilig, Lauren F; D'Ambrosia, Renee; Drake, Amanda L; Schilling, Lisa M; Dellavalle, Robert P

2005-08-01

To describe youth access to indoor UV tanning and youth discount pricing incentives in 4 states with different age restrictions: Colorado (no age restrictions), Texas (age 13 years), Illinois (age 14 years), and Wisconsin (age 16 years). Cross-sectional telephone survey conducted in October 2003 using a standardized script to assess the practices of randomly selected UV tanning operators. Randomly selected licensed indoor UV tanning facility operators in Colorado, Texas, Illinois, and Wisconsin. Number of facilities (1) complying with indoor UV tanning minimum age regulations for a 12-year-old potential patron and a 15-year-old potential patron and (2) offering youth discounts. For a 12-year-old potential patron, 62% of facilities in states with minimum age restrictions prohibiting 12-year-olds had an operator report that they would not permit indoor tanning (Texas, 23%; Illinois, 74%; and Wisconsin, 89%) compared with 18% in Colorado, a state without youth access regulations. For a 15-year-old patron, most facilities in Wisconsin, the only state with a minimum age restriction for 15-year-olds, prohibited access (77%). Overall, 15% of operators offered youth discounts: Texas, 23%; Illinois, 14%; Wisconsin, 11%; and Colorado, 11%. Tanning facilities in 4 states offered price incentives directed at youths. State youth access regulations were associated with decreased youth access to indoor tanning. High compliance levels in states with long-standing youth access regulations (Illinois and Wisconsin) demonstrate the potential for successful tanning industry youth access regulation.

Effect of Reverse Bias Stress on Leakage Currents and Breakdown Voltages of Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2011-01-01

The majority of solid tantalum capacitors are produced by high-temperature sintering of a fine tantalum powder around a tantalum wire followed by electrolytic anodization that forms a thin amorphous Ta2O5 dielectric layer and pyrolysis of manganese nitrite on the oxide to create a conductive manganese dioxide electrode. A contact to tantalum wire is used as anode terminal and to the manganese layer as a cathode terminal of the device. This process results in formation of an asymmetric Ta -- Ta2O5 -- MnO2 capacitor that has different characteristics at forward (positive bias applied to tantalum) and reverse (positive bias applied to manganese cathode) voltages. Reverse bias currents might be several orders of magnitude larger than forward leakage currents so I-V characteristics of tantalum capacitors resemble characteristics of semiconductor rectifiers. Asymmetric I-V characteristics of Ta -- anodic Ta2O5 systems have been observed at different top electrode materials including metals, electrolytes, conductive polymers, and manganese oxide thus indicating that this phenomenon is likely related to the specifics of the Ta -- Ta2O5 interface. There have been multiple attempts to explain rectifying characteristics of capacitors employing anodic tantalum pentoxide dielectrics. A brief review of works related to reverse bias (RB) behavior of tantalum capacitors shows that the mechanism of conduction in Ta -- Ta2O5 systems is still not clear and more testing and analysis is necessary to understand the processes involved. If tantalum capacitors behave just as rectifiers, then the assessment of the safe reverse bias operating conditions would be a relatively simple task. Unfortunately, these parts can degrade with time under reverse bias significantly, and this further complicates analysis of the I-V characteristics and establishing safe operating areas of the parts. On other hand, time dependence of reverse currents might provide additional information for investigation of

Method for preparing actinide nitrides

DOEpatents

Bryan, G.H.; Cleveland, J.M.; Heiple, C.R.

1975-12-01

Actinide nitrides, and particularly plutonium and uranium nitrides, are prepared by reacting an ammonia solution of an actinide compound with an ammonia solution of a reactant or reductant metal, to form finely divided actinide nitride precipitate which may then be appropriately separated from the solution. The actinide nitride precipitate is particularly suitable for forming nuclear fuels.

Valorization of titanium metal wastes as tanning agent used in leather industry.

PubMed

Crudu, Marian; Deselnicu, Viorica; Deselnicu, Dana Corina; Albu, Luminita

2014-10-01

The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77°C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clustering of transmutation elements tantalum, rhenium and osmium in tungsten in a fusion environment

NASA Astrophysics Data System (ADS)

You, Yu-Wei; Kong, Xiang-Shan; Wu, Xuebang; Liu, C. S.; Fang, Q. F.; Chen, J. L.; Luo, G.-N.

2017-08-01

The formation of transmutation solute-rich precipitates has been reported to seriously degrade the mechanical properties of tungsten in a fusion environment. However, the underlying mechanisms controlling the formation of the precipitates are still unknown. In this study, first-principles calculations are therefore performed to systemically determine the stable structures and binding energies of solute clusters in tungsten consisting of tantalum, rhenium and osmium atoms as well as irradiation-induced vacancies. These clusters are known to act as precursors for the formation of precipitates. We find that osmium can easily segregate to form clusters even in defect-free tungsten alloys, whereas extremely high tantalum and rhenium concentrations are required for the formation of clusters. Vacancies greatly facilitate the clustering of rhenium and osmium, while tantalum is an exception. The binding energies of vacancy-osmium clusters are found to be much higher than those of vacancy-tantalum and vacancy-rhenium clusters. Osmium is observed to strongly promote the formation of vacancy-rhenium clusters, while tantalum can suppress the formation of vacancy-rhenium and vacancy-osmium clusters. The local strain and electronic structure are analyzed to reveal the underlying mechanisms governing the cluster formation. Employing the law of mass action, we predict the evolution of the relative concentration of vacancy-rhenium clusters. This work presents a microscopic picture describing the nucleation and growth of solute clusters in tungsten alloys in a fusion reactor environment, and thereby explains recent experimental phenomena.

1. VIEW LOOKING SOUTHWEST AT TURNOUT ON SAN TAN FLOODWATER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW LOOKING SOUTHWEST AT TURNOUT ON SAN TAN FLOOD-WATER CANAL TO SAN TAN INDIAN CANAL - San Carlos Irrigation Project, San Tan Flood Water Canal, North Side of Gila River, Coolidge, Pinal County, AZ

Process for the production of metal nitride sintered bodies and resultant silicon nitride and aluminum nitride sintered bodies

NASA Technical Reports Server (NTRS)

Yajima, S.; Omori, M.; Hayashi, J.; Kayano, H.; Hamano, M.

1983-01-01

A process for the manufacture of metal nitride sintered bodies, in particular, a process in which a mixture of metal nitrite powders is shaped and heated together with a binding agent is described. Of the metal nitrides Si3N4 and AIN were used especially frequently because of their excellent properties at high temperatures. The goal is to produce a process for metal nitride sintered bodies with high strength, high corrosion resistance, thermal shock resistance, thermal shock resistance, and avoidance of previously known faults.

Mineral resource of the month: tantalum

USGS Publications Warehouse

Cunningham, Larry D.

2004-01-01

Tantalum is a metal that is critical to the United States because of its defense-related applications in aircraft, missiles and radio communications. It is ductile, easily fabricated, highly resistant to corrosion by acids, a good conductor of heat and electricity, and has a high melting point. Tantalum’s first commercial usage was as filament material in incandescent electric lamps in the early 1900s.

Tantalum coating of porous carbon scaffold supplemented with autologous bone marrow stromal stem cells for bone regeneration in vitro and in vivo.

PubMed

Wei, Xiaowei; Zhao, Dewei; Wang, Benjie; Wang, Wei; Kang, Kai; Xie, Hui; Liu, Baoyi; Zhang, Xiuzhi; Zhang, Jinsong; Yang, Zhenming

2016-03-01

Porous tantalum metal with low elastic modulus is similar to cancellous bone. Reticulated vitreous carbon (RVC) can provide three-dimensional pore structure and serves as the ideal scaffold of tantalum coating. In this study, the biocompatibility of domestic porous tantalum was first successfully tested with bone marrow stromal stem cells (BMSCs) in vitro and for bone tissue repair in vivo. We evaluated cytotoxicity of RVC scaffold and tantalum coating using BMSCs. The morphology, adhesion, and proliferation of BMSCs were observed via laser scanning confocal microscope and scanning electron microscopy. In addition, porous tantalum rods with or without autologous BMSCs were implanted on hind legs in dogs, respectively. The osteogenic potential was observed by hard tissue slice examination. At three weeks and six weeks following implantation, new osteoblasts and new bone were observed at the tantalum-host bone interface and pores. At 12 weeks postporous tantalum with autologous BMSCs implantation, regenerated trabecular equivalent to mature bone was found in the pore of tantalum rods. Our results suggested that domestic porous tantalum had excellent biocompatibility and could promote new bone formation in vivo. Meanwhile, the osteogenesis of porous tantalum associated with autologous BMSCs was more excellent than only tantalum implantation. Future clinical studies are warranted to verify the clinical efficacy of combined implantation of this domestic porous tantalum associated with autologous BMSCs implantation and compare their efficacy with conventional autologous bone grafting carrying blood vessel in patients needing bone repairing. © 2016 by the Society for Experimental Biology and Medicine.

Youth indoor tanning and skin cancer prevention: lessons from tobacco control.

PubMed

Seidenberg, Andrew B; Mahalingam-Dhingra, Aditya; Weinstock, Martin A; Sinclair, Craig; Geller, Alan C

2015-02-01

Youth use of ultraviolet-emitting indoor tanning beds represents a present and emerging public health crisis. Nearly 30% of white female high school students report tanning indoors, and a quarter of high school tanners have used a tanning bed more than 20 times in the past year. Despite the significant health risks of tanning beds, including potentially deadly melanoma and eye problems, limited actions have been taken in the U.S. to protect youth. Tobacco control policies and campaigns, which have sharply reduced youth smoking, may provide a useful framework to control indoor tanning among young people. This article describes several evidence-based tobacco control strategies with potential applicability to indoor tanning within the context of the U.S. Further, current tobacco control policies and current indoor tanning policies in the U.S. are compared, and recommendations on how to curtail youth indoor tanning are discussed. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

North American Magazine Coverage of Skin Cancer and Recreational Tanning Before and After the WHO/IARC 2009 Classification of Indoor Tanning Devices as Carcinogenic.

PubMed

McWhirter, Jennifer E; Hoffman-Goetz, Laurie

2015-09-01

The mass media is an influential source of skin cancer information for the public. In 2009, the World Health Organization's International Agency for Research on Cancer classified UV radiation from tanning devices as carcinogenic. Our objective was to determine if media coverage of skin cancer and recreational tanning increased in volume or changed in nature after this classification. We conducted a directed content analysis on 29 North American popular magazines (2007-2012) to investigate the overall volume of articles on skin cancer and recreational tanning and, more specifically, the presence of skin cancer risk factors, UV behaviors, and early detection information in article text (n = 410) and images (n = 714). The volume of coverage on skin cancer and recreational tanning did not increase significantly after the 2009 classification of tanning beds as carcinogenic. Key-related messages, including that UV exposure is a risk factor for skin cancer and that indoor tanning should be avoided, were not reported more frequently after the classification, but the promotion of the tanned look as attractive was conveyed more often in images afterwards (p < .01). Content promoting high-SPF sunscreen use increased after the classification (p < .01), but there were no significant positive changes in the frequency of coverage of skin cancer risk factors, other UV behaviors, or early detection information over time. The classification of indoor tanning beds as carcinogenic had no significant impact on the volume or nature of skin cancer and recreational tanning coverage in magazines.

FDA's regulation of tanning beds: how much heat?

PubMed

Knapp, Veronica

2011-01-01

This paper considers the problem of indoor tanning bed use by teenagers. The paper explores FDA's current authority to regulate tanning lamps as Class I medical devices, concluding that FDA's authority is poorly tailored to affect teenagers' repeated use of these products. An outright ban is unlikely; therefore, the best available options are to regulate access by minors and to amend the warning label requirements to reflect the current state of knowledge about the risks of tanning bed use.

Indoor tanning knowledge, attitudes, and behavior among young adults from 1988-2007.

PubMed

Robinson, June K; Kim, Julie; Rosenbaum, Sara; Ortiz, Sara

2008-04-01

To compare knowledge, attitudes, and behavior about indoor tanning and sources of information among young adults in the summer of 1988, 1994, and 2007. Convenience survey of 100 Chicago, Illinois, beachgoers aged 18 to 30 years who were age- and sex-matched with Chicago-area residents who participated in random-digit-dialed telephone interviews in 1988 and 1994. Lakefront beach on weekday afternoons in July 2007. Knowledge of melanoma/skin cancer link with tanning, and limiting tanning to help prevent melanoma/skin cancer; attitude about the appearance of tanned people; and knowledge of relevant information sources; and UV indoor tanning use in the past year. Knowledge of the melanoma/skin cancer link with tanning changed from 1988 (42%) to 1994 (38%) to 2007 (87%). Knowledge of limiting tanning to help prevent melanoma increased from 1988 (25%) to 1994 (77%), but decreased from 1994 to 2007 (67%). This decline in knowledge about limiting tanning was concurrent with an increase in the attitude that having a tan looks better (1994, 69%; 2007, 81%). Use of indoor tanning beds increased from 1988 (1%) to 1994 (26%) and remained at the same level in 2007 (27%). Although physicians, especially dermatologists, were sources of information about tanning (1988, 2%; 1994, 18%; 2007, 31%) and were considered the most trusted source, only 14% of respondents in 1994 and 2007 reported ever talking to a doctor about indoor tanning. Conclusion Because young adults report that physicians are their most trusted source of information about tanning, a potential opportunity exists for physicians to influence indoor tanning behavior by counseling their patients.

Preventing skin cancer through reduction of indoor tanning: current evidence.

PubMed

Watson, Meg; Holman, Dawn M; Fox, Kathleen A; Guy, Gery P; Seidenberg, Andrew B; Sampson, Blake P; Sinclair, Craig; Lazovich, DeAnn

2013-06-01

Exposure to ultraviolet radiation from indoor tanning devices (tanning beds, booths, and sun lamps) or from the sun contributes to the risk of skin cancer, including melanoma, which is the type of skin cancer responsible for most deaths. Indoor tanning is common among certain groups, especially among older adolescents and young adults, adolescent girls and young women, and non-Hispanic whites. Increased understanding of the health risks associated with indoor tanning has led to many efforts to reduce use. Most environmental and systems efforts in the U.S. (e.g., age limits or requiring parental consent/accompaniment) have occurred at the state level. At the national level, the U.S. Food and Drug Administration and the Federal Trade Commission regulate indoor tanning devices and advertising, respectively. The current paper provides a brief review of (1) the evidence on indoor tanning as a risk factor for skin cancer; (2) factors that may influence use of indoor tanning devices at the population level; and (3) various environmental and systems options available for consideration when developing strategies to reduce indoor tanning. This information provides the context and background for the companion paper in this issue of the American Journal of Preventive Medicine, which summarizes highlights from an informal expert meeting convened by the CDC in August 2012 to identify opportunities to prevent skin cancer by reducing use of indoor tanning devices. Published by Elsevier Inc.

Risky sun tanning behaviours amongst Irish University students: a quantitative analysis.

PubMed

Flannery, C; Burke, L-A; Grainger, L; Williams, P; Gage, H

2016-11-01

Despite Ireland's temperate maritime climate, it has the third highest rate of malignant melanoma in the European Union, indicating the need to recognise tanning practices as a risky behaviour, especially amongst those most at risk (the younger population). To explore the factors associated with deliberate sun tanning amongst university students in Cork, Ireland. Self-reported sun exposure, attitudes to tanning and sun protection practices were investigated using an online questionnaire in April 2010. There were 833 responses (8.33 %), mean age 22 years, 75 % female. Reporting deliberate tanning in the previous summer (n = 389, 46.7 %) was positively correlated (r = 0.622, p < 0.001) with stating an intention to tan next summer (n = 532, 63.9 %). Women and respondents with darker (vs. fairer) complexion were more likely to engage in deliberate tanning (p < 0.001). Deliberate tanning was associated with reporting enjoying tanning (p < 0.001), with reporting peer pressure into tanning (p = 0.039), and (marginally) with thinking it is worth getting burnt to get a tan (p = 0.068). Younger students were significantly more likely to report these attitudes; being a current smoker was associated with reporting peer pressure and that burning is worth a tan, indicating a level of risk-taking. Respondents reported (average) three sources of information on sun risks. Tanning is a form of strongly motivated risk-taking as much in a sun-limited country like Ireland as in hotter sun-rich climates. Risk communication strategies on sun exposure should be developed that target young people and improve their risk awareness.

Tantalum coating of porous carbon scaffold supplemented with autologous bone marrow stromal stem cells for bone regeneration in vitro and in vivo

PubMed Central

Wei, Xiaowei; Wang, Benjie; Wang, Wei; Kang, Kai; Xie, Hui; Liu, Baoyi; Zhang, Xiuzhi; Zhang, Jinsong; Yang, Zhenming

2016-01-01

Porous tantalum metal with low elastic modulus is similar to cancellous bone. Reticulated vitreous carbon (RVC) can provide three-dimensional pore structure and serves as the ideal scaffold of tantalum coating. In this study, the biocompatibility of domestic porous tantalum was first successfully tested with bone marrow stromal stem cells (BMSCs) in vitro and for bone tissue repair in vivo. We evaluated cytotoxicity of RVC scaffold and tantalum coating using BMSCs. The morphology, adhesion, and proliferation of BMSCs were observed via laser scanning confocal microscope and scanning electron microscopy. In addition, porous tantalum rods with or without autologous BMSCs were implanted on hind legs in dogs, respectively. The osteogenic potential was observed by hard tissue slice examination. At three weeks and six weeks following implantation, new osteoblasts and new bone were observed at the tantalum–host bone interface and pores. At 12 weeks postporous tantalum with autologous BMSCs implantation, regenerated trabecular equivalent to mature bone was found in the pore of tantalum rods. Our results suggested that domestic porous tantalum had excellent biocompatibility and could promote new bone formation in vivo. Meanwhile, the osteogenesis of porous tantalum associated with autologous BMSCs was more excellent than only tantalum implantation. Future clinical studies are warranted to verify the clinical efficacy of combined implantation of this domestic porous tantalum associated with autologous BMSCs implantation and compare their efficacy with conventional autologous bone grafting carrying blood vessel in patients needing bone repairing. PMID:26843518

Personal UV biodosimeter for healthy indoor tanning

NASA Astrophysics Data System (ADS)

Terenetskaya, I. P.; Orlova, T. N.

2008-04-01

The practice of indoor tanning has led to the development of a large artificial tanning industry. In addition to psychological benefits, exposure to UVB light helps the body produce the activated form of vitamin D, which is necessary for many cellular functions. But uncontrolled tanning and UV overexposure can increase the risk of skin cancer. For direct checkout of the vitamin D synthetic capacity of a UV source the bio-equivalent UV dosimeter has been developed that is based on the same molecular photochemistry from which vitamin D is photosynthesized in human skin and makes possible both instrumental and visual indication of vitamin D synthesis.

Florence Tan Maniac Lecture, April 13, 2016

NASA Image and Video Library

2016-04-13

Florence Tan Maniac Lecture, April 13, 2016 NASA Engineer Florence Tan presented a Maniac Lecture entitled, "From Malaysia to Mars." Florence talked about her journey from Malaysia to NASA Goddard Space Flight Center, where she has been working on planetary mass spectrometers, which is characterized by challenges, frustration, excitement, and rewards.

Antimicrobial activity of tantalum oxide coatings decorated with Ag nanoparticles

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

Cao, Huiliang, E-mail: hlc@mail.sic.ac.cn; Meng, Fanhao; Liu, Xuanyong, E-mail: xyliu@mail.sic.ac.cn

Silver plasma immersion ion implantation was used to decorate silver nanoparticles (Ag NPs) on tantalum oxide (TO) coatings. The coatings acted against bacterial cells (Staphylococcus epidermidis) in the dark by disrupting their integrity. The action was independent of silver release and likely driven by the electron storage capability of the Schottky barriers established at the interfaces between Ag NPs and the TO support. Moreover, no apparent side effect on the adhesion and differentiation of rat bone mesenchymal stem cells was detected when using Ag NPs-modified TO coatings. These results demonstrate that decoration of tantalum oxide using Ag NPs could bemore » a promising procedure for improving the antibacterial properties for orthopedic and dental implants.« less

An Intervention to Decrease Adolescent Indoor Tanning: A Multi-Method Pilot Study

PubMed Central

Lazovich, DeAnn; Choi, Kelvin; Rolnick, Cheri; Jackson, Jody M.; Forster, Jean; Southwell, Brian

2013-01-01

Purpose Indoor tanning usually begins during adolescence, but few strategies exist to discourage adolescent use. We developed and tested a parent–teenager intervention to decrease indoor tanning use. Methods Through focus groups, we identified key messages to enhance parent–teenager communication about indoor tanning, and then developed a pamphlet for parents and postcards for adolescents to use in a direct mail experiment with randomly selected households. Two weeks after the mailing, we asked intervention parents (n = 87) and adolescents (n = 69) and nonintervention parents (n = 31) and adolescents (n = 28) about intervention receipt and content recall, parental concern, monitoring, parent–teenager conversations, and indoor tanning intention. Results In intervention households, 54% of mothers and 56% of girls recalled receipt and reported reading materials, but few boys and no fathers did. Among mothers, 57% in intervention households indicated concern about daughters’ indoor tanning, and 25% would allow daughters to tan indoors, whereas 43% of nonintervention mothers had concerns and 46% would allow indoor tanning. Fewer girls in intervention households than in nonintervention households thought parents would allow indoor tanning (44% vs. 65%), and fewer intended to tan indoors (36% vs. 60%). Most mothers and daughters who read the intervention materials also reported discussions about indoor tanning. Moreover, the less likely girls were to think that their mothers would allow indoor tanning, the less likely it was that they intended to tan indoors, a relationship mediated by perceptions of maternal monitoring. Conclusions A systematic qualitative and quantitative research approach yielded well-received indoor tanning prevention messages for mothers and female adolescents. Enhancing maternal monitoring has potential to decrease adolescent indoor tanning. PMID:23601614

The effect of sunless tanning on behavior in the sun: a pilot study.

PubMed

Sheehan, Daniel J; Lesher, Jack L

2005-12-01

In the United States, indoor tanning is a booming industry and contributes to the ultraviolet light (UVL) burden that ultimately leads to skin cancer. "Sunless" tanning methods that avoid UVL exposure may represent a safe alternative. However, the effects of sunless tanning methods on ultraviolet light-related behaviors have never been investigated. Anonymous survey of 121 individuals who underwent a spray-on sunless tanning treatment between February and May 2004. Women completed 107 surveys. Men completed 14 surveys. The majority of individuals reported that they had not or would not change their time spent outdoors or their sunscreen use as a result of undergoing sunless tanning. However, 73% of individuals who had used UVL tanning beds said they had decreased or would decrease their UVL tanning bed use. Sunless tanning is associated with a self-reported decrease in traditional UVL tanning bed use among tanning bed users. Physicians should advocate the use of sunless tanning to their patients who use traditional UVL tanning beds as a means of decreasing their UVL exposure and cancer risk.

The Development and Validation of the Mood-based Indoor Tanning Scale.

PubMed

Carcioppolo, Nick; Chen, Yixin; John, Kevin K; Gonzalez, Andrea Martinez; King, Andy J; Morgan, Susan E; Hu, Shasa

2017-01-01

Research indicates that mood-based motivations may be an important predictor of indoor tanning bed use and may be related to indoor tanning dependence. Problematically, little research has been conducted to develop a psychometric measure of mood-based tanning motivations. The current study seeks to develop and validate the moodbased indoor tanning scale (MITS). Two studies were conducted to identify and verify the MITS factor structure as well as assess construct validity. Study 1 was conducted at 5 geographically diverse universities in the United States. Study 2 was conducted by using a national online sample in the United States. Results from study 1 specified the factor structure of the MITS. Results from study 2 suggest that a one-point increase in the MITS measure corresponds with using indoor tanning beds 11 more times in the past year. These findings demonstrate that moodbased tanning motivations are a strong predictor of indoor tanning intentions and behavior. Further, they suggest that health behavior researchers and healthcare practitioners can use the MITS to assess the extent to which mood-based motivations impact indoor tanning bed use.

Application of pyrolysis to recycling organics from waste tantalum capacitors.

PubMed

Niu, Bo; Chen, Zhenyang; Xu, Zhenming

2017-08-05

Tantalum capacitors (TCs) are widely used in electronic appliances. The rapid replacement of electronic products results in generating large amounts of waste TCs (WTCs). WTCs, rich in valuable tantalum, are considered as high quality tantalum resources for recycling. However, environmental pollution will be caused if the organics of WTCs were not properly disposed. Therefore, effectively recycling the organics of WTCs is significant for recovering the valuable parts. This study proposed an argon (Ar) pyrolysis process to recycle the organics from WTCs. The organic decomposition kinetic was first analyzed by thermogravimetry. The results showed that the organics were decomposed in two major steps and the average activation energy was calculated to 234kJ/mol. Then, the suitable pyrolysis parameters were determined as 550°C, 30min and 100ml/min. The organics were effectively decomposed and converted to oils (mainly contained phenol homologs and benzene homologs) and gases (some hydrocarbon). These pyrolysis products could be reutilized as energy sources. Moreover, based on the products and bond energy theory, the pyrolysis mechanisms of the organics were also discussed. Finally, a reasonable technological process for products utilization was presented. This study contributes to the efficient recycling the organics before valuable material recovery from WTCs. Copyright © 2017 Elsevier B.V. All rights reserved.

Tanning beds: A call to action for further educational and legislative efforts.

PubMed

Farley, Clara; Alimi, Yewande; Espinosa, Lauren R; Perez, Sebastian; Knechtle, William; Hestley, Andrea; Carlson, Grant W; Russell, Maria C; Delman, Keith A; Rizzo, Monica

2015-08-01

Melanoma is steadily increasing over the past decade. Recent studies confirmed a link between tanning bed use and melanoma. We sought to determine the prevalence and frequency of tanning bed among young patients with melanoma. We retrospectively analyzed tanning bed use among young melanoma patients compared to controls selected from the hospital medical records. A telephone survey investigated family history of melanoma or skin cancer, hair color, eye color, skin type, tanning bed use, and patient awareness of dangers of tanning bed use. A total of 601 melanoma cases were identified; 265 (44%) completed the telephone survey as did 195 (31%) controls. Of these 460 subjects, 260 were female. Females were 3.0 times more likely to have used a tanning bed. Melanoma patients had natural light color hair, blue-green eyes, and 2.0 times more likely to use a tanning bed than controls. Among the tanning bed users, 90% were aware of danger of tanning bed. Our study found that tanning beds were more likely to be used by young women, the majority of whom are aware of the associated risks. Eliminating the use of tanning beds should be considered to decrease the incidence of melanoma. © 2015 Wiley Periodicals, Inc.

Decreases in tanning behaviors following a short online survey: Potential for prevention?

PubMed

Rodgers, Rachel F; Franko, Debra L; Gottlieb, Mark; Daynard, Richard

2015-01-01

To date, tanning prevention programs have led to limited success. The aim of the present study was to investigate potential unexpected prevention effects of completing an online survey focused on tanning attitudes, behaviors, and knowledge among female college tanners. A sample of 92 female undergraduate students from the USA, mean age = 20.09, SD = 1.41 years, who engaged in indoor tanning completed an online survey assessing awareness of tanning-related health risks, appearance-based motivations to tan and not to tan, media literacy related to tanning marketing, and tanning behaviors in 2013. Four months later, participants were invited to complete a follow-up survey assessing tanning intentions and behaviors since completing the initial survey. Fifty-one participants (55%) completed the follow-up questions, of whom 43 (84.3%) reported having decreased or ceased engaging in indoor tanning. In addition participants provided comments indicating that completing the survey had lead to decreases in their tanning behaviors. Our study presents novel and compelling support for using brief online surveys for decreasing health-risk behaviors such as sunbed use. Such measures are extremely cost-effective and easy to disseminate and implement. Replication and extension of these findings are warranted.

An initial study of behavioral addiction symptom severity and demand for indoor tanning.

PubMed

Becirevic, Amel; Reed, Derek D; Amlung, Michael; Murphy, James G; Stapleton, Jerod L; Hillhouse, Joel J

2017-10-01

Indoor tanning remains a popular activity in Western cultures despite a growing body of literature suggesting its link to skin cancer and melanoma. Advances in indoor tanning research have illuminated problematic patterns of its use. With problems such as difficulty quitting, devoting resources toward its use at the expense of healthy activities, and excessive motivation and urges to tan, symptoms of excessive indoor tanning appear consistent with behavioral addiction. The present study bridges the gap between clinical approaches to understanding indoor tanning problems and behavioral economic considerations of unhealthy habits and addiction. Eighty undergraduate females completed both the Behavioral Addiction Indoor Tanning Screener and the Tanning Purchase Task. Results suggest that behavioral economic demand for tanning significantly differs between risk classification groups, providing divergent validity to the Behavioral Addiction Indoor Tanning Screener and offering additional evidence of the sensitivity of the Tanning Purchase Task to differentiating groups according to tanning profiles. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Achieving surface chemical and morphologic alterations on tantalum by plasma electrolytic oxidation.

PubMed

Goularte, Marcelo Augusto Pinto Cardoso; Barbosa, Gustavo Frainer; da Cruz, Nilson Cristino; Hirakata, Luciana Mayumi

2016-12-01

Search for materials that may either replace titanium dental implants or constitute an alternative as a new dental implant material has been widely studied. As well, the search for optimum biocompatible metal surfaces remains crucial. So, the aim of this work is to develop an oxidized surface layer on tantalum using plasma electrolytic oxidation (PEO) similar to those existing on oral implants been marketed today. Cleaned tantalum samples were divided into group 1 (control) and groups 2, 3, and 4 (treated by PEO for 1, 3, and 5 min, respectively). An electrolytic solution diluted in 1-L deionized water was used for the anodizing process. Then, samples were washed with anhydrous ethyl alcohol and dried in the open air. For complete anodic treatment disposal, the samples were immersed in acetone altogether, taken to the ultrasonic tank for 10 min, washed again in distilled water, and finally air-dried. For the scanning electron microscopy (SEM) analysis, all samples were previously coated with gold; the salt deposition analysis was conducted with an energy-dispersive X-ray spectroscopy (EDS) system integrated with the SEM unit. SEM images confirmed the changes on tantalum strips surface according to different exposure times while EDS analysis confirmed increased salt deposition as exposure time to the anodizing process also increased. PEO was able to produce both surface alteration and salt deposition on tantalum strips similar to those existing on oral implants been marketed today.

Indoor tanning facility density in eighty U.S. cities.

PubMed

Palmer, Richard C; Mayer, Joni A; Woodruff, Susan I; Eckhardt, Laura; Sallis, James F

2002-06-01

The purpose of this study was to examine the number of tanning facilities in select U.S. cities. The twenty most populated cities from each of 4 U.S. regions were selected for the sample. For each city, data on the number of tanning facilities, climate, and general demographic profile were collected. Data for state tanning facility legislation also were collected. A tanning facility density variable was created by dividing the city's number of facilities by its population size. The 80 cities had an average of 50 facilities each. Results of linear regression analysis indicated that higher density was significantly associated with colder climate, lower median income, and higher proportion of Whites. These data indicate that indoor tanning facilities are prevalent in the environments of U.S. urban-dwellers. Cities having the higher density profile may be logical targets for interventions promoting less or safer use of these facilities.

X-ray analyses of thermally grown and reactively sputtered tantalum oxide films on NiTi alloy

NASA Astrophysics Data System (ADS)

McNamara, Karrina; Tofail, Syed A. M.; Conroy, Derek; Butler, James; Gandhi, Abbasi A.; Redington, Wynette

2012-08-01

Sputter deposition of tantalum (Ta) on the surface of NiTi alloy is expected to improve the alloy's corrosion resistance and biocompatibility. Tantalum is a well-known biomaterial which is not affected by body fluids and is not irritating to human tissue. Here we compare the oxidation chemistry crystal structure evolution of tantalum oxide films grown on NiTi by reactive O2 sputtering and by thermal oxidation of sputter deposited Ta films. The effect of sputtering parameters and post-sputtering treatments on the morphology, oxidation state and crystal structure of the tantalum oxide layer have been investigated by field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The study has found that it may be better to avoid oxidation at and above 600 °C. The study establishes that reactive sputtering in presence of low oxygen mixture yields thicker film with better control of the film quality except that the surface oxidation state of Ta is slightly lower.

Synthesis and characterization of polystyrene embolization particles doped with tantalum oxide nanoparticles for X-ray contrast.

PubMed

Morrison, Rachel; Thompson, James; Bird, Luke; Hill, Mark A; Townley, Helen

2015-08-01

Radiopaque and fluorescent embolic particles have been synthesized and characterised to match the size of vasculature found in tumours to ensure effective occlusion of the vessels. A literature search showed that the majority of vessels surrounding a tumour were less than 50 µm and therefore polydispersed polystyrene particles with a peak size of 50 µm have been synthesised. The embolic particles contain 5-8 nm amorphous tantalum oxide nanoparticles which provide X-ray contrast. Embolic particles containing up to 9.4 wt% tantalum oxide were prepared and showed significant contrast compared to the undoped polystyrene particles. The X-ray contrast of the embolic particles was shown to be linear (R(2) = 0.9) with respect to the concentration of incorporated tantalum nanoparticles. A model was developed which showed that seventy-five 50 µm embolic particles containing 10% tantalum oxide could provide the same contrast as 5 cm of bone. Therefore, the synthesized particles would provide sufficient X-ray contrast to enable visualisation within a tumour.

Tanning bed exposure increases the risk of malignant melanoma.

PubMed

Ting, William; Schultz, Kara; Cac, Natalie N; Peterson, Michael; Walling, Hobart W

2007-12-01

Epidemiologic studies have associated tanning bed exposure and cutaneous melanoma. The relationship between the extent of tanning bed exposure and the risk of melanoma has not been elucidated in detail. Surveys assessing the extent of tanning bed exposure and the history of skin cancer, including malignant melanoma, were collected from academic dermatology clinic patients (n = 1518). Of these, 551 (36.3%) completed all components of the survey. The available medical records, including pathology reports (n = 501; 33%), were reviewed to confirm cases of skin cancer. Data on potential confounding factors, including indoor vs. outdoor occupation and leisure activities, Fitzpatrick skin type, history of blistering sunburn, use of sunscreen and sun protective clothing, history of phototherapy, and level of education, were assessed and compared. Of the patients surveyed, 487 (32.1%) reported tanning bed exposure. Women aged 45 years or younger accounted for about 60% of all tanning bed users. Seventy-nine cases of malignant melanoma were reported, 22 in women aged 45 years or younger. In the entire cohort, the "ever-use" of tanning beds was found to be a significant risk factor for the development of melanoma [P < 0.05; odds ratio (OR), 1.64; 95% confidence interval (95% CI), 1.01-2.67]. The risk was greater in women aged 45 years or younger (P < 0.05; OR, 3.22; 95% CI, 1.01-11.46). Patients with a history of melanoma were significantly more likely to report tanning bed sessions exceeding 20 min (P < 0.01; OR, 3.18; 95% CI, 1.48-6.82); this association was even stronger for women aged 45 years or younger (OR, 4.12; 95% CI, 1.41-12.02). The study was subject to recall bias, included only patients at a midwestern academic practice, and had a relatively low response rate. Exposure to tanning beds increases the risk of malignant melanoma, especially in women aged 45 years or younger. These findings reinforce the hazards of tanning bed exposure.

Effect of the oxygen content in a salt solution on the characteristics of sodium-reduced tantalum powders

NASA Astrophysics Data System (ADS)

Kolosov, V. N.; Orlov, V. M.; Miroshnichenko, M. N.; Prokhorova, T. Yu.; Masloboeva, S. M.; Belyaevskii, A. T.

2009-02-01

The characteristics of the tantalum powders produced by sodium thermal reduction from salt melts based on K2TaF7 and NaCl with various amounts of added oxycompounds K3TaOF6 and K2Ta2O3F6 are studied. At a molar ratio of oxygen to tantalum of 1.25 in the initial melt, capacitor tantalum powders with a specific surface area more than 3 m2/g are produced. The specific capacitance of the anodes made from these powders reaches 58 mC/g.

The elevated temperature mechanical properties of silicon nitride/boron nitride fibrous monoliths

NASA Astrophysics Data System (ADS)

Trice, Rodney Wayne

A unique, all-ceramic material capable of non-brittle fracture via crack deflection has been characterized from 25sp°C through 1400sp°C. This material, called fibrous monoliths (FMs), was comprised of unidirectionally aligned 250 mum diameter cells of silicon nitride surrounded by 10 mum thick cell boundaries of boron nitride. Six weight percent yttria and two weight percent alumina were added to the silicon nitride to aid in densification. TEM experiments revealed that the sintering aids used to densify the silicon nitride cells were migrating into the boron nitride cell boundary during hot-pressing and that a fine network of micro-cracks existed between basal planes of boron nitride. Elevated temperature four point bending tests were performed on fibrous monolith ceramics from room temperature through 1400sp°C. Peak strengths of FMs averaged 510 MPa for specimens tested at room temperature through 176 MPa at 1400sp°C. Work of fractures ranged from 7300 J/msp2 to 3200 J/msp2 under the same temperature conditions. The interfacial fracture energy of boron nitride, GammasbBN, as a function of temperature has been determined using the Charalambides method. The fracture energy of boron nitride is approximately 40 J/msp2 and remained constant from 25sp°C through 950sp°C. A sharp increase in GammasbBN, to about 60 J/msp2, was observed at 1000sp°C-1050sp°C. This increase in GammasbBN was attributed to interactions of the crack tip with the cell boundary glassy phase. Subsequent measurements at 1075sp°C indicated a marked decrease in GammasbBN to near 40 J/msp2 before plateauing at 17-20 J/msp2 in the 1200sp°C-1300sp°C regime. The Mode I fracture toughness of silicon nitride was also determined using the single edge precracked beam method as a function of temperature. The He and Hutchinson model relating crack deflection at an interface to the Dundurs' parameter was applied to the current data set using the temperature dependent fracture energies of the boron

Correlates of tanning facility densities in North Carolina.

PubMed

Treme, Julianne; Allen, Samuel K

2013-01-01

The indoor tanning industry is currently receiving increased attention from policymakers, but this industry has not been well researched. Our study examines economic, demographic, and climate-related variables to better understand variations among North Carolina counties in terms of the number of tanning beds and booths per capita during a recent 3-year period. This study used regression analysis to estimate the magnitude and statistical significance of correlations between the density of tanning beds and other relevant variables from 2007 through 2009. The number of indoor tanning beds per capita in a county is positively correlated with the county's unemployment rate and with the proportion of the county's population that consists of white females 18-49 years of age; there is also a weakly positive correlation with the number of days per year of hot weather in the county. All else being equal, tanning beds are marginally more common in counties with higher rates of unemployment, with a greater number of days when the temperature exeeds 90 degrees Fahrenheit, and with residents who are more likely to engage in risky behaviors (as measured by the gonorrhea infection rate and the percentage of the population who smoke cigarettes). The data span a 3-year period (2007-2009) during which economic conditions were depressed. Economic, demographic, geographic, and climate-related factors should be considered when policies that affect the tanning industry in North Carolina are being developed and implemented.

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.

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.

Crystalline phase-stability of tantalum pentoxide

NASA Astrophysics Data System (ADS)

Walton, Santiago; Padilha, Antonio; Dalpian, Gustavo; Guillén, Jorge; Dalpian's Research Group Collaboration; Grupo de Estado Solido Collaboration; Gritad Collaboration

2013-03-01

Memristive devices are attractive candidates to provide a paradigm change in memory devices fabrication. These new devices would be faster, denser and less power consuming than those available today. However, the mechanism of memristance is not yet well understood. It is believed that a voltage/current-driven phase transition occurs in the material, which leads to significant changes in the device's conductivity. In the particular case of tantalum-oxide-based devices the relevant crystalline phases are still a matter of debate. Some of these phases are not even completely known and there is no agreement about which model best explains the crystallographic results. In this work we have performed ab-initio DFT based calculations to study the structural properties of different phases (and models) of Ta2O5 - the structure which is believed to exist inside Tantalum Oxide based devices. The equations of state for this material were constructed through first principles total energy calculations and we have also calculated the phonon frequencies at Γ. These results show that the most stable phase of this oxide (B-Ta2O5) is in fact composed of octahedral, instead of pentagonal (as L-Ta2O5) or hexagonal (as δ-Ta2O5) bipyramids. Fapesp, CNPq, Capes,CODI-UdeA

Ion-beam nitriding of steels

NASA Technical Reports Server (NTRS)

Salik, J.

1984-01-01

The application of the ion beam technique to the nitriding of steels is described. It is indicated that the technique can be successfully applied to nitriding. Some of the structural changes obtained by this technique are similar to those obtained by ion nitriding. The main difference is the absence of the iron nitride diffraction lines. It is found that the dependence of the resultant microhardness on beam voltage for super nitralloy is different from that of 304 stainless steel.

76 FR 46677 - Indoor Tanning Services; Cosmetic Services Excise Taxes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-03

... 1545-BJ40 Indoor Tanning Services; Cosmetic Services Excise Taxes AGENCY: Internal Revenue Service (IRS... of public hearing on proposed rulemaking providing guidance on the indoor tanning services excise tax... indoor tanning services. DATES: The public hearing is being held on Tuesday, October 11, 2011, at 10 a.m...

Evaluation of the 3D Finite Element Method Using a Tantalum Rod for Osteonecrosis of the Femoral Head

PubMed Central

Shi, Jingsheng; Chen, Jie; Wu, Jianguo; Chen, Feiyan; Huang, Gangyong; Wang, Zhan; Zhao, Guanglei; Wei, Yibing; Wang, Siqun

2014-01-01

Background The aim of this study was to contrast the collapse values of the postoperative weight-bearing areas of different tantalum rod implant positions, fibula implantation, and core decompression model and to investigate the advantages and disadvantages of tantalum rod implantation in different ranges of osteonecrosis in comparison with other methods. Material/Methods The 3D finite element method was used to establish the 3D finite element model of normal upper femur, 3D finite element model after tantalum rod implantation into different positions of the upper femur in different osteonecrosis ranges, and other 3D finite element models for simulating fibula implant and core decompression. Results The collapse values in the weight-bearing area of the femoral head of the tantalum rod implant model inside the osteonecrosis area, implant model in the middle of the osteonecrosis area, fibula implant model, and shortening implant model exhibited no statistically significant differences (p>0.05) when the osteonecrosis range was small (60°). The stress values on the artificial bone surface for the tantalum rod implant model inside the osteonecrosis area and the shortening implant model exhibited statistical significance (p<0.01). Conclusions Tantalum rod implantation into the osteonecrosis area can reduce the collapse values in the weight-bearing area when osteonecrosis of the femoral head (ONFH) was in a certain range, thereby obtaining better clinical effects. When ONFH was in a large range (120°), the tantalum rod implantation inside the osteonecrosis area, shortening implant or fibula implant can reduce the collapse values of the femoral head, as assessed by other methods. PMID:25479830

The effect of tantalum and carbon on the structure/properties of a single crystal nickel-base superalloy. M.S. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Nguyen, H. C.

1984-01-01

The microstructure, phase chemistry, and creep and hot tensile properties were studied as a function of tantalum and carbon levels in Mar-M247 type single crystal alloys. Microstructural studies showed that several types of carbides (MC, M23C6 and M5C) are present in the normal carbon (0.10 wt % C) alloys after heat treatment. In general, the composition of the MC carbides changes from titanium rich to tantalum rich as the tantalum level in the alloy increases. Small M23C6 carbides are present in all alloys. Tungsten rich M6C carbides are also observed in the alloy containing no tantalum. No carbides are present in the low carbon (0.01 wt % C) alloy series. The morphology of gamma prime is observed to be sensitive to heat treatment and tantalum level in the alloy. Cuboidal gamma prime is present in all the as cast structures. After heat treatment, the gamma prime precipitates tend to have a more spheroidal like morphology, and this tendency increases as the tantalum level decreases. On prolonged aging, the gamma prime reverts back to a cuboidal morphology or under stress at high temperatures, forms a rafted structure. The weight fraction and lattice parameter of the spheroidal gamma prime increases with increasing tantalum content. Changes in the phase chemistry of the gamma prime matrix and gamma prime have also been analyzed using phase extraction techniques. The partitioning ratio decreases for tungsten and aluminum and increases for tantalum as the tantalum content increases for both alloy series; no significant changes occur in the partitioning ratios of the other alloying elements. A reduction in secondary creep rate and an increase in rupture time result from increasing the tantalum content and decreasing the carbon level.

Conflict minerals from the Democratic Republic of the Congo: global tantalum processing plants, a critical part of the tantalum supply chain

USGS Publications Warehouse

Papp, John F.

2014-01-01

Post-beneficiation processing plants (generally called smelters and refineries) for 3TG mineral ores and concentrates were identified by company and industry association representatives as being the link in the 3TG mineral supply chain through which these minerals can be traced to their source of origin (mine). The determination of the source of origin is critical to the development of a complete and transparent conflict-free mineral supply chain. Tungsten processing plants were the subject of the first fact sheet in this series published by USGS NMIC in August 2014. Background information about historical conditions and multinational stakeholders’ voluntary due diligence guidance for minerals from conflict-affected and high-risk areas is presented in the tungsten fact sheet. This fact sheet, the second in a series about 3TG minerals, focuses on the tantalum supply chain by listing selected processors that produced tantalum materials commercially worldwide during 2013–14. It does not provide any information regarding the sources of material processed in these facilities.

Indoor Tanning within UK Young Adults: An Extended Theory of Planned Behaviour Approach.

PubMed

Dodd, Lorna J; Forshaw, Mark J; Williams, Stella

2013-01-01

The indoor tanning industry poses a long-term public health risk. Despite the adverse health effects, indoor tanning seems to be gaining considerable popularity. The study examined indoor tanning intentions and behaviour within UK young adults using an extended theory of planned behaviour model, which included variables on "appearance reasons to tan," "perceived susceptibility to damaging appearance," "perceived susceptibility to health consequences," and "tanning knowledge." The model was successful in predicting indoor tanning intentions and behaviour (explained 17% and 71%, resp.). An interesting outcome was the magnitude of the variable "appearance reasons to tan." A current tanned appearance therefore seemed to outweigh any adverse future appearance or health consequences caused by indoor tanning. Appearance-focused interventions to reduce such behaviour may now prove to be efficacious within a UK sample.

Gallium nitride optoelectronic devices

NASA Technical Reports Server (NTRS)

Chu, T. L.; Chu, S. S.

1972-01-01

The growth of bulk gallium nitride crystals was achieved by the ammonolysis of gallium monochloride. Gallium nitride single crystals up to 2.5 x 0.5 cm in size were produced. The crystals are suitable as substrates for the epitaxial growth of gallium nitride. The epitaxial growth of gallium nitride on sapphire substrates with main faces of (0001) and (1T02) orientations was achieved by the ammonolysis of gallium monochloride in a gas flow system. The grown layers had electron concentrations in the range of 1 to 3 x 10 to the 19th power/cu cm and Hall mobilities in the range of 50 to 100 sq cm/v/sec at room temperature.

A novel tantalum-based sol-gel packed microextraction syringe for highly specific enrichment of phosphopeptides in MALDI-MS applications.

PubMed

Çelikbıçak, Ömür; Atakay, Mehmet; Güler, Ülkü; Salih, Bekir

2013-08-07

A new tantalum-based sol-gel material was synthesized using a unique sol-gel synthesis pathway by PEG incorporation into the sol-gel structure without performing a calcination step. This improved its chemical and physical properties for the high capacity and selective enrichment of phosphopeptides from protein digests in complex biological media. The specificity of the tantalum-based sol-gel material for phosphopeptides was evaluated and compared with tantalum(V) oxide (Ta2O5) in different phosphopeptide enrichment applications. The tantalum-based sol-gel and tantalum(V) oxide were characterized in detail using FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), and also using a surface area and pore size analyzer. In the characterization studies, the surface morphology, pore volume, crystallinity of the materials and PEG incorporation into the sol-gel structure to produce a more hydrophilic material were successfully demonstrated. The X-ray diffractograms of the two different materials were compared and it was noted that the broad signals of the tantalum-based sol-gel clearly represented the amorphous structure of the sol-gel material, which was more likely to create enough surface area and to provide more accessible tantalum atoms for phosphopeptides to be easily adsorbed when compared with the neat and more crystalline structure of Ta2O5. Therefore, the phosphopeptide enrichment performance of the tantalum-based sol-gels was found to be remarkably higher than the more crystalline Ta2O5 in our studies. Phosphopeptides at femtomole levels could be selectively enriched using the tantalum-based sol-gel and detected with a higher signal-to-noise ratio by matrix-assisted laser desorption/ionization-mass spectrometer (MALDI-MS). Moreover, phosphopeptides in a tryptic digest of non-fat bovine milk as a complex real-world biological sample were retained with higher yield using a tantalum-based sol-gel. Additionally, the sol-gel material

Effect of Temperature Cycling and Exposure to Extreme Temperatures on Reliability of Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2007-01-01

In this work, results of multiple temperature cycling (TC) (up to 1,000 cycles) of different types of solid tantalum capacitors are analyzed and reported. Deformation of chip tantalum during temperature variations simulating reflow soldering conditions was measured to evaluate the possibility of the pop-corning effect in the parts. To simulate the effect of short-time exposures to solder reflow temperatures on the reliability of tantalum capacitors, several part types were subjected to multiple cycles (up to 100) between room temperature and 240 C with periodical measurements of electrical characteristics of the parts. Mechanisms of degradation caused by temperature cycling and exposure to high temperatures, and the requirements of MIL-PRF-55365 for assessment of the resistance of the parts to soldering heat are discussed.

CONTRIBUTION TO THE GEOCHEMISTRY OF TANTALUM AND NIOBIUM IN THE HYDROTHERMAL-PNEUMATHOLYTIC PROCESS (in Russian)

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

Beus, A.A.; Sitnin, A.A.

1961-01-01

S>Data obtained as a result of geochemical investigations show that tantalum and niobium are typical elements of high-temperature postmagmatic processes (early albitization, greysening) connected with granites. The separation of tantalum and niobium in the hydrothermal-pneumatholytic process (greysening stage), which leads to the concentration of tantalum in albitized and greysenized granites (40 to 100 times compared to the average content in granites) is connected with the different mobility and stability of their acido- complex compounds (in particular fluor- and oxyfluorcomplexes), the existence of which in greysening solutions is suggested. A natural analogy in the behavior of both elements in the processesmore » of postmagmatic metasomatose in granites and granitic pegmatites is suggested. (tr-auth)« less

Early/Late Heterobimetallic Tantalum/Rhodium Species Assembled Through a Novel Bifunctional NHC-OH Ligand.

PubMed

Srivastava, Ravi; Moneuse, Raphaël; Petit, Julien; Pavard, Paul-Alexis; Dardun, Vincent; Rivat, Madleen; Schiltz, Pauline; Solari, Marius; Jeanneau, Erwann; Veyre, Laurent; Thieuleux, Chloé; Quadrelli, Elsje Alessandra; Camp, Clément

2018-03-20

The straightforward synthesis of a new unsymmetrical hydroxy-tethered N-heterocyclic carbene (NHC) ligand, HL, is presented. The free ligand exhibits an unusual OH-carbene hydrogen-bonding interaction. This OH-carbene motif was used to yield 1) the first tantalum complex displaying both a Fischer- and Schrock-type carbene ligand and 2) a unique NHC-based early/late heterobimetallic complex. More specifically, the protonolysis chemistry between the ligand's hydroxy group and imido-alkyl or alkylidene-alkyl tantalum precursor complexes yielded the rare monometallic tantalum-NHC complexes [Ta(XtBu)(L)(CH 2 tBu) 2 ] (X=N, CH), in which the alkoxy-carbene ligand acts as a chelate. In contrast, HL only binds to rhodium through the NHC unit in [Rh(HL)(cod)Cl] (cod=cycloocta-1,5-diene), the hydroxy pendant arm remaining unbound. This bifunctional ligand scaffold successfully promoted the assembly of rhodium/tantalum heterobimetallic complexes upon either 1) the insertion of [Rh(cod)Cl] 2 into the Ta-NHC bond in [Ta(NtBu)(L)(CH 2 tBu) 2 ] or 2) protonolysis between the free hydroxy group in [Rh(HL)(cod)Cl] and one alkyl group in [Ta(NtBu)(CH 2 tBu) 3 ]. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of tantalum on the structure/properties of two polycrystalline nickel-base superalloys: B-1900 + Hf MAR-M247. M.S. Thesis, Final Report

NASA Technical Reports Server (NTRS)

Janowski, G. M.

1985-01-01

The microstructure, phase compositions, and phase fractions were studied in conventionally cast B-1900 + Hf and both conventionally cast and directionally solidified MAR-M247 as a function of tantalum concentration. The hot tensile and creep rupture properties of the solutionized and aged MAR-M247-type alloys were also determined as a function of tantalum level. The effects of tantalum on the microstructure and phase compositions of B-1900 + Hf and MAR-M247 (conventionally cast and directionally solidified) were found to be very similar. The addition of tantalum to the as cast and heat treated alloys was shown to cause the partial replacement of the Hf in the MC carbides by Ta, although the degree of replacement was decreased by the solutionizing and aging heat treatment. The gamma prime and minor phase fractions (primarily MC type carbides) both increased approximately linearly with tantalum concentration. The gamma prime phase compositions were relatively insensitive to tantalum variations with the exception of the tantalum and/or hafnium levels. Bulk tantalum additions increased the tantalum, chromium, and cobalt levels of the gamma phase in both alloy series. The increase in the concentrations of the latter two elements in the gamma phase was a result of the decrease in the gamma phase fraction with increasing bulk tantalum concentration and constant gamma/gamma prime partitioning ratio. Tantalum additions increased the yield stress and ultimate tensile strength of the directionally solidified MAR-M247 type alloys and had no significant effect on ductility.

Primary human osteoblasts grow into porous tantalum and maintain an osteoblastic phenotype.

PubMed

Welldon, Katie J; Atkins, Gerald J; Howie, Donald W; Findlay, David M

2008-03-01

Porous tantalum (Ta) has found application in orthopedics, although the interaction of human osteoblasts (HOB) with this material has not been reported. The aim of this study was to investigate the interaction of primary HOB with porous tantalum, using 5-mm thick discs of porous tantalum. Comparison was made with discs of solid tantalum and tissue culture plastic. Confocal microscopy was used to investigate the attachment and growth of cells on porous Ta, and showed that HOB attached successfully to the metal "trabeculae," underwent extensive cell division, and penetrated into the Ta pores. The maturation of HOB on porous Ta was determined in terms of cell expression of the osteoblast phenotypic markers, STRO-1, and alkaline phosphatase. Despite some donor-dependent variation in STRO-1/AlkPhos expression, growth of cells grown on porous Ta either promoted, or did not impede, the maturation of HOB. In addition, the expression of key osteoblastic genes was investigated after 14 days of culture. The relative levels of mRNA encoding osteocalcin, osteopontin and receptor activator of NFkappaB ligand (RANKL) was not different between porous or solid Ta or plastic, although these genes were expressed differently by cells of different donors. However, bone sialoprotein and type I collagen mRNA species showed a decreased expression on porous Ta compared with expression on plastic. No substrate-dependent differences were seen in the extent of in vitro mineralization by HOB. These results indicate that porous Ta is a good substrate for the attachment, growth, and differentiated function of HOB. (c) 2007 Wiley Periodicals, Inc.

Significant Engagement in Tanning Behaviors by Men at a U.S. University.

PubMed

Daniel, Casey L; Fernandez, Alyssa M; Gassman, Natalie R; Bae, Sejong; Blashill, Aaron J; Tan, Marcus C

2017-12-30

Adolescent and young adult men are a potentially overlooked population with respect to risky tanning behaviors. This study sought to determine the prevalence of various modes of tanning and associated variables among young men in a university setting in the southeastern United States. Undergraduate students at a public institution in Mobile, Alabama were surveyed electronically in March 2016. Of the 818 undergraduate men surveyed, over 90% reported tanning behaviors, with 37% reporting engaging in indoor tanning. Additionally, over 25% reported engaging in two or more types of tanning concurrently. These findings indicate that early intervention efforts targeting young men are needed to reduce risky tanning behaviors and associated negative health outcomes.

Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2015-01-01

Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

Education versus regulation: The case for regulating the indoor tanning industry.

PubMed

Benet, Suzeanne; Kraft, Frederic

2016-05-01

We examine marketing strategies for indoor tanning services that often target young adult females. Evidence of the addictive nature of indoor tanning suggests that young adults may be vulnerable to the promotion of indoor tanning and as a result deserve greater protection from the marketing of these services. As public awareness of the rising numbers of skin cancers linked to indoor tanning grows, we believe that the public will support increased regulation of this industry.

A&M. Hot liquid waste treatment building (TAN616). Contextual view, facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste treatment building (TAN-616). Contextual view, facing south. Wall of hot shop (TAN-607) with high bay at left of view. Lower-roofed building at left edge of view is TAN- 633, hot cell annex. Complex at center of view is TAN-616. Tall metal building with gable roof is TAN-615. Photographer: Ron Paarmann. Date: September 22, 1997. INEEL negative no. HD-20-2-2 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Boron Nitride Nanoribbons from Exfoliation of Boron Nitride Nanotubes

NASA Technical Reports Server (NTRS)

Hung, Ching-Cheh; Hurst, Janet; Santiago, Diana

2017-01-01

Two types of boron nitride nanotubes (BNNTs) were exfoliated into boron nitride nanoribbons (BNNR), which were identified using transmission electron microscopy: (1) commercial BNNTs with thin tube walls and small diameters. Tube unzipping was indicated by a large decrease of the sample's surface area and volume for pores less than 2 nm in diameter. (2) BNNTs with large diameters and thick walls synthesized at NASA Glenn Research Center. Here, tube unraveling was indicated by a large increase in external surface area and pore volume. For both, the exfoliation process was similar to the previous reported method to exfoliate commercial hexagonal boron nitride (hBN): Mixtures of BNNT, FeCl3, and NaF (or KF) were sequentially treated in 250 to 350 C nitrogen for intercalation, 500 to 750 C air for exfoliation, and finally HCl for purification. Property changes of the nanosized boron nitride throughout this process were also similar to the previously observed changes of commercial hBN during the exfoliation process: Both crystal structure (x-ray diffraction data) and chemical properties (Fourier-transform infrared spectroscopy data) of the original reactant changed after intercalation and exfoliation, but most (not all) of these changes revert back to those of the reactant once the final, purified products are obtained.

Association Between Indoor Tanning and Melanoma in Younger Men and Women.

PubMed

Lazovich, DeAnn; Isaksson Vogel, Rachel; Weinstock, Martin A; Nelson, Heather H; Ahmed, Rehana L; Berwick, Marianne

2016-03-01

In the United States and Minnesota, melanoma incidence is rising more steeply among women than men younger than 50 years. To our knowledge, no study has examined age- and sex-specific associations between indoor tanning and melanoma to determine if these trends could be due to greater indoor tanning use among younger women. To examine associations between indoor tanning and melanoma among men and women younger than 50 years. Population-based case-control study conducted in Minnesota of 681 patients (465 [68.3%] women) diagnosed as having melanoma between 2004 and 2007, and 654 controls (446 [68.2%] women), ages 25 to 49 years. Indoor tanning, defined as any use, first age of use, and total sessions. Crude and adjusted odds ratios (ORs) and 95% CIs were calculated for melanoma in relation to indoor tanning exposure for men and women by diagnosis or reference age (<30, 30-39, 40-49 years). Sex-specific associations for indoor tanning and melanoma by anatomic site were examined. Compared with women aged 40 to 49 years, women younger than 40 years initiated indoor tanning at a younger age (16 vs 25 years, P < .001) and reported more frequent indoor tanning (median number of sessions, 100 vs 40, P < .001). Women younger than 30 years were 6 times more likely to be in the case than the control group if they tanned indoors (crude OR, 6.0; 95% CI, 1.3-28.5). Odds ratios were also significantly elevated among women, ages 30 to 49 years (adjusted OR, 3.5; 95% CI, 1.2-9.7 for women 30-39 years; adjusted OR, 2.3; 95% CI, 1.4-3.6 for women 40-49 years); a dose response was observed among women regardless of age. Among men, results by age were inconsistent. The strongest OR for indoor tanning by anatomic site was for melanomas arising on the trunk of women (adjusted OR, 3.7; 95% CI, 1.9-7.2). Indoor tanning is a likely factor for the steeper increase in melanoma rates in the United States among younger women compared with men, given the timing of when women initiated indoor

Indoor Tanning Among High School Students in the United States, 2009 and 2011

PubMed Central

Guy, Gery P.; Berkowitz, Zahava; Tai, Eric; Holman, Dawn M.; Jones, Sherry Everett; Richardson, Lisa C.

2015-01-01

IMPORTANCE Indoor tanning is associated with an increased risk of skin cancer, including melanoma, and is particularly dangerous for younger and more frequent indoor tanners. OBJECTIVE To examine the prevalence of indoor tanning and frequent indoor tanning (≥10 times during the 12 months before each survey) and their association with health-related behaviors. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional study examined data from the 2009 and 2011 national Youth Risk Behavior Surveys, which used nationally representative samples of US high school students representing approximately 15.5 million students each survey year. The study included 25 861 students who answered the indoor tanning question. MAIN OUTCOMES AND MEASURES The prevalence of indoor tanning and frequent indoor tanning were examined as well as their association with demographic characteristics and health-related behaviors using multivariable logistic regression modeling. RESULTS The prevalence of indoor tanning was greater among female, older, and non-Hispanic white students. Indoor tanning was highest among female students aged 18 years or older, with 31.5% engaging in indoor tanning in 2011, and among non-Hispanic white female students, with 29.3% engaging in indoor tanning in 2011. Among female students, the adjusted prevalence of indoor tanning decreased from 26.4% in 2009 to 20.7% in 2011. Among female and male students, indoor tanning was associated with other risk-taking behaviors, such as binge drinking (P < .001 and P = .006, respectively), unhealthy weight control practices (P < .001, for both), and having sexual intercourse (P < .001, for both). Additionally, indoor tanning among female students was associated with using illegal drugs (P < .001) and having sexual intercourse with 4 or more persons (P = .03); use among male students was associated with taking steroids without a physician’s prescription (P < .001), smoking cigarettes daily (P = .03), and attempting suicide (P = .006

Exposure to indoor tanning without burning and melanoma risk by sunburn history.

PubMed

Vogel, Rachel Isaksson; Ahmed, Rehana L; Nelson, Heather H; Berwick, Marianne; Weinstock, Martin A; Lazovich, DeAnn

2014-07-01

Indoor tanning is carcinogenic to humans. Individuals report that they tan indoors before planning to be in the sun to prevent sunburns, but whether skin cancer is subsequently reduced is unknown. Using a population-based case-control study, we calculated the association between melanoma and indoor tanning after excluding exposed participants reporting indoor tanning-related burns, stratified by their number of lifetime sunburns (0, 1-2, 3-5, >5). Confounding was addressed using propensity score analysis methods. All statistical tests were two-sided. We observed increased risk of melanoma across all sunburn categories for participants who had tanned indoors without burning compared with those who never tanned indoors, including those who reported zero lifetime sunburns (odds ratio = 3.87; 95% confidence interval = 1.68 to 8.91; P = .002). These data provide evidence that indoor tanning is a risk factor for melanoma even among persons who reported never experiencing burns from indoor tanning or outdoor sun exposure. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Exposure to indoor tanning without burning and melanoma risk by sunburn history.

PubMed

Vogel, Rachel Isaksson; Ahmed, Rehana L; Nelson, Heather H; Berwick, Marianne; Weinstock, Martin A; Lazovich, DeAnn

2014-06-01

Indoor tanning is carcinogenic to humans. Individuals report that they tan indoors before planning to be in the sun to prevent sunburns, but whether skin cancer is subsequently reduced is unknown. Using a population-based case-control study, we calculated the association between melanoma and indoor tanning after excluding exposed participants reporting indoor tanning-related burns, stratified by their number of lifetime sunburns (0, 1-2, 3-5, >5). Confounding was addressed using propensity score analysis methods. All statistical tests were two-sided. We observed increased risk of melanoma across all sunburn categories for participants who had tanned indoors without burning compared with those who never tanned indoors, including those who reported zero lifetime sunburns (odds ratio = 3.87; 95% confidence interval = 1.68 to 8.91; P = .002). These data provide evidence that indoor tanning is a risk factor for melanoma even among persons who reported never experiencing burns from indoor tanning or outdoor sun exposure. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Effect of Mechanical Stresses on Characteristics of Chip Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2007-01-01

The effect of compressive mechanical stresses on chip solid tantalum capacitors is investigated by monitoring characteristics of different part types under axial and hydrostatic stresses. Depending on part types, an exponential increase of leakage currents was observed when stresses exceeded 10 MPa to 40 MPa. For the first time, reversible variations of leakage currents (up to two orders of magnitude) with stress have been demonstrated. Mechanical stresses did not cause significant changes of AC characteristics of the capacitors, whereas breakdown voltages measured during the surge current testing decreased substantially indicating an increased probability of failures of stressed capacitors in low impedance applications. Variations of leakage currents are explained by a combination of two mechanisms: stress-induced scintillations and stress-induced generation of electron traps in the tantalum pentoxide dielectric.

Heat of combustion of tantalum-tungsten oxide thermite composites

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

Cervantes, Octavio G.; Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616; Kuntz, Joshua D.

2010-12-15

The heat of combustion of two distinctly synthesized stoichiometric tantalum-tungsten oxide energetic composites was investigated by bomb calorimetry. One composite was synthesized using a sol-gel (SG) derived method in which micrometric-scale tantalum is immobilized in a tungsten oxide three-dimensional nanostructured network structure. The second energetic composite was made from the mixing of micrometric-scale tantalum and commercially available (CA) nanometric tungsten oxide powders. The energetic composites were consolidated using the spark plasma sintering (SPS) technique under a 300 MPa pressure and at temperatures of 25, 400, and 500 C. For samples consolidated at 25 C, the density of the CA compositemore » is 61.65 {+-} 1.07% in comparison to 56.41 {+-} 1.19% for the SG derived composite. In contrast, the resulting densities of the SG composite are higher than the CA composite for samples consolidated at 400 and 500 C. The theoretical maximum density for the SG composite consolidated to 400 and 500 C are 81.30 {+-} 0.58% and 84.42 {+-} 0.62%, respectively. The theoretical maximum density of the CA composite consolidated to 400 and 500 C are 74.54 {+-} 0.80% and 77.90 {+-} 0.79%, respectively. X-ray diffraction analyses showed an increase of pre-reaction of the constituents with an increase in the consolidation temperature. The increase in pre-reaction results in lower stored energy content for samples consolidated to 400 and 500 C in comparison to samples consolidated at 25 C. (author)« less

Oncology nurses and indoor tanning: stylish or risky behavior?

PubMed

Leong, Christina Marie; Palos, Guadalupe R

2014-06-01

Being tan has become a social norm, and some nurses engage in that widely accepted lifestyle. Mounting evidence of the increased risk to melanoma and nonmelanoma skin cancers associated with indoor tanning supports the need for nurses to integrate skin cancer education, counseling, and referrals into routine practice. The current article presents an overview of the risks associated with indoor tanning, discusses its acceptance as a social norm, and offers strategies to support oncology nurses in changing the widespread trend.

Indoor Tanning (For Teens)

MedlinePlus

... young patients for skin cancer. Indoor Tanning vs. Sunlight The sun's rays contain two types of ultraviolet radiation that ... as much — if not more — damage as the sun. Plus, the concentration of UVA rays from a ...

Use of a Tantalum Liner to Reduce Bore Erosion and Increase Muzzle Velocity in Two-Stage Light Gas Guns

NASA Technical Reports Server (NTRS)

Bogdanoff, David W.

2015-01-01

Muzzle velocities and gun erosion predicted by earlier numerical simulations of two stage light gas guns with steel gun tubes were in good agreement with experimental values. In a subsequent study, simulations of high performance shots were repeated with rhenium (Re) gun tubes. Large increases in muzzle velocity (2 - 4 km/sec) were predicted for Re tubes. In addition, the hydrogen-produced gun tube erosion was, in general, predicted to be zero with Re tubes. Tantalum (Ta) has some mechanical properties superior to those of Re. Tantalum has a lower modulus of elasticity than Re for better force transmission from the refractory metal liner to an underlying thick wall steel tube. Tantalum also has greater ductility than Re for better survivability during severe stress/strain cycles. Also, tantalum has been used as a coating or liner in military powder guns with encouraging results. Tantalum has, however, somewhat inferior thermal properties to those of rhenium, with a lower melting point and lower density and thermal conductivity. The present study was undertaken to see to what degree the muzzle velocity gains of rhenium gun tubes (over steel tubes) could be achieved with tantalum gun tubes. Nine high performance shots were modeled with a new version of our CFD gun code for steel, rhenium and tantalum gun tubes. For all except the highest velocity shot, the results with Ta tubes were nearly identical with those for Re tubes. Even for the highest velocity shot, the muzzle velocity gain over a steel tube using Ta was 82% of the gain obtained using Re. Thus, the somewhat inferior thermal properties of Ta (when compared to those of Re) translate into only very slightly poorer overall muzzle velocity performance. When this fact is combined with the superior mechanical properties of Ta and the encouraging performance of Ta liners/coatings in military powder guns, tantalum is to be preferred over Re as a liner/coating material for two stage light gas guns to increase muzzle

Evaluation of Ferrite Chip Beads as Surge Current Limiters in Circuits with Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2014-01-01

Limiting resistors are currently required to be connected in series with tantalum capacitors to reduce the risk of surge current failures. However, application of limiting resistors decreases substantially the efficiency of the power supply systems. An ideal surge current limiting device should have a negligible resistance for DC currents and high resistance at frequencies corresponding to transients in tantalum capacitors. This work evaluates the possibility of using chip ferrite beads (FB) as such devices. Twelve types of small size FBs from three manufacturers were used to evaluate their robustness under soldering stresses and at high surge current spikes associated with transients in tantalum capacitors. Results show that FBs are capable to withstand current pulses that are substantially greater than the specified current limits. However, due to a sharp decrease of impedance with current, FBs do not reduce surge currents to the required level that can be achieved with regular resistors.

Tantalum-containing catalyst useful for producing alcohols from synthesis gas

DOEpatents

Kinkade, Nancy E.

1991-01-01

A catalyst useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols consisting essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

Tantalum-containing catalyst useful for producing alcohols from synthesis gas

DOEpatents

Kinkade, Nancy E.

1992-01-01

A catalyst useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols consisting essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

Predictors of tanning salon use: behavioral alternatives for enhancing appearance, relaxing and socializing.

PubMed

Danoff-Burg, Sharon; Mosher, Catherine E

2006-05-01

This study investigated cognitive predictors of tanning salon use, based on Jaccard's Theory of Alternative Behavior. A total of 164 undergraduates completed questionnaires that assessed tanning salon use, attitudes toward tanning salon use and attitudes toward behavioral alternatives for enhancing appearance, relaxing and socializing. Results indicated that attitudes toward alternatives for enhancing appearance were not significantly related to tanning salon use. However, favorable attitudes toward engaging in a hobby to relax and going to the gym to socialize were inversely related to frequency of tanning salon use. Findings suggest that interventions for reducing skin cancer risk should focus not only on decreasing favorable attitudes toward tanning, but also on increasing favorable attitudes toward healthier alternatives to tanning salon use.

Exposure to Indoor Tanning Without Burning and Melanoma Risk by Sunburn History

PubMed Central

Vogel, Rachel Isaksson; Ahmed, Rehana L.; Nelson, Heather H.; Berwick, Marianne; Weinstock, Martin A.

2014-01-01

Indoor tanning is carcinogenic to humans. Individuals report that they tan indoors before planning to be in the sun to prevent sunburns, but whether skin cancer is subsequently reduced is unknown. Using a population-based case–control study, we calculated the association between melanoma and indoor tanning after excluding exposed participants reporting indoor tanning–related burns, stratified by their number of lifetime sunburns (0, 1–2, 3–5, >5). Confounding was addressed using propensity score analysis methods. All statistical tests were two-sided. We observed increased risk of melanoma across all sunburn categories for participants who had tanned indoors without burning compared with those who never tanned indoors, including those who reported zero lifetime sunburns (odds ratio = 3.87; 95% confidence interval = 1.68 to 8.91; P = .002). These data provide evidence that indoor tanning is a risk factor for melanoma even among persons who reported never experiencing burns from indoor tanning or outdoor sun exposure. PMID:25031276

Exposure to Indoor Tanning Without Burning and Melanoma Risk by Sunburn History

PubMed Central

Vogel, Rachel Isaksson; Ahmed, Rehana L.; Nelson, Heather H.; Berwick, Marianne; Weinstock, Martin A.

2014-01-01

Indoor tanning is carcinogenic to humans. Individuals report that they tan indoors before planning to be in the sun to prevent sunburns, but whether skin cancer is subsequently reduced is unknown. Using a population-based case–control study, we calculated the association between melanoma and indoor tanning after excluding exposed participants reporting indoor tanning–related burns, stratified by their number of lifetime sunburns (0, 1–2, 3–5, >5). Confounding was addressed using propensity score analysis methods. All statistical tests were two-sided. We observed increased risk of melanoma across all sunburn categories for participants who had tanned indoors without burning compared with those who never tanned indoors, including those who reported zero lifetime sunburns (odds ratio = 3.87; 95% confidence interval = 1.68 to 8.91; P = .002). These data provide evidence that indoor tanning is a risk factor for melanoma even among persons who reported never experiencing burns from indoor tanning or outdoor sun exposure. PMID:24872541

A Topical Solution to the Sunless Tanning Problem.

PubMed

Michael, Helen T; Merlino, Glenn

2017-09-01

Skin cancer is the most commonly diagnosed type of cancer and is strongly associated with UV exposure and skin pigmentation. Recent advances in pharmacologic non-UV tanning methods open the possibility of preventing melanoma and non-melanoma skin cancer, especially in people who do not tan in the sun. Published by Elsevier Ltd.

Acculturation, Skin Tone Preferences, and Tanning Behaviours Among Young Adult Asian Australians.

PubMed

Day, Ashley K; Wilson, Carlene J; Hutchinson, Amanda D; Roberts, Rachel M

2016-10-01

Australia has a significant proportion of residents of Asian heritage. Although the incidence of skin cancer is lower in those of Asian heritage than Caucasians, their prognosis is often worse. Sociocultural variables are central to the tanning behaviours of individuals from Western cultures. We examined the role of sociocultural variables in the tanning behaviours (outdoor tanning, indoor/solarium and fake tan use) among Asian Australians. A sample of 399 young adults identifying either as a person of Asian heritage or as Asian Australian participated in an online survey. Our results suggest that Asian Australians are at risk of skin cancer; over 35 % of the sample reported engaging in outdoor tanning and over 10 % in solarium tanning. After controlling for demographic factors and skin cancer knowledge, preferring a darker skin tone and being acculturated to Australia were significantly associated with tanning behaviour. Participants' low levels of skin cancer knowledge are of concern, and possibilities for improving knowledge levels in this group are considered. Further, we recommended that future research studies investigate sociocultural and appearance-related beliefs associated with tanning behaviours in this population, in order to determine best avenues for intervention.

Method to synthesize bulk iron nitride

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

Monson, Todd; Lavernia, Enrique J.; Zheng, Baolong

Bulk iron nitride can be synthesized from iron nitride powder by spark plasma sintering. The iron nitride can be spark plasma sintered at a temperature of less than 600°C. and a pressure of less than 600 MPa, with 400 MPa or less most often being sufficient. High pressure SPS can consolidate dense iron nitrides at a lower temperature to avoid decomposition. The higher pressure and lower temperature of spark discharge sintering avoids decomposition and limits grain growth, enabling enhanced magnetic properties. The method can further comprise synthesis of nanocrystalline iron nitride powders using two-step reactive milling prior to high-pressure sparkmore » discharge sintering.« less

Surface modification of 17-4PH stainless steel by DC plasma nitriding and titanium nitride film duplex treatment

NASA Astrophysics Data System (ADS)

Qi, F.; Leng, Y. X.; Huang, N.; Bai, B.; Zhang, P. Ch.

2007-04-01

17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.

Intentional tanning among adolescents in seven Canadian provinces: Provincial comparisons (CRAYS 2015).

PubMed

Nadalin, V; Marrett, L D; Cawley, C; Minaker, L M; Manske, S

2018-06-01

This report explores intentional tanning behaviors among Canadian high school students in light of provincial restrictions on UV tanning device use among youth. Data are from the Cancer Risk Assessment in Youth Survey (CRAYS), collected from January to December 2015, at randomly selected high schools in 7 provinces. Relevant variables were: tanning methods ever used, demographics, and location and refusal of UV tanning device (beds, lamps) use in the past 12 months. Data were weighted so total survey weights by male/female, grade and province equal actual enrolments in these groups. Analyses were conducted in SAS, mostly for grades 10 and 11. Rao-Scott chi squared tests and p-values were calculated. Among 6803 grade 10 and 11 participants, 82% tanned intentionally, mostly by being/playing outside, or laying in the sun. Spray/self-tanners were used by 15% of participants. UV tanning device use was uncommon (4.4%), lowest in Ontario (2.7%) and British Columbia (3.8%), which have legislation against use among youth. Of 202 who used UV tanning devices in the past 12 months, most did at salons/studios (85%), 35% at home and 30% at a gym. Two hundred and forty-nine participants (3.4%) were refused use of UV tanning devices in the past 12 months. While legislation appears to deter UV tanning device use, it appears to have no impact on UV exposure among high school students overall. Greater prevention efforts are required to deter intentional tanning among high school students. Copyright © 2018 Elsevier Inc. All rights reserved.

Inferring Strength of Tantalum from Hydrodynamic Instability Recovery Experiments

NASA Astrophysics Data System (ADS)

Sternberger, Z.; Maddox, B.; Opachich, Y.; Wehrenberg, C.; Kraus, R.; Remington, B.; Randall, G.; Farrell, M.; Ravichandran, G.

2018-05-01

Hydrodynamic instability experiments allow access to material properties at extreme conditions, where strain rates exceed 105 s-1 and pressures reach 100 GPa. Current hydrodynamic instability experimental methods require in-flight radiography to image the instability growth at high pressure and high strain rate, limiting the facilities where these experiments can be performed. An alternate approach, recovering the sample after loading, allows measurement of the instability growth with profilometry. Tantalum samples were manufactured with different 2D and 3D initial perturbation patterns and dynamically compressed by a blast wave generated by laser ablation. The samples were recovered from peak pressures between 30 and 120 GPa and strain rates on the order of 107 s-1, providing a record of the growth of the perturbations due to hydrodynamic instability. These records are useful validation points for hydrocode simulations using models of material strength at high strain rate. Recovered tantalum samples were analyzed, providing an estimate of the strength of the material at high pressure and strain rate.

Prevalence and correlates of indoor tanning and sunless tanning product use among female teens in the United States

PubMed Central

Quinn, Megan; Alamian, Arsham; Hillhouse, Joel; Scott, Colleen; Turrisi, Rob; Baker, Katie

2014-01-01

Background Indoor tanning (IT) before the age of 35 increases melanoma risk by 75%. Nevertheless, IT and sunless tanning product (STP) use have gained popularity among youth. However, there are limited data on the prevalence and sociodemographic correlates of both IT and STP use in a representative sample of American teens. Methods Teenage females (N = 778) aged 12–18 years were recruited as part of an on-going longitudinal study conducted between May 2011 and May 2013. Descriptive statistics explored IT and STP usage in teen females at baseline. Logistic regression was used to determine sociodemographic correlates of IT and STP use. Results Approximately 16% of female teens engaged in IT behavior and 25% engaged in using STPs. Female teens living in non-metropolitan areas were 82% more likely to indoor tan compared to those in metropolitan areas (OR = 1.82, 95% CI: 1.07–3.10). Age, geographic regions, and race increased the likelihood of IT and STP use. Conclusions Results indicate a significant proportion of teen females engage in IT and STP use. There was evidence that in teens that have never used IT before, STP use precedes IT initiation. Given the evidence for increased IT in rural populations, research focused on rural tanning bed use is needed. PMID:25621199

Addiction to indoor tanning: relation to anxiety, depression, and substance use.

PubMed

Mosher, Catherine E; Danoff-Burg, Sharon

2010-04-01

To assess the prevalence of addiction to indoor tanning among college students and its association with substance use and symptoms of anxiety and depression. Two written measures, the CAGE (Cut down, Annoyed, Guilty, Eye-opener) Questionnaire, used to screen for alcoholism, and the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) (DSM-IV-TR) criteria for substance-related disorders, were modified to evaluate study participants for addiction to indoor tanning. Standardized self-report measures of anxiety, depression, and substance use also were administered. A large university (approximately 18 000 students) in the northeastern United States. A total of 421 college students were recruited from September through December 2006. Self-reported addiction to indoor tanning, substance use, and symptoms of anxiety and depression. Among 229 study participants who had used indoor tanning facilities, 90 (39.3%) met DSM-IV-TR criteria and 70 (30.6%) met CAGE criteria for addiction to indoor tanning. Students who met DSM-IV-TR and CAGE criteria for addiction to indoor tanning reported greater symptoms of anxiety and greater use of alcohol, marijuana, and other substances than those who did not meet these criteria. Depressive symptoms did not significantly vary by indoor tanning addiction status. Findings suggest that interventions to reduce skin cancer risk should address the addictive qualities of indoor tanning for a minority of individuals and the relationship of this behavior to other addictions and affective disturbance.

Addiction to Indoor Tanning: Relations to Anxiety, Depression, and Substance Use

PubMed Central

Mosher, Catherine E.; Danoff-Burg, Sharon

2013-01-01

Objective To assess the prevalence of addiction to indoor tanning among college students and its association with substance use and symptoms of anxiety and depression. Design Two written measures, the CAGE (Cut down, Annoyed, Guilty, Eye-opener) Questionnaire, used to screen for alcoholism, and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria for substance-related disorders, were modified to evaluate participants for addiction to indoor tanning. Standardized self-report measures of anxiety, depression, and substance use also were administered. Setting Large (i.e., approximately 18,000 students) university in the northeastern United States. Participants A total of 421 college students. Main Outcome Measures Self-reported addiction to indoor tanning, substance use, and symptoms of anxiety and depression. Results Among respondents who had used indoor tanning facilities (n = 229), 39% met DSM-IV-TR criteria and 31% met CAGE criteria for addiction to indoor tanning. Students who met DSM-IV-TR and CAGE criteria for addiction to indoor tanning reported greater symptoms of anxiety and greater use of alcohol, marijuana, and other substances than those who did not meet these criteria. Depressive symptoms did not significantly vary by indoor tanning addiction status. Conclusions Findings suggest that interventions to reduce skin cancer risk should address the addictive qualities of indoor tanning for a minority of individuals as well as the relationship of this behavior to other addictions and affective disturbance. PMID:20404230

[Tanning beds: effect on skin cancer risk unclear].

PubMed

de Winter, S; Pavel, S

2000-03-04

Recent estimations show that over 25% of the Dutch population make regular use of tanning equipment. This use is still increasing, in spite of improving knowledge on the potential hazards of ultraviolet radiation. There are different motivations to use the tanning equipment. Younger women are largely represented in the group of sunbed users. Recent studies have brought the testimony that intermittent sun exposure (e.g. during holidays) is an important risk factor for skin cancer (notably basal cell carcinoma and melanoma). The investigations have not provided convincing evidence on the relation between the use of artificial devices and the development of skin cancer. This is partly caused by the fact that sunbed users are generally very motivated to get a tan. It is therefore difficult to distinguish between the effect of natural sun and of artificial UV radiation. In the Netherlands, the analyses of scientific data provide the basis for recommendations concerning sun exposure and use of sunbeds. There is an effort to provide the general public with qualified, professional information on the responsible way of tanning.

Theory-Driven Longitudinal Study Exploring Indoor Tanning Initiation in Teens Using a Person-Centered Approach

PubMed Central

Hillhouse, Joel; Turrisi, Rob; Cleveland, Michael J.; Scaglione, Nichole M.; Baker, Katie; Florence, L. Carter

2015-01-01

Background Younger indoor tanning initiation leads to greater melanoma risk due to more frequent and persistent behavior. Despite this, there are no published studies exploring the predictors of indoor tanning initiation in teen populations. Purpose This longitudinal study uses latent profile analysis to examine indoor tanning initiation in indoor tanning risk subgroups from a national sample of female adolescents. Methods Latent profile analysis used indoor tanning beliefs and perceptions to identify indoor tanning initiation risk subgroups. The teens in each subgroup were reassessed on indoor tanning initiation after a year. Results Three subgroups were identified: a low-risk, Anti-Tanning subgroup (18.6%) characterized by low scores on positive indoor tanning belief scales and high scores on beliefs about indoor tanning dangers; a moderate-risk Aware Social Tanner subgroup (47.2%) characterized by high scores on positive indoor tanning belief scales but also high scores on beliefs about indoor tanning dangers; and a high-risk Risky Relaxation Tanner subgroup (34.2%) characterized by high scores on positive indoor tanning belief scales and low scores on beliefs about indoor tanning dangers. Teens in the Aware Social Tanner and Risky Relaxation Tanner subgroups were significantly more likely to initiate indoor tanning in the following year. Conclusions These findings highlight the need to identify teens at risk for indoor tanning initiation and develop tailored interventions that will move them to the lowest risk subgroup. Subgroup correlates suggest parent and peer-based interventions may be successful. PMID:26370893

Theory-Driven Longitudinal Study Exploring Indoor Tanning Initiation in Teens Using a Person-Centered Approach.

PubMed

Hillhouse, Joel; Turrisi, Rob; Cleveland, Michael J; Scaglione, Nichole M; Baker, Katie; Florence, L Carter

2016-02-01

Younger indoor tanning initiation leads to greater melanoma risk due to more frequent and persistent behavior. Despite this, there are no published studies exploring the predictors of indoor tanning initiation in teen populations. This longitudinal study uses latent profile analysis to examine indoor tanning initiation in indoor tanning risk subgroups from a national sample of female adolescents. Latent profile analysis used indoor tanning beliefs and perceptions to identify indoor tanning initiation risk subgroups. The teens in each subgroup were reassessed on indoor tanning initiation after a year. Three subgroups were identified: a low risk, anti-tanning subgroup (18.6 %) characterized by low scores on positive indoor tanning belief scales and high scores on beliefs about indoor tanning dangers; a moderate risk aware social tanner subgroup (47.2 %) characterized by high scores on positive indoor tanning belief scales but also high scores on beliefs about indoor tanning dangers; and a high risk risky relaxation tanner subgroup (34.2 %) characterized by high scores on positive indoor tanning belief scales and low scores on beliefs about indoor tanning dangers. Teens in the aware social tanner and risky relaxation tanner subgroups were significantly more likely to initiate indoor tanning in the following year. These findings highlight the need to identify teens at risk for indoor tanning initiation and develop tailored interventions that will move them to the lowest risk subgroup. Subgroup correlates suggest parent and peer-based interventions may be successful.

Tantalum pentoxide waveguides and microresonators for VECSEL based frequency combs

NASA Astrophysics Data System (ADS)

Chen Sverre, T.; Woods, J. R. C.; Shaw, E. A.; Hua, Ping; Apostolopoulos, V.; Wilkinson, J. S.; Tropper, A. C.

2018-02-01

Tantalum pentoxide (Ta2O5) is a promising material for mass-producible, multi-functional, integrated photonics circuits on silicon, exhibiting robust electrical, mechanical and thermal properties, as well as good CMOS compatibility. In addition, Ta2O5 has been reported to demonstrate a non-linear response comparable to that of chalcogenide glass, in the region of 3-6 times larger than that of materials such as silica (SiO2) or silicon nitride (Si3N4). In contrast to Si-based dielectrics, it will accept trivalent ytterbium and erbium dopant ions, opening the possibility of on-chip amplification. The high refractive index of Ta2O5 is consistent with small guided mode cross-section area, and allows the construction of micro-ring resonators. Propagation losses as low as 0.2 dB=cm have been reported. In this paper we describe the design of a planar Ta2O5 waveguides optimised for the generation of coherent continuum with near infrared pulse trains at kW peak powers. The Pulse Repetition Frequency (PRF) of the VECSEL can be tuned to a sub-harmonic of the planar micro-ring and the optical pump power applied to the VECSEL can be adjusted so that mode-matching of the VECSEL pulse train with the micro-ring resonator can be achieved. We shall describe the fabrication of Ta2O5 guiding structures, and the characterisation of their nonlinear and other optical properties. Characterisation with conventional lasers will be used to assess the degree of coherent spectral broadening likely to be achievable using these devices when driven by mode-locked VECSELs operating near the current state-of- art for pulse energy and duration.

Boron nitride composites

DOEpatents

Kuntz, Joshua D.; Ellsworth, German F.; Swenson, Fritz J.; Allen, Patrick G.

2016-02-16

According to one embodiment, a composite product includes hexagonal boron nitride (hBN), and a plurality of cubic boron nitride (cBN) particles, wherein the plurality of cBN particles are dispersed in a matrix of the hBN. According to another embodiment, a composite product includes a plurality of cBN particles, and one or more borate-containing binders.

Indoor Tanning, Skin Cancer and the Young Female Patient: A Review of the Literature.

PubMed

Friedman, Blake; English, Joseph C; Ferris, Laura K

2015-08-01

Young, non-Hispanic white females represent the population most likely to use indoor tanning facilities. This population may be at increased risk of skin cancer as recent meta-analyses support a strong association between cutaneous malignancy and indoor tanning. Public perception of the purported health benefits of indoor tanning may be partially to blame for the popularity of tanning salons as a desire to prepare skin prior to sun exposure is among the most commonly cited motivations for indoor tanning. Improving education and counseling to address misconceptions regarding tanning safety will require the participation of healthcare providers for both physical and psychological screenings as well as for information dissemination. This review presents the association between tanning bed use and skin cancer, biological effects of UV radiation exposure, UV burden associated with tanning devices, public perception of tanning, demographic and psychological profile of indoor tanners, and current legislation regulating tanning bed use. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Thermal Degradation Characteristics of Oil Filled Cable Joint with Extremely Degraded tan δ Oil

NASA Astrophysics Data System (ADS)

Ide, Kenichi; Nakade, Masahiko; Takahashi, Tohru; Nakajima, Takenori

Much of oil filled (OF) cable has been used for a long time for 66∼500kV extra high voltage cable. Sometimes we can see extremely degraded tanδ oil (several tens % of tanδ, for example) in joint box etc. The calculation results of tanδ on a simple combination model of paper/oil show that, tanδ of oil impregnated paper with such a high tanδ oil is extremely high and it must result in a thermal breakdown. However such an event has not taken place up to the present in actually operated transmission line. This fact suggests that some suppression mechanism of tanδ has acted in the degraded tanδ oil impregnated paper insulation. Therefore we investigated the tanδ characteristics of oil impregnated paper with extremely high tanδ oil in detail. In addition, based on the investigation results, we developed a simulation method of heat generation by dielectric loss in OF cable joint (which has degraded tanδ oil).

Upgrading tantalum and niobium oxides content in Bangka tin slag with double leaching

NASA Astrophysics Data System (ADS)

Soedarsono, J. W.; Permana, S.; Hutauruk, J. K.; Adhyputra, R.; Rustandi, A.; Maksum, A.; Widana, K. S.; Trinopiawan, K.; Anggraini, M.

2018-03-01

Tantalum has become one of the 14 types of critical materials where the level of its availability is assumed as the midterm critical metal. Benefits of the element tantalum in the electronics field increased the deficit balance of supply / demand, as more variations of electronic products developed. The tantalum experts calculated the level of availability until 2020. Base on the previous studies, tin slag is a secondary source of tantalum and niobium. This study uses tin slag from Bangka, Indonesia, abbreviated, Bangka Tin Slag (BTS). BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS-RQS was roasted at a temperature 700□C given sample code BTS-R700QS, while roasted at 800°C given sample code BTS-R800QS.A variable leaching experiment on BTS-R700QS was solvent concentration variable and on BTS-R800QS was time variable. The entire residue was characterized by X-Ray Fluorescence (XRF), and the optimum results are on the BTS-R800QS leaching into 5 M NaOH for 20 min followed by 5M HCl for 50 min, with content of Ta2O5 and Nb2O51.56% and 1.11%, respectively. The result of XRF measurement showed was the increasing of TNO content due to the increasing solvent concentration and time of acid leaching. The discussion of thermodynamics this study used was HSC Chemistry 6 as a supporting data.

Evaluation of Polymer Hermetically Sealed Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2014-01-01

Polymer cathode tantalum capacitors have lower ESR (equivalent series resistance) compared to other types of tantalum capacitors and for this reason have gained popularity in the electronics design community. Their use allows improved performance of power supply systems along with substantial reduction of size and weight of the components used. However, these parts have poor thermal stability and can degrade in humid environments. Polymer hermetically sealed (PHS) capacitors avoid problems related to environmental degradation of molded case parts and can potentially replace current wet and solid hermetically sealed capacitors. In this work, PHS capacitors manufactured per DLA LAM DWG#13030 are evaluated for space applications. Several lots of capacitors manufactured over period from 2010 to 2014 were tested for the consistency of performance, electrical and thermal characteristics, highly accelerated life testing, and robustness under reverse bias and random vibration conditions. Special attention was given to analysis of leakage currents and the effect of long-term high temperature storage on capacitors in as is condition and after hermeticity loss. The results show that PHS capacitors might be especially effective for low-temperature applications or for system requiring a cold start-up. Additional screening and qualification testing have been recommended to assure the necessary quality of capacitors for space projects.

Exposure to sunlamps, tanning beds, and melanoma risk.

PubMed

Clough-Gorr, Kerri M; Titus-Ernstoff, Linda; Perry, Ann E; Spencer, Steven K; Ernstoff, Marc S

2008-09-01

To estimate the separate effects of sunlamp and tanning bed device use on melanoma risk. Population-based case-control study of 423 cases of melanoma and 678 controls in the state of New Hampshire. Exposure data, including sunlamp and tanning bed use, were collected by telephone interview. Associations were evaluated using logistic regression analyses. About 17% of participants ever used a sunlamp, and most use (89%) occurred before 1980. The OR was 1.39 (95% CI 1.00-1.96) for ever using a sunlamp, 1.23 (95% CI 0.81-1.88) for those starting sunlamp use <20 years, and 1.71 (95% CI 1.00-2.92) for those starting >/=20 years. Data suggested increasing risk with number of sunlamp uses and with duration of use (tests of trend p = 0.02). The overall prevalence of tanning bed use was 22% and most use (83%) occurred after 1980. The OR was 1.14 (95% CI 0.80-1.61) for ever using a tanning bed; there was no evidence that risk increased with frequency or duration of use. The OR was 1.96 (95% CI 1.06-3.61) for having used both devices. Results suggest a modest association between sunlamp use and melanoma risk, and increasing risk with greater frequency and duration of use. No association with tanning bed use was found, but sufficient lag time may not have elapsed to assess a potential effect.

Density of indoor tanning facilities in 116 large U.S. cities.

PubMed

Hoerster, Katherine D; Garrow, Rebecca L; Mayer, Joni A; Clapp, Elizabeth J; Weeks, John R; Woodruff, Susan I; Sallis, James F; Slymen, Donald J; Patel, Minal R; Sybert, Stephanie A

2009-03-01

U.S. adolescents and young adults are using indoor tanning at high rates, even though it has been linked to both melanoma and squamous cell cancer. Because the availability of commercial indoor tanning facilities may influence use, data are needed on the number and density of such facilities. In March 2006, commercial indoor tanning facilities in 116 large U.S. cities were identified, and the number and density (per 100,000 population) were computed for each city. Bivariate and multivariate analyses conducted in 2008 tested the association between tanning-facility density and selected geographic, climatologic, demographic, and legislative variables. Mean facility number and density across cities were 41.8 (SD=30.8) and 11.8 (SD=6.0), respectively. In multivariate analysis, cities with higher percentages of whites and lower ultraviolet (UV)index scores had significantly higher facility densities than those with lower percentages of whites and higher UV index scores. These data indicate that commercial indoor tanning is widely available in the urban U.S., and this availability may help explain the high usage of indoor tanning.

Tantalum-containing catalyst useful for producing alcohols from synthesis gas

DOEpatents

Kinkade, N.E.

1992-04-07

A catalyst is described which is useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols. The catalyst consists essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

The Relationships Between Female Adolescents' Media Use, Indoor Tanning Outcome Expectations, and Behavioral Intentions.

PubMed

Myrick, Jessica Gall; Noar, Seth M; Kelley, Dannielle; Zeitany, Alexandra E

2017-06-01

Unlike other types of cancer, skin cancer incidence rates are on the rise and adolescent females are particularly likely to tan indoors, a major risk factor. However, little research has examined the role of media use in encouraging or discouraging this dangerous behavior in this population. To empirically assess the links between media use, indoor tanning-related outcome expectations, and behavioral intentions. A survey of adolescent females ( N = 510) ages 15 to 18 in the Southeastern United States assessed demographics, types of media use, and indoor tanning intentions. Significant correlations between media use and indoor tanning outcome expectations were found. Use of interpersonal and social media (i.e., talking on the phone, texting, and online social media) were positively associated with positive outcome expectations about indoor tanning and negatively associated with negative outcome expectations. A path analysis revealed that interpersonal/social media use had indirect associations with indoor tanning intentions via tanning outcome expectations. Mass media use (e.g., news media, entertainment media, and magazines) was not significantly associated with most indoor tanning outcome expectations but did have a direct negative association with behavioral intentions. There are important relationships between media use, indoor tanning outcome expectations, and behavioral intentions. Interpersonal and social media use may help cultivate outcome expectations that encourage indoor tanning, which in turn may increase intentions to tan, while news media consumption in particular may reduce intentions to tan. These findings highlight the social nature of adolescent females and point to specific intervention channels for reducing indoor tanning among this population.

Correlates of intentional tanning among adolescents in the United States: a systematic review of the literature.

PubMed

Holman, Dawn M; Watson, Meg

2013-05-01

Exposure to ultraviolet radiation and a history of sunburn in childhood contribute to risk of skin cancer in adolescence and in adulthood, but many adolescents continue to seek a tan, either from the sun or from tanning beds (i.e., intentional tanning). To understand tanning behavior among adolescents, we conducted a systematic review of the literature to identify correlates of intentional tanning in the United States. We included articles on original research published in English between January 1, 2001, and October 31, 2011, that used self-reported data on intentional tanning by U.S. adolescents aged 8 to 18 years and examined potential correlates of tanning behaviors. Thirteen articles met our criteria; all used cross-sectional survey data and quantitative methods to assess correlates of intentional tanning. Results indicate that multiple factors influence tanning among adolescents. Individual factors that correlated with intentional tanning include demographic factors (female sex, older age), attitudes (preferring tanned skin), and behaviors (participating in other risky or appearance-focused behaviors such as dieting). Social factors correlated with intentional tanning include parental influence (having a parent who tans or permits tanning) and peer influence (having friends who tan). Only four studies examined broad contextual factors such as indoor tanning laws and geographic characteristics; they found that proximity to tanning facilities and geographic characteristics (living in the Midwest or South, living in a low ultraviolet area, and attending a rural high school) are associated with intentional tanning. These findings inform future public health research and intervention efforts to reduce intentional tanning. Published by Elsevier Inc.

Correlates of Intentional Tanning Among Adolescents in the United States: A Systematic Review of the Literature

PubMed Central

Holman, Dawn M.; Watson, Meg

2015-01-01

Purpose Exposure to ultraviolet radiation and a history of sunburn in childhood contribute to risk of skin cancer in adolescence and in adulthood, but many adolescents continue to seek a tan, either from the sun or from tanning beds (i.e., intentional tanning). To understand tanning behavior among adolescents, we conducted a systematic review of the literature to identify correlates of intentional tanning in the United States. Methods We included articles on original research published in English between January 1, 2001, and October 31, 2011, that used self-reported data on intentional tanning by U.S. adolescents aged 8 to 18 years and examined potential correlates of tanning behaviors. Thirteen articles met our criteria; all used cross-sectional survey data and quantitative methods to assess correlates of intentional tanning. Results Results indicate that multiple factors influence tanning among adolescents. Individual factors that correlated with intentional tanning include demographic factors (female sex, older age), attitudes (preferring tanned skin), and behaviors (participating in other risky or appearance-focused behaviors such as dieting). Social factors correlated with intentional tanning include parental influence (having a parent who tans or permits tanning) and peer influence (having friends who tan). Only four studies examined broad contextual factors such as indoor tanning laws and geographic characteristics; they found that proximity to tanning facilities and geographic characteristics (living in the Midwest or South, living in a low ultraviolet area, and attending a rural high school) are associated with intentional tanning. Conclusions These findings inform future public health research and intervention efforts to reduce intentional tanning. PMID:23601612

Method of manufacture of atomically thin boron nitride

DOEpatents

Zettl, Alexander K

2013-08-06

The present invention provides a method of fabricating at least one single layer hexagonal boron nitride (h-BN). In an exemplary embodiment, the method includes (1) suspending at least one multilayer boron nitride across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure. The present invention also provides a method of fabricating single layer hexagonal boron nitride. In an exemplary embodiment, the method includes (1) providing multilayer boron nitride suspended across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure.

Thermal conversion of an iron nitride-silicon nitride precursor into a ferromagnetic nanocomposite

NASA Astrophysics Data System (ADS)

Maya, L.; Thompson, J. R.; Song, K. J.; Warmack, R. J.

1998-01-01

Iron nitride films, FeN, in a pure form and in the form of a nanocomposite in silicon nitride were prepared by reactive sputtering using iron or iron disilicide, respectively, as targets in a nitrogen plasma. Iron nitride decomposes into the elements by heating in vacuum to 800 °C. Intermediate phases such as Fe2N or Fe4N form at lower temperatures. The nanocomposites contain the iron phases as particles with an average size of ˜5 nm dispersed in the amorphous silicon nitride matrix. The magnetic properties of the nanocomposites were established. The precursor FeN-Si3N4 film is paramagnetic, while the Fe-Si3N4, obtained by heating in vacuum, is ferromagnetic and shows typical superparamagnetic behavior. These films are of interest as recording media with superior chemical and mechanical stability and may be encoded by localized heating.

Control of Defects in Aluminum Gallium Nitride ((Al)GaN) Films on Grown Aluminum Nitride (AlN) Substrates

DTIC Science & Technology

2013-02-01

Nord, J.; Albe, K.; Erhart, P.; Nordlund, K. Modelling of Compound Semiconductors: Analytical Bond-order Potential for Gallium , Nitrogen and Gallium ...Control of Defects in Aluminum Gallium Nitride ((Al)GaN) Films on Grown Aluminum Nitride (AlN) Substrates by Iskander G. Batyrev, Chi-Chin Wu...Aluminum Gallium Nitride ((Al)GaN) Films on Grown Aluminum Nitride (AlN) Substrates Iskander G. Batyrev and N. Scott Weingarten Weapons and

Hard carbon nitride and method for preparing same

DOEpatents

Haller, Eugene E.; Cohen, Marvin L.; Hansen, William L.

1992-01-01

Novel crystalline .alpha. (silicon nitride-like)-carbon nitride and .beta. (silicon nitride-like)-carbon nitride are formed by sputtering carbon in the presence of a nitrogen atmosphere onto a single crystal germanium or silicon, respectively, substrate.

Compliance with indoor tanning bans for minors among businesses in the USA.

PubMed

Choy, Courtney C; Cartmel, Brenda; Clare, Rachel A; Ferrucci, Leah M

2017-12-01

Indoor tanning is a known risk factor for skin cancer and is especially dangerous for adolescents. Some states have passed indoor tanning bans for minors, but business compliance with the bans is not well understood. Thus far, studies have assessed ban compliance in one or two states at a time. This study aimed to assess compliance with indoor tanning bans for minors and knowledge of dangers and benefits of tanning among indoor tanning businesses. Female research assistants posing as minors telephoned a convenience sample of 412 businesses in 14 states with tanning bans for minors under age 17 or 18. We evaluated differences in compliance by census region and years since ban was implemented and differences in reported dangers and benefits by compliance. Most (80.1%) businesses told the "minor" caller she could not use the tanning facilities. Businesses in the south and in states with more recent bans were less compliant. Among those (n = 368) that completed the full interview, 52.2% identified burning and 20.1% mentioned skin cancer as potential dangers. However, 21.7% said dangers were no worse than the sun and 10.3% denied any dangers. Stated benefits included vitamin D (27.7%), social/cosmetic (27.2%), and treats skin diseases (26.4%), with only 4.9% reporting no benefits. While most businesses followed the indoor tanning ban when a minor called, one-fifth did not. Many stated inaccurate health claims. Additional enforcement or education might increase compliance with indoor tanning bans and action is needed to prevent businesses from stating false health information.

Changes in sunburn and tanning attitudes among lifeguards over a summer season.

PubMed

Hiemstra, Marieke; Glanz, Karen; Nehl, Eric

2012-03-01

Skin cancer is one of the most common cancers in the United States. Lifeguards are at increased risk of excessive sun exposure and sunburn. We sought to examine changes in: (1) sunburn frequency over a summer while controlling for sun exposure, sun protection habits, and participation in a skin cancer prevention program; and (2) tanning attitudes while controlling for participation in the program. Participants in this study were lifeguards (n = 3014) at swimming pools participating in the Pool Cool program in 2005. Lifeguards completed surveys at the beginning and end of the summer. Sequential regression analyses were used to assess changes in sunburn frequency and tanning attitudes. Sunburn frequency decreased between baseline and follow-up. Having a sunburn over the summer was significantly predicted by baseline sunburn history, ethnicity, skin cancer risk, and sun exposure. The tanning attitude, "People are more attractive if they have a tan," was significantly predicted from baseline tanning attitude and ethnicity. The second tanning attitude, "It helps to have a good base suntan," was significantly predicted by baseline tanning attitude, ethnicity, basic/enhanced group, and moderate skin cancer risk. Self-reported data and limited generalizability to lifeguards at other outdoor pools are limitations. The findings showed that previous sunburn history is an important predictor of sunburn prospectively. In addition, a more risky tanning attitude is an important predictor of future attitudes toward tanning. Active involvement in targeted prevention programs may help to increase preventive behavior and health risk reduction. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Changes in sunburn and tanning attitudes among lifeguards over a summer season

PubMed Central

Hiemstra, Marieke; Glanz, Karen; Nehl, Eric

2013-01-01

Background Skin cancer is one of the most common cancers in the United States. Lifeguards are at increased risk of excessive sun exposure and sunburn. Objectives We sought to examine changes in: (1) sunburn frequency over a summer while controlling for sun exposure, sun protection habits, and participation in a skin cancer prevention program; and (2) tanning attitudes while controlling for participation in the program. Methods Participants in this study were lifeguards (n = 3014) at swimming pools participating in the Pool Cool program in 2005. Lifeguards completed surveys at the beginning and end of the summer. Sequential regression analyses were used to assess changes in sunburn frequency and tanning attitudes. Results Sunburn frequency decreased between baseline and follow-up. Having a sunburn over the summer was significantly predicted by baseline sunburn history, ethnicity, skin cancer risk, and sun exposure. The tanning attitude, “People are more attractive if they have a tan,” was significantly predicted from baseline tanning attitude and ethnicity. The second tanning attitude, “It helps to have a good base suntan,” was significantly predicted by baseline tanning attitude, ethnicity, basic/enhanced group, and moderate skin cancer risk. Limitations Self-reported data and limited generalizability to lifeguards at other outdoor pools are limitations. Conclusion The findings showed that previous sunburn history is an important predictor of sunburn prospectively. In addition, a more risky tanning attitude is an important predictor of future attitudes toward tanning. Active involvement in targeted prevention programs may help to increase preventive behavior and health risk reduction. PMID:21745696

Hard carbon nitride and method for preparing same

DOEpatents

Haller, E.E.; Cohen, M.L.; Hansen, W.L.

1992-05-05

Novel crystalline [alpha](silicon nitride-like)-carbon nitride and [beta](silicon nitride-like)-carbon nitride are formed by sputtering carbon in the presence of a nitrogen atmosphere onto a single crystal germanium or silicon, respectively, substrate. 1 figure.

P-type gallium nitride

DOEpatents

Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.

1997-08-12

Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.

P-type gallium nitride

DOEpatents

Rubin, Michael; Newman, Nathan; Fu, Tracy; Ross, Jennifer; Chan, James

1997-01-01

Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5.times.10.sup.11 /cm.sup.3 and hole mobilities of about 500 cm.sup.2 /V-sec, measured at 250.degree. K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al.

77 FR 37838 - Disregarded Entities and the Indoor Tanning Services Excise Tax

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... 1545-BK38 Disregarded Entities and the Indoor Tanning Services Excise Tax AGENCY: Internal Revenue... the indoor tanning services excise tax. These regulations affect disregarded entities responsible for collecting the indoor tanning services excise tax and owners of those disregarded entities. The text of the...

Risky business: Behaviors associated with indoor tanning in US high school students.

PubMed

Chapman, Stephanie; Ashack, Kurt; Bell, Eric; Sendelweck, Myra Ann; Dellavalle, Robert

2017-09-15

Understanding of associations between indoor tanning and risky health related behaviors such as sexual activity and substance abuse among high school students across the United States is incomplete. To identify risky health related behaviors among high school students utilizing indoor tanning and analyze differences between state specific data. Results from the Youth Risk Behavior Surveillance System (YRBSS) 2013 in 14 different states were analyzed. Participants were 90,414 high school students. Responses to questions assessing indoor tanning habits, sexual activity, and use of substances were analyzed. Sexual activity was associated with indoor tanning in 10 of 14 states, with Nebraska having the strongest association (adjusted odds ratio, 3.8; 95% CI, 2.4-6.2; p<0.001). Indoor tanning was also associated with use of alcohol, marijuana, ecstasy, cocaine, prescription medications, and cigarettes. Only 15 states asked students about their personal history of indoor tanning use, and Minnesota was excluded from our analysis as they administered a non-YRBS questionnaire. Additionally, our study only analyzed results from the 2013 YRBS. Lastly, our data was analyzed in 14 individual data sets, giving a high likelihood of Type 1 error. High school students utilizing indoor tanning are more likely to engage in sexual activity and substance abuse as compared to students who do not utilize indoor tanning.

Frequency spectrum of tantalum at temperatures of 293-2300 K

NASA Astrophysics Data System (ADS)

Semenov, V. A.; Kozlov, Zh. A.; Krachun, L.; Mateescu, G.; Morozov, V. M.; Oprea, A. I.; Oprea, K.; Puchkov, A. V.

2010-05-01

The temperature dependence of the frequency spectrum of tantalum in the temperature range from room temperature to 2300 K has been studied for the first time using inelastic slow-neutron scattering. The inelastic slow-neutron scattering spectra have been measured at different temperatures on a DIN-2PI time-of-flight spectrometer installed at the IBR-2 nuclear reactor (Joint Institute for Nuclear Research, Dubna, Russia) with the use of a TS3000K high-temperature thermostat. From the measured spectra, the frequency spectra of the tantalum crystal lattice have been determined at temperatures of 293, 1584, and 2300 K by the iteration method. As the temperature increases, the frequency spectrum, on the whole, is softened and the specific features manifested themselves at room temperature are smoothed. The variations observed have been explained by the increase in the role of the effects of vibration anharmonism at high temperatures.

Exposure to the 'Dark Side of Tanning' skin cancer prevention mass media campaign and its association with tanning attitudes in New South Wales, Australia.

PubMed

Perez, Donna; Kite, James; Dunlop, Sally M; Cust, Anne E; Goumas, Chris; Cotter, Trish; Walsberger, Scott C; Dessaix, Anita; Bauman, Adrian

2015-04-01

Melanoma is the most common cancer among 15- to 29-year-olds in Australia, with rates increasing with age. The 'Dark Side of Tanning' (DSOT) mass media campaign was developed in 2007 to influence attitudes related to tanning. This study aimed to assess recall and impact of the DSOT campaign. Data were collected using online surveys of 13- to 44-year-olds living in New South Wales in the summer months of 2007-2010 (n = 7490). Regression models were used to determine predictors of recall of DSOT and to investigate associations between exposure to the campaign and tanning attitudes. The campaign achieved consistently high recall (unprompted recall 42-53% during campaign periods; prompted recall 76-84%). Those who recalled DSOT advertisements had a higher likelihood of reporting negative tanning attitudes compared with those who reported no recall, after adjusting for other factors (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.01-1.27 for unprompted recall; OR 1.19, 95% CI 1.03-1.36 for prompted recall). Being interviewed in later campaign years was also a significant predictor of negative tanning attitudes (e.g. fourth year of campaign versus first year: OR 1.24, 95% CI 1.01-1.53). These results suggest that mass media campaigns have potential to influence tanning-related attitudes and could play an important role in skin cancer prevention. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Experimental observation of boron nitride chains.

PubMed

Cretu, Ovidiu; Komsa, Hannu-Pekka; Lehtinen, Ossi; Algara-Siller, Gerardo; Kaiser, Ute; Suenaga, Kazu; Krasheninnikov, Arkady V

2014-12-23

We report the formation and characterization of boron nitride atomic chains. The chains were made from hexagonal boron nitride sheets using the electron beam inside a transmission electron microscope. We find that the stability and lifetime of the chains are significantly improved when they are supported by another boron nitride layer. With the help of first-principles calculations, we prove the heteroatomic structure of the chains and determine their mechanical and electronic properties. Our study completes the analogy between various boron nitride and carbon polymorphs, in accordance with earlier theoretical predictions.

Atomization from a tantalum surface in graphite furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Gregoire, D. C.; Chakrabarti, C. L.

The mechanism of atom formation of U, V, Mo, Ni, Mn, Cu and Mg atomized from pyrolytic graphite and tantalum metal surfaces has been studied. The mechanism of atom formation for U from a graphite tube atomizer is reported for the first time. The peak absorbance for U and Cu is increased by factors of 59.7 and 2.0, respectively, whereas that of V, Mo and Ni is reduced by several orders of magnitude when they are atomized from a tantalum metal surface. The peak absorbance of Mn and Mg is not appreciably affected by the material of the atomization surface. Interaction of Mn and Mg with the graphite surface and formation of their refractory carbides was found to be negligible. Uranium forms a refractory carbide when heated from a graphite surface.

International prevalence of indoor tanning: a systematic review and meta-analysis.

PubMed

Wehner, Mackenzie R; Chren, Mary-Margaret; Nameth, Danielle; Choudhry, Aditi; Gaskins, Matthew; Nead, Kevin T; Boscardin, W John; Linos, Eleni

2014-04-01

Indoor tanning is a known carcinogen, but the scope of exposure to this hazard is not known. To summarize the international prevalence of exposure to indoor tanning. Studies were identified through systematic searches of PubMed (1966 to present), Scopus (1823 to present), and Web of Science (1898 to present) databases, last performed on March 16, 2013. We also hand searched reference lists to identify records missed by database searches and publicly available data not yet published in the scientific literature. Records reporting a prevalence of indoor tanning were eligible for inclusion. We excluded case-control studies, reports with insufficient study information, and reports of groups recruited using factors related to indoor tanning. Two independent investigators performed searches and study selection. Our search yielded 1976 unique records. After exclusions, 161 records were assessed for eligibility in full text, and 88 were included. Two independent investigators extracted data on characteristics of study participants, inclusion/exclusion criteria, data collection format, outcomes, and statistical methods. Random-effects meta-analyses were used to summarize the prevalence of indoor tanning in different age categories. We calculated the population proportional attributable risk of indoor tanning in the United States, Europe, and Australia for nonmelanoma skin cancer (NMSC) and melanoma. Ever and past-year exposure to indoor tanning. The summary prevalence of ever exposure was 35.7% (95% CI, 27.5%-44.0%) for adults, 55.0% (33.0%-77.1%) for university students, and 19.3% (14.7%-24.0%) for adolescents. The summary prevalence of past-year exposure was 14.0% (95% CI, 11.5%-16.5%) for adults, 43.1% (21.7%-64.5%) for university students, and 18.3% (12.6%-24.0%) for adolescents. These results included data from 406 696 participants. The population proportional attributable risk were 3.0% to 21.8% for NMSC and 2.6% to 9.4% for melanoma, corresponding to more than 450�

The association of tanning behavior with psycho-tropic medication use among young adult women.

PubMed

Heckman, Carolyn J; Munshi, Teja; Darlow, Susan; Kloss, Jacqueline D; Manne, Sharon L; Perlis, Clifford; Oslin, David

2016-01-01

Despite its known association with skin cancer, tanning remains popular among young adult women. Indoor tanning behavior has been found to be associated with affective and addictive disorders. To better understand potential psychological and biological mechanisms of tanning behavior, we investigated associations between tanning and medication (psychotropic and other) use among young women. Two hundred and fifty-three women age 18-29 years old were recruited from two northeastern university campus communities. Women self-reported tanning frequency and chronic medication use. In both univariate and multivariate analyses, indoor tanning ≥12 times last year was significantly associated with use of psychotropic medication and anti-depressants in particular. Sunbathing was not associated with medication use. Potential reasons for associations between tanning and psychotropic medication use are discussed. Indoor tanners should be warned that some psychotropic medications are photosensitizing, thus increasing risk for burns and other skin damage from indoor tanning.

Social Predictors of Sunscreen and Self-Tanning Product Use

ERIC Educational Resources Information Center

Mosher, Catherine E.; Danoff-Burg, Sharon

2005-01-01

This study investigated social predictors of sunscreen and self-tanning product use among 164 undergraduates. Immediate family members' sunscreen use predicted participants' facial sunscreen use while sunbathing but not their sunscreen use on other areas of the body. In addition, familial support of a tanned appearance was inversely associated…

[Superbrown beauty : The surface of tanorexia and tanning dependence].

PubMed

Harth, W

2017-12-01

Brown skin symbolizes fitness, health, youthfulness and beauty, combined with leisure, activity, and joy of life in the Central European culture. Tanorexia is a tanning dependence that describes the morbid excessive desire for constant skin tanning. Particularly young women are affected. This article shows the underlying psychodermatological disorders.

Density of Indoor Tanning Facilities in 116 Large U.S. Cities

PubMed Central

Hoerster, Katherine D.; Garrow, Rebecca L.; Mayer, Joni A.; Clapp, Elizabeth J.; Weeks, John R.; Woodruff, Susan I.; Sallis, James F.; Slymen, Donald J.; Patel, Minal R.; Sybert, Stephanie A.

2009-01-01

Background U.S. adolescents and young adults are using indoor tanning at high rates, even though it has been linked to both melanoma and squamous cell cancer. Because the availability of commercial indoor tanning facilities may influence use, data are needed on the number and density of such facilities. Methods In March 2006, commercial indoor tanning facilities in 116 large U.S. cities were identified, and the number and density (per 100,000 population) were computed for each city. Bivariate and multivariate analyses conducted in 2008 tested the association between tanning-facility density and selected geographic, climatologic, demographic, and legislative variables. Results Mean facility number and density across cities were 41.8 (SD=30.8) and 11.8 (SD=6.0), respectively. In multivariate analysis, cities with higher percentages of whites and lower ultraviolet (UV)index scores had significantly higher facility densities than those with lower percentages of whites and higher UV index scores. Conclusions These data indicate that commercial indoor tanning is widely available in the urban U.S., and this availability may help explain the high usage of indoor tanning. PMID:19215849

Randomized controlled trial of a web-based indoor tanning intervention: Acceptability and preliminary outcomes.

PubMed

Stapleton, Jerod L; Manne, Sharon L; Darabos, Katie; Greene, Kathryn; Ray, Anne E; Turner, Amber L; Coups, Elliot J

2015-12-01

This article describes the acceptability and preliminary behavioral outcomes of a pilot randomized control trial of a web-based indoor tanning intervention for young adult women. The intervention targets indoor tanning users' perceptions of the benefits and value of tanning and addresses the role of body image-related constructs in indoor tanning. Participants were 186 young adult women who reported indoor tanning at least once in the past 12 months. The study design was a 2-arm randomized controlled trial with pre- and postintervention assessments and random assignment to an intervention or control condition. Intervention acceptability was assessed by obtaining participants' evaluation of the intervention. Regression analyses were used to test for intervention condition differences in preliminary behavioral outcomes measured at 6 weeks postintervention. Participants provided favorable evaluations of the intervention on several dimensions and a highly positive overall rating. Intervention participants were more likely to report abstaining from indoor tanning and indicated a lower likelihood of using indoor tanning in the future compared with control participants on the postintervention assessment. No differences were found for sunburns. The results of this pilot randomized controlled trial provide evidence that the indoor tanning intervention is acceptable to participants and may encourage cessation of indoor tanning behavior. The findings provide preliminary support for an indoor tanning intervention that engages tanners to challenge their beliefs about the benefits of indoor tanning. The use of a web-based indoor tanning intervention is unique and provides strong potential for dissemination. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Current versus ideal skin tones and tanning behaviors in Caucasian college women.

PubMed

Hemrich, Ashley; Pawlow, Laura; Pomerantz, Andrew; Segrist, Dan

2014-01-01

To explore tanning behaviors and whether a discrepancy between current and ideal skin tones exists. The sample included 78 Caucasian women from a mid-sized midwestern university. Data were collected in spring 2012 via a paper questionnaire. Sixty-two percent of the sample regularly engaged in salon tanning at least once per week, with an average frequency of 2.5 visits per week. Thirteen percent endorsed regularly tanning 4 or more times per week, and 26% reported visiting a tanning bed more than once in a 24-hour period. Ninety-four percent wished their current skin tone was darker, and ideal tone was significantly darker than current tone. The data suggest that the young Caucasian women in this sample tend to be dissatisfied with their current skin tone to an extent that leads the majority of them to engage in risky, potentially cancer-causing behavior by either salon tanning or considering tanning in the future as time and finances become available.

Molecular Beam Epitaxial Growth of Iron Nitrides on Zinc-Blende Gallium Nitride(001)

NASA Astrophysics Data System (ADS)

Pak, Jeongihm; Lin, Wenzhi; Chinchore, Abhijit; Wang, Kangkang; Smith, Arthur R.

2008-03-01

Iron nitrides are attractive materials for their high magnetic moments, corrosion, and oxidation resistance. We present the successful epitaxial growth of iron nitride on zinc-blende gallium nitride (c-GaN) in order to develop a novel magnetic transition metal nitride/semiconductor system. First, GaN is grown on magnesium oxide (MgO) substrates having (001) orientation using rf N2-plasma molecular beam epitaxy. Then we grow FeN at substrate temperature of ˜ 210 ^oC up to a thickness of ˜ 10.5 nm. In-situ reflection high-energy electron diffraction (RHEED) is used to monitor the surface during growth. Initial results suggest that the epitaxial relationship is FeN[001] || GaN[001] and FeN[100] || GaN[100]. Work in progress is to investigate the surface using in-situ scanning tunneling microscopy (STM) to reveal the surface structure at atomic scale, as well as to explore more Fe-rich magnetic phases.

IET. Aerial view during construction, facing southwest. Control building (TAN620) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

IET. Aerial view during construction, facing southwest. Control building (TAN-620) in center. Retaining wall in place on west side. Tank building (TAN-627) and fuel transfer pump building (TAN-625) north of control building. Shielded roadway not yet built. Foundation of stack at right edge of view. Date: November 24, 1954. INEEL negative no. 13198 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Mood Changes After Indoor Tanning Among College Women: Associations with Psychiatric/Addictive Symptoms

PubMed Central

Heckman, Carolyn; Darlow, Susan; Cohen-Filipic, Jessye; Kloss, Jacqueline

2016-01-01

Indoor tanning (IT) has been linked with psychiatric and addictive symptoms, and frequent tanning may indicate tanning dependence (addiction). The current study evaluated the effects of an IT episode on mood states and the association of these effects with psychiatric and addictive symptoms among young adult female indoor tanners. One-hundred thirty-nine female university students aged 18-25 years who had indoor tanned completed an online survey including the Positive and Negative Affects Scales and a standardized psychiatric interview (the MINI International Neuropsychiatric Interview) via telephone. Psychiatric and addictive symptoms were relatively common among these young adult female indoor tanners. Overall, participants reported significant decreases in both negative (upset, scared, irritable, nervous, jittery, afraid) and positive (feeling interested) mood states after their most recent tanning episode. Multivariable linear regression analyses showed that more frequent indoor tanning in the past month and symptoms of illicit drug use disorders were associated with decreases in negative mood, and symptoms of generalized anxiety disorder were associated with a decrease in feeling interested. In summary, indoor tanners report relatively high rates of psychiatric and substance use symptoms, including symptoms of tanning dependence, and indoor tanning appears to alter mood. Women with certain substance use and psychiatric characteristics may be more vulnerable to such mood changes after tanning indoors. Further research is needed to clarify the relationships among these variables. PMID:27403462

Mood Changes After Indoor Tanning Among College Women: Associations with Psychiatric/Addictive Symptoms.

PubMed

Heckman, Carolyn; Darlow, Susan; Cohen-Filipic, Jessye; Kloss, Jacqueline

2016-06-23

Indoor tanning (IT) has been linked with psychiatric and addictive symptoms, and frequent tanning may indicate tanning dependence (addiction). The current study evaluated the effects of an IT episode on mood states and the association of these effects with psychiatric and addictive symptoms among young adult female indoor tanners. One-hundred thirty-nine female university students aged 18-25 years who had indoor tanned completed an online survey including the Positive and Negative Affects Scales and a standardized psychiatric interview (the MINI International Neuropsychiatric Interview) via telephone. Psychiatric and addictive symptoms were relatively common among these young adult female indoor tanners. Overall, participants reported significant decreases in both negative (upset, scared, irritable, nervous, jittery, afraid) and positive (feeling interested) mood states after their most recent tanning episode. Multivariable linear regression analyses showed that more frequent indoor tanning in the past month and symptoms of illicit drug use disorders were associated with decreases in negative mood, and symptoms of generalized anxiety disorder were associated with a decrease in feeling interested. In summary, indoor tanners report relatively high rates of psychiatric and substance use symptoms, including symptoms of tanning dependence, and indoor tanning appears to alter mood. Women with certain substance use and psychiatric characteristics may be more vulnerable to such mood changes after tanning indoors. Further research is needed to clarify the relationships among these variables.

College tanning behaviors, attitudes, beliefs, and intentions: A systematic review of the literature.

PubMed

Gambla, William C; Fernandez, Alyssa M; Gassman, Natalie R; Tan, Marcus C B; Daniel, Casey L

2017-12-01

Despite well-established links between exposure to ultraviolet radiation (UVR) and skin cancer, UVR-based tanning behaviors persist among college students. Understanding tanning motivations, perceptions, barriers, and demographic characteristics of this population is critical to modifying these behaviors, but is limited by variability in study design, sample size, and outcomes measured in the current literature. To help clarify the tanning behaviors of this population and provide a concise reference for future studies, this review examines existing reports to determine the comparability of tanning behaviors across multiple U.S. college populations. A systematic review of the literature was performed in July 2016 to identify studies investigating tanning behaviors among U.S. college students. Twenty-three studies met inclusion criteria. High rates of indoor tanning (IT) and outdoor tanning (OT) were found among college students. Key motivators included appearance, emotion, health perceptions, and the influence of parents, peers, and the media. Misconceptions regarding skin protection, low rates of sun protective behaviors, and tanning dependence were barriers against safe UVR exposure. Understudied demographic factors may account for variance in observed tanning behaviors, emphasizing the need for standardization efforts to consistently identify trends associated with geographical region, age, year in college, and sex. The findings presented in this review reaffirm that college students are at high risk for tanning-associated skin cancer, emphasizing the critical need for effective, targeted interventions. Improved interventions will reduce the burden of skin cancer within this group, ultimately contributing to longer, healthier lives. Copyright © 2017 Elsevier Inc. All rights reserved.

A&M. TAN607. Construction view, facing southwest. At upper left of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. TAN-607. Construction view, facing southwest. At upper left of view, north-wall equipment and operating galleries take shape on hot shop. Pumice-block side of storage pool section in center left of view. Water filter building (TAN-608) next to north wall of pool. Hot liquid waste building (TAN-616) at right of view. Note concrete construction of TAN-608 and 616. Date: January 18, 1954. INEEL negative no. 9604 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Use of indoor tanning facilities by white adolescents in the United States.

PubMed

Demko, Catherine A; Borawski, Elaine A; Debanne, Sara M; Cooper, Kevin D; Stange, Kurt C

2003-09-01

Indoor tanning is a risk factor for skin cancer, but the population-based prevalence of this behavior among adolescents is not clearly known. To describe the prevalence of tanning booth use among white US adolescents and to assess its association with sociodemographic factors, health behaviors, and appearance. A nationally representative sample of 6903 non-Hispanic white adolescents, aged 13 to 19 years, who participated in Wave II (between April 1, 1996, and August 31, 1996) of the National Longitudinal Study of Adolescent Health. Frequency of lifetime use of indoor artificial tanning facilities. With the data weighted to national levels, 36.8% of the white female adolescents and 11.2% of the white male adolescents have used a tanning booth at least once in their life, while 28.1% and 6.9% of the female and male adolescents, respectively, reported tanning booth use 3 or more times. The percentage of female adolescents using tanning booths 3 or more times increased with age, from 11.2% of the 13- to 14-year-olds to 47.0% of 18- to 19-year-olds and also increased with greater tanning ability, from 12.6% of the poor tanners to 38.1% of those with a strong tan response. After multivariate adjustment, those residing in the Midwest (adjusted odds ratio [aOR], 2.38; 95% confidence interval [CI], 1.53-3.68) or South (aOR, 2.91; 95% CI, 1.89-4.53), attending a rural high school (aOR, 1.80; 95% CI, 1.09-2.98), and reporting the use of 2 or 3 substances (aOR, 3.06; 95% CI, 2.44-3.82) were more likely to use indoor tanning facilities, as were dieters (aOR, 1.26; 95% CI, 1.01-1.57) regardless of their body mass index. Decreased odds of indoor tanning were observed among those with a college-educated mother (aOR, 0.68; 95% CI, 0.51-0.90) and greater cognitive ability (per 10-point score increase; aOR, 0.89; 95% CI, 0.82-0.96) while routine participation in physical activity significantly lowered the odds of indoor tanning only among female adolescents. Indoor tanning is

2014 NEPP Tasks Update for Ceramic and Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2014-01-01

Presentation describes recent development in research on MnO2, wet, and polymer tantalum capacitors. Low-voltage failures in multilayer ceramic capacitors and techniques to reveal precious metal electrode (PME) and base metal electrode (BME) capacitors with cracks are discussed. A voltage breakdown technique is suggested to select high quality low-voltage BME ceramic capacitors.

Developing Multilayer Thin Film Strain Sensors With High Thermal Stability

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Gonzalez, Jose M., III

2006-01-01

A multilayer thin film strain sensor for large temperature range use is under development using a reactively-sputtered process. The sensor is capable of being fabricated in fine line widths utilizing the sacrificial-layer lift-off process that is used for micro-fabricated noble-metal sensors. Tantalum nitride films were optimized using reactive sputtering with an unbalanced magnetron source. A first approximation model of multilayer resistance and temperature coefficient of resistance was used to set the film thicknesses in the multilayer film sensor. Two multifunctional sensors were fabricated using multilayered films of tantalum nitride and palladium chromium, and tested for low temperature resistivity, TCR and strain response. The low temperature coefficient of resistance of the films will result in improved stability in thin film sensors for low to high temperature use.

Early-Onset Basal Cell Carcinoma and Indoor Tanning: A Population-Based Study

PubMed Central

Zens, M. Scot; Li, Zhigang; Stukel, Therese A.; Perry, Ann E.; Gilbert-Diamond, Diane; Sayarath, Vicki; Stephenson, Rita S.; Barton, Dorothea; Nelson, Heather H.; Spencer, Steven K.

2014-01-01

OBJECTIVE: Indoor tanning with UV radiation–emitting lamps is common among adolescents and young adults. Rising incidence rates of basal cell carcinoma (BCC) have been reported for the United States and elsewhere, particularly among those diagnosed at younger ages. Recent epidemiologic studies have raised concerns that indoor tanning may be contributing to early occurrence of BCC, and younger people may be especially vulnerable to cancer risk associated with this exposure. Therefore, we sought to address these issues in a population-based case–control study from New Hampshire. METHODS: Data on indoor tanning were obtained on 657 cases of BCC and 452 controls ≤50 years of age. RESULTS: Early-onset BCC was related to indoor tanning, with an adjusted odds ratio (OR) of 1.6 (95% confidence interval, 1.3–2.1). The strongest association was observed for first exposure as an adolescent or young adult, with a 10% increase in the OR with each age younger at first exposure (OR per year of age ≤23 = 1.1; 95% confidence interval, 1.0–1.2). Associations were present for each type of device examined (ie, sunlamps, tanning beds, and tanning booths). CONCLUSIONS: Our findings suggest early exposure to indoor tanning increases the risk of early development of BCC. They also underscore the importance of counseling adolescents and young adults about the risks of indoor tanning and for discouraging parents from consenting minors to this practice. PMID:24958589

Early-onset basal cell carcinoma and indoor tanning: a population-based study.

PubMed

Karagas, Margaret R; Zens, M Scot; Li, Zhigang; Stukel, Therese A; Perry, Ann E; Gilbert-Diamond, Diane; Sayarath, Vicki; Stephenson, Rita S; Barton, Dorothea; Nelson, Heather H; Spencer, Steven K

2014-07-01

Indoor tanning with UV radiation-emitting lamps is common among adolescents and young adults. Rising incidence rates of basal cell carcinoma (BCC) have been reported for the United States and elsewhere, particularly among those diagnosed at younger ages. Recent epidemiologic studies have raised concerns that indoor tanning may be contributing to early occurrence of BCC, and younger people may be especially vulnerable to cancer risk associated with this exposure. Therefore, we sought to address these issues in a population-based case-control study from New Hampshire. Data on indoor tanning were obtained on 657 cases of BCC and 452 controls ≤50 years of age. Early-onset BCC was related to indoor tanning, with an adjusted odds ratio (OR) of 1.6 (95% confidence interval, 1.3-2.1). The strongest association was observed for first exposure as an adolescent or young adult, with a 10% increase in the OR with each age younger at first exposure (OR per year of age ≤23 = 1.1; 95% confidence interval, 1.0-1.2). Associations were present for each type of device examined (ie, sunlamps, tanning beds, and tanning booths). Our findings suggest early exposure to indoor tanning increases the risk of early development of BCC. They also underscore the importance of counseling adolescents and young adults about the risks of indoor tanning and for discouraging parents from consenting minors to this practice. Copyright © 2014 by the American Academy of Pediatrics.

Alkyl group effects on CO insertion into coordinatively unsaturated early-transition-metal alkyls. Preparations and the first structural characterizations of tantalum enolate-O and tantalum. eta. sup 2 -acyl complexes

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

Meyer, T.Y.; Garner, L.R.; Baenziger, N.C.

1990-10-03

Low-pressure carbonylation of the mono(peralkylcyclopentadienyl)tantalum(V) alkyls ({eta}-C{sub 5}Me{sub 4}R)TaR{prime}Cl{sub 3} (R = Me, Et; R{prime} = CH{sub 2}C{sub 6}H{sub 4}-p-Me, CH{sub 2}CMe{sub 3}) yields either the O-bound enolate or the {eta}{sup 2}-acyl as shown by ir/NMR spectroscopy and x-ray diffractometry. The p-tolyl enolate ({eta}-C{sub 5}Me{sub 5})Ta(OCH{double bond}CHC{sub 6}H{sub 4}-p-Me)Cl{sub 3}, derived directly from carbonylation of the tantalum 4-methylbenzyl precursor, is shown to possess a cis configuration in solution and in the solid state. Key structural features from a single-crystal x-ray diffraction study of the tetrahydrofuran-ligated enolate complex are reported. The mechanism of formation of the enolate from carbonylation of themore » 4-methylbenzyl complex is discussed. The previously reported acyl ({eta}-C{sub 5}Me{sub 4}R)Ta(C(O)CH{sub 2}CMe{sub 3})Cl{sub 3} has been reexamined and found to possess a symmetric, strongly distorted {eta}{sup 2}-acyl coordination by solution {sup 1}H NMR spectroscopy and solid-state x-ray diffractometry. The molecular structures of ({eta}-C{sub 5}Me{sub 5})Ta(OCH{double bond}CHC{sub 6}H{sub 4}-p-Me)Cl{sub 3} and ({eta}-C{sub 5}Me{sub 5})Ta(C(O)CH{sub 2}CMe{sub 3})Cl{sub 3}, which are reported here, are the first structural determinations of a tantalum enolate and of a tantalum {eta}{sup 2}-acyl. 41 refs., 2 figs., 8 tabs.« less

A Cross-Sectional Study of Indoor Tanning in Fitness Centres.

PubMed

Huang, Christina M; Kirchhof, Mark G

Ultraviolet (UV) radiation is a human carcinogen and is associated with the development of skin cancer. The promotion of indoor tanning (IT) at fitness centres is of particular concern as it reinforces the idea that a tan is associated with health and fitness. The purpose of this study was to investigate the prevalence of IT in fitness centres, with an emphasis on determining the financial costs, adherence to regulations, and safety precautions. Ten cities, representing 9 different Canadian provinces, were chosen for the study. From each province, a minimum of 20 and a maximum of 30 fitness centres were randomly selected from the Yellow Pages website. Each fitness centre was contacted by the principal investigator and inquiries were made from a consumer's perspective. Of the 203 gyms surveyed, 43% (88/203) offered tanning facilities. Of these, 10.23% (9/88) were found to be noncompliant with the provincial IT regulations for age and/or time between tanning sessions. Despite the known risks of IT, not all fitness centres are compliant with provincial legislations regarding IT, and some continue to promote tanning access to minors.

LOFT complex, camera facing west. Mobile entry (TAN624) is position ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LOFT complex, camera facing west. Mobile entry (TAN-624) is position next to containment building (TAN-650). Shielded roadway entrance in view just below and to right of stack. Borated water tank has been covered with weather shelter and is no longer visible. ANP hangar (TAN-629) in view beyond LOFT. Date: 1974. INEEL negative no. 74-4191 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Boron nitride housing cools transistors

NASA Technical Reports Server (NTRS)

1965-01-01

Boron nitride ceramic heat sink cools transistors in r-f transmitter and receiver circuits. Heat dissipated by the transistor is conducted by the boron nitride housing to the metal chassis on which it is mounted.

Youth access to indoor tanning salons in urban versus rural/suburban communities.

PubMed

Nahar, Vinayak K; Rosenthal, Meagen; Lemon, Stephenie C; Kane, Kevin; Cheng, Jie; Oleski, Jessica L; Li, Wenjun; Hillhouse, Joel J; Pagoto, Sherry L

2018-03-01

Research suggests that youth proximity to tanning salons may promote use; however, little is known about tanning salon proximity to schools. We assessed the proximity of tanning salons to schools in urban versus rural/suburban communities across Worcester County, Massachusetts (population > 800K). To put findings in context, we compared school proximity to tanning salons to school proximity to McDonald's restaurants, a large franchise that also caters to young people. Accessibility was measured by ArcGIS 10.2 Network Analyzer (ESRI, Redlands, CA, USA) and the most current road network data layer from Massachusetts Department of Transportation (MassDOT). A total of 145 schools were observed in the study area, of which about 39% of schools were within 1 mile from a tanning salon. Urban schools (53.41%) had a higher proportion within 1 mile of a tanning salon than rural/suburban schools (17.54%; P < .001). More schools (39.31%) were within 1 mile of a tanning salon than schools within 1 mile of a McDonald's (22.70%; P < .001). Schools may be particularly impactful for implementing skin cancer prevention programing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reasons for tanning bed use: a survey of community college students in North Carolina.

PubMed

Neenan, Ashley; Lea, C Suzanne; Lesesky, Erin B

2012-01-01

Tanning bed use is classified as carcinogenic and is associated with an increased risk of skin cancer. The aim of this cross-sectional survey was to identify the most commonly stated reasons for tanning bed use among a sample of male and female community college students in eastern North Carolina. A brief, self-administered survey was distributed to students during English, Art, or Psychology class periods in 5 eastern North Carolina community colleges during the 2010 fall semester. The 95% response rate consisted of 487 returned surveys. Of the 487 respondents, 12.7% (N = 62) were current users, 24.5% (N = 119) were past users, and 62.2% (N = 303) reported never using tanning beds. Women (79%) were more likely than men (18%) to be current or former tanning bed users. Three African Americans reported current tanning bed use (4.8%). Reasons for tanning bed use were similar among men and women, with "I think I look better when I am tan" being the most commonly cited reason (70.2%) for tanning bed use. A convenience sample limits generalizability to all North Carolina students attending community college. Current tanning bed use was not widely reported. However, educational strategies for preventing tanning bed initiation or recurrence among male and female community college students should include appearance-driven factors.

Prevalence of Tanning Addiction and Behavioral Health Conditions among Ethnically and Racially Diverse Adolescents.

PubMed

Miller, Kimberly A; Piombo, Sarah E; Cho, Junhan; Higgins, Shauna; Wysong, Ashley; Sussman, Steve; Cockburn, Myles G; Leventhal, Adam M

2018-02-23

Evidence indicates that tanning may be addictive and is associated with other behavioral health conditions. Few studies have examined tanning addiction among adolescents. We performed a cross-sectional study to explore the relationship between tanning addiction, substance use, and psychological conditions among a racially and ethnically diverse adolescent population. Tanning addiction was assessed using the modified CAGE measure among 11th grade students in Los Angeles (N = 2,637; response rate 78%). Overall, 7.02% of the sample met tanning addiction criteria. Tanning addiction was significantly associated with past 30-day smoking and marijuana use, problem substance use, depression, panic disorder, obsessive-compulsive disorder, and bipolar disorder in regression models. After controlling for all significant substance use and psychological variables, we found that problem marijuana use and obsessive-compulsive disorder remained significantly associated with tanning addiction (odds ratio = 2.06 [95% confidence interval = 1.03-4.09] and odds ratio = 2.54 [95% confidence interval = 1.73-3.72], respectively.) Tanning addiction was also significantly associated with multiple problem substance use and behavioral health conditions. Our findings indicate an appreciable prevalence of tanning addiction among ethnically and racially diverse adolescents and suggest the importance of addressing tanning addiction in the context of comorbid behavioral conditions to reduce this high-risk behavior among diverse youth. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Silicon nitride/silicon carbide composite powders

DOEpatents

Dunmead, Stephen D.; Weimer, Alan W.; Carroll, Daniel F.; Eisman, Glenn A.; Cochran, Gene A.; Susnitzky, David W.; Beaman, Donald R.; Nilsen, Kevin J.

1996-06-11

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

Study of surge current effects on solid tantalum capacitors

NASA Technical Reports Server (NTRS)

1980-01-01

Results are presented of a 2,000 hour cycled life test program conducted to determine the effect of short term surge current screening on approximately 47 micron f/volt solid tantalum capacitors. The format provides average values and standard deviations of the parameters, capacitance, dissipation factor, and equivalent series resistance at 120 Hz, 1KHz, abd 40 KHz.

Tanning and increased nevus development in very-light-skinned children without red hair.

PubMed

Aalborg, Jenny; Morelli, Joseph G; Mokrohisky, Stefan T; Asdigian, Nancy L; Byers, Tim E; Dellavalle, Robert P; Box, Neil F; Crane, Lori A

2009-09-01

To examine the relationship between tanning and nevus development in very-light-skinned children. Prospective cohort nested within a randomized controlled trial. Skin examinations in 3 consecutive years (2004, 2005, and 2006) included full-body counts of nevi, skin color and tanning measurement using colorimetry, and hair and eye color evaluation by comparison with charts. Telephone interviews of parents provided sun exposure, sun protection, and sunburn history. Large managed-care organization and private pediatric offices in the Denver, Colorado, metropolitan area. A total of 131 very-light-skinned white children without red hair and 444 darker-skinned white children without red hair born in Colorado in 1998. Full-body nevus counts at ages 6 to 8 years. Among very-light-skinned white children, geometric mean numbers of nevi for minimally tanned children were 14.8 at age 6 years; 18.8 at age 7 years; and 22.3 at age 8 years. Mean numbers of nevi for tanned children were 21.2 at age 6 years; 27.9 at age 7 years; and 31.9 at age 8 years. Differences in nevus counts between untanned and tanned children were statistically significant at all ages (P < .05 for all comparisons). The relationship between tanning and number of nevi was independent of the child's hair and eye color, parent-reported sun exposure, and skin phototype. Among darker-skinned white children, there was no relationship between tanning and nevi. Very-light-skinned children who tan (based on objective measurement) develop more nevi than children who do not tan. These results suggest that light-skinned children who develop tans may be increasing their risk for developing melanoma later in life.

Tanning lamps: health effects and reclassification by the Food and Drug Administration.

PubMed

Ernst, Alexander; Grimm, Amanda; Lim, Henry W

2015-01-01

Tanning lamps have long been considered a class I medical device under regulation by the Food and Drug Administration (FDA). A growing body of research has repeatedly documented the association between elective indoor tanning and several negative health consequences. These accepted findings have prompted action by the FDA to officially reclassify tanning lamps as a class II medical device. The main purpose of this review is to update practitioners on the current state of tanning lamp classification and highlight the practical implications of this recent change. This information can be used by clinicians to easily reference this important action, and empower patients with a better understanding of the risks associated with indoor tanning. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

The potential carcinogenic risk of tanning beds: clinical guidelines and patient safety advice.

PubMed

Mogensen, Mette; Jemec, Gregor Be

2010-10-28

In 2009, the WHO listed ultraviolet (UV) radiation as a group 1 carcinogen. In spite of this, each year, millions of people tan indoor in Western countries. The aim of this review is to summarize evidence of tanning bed carcinogenesis and to present guidelines for use of tanning beds and patient safety advice. A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers. Use of indoor tanning beds represents a significant and avoidable risk factor for the development of both melanoma and nonmelanoma skin cancers. Frequent tanners are more often adolescent females. Tanning beds have additional potential adverse effects such as burns, solar skin damage, infection, and possibly also addictive behavior. The effort in preventing UV light-induced carcinogenesis should currently be aimed at developing new strategies for public health information. Tanning beds are one preventable source of UV radiation. In the majority of people solar UV radiation continues to be the major factor and therefore anti-tanning campaigns must always include sunbathers.

The potential carcinogenic risk of tanning beds: clinical guidelines and patient safety advice

PubMed Central

Mogensen, Mette; Jemec, Gregor BE

2010-01-01

Introduction: In 2009, the WHO listed ultraviolet (UV) radiation as a group 1 carcinogen. In spite of this, each year, millions of people tan indoor in Western countries. The aim of this review is to summarize evidence of tanning bed carcinogenesis and to present guidelines for use of tanning beds and patient safety advice. Methods: A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers. Results: Use of indoor tanning beds represents a significant and avoidable risk factor for the development of both melanoma and nonmelanoma skin cancers. Frequent tanners are more often adolescent females. Tanning beds have additional potential adverse effects such as burns, solar skin damage, infection, and possibly also addictive behavior. Discussion: The effort in preventing UV light-induced carcinogenesis should currently be aimed at developing new strategies for public health information. Tanning beds are one preventable source of UV radiation. In the majority of people solar UV radiation continues to be the major factor and therefore anti-tanning campaigns must always include sunbathers. PMID:21188119

Photodetectors using III-V nitrides

DOEpatents

Moustakas, Theodore D.; Misra, Mira

1997-01-01

A photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The photodetector includes a substrate with interdigitated electrodes formed on its surface. The substrate has a sapphire base layer, a buffer layer formed from a III-V nitride and a single crystal III-V nitride film. The three layers are formed by electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-assisted MBE). Use of the ECR-assisted MBE process allows control and predetermination of the electrical properties of the photodetector.

Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

NASA Technical Reports Server (NTRS)

Skalare, Anders; McGrath, William; Bumble, Bruce; LeDuc, Henry

2004-01-01

A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

Preparation of refractory cermet structures for lithium compatibility testing

NASA Technical Reports Server (NTRS)

Heestand, R. L.; Jones, R. A.; Wright, T. R.; Kizer, D. E.

1973-01-01

High-purity nitride and carbide cermets were synthesized for compatability testing in liquid lithium. A process was developed for the preparation of high-purity hafnium nitride powder, which was subsequently blended with tungsten powder or tantalum nitride and tungsten powders and fabricated into 3 in diameter billets by uniaxial hot pressing. Specimens were then cut from the billets for compatability testing. Similar processing techniques were applied to produce hafnium carbide and zirconium carbide cermets for use in the testing program. All billets produced were characterized with respect to chemistry, structure, density, and strength properties.

Tensile strength of aluminium nitride films

NASA Astrophysics Data System (ADS)

Zong, Deng Gang; Ong, Chung Wo; Aravind, Manju; Tsang, Mei Po; Loong Choy, Chung; Lu, Deren; Ma, Dejun

2004-11-01

Two-layered aluminium nitride (AlN)/silicon nitride microbridges were fabricated for microbridge tests to evaluate the elastic modulus, residual stress and tensile strength of the AlN films. The silicon nitride layer was added to increase the robustness of the structure. In a microbridge test, load was applied to the centre of a microbridge and was gradually increased by a nano-indenter equipped with a wedge tip until the sample was broken, while displacement was recorded coherently. Measurements were performed on single-layered silicon nitride microbridges and two-layered AlN/silicon nitride microbridges respectively. The data were fitted to a theory to derive the elastic modulus, residual stress and tensile strength of the silicon nitride films and AlN films. For the AlN films, the three parameters were determined to be 200, 0.06 and 0.3 GPa, respectively. The values of elastic modulus obtained were consistent with those measured by conventional nano-indentation method. The tensile strength value can be used as a reference to reflect the maximum tolerable tensile stress of AlN films when they are used in micro-electromechanical devices.

Electron-ion temperature equilibration in warm dense tantalum

DOE PAGES

Doppner, T; LePape, S.; Ma, T.; ...

2014-11-05

We present measurements of electron-ion temperature equilibration in proton-heated tantalum, under warm dense matter conditions. Our results agree with theoretical predictions for metals calculated using input data from ab initio simulations. Furthermore, the fast relaxation observed in the experiment contrasts with much longer equilibration times found in proton heated carbon, indicating that the energy flow pathways in warm dense matter are far from being fully understood.

Alloy Effects on the Gas Nitriding Process

NASA Astrophysics Data System (ADS)

Yang, M.; Sisson, R. D.

2014-12-01

Alloy elements, such as Al, Cr, V, and Mo, have been used to improve the nitriding performance of steels. In the present work, plain carbon steel AISI 1045 and alloy steel AISI 4140 were selected to compare the nitriding effects of the alloying elements in AISI 4140. Fundamental analysis is carried out by using the "Lehrer-like" diagrams (alloy specific Lehrer diagram and nitriding potential versus nitrogen concentration diagram) and the compound layer growth model to simulate the gas nitriding process. With this method, the fundamental understanding for the alloy effect based on the thermodynamics and kinetics becomes possible. This new method paves the way for the development of new alloy for nitriding.

Finishing Techniques for Silicon Nitride Bearings

DTIC Science & Technology

1976-03-01

finishing procedures. Rolling contact fatigue lives of silicon nitride with selected smoother finishes tested at 800 ksi Hertz stress were an order...grinding. Rolling contact fatigue lives of silicon nitride with selected smoother finishes tested at 800 ksi Hertz stress were an order of magnitude...lives of silicon nitride with selected smoother finishes tested at 800 ksi Hertz stress were an order of magnitude longer than those

Response and representation of ductile damage under varying shock loading conditions in tantalum

DOE PAGES

Bronkhorst, C. A.; Gray, III, G. T.; Addessio, F. L.; ...

2016-02-25

The response of polycrystalline metals, which possess adequate mechanisms for plastic deformation under extreme loading conditions, is often accompanied by the formation of pores within the structure of the material. This large deformation process is broadly identified as progressive with nucleation, growth, coalescence, and failure the physical path taken over very short periods of time. These are well known to be complex processes strongly influenced by microstructure, loading path, and the loading profile, which remains a significant challenge to represent and predict numerically. In the current study, the influence of loading path on the damage evolution in high-purity tantalum ismore » presented. Tantalum samples were shock loaded to three different peak shock stresses using both symmetric impact, and two different composite flyer plate configurations such that upon unloading the three samples displayed nearly identical “pull-back” signals as measured via rear-surface velocimetry. While the “pull-back” signals observed were found to be similar in magnitude, the sample loaded to the highest peak stress nucleated a connected field of ductile fracture which resulted in complete separation, while the two lower peak stresses resulted in incipient damage. The damage evolution in the “soft” recovered tantalum samples was quantified using optical metallography, electron-back-scatter diffraction, and tomography. These experiments are examined numerically through the use of a model for shock-induced porosity evolution during damage. The model is shown to describe the response of the tantalum reasonably well under strongly loaded conditions but less well in the nucleation dominated regime. As a result, numerical results are also presented as a function of computational mesh density and discussed in the context of improved representation of the influence of material structure upon macro-scale models of ductile damage.« less

Photodetectors using III-V nitrides

DOEpatents

Moustakas, T.D.; Misra, M.

1997-10-14

A photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The photodetector includes a substrate with interdigitated electrodes formed on its surface. The substrate has a sapphire base layer, a buffer layer formed from a III-V nitride and a single crystal III-V nitride film. The three layers are formed by electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-assisted MBE). Use of the ECR-assisted MBE process allows control and predetermination of the electrical properties of the photodetector. 24 figs.

A survey of attitudes, beliefs, and behavior regarding tanning bed use, sunbathing, and sunscreen use.

PubMed

Mawn, V B; Fleischer, A B

1993-12-01

Although cosmetic tanning and unprotected solar exposure are common, little is known about general attitudes, beliefs, and behavior regarding sunbathing, sunscreen use, and tanning salon use. We sought to determine the frequency of UV exposure in a select sample and to assess the knowledge and beliefs of the effects of UV irradiation. A written, anonymous questionnaire was distributed to a sample of 477 persons in a shopping mall, at a social gathering, and on a vacation cruise ship. The instrument explored demographic information, sunscreen use, sunbathing habits, tanning bed use, and cutaneous solar effects. Forty-two percent of respondents seldom or never used sunscreen, and 33% sunbathed at least once a week. Although the three sample populations differed in education, sunbathing habits, sunscreen use, and tanning bed use, they were equally informed about UV light hazards. Compared with those who had not used tanning beds, tanning bed users were more likely to be female and more knowledgeable about the long-term effects of UV. Tanning beds were most commonly used in tanning or hair salons, (mean 23 +/- 7 minutes at 2.3 +/- 1.1 times per week). Reported positive psychologic sequelae from tanning bed use were more common than negative physical sequelae. At least 10% would continue to use tanning beds if these were proved to cause skin cancer. In this select sample, sunbathing and tanning bed use were common. No group surveyed universally practiced sun protection and avoidance. Clientele of tanning beds may be aware of the damaging effects of the sun, but may not be aware that tanning bed use is associated with skin damage.

77 FR 43157 - Disregarded Entities and the Indoor Tanning Services Excise Tax; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... Disregarded Entities and the Indoor Tanning Services Excise Tax; Correction AGENCY: Internal Revenue Service... disregarded entities (including qualified subchapter S subsidiaries) and the indoor tanning services excise... with respect to the indoor tanning services excise tax--(A) In general. Notwithstanding any other...

Testing a social cognitive theory-based model of indoor tanning: implications for skin cancer prevention messages.

PubMed

Noar, Seth M; Myrick, Jessica Gall; Zeitany, Alexandra; Kelley, Dannielle; Morales-Pico, Brenda; Thomas, Nancy E

2015-01-01

The lack of a theory-based understanding of indoor tanning is a major impediment to the development of effective messages to prevent or reduce this behavior. This study applied the Comprehensive Indoor Tanning Expectations (CITE) scale in an analysis of indoor tanning behavior among sorority women (total N = 775). Confirmatory factor analyses indicated that CITE positive and negative expectations were robust, multidimensional factors and that a hierarchical structure fit the data well. Social cognitive theory-based structural equation models demonstrated that appearance-oriented variables were significantly associated with outcome expectations. Outcome expectations were, in turn, significantly associated with temptations to tan, intention to tan indoors, and indoor tanning behavior. The implications of these findings for the development of messages to prevent and reduce indoor tanning behavior are discussed in two domains: (a) messages that attempt to change broader societal perceptions about tan skin, and (b) messages that focus more narrowly on indoor tanning-challenging positive expectations, enhancing negative expectations, and encouraging substitution of sunless tanning products.

A Web-Based Intervention to Reduce Indoor Tanning Motivations In Adolescents: A Randomized Controlled Trial

PubMed Central

Hillhouse, Joel; Turrisi, Rob; Scaglione, Nichole M.; Cleveland, Michael J.; Baker, Katie; Florence, L. Carter

2016-01-01

Youthful indoor tanning as few as ten sessions can increase the risk of melanoma by 2 to 4 times with each additional session adding another 2% to the risk. Recent research estimates that indoor tanning can be linked to approximately 450,000 cases of skin cancer annually in the United States, Europe, and Australia. Despite these risks, indoor tanning remains popular with adolescents. This study tested the efficacy of a web-based skin cancer prevention intervention designed to reduce indoor tanning motivations in adolescent females. A nationally representative sample of 443 female teens were enrolled from an online panel into a two-arm, parallel group design, randomized controlled trial. Treatment participants received an appearance-focused intervention grounded in established health behavior change models. Controls viewed a teen alcohol prevention website. Outcome variables included willingness and intentions to indoor tan, willingness to sunless tan and measures of indoor tanning attitudes and beliefs. The intervention decreased willingness and intentions to indoor tan and increased sunless tanning willingness relative to controls. We also examined indirect mechanisms of change through intervening variables (e.g., indoor tanning attitudes, norms, positive and negative expectancies) using the product of coefficients approach. The web-based intervention demonstrated efficacy in changing adolescent indoor tanning motivations and improving their orientation toward healthier alternatives. Results from the intervening variable analyses give guidance to future adolescent skin cancer prevention interventions. PMID:27549602

A Web-Based Intervention to Reduce Indoor Tanning Motivations in Adolescents: a Randomized Controlled Trial.

PubMed

Hillhouse, Joel; Turrisi, Rob; Scaglione, Nichole M; Cleveland, Michael J; Baker, Katie; Florence, L Carter

2017-02-01

Youthful indoor tanning as few as ten sessions can increase the risk of melanoma by two to four times with each additional session adding another 2 % to the risk. Recent research estimates that indoor tanning can be linked to approximately 450,000 cases of skin cancer annually in the USA, Europe, and Australia. Despite these risks, indoor tanning remains popular with adolescents. This study tested the efficacy of a web-based skin cancer prevention intervention designed to reduce indoor tanning motivations in adolescent females. A nationally representative sample of 443 female teens was enrolled from an online panel into a two-arm, parallel group design, randomized controlled trial. Treatment participants received an appearance-focused intervention grounded in established health behavior change models. Controls viewed a teen alcohol prevention website. Outcome variables included willingness and intentions to indoor tan, willingness to sunless tan, and measures of indoor tanning attitudes and beliefs. The intervention decreased willingness and intentions to indoor tan and increased sunless tanning willingness relative to controls. We also examined indirect mechanisms of change through intervening variables (e.g., indoor tanning attitudes, norms, positive and negative expectancies) using the product of coefficient approach. The web-based intervention demonstrated efficacy in changing adolescent indoor tanning motivations and improving their orientation toward healthier alternatives. Results from the intervening variable analyses give guidance to future adolescent skin cancer prevention interventions.

Tanning and Increased Nevus Development in Very-Light-Skinned Children Without Red Hair

PubMed Central

Aalborg, Jenny; Morelli, Joseph G.; Mokrohisky, Stefan T.; Asdigian, Nancy L.; Byers, Tim E.; Dellavalle, Robert P.; Box, Neil F.; Crane, Lori A.

2010-01-01

Objective To examine the relationship between tanning and nevus development in very-light-skinned children. Design Prospective cohort nested within a randomized controlled trial. Skin examinations in 3 consecutive years (2004, 2005, and 2006) included full-body counts of nevi, skin color and tanning measurement using colorimetry, and hair and eye color evaluation by comparison with charts. Telephone interviews of parents provided sun exposure, sun protection, and sunburn history. Setting Large managed-care organization and private pediatric offices in the Denver, Colorado, metropolitan area. Participants A total of 131 very-light-skinned white children without red hair and 444 darker-skinned white children without red hair born in Colorado in 1998. Main Outcome Measures Full-body nevus counts at ages 6 to 8 years. Results Among very-light-skinned white children, geometric mean numbers of nevi for minimally tanned children were 14.8 at age 6 years; 18.8 at age 7 years; and 22.3 at age 8 years. Mean numbers of nevi for tanned children were 21.2 at age 6 years; 27.9 at age 7 years; and 31.9 at age 8 years. Differences in nevus counts between untanned and tanned children were statistically significant at all ages (P < .05 for all comparisons). The relationship between tanning and number of nevi was independent of the child’s hair and eye color, parent-reported sun exposure, and skin phototype. Among darker-skinned white children, there was no relationship between tanning and nevi. Conclusions Very-light-skinned children who tan (based on objective measurement) develop more nevi than children who do not tan. These results suggest that light-skinned children who develop tans may be increasing their risk for developing melanoma later in life. PMID:19770437

Molten-Salt-Based Growth of Group III Nitrides

DOEpatents

Waldrip, Karen E.; Tsao, Jeffrey Y.; Kerley, Thomas M.

2008-10-14

A method for growing Group III nitride materials using a molten halide salt as a solvent to solubilize the Group-III ions and nitride ions that react to form the Group III nitride material. The concentration of at least one of the nitride ion or Group III cation is determined by electrochemical generation of the ions.

Synthesis of reduced carbon nitride at the reduction by hydroquinone of water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O

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

Kharlamov, Alexey; Bondarenko, Marina, E-mail: mebondarenko@ukr.net; Kharlamova, Ganna

For the first time at the reduction by hydroquinone of water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O reduced carbon nitride (or reduced multi-layer azagraphene) is obtained. It is differed from usually synthesized carbon nitride by a significantly large (on 0.09 nm) interplanar distance is. At the same time, the chemical bonds between atoms in a heteroatomic plane of reduced carbon nitride correspond to the bonds in a synthesized g-C{sub 3}N{sub 4}. The samples of water-soluble carbon nitride oxide were synthesized under the special reactionary conditions of a pyrolysis of melamine and urea. We believe that reduced carbon nitride consists ofmore » weakly connected carbon-nitrogen monosheets (azagraphene sheets) as well as reduced (from graphene oxide) graphene contains weakly connected graphene sheets. - Graphical abstract: XRD pattern and schematic atomic model of one layer of reduced carbon nitride, carbon nitride oxide and synthesized carbon nitride. For the first time at the reduction by hydroquinone of the water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O is obtained the reduced carbon nitride (or reduced multi-layer azagraphene). Display Omitted - Highlights: • First the reduced carbon nitride (RCN) at the reduction of the carbon nitride oxide was obtained. • Water-soluble carbon nitride oxide was reduced by hydroquinone. • The chemical bonds in a heteroatomic plane of RCN correspond to the bonds in a synthesized g-C{sub 3}N{sub 4}. • Reduced carbon nitride consists of poorly connected heteroatomic azagraphene layers.« less

Boron Nitride Nanotubes

NASA Technical Reports Server (NTRS)

Jordan, Kevin (Inventor); Smith, Michael W. (Inventor); Park, Cheol (Inventor)

2012-01-01

Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.

Boron nitride nanotubes

DOEpatents

Smith, Michael W [Newport News, VA; Jordan, Kevin [Newport News, VA; Park, Cheol [Yorktown, VA

2012-06-06

Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.

Growth of gallium nitride and indium nitride nanowires on conductive and flexible carbon cloth substrates.

PubMed

Yang, Yi; Ling, Yichuan; Wang, Gongming; Lu, Xihong; Tong, Yexiang; Li, Yat

2013-03-07

We report a general strategy for synthesis of gallium nitride (GaN) and indium nitride (InN) nanowires on conductive and flexible carbon cloth substrates. GaN and InN nanowires were prepared via a nanocluster-mediated growth method using a home built chemical vapor deposition (CVD) system with Ga and In metals as group III precursors and ammonia as a group V precursor. Electron microscopy studies reveal that the group III-nitride nanowires are single crystalline wurtzite structures. The morphology, density and growth mechanism of these nanowires are determined by the growth temperature. Importantly, a photoelectrode fabricated by contacting the GaN nanowires through a carbon cloth substrate shows pronounced photoactivity for photoelectrochemical water oxidation. The ability to synthesize group III-nitride nanowires on conductive and flexible substrates should open up new opportunities for nanoscale photonic, electronic and electrochemical devices.

Peer Crowd Identification and Indoor Artificial UV Tanning Behavioral Tendencies

PubMed Central

STAPLETON, JEROD; TURRISI, ROB; HILLHOUSE, JOEL

2014-01-01

In this study, the relation between peer crowd identification and indoor tanning behavioral tendencies was examined. Participants were 174 undergraduate students at a large university in the USA. Results indicated peer crowd identification was significantly associated with indoor artificial UV tanning behavioral tendencies (attitudes, normative beliefs, past year use and intentions) independent of gender and skin type. Participants who identified with the popular peer crowd were at the greatest risk for indoor tanning UV exposure while identification with the brain crowd was protective against such behavior. The findings are discussed in terms of implications for future skin cancer intervention efforts. PMID:18809645

In-group rationalizations of risk and indoor tanning: A textual analysis of an online forum.

PubMed

Carcioppolo, Nick; Chudnovskaya, Elena V; Martinez Gonzalez, Andrea; Stephan, Tyler

2016-07-01

Unlike other health behaviors, there does not appear to be a strong relationship between perceived skin cancer risk and reduction or cessation of indoor tanning bed use. This study seeks to address this inconsistency by determining how indoor tanning bed users rationalize skin cancer risk with their tanning behavior. Qualitative textual analysis of indoor tanning message board posts (N = 330) revealed varied perceptions of risk, including acknowledging the risk of indoor tanning; denying or downplaying risk, often citing perceived health benefits associated with tanning; blaming outside forces for cancer, such as lotion or genetics; and fatalistic beliefs about cancer. These results highlight the nuanced relationship between perceived skin cancer risk and indoor tanning bed use. © The Author(s) 2014.

Counseling on Sun Protection and Indoor Tanning.

PubMed

Balk, Sophie J; Gottschlich, Elizabeth A; Holman, Dawn M; Watson, Meg

2017-12-01

The US Preventive Services Task Force recommends clinical counseling for individuals ages 10 to 24 years to decrease skin cancer risk. A national, random sample of US American Academy of Pediatrics members practicing primary care in 2002 (response rate 55%) and 2015 (response rate 43%). Surveys explored attitudes and experiences regarding sun protection counseling; indoor tanning questions were added in 2015. χ 2 tests compared demographics and counseling responses across years, and multivariable logistic regression models examined counseling predictors. More pediatricians in 2015 (34%) than in 2002 (23%) reported discussing sun protection during recent summer months with ≥75% of patients. This pattern held across all patient age groups (each P <.001). Female and suburban pediatricians counseled more; those in the South and West counseled less. More pediatricians in 2015 than in 2002 named time as a barrier. Sun protection ranked lowest among preventive topics in both years. In 2015, approximately one-third of pediatricians reported discussing indoor tanning at least once with 10 to 13 year-old patients; approximately half discussed this with older adolescents. Most (70%) did not know if their states had laws on minors' indoor tanning access; those stating they knew whether a law existed counseled more. Although improved, sun protection counseling rates remain low. Indoor tanning counseling can be improved. Because early-life exposure to UV radiation increases risk and clinician counseling can positively impact prevention behaviors, pediatricians have an important role in skin cancer prevention; counseling may save lives. Time constraints remain a barrier. Copyright © 2017 by the American Academy of Pediatrics.

The structure, bond strength and apatite-inducing ability of micro-arc oxidized tantalum and their response to annealing

NASA Astrophysics Data System (ADS)

Wang, Cuicui; Wang, Feng; Han, Yong

2016-01-01

In this study, the tantalum oxide coatings were formed on pure tantalum (Ta) by micro-arc oxidation (MAO) in electrolytic solutions of calcium acetate and β-glycerophosphate disodium, and the effect of the applied voltage on the microstructure and bond strength of the MAO coatings was systematically investigated. The effect of annealing treatment on the microstructure, bond strength and apatite-inducing ability of the MAO coatings formed at 350 and 450 V was also studied. The study revealed that during the preparation of tantalum oxide coatings on Ta substrate by MAO, the applied voltage considerably affected the phase components, morphologies and bond strength of the coatings, but had little effect on surface chemical species. After annealing treatment, newly formed CaTa4O11 phase mainly contributed to the much more stronger apatite-inducing ability of the annealed tantalum oxide coatings than those that were not annealed. The better apatite-inducing ability of the MAO coatings formed at 450 V compared to those formed at 350 V was attributed to the less amorphous phase and more crystalline phase as well as more Ca and P contained in the MAO coatings with increasing the applied voltage.

Comparison of advertising strategies between the indoor tanning and tobacco industries.

PubMed

Greenman, Jennifer; Jones, David A

2010-04-01

The indoor tanning industry is large and continues to grow, with 2007 domestic sales in excess of $5 billion. Advertising is central to shaping the consumer's perception of indoor tanning as well as driving industry demand. This article aims to identify key drivers of consumer appeal by comparing tanning advertising strategies to those used by tobacco marketers. Tobacco advertising was selected as a reference framework because it is both well documented and designed to promote a product with known health hazards. Two thousand advertisements from 4 large tobacco advertisement databases were analyzed for type of advertisement strategy used, and 4 advertising method categories were devised to incorporate the maximum number of advertisements reviewed. Subsequently, contemporary tanning advertisements were collected from industry magazines and salon websites and evaluated relative to the identified strategy profiles. Both industries have relied on similar advertising strategies, including mitigating health concerns, appealing to a sense of social acceptance, emphasizing psychotropic effects, and targeting specific population segments. This examination is a small observational study, which was conducted without rigorous statistical analysis, and which is limited both by the number of advertisements and by advertising strategies examined. Given the strong parallels between tobacco and tanning advertising methodologies, further consumer education and investigation into the public health risks of indoor tanning is needed. Copyright 2009 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Low temperature route to uranium nitride