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Sample records for adherent diamond-like carbon

  1. Graphene diamond-like carbon films heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fang; Afandi, Abdulkareem; Jackman, Richard B., E-mail: r.jackman@ucl.ac.uk [London Centre for Nanotechnology, Electronic and Electrical Engineering Department, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom)

    2015-03-09

    A limitation to the potential use of graphene as an electronic material is the lack of control over the 2D materials properties once it is deposited on a supporting substrate. Here, the use of Diamond-like Carbon (DLC) interlayers between the substrate and the graphene is shown to offer the prospect of overcoming this problem. The DLC films used here, more properly known as a-C:H with ∼25% hydrogen content, have been terminated with N or F moieties prior to graphene deposition. It is found that nitrogen terminations lead to an optical band gap shrinkage in the DLC, whilst fluorine groups reduce the DLC's surface energy. CVD monolayer graphene subsequently transferred to DLC, N terminated DLC, and F terminated DLC has then been studied with AFM, Raman and XPS analysis, and correlated with Hall effect measurements that give an insight into the heterostructures electrical properties. The results show that different terminations strongly affect the electronic properties of the graphene heterostructures. G-F-DLC samples were p-type and displayed considerably higher mobility than the other heterostructures, whilst G-N-DLC samples supported higher carrier densities, being almost metallic in character. Since it would be possible to locally pattern the distribution of these differing surface terminations, this work offers the prospect for 2D lateral control of the electronic properties of graphene layers for device applications.

  2. Graphene diamond-like carbon films heterostructure

    Science.gov (United States)

    Zhao, Fang; Afandi, Abdulkareem; Jackman, Richard B.

    2015-03-01

    A limitation to the potential use of graphene as an electronic material is the lack of control over the 2D materials properties once it is deposited on a supporting substrate. Here, the use of Diamond-like Carbon (DLC) interlayers between the substrate and the graphene is shown to offer the prospect of overcoming this problem. The DLC films used here, more properly known as a-C:H with ˜25% hydrogen content, have been terminated with N or F moieties prior to graphene deposition. It is found that nitrogen terminations lead to an optical band gap shrinkage in the DLC, whilst fluorine groups reduce the DLC's surface energy. CVD monolayer graphene subsequently transferred to DLC, N terminated DLC, and F terminated DLC has then been studied with AFM, Raman and XPS analysis, and correlated with Hall effect measurements that give an insight into the heterostructures electrical properties. The results show that different terminations strongly affect the electronic properties of the graphene heterostructures. G-F-DLC samples were p-type and displayed considerably higher mobility than the other heterostructures, whilst G-N-DLC samples supported higher carrier densities, being almost metallic in character. Since it would be possible to locally pattern the distribution of these differing surface terminations, this work offers the prospect for 2D lateral control of the electronic properties of graphene layers for device applications.

  3. XPS, XRD and laser Raman analysis of surface modified of 6150 steel substrates for the deposition of thick and adherent diamond-like carbon coatings

    Energy Technology Data Exchange (ETDEWEB)

    Silva, William de Melo; Carneiro, Jose Rubens Goncalves, E-mail: williammelosilva@gmail.com [Pontificia Universidade Catolica de Minas Gerais (PUC-MG), Belo Horizonte (Brazil). Dept. de Engenharia Mecanica; Trava-Airoldi, Vladimir Jesus [Associate Laboratory of Sensors and Materials, National Institute for Space Research, Sao Jose dos Campos, SP (Brazil)

    2013-11-01

    Although the 6150 steel has an excellent fatigue and impact resistance, it is unsuitable to operate it when the corrosion is a limited factor. We propose here a sequence of steel pre-treatment by carburizing, carbonitriding and nitriding in order to improve the poor adhesion between Diamond Like-Carbon coatings on steel. This sequence is our attempt to reduce the difference between the coefficients of thermal expansion of steel and DLC through the graded interface. This work demonstrates the quantitative analysis of the molecules present at surface using X-ray photoelectron spectroscopy. The crystallographic structures are investigated by X-ray diffraction which shows the formation of carbides and nitride phases. Raman spectroscopy reveals the carburizing surface characteristics where DLC coating is nucleated and grown at the substrate. At the end of the analysis it is possible to verify which molecules and phases are formed on the steel surface interface after each step of pre-treatment. (author)

  4. XPS, XRD and laser raman analysis of surface modified of 6150 steel substrates for the deposition of thick and adherent diamond-like carbon coatings

    Directory of Open Access Journals (Sweden)

    William de Melo Silva

    2013-06-01

    Full Text Available Although the 6150 steel has an excellent fatigue and impact resistance, it is unsuitable to operate it when the corrosion is a limited factor. We propose here a sequence of steel pre-treatment by carburizing, carbonitriding and nitriding in order to improve the poor adhesion between Diamond Like-Carbon coatings on steel. This sequence is our attempt to reduce the difference between the coefficients of thermal expansion of steel and DLC through the graded interface. This work demonstrates the quantitative analysis of the molecules present at surface using X-ray photoelectron spectroscopy. The crystallographic structures are investigated by X-ray diffraction which shows the formation of carbides and nitride phases. Raman spectroscopy reveals the carburizing surface characteristics where DLC coating is nucleated and grown at the substrate. At the end of the analysis it is possible to verify which molecules and phases are formed on the steel surface interface after each step of pre-treatment.

  5. Cell attachment on diamond-like carbon coating

    Indian Academy of Sciences (India)

    D J Li; H Q Gu

    2002-02-01

    Preliminary results of diamond-like carbon (DLC) coating with its novel properties with no toxicity have caused a strong interest of commercial manufacturers of surgical implants. DLC coatings were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). It could be shown by X-ray photoelectron spectroscopy, Auger electron spectroscopy, and Raman spectroscopy that DLC coating prepared by 800 eV CH+ beam bombardment possessed a higher fraction of 3 bonds in the structure of mixed 3 + 2 bonding, resulting in a higher hydrophobicity. The results of the cell attachment tests indicated that DLC coatings exhibited low macrophage attachment and provided desirable surface for the normal cellular growth and morphology of the fibroblasts. At the same time, the number of both neutral granulocytes and platelets adhering to DLC coatings decreased significantly. These findings showed that DLC was a better coating with desirable tissue and blood compatibility.

  6. Optically transparent, scratch-resistant, diamond-like carbon coatings

    Science.gov (United States)

    He, Xiao-Ming; Lee, Deok-Hyung; Nastasi, Michael A.; Walter, Kevin C.; Tuszewski, Michel G.

    2003-06-03

    A plasma-based method for the deposition of diamond-like carbon (DLC) coatings is described. The process uses a radio-frequency inductively coupled discharge to generate a plasma at relatively low gas pressures. The deposition process is environmentally friendly and scaleable to large areas, and components that have geometrically complicated surfaces can be processed. The method has been used to deposit adherent 100-400 nm thick DLC coatings on metals, glass, and polymers. These coatings are between three and four times harder than steel and are therefore scratch resistant, and transparent to visible light. Boron and silicon doping of the DLC coatings have produced coatings having improved optical properties and lower coating stress levels, but with slightly lower hardness.

  7. Flexible diamond-like carbon film coated on rubber

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Pal, J.P. van der; Martinez-Martinez, D.; Hosson, J.Th.M. De

    2013-01-01

    Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 70% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin films by which the coefficient of friction is reduced to less than one tenth. Coating

  8. Flexible protective diamond-like carbon film on rubber

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Hosson, J.Th.M. De

    2010-01-01

    In this paper we report an experimental approach to deposit flexible diamond-like carbon (DLC) films on rubber via self-segmentation. By making use of the substantial thermal mismatch between the DLC film and rubber substrate a dense network of cracks forms in the DLC film, contributing to its flexi

  9. Stress in tungsten carbide-diamond like carbon multilayer coatings

    NARCIS (Netherlands)

    Pujada, B.R.; Tichelaar, F.D.; Janssen, G.C.A.M.

    2007-01-01

    Tungsten carbide-diamond like carbon (WC-DLC) multilayer coatings have been prepared by sputter deposition from a tungsten-carbide target and periodic switching on and off of the reactive acetylene gas flow. The stress in the resulting WC-DLC multilayers has been studied by substrate curvature. Peri

  10. Growth stress in tungsten carbide-diamond-like carbon coatings

    NARCIS (Netherlands)

    Pujada, B.R.; Tichelaar, F.D.; Arnoldbik, W.M.; Sloof, W.G.; Janssen, G.C.A.M.

    2009-01-01

    Growth stress in tungsten carbide-diamond-like carbon coatings, sputter deposited in a reactive argon/acetylene plasma, has been studied as a function of the acetylene partial pressure. Stress and microstructure have been investigated by wafer curvature and transmission electron microscopy (TEM) whe

  11. Plasma deposited diamond-like carbon films for large neutralarrays

    Energy Technology Data Exchange (ETDEWEB)

    Brown, I.G.; Blakely, E.A.; Bjornstad, K.A.; Galvin, J.E.; Monteiro, O.R.; Sangyuenyongpipat, S.

    2004-07-15

    To understand how large systems of neurons communicate, we need to develop methods for growing patterned networks of large numbers of neurons. We have found that diamond-like carbon thin films formed by energetic deposition from a filtered vacuum arc carbon plasma can serve as ''neuron friendly'' substrates for the growth of large neural arrays. Lithographic masks can be used to form patterns of diamond-like carbon, and regions of selective neuronal attachment can form patterned neural arrays. In the work described here, we used glass microscope slides as substrates on which diamond-like carbon was deposited. PC-12 rat neurons were then cultured on the treated substrates and cell growth monitored. Neuron growth showed excellent contrast, with prolific growth on the treated surfaces and very low growth on the untreated surfaces. Here we describe the vacuum arc plasma deposition technique employed, and summarize results demonstrating that the approach can be used to form large patterns of neurons.

  12. Preparation and Thermal Characterization of Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    BAI Su-Yuan; TANG Zhen-An; HUANG Zheng-Xing; Yu Jun; WANG Jing; LIU Gui-Chang

    2009-01-01

    Diamond-like carbon (DLC) films are prepared on silicon substrates by microwave electron cyclotron resonance plasma enhanced chemical vapor deposition. Raman spectroscopy indicates that the films have an amorphous structure and typical characteristics. The topographies of the films are presented by AFM images. Effective thermal conductivities of the films are measured using a nanosecond pulsed photothermal reflectance method. The results show that thermal conductivity is dominated by the microstructure of the films.

  13. High Energy Radial Deposition of Diamond-Like Carbon Coatings

    Directory of Open Access Journals (Sweden)

    Konrad Suschke

    2015-07-01

    Full Text Available Diamond-like carbon (DLC coatings were deposited with a new direct ion deposition system using a novel 360 degree ion source operating at acceleration voltage between 4 and 8 kV. Cross-sectional TEM images show that the coatings have a three layered structure which originates from changes in the deposition parameters taking into account ion source condition, ion current density, deposition angles, ion sputtering and ion source movement. Varying structural growth conditions can be achieved by tailoring the deposition parameters. The coatings show good promise for industrial use due to their high hardness, low friction and excellent adhesion to the surface of the samples.

  14. Diamond-Like Carbon Nanorods and Fabrication Thereof

    Science.gov (United States)

    Varshney, Deepak (Inventor); Makarov, Vladimir (Inventor); Morell, Gerardo (Inventor); Saxena, Puja (Inventor); Weiner, Brad (Inventor)

    2017-01-01

    Novel sp. (sup 3) rich diamond-like carbon (DLC) nanorod films were fabricated by hot filament chemical vapor deposition technique. The results are indicative of a bottom-up self-assembly synthesis process, which results in a hierarchical structure that consists of microscale papillae comprising numerous nanorods. The papillae have diameters ranging from 2 to 4 microns and the nanorods have diameters in the 35-45 nanometer range. A growth mechanism based on the vapor liquid-solid mechanism is proposed that accounts for the morphological aspects in the micro- and nano-scales.

  15. Plasma Processes : Microwave plasma deposition of diamond like carbon coatings

    Indian Academy of Sciences (India)

    D S Patil; K Ramachandran; N Venkatramani; M Pandey; R D'Cunha

    2000-11-01

    The promising applications of the microwave plasmas have been appearing in the fields of chemical processes and semiconductor manufacturing. Applications include surface deposition of all types including diamond/diamond like carbon (DLC) coatings, etching of semiconductors, promotion of organic reactions, etching of polymers to improve bonding of the other materials etc. With a 2.45 GHz, 700 W, microwave induced plasma chemical vapor deposition (CVD) system set up in our laboratory we have deposited diamond like carbon coatings. The microwave plasma generation was effected using a wave guide single mode applicator. We have deposited DLC coatings on the substrates like stainless steel, Cu–Be, Cu and Si. The deposited coatings have been characterized by FTIR, Raman spectroscopy and ellipsometric techniques. The results show that we have achieved depositing ∼ 95% sp3 bonded carbon in the films. The films are uniform with golden yellow color. The films are found to be excellent insulators. The ellipsometric measurements of optical constant on silicon substrates indicate that the films are transparent above 900 nm.

  16. Formation of conducting nanochannels in diamond-like carbon films

    Science.gov (United States)

    Evtukh, A.; Litovchenko, V.; Semenenko, M.; Yilmazoglu, O.; Mutamba, K.; Hartnagel, H. L.; Pavlidis, D.

    2006-09-01

    A sharp increase of the emission current at high electric fields and a decrease of the threshold voltage after pre-breakdown conditioning of diamond-like carbon (DLC) films have been measured. This effect was observed for DLC-coated silicon tips and GaAs wedges. During electron field emission (EFE) at high electric fields the energy barriers caused by an sp3 phase between sp2 inclusions can be broken, resulting in the formation of conducting nanochannels between the semiconductor-DLC interface and the surface of the DLC film. At high current densities and the resulting local heating, the diamond-like sp3 phase transforms into a conducting graphite-like sp2 phase. As a result an electrical conducting nanostructured channel is formed in the DLC film. The diameter of the conducting nanochannel was estimated from the reduced threshold voltage after pre-breakdown conditioning to be in the range of 5-25 nm. The presence of this nanochannel in an insulating matrix leads to a local enhancement of the electric field and a reduced threshold voltage for EFE. Based on the observed features an efficient method of conducting nanochannel matrix formation in flat DLC films for improved EFE efficiency is proposed. It mainly uses a silicon tip array as an upper electrode in contact with the DLC film. The formation of nanochannels starts at the interface between the tips and the DLC film. This opens new possibilities of aligned and high-density conducting channel formation.

  17. Atmospheric Plasma Deposition of Diamond-like Carbon Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ladwig, Angela

    2008-01-23

    There is great demand for thin functional coatings in the semiconductor, optics, electronics, medical, automotive and aerospace industries [1-13]. As fabricated components become smaller and more complex, the properties of the materials’ surface take on greater importance. Thin coatings play a key role in tailoring surfaces to give them the desired hardness, wear resistance, chemical inertness, and electrical characteristics. Diamond-like carbon (DLC) coatings possess an array of desirable properties, including outstanding abrasion and wear resistance, chemical inertness, hardness, a low coefficient of friction and exceptionally high dielectric strength [14-22]. Diamond-like carbon is considered to be an amorphous material, containing a mixture of sp2 and sp3 bonded carbon. Based on the percentage of sp3 carbon and the hydrogen content, four different types of DLC coatings have been identified: tetrahedral carbon (ta-C), hydrogenated amorphous carbon (a-C:H) hard, a-C:H soft, and hydrogenated tetrahedral carbon (ta-C:H) [20,24,25]. Possessing the highest hardness of 80 GPa, ta-C possesses an sp3 carbon content of 80 to 88u%, and no appreciable hydrogen content whereas a-C:H soft possesses a hardness of less than 10 GPa, contains an sp3 carbon content of 60% and a hydrogen content between 30 to 50%. Methods used to deposit DLC coatings include ion beam deposition, cathodic arc spray, pulsed laser ablation, argon ion sputtering, and plasma-enhanced chemical vapor deposition [73-83]. Researchers contend that several advantages exist when depositing DLC coatings in a low-pressure environment. For example, ion beam processes are widely utilized since the ion bombardment is thought to promote denser sp3-bonded carbon networks. Other processes, such as sputtering, are better suited for coating large parts [29,30,44]. However, the deposition of DLC in a vacuum system has several disadvantages, including high equipment cost and restrictions on the size and shape of

  18. Development of Diamond-like Carbon Fibre Wheel

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 山口勝美; 洞口巌; 竹内雅之

    2004-01-01

    A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned normally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5nm (Ry26nm) was achieved.

  19. Advances in targetry with thin diamond-like carbon foils

    CERN Document Server

    Liechtenstein, V K; Olshanski, E D; Repnow, R; Levin, J; Hellborg, R; Persson, P; Schenkel, T

    2002-01-01

    Thin and stable diamond-like carbon (DLC) foils, which were fabricated at the Kurchatov Institute by sputter deposition, have proved recently to be advantageous for stripping and secondary electron timing of high energy heavy ions in a number of accelerator experiments. This resulted in expanding applications of these DLC foils which necessitated further development efforts directed toward the following applications of DLC targetry: (i) thin stripper foils for lower energy tandem accelerators, (ii) enlarged (up to 66 mm in diameter) stop foils for improved time-of-flight elastic recoil detection ion beam analysis, and (iii) ultra-thin (about 0.6 mu g/cm sup 2) DLC foils for some fundamental and applied physics experiments. Along with the fabrication of thin DLC stripper foils for tandem accelerators, much thicker (up to 200 mu g/cm sup 2) foils for post-stripping of heavy-ion beams in higher energy linacs, are within reach.

  20. Electronic Power System Application of Diamond-Like Carbon Films

    Science.gov (United States)

    Wu, Richard L. C.; Kosai, H.; Fries-Carr, S.; Weimer, J.; Freeman, M.; Schwarze, G. E.

    2003-01-01

    A prototype manufacturing technology for producing high volume efficiency and high energy density diamond-like carbon (DLC) capacitors has been developed. Unique dual ion-beam deposition and web-handling systems have been designed and constructed to deposit high quality DLC films simultaneously on both sides of capacitor grade aluminum foil and aluminum-coated polymer films. An optimized process, using inductively coupled RF ion sources, has been used to synthesize electrically robust DLC films. DLC films are amorphous and highly flexible, making them suitable for the production of wound capacitors. DLC capacitors are reliable and stable over a wide range of AC frequencies from 20 Hz to 1 MHz, and over a temperature range from .500 C to 3000 C. The compact DLC capacitors offer at least a 50% decrease in weight and volume and a greater than 50% increase in temperature handling capability over equal value capacitors built with existing technologies. The DLC capacitors will be suitable for high temperature, high voltage, pulsed power and filter applications.

  1. The irradiation studies on diamond-like carbon films

    CERN Document Server

    LiuGuIang; Xie Er Qin

    2002-01-01

    Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (r.f.) plasma deposition method. gamma-ray, ultraviolet (UV) ray and neutron beam were used to irradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were used to characterize the changing characteristics of SP sup 3 C-H bond and hydrogen content in the films due to the irradiations. It showed that, the damage degrees of the gamma-ray, UV ray and neutron beam on the SP sup 3 C-H bonds are different. Among them, the damage of gamma-ray on the SP sup 3 C-H bond is the weakest. When the irradiation dose of gamma-ray reaches 10x10 sup 4 Gy, the SP sup 3 C-H bond reduces about 50% in number. The square resistance of the films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of the films. Compared with that of the as-deposited one, the IR transmittance of the films irradiated by both gamma-ray and neutron beam is increased to some extent. By using the results on optical...

  2. Low voltage electrodeposition of diamond like carbon (DLC)

    Science.gov (United States)

    Sreejith, K.; Nuwad, J.; Pillai, C. G. S.

    2005-10-01

    Attempt has been made to deposit diamond like carbon (DLC) films from ethanol through electrodeposition at low voltages (80-300 V) at 1 mm interelectrode separation. The films were characterized by atomic force microscopy (AFM), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and Auger electron Spectroscopy (AES). AFM investigations revealed the grain sizes are of tens of nanometers. The films were found to be continuous, smooth and close packed. Presence of peaks at 2958, 2929 and 2869 cm -1 in FTIR spectrum indicates the bonding states to be of predominantly sp 3 type (C-H). Raman spectroscopy analysis revealed two broad bands at ˜1350 and ˜1570 cm -1. The downshift of the G-band of graphite is indicative of presence of DLC. Analysis of the Raman spectra for the samples revealed an improvement in the film quality with increase in the voltage. Micro Raman investigations indicate the formation of diamond phase at the deposition potential of 80 V. The sp 2 contents the films calculated from Auger electron spectra were calculated and were found to be 31, 19 and 7.8% for the samples prepared at 80, 150 and 300 V, respectively. A tentative mechanism for the formation of DLC has been proposed. These results indicate the possibility of deposition of DLC at low voltage.

  3. Low voltage electrodeposition of diamond like carbon (DLC)

    Energy Technology Data Exchange (ETDEWEB)

    Sreejith, K. [Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nuwad, J. [Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Pillai, C.G.S. [Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)]. E-mail: cgspil@apsara.barc.ernet.in

    2005-10-15

    Attempt has been made to deposit diamond like carbon (DLC) films from ethanol through electrodeposition at low voltages (80-300 V) at 1 mm interelectrode separation. The films were characterized by atomic force microscopy (AFM), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and Auger electron Spectroscopy (AES). AFM investigations revealed the grain sizes are of tens of nanometers. The films were found to be continuous, smooth and close packed. Presence of peaks at 2958, 2929 and 2869 cm{sup -1} in FTIR spectrum indicates the bonding states to be of predominantly sp{sup 3} type (C-H). Raman spectroscopy analysis revealed two broad bands at {approx}1350 and {approx}1570 cm{sup -1}. The downshift of the G-band of graphite is indicative of presence of DLC. Analysis of the Raman spectra for the samples revealed an improvement in the film quality with increase in the voltage. Micro Raman investigations indicate the formation of diamond phase at the deposition potential of 80 V. The sp{sup 2} contents the films calculated from Auger electron spectra were calculated and were found to be 31, 19 and 7.8% for the samples prepared at 80, 150 and 300 V, respectively. A tentative mechanism for the formation of DLC has been proposed. These results indicate the possibility of deposition of DLC at low voltage.

  4. STUDY OF RAY IRRADIATION ON DIAMOND-LIKE CARBON FILMS

    Institute of Scientific and Technical Information of China (English)

    G.A.Liu; T.M.Wang; E.Q.Xie

    2002-01-01

    Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (rf) plasma deposition method, γ-ray, ultraviolet (UV) ray were used toirradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were usedto characterize the changing characteristics of SP3 C-H bond and hydrogen content inthe films due to the irradiations. The results show that, the damage degrees induced bythe UV ray on the SP3 C-H bonds are much stronger than that by the γ-ray. When theirradiation dose of γ-ray reaches 10× 104Gy, the SP3 C-H bond reduces about 50% innumber. The square electrical resistance of the films is reduced due to the irradiationof UV ray and this is caused by severe oxidation of the films. By using the results onoptical gap of the films and the fully constrained network theory, the hydrogen contentin the as-deposited films is estimated to be 10-25at.%.

  5. Electrical conditioning of diamond-like carbon films for the formation of coated field emission cathodes

    Science.gov (United States)

    Semenenko, M.; Okrepka, G.; Yilmazoglu, O.; Hartnagel, H. L.; Pavlidis, D.

    2010-11-01

    Diamond-like carbon (DLC) films deposited on different substrates by plasma enhanced chemical vapour deposition were investigated. Bonding states and film quality were characterized by FT-IR spectroscopy. The influence of the power of plasma and the deposition time on the sp2/sp3 ratio as well as the concentration of CHn bonds was studied. The influence of sp2/sp3 ratio on the formation process of conducting channels in diamond-like carbon films as a result of electrical breakdown was determined. Reproducible increase of diamond-like carbon film conductivity, with initial sp2/sp3 ratio larger than 0.16, was observed after electrical breakdown.

  6. Characterization of Diamond Like Carbon Film%DLC膜的表征方法

    Institute of Scientific and Technical Information of China (English)

    孙艳明

    2012-01-01

    DLC(Diamond like carbon)薄膜的表征方法很多,发展的很快,在实验中我们经常采用多种性能测试方法,综合分析,得到较可靠的信息。%Diamond like carbon film has many characterization,growing fast.In the experiment,we often use a variety of performance test,comprehensive analysis,to obtain more reliable information.

  7. Superlow friction behavior of diamond-like carbon coatings: Time and speed effects

    Science.gov (United States)

    Heimberg, J. A.; Wahl, K. J.; Singer, I. L.; Erdemir, A.

    2001-04-01

    The friction behavior of a diamond-like carbon coating was studied in reciprocating sliding contact at speeds from 0.01 to 5 mm/s, in dry nitrogen. "Superlow" friction coefficients of 0.003-0.008 were obtained in continuous sliding at the higher speeds (>1 mm/s). However, friction coefficients rose to values typical of diamond-like carbon in dry and ambient air (0.01-0.1) at lower speeds (sustained, suppressed, and recovered as a function of exposure time, demonstrating that duty cycle cannot be ignored when predicting performance of superlow friction coatings in devices.

  8. INFLUENCE OF THE SILICON INTERLAYER ON DIAMOND-LIKE CARBON FILMS DEPOSITED ON GLASS SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Deiler Antonio Lima Oliveira

    2012-06-01

    Full Text Available Diamond-like carbon (DLC films as a hard protective coating have achieved great success in a diversity of technological applications. However, adhesion of DLC films to substrates can restrict their applications. The influence of a silicon interlayer in order to improve DLC adhesion on glass substrates was investigated. Amorphous silicon interlayer and DLC films were deposited using plasma enhanced chemical vapor deposition from silane and methane, respectively. The bonding structure, transmittance, refraction index, and adherence of the films were also evaluated regarding the thickness of the silicon interlayer. Raman scattering spectroscopy did not show any substantial difference in DLC structure due to the interlayer thickness of the silicon. Optical measurements showed a sharp decrease of transmittance in the ultra-violet region caused by the fundamental absorption of the light. In addition, the absorption edge of transmittance shifted toward longer wavelength side in the ultra-violet region as the thickness of the silicon interlayer increased. The tribological results showed an increase of DLC adherence as the silicon interlayer increased, which was characterized by less cracks around the grooves.

  9. Investigation on the formation of tungsten carbide in tungsten-containing diamond like carbon coatings

    NARCIS (Netherlands)

    Strondl, C.; Carvalho, N.M.; Hosson, J.Th.M. De; Kolk, G.J. van der

    2003-01-01

    A series of tungsten-containing diamond-like carbon (Me-DLC) coatings have been produced by unbalanced magnetron sputtering using a Hauzer HTC-1000 production PVD system. Sputtering from WC targets has been used to form W-C:H coatings. The metal to carbon ratio has been varied to study changes in th

  10. On the quantification of unbound hydrogen in diamond-like carbon-based thin films

    NARCIS (Netherlands)

    Pei, Y.T.; Chechenin, N.G.; Chernykh, P.N.; Turkin, A; Vainchtein, David; Hosson, J.Th.M. De

    2009-01-01

    This paper presents a new and straightforward approach to quantify the content of unbound hydrogen in diamond-like carbon-based films. In the case of TiC/a-C:H nanocomposite films it is shown that the content of unbound and bound hydrogen can be deconvoluted via thermal release and elastic recoil de

  11. Modification of rubber surface with hydrogenated diamond-like carbon thin films

    NARCIS (Netherlands)

    Pei, Y. T.; Bui, X. L.; De Hosson, J. Th. M.; Laudon, M; Romanowicz, B

    2009-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals, by sputtering graphite targets in C(2)H(2)/Ar plasma. The wax removal and pre-deposition plas

  12. Flexible diamond-like carbon thin film coated rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Y.T.

    2015-01-01

    Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 75% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin film, by which the coefficient of friction is reduced to less than one tenth. Coating

  13. Flexible diamond-like carbon thin film coated on rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Yutao

    2015-01-01

    Dynamic rubber seals are the major source of friction in lubrication systems and bearings, which may take up to 70% of the total friction. Our solution is to coat rubbers with flexible diamond-like carbon (DLC) thin film by which the coefficient of friction is reduced from above 1.5 to below 0.15. C

  14. Microstructure and tribological performance of diamond-like carbon films deposited on hydrogenated rubber

    NARCIS (Netherlands)

    Pal, J.P. van der; Martinez Martinez, Diego; Pei, Y.T.; Rudolf, P.; Hosson, J.Th.M. De

    2012-01-01

    In this paper, the microstructure and tribological performance of diamond-like carbon (DLC) films prepared by plasma chemical vapor deposition on hydrogenated nitrile butadiene rubbers (HNBR) are studied. Different negative variations of temperature during film growth were selected by proper changes

  15. Deposition and characterization of hydrogenated diamond-like carbon thin films on rubber seals

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Hosson, J.Th.M. De

    2010-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals. The wax removal and pre-deposition plasma treatment of HNBR substrates are proven to be cruci

  16. Bacterial Adhesion to Diamond-like Carbon as Compared to Stainless Steel

    NARCIS (Netherlands)

    Soininen, Antti; Tiainen, Veli-Matti; Konttinen, Yrjo T.; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant K.

    2009-01-01

    Recent studies suggest that diamond-like carbon (DLC) coatings are suitable candidates for application on biomedical devices and implants, due to their high hardness, low friction, high wear and corrosion resistance, chemical inertness, smoothness, and tissue and blood compatibility. However, most s

  17. A New Empirical Model for Estimation of sp3 Fraction in Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    DAI Hai-Yang; WANG Li-Wu; JIANG Hui; HUANG Ning-Kang

    2007-01-01

    A new empirical model to estimate the content of sp3 in diamond-like carbon (DLC) films is presented, based on the conventional Raman spectra excited by 488nm or 514nm visible light for different carbons. It is found that bandwidth of the G peak is related to the sp3 fraction. A wider bandwidth of the G peak shows a higher sp3 fraction in DLC films.

  18. Preparation and Investigation of Diamond-like Carbon Stripper Foils

    Institute of Scientific and Technical Information of China (English)

    FAN; Qi-wen; DU; Ying-hui; ZHANG; Rong; XU; Guo-ji

    2013-01-01

    1 Preparation of DLC stripper foils For DLC stripper foils of about 5μg/cm2 thickness,the following methods were used.The DLC foils of about 4μg/cm2 thicknesses were produced by FCVA onto glass slides coated with betaine-saccharose as releasing agent,which was previously covered with the evaporated carbon layers of about 1μg/cm2

  19. Nanostructured Diamond-Like Carbon Films Grown by Off-Axis Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Seong Shan Yap

    2015-01-01

    Full Text Available Nanostructured diamond-like carbon (DLC films instead of the ultrasmooth film were obtained by pulsed laser ablation of pyrolytic graphite. Deposition was performed at room temperature in vacuum with substrates placed at off-axis position. The configuration utilized high density plasma plume arriving at low effective angle for the formation of nanostructured DLC. Nanostructures with maximum size of 50 nm were deposited as compared to the ultrasmooth DLC films obtained in a conventional deposition. The Raman spectra of the films confirmed that the films were diamond-like/amorphous in nature. Although grown at an angle, ion energy of >35 eV was obtained at the off-axis position. This was proposed to be responsible for subplantation growth of sp3 hybridized carbon. The condensation of energetic clusters and oblique angle deposition correspondingly gave rise to the formation of nanostructured DLC in this study.

  20. Plasmonic Properties of Nanostructured Diamond Like Carbon/Silver Nanocomposite Films with Nanohole Arrays

    Directory of Open Access Journals (Sweden)

    Šarūnas MEŠKINIS

    2016-11-01

    Full Text Available Plasmonic properties of the diamond like carbon nanocomposite films with embedded silver nanoparticles with patterned nanohole arrays were analyzed in this study. The films were deposited by unbalanced reactive magnetron sputtering of silver target. Nanopatterning of the films was performed by combining electron beam nanolithography and ion beam etching techniques. Modeling of plasmonic properties was done using the classical Maxwell-Garnett theory. Modeling data and experimental results were in good accordance. Formation of the nanohole pattern in diamond like carbon films doped with silver resulted in decreased intensity of the surface plasmon resonance absorbance peak. No new absorbance or transmittance peaks were observed after the nanopattering. It was explained by extraordinary transmission effect in nanostructured DLC : Ag film films due to plasmon polariton resonance inside of the nanoholes.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.13193

  1. Diamond-like carbon formation for various positions by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Seong-Shan [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)]. E-mail: ssyap@mmu.edu.my; Tou, Teck-Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

    2005-07-30

    Pulsed laser ablation of pyrolytic graphite target was carried out by an Nd-YAG laser with {lambda} = 1064 nm and fluence in the range of 1-10 J/cm{sup 2}. The plume was produced by focusing the laser beam and rastering over a 6.5 mm x 6.5 mm area on the graphite target. The substrates were placed at two positions: on-axis position facing the target and off-axis position in the target plane with 2 mm offset from the ablation site. Diamond-like carbon was formed on the substrates at both positions and on the ablated area as detected by Raman spectroscopy. Rough and granular surface was observed for the samples placed in the target plane and smooth diamond-like carbon films for the samples placed facing the target as observed by SEM and optical microscopy.

  2. Optical and morphological properties of porous diamond-like-carbon films deposited by magnetron sputtering

    OpenAIRE

    Baroni, M. P. M. A.; Conceição, M. Ventura; Rosa, R. R.; Persson, C.; Arwin, H.; Silva Jr., E.F. da; Roman, L.S.; Nakamura, O.; I. Pepe; Silva, A. Ferreira da

    2006-01-01

    RESTRITO Porous diamond-like-carbon (PDLC) thin films obtained on silicon substrate by DC low energy magnetron sputtering have been investigated by photoluminescence, transmission and reflection spectroscopy, photoacoustic and spectroscopic ellipsometry. The absorption features observed for these films show similarities with those of porous silicon (PS) as well as in the performed gradient structural pattern classification of the SFM porosity, by means of the computational GPA-flyby enviro...

  3. Irradiation Effect of γ Rays on Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Diamond-like carbon films, prepared by RF glow discharge on glasssubstrates, were irradiated by γ rays. The as-deposited and irradiated films were characterized by Raman spectroscopy, electrical resistivity, and infrared transmittance. It is shown that the irradiation of the γ rays can lead to the breaking of SP3C-H and SP2C-H bonds, slight increasing of SP3C-C bonds, and induced hydrogen recombination with H2 molecules, subsequently diffusing to the surface of the films. When the γ rays irradiation dose reached 10×104 Gy, the numbers of SP3C-H bonds was decreased by about 50%, the resistivity of irradiated DLC films was increased, and the diamond-like character of the films became more obvious. The structure of DLC films was modified when irradiated by γ rays. The irradiation mechanisms are briefly discussed.

  4. Selective formation of diamond-like carbon coating by surface catalyst patterning

    DEFF Research Database (Denmark)

    Palnichenko, A.V.; Mátéfi-Tempfli, M.; Mátéfi-Tempfli, Stefan

    2004-01-01

    The selective formation of diamond-like carbon coating by surface catalyst patterning was studied. DLC films was deposited using plasma enhanced chemical vapor deposition, filtered vacuum arc deposition, laser ablation, magnetron sputtering and ion-beam lithography methods. The DLC coatings were...... obtained by means of a single short and intensive carbon plasma deposition pulse. The deposited DLC coating was characterized by micro-Raman spectroscopy measurements. The DLC coating process gave rise to wide potential possibilities in micro-devices manufacturing productions....

  5. Compilation of diamond-like carbon properties for barriers and hard coatings

    Energy Technology Data Exchange (ETDEWEB)

    Outka, D.A.; Hsu, Wen L.; Phillips, K.; Boehme, D.R.; Yang, N.Y.C.; Ottesen, D.K.; Johnsen, H.A.; Clift, W.M. [Sandia National Labs., Livermore, CA (United States); Headley, T.J. [Sandia National Labs., Albuquerque, NM (United States)

    1994-05-01

    Diamond-like carbon (DLC) is an amorphous form of carbon which resembles diamond in its hardness, lubricity, and resistance to chemical attack. Such properties make DLC of interest for use in barrier and hard coating technology. This report examines a variety of properties of DLC coatings. This includes examining substrates on which DLC coatings can be deposited; the resistance of DLC coatings to various chemical agents; adhension of DLC coatings; and characterization of DLC coatings by electron microscopy, FTIR, sputter depth profiling, stress measurements and nanoindentation.

  6. Study of facing target sputtered diamond-like carbon overcoats for hard disk drive media

    Energy Technology Data Exchange (ETDEWEB)

    Seet, H.L., E-mail: SEET_Hang_Li@dsi.a-star.edu.sg [Data Storage Institute, A*STAR Agency for Science, Technology and Research, 5 Engineering Drive 1, 117608 (Singapore); Ng, K.K.; Chen, X.Y. [Data Storage Institute, A*STAR Agency for Science, Technology and Research, 5 Engineering Drive 1, 117608 (Singapore); Yang, P. [Singapore Synchrotron Light Source (SSLS), National University of Singapore, 5 Research Link, 117603 (Singapore); Shen, L. [Institute of Materials Research and Engineering, A*STAR Agency for Science, Technology and Research, 3 Research Link, 117602 (Singapore); Ji, R.; Ng, H.X.; Lim, C.B. [Data Storage Institute, A*STAR Agency for Science, Technology and Research, 5 Engineering Drive 1, 117608 (Singapore)

    2015-07-01

    The demand for higher areal density in the hard disk drive industry has fuelled extensive research efforts and focuses on magnetic spacing reduction. In the head–disk interface arena, one of the key focuses is to reduce the carbon overcoat thickness without compromising the overcoat protection performance. Thus, in the search for alternative methods to reduce the carbon overcoat thickness, the facing target sputtering (FTS) process for diamond-like carbon deposition has been investigated. The resulting properties have been presented in this paper, with comparison to conventional diamond-like carbon (DLC) layers by other processes such as chemical vapor deposition and reactive sputtering with nitrogen. X-ray reflectometry results showed that facing target sputtered DLC samples displayed significantly higher density, at 2.87 g/cm{sup 3}, as compared to hydrogenated and nitrogenated DLC samples. This was attributed to the higher sp{sup 3} content, as obtained by X-ray photoelectron spectroscopy measurements. As a result of the high sp{sup 3} content, hardness of the FTS deposited samples was higher than that of the hydrogenated and nitrogenated DLC samples. In addition, the surface energy of FTS samples was observed to be comparable, but lower, than that of nitrogenated DLC samples through contact angle measurements. Clearances comparable to that of conventional DLC samples were achieved and the sample disks were flyable. Wear performance tests also revealed more wear resistance for the FTS deposited DLC samples, but also higher head wear. - Highlights: • Facing target sputtered (FTS) diamond-like carbon (DLC) samples were studied. • FTS DLC samples possess higher density and hardness. • Surface conditions and flyability performances for FTS DLC samples were comparable. • Wear tests on FTS DLC samples showed lower media wear, but higher head wear.

  7. Surface characterization and orientation interaction between diamond- like carbon layer structure and dimeric liquid crystals

    Science.gov (United States)

    Naradikian, H.; Petrov, M.; Katranchev, B.; Milenov, T.; Tinchev, S.

    2017-01-01

    Diamond-like carbon (DLC) and amorphous carbon films are very promising type of semiconductor materials. Depending on the hybridization sp2/sp3 ratio, the material’s band gap varies between 0.8 and 3 eV. Moreover carbon films possess different interesting for practice properties: comparable to the Silicon, Diamond like structure has 22-time better thermal conductivity etc. Here we present one type of implementation of such type nanostructure. That is one attempt for orientation of dimeric LC by using of pre-deposited DLC layer with different ratio of sp2/sp3 hybridized carbon content. It could be expected a pronounced π1-π2interaction between s and p orbital levels on the surface and the dimeric ring of LC. We present comparison of surface anchoring strengths of both orientation inter-surfaces DLC/dimeric LC and single wall carbon nanotubes (SWCNT)/dimeric LC. The mechanism of interaction of dimeric LC and activated surfaces with DLC or SWCNT will be discussed. In both cases we have π-π interaction, which in combination with hydrogen bonding, typical for the dimeric LCs, influence the LC alignment. The Raman spectroscopy data evidenced the presence of charge transfer between contacting hexagonal rings of DLC and the C = O groups of the LC molecules.

  8. Panel 2 - properties of diamond and diamond-like-carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.; Clausing, R.E. [Oak Ridge National Lab., TN (United States); Ajayi, O.O.; Liu, Y.Y.; Purohit, A. [Argonne National Lab., IL (United States); Bartelt, P.F. [Deere & Co., Moline, IL (United States); Baughman, R.H. [Allied Signal, Morristown, NJ (United States); Bhushan, B. [Ohio State Univ., Columbus (United States); Cooper, C.V. [United Technologies Research Center, East Hartford, CT (United States); Dugger, M.T. [Sandia National Laboratories, Albuquerque, NM (United States); Freedman, A. [Aerodyne Research, Inc., Billerica, MA (United States); Larsen-Basse, J. [National Science Foundation, Washington, DC (United States); McGuire, N.R. [Caterpillar, Peoria, IL (United States); Messier, R.F. [Pennsylvania State Univ., University Park (United States); Noble, G.L.; Ostrowki, M.H. [John Crane, Inc., Morton Grove, IL (United States); Sartwell, B.D. [Naval Research Lab., Washington, DC (United States); Wei, R. [Colorado State Univ., Fort Collins (United States)

    1993-01-01

    This panel attempted to identify and prioritize research and development needs in determining the physical, mechanical and chemical properties of diamond and diamond-like-carbon films (D/DLCF). Three specific goals were established. They were: (1) To identify problem areas which produce concern and require a better knowledge of D/DLCF properties. (2) To identify and prioritize key properties of D/DLCF to promote transportation applications. (3) To identify needs for improvement in properties-measurement methods. Each of these goals is addressed subsequently.

  9. Preparation and Characteristics of Nanoscale Diamond-Like Carbon Films for Resistive Memory Applications

    Institute of Scientific and Technical Information of China (English)

    FU Di; XIE Dan; ZHANG Chen-Hui; ZHANG Di; NIU Jie-Bin; QIAN He; LIU Li-Tian

    2010-01-01

    @@ We propose diamond-like carbon(DLC)as the resistance change material for nonvolatile memory applications.Nanoscale DLC films are prepared by filtered cathodic vacuum arc technique and integrated to W/DLC/W structure devices.The deposited DLC film has a thickness of about 2O nm and high sp3 fraction content.Reversible bistable resistive switching from a high resistance state to a low resistance state,and vice versa,is observed under appropriate unipolar stimulation pulses.

  10. Deposition of diamond like carbon films by using a single ion gun with varying beam source

    Institute of Scientific and Technical Information of China (English)

    JIANG Jin-qiu; Chen Zhu-ping

    2001-01-01

    Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.

  11. Advances in multi-spectral Diamond-Like Carbon (DLC) coatings

    Science.gov (United States)

    Keck, Jason; Karp, Christopher

    2014-05-01

    We discuss the development and applications of a new approach to Diamond-Like Carbon (DLC) coating that provides the durability of traditional DLC coatings, with the addition of significantly more transmission at visible wavelengths and greater transmission in the IR. We developed a deposition system design that incorporates multiple coating technologies, allowing for multiple material design approaches. This has enabled the manufacture of DLC coatings with improved extended spectral properties, suitable for applications in which the coating must withstand airborne particulate impacts, corrosive fluids, environmental extremes, and abrasive physical handling, while offering better than typical transmission in the visible or infrared wavelength regions, or both.

  12. Study of relationship between structure and transmittance of diamond-like carbon (DLC) films

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, the transparent hard diamond-like carbon (DLC) films were deposited on glass substrate by magnetic confined radio-frequency plasma chemical vapor deposition. The structure of films was studied by Raman spectra and X-ray photoelectron spectra (XPS), the transmittance of films by Spectrophotometer. The mechanism of the influence of films structure on transmittance of the films was discussed. The results show that the thickness of films was lower than 100nm, and the transmittance was over 90% in 380-780 nm region. Discussion in theory on the influence of film structure on transmittance was correspondence to experiment results.

  13. Microstructure and chemical bond evolution of diamond-like carbon films machined by femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing; Wang, Chunhui [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an 710072 (China); Liu, Yongsheng, E-mail: yongshengliu@nwpu.edu.cn [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an 710072 (China); Cheng, Laifei [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Weinan [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 10068 (China); Zhang, Qing [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an 710072 (China); Yang, Xiaojun [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 10068 (China)

    2015-06-15

    Highlights: • The machining depth was essentially proportional to the laser power. • The well patterned microgrooves and ripple structures with nanoparticles were formed distinctly in the channels. And the number of nanoparticles increased with the processing power as well. • It revealed a conversion from amorphous carbon to nanocrystalline graphite after laser treated with increasing laser power. • It showed that a great decrease of sp{sup 3}/sp{sup 2} after laser treatment. - Abstract: Femtosecond laser is of great interest for machining high melting point and hardness materials such as diamond-like carbon, SiC ceramic, et al. In present work, the microstructural and chemical bond evolution of diamond-like carbon films were investigated using electron microscopy and spectroscopy techniques after machined by diverse femtosecond laser power in air. The results showed the machining depth was essentially proportional to the laser power. The well patterned microgrooves and ripple structures with nanoparticles were formed distinctly in the channels. Considering the D and G Raman band parameters on the laser irradiation, it revealed a conversion from amorphous carbon to nanocrystalline graphite after laser treated with increasing laser power. X-ray photoelectron spectroscopy analysis showed a great decrease of sp{sup 3}/sp{sup 2} after laser treatment.

  14. Workshop on diamond and diamond-like-carbon films for the transportation industry

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, F.A.; Moores, D.K. [eds.

    1993-01-01

    Applications exist in advanced transportation systems as well as in manufacturing processes that would benefit from superior tribological properties of diamond, diamond-like-carbon and cubic boron nitride coatings. Their superior hardness make them ideal candidates as protective coatings to reduce adhesive, abrasive and erosive wear in advanced diesel engines, gas turbines and spark-ignited engines and in machining and manufacturing tools as well. The high thermal conductivity of diamond also makes it desirable for thermal management not only in tribological applications but also in high-power electronic devices and possibly large braking systems. A workshop has been recently held at Argonne National Laboratory entitled ``Diamond and Diamond-Like-Carbon Films for Transportation Applications`` which was attended by 85 scientists and engineers including top people involved in the basic technology of these films and also representatives from many US industrial companies. A working group on applications endorsed 18 different applications for these films in the transportation area alone. Separate abstracts have been prepared.

  15. Dual-ion-beam deposition of carbon films with diamond-like properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1985-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamond like films generated by sputtering a graphite target.

  16. Architectural design of diamond-like carbon coatings for long-lasting joint replacements.

    Science.gov (United States)

    Liu, Yujing; Zhao, Xiaoli; Zhang, Lai-Chang; Habibi, Daryoush; Xie, Zonghan

    2013-07-01

    Surface engineering through the application of super-hard, low-friction coatings as a potential approach for increasing the durability of metal-on-metal replacements is attracting significant attention. In this study innovative design strategies are proposed for the development of diamond-like-carbon (DLC) coatings against the damage caused by wear particles on the joint replacements. Finite element modeling is used to analyze stress distributions induced by wear particles of different sizes in the newly-designed coating in comparison to its conventional monolithic counterpart. The critical roles of architectural design in regulating stress concentrations and suppressing crack initiation within the coatings is elucidated. Notably, the introduction of multilayer structure with graded modulus is effective in modifying the stress field and reducing the magnitude and size of stress concentrations in the DLC diamond-like-carbon coatings. The new design is expected to greatly improve the load-carrying ability of surface coatings on prosthetic implants, in addition to the provision of damage tolerance through crack arrest.

  17. Influence of thermal heating on diamond-like carbon film properties prepared by filtered cathodic arc

    Energy Technology Data Exchange (ETDEWEB)

    Khamnualthong, N., E-mail: nattapornkh@gmail.com [Department of Physics, Faculty of Science, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Western Digital Thailand Co. Ltd, Ayutthaya, 13160 (Thailand); Siangchaew, K. [Western Digital Thailand Co. Ltd, Ayutthaya, 13160 (Thailand); Limsuwan, P. [Department of Physics, Faculty of Science, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400 (Thailand)

    2013-10-01

    Tetrahedral amorphous diamond-like carbon (ta-DLC) films were deposited on magnetic recording heads using the filtered cathodic arc method. The deposited film thickness was on the order of several nanometers. The DLC films were then annealed to 100 °C–300 °C for 30 and 60 min, and the structure of the ta-DLC films was investigated using Raman spectroscopy, where the gross changes were observed in the Raman D and G peaks. Detailed interpretation concluded that there was sp{sup 2} clustering as a function of temperature, and there was no sp{sup 3}-to-sp{sup 2} conversion after heating up to 300 °C. Furthermore, X-ray photoelectron spectroscopy suggested that oxidation of both the ta-DLC film and the adhesion layer occurs at 300 °C. Additionally, more film wear was observed with heating as measured by a nanoindenter. - Highlights: • Tetrahedral-amorphous diamond-like carbon (ta-DLC) by filtered cathodic arc • ta-DLC used in magnetic recording head as head overcoat • ta-DLC thickness range of less than 2 nm • ta-DLC property dependence on heating • Temperature effect range of up to 300 °C.

  18. Characterization of the Diamond-like Carbon Based Functionally Gradient Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their goodphysical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasmaimmersion ion implantation (PIll) was adopted to fabricate diamond-like carbon-based functionally gradient film,N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopyand glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed usingAFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surfaceroughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness andinterfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa,3.75 MPa.m1/2 and 5.68 MPa@m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer,this DLC gradient film has better qualities as a solid lubricating coating.

  19. Synthesis and characterization of boron incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.L. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Yang, Q., E-mail: qiaoqin.yang@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Tang, Y.; Yang, L.; Zhang, C. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Hu, Y.; Cui, X. [Canadian Light Source Inc., 101 Perimeter Road, Saskatoon, SK S7N 0X4 (Canada)

    2015-08-31

    Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B{sub 4}C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B{sub 4}C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp{sup 3} bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp{sup 3} bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp{sup 3} bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films.

  20. Diamond-Like Carbon Film Deposition Using DC Ion Source with Cold Hollow Cathode

    Directory of Open Access Journals (Sweden)

    E. F. Shevchenko

    2014-01-01

    Full Text Available Carbon diamond-like thin films on a silicon substrate were deposited by direct reactive ion beam method with an ion source based on Penning direct-current discharge system with cold hollow cathode. Deposition was performed under various conditions. The pressure (12–200 mPa and the plasma-forming gas composition consisting of different organic compounds and hydrogen (C3H8, CH4, Si(CH32Cl2, H2, the voltage of accelerating gap in the range 0.5–5 kV, and the substrate temperature in the range 20–850°C were varied. Synthesized films were researched using nanoindentation, Raman, and FTIR spectroscopy methods. Analysis of the experimental results was made in accordance with a developed model describing processes of growth of the amorphous and crystalline carbon materials.

  1. Stress reduction of Cu-doped diamond-like carbon films from ab initio calculations

    Directory of Open Access Journals (Sweden)

    Xiaowei Li

    2015-01-01

    Full Text Available Structure and properties of Cu-doped diamond-like carbon films (DLC were investigated using ab initio calculations. The effect of Cu concentrations (1.56∼7.81 at.% on atomic bond structure was mainly analyzed to clarify the residual stress reduction mechanism. Results showed that with introducing Cu into DLC films, the residual compressive stress decreased firstly and then increased for each case with the obvious deterioration of mechanical properties, which was in agreement with the experimental results. Structural analysis revealed that the weak Cu-C bond and the relaxation of both the distorted bond angles and bond lengths accounted for the significant reduction of residual compressive stress, while at the higher Cu concentration the increase of residual stress attributed to the existence of distorted Cu-C structures and the increased fraction of distorted C-C bond lengths.

  2. Stress reduction of Cu-doped diamond-like carbon films from ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaowei; Ke, Peiling; Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-01-15

    Structure and properties of Cu-doped diamond-like carbon films (DLC) were investigated using ab initio calculations. The effect of Cu concentrations (1.56∼7.81 at.%) on atomic bond structure was mainly analyzed to clarify the residual stress reduction mechanism. Results showed that with introducing Cu into DLC films, the residual compressive stress decreased firstly and then increased for each case with the obvious deterioration of mechanical properties, which was in agreement with the experimental results. Structural analysis revealed that the weak Cu-C bond and the relaxation of both the distorted bond angles and bond lengths accounted for the significant reduction of residual compressive stress, while at the higher Cu concentration the increase of residual stress attributed to the existence of distorted Cu-C structures and the increased fraction of distorted C-C bond lengths.

  3. Tribological Characteristic of Diamond-like Carbon Films Investigated by Lateral Force Microscope

    Institute of Scientific and Technical Information of China (English)

    DINGJian-ning; ZHUShou-xing; FANZhen; LIChang-sheng; CAILan; YANGJi-chang

    2004-01-01

    Tribological characteristic of different thick diamond- like carbon (DLC) fihns was stymied. A geometrical method was applied to calibrate the cantilever spring constant and to calculate tbe normal and lateral forces, respectively. Experimental results show that the lateral force under different applied loads is proportional to the normal force for the DLC films with the thickness of 153.4nm and 64.9nm. However, for the thickness of 4.48nm and 2.78nm DLC films, lateral force is nonlinear to normal force, which is opposed to the Amonton's law. The single asperity regime and the DMT model were put forward to predict the possible nanotribological mecb-anism between the probe and DLC film.

  4. Properties of Diamond-Like Carbon Films Synthesized by Dual-Target Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    LIU Cui; LI Guo-Qing; GOU Wei; MU Zong-Xin; ZHANG Cheng-Wu

    2004-01-01

    @@ Smooth, dense and uniform diamond-like carbon films (DLC films) for industrial applications have successfully been prepared by dual-target unbalanced magnetron sputtering and the DLC characteristics of the films are confirmed by Raman spectra. It is found that the sputtering current of target plays an important role in the DLC film deposition. Deposition rate of 3.5μm/h is obtained by using the sputtering current of 30 A. The friction coefficient of the films is 0.2-0.225 measured by using a pin-on-disc microtribometer. The structure of the films tends to have a growth of sp3 bonds content at high sputtering current. The compressive residual stress in the films increases with the increasing sputtering current of the target.

  5. Role of atomic transverse migration in growth of diamond-like carbon films

    Institute of Scientific and Technical Information of China (English)

    Ma Tian-Bao; Hu Yuan-Zhong; Wang Hui

    2007-01-01

    The growth of diamond-like carbon (DLC) films is studied using molecular dynamics simulations. The effect of impact angle on film structure is carefully studied, which shows that the transverse migration of the incident atoms is the main channel of film relaxation. A transverse-migration-induced film relaxation model is presented to elucidate the process of film relaxation which advances the original model of subplantation. The process of DLC film growth on a rough surface is also investigated, as well as the evolution of microstructure and surface morphology of the film. A preferential-to-homogeneous growth mode and a smoothing of the film are observed, which are due to the transverse migration of the incident atoms.

  6. Fabrication of Diamond-like Carbon Films by Ion Assisted Middle Frequency Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-chen; SUN Shao-ni; ZHOU Yi; MA Sheng-ge; BA De-chun

    2006-01-01

    Diamond-like carbon (DLC) films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the Hall discharging current and the argon/nitrogen ratio on the DLC film's performance were studied. The experimental results show that the film's surface roughness, the hardness and the Young's modulus increase firstly and then decrease with the bias voltage incrementally increases. Also when the substrate temperature rises, the surface roughness of the film varies slightly, but its hardness and Young's modulus firstly increase followed by a sharp decrease when the temperature surpassing 120 ℃. With the Hall discharging current incrementally rising, the hardness and Young's modulus of the film decrease and the surface roughness of the film on 316L stainless steel firstly decreased and then remains constant.

  7. Electron-beam induced diamond-like-carbon passivation of plasmonic devices

    Science.gov (United States)

    Balaur, Eugeniu; Sadatnajafi, Catherine; Langley, Daniel; Lin, Jiao; Kou, Shan Shan; Abbey, Brian

    2015-12-01

    Engineered materials with feature sizes on the order of a few nanometres offer the potential for producing metamaterials with properties which may differ significantly from their bulk counterpart. Here we describe the production of plasmonic colour filters using periodic arrays of nanoscale cross shaped apertures fabricated in optically opaque silver films. Due to its relatively low loss in the visible and near infrared range, silver is a popular choice for plasmonic devices, however it is also unstable in wet or even ambient conditions. Here we show that ultra-thin layers of Diamond-Like Carbon (DLC) can be used to prevent degradation due to oxidative stress, ageing and corrosion. We demonstrate that DLC effectively protects the sub-micron features which make up the plasmonic colour filter under both atmospheric conditions and accelerated aging using iodine gas. Through a systematic study we confirm that the nanometre thick DLC layers have no effect on the device functionality or performance.

  8. Optical and Electrical Properties Evolution of Diamond-Like Carbon Thin Films with Deposition Temperature

    Institute of Scientific and Technical Information of China (English)

    DING Xu-Li; LI Qing-Shan; KONG Xiang-He

    2009-01-01

    Optical and electrical properties of diamond-like carbon (DLC) films deposited by pulsed laser ablation of graphite target at different substrate temperatures are reported. By varying the deposition temperature from 400 to 25℃, the film optical transparency and electrical resistivity increase severely. Most importantly, the transparency and resistivity properties of the DLC films can be tailored to approaching diamond by adjusting the deposition temperature, which is critical to many applications. DLC films deposited at low temperatures show excellent optical transmittance and high resistivity. Over the same temperature regime an increase of the spa bonded C content is observed using visible Raman spectroscopy, which is responsible for the enhanced transparency and resistivity properties.

  9. Diamond like carbon coatings deposited by microwave plasma CVD: XPS and ellipsometric studies

    Indian Academy of Sciences (India)

    R M Dey; M Pandey; D Bhattacharyya; D S Patil; S K Kulkarni

    2007-12-01

    Diamond-like carbon (DLC) films were deposited by microwave assisted chemical vapour deposition system using d.c. bias voltage ranging from –100 V to –300 V. These films were characterized by X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry techniques for estimating 3/2 ratio. The 3/2 ratio obtained by XPS is found to have an opposite trend to that obtained by spectroscopic ellipsometry. These results are explained using sub-plantation picture of DLC growth. Our results clearly indicate that the film is composed of two different layers, having entirely different properties in terms of void percentage and 3/2 ratio. The upper layer is relatively thinner as compared to the bottom layer.

  10. Oxygen plasma etching of silver-incorporated diamond-like carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Marciano, F.R., E-mail: fernanda@las.inpe.b [Instituto Nacional de Pesquisas Espaciais (INPE), Laboratorio Associado de Sensores e Materiais (LAS), Av. dos Astronautas 1758, Sao Jose dos Campos, 12227-010, SP (Brazil); Instituto Tecnologico de Aeronautica (ITA), Centro Tecnico Aeroespacial (CTA), Pca. Marechal Eduardo Gomes, 50-Sao Jose dos Campos, 12228-900, SP (Brazil); Bonetti, L.F. [Clorovale Diamantes Industria e Comercio Ltda, Estr. do Torrao de Ouro, 500-Sao Jose dos Campos, 12229-390, SP (Brazil); Pessoa, R.S.; Massi, M. [Instituto Tecnologico de Aeronautica (ITA), Centro Tecnico Aeroespacial (CTA), Pca. Marechal Eduardo Gomes, 50-Sao Jose dos Campos, 12228-900, SP (Brazil); Santos, L.V.; Trava-Airoldi, V.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Laboratorio Associado de Sensores e Materiais (LAS), Av. dos Astronautas 1758, Sao Jose dos Campos, 12227-010, SP (Brazil)

    2009-08-03

    Diamond-like carbon (DLC) film as a solid lubricant coating represents an important area of investigation related to space devices. The environment for such devices involves high vacuum and high concentration of atomic oxygen. The purpose of this paper is to study the behavior of silver-incorporated DLC thin films against oxygen plasma etching. Silver nanoparticles were produced through an electrochemical process and incorporated into DLC bulk during the deposition process using plasma enhanced chemical vapor deposition technique. The presence of silver does not affect significantly DLC quality and reduces by more than 50% the oxygen plasma etching. Our results demonstrated that silver nanoparticles protect DLC films against etching process, which may increase their lifetime in low earth orbit environment.

  11. In Vitro Durability - Pivot bearing with Diamond Like Carbon for Ventricular Assist Devices

    CERN Document Server

    de Sá, Rosa Corrêa Leoncio; Leão, Tarcísio Fernandes; da Silva, Evandro Drigo; da Fonseca, Jeison Willian Gomes; da Silva, Bruno Utiyama; Leal, Edir Branzoni; Moro, João Roberto; de Andrade, Aron José Pazin; Bock, Eduardo Guy Perpétuo

    2015-01-01

    Institute Dante Pazzanese of Cardiology (IDPC) develops Ventricular Assist Devices (VAD) that can stabilize the hemodynamics of patients with severe heart failure before, during and/or after the medical practice; can be temporary or permanent. The ADV's centrifugal basically consist of a rotor suspended for system pivoting bearing; the PIVOT is the axis with movement of rotational and the bearing is the bearing surface. As a whole system of an implantable VAD should be made of long-life biomaterial so that there is no degradation or deformation during application time; surface modification techniques have been widely studied and implemented to improve properties such as biocompatibility and durability of applicable materials. The Chemical Vapour Deposition technique allows substrates having melting point higher than 300 {\\deg}C to be coated, encapsulated, with a diamond like carbon film (DLC); The test simulated the actual conditions in which the system of support remains while applying a ADV. The results hav...

  12. Velocity dependence of coefficient of friction of diamond like carbon coatings

    Science.gov (United States)

    Sharma, Neha; Kumar, Niranjan; Dash, S.; Tyagi, A. K.

    2012-06-01

    The velocity dependence of coefficient of friction (CoF) of hydrogen-free and hydrogenated Diamond Like Carbon (DLC) coatings was studied on sliding. In low velocity regime, CoF of hydrogen-free DLC was found to increase which may be linked to a thermally activated pre-mature breaking of the surface asperities. However, CoF of hydrogenated DLC was found to decrease due to formation of graphite like lubricious layer and sustainability of cross-linked network of H-bonded atoms. In high velocity regime, CoF of hydrogen free DLC increases marginally due to an inefficient transfer of thermal energy while that of hydrogenated DLC increases due to rapid formation and rupture of atomic bonds.

  13. Mechanical stability of the diamond-like carbon film on nitinol vascular stents under cyclic loading

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Jong [Department of Materials Science and Engineering, Seoul National University, Kwan-ak, Seoul 151-744 (Korea, Republic of); Advanced Functional Materials Research Center, Korea Institute of Science and Technology, Seung-buk, Seoul 136-791 (Korea, Republic of); Moon, Myoung-Woon [Future Fusion Technology Laboratory, Korea Institute of Science and Technology, Seung-buk, Seoul 136-791 (Korea, Republic of)], E-mail: mwmoon@kist.re.kr; Lee, Kwang-Ryeol [Future Fusion Technology Laboratory, Korea Institute of Science and Technology, Seung-buk, Seoul 136-791 (Korea, Republic of); Seok, Hyun-Kwang; Han, Seung-Hee [Advanced Functional Materials Research Center, Korea Institute of Science and Technology, Seung-buk, Seoul 136-791 (Korea, Republic of); Ryu, Jae-Woo; Shin, Kyong-Min [Taewoong Medical Inc. Ltd, Gimpo, Gyeonggi 415-873 (Korea, Republic of); Oh, Kyu Hwan [Department of Materials Science and Engineering, Seoul National University, Kwan-ak, Seoul 151-744 (Korea, Republic of)

    2008-12-01

    The mechanical stability of diamond-like carbon (DLC) films coated on nitinol vascular stents was investigated under cyclic loading condition by employing a stent crimping system. DLC films were coated on the vascular stent of a three dimensional structure by using a hybrid ion beam system with rotating jig. The cracking or delamination of the DLC coating occurred dominantly near the hinge connecting the V-shaped segments of the stent where the maximum strain was induced by a cyclic loading of contraction and extension. However the failures were significantly suppressed as the amorphous Si (a-Si) buffer layer thickness increased. Interfacial adhesion strength was estimated from the spalled crack size in the DLC coating for various values of the a-Si buffer layer thickness.

  14. Kinetics and thermodynamics of human serum albumin adsorption on silicon doped diamond like carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Mukhtar H., E-mail: ahmed-m@email.ulster.ac.uk; Byrne, John A.; McLaughlin, James

    2015-03-15

    To gain a better understanding of protein adsorption onto biomaterial surfaces is required for the control of biocompatibility and bioactivity. Various samples of diamond like carbon (DLC) and silicon-doped DLC were synthesised using plasma enhanced chemical vapour deposition (PECVD). The effects of surface morphology on the interaction of human serum albumin (HSA) with doped and undoped DLC films was investigated using spectroscopic ellipsometry (SE) and other surface analysis techniques. The results highlighted an increase in both contact angle and hydrophobicity with increasing silicon dopant levels. A reduction on the contact angle values. After adsorption of HSA, the films showed a reduction in the contact angle with a significant change in the cosΔ and this gap increased with increasing surface coverage of HSA. The adsorption kinetics of HSA were also investigated and revealed that the maximum adsorption occurred at pH 5.0 and the process involved chemisorption. The experimental isotherm data were analysed using the Langmuir and Freundlich‎ models. The amount of HSA adsorbed increased with contact time and reached saturation ‎after 30 min. The adsorption ‎process was found to be pseudo first order with respect to the bulk concentration and was dependent on both the concentration of protein and surface characteristics of the samples. The amount of adsorbed HSA was higher with higher levels of silicon doping of the DLC. Therefore, doping DLC may provide an approach to controlling the protein adsorption. - Graphical abstract: The average thickness layer of HSA measurement onto surfaces of DLC and Si-DLC. - Highlights: • Diamond Like Carbon (DLC) and Silicon doped DLC were synthesised and characterised. • Si-DLC increases the hydrophobicity and decreases the surface free energy. • Adsorption study using human serum albumin (HSA). • The adsorbed amount of HSA increases with increasing of Silicon content DLC. • Adsorption process follow pseudo

  15. Modification of diamond-like carbon films by nitrogen incorporation via plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Flege, S., E-mail: flege@ca.tu-darmstadt.de [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany); Hatada, R.; Hoefling, M.; Hanauer, A.; Abel, A. [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany); Baba, K. [Industrial Technology Center of Nagasaki, Applied Technology Division, Omura, Nagasaki 856-0026 (Japan); Ensinger, W. [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany)

    2015-12-15

    Highlights: • Nitrogen containing diamond-like carbon films were prepared by a plasma ignited by a high voltage. • Variation of preparation method (N{sub 2} implantation, N{sub 2} and C{sub 2}H{sub 4} co-deposition). • Maximum nitrogen content similar for co-deposition and implantation. • Electrical resistivity decreases for small nitrogen contents, increases again for higher contents. - Abstract: The addition of nitrogen to diamond-like carbon films affects properties such as the inner stress of the film, the conductivity, biocompatibility and wettability. The nitrogen content is limited, though, and the maximum concentration depends on the preparation method. Here, plasma immersion ion implantation was used for the deposition of the films, without the use of a separate plasma source, i.e. the plasma was generated by a high voltage applied to the samples. The plasma gas consisted of a mixture of C{sub 2}H{sub 4} and N{sub 2}, the substrates were silicon and glass. By changing the experimental parameters (high voltage, pulse length and repetition rate and gas flow ratio) layers with different N content were prepared. Additionally, some samples were prepared using a DC voltage. The nitrogen content and bonding was investigated with SIMS, AES, XPS, FTIR and Raman spectroscopy. Their influence on the electrical resistivity of the films was investigated. Depending on the preparation conditions different nitrogen contents were realized with maximum contents around 11 at.%. Those values were compared with the nitrogen concentration that can be achieved by implantation of nitrogen into a DLC film.

  16. Surface properties of diamond-like carbon films prepared by CVD and PVD methods

    Institute of Scientific and Technical Information of China (English)

    Liu Dong-Ping; Liu Yan-Hong; Chen Bao-Xiang

    2006-01-01

    Diamond-like carbon (DLC) films have been deposited using three different techniques: (a) electron cyclotron resonance-plasma source ion implantation, (b) low-pressure dielectric barrier discharge, (c) filtered-pulsed cathodic arc discharge. The surface and mechanical properties of these films are compared using atomic force microscopebased tests. The experimental results show that hydrogenated DLC films are covered with soft surface layers enriched with hydrogen and sp3 hybridized carbon while the soft surface layers of tetrahedral amorphous carbon (ta-C) films have graphite-like structure. The formation of soft surface layers can be associated with the surface diffusion and growth induced by the low-energy deposition process. For typical CVD methods, the atomic hydrogen in the plasmas can contribute to the formation of hydrogen and sp3 hybridized carbon enriched surface layers. The high-energy ion implantation causes the rearrangement of atoms beneath the surface layer and leads to an increase in film density. The ta-C films can be deposited using the medium energy carbon ions in the highly-ionized plasma.

  17. Flexible diamond-like carbon films on rubber : On the origin of self-acting segmentation and film flexibility

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Pal, J.P. van der; Martinez-Martinez, D.; Zhou, X.B.; Hosson, J.Th.M. De

    2012-01-01

    This paper reports an experimental approach to deposit flexible diamond-like carbon (DLC) films on hydrogenated nitrile butadiene rubber (HNBR) with plasma-assisted chemical vapor deposition and an analytical model to describe the self-segmentation mechanism of the DLC films. By making use of the su

  18. Flexible diamond-like carbon films on rubber : Friction and the effect of viscoelastic deformation of rubber substrates

    NARCIS (Netherlands)

    Pei, Y. T.; Martinez-Martinez, D.; van der Pal, J. P.; Bui, X. L.; Zhou, X. B.; De Hosson, J. Th. M.

    2012-01-01

    This paper focuses on the frictional behavior of flexible diamond-like carbon (DLC) film-coated hydrogenated nitrile butadiene rubber. By making use of the substantial thermal mismatch between DLC film and rubber substrate, a dense network of cracks forms in the DLC films and contributes to flexibil

  19. Crack formation mechanisms during micro and macro indentation of diamond-like carbon coatings on elastic-plastic substrates

    DEFF Research Database (Denmark)

    Thomsen, N.B.; Fischer-Cripps, A.C.; Swain, M.V.

    1998-01-01

    of cracking and the fracture mechanisms taking place. In the study various diamond-like carbon (DLC) coatings deposited onto stainless steel and tool steel were investigated. Results primarily for one DLC system will be presented here. (C) 1998 Published by Elsevier Science S.A. All rights reserved....

  20. Adhesion improvement of hydrogenated diamond-like carbon thin films by pre-deposition plasma treatment of rubber substrate

    NARCIS (Netherlands)

    Bui, X.L.; Pei, Y.T.; Mulder, E.D.G.; Hosson, J.Th.M. De

    2009-01-01

    For reduction of friction and enhancement of wear resistance of dynamic rubber seals, thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma trea

  1. Influence of load on the dry frictional performance of alkyl acrylate copolymer elastomers coated with diamond-like carbon films

    NARCIS (Netherlands)

    Martinez, D. Martinez; Nohava, Jiri; De Hosson, J. Th. M.

    2015-01-01

    In this work, the influence of applied load on the frictional behavior of alkyl acrylate copolymer elastomers coated with diamond- like carbon films is studied at dry conditions. The performance of two coatings with very different microstructure (patched vs. continuous film) is compared with the unc

  2. On the nature of the coefficient of friction of diamond-like carbon films deposited on rubber

    NARCIS (Netherlands)

    Martinez-Martinez, D.; van der Pal, J. P.; Schenkel, M.; Shaha, K. P.; Pei, Y. T.; De Hosson, J. Th M.

    2012-01-01

    In this paper, the nature of the coefficient of friction (CoF) of diamond-like carbon (DLC)-protected rubbers is studied. The relative importance of the viscoelastic and adhesive contributions to the overall friction is evaluated experimentally by modifying the contact load and the adhesive strength

  3. Electrochemical performance of porous diamond-like carbon electrodes for sensing hormones, neurotransmitters, and endocrine disruptors.

    Science.gov (United States)

    Silva, Tiago A; Zanin, Hudson; May, Paul W; Corat, Evaldo J; Fatibello-Filho, Orlando

    2014-12-10

    Porous diamond-like carbon (DLC) electrodes have been prepared, and their electrochemical performance was explored. For electrode preparation, a thin DLC film was deposited onto a densely packed forest of highly porous, vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the carbon nanotubes to clump together to form a microstructured surface with an enlarged surface area. DLC:VACNT electrodes show fast charge transfer, which is promising for several electrochemical applications, including electroanalysis. DLC:VACNT electrodes were applied to the determination of targeted molecules such as dopamine (DA) and epinephrine (EP), which are neurotransmitters/hormones, and acetaminophen (AC), an endocrine disruptor. Using simple and low-cost techniques, such as cyclic voltammetry, analytical curves in the concentration range from 10 to 100 μmol L(-1) were obtained and excellent analytical parameters achieved, including high analytical sensitivity, good response stability, and low limits of detection of 2.9, 4.5, and 2.3 μmol L(-1) for DA, EP, and AC, respectively.

  4. Molecular dynamics simulation of the deposition process of hydrogenated diamond-like carbon (DLC) films

    Institute of Scientific and Technical Information of China (English)

    ZHANG YuJun; DONG GuangNeng; MAO JunHong; XIE YouBai

    2008-01-01

    The deposition process of hydrogenated diamond-like carbon (DLC) film greatly affects its frictional properties. In this study, CH3 radicals are selected as source species to deposit hydrogenated DLC films for molecular dynamics simulation. The growth and structural properties of hydrogenated DLC films are investigated and elucidated in detail. By comparison and statistical analysis, the authors find that the ratio of carbon to hydrogen in the films generally shows a monotonously increasing trend with the increase of impact energy. Carbon atoms are more reactive during deposition and more liable to bond with substrate atoms than hydrogen atoms. In addition, there exists a peak value of the number of hydrogen atoms deposited in hydrogenated DLC films. The trends of the variation are opposite on the two sides of this peak point, and itbecomes stable when impact energy is greater than 80 eV. The average relative density also indicates a rising trend along with the increment of impact energy, while it does not reach the saturation value until impact energy comes to 50 eV. The hydrogen content in source species is a key factor to determine the hydrogen content in hydrogenated DLC films. When the hydrogen content in source species is high, the hydrogen content in hydrogenated DLC films is accordingly high.

  5. Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, Andreas, E-mail: A.Markwitz@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Gupta, Prasanth [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, Berit [GNS Science, Lower Hutt (New Zealand); Hübner, René [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Leveneur, Jerome; Zondervan, Albert [GNS Science, Lower Hutt (New Zealand); Becker, Hans-Werner [RUBION, Ruhr-University Bochum (Germany)

    2016-03-15

    Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction {sup 1}H({sup 15}N, αγ){sup 12}C (E{sub res} = 6.385 MeV). The films produced at 3.0–10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp{sup 2} hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

  6. Structural and mechanical properties of diamond-like carbon films deposited by direct current magnetron sputtering

    Science.gov (United States)

    Broitman, E.; Hellgren, N.; Czigány, Zs.; Twesten, R. D.; Luning, J.; Petrov, I.; Hultman, L.; Holloway, B. C.

    2003-07-01

    The microstructure, morphology, and mechanical properties of diamond-like carbon (DLC) films deposited by direct current magnetron sputtering were investigated for microelectromechanical systems applications. Film properties were found to vary markedly with the ion energy (Eion) and ion-to-carbon flux ratio (Jion/JC). Cross-sectional high-resolution transmission electron microscopy revealed an amorphous microstructure. However, the presence of nanometer-sized domains at Eion~85 eV was detected. Film stresses, σ, which were compressive in all cases, ranged from 0.5 to 3.5 GPa and depended on the flux ratio as well as ion energy. The hardness (H), Young's moduli (ɛ), and elastic recovery (R) increased with Eion to maximum values of H=27 GPa, ɛ=250 GPa, and R=68% at Eion=85 eV and Jion/JC=4.4. However, near edge x-ray absorption fine structure and electron energy-loss spectrum analysis showed that the sp2/sp3 content of the films does not change with Eion or Jion/JC. The measured change in mechanical properties without a corresponding change in sp2/sp3 ratio is not consistent with any previously published models. We suggest that, in the ranges 5 eV <=Eion<=85 eV and 1.1 <=Jion/JC<=6.8, the presence of defective graphite formed by subplanted C and Ar atoms has the dominant influence on the mechanical properties of DLC films.

  7. Graphite-like and Diamond-like Carbon Coatings with Exceptional Tribological Properties

    Institute of Scientific and Technical Information of China (English)

    M.Jarratt; S.K.Field; S.Yang; D.G.Teer

    2004-01-01

    Two hard, carbon-based solid lubricant coatings, Graphit-iCTM and Dymon-iCTM, have been developed that offer considerable benefits for industry. Both of these new coatings have a high tribological load-bearing capacity, exceptional wear resistance and very low friction, even in dry or lubricant-starved contact. This is in contrast to many commercial diamond-like carbon, DLC coatings, which tend to be highly stressed and therefore brittle, making them unsuitable for high load bearing industrial applications. The development of the new solid lubricant coatings is described, and details of their tribological performance in dry, water and oil-lubricated environments are given. The structure of the coatings has been investigated and related to the tribological properties, and the mechanism for the low friction and wea rrates is discussed. The coatings have been used to successfully improve the lifetime and efficiency of many highly loaded mechanical parts, including automotive fuel injection components, gears, bearings, tappets (cam followers), gudgeon (wrist) pins, etc. They also offer benefits for tooling and are widely used in forming or machining of non-ferrous alloys, and extensively on dies and moulds. Other industrial application areas include electrical devices that require either high conductivity or insulation, optical devices requiring abrasion resistance and surgical tools and implants.

  8. Graphite-like and Diamond-like Carbon Coatings with Exceptional Tribological Properties

    Institute of Scientific and Technical Information of China (English)

    M. Jarratt; S. K. Field; S. Yang; D.G. Teer

    2004-01-01

    Two hard, carbon-based solid lubricant coatings, Graphit-iCTM and Dymon-iCTM, have been developed that offer considerable benefits for industry. Both of these new coatings have a high tribological load-bearing capacity,exceptional wear resistance and very low friction, even in dry or lubricant-starved contact. This is in contrast to many commercial diamond-like carbon, DLC coatings, which tend to be highly stressed and therefore brittle, making them unsuitable for high load bearing industrial applications. The development of the new solid lubricant coatings is described,and details of their tribological performance in dry, water and oil-lubricated environments are given. The structure of the coatings has been investigated and related to the tribological properties, and the mechanism for the low friction and wear rates is discussed. The coatings have been used to successfully improve the lifetime and efficiency of many highly loaded mechanical parts, including automotive fuel injection components, gears, bearings, tappets (cam followers), gudgeon (wrist)pins, etc. They also offer benefits for tooling and are widely used in forming or machining of non-ferrous alloys, and extensively on dies and moulds. Other industrial application areas include electrical devices that require either high conductivity or insulation, optical devices requiring abrasion resistance and surgical tools and implants.

  9. Target-plane deposition of diamond-like carbon in pulsed laser ablation of graphite

    Energy Technology Data Exchange (ETDEWEB)

    Yap, S.S. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Tou, T.Y. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)], E-mail: tytou@mmu.edu.my

    2007-10-15

    In pulsed Nd:YAG laser ablation of highly oriented pyrolytic graphite (HOPG) at 10{sup -6} Torr, diamond-like carbon (DLC) are deposited at laser wavelengths of 1064, 532, and 355 nm on substrates placed in the target-plane. These target-plane samples are found to contain varying sp{sup 3} content and composed of nanostructures of 40-200 nm in size depending on the laser wavelength and laser fluence. The material and origin of sp{sup 3} in the target-plane samples is closely correlated to that in the laser-modified HOPG surface layer, and hardly from the backward deposition of ablated carbon plume. The surface morphology of the target-plane samples shows the columnar growth and with a tendency for agglomeration between nanograins, in particular for long laser wavelength at 1064 nm. It is also proposed that DLC formation mechanism at the laser-ablated HOPG is possibly via the laser-induced subsurface melting and resolidification.

  10. Advances in PSII Deposited Diamond-Like Carbon Coatings for Use as a Barrier to Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Lillard, R.S.; Butt, D.P.; Baker, N.P.; Walter, K.C.; Nastasi, M.

    1998-10-01

    Plasma source ion implantation (PSII) is a non line of sight process for implanting complex shaped targets without the need for complex fixturing. The breakdown initiation of materials coated with diamond-like carbon (DLC) produced by PSII occurs at defects in the DLC which expose the underlying material. To summarize these findings, a galvanic couple is established between the coating and exposed material at the base of the defect. Pitting and oxidation of the base and metal leads to the development of mechanical stress in the coating and eventually spallation of the coating. This paper presents our current progress in attempting to mitigate the breakdown of these coatings by implanting the parent material prior to coating with DLC. Ideally one would like to implant the parent material with chromium or molybdenum which are known to improve corrosion resistance, however, the necessary organometallics needed to implant these materials with PSII are not yet available. Here we report on the effects of carbon, nitrogen, and boron implantation on the susceptibility of PSII-DLC coated mild steel to breakdown.

  11. Conditions for forming composite carbon nanotube-diamond like carbon material that retain the good properties of both materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Wei, E-mail: wei.ren@helsinki.fi; Avchaciov, Konstantin; Nordlund, Kai [Department of Physics, University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Iyer, Ajai; Koskinen, Jari [Department of Materials Science and Engineering, School of Chemical Technology, Aalto University, P.O. Box 16200, 00076 Espoo (Finland); Kaskela, Antti; Kauppinen, Esko I. [NanoMaterials Group, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto (Finland)

    2015-11-21

    Carbon nanotubes are of wide interest due to their excellent properties such as tensile strength and electrical and thermal conductivity, but are not, when placed alone on a substrate, well resistant to mechanical wear. Diamond-like carbon (DLC), on the other hand, is widely used in applications due to its very good wear resistance. Combining the two materials could provide a very durable pure carbon nanomaterial enabling to benefit from the best properties of both carbon allotropes. However, the synthesis of high-quality diamond-like carbon uses energetic plasmas, which can damage the nanotubes. From previous works it is neither clear whether the quality of the tubes remains good after DLC deposition, nor whether the DLC above the tubes retains the high sp{sup 3} bonding fraction. In this work, we use experiments and classical molecular dynamics simulations to study the mechanisms of DLC formation on various carbon nanotube compositions. The results show that high-sp{sup 3}-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the tubes. Under optimal DLC formation energies of around 40–70 eV, the top two nanotube atom layers are fully destroyed by the plasma deposition, but layers below this can retain their structural integrity.

  12. Conditions for forming composite carbon nanotube-diamond like carbon material that retain the good properties of both materials

    Science.gov (United States)

    Ren, Wei; Iyer, Ajai; Koskinen, Jari; Kaskela, Antti; Kauppinen, Esko I.; Avchaciov, Konstantin; Nordlund, Kai

    2015-11-01

    Carbon nanotubes are of wide interest due to their excellent properties such as tensile strength and electrical and thermal conductivity, but are not, when placed alone on a substrate, well resistant to mechanical wear. Diamond-like carbon (DLC), on the other hand, is widely used in applications due to its very good wear resistance. Combining the two materials could provide a very durable pure carbon nanomaterial enabling to benefit from the best properties of both carbon allotropes. However, the synthesis of high-quality diamond-like carbon uses energetic plasmas, which can damage the nanotubes. From previous works it is neither clear whether the quality of the tubes remains good after DLC deposition, nor whether the DLC above the tubes retains the high sp3 bonding fraction. In this work, we use experiments and classical molecular dynamics simulations to study the mechanisms of DLC formation on various carbon nanotube compositions. The results show that high-sp3-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the tubes. Under optimal DLC formation energies of around 40-70 eV, the top two nanotube atom layers are fully destroyed by the plasma deposition, but layers below this can retain their structural integrity.

  13. Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Qiwen, E-mail: fanqiwen0926@163.com [Department of Nuclear Physics, China Institute of Atomic Energy, P.O. Box 275(62), Beijing 102413 (China); Du, Yinghui; Zhang, Rong; Xu, Guoji [Department of Nuclear Physics, China Institute of Atomic Energy, P.O. Box 275(62), Beijing 102413 (China)

    2013-04-21

    Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm{sup 2} in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm{sup 2} in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine–saccharose as releasing agent, which were previously covered with evaporated carbon layers ∼1μg/cm{sup 2} in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4 for the {sup 197}Au{sup −} (∼9MeV, ∼1μA) and {sup 63}Cu{sup −} (∼9MeV, ∼1μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp{sup 3} bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (I{sub D}/I{sub G}) measured by the Raman spectroscopy is 0.78.

  14. Influence of Third Particle on the Tribological Behaviors of Diamond-like Carbon Films

    Science.gov (United States)

    Bai, Lichun; Srikanth, Narasimalu; Kang, Guozheng; Zhou, Kun

    2016-12-01

    Tribological mechanisms of diamond-like carbon (DLC) films in a sand-dust environment are commonly unclear due to the complicated three-body abrasion caused by sand particles. This study investigates the three-body abrasion of the DLC film via molecular dynamics simulations. The influence factors such as the load, velocity, shape of the particle and its size are considered. It has been found that the friction and wear of the DLC film are determined by adhesion at a small load but dominated by both adhesion and plowing at a large load. A high velocity can increase the friction of the DLC film but decrease its wear, due to the response of its networks to a high strain rate indicated by such velocity. The shape of the particle highly affects its movement mode and thus changes the friction and wear of the DLC film. It is found that a small-sized particle can increase the friction and wear of the DLC film by enhancing plowing. These unique tribological mechanisms of the DLC film can help to promote its wide applications in a sand-dust environment.

  15. Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

    Science.gov (United States)

    Gupta, P.; Becker, H.-W.; Williams, G. V. M.; Hübner, R.; Heinig, K.-H.; Markwitz, A.

    2017-03-01

    Hydrogenated diamond-like carbon films produced by C3H6 deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

  16. Cavitation erosion resistance of diamond-like carbon coating on stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Feng; Jiang, Shuyun, E-mail: jiangshy@seu.edu.cn

    2014-02-15

    Two diamond-like carbon (DLC) coatings are prepared on stainless steel 304 by cathodic arc plasma deposition technology at different substrate bias voltages and arc currents (−200 V/80 A, labeled DLC-1, and −100 V/60 A, labeled DLC-2). Cavitation tests are performed by using a rotating-disk test rig to explore the cavitation erosion resistance of the DLC coating. The mass losses, surface morphologies, chemical compositions and the phase constituents of the specimens after cavitation tests are examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the DLC-2 coatings can elongate the incubation period of stainless steel, leading to an excellent cavitation erosion resistance as compared to the untreated stainless steel specimens. After duration of 100 h cavitation test, serious damaged surfaces and plenty of scratches can be observed on the surfaces of the stainless steel specimens, while only a few grooves and tiny pits are observed on the DLC-2 coatings. It is concluded that, decreasing micro defects and increasing adhesion can reduce the delamination of DLC coating, and the erosion continues in the stainless steel substrate after DLC coating failure, and the eroded surface of the substrate is subjected to the combined action from cavitation erosion and slurry erosion.

  17. Antithrombogenicity of Fluorinated Diamond-Like Carbon Films Coated Nano Porous Polyethersulfone (PES Membrane

    Directory of Open Access Journals (Sweden)

    Norihisa Miki

    2013-09-01

    Full Text Available A nano porous polyethersulfone (PES membrane is widely used for aspects of nanofiltration, such as purification, fractionation and dialysis. However, the low-blood-compatibility characteristic of PES membrane causes platelets and blood cells to stick to the surface of the membrane and degrades ions diffusion through membrane, which further limits its application for dialysis systems. In this study, we deposited the fluorinated-diamond-like-carbon (F-DLC onto the finger like structure layer of the PES membrane. By doing this, we have the F-DLC films coating the membrane surface without sacrificing the membrane permeability. In addition, we examined antithrombogenicity of the F-DLC/PES membranes using a microfluidic device, and experimentally found that F-DLC drastically reduced the amount of blood cells attached to the surface. We have also conducted long-term experiments for 24 days and the diffusion characteristics were found to be deteriorated due to fouling without any surface modification. On the other hand, the membranes coated by F-DLC film gave a consistent diffusion coefficient of ions transfer through a membrane porous. Therefore, F-DLC films can be a great candidate to improve the antithrombogenic characteristics of the membrane surfaces in hemodialysis systems.

  18. Iron, nitrogen and silicon doped diamond like carbon (DLC) thin films: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Sekhar C., E-mail: Raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg (South Africa); Pong, W.F. [Department of Physics, Tamkang University, Tamsui 251, New Taipei City, Taiwan (China); Papakonstantinou, P. [Nanotechnology and Integrated Bio-Engineering Centre, University of Ulster, Shore Road, Newtownabbey BT37 0QB (United Kingdom)

    2016-07-01

    The X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), valence band photoemission (VB-PES) and Raman spectroscopy results show that the incorporation of nitrogen in pulsed laser deposited diamond like carbon (DLC) thin films, reverts the sp{sup 3} network to sp{sup 2} as evidenced by an increase of the sp{sup 2} cluster and I{sub D}/I{sub G} ratio in C K-edge XANES and Raman spectra respectively which reduces the hardness/Young's modulus into the film network. Si-doped DLC film deposited in a plasma enhanced chemical vapour deposition process reduces the sp{sup 2} cluster and I{sub D}/I{sub G} ratio that causes the decrease of hardness/Young's modulus of the film structure. The Fe-doped DLC films deposited by dip coating technique increase the hardness/Young's modulus with an increase of sp{sup 3}-content in DLC film structure. - Highlights: • Fe, N and Si doped DLC films deposited by dip, PLD and PECVD methods respectively • DLC:Fe thin films have higher hardness/Young's modulus than DLC:N(:Si) thin films. • sp{sup 3} and sp{sup 2} contents are estimated from C K-edge XANES and VB-PES measurements.

  19. Characterization of boron doped diamond-like carbon film by HRTEM

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.J., E-mail: lixj@alum.imr.ac.cn [College of Material Science and Engineering, Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology, Changchun 130012 (China); He, L.L., E-mail: llhe@imr.ac.cn [Shenyang National Lab of Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Y.S. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Plasma Physics Laboratory, University of Saskatchewan, Saskatoon, SK S7N 5E2 (Canada); Yang, Q. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Hirose, A. [Plasma Physics Laboratory, University of Saskatchewan, Saskatoon, SK S7N 5E2 (Canada)

    2015-12-01

    Graphical abstract: - Highlights: • The microstructure of B-DLC film is studied by HRTEM in cross-sectional observation. • Many crystalline nanoparticles dispersed in the amorphous matrix film are observed. • Through composition and structure analysis, the nanoparticles are identified as B{sub 2}O. • The work implies the doped B element exists as oxide state in the B-DLC film. - Abstract: Boron doped diamond-like carbon (B-DLC) film was synthesized on silicon (1 0 0) wafer by biased target ion beam deposition. High-resolution transmission electron microscopy (HRTEM) is employed to investigate the microstructure of the B-DLC thin film in cross-sectional observation. Many crystalline nanoparticles randomly dispersed and embedded in the amorphous matrix film are observed. Through chemical compositional analysis of the B-DLC film, some amount of O element is confirmed to be contained. And also, some nanoparticles with near zone axes are indexed, which are accordance with B{sub 2}O phase. Therefore, the contained O element causing the B element oxidized is proposed, resulting in the formation of the nanoparticles. Our work indicates that in the B-DLC film a significant amount of the doped B element exists as boron suboxide nanoparticles.

  20. Effect of composition on mechanical behaviour of diamond-like carbon coatings modified with titanium

    Energy Technology Data Exchange (ETDEWEB)

    Caschera, D., E-mail: daniela.caschera@ismn.cnr.i [Institute for the Study of Nanostructured Materials, ISMN - CNR, P.O. Box 10, 00015 Monterotondo Stazione (Italy); Federici, F.; Pandolfi, L.; Kaciulis, S. [Institute for the Study of Nanostructured Materials, ISMN - CNR, P.O. Box 10, 00015 Monterotondo Stazione (Italy); Sebastiani, M.; Bemporad, E. [Dip.to di Ingegneria Industriale e Meccanica, Universita di Roma Tre, Via Vasca Navale 84, 00146 Roma (Italy); Padeletti, G. [Institute for the Study of Nanostructured Materials, ISMN - CNR, P.O. Box 10, 00015 Monterotondo Stazione (Italy)

    2011-03-01

    In this study, diamond-like carbon (DLC) films modified with titanium were deposited by plasma decomposition of metallorganic precursor, titanium isopropoxide in CH{sub 4}/H{sub 2}/Ar gas atmosphere. The obtained films were composed of amorphous titanium oxide and nanocrystalline titanium carbide, embedded in an amorphous hydrogenated (a-C:H) matrix. The TiC/TiO{sub 2} ratio in the DLC matrix was found to be dependent on the deposition parameters. The dependence of the films chemical composition on gas mixture and substrate temperature was investigated by X-ray photoelectron spectroscopy, whereas the crystallinity of TiC nanoparticles and their dimension were evaluated by X-ray diffraction. The size of TiC crystallites varied from 10 to 35 nm, depending on the process parameters. The intrinsic hardness of 10-13 GPa, elastic modulus of 170-200 GPa and hardness-to-modulus ratio of obtained coatings were measured by the nanoindentation technique. Obtained results demonstrated a correlation of mechanical properties with the chemical composition and the ratio of amorphous/crystalline phases in the films. In particular, the formation of nanocrystalline TiC with atomic concentration not exceeding 10% and with grain size between 10 nm and 15 nm resulted in significantly enhanced mechanical properties of composite material in comparison with ordinary DLC films.

  1. Optical and mechanical properties of diamond like carbon films deposited by microwave ECR plasma CVD

    Indian Academy of Sciences (India)

    S B Singh; M Pandey; N Chand; A Biswas; D Bhattacharya; S Dash; A K Tyagi; R M Dey; S K Kulkarni; D S Patil

    2008-10-01

    Diamond like carbon (DLC) films were deposited on Si (111) substrates by microwave electron cyclotron resonance (ECR) plasma chemical vapour deposition (CVD) process using plasma of argon and methane gases. During deposition, a d.c. self-bias was applied to the substrates by application of 13.56 MHz rf power. DLC films deposited at three different bias voltages (–60 V, –100 V and –150 V) were characterized by FTIR, Raman spectroscopy and spectroscopic ellipsometry to study the variation in the bonding and optical properties of the deposited coatings with process parameters. The mechanical properties such as hardness and elastic modulus were measured by load depth sensing indentation technique. The DLC film deposited at –100 V bias exhibit high hardness (∼ 19 GPa), high elastic modulus (∼ 160 GPa) and high refractive index (∼ 2.16–2.26) as compared to films deposited at –60 V and –150 V substrate bias. This study clearly shows the significance of substrate bias in controlling the optical and mechanical properties of DLC films.

  2. The Influence of Titanium Dioxide on Diamond-Like Carbon Biocompatibility for Dental Applications

    Directory of Open Access Journals (Sweden)

    C. C. Wachesk

    2016-01-01

    Full Text Available The physical and chemical characteristics of diamond-like carbon (DLC films make them suitable for implantable medical and odontological interests. Despite their good interactions with biological environment, incorporated nanoparticles can significantly enhance DLC properties. This manuscript studies the potential of titanium dioxide (TiO2 incorporated-DLC films in dental applications. In this scene, both osteoblasts attachment and spreading on the coatings and their corrosion characteristics in artificial saliva were investigated. The films were grown on 304 stainless steel substrates using plasma enhanced chemical vapor deposition. Raman scattering spectroscopy characterized the film structure. As the concentration of TiO2 increased, the films increased the osteoblast viability (MTT assay, becoming more thermodynamically favorable to cell spreading (WAd values became more negative. The increasing number of osteoblast nuclei indicates a higher adhesion between the cells and the films. The potentiodynamic polarization test in artificial saliva shows an increase in corrosion protection when TiO2 are present. These results show the potential use of TiO2-DLC films in implantable surfaces.

  3. Strength and Fracture Resistance of Amorphous Diamond-Like Carbon Films for MEMS

    Directory of Open Access Journals (Sweden)

    K. N. Jonnalagadda

    2009-01-01

    Full Text Available The mechanical strength and mixed mode I/II fracture toughness of hydrogen-free tetrahedral amorphous diamond-like carbon (ta-C films, grown by pulsed laser deposition, are discussed in connection to material flaws and its microstructure. The failure properties of ta-C were obtained from films with thicknesses 0.5–3 μm and specimen widths 10–20 μm. The smallest test samples with 10 μm gage section averaged a strength of 7.3 ± 1.2 GPa, while the strength of 20-μm specimens with thicknesses 0.5–3 μm varied between 2.2–5.7 GPa. The scaling of the mechanical strength with specimen thickness and dimensions was owed to deposition-induced surface flaws, and, only in the smallest specimens, RIE patterning generated specimen sidewall flaws. The mode I fracture toughness of ta-C films is KIc=4.4±0.4 MPam, while the results from mixed mode I/II fracture experiments with cracks arbitrarily oriented in the plane of the film compared very well with theoretical predictions.

  4. Effects of diamond-like carbon thin film in organic light emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Seong-Shan; Yong, Thian-Khok [Faculty of Engineering, Multimedia University, Cyberjaya, 63100 Selangor (Malaysia); Tou, Teck-Yong, E-mail: tytou@mmu.edu.m [Faculty of Engineering, Multimedia University, Cyberjaya, 63100 Selangor (Malaysia)

    2009-07-01

    Ultrathin diamond-like carbon (DLC) was deposited by pulsed Nd:YAG laserablation of graphite target on the indium tin oxide (ITO) surface that functioned as the buffered anode for single-layer organic light emitting devices (OLEDs). Deposited by 355 nm Nd:YAG laser, DLC films were characterized by the Raman spectroscopy and the bulk resistivity measurement. Insertion of DLC in the hole-transport ITO/DLC/TPD/Al device slightly increased the injection current density and reduced the turn-on voltage. But DLC insertion in the electron-transport ITO/DLC/Alq{sub 3}/Al device greatly decreased the injection current density and increased the turn-on voltage. For the ITO/DLC/(TPD + Alq{sub 3} + PVK)/Al device, that was doped with Alq{sub 3} and TPD, improved performance with a higher current density and brightness were consistently obtained. Possible mechanisms for the DLC effect in these single-layer devices were discussed.

  5. X-ray reflectivity study of bias graded diamond like carbon film synthesized by ECR plasma

    Indian Academy of Sciences (India)

    R M Dey; S K Deshpande; S B Singh; N Chand; D S Patil; S K Kulkarni

    2013-02-01

    Diamond like carbon (DLC) coatings were deposited on silicon substrates by microwave electron cyclotron resonance (ECR) plasma CVD process using plasma of Ar and CH4 gases under the influence of negative d.c. self bias generated on the substrates by application of RF (13.56 MHz) power. The negative bias voltage was varied from −60 V to −150 V during deposition of DLC films on Si substrate. Detailed X-ray reflectivity (XRR) study was carried out to find out film properties like surface roughness, thickness and density of the films as a function of variation of negative bias voltage. The study shows that the DLC films constituted of composite layer i.e. the upper sub surface layer followed by denser bottom layer representing the bulk of the film. The upper layer is relatively thinner as compared to the bottom layer. The XRR study was an attempt to substantiate the sub-plantation model for DLC film growth.

  6. Synthesis and Characteristics of Diamond-like Carbon Films Deposited on Quartz Substrate

    Institute of Scientific and Technical Information of China (English)

    黄卫东; 丁鼎; 詹如娟

    2004-01-01

    Diamond-like carbon (DLC) films are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias effect on the film characteristics. Deposited films are characterized by Raman spectroscopy, infrared (IR) and ultraviolet-visible absorption techniques.There are two broad Raman peaks around 1340 cm-1 and 1600 cm-1 and the first one has a greater sp3 component with an increased bias. Infrared spectroscopy has three sp3 C-H modes at 2852 cm-1, 2926 cm- 1 and 2962 cm-1, respectively and also shows an intensity increase with the negative bias. Optical band gap is calculated from the ultraviolet-visible absorption spectroscopy and the increased values with negative bias and deposition time are obtained. After a thermal anneal at about 500 ℃ for an hour to the film deposited under the bias of-90 V, we get an almost unchanged Raman spectrum and a peak intensity-reduced IR signal, which indicates a reduced H-content in the film. Meanwhile the optical band gap changed from 0.85 eV to 1.5 eV.

  7. The nano-scratch behaviour of different diamond-like carbon film-substrate systems

    Energy Technology Data Exchange (ETDEWEB)

    Huang Liye [State-Key Laboratory for Mechanical Behaviour of Materials, Xi' an Jiaotong University, Xi' an, 710049 (China); Lu Jian [LASMIS, Universite de Technologie de Troyes, 10010 Troyes (France); Xu Kewei [State-Key Laboratory for Mechanical Behaviour of Materials, Xi' an Jiaotong University, Xi' an, 710049 (China)

    2004-08-07

    The nano-scratch behaviour of diamond-like carbon films on a Ti alloy and Si substrate was evaluated. For both samples, three processes-fully elastic recovery, plastic deformation, and delamination and pulling-off of the films, occur successively with increasing load during scratching. The loads (Lc{sub L}) corresponding to the peeling-off of the films during the up-loading were 75 and 70 mN for Ti alloy and Si. However, the films on Si were delaminated during unloading, and the relevant load (Lc{sub U}) was only 45 mN. This probably originates from the distribution status of the plastic deformation both in the films and the substrates. Therefore, the nano-scratch test can be applied not only to obtain the cracking resistance (Lc{sub L}) characterizing the cohesion strength of films during up-loading but also to determine the delamination resistance (Lc{sub U}) related to the adhesion strength of the film-substrate during unloading.

  8. Cavitation erosion resistance of diamond-like carbon coating on stainless steel

    Science.gov (United States)

    Cheng, Feng; Jiang, Shuyun

    2014-02-01

    Two diamond-like carbon (DLC) coatings are prepared on stainless steel 304 by cathodic arc plasma deposition technology at different substrate bias voltages and arc currents (-200 V/80 A, labeled DLC-1, and -100 V/60 A, labeled DLC-2). Cavitation tests are performed by using a rotating-disk test rig to explore the cavitation erosion resistance of the DLC coating. The mass losses, surface morphologies, chemical compositions and the phase constituents of the specimens after cavitation tests are examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the DLC-2 coatings can elongate the incubation period of stainless steel, leading to an excellent cavitation erosion resistance as compared to the untreated stainless steel specimens. After duration of 100 h cavitation test, serious damaged surfaces and plenty of scratches can be observed on the surfaces of the stainless steel specimens, while only a few grooves and tiny pits are observed on the DLC-2 coatings. It is concluded that, decreasing micro defects and increasing adhesion can reduce the delamination of DLC coating, and the erosion continues in the stainless steel substrate after DLC coating failure, and the eroded surface of the substrate is subjected to the combined action from cavitation erosion and slurry erosion.

  9. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, K., E-mail: ozeki@mx.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Frontier Research Center for Applied Atomic Sciences, 162-1 Shirakata, Toukai, Ibaraki 319-1106 (Japan); Hirakuri, K.K. [Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2011-04-15

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO{sub 2}) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO{sub 2} films and DLC/TiO{sub 2}/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO{sub 2}-coated and the DLC/TiO{sub 2}/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO{sub 2} coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO{sub 2}/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO{sub 2}/DLC film had a photocatalytic effect even though the TiO{sub 2} film was covered with the DLC film.

  10. Annealing Effects on Structure and Optical Properties of Diamond-Like Carbon Films Containing Silver.

    Science.gov (United States)

    Meškinis, Šarūnas; Čiegis, Arvydas; Vasiliauskas, Andrius; Šlapikas, Kęstutis; Gudaitis, Rimantas; Yaremchuk, Iryna; Fitio, Volodymyr; Bobitski, Yaroslav; Tamulevičius, Sigitas

    2016-12-01

    In the present study, diamond-like carbon films with embedded Ag nanoparticles (DLC:Ag) were deposited by reactive magnetron sputtering. Structure of the films was investigated by Raman scattering spectroscopy. Atomic force microscopy was used to define thickness of DLC:Ag films as well as to study the surface morphology and size distribution of Ag nanoparticles. Optical absorbance and reflectance spectra of the films were studied in the 180-1100-nm range. Air annealing effects on structure and optical properties of the DLC:Ag were investigated. Annealing temperatures were varied in the 180-400 °C range. Changes of size and shape of the Ag nanoclusters took place due to agglomeration. It was found that air annealing of DLC:Ag films can result in graphitization following destruction of the DLC matrix. Additional activation of surface-enhanced Raman scattering (SERS) effect in DLC:Ag films can be achieved by properly selecting annealing conditions. Annealing resulted in blueshift as well as significant narrowing of the plasmonic absorbance and reflectance peaks. Moreover, quadrupole surface plasmon resonance peaks appeared. Modeling of absorption spectra of the nanoclusters depending on the shape and surrounding media has been carried out.

  11. Porous Silicon Coated with Ultrathin Diamond-Like Carbon Film Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Evtukh, A A; Litovchenko, V G; Litvin, Y M; Fedin, D V; Rassamakin, Y V; Sarikov, A V; Chakhovskoi, A G; Felter, T E

    2001-04-01

    The main requirements to electron field emission cathodes are their efficiency, stability and uniformity. In this work we combined the properties of porous silicon layers and diamond-like carbon (DLC) film to obtain emission cathodes with improved parameters. The layered structures of porous silicon and DLC film were formed both on flat n-Si surface and silicon tips created by chemical etching. The conditions of the anodic and stain etching of silicon in HF containing solution under the illumination have been widely changed. The influence of thin ({le} 10nm) DLC film coating of the porous silicon layer on electron emission has been investigated. The parameters of emission efficiency such as field enhancement coefficient, effective emission areas and threshold voltages have been estimated from current-voltage dependencies to compare and characterize different layered structures. The improvement of the emission efficiency of silicon tip arrays with porous layers coated with thin DLC film has been observed. These silicon-based structures are promising for flat panel display applications.

  12. Negative Resistance Effect and Charge Transfer Mechanisms in the lon Beam Deposited Diamond Like Carbon Superlattices

    Directory of Open Access Journals (Sweden)

    Andrius VASILIAUSKAS

    2011-03-01

    Full Text Available In the present study DLC:SiOx/DLC/DLC:SiOx/nSi and DLC:SiOx/DLC/DLC:SiOx/pSi structures were fabricated by ion beam deposition using a closed drift ion source. Current-voltage (I-V characteristics of the multilayer samples were measured at room temperature. The main charge transfer mechanisms were considered. Unstable negative resistance effect was observed for some DLC:SiOx/DLC/DLC:SiOx/nSi and DLC:SiOx/DLC/DLC:SiOx/pSi structures. In the case of the diamond like carbon superlattices fabricated on nSi it was observed only during the first measurement. In the case of the some DLC:SiOx/DLC/DLC:SiOx/pSi negative resistance "withstood" several measurements. Changes of the charge carrier mechanisms were observed along with the dissapear of the negative resistance peaks. It seems, that in such a case influence of the bulk related charge transfer mechanisms such as Poole-Frenkel emission increased, while the influence of the contact limited charge transfer mechanisms such as Schottky emission decreased. Observed results were be explained by current flow through the local microconducting channels and subsequent destruction of the localized current pathways as a result of the heating by flowing electric current.http://dx.doi.org/10.5755/j01.ms.17.1.240

  13. Preparation of Diamond-like Carbon Films on the Surface of Ti Alloy by Electro-deposition

    Institute of Scientific and Technical Information of China (English)

    Fenglei SHEN; Hongwei WANG; Dijiang WEN

    2004-01-01

    In this paper, diamond-like carbon (DLC) fi[ms were deposited on Ti alloy by electro-deposition. DLC films were brown and composed of the compact grains whose diameter was about 400 nm. Examined by XPS, the main composition of the films was carbon. In the Raman spectrum, there were a broad peak at 1350 cm-1 and a broad peak at 1600 cm-1, which indicated that the films were DLC films.

  14. Cathodoluminescence of Cr-doped diamond-like carbon film by filtered cathodic vacuum arc plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Meng-Wen; Jao, Jui-Yun [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Lin, Chun-Chun; Hsieh, Wei-Jen; Yang, Yu-Hsiang [Department of Materials Science and Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300, Taiwan (China); Cheng, Li-Shin; Shieu, F.S. [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Shih, Han C., E-mail: hcshih@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Department of Materials Science and Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300, Taiwan (China); Institute of Materials Science and Nanotechnology, Chinese Culture University, 55 Hwa Kang Road, Yang Ming Shan, Taipei 111, Taiwan (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The formation of the DLC:Cr films dependent on the flow rates of C{sub 2}H{sub 2}/Ar have been achieved in our FCVA plasma. Black-Right-Pointing-Pointer The amorphous DLC:Cr have high sp{sup 2} content can be completely converted to nanocrystalline Cr{sub 3}C{sub 2}. Black-Right-Pointing-Pointer The effect of doping with Cr is apparently to change the band structure of the DLC and its consequent cathodoluminescence property. - Abstract: Cr doped diamond-like carbon (DLC:Cr) film was synthesized in various flow rates of C{sub 2}H{sub 2}/Ar under a substrate voltage of -50 V at 500 Degree-Sign C by a filtered cathodic vacuum arc plasma. This work has found that the structure of the films was correlated to the flow rate of C{sub 2}H{sub 2}/Ar but the luminescence properties are similar. The cathodoluminescence spectra of DLC:Cr films obtained at 1.9-2.4 eV verifies that the luminescence from the films is in the visible region. The incorporation of Cr into the carbon network results in red emission shifted to 1.99 eV and the orange emission (2.03 eV) also appeared due to the transitions between chromium-related electron levels and {sigma}* states. The peak at 2.10 eV may result from the defects of the structures in DLC:Cr films.

  15. Free standing diamond-like carbon thin films by PLD for laser based electrons/protons acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Thema, F.T.; Beukes, P.; Ngom, B.D. [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Manikandan, E., E-mail: mani@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital (SBMCH), Chrompet, Bharath University, Chennai, 600044 (India); Maaza, M., E-mail: maaza@tlabs.ac.za [UNESCO Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West, 7129, PO Box722, Western Cape Province (South Africa)

    2015-11-05

    This study we reports for the first time on the synthesis and optical characteristics of free standing diamond-like carbon (DLC) deposited by pulsed laser deposition (PLD) onto graphene buffer layers for ultrahigh intensity laser based electron/proton acceleration applications. The fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations indicate that the suitability of such free standing DLC thin-films within the laser window and long wave infrared (LWIR) spectral range and hence their appropriateness for the targeted applications. - Highlights: • We report for the first time synthesis of free standing diamond-like carbon. • Pulsed laser deposition onto graphene buffer layers. • Fingerprint techniques of micro-Raman, UV–VIS–NIR and the IR spectroscopic investigations. • Ultrahigh intensity laser based electron/proton acceleration applications. • This material's suitable for the laser window and long wave infrared (LWIR) spectral range.

  16. Dry And Ringer Solution Lubricated Tribology Of Thin Osseoconductive Metal Oxides And Diamond-Like Carbon Films

    Directory of Open Access Journals (Sweden)

    Waldhauser W.

    2015-09-01

    Full Text Available Achieving fast and strong adhesion to jawbone is essential for dental implants. Thin deposited films may improve osseointegration, but they are prone to cohesive and adhesive fracture due to high stresses while screwing the implant into the bone, leading to bared, less osteoconductive substrate surfaces and nano- and micro-particles in the bone. Aim of this work is the investigation of the cohesion and adhesion failure stresses of osteoconductive tantalum, titanium, silicon, zirconium and aluminium oxide and diamond-like carbon films. The tribological behaviour under dry and lubricated conditions (Ringer solution reveals best results for diamond-like carbon, while cohesion and adhesion of zirconium oxide films is highest.

  17. Fabrication of ZnO nanoparticles-embedded hydrogenated diamond-like carbon films by electrochemical deposition technique

    Institute of Scientific and Technical Information of China (English)

    Zhang Pei-Zeng; Li Rui-Shan; Pan Xiao-Jun; Xie Er-Qing

    2013-01-01

    ZnO nanoparticles-embedded hydrogenated diamond-like carbon (ZnO-DLC) films have been prepared by electrochemical deposition in ambient conditions.The morphology,composition,and microstructure of the films have been investigated.The results show that the resultant films are hydrogenated diamond-like carbon films embedded with ZnO nanoparticles in wurtzite structure,and the content and size of the ZnO nanoparticles increase with increasing deposition voltage,which are confirmed by X-ray photoelectron spectroscopy (XPS),Raman,and transmission electron microscope (TEM).Furthermore,a possible mechanism used to describe the growth process of ZnO-DLC films by electrochemical deposition is also discussed.

  18. Adhesion improvement of hydrogenated diamond-like carbon thin films by pre-deposition plasma treatment of rubber substrate

    OpenAIRE

    Bui, X. L.; Pei, Y.T.; Mulder, E.D.G.; De Hosson, J. Th. M.

    2009-01-01

    For reduction of friction and enhancement of wear resistance of dynamic rubber seals, thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma treatment of HNBR substrate is proved to be crucial for the improvement of film performance due to enhanced interfacial adhesion. The columnar structure and the crack network formed during deposition e...

  19. Protein arrangement on modified diamond-like carbon surfaces – An ARXPS study

    Energy Technology Data Exchange (ETDEWEB)

    Oosterbeek, Reece N., E-mail: reece.oosterbeek@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019 (New Zealand); Seal, Christopher K. [Light Metals Research Centre, The University of Auckland, Private Bag 92019 (New Zealand); Hyland, Margaret M. [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019 (New Zealand)

    2014-12-01

    Highlights: • DLC coatings were modified by Ar{sup +} ion sputtering and laser graphitisation. • The surface properties of the coatings were measured, and it was found that the above methods increased sp{sup 2} content and altered surface energy. • ARXPS was used to observe protein arrangement on the surface. • Polar CO/CN groups were seen to be segregated towards the interface, indicating they play an important role in bonding. • This segregation increased with increasing polar surface energy, indicating an increased net attraction between polar groups. - Abstract: Understanding the nature of the interface between a biomaterial implant and the biological fluid is an essential step towards creating improved implant materials. This study examined a diamond-like carbon coating biomaterial, the surface energy of which was modified by Ar{sup +} ion sputtering and laser graphitisation. The arrangement of proteins was analysed by angle resolved X-ray photoelectron spectroscopy, and the effects of the polar component of surface energy on this arrangement were observed. It was seen that polar groups (such as CN, CO) are more attracted to the coating surface due to the stronger polar interactions. This results in a segregation of these groups to the DLC–protein interface; at increasing takeoff angle (further from to DLC–protein interface) fewer of these polar groups are seen. Correspondingly, groups that interact mainly by dispersive forces (CC, CH) were found to increase in intensity as takeoff angle increased, indicating they are segregated away from the DLC–protein interface. The magnitude of the segregation was seen to increase with increasing polar surface energy, this was attributed to an increased net attraction between the solid surface and polar groups at higher polar surface energy (γ{sub S}{sup p})

  20. The Comparison of Biocompatibility Properties between Ti Alloys and Fluorinated Diamond-Like Carbon Films

    Directory of Open Access Journals (Sweden)

    Chavin Jongwannasiri

    2012-01-01

    Full Text Available Titanium and titanium alloys have found several applications in the biomedical field due to their unique biocompatibility. However, there are problems associated with these materials in applications in which there is direct contact with blood, for instance, thrombogenesis and protein adsorption. Surface modification is one of the effective methods used to improve the performance of Ti and Ti alloys in these circumstances. In this study, fluorinated diamond-like carbon (F-DLC films are chosen to take into account the biocompatible properties compared with Ti alloys. F-DLC films were prepared on NiTi substrates by a plasma-based ion implantation (PBII technique using acetylene (C2H2 and tetrafluoromethane (CF4 as plasma sources. The structure of the films was characterized by Raman spectroscopy. The contact angle and surface energy were also measured. Protein adsorption was performed by treating the films with bovine serum albumin and fibrinogen. The electrochemical corrosion behavior was investigated in Hanks’ solution by means of a potentiodynamic polarization technique. Cytotoxicity tests were performed using MTT assay and dyed fluorescence. The results indicate that F-DLC films present their hydrophobic surfaces due to a high contact angle and low surface energy. These films can support the higher albumin-to-fibrinogen ratio as compared to Ti alloys. They tend to suppress the platelet adhesion. Furthermore, F-DLC films exhibit better corrosion resistance and less cytotoxicity on their surfaces. It can be concluded that F-DLC films can improve the biocompatibility properties of Ti alloys.

  1. Electrical and magnetic properties of electrodeposited nickel incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B., E-mail: pandey.beauty@yahoo.com [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Das, D. [UGC-DAE CSR, Sector III/LB-8, Bidhan Nagar, Kolkata 700098 (India); Kar, A.K. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

    2015-05-15

    Highlights: • Electrical and magnetic properties of DLC and Ni-DLC thin films are studied. • The ohmicity and conductivity of DLC films rise with nickel addition. • The ohmicity of Ni-DLC is enhanced with increase in dilution of electrolyte. • Dielectric loss is high for Ni-DLC and decreases with frequency till 100 kHz. • (m–H) and (m–T) curves of Ni-DLC indicate superparamagnetic behavior. - Abstract: Nanocomposite diamond-like carbon (DLC) thin films have been synthesized by incorporating nickel (Ni) nanoparticles in DLC matrix with varying concentration of nickel. DLC and Ni-DLC thin films have been deposited on ITO coated glass substrates employing low voltage electrodeposition method. Electrical properties of the samples were studied by measuring current–voltage characteristics and dielectric properties. The current approaches toward an ohmic behavior with metal addition. This tendency of increasing ohmicity is enhanced with increase in dilution of the electrolyte. The conductivity increases with Ni addition and interestingly it continues to increase with dilution of Ni concentration in the electrolyte in the range of our study. Magnetic properties for DLC and Ni-DLC thin film samples were examined by electron paramagnetic resonance (EPR) measurements and Super Conducting Quantum Interference Device (SQUID) measurements. g-Value for DLC is 2.074, whereas it decreases to 2.055 with Ni addition in the electrolyte. This decrement arises from the increased sp{sup 2} content in DLC matrix. The magnetic moment vs. magnetic field (m–H) curves of Ni-DLC indicate superparamagnetic behavior which may be due to ferromagnetic contribution from the incorporated nickel nanoparticles in the DLC matrix. The ZFC curve of Ni-DLC after the blocking temperature shows a combined contribution of ferromagnetic, superparamagnetic and paramagnetic nature of the materials persisting up to 300 K.

  2. Microstructure and tribological performance of diamond-like carbon films deposited on hydrogenated rubber

    Energy Technology Data Exchange (ETDEWEB)

    Pal, J.P. van der [Materials Innovation Institute M2i, Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Martinez-Martinez, D., E-mail: d.martinez.martinez@rug.nl [Materials Innovation Institute M2i, Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Pei, Y.T., E-mail: y.pei@rug.nl [Materials Innovation Institute M2i, Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Rudolf, P. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); De Hosson, J.Th.M. [Materials Innovation Institute M2i, Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2012-12-01

    In this paper, the microstructure and tribological performance of diamond-like carbon (DLC) films prepared by plasma chemical vapor deposition on hydrogenated nitrile butadiene rubbers (HNBR) are studied. Different negative variations of temperature during film growth were selected by proper changes of the bias voltage. Raman measurements show a similar bonding regardless of the voltages used. A columnar growth and a tile-like microstructure of the DLC films were identified by scanning electron microscopy. Patch sizes can be correlated with the deposition conditions. The coefficient of friction (CoF) of DLC film coated HNBR was found to be much lower than that of the unprotected rubber, and more reduced for the DLC films with smaller patch sizes, which is explained by a better flexibility and conformity of the film during testing. In one of the samples, unexpected low CoF was observed, which was attributed to a modification of the mechanical properties of the rubber during the plasma treatment at high voltage. This issue was confirmed by X-ray photoelectron spectroscopy, which indicated a modification of the cross linking in the rubber. - Highlights: Black-Right-Pointing-Pointer Bias voltage does not vary the chemical bonding and surface morphology of films. Black-Right-Pointing-Pointer Film structure is patched, whose size depends on the etching and deposition voltages. Black-Right-Pointing-Pointer The frictional behavior can be correlated with the patch size of the films. Black-Right-Pointing-Pointer Surface analysis showed that rubber x-linking is modified by etching at high voltage. Black-Right-Pointing-Pointer Modification of rubber x-linking leads to a different frictional behavior.

  3. Dissolution effect and cytotoxicity of diamond-like carbon coatings on orthodontic archwires.

    Science.gov (United States)

    Kobayashi, Shinya; Ohgoe, Yasuharu; Ozeki, Kazuhide; Hirakuri, Kenji; Aoki, Hideki

    2007-12-01

    Nickel-titanium (NiTi) has been used for implants in orthodontics due to the unique properties such as shape memory effect and superelasticity. However, NiTi alloys are eroded in the oral cavity because they are immersed by saliva with enzymolysis. Their reactions lead corrosion and nickel release into the body. The higher concentrations of Ni release may generate harmful reactions. Ni release causes allergenic, toxic and carcinogenic reactions. It is well known that diamond-like carbon (DLC) films have excellent properties, such as extreme hardness, low friction coefficients, high wear resistance. In addition, DLC film has many other superior properties as a protective coating for biomedical applications such as biocompatibility and chemical inertness. Therefore, DLC film has received enormous attention as a biocompatible coating. In this study, DLC film coated NiTi orthodontic archwires to protect Ni release into the oral cavity. Each wire was immersed in physiological saline at the temperature 37 degrees C for 6 months. The release concentration of Ni ions was detected using microwave induced plasma mass spectrometry (MIP-MS) with the resolution of ppb level. The toxic effect of Ni release was studied the cell growth using squamous carcinoma cells. These cells were seeded in 24 well culture plates and materials were immersed in each well directly. The concentration of Ni ions in the solutions had been reduced one-sixth by DLC films when compared with non-coated wire. This study indicated that DLC films have the protective effect of the diffusion and the non-cytotoxicity in corrosive environment.

  4. Diamond-like carbon coatings for the protection of metallic artefacts: effect on the aesthetic appearance

    Science.gov (United States)

    Faraldi, Federica; Angelini, Emma; Caschera, Daniela; Mezzi, Alessio; Riccucci, Cristina; Caro, Tilde De

    2014-03-01

    Plasma-enhanced chemical vapour deposition (PECVD) is an environmentally friendly process used to deposit a variety of nano-structured coatings for the protection or the surface modification of metallic artefacts like the SiO2-like films that have been successfully tested on ancient silver, bronze and iron artefacts as barriers against aggressive agents. This paper deals with the preliminary results of a wider investigation aimed to the development of eco-sustainable coatings for the protection of Cu and Ag-based artefacts of archaeological and historic interest. Diamond-like carbon (DLC) coatings have been deposited by PECVD in different experimental conditions, in a capacitively coupled asymmetric plasma reactor, placing the substrates either on electrically powered electrode (cathodic mode) or grounded electrode (anodic mode) with and without hydrogen addition in the gas mixture. The final goal is to develop a coating with good protective effectiveness against aggressive atmospheres and contemporarily with negligible effects on the aesthetic appearance of the artefacts. The evaluation of possible colour changes of the surface patinas, due to coating process, was performed by optical microscopy and colorimetric measurements. Furthermore, to evaluate the reversibility of the thin DLC layer, an etching treatment in oxygen plasma has been successfully carried out and optimized. The chemical-physical characterization of the deposited DLC coatings was performed by means of the combined use of micro-Raman and XPS spectroscopies. The results show that the DLC films obtained in the anodic mode, may be proposed as a viable alternative to polymeric coatings for the protection of metallic ancient objects.

  5. Intertwisted fibrillar diamond-like carbon films prepared by electron cyclotron resonance microwave plasma enhanced chemical vapour deposition

    Institute of Scientific and Technical Information of China (English)

    杨武保; 王久丽; 张谷令; 范松华; 刘赤子; 杨思泽

    2003-01-01

    In this paper, the structures, optical and mechanical properties of diamond-like carbon films are studied, which are prepared by a self-fabricated electron cyclotron resonance microwave plasma chemical vapour deposition method at room temperature in the ambient gases of mixed acetylene and nitrogen. The morphology and microstructure of the processed film are characterized by the atomic force microscope image, Raman spectra and middle Fourier transform infrared transmittance spectra, which reveal that there is an intertwisted fibrillar diamond-like structure in the film and the film is mainly composed of sp3 CH, sp3 C-C, sp2 C=C, C=N and C60. The film micro-hardness and bulk modulus are measured by a nano-indenter and the refractive constant and deposition rate are also calculated.

  6. Diamond-like carbon films synthesized on bearing steel surface by plasma immersion ion implantation and deposition

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-xi; TANG Bao-yin; WANG Lang-ping; WANG Xiao-feng; YU Yong-hao; SUN Tao; HU Li-guo

    2004-01-01

    Diamond-like carbon (DLC) films were synthesized by plasma immersion ion implantation and deposition (PIIID) on 9Cr18 bearing steel surface. Influences of working gas pressure and pulse width of the bias voltage on properties of the thin film were investigated. The chemical compositions of the as-deposited films were characterized by Raman spectroscopy. The micro-hardness, friction and wear behavior, corrosion resistance of the samples were evaluated, respectively. Compared with uncoated substrates, micro-hardness results reveal that the maximum is increased by 88.7%. In addition, the friction coefficient decreases to about 0.1, and the corrosion resistance of treated coupons surface are improved significantly.

  7. Deposition of Diamond-Like carbon Films by High-Intensity Pulsed Ion Beam Ablation at Various Substrate Temperatures

    Institute of Scientific and Technical Information of China (English)

    梅显秀; 刘振民; 马腾才; 董闯

    2003-01-01

    Diamond-like carbon (DLC) films have been deposited on to Si substrates at substrate temperatures from 25℃to 400 ℃ by a high-intensity pulsed-ion-beam (HIPIB) ablation deposition technique. The formation of DLC is confirmed by Raman spectroscopy. According to an x-ray photoelectron spectroscopy analysis, the concentration of spa carbon in the films is about 40% when the substrate temperature is below 300 ℃. With increasing substrate temperature from 25 ℃ to 400 ℃, the concentration of sp3 carbon decreases from 43% to 8%. In other words,sp3 carbon is graphitized into sp2 carbon when the substrate temperature is above 300 ℃. The results of xray diffraction and atomic force microscopy show that, with increasing the substrate temperature, the surface roughness and the friction coefficient increase, and the microhardness and the residual stress of the films decrease.

  8. Electrodeposition of diamond-like carbon films on titanium alloy using organic liquids: Corrosion and wear resistance

    Energy Technology Data Exchange (ETDEWEB)

    Falcade, Tiago, E-mail: tiago.falcade@ufrgs.br [Federal University of Rio Grande do Sul, 9500 Bento Goncalves Ave. Sector 4, Building 75, 2nd floor, Porto Alegre, RS (Brazil); Shmitzhaus, Tobias Eduardo, E-mail: tobiasschmitzhaus@gmail.com [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Gomes dos Reis, Otavio, E-mail: otavio_gomes214@hotmail.com [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Vargas, Andre Luis Marin; Huebler, Roberto [Pontificia Universidade Catolica do Rio Grande do Sul (Brazil); Mueller, Iduvirges Lourdes, E-mail: ilmuller@ufrgs.br [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Fraga Malfatti, Celia de, E-mail: celia.malfatti@ufrgs.br [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The electrodeposition may be conducted at room temperature. Black-Right-Pointing-Pointer The DLC films have good resistance to corrosion in saline environments. Black-Right-Pointing-Pointer The films have lower coefficient of friction than the uncoated substrate. Black-Right-Pointing-Pointer The abrasive wear protection is evident in coated systems. - Abstract: Diamond-like carbon (DLC) films have been studied as coatings for corrosion protection and wear resistance because they have excellent chemical inertness in traditional corrosive environments, besides presenting a significant reduction in coefficient of friction. Diamond-like carbon (DLC) films obtained by electrochemical deposition techniques have attracted a lot of interest, regarding their potential in relation to the vapor phase deposition techniques. The electrochemical deposition techniques are carried out at room temperature and do not need vacuum system, making easier this way the technological transfer. At high electric fields, the organic molecules polarize and react on the electrode surface, forming carbon films. The aim of this work was to obtain DLC films onto Ti6Al4V substrate using as electrolyte: acetonitrile (ACN) and N,N-dimethylformamide (DMF). The films were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, potentiodynamic polarization and wear tests. The results show that these films can improve, significantly, the corrosion resistance of titanium and its alloys and their wear resistance.

  9. Composition and morphology of metal-containing diamond-like carbon films obtained by reactive magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, C. [FEMAN Group, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, E08028 Barcelona (Spain)]. E-mail: corbella@ub.edu; Pascual, E. [FEMAN Group, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, E08028 Barcelona (Spain); Oncins, G. [Serveis Cientificotecnics, Universitat de Barcelona, PCB, c/ Josep Samitier 1-5, E08028 Barcelona (Spain); Canal, C. [Departamento de Tecnologia de Tensioactivos IQAB-CSIC, c/ Jordi Girona 18-26, E08034 Barcelona (Spain); Andujar, J.L. [FEMAN Group, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, E08028 Barcelona (Spain); Bertran, E. [FEMAN Group, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, E08028 Barcelona (Spain)

    2005-06-22

    The addition of metal atoms within the matrix of diamond-like carbon films leads to the improvement of their mechanical properties. The present paper discusses the relationship between the composition and morphology of metal-containing (W, Nb, Mo, Ti) diamond-like carbon thin films deposited at room temperature by reactive magnetron sputtering from a metal target in an argon and methane atmosphere. Composition was measured either by electron microprobe technique or by X-ray photoelectron spectroscopy and shows a smooth variation with relative methane flow. High relative methane flows lead to a bulk saturation of carbon atoms, which leads to a lack of homogeneity in the films as confirmed by secondary ion mass spectrometry. Cross-section micrographs were observed by transmission electron microscopy and revealed a structure strongly influenced by the metal inserted and its abundance. The surface pattern obtained by scanning electrochemical potential microscopy provided the metallicity distribution. These measurements were completed with atomic force microscopy of the surface. Selected area electron diffraction and X-ray diffraction measurements provided data of the crystalline structure along with nano-crystallite size. High-resolution transmission electron microscopy provided images of these crystallites.

  10. Gas Permeation, Mechanical Behavior and Cytocompatibility of Ultrathin Pure and Doped Diamond-Like Carbon and Silicon Oxide Films

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-12-01

    Full Text Available Protective ultra-thin barrier films gather increasing economic interest for controlling permeation and diffusion from the biological surrounding in implanted sensor and electronic devices in future medicine. Thus, the aim of this work was a benchmarking of the mechanical oxygen permeation barrier, cytocompatibility, and microbiological properties of inorganic ~25 nm thin films, deposited by vacuum deposition techniques on 50 µm thin polyetheretherketone (PEEK foils. Plasma-activated chemical vapor deposition (direct deposition from an ion source was applied to deposit pure and nitrogen doped diamond-like carbon films, while physical vapor deposition (magnetron sputtering in pulsed DC mode was used for the formation of silicon as well as titanium doped diamond-like carbon films. Silicon oxide films were deposited by radio frequency magnetron sputtering. The results indicate a strong influence of nanoporosity on the oxygen transmission rate for all coating types, while the low content of microporosity (particulates, etc. is shown to be of lesser importance. Due to the low thickness of the foil substrates, being easily bent, the toughness as a measure of tendency to film fracture together with the elasticity index of the thin films influence the oxygen barrier. All investigated coatings are non-pyrogenic, cause no cytotoxic effects and do not influence bacterial growth.

  11. Development of a radio frequency atmospheric pressure plasma jet for diamond-like carbon coatings on stainless steel substrates

    Science.gov (United States)

    Sohbatzadeh, F.; Samadi, O.; Siadati, S. N.; Etaati, G. R.; Asadi, E.; Safari, R.

    2016-10-01

    In this paper, an atmospheric pressure plasma jet with capacitively coupled radio frequency discharge was developed for diamond-like carbon (DLC) coatings on stainless steel substrates. The plasma jet was generated by argon-methane mixture and its physical parameters were investigated. Relation between the plasma jet length and width of the powered electrode was discussed. Optical and electrical characteristics were studied by optical emission spectroscopy, voltage and current probes, respectively. The evolutions of various species like ArI, C2 and CH along the jet axis were investigated. Electron temperature and density were estimated by Boltzmann plot method and Saha-Boltzmann equation, respectively. Finally, a diamond-like carbon coating was deposited on stainless steel-304 substrates by the atmospheric pressure radio frequency plasma jet in ambient air. Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy and Vickers hardness test were used to study the deposited films. The length of the jet was increased by increasing the width of the powered electrode. The estimated electron temperature and density were 1.43 eV and 1.39 × 1015 cm-3, respectively. Averaged Vicker's hardness of the coated sample was three times greater than that of the substrate. The SEM images of the deposited thin films revealed a 4.5 μm DLC coated for 20 min.

  12. Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre; Fong, Walton; Kulkarni, Ashok; Ryan, Francis W.; Bhatia, C. Singh

    2001-07-13

    Ultrathin (< 5 nm) hard carbon films are of great interest to the magnetic storage industry as the areal density approaches 100 Gbit/in{sup 2}. These films are used as overcoats to protect the magnetic layers on disk media and the active elements of the read-write slider. Tetrahedral amorphous carbon films can be produced by filtered cathodic arc deposition, but the films will only be accepted by the storage industry only if the ''macroparticle'' issue has been solved. Better plasma filters have been developed over recent years. Emphasis is put on the promising twist filter system - a compact, open structure that operates with pulsed arcs and high magnetic field. Based on corrosion tests it is shown that the macroparticle reduction by the twist filter is satisfactory for this demanding application, while plasma throughput is very high. Ultrathin hard carbon films have been synthesized using S-filter and twist filter systems. Film properties such as hardness, elastic modulus, wear, and corrosion resistance have been tested.

  13. Characteristics of Nitrogen Doped Diamond-Like Carbon Films Prepared by Unbalanced Magnetron Sputtering for Electronic Devices.

    Science.gov (United States)

    Lee, Jaehyeong; Choi, Byung Hui; Yun, Jung-Hyun; Park, Yong Seob

    2016-05-01

    Synthetic diamond-like carbon (DLC) is a carbon-based material used mainly in cutting tool coatings and as an abrasive material. The market for DLC has expanded into electronics, optics, and acoustics because of its distinct electrical and optical properties. In this work, n-doped DLC (N:DLC) films were deposited on p-type silicon substrates using an unbalanced magnetron sputtering (UBMS) method. We investigated the effect of the working pressure on the microstructure and electrical properties of n-doped DLC films. The structural properties of N:DLC films were investigated by Raman spectroscopy and SEM-EDX, and the electrical properties of films were investigated by observing the changes in the resistivity and current-voltage (I-V) properties. The N:DLC films prepared by UBMS in this study demonstrated good conducting and physical properties with n-doping.

  14. Structural characteristics of surface-functionalized nitrogen-doped diamond-like carbon films and effective adjustment to cell attachment

    Science.gov (United States)

    Liu, Ai-Ping; Liu, Min; Yu, Jian-Can; Qian, Guo-Dong; Tang, Wei-Hua

    2015-05-01

    Nitrogen-doped diamond-like carbon (DLC:N) films prepared by the filtered cathodic vacuum arc technology are functionalized with various chemical molecules including dopamine (DA), 3-Aminobenzeneboronic acid (APBA), and adenosine triphosphate (ATP), and the impacts of surface functionalities on the surface morphologies, compositions, microstructures, and cell compatibility of the DLC:N films are systematically investigated. We demonstrate that the surface groups of DLC:N have a significant effect on the surface and structural properties of the film. The activity of PC12 cells depends on the particular type of surface functional groups of DLC:N films regardless of surface roughness and wettability. Our research offers a novel way for designing functionalized carbon films as tailorable substrates for biosensors and biomedical engineering applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51272237, 51272231, and 51010002) and the China Postdoctoral Science Foundation (Grant Nos. 2012M520063, 2013T60587, and Bsh1201016).

  15. Effect of Fe ion implantation on tribological properties and Raman spectra characteristics of diamond-like carbon film

    Institute of Scientific and Technical Information of China (English)

    JIA Wen-Bao; SUN Zhuo

    2004-01-01

    Fe ions in the fluence range of 2 × 1015 to 1×1017 cm -2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor deposition.Effects of Fe ion implantation on microstructure and friction coefficient of the DLC were studied. With increasing Fe ion fluence, friction coefficient of the DLC film increased as compared with that of DLC without implantation, and then decreased. The Raman spectra characteristics also show a dependence on the Fe ion fluence. With increasing the ion fluence, the sp2 bonding increased in the DLC film, resulting in the decrease of friction coefficient of the film after implantation. Substantial surface roughness was also measured.

  16. Nanopatterning on silicon surface using atomic force microscopy with diamond-like carbon (DLC-coated Si probe

    Directory of Open Access Journals (Sweden)

    Zhou Jingfang

    2011-01-01

    Full Text Available Abstract Atomic force microscope (AFM equipped with diamond-like carbon (DLC-coated Si probe has been used for scratch nanolithography on Si surfaces. The effect of scratch direction, applied tip force, scratch speed, and number of scratches on the size of the scratched geometry has been investigated. The size of the groove differs with scratch direction, which increases with the applied tip force and number of scratches but decreases slightly with scratch speed. Complex nanostructures of arrays of parallel lines and square arrays are further fabricated uniformly and precisely on Si substrates at relatively high scratch speed. DLC-coated Si probe has the potential to be an alternative in AFM-based scratch nanofabrication on hard surfaces.

  17. Investigation of Physical Properties and Electrochemical Behavior of Nitrogen-Doped Diamond-Like Carbon Thin Films

    Directory of Open Access Journals (Sweden)

    Rattanakorn Saensak

    2014-03-01

    Full Text Available This work reports characterizations of diamond-like carbon (DLC films used as electrodes for electrochemical applications. DLC thin films are prepared on glass slides and silicon substrates by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD using a gas mixture of methane and hydrogen. In addition, the DLC films are doped with nitrogen in order to reduce electrical resistivity. Compared to the undoped DLC films, the electrical resistivity of nitrogen-doped (N-doped DLC films is decreased by three orders of magnitude. Raman spectroscopy and UV/Vis spectroscopy analyses show the structural transformation in N-doped DLC films that causes the reduction of band gap energy. Contact angle measurement at N-doped DLC films indicates increased hydrophobicity. The results obtained from the cyclic voltammetry measurements with Fe(CN63-/Fe(CN64- redox species exhibit the correlation between the physical properties and electrochemical behavior of DLC films.

  18. Dynamic optical properties of amorphous diamond-like carbon nanocomposite films doped with Cu and Ag nanoparticles

    Science.gov (United States)

    Tamulevičius, Tomas; Peckus, Domantas; Tamulevičiene, Asta; Vasiliauskas, Andrius; Čiegis, Arvydas; Meškinis, Šarūnas; Tamulevičius, Sigitas

    2014-09-01

    The investigation of relaxation processes in noble metal nanoparticles upon ultrafast excitations by femtosecond laser pulses is useful to understand the origin and the enhancement mechanism of the nonlinear optical properties for metaldielectric nanocomposites. In the current work we analyze diamond like carbon (DLC) film based copper and silver nanocomposites with different metal content synthesized employing unbalanced magnetron sputtering of metal targets with argon ions in acetylene gas atmosphere. Surface morphology and nanoparticle sizes were analyzed employing scanning electron and atomic force microscopy. Optical properties of the nanocomposite films were analyzed employing UV-VIS-NIR spectrometry. Transient absorption measurements were obtained employing Yb:KGW femtosecond laser spectroscopic system (HARPIA, Light Conversion Ltd.). Energy relaxation dynamics in Cu nanoparticles showed some significant differences from Ag nanoparticles. The increase of excitation intensity hasn't show additional nonlinear effects for the excited state relaxation dynamics for both kinds of samples.

  19. Hydrophobic and high transparent honeycomb diamond-like carbon thin film fabricated by facile self-assembled nanosphere lithography

    Science.gov (United States)

    Peng, Kai-Yu; Wei, Da-Hua; Lin, Chii-Ruey; Yu, Yueh-Chung; Yao, Yeong-Der; Lin, Hong-Ming

    2014-01-01

    In this paper, we take advantage of a facile fabrication technique called self-assembled nanosphere lithography (SANSL) combining with proper two-step reactive ion etching (RIE) method and radio frequency (RF) sputtering deposition process for manufacturing honeycomb diamond-like carbon (DLC) thin film structures with hydrophobic and high transparent properties. It is found that the DLC thin films deposited on clean glass substrates at the RF power of 100 W with the surface roughness (Ra) of 2.08 nm and the ID/IG ratio of 1.96 are realized. With a fill-factor of 0.691, the honeycomb DLC patterned thin film shows the best transmittance performance of 87% in the wavelength of visible light, and the optimized contact angle measurement is ˜108°. Compared with the pure DLC thin film and original glass substrate, the hydrophobic property of the patterned DLC films is significantly improved by 80 and 160%, respectively.

  20. Reduction in static friction by deposition of a homogeneous diamond-like carbon (DLC) coating on orthodontic brackets.

    Science.gov (United States)

    Akaike, Shun; Hayakawa, Tohru; Kobayashi, Daishiro; Aono, Yuko; Hirata, Atsushi; Hiratsuka, Masanori; Nakamura, Yoshiki

    2015-01-01

    In orthodontics, a reduction in static friction between the brackets and wire is important to enable easy tooth movement. The aim of this study was to examine the effects of a homogeneous diamond-like carbon (DLC) coating on the whole surfaces of slots in stainless steel orthodontic brackets on reducing the static friction between the brackets and the wire. The DLC coating was characterized using Raman spectroscopy, surface roughness and contact angle measurements, and SEM observations. Rectangular stainless steel and titanium-molybdenum alloy wires with two different sizes were employed, and the static friction between the brackets and wire was measured under dry and wet conditions. The DLC coating had a thickness of approximately 1.0 μm and an amorphous structure was identified. The results indicated that the DLC coating always led to a reduction in static friction.

  1. Thermal effects on structure and photoluminescence properties of diamond-like carbon films prepared by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    CHEN Da; LI Qing-shan; WANG Jing-jing; ZHENG Xue-gang

    2006-01-01

    Un-hydrogenated Diamond-like Carbon (DLC) films were prepared by pulsed laser deposition technique at different substrate temperature.The Raman spectra,the absorption and the photoluminescence spectra were measured.The dependence of structure and photoluminescence properties on deposition temperature were studied in detail.The experimental results indicate that the sp2 sites form small clusters that consist of both olefinic chains and aromatic ring groups within the sp3 matrix.With raising deposition temperature,the optical band gaps increase from 1.87 to 2.85 eV.The main band of photoluminescence centered at around 700nm shifts to short wavelength,and the intensity of this band increases.The photoluminescence can be attributed to carrier localization within an increasing sp2 clusters.It was clarified that the DLC films are ordered with increasing deposition temperature.

  2. Plasma deposition of diamond-like carbon and fluorinated amorphous carbon and the resultant properties and structure

    Science.gov (United States)

    Glew, Alexander David

    Researchers first created diamondlike carbon (DLC) 50 years ago, but it has only been the subject of intense research for the last decade. DLC is a highly stressed thin film that exists as a mixture of diamond like sp 3 and graphite like sp2 bonded carbon, with 0--50% H. Many believe that high intrinsic stress states are necessary to stabilize the carbon spa content responsible for the high hardness of DLC. This author's goals include fabricating high quality fluorinated amorphous carbon (FLAC) films by plasma enhanced chemical vapor deposition (PECVD), exploring the relationships between the processing parameters and the dielectric value, as well as the related material properties which limit the useful application of FLAC. An improved understanding of the fundamentals behind FLAC processing may allow workers to improve upon the properties limiting its use, such as intrinsic stress, thermal stability, and thermal conductivity. DLC and FLAC film hardness ranged from 14--16 GP and 16--18 GPa respectively. Their film stress ranged from 800 MPa to a 10 GPa. A study of the thickness dependent properties showed that only films thicker than 200 nm were able to achieve stresses greater than approximately 1.6 GPa, the room temperature transition pressure of graphite to diamond. X-ray photoelectron spectroscopy measurements also yielded different C sp3 contents for films of varying thickness deposited under the same conditions, helping to confirm a thickness dependence of film properties greater than 200 nm. Observation of the stress in real time during annealing of the films on Si wafers yielded activation energy values for the stress relief of DLC and FLAC as 0.11 and 0.24 eV respectively, and the CTE of DLC as 10.6 x 10-6 C-1. The stress relief mechanism consists of kinetically limited network arrangements that occur in highly stressed zones due heating, which are also the cause of the reduction in dielectric constant that occurs during rapid thermal annealing. Thermal

  3. Transition Metal Ion Implantation into Diamond-Like Carbon Coatings: Development of a Base Material for Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Andreas Markwitz

    2015-01-01

    Full Text Available Micrometre thick diamond-like carbon (DLC coatings produced by direct ion deposition were implanted with 30 keV Ar+ and transition metal ions in the lower percentage (<10 at.% range. Theoretical calculations showed that the ions are implanted just beneath the surface, which was confirmed with RBS measurements. Atomic force microscope scans revealed that the surface roughness increases when implanted with Ar+ and Cu+ ions, whereas a smoothing of the surface from 5.2 to 2.7 nm and a grain size reduction from 175 to 93 nm are measured for Ag+ implanted coatings with a fluence of 1.24×1016 at. cm−2. Calculated hydrogen and carbon depth profiles showed surprisingly significant changes in concentrations in the near-surface region of the DLC coatings, particularly when implanted with Ag+ ions. Hydrogen accumulates up to 32 at.% and the minimum of the carbon distribution is shifted towards the surface which may be the cause of the surface smoothing effect. The ion implantations caused an increase in electrical conductivity of the DLC coatings, which is important for the development of solid-state gas sensors based on DLC coatings.

  4. STRUCTURE, MECHANICAL PROPERTIES AND THERMAL STABILITY OF DIAMOND-LIKE CARBON FILMS PREPARED BY ARC ION PLATING

    Institute of Scientific and Technical Information of China (English)

    Y.S. Zou; J.D. Zheng; J. Gong; C. Sun; R.F. Huang; L.S. Wen

    2005-01-01

    Diamond-like Carbon (DLC) films have been prepared on Si(100) substrates by arc ion plating in conjunction with pulse bias voltage under H2 atmosphere. The deposited films have been characterized by scanning electron microscopy and atomic force microscopy. The results show that the surface of the film is smooth and dense without any cracks, and the surface roughness is low. The bonding characteristic of the films has been studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. It shows the sp3 bond content of the film deposited at -200V is 26.7%. The hardness and elastic modulus of the film determined by nanoindentation technique are 30.8 and 250.1GPa, respectively. The tribological characteristic of the films reveals that they have low friction coefficient and good wear-resistance. After deposition, the films have been annealed in the range of 350-700℃ for 1h in vacuum to investigate the thermal stability. Raman spectra indicate that the ID/IG ratio and G peak position have few detectable changes below 500℃. Further increasing the annealing temperature, the hydrogen can be released, the structure rearranges, and the phase transition of sp3 configured carbon to sp2 configured carbon appears.

  5. Study of Fluorine Addition Influence in the Dielectric Constant of Diamond-Like Carbon Thin Film Deposited by Reactive Sputtering

    Science.gov (United States)

    Trippe, S. C.; Mansano, R. D.

    The hydrogenated amorphous carbon films (a-C:H) or DLC (Diamond-Like Carbon) films are well known for exhibiting high electrical resistivity, low dielectric constant, high mechanical hardness, low friction coefficient, low superficial roughness and also for being inert. In this paper, we produced fluorinated DLC films (a-C:F), and studied the effect of adding CF4 on the above-mentioned properties of DLC films. These films were produced by a reactive RF magnetron sputtering system using a target of pure carbon in stable graphite allotrope. We performed measurements of electrical characteristic curves of capacitance as a function of applied tension (C-V) and current as a function of the applied tension (I-V). We showed the dielectric constant (k) and the resistivity (ρ) as functions of the CF4 concentration. On films with 65% CF4, we found that k = 2.7, and on films with 70% CF4, ρ = 12.3 × 1011 Ω cm. The value of the electrical breakdown field to films with 70% CF4 is 5.3 × 106 V/cm.

  6. Further improvement of mechanical and tribological properties of Cr-doped diamond-like carbon nanocomposite coatings by N codoping

    Science.gov (United States)

    Zou, Changwei; Xie, Wei; Tang, Xiaoshan

    2016-11-01

    In this study, the effects of nitrogen codoping on the microstructure and mechanical properties of Cr-doped diamond-like carbon (DLC) nanocomposite coatings were investigated in detail. Compared with undoped DLC coatings, the Cr-DLC and N/Cr-DLC coatings showed higher root-mean-square (RMS) roughness values. However, from the X-ray photoelectron spectroscopy (XPS) and Raman results, the fraction of sp2 carbon bonds of N/Cr-DLC coatings increased with increasing N content, which indicated the graphitization of the coatings. The hardness and elastic modulus of N/Cr-DLC coatings with 1.8 at. % N were about 26.8 and 218 GPa, respectively. The observed hardness increase with N codoping was attributed to the incorporation of N in the C network along with the formation of CrC(N) nanoparticles, as confirmed from the transmission electron microscopy (TEM) results. The internal stress markedly decreased from 0.93 to 0.32 GPa as the N content increased from 0 to 10.3 at. %. Furthermore, N doping significantly improved the high-temperature dry friction behavior of DLC coatings. The friction coefficient of N/Cr-DLC coatings with 8.0 and 10.3 at. % N was kept at about 0.2 during the overall sliding test at 500 °C. These results showed that appropriate N doping could promote the mechanical and tribological properties of Cr-DLC nanocomposite coatings.

  7. Synthesis of flat sticky hydrophobic carbon diamond-like films using atmospheric pressure Ar/CH4 dielectric barrier discharge

    Science.gov (United States)

    Rincón, R.; Hendaoui, A.; de Matos, J.; Chaker, M.

    2016-06-01

    An Ar/CH4 atmospheric pressure dielectric barrier discharge (AP-DBD) was used to synthesize sticky hydrophobic diamond-like carbon (DLC) films on glass surface. The film is formed with plasma treatment duration shorter than 30 s, and water contact angles larger than 90° together with contact angle hysteresis larger than 10° can be achieved. According to Fourier transform infrared spectroscopy and atomic force microscopy analysis, hydrocarbon functional groups are created on the glass substrate, producing coatings with low surface energy (˜35 mJ m-2) with no modification of the surface roughness. To infer the plasma processes leading to the formation of low energy DLC surfaces, optical emission spectroscopy was used. From the results, a direct relationship between the CH species present in the plasma and the carbon concentration in the hydrophobic layer was found, which suggests that the CH species are the precursors of DLC film growth. Additionally, the plasma gas temperature was measured to be below 350 K which highlights the suitability of using AP-DBD to treat thermo-sensitive surfaces.

  8. Diamond-like carbon films deposited on three-dimensional shape substrate model by liquid electrochemical technique

    Energy Technology Data Exchange (ETDEWEB)

    He, Y.Y. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Zhang, G.F. [School of Materials Science and Engineering, Dalian University of Technology, 116024, Dalian China (China); Zhao, Y.; Liu, D.D. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Cong, Y., E-mail: congyan@ciomp.ac.cn [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Buck, V. [Thin Film Technology Group, Faculty of Physics, University Duisburg-Essen and CeNIDE, 47057 Duisburg (Germany)

    2015-09-01

    Diamond-like carbon (DLC) films were deposited on three-dimensional (3D) shape substrate model by electrolysis of 2-propanol solution at low temperature (60 °C). This 3D shape model was composed of a horizontally aligned stainless steel wafer and vertically aligned stainless steel rods. Morphology and microstructure of the films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, respectively. The results suggested there were only differences in film uniformity and thickness for two kinds of samples. The hydrogenated amorphous carbon films deposited on horizontally aligned substrate were smooth and homogeneous. And the film thickness of DLC films gained on the vertical substrates decreased along vertical direction. It is believed that bubble formation could enhance nucleation on the wetted capillary area. This experiment shows that deposition of DLC films by liquid phase deposition on 3D shape conductive substrates is possible. - Highlights: • DLC film is expected to be deposited on complex surface/shape substrate. • DLC film is deposited on 3D shape substrate by liquid electrochemical method. • Horizontal substrate is covered by smooth and homogeneous DLC films. • Film thickness decreases along vertical direction due to boiling effect.

  9. Debris reduction for copper and diamond-like carbon thin films produced by magnetically guided pulsed laser deposition

    CERN Document Server

    Tsui, Y Y; Vick, D; Fedosejevs, R

    2002-01-01

    The effectiveness of debris reduction using magnetically guided pulsed laser deposition (MGPLD) is reported here. KrF laser pulses (248 nm) of 100 mJ energy were focused to intensities of 6x10 sup 9 W/cm sup 2 onto the surface of a copper or a carbon source target and a magnetic field of 0.3 T as used to steer the plasma around a curved arc of 0.5 m length to the deposition substrate. Debris counts were compared for films produced by the MGPLD and conventional PLD (nonguided) techniques. A significant reduction in particulates of size greater than 0.1 mu m was achieved using MGPLD. For the copper films, particulate count was reduced from 150 000 particles/cm sup 2 /nm to 50 particulates/cm sup 2 /nm and for diamond-like carbon thin films particulate count was reduced from 25 000 particles/cm sup 2 /nm to 1200 particles/cm sup 2 /nm.

  10. Tribological behaviors of diamond-like carbon coatings on plasma nitrided steel using three BN-containing lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Jia Zhengfeng [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 73000 (China); College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China); Graduate School of the Chinese Academy of Sciences, Beijing 10039 (China); Wang Peng [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 73000 (China); Xia Yanqiu, E-mail: xiayanqiu@yahoo.com [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 73000 (China); Zhang Haobo; Pang Xianjuan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 73000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 10039 (China); Li Bin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 73000 (China)

    2009-04-15

    In this work, diamond-like carbon (DLC) coatings were deposited on plasma nitrided AISI 1045 steel by magnetron sputtering. Three BN-containing additives and molybdenum dithiocarbamate (MoDTC) were added to poly-alpha-olefin (PAO) as additives. The additive content (mass fraction) in PAO was fixed at 0.5 wt%. The friction and wear characters of DLC coatings on nitrided steel discs sliding against AISI 52100 steel balls were tested under the lubricated conditions. It was found that borate esters have a higher load carrying capacity and much better anti-wear and friction-reducing ability than that of MoDTC. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were employed to explore the properties of the worn surface and the mechanism of friction and wear. According to the XPS analysis, the adsorbed organic N-containing compounds and BN are, possibly, the primary reason for the novel borate esters to possess a relatively constant coefficient of friction and lower wear rate. On the other hand, possibly, the MoDTC molecules break down during sliding and produce many Mo-oxides, and then the Mo-oxides destroy the DLC coating because of its sharp edge crystalline solid structure. After destroying the DLC coating, the MoDTC react with metals and form MoS{sub 2} tribofilm, and decrease coefficient of friction of rubbing pairs.

  11. Preparation and Properties of Ag-Containing Diamond-Like Carbon Films by Magnetron Plasma Source Ion Implantation

    Directory of Open Access Journals (Sweden)

    K. Baba

    2012-01-01

    Full Text Available The doping effect of silver on the structure and properties of diamond-like carbon (DLC films was investigated. The samples were prepared by a process combining acetylene plasma source ion implantation (high-voltage pulses of −10 kV with reactive magnetron sputtering of an Ag disc. A mixture of two gases, argon, and acetylene was introduced into the discharge chamber as working gas for plasma formation. A negative high-voltage pulse was applied to the substrate holder, thus, accelerating ions towards the substrate. The chemical composition of the deposited films was modified by the respective gas flows and determined using X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The silver concentration within the DLC films influenced the structure and the tribological properties. The surface roughness, as observed by scanning electron microscopy, increased with silver concentration. The film structure was characterized by Raman spectroscopy and X-ray diffractometry (XRD. The DLC films were mainly amorphous, containing crystalline silver, with the amount of silver depending on the process conditions. The tribological properties of the films were improved by the silver doping. The lowest friction coefficient of around 0.06 was derived at a low silver content.

  12. Surface Structure of Hydrogenated Diamond-like Carbon: Origin of Run-In Behavior Prior to Superlubricious Interfacial Shear

    Energy Technology Data Exchange (ETDEWEB)

    Al-Azizi, Ala A; Eryilmaz, Osman; Erdemir, Ali; Kim, Seong H.

    2015-01-01

    The oxidized layers at the surface of hydrogenated diamond-like carbon (H-DLC) were studied with X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure, and Raman spectroscopy. The structure of these layers was correlated with the friction and wear behavior observed on H-DLC. H-DLC is well-known for its ultralow friction in inert environments, but the steady superlubricious state is always preceded by a run-in period with a high friction. It was hypothesized that the run-in period is related to the surface oxide layer formed naturally upon exposure of the sample to air. To test this hypothesis, thermal oxide layers were grown, and their structures were analyzed and compared with the native oxide layer on a pristine sample. It was found that the Raman spectra of the surface oxide layers of H-DLC have higher D/G band ratio than the bulk, indicating a larger amount of aromatic clusters compared to the bulk film. Thick oxide layers grown at 300 °C showed a run-in friction behavior that resembled the friction of graphite. The run-in periods were found to become longer when the thickness of the oxide layers increased, indicating that the run-in behavior of H-DLC is attributed to the removal of the surface oxide layers.

  13. Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages

    Directory of Open Access Journals (Sweden)

    Tadas Juknius

    2016-05-01

    Full Text Available In the current work, a new antibacterial bandage was proposed where diamond-like carbon with silver nanoparticle (DLC:Ag-coated synthetic silk tissue was used as a building block. The DLC:Ag structure, the dimensions of nanoparticles, the silver concentration and the silver ion release were studied systematically employing scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic absorption spectroscopy, respectively. Antimicrobial properties were investigated using microbiological tests (disk diffusion method and spread-plate technique. The DLC:Ag layer was stabilized on the surface of the bandage using a thin layer of medical grade gelatin and cellulose. Four different strains of Staphylococcus aureus extracted from humans’ and animals’ infected wounds were used. It is demonstrated that the efficiency of the Ag+ ion release to the aqueous media can be increased by further RF oxygen plasma etching of the nanocomposite. It was obtained that the best antibacterial properties were demonstrated by the plasma-processed DLC:Ag layer having a 3.12 at % Ag surface concentration with the dominating linear dimensions of nanoparticles being 23.7 nm. An extra protective layer made from cellulose and gelatin with agar contributed to the accumulation and efficient release of silver ions to the aqueous media, increasing bandage antimicrobial efficiency up to 50% as compared to the single DLC:Ag layer on textile.

  14. Functionalization of Hydrogen-free Diamond-like Carbon Films using Open-air Dielectric Barrier Discharge Atmospheric Plasma Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Instituto de Materiales de Madrid, C.S.I.C., Cantoblanco, 28049 Madrid, Spain; Instituto de Quimica-Fisica" Rocasolano" C.S.I.C., 28006 Madrid, Spain; Mahasarakham University, Mahasarakham 44150, Thailand; CASTI, CNR-INFM Regional Laboratory, L' Aquila 67100, Italy; SUNY Upstate Medical University, Syracuse, NY 13210, USA; Endrino, Jose; Endrino, J. L.; Marco, J. F.; Poolcharuansin, P.; Phani, A.R.; Allen, M.; Albella, J. M.; Anders, A.

    2007-12-28

    A dielectric barrier discharge (DBD) technique has been employed to produce uniform atmospheric plasmas of He and N2 gas mixtures in open air in order to functionalize the surface of filtered-arc deposited hydrogen-free diamond-like carbon (DLC) films. XPS measurements were carried out on both untreated and He/N2 DBD plasma treated DLC surfaces. Chemical states of the C 1s and N 1s peaks were collected and used to characterize the surface bonds. Contact angle measurements were also used to record the short- and long-term variations in wettability of treated and untreated DLC. In addition, cell viability tests were performed to determine the influence of various He/N2 atmospheric plasma treatments on the attachment of osteoblast MC3T3 cells. Current evidence shows the feasibility of atmospheric plasmas in producing long-lasting variations in the surface bonding and surface energy of hydrogen-free DLC and consequently the potential for this technique in the functionalization of DLC coated devices.

  15. On the performances and wear of WC-diamond like carbon coated tools in drilling of CFRP/Titanium stacks

    Science.gov (United States)

    Boccarusso, L.; Durante, M.; Impero, F.; Minutolo, F. Memola Capece; Scherillo, F.; Squillace, A.

    2016-10-01

    The use of hybrid structures made of CFRP and titanium alloys is growing more and more in the last years in the aerospace industry due to the high strength to weight ratio. Because of their very different characteristics, the mechanical fastening represent the most effective joining technique for these materials. As a consequence, drilling process plays a key role in the assembly. The one shot drilling, i.e. the contemporary drilling of the stack of the two materials, seems to be the best option both in terms of time saving and assembly accuracy. Nevertheless, due to the considerable different machinability of fiber reinforced plastics and metallic materials, the one shot drilling is a critical process both for the holes quality and for the tools wear. This research was carried out to study the effectiveness of new generation tools in the drilling of CFRP/Titanium stacks. The tools are made of sintered grains of tungsten carbide (WC) in a binder of cobalt and coated with Diamond like carbon (DLC), and are characterized by a patented geometry; they mainly differ in parent WC grain size and binder percentage. Both the cutting forces and the wear phenomena were accurately investigated and the results were analyzed as a function of number of holes and their quality. The results show a clear increase of the cutting forces with the number of holes for all the used drilling tools. Moreover, abrasive wear phenomena that affect initially the tools coating layer were observed.

  16. Molecular dynamics simulations on the frictional behavior of a perfluoropolyether film sandwiched between diamond-like-carbon coatings.

    Science.gov (United States)

    Dai, L; Sorkin, V; Sha, Z D; Pei, Q X; Branicio, P S; Zhang, Y W

    2014-02-18

    We perform molecular dynamics simulations to investigate the nanoscale frictional behavior of a perfluoropolyether (PFPE) film sandwiched between two diamond-like-carbon (DLC) coatings. We show that the PFPE films behave like a solid and can perform either a motion-station movement or a continuous motion with fluctuating velocities. The former movement is caused by the alternating stick and slip at the two individual interfaces, while the latter is due to the dynamic sliding motions simultaneously occurring at both interfaces. We reveal that these motion characteristics are governed by the competition between the two interfacial adhesion energies, which are strongly affected by the thermal vibrations and interface roughness fluctuations. We also find that the Amonton's law modified by incorporating the adhesion effect can be used to describe the mean friction traction vs normal pressure relation, but large fluctuations are present at low contact pressures. The magnitude of atomic level friction forces at the interface is found to be highly nonuniform. The directions of atomic level friction forces can even be opposite. With increasing the normal pressure, the nonuniformity of atomic level friction forces decreases first and then increases again. This change can be explained by the concurrent effects from the large difference in material stiffness and the changes in surface roughness under normal pressure. The present work reveals interesting insights into the sliding mechanisms in sandwiched structures and provides useful guidelines for the design of nanoscale lubricant systems.

  17. Influence of Hydrogen Content on Optical and Mechanical Performances of Diamond-Like Carbon Films on Glass Substrate

    Science.gov (United States)

    Sun, Yao; Huang, Xing-Ye; Wang, Hong

    2016-04-01

    The protective layer for cover glass of touch panel screen for electronic mobile devices is required to have good mechanical properties and decent optical transparency simultaneously. The hydrogenated diamond-like carbon (a-C:H) films were deposited on glass substrate by RF-PECVD in the negative stage potential mode (NP mode), as well as the ground stage potential mode (GP mode). The impact of hydrogen content, affected by stage potential and RF power, on optical and mechanical properties was investigated. The results show that hydrogen content decreases with increasing RF power, due to the dehydrogenation effect. Higher hydrogen content in films results in lower refractive index, lower extinction coefficient, lower optical absorptions, larger optical band gap and higher transmittance, but lower hardness and wearing resistance. Therefore, although the GP mode DLC is optically favorable because of higher hydrogen content, the NP mode one is far more superior from mechanical standpoint. A compromise can be reached to deposit an ultrathin layer of DLC in NP mode, which offers a good combination of properties to meet the requirement for the protective layer of cover glass.

  18. Effects of nitrogen content on structure and electrical properties of nitrogen-doped fluorinated diamond-like carbon films

    Institute of Scientific and Technical Information of China (English)

    XIAO Jian-rong; LI Xin-hai; WANG Zhi-xing

    2009-01-01

    Nitrogen-doped fluorinated diamond-like carbon (FN-DLC) films were prepared on single crystal silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) under different deposited conditions with CF4,CH4 and nitrogen as source gases.The influence of nitrogen content on the structure and electrical properties of the films was studied.The films were investigated in terms of surface morphology,microstructure,chemical composition and electrical properties.Atomic force microscopy (AFM) results revealed that the surface morphology of the films became smooth due to doping nitrogen.Fourier transform infrared absorption spectrometry (FTIR) results showed that amouts of C=N and C≡N bonds increased gradually with increasing nitrogen partial pressure r (r=p(N_2)/p(N_2+CF_4+CH_4)).Gaussian fit results of C 1s and N 1s in X-ray photoelectron spectra (XPS) showed that the incorporation of nitrogen presented mainly in the forms of β-C_3N_4 and a-CN_x (x=1,2,3) in the films.The current-voltage (I-V) measurement results showed that the electrical conductivity of the films increased with increasing nitrogen content.

  19. Ti-doped hydrogenated diamond like carbon coating deposited by hybrid physical vapor deposition and plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Lee, Na Rae; Sle Jun, Yee; Moon, Kyoung Il; Sunyong Lee, Caroline

    2017-03-01

    Diamond-like carbon films containing titanium and hydrogen (Ti-doped DLC:H) were synthesized using a hybrid technique based on physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD). The film was deposited under a mixture of argon (Ar) and acetylene gas (C2H2). The amount of Ti in the Ti-doped DLC:H film was controlled by varying the DC power of the Ti sputtering target ranging from 0 to 240 W. The composition, microstructure, mechanical and chemical properties of Ti-doped DLC:H films with varying Ti concentrations, were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nano indentation, a ball-on-disk tribometer, a four-point probe system and dynamic anodic testing. As a result, the optimum composition of Ti in Ti-doped DLC:H film using our hybrid method was found to be a Ti content of 18 at. %, having superior electrical conductivity and high corrosion resistance, suitable for bipolar plates. Its hardness value was measured to be 25.6 GPa with a low friction factor.

  20. Fluorine and boron co-doped diamond-like carbon films deposited by pulsed glow discharge plasma immersion ion processing

    CERN Document Server

    He, X M; Peters, A M; Taylor, B; Nastasi, M

    2002-01-01

    Fluorine (F) and boron (B) co-doped diamond-like carbon (FB-DLC) films were prepared on different substrates by the plasma immersion ion processing (PIIP) technique. A pulse glow discharge plasma was used for the PIIP deposition and was produced at a pressure of 1.33 Pa from acetylene (C sub 2 H sub 2), diborane (B sub 2 H sub 6), and hexafluoroethane (C sub 2 F sub 6) gas. Films of FB-DLC were deposited with different chemical compositions by varying the flow ratios of the C sub 2 H sub 2 , B sub 2 H sub 6 , and C sub 2 F sub 6 source gases. The incorporation of B sub 2 H sub 6 and C sub 2 F sub 6 into PIIP deposited DLC resulted in the formation of F-C and B-C hybridized bonding structures. The levels of the F and B concentrations effected the chemical bonding and the physical properties as was evident from the changes observed in density, hardness, stress, friction coefficient, and contact angle of water on films. Compared to B-doped or F-doped DLC films, the F and B co-doping of DLC during PIIP deposition...

  1. Diamond-like carbon produced by plasma source ion implantation as a corrosion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Lillard, R.S.; Butt, D.P.; Taylor, T.N.; Walter, K.C.; Nastasi, M.

    1998-03-01

    There currently exists a broad range of applications for which the ability to produce an adherent, hard, wear and, corrosion-resistant coating plays a vital role. These applications include engine components, orthopedic devices, textile manufacturing components, hard disk media, optical coatings, and cutting and machining tools (e.g., punches, taps, scoring dies, and extrusion dies). Ion beam processing can play an important role in all of these technologies. Plasma source ion implantation (PSII) is an emerging technology which has the potential to overcome the limitations of conventional ion implantation by: (1) reducing the time and expense for implanting onto complex shapes and large areas and (2) extending the thickness of the modification zone through ion beam enhanced plasma growth of surface coatings. In PSII, targets are placed directly in a plasma source and then pulse biased to produce a non-line-of-sight process for complex-shaped targets without complex fixturing. If the pulse bias is a relatively high negative potential (20 to 100 kV) ion implantation will result. If however, a low voltage (50--1,200 eV) high duty cycle pulse bias is applied, film deposition from the chamber gas will result, thereby increasing the extent of the surface modification into the 1--10 micron regime. To evaluate the potential for DLC to be used as a corrosion barrier, Electrochemical Impedance Spectroscopy (EIS) and traditional electrochemistry techniques were used to investigate the breakdown mechanism in chloride and nonchloride containing environments. The effect of surface preparation on coating breakdown was also evaluated.

  2. Studies of diamond-like carbon (DLC) films deposited on stainless steel substrate with Si/SiC intermediate layers

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Liu Gui-Chang; Wang Li-Da; Deng Xin-Lü; Xu Jun

    2008-01-01

    In this work, diamond-like carbon (DLC) films were deposited on stainless steel substrates with Si/SiC intermediate layers by combining plasma enhanced sputtering physical vapour deposition (PEUMS-PVD) and microwave electron cyclotron resonance plasma enhanced chemical vapour deposition (MW-ECRPECVD) techniques. The influence of substrate negative self-bias voltage and Si target power on the structure and nano-mechanical behaviour of the DLC films were investigated by Raman spectroscopy, nano-indentation, and the film structural morphology by atomic force microscopy (AFM). With the increase of deposition bias voltage, the G band shifted to higher wave-number and the integrated intensity ratio ID/IG increased. We considered these as evidences for the development of graphitization in the films. As the substrate negative self-bias voltage increased, particle bombardment function was enhanced and thesp3-bond carbon density reducing, resulted in the peak values of hardness (H) and elastic modulus (E). Silicon addition promoted the formation of sp3 bonding and reduced the hardness. The incorporated Si atoms substituted sp2- bond carbon atoms in ring structures, which promoted the formation of sp3-bond. The structural transition from C-C to C-Si bonds resulted in relaxation of the residual stress which led to the decrease of internal stress and hardness. The results of AFM indicated that the films was dense and homogeneous, the roughness of the films was decreased due to the increase of substrate negative self-bias voltage and the Si target power.

  3. Investigation of superfast deposition of metal oxide and Diamond-Like Carbon thin films by nanosecond Ytterbium (Yb+) fiber laser

    Science.gov (United States)

    Serbezov, V.; Sotirov, S.; Benkhouja, K.; Zawadzka, A.; Sahraoui, B.

    2013-11-01

    Metal oxide (MOx, M: titanium, magnesium) and Diamond-Like Carbon (DLC) thin films were synthesized by Pulsed Laser Deposition (PLD) at room temperature and low vacuum of 2 Pa for MOx and vacuum of 4 × 10-3 Pa for DLC films. A fiber based Ytterbium (Yb+) laser operating in the nanosecond regime at a repetition rate of 20 kHz was used as an ablation source. Dense and smooth thin films with a thickness from 120 to 360 nm and an area of up to 10 cm2 were deposited on glass and stainless steel substrates at high growth rates up to 2 nm/s for a laser intensity of 10-12 J/cm2. The thin films synthesis was compared for two fiber laser modes of operation, at a repetition rate of 20 kHz and with an additional modulation at 1 kHz. The morphology, chemical composition and structure of the obtained thin films were evaluated using optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and Raman spectroscopy. The morphology of the MOx thin films and the deposition rate strongly depend on the fiber laser mode of operation. Very smooth surfaces were obtained for the metal oxide thin films deposited at lower deposition rates in the modulation mode at 1 kHz. The effect of the substrate on the DLC film structure was studied. The films deposited on dielectric substrates were identified as typical tetrahedral (ta-C) DLC with high sp3 content. DLC films on metal substrates were found typical a-C amorphous carbon films with mixing sp2/sp3 bonds.

  4. In vitro Cyto and Blood Compatibility of Titanium Containing Diamond-Like Carbon Prepared by Hybrid Sputtering Method

    Institute of Scientific and Technical Information of China (English)

    Krishnasamy NAVANEETHA PANDIYARAJ; Jan HEEG; Andreas LAMPKA; Fabian JUNGE; Torsten BARFELS; Marion WIENECKE; Young Ha RHEE; Hyoung Woo KIM

    2012-01-01

    In recent years, diamond-like carbon films (DLC) have been given more attention in research in the biomedical industry due to their potential application as surface coating on biomedical materials such as metals and polymer substrates. There are many ways to prepare metal containing DLC films deposited on polymeric film substrates, such as coatings from car- bonaceous precursors and some means that incorporate other elements. In this study, we in- vestigated both the surface and biocompatible properties of titanium containing DLC (Ti-DLC) films. The Ti-DLC films were prepared on the surface of poly (ethylene terephthalate) (PET) film as a function of the deposition power level using reactive sputtering technique. The films' hydrophilicity was studied by contact angle and surface energy tests. Their surface morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Their elemental chemical composition was analyzed using energy dispersive X-spectra (EDX) and X-ray photoelectron spectroscopy (XPS). Their blood and cell compatibility was studied by in vitro tests, including tests on platelet adhesion, thrombus formation, whole blood clotting time and osteoblast cell compatibility. Significant changes in the morphological and chemical composition of the Ti-DLC films were observed and found to be a function of the deposition level. These morphological and chemical changes reduced the interfacial tension between Ti-DLC and blood proteins as well as resisted the adhesion and activation of platelets on the surface of the Ti-DLC films. The cell compatibility results exhibited significant growth of osteoblast cells on the surface of Ti incorporated DLC film compared with that of DLC film surface.

  5. Wear resistance of thick diamond like carbon coatings against polymeric materials used in single screw plasticizing technology

    Science.gov (United States)

    Zitzenbacher, G.; Liu, K.; Forsich, C.; Heim, D.

    2015-05-01

    Wear on the screw and barrel surface accompany polymer single screw plasticizing technology from the beginning. In general, wear on screws can be reduced by using nitrided steel surfaces, fused armour alloys on the screw flights and coatings. However, DLC-coatings (Diamond Like Carbon) comprise a number of interesting properties such as a high hardness, a low coefficient of friction and an excellent corrosion resistance due to their amorphous structure. The wear resistance of about 50 µm thick DLC-coatings against polyamide 6.6, polybutylene terephthalate and polypropylene is investigated in this paper. The tribology in the solids conveying zone of a single screw extruder until the beginning of melting is evaluated using a pin on disc tribometer and a so called screw tribometer. The polymeric pins are pressed against coated metal samples using the pin on disc tribometer and the tests are carried out at a defined normal force and sliding velocity. The screw tribometer is used to perform tribological experiments between polymer pellets and rotating coated metal shafts simulating the extruder screw. Long term experiments were performed to evaluate the wear resistance of the DLC-coating. A reduction of the coefficient of friction can be observed after a frictional distance of about 20 kilometers using glass fibre reinforced polymeric materials. This reduction is independent on the polymer and accompanied by a black layer on the wear surface of the polymeric pins. The DLC-coated metal samples show an up to 16 µm deep wear track after the 100 kilometer test period against the glass fiber filled materials only.

  6. Cell adhesion and growth on ultrananocrystalline diamond and diamond-like carbon films after different surface modifications

    Energy Technology Data Exchange (ETDEWEB)

    Miksovsky, J. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Voss, A. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Kozarova, R. [Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Kocourek, T.; Pisarik, P. [Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Ceccone, G. [Unit Nanobiosciences, European Commission Joint Research Centre, Ispra (Italy); Kulisch, W. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Jelinek, M. [Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Apostolova, M.D. [Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Reithmaier, J.P. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Popov, C., E-mail: popov@ina.uni-kassel.de [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany)

    2014-04-01

    Graphical abstract: - Highlights: • UNCD and DLC films were modified by UV/O{sub 3} treatments, O{sub 2} or NH{sub 3}-containing plasmas. • Surface composition, wettability and surface energy change upon modifications. • Higher efficiency of UNCD modifications was observed. • Cell attachment and growth were influenced by the surface termination and roughness. - Abstract: Diamond and diamond-like carbon (DLC) films possess a set of excellent physical and chemical properties which together with a high biocompatibility make them attractive candidates for a number of medical and biotechnological applications. In the current work thin ultrananocrystalline diamond (UNCD) and DLC films were comparatively investigated with respect to cell attachment and proliferation after different surface modifications. The UNCD films were prepared by microwave plasma enhanced chemical vapor deposition, the DLC films by pulsed laser deposition (PLD). The films were comprehensively characterized with respect to their basic properties, e.g. crystallinity, morphology, chemical bonding nature, etc. Afterwards the UNCD and DLC films were modified applying O{sub 2} or NH{sub 3}/N{sub 2} plasmas and UV/O{sub 3} treatments to alter their surface termination. The surface composition of as-grown and modified samples was studied by X-ray photoelectron spectroscopy (XPS). Furthermore the films were characterized by contact angle measurements with water, formamide, 1-decanol and diiodomethane; from the results obtained the surface energy with its dispersive and polar components was calculated. The adhesion and proliferation of MG63 osteosarcoma cells on the different UNCD and DLC samples were assessed by measurement of the cell attachment efficiency and MTT assays. The determined cell densities were compared and correlated with the surface properties of as-deposited and modified UNCD and DLC films.

  7. Diamond-like carbon coatings enhance the hardness and resilience of bearing surfaces for use in joint arthroplasty.

    Science.gov (United States)

    Roy, M E; Whiteside, L A; Xu, J; Katerberg, B J

    2010-04-01

    The purpose of this study was to evaluate the potential of a hard diamond-like carbon (DLC) coating to enhance the hardness and resilience of a bearing surface in joint replacement. The greater hardness of a magnesium-stabilized zirconium (Mg-PSZ) substrate was expected to provide a harder coating-substrate composite microhardness than the cobalt-chromium alloy (CoCr) also used in arthroplasty. Three femoral heads of each type (CoCr, Mg-PSZ, DLC-CoCr and DLC-Mg-PSZ) were examined. Baseline (non-coated) and composite coating/substrate hardness was measured by Vickers microhardness tests, while nanoindentation tests measured the hardness and elastic modulus of the DLC coating independent of the Mg-PSZ and CoCr substrates. Non-coated Mg-PSZ heads were considerably harder than non-coated CoCr heads, while DLC coating greatly increased the microhardness of the CoCr and Mg-PSZ substrates. On the nanoscale the non-coated heads were much harder than on the microscale, with CoCr exhibiting twice as much plastic deformation as Mg-PSZ. The mechanical properties of the DLC coatings were not significantly different for both the CoCr and Mg-PSZ substrates, producing similar moduli of resilience and plastic resistance ratios. DLC coatings greatly increased hardness on both the micro and nano levels and significantly improved resilience and resistance to plastic deformation compared with non-coated heads. Because Mg-PSZ allows less plastic deformation than CoCr and provides a greater composite microhardness, DLC-Mg-PSZ will likely be more durable for use as a bearing surface in vivo.

  8. Structural Analysis of Planar sp3 and sp2 Films: Diamond-Like Carbon and Graphene Overlayers

    KAUST Repository

    Mansour, Ahmed

    2011-07-07

    The special electronic configuration of carbon enables the existence of wide ranging allotropes taking all possible dimensionalities. The allotropes of carbon are characterized by the type of hybridized bonding forming its structure, ranging from pure sp2 as in graphene, carbon nanotubes and fullerenes, to pure sp3 as in diamond. Amorphous and diamond-like carbon consists of a mixture of both hybridizations. This variation in hybridization in carbon materials enables a wide spectrum of properties, ranging from high bulk mechanical hardness, tribological properties and chemical inertness made possible by moving towards pure sp3 bonding to the extraordinary electrical conductivity, optical properties and in-plane mechanical strength resulting from pure sp2 bonding. Two allotropes at the extremes of this spectrum, diamond like carbon (DLC) and graphene, are investigated in this thesis; the former is investigated as a protective coating in hard drive applications, while the latter is investigated in the context of chemically derived graphene as material for transparent conducting electrode applications. DLC thin films are a main component in computer hard drives, acting as a protective coating against corrosion and mechanical wear of the magnetic layer and read-write head. The thickness of DLC films greatly affects the storage density in such devices, as larger separation between the read/write head and the magnetic layer decreases the storage density. A targeted DLC thickness of 2 nm would increase the storage density towards 1 Tbits/inch2. However, difficulty achieving continuous films at such thicknesses by commonly used sputtering methods challenges the industry to investigate alternative methods. Filtered cathodic vacuum arc (FCVA) has been proposed as an efficient technique to provide continuous, smooth and ultra-thin DLC films. We investigate the influence of deposition angle, deposition time, and substrate biasing to define the optimum process window to obtain

  9. The Structure and Characteristics of Tribological Systems with Diamond Like Carbon Coatings under Ionic Liquid Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Madej M.

    2016-06-01

    Full Text Available The results from the tests on tribological a-C:H diamond coatings deposited by PACVD (plasma assisted chemical vapour deposition on 100Cr6 steel components are presented in this work. Mechanical properties - nanohardness and Young’s modulus - were assessed by instrumented indentation. Tribological tests were conducted with T-01M tester in a ball-on-disc test under dry and boundary friction conditions. Selected ionic liquids - synthetic new generation lubricants - were used for lubrication. The results from the experiments indicate that diamond-like coatings improved tribological characteristics of the friction pairs tested, with the ionic liquids intensifying this effect.

  10. Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng; Sun, Lili; Li, Xiaowei [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xu, Sheng [Gao Hong Coating Technology Co., Ltd, Huzhou 313000 (China); Ke, Peiling [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-06-01

    Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m{sup 2} for pure carbon film to 2.48 mJ/m{sup 2} for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness.

  11. Structure and properties of Mo-containing diamond-like carbon films produced by ion source assisted cathodic arc ion-plating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.L. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 China (China); Wang, R.Y. [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Yan, S.J.; Zhang, R. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 China (China); Yang, B. [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Zhang, Z.D.; Huang, Z.H. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 China (China); Fu, D.J., E-mail: djfu@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 China (China)

    2013-12-01

    Ion source assisted cathodic arc ion-plating was used to synthesize molybdenum containing diamond-like carbon films. The element of molybdenum is uniformly distributed in our sample as analyzed by Rutherford backscattering spectroscopy. The surface morphology of the films was analyzed by scanning electron microscope and atomic force microscope. The structure and bond state of the molybdenum containing diamond-like carbon films were characterized by X-ray diffraction, high resolution transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy. The Mo content in the films was controlled by varying of the acetylene gas flow rates. The root-mean square roughness of the as-deposited sample was found in the range of 1.5 nm. The hardness of 35 GPa has been achieved at the optimum conditions of synthesis. This can be attributed to formation multilayer structure during deposition process and the formation of hard molybdenum carbide phase with C=Mo bonding. The results show that ion source assisted cathodic arc ion-plating is an effective technique to fabricate metal-containing carbon films with controlled metal contents.

  12. Patterning of diamond like carbon films for sensor applications using silicon containing thermoplastic resist (SiPol) as a hard mask

    Energy Technology Data Exchange (ETDEWEB)

    Virganavičius, D. [Paul Scherrer Institute, Laboratory for Micro- and Nanotechnology, 5232 Villigen PSI (Switzerland); Kaunas University of Technology, Institute of Materials Science, 51423 Kaunas (Lithuania); Cadarso, V.J.; Kirchner, R. [Paul Scherrer Institute, Laboratory for Micro- and Nanotechnology, 5232 Villigen PSI (Switzerland); Stankevičius, L.; Tamulevičius, T.; Tamulevičius, S. [Kaunas University of Technology, Institute of Materials Science, 51423 Kaunas (Lithuania); Schift, H., E-mail: helmut.schift@psi.ch [Paul Scherrer Institute, Laboratory for Micro- and Nanotechnology, 5232 Villigen PSI (Switzerland)

    2016-11-01

    Highlights: • Nanopatterning of thin diamond-like carbon (DLC) films and silver containing DLC composites. • Nanoimprint lithography with thermoplastic silicon containing resist. • Zero-residual layer imprinting and pattern transfer by reactive ion etching. • Robust leaky waveguide sensors with sensitivity up to 319 nm/RIU. - Abstract: Patterning of diamond-like carbon (DLC) and DLC:metal nanocomposites is of interest for an increasing number of applications. We demonstrate a nanoimprint lithography process based on silicon containing thermoplastic resist combined with plasma etching for straightforward patterning of such films. A variety of different structures with few hundred nanometer feature size and moderate aspect ratios were successfully realized. The quality of produced patterns was directly investigated by the means of optical and scanning electron microscopy (SEM). Such structures were further assessed by employing them in the development of gratings for guided mode resonance (GMR) effect. Optical characterization of such leaky waveguide was compared with numerical simulations based on rigorous coupled wave analysis method with good agreement. The use of such structures as refractive index variation sensors is demonstrated with sensitivity up to 319 nm/RIU, achieving an improvement close to 450% in sensitivity compared to previously reported similar sensors. This pronounced GMR signal fully validates the employed DLC material, the technology to pattern it and the possibility to develop DLC based gratings as corrosion and wear resistant refractometry sensors that are able to operate under harsh conditions providing great value and versatility.

  13. Preparation of Ag-containing diamond-like carbon films on the interior surface of tubes by a combined method of plasma source ion implantation and DC sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Hatada, R., E-mail: hatada@ca.tu-darmstadt.de [Technische Universität Darmstadt, Department of Materials Science, 64287 Darmstadt (Germany); Flege, S.; Bobrich, A.; Ensinger, W.; Dietz, C. [Technische Universität Darmstadt, Department of Materials Science, 64287 Darmstadt (Germany); Baba, K. [Industrial Technology Center of Nagasaki, Applied Technology Division, Omura, Nagasaki 856-0026 (Japan); Sawase, T.; Watamoto, T. [Nagasaki University, Department of Applied Prosthodontics, Nagasaki 852-8523 (Japan); Matsutani, T. [Technische Universität Darmstadt, Department of Materials Science, 64287 Darmstadt (Germany); Kinki University, Department of Electric and Electronic Engineering, Higashi-osaka 577-2332 (Japan)

    2014-08-15

    Highlights: • Deposition of Ag-containing diamond-like carbon films inside of tubes. • Combination of plasma source ion implantation and DC sputtering. • Antibacterial effect against S. aureus bacteria. - Abstract: Adhesive diamond-like carbon (DLC) films can be prepared by plasma source ion implantation (PSII), which is also suitable for the treatment of the inner surface of a tube. Incorporation of a metal into the DLC film provides a possibility to change the characteristics of the DLC film. One source for the metal is DC sputtering. In this study PSII and DC sputtering were combined to prepare DLC films containing low concentrations of Ag on the interior surfaces of stainless steel tubes. A DLC film was deposited using a C{sub 2}H{sub 4} plasma with the help of an auxiliary electrode inside of the tube. This electrode was then used as a target for the DC sputtering. A mixture of the gases Ar and C{sub 2}H{sub 4} was used to sputter the silver. By changing the gas flow ratios and process time, the resulting Ag content of the films could be varied. Sample characterizations were performed by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, atomic force microscopy and Raman spectroscopy. Additionally, a ball-on-disk test was performed to investigate the tribological properties of the films. The antibacterial activity was determined using Staphylococcus aureus bacteria.

  14. Electron Cyclotron Resonance-Sputtered Nanocarbon Film Electrode Compared with Diamond-Like Carbon and Glassy Carbon Electrodes as Regards Electrochemical Properties and Biomolecule Adsorption

    Science.gov (United States)

    Xue, Qiang; Kato, Dai; Kamata, Tomoyuki; Umemura, Shigeru; Hirono, Shigeru; Niwa, Osamu

    2012-09-01

    The electrochemical properties and biocompatible characteristics at an electron cyclotron resonance (ECR)-sputtered nanocarbon film electrode, a diamond-like carbon (DLC) electrode and a glassy carbon (GC) electrode have been studied. The three carbon electrodes show significant current reductions with increased peak separations as a result of protein fouling before oxygen plasma treatment, but the current reductions of the ECR-sputtered nanocarbon and DLC film electrodes are smaller than that of the GC electrode due to their superior surface flatness. The oxygen plasma pretreated ECR-sputtered nanocarbon film electrode exhibits a significant improvement in anti-fouling performance with an improved electron transfer. This is because the pretreated ECR-sputtered nanocarbon film enabled the surface to introduce surface oxygen functionalities that not only improve the interaction between the analytes and the electrode surface but also make the film surface more hydrophilic, which is important for the suppression of biomolecule adsorption. At the same time, the pretreated ECR-sputtered nanocarbon film also retained an ultraflat surface even after pretreatment as a result of the low background current. This excellent performance can only be achieved with our ECR-sputtered nanocarbon film, indicating that our film is promising for application to electrochemical detectors for various biomolecular analytes.

  15. In vitro evaluation of diamond-like carbon coatings with a Si/SiC {sub x} interlayer on surgical NiTi alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: paul.chu@cityu.edu.hk; Yang, D.Z. [State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China)

    2007-04-15

    Diamond-like carbon (DLC) coatings were produced with a Si/SiC {sub x} interlayer by a hybrid plasma immersion ion implantation and deposition process to improve the adhesion between the carbon layer and surgical NiTi alloy substrate. The structure, mechanical properties, corrosion resistance and biocompatibility of the coatings were evaluated in vitro by Raman spectroscopy, pin-on-disk tests, potentiodynamic polarization tests and simulated fluid immersion tests. The DLC coatings with a Si/SiC {sub x} interlayer of a suitable thickness have better adhesion, lower friction coefficients and enhanced corrosion resistance. In the simulated body fluid tests, the coatings exhibit effective corrosion protection and good biocompatibility as indicated by PC12 cell cultures. DLC films fabricated on a Si/SiC {sub x} interlayer have high potential as protective coatings for biomedical NiTi materials.

  16. Preparation of Metal-Containing Diamond-Like Carbon Films by Magnetron Sputtering and Plasma Source Ion Implantation and Their Properties

    Directory of Open Access Journals (Sweden)

    Stefan Flege

    2017-01-01

    Full Text Available Metal-containing diamond-like carbon (Me-DLC films were prepared by a combination of plasma source ion implantation (PSII and reactive magnetron sputtering. Two metals were used that differ in their tendency to form carbide and possess a different sputter yield, that is, Cu with a relatively high sputter yield and Ti with a comparatively low one. The DLC film preparation was based on the hydrocarbon gas ethylene (C2H4. The preparation technique is described and the parameters influencing the metal content within the film are discussed. Film properties that are changed by the metal addition, such as structure, electrical resistivity, and friction coefficient, were evaluated and compared with those of pure DLC films as well as with literature values for Me-DLC films prepared with a different hydrocarbon gas or containing other metals.

  17. Thermal Characteristics of InGaN/GaN Flip-Chip Light Emitting Diodes with Diamond-Like Carbon Heat-Spreading Layers

    Directory of Open Access Journals (Sweden)

    Pai-Yang Tsai

    2014-01-01

    Full Text Available The temperature-dependent optical, electrical, and thermal properties of flip-chip light emitting diodes (FCLEDs with diamond-like carbon (DLC heat-spreading layers were investigated. On the basis of the measured results in the 20°C to 100°C temperature range, a significant performance improvement can be achieved for FCLEDs with DLC heat-spreading layers (DLC-FCLED compared with FCLEDs without DLC heat-spreading layers (non-DLC-FCLED. The external quantum efficiency (EQE of the DLC-FCLED improves by 9% at an injection current of 1000 mA and a temperature of 100°C. The forward voltage and spectra variations are smaller than those of non-DLC-FCLEDs. The DLC-FCLED provides high efficiency and high stability performance for high-power and high-temperature applications.

  18. Low reflection and high transmission by a layered structure containing diamond-like carbon, porous silicon, and left-handed material

    Science.gov (United States)

    Ubeid, Muin F.; Shabat, Mohammed M.; Altanany, Sameh M.

    2017-03-01

    In this paper, we propose and theoretically analyze a stratified waveguide structure comprised of diamond-like carbon (DLC), porous silicon (PS), and left-handed material (LHM) subjected to incident light in order to achieve low reflection and high transmission. The proposed waveguide structure is situated between two half free spaces and a TE polarized plane wave incident on it. The main parameters of each material are given and the required equations for the electromagnetic plane wave propagation are presented. Transfer matrix method is implemented to find out the characteristics of the reflected and transmitted powers. In the numerical results, the mentioned powers are computed and illustrated as a function of the incidence angle, the frequency, and the slab thickness to demonstrate the main parameters for low reflection and high transmission. These theoretical parameters could be useful to the researchers and designers working in the area of solar cells and optical sensors.

  19. Thickness Effects of TiC Interlayer on Tribological Properties of Diamond-Like Carbon Prepared by Unbalanced Magnetron Sputtering Method.

    Science.gov (United States)

    Park, Chulmin; Lee, Jaehyeong; Park, Yong Seob

    2015-11-01

    We investigated the tribological properties of diamond-like carbon (DLC) films prepared with TiC interlayer of various thicknesses as the adhesive layer. DLC and TiC thin films were prepared using unbalanced magnetron (UBM) sputtering method using graphite and titanium as targets. TiC films as the interlayer were deposited under DLC films and various physical, tribological, and structural properties of the films fabricated with various TiC interlayer thicknesses were investigated. With various TiC interlayer thicknesses under DLC films, the tribological properties of films were improved with increasing thickness and the DLC/TiC layer fabricated by unbalanced magnetron sputtering method are exhibited maximum high hardness over 27 GPa and high elastic modulus over 242 GPa, and a smooth surface below 0.09 nm.

  20. Study of Diamond like Carbon as template for nanoimprint lithography and as a filler material for vertically aligned carbon nanotube forests

    Science.gov (United States)

    Ramachandran, Seetharaman

    Due to its tunable properties like hardness, optical gap, chemical inertness, electrical resistivity, biocompatibility etc., coatings of the material Diamond like Carbon (DLC) have been used as protective layers for various applications. In this research effort, we add to the growing list of its potential applications by proposing them as a template material for the emerging field of nanoimprint lithography. Using capacitive and inductive plasmas, we demonstrate the possibility of depositing DLC films of reasonable hardness (10-25 GPa) and wear resistance (2X that of Si and 3X that of Quartz). We have successfully used these films as a mold material to obtain feature sizes as small as 40 nm. In addition, to further the understanding of the effect of the gas phase chemistry on the film properties, the Methane discharge used for obtaining these films has been studied using techniques like Fourier Transform Infrared Spectroscopy and Optical Emission Spectroscopy. The higher degree of dissociation (up to 70%) of the precursor in case of inductive plasmas leads to selected conditions under which hard DLC films are obtained. We also show that for the same deposition conditions, films deposited on the insulating Quartz substrates are softer and more polymeric than those deposited on Si substrates. Carbon nanotubes with their unique physical properties are seen as ideal candidates for applications like field effect transistors, supercapacitors, AFM tips and electronic devices. One of the chief challenges in using them for these applications is obtaining them in a form that is easier to handle, thus enabling them to withstand the various post-processing steps. The second part of this dissertation focuses on the possibility of obtaining a Carbon-Carbon composite structure by subjecting vertically aligned Carbon nanotube forests to a PECVD based process. The distance from the top of the CNT forest that is coated with the deposited film (termed as the depth of infusion) shows

  1. Optical properties of diamond like carbon films containing copper, grown by high power pulsed magnetron sputtering and direct current magnetron sputtering: Structure and composition effects

    Energy Technology Data Exchange (ETDEWEB)

    Meškinis, Š., E-mail: sarunas.meskinis@ktu.lt; Čiegis, A.; Vasiliauskas, A.; Šlapikas, K.; Tamulevičius, T.; Tamulevičienė, A.; Tamulevičius, S.

    2015-04-30

    In the present study chemical composition, structure and optical properties of hydrogenated diamond like carbon films containing copper (DLC:Cu films) deposited by reactive magnetron sputtering were studied. Different modes of deposition — direct current (DC) sputtering and high power pulsed magnetron sputtering (HIPIMS) as well as two configurations of the magnetron magnetic field (balanced and unbalanced) were applied. X-ray diffractometry, Raman scattering spectroscopy, energy-dispersive X-ray spectroscopy and atomic force microscopy were used to study the structure and composition of the films. It was shown that by using HIPIMS mode contamination of the cathode during the deposition of DLC:Cu films can be suppressed. In all cases oxygen atomic concentration in the films was in 5–10 at.% range and it increased with the copper atomic concentration. The highest oxygen content was observed in the films deposited employing low ion/neutral ratio balanced DC magnetron sputtering process. According to the analysis of the parameters of Raman scattering spectra, sp{sup 3}/sp{sup 2} bond ratio decreased with the increase of Cu atomic concentration in the DLC films. Clear dependence of the extinction, absorbance and reflectance spectra on copper atomic concentration in the films was observed independently of the method of deposition. Surface plasmon resonance effect was observed only when Cu atomic concentration in DLC:Cu film was at least 15 at.%. The maximum of the surface plasmon resonance peak of the absorbance spectra of DLC:Cu films was in 600–700 nm range and redshifted with the increase of Cu amount. The ratio between the intensities of the plasmonic peak and hydrogenated amorphous carbon related peak at ~ 220 nm both in the extinction and absorbance spectra as well as peak to background ratio of DLC:Cu films increased linearly with Cu amount in the investigated 0–40 at.% range. Reflectance of the plasmonic DLC:Cu films was in 30–50% range that could be

  2. Fabrication of High Transparency Diamond-Like Carbon Film Coating on D263T Glass at Room Temperature as an Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2013-01-01

    Full Text Available This study intends to deposit high transmittance diamond-like carbon (DLC thin films on D263T glass substrate at room temperature via a diamond powder target using the radio frequency (RF magnetron sputtering technique. Moreover, various process parameters were used to tune the properties of the thin films by using the Taguchi method. Experimental results show that the content of sp3 bonded carbon decreases in accordance with the effect of the substrate temperature. In addition, the hardness of all as-deposited single-layer DLC films ranges from 13.2 to 22.5 GPa, and the RMS surface roughness was improved significantly with the decrease in sputtering pressure. The water repellent of the deposited DLC films improved significantly with the increase of the sp3 content, and its contact angle was larger than that of the noncoated one by 1.45 times. Furthermore, the refraction index (n of all as-deposited DLC films ranges from 1.95 to 2.1 at λ = 600 nm. These results demonstrate that the thickness increased as the reflectance increased. DLC film under an RF power of 150 W possesses high transmissive ability (>81% and low average reflectance ability (<9.5% in the visible wavelengths (at λ = 400–700 nm.

  3. Ion induced transformation of polymer films into diamond-like carbon incorporating silver nano particles; Ioneninduzierte Umwandlung von Polymerschichten zu diamantaehnlichem Kohlenstoff mit darin enthaltenen Silber-Nanopartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Florian P.

    2010-03-26

    Silver containing diamond-like carbon (DLC) is an interesting material for medical engineering from several points of view. On the one hand DLC provides high mechanical robustness. It can be used as biocompatible and wear resistant coating for joint replacing implants. On the other hand silver has antimicrobial properties, which could reduce post-operative inflammations. However conventional production of Ag-DLC by co-deposition of silver and carbon in a plasma process is problematic since it does not allow for a separate control of nano particle morphology and matrix properties. In this work an alternative production method has been developed to circumvent this problem. In metall-DLC-production by ion implantation into a nano composite, silver nano particles are initially formed in solution and then incorporated within a polymer matrix. Finally the polymer is transformed into DLC by ion implantation. The aspects and single steps of this method were investigated with regard to the resulting material's properties. The goal was to design an economically relevant deposition method. Based on experimental results a model of the transformation process has been established, which has also been implemented in a computer simulation. Finally the antibacterial properties of the material have been checked in a biomedical test. Here a bacterial killing rate of 90% could be achieved. (orig.)

  4. Incorporation of Si and SiO(x) into diamond-like carbon films: impact on surface properties and osteoblast adhesion.

    Science.gov (United States)

    Randeniya, L K; Bendavid, A; Martin, P J; Amin, Md S; Preston, E W; Magdon Ismail, F S; Coe, S

    2009-06-01

    The interaction of human osteoblast cells with diamond-like carbon films incorporating silicon and silicon oxide (SiO(x), 1 activated chemical vapour deposition method was investigated. Cell culture studies were performed for films with Si contents ranging from approximately 4 at.% to 15 at.%. Substantial differences between Si-incorporated and SiO(x)-incorporated films were found for the bonding environments of Si atoms and the hybridization of underlying carbon structures. However, osteoblast-attachment studies did not show statistically significant trends in properties of cell growth (count, area and morphology) that can be attributed either to the Si content of the films or to the chemical structure of the films. The surface energy decreased by 40% as the Si content of the SiO(x) incorporated DLC films increased to 13 at.%. The cell adhesion properties however did not change in response to lowering of the surface energy. The incorporation of both Si and SiO(x) leads to a beneficial reduction in the residual stress of the films. The average roughness of the films increases and the hardness decreases when Si and SiO(x) are added to DLC films. The impact of these changes for load-bearing biomedical applications can be determined only by carefully controlled experiments using anatomic simulators.

  5. Effect of boron incorporation on the structure and electrical properties of diamond-like carbon films deposited by femtosecond and nanosecond pulsed laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, A. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Bourgeois, O. [Institut Neel, UPR 2940 CNRS, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Sanchez-Lopez, J.C. [Instituto de Ciencia de Materiales de Sevilla, Avda. Americo Vespucio, 49 41092 Sevilla (Spain); Rouzaud, J.-N. [Laboratoire de Geologie, UMR 8538 CNRS, Ecole Normale Superieure, 45 Rue d' Ulm, 75230 Paris Cedex 05 (France); Rojas, T.C. [Instituto de Ciencia de Materiales de Sevilla, Avda. Americo Vespucio, 49 41092 Sevilla (Spain); Loir, A.-S. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Garden, J.-L. [Institut Neel, UPR 2940 CNRS, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Garrelie, F. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Donnet, C., E-mail: christophe.donnet@univ-st-etienne.f [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France)

    2009-12-31

    The influence of the incorporation of boron in diamond-like carbon (DLC) films on the microstructure of the coatings has been investigated. The boron-containing DLC films (a-C:B) have been deposited by pulsed laser deposition (PLD) at room temperature in high vacuum conditions, by ablating graphite and boron targets either with a femtosecond pulsed laser (800 nm, 150 fs, fs-DLC) or with a nanosecond pulsed laser (248 nm, 20 ns, ns-DLC). Alternative ablation of the graphite and boron targets has been carried out to deposit the a-C:B films. The film structure and composition have been highlighted by coupling Field Emission Scanning Electron Microscopy, Electron Energy Loss Spectroscopy and High Resolution Transmission Electron Microscopy. Using the B K-edge, EELS characterization reveals the boron effect on the carbon bonding. Moreover, the plasmon energy reveals a tendency of graphitization associated to the boron doping. Pure boron particles have been characterized by HRTEM and reveal that those particles are amorphous or crystallized. The nanostructures of the boron-doped ns-DLC and the boron-doped fs-DLC are thus compared. In particular, the incorporation of boron in the DLC matrix is highlighted, depending on the laser used for deposition. Electrical measurements show that some of these films have potentialities to be used in low temperature thermometry, considering their conductivity and temperature coefficient of resistance (TCR) estimated within the temperature range 160-300 K.

  6. Tribological properties and thermal stability of hydrogenated, silicon/nitrogen-coincorporated diamond-like carbon films prepared by plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Nakazawa, Hideki; Okuno, Saori; Magara, Kohei; Nakamura, Kazuki; Miura, Soushi; Enta, Yoshiharu

    2016-12-01

    We have deposited hydrogenated, silicon/nitrogen-incorporated diamond-like carbon (Si-N-DLC) films by plasma-enhanced chemical vapor deposition using hexamethyldisilazane [((CH3)3Si)2NH; HMDS] as the Si and N source, and compared the tribological performance and thermal stability of the Si-N-DLC films with those of hydrogenated, Si-incorporated DLC (Si-DLC) films prepared using dimethylsilane [SiH2(CH3)2] as the Si source. The deposited films were annealed at 723-873 K in air atmosphere. The friction coefficients of hydrogenated DLC films after annealing significantly increased at the initial stages of friction tests. On the other hand, the friction coefficients of the Si-N-DLC films deposited at an HMDS flow ratio [HMDS/(HMDS+CH4)] of 2.27% remained low after the annealing even at 873 K. We found that the wear rate of the Si-N-DLC film deposited at 2.27% and -1000 V remained almost unchanged after the annealing at 873 K, whereas that of the Si-DLC film with a similar Si fraction deposited at -1000 V significantly increased after the annealing at 773 K.

  7. The Effect of Bias Voltage and Gas Pressure on the Structure, Adhesion and Wear Behavior of Diamond Like Carbon (DLC Coatings With Si Interlayers

    Directory of Open Access Journals (Sweden)

    Liam Ward

    2014-04-01

    Full Text Available In this study diamond like carbon (DLC coatings with Si interlayers were deposited on 316L stainless steel with varying gas pressure and substrate bias voltage using plasma enhanced chemical vapor deposition (PECVD technology. Coating and interlayer thickness values were determined using X-ray photoelectron spectroscopy (XPS which also revealed the presence of a gradient layer at the coating substrate interface. Coatings were evaluated in terms of the hardness, elastic modulus, wear behavior and adhesion. Deposition rate generally increased with increasing bias voltage and increasing gas pressure. At low working gas pressures, hardness and modulus of elasticity increased with increasing bias voltage. Reduced hardness and modulus of elasticity were observed at higher gas pressures. Increased adhesion was generally observed at lower bias voltages and higher gas pressures. All DLC coatings significantly improved the overall wear resistance of the base material. Lower wear rates were observed for coatings deposited with lower bias voltages. For coatings that showed wear tracks considerably deeper than the coating thickness but without spallation, the wear behavior was largely attributed to deformation of both the coating and substrate with some cracks at the wear track edges. This suggests that coatings deposited under certain conditions can exhibit ultra high flexible properties.

  8. Investigation of the microstructure, mechanical properties and tribological behaviors of Ti-containing diamond-like carbon films fabricated by a hybrid ion beam method

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Wei [Ningbo Key Laboratory of Marine Protection Materials, Division of Surface Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Future Convergence Technology Division, Korea Institute of Science and Technology, Seoul, 130-650 (Korea, Republic of); Ke, Peiling [Ningbo Key Laboratory of Marine Protection Materials, Division of Surface Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Moon, Myoung-Woon; Lee, Kwang-Ryeol [Future Convergence Technology Division, Korea Institute of Science and Technology, Seoul, 130-650 (Korea, Republic of); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Ningbo Key Laboratory of Marine Protection Materials, Division of Surface Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2012-07-31

    Diamond-like carbon (DLC) films with various titanium contents were investigated using a hybrid ion beam system comprising an anode-layer linear ion beam source and a DC magnetron sputtering unit. The film composition and microstructure were characterized carefully by X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy, revealing that the doped Ti atoms had high solubility in the DLC films. The maximum solubility was found to lie between about 7 and 13 at.%. When the Ti content was lower than this solubility, the doped Ti atoms dissolved in the DLC matrix and the films exhibited the typical features of the amorphous DLC structure and displayed low compressive stresses, friction coefficients and wear rates. However, as the doped content exceeded the solubility, Ti atoms bonded with C atoms, resulting in the formation of carbide nano-particles embedded in the DLC matrix. Although the emergence of the carbide nano-particles promoted graphitizing due to a catalysis effect, the film hardness was enhanced to a great extent. On the other hand, the hard carbides particles caused abrasive wear behavior, inducing a high friction coefficient and wear rate. - Highlights: Black-Right-Pointing-Pointer Ti doped DLC films (Ti {approx} 24 at.% )were deposited by a hybrid ion beam system. Black-Right-Pointing-Pointer Solubility of the Ti atoms in the DLC films was found around 7 {approx} 13 at .%. Black-Right-Pointing-Pointer Microstructure evolution from DLC to nanocomposite played key role in film behaviors.

  9. Surface treatment of diamond-like carbon films by reactive Ar/CF{sub 4} high-power pulsed magnetron sputtering plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Takashi, E-mail: t-kimura@nitech.ac.jp [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Nishimura, Ryotaro [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Azuma, Kingo [Department of Electrical Engineering and Computer Sciences, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Nakao, Setsuo; Sonoda, Tsutomu; Kusumori, Takeshi; Ozaki, Kimihiro [National Institute of Advanced Industrial Science and Technology (AIST) - Chubu, 2266-98 Anagahora, Moriyama, Nagoya 463-8560 (Japan)

    2015-12-15

    Surface modification of diamond-like carbon films deposited by a high-power pulsed magnetron sputtering (HPPMS) of Ar was carried out by a HPPMS of Ar/CF{sub 4} mixture, changing a CF{sub 4} fraction from 2.5% to 20%. The hardness of the modified films markedly decreased from about 13 to about 3.5 GPa with increasing CF{sub 4} fraction, whereas the water contact angle of the modified films increased from 68° to 109° owing to the increase in the CF{sub x} content on the film surface. C 1s spectra in X-ray photoelectron spectroscopy indicated that a graphitic structure of modified films was formed at CF{sub 4} fractions less than 5%, above which the modified films possessed a polymer-like structure. Influence of treatment time on the properties of the modified films was also investigated in the range of treatment time from 5 to 30 min. The properties of the modified films did not depend on the treatment time in the range of treatment time longer than 10 min, whereas the water contact angle was not sensitive to the treatment time at any treatment time.

  10. Patterning of diamond like carbon films for sensor applications using silicon containing thermoplastic resist (SiPol) as a hard mask

    Science.gov (United States)

    Virganavičius, D.; Cadarso, V. J.; Kirchner, R.; Stankevičius, L.; Tamulevičius, T.; Tamulevičius, S.; Schift, H.

    2016-11-01

    Patterning of diamond-like carbon (DLC) and DLC:metal nanocomposites is of interest for an increasing number of applications. We demonstrate a nanoimprint lithography process based on silicon containing thermoplastic resist combined with plasma etching for straightforward patterning of such films. A variety of different structures with few hundred nanometer feature size and moderate aspect ratios were successfully realized. The quality of produced patterns was directly investigated by the means of optical and scanning electron microscopy (SEM). Such structures were further assessed by employing them in the development of gratings for guided mode resonance (GMR) effect. Optical characterization of such leaky waveguide was compared with numerical simulations based on rigorous coupled wave analysis method with good agreement. The use of such structures as refractive index variation sensors is demonstrated with sensitivity up to 319 nm/RIU, achieving an improvement close to 450% in sensitivity compared to previously reported similar sensors. This pronounced GMR signal fully validates the employed DLC material, the technology to pattern it and the possibility to develop DLC based gratings as corrosion and wear resistant refractometry sensors that are able to operate under harsh conditions providing great value and versatility.

  11. Preparation of Ag-containing diamond-like carbon films on the interior surface of tubes by a combined method of plasma source ion implantation and DC sputtering

    Science.gov (United States)

    Hatada, R.; Flege, S.; Bobrich, A.; Ensinger, W.; Dietz, C.; Baba, K.; Sawase, T.; Watamoto, T.; Matsutani, T.

    2014-08-01

    Adhesive diamond-like carbon (DLC) films can be prepared by plasma source ion implantation (PSII), which is also suitable for the treatment of the inner surface of a tube. Incorporation of a metal into the DLC film provides a possibility to change the characteristics of the DLC film. One source for the metal is DC sputtering. In this study PSII and DC sputtering were combined to prepare DLC films containing low concentrations of Ag on the interior surfaces of stainless steel tubes. A DLC film was deposited using a C2H4 plasma with the help of an auxiliary electrode inside of the tube. This electrode was then used as a target for the DC sputtering. A mixture of the gases Ar and C2H4 was used to sputter the silver. By changing the gas flow ratios and process time, the resulting Ag content of the films could be varied. Sample characterizations were performed by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, atomic force microscopy and Raman spectroscopy. Additionally, a ball-on-disk test was performed to investigate the tribological properties of the films. The antibacterial activity was determined using Staphylococcus aureus bacteria.

  12. Prospective multi-center registry to evaluate efficacy and safety of the newly developed diamond-like carbon-coated cobalt-chromium coronary stent system.

    Science.gov (United States)

    Ando, Kenji; Ishii, Katsuhisa; Tada, Eiji; Kataoka, Kazuaki; Hirohata, Atsushi; Goto, Kenji; Kobayashi, Katsuyuki; Tsutsui, Hiroshi; Nakahama, Makoto; Nakashima, Hitoshi; Uchikawa, Shinichiroh; Kanda, Junji; Yasuda, Satoshi; Yajima, Junji; Kitabayashi, Hiroshi; Sakurai, Shumpei; Nakanishi, Keita; Inoue, Naoto; Noike, Hirofumi; Hasebe, Terumitsu; Sato, Tetsuya; Yamasaki, Masao; Kimura, Takeshi

    2016-07-22

    The purpose of this multi-center, non-randomized, and open-label clinical trial was to determine the non-inferiority of diamond-like carbon (DLC)-coated cobalt-chromium coronary stent, the MOMO DLC coronary stent, relative to commercially available bare-metal stents (MULTI-LINK VISION(®)). Nineteen centers in Japan participated. The study cohort consisted of 99 patients from 19 Japanese centers with single or double native coronary vessel disease with de novo and restenosis lesions who met the study eligibility criteria. This cohort formed the safety analysis set. The efficacy analysis set consisted of 98 patients (one case was excluded for violating the eligibility criteria). The primary endpoint was target vessel failure (TVF) rate at 9 months after stent placement. Of the 98 efficacy analysis set patients, TVF occurred in 11 patients (11.2 %, 95 % confidence interval 5.7-19.2 %) at 9 months after the index stent implantation. The upper 95 % confidence interval for TVF of the study stent was lower than that previously reported for the commercially available MULTI-LINK VISION(®) (19.6 %), demonstrating non-inferiority of the study stent to MULTI-LINK VISION(®). All the TVF cases were related to target vascular revascularization. None of the cases developed in-stent thrombosis or myocardial infarction. The average in-stent late loss and binary restenosis rate at the 6-month follow-up angiography were 0.69 mm and 10.5 %, respectively, which are lower than the reported values for commercially available bare-metal stents. In conclusion, the current pivotal clinical study evaluating the new MOMO DLC-coated coronary stent suggested its low rates of TVF and angiographic binary restenosis, and small in-stent late loss, although the data were considered preliminary considering the small sample size and single arm study design.

  13. Diamond-like carbon (DLC) thin film bioelectrodes: Effect of thermal post-treatments and the use of Ti adhesion layer

    Energy Technology Data Exchange (ETDEWEB)

    Laurila, Tomi, E-mail: tomi.laurila@aalto.fi [Department of Electronics, School of Electrical Engineering, Aalto University, Espoo (Finland); Rautiainen, Antti [Department of Electronics, School of Electrical Engineering, Aalto University, Espoo (Finland); Sintonen, Sakari [Department of Micro- and Nanotechnology, School of Electrical Engineering, Aalto University, Espoo (Finland); Jiang, Hua [Department of Applied Physics, School of Science, Aalto University, Espoo (Finland); Kaivosoja, Emilia [Department of Electronics, School of Electrical Engineering, Aalto University, Espoo (Finland); Helsinki University Central Hospital, Institute of Clinical Medicine (Finland); Koskinen, Jari [Department of Materials Science, School of Chemical Technology, Aalto University, Espoo (Finland)

    2014-01-01

    The effect of thermal post-treatments and the use of Ti adhesion layer on the performance of thin film diamond like carbon bioelectrodes (DLC) have been investigated in this work. The following results were obtained: (i) The microstructure of the DLC layer after the deposition was amorphous and thermal annealing had no marked effect on the structure, (ii) formation of oxygen containing SiO{sub x} and Ti[O,C] layers were detected at the Si/Ti and Ti/DLC interfaces with the help of transmission electron microscope (TEM), (iii) thermal post-treatments increased the polar fraction of the surface energy, (iv) cyclic voltammetry (CV) measurements showed that the DLC films had wide water windows and were stable in contact with dilute sulphuric acid and phosphate buffered saline (PBS) solutions, (v) use of Ti interlayer between Pt(Ir) microwire and DLC layer was crucial for the electrodes to survive the electrochemical measurements without the loss of adhesion of the DLC layer, (vi) DLC electrodes with small exposed Pt areas were an order of magnitude more sensitive towards dopamine than Pt electrodes and (vii) thermal post-treatments did not markedly change the electrochemical behavior of the electrodes despite the significant increase in the polar nature of the surfaces. It can be concluded that thin DLC bioelectrodes are stable under physiological conditions and can detect dopamine in micro molar range, but their sensitivity must be further improved. - Highlights: • Crucial effect of Ti adhesion layer on the performance of DLC bioelectrodes is shown. • Amorphous SiOx and Ti[C,O]x are shown to form at the Si/Ti and Ti/DLC interfaces. • Thermal annealing can be used to oxidize the surface of DLC films. • However, there is no change in the sensitivity of the electrodes towards dopamine. • DLC/Pt composite electrodes have improved sensitivity.

  14. The change of bacterial adhesion during deposition nitrogen-diamond like carbon coating on pure titanium%渗氮类金刚石薄膜应用于纯钛后的细菌黏附变化

    Institute of Scientific and Technical Information of China (English)

    尹路; 肖云

    2011-01-01

    Objective The aim of this study was to observe the change of bacterial adhesion on pure titanium coated with nitrogen-diamond like carbon (N-DLC) films and to guide the clinical application. Methods N-DLC was deposited on titanium using ion plating machine, TiN film, anodic oxide film and non-deposition were used as control, then made specimens adhering on the surface of resin denture base for 6 months. The adhesion of Saccharomyces albicans on the titanium surface was observed using scanning electron microscope, and the roughness was tested by roughness detector. Results The number of Saccharomyces albicans adhering on diamond-like carbon film was significantly less than on the other groups (P<0.05), and the growth of bacterial cell was inhibited and in a poor state. The largest number of adhesion and cell strains grew well on anodic oxide film group and non-deposition control group. The change of surface roughness of N-DLC film was less than other group (P<0.05). Conclusion Pure titanium coated with N-DLC film reduced the adhesion of Saccharomyces albicans after clinical application, thereby reduced the risk of denture stomatitis.%目的 观察纯钛试件应用等离子镀膜法镀制纳米渗氮类金刚石(N-DLC)薄膜后的细菌黏附变化,以期对临床应用有所指导.方法 采用等离子镀膜机,在纯钛试件表面沉积N -DLC薄膜、TiN薄膜、阳极氧化膜以及空白对照,然后将其黏附于树脂基托表面,实际使用6个月后,扫描电子显微镜观察白色假丝酵母菌黏附试件情况;粗糙度检测仪对比检测试件粗糙度变化.结果 白色假丝酵母菌在N-DLC膜表面附着数量比其他组试件明显少(P<0.05),且菌体生长不良,处于抑制状态;阳极氧化膜和空白对照试件表面黏附菌量最多,且菌体生长旺盛.N-DLC膜表面粗糙度在戴用前后变化最小(P<0.05).结论 纯钛表面镀制N-DLC膜在口腔实际应用过程中可以明显降低白色假丝酵母菌的黏

  15. Influence of zinc dialkyldithiophosphate tribofilm formation on the tribological performance of self-mated diamond-like carbon contacts under boundary lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah Tasdemir, H., E-mail: habdullah46@gmail.com [Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Tokoroyama, Takayuki; Kousaka, Hiroyuki; Umehara, Noritsugu [Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Mabuchi, Yutaka [Nissan Motor Co. (Japan)

    2014-07-01

    Diamond-like carbon (DLC) coatings offer excellent mechanical and tribological properties that make them suitable protective coatings for various industrial applications. In recent years, several engine and power train components in passenger cars, which work under boundary lubricated conditions, have been coated with DLC coatings. Since conventional lubricants and lubricant additives are formulated for metal surfaces, there are still controversial questions concerning chemical reactivity between DLC surfaces and common lubricant additives owing to the chemical inertness of DLC coatings. In this work, we present the influence of zinc dialkyldithiophosphate (ZnDTP) anti-wear additives on the tribological performance of various self-mated DLC coatings under boundary lubrication conditions. The effects of hydrogen, doping elements, and surface morphology on the reactivity of DLC coatings to form a ZnDTP-derived tribofilm were investigated by atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The results confirmed that ZnDTP-derived pad-like or patchy tribofilm forms on the surfaces depending on the DLC coating. It is seen that hydrogen content and doping elements increase pad-like tribofilm formation. Doped DLC coatings are found to give better wear resistance than non-doped DLC coatings. Furthermore, the addition of ZnDTP additives to the base oil significantly improves the wear resistance of hydrogenated DLC, silicon-doped hydrogenated DLC, and chromium-doped hydrogenated DLC. Hydrogen-free tetrahedral amorphous DLC coatings provide the lowest friction coefficient both in PAO (poly-alpha-olefin) and PAO + ZnDTP oils. - Highlights: • Zinc dialkyldithiophosphate (DTP) tribofilm formation on various DLC surfaces was evidenced. • Pad-like tribofilm was found on a-C:H, a-C, Si-DLC and Cr-DLC. • Pad-like tribofilm on DLC surfaces greatly increased the wear resistance. • Hydrogenated and doped DLC coatings are

  16. The Role of Ambient Gas and Pressure on the Structuring of Hard Diamond-Like Carbon Films Synthesized by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Andrei C. Popescu

    2015-06-01

    Full Text Available Hard carbon thin films were synthesized on Si (100 and quartz substrates by the Pulsed Laser Deposition (PLD technique in vacuum or methane ambient to study their suitability for applications requiring high mechanical resistance. The deposited films’ surface morphology was investigated by scanning electron microscopy, crystalline status by X-ray diffraction, packing and density by X-ray reflectivity, chemical bonding by Raman and X-ray photoelectron spectroscopy, adherence by “pull-out” measurements and mechanical properties by nanoindentation tests. Films synthesized in vacuum were a-C DLC type, while films synthesized in methane were categorized as a-C:H. The majority of PLD films consisted of two layers: one low density layer towards the surface and a higher density layer in contact with the substrate. The deposition gas pressure played a crucial role on films thickness, component layers thickness ratio, structure and mechanical properties. The films were smooth, amorphous and composed of a mixture of sp3-sp2 carbon, with sp3 content ranging between 50% and 90%. The thickness and density of the two constituent layers of a film directly determined its mechanical properties.

  17. 含硅类金刚石膜硬度压痕测试的有限元模拟%Finite Element Simulation of Indentation Testing for Hardness of Si-Containing Diamond-Like Carbon Film

    Institute of Scientific and Technical Information of China (English)

    刘璨; 兰惠清

    2012-01-01

    使用Abaqus有限元软件通过加载荷与加载位移两种方法对含硅类金刚石膜进行了压痕测试模拟,得到了不同硅含量类金刚石膜的硬度曲线。结果表明:两种方法的模拟结果较吻合,其中加载位移的方法较稳定,速度较快,含硅类金刚石膜的硬度随着硅含量的增加而减小;模拟结果得到了相关试验的验证。%The simulation for indentation testing of Si-containing diamond-like carbon(Si-DLC) film was carried out by infinite element simulation software Abaqus using loading and displacement methods,and the hardness of the diamond-like carbon film with different silicon contents was obtained.The results show that the two methods fit fairly well,the displacement method was fairly stable and its speed also was fairly quick,and the hardness of Si-DLC film decreased with the increase of the silicon content.The finite element simulation was in agreement with correlative experiments.

  18. Bacterial adherence on fluorinated carbon based coatings deposited on polyethylene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Terriza, A; Del Prado, G; Perez, A Ortiz; Martinez, M J; Puertolas, J A; Manso, D Molina; Gonzalez-Elipe, A R; Yubero, F; Barrena, E Gomez; Esteban, J, E-mail: antonia.terriza@icmse.csic.es

    2010-11-01

    Development of intrinsically antibacterial surfaces is of key importance in the context of prostheses used in orthopaedic surgery. In this work we present a thorough study of several plasma based coatings that may be used with this functionality: diamond like carbon (DLC), fluorine doped DLC (F-DLC) and a high fluorine content carbon-fluor polymer (CF{sub X}). The study correlates the surface chemistry and hydrophobicity of the coating surfaces with their antibacterial performance. The coatings were deposited by RF-plasma assisted deposition at room temperature on ultra high molecular weight polyethylene (UHMWPE) samples. Fluorine content and relative amount of C-C and C-F bond types was monitored by X-ray photoelectron spectroscopy and hydrophobicity by water contact angle measurements. Adherence of Staphylococcus aureus and Staphylococcus epidermidis to non-coated and coated UHMWPE samples was evaluated. Comparisons of the adherence performance were evaluated using a paired t test (two materials) and a Kruskall Wallis test (all the materials). S. aureus was statistically significant (p< 0.001) less adherent to DLC and F-DLC surfaces than S. epidermidis. Both bacteria showed reduction of adherence on DLC/UHMWPE. For S. aureus, reduction of bacterial adherence on F-DLC/UHMWPE was statistically significant respect to all other materials.

  19. Regression Analysis of the Effect of Bias Voltage on Nano- and Macrotribological Properties of Diamond-Like Carbon Films Deposited by a Filtered Cathodic Vacuum Arc Ion-Plating Method

    Directory of Open Access Journals (Sweden)

    Shojiro Miyake

    2014-01-01

    Full Text Available Diamond-like carbon (DLC films are deposited by bend filtered cathodic vacuum arc (FCVA technique with DC and pulsed bias voltage. The effects of varying bias voltage on nanoindentation and nanowear properties were evaluated by atomic force microscopy. DLC films deposited with DC bias voltage of −50 V exhibited the greatest hardness at approximately 50 GPa, a low modulus of dissipation, low elastic modulus to nanoindentation hardness ratio, and high nanowear resistance. Nanoindentation hardness was positively correlated with the Raman peak ratio Id/Ig, whereas wear depth was negatively correlated with this ratio. These nanotribological properties highly depend on the films’ nanostructures. The tribological properties of the FCVA-DLC films were also investigated using a ball-on-disk test. The average friction coefficient of DLC films deposited with DC bias voltage was lower than that of DLC films deposited with pulse bias voltage. The friction coefficient calculated from the ball-on-disk test was correlated with the nanoindentation hardness in dry conditions. However, under boundary lubrication conditions, the friction coefficient and specific wear rate had little correlation with nanoindentation hardness, and wear behavior seemed to be influenced by other factors such as adhesion strength between the film and substrate.

  20. P掺杂类金刚石薄膜的制备及生物学行为研究%Phosphorus doped diamond-like carbon films fabricated by plasma immersion ion implantation - deposition and study of biological behavior

    Institute of Scientific and Technical Information of China (English)

    王进; 杨萍; 陈俊英; 冷永祥; 万国江; 孙鸿; 赵安莎; 黄楠

    2004-01-01

    应用等离子体浸没离子注入与沉积方法合成了磷掺杂的类金刚石(diamond like carbon,DLC)薄膜.结构分析表明磷以微米级岛状结构分散于DLC薄膜表层,P的掺杂增加了DLC薄膜的无序性,俄歇能谱表明岛型区域是由P、C、O三种元素形成的化合物.掺杂表面表现出强烈的亲水性(水接触角为16.9°),体外血小板粘附实验结果显示,P掺杂DLC薄膜表面粘附的血小板少且变形小,表现出的血液相容性优于热解碳和未改性DLC.

  1. Depth profiling of fluorine-doped diamond-like carbon (F-DLC) film: Localized fluorine in the top-most thin layer can enhance the non-thrombogenic properties of F-DLC

    Energy Technology Data Exchange (ETDEWEB)

    Hasebe, Terumitsu [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Department of Radiology, Tachikawa Hospital, 4-2-22, Nishiki-cho, Tachikawa, Tokyo 190-8531 (Japan)], E-mail: teru_hasebe@hotmail.com; Nagashima, So [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Kamijo, Aki [Department of Transfusion Medicine, the University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Yoshimura, Taichi; Ishimaru, Tetsuya; Yoshimoto, Yukihiro; Yohena, Satoshi; Kodama, Hideyuki; Hotta, Atsushi [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Takahashi, Koki [Department of Transfusion Medicine, the University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Suzuki, Tetsuya [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan)

    2007-12-03

    Fluorine-doped diamond-like carbon (F-DLC) has recently drawn a great deal of attention as a more non-thrombogenic coating than conventional DLC for blood-contacting medical devices. We conducted quantitative depth profiling of F-DLC film by X-ray photoelectron spectroscopy (XPS) in order to elucidate the effects of fluorine and fluorine distribution in F-DLC film in connection with the prevention of surface blood adhesion. F-DLC films were prepared on silicon substrates using the radio frequency plasma enhanced chemical vapor deposition method, and the thickness of films was {approx} 50 nm. 50-nm-thick F-DLC film samples were etched at 10-nm thickness intervals using argon plasma, and each surface was examined by XPS. Thereafter, each etched film layer was incubated with platelet-rich plasma isolated from human whole blood, and the platelet-covered area per unit area was evaluated for each surface. XPS spectra showed the localization of doped fluorine in the top-most thin layer of the film. Platelet-covered areas represented progressively larger portions of the surfaces of deeper etched layers, corresponding to the decreasing fluorine content in such sample surfaces. These results indicate that the localized fluorine in the top-most thin layer is one of the key factors in the promotion of the non-thrombogenicity of F-DLC film.

  2. Diamond and diamond-like films for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J.M.

    1993-01-01

    This section is a compilation of transparency templates which describe the goals of the Office of Transportation Materials (OTM) Tribology Program. The positions of personnel on the OTM are listed. The role and mission of the OTM is reviewed. The purpose of the Tribology Program is stated to be `to obtain industry input on program(s) in tribology/advanced lubricants areas of interest`. The objective addressed here is to identify opportunities for cost effective application of diamond and diamond-like carbon in transportation systems.

  3. Microstructure and property of diamond-like carbon films with Al and Cr co-doping deposited using a hybrid beams system

    Science.gov (United States)

    Dai, Wei; Liu, Jingmao; Geng, Dongsen; Guo, Peng; Zheng, Jun; Wang, Qimin

    2016-12-01

    DLC films with weak carbide former Al and carbide former Cr co-doping (Al:Cr-DLC) were deposited by a hybrid beams system comprising an anode-layer linear ion beam source (LIS) and high power impulse magnetron sputtering using a gas mixture of C2H2 and Ar as the precursor. The doped Al and Cr contents were controlled via adjusting the C2H2 fraction in the gas mixture. The composition, microstructure, compressive stress, mechanical properties and tribological behaviors of the Al:Cr-DLC films were researched carefully using X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, stress-tester, nanoindentation and ball-on-plate tribometer as function of the C2H2 fraction. The results show that the Al and Cr contents in the films increased continuously as the C2H2 fraction decreased. The doped Cr atoms preferred to bond with the carbon while the Al atoms mainly existed in metallic state. Structure modulation with alternate multilayer consisted of Al-poor DLC layer and Al-rich DLC layer was found in the films. Those periodic Al-rich DLC layers can effectively release the residual stress of the films. On the other hand, the formation of the carbide component due to Cr incorporation can help to increase the film hardness. Accordingly, the residual stress of the DLC films can be reduced without sacrificing the film hardness though co-doping Al and Cr atoms. Furthermore, it was found that the periodic Al-rich layer can greatly improve the elastic resilience of the DLC films and thus decreases the film friction coefficient and wear rate significantly. However, the existence of the carbide component would cause abrasive wear and thus deteriorate the wear performance of the films.

  4. Electron Injection Enhancement by Diamond-Like Carbon Film in Polymer Electroluminescence Devices%聚合物电致发光器件中用类金刚石碳膜增强电子注入

    Institute of Scientific and Technical Information of China (English)

    李宏建; 闫玲玲; 黄伯云; 易丹青; 胡锦; 何英旋; 彭景翠

    2006-01-01

    A diamond-like carbon (DLC) film is deposited as an electron injection layer between the polymer light-emitting layer (MEH-PPV) and aluminum (Al) cathode electrode in polymer electroluminescence devices (PLEDs) using a radio frequency plasma deposition system. The source material of the DLC is n-butylamine. The devices consist of indium tin oxide (ITO)/MEH-PPV/DLC/Al. Electron injection properties are investigated through I-V characteristics, and the mechanism of electron injection enhancement due to a thin DLC layer has been studied. It is found that: (1) a DLC layer thinner than 1. 0nm leads to a higher turn-on voltage and decreased electroluminescent (EL) efficiency; (2) a 5.0nm DLC layer significantly enhances the electron injection and re sults in the lowest turn-on voltage and the highest EL efficiency; (3) DLC layer that exceeds 5.0nm results in poor device performance; and(4) EL emission can hardly be detected when the layer exceeds 10.0nm. The properties ofITO/MEH-PPV/DLC/Al and ITO/MEH-PPV/LiF/Al are investigated comparatively.%用正丁胺作碳源,采用射频辉光等离子系统制备类金刚石碳膜(DLC),沉积在聚合物发光器件中的发光层(MEH-PPV)和铝(Al)阴极间作电子注入层.制备了结构为ITO/MEH-PPV/DLC/Al的不同DLC厚度的器件,测量了器件的I-V特性、亮度及效率,研究了DLC层对器件电子注入性能影响的机制.结果表明:当DLC厚度小于1.0nm时,其器件有较ITO/MEH-PPV/Al高的启动电压和低的发光效率;当DLC厚度在1.0~5.0nm之间时,器件的性能随着DLC厚度增加而变好;当DLC厚度为5.0nm时,器件具有最低的启动电压与最高的发光效率;当DLC厚度继续增加时,器件的性能随着DLC厚度增加而变差.并对ITO/MEH-PPV/DLC/Al和ITO/MEH-PPV/LiF/Al的器件性能进行了比较研究.

  5. Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Mobarak, H.M., E-mail: mobarak.ho31@yahoo.com; Masjuki, H.H.; Mohamad, E. Niza, E-mail: edzrol@um.edu.my; Kalam, M.A.; Rashedul, H.K.; Rashed, M.M.; Habibullah, M.

    2014-10-30

    Highlights: • We tested a-C:H and ta-C DLC coatings as a function of temperature. • Jatropha oil contains large amounts of polar components that enhanced the lubricity of coatings. • CoF decreases with increasing temperature for both contacts. • Wear rate increases with increasing temperature in a-C:H and decreases in ta-C DLC. • At high temperature, ta-C coatings confer more protection than a-C:H coatings. - Abstract: The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC.

  6. Diamond-like Carbon Film and Its Application on Articular Surface of Artificial Joint for Increasing Wear Resistance%类金刚石薄膜在人工关节摩擦配副表面改性的应用

    Institute of Scientific and Technical Information of China (English)

    邓乔元; 张腾飞; 武冰洁; 李仕莎; 冷永祥; 黄楠

    2016-01-01

    关节置换术是目前治疗关节疾病最直接、有效的手段,随着国民经济的增长,人工关节在我国的需求量不断增加。介绍了常见人工关节的类型及特点,以及目前用于提高人工关节摩擦副表面耐磨损性及耐腐蚀性的方法,通过比较发现,类金刚石(DLC)薄膜在提高人工关节耐磨损、耐腐蚀性能方面具有更好的应用前景。阐述了DLC薄膜结构、性能及其制备方法,并结合目前DLC薄膜在人工关节摩擦配副表面改性中应用所面临的主要问题,介绍了目前用于降低DLC薄膜内应力、增加DLC薄膜/基体结合力的方法。最后,针对 DLC 薄膜应用于人工关节摩擦配副表面改性中存在的缝隙腐蚀及结合失效问题,并结合人工关节体内服役环境特点,提出了利用金属离子催化人工关节摩擦配副表面吸附蛋白的变性、分解,形成致密生物薄膜,对DLC薄膜的磨痕和缺陷进行修复的思想,展望了新型DLC薄膜在人工关节表面改性中的应用前景。%Arthroplasty is the most effective method for the treatment of joint disease in clinical practice, and there are in-creasing needs for artificial joints with the development of national economy. There are three types of artificial joints in clinical practice. Lots of methods have been used to enhance the wear and corrosion resistance of artificial joints. Diamond-like carbon (DLC) film has low friction coefficient, high wear resistance and good biocompatibility, which has been used to improve the wear and corrosion resistance of artificial joints. But the clinical use of DLC coated artificial joint is unsatisfying. This paper discussed the reasons for DLC failure in vivo. Metal doping DLC film or multilayer DLC film could lower the internal stress, improve the adhesion and postpone the DLC film failure. Concerning the service environment of artificial joints, the crevice corrosion and adhesion of DLC film

  7. The effects of the diamond-like carbon film on the abrasive resistance of dental bur%类金刚石膜在牙科车针表面的初步应用

    Institute of Scientific and Technical Information of China (English)

    李雅瑾; 韩建民; 张仁国; 葛春玲; 王兵

    2011-01-01

    Objective; To study the effect of the diamond-like carbon film ( DLC) on the abrasive resistance of dental bur. Methods; Unused new diamond burs. Tungsten steel resin grinding heads and low-speed carbon steel ball burs were divided into two groups respectively, those with DLC costing were used in test group, those without coating were used as the controls. For the diamond bur, an experienced dentist used the coating and non-coating diamond burs respectively to grind the extracted tooth under the standard of all-crown reduction. One bur was used to grind five teeth, the effects of the two groups were judged by the dentist subjective feeling. For the Tungsten steel resin grinding head, the time of breaking through the resin block under the same rotation speed and same load were compared for the coating and non-coating heads. For the carbon steel ball bur, the edge of the ball burs was examined under microscope with the magnification of 75 times after the bur prepared type I cavity in three extracted teeth. Results: The coating diamond burs were belter than the non-coating judged by the dentist subjective feeling. The time of breaking through the resin block of the Tungsten steel resin grinding head in coating group was less than that in non-coating group, The wear of low-speed ball bur in coating group was slighter than that in non-coating group. Conclusion: DLC can increase the cutting efficiency, decrease the wear, and extend the working life of the bur, especially for the Tungsten steel grinding head and low-speed carbon steel ball bur.%目的:通过类金刚石镀膜(DLC)的方法提高牙科车针的耐磨性.方法:选择临床常用3种类型新车针,每种车针选择同种型号若干支,一组非镀膜作为对照组,一组镀膜作为试验组.对于金刚砂车针:由1名临床经验丰富的医生,使用镀膜与未镀膜车针,按照全冠牙体预备要求磨除离体牙(同一名正畸患者拔除的同名牙),同一根车针磨除5颗离体牙,记

  8. The effect of diamond-like carbon coating on LiNi0.8Co0.15Al0.05O2 particles for all solid-state lithium-ion batteries based on Li2S-P2S5 glass-ceramics

    Science.gov (United States)

    Visbal, Heidy; Aihara, Yuichi; Ito, Seitaro; Watanabe, Taku; Park, Youngsin; Doo, Seokgwang

    2016-05-01

    There have been several reports on improvements of the performance of all solid-state battery using lithium metal oxide coatings on the cathode active material. However, the mechanism of the performance improvement remains unclear. To better understand the effect of the surface coating, we studied the impact of diamond-like carbon (DLC) coating on LiNi0.8Co0.15Al0.05O2 (NCA) by chemical vapor deposition (CVD). The DLC coated NCA showed good cycle ability and rate performance. This result is further supported by reduction of the interfacial resistance of the cathode and electrolyte observed in impedance spectroscopy. The DLC layer was analyzed by transmission electron microscopy electron energy loss spectroscopy (TEM-EELS). After 100 cycles the sample was analyzed by X-ray photo spectroscopy (XPS), and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). These analyses showed that the thickness of the coating layer was around 4 nm on average, acting to hinder the side reactions between the cathode particle and the solid electrolyte. The results of this study will provide useful insights for understanding the nature of the buffer layer for the cathode materials.

  9. Kinetics of diamond-like film growth using filament-assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gorsuch, G.; Jin, Y.; Ingle, N.K.; Mountziaris, T.J.; Yu, W.Y.; Petrou, A. [State Univ. of New York, Buffalo, NY (United States)

    1995-08-01

    A detailed kinetic model of diamond-like film growth from methane diluted in hydrogen using low-pressure, filament-assisted chemical vapor deposition (FACVD) has been developed. The model includes both gas-phase and surface reactions. The surface kinetics include adsorption of CH{sub 3}{center_dot} and H{center_dot}, abstraction reactions by gas phase radicals, desorption, and two pathways for diamond (sp{sup 3}) and graphitic carbon (sp{sup 2}) growth. It is postulated that adsorbed CH{sub 2}{center_dot} species are the major film precursors. The proposed kinetic model was incorporated into a transport model describing flow, heat and mass transfer in stagnation flow FACVD reactors. Diamond-like films were deposited on preceded Si substrates in such a reactor as a pressure of 26 Torr, inlet gas composition ranging from 0.5% to 1.5% methane in hydrogen and substrate temperatures ranging from 600 to 950 C. The best films were obtained at low methane concentrations and substrate temperature of 700 C. The films were characterized using Scanning Electron Microscopy (SEM) and Raman spectroscopy. Observations from their experiments and growth rates, compositions and stable species distributions in the gas phase. It is the first complete model of FACVD that includes gas-phase and surface kinetics coupled with transport phenomena.

  10. 等离子体刻蚀并沉积类金刚石膜制备超疏水木材%Fabrication of superhydrophobic wood by plasma etching and deposition of diamond-like carbon films

    Institute of Scientific and Technical Information of China (English)

    解林坤; 王洪艳; 代沁伶; 杜官本

    2016-01-01

    This study presents the fabrication of superhydrophobic wood of Acer saccharum Marsh. using a combination of O2 plasma etching and plasma deposition of a thin hydrophilic diamond⁃like carbon ( DLC) coating in order to impart wood with controlled wetting properties. The effect of O2 plasma etching on roughness was investigated using the scanning electron microscopy ( SEM) and laser scanning confocal microscope ( LSCM) profilometry. The wetting behavior was de⁃termined by the static water contact angle measurement. Furthermore, the morphology, thickness of deposited films, ele⁃ment composition and their chemical bonding information of the wood surfaces before and after the treatment were also examined with SEM, the ellipsometer and X-ray photoelectron spectroscopy ( XPS) . The results showed that the wood surfaces of the average roughness, root mean square roughness and peak⁃to⁃valley roughness increased with longer etching time within 30 min. However, the wood surface roughness decreased slightly after the prolonged etching time of 45 min. The static water contact angles of the wood surface increased firstly and then decreased with the increase of etch⁃ing time and attained a maximum value for 157�2° with 30 min etching and after depositing DLC film for 1�5 min, but the static water contact angle of the wood surface etched for 45 min and after depositing DLC film for the same time was 152�3° . The static water contact angles decreased gradually with an increase in deposition times if the wood surfaces were subjected to the same time etching. From the data of the deposition thickness, the deposition rate of DLC films was calculated, which was constant (51�7±4�5) nm/min over the deposition times investigated. The content of oxygen ele⁃ment reduced obviously and the diamond⁃like characteristic peaks of sp2-C and sp3-C presented after the wood surfaces deposited with the DLC film coating.%为使木材表面具备疏水性能,采用等离

  11. UV Raman and XPS studies of hydrogenous diamond-like carbon films prepared by PECVD%等离子体增强化学气相沉积法制备含氢类金刚石膜的紫外Raman光谱和X射线光电子能谱研究

    Institute of Scientific and Technical Information of China (English)

    杨发展; 沈丽如; 王世庆; 唐德礼; 金凡亚; 刘海峰

    2013-01-01

    利用脉冲辉光放电的方法,在硅片上采用不同的沉积工艺制备了含氢类金刚石膜层,并采用Raman光谱和X射线光电子能谱(XPS)对膜层进行表征.用Raman光谱仪在波长为325 nm的紫外光源的激励下观察膜层的键结构.紫外Raman光谱对含氢类金刚石膜是非常有用的,它能有效避免可见光Raman光谱测量时的荧光干扰,清晰地得到膜层的D峰和G峰.同时利用XPS分析得到膜层的sp3键含量,并与Raman光谱所得数据进行比较.通过Raman光谱和XPS分析可以发现,在紫外光源的激励下,膜层的G峰峰位向高频移方向移动,G峰峰位、I(D)/I(G),G峰半高宽和sp3键含量之间存在一定的关系.%The hydrogenous diamond-like carbon (DLC) films deposited on Si substrates using pulsed glow discharge method are investigated using Raman spectroscopy and X-ray photoelectron spectroscopy method. The UV Raman spectrum for excitation wavelength is 325 nm. UV Raman is particularly useful for hydrogenous DLC, as it gives clear measurements in the D and G peak spectral region even for highly hydrogenated samples, for which the visible Raman spectra are overshadowed by photoluminescence. The sp3 bonding of hydrogenous DLC film can be effectively studied by X-ray photoelectron spectroscopy method, and the data from the X-ray photo-electron spectroscopy method are compared with Raman results. It is found that G peak shows a shift to ward a higher wave under UV excitation. For the G peak, I(D)/I(G), G-FWHM and sp3, there exists a relationship among them.

  12. Diamond-like nanocomposite coatings for LIGA-fabricated nickel alloy parts.

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Somuri V.; Scharf, Thomas W.

    2005-03-01

    A commercial plasma enhanced chemical vapor deposition (PECVD) technique with planetary substrate rotation was used to apply a thin (200-400 nm thick) conformal diamond-like carbon (DLC) coating (known as a diamond-like nanocomposite (DLN)) on LIGA fabricated Ni-Mn alloy parts. The PECVD technique is known to overcome the drawbacks associated with the line-of-sight nature of physical vapor deposition (PVD) and substrate heating inherent with traditional chemical vapor deposition (CVD). The purpose of the present study is to characterize the coverage, adhesion, and tribological (friction and wear) behavior of DLN coatings applied to planar and sidewall surfaces of small featured LIGA Ni-Mn fabricated parts, e.g. 280 {micro}m thick sidewalls. Friction and wear tests were performed in dry nitrogen, dry air, and air with 50% RH at Hertzian contact pressures ranging from 0.3 to 0.6 GPa. The friction coefficient of bare Ni-Mn alloy was determined to be 0.9. In contrast, low friction coefficients ({approx}0.02 in dry nitrogen and {approx}0.2 in 50% RH air) and minimal amount of wear were exhibited for the DLN coated LIGA Ni-Mn alloy parts and test coupons. This behavior was due to the ability of the coating to transfer to the rubbing counterface providing low interfacial shear at the sliding contact; resultantly, coating one surface was adequate for low friction and wear. In addition, a 30 nm thick titanium bond layer was determined to be necessary for good adhesion of DLN coating to Ni-Mn alloy substrates. Raman spectroscopy and cross-sectional SEM with energy dispersive x-ray analysis revealed that the DLN coatings deposited by the PECVD with planetary substrate rotation covered both the planar and sidewall surfaces of LIGA fabricated parts, as well as narrow holes of 300 {micro}m (0.012 inch) diameter.

  13. 组织工程化类金刚石膜复合材料与人血管内皮细胞的相容性研究%Biocompatibility between tissue-engineering diamond-like carbon film and human vascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    程光存; 严中亚; 罗乐; 方晓东; 沙自明

    2009-01-01

    OBJECTIVE: To verify the biocompatibility between diamond-like carbon (DLC) film and human vascular endothelial cells and to provide evidences for construction of artificial mechanical valve prosthesis. METHODS: Nanophase DLC film was deposited using pulse laser deposition, while vascular endothelial cells derived from human umbilical vein was cultured with nanophase DLC film in vitro. Cell growth and adhesion were observed under inverted microscope, and cell proliferation was measured with MIT method. In addition, levels of nitric oxide (NO) and prostacyclin (PGI2) were measured in the DLC group and blank control group in order to evaluate their activities. RESULTS: Adhesion, proliferation, and growth of vascular endothelial cells derived from human umbilical vein were great on the surface of nanophase DLC film. There were no significant differences in the levels of NO and PGI2 between DLC group and blank control group (P > 0.05), showing that nanophase DLC film had no effect on activity of vascular endothelial cells derived from human umbilical vein. CONCLUSION: Nanophase DLC film has a good biocompatibility, and it can become an ideal material of tissue-engineering artificial mechanical valve prosthesis.%目的:验证纳米相类金刚石薄膜复合材料与人血管内皮细胞相容性,为组织上程化机械瓣膜材料的构建提供依据.方法:利用脉冲激光沉积法在人工心脏机械瓣膜上沉积纳米相类金刚石薄膜,将人脐静脉血管内皮细胞与纳米相类金刚石薄膜复合材料体外复合培养.倒置显微镜及扫描电镜观察细胞在材料表面的生长、附着情况;MTT法检测细胞在材料上增殖情况;同时分别测定人脐静脉血管内皮细胞在类金刚石溥膜材料和空白对照组中一氧化氮及前列环素分泌水平,以评价其活性.结果:人脐静脉血管内皮细胞能在纳米相类金刚石薄膜复合材料上良好地黏附、增殖、生长.人脐静脉血管内皮细胞分泌

  14. Diamond-like Carbon Thin Films Deposited on Ti6Al4V Alloy Surface by Plasma Gun at Atmospheric Pressure%钛合金表面大气压等离子体枪制备类金刚石薄膜

    Institute of Scientific and Technical Information of China (English)

    陈飞; 周海; 张跃飞; 吕反修

    2012-01-01

    在大气下,采用大气压介质阻挡放电(DBD)等离子体枪在低温下<350℃),以甲烷为单体,氩气为工作气体,在Ti6Al4V钛合金表面制备一层类金刚石薄膜(DLC),以期改善钛合金表面摩擦学性能.利用激光拉曼(Raman)光谱和X射线光电子能谱(XPS)分析了所制备DLC薄膜的结构;利用扫描电子显微镜(SEM)观察DLC薄膜的表面形貌;利用划痕仪测量了DLC薄膜与基体的结合力;利用球-盘摩擦磨损实验仪对DLC薄膜的耐磨性能进行了研究.结果表明:在本实验工艺条件下沉积的类金刚石薄膜厚度约为1.0 μm,薄膜均匀且致密,表面粗糙度Ra为13.23 nm.类金刚石薄膜与基体结合力的临界载荷达到31.0N.DLC薄膜具有优良的减摩性,Ti6Al4V表面沉积DLC薄膜后摩擦系数为0.15,较Ti6Al4V基体的摩擦系数0.50明显减小,耐磨性能得到提高.%At atmospheric pressure, diamond-like carbon (DLC) thin films were deposited on the T16A14V alloy surface by a DBD plasma gun at low temperature (<350℃), with CH4 as a precursor and Ar as dilution gas. The structure of the DLC thin film was analyzed by Laser Raman spectroscope and X-ray photoelectron spectroscopy. The surface morphology was observed through scanning electron microscopy. The adhesion between the DLC thin film and the substrate was investigated with the scribe testing. The friction and wear behavior of the DLC thin films under dry sliding against GCrlS steel was evaluated on a ball-on-disc test rig. The results show that it is feasible to prepare a DLC thin film of 1.0 um thickness by a plasma gun. The film is uniform and dense and the surface roughness R. Is about 13.23 nm. The critical load of adhesion force between the DLC thin film and the substrate is 31.0 N. It has been found that the DLC thin film has excellent friction- and wear-resistant behavior. The friction coefficient of the Ti6A14V substrate is about 0.50 under dry sliding against steel, while the DLC thin

  15. Effects of pretreatment and post-annealing on the field emission property of diamond-like carbon grown on a titanium/silicon substrate%利用前后处理技术改进钛/硅基板上的类金刚石场发射特性

    Institute of Scientific and Technical Information of China (English)

    黄柏仁; 叶忠信; 李世鸿; 汪岛军; 陈昆歧

    2008-01-01

    采用微波等离子体化学气相沉积系统存钛/硅基板上沉积类金刚石薄膜,并利用拉曼光谱仪、扫瞄式电子显微镜及原子力显微镜研究了氢等离子体前处理及快速退火后处理对类金刚石薄膜场发射特性之影响.在沉积类金刚石薄膜之前,钛/硅基板使用了两种前处理技术:第一种为研磨金刚石粉末,第二种为研磨金刚石粉末后外加氢等离子体刻蚀处理.成长类金刚石薄膜后进行快速退火处理.发现不论是氢等离子体前处理还是快速退火后处理皆能改善场发射特性,其中经退火后处理的场发射特性比氢等离子体前处理的场发射特性改善更明显.其因之一在于快速退火后处理可在类金刚石薄膜表而形成sp2丛聚,提供了很多的场发射子,也同时增加了表面粗糙度;另一个原因可能是在快速退火后处理期间会使类金刚石薄膜进一步石墨化,因而提供了许多电子在通过类金刚石薄膜时的传输路径.研究结果表明:利用适当的前后处理技术可改进类金刚石薄膜的场发射特性,进而做为冷阴极材料之应用.%Diamond-like carbon (DLC) films were deposited on titanium/silicon substrates with the help of the micro-wave plasma chemical vapor deposition (CVD) method with At, H2, and CH4 as a mixed gas source. Titanium/silicon substrates were polished by diamond powder and etched by hydrogen ( H2 ) plasma, prior to deposition. After deposi-tion, rapid thermal annealing (RTA) was used as a post-treatment. The effects of hydrogen plasma pretreatment and RTA post-treatment on the electron field emission characteristics of the DLC films was examined and correlated by Ra-man scattering, average surface roughness, and surface morphology. It is found that both treatments can improve the field emission characteristics of DLC films. However, RTA post-treatment demonstrates a more pronounced effect on the enhancement of field emission than does the

  16. Ultimate strength of crystals, nanoparticles and nano-ceramics having diamond-like structure

    Directory of Open Access Journals (Sweden)

    Dora Zakarian

    2016-11-01

    Full Text Available A mathematical model for calculating the interplanar interaction energy of diamond-like structure ceramics at free surface of stock material in pseudopotential method has been developed. We have considered uniaxial [111] deformation of materials and obtained the “inverse Hall–Petch’s law” for strength. It is shown that nanoceramics has higher strength than the nanoparticles included in its composition.

  17. Julia sets and complex singularities in diamond-like hierarchical Potts models

    Institute of Scientific and Technical Information of China (English)

    QIAO; Jianyong

    2005-01-01

    We study the phase transition of the Potts model on diamond-like hierarchical lattices. It is shown that the set of the complex singularities is the Julia set of a rational mapping. An interesting problem is how are these singularities continued to the complex plane. In this paper, by the method of complex dynamics, we give a complete description about the connectivity of the set of the complex singularities.

  18. Diamond-like a-C:H coatings deposited in a non-self-sustained discharge with plasma cathode

    Science.gov (United States)

    Gavrilov, N. V.; Mamaev, A. S.; Kaĭigorodov, A. S.

    2009-01-01

    Hydrogenated amorphous carbon (a-C:H) coatings have been obtained by means of acetylene decomposition in a non-self-sustained periodic pulse discharge (2A, 50 kHz, 10 μs) with hollow cathode. The discharge operation was maintained by plasma cathode emission with grid stabilization based on dc glow discharge. Using the proposed method, it is possible to control the deposition conditions (total pressure of the Ar + C2H2 mixture, partial pressure of C2H2, ion current density, carbon ion energy) within broad limits, to apply a-C:H coatings onto large-area articles, and to perform deposition in one technological cycle with ion etching and ion implantation treatments aimed at improving the adhesion of coatings to substrates (Ti, Al, stainless steel, VK8 hard alloy) at temperatures below 150°C. Results of determining the deposition rate (1-8 μm), the nanohardness of coatings (up to 70 GPa), and the fraction of sp 3 bonds (25-70%) in the diamond-like coating material are presented.

  19. ANALYSIS OF THE FUNDAMENTAL CHARACTERISTICS OF DIAMOND-LIKE CRYSTALS AND LOW-DIMENSIONAL STRUCTURES

    Directory of Open Access Journals (Sweden)

    V.G.Litovchenko

    2004-01-01

    Full Text Available The principle has been developed for systematizing the diamond-like crystals with tetrahedral structure of the elementary cells and with valence chemical bonds, based on the calculation of the lattice constant. The approach proposed permits to predict basic parameters such as energy gap Eg, electron affinity (optical work function X, mechanical hardness H, melting temperature Tm, optical phonon frequency etc. These parameters have been calculated and the table is presented for a number of chemical compositions. For materials with mixed chemical bonds (valence and ionic the corrections can be calculated using Pouling electronegativity conception. The comparison with experiment demonstrates good agreement between the latter and the proposed procedure.

  20. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    Energy Technology Data Exchange (ETDEWEB)

    Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

    2009-01-06

    The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

  1. Modulation polarimetry of full internal reflection, broken by diamond-like films

    Directory of Open Access Journals (Sweden)

    Maksimenko L. S.

    2013-02-01

    Full Text Available This article presents research results on diamond-like films produced under different technological conditions. The parameter ρ — polarization difference — has been introduced. It has been found from spectral features of the parameter ρ that the interaction of electromagnetic radiation with the electronic system of specimens, which occurs in the used spectral range, consists of local and polariton surface resonances, differing in frequencies and times of relaxations. The autors concluded that the correlation in resonance intensity is defined by the structural characteristics of the specimens. These results show that modulation polarimetry is a perspective technique for diagnostics of the structural homogeneity of composite nanocluster films.

  2. Deposition and characterization of diamond-like nanocomposite coatings grown by plasma enhanced chemical vapour deposition over different substrate materials

    Indian Academy of Sciences (India)

    Awadesh Kr Mallik; Nanadadulal Dandapat; Prajit Ghosh; Utpal Ganguly; Sukhendu Jana; Sayan Das; Kaustav Guha; Garfield Rebello; Samir Kumar Lahiri; Someswar Datta

    2013-04-01

    Diamond-like nanocomposite (DLN) coatings have been deposited over different substrates used for biomedical applications by plasma-enhanced chemical vapour deposition (PECVD). DLN has an interconnecting network of amorphous hydrogenated carbon and quartz-like oxygenated silicon. Raman spectroscopy, Fourier transform–infra red (FT–IR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) have been used for structural characterization. Typical DLN growth rate is about 1 m/h, measured by stylus profilometer. Due to the presence of quartz-like Si:O in the structure, it is found to have very good adhesive property with all the substrates. The adhesion strength found to be as high as 0.6 N on SS 316 L steel substrates by scratch testing method. The Young’s modulus and hardness have found to be 132 GPa and 14.4 GPa, respectively. DLN coatings have wear factor in the order of 1 × 10-7 mm3/N-m. This coating has found to be compatible with all important biomedical substrate materials and has successfully been deposited over Co–Cr alloy based knee implant of complex shape.

  3. Tritrichomonas foetus adhere to superhydrophilic vertically aligned multi-walled carbon nanotube surface

    Energy Technology Data Exchange (ETDEWEB)

    Moreira Machado, Susane [Laboratorio de Biologia Celular e Tecidual, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi 2911, 12244-000, Sao Jose dos Campos, SP (Brazil); Oliveira Lobo, Anderson, E-mail: loboao@yahoo.com [Laboratorio de Nanotecnologia Biomedica (NanoBio), Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil); Laboratorio de Espectroscopia Vibracional Biomedica, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Avenida Shishima Hifumi, 2911, CEP 12244-000, Sao Jose dos Campos, SP (Brazil); Bueno Loureiro Sapucahy, Ariel [Laboratorio de Biologia Celular e Tecidual, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi 2911, 12244-000, Sao Jose dos Campos, SP (Brazil); Marciano, Fernanda Roberta [Laboratorio de Nanotecnologia Biomedica (NanoBio), Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil); Laboratorio de Espectroscopia Vibracional Biomedica, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Avenida Shishima Hifumi, 2911, CEP 12244-000, Sao Jose dos Campos, SP (Brazil); Corat, Evaldo Jose [Instituto Nacional de Pesquisas Espaciais (INPE), Laboratorio Associado de Sensores e Materiais (LAS), Av. dos Astronautas 1758, Sao Jose dos Campos, 12227-010 SP (Brazil); Soares da Silva, Newton [Laboratorio de Biologia Celular e Tecidual, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi 2911, 12244-000, Sao Jose dos Campos, SP (Brazil)

    2011-10-10

    For the first time, we show that Tritrichomonas foetus can adhere on superhydrophilic vertically aligned carbon nanotubes (VACNT) films. Scanning electron microscopy shows an unusual adhesion with a higher membrane filopodium projection in all directions, directly attached to superhydrophilic VACNT tips. Highlights: {yields} This is a new method to study the T. foetus adhesion mechanism. {yields} SEM images and interfacial adhesion force show a high adhesion level. {yields} It is very important for future understanding mechanism adhesion and protein expression.

  4. 磁控溅射Al靶功率对类金刚石薄膜结构和摩擦学性能的影响%Effect of Al Target Power of Magnetron Sputtering on the Structure and Tribological Properties of Diamond-like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    周升国; 王立平; 薛群基

    2011-01-01

    本文采用中频磁控溅射金属Al靶,以CH4为反应气体,通过调整Al靶溅射功率,在p(100)单晶硅片和不锈钢基底上成功制备出不同Al含量的Al/a-C∶H纳米复合薄膜.并利用HR-TEM、XPS、纳米压痕仪和摩擦磨损试验机等手段分析和研究了Al/a-C∶H薄膜的结构、机械及摩擦学性能.结果表明:金属Al以纳米晶颗粒形式镶嵌在非晶碳网络中,使得所制备Al/a-C∶H薄膜呈现出典型的纳米晶/非晶复合结构;同时,Al掺杂促进了薄膜中sp2杂化碳形成,且有效地释放残余内应力.Al靶溅射功率为800W时所制备的Al/a-C∶H薄膜具有结构致密、内应力低、硬度高的特性;在大气环境中,该薄膜与Si3N4陶瓷球干摩擦时显示出优越的摩擦学性能,其摩擦系数约为0.055,磨损率约为2.9×10-16m3/(N·m).%Aluminum/amorphous hydrogenated carbon (Al/a-C: H) nanocomposite thin films were deposited on silicon p( 100) wafer and stainless steel substrates by magnetron sputtering of aluminum in an argon and methane atmosphere with different Al target power. The composition, microstructure, mechanical and tribological properties of composite films were systemically investigated by HR - TEM, XPS, nano - indenter and tribo - tester. The results showed that the Al nanocrystallites could be easily formed in the amorphous carbon matrix, the sp2 hybrid carbon was increased as the Al was embedded into the films, and Al - doping could relax the internal stress whilst keeping high hardness of as - deposited films. The film containing 4.7 % Al prepared by target power of 800 W exhibited a high hardness about 16.5 Cpa, a low internal stress about 0.62 Gpa, a low friction coefficient about 0.055 and a low wear rate about 2.9 × 10-16 m3/(N ? M) in the ambient atmosphere.

  5. The characterisation of the microstructure and mechanical properties of diamond - like carbon (DLC for endoprosthesis

    Directory of Open Access Journals (Sweden)

    R. Gałuszka

    2017-01-01

    Full Text Available The paper presents the results of research of DLC coating of a - C:H type obtained by using a technique of physical vapor deposition (PVD on the surface of CoCrMo alloy, commonly used for the elements of the endoprosthesis. The surface has been observed using a scanning electron microscope (SEM. Analysis of the chemical composition and distribution of the different elements were performed using glow discharge optical emission spectrometry analysis (GDOES. It has been shown that the DLC elements are characterized by high hardness and good adhesion to the substrate.

  6. Improved tribological performance of PEEK polymers by application of diamond-like carbon coatings

    NARCIS (Netherlands)

    KTomaszewski, P.; Pei, Y. T.; Verkerke, G. J.; De Hosson, J. Th M.

    2014-01-01

    Overall high mechanical strength, an elastic modulus comparable to bone and low cost make polyetheretherketone (PEEK) an interesting biomaterial. However, high friction coefficient (CoF) and wear restrict its orthopaedic use to non-articulating applications. A solution might be offered by diamond-li

  7. Diamond or Diamond Like Carbon Coated Chemical Sensors and a Method of Making Same

    Science.gov (United States)

    1997-04-30

    halogen lamp ; an optical waveguide such as a fiber optic or a planar waveguide substrate; a chemoselective or bioselective film deposited en the...Patent Application Serial Number: Navy Case Number: 77,845 is then exposed to a pulsed laser, usually a Kr-F excimer laser with a wavelength of...located abtut 4 centimeters from the graphite target. Other suitable laser sources for depositing the protective coating include argon fluorine at 193 nm

  8. Diamond-like carbon and ceramic materials as protective coatings grown by pulsed laser deposition

    OpenAIRE

    Perera Mercado, Yibran Argenis

    2004-01-01

    A rather large number of nitride, carbide, and oxide thin films are used as hard and wear-resistant coatings, for optical, corrosive, and refractory applications that are of crucial importance. Additional requirements place even more stringent conditions on the deposition processes. The properties of coatings deposited by pulsed laser deposition are determined by the deposition parameters, the composition of the PLD plasma and its ionization states, the substrate conditions, etc.. In this way...

  9. Surface modification of diamond-like carbon films with protein via polydopamine inspired coatings

    Science.gov (United States)

    Tao, Caihong; Yang, Shengrong; Zhang, Junyan; Wang, Jinqing

    2009-10-01

    In this paper, we report a facile two-step approach to immobilize proteins onto DLC surfaces. The first step was a simple immersion of DLC in a solution of dopamine. Polydopamine was deposited on DLC as a stable anchor to present protein molecules. Then the protein ad-layer was deposited on it. The chemical components of the modified DLC surfaces were characterized by Fourier transform infrared spectra and X-ray photoelectron spectroscopy. The biocompatibility of it was evaluated in vitro by the tetrazolium salt method. And it was indicated that the BSA modified surface had good haemocompatibility properties, and was cytocompatible to PC-12 cells.

  10. Surface modification of diamond-like carbon films with protein via polydopamine inspired coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tao Caihong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); China and Graduate University of Chinese Academy of Sciences, Beijing 100080 (China); Yang Shengrong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); Zhang Junyan, E-mail: zhangjunyan@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); Wang Jinqing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China)

    2009-10-15

    In this paper, we report a facile two-step approach to immobilize proteins onto DLC surfaces. The first step was a simple immersion of DLC in a solution of dopamine. Polydopamine was deposited on DLC as a stable anchor to present protein molecules. Then the protein ad-layer was deposited on it. The chemical components of the modified DLC surfaces were characterized by Fourier transform infrared spectra and X-ray photoelectron spectroscopy. The biocompatibility of it was evaluated in vitro by the tetrazolium salt method. And it was indicated that the BSA modified surface had good haemocompatibility properties, and was cytocompatible to PC-12 cells.

  11. Mechanical Properties and Atomic Explanation of Plastic Deformation for Diamond-Like BC2

    Directory of Open Access Journals (Sweden)

    Baobing Zheng

    2016-06-01

    Full Text Available Motivated by a recently predicted structure of diamond-like BC2 with a high claimed hardness of 56 GPa (J. Phys. Chem. C 2010, 114, 22688–22690, we focus on whether this tetragonal BC2 (t-BC2 is superhard or not in spite of such an ultrahigh theoretical hardness. The mechanical properties of t-BC2 were thus further extended by using the first principles in the framework of density functional theory. Our results suggest that the Young’s and shear moduli of t-BC2 exhibit a high degree of anisotropy. For the weakest shear direction, t-BC2 undergoes an electronic instability and structural collapse upon a shear strain of about 0.11, with its theoretically ideal strength of only 36.2 GPa. Specifically, the plastic deformation under shear strain along the (110[001] direction can be attributed to the breaking of d1 B–C bonds.

  12. Characterization of diamond-like nanocomposite thin films grown by plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Santra, T. S.; Liu, C. H.; Bhattacharyya, T. K.; Patel, P.; Barik, T. K.

    2010-06-01

    Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were deposited on pyrex glass or silicon substrate using gas precursors (e.g., hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, or their different combinations) mixed with argon gas, by plasma enhanced chemical vapor deposition technique. Surface morphology of DLN films was analyzed by atomic force microscopy. High-resolution transmission electron microscopic result shows that the films contain nanoparticles within the amorphous structure. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine the structural change within the DLN films. The hardness and friction coefficient of the films were measured by nanoindentation and scratch test techniques, respectively. FTIR and XPS studies show the presence of CC, CH, SiC, and SiH bonds in the a-C:H and a-Si:O networks. Using Raman spectroscopy, we also found that the hardness of the DLN films varies with the intensity ratio ID/IG. Finally, we observed that the DLN films has a better performance compared to DLC, when it comes to properties like high hardness, high modulus of elasticity, low surface roughness and low friction coefficient. These characteristics are the critical components in microelectromechanical systems (MEMS) and emerging nanoelectromechanical systems (NEMS).

  13. Lanthanum carbonate oral powder: satisfaction, preference and adherence in French and Spanish patients with end-stage renal disease

    Science.gov (United States)

    Keith, Michael; de Sequera, Patricia; Clair, François; Pedersini, Riccardo

    2016-01-01

    Background Phosphate binders, such as lanthanum carbonate, control elevated serum-phosphate levels in patients with end-stage renal disease (ESRD). Lanthanum carbonate is available in oral powder and tablet form. The aim of this survey was to investigate satisfaction with, preference for, and adherence to lanthanum carbonate oral powder in patients with ESRD. Scope Patients from France and Spain who had been taking lanthanum carbonate powder for at least 4 weeks, and who had experience of other phosphate binders of any formulation, were asked to complete an online or telephone survey. Treatment satisfaction was measured using the Treatment Satisfaction Questionnaire for Medication-9; preference was measured using 5-point Likert scale agreement ratings; and adherence was measured using the Morisky Medication Adherence Scale-4. Data were evaluated using bivariate analyses. Findings Overall, 160 patients participated (80 per country). Lanthanum carbonate powder was reported to have a higher effectiveness rating (psubject to change over time. Although most participants completed the online survey in this study, a telephone survey was used for individuals who could not access the online version; if only one method of data recording had been used, there may have been reduced variation in responses. Conclusion Patients with ESRD report increased satisfaction with and preference for lanthanum carbonate powder over other formulations, suggesting that lanthanum carbonate powder is more convenient and easier to use than other formulations. PMID:27803726

  14. Copper-based diamond-like ternary semiconductors for thermoelectric applications

    Science.gov (United States)

    Skoug, Eric John

    Heightened global concern over greenhouse gas emissions has led to an increased demand for clean energy conversion technologies. Thermoelectric materials convert directly between thermal and electrical energy and can increase the efficiency of existing processes via waste heat recovery and solid-state climate control applications. The conversion efficiency of available thermoelectric materials and the devices comprised of them is unfortunately quite low, and thus new materials must be developed in order for thermoelectrics to keep pace with competing technologies. One approach to increasing the conversion efficiency of a given material is to decrease its lattice thermal conductivity, which has traditionally been accomplished by introducing phonon scattering centers into the material. These scattering centers also tend to degrade electronic transport in the material, thereby minimizing the overall effect on the thermoelectric performance. The purpose of this work is to develop materials with inherently low lattice thermal conductivity such that no extrinsic modifications are required. A novel approach in which complex ternary semiconductors are derived from well-known binary or elemental semiconductors is employed to identify candidate materials. Ternary diamond-like compounds, namely Cu2SnSe 3 and Cu3SbSe4, are synthesized, characterized, and optimized for thermoelectric applications. It is found that sample-to-sample variations in hole concentration limits the plausibility of Cu2SnSe3 as a thermoelectric material. Cu3SbSe 4 is found to be a promising material that can achieve thermoelectric performance comparable to state-of-the-art materials when optimized. This work uncovers anomalous thermal conductivity in several Cu-Sb-Se ternary compounds, which is used to develop a set of guidelines relating crystal structure to inherently low lattice thermal conductivity.

  15. DLC coatings for UHMWPE: relationship between bacterial adherence and surface properties.

    Science.gov (United States)

    Del Prado, G; Terriza, A; Ortiz-Pérez, A; Molina-Manso, D; Mahillo, I; Yubero, F; Puértolas, J A; Manrubia-Cobo, M; Gómez Barrena, E; Esteban, J

    2012-10-01

    Development of intrinsically antibacterial surfaces is of key importance in the context of prostheses used in orthopedic surgery. This work presents a thorough study of several plasma-based coatings that may be used with this functionality: diamond-like carbon (DLC), fluorine-doped DLC (F-DLC), and a high-fluorine-content-carbon-fluor polymer (CF(X)). The coatings were obtained by a radio-frequency plasma-assisted deposition on ultra high molecular weight polyethylene (UHMWPE) samples and physicochemical properties of the coated surfaces were correlated with their antibacterial performance against collection and clinical Staphylococcus aureus and Staphylococcus epidermidis strains. The fluorine content and the relative amount of C-C and C-F bonds were controlled by X-ray photoelectron spectroscopy, and hydrophobicity and surface tension by contact angle measurements. Surface roughness was studied by Atomic Force Microscopy. Additional nanoidentation studies were performed for DLC and F-DLC coatings. Unpaired t test and regression linear models evaluated the adherence of S. aureus and S. epidermidis on raw and coated UHMWPE samples. Comparing with UHMWPE, DLC/UHMWPE was the least adherent surface with independence of the bacterial species, finding significant reductions (p ≤ 0.001) for nine staphylococci strains. Bacterial adherence was also significantly reduced in F-DLC/ UHMWPE and CFx/UHMWPE for six strains.

  16. Exact Realization of a Quantum-Dimer Model in Heisenberg Antiferromagnets on a Diamond-Like Decorated Lattice

    Science.gov (United States)

    Hirose, Yuhei; Oguchi, Akihide; Fukumoto, Yoshiyuki

    2016-09-01

    We study Heisenberg antiferromagnets on a diamond-like decorated square lattice perturbed by further neighbor couplings. The second-order effective Hamiltonian is calculated and the resultant Hamiltonian is found to be a square-lattice quantum-dimer model with a finite hopping amplitude and no repulsion, which suggests the stabilization of the plaquette phase. Our recipe for constructing quantum-dimer models can be adopted for other lattices and provides a route for the experimental realization of quantum-dimer models.

  17. Ground States of Spin-1/2 Heisenberg Antiferromagnets with Frustration on a Diamond-Like-Decorated Square Lattice

    Science.gov (United States)

    Hirose, Yuhei; Oguchi, Akihide; Fukumoto, Yoshiyuki

    2017-01-01

    We study the ground-state phase diagram of a Heisenberg model with spin S = 1/2 on a diamond-like-decorated square lattice. A diamond unit has two types of antiferromagnetic exchange interactions, and the ratio λ of the length of the diagonal bond to that of the other four edges determines the strength of frustration. It has been pointed out [https://doi.org/10.7566/JPSJ.85.033705" xlink:type="simple">J. Phys. Soc. Jpn 85, 033705 (2016)] that the so-called tetramer-dimer states, which are expected to be stabilized in an intermediate region of λc < λ < 2, are identical to the square-lattice dimer-covering states, which ignited renewed interest in high-dimensional diamond-like-decorated lattices. In order to determine the phase boundary λc, we employ the modified spin wave method to estimate the energy of the ferrimagnetic state and obtain λc = 0.974. Furthermore, our numerical diagonalization study suggests that other cluster states do not appear in the ground-state phase diagram.

  18. A novel zinc(ii) metal-organic framework with a diamond-like structure: synthesis, study of thermal robustness and gas adsorption properties.

    Science.gov (United States)

    Almáši, Miroslav; Zeleňák, Vladimír; Zukal, Arnošt; Kuchár, Juraj; Čejka, Jiří

    2016-01-21

    A solvothermal reaction of Zn(ii) salt with methanetetrabenzoic acid (H4MTB) and 1,4,8,11-tetraazacyclotetradecane (cyclam, CYC) created a new microporous metal-organic framework {[Zn2(μ4-MTB)(κ(4)-CYC)2]·2DMF·7H2O}n (DMF = N,N'-dimethylformamide). Single crystal X-ray diffraction showed that the complex exhibits a four-fold interpenetrated diamond-like structure topology with 1D jar-like channels with sizes about 14.1 × 14.1 and 2.4 × 2.4 Å(2). The stability of the framework and activation conditions of the compound have been studied by high-energy powder X-ray diffraction during in situ heating, thermogravimetric analysis coupled with mass spectrometry and infrared spectroscopy performed at different temperatures. The gas adsorption behaviour of {[Zn2(μ4-MTB)(κ(4)-CYC)2]·2DMF·7H2O}n was studied by adsorption of Ar, N2, CO2 and H2. Nitrogen and argon adsorption showed that the activated sample exhibits Brunauer-Emmet-Teller (BET) specific surface areas of 644 m(2) g(-1) (N2) and 562 m(2) g(-1) (Ar). The complex adsorbs carbon dioxide with a maximum storage capacity of 10.5 wt% at 273 K and 101 kPa. The observed hydrogen uptake was 1.27 wt% at 77 K and 800 Torr, which is the highest value reported for the compounds containing a MTB(4-) linker. The adsorption heats of carbon dioxide and hydrogen, calculated according to the Clausius-Clapeyron equation, were in the range 22.8-22.4 kJ mol(-1) for CO2 and 8.9-3.2 kJ mol(-1) for H2, indicating weak interactions of the gases with the framework.

  19. Investigation of electronic structure and thermodynamic properties of quaternary Li-containing chalcogenide diamond-like semiconductors

    Science.gov (United States)

    Berarma, K.; Charifi, Z.; Soyalp, F.; Baaziz, H.; Uğur, G.; Uğur, Ş.

    2016-12-01

    Using first-principles calculations based on density functional theory, the structural, electronic and thermodynamic properties of Li2CdGeS4 and Li2CdSnS4 compounds are investigated. We confirmed that both Li2CdGeS4 and Li2CdSnS4 are diamond-like semiconductors of the wurtz-stannite structure type based on that of diamond in terms of tetrahedra volume. All the tetrahedra are almost regular with major distortion from the ideal occurring in the LiS4 tetrahedron, with values for S-Li-S ranging from 105.69° to 112.84° in the Li2CdGeS4 compound. Furthermore, the Cd-S bond possesses a stronger covalent bonding strength than the Li/Ge-S bonds. In addition, the inter-distances in Li2CdSnS4 show a larger spread than the distances in the Li2CdGeS4 compound. The electronic structures have been calculated to understand the bonding mechanism in quaternary Li-containing chalcogenide diamond-like semiconductors. Our results show that Li2CdGeS4 and Li2CdSnS4 are semiconductors with a direct band gap of 2.79 and 2.42 eV and exhibit mixed ionic-covalent bonding. It is also noted that replacing Ge by Sn leads to a decrease in the band gap; this behavior is explained in terms of bond lengths and electronegativity differences between atoms. Optical properties, including the dielectric function, reflectivity, and absorption coefficient, each as a function of photon energy are calculated and show an optical anisotropy for Li2CdGeS4 and Li2CdSnS4. The static dielectric constant {\\varepsilon }1(0) and static refractive index n(0) decrease when Ge is replaced by Sn. The influence of pressures and temperatures on the thermodynamic properties like the specific heat at constant volume {C}v, and at constant pressure {C}p, the Debye temperature {{{\\Theta }}}{{D}}, the entropy S and the Grüneisen parameter γ have been predicted at enlarged pressure and temperature ranges. The principal aspect from the obtained results is the close similarity of both compounds.

  20. Design of a 3D photonic band gap cavity in a diamond-like inverse woodpile photonic crystal

    CERN Document Server

    Woldering, Léon A; Vos, Willem L

    2014-01-01

    We theoretically investigate the design of cavities in a three-dimensional (3D) inverse woodpile photonic crystal. This class of cubic diamond-like crystals has a very broad photonic band gap and consists of two perpendicular arrays of pores with a rectangular structure. The point defect that acts as a cavity is centred on the intersection of two intersecting perpendicular pores with a radius that differs from the ones in the bulk of the crystal. We have performed supercell bandstructure calculations with up to $5 \\times 5 \\times 5$ unit cells. We find that up to five isolated and dispersionless bands appear within the 3D photonic band gap. For each isolated band, the electric-field energy is localized in a volume centred on the point defect, hence the point defect acts as a 3D photonic band gap cavity. The mode volume of the cavities resonances is as small as 0.8 $\\lambda^{3}$ (resonance wavelength cubed), indicating a strong confinement of the light. By varying the radius of the defect pores we found that o...

  1. Effect of Magnetic Field on the Deposition of Transparent Diamond-Like Carbon ( DLC ) Films by RF-PCVD

    Institute of Scientific and Technical Information of China (English)

    HOU Hui-jun; ZhU Xia-gao; LIN Song-sheng; YUAN Zhen-hai; DAI Da-huang

    2004-01-01

    In order to deposit transparent and hard DLC films, magnetic field was introduced to enhance the plasma density of radiofrequency plasma chemical vapor deposition (RF-PCVD). In this paper, the configuration and computation of external magnetic field B are introduced. The restriction effect of magnetic field B on the charged particles and the effect of magnetic field B on the primary parameters-nonindependent power Pf and self-bias Uz were also studied. The mechanism of how magnetic field B affects self-bias Uz was analyzed.

  2. Voltage assisted asymmetric nanoscale wear on ultra-smooth diamond like carbon thin films at high sliding speeds

    Science.gov (United States)

    Rajauria, Sukumar; Schreck, Erhard; Marchon, Bruno

    2016-01-01

    The understanding of tribo- and electro-chemical phenomenons on the molecular level at a sliding interface is a field of growing interest. Fundamental chemical and physical insights of sliding surfaces are crucial for understanding wear at an interface, particularly for nano or micro scale devices operating at high sliding speeds. A complete investigation of the electrochemical effects on high sliding speed interfaces requires a precise monitoring of both the associated wear and surface chemical reactions at the interface. Here, we demonstrate that head-disk interface inside a commercial magnetic storage hard disk drive provides a unique system for such studies. The results obtained shows that the voltage assisted electrochemical wear lead to asymmetric wear on either side of sliding interface. PMID:27150446

  3. Influence of flow rate on different properties of diamond-like nanocomposite thin films grown by PECVD

    Directory of Open Access Journals (Sweden)

    T. S. Santra

    2012-06-01

    Full Text Available Diamond-like nanocomposite (DLN thin films were deposited on pyrex glass substrate using different flow rate of haxamethyldisiloxane (HMDSO based liquid precursor with nitrogen gas as a glow discharged decomposition by plasma enhanced chemical vapor deposition (PECVD technique. The significant influence of different precursor flow rates on refractive index and thickness of the DLN films was measured by using spectroscopic filmatrics and DEKTAK profilometer. Optical transparency of the DLN thin films was analyzed by UV-VIS-NIR spectrometer. FTIR spectroscopy, provides the information about shifted bonds like SiC2, Si-C, Si-O, C-C, Si-H, C-H, N-H, and O-H with different precursor flow rate. We have estimated the hardness of the DLN films from Raman spectroscopy using Gaussian deconvolution method and tried to investigate the correlation between hardness, refractive index and thickness of the films with different precursor flow rates. The composition and surface morphology of the DLN films were investigated by X-ray photo electron spectroscopy (XPS and atomic force microscopy (AFM respectively. We have analyzed the hardness by intensity ratio (ID/IG of D and G peaks and correlates with hardness measurement by nanoindentation test where hardness increases from 27.8 μl/min to 80.6μl/min and then decreases with increase of flow rate from 80.6μl/min to 149.5μl/min. Finally, we correlates different parameters of structural, optical and tribological properties like film-thickness, refractive index, light transmission, hardness, surface roughness, modulus of elasticity, contact angle etc. with different precursor flow rates of DLN films.

  4. Influence of flow rate on different properties of diamond-like nanocomposite thin films grown by PECVD

    Science.gov (United States)

    Santra, T. S.; Bhattacharyya, T. K.; Tseng, F. G.; Barik, T. K.

    2012-06-01

    Diamond-like nanocomposite (DLN) thin films were deposited on pyrex glass substrate using different flow rate of haxamethyldisiloxane (HMDSO) based liquid precursor with nitrogen gas as a glow discharged decomposition by plasma enhanced chemical vapor deposition (PECVD) technique. The significant influence of different precursor flow rates on refractive index and thickness of the DLN films was measured by using spectroscopic filmatrics and DEKTAK profilometer. Optical transparency of the DLN thin films was analyzed by UV-VIS-NIR spectrometer. FTIR spectroscopy, provides the information about shifted bonds like SiC2, Si-C, Si-O, C-C, Si-H, C-H, N-H, and O-H with different precursor flow rate. We have estimated the hardness of the DLN films from Raman spectroscopy using Gaussian deconvolution method and tried to investigate the correlation between hardness, refractive index and thickness of the films with different precursor flow rates. The composition and surface morphology of the DLN films were investigated by X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM) respectively. We have analyzed the hardness by intensity ratio (ID/IG) of D and G peaks and correlates with hardness measurement by nanoindentation test where hardness increases from 27.8 μl/min to 80.6μl/min and then decreases with increase of flow rate from 80.6μl/min to 149.5μl/min. Finally, we correlates different parameters of structural, optical and tribological properties like film-thickness, refractive index, light transmission, hardness, surface roughness, modulus of elasticity, contact angle etc. with different precursor flow rates of DLN films.

  5. Abdominal X-ray might be a useful tool for assessing medication adherence in patients receiving Lanthanum carbonate

    Directory of Open Access Journals (Sweden)

    Hiroaki Ogata

    2012-06-01

    Full Text Available Control of the serum phosphate (P level is the most important and challenging in dialysis patients, because hyperphosphatemia is closely associated with higher cardiovascular morbidity and mortality. Lanthanum carbonate (LC, which is a novel non-calcium phosphate P binder, is effective in decreasing the serum P level and is well-tolerated with fewer adverse effects. However, LC has been reported that ingested LC fragments could be detectable in abdominal X-ray and computed tomography, because its density is between that of bone and metal. We performed an observational study to assess the relationship clinical effects of LC and abdominal X-ray findings in dialysis patients receiving LC. The enrolled 39 patients (female 7 (17.9%, age 59.6 yrs, dialysis vintage 11.2 yrs, diabetes 15 (38.5% were made abdominal X-ray examination at 4, 8, and 12 weeks after LC administration. Serum albumin, creatinine, and alkaline phosphatase levels did not change significantly during the 12-week treatment period. The P and the parathyroid hormone levels decreased after LC administration. Abdominal X-ray examination revealed digested LC tablets, in a variety of forms, through the intestinal tract in 37 patients (94.9%. The two patients without any digested LC fragment were still hyperphosphatemic after LC prescription, and they admitted not to have taken LC. Their serum P levels rapidly decreased after a series of medication counseling. In conclusion, this study suggested that abdominal X-ray might be useful tool for assessing medication adherence in patients receiving LC.

  6. Dep osition and thermal conductivity of diamond-like carb on film on a silicon substrate%类金刚石薄膜在硅基底上的沉积及其热导率∗

    Institute of Scientific and Technical Information of China (English)

    艾立强; 张相雄; 陈民; 熊大曦

    2016-01-01

    Diamond-Like Carbon (DLC) is thought to be a potential material in solving heat dissipation problems in light emitting diode module packages. It is of vital importance in evaluating the thermal conductivity of DLC film deposited on a silicon substrate. In this paper, the molecular dynamics method is used to simulate the formation of a DLC film by the deposition of carbon atoms on a isilicon substrate. Tersoff potential is adopted to reproduce the structures and densities of silicon, carbon, and SiC. A silicon substrate consisting of 544 atoms is located at the bottom of the simulation domain. The substrate is kept at a temperature of 600 K through a Noose-Hover thermostat. Carbon atoms are injected into the substrate individually every 0.5 ps at an energy of 1 eV. After a 7.5 ns deposition process, a 4 nm amorphous film containing 15000 carbon atoms is formed. Injected carbon atoms and substrate silicon atoms are intermixed at the bottom layer of the deposited film while the rest of the film contains only carbon atoms. The density of the film decreases slightly with the increase of the height of the deposited film and the average density is 2.8 g/cm3. Analysis of the coordination number shows that the sp3 fraction of carbon atoms in the film also decreases with the increase of the height of the deposited film, with a maximum value of 22%. It might be caused by the continuous impacts of the subsequently injected carbon atoms on the previously formed DLC film. The thermal conductivities of the DLC film in the planar and normal directions are calculated by the Green-Kubo method. The thermal conductivity of pure diamond film is also calculated for comparison. The results show that the planar thermal conductivity of the deposited DLC film is approximately half of that of the pure diamond film with the same size. It is higher than the normal thermal conductivity of the deposited film. The thermal conductivities of the DLC film in both planar and normal directions

  7. Phase transitions of geometrically frustrated mixed spin-1/2 and spin-1 Ising-Heisenberg model on diamond-like decorated planar lattices

    Directory of Open Access Journals (Sweden)

    L. Gálisová

    2011-03-01

    Full Text Available Phase transitions of the mixed spin-1/2 and spin-1 Ising-Heisenberg model on several decorated planar lattices consisting of interconnected diamonds are investigated within the framework of the generalized decoration-iteration transformation. The main attention is paid to the systematic study of the finite-temperature phase diagrams in dependence on the lattice topology. The critical behaviour of the hybrid quantum-classical Ising-Heisenberg model is compared with the relevant behaviour of its semi-classical Ising analogue. It is shown that both models on diamond-like decorated planar lattices exhibit a striking critical behaviour including reentrant phase transitions. The higher the lattice coordination number is, the more pronounced reentrance may be detected.

  8. Electronic, optical and lattice dynamic properties of the novel diamond-like semiconductors Li2CdGeS4 and Li2CdSnS4

    Science.gov (United States)

    Li, Yanlu; Fan, Weiliu; Sun, Honggang; Cheng, Xiufeng; Li, Pan; Zhao, Xian

    2011-06-01

    Li2CdGeS4 and Li2CdSnS4 are novel quaternary diamond-like semiconductors (DLSs) which have been synthesized recently. We present first-principles calculations of their electronic, optical and lattice dynamic properties with the plane-wave pseudopotential method. We have found an indirect band gap of 2.78 eV for Li2CdGeS4 and a direct band gap of 2.50 eV for Li2CdSnS4. The serious stretching vibrations of the Ge/Sn-S and Li-S bonds may enhance their phonon energies, and cause them to exhibit high heat capacities and Debye temperatures, which are promising for nonlinear optical applications. Compared with Cu-based DLSs, Li plays a key role in enlarging the band gaps and increasing the lattice phonon energies, which would increase the thermal conductivity accompanied by an increase of the optical damage threshold.

  9. Properties of amorphous carbon

    CERN Document Server

    2003-01-01

    Amorphous carbon has a wide range of properties that are primarily controlled by the different bond hydridisations possible in such materials. This allows for the growth of an extensive range of thin films that can be tailored for specific applications. Films can range from those with high transparency and are hard diamond-like, through to those which are opaque, soft and graphitic-like. Films with a high degree of sp3 bonding giving the diamond-like properties are used widely by industry for hard coatings. Application areas including field emission cathodes, MEMS, electronic devices, medical and optical coatings are now close to market. Experts in amorphous carbon have been drawn together to produce this comprehensive commentary on the current state and future prospects of this highly functional material.

  10. Lanthanum carbonate for the control of hyperphosphatemia in chronic renal failure patients: a new oral powder formulation - safety, efficacy, and patient adherence.

    Science.gov (United States)

    Lloret, M Jesús; Ruiz-García, César; Dasilva, Iara; Furlano, Mónica; Barreiro, Yaima; Ballarín, José; Bover, Jordi

    2013-11-06

    Chronic kidney disease (CKD) is associated with very high mortality rates, mainly of cardiovascular origin. The retention of phosphate (P) and increased fibroblast growth factor-23 levels are common, even at early stages of CKD, due to disturbances in normal P homeostasis. Later, hyperphosphatemia appears, which has also been strongly associated with high mortality rates linked to P-mediated cardiovascular and procalcifying effects. Treatment guidelines for these patients continue to be poorly implemented, at least partially due to the lack of adherence to a P-restricted diet and P-binder therapy. Calcium-free P binders, such as lanthanum carbonate, have been associated with a decreased progression of vascular calcification, rendering them an important therapeutic alternative for these high cardiovascular risk CKD patients. Lanthanum carbonate has typically been available as chewable tablets, and the new presentation as an oral powder may provide a useful alternative in the therapeutic armamentarium. This powder is a tasteless, odorless, and colorless semisolid compound miscible with food. In a recent study in healthy individuals, the safety and efficacy of this novel form were evaluated, and it was concluded that it is well tolerated and pharmacodynamically equivalent to the chewable form. In the long run, individualization of preferences and treatments seems an achievable goal prior to final demonstration of improvements in hard outcomes in wide clinical trials in CKD patients.

  11. Cold cathodes based on carbonic nanostructured layered structures

    Directory of Open Access Journals (Sweden)

    Belyanin A. F.

    2013-06-01

    Full Text Available The paper describes formation conditions for and the structure of diamond-like materials films used in the manufacture of layered cold cathodes of emission electronics devices. The authors study the structure and field emission properties of layered structures with polycluster diamond and diamond-like carbon films (DCF formed by various methods. It has been found that the best emission properties are characteristic of DCFs obtained by cathode sputtering. Emission from the surface of such films occurs on the boundaries of the globules.

  12. Performance of diamond-like carbon-protected rubber under cyclic friction. I. Influence of substrate viscoelasticity on the depth evolution

    NARCIS (Netherlands)

    Martinez-Martinez, D.; Pal, J.P. van der; Pei, Y.T.; Hosson, J.Th.M. De

    2011-01-01

    In this paper, the influence of the viscoelastic properties of rubber substrate on the tribological behavior of DLC film-coated alkyl acrylate rubber is studied. The mechanical behavior of the rubber was first characterized by creep experiments using spherical indentations. The results were adjusted

  13. Effect of deposition time on structure of silver nanoparticles embedded in diamond-like carbon matrix made by RF-PECVD method

    Directory of Open Access Journals (Sweden)

    S Abdolghaderi

    2015-01-01

    Full Text Available Silver nanoparticles embedded in DLC matrix, were prepared by co-deposition of RF-Sputtering and RF-PECVD method from acetylene gas and sliver target. The RF power and initial pressure of chamber were fixed. Variations of morphology, optical and electrical properties of these films over time were investigated

  14. Optical Analysis of Diamond-like Carbon Films Prepared by PECVD%PECVD制备类金刚石薄膜的光学特性

    Institute of Scientific and Technical Information of China (English)

    潘德芳; 苑进社

    2011-01-01

    在室温条件下利用射频等离子增强化学气相沉积技术在Si衬底和玻璃沉底上制备了类金刚石薄膜。通过对Si衬底生长的DLC薄膜的反射光谱分析发现DLC薄膜具有一定的减反射效果。玻璃衬底上制备的DLC薄膜的透射光谱分析表明制备的DLC薄膜在可见光区具有一定的增透作用。理论分析认为DLC薄膜透光性能主要与薄膜的sp3键的百分含量有关,当sp3键含量高时,光学透过性好,当sp3键含量低时,光学透过性差。DLC薄膜在He-Cd脉冲光激发下PL谱分析发现DLC薄膜的发光峰为460 nm,在该条件下制备的DLC薄膜光学带宽是2.7eV,认为DLC薄膜发光主要是通过sp2原子团簇中电子空穴对的辐射复合而完成。%In this paper,the films were successfully prepared on Si and glass substrates by radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) under the condition of room temperature.It is noted that the reflection spectrum of DLC films prepared on Si substrate has the property of protective reflective layer.Obviously,the transmission spectrum of DLC films shows that DLC films have certainly increased transmission within the visible area.It was found that the transmission of the DLC films was primarily related to percentage of sp3 bonds.In the case of the proportion of sp3 bonds,when it was high the optical transmission was excellent,otherwise,the optical transmission was poor.It was also found that the illumination peak of DLC films from the PL spectrum locates at 460nm with the DLC films analysis by the He-Cd pulse photoexcitation.As a result,the DLC thin-films band gap was calculated to be as 2.7eV.It is theoretically noted that the light-emitting of DLC films results mainly from the radiative recombination of electron-hole pair of the sp2 clusters.Meanwhile,the experimental study indicated that the DLC films have few sp2 bonds.

  15. Microstructures of Titanium Carbide/Diamond-Like Carbon Multilayered Films%TiC/DLC多层膜的制备及组织形态

    Institute of Scientific and Technical Information of China (English)

    肖晓玲; 张馨; 李福球; 侯惠君; 林松盛

    2010-01-01

    本文采用非平衡磁控溅射沉积技术,以甲烷气体为碳源,99.99%Ti为靶材制备了TiC/DLC多层膜.利用X射线衍射仪、电子显微镜、俄歇电子能谱仪和拉曼光谱仪等对TiC/DLC多层膜的组织、结构、形态及成分进行了分析.结果表明:Ti与C结合生成TiC晶相,过渡层中TiC相呈柱状晶生长,多层膜中的TiC分层以岛状模式生长,DLC分层以层状模式生长,TiC/DLC膜层中含有金刚石成分.TiC/DLC的多层结构受沉积参数的影响,当分层的沉积时间少于1 min时,很难获得清晰的层状结构薄膜,膜中Ti的含量随Ti靶电流的增加而增加;过渡层的引入,提高了膜与基体的结合力,并且过渡层的厚度增加,TiC/DLC膜层同基体之间的结合力增强.

  16. In-situ reflection-XANES study of ZDDP and MoDTC lubricant films formed on steel and diamond like carbon (DLC) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Morina, Ardian, E-mail: A.Morina@leeds.ac.uk [Institute of Engineering Thermofluids, Surfaces and Interfaces, School of Mechanical Engineering, University of Leeds, Leeds (United Kingdom); Zhao, Hongyuan [Institute of Engineering Thermofluids, Surfaces and Interfaces, School of Mechanical Engineering, University of Leeds, Leeds (United Kingdom); Mosselmans, J. Fred W. [Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2014-04-01

    Highlights: • S, P, Zn and Mo species formed in lubricant films can be characterised in-situ and in-lubro by using the reflection mode XAS technique. • Heating the lubricated steel and DLC samples affects the chemical reaction between the adsorbed species and the surface, resulting in different chemical composition of the ZDDP + MoDTC thermal film formed on steel or DLC. • There is a greater effect of temperature on S species than P species formed on ZDDP thermal films. - Abstract: Chemical characterisation of boundary lubricated interfaces is essential for developing mechanistic models that describe lubricant additive interactions with the surface and their effect on tribological performance. In this study the potential for using the synchrotron-based reflection mode X-ray absorption spectroscopy (XAS) technique for in-situ chemical characterisation of lubricant films has been studied. Thermal films formed from zinc dialkyl dithio phosphate (ZDDP) and molybdenum dialkyl dithio carbamate (MoDTC) lubricant additives have been formed and analysed in-situ using the X-ray absorption near edge structure (XANES) spectroscopy technique. The surface sensitivity of this approach was improved by doing the analysis in reflection mode, enabling analysis of only top layer (up to around 10 nm) of the solid surface. In addition, in-lubro analysis of pre-formed tribofilms from the same additives was done using non-vacuum conditions. The results are discussed in conjunction with XANES and X-ray photoelectron spectroscopy (XPS) analysis of similar additives published in the literature. The results obtained are consistent with the existing ZDDP and MoDTC literature and provide some new insight into intermediate species not reported before. The advantages and disadvantages of the developed XANES methodology for in-situ surface chemical analysis of lubricated conditions are discussed.

  17. Lanthanum carbonate for the control of hyperphosphatemia in chronic renal failure patients: a new oral powder formulation – safety, efficacy, and patient adherence

    Directory of Open Access Journals (Sweden)

    Lloret MJ

    2013-11-01

    Full Text Available MªJesús Lloret, César Ruiz-García, Iara DaSilva, Mónica Furlano, Yaima Barreiro, José Ballarín, Jordi Bover Nephrology Department, Fundació Puigvert, IIB Sant Pau, Barcelona, Spain; REDinREN, Instituto de Investigación Carlos III, Madrid, Spain Abstract: Chronic kidney disease (CKD is associated with very high mortality rates, mainly of cardiovascular origin. The retention of phosphate (P and increased fibroblast growth factor-23 levels are common, even at early stages of CKD, due to disturbances in normal P homeostasis. Later, hyperphosphatemia appears, which has also been strongly associated with high mortality rates linked to P-mediated cardiovascular and procalcifying effects. Treatment guidelines for these patients continue to be poorly implemented, at least partially due to the lack of adherence to a P-restricted diet and P-binder therapy. Calcium-free P binders, such as lanthanum carbonate, have been associated with a decreased progression of vascular calcification, rendering them an important therapeutic alternative for these high cardiovascular risk CKD patients. Lanthanum carbonate has typically been available as chewable tablets, and the new presentation as an oral powder may provide a useful alternative in the therapeutic armamentarium. This powder is a tasteless, odorless, and colorless semisolid compound miscible with food. In a recent study in healthy individuals, the safety and efficacy of this novel form were evaluated, and it was concluded that it is well tolerated and pharmacodynamically equivalent to the chewable form. In the long run, individualization of preferences and treatments seems an achievable goal prior to final demonstration of improvements in hard outcomes in wide clinical trials in CKD patients. Keywords: chronic kidney disease, phosphate, phosphate binder

  18. Coaxial carbon plasma gun deposition of amorphous carbon films

    Science.gov (United States)

    Sater, D. M.; Gulino, D. A.; Rutledge, S. K.

    1984-01-01

    A unique plasma gun employing coaxial carbon electrodes was used in an attempt to deposit thin films of amorphous diamond-like carbon. A number of different structural, compositional, and electrical characterization techniques were used to characterize these films. These included scanning electron microscopy, scanning transmission electron microscopy, X ray diffraction and absorption, spectrographic analysis, energy dispersive spectroscopy, and selected area electron diffraction. Optical absorption and electrical resistivity measurements were also performed. The films were determined to be primarily amorphous, with poor adhesion to fused silica substrates. Many inclusions of particulates were found to be present as well. Analysis of these particulates revealed the presence of trace impurities, such as Fe and Cu, which were also found in the graphite electrode material. The electrodes were the source of these impurities. No evidence of diamond-like crystallite structure was found in any of the film samples. Details of the apparatus, experimental procedure, and film characteristics are presented.

  19. HIV Medication Adherence

    Science.gov (United States)

    HIV Treatment HIV Medication Adherence (Last updated 3/2/2017; last reviewed 3/2/2017) Key Points Medication adherence means sticking firmly to ... Before and After Starting HIV Medicines . What is medication adherence? Adherence means “to stick firmly.” So for ...

  20. New nanoforms of carbon and boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Pokropivny, V V [Institute for Problems of Materials Science of National Academy of Sciences of Ukraine (Ukraine); Ivanovskii, A L [Institute of Solid State Chemistry, Urals Branch of the Russian Academy of Sciences, Ekaterinburg (Russian Federation)], e-mail: Ivanovskii@ihim.uran.ru

    2008-10-31

    Data on new carbon nanostructures including those based on fullerenes, nanotubes as well monolithic diamond-like nanoparticles, nanofibres, various nanocomposites, etc., published in the last decade are generalised. The experimental and theoretical data on their atomic and electronic structures, the nature of chemical bonds and physicochemical properties are discussed. These data are compared with the results obtained in studies of nanoforms of boron nitride, an isoelectronic analogue of carbon. Potential fields of applications of the new nanostructures are considered.

  1. New nanoforms of carbon and boron nitride

    Science.gov (United States)

    Pokropivny, V. V.; Ivanovskii, A. L.

    2008-10-01

    Data on new carbon nanostructures including those based on fullerenes, nanotubes as well monolithic diamond-like nanoparticles, nanofibres, various nanocomposites, etc., published in the last decade are generalised. The experimental and theoretical data on their atomic and electronic structures, the nature of chemical bonds and physicochemical properties are discussed. These data are compared with the results obtained in studies of nanoforms of boron nitride, an isoelectronic analogue of carbon. Potential fields of applications of the new nanostructures are considered.

  2. Formation of Nanofoam carbon and re-emergence of Superconductivity in compressed CaC6.

    Science.gov (United States)

    Li, Yan-Ling; Luo, Wei; Chen, Xiao-Jia; Zeng, Zhi; Lin, Hai-Qing; Ahuja, Rajeev

    2013-11-26

    Pressure can tune material's electronic properties and control its quantum state, making some systems present disconnected superconducting region as observed in iron chalcogenides and heavy fermion CeCu2Si2. For CaC6 superconductor (Tc of 11.5 K), applying pressure first Tc increases and then suppresses and the superconductivity of this compound is eventually disappeared at about 18 GPa. Here, we report a theoretical finding of the re-emergence of superconductivity in heavily compressed CaC6. The predicted phase III (space group Pmmn) with formation of carbon nanofoam is found to be stable at wide pressure range with a Tc up to 14.7 K at 78 GPa. Diamond-like carbon structure is adhered to the phase IV (Cmcm) for compressed CaC6 after 126 GPa, which has bad metallic behavior, indicating again departure from superconductivity. Re-emerged superconductivity in compressed CaC6 paves a new way to design new-type superconductor by inserting metal into nanoporous host lattice.

  3. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  4. Synthesis of hydrogen-carbon clathrate material and hydrogen evolution therefrom at moderate temperatures and pressures

    Science.gov (United States)

    Lueking, Angela; Narayanan, Deepa

    2011-03-08

    A process for making a hydrogenated carbon material is provided which includes forming a mixture of a carbon source, particularly a carbonaceous material, and a hydrogen source. The mixture is reacted under reaction conditions such that hydrogen is generated and/or released from the hydrogen source, an amorphous diamond-like carbon is formed, and at least a portion of the generated and/or released hydrogen associates with the amorphous diamond-like carbon, thereby forming a hydrogenated carbon material. A hydrogenated carbon material including a hydrogen carbon clathrate is characterized by evolution of molecular hydrogen at room temperature at atmospheric pressure in particular embodiments of methods and compositions according to the present invention.

  5. Adherence to antidepressants

    Directory of Open Access Journals (Sweden)

    Abimbola Farinde

    2013-01-01

    Full Text Available While major depression is considered a frequent mental illness there are ongoing reports of high non-adherence to antidepressant medications which places suffers at high risk for relapse, recurrence, or greater impairment,. The World Health Organization (WHO defines adherence as the extent to which a person′s behavior (e.g. taking medications can align with the agreed recommendations of a health care provider. Unfortunately while patient may recognize the importance of adherence to antidepressant medications the majority of patients do not adhere to their prescribed antidepressants. Some of the factors that may contribute to or lead to non-adherence include knowingly or unknowingly missing doses, taking extra doses, delaying administration times, or taking drug holidays. Pharmacists have the unique ability to deter non-adherence through the performance of continuous assessment and monitoring of adherence in this population given these accessibility. Additionally, pharmacists are able to develop therapeutic alliances with patients that can help to increase the likelihood of achieving positive patient outcomes. Antidepressant non-adherence can be viewed as a significant public health concern so it is important for patients to be educated about the importance of adherence, and health care professionals should be aware of factors or patient characteristics that can serve as barriers to non-adherence.

  6. An Adherence Semigroup

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By a dynamical system we mean a pair of (X,T), where X is compact Hausdorff space. In this paper we define an adherence semigroup A(X,T)∈XX, which is the set of all pointwise limit of subnets of (Tn)n∈N. We will prove some commonness between adherence semigroup and Ellis semigroup.

  7. Characterization of carbon contamination under ion and hot atom bombardment in a tin-plasma extreme ultraviolet light source

    Energy Technology Data Exchange (ETDEWEB)

    Dolgov, A., E-mail: a.dolgov@utwente.nl [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Lopaev, D. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Lee, C.J. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Zoethout, E. [Dutch Institute for Fundamental Energy Research (DIFFER), Nieuwegein (Netherlands); Medvedev, V. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Yakushev, O. [Institute for Spectroscopy Russian Academy of Sciences, Moscow (Russian Federation); Bijkerk, F. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands)

    2015-10-30

    Highlights: • Carbon film grown during exposure to EUV radiation and high energy ions was studied. • The carbon film is highly resistant to chemical and physical sputtering. • Surface contamination of plasma-facing components is similar to hydrogenated DLC. - Abstract: Molecular contamination of a grazing incidence collector for extreme ultraviolet (EUV) lithography was experimentally studied. A carbon film was found to have grown under irradiation from a pulsed tin plasma discharge. Our studies show that the film is chemically inert and has characteristics that are typical for a hydrogenated amorphous carbon film. It was experimentally observed that the film consists of carbon (∼70 at.%), oxygen (∼20 at.%) and hydrogen (bound to oxygen and carbon), along with a few at.% of tin. Most of the oxygen and hydrogen are most likely present as OH groups, chemically bound to carbon, indicating an important role for adsorbed water during the film formation process. It was observed that the film is predominantly sp{sup 3} hybridized carbon, as is typical for diamond-like carbon. The Raman spectra of the film, under 514 and 264 nm excitation, are typical for hydrogenated diamond-like carbon. Additionally, the lower etch rate and higher energy threshold in chemical ion sputtering in H{sub 2} plasma, compared to magnetron-sputtered carbon films, suggests that the film exhibits diamond-like carbon properties.

  8. Hard Carbon Films Deposited under Various Atmospheres

    Science.gov (United States)

    Wei, M.-K.; Chen, S.-C.; Wu, T. C.; Lee, Sanboh

    1998-03-01

    Using a carbon target ablated with an XeCl-excimer laser under various gas atmospheres at different pressures, hard carbon was deposited on silicon, iron and tungsten carbide substrates. The hardness, friction coefficient, and wear rate of the film against steel are better than pure substrate material, respectively, so that it has potential to be used as a protective coating for micromechanical elements. The influences of gas pressure, gas atmosphere, and power density of laser irradiation on the thermal stability of film were analyzed by means of Raman-spectroscope, time-of-flight method, and optical emission spectrum. It was found that the film deposited under higher pressure has less diamond-like character. The film deposited under rest gas or argon atmosphere was very unstable and looked like a little graphite-like character. The film deposited at high vacuum (10-5 mbar rest gas) was the most stable and looked like the most diamond-like character. The film deposited at higher power density was more diamond-like than that at lower power density.

  9. Adherence to Pharmacological Treatment for Juvenile Bipolar Disorder

    Science.gov (United States)

    Drotar, Dennis; Greenley, Rachel Neff; Demeter, Christine A.; McNamara, Nora K.; Stansbrey, Robert J.; Calabrese, Joseph R.; Stange, Jonathan; Vijay, Priya; Findling, Robert L.

    2007-01-01

    Objective: The objective of this study was to describe the prevalence and correlates of adherence to divalproex sodium (DVPX) and lithium carbonate (Li) combination treatment during the initial stabilization treatment phase. Method: Adherence to Li/DVPX combination therapy was measured by the presence or absence of minimum serum concentrations of…

  10. Recent development of carbon electrode materials and their bioanalytical and environmental applications.

    Science.gov (United States)

    Zhang, Wei; Zhu, Shuyun; Luque, Rafael; Han, Shuang; Hu, Lianzhe; Xu, Guobao

    2016-02-07

    Carbon materials have been extensively investigated due to their diversity, favorable properties, and active applications including electroanalytical chemistry. This critical review discusses new synthetic methods, novel carbon materials, new properties and electroanalytical applications of carbon materials particularly related to the preparation as well as bioanalytical and environmental applications of highly oriented pyrolytic graphite, graphene, carbon nanotubes, various carbon films (e.g. pyrolyzed carbon films, boron-doped diamond films and diamond-like carbon films) and screen printing carbon electrodes. Future perspectives in the field have also been discussed (366 references).

  11. HIV Treatment Adherence

    Science.gov (United States)

    ... Viral Suppression Doctor, Clinical & Dental Visits Treatment Adherence Mental Health Substance Abuse Issues Sexual Health Nutrition & Food Safety Exercise Immunizations Aging with HIV/AIDS Women’s Health Housing ...

  12. FTIR Spectroscopy for Carbon Family Study.

    Science.gov (United States)

    Ţucureanu, Vasilica; Matei, Alina; Avram, Andrei Marius

    2016-11-01

    Fourier transform Infrared (FTIR) spectroscopy is a versatile technique for the characterization of materials belonging to the carbon family. Based on the interaction of the IR radiation with matter this technique may be used for the identification and characterization of chemical structures. Most important features of this method are: non-destructive, real-time measurement and relatively easy to use. Carbon basis for all living systems has found numerous industrial applications from carbon coatings (i.e. amorphous and nanocrystalline carbon films: diamond-like carbon (DLC) films) to nanostructured materials (fullerenes, nanotubes, graphene) and carbon materials at nanoscale or carbon dots (CDots). In this paper, we present the FTIR vibrational spectroscopy for the characterization of diamond, amorphous carbon, graphite, graphene, carbon nanotubes (CNTs), fullerene and carbon quantum dots (CQDs), without claiming to cover entire field.

  13. A comparative study of the field emission properties of aligned carbon nanostructures films, from carbon nanotubes to diamond

    OpenAIRE

    Le Normand, Francois; Cojocaru, Costel Sorin; Fleaca, Claudiu; Li, J. Q.; Vincent, Pascal; Pirio, Gilles; Gangloff, Laurent; Nedellec, Yanick; Legagneux, Pierre

    2007-01-01

    International audience; The electron field emission properties of different graphitic and diamond-like nanostructures films are compared. They are prepared in the same CVD chamber on SiO{2}/Si(100) and Si(100) flat surfaces, respectively. These nanostructures are thoroughly characterized by scanning electron emission (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Films of dense aligned carbon nan...

  14. Collisionless shocks driven by 800 nm laser pulses generate high-energy carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Shen, B. F., E-mail: bfshen@mail.shcnc.ac.cn; Wang, W. P.; Xu, Y.; Liu, Y. Q.; Liang, X. Y.; Leng, Y. X.; Li, R. X., E-mail: ruxinli@mail.shcnc.ac.cn; Xu, Z. Z. [State Key Laboratory of High Filed Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, X. Q.; Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2015-01-15

    We present experimental studies on ion acceleration from diamond-like carbon (DLC) foils irradiated by 800 nm, linearly polarized laser pulses with peak intensity of 1.7 × 10{sup 19 }W/cm{sup 2} to 3.5 × 10{sup 19 }W/cm{sup 2} at oblique incidence. Diamond-like carbon foils are heated by the prepulse of a high-contrast laser pulse and expand to form plasmas of near-critical density caused by thermal effect before the arrival of the main pulse. It is demonstrated that carbon ions are accelerated by a collisionless shock wave in slightly overdense plasma excited by forward-moving hot electrons generated by the main pulse.

  15. Modification of the Properties of Carbon Films for Photovoltaic Converters

    Directory of Open Access Journals (Sweden)

    S.O. Rudchenko

    2012-12-01

    Full Text Available The semiconductor materials with values of energy band gap in the range of 1-2 eV are the most suitable for manufacturing solar cells. These objects include some of the carbon allotropic modifications, as well as quantum dots on the surface of these materials, which use as the basis for the creation of new optoelectronic devices based on nanostructures. This paper presents the investigations of optical properties and structure of synthesized multilayer system diamond-like carbon film/ carbon quantum dots/C60film (DLC/Qdots/C60.

  16. Structural morphology of amorphous conducting carbon film

    Indian Academy of Sciences (India)

    P N Vishwakarma; V Prasad; S V Subramanyam; V Ganesan

    2005-10-01

    Amorphous conducting carbon films deposited over quartz substrates were analysed using X-ray diffraction and AFM technique. X-ray diffraction data reveal disorder and roughness in the plane of graphene sheet as compared to that of graphite. This roughness increases with decrease in preparation temperature. The AFM data shows surface roughness of carbon films depending on preparation temperatures. The surface roughness increases with decrease in preparation temperature. Also some nucleating islands were seen on the samples prepared at 900°C, which are not present on the films prepared at 700°C. Detailed analysis of these islands reveals distorted graphitic lattice arrangement. So we believe these islands to be nucleating graphitic. Power spectrum density (PSD) analysis of the carbon surface indicates a transition from the nonlinear growth mode to linear surface-diffusion dominated growth mode resulting in a relatively smoother surface as one moves from low preparation temperature to high preparation temperature. The amorphous carbon films deposited over a rough quartz substrate reveal nucleating diamond like structures. The density of these nucleating diamond like structures was found to be independent of substrate temperature (700–900°C).

  17. Adherence as a language game.

    Science.gov (United States)

    Kolberg, Espen Skarstein

    2017-03-02

    Non-adherence, i.e. medication intake behavior not corresponding with agreed recommendations, is associated with increased morbidity and death, and it has been estimated that as many as 50% of patients in developed countries are not taking their medications as prescribed. But even as efforts in improving medication adherence over the years have increased, results are inconsistent, with only a minority of clinical trials showing any improvement in both adherence and clinical outcome. Since patient education is central to promoting good medication adherence, and language is integral to education, perhaps an exploration of the meaning and use of language, using the philosophy of Ludwig Wittgenstein, is in order.

  18. Investigation of Diamond-like Carbon Films Synthesized by Plasma Gun at an Atmospheric Pressure%大气等离子体枪制备类金刚石薄膜

    Institute of Scientific and Technical Information of China (English)

    汤文杰; 张跃飞; 陈强; 葛袁静

    2006-01-01

    大气下,采用DBD等离子体枪为等离子体聚合装置,以甲烷为单体,氩气为工作气体,在载玻片和单晶硅片上沉积类金刚石薄膜(DLC).考察了基片预处理、内电极形状、进气方式、以及等离子体炬喷口和基材的距离对DLC薄膜沉积的影响.通过傅立叶变换红外光谱(FTIR)分析聚合膜结构并探索可能的沉积机理;表面轮廓仪测定了成膜速率;并对薄膜进行了机械性能测量.

  19. Study on the thermal conductivity of diamond-like carbon functionally graded material on copper substrate%铜基类金刚石膜功能梯度材料作为散热材料的研究

    Institute of Scientific and Technical Information of China (English)

    王静; 刘贵昌; 李红玲; 侯保荣

    2012-01-01

    随着电子技术、信息产业的发展,Cu在微型散热材料、电子封装材料上应用日益广泛.Cu在应用过程中存在强度低、易氧化、易磨损等缺点.采用等离子体复合沉积技术,在铜基体上制备了Ti/TiC/DLC功能梯度材料,改善铜基体与美金刚石(DLC)膜的结合力,强化了铜的机械性能.瞬态热反射法检测结果表明,DLC功能梯度材料不会影响铜基体的散热效果.%In recent years, with the rapid development of electronic technology and digital network information, copper has increasing applications in micro-electronics, micro-electro-mechanical systems and Hi-tech materials. However copper has its material limitations. In particular, it has relatively low hardness, high oxidation and wear rate, which have severely restricted its widespread applications. In this paper, aiming at difficulties of copper applications, Ti/TiC/DLC has been proposed as functionally graded material to deposit on the copper substrate with plasma depositing method, which intensifies the adhesion between DLC film and copper substrate and improves the properties of copper. The maximal value of thermal conductivity of DLC film with optimized parameter of graded intermediate layer is 3.63 Wm-1.K-1, which enhances the heat transfer effect of copper substrate.

  20. Preparation and characterization of carbon nano-sheet powders

    Institute of Scientific and Technical Information of China (English)

    Yang Wubao; Zhao Zhen; Fang Songhua; Wang Yong; Yang Size; Lin Li

    2008-01-01

    Carbon nanosheet films were deposited on Al substrates by using plasma assisted chemical vapor deposition (PACVD) technique. And after being peeled off from Al substrates, carbon nanosheet powders (CNSPs) were obtained. In Raman spectrum of carbon film, there was a strong and broadened peak at about 1,580 cm-1, indicating a carbon diamond-like film. Atomic force microscope image showed that the carbon diamond-like film had a grain size less than 100 nm, and its surface roughness Ra was 17.95 nm in an area of 5×5 μm2. The CNSPs were irregular sheets with curly edges and a length of several micrometers to several hundreds of micrometers. The BET surface area of CNSPs was 6.66 m2/g with no micro-pore present, which was confirmed by N2 adsorption-desorption characterization. In the adsorption testing, when the relative pressure P/P0 was higher than 0.3, the adsorption behavior did not follow the Langmuir equation. The addition of CNSPs to carbon black (catalyst support) could improve hydrodesuifurization performance of carbon supported Ni-W catalysts for diesel oil.

  1. [Adherence to psychopharmacological treatment: Psychotherapeutic strategies to enhance adherence].

    Science.gov (United States)

    Lencer, R; Korn, D

    2015-05-01

    Effective psychopharmacological medication with good tolerability represents the cornerstone of treatment for severe mental illness; however, the 1-year adherence rates are only approximately 50%. The term adherence emphasizes the collaborative responsibility of the clinician and the patient for a positive treatment outcome. Reasons for non-adherence are manifold and include patient-specific factors, such as self-stigmatization, lack of social and familial support, cognitive impairment and substance use besides insufficient effectiveness and the occurrence of side effects of the psychotropic drugs. To enhance adherence, both clinician and patient have to fully understand all the reasons for and against adherence to medication before a collaborative decision is made on future long-term treatment. A positive attitude towards medication critically depends on whether patients feel that the medication supports the attainment of the individual goals.

  2. Biologic Influences on Exercise Adherence.

    Science.gov (United States)

    Dishman, Rod K.

    1981-01-01

    Diagnostic profiles of 362 male participants in an exercise program were analyzed to determine the biological variables between exercise adherence and symptoms of coronary disease. Findings indicated that individuals with lower metabolic capacity tended to adhere longer, to be less fit, were leaner, and began with more symptoms related to coronary…

  3. Carbon The Future Material for Advanced Technology Applications

    CERN Document Server

    Messina, Giacomo

    2006-01-01

    Carbon-based materials and their applications constitute a burgeoning topic of scientific research among scientists and engineers attracted from diverse areas such as applied physics, materials science, biology, mechanics, electronics and engineering. Further development of current materials, advances in their applications, and discovery of new forms of carbon are the themes addressed by the frontier research in these fields. This book covers all the fundamental topics concerned with amorphous and crystalline C-based materials, such as diamond, diamond-like carbon, carbon alloys, carbon nanotubes. The goal is, by coherently progressing from growth - and characterisation techniques to technological applications for each class of material, to fashion the first comprehensive state-of-the-art review of this fast evolving field of research in carbon materials.

  4. Adherence to Treatment of Phenylketonuria

    Directory of Open Access Journals (Sweden)

    Tatiane Alves Vieira

    2015-05-01

    Full Text Available Introduction: Phenylketonuria (PKU is caused by the deficient activity of phenylalanine hydroxylase. Aim: To identify the factors associated with treatment adherence among patients with PKU seen at a southern Brazil reference center. Methodology: A cross-sectional, outpatient-based study including 56 patients with PKU (median age, 12 years for whom a Phe-restrict diet plus specific metabolic formula have been prescribed. Patients were considered adherent or nonadherent depending on the median phenylalanine concentration for the 12 months prior to study and target levels of phenylalanine for each age range (<13 years = ≤360 µmol/L; ≥13 years = ≤900 µmol/L. Data were collected through a review of patient’s medical records and a set of interviews with patients and their relatives. Results: Eighteen patients (32.1%; ≥13 years, 11 were classified as treatment adherent. Among all factors analyzed, only mental retardation, living with parents, and level of maternal education were associated with adherence to treatment. Conclusion: Our findings reinforce the importance of the family as promoting factor for treatment adherence.

  5. Study of Adherent Oxide Scales

    Science.gov (United States)

    1987-09-14

    The bond between alumina and NiCrAl substrate is intrinsically strong. The segregation of sulfur to the interface reduces bond strength, sulfur is...which laser-processing and minor element additions improve oxide scale adherence of a NiCrAl turbine coating composition. However, it was shown at the...adherence. However, significant observations were made with respect to the morphology of the oxide scale that forms on NiCrAl and NiCrAlY and these are

  6. Adherence with Preventive Medication in Childhood Asthma

    Directory of Open Access Journals (Sweden)

    Scott Burgess

    2011-01-01

    Full Text Available Suboptimal adherence with preventive medication is common and often unrecognised as a cause of poor asthma control. A number of risk factors for nonadherence have emerged from well-conducted studies. Unfortunately, patient report a physician's estimation of adherence and knowledge of these risk factors may not assist in determining whether non-adherence is a significant factor. Electronic monitoring devices are likely to be more frequently used to remind patients to take medication, as a strategy to motivate patients to maintain adherence, and a tool to evaluate adherence in subjects with poor disease control. The aim of this paper is to review non-adherence with preventive medication in childhood asthma, its impact on asthma control, methods of evaluating non-adherence, risk factors for suboptimal adherence, and strategies to enhance adherence.

  7. Investigation of the plasma processability of natural carbon bearing formations

    Science.gov (United States)

    Molchanov, V. P.

    2017-01-01

    In the south of the Russian Far East, a new perspective source of minerals was pioneered, which is the metal-bearing high carbon rocks of the Ruzhinskaya square. The rocks are rich in crystalline graphite, gold, platinum and carbon nanostructures (fullerene, nanotubes and diamond-like carbon). The technique of extraction of ultrapure (99.98%) crystalline graphite from these rocks has been developed using hydrometallugical methods. The obtained graphite was used as a raw material for plasma-chemical tests succeeded in the separation of nanodimensional carbon structures, part of which could be inherited from the natural graphite-bearing rocks. The results of investigation will be used in the development of resource-saving technology of minerals extraction.

  8. Fabrication of periodical surface structures by picosecond laser irradiation of carbon thin films: transformation of amorphous carbon in nanographite

    Science.gov (United States)

    Popescu, C.; Dorcioman, G.; Bita, B.; Besleaga, C.; Zgura, I.; Himcinschi, C.; Popescu, A. C.

    2016-12-01

    Thin films of carbon were synthesized by ns pulsed laser deposition in vacuum on silicon substrates, starting from graphite targets. Further on, the films were irradiated with a picosecond laser source emitting in visible at 532 nm. After tuning of laser parameters, we obtained a film surface covered by laser induced periodical surface structures (LIPSS). They were investigated by optical, scanning electron and atomic force microscopy. It was observed that changing the irradiation angle influences the LIPSS covered area. At high magnification it was revealed that the LIPSS pattern was quite complex, being composed of other small LIPSS islands, interconnected by bridges of nanoparticles. Raman spectra for the non-irradiated carbon films were typical for a-C type of diamond-like carbon, while the LIPSS spectra were characteristic to nano-graphite. The pristine carbon film was hydrophilic, while the LIPSS covered film surface was hydrophobic.

  9. Adherence to the Treatment in Psychiatric Patients

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Demirkol

    2015-09-01

    Conclusion: Although medical treatments and drug industry develop day by day, there have been no changes in the treatment adherence ratios in the past years. To generate possible solutions, treatment adherence should be assessed in all clinical interviews and if patient is non-adherent this issue should be handled seriously. [Cukurova Med J 2015; 40(3.000: 555-568

  10. Preparation of hollow spherical carbon nanocages

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.-K.; Kang, H. Y.; Hong, C.-I; Huang, C.-H.; Chang, F.-C.; Wang, H. Paul, E-mail: wanghp@mail.ncku.edu.tw [National Cheng Kung University, Department of Environmental Engineering, Taiwan (China)

    2012-12-15

    This study presents a new and simple method for the synthesis of hollow carbon spheres possessing nanocage sizes of 7.1, 14, and 20 nm in diameter. The core-shell (i.e., Cu-C) nanoparticles prepared by carbonization of the Cu{sup 2+}-cyclodextrin (CD) complexes at 573 K for 2 h was etched with HCl (6N) to yield the hollow carbon spheres. The carbon-shell of the hollow carbon nanospheres, which consisted of mainly diamond-like and graphite carbons, is not perturbed during etching. In addition to the nanocages, the hollow carbon nanospheres also possess micropores with an opening of 0.45 nm, allowing small molecules to diffuse in and out through the carbon-shell. Many elements (such as Zn{sup 2+} or Cu{sup 2+}) can therefore be filled into the nanocages of the hollow carbon nanospheres. With these unique properties, for instance, designable active species such as Cu and ZnO encapsulated in the carbon-shell can act as Cu-ZnO-C yolk-shell nanoreactors which are found very effective in the catalytic decomposition of methanol.

  11. Adherence and health care costs

    Directory of Open Access Journals (Sweden)

    Iuga AO

    2014-02-01

    Full Text Available Aurel O Iuga,1,2 Maura J McGuire3,4 1Johns Hopkins Bloomberg School of Public Health, 2Johns Hopkins University, 3Johns Hopkins Community Physicians, 4Johns Hopkins University School of Medicine, Baltimore, MD, USA Abstract: Medication nonadherence is an important public health consideration, affecting health outcomes and overall health care costs. This review considers the most recent developments in adherence research with a focus on the impact of medication adherence on health care costs in the US health system. We describe the magnitude of the nonadherence problem and related costs, with an extensive discussion of the mechanisms underlying the impact of nonadherence on costs. Specifically, we summarize the impact of nonadherence on health care costs in several chronic diseases, such as diabetes and asthma. A brief analysis of existing research study designs, along with suggestions for future research focus, is provided. Finally, given the ongoing changes in the US health care system, we also address some of the most relevant and current trends in health care, including pharmacist-led medication therapy management and electronic (e-prescribing. Keywords: patient, medication, adherence, compliance, nonadherence, noncompliance, cost

  12. Cryopreservation of adherent neuronal networks.

    Science.gov (United States)

    Ma, Wu; O'Shaughnessy, Thomas; Chang, Eddie

    2006-07-31

    Neuronal networks have been widely used for neurophysiology, drug discovery and toxicity testing. An essential prerequisite for future widespread application of neuronal networks is the development of efficient cryopreservation protocols to facilitate their storage and transportation. Here is the first report on cryopreservation of mammalian adherent neuronal networks. Dissociated spinal cord cells were attached to a poly-d-lysine/laminin surface and allowed to form neuronal networks. Adherent neuronal networks were embedded in a thin film of collagen gel and loaded with trehalose prior to transfer to a freezing medium containing DMSO, FBS and culture medium. This was followed by a slow rate of cooling to -80 degrees C for 24 h and then storage for up to 2 months in liquid nitrogen at -196 degrees C. The three components: DMSO, collagen gel entrapment and trehalose loading combined provided the highest post-thaw viability, relative to individual or two component protocols. The post-thaw cells with this protocol demonstrated similar neuronal and astrocytic markers and morphological structure as those detected in unfrozen cells. Fluorescent dye FM1-43 staining revealed active recycling of synaptic vesicles upon depolarizing stimulation in the post-thaw neuronal networks. These results suggest that a combination of DMSO, collagen gel entrapment and trehalose loading can significantly improve conventional slow-cooling methods in cryopreservation of adherent neuronal networks.

  13. Corrosion, friction and wear performance of diamond – like carbon (DLC coatings

    Directory of Open Access Journals (Sweden)

    M. Madej

    2016-10-01

    Full Text Available The a - C:H:W, TiN/a - C:H:W and the CrN/a - C:H:W coatings were deposited on steel surface by physical vapour deposition methods and studied for corrosion and tribological properties, after elemental and structural analysis. In friction pairs the elements coated with diamond-like carbon showed better tribological properties than the elements without coatings. The presence of interlayers in coatings contributed to an improvement in the tribological properties but decreased corrosion resistance.

  14. Silicon Carbide Derived Carbons: Experiments and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kertesz, Miklos [Georgetown University, Washington DC 20057

    2011-02-28

    The main results of the computational modeling was: 1. Development of a new genealogical algorithm to generate vacancy clusters in diamond starting from monovacancies combined with energy criteria based on TBDFT energetics. The method revealed that for smaller vacancy clusters the energetically optimal shapes are compact but for larger sizes they tend to show graphitized regions. In fact smaller clusters of the size as small as 12 already show signatures of this graphitization. The modeling gives firm basis for the slit-pore modeling of porous carbon materials and explains some of their properties. 2. We discovered small vacancy clusters and their physical characteristics that can be used to spectroscopically identify them. 3. We found low barrier pathways for vacancy migration in diamond-like materials by obtaining for the first time optimized reaction pathways.

  15. Factors associated with adherence to the Mediterranean diet in the adult population.

    Science.gov (United States)

    Patino-Alonso, Maria C; Recio-Rodríguez, José I; Belio, Jose Felix Magdalena; Colominas-Garrido, Ruben; Lema-Bartolomé, Jorge; Arranz, Amparo Gómez; Agudo-Conde, Cristina; Gomez-Marcos, Manuel A; García-Ortiz, Luis

    2014-04-01

    Our aim was to analyze the variables associated with adherence to the Mediterranean diet in the adult population. We conducted a cross-sectional study in an established cohort of 1,553 healthy study participants (mean age=55 ± 14 years; 60.3% women). Mediterranean diet adherence was evaluated based on a 14-item questionnaire and the Mediterranean diet adherence screener, which defines adequate adherence as a score of ≥ 9. Physical activity was evaluated using the 7-day physical activity record. Sociodemographic, biological, and anthropometric variables were also evaluated. The differences between Mediterranean diet compliers and noncompliers are defined by the consumption of fruit, red meats, carbonated beverages, wine, fish/shellfish, legumes, pasta, and rice (PMediterranean diet adherence: more physical exercise (odds ratio=1.588), older age (odds ratio=2.162), and moderate alcohol consumption (odds ratio=1.342). The factors associated with improved Mediterranean diet adherence included female sex, age older than 62 years, moderate alcohol consumption, and more than 17 metabolic equivalents (METs)/h/wk of physical exercise. Poorer adherence was associated with males and obesity.

  16. Irradiation of the amorphous carbon films by picosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Marcinauskas, L., E-mail: liutauras.marcinauskas@ktu.lt [Kaunas University of Technology, Studentu 50, LT-51368 Kaunas (Lithuania); Grigonis, A. [Kaunas University of Technology, Studentu 50, LT-51368 Kaunas (Lithuania); Račiukaitis, G.; Gedvilas, M. [Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300 Vilnius (Lithuania); Vinciūnaitė, V. [Kaunas University of Technology, Studentu 50, LT-51368 Kaunas (Lithuania)

    2015-10-30

    The effect of a picosecond laser irradiation on structure modification of diamond-like carbon (DLC) and graphite-like carbon (GLC) films was analyzed in this work. The DLC films were irradiated by Nd:YVO{sub 4} laser operating at the 532 nm wavelength with the picosecond (10 ps) pulse duration at the fluence in the range of (0.08–0.76) J/cm{sup 2}. The GLC films were irradiated only at the fluence of 0.76 J/cm{sup 2}. The different pulse number (1, 10, and 100) was used for irradiation the films. The micro-Raman spectroscopy measurements indicated that the laser irradiation led to rearrangement of the sp{sup 3} C–C bonds to the sp{sup 2} C=C bonds in the DLC films. The formation of silicon carbide (SiC) was found in the irradiated spot after 10 and 100 pulses. Modifications in the structure of the DLC film took place even in the areas with low intensity of the Gaussian beam wings (heat affected areas). The increase in the oxygen concentration up to ten times was detected in the heat affected areas after 100 pulses. Opposite to that, the laser irradiation decreased the oxygen concentration and smoothened the surface microrelief of the GLC films. The bonding type remained unchanged in the GLC films even after irradiation with 100 pulses per spot. - Highlights: • The picosecond laser irradiation led to the rearrangement of sp{sup 3} C-C to the sp{sup 2} C = C bonds in the diamond-like carbon film. • The ps-laser irradiation of the DLC films stipulates appearance of the aromatic carbon structures. • The bonding type of the graphite-like carbon films remained unchanged even after ps laser irradiation with 100 pulses.

  17. Intent-to-adhere and adherence to malaria prevention recommendations in two travel clinics.

    Science.gov (United States)

    Goldstein, Irit; Grefat, Rami; Ephros, Moshe; Rishpon, Shmuel

    2015-01-01

    Malaria infects 30,000 travelers annually worldwide. At greatest risk are those who travel for long duration. Prevention of malaria includes chemoprophylaxis. This prospective study on 121 travelers who visited two travel clinics shows that adherence to prophylactic treatment was low, especially in long duration trips, and that adherence rate could be predicted by the much more available intent-to-adhere rate.

  18. Measurement of oxide adherence to PFM alloys.

    Science.gov (United States)

    Mackert, J R; Parry, E E; Hashinger, D T; Fairhurst, C W

    1984-11-01

    A method has been reported for evaluating adherence of an oxide to its substrate metal to a maximum value of about 40 MPa. Oxidized alloy plates were cemented between two aluminum cylinders with a high-strength cyanoacrylate cement and loaded in tension until failure occurred either at the oxide/metal interface, within the oxide layer, or in the cement itself. Significant differences were found among the oxide adherence values obtained from different PFM alloys. The oxides formed on five of the alloys exhibited adherence strengths in excess of the published value for cohesive strength of dental opaque porcelain, indicating that they possess sufficient adherence to act as the transition zone between the porcelain and the alloy. In addition, a correspondence was found between the quality of porcelain bond for a given alloy and its oxide adherence strength. These results remove the principal objection to the oxide-layer theory of porcelain bonding in dental alloy systems and emphasize the importance of oxide adherence in the establishment of a bond. It is therefore suggested that future work devoted to porcelain-metal bonding should seek to elucidate the mechanism of oxide adherence to PFM alloys and explore the development of new alloys which form adherent oxides.

  19. Asthma and Adherence to Inhaled Corticosteroids

    DEFF Research Database (Denmark)

    Bårnes, Camilla Boslev; Ulrik, Charlotte Suppli

    2015-01-01

    Inhaled corticosteroids (ICS) are the cornerstone of maintenance asthma therapy. However, in spite of this, adherence to ICS remains low. The aim of this systematic literature review was to provide an overview of the current knowledge of adherence to ICS, effects of poor adherence, and means...... was found to be between 22 and 63%, with improvement up to and after an exacerbation. Poor adherence was associated with youth, being African-American, having mild asthma, ... prescribed fixed-combination therapy (ICS and long-acting β2 agonists). Good adherence was associated with higher FEV1, a lower percentage of eosinophils in sputum, reduction in hospitalizations, less use of oral corticosteroids, and lower mortality rate. Overall, 24% of exacerbations and 60% of asthma...

  20. Surface bioactivity of plasma implanted silicon and amorphous carbon

    Institute of Scientific and Technical Information of China (English)

    Paul K CHU

    2004-01-01

    Plasma immersion ion implantation and deposition (PⅢ&D) has been shown to be an effective technique to enhance the surface bioactivity of materials. In this paper, recent progress made in our laboratory on plasma surface modification single-crystal silicon and amorphous carbon is reviewed. Silicon is the most important material in the integrated circuit industry but its surface biocompatibility has not been investigated in details. We have recently performed hydrogen PⅢ into silicon and observed the biomimetic growth of apatite on its surface in simulated body fluid. Diamond-like carbon (DLC) is widely used in the industry due to its excellent mechanical properties and chemical inertness. The use of this material in biomedical engineering has also attracted much attention. It has been observed in our laboratory that doping DLC with nitrogen by means of PⅢ can improve the surface blood compatibility. The properties as well as in vitro biological test results will be discussed in this article.

  1. COMMITTED TO CARBON REDUCTION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Chinese efforts to lower carbon emissions through environmentally friendly means begin gaining momentum Efforts to curb carbon emissions continue to take shape as China adheres to its pledge for a brighter, greener future. More importantly, as environmental measures take hold and develop

  2. Structure and properties of diamond and diamond-like films

    Energy Technology Data Exchange (ETDEWEB)

    Clausing, R.E. [Oak Ridge National Lab., TN (United States)

    1993-01-01

    This section is broken into four parts: (1) introduction, (2) natural IIa diamond, (3) importance of structure and composition, and (4) control of structure and properties. Conclusions of this discussion are that properties of chemical vapor deposited diamond films can compare favorably with natural diamond, that properties are anisotropic and are a strong function of structure and crystal perfection, that crystal perfection and morphology are functions of growth conditions and can be controlled, and that the manipulation of texture and thereby surface morphology and internal crystal perfection is an important step in optimizing chemically deposited diamond films for applications.

  3. Transient improvement of urticaria induces poor adherence as assessed by Morisky Medication Adherence Scale-8.

    Science.gov (United States)

    Kaneko, Sakae; Masuda, Koji; Hiragun, Takaaki; Inomata, Naoko; Furue, Masutaka; Onozuka, Daisuke; Takeuchi, Satoshi; Murota, Hiroyuki; Sugaya, Makoto; Saeki, Hidehisa; Shintani, Yoichi; Tsunemi, Yuichiro; Abe, Shinya; Kobayashi, Miwa; Kitami, Yuki; Tanioka, Miki; Imafuku, Shinichi; Abe, Masatoshi; Hagihara, Akihito; Morisky, Donald E; Katoh, Norito

    2015-11-01

    Poor adherence to medication is a major public health challenge. Here, we aimed to determine the adherence to oral and topical medications and to analyze underlying associated factors using the translated Japanese version of Morisky Medication Adherence Scale-8 regarding urticaria treatment. Web-based questionnaires were performed for 3096 registered dermatological patients, along with a subanalysis of 751 registered urticaria patients in this study. The adherence to oral medication was significantly associated with the frequency of hospital visits. Variables that affected the adherence to topical medication included age and experience of drug effectiveness. The rate of responses that "It felt like the symptoms had improved" varied significantly among the dermatological diseases treated with oral medications. Dermatologists should be aware that adherence to the treatment of urticaria is quite low. Regular visits and active education for patients with urticaria are mandatory in order to achieve a good therapeutic outcome by increasing the adherence.

  4. Improving adherence with inhaler therapy in COPD

    Directory of Open Access Journals (Sweden)

    Suzanne C Lareau

    2010-11-01

    Full Text Available Suzanne C Lareau1, Barbara P Yawn21College of Nursing, University of Colorado Denver, Aurora, Colorado; 2Department of Research, Olmsted Medical Center, Rochester, Minnesota, USAAbstract: Chronic obstructive pulmonary disease (COPD is a major public health problem, associated with considerable morbidity and health care costs. The global burden of COPD morbidity is predicted to rise substantially in the coming decade, but could be moderated by better use of existing management strategies. Smoking cessation, medication therapy, and pulmonary rehabilitation have all been shown to diminish morbidity and improve patient outcomes. But each of these strategies requires adherence. Adherence is crucial for optimizing clinical outcomes in COPD, with nonadherence resulting in a significant health and economic burden. Suboptimal medication adherence is common among COPD patients, due to a number of factors that involve the medication, the delivery device, the patient, and the health professionals caring for the patient. Lack of medication adherence needs to be identified and addressed by using simplified treatment regimens, increasing patient knowledge about self-management, and enhancing provider skills in patient education, communication, and adherence counseling. This article reports some of the challenges of medication nonadherence faced by the clinician in the management of COPD, and suggests ways to evaluate and improve adherence effectively in primary care.Keywords: chronic obstructive pulmonary disease, adherence, clinician

  5. Adherence to Antihypertensive Medications in Iranian Patients

    Directory of Open Access Journals (Sweden)

    Azin Behnood-Rod

    2016-01-01

    Full Text Available Introduction. Appropriate adherence to medication is still a challenging issue for hypertensive patients. We determined adherence to antihypertensive(s and its associated factors among 280 Iranian patients. Methods. They were recruited consecutively from private and university health centers and pharmacies in four cities. The validated Persian version of the 8-item Morisky Medication Adherence Scale (MMAS-8 was administered to measure adherence. Results. Mean (±SD overall MMAS-8 score was 5.75 (±1.88. About half of the sample (139 cases, 49.6% showed low adherence (MMAS-8 score < 6. There was a negative linear association between the MMAS-8 score and systolic BP (r=-0.231, P<0.001 as well as diastolic BP (r=-0.280, P<0.001. In linear regression model, overweight/obesity (B=-0.52, P=0.02, previous history of admission to emergency services due to hypertensive crisis (B=-0.79, P=0.001, and getting medication directly from drugstore without refill prescription in hand (B=-0.51, P=0.04 were factors recognized to have statistically significant association with the MMAS-8 score. Conclusion. Antihypertensive adherence was unsatisfactory. We suggest that health care providers pay special attention and make use of the aforementioned findings in their routine visits of hypertensive patients to recognize those who are vulnerable to poor adherence.

  6. Patient Adherence to Biologic Agents in Psoriasis

    DEFF Research Database (Denmark)

    Hsu, Der Yi; Gniadecki, Robert

    2016-01-01

    BACKGROUND: Low adherence to therapies in psoriasis decreases treatment outcomes and increases the total health care costs. In spite of the wide use of biologic agents, patients' adherence to these drugs has not been extensively investigated. OBJECTIVE: The aim of this study is to measure adherence...... adverse effects, and positive attitudes to the treatment. CONCLUSION: Adherence to biologic therapies is very high in patients with psoriasis, which is consistent with a positive attitude to the treatment....... to the biologic drugs in a population of patients treated for psoriasis vulgaris using the medication possession ratio (MPR) index and to survey patients' attitudes to the treatment. METHODS: This is a single-center study on 247 patients with psoriasis vulgaris treated with adalimumab (n = 113), etanercept (n...

  7. Adherence to anti-depressant medication

    DEFF Research Database (Denmark)

    Buus, Niels

    2014-01-01

    The study of medicine taking is controversial as it often reveals a discrepancy between healthcare professionals' advice and patients' actual behaviour. Qualitative researchers have examined depressed people's adherence to prescriptions of antidepressants by exploring the meaning they impute to t...

  8. Superlubricity in vehicles. New carbon-based materials reduce fuel consumption and wear; Supraschmierung im Automobil. Neue, kohlenstoffbasierte Werkstoffe mindern Kraftstoffverbrauch und Verschleiss

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Franz

    2012-07-01

    During the long development history of mechanical engineering, engineers have substantially exhausted the traditional methods of reducing friction. Further optimisations are mostly just a matter of a few per cent. Innovative coatings made of diamond-like, shiny black carbon compounds can now exploit their advantages. They combine extraordinary lubricity with anti-adhesive properties, chemical stability and extreme material hardness. In the Pegasus research project, scientists from research and industry are working on their large-scale use for drive trains in vehicles. (orig.)

  9. Mobile Applications to Improve Medication Adherence.

    Science.gov (United States)

    Haase, Jamie; Farris, Karen B; Dorsch, Michael P

    2017-02-01

    Background and Introduction: Mobile applications are useful tools to improve medication adherence. As developers continue to improve the features of existing mobile applications, pharmacists should be aware of the current features that are available to patients. There are limited studies available that discuss which applications have the most desirable features. The aim of this study was to compare available mobile applications and identify ideal application features used to improve medication adherence.

  10. Microbicide clinical trial adherence: insights for introduction

    Directory of Open Access Journals (Sweden)

    Cynthia Woodsong

    2013-04-01

    Full Text Available After two decades of microbicide clinical trials it remains uncertain if vaginally- delivered products will be clearly shown to reduce the risk of HIV infection in women and girls. Furthermore, a microbicide product with demonstrated clinical efficacy must be used correctly and consistently if it is to prevent infection. Information on adherence that can be gleaned from microbicide trials is relevant for future microbicide safety and efficacy trials, pre-licensure implementation trials, Phase IV post-marketing research, and microbicide introduction and delivery. Drawing primarily from data and experience that has emerged from the large-scale microbicide efficacy trials completed to-date, the paper identifies six broad areas of adherence lessons learned: (1 Adherence measurement in clinical trials, (2 Comprehension of use instructions/Instructions for use, (3 Unknown efficacy and its effect on adherence/Messages regarding effectiveness, (4 Partner influence on use, (5 Retention and continuation and (6 Generalizability of trial participants' adherence behavior. Each is discussed, with examples provided from microbicide trials. For each of these adherence topics, recommendations are provided for using trial findings to prepare for future microbicide safety and efficacy trials, Phase IV post-marketing research, and microbicide introduction and delivery programs.

  11. Nanocomposite tantalum-carbon-based films deposited by femtosecond pulsed laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Benchikh, N. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Garrelie, F. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Wolski, K. [Ecole Nationale Superieure des Mines de Saint-Etienne, Centre SMS - URA CNRS 5146, 158 cours Fauriel, 42023 Saint-Etienne, Cedex 02 (France); Donnet, C. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France)]. E-mail: Christophe.Donnet@univ-st-etienne.fr; Fillit, R.Y. [Ecole Nationale Superieure des Mines de Saint-Etienne, Centre SMS - URA CNRS 5146, 158 cours Fauriel, 42023 Saint-Etienne, Cedex 02 (France); Rogemond, F. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Subtil, J.L. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Rouzaud, J.N. [Laboratoire de Geologie de l' Ecole Normale Superieure de Paris 24, rue Lhomond 75231-Paris Cedex 5 (France); Laval, J.Y. [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, 10 rue Vauquelin 75231-Paris Cedex 05 (France)

    2006-01-03

    Nanostructured coatings of metal (tantalum) containing diamond-like carbon (a-C:Ta) have been prepared by femtosecond pulsed laser deposition (PLD). The films, containing 15 at.% tantalum, have been deposited by ablating sequentially graphite and metallic tantalum in vacuum conditions with an amplified Ti:sapphire laser. The coatings have been investigated by X-ray photoelectron spectroscopy, grazing angle X-ray diffraction, energy filtered transmission electron microscopy, scanning and high resolution transmission electron microscopies. Evidence of metallic {alpha}-Ta and {beta}-Ta particles (diameter in the 100 nm range) and smaller quasi-amorphous tantalum clusters embedded in the carbonaceous matrix have been shown. A thin tantalum carbide interface between the carbon matrix and the top surface of the tantalum nodules has also been identified. The ability of femtosecond pulsed laser deposition to synthetize nanocomposite carbon-based films and to control their nanostructure is discussed.

  12. In situ electron spectroscopic identification of carbon species deposited by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Samano, E.C.; Gamietea, A.; Cota, L. [IFUNAM, Ensenada (Mexico). Lab. de Ensenada; Soto, G. [IFUNAM, Ensenada (Mexico). Lab. de Ensenada]|[Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico). Programa de Posgrado en Fisica de Materiales

    1997-05-01

    Thin carbon films were grown on Si (111) substrates by ablating a graphite target utilizing an excimer pulsed laser in a UHV Riber {copyright} LDM-32 system. Two kinds of films were produced, a highly oriented pyrolytic graphite (HOPG) type and a diamond-like carbon (DLC) type. A relationship of the films microstructure with laser power density and substrate conditions was observed. The HOPG films were homogeneous but the DLC films were heterogeneous, as shown by micrographs. The thin films are monitored and analyzed in situ during the first stages of the deposition process. The monitoring was done by RHEED and the characterization by several surface spectroscopic techniques, AES, XPS and EELS. The formation of a SiC interface was observed for both films due to the reaction of the first carbon species with the substrate surface.

  13. Amorphous carbon buffer layers for separating free gallium nitride films

    Science.gov (United States)

    Altakhov, A. S.; Gorbunov, R. I.; Kasharina, L. A.; Latyshev, F. E.; Tarala, V. A.; Shreter, Yu. G.

    2016-11-01

    The possibility of using amorphous diamond-like carbon (DLC) films for self-separation of gallium nitride (GaN) layers grown by hydride vapor-phase epitaxy has been analyzed. DLC films have been synthesized by plasma-enhanced chemical vapor deposition under low pressure on sapphire (Al2O3) substrates with a (0001) crystallographic orientation. The samples have been studied by the methods of Raman scattering and X-ray diffraction analysis. It is shown that thin DLC films affect only slightly the processes of nucleation and growth of gallium nitride films. Notably, the strength of the "GaN film-Al2O3" substrate interface decreases, which facilitates separation of the GaN layers.

  14. Adherence in patients with chronic treatment: data of “adherence day 2013”

    Directory of Open Access Journals (Sweden)

    Olatz Ibarra Barrueta

    2015-01-01

    Full Text Available Objetive: The primary objective of this study was to evaluate the adherence level in chronic conditions patients during “The Adherence Day” celebrated on November 15, 2013. Methods: We performed a transversal, observational and multicenter study at 43 Spanish hospitals, in order to estimate adherence in chronic treatments. We used the validated questionnaires Haynes- Sackett and Morisky- Green to measure medication adherence; but also a visual analogue scale and questions related with treatment complexity and selective adherence were applied. We performed a descriptive analysis and the closeness of agreement between questionnaires results. Results: A total of 723 surveys were collected especially among outpatients. 43% of the participants were women, with a median age of 51 and taking 3 drugs per day. 10.8% of the patients reported to have difficulty taking their pills according to Haynes- Sackett test. However, depending on Morisky- Green questionnaire, 56.4% of the participants were totally compliant; but considering only the question about forgetfulness, more were adherents (77%. 71% of the patients considered their compliance level as good (more than 8 according to visual analogue scale. And 11% presented a selective adherence, no taking equally well all the medications. The closeness of agreement between questionnaires and Morisky- Green test, as gold standard, was poor for Haynes- Sackett and weak for visual analogue scale. Conclusions: In our study only 56% of the patients with chronic treatment had a perfect adherence

  15. Assessing adherence factors in patients under topical treatment: development of the Topical Therapy Adherence Questionnaire (TTAQ).

    Science.gov (United States)

    Zschocke, Ina; Mrowietz, Ulrich; Lotzin, Annett; Karakasili, Eleni; Reich, Kristian

    2014-04-01

    Medication adherence rates strongly depend on favorable disease outcomes. It is known that medication adherence rates are lower for topical treatment than for systemic treatment. However, to date no validated instrument for the assessment of adherence factors in topical treatment is available. The aim of this study was to develop a new questionnaire to assess adherence risk factors in topical treatment. The development of the Topical Therapy Adherence Questionnaire (TTAQ) and Patient Preference Questionnaire (PPQ) was based on a systematic literature review, and qualitative patient focus interviews and expert focus groups' input. The psychometric properties and comprehensibility of the TTAQ and PPQ were assessed in a feasibility study with 59 psoriasis patients. Our first preliminary results indicate that the TTAQ and PPQ are psychometrically sound and reliable measures for the assessment of factors influencing topical treatment adherence. The questionnaires are currently being further developed and various parameters (e.g., time point of assessment) are currently being tested in an exploratory pilot study with ca. 2,000 psoriasis patients receiving topical treatment in a European clinical trial. The use of the final versions of TTAQ and PPQ in clinical practice may facilitate the early identification of specific non-adherence factors in patients under topical treatment, which could enable designing and applying adherence-enhancing interventions according to the patient's individual needs.

  16. Synthesis and characterization of carbon-coated cobalt ferrite nanoparticles

    Science.gov (United States)

    Bakhshi, Hamed; Shokuhfar, Ali; Vahdati, Nima

    2016-09-01

    Cobalt ferrite nanoparticles (CFNPs) were prepared via a reverse micelle method. The CFNPs were subsequently coated with carbon shells by means of thermal chemical vapor deposition (TCVD). In this process, acetylene gas (C2H2) was used as a carbon source and the coating was carried out for 1, 2, or 3 h at 750°C. The Ar/C2H2 ratio was 10:1. Heating during the TCVD process resulted in a NP core size that approached 30 nm; the thickness of the shell was less than 10 nm. The composition, structure, and morphology of the fabricated composites were characterized using X-ray diffraction, simultaneous thermal analysis, transmission electron microscopy, high-resolution transmission electron microscopy, and selected-area diffraction. A vibrating sample magnetometer was used to survey the samples' magnetic properties. The deposited carbon shell substantially affected the growth and magnetic properties of the CFNPs. Micro-Raman spectroscopy was used to study the carbon coating and revealed that the deposited carbon comprised graphite, multiwalled carbon nanotubes, and diamond- like carbon. With an increase in coating time, the intensity ratio between the amorphous and ordered peaks in the Raman spectra decreased, which indicated an increase in crystallite size.

  17. Improving medication adherence in patients with hypertension

    DEFF Research Database (Denmark)

    Hedegaard, Ulla; Kjeldsen, Lene Juel; Pottegård, Anton

    2015-01-01

    BACKGROUND: and Purpose: In patients with hypertension, medication adherence is often suboptimal, thereby increasing the risk of ischemic heart disease and stroke. In a randomized trial, we investigated the effectiveness of a multifaceted pharmacist intervention in a hospital setting to improve...... medication adherence in hypertensive patients. Motivational interviewing was a key element of the intervention. METHODS: Patients (N=532) were recruited from 3 hospital outpatient clinics and randomized to usual care or a 6-month pharmacist intervention comprising collaborative care, medication review......, tailored adherence counselling including motivational interviewing and telephone follow-ups. The primary outcome was composite medication possession ratio (MPR) to antihypertensive and lipid-lowering agents, at one-year follow-up, assessed by analyzing pharmacy records. Secondary outcomes at 12 months...

  18. Adherence to diabetes medication in individuals with schizophrenia:a systematic review of rates and determinants of adherence

    OpenAIRE

    Gorczynski, Paul; Patel, Hiren; Ganguli, Rohan

    2014-01-01

    Introduction: Despite the importance of medication adherence for the effective treatment of type II diabetes mellitus (T2DM), little research has examined adherence with diabetes medication treatment in schizophrenia. The purpose of this systematic review was to 1) evaluate rates of adherence and determinants of adherence with medication for T2DM in individuals with schizophrenia, and, where possible, 2) examine the relationship between medication adherence and glycemic control. Methods: Stud...

  19. Factors affecting medication adherence in elderly people

    Directory of Open Access Journals (Sweden)

    Jin HK

    2016-10-01

    Full Text Available Hyekyung Jin,1 Yeonhee Kim,2 Sandy Jeong Rhie1,3 1College of Pharmacy, 2Center for Excellence in Teaching & Learning, 3Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul, Republic of Korea Background: Little is known about the functional health literacy (FHL associated with medication adherence in elderly patients. The aim of this study was to examine the FHL among older adults and identify influencing factors that can predict medication adherence. Methods: This was a cross-sectional survey. Participants (n=160 aged 65 years and older were selected from outpatient clinics of 3 tertiary care hospitals, 6 community pharmacies, and 2 senior centers between November 1 and 30, 2014. The participants’ FHL was measured using the Korean Functional Health Literacy Test, which consists of 15 items including 8 numeracy and 7 reading comprehension items. Medication adherence was measured by the Adherence to Refills and Medication Scale. Descriptive statistics, chi-square or Fisher’s exact test, and multiple regression analyses were used to analyze the data. Results: The mean score of the total FHL was 7.72±3.51 (range 0–15. The percentage of the total number of correct answers for the reading comprehension subtest and numeracy subtest were 48.1% and 54.4%, respectively. Among 160 participants, 52.5% showed low adherence to medication. The factors affecting medication adherence included the patient’s degree of satisfaction with the service (β=-0.215, P=0.022, sufficient explanation of medication counseling (β=-0.335, P=0.000, education level (β=-0.153, P=0.045, health-related problems (β=-0.239, P=0.004, and dosing frequency (β=0.189, P=0.018. Conclusion: In this study, we found medication adherence of elderly patients was associated with education level, health-related problems, dosing frequency, satisfaction with patient counseling, and explanation of medication, but no association was found with FHL. Pharmacists

  20. Adherence to methotrexate in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Bliddal, Henning; Eriksen, Stine A; Christensen, Robin;

    2015-01-01

    Objectives. To study adherence to methotrexate (MTX) and factors of importance thereof in patients with rheumatoid arthritis (RA). Methods. Patients with a hospital diagnosis of RA (ICD10 codes M05.X or M06.X) after January 1, 1997, and aged ≥18 years at the date of first diagnosis/contact, with ......Objectives. To study adherence to methotrexate (MTX) and factors of importance thereof in patients with rheumatoid arthritis (RA). Methods. Patients with a hospital diagnosis of RA (ICD10 codes M05.X or M06.X) after January 1, 1997, and aged ≥18 years at the date of first diagnosis...

  1. Antibacterial efficacy of advanced silver-amorphous carbon coatings deposited using the pulsed dual cathodic arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Endrino, J L; Anders, A; Albella, J M; Horton, J A; Horton, T H; Ayyalasomayajula, P R; Allen, M, E-mail: jlendrino@icmm.csic.es

    2010-11-01

    Amorphous carbon (a-C) also referred as diamond-like carbon (DLC) films are well known to be a biocompatible material with good chemical in ertness; this makes it a strong candidate to be used as a matrix that embeds metallic elements with an antimicrobial effect. We have deposited as et of a-C:Ag films using a dual-cathode pulsed filtered cathodic arc source, the arc pulse frequency of the silver and graphite cathodes was controlled in order to obtain samples with various silver contents. In this study, we show the deposition of silver and carbon ions using this technique and analyze the advantages of incorporating silver into a-C by studying the antimicrobial properties against staphylococcus of samples deposited on Ti{sub 6}Al{sub 4}V coupons and evaluated using 24-well tissue culture plates.

  2. Introducing the Adherence Strategy Engineering Framework (ASEF)

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Toftegaard, Thomas Skjødeberg; Bertelsen, Olav W.

    2013-01-01

    Background: Patients performing self-care in the unsupervised setting do not always adhere to the instructions they were initially provided with. As a consequence, a patient’s ability to successfully comply with the treatment plan cannot be verified by the treating healthcare professional, possib...

  3. Community health workers adherence to referral guidelines

    DEFF Research Database (Denmark)

    Lal, Sham; Ndyomugenyi, Richard; Paintain, Lucy

    2016-01-01

    Background Many malaria-endemic countries have implemented national community health worker (CHW) programmes to serve remote populations that have poor access to malaria diagnosis and treatment. Despite mounting evidence of CHWs’ ability to adhere to malaria rapid diagnostic tests (RDTs) and trea......Background Many malaria-endemic countries have implemented national community health worker (CHW) programmes to serve remote populations that have poor access to malaria diagnosis and treatment. Despite mounting evidence of CHWs’ ability to adhere to malaria rapid diagnostic tests (RDTs......) and treatment guidelines, there is limited evidence whether CHWs adhere to the referral guidelines and refer severely ill children for further management. In southwest Uganda, this study examined whether CHWs referred children according to training guidelines and described factors associated with adherence...... to the referral guideline. Methods A secondary analysis was undertaken of data collected during two cluster-randomized trials conducted between January 2010 and July 2011, one in a moderate-to-high malaria transmission setting and the other in a low malaria transmission setting. All CHWs were trained to prescribe...

  4. Barriers to adherence in cystic fibrosis

    DEFF Research Database (Denmark)

    Bregnballe, Vibeke; Schiøtz, Peter Oluf

    2012-01-01

    Danish patients with cystic fibrosis aged 14 to 25 years and their parents. Conclusions: The present study showed that the majority of adolescents with CF and their parents experienced barriers to treatment adherence. Patients and parents agreed that the three most common barriers encountered lack...

  5. DRUG COMPLIANCE AND ADHERENCE TO TREATMENT

    Directory of Open Access Journals (Sweden)

    Manmohan

    2012-09-01

    Full Text Available ABSTRACT: BACKGROUND: In spite of any number of medicines will not be of use unless patient takes’ them. After diagnosing the disease, the next most i mportant step is to follow the instructions of physician in terms of treatment. The doctor’s respons ibility does not end with writing prescription, assuming patient will adhere to it. He/ she should cross check the behavior of patient for drug compliance and see that patient follo ws it and get the benefit. Non compliance is the main barrier for the effective delivery of the medical care. This will have greater implications on the economic burde n on the country in terms of frequent hospitalization, use of expensive medicines in case o f relapse due to non adherence.Though the terms compliance and adherence are used synonymously , they differ in the delivery of quality of the medicare as the former implicates the passive fol lowing of the physician instruction, while in the later, patient actively participates in the dev elopment of the treatment plan, which will improves outcome of the treatment. Adherence is the preferred term over compliance by WHO.

  6. Psoriasis: improving adherence to topical therapy.

    NARCIS (Netherlands)

    Feldman, S.R.; Horn, E.J.; Balkrishnan, R.; Basra, M.K.; Finlay, A.Y.; McCoy, D.; Menter, A.; Kerkhof, P.C.M. van de

    2008-01-01

    Topical therapy has an important role in psoriasis treatment. It is efficacious and has a favorable safety profile as demonstrated in clinical trials. However, poor treatment outcomes from topical therapy regimens likely result from poor adherence and ineffective use of the medication. The Internati

  7. Adherence to Exercise and Physical Activity: Preface.

    Science.gov (United States)

    Morgan, William P.; Dishman, Rod K.

    2001-01-01

    Introduces a collection of papers on adherence to exercise programs and physical activity from the 2000 American Academy of Kinesiology and Physical Education conference, which included research on middle school boys and girls, college men and women, and men and women in the later years, as well as on the more traditional subject of middle aged…

  8. Non-adherence in difficult asthma and advances in detection.

    Science.gov (United States)

    Lindsay, John T; Heaney, Liam G

    2013-12-01

    Non-adherence to anti-inflammatory therapies is common in patients referred for specialist assessment at difficult-to-treat asthma services. In the difficult asthma setting, non-adherence to treatment is associated with poor baseline asthma control, increased frequency of exacerbations and asthma-related hospitalizations, as well as increased risk of death. Here, we present a review of the current literature surrounding the prevalence and risks of non-adherence in difficult asthma and we report on current methods of measuring treatment adherence and advances in the detection of non-adherence. We will also explore methods by which non-adherence in difficult asthma can be addressed.

  9. Hybrid carbon nanomaterials for electrochemical detection of biomolecules

    Science.gov (United States)

    Laurila, Tomi

    2015-09-01

    Electrochemical detection of different biomolecules in vivo is a promising path towards in situ monitoring of human body and its functions. However, there are several major obstacles, such as sensitivity, selectivity and biocompatiblity, which must be tackled in order to achieve reliably and safely operating sensor devices. Here we show that by utilizing hybrid carbon materials as electrodes to detect two types of neurotransmitters, dopamine and glutamate, several advantages over commonly used electrode materials can be achieved. In particular, we will demonstrate here that it is possible to combine the properties of different carbon allotropes to obtain hybrid materials with greatly improved electrochemical performance. Three following examples of the approach are given: (i) diamond-like carbon (DLC) thin film electrodes with different layer thicknesses, (ii) multi-walled carbon nanotubes grown directly on top of DLC and (iii) carbon nanofibres synthesized on top of DLC thin films. Detailed structural and electrochemical characterization is carried out to rationalize the reasons behind the observed behvior. In addition, results from the atomistic simulations are utilized to obtain more information about the properties of the amorphous carbon thin films.

  10. A novel method for preparing adherent hydroxyapatite coating on carbon/carbon composite surface%一种碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法

    Institute of Scientific and Technical Information of China (English)

    李冬梅; 熊信柏; 邹春莉; 马楚凡

    2011-01-01

    背景:目前在碳/碳表面制备羟基磷灰石涂层的方法有很多种,但所制涂层与基体的结合强度不高.目的:提出一种在碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法.方法:首先利用感应加热法在基体表面制备出无水磷酸氢钙涂层,而后对其进行水热处理,转变为羟基磷灰石相.扫描电镜观察涂层的形貌,划痕法测试涂层的临界载荷,顶出法测试剪切强度.结果与结论:感应热沉积法可以在碳/碳复合材料表面制备出致密的块状晶粒结构的无水磷酸氢钙涂层;通过水热处理可以将其转变成结晶完好致密的羟基磷灰石涂层.涂层的临界载荷为13.31 N,剪切强度约为47 MPa.%BACKGROUND:At present, there are many methods for preparing hydroxyapatite (HA) coating on carbon/carbon composite surface, but the bonding strength between the prepared coating and the substrate is not high.OBJECTIVE:To propose a novel method for preparing HA coating with high bonding strength on carbon/carbon composite surface.METHODS:Firstly, monetite coating was deposited on carbon/carbon composite using induction heating technique, and then the monetite coating was converted to HA by hydrothermal method in ammonia solution. The morphology of the coating was observed under scanning electron microscopy, the critical load of HA coating was determined using scratch test, and shear strength was detected with extrusion method.RESULTS AND CONCLUSION:Using induction heat deposition method, dense block anhydrous dicalcium phosphate coating with grain structure was prepared in the carbon/carbon composite surface, and then transformed into dense HA coating with good crystals by hydrothermal method. The critical load of HA coating is 13.31 N and shear strength is 47 MPa.

  11. Bacterial adherence to anodized titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Peremarch, C Perez-Jorge; Tanoira, R Perez; Arenas, M A; Matykina, E; Conde, A; De Damborenea, J J; Gomez Barrena, E; Esteban, J, E-mail: cperemarch@fjd.es

    2010-11-01

    The aim of this study was to evaluate Staphylococcus sp adhesion to modified surfaces of anodized titanium alloy (Ti-6Al-4V). Surface modification involved generation of fluoride-containing titanium oxide nanotube films. Specimens of Ti-6Al-4V alloy 6-4 ELI-grade 23- meets the requirements of ASTM F136 2002A (AMS 2631B class A1) were anodized in a mixture of sulphuric/hydrofluoric acid at 20 V for 5 and 60 min to form a 100 nm-thick porous film of 20 nm pore diameter and 230 nm-thick nanotube films of 100 nm in diameter. The amount of fluorine in the oxide films was of 6% and of 4%, respectively. Collection strains and six clinical strains each of Staphylococcus aureus and Staphylococcus epidermidis were studied. The adherence study was performed using a previously published protocol by Kinnari et al. The experiments were performed in triplicates. As a result, lower adherence was detected for collection strains in modified materials than in unmodified controls. Differences between clinical strains were detected for both species (p<0.0001, Kruskal-Wallis test), although global data showed similar results to that of collection strains (p<0.0001, Kruskal-Wallis test). Adherence of bacteria to modified surfaces was decreased for both species. The results also reflect a difference in the adherence between S. aureus and S. epidermidis to the modified material. As a conclusion, not only we were able to confirm the decrease of adherence in the modified surface, but also the need to test multiple clinical strains to obtain more realistic microbiological results due to intraspecies differences.

  12. Experiencing antiretroviral adherence: helping healthcare staff better understand adherence to paediatric antiretrovirals

    Directory of Open Access Journals (Sweden)

    Phelps Benjamin R

    2010-12-01

    Full Text Available Abstract Background Lack of adherence to antiretroviral medications is one of the key challenges for paediatric HIV care and treatment programmes. There are few hands-on opportunities for healthcare workers to gain awareness of the psychosocial and logistic challenges that caregivers face when administering daily antiretroviral therapy to children. This article describes an educational activity that allows healthcare workers to simulate this caregiver role. Methods Paediatric formulations of several antiretroviral medications were dispensed to a convenience sample of staff at the Baylor College of Medicine-Bristol-Myers Squibb Children's Clinical Center of Excellence in Mbabane, Swaziland. The amounts of the medications remaining were collected and measured one week later. Adherence rates were calculated. Following the exercise, a brief questionnaire was administered to all staff participants. Results The 27 clinic staff involved in the exercise had varying and low adherence rates over the week during which the exercise was conducted. Leading perceived barriers to adherence included: "family friends don't help me remember/tell me I shouldn't take it" and "forgot". Participants reported that the exercise was useful as it allowed them to better address the challenges faced by paediatric patients and caregivers. Conclusions Promoting good adherence practices among caregivers of children on antiretrovirals is challenging but essential in the treatment of paediatric HIV. Participants in this exercise achieved poor adherence rates, but identified with many of the barriers commonly reported by caregivers. Simulations such as this have the potential to promote awareness of paediatric ARV adherence issues among healthcare staff and ultimately improve adherence support and patient outcomes.

  13. Ensuring medication adherence with direct oral anticoagulant drugs: lessons from adherence with vitamin K antagonists (VKAs).

    Science.gov (United States)

    Di Minno, Alessandro; Spadarella, Gaia; Tufano, Antonella; Prisco, Domenico; Di Minno, Giovanni

    2014-05-01

    Medication adherence (taking drugs properly) is uncommon among patients on warfarin. Poor adherence to warfarin leads to an increase in adverse medical events, including stroke in atrial fibrillation (AF). Factors related to patients, physicians and the health system account for poor adherence. Direct oral anticoagulants (DOACs) are easier to use than warfarin, with fewer drug and food interactions and no need for routine blood monitoring. A proper use of DOACs may reduce the risk of stroke in AF. However, in clinical settings where no laboratory monitoring is needed, a poor medication adherence is common and may impact clinical outcomes. In the management of chronic disorders, careful knowledge of the individual patient's attitudes and behaviors is a pre-requisite for a successful doctor-patient communication. To increase patient's awareness of the risks and benefits of DOACs and, in turn, increase medication adherence, at each follow-up visit physicians should screen for priorities and motivational problems; check for the lack of understanding and/or knowledge; assess any health system or personal barriers to medication adherence; identify appropriate interventions and provide tailored support to patient needs. Dissemination of guidelines to the health care chain (prescribing physician, general practitioners, caregivers, nurses, pharmacists) further encourages medication adherence. However, the long-term effect of some of these strategies is unknown; one tool may not fit all patients, and the prescribing physician should consider individualization of these aids to ensure medication adherence and persistence (continuing to take drugs properly in long-term treatments) for DOACs in every day practice.

  14. Controlled Deposition and Alignment of Carbon Nanotubes

    Science.gov (United States)

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  15. Adherence of Moraxella bovis to cell cultures of bovine origin.

    Science.gov (United States)

    Annuar, B O; Wilcox, G E

    1985-09-01

    The adherence of five strains of Moraxella bovis to cell cultures was investigated. M bovis adhered to cultures of bovine corneal epithelial and Madin-Darby bovine kidney cells but not to cell types of non-bovine origin. Both piliated and unpiliated strains adhered but piliated strains adhered to a greater extent than unpiliated strains. Antiserum against pili of one strain inhibited adherence of piliated strains but caused only slight inhibition of adherence to the unpiliated strains. Treatment of bacteria with magnesium chloride caused detachment of pili from the bacterial cell and markedly inhibited adherence of piliated strains but caused only slight inhibition of adherence by the unpiliated strains. The results suggested that adhesion of piliated strains to cell cultures was mediated via pili but that adhesins other than pili may be involved in the attachment of unpiliated strains of M bovis to cells.

  16. Improving adherence to medical regimens for juvenile rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Lindsley Carol B

    2007-05-01

    Full Text Available Abstract Poor adherence to medical regimens can compromise the efficacy of treatments for children and adolescents with juvenile rheumatoid arthritis (JRA. The purpose of this review is to describe medical regimens for the treatment of JRA and the rates of adherence to these regimens. We also summarize and critically the few research studies aimed at improving adherence to regimens for JRA. Finally, we summarize strategies for enhancing adherence in clinical practice.

  17. Iron Chelation Adherence to Deferoxamine and Deferasirox in Thalassemia

    OpenAIRE

    Trachtenberg, Felicia; Vichinsky, Elliott; Haines, Dru; Pakbaz, Zahra; Mednick, Lauren; Sobota, Amy; Kwiatkowski, Janet; Thompson, Alexis A.; Porter, John; Coates, Thomas; Giardina, Patricia J.; Olivieri, Nancy; Yamashita, Robert; Neufeld, Ellis J.

    2011-01-01

    The Thalassemia Clinical Research Network collected adherence information from 79 patients on deferoxamine and 186 on deferasirox from 2007 to 2009. Chelation adherence was defined as percent of doses administered in the last 4 weeks (patient report) out of those prescribed (chart review). Chelation history since 2002 was available for 97 patients currently on deferoxamine and 217 on deferasirox, with crude estimates of adherence from chart review. Self-reported adherence to both deferoxamine...

  18. Medication adherence among transgender women living with HIV

    OpenAIRE

    2016-01-01

    Medication adherence is linked to health outcomes among adults with HIV infection. Transgender women living with HIV (TWLWH) in the U.S. report suboptimal adherence to medications and are found to have difficulty integrating HIV medication into their daily routine, but few studies explore factors associated with medication adherence among transgender women. Thus, the purpose of this paper is to examine demographic and clinical factors related to self-reported medication adherence among transg...

  19. Understanding how adherence goals promote adherence behaviours: a repeated measure observational study with HIV seropositive patients

    Directory of Open Access Journals (Sweden)

    Jones Gareth

    2012-08-01

    Full Text Available Abstract Background The extent to which patients follow treatments as prescribed is pivotal to treatment success. An exceptionally high level (> 95% of HIV medication adherence is required to suppress viral replication and protect the immune system and a similarly high level (> 80% of adherence has also been suggested in order to benefit from prescribed exercise programmes. However, in clinical practice, adherence to both often falls below the desirable level. This project aims to investigate a wide range of psychological and personality factors that may lead to adherence/non-adherence to medical treatment and exercise programmes. Methods HIV positive patients who are referred to the physiotherapist-led 10-week exercise programme as part of the standard care are continuously recruited. Data on social cognitive variables (attitude, intention, subjective norms, self-efficacy, and outcome beliefs about the goal and specific behaviours, selected personality factors, perceived quality of life, physical activity, self-reported adherence and physical assessment are collected at baseline, at the end of the exercise programme and again 3 months later. The project incorporates objective measures of both exercise (attendance log and improvement in physical measures such as improved fitness level, weight loss, improved circumferential anthropometric measures and medication adherence (verified by non-invasive hair analysis. Discussion The novelty of this project comes from two key aspects, complemented with objective information on exercise and medication adherence. The project assesses beliefs about both the underlying goal such as following prescribed treatment; and about the specific behaviours such as undertaking the exercise or taking the medication, using both implicit and explicit assessments of patients’ beliefs and attitudes. We predict that i the way people think about the underlying goal of their treatments explains medication and exercise

  20. Medication Adherence in Psychopharmacologically Treated Adults with ADHD

    Science.gov (United States)

    Safren, Steven A.; Duran, Petra; Yovel, Iftah; Perlman, Carol A.; Sprich, Susan

    2007-01-01

    Objective: One of the potential causes of residual symptoms of ADHD in adults can be difficulties with consistent adherence to medications. Method: This formative study examined self-reported medication adherence in adults with ADHD with clinically significant symptoms despite medication treatment. Results: Mean adherence for the two-week period…

  1. Adhesion Forces and Composition of Planktonic and Adhering Oral Microbiomes

    NARCIS (Netherlands)

    Wessel, S. W.; Chen, Y.; Maitra, A.; van den Heuvel, E. R.; Slomp, A. M.; Busscher, H. J.; van der Mei, H. C.

    2014-01-01

    The oral microbiome consists of a planktonic microbiome residing in saliva and an adhering microbiome (the biofilm adhering to oral hard and soft tissues). Here we hypothesized that possible differences in microbial composition of the planktonic and adhering oral microbiome on teeth can be related t

  2. Measuring adherence to treatment of paediatric HIV/AIDS.

    Science.gov (United States)

    Naar-King, S; Frey, M; Harris, M; Arfken, C

    2005-04-01

    Parent, child, physician report and pill counts were used to measure adherence in paediatric HIV. Relationships to viral load were assessed. Pill counts were considered invalid. Adherence measures did not correlate with one another. Physicians reported lower adherence than parents, but parent and physician report correlated with viral load. The clinical and research utility of the various measures are discussed.

  3. 78 FR 34109 - ``Script Your Future'' Medication Adherence Campaign

    Science.gov (United States)

    2013-06-06

    ... HUMAN SERVICES Food and Drug Administration ``Script Your Future'' Medication Adherence Campaign AGENCY... importance of medication adherence to enhance the health of Americans. Medication adherence is taking... each patient. Nearly three out of four Americans report that they do not take their medication...

  4. A Matter of Trust: Patient Barriers to Primary Medication Adherence

    Science.gov (United States)

    Polinski, J. M.; Kesselheim, A. S.; Frolkis, J. P.; Wescott, P.; Allen-Coleman, C.; Fischer, M. A.

    2014-01-01

    Primary medication adherence occurs when a patient properly fills the first prescription for a new medication. Primary adherence only occurs about three-quarters of the time for antihypertensive medications. We assessed patients' barriers to primary adherence and attributes of patient-provider discussions that might improve primary adherence…

  5. Raman spectra of amorphous carbon films deposited by SWP

    Science.gov (United States)

    Xu, Junqi; Liu, Weiguo; Hang, Lingxia; Su, Junhong; Fan, Huiqing

    2010-10-01

    Amorphous carbon film is one of the most important anti-reflection protective films coated on infrared optical components. In this paper, hydrogen-free amorphous carbon films were deposited by new type surface-wave-sustained plasma (SWP) source with a graphite target at various experiment parameters. The laser Raman spectroscopy at wavelength of 514 nm was used to investigate the structure and bonding of these carbon films. The results showed consanguineous correlations between the intensity ratio ID/IG and the experiment parameters such as microwave power, target voltage and gas pressure applied to the SWP source. Raman spectra proved the structure of these carbon films prepared by SWP technique is typical diamond-like carbon (DLC). The analysis on G peak position and intensity ratio ID/IG indicated that Raman shifts moves to low wavenumber and ID/IG decreases with the increasing of microwave power from 150 W to 330 W. These results means the formation of sp3 bond prefers higher microwave power. DLC films prepared at target voltage of -200 V have higher sp3 content than that of -350 V, moreover, an increase of gas pressure during experiments yields higher sp3 content at the microwave power below 270 W, whereas the change of sp3 content is slight with the various conditions when microwave power exceeds 270 W.

  6. Medication adherence among older adults with schizophrenia.

    Science.gov (United States)

    Leutwyler, Heather C; Fox, Patrick J; Wallhagen, Margaret

    2013-02-01

    Older adults with schizophrenia are a growing segment of the population, yet their physical and mental health status is extremely poor. This article presents findings from a qualitative study that explored the understanding older adults with schizophrenia have of their physical health status. The study was conducted among 28 older adults with schizophrenia from a variety of settings using semi-structured interviews and participant observation. Self-management of psychiatric and non-psychiatric medications and its effect on participants' health status was one of the central themes that emerged from the study. Different styles of medication adherence were identified and factors associated with each style are presented. The findings provide insights into the design of clinical interventions aimed at promoting medication adherence among older adults with schizophrenia.

  7. Improving diabetes medication adherence: successful, scalable interventions

    Directory of Open Access Journals (Sweden)

    Zullig LL

    2015-01-01

    Full Text Available Leah L Zullig,1,2 Walid F Gellad,3,4 Jivan Moaddeb,2,5 Matthew J Crowley,1,2 William Shrank,6 Bradi B Granger,7 Christopher B Granger,8 Troy Trygstad,9 Larry Z Liu,10 Hayden B Bosworth1,2,7,11 1Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, NC, USA; 2Department of Medicine, Duke University, Durham, NC, USA; 3Center for Health Equity Research and Promotion, Pittsburgh Veterans Affairs Medical Center, Pittsburgh, PA, USA; 4Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, PA, USA; 5Institute for Genome Sciences and Policy, Duke University, Durham, NC, USA; 6CVS Caremark Corporation; 7School of Nursing, Duke University, Durham, NC, USA; 8Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC, USA; 9North Carolina Community Care Networks, Raleigh, NC, USA; 10Pfizer, Inc., and Weill Medical College of Cornell University, New York, NY, USA; 11Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA Abstract: Effective medications are a cornerstone of prevention and disease treatment, yet only about half of patients take their medications as prescribed, resulting in a common and costly public health challenge for the US healthcare system. Since poor medication adherence is a complex problem with many contributing causes, there is no one universal solution. This paper describes interventions that were not only effective in improving medication adherence among patients with diabetes, but were also potentially scalable (ie, easy to implement to a large population. We identify key characteristics that make these interventions effective and scalable. This information is intended to inform healthcare systems seeking proven, low resource, cost-effective solutions to improve medication adherence. Keywords: medication adherence, diabetes mellitus, chronic disease, dissemination research

  8. A Study of Adherent Oxide Formation

    Science.gov (United States)

    1983-10-01

    improve oxide scale adherence to NiCrAl were investigated. Laser-processed materials were isothermally and cyclically oxidized and oxide scale...modified NiCrAl altered the morphology of the alumina scale and promoted the formation of a thinner, dense protective layer. • Thin aluminum oxide films...6 A. Materials. ........................... 6 B. Oxidation Studies. ....................... 7 1. NiCrAl .. .......................... 7a2

  9. Pharmacy Adherence Measures to Assess Adherence to Antiretroviral Therapy: Review of the Literature and Implications for Treatment Monitoring

    OpenAIRE

    Mayer, Kenneth H.; McMahon, James H.; Jordan, Michael R.; Kelley, Karen; Bertagnolio, Silvia; Hong, Steven Y.; Wanke, Christine A.; Sharon R Lewin; Elliott, Julian H.

    2011-01-01

    Prescription or pill-based methods for estimating adherence to antiretroviral therapy (ART), pharmacy adherence measures (PAMs), are objective estimates calculated from routinely collected pharmacy data. We conducted a literature review to evaluate PAMs, including their association with virological and other clinical outcomes, their efficacy compared with other adherence measures, and factors to consider when selecting a PAM to monitor adherence. PAMs were classified into 3 categories: medica...

  10. Concordance of adherence measurement using self-reported adherence questionnaires and medication monitoring devices.

    Science.gov (United States)

    Shi, Lizheng; Liu, Jinan; Koleva, Yordanka; Fonseca, Vivian; Kalsekar, Anupama; Pawaskar, Manjiri

    2010-01-01

    The primary objective of this review was to identify and examine the literature on the association between medication adherence self-reported questionnaires (SRQs) and medication monitoring devices. The primary literature search was performed for 1980-2009 using PubMed, PubMed In Process and Non-Indexed, Ovid MEDLINE, Ovid MEDLINE In-Process, PsycINFO (EBSCO), CINAHL (EBSCO), Ovid HealthStar, EMBASE (Elsevier) and Cochrane Databases and using the following search terms: 'patient compliance', 'medication adherence', 'treatment compliance', 'drug monitoring', 'drug therapy', 'electronic', 'digital', 'computer', 'monitor', 'monitoring', 'drug', 'drugs', 'pharmaceutical preparations', 'compliance' and 'medications'. We identified studies that included SRQs and electronic monitoring devices to measure adherence and focused on the SRQs that were found to be moderately to highly correlated with the monitoring devices. Of the 1679 citations found via the primary search, 41 full-text articles were reviewed for correlation between monitoring devices and SRQs. A majority (68%) of articles reported high (27%), moderate (29%) or significant (12%) correlation between monitoring devices (37 using Medication Event Monitoring System [MEMS®] and four using other devices) and SRQs (11 identified and numerous other unnamed SRQs). The most commonly used SRQs were the Adult/Pediatric AIDS Clinical Trial Group (AACTG/PACTG; 24.4%, 10/41) followed by the 4-item Morisky (9.8%, 4/41), Brief Medication Questionnaire (9.8%, 4/41) and visual analogue scale (VAS; 7.3%, 3/41). Although study designs differed across the articles, SRQs appeared to report a higher rate of medication adherence (+14.9%) than monitoring devices. In conclusion, several medication adherence SRQs were validated using electronic monitoring devices. A majority of them showed high or moderate correlation with medication adherence measured using monitoring devices, and could be considered for measuring patient

  11. Can adherence to antihypertensive therapy be used to promote adherence to statin therapy?

    Directory of Open Access Journals (Sweden)

    Richard H Chapman

    2009-08-01

    Full Text Available Richard H Chapman1, Elise M Pelletier1, Paula J Smith1, Craig S Roberts21US Health Economics and Outcomes Research, IMS Health, Falls Church, VA, USA; 2Global Outcomes Research, Pfizer Inc, New York, NY, USAObjective: To compare adherence with statin therapy in patients switching to single-pill amlodipine besylate/atorvastatin calcium with patients adding a separate statin to their amlodipine regimen.Methods: We identified hypertensive patients prescribed amlodipine who switched to amlodipine/atorvastatin (switch or added a statin to their amlodipine regimen (add-on from July 2004 to June 2007. Propensity score matching (1 switch:3 add-on was applied based on ‘nearest neighbor’ approach. The primary adherence measure was patients with proportion of days covered (PDC ≥0.80 at 180 days; secondary measures included mean PDC and persistence. A sensitivity analysis was performed, accounting for total statin/amlodipine exposure.Results: Among 4556 matched patients (n = 1139 switch; n = 3417 add-on, mean age was 53.9 years and 52.1% were male. After 180 days, adherence with statin therapy was higher for the switch vs add-on cohort (50.8% vs 44.3%; P < 0.001. After adjusting for pre-index amlodipine adherence, the switch cohort was more likely to be adherent than the add-on cohort (odds ratio: 1.64 [95% confidence interval: 1.42 to 1.89]. Persistence was higher in the switch than the add-on cohort (127.6 vs 117 days; P < 0.001.Conclusion: Hypertensive patients taking amlodipine who initiated statin therapy via single-pill amlodipine/atorvastatin were more likely to remain adherent to their statin than patients adding a separate statin to their antihypertensive regimen.Keywords: adherence, amlodipine, atorvastatin, cardiovascular disease, persistence, single-pill

  12. Adherence to asthma guidelines in general practices.

    Science.gov (United States)

    Roghmann, M C; Sexton, M

    1999-06-01

    Adherence to asthma practice guidelines is low. Improved compliance could potentially improve care of patients with asthma. The purpose of this study was to determine if patients managed in a general practice with an associated asthma clinic are more likely to use asthma medications according to clinical practice guidelines than patients managed in the general surgery of the practice. A cross-sectional study of adult asthmatics, aged 18-55 years, was conducted in six British general practices. Prescription data on all asthma medication was collected for a 6-month period. Information on asthma clinic attendance, age, sex, employment status, other medical illness, and how patients used their inhaled beta2-agonist was collected through questionnaire. The prescription data for asthma medication and patient use of inhaled beta2-agonist were compared to the British Thoracic Society's (BTS) Guidelines for Management of Asthma in Adults to determine if the patient's asthma medication regimen was appropriate. There was no significant association found between appropriate asthma medication and asthma clinic attendance or other patient characteristics. Adherence to the BTS guidelines was low. Fifty-eight percent of the asthma patients used asthma medication regimens that were not consistent with the BTS guidelines published 1 year earlier. Adherence to the BTS guidelines was low regardless of patient characteristics, including asthma clinic attendance, age, sex, employment status, other medical illness, or individual practice. These findings underscore the need to document the utility of clinical practice guidelines which may improve physician compliance.

  13. Estudo comparativo randomizado do implante de Stent de aço inoxidável recoberto por carbono semelhante ao diamante versus não recoberto em pacientes com doença arterial coronariana Randomized comparative study of diamond-like carbon coated stainless steel stent versus uncoated stent implantation in patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    George César Ximenes Meireles

    2007-04-01

    Full Text Available OBJETIVO: Comparar as taxas de reestenose e de eventos cardíacos maiores em um e seis meses pós-implante de stents recobertos com CSD com os não-recobertos. MÉTODOS: Estudo comparativo, prospectivo, randomizado, de 180 pacientes com diagnóstico de insuficiência coronária, submetidos a implante de stent recoberto com CSD (Phytis® ou stent não-recobertos (Penta®, no período de janeiro de 2003 a julho de 2004. Foram critérios de inclusão: lesão de novo com porcentual de estenose em diâmetro > 50% em artéria coronária com diâmetro de referência > 2,5 mm e OBJECTIVE: To compare restenosis and major cardiac event rates at one and six months after DLC-coated stent implantation with those of uncoated stents. METHODS: Randomized, prospective, comparative study of 180 patients with coronary insufficiency undergoing DLC coated stent (Phytis™ or uncoated stent (Penta™ implantation, from January, 2003 to July, 2004. Inclusion criteria were: de novo lesion with >50% diameter stenosis in a coronary artery with reference diameter > 2,5 mm and < 4 mm, and length < 20 mm. Exclusion criteria were: left main coronary artery and bifurcation lesions, chronic total occlusion, and in-stent restenosis. RESULTS: Clinical and angiographic baseline characteristics of the groups were similar. Procedural success was achieved in 98.9% of the patients in both groups. One cardiac death occurred in each group during hospitalization. Reference diameter and acute gain were greater in the Penta™ group (3.21±0.37 mm vs. 3.34±0.8 mm, p=0.02 and 2.3±0.5 vs. 2.49±0.5, p=0.009, respectively. Angiographic follow-up at six months showed similar rates of restenosis (24.3% vs. 21.8%, p=0.84 and of major cardiac events (16.8% vs. 17.5%, p=1. CONCLUSION: DLC coated stents did not provide better outcomes in relation to uncoated stents.

  14. 中频磁控溅射沉积DLC/TiAlN复合薄膜的结构与性能研究%Microstructures and Properties of Diamond-Like Carbon/TiAlN Composite Films by MF Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    张以忱; 巴德纯; 于大洋; 马胜歌

    2008-01-01

    采用中频非平衡磁控溅射沉积工艺,并施加霍尔离子源辅助沉积,在高速钢W18Cr4V及单晶硅基体上制备了梯度过渡的DIE/TiAlN复合薄膜.利用扫描电镜(SEM)、X射线光电子能谱仪(XPS)、显微硬度计、摩擦磨损仪等分析检测仪器对DLC/TiAlN复合薄膜的表面形貌、晶体结构、显微硬度、耐磨性等性能进行了检测分析.实验及分析结果表明:DLC/TrAlN薄膜平均膜厚为1.1μm,由于薄膜中的Al含量较多,使得复合薄膜的表面比DLC薄膜的表面要粗糙一些;通过对复合薄膜表层的XPS分析可知,ID/IG为2.63.由XPS深层剖析可知,DLC/TiAlN薄膜表层结构与DLC薄膜基本相同,里层则与TiAlN薄膜相似.在梯度过渡膜中,复合膜层之间的界面呈现为渐变过程,结合的非常好.DLC/TiAlN薄膜的显微硬度为2030 HV左右.与DLC薄膜显微硬度接近,低于TiAlN薄膜的显微硬度.但是DLC/TiAlN薄膜的耐磨性要好于TiAlN薄膜和DLC薄膜;DLC/TiAlN薄膜的耐腐蚀性能略好于DLC薄膜.

  15. PMMA树脂义齿表面沉积类金刚石碳膜改善耐磨性的研究%A Study to Improve the Function of Wear-resistance of PMMA Resin Denture Through Depositing the Film of Diamond Like Carbon on the Surface

    Institute of Scientific and Technical Information of China (English)

    马丽丽; 杨喜昆; 李智刚; 朱发坤; 钱天才; 刘磊; 何祥

    2003-01-01

    目的在PMMA树脂义齿表面沉积类金刚石碳(DLC)膜改善义齿的耐磨性能.方法采用真空阴极镀膜方法在PMMA树脂及义齿表面沉积DLC膜,应用光电子能谱仪及喇曼光谱仪确定为DLC膜,通过沉积DLC膜及未沉积DLC膜树脂样品的显微硬度测试、耐磨试验及耐磨试验前后磨痕宽度的测定,观察结果进行统计学处理.结果镀膜与未镀膜PMMA树脂试件显微硬度、磨痕宽度经统计学检验差异有显著性,经显微观察镀膜后PMMA树脂试件磨痕浅而窄,未镀膜试件磨痕深而宽.结论 PMMA树脂义齿表面沉积DLC膜能显著改善耐磨性.

  16. RF-PCVD低温沉积无色透明类金刚石保护膜的工艺研究%Study on the process parameters of colorless transparent diamond-like carbon (DLC) films deposited by RF-PCVD

    Institute of Scientific and Technical Information of China (English)

    朱霞高; 侯惠君; 林松盛; 袁镇海; 戴达煌

    2006-01-01

    采用磁约束增强射频辉光放电等离子体辅助化学气相沉积法(RF-PCVD)低温沉积出无色透明的类金刚石保护膜(DLC),主要研究了炉压P0、射频功率Pf、自生负偏压Uz、磁感应强度B、电极间距d、反应气体、镀膜时间t等工艺参数对成膜的影响.试验结果表明,外加磁场B制约了带电粒子逃逸出电极空间,提高了反应气体的离化率及等离子体浓度和活性,并使非独立变量Pf和Uz成为独立变量,有利于工艺调节.当极间距大时,需适当提高Pf,Uz和C-H流量才可得到无色、较硬的DLC膜.在比功率密度大于0.009 W·cm-2·Pa-1、C-H浓度即体积分数0.9%~1.4%及膜厚小于90nm的条件下,可沉积出无色透明、硬度较高的DLC膜.

  17. Experimental investigation of dropwise condensation of steam on diamond-like carbonate and thick fluor-containing organic films%类金刚石和厚有机膜促进水蒸气滴状冷凝传热的实验研究

    Institute of Scientific and Technical Information of China (English)

    马学虎; 朱晓波; 安家明; 陈嘉宾

    2003-01-01

    为了寻找适宜的表面处理技术制备能长期地维持滴状冷凝传热型态,实验研究了垂直黄铜管外类金刚石和含氟有机薄膜水蒸气常压下冷凝传热特性.两种表面均能促进水蒸气的滴状冷凝型态,但类金刚石表面上液滴形状较扁,脱落频率不高,而有机膜表面的液滴形状、大小以及脱落频率均优于类金刚石表面.在管内冷却水雷诺数为1.0×104~2.0×105时,类金刚石和含氟有机薄膜表面的热流密度和冷凝传热系数分别为485~807 kW/m2和18~23 kW/(m2@K)、171~330 kW/m2和4.8~7.2 kW/(m2@K).含氟有机薄膜表面表现了优良的涂层结合强度,寿命实验已经持续了近10个月.

  18. Adherence to physical and mental activity interventions: Coping plans as a mediator and prior adherence as a moderator.

    NARCIS (Netherlands)

    Evers, A.W.M.; Klusmann, V.; Schwarzer, R.; Heuser, I.

    2012-01-01

    Objective. Adherence to behavioural intervention programmes is a necessary condition for beneficial outcomes to be achieved. This study tested whether social cognitive variables and coping plans predict adherence. Design and methods. Adherence was examined in a randomized controlled trial with healt

  19. Adherence of Helicobacter pylori to the Gastric Mucosa

    Directory of Open Access Journals (Sweden)

    Marguerite Clyne

    1997-01-01

    Full Text Available Bacterial adhesion to the intestinal epithelium is a critical initial step in the pathogenesis of many enteric diseases. Helicobacter pylori is a duodenal pathogen that adheres to the gastric epithelium and causes gastritis and peptic ulceration. The mechanism by which H pylori causes disease has not yet been elucidated but adherence to the gastric mucosa is thought to be an important virulence determinant of the organism. What is known about adherence of H pylori to the gastric mucosa is summarized. Topics discussed are the mechanism of H pylori adherence; in vitro and in vivo models of H pylori infection; and adherence and potential adhesins and receptors for H pylori.

  20. Adherence Characteristics of Cement Clinker on Basic Bricks

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi; Michel Rigaud

    2002-01-01

    Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodoluminescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3 S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks, fine, crystalline spinel easily reacts with lime containing phases from clinker to form lowmelting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.

  1. Sharia Adherence Mosque Survey: Correlations between Sharia Adherence and Violent Dogma in U.S. Mosques

    Directory of Open Access Journals (Sweden)

    Mordechai Kedar

    2011-12-01

    Full Text Available A random survey of 100 representative mosques in the U.S. was conducted to measure the correlation between Sharia adherence and dogma calling for violence against non-believers.  Of the 100 mosques surveyed, 51% had texts on site rated as severely advocating violence; 30% had texts rated as moderately advocating violence; and 19% had no violent texts at all.  Mosques that presented as Sharia adherent were more likely to feature violence-positive texts on site than were their non-Sharia-adherent counterparts.  In 84.5% of the mosques, the imam recommended studying violence-positive texts.  The leadership at Sharia-adherent mosques was more likely to recommend that a worshipper study violence-positive texts than leadership at non-Sharia-adherent mosques.  Fifty-eight percent of the mosques invited guest imams known to promote violent jihad.  The leadership of mosques that featured violence-positive literature was more likely to invite guest imams who were known to promote violent jihad than was the leadership of mosques that did not feature violence-positive literature on mosque premises.  

  2. Iron Chelation Adherence to Deferoxamine and Deferasirox in Thalassemia

    Science.gov (United States)

    Trachtenberg, Felicia; Vichinsky, Elliott; Haines, Dru; Pakbaz, Zahra; Mednick, Lauren; Sobota, Amy; Kwiatkowski, Janet; Thompson, Alexis A.; Porter, John; Coates, Thomas; Giardina, Patricia J.; Olivieri, Nancy; Yamashita, Robert; Neufeld, Ellis J.

    2015-01-01

    The Thalassemia Clinical Research Network collected adherence information from 79 patients on deferoxamine and 186 on deferasirox from 2007 to 2009. Chelation adherence was defined as percent of doses administered in the last 4 weeks (patient report) out of those prescribed (chart review). Chelation history since 2002 was available for 97 patients currently on deferoxamine and 217 on deferasirox, with crude estimates of adherence from chart review. Self-reported adherence to both deferoxamine and deferasirox were quite high, with slightly higher adherence to the oral chelator (97 vs. 92%). Ninety percent of patients on deferasirox reported at least 90% adherence, compared with 75% of patients on deferoxamine. Adherence to both chelators was highest in children, followed by adolescents and older adults. Predictors of lower deferoxamine adherence were smoking in the past year, problems sticking themselves (adults only), problems wearing their pump, and fewer transfusions in the past year. Predictors of lower deferasirox adherence were bodily pain and depression. Switching chelators resulted in increased adherence, regardless of the direction of the switch, although switching from deferoxamine to deferasirox was far more common. As adherence to deferoxamine is higher than previously reported, it appears beneficial for patients to have a choice in chelators. PMID:21523808

  3. Iron chelation adherence to deferoxamine and deferasirox in thalassemia.

    Science.gov (United States)

    Trachtenberg, Felicia; Vichinsky, Elliott; Haines, Dru; Pakbaz, Zahra; Mednick, Lauren; Sobota, Amy; Kwiatkowski, Janet; Thompson, Alexis A; Porter, John; Coates, Thomas; Giardina, Patricia J; Olivieri, Nancy; Yamashita, Robert; Neufeld, Ellis J

    2011-05-01

    The Thalassemia Clinical Research Network collected adherence information from 79 patients on deferoxamine and 186 on deferasirox from 2007 to 2009. Chelation adherence was defined as percent of doses administered in the last 4 weeks (patient report) out of those prescribed(chart review). Chelation history since 2002 was available for 97 patients currently on deferoxamine and 217 on deferasirox, with crude estimates of adherence from chart review. Self-reported adherence to both deferoxamine and deferasirox were quite high, with slightly higher adherence to the oral chelator (97 vs. 92%). Ninety percent of patients on deferasirox reported at least 90% adherence, compared with 75% of patients on deferoxamine. Adherence to both chelators was highest in children, followed by adolescents and older adults.Predictors of lower deferoxamine adherence were smoking in the past year, problems sticking themselves (adults only), problems wearing their pump, and fewer transfusions in the past year. Predictors of lower deferasirox adherence were bodily pain and depression. Switching chelators resulted in increased adherence, regardless of the direction of the switch, although switching from deferoxamine to deferasirox was far more common. As adherence to deferoxamine is higher than previously reported, it appears beneficial for patients to have a choice in chelators.

  4. Enhanced tunnel transport in disordered carbon superlattice structures incorporated with nitrogen

    Science.gov (United States)

    Katkov, Mikhail V.; Bhattacharyya, Somnath

    2012-06-01

    The possibility for enhanced tunnel transport through the incorporation of nitrogen in a quasi-one dimensional superlattice structure of amorphous carbon (a -C) made of sp2-C and sp3-C rich phases is shown by using a tight-binding model. The proposed superstructure can be described by a set of disordered graphite-like carbon clusters (acting as quantum wells) separated by a thin layer of diamond-like carbon (barriers) where the variation of the width and depth of the carbon clusters significantly control the electron transmission peaks. A large structural disorder in the pure carbon system, introduced through the variation of the bond length and associated deformation potential for respective carbon phases, was found to suppress the sharp features of the transmission coefficients. A small percentage of nitrogen addition to the carbon clusters can produce a distinct transmission peak at the low energy; however, it can be practically destroyed due to increase of the level of disorder of carbon sites. Whereas pronounced resonance peaks, both for C and N sites can be achieved through controlling the arrangement of the nitrogen sites of increased concentration within the disordered sp2-C clusters. The interplay of disorder associated with N and C sites illustrated the tunable nature of resistance of the structures as well as their characteristic times.

  5. Pharmacy adherence measures to assess adherence to antiretroviral therapy: review of the literature and implications for treatment monitoring.

    Science.gov (United States)

    McMahon, James H; Jordan, Michael R; Kelley, Karen; Bertagnolio, Silvia; Hong, Steven Y; Wanke, Christine A; Lewin, Sharon R; Elliott, Julian H

    2011-02-15

    Prescription or pill-based methods for estimating adherence to antiretroviral therapy (ART), pharmacy adherence measures (PAMs), are objective estimates calculated from routinely collected pharmacy data. We conducted a literature review to evaluate PAMs, including their association with virological and other clinical outcomes, their efficacy compared with other adherence measures, and factors to consider when selecting a PAM to monitor adherence. PAMs were classified into 3 categories: medication possession ratio (MPR), pill count (PC), and pill pick-up (PPU). Data exist to recommend PAMs over self-reported adherence. PAMs consistently predicted patient outcomes, but additional studies are needed to determine the most predictive PAM parameters. Current evidence suggests that shorter duration of adherence assessment (≤ 6 months) and use of PAMs to predict future outcomes may be less accurate. PAMs which incorporate the number of days for which ART was prescribed without the counting of remnant pills, are reasonable minimum-resource methods to assess adherence to ART.

  6. Electrochemical Corrosion Behavior of the DLC Coated and Uncoated NiTi Alloys

    Institute of Scientific and Technical Information of China (English)

    Jiehe SUI; Wei CAI; Liancheng ZHAO

    2006-01-01

    A dense and well-adhered diamond-like carbon(DLC)coating was prepared on the nickel-titanium(NiTi)alloys by plasma immersion ion implantation and deposition(PⅢD). Potentiodynamic polarization tests indicated the corrosion resistance of the NiTi alloys was markedly improved by the DLC coating. The Ni ions release of the NiTi alloys was effectively blocked by the DLC coating.

  7. Three-dimensional polymeric structures of single-wall carbon nanotubes

    Science.gov (United States)

    Lian, Chao-Sheng; Wang, Jian-Tao

    2014-05-01

    We explore by ab initio calculations the possible crystalline phases of polymerized single-wall carbon nanotubes (P-SWNTs) and determine their structural, elastic, and electronic properties. Based on direct cross-linking and intertube sliding-assisted cross-linking mechanisms, we have identified a series of stable three-dimensional polymeric structures for the zigzag nanotubes up to (10,0). Among proposed P-SWNT phases, the structures with favorable diamond-like sp3 intertube bonding configuration and small tube cross-section distortion are found to be the most energetically stable ones. These polymeric crystalline phases exhibit high bulk and shear moduli superior to SWNT bundles, and show metallic or semiconducting properties depending on the diameter of constituent tubes. We also propose by hydrostatic pressure simulations that the intertube sliding between van der Waals bonded nanotubes may be an effective route to promote the polymerization of SWNTs under pressure.

  8. Three-dimensional polymeric structures of single-wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Chao-Sheng; Wang, Jian-Tao, E-mail: wjt@aphy.iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-05-28

    We explore by ab initio calculations the possible crystalline phases of polymerized single-wall carbon nanotubes (P-SWNTs) and determine their structural, elastic, and electronic properties. Based on direct cross-linking and intertube sliding-assisted cross-linking mechanisms, we have identified a series of stable three-dimensional polymeric structures for the zigzag nanotubes up to (10,0). Among proposed P-SWNT phases, the structures with favorable diamond-like sp{sup 3} intertube bonding configuration and small tube cross-section distortion are found to be the most energetically stable ones. These polymeric crystalline phases exhibit high bulk and shear moduli superior to SWNT bundles, and show metallic or semiconducting properties depending on the diameter of constituent tubes. We also propose by hydrostatic pressure simulations that the intertube sliding between van der Waals bonded nanotubes may be an effective route to promote the polymerization of SWNTs under pressure.

  9. A comparative study of the field emission properties of aligned carbon nanostructures films, from carbon nanotubes to diamond

    Science.gov (United States)

    Le Normand, F.; Cojocaru, C. S.; Fleaca, C.; Li, J. Q.; Vincent, P.; Pirio, G.; Gangloff, L.; Nedellec, Y.; Legagneux, P.

    2007-05-01

    The electron field emission properties of different graphitic and diamond-like nanostructures films are compared. They are prepared in the same CVD chamber on SiO{2}/Si(100) and Si(100) flat surfaces, respectively. These nanostructures are thoroughly characterized by scanning electron emission (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Films of dense aligned carbon nanotubes by far display the lowest threshold fields around few V/μ m and the largest emission currents. Carbon nanofibers, with platelet arrangement of the graphitic planes parallel to the substrate, exhibit higher emission thresholds around 10 V/μ m. Diamond nanostructures, either modified through ammonia incorporation within the gas phase or not, exhibit the largest emission threshold around 25 V/μ m. The high enhancement factors, deduced from the Fowler-Nordheim plots, can explain the low emission thresholds whereas limitations to the electron transport ever occur through different processes (i) surface modifications of the surface, as the transformation of the SiO{2} barrier layer into SiN{x} in the presence of ammonia evidenced by XPS; (ii) different orientation of the graphitic basal planes relative to the direction of electron transport (carbon nanofiber) and (iii) presence of a graphitic nest at the interface of the carbon nanostructure and the substrate, observed when catalyst is deposited through mild evaporation.

  10. Adherence to Mediterranean diet and bone health

    Directory of Open Access Journals (Sweden)

    Antonio Romero Pérez

    2014-05-01

    Full Text Available Introduction: Several studies have concluded that incidences of osteoporosis and osteoporosis-related fractures vary across the European Union, the lowest incidence being reported in the Mediterranean area. The beneficial effect is mainly attributed to a specific eating pattern. The Mediterranean diet contain a complex array of naturally occurring bioactive molecules with antioxidant, anti-inflammatory and alkalinising properties that may contribute to the bone-sparing effect of the Mediterranean diet. Objective: The purpose of this review is to examine the evidence to date on the effects of Mediterranean diet on bone health. Methods: The search for articles came from extensive research in the following databases: PubMed, Scopus and Web of Science. We used the search terms "Mediterranean diet", "adherence", "fruit and vegetable", "olive oil", "fish" "legume", "cereal" "alcohol", "bone", "osteoporosis", "fracture", and combinations, such as "Mediterranean diet and bone" or "Mediterranean diet and fracture". Results: A limited number of studies have examined the relationship between Mediterranean Diet and bone health, and they have reported conflicting results. On the one hand, adherence to a traditional MeDi has been associated with higher bone mineral density and lower fracture risk. The results of these studies could be attributed to the combined beneficial effects of individual components of the Mediterranean diet. On the contrary, several studies failed to show any association between adherence to the MeDi and indices of bone mass. Conclusions: Further large-scale studies are required to clarify the effect of Mediterranean diet on bone health, in order to establish the role of this diet in the prevention of osteoporosis.

  11. On World Religion Adherence Distribution Evolution

    Science.gov (United States)

    Ausloos, Marcel; Petroni, Filippo

    Religious adherence can be considered as a degree of freedom, in a statistical physics sense, for a human agent belonging to a population. The distribution, performance and life time of religions can thus be studied having in mind heterogeneous interacting agent modeling. We present a comprehensive analysis of 58 so-called religions (to be better defined in the main text) as measured through their number of adherents evolutions, between 1900 and 2000, - data taken from the World Christian Trends (Barrett and Johnson, "World Christian Trends AD 30 - AD 2200: Interpreting the Annual Christian Megacensus", William Carey Library, 2001): 40 are considered to be "presently growing" cases, including 11 turn overs in the twentieth century; 18 are "presently decaying", among which 12 are found to have had a recent maximum, in the nineteenth or the twentieth century. The Avrami-Kolmogorov differential equation which usually describes solid state transformations, like crystal growth, is used in each case in order to obtain the preferential attachment parameter introduced previously (Europhys Lett 77:38002, 2007). It is not often found close to unity, though often corresponding to a smooth evolution. However large values suggest the occurrence of extreme cases which we conjecture are controlled by so-called external fields. A few cases indicate the likeliness of a detachment process. We discuss a few growing and decaying religions, and illustrate various fits. Some cases seem to indicate the lack of reliability of the data, but others some marked departure from Avrami law. Whence the Avrami evolution equation might be surely improved, in particular, and somewhat obviously, for the decaying religion cases. We point out two major difficulties in such an analysis: (1) the "precise" original time of apparition of a religion, (2) the time at which there is a maximum number of adherents, both information being necessary for integrating reliably any evolution equation.

  12. Community health workers adherence to referral guidelines

    DEFF Research Database (Denmark)

    Lal, Sham; Ndyomugenyi, Richard; Paintain, Lucy;

    2016-01-01

    Background Many malaria-endemic countries have implemented national community health worker (CHW) programmes to serve remote populations that have poor access to malaria diagnosis and treatment. Despite mounting evidence of CHWs’ ability to adhere to malaria rapid diagnostic tests (RDTs...... artemisinin-based combination therapy (ACT) and recognize symptoms in children that required immediate referral to the nearest health centre. Intervention arm CHWs had additional training on how to conduct an RDT; CHWs in the control arm used a presumptive diagnosis for malaria using clinical signs...

  13. Adherence to antiretroviral therapy among people living with HIV

    Directory of Open Access Journals (Sweden)

    Basavaprabhu Achappa

    2013-01-01

    Full Text Available Background: Acquired immune deficiency syndrome (AIDS is now considered as a manageable chronic illness. There has been a dramatic reduction in human immunodeficiency virus (HIV related morbidity and mortality due to antiretroviral therapy. A high level of adherence (>95% is required for antiretroviral therapy to be effective. There are many barriers to adherence in both developed and developing countries. Aim: The aim of our study was to determine adherence levels and factors influencing adherence to antiretroviral therapy among people living with HIV. Materials and Methods: Using a cross-sectional study design, 116 HIV positive patients receiving antiretroviral therapy for at least 1 year were interviewed using a semi structured questionnaire. The collected data was analyzed using Statistical Product and Service Solutions (SPSS version 11.5. Chi-square test was done. A P value of < 0.05 was considered statistically significant. Results: Of 116 participants, 63.7% reported adherence ≥ 95%. Mean adherence index was 91.25%. Financial constraints, forgetting to take medication, lack of family care, depression, alcohol use, social stigma and side effects to antiretroviral therapy were barriers for adherence in our study. Conclusion: Adherence to antiretroviral therapy in south India is suboptimal. Intensive adherence counseling should be provided to all patients before initiation ofantiretroviral therapy. Health care providers must identify possible barriers to adherence at the earliest and provide appropriate solutions.

  14. Patient adherence to medical treatment: a review of reviews

    Directory of Open Access Journals (Sweden)

    Heerdink Rob

    2007-04-01

    Full Text Available Abstract Background Patients' non-adherence to medical treatment remains a persistent problem. Many interventions to improve patient adherence are unsuccessful and sound theoretical foundations are lacking. Innovations in theory and practice are badly needed. A new and promising way could be to review the existing reviews of adherence to interventions and identify the underlying theories for effective interventions. That is the aim of our study. Methods The study is a review of 38 systematic reviews of the effectiveness of adherence interventions published between 1990 and 2005. Electronic literature searches were conducted in Medline, Psychinfo, Embase and the Cochrane Library. Explicit inclusion and exclusion criteria were applied. The scope of the study is patient adherence to medical treatment in the cure and care sector. Results Significant differences in the effectiveness of adherence interventions were found in 23 of the 38 systematic reviews. Effective interventions were found in each of four theoretical approaches to adherence interventions: technical, behavioural, educational and multi-faceted or complex interventions. Technical solutions, such as a simplification of the regimen, were often found to be effective, although that does not count for every therapeutic regimen. Overall, our results show that, firstly, there are effective adherence interventions without an explicit theoretical explanation of the operating mechanisms, for example technical solutions. Secondly, there are effective adherence interventions, which clearly stem from the behavioural theories, for example incentives and reminders. Thirdly, there are other theoretical models that seem plausible for explaining non-adherence, but not very effective in improving adherence behaviour. Fourthly, effective components within promising theories could not be identified because of the complexity of many adherence interventions and the lack of studies that explicitly compare

  15. Using communication skills to improve adherence in children with chronic disease : The adherence equation

    NARCIS (Netherlands)

    Brand, Paul L. P.; Klok, Ted; Kaptein, Adrian A.

    2013-01-01

    Nonadherence to maintenance medication is common in paediatric chronic conditions. Despite the common belief that nonadherence is therapy-resistant, and the apparent lack of evidence for successful interventions to improve adherence, there is, in fact, a considerable body of evidence suggesting that

  16. Accurate reporting of adherence to inhaled therapies in adults with cystic fibrosis: methods to calculate normative adherence

    Directory of Open Access Journals (Sweden)

    Hoo ZH

    2016-05-01

    Full Text Available Zhe Hui Hoo,1,2 Rachael Curley,1,2 Michael J Campbell,1 Stephen J Walters,1 Daniel Hind,3 Martin J Wildman1,2 1School of Health and Related Research (ScHARR, University of Sheffield, 2Sheffield Adult Cystic Fibrosis Centre, Northern General Hospital, 3Sheffield Clinical Trials Research Unit, University of Sheffield, Sheffield, UK Background: Preventative inhaled treatments in cystic fibrosis will only be effective in maintaining lung health if used appropriately. An accurate adherence index should therefore reflect treatment effectiveness, but the standard method of reporting adherence, that is, as a percentage of the agreed regimen between clinicians and people with cystic fibrosis, does not account for the appropriateness of the treatment regimen. We describe two different indices of inhaled therapy adherence for adults with cystic fibrosis which take into account effectiveness, that is, “simple” and “sophisticated” normative adherence. Methods to calculate normative adherence: Denominator adjustment involves fixing a minimum appropriate value based on the recommended therapy given a person’s characteristics. For simple normative adherence, the denominator is determined by the person’s Pseudomonas status. For sophisticated normative adherence, the denominator is determined by the person’s Pseudomonas status and history of pulmonary exacerbations over the previous year. Numerator adjustment involves capping the daily maximum inhaled therapy use at 100% so that medication overuse does not artificially inflate the adherence level. Three illustrative cases: Case A is an example of inhaled therapy under prescription based on Pseudomonas status resulting in lower simple normative adherence compared to unadjusted adherence. Case B is an example of inhaled therapy under-prescription based on previous exacerbation history resulting in lower sophisticated normative adherence compared to unadjusted adherence and simple normative adherence

  17. Novel phase of carbon, ferromagnetism, and conversion into diamond

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Jagdish, E-mail: narayan@ncsu.edu; Bhaumik, Anagh [Department of Materials Science and Engineering, Centennial Campus, North Carolina State University, Raleigh, North Carolina 27695-7907 (United States)

    2015-12-07

    We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp{sup 3} (75%–85%) with the rest being threefold sp{sup 2} bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g{sup −1}. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing

  18. Statistical Dynamics of Religions and Adherents

    CERN Document Server

    Ausloos, M; Ausloos, Marcel; Petroni, Filippo

    2006-01-01

    Religiosity is one of the most important sociological aspects of populations. All religions may evolve in their beliefs and adapt to the society developments. A religion is a social variable, like a language or wealth, to be studied like any other organizational parameter. Several questions can be raised, as considered in this study: e.g. (i) from a ``macroscopic'' point of view : How many religions exist at a given time? (ii) from a ``microscopic'' view point: How many adherents belong to one religion? Does the number of adherents increase or not, and how? No need to say that if quantitative answers and mathematical laws are found, agent based models can be imagined to describe such non-equilibrium processes. It is found that empirical laws can be deduced and related to preferential attachment processes, like on evolving network; we propose two different algorithmic models reproducing as well the data. Moreover, a population growth-death equation is shown to be a plausible modeling of evolution dynamics in a...

  19. Automated microinjection system for adherent cells

    Science.gov (United States)

    Youoku, Sachihiro; Suto, Yoshinori; Ando, Moritoshi; Ito, Akio

    2007-07-01

    We have developed an automated microinjection system that can handle more than 500 cells an hour. Microinjection injects foreign agents directly into cells using a micro-capillary. It can randomly introduce agents such as DNA, proteins and drugs into various types of cells. However, conventional methods require a skilled operator and suffer from low throughput. The new automated microinjection techniques we have developed consist of a Petri dish height measuring method and a capillary apex position measuring method. The dish surface height is measured by analyzing the images of cells that adhere to the dish surface. The contrast between the cell images is minimized when the focus plane of an object lens coincides with the dish surface. We have developed an optimized focus searching method with a height accuracy of +/-0.2 um. The capillary apex position detection method consists of three steps: rough, middle, and precise. These steps are employed sequentially to cover capillary displacements of up to +/-2 mm, and to ultimately accomplish an alignment accuracy of less than one micron. Experimental results using this system we developed show that it can introduce fluorescent material (Alexa488) into adherent cells, HEK293, with a success rate of 88.5%.

  20. Statistical dynamics of religions and adherents

    Science.gov (United States)

    Ausloos, M.; Petroni, F.

    2007-02-01

    Religiosity is one of the most important sociological aspects of populations. All religions may evolve in their beliefs and adapt to the society developments. A religion is a social variable, like a language or wealth, to be studied like any other organizational parameter. Several questions can be raised, as considered in this study; e.g.: i) From a "macroscopic" point of view: How many religions exist at a given time? ii) From a "microscopic" viewpoint: How many adherents belong to one religion? Does the number of adherents increase or not, and how? No need to say that if quantitative answers and mathematical laws are found, agent-based models can be imagined to describe such non-equilibrium processes. It is found that empirical laws can be deduced and related to preferential attachment processes, like on an evolving network; we propose two different algorithmic models reproducing as well the data. Moreover, a population growth-death equation is shown to be a plausible modeling of evolution dynamics in a continuous-time framework. Differences with language dynamic competition are emphasized.

  1. Side effects, adherence self-efficacy, and adherence to antiretroviral treatment: a mediation analysis in a Chinese sample.

    Science.gov (United States)

    Zhang, Liying; Li, Xiaoming; Lin, Zhenping; Jacques-Tiura, Angela J; Xu, Jinping; Zhou, Yuejiao; Qiao, Shan; Shen, Zhiyong; Stanton, Bonita

    2016-07-01

    Antiretroviral therapy (ART) is a lifelong treatment. To date, ART adherence is suboptimal for most patients in resource-poor settings. Previous research indicates that medication side effects are perceived to be a significant barrier of high ART adherence. Data regarding the role of adherence self-efficacy in mediating the relationship between side effects from ART and adherence to ART are limited; thus, this study examines this potential mediational role of self-efficacy. A cross-sectional survey of 2987 people living with HIV aged ≥18 years was conducted in 2012-2013 in Guangxi Autonomous Region (Guangxi) which has one of the fastest-growing HIV rates in China. Of the total sample, 2146 (72.1%) participants had initiated ART. Participants reported the number of days of completing the daily dose of ART in the past month; adherence was defined as completing the daily dose at least 28 days in the last month (≥90%). Side effects were significantly negatively related to adherence to ART. Mediation analyses indicated that adherence self-efficacy significantly mediated the side effects-adherence relationship. Future interventions to increase adherence self-efficacy and effective coping with side effects among HIV patients are needed in order to improve their ART adherence.

  2. Stability of adherence to highly active antiretroviral therapy over time among clients enrolled in the treatment adherence demonstration project.

    Science.gov (United States)

    Tesoriero, James; French, Tyler; Weiss, Linda; Waters, Mark; Finkelstein, Ruth; Agins, Bruce

    2003-08-01

    Adherence to antiretroviral medications is essential to therapeutic success. Many published studies have investigated the degree of adherence or nonadherence, but sample sizes have generally been small, and adherence has seldom been viewed as a longitudinal process. This paper investigates the stability of adherence over time among HIV-infected individuals attending adherence support programs in New York State. The study cohort consists of 435 clients who were on HAART at baseline and who completed at least 2 follow-up interviews. Although cross-sectional nonadherence did not exceed 35%, nonadherence reached 54% when considered across all 3 interviews. Analysis of transition matricies revealed moderate stability in adherence over time (e.g., first follow-up adherence was 81.0% for clients adherent at baseline, compared with 58.3% for clients nonadherent at baseline). Second-order transition matricies offered additional predictive utility. Multivariate results indicated that, for some, it was the transition from a desirable to an undesirable state (e.g., from no illicit drug use to illicit drug use) that increased the likelihood of nonadherence, rather than the presence of these characteristics over time. Findings illustrate the importance of multiple, periodic assessments of adherence and the need to consider strategies to increase stability in the factors affecting adherence to HAART.

  3. [e-Health interventions and improvement in treatment adherence].

    Science.gov (United States)

    Sieben, Angelien; Bredie, S J H Bas; van Laarhoven, C J H M Kees; Schoonhoven, Lisette; Burger, David M; van Onzenoort, Hein A W

    2014-01-01

    Poor adherence to medication is one of the most important determinants in the treatment of patients with chronic disorders. e-Health-based interventions may be able to improve treatment adherence. This article gives an overview of the available e-Health interventions and the extent to which they can improve adherence. We searched in the PubMed, Cinahl, PsycInfo, and Embase databases for e-Health interventions that aimed at improving adherence to treatment. Of the 16 included studies, 15 used a website and one used an app. Ten studies showed a significant improvement in treatment adherence by using the intervention. e-Health interventions were generally complex. Simple interventions were the most successful in improving treatment adherence.

  4. Measuring insulin adherence among adults with type 2 diabetes.

    Science.gov (United States)

    Osborn, Chandra Y; Gonzalez, Jeffery S

    2016-08-01

    Non-adherence to insulin is common and associated with suboptimal health. We adapted the Morisky Medication Adherence Scale to specify insulin adherence (MIAS) and compared it to the Adherence to Refills and Medication Scale for Diabetes (ARMS-D) and the Summary of Diabetes Self-Care Activities medications subscale (SDSCA-MS) and an insulin-specific (SDSCA-IS) version. A sample of 144 insulin-treated adults (58 % African American/Black, 34 % Caucasian/White, 8 % Other/Mixed race; 6.9 % Hispanic) completed these measures along with a HbA1C test. The internal consistency and factor structure of the MIAS were adequate; 59 % of participants forgot to take insulin and 46 % reported non-adherence. The MIAS was associated with the ARMS-D, SDSCA-MS, and SDSCA-IS (p insulin adherence assessment tool for practice and research applications.

  5. What strategies do ulcerative colitis patients employ to facilitate adherence?

    Science.gov (United States)

    Kawakami, Aki; Tanaka, Makoto; Naganuma, Makoto; Maeda, Shin; Kunisaki, Reiko; Yamamoto-Mitani, Noriko

    2017-01-01

    Background Overall, 30%–45% of patients with ulcerative colitis (UC) are non-adherent and have difficulties taking their medications; this non-adherence increases the risk of clinical relapse 1.4- to 5.5-fold. This study aimed to clarify the strategies patients employ to facilitate adherence and determine whether the strategies had an impact on good adherence. Methods This was a cross-sectional survey using a self-administered questionnaire and review of medical records. Patients diagnosed as having UC and attending one of the outpatient clinics of four urban hospitals from June 2009 to December 2012 were enrolled. A questionnaire was developed to identify the strategies patients employ to facilitate adherence and then administered to patients with UC. Adherence to 5-aminosalicylic acid was calculated, and univariate and multiple logistic regression analyses were performed to determine the strategies that were associated with good adherence. Results The final analyses included 671 participants (mean age 40.2 years; 54.3% males). The valid response rate was 96.9%; 186 (27.7%) participants were classified as non-adherent, the mean adherence rate being 86.1% (standard deviation [SD] 17.9). Seven strategies that patients employ to facilitate adherence were identified, the following two being significantly associated with good adherence: “I keep my medicines where I eat meals” and “I keep each day’s medicine in a pill case or something similar to make sure I have taken them”. Conclusion The identified strategies might be used to develop a program to improve medication adherence in patients with UC. PMID:28203059

  6. Concern between medication non-adherence and diabetes associated depression

    OpenAIRE

    Krishnan Vengadaragava Chary; Porchelvan Swaminathan

    2016-01-01

    Background: Diabetes mellitus is one of the health disorders that acquire mankind immensely. An ominous twin of diabetes mellitus is diabetes associated depression which is often unrecognised in routine diabetic care. The objective of this study was to find the prevalence and correlation between medication adherence and diabetes associated depression. Methods: It is a conducted as cross sectional study using Morisky medication adherence scale to evaluate treatment adherence of type II diab...

  7. Carbon-based tribofilms from lubricating oils

    Science.gov (United States)

    Erdemir, Ali; Ramirez, Giovanni; Eryilmaz, Osman L.; Narayanan, Badri; Liao, Yifeng; Kamath, Ganesh; Sankaranarayanan, Subramanian K. R. S.

    2016-08-01

    Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid ‘tribofilms’, which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant’s anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids. Here, we describe the in operando formation of carbon-based tribofilms via dissociative extraction from base-oil molecules on catalytically active, sliding nanometre-scale crystalline surfaces, enabling base oils to provide not only the fluid but also the solid tribofilm. We study nanocrystalline catalytic coatings composed of nitrides of either molybdenum or vanadium, containing either copper or nickel catalysts, respectively. Structurally, the resulting tribofilms are similar to diamond-like carbon. Ball-on-disk tests at contact pressures of 1.3 gigapascals reveal that these tribofilms nearly eliminate wear, and provide lower friction than tribofilms formed with zinc dialkyldithiophosphate. Reactive and ab initio molecular-dynamics simulations show that the catalytic action of the coatings facilitates dehydrogenation of linear olefins in the lubricating oil and random scission of their carbon-carbon backbones; the products recombine to nucleate and grow a compact, amorphous lubricating tribofilm.

  8. The role of family caregivers in HIV medication adherence.

    Science.gov (United States)

    Beals, K P; Wight, R G; Aneshensel, C S; Murphy, D A; Miller-Martinez, D

    2006-08-01

    This study examines the role that mid-life and older wives and mothers play in promoting medication adherence among their HIV-infected husbands or adult sons who require daily living assistance. Interviews were conducted with 112 caregiving dyads, with caregivers reporting on their own behaviours and attitudes towards medications, and care-recipients (persons living with HIV [PLH]) providing information about their own adherence practices. By examining how caregiver characteristics, behaviours, and attitudes may influence PLH adherence it is explicitly recognized that caregivers and PLH are linked within a caregiving dyad. Findings indicate that caregivers often remind PLH to take medications, but these reminders are not significantly associated with adherence. Caregivers also report strong attitudes about medication hassles, concerns over treatment failure and general concerns about adherence. Controlling for background characteristics, high perceived adherence hassles on the part of the caregiver were associated with low PLH adherence, providing evidence of shared influence within the caregiving dyad. Adherence interventions may maximize their effectiveness if they consider the role of the family caregiver because these data suggest that caregiver attitudes are linked with PLH adherence behaviours.

  9. Factors influencing adherence among older people with osteoarthritis.

    Science.gov (United States)

    Loew, Laurianne; Brosseau, Lucie; Kenny, Glen P; Durand-Bush, Natalie; Poitras, Stéphane; De Angelis, Gino; Wells, George A

    2016-09-01

    This study aims to identify potential factors that could affect adherence and influence the implementation of an evidence-based structured walking program, among older adults diagnosed with knee osteoarthritis. A total of 69 participants with mild to moderate osteoarthritis of the knee fulfilled an online survey on potential factors that could affect their adherence to an evidence-based structured walking program. Adherence with regard to the influencing factors was explored using a logistic regression model. Results tend to show higher odds of adhering to the evidence-based walking program if the participants were supervised (more than 2.9 times as high), supported by family/friends (more than 3.7 times as high), and not influenced by emotional involvement (more than 11 times as high). The odds of adhering were 3.6 times lower for participants who indicated a change in their medication intake and 3.1 times lower for individuals who considered themselves as less physically active (95 % confidence interval (CI)). Our exploratory findings identified and defined potential adherence factors that could guide health professionals in their practice to better identify positive influences and obstacles to treatment adherence, which would lead to the adoption of a more patient-centered approach. A large-scale study is required to clearly delineate the key factors that would influence adherence. We addressed a new knowledge gap by identifying the main strategies to promote the long-term adherence of community-based walking program.

  10. The effect of reminder systems on patients' adherence to treatment

    Directory of Open Access Journals (Sweden)

    Fenerty SD

    2012-02-01

    Full Text Available Sarah D Fenerty1, Cameron West1, Scott A Davis1, Sebastian G Kaplan3, Steven R Feldman1,2,41Center for Dermatology Research, Department of Dermatology, 2Department of Pathology, 3Department of Psychiatry and Behavioral Medicine, 4Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USABackground: Patient adherence is an important component of the treatment of chronic disease. An understanding of patient adherence and its modulating factors is necessary to correctly interpret treatment efficacy and barriers to therapeutic success.Purpose: This meta-analysis aims to systematically review published randomized controlled trials of reminder interventions to assist patient adherence to prescribed medications.Methods: A Medline search was performed for randomized controlled trials published between 1968 and June 2011, which studied the effect of reminder-based interventions on adherence to self-administered daily medications.Results: Eleven published randomized controlled trials were found between 1999 and 2009 which measured adherence to a daily medication in a group receiving reminder interventions compared to controls receiving no reminders. Medication adherence was measured as the number of doses taken compared to the number prescribed within a set period of time. Meta-analysis showed a statistically significant increase in adherence in groups receiving a reminder intervention compared to controls (66.61% versus 54.71%, 95% CI for mean: 0.8% to 22.4%. Self-reported and electronically monitored adherence rates did not significantly differ (68.04% versus 63.67%, P = 1.0. Eight of eleven studies showed a statistically significant increase in adherence for at least one of the reminder group arms compared to the control groups receiving no reminder intervention.Limitations: The data are limited by imperfect measures of adherence due to variability in data collection methods. It is also likely

  11. Impact of prescription size on statin adherence and cholesterol levels

    Directory of Open Access Journals (Sweden)

    Mehler Phillip S

    2007-10-01

    Full Text Available Abstract Background Therapy with 3-Hydroxy-3-methylglutaryl Co-enzyme A reductase inhibitors (statins improve outcomes in a broad spectrum of patients with hyperlipidemia. However, effective therapy requires ongoing medication adherence; restrictive pharmacy policies may represent a barrier to successful adherence, particularly among vulnerable patients. In this study we sought to assess the relationship between the quantity of statin dispensed by the pharmacy with patient adherence and total cholesterol. Methods We analyzed a cohort of 3,386 patients receiving more than one fill of statin medications through an integrated, inner-city health care system between January 1, 2000 and December 31, 2002. Our measure of adherence was days of drug acquisition divided by days in the study for each patient, with adequate adherence defined as ≥ 80%. Log-binomial regression was used to determine the relative risk of various factors, including prescription size, on adherence. We also assessed the relationship between adherence and total cholesterol using multiple linear regression. Results After controlling for age, gender, race, co-payment, comorbidities, and insurance status, patients who obtained a majority of fills as 60-day supply compared with 30-day supply were more likely to be adherent to their statin medications (RR 1.41, 95% CI 1.28–1.55, P Conclusion In a healthcare system serving predominantly indigent patients, the provision of a greater quantity of statin medication at each prescription fill contributes to improved adherence and greater drug effectiveness.

  12. Tuberculosis treatment adherence and fatality in Spain

    Directory of Open Access Journals (Sweden)

    Vidal Rafael

    2009-12-01

    Full Text Available Abstract Background The adherence to long tuberculosis (TB treatment is a key factor in TB control programs. Always some patients abandon the treatment or die. The objective of this study is to identify factors associated with defaulting from or dying during antituberculosis treatment. Methods Prospective study of a large cohort of TB cases diagnosed during 2006-2007 by 61 members of the Spanish Society of Pneumology and Thoracic Surgery (SEPAR. Predictive factors of completion outcome (cured plus completed treatment vs. defaulters plus lost to follow-up and fatality (died vs. the rest of patients were based on logistic regression, calculating odds ratios (OR and 95% confidence intervals (CI. Results Of the 1490 patients included, 29.7% were foreign-born. The treatment outcomes were: cured 792 (53.2%, completed treatment 540 (36.2%, failure 2 (0.1%, transfer-out 33 (2.2%, default 27 (1.8%, death 27 (1.8%, lost to follow-up 65 (4.4%, other 4 (0.3%. Completion outcome reached 93.5% and poor adherence was associated with: being an immigrant (OR = 2.03; CI:1.06-3.88, living alone (OR = 2.35; CI:1.05-5.26, residents of confined institutions (OR = 4.79; CI:1.74-13.14, previous treatment (OR = 2.93; CI:1.44-5.98, being an injecting drug user (IDU (OR = 9.51; CI:2.70-33.47 and treatment comprehension difficulties (OR = 2.93; CI:1.44-5.98. Case fatality was 1.8% and it was associated with the following variables: age 50 or over (OR = 10.88; CI:1.12-105.01, retired (OR = 12.26;CI:1.74-86.04, HIV-infected (OR = 9.93; CI:1.48-66.34, comprehension difficulties (OR = 4.07; CI:1.24-13.29, IDU (OR = 23.59; CI:2.46-225.99 and Directly Observed Therapy (DOT (OR = 3.54; CI:1.07-11.77. Conclusion Immigrants, those living alone, residents of confined institutions, patients treated previously, those with treatment comprehension difficulties, and IDU patients have poor adherence and should be targeted for DOT. To reduce fatality rates, stricter monitoring is required

  13. Diamond and Carbon Nanotube Composites for Supercapacitor Devices

    Science.gov (United States)

    Moreira, João Vitor Silva; May, Paul William; Corat, Evaldo José; Peterlevitz, Alfredo Carlos; Pinheiro, Romário Araújo; Zanin, Hudson

    2017-02-01

    We report on the synthesis and electrochemical properties of diamond grown onto vertically aligned carbon nanotubes with high surface areas as a template, resulting in a composite material exhibiting high double-layer capacitance as well as low electrochemical impedance electrodes suitable for applications as supercapacitor devices. We contrast results from devices fabricated with samples which differ in both their initial substrates (Si and Ti) and their final diamond coatings, such as boron-doped diamond and diamond-like carbon (DLC). We present for first time a conducting model for non-doped DLC thin-films. All samples were characterized by scanning and transmission electron microscopy and Fourier transform infrared and Raman spectroscopy. Our results show specific capacitance as high as 8.25 F g-1 (˜1 F cm-2) and gravimetric specific energy and power as high as 0.7 W h kg-1 and 176.4 W kg-1, respectively, which suggest that these diamond/carbon nanotube composite electrodes are excellent candidates for supercapacitor fabrication.

  14. Coherent quantum transport features in carbon superlattice structures

    Science.gov (United States)

    McIntosh, R.; Henley, S. J.; Silva, S. R. P.; Bhattacharyya, S.

    2016-10-01

    Whilst resonant transmission is well understood and can be fully harnessed for crystalline superlattices, a complete picture has not yet emerged for disordered superlattices. It has proven difficult to tune resonant transmission in disordered diamond-like carbon (DLC) superlattices as conventional models are not equipped to incorporate significant structural disorder. In this work, we present concurrent experimental and theoretical analysis which addresses resonant transmission in DLC superlattices. Devices were fabricated by growing alternate layers of DLC with different percentages of sp3 hybridized carbon.Coherent quantum transport effects were demonstrated in these structurally disordered DLC superlattices through distinct current modulation with negative differential resistance (NDR) in the current-voltage (I-V) measurements. A model was developed using tight-binding calculations assuming a random variation of the hopping integral to simulate structural (bond-length) disorder. Calculations of the I-V characteristics compliment the interpretation of the measurements and illustrate that while DLC superlattice structures are unlike their classical counterparts, the near-field structural order will help with the confinement of quantised states. The present model provides an empirical guide for tailoring the properties of future devices, giving rise to much hope that carbon electronics operating at high frequencies over large areas can now be developed.

  15. Diamond and Carbon Nanotube Composites for Supercapacitor Devices

    Science.gov (United States)

    Moreira, João Vitor Silva; May, Paul William; Corat, Evaldo José; Peterlevitz, Alfredo Carlos; Pinheiro, Romário Araújo; Zanin, Hudson

    2016-10-01

    We report on the synthesis and electrochemical properties of diamond grown onto vertically aligned carbon nanotubes with high surface areas as a template, resulting in a composite material exhibiting high double-layer capacitance as well as low electrochemical impedance electrodes suitable for applications as supercapacitor devices. We contrast results from devices fabricated with samples which differ in both their initial substrates (Si and Ti) and their final diamond coatings, such as boron-doped diamond and diamond-like carbon (DLC). We present for first time a conducting model for non-doped DLC thin-films. All samples were characterized by scanning and transmission electron microscopy and Fourier transform infrared and Raman spectroscopy. Our results show specific capacitance as high as 8.25 F g-1 (˜1 F cm-2) and gravimetric specific energy and power as high as 0.7 W h kg-1 and 176.4 W kg-1, respectively, which suggest that these diamond/carbon nanotube composite electrodes are excellent candidates for supercapacitor fabrication.

  16. Adherence to COPD guidelines in general practice

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli; Sørensen, Tina Brandt; Højmark, Torben Brunse

    2013-01-01

    BACKGROUND: The general practitioner (GP) is often the first healthcare contact for patients with chronic obstructive pulmonary disease (COPD). AIMS: To determine whether participating in a standardised educational programme delivered in the GP's own practice is associated with adherence to COPD...... guidelines. METHODS: A nationwide register-based observational before and after study was undertaken with a control group of propensity-matched practices (follow-up period 6 months). COPD was defined as age 40+ years and at least two prescriptions for inhaled medication. The educational programme consisted...... were used to compare the rate of spirometry testing, preventive consultations, and influenza vaccinations provided to COPD patients and the rate of spirometry testing in non-COPD individuals, assumed to reflect diagnostic activity. RESULTS: Data for 102 participating GP practices were analysed...

  17. Sister Carrie, an Adherent of Desires

    Institute of Scientific and Technical Information of China (English)

    裴水妹

    2007-01-01

    Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.

  18. Associations between patients' adherence and GPs' attitudes towards risk, statin therapy and management of non-adherence

    DEFF Research Database (Denmark)

    Barfoed, Benedicte L; Paulsen, Maja S; Christensen, Palle M;

    2016-01-01

    BACKGROUND: Previous studies suggest that doctors' personal lifestyle, risk taking personality and beliefs about risk reducing therapies may affect their clinical decision-making. Whether such factors are further associated with patients' adherence with medication is largely unknown. OBJECTIVE......: To estimate associations between GPs' attitudes towards risk, statin therapy and management of non-adherence and their patients' adherence, and to identify subgroups of GPs with poor patient adherence. METHODS: All Danish GPs were invited to participate in an online survey. We asked whether they regarded...

  19. Modelling imperfect adherence to HIV induction therapy

    Directory of Open Access Journals (Sweden)

    Smith? Robert J

    2010-01-01

    Full Text Available Abstract Background Induction-maintenance therapy is a treatment regime where patients are prescribed an intense course of treatment for a short period of time (the induction phase, followed by a simplified long-term regimen (maintenance. Since induction therapy has a significantly higher chance of pill fatigue than maintenance therapy, patients might take drug holidays during this period. Without guidance, patients who choose to stop therapy will each be making individual decisions, with no scientific basis. Methods We use mathematical modelling to investigate the effect of imperfect adherence during the inductive phase. We address the following research questions: 1. Can we theoretically determine the maximal length of a possible drug holiday and the minimal number of doses that must subsequently be taken while still avoiding resistance? 2. How many drug holidays can be taken during the induction phase? Results For a 180 day therapeutic program, a patient can take several drug holidays, but then has to follow each drug holiday with a strict, but fairly straightforward, drug-taking regimen. Since the results are dependent upon the drug regimen, we calculated the length and number of drug holidays for all fifteen protease-sparing triple-drug cocktails that have been approved by the US Food and Drug Administration. Conclusions Induction therapy with partial adherence is tolerable, but the outcome depends on the drug cocktail. Our theoretical predictions are in line with recent results from pilot studies of short-cycle treatment interruption strategies and may be useful in guiding the design of future clinical trials.

  20. Treatment adherence in multiple sclerosis: a survey of Belgian neurologists

    Directory of Open Access Journals (Sweden)

    Decoo D

    2015-11-01

    Full Text Available Danny Decoo,1 Mathieu Vokaer2 1Department of Neurology and Neurorehab, AZ Alma, Sijsele, Belgium; 2Multiple Sclerosis Clinic, Edith Cavell Hospital, CHIREC group, Brussels, Belgium Background: Poor treatment adherence is common among patients with multiple sclerosis (MS. This survey evaluated neurologists’ perception of treatment adherence among MS patients.Materials and methods: This questionnaire-based survey of Belgian neurologists treating MS patients was conducted between June and July 2014. Face-to-face interviews with the neurologists were based on a semistructured questionnaire containing questions regarding the perception of the treatment-adherence level.Results: A total of 41 neurologists participated in the survey. Of these, 88% indicated frequent discussions about treatment adherence as beneficial for treatment efficacy. The mean time spent on the treatment-adherence discussion during the initial consultation was 11 minutes, with 24% of doctors spending 5 minutes and 24% of doctors spending 10 minutes discussing this issue. The majority of neurologists (56% perceived the adherence level in MS as good, and 12% perceived it as excellent. The majority of neurologists (64% indicated intolerance as a main cause of poor adherence, and all neurologists reported insufficient efficacy as a consequence of nonadherence. The importance of adherence in the neurologists’ practice was evaluated on a scale of 1–10, with 1= “not very important” and 10= “very important”: 44% of doctors indicated a score of 10, and the mean score was 9.0.Conclusion: Belgian neurologists consider treatment adherence in MS as essential for the benefits of therapies. However, although neurologists are aware of the consequences of nonadherence, they generally spend limited time discussing the importance of treatment adherence with their patients. Keywords: multiple sclerosis, treatment adherence, physician survey

  1. Non-adherence to topical treatments for actinic keratosis

    Science.gov (United States)

    Shergill, Bav; Zokaie, Simon; Carr, Alison J

    2014-01-01

    Background There is limited information on the patterns of use, adherence rates, and factors that impact adherence with topical treatments for actinic keratosis (AK). Objectives To establish patterns of use and adherence with topical treatments for AK and to identify treatment-related factors that impact on adherence. Methods A community-based, cross-sectional study was performed using a standardized questionnaire completed online or via telephone interview. Patients were stratified according to the presence of AK lesions on the scalp and/or other extremities; and presence of scarring resulting from treatment. Results This study included 305 patients with AK who were currently using a patient-applied topical therapy for AK or had used one within the previous 12 months. In total, 88% (n = 268/305) of patients were either non-adherent, non-persistent or both non-adherent and non-persistent to topical therapy. Duration of treatment was associated with increasing rates of non-adherence (adjusted odds ratio [OR]; for treatment durations greater than 4 weeks, 2.2, P < 0.01): 52% of patients were non-adherent with 3–4 week treatment duration; 69% of patients with 4–8 week treatment duration; and 71% of patients with 6–12 week treatment duration. There were similar increases in non-persistence with increasing treatment duration (adjusted OR; for treatment durations greater than 4 weeks, 2.1, P < 0.05). Conclusion This study found high rates of non-adherence and non-persistence in patients with AK. Duration of treatment was a significant factor contributing to non-adherence and non-persistence to topical treatments. Patient-applied topical therapies that require less frequent application and have shorter treatment duration may be associated with improved adherence rates. PMID:24379656

  2. Social Support and the Mediating Roles of Alcohol Use and Adherence Self-Efficacy on Antiretroviral Therapy (ART) Adherence Among ART Recipients in Gauteng, South Africa.

    Science.gov (United States)

    Kekwaletswe, Connie T; Jordaan, Esmé; Nkosi, Sebenzile; Morojele, Neo K

    2016-11-11

    We sought to (a) replicate and (b) extend (via the addition of alcohol use) Cha et al.'s cross-sectional multi-component model of ART adherence on the relationship between social support, depression, self-efficacy beliefs, and antiretroviral therapy (ART) adherence, among HIV patients in Tshwane, South Africa. Using purposive sampling, 304 male and female ART recipients were recruited. ART adherence was assessed using three manifest indicators: total adherence ratio, the CASE adherence index and 1-month adherence measure. Data were analysed using structural equation modeling. In our replicated model, social support had both direct and indirect relationships with ART adherence, and inclusion of alcohol use improved prediction of ART adherence. Direct and indirect effects of alcohol use on ART adherence emerged: adherence self-efficacy beliefs partially mediated the latter path. Findings highlight the importance of integrating into ART promotion interventions, the reduction of alcohol use, provision of social support, and enhancement of adherence self-efficacy beliefs.

  3. Pinpointing differences in cisplatin-induced apoptosis in adherent and non-adherent cancer cells

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup; Holm, Jacob Bak; Poulsen, Kristian Arild

    2010-01-01

    Platinum compounds are used in the treatment of cancer. We demonstrate that cisplatin-induced (10 µM) apoptosis (caspase-3 activity) is pronounced within 18 hours in non-adherent Ehrlich ascites tumour cells (EATC), whereas there is no increase in caspase-3 activity in the adherent Ehrlich Lettré...... ascites tumour cells (ELA). Loss of KCl and cell shrinkage are hallmarks in apoptosis and has been shown in EATC. However, we find no reduction in cell volume and only a minor loss of K(+) which is accompanied by net uptake of Na(+) following 18 hours cisplatin exposure in ELA. Glutathione and taurine...... have previously been demonstrated to protect cells from apoptosis. We find, however, that increase or decrease in the cellular content of glutathione and taurine has no effect on cisplatin-induced cell death in EATC and ELA. Nevertheless, knock-down of the taurine transporter TauT leads...

  4. Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ion beam-assisted diamond-like carbon (DLC) coatings have beenused for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocompatibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp\\+3 bonds in the structure of mixed sp\\+2+sp\\+3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.

  5. 14 CFR 1260.72 - Adherence to original budget estimates.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Adherence to original budget estimates. 1260.72 Section 1260.72 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GRANTS AND COOPERATIVE AGREEMENTS General Post-Award Requirements § 1260.72 Adherence to original budget estimates....

  6. Concern between medication non-adherence and diabetes associated depression

    Directory of Open Access Journals (Sweden)

    Krishnan Vengadaragava Chary

    2016-04-01

    Conclusions: Unnoticed depression among diabetic individuals reduces treatment adherence and must be addressed in any patient showing poor response to the treatment. Improving treatment adherence helps to combat diabetes as well as depression. [Int J Basic Clin Pharmacol 2016; 5(2.000: 523-527

  7. Treatment Adherence among Latina Female Adolescent Suicide Attempters.

    Science.gov (United States)

    Rotheram-Borus, Mary Jane; Piacentini, John; Van Rossem, Ronan; Graae, Flemming; Cantwell, Coleen; Castro-Blanco, David; Feldman, Julie

    1999-01-01

    Disenfranchised Latina adolescents (N=140) and their mothers presenting at a large urban emergency room after a suicide attempt by the adolescent were assessed to examine treatment adherence. Predictor variables for treatment adherence were established. Results are discussed in relation to treatment session attendance. Implications for the…

  8. Improving Adherence to Hand Hygiene among Health Care Workers

    Science.gov (United States)

    Maskerine, Courtney; Loeb, Mark

    2006-01-01

    Increased adherence to hand hygiene is widely acknowledged to be the most important way of reducing infections in health care facilities. Despite evidence of benefit, adherence to hand hygiene among health care professionals remains low. Several behavioral and organizational theories have been proposed to explain this. As a whole, the success of…

  9. Associations between patient factors and medication adherence: A Jordanian experience

    Directory of Open Access Journals (Sweden)

    Basheti IA

    2016-03-01

    Full Text Available Objective: To explore the effect of patient characteristics and health beliefs on their medication adherence. Methods: Patients (n=167 with chronic conditions (mean age 58.9; SD=13.54, 53% males were recruited from March 2009- to March 2010 using a cross sectional study design. Data collected included patients’ demographics, medical conditions, medications therapeutic regimen, frequency of physician visits and health beliefs. Patient self-reported adherence to medications was assessed by the researcher using a validated and published scale. Treatment related problems (TRPs were evaluated for each patient by competent clinical pharmacists. Associations between patient characteristics/health beliefs with adherence were explored. Results: About half of the patients (46.1% were non-adherent. A significant association was found between lower adherence and higher number of disease states (p<0.001, higher number of medications (p=0.001, and higher number of identified TRPs (p = 0.003. Patient adherence was positively affected by older age, higher educational level, and higher number of physician visits per month, while it was negatively affected by reporting difficulties with getting prescription refills on time. Conclusion: This study identified different factors that may negatively affect adherence, including higher number of medications and disease states, higher number of identified TRPs and inability to getting prescription refills on time. Hence, more care needs to be provided to patients with complex therapeutic regimens in order to enhance adherence.

  10. Method for preventing micromechanical structures from adhering to another object

    Science.gov (United States)

    Smith, J.H.; Ricco, A.J.

    1998-06-16

    A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface. 3 figs.

  11. Reliability of assessment of adherence to an antimicrobial treatment guideline

    NARCIS (Netherlands)

    Mol, PGM; Gans, ROB; Panday, PVN; Degener, JE; Laseur, M; Haaijer-Ruskamp, FM

    2005-01-01

    Assessment procedures for adherence to a guideline must be reliable and credible. The aim of this study was to explore the reliability of assessment of adherence, taking account of the professional backgrounds of the observers. A secondary analysis explored the impact of case characteristics on asse

  12. Unravelling adherence to prophylaxis in haemophilia : A patients' perspective

    NARCIS (Netherlands)

    Schrijvers, L. H.; Kars, M. C.; Beijlevelt-van der Zande, M.; Peters, M.; Schuurmans, M. J.; Fischer, K.

    2015-01-01

    Given the lifelong therapy in haemophilia patients, insight in non-adherence behaviour from a patient perspective is important to understand patients' difficulties with the following treatment recommendations. The aim of this study was to clarify the process underlying adherence (behaviour) to proph

  13. 42 CFR 447.304 - Adherence to upper limits; FFP.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Adherence to upper limits; FFP. 447.304 Section 447... Noninstitutional Services § 447.304 Adherence to upper limits; FFP. (a) The Medicaid agency must not pay more than... payments may be made only up to the reasonable charge under Medicare. (c) FFP is not available for a...

  14. Genetic factors in exercise adoption, adherence and obesity.

    Science.gov (United States)

    Herring, M P; Sailors, M H; Bray, M S

    2014-01-01

    Physical activity and exercise play critical roles in energy balance. While many interventions targeted at increasing physical activity have demonstrated efficacy in promoting weight loss or maintenance in the short term, long term adherence to such programmes is not frequently observed. Numerous factors have been examined for their ability to predict and/or influence physical activity and exercise adherence. Although physical activity has been demonstrated to have a strong genetic component in both animals and humans, few studies have examined the association between genetic variation and exercise adherence. In this review, we provide a detailed overview of the non-genetic and genetic predictors of physical activity and adherence to exercise. In addition, we report the results of analysis of 26 single nucleotide polymorphisms in six candidate genes examined for association to exercise adherence, duration, intensity and total exercise dose in young adults from the Training Interventions and Genetics of Exercise Response (TIGER) Study. Based on both animal and human research, neural signalling and pleasure/reward systems in the brain may drive in large part the propensity to be physically active and to adhere to an exercise programme. Adherence/compliance research in other fields may inform future investigation of the genetics of exercise adherence.

  15. Cognitive-Behavioral Therapy for HIV Medication Adherence and Depression

    Science.gov (United States)

    Safren, Steven A.; Hendriksen, Ellen S.; Mayer, Kenneth H.; Mimiaga, Matthew J.; Pickard, Robert; Otto, Michael W.

    2004-01-01

    For patients with HIV, depression is a common, distressing condition that can interfere with a critical self-care behavior--adherence to antiretroviral therapy. The present study describes a cognitive-behavioral treatment designed to integrate cognitive-behavioral therapy for depression with our previously tested approach to improving adherence to…

  16. Psychosocial factors and treatment adherence in paediatric HIV/AIDS.

    Science.gov (United States)

    Naar-King, S; Arfken, C; Frey, M; Harris, M; Secord, E; Ellis, D

    2006-08-01

    A social ecological model provides a promising framework for understanding the individual, family, and societal factors contributing to non-adherence to treatment of paediatric HIV. This study explored which factors relevant to this model are associated with caregivers' adherence and child health outcomes. A cross-sectional design was utilized to assess relationships among current individual, familial, extra-familial factors, caregiver adherence, and viral load. Data were collected from 43 caregivers, and viral load data were obtained from the medical records of their HIV+ children. Caregiver drug and alcohol use and HIV+ status were associated with non-adherence and elevated viral load. Negative outcome expectancy was associated with lower adherence but was not significant in the multivariate analyses. Family factors were not significant, but these measures had low reliability in this sample. Extra-familial factors such as dissatisfaction with medical specialty care and more stressful life events were not directly associated with adherence but were related to increased caregiver substance use. Results of this first study to explore multiple predictors of adherence and health outcomes in paediatric HIV require replication with larger samples, but findings suggest caregiver characteristics that place children at risk for disease progression due to poor adherence to treatment.

  17. Towards tailored and targeted adherence assessment to optimise asthma management

    NARCIS (Netherlands)

    van Boven, Job F. M.; Trappenburg, Jaap C. A.; van der Molen, Thys; Chavannes, Niels H.

    2015-01-01

    In this paper, we aim to emphasise the need for a more comprehensive and tailored approach to manage the broad nature of non-adherence, to personalise current asthma management. Although currently several methods are available to measure the extent of asthma patients' adherence, the vast majority do

  18. 77 FR 20637 - Request for Information on Prescription Medication Adherence

    Science.gov (United States)

    2012-04-05

    ... HUMAN SERVICES Request for Information on Prescription Medication Adherence AGENCY: Department of Health... potential solutions associated with the public health problem of prescription medication non-adherence in..., health care providers, and industry and private organizations in efforts to improve medication...

  19. Medication Adherence in Older Adults: A Qualitative Study

    Science.gov (United States)

    Holt, Elizabeth W.; Rung, Ariane L.; Leon, Kyla A.; Firestein, Catherine; Krousel-Wood, Marie

    2014-01-01

    To effectively address medication adherence and improve cardiovascular health among older adults, a deeper understanding is needed of the barriers that this age group faces and of approaches that would be most effective and feasible for improving adherence. We conducted a focus group study (n = 25) in a diverse population of older adults with…

  20. Medication Adherence in a Comparative Effectiveness Trial for Bipolar Disorder

    Science.gov (United States)

    Sylvia, Louisa G.; Reilly-Harrington, Noreen A.; Leon, Andrew C.; Kansky, Christine I.; Calabrese, Joseph R.; Bowden, Charles L.; Ketter, Terence A.; Friedman, Edward S.; Iosifescu, Dan V.; Thase, Michael E.; Ostacher, Michael J.; Keyes, Michelle; Rabideau, Dustin; Nierenberg, Andrew A.

    2013-01-01

    Objective Psychopharmacology remains the foundation of treatment for bipolar disorder, but medication adherence in this population is low (Range = 20% to 64%). We examined medication adherence in a multi-site, comparative effectiveness study of lithium. Method The Lithium Moderate Dose Use Study (LiTMUS) was a six-month, six-site, randomized effectiveness trial of adjunctive moderate dose lithium therapy compared to optimized treatment in adult outpatients with bipolar I or II disorder (N=283). Medication adherence was measured at each study visit with the Tablet Routine Questionnaire. Results We found that 4.50% of participants reported missing at least 30% of their medications in the past week at baseline and non-adherence remained low throughout the trial (< 7%). Poor medication adherence was associated with more manic symptoms and side effects as well as lower lithium serum levels at mid- and post-treatment, but not with poor quality of life, overall severity of illness, or depressive symptoms. Conclusion Participants in LiTMUS were highly adherent with taking their medications. The lack of association with possible predictors of adherence, such as depression and quality of life, could be explained by the limited variance or other factors as well as by not using an objective measure of adherence. PMID:24117232

  1. Patient adherence to medical treatment. A review of reviews.

    NARCIS (Netherlands)

    Dulmen, S. van; Sluijs, E.; Dijk, L. van; Ridder, D. de; Heerdink, R.; Bensing, J.

    2007-01-01

    BACKGROUND: Patients' non-adherence to medical treatment remains a persistent problem. Many interventions to improve patient adherence are unsuccessful and sound theoretical foundations are lacking. Innovations in theory and practice are badly needed. A new and promising way could be to review the e

  2. Factors related to adherence to treatment for systemic hypertension

    Directory of Open Access Journals (Sweden)

    Silvana Maria Coelho Leite Fava

    2014-06-01

    Full Text Available This study aimed to seek the evidence available in the literature regarding the factors related to adherence to treatment for systemic hypertension. It used the method of integrative review in the databases MEDLINE, CINAHL, and LILACS, using the keywords: hypertension, compliance, non-compliance, adherence, non-adherence, patient compliance, in the period 2004 – 2008, and articles in Portuguese, English and Spanish, with the use of a validated instrument and content analysis. 28 studies were selected, 64.3% of which had level of evidence VI. The following were identified as factors related to adherence to treatment: treatment costs, educational activities, sex, physician-patient relationship, physiological and behavioral aspects, drug therapy, attending checkups and lifestyle. The use of combined strategies is suggested in order to increase the individuals’ adherence to the treatment. Gaps point to the valorization of dialogic relationships for integrated and more efficacious health practices.

  3. Interventional tools to improve medication adherence: review of literature

    Science.gov (United States)

    Costa, Elísio; Giardini, Anna; Savin, Magda; Menditto, Enrica; Lehane, Elaine; Laosa, Olga; Pecorelli, Sergio; Monaco, Alessandro; Marengoni, Alessandra

    2015-01-01

    Medication adherence and persistence is recognized as a worldwide public health problem, particularly important in the management of chronic diseases. Nonadherence to medical plans affects every level of the population, but particularly older adults due to the high number of coexisting diseases they are affected by and the consequent polypharmacy. Chronic disease management requires a continuous psychological adaptation and behavioral reorganization. In literature, many interventions to improve medication adherence have been described for different clinical conditions, however, most interventions seem to fail in their aims. Moreover, most interventions associated with adherence improvements are not associated with improvements in other outcomes. Indeed, in the last decades, the degree of nonadherence remained unchanged. In this work, we review the most frequent interventions employed to increase the degree of medication adherence, the measured outcomes, and the improvements achieved, as well as the main limitations of the available studies on adherence, with a particular focus on older persons. PMID:26396502

  4. Quantification of the Forgiveness of Drugs to Imperfect Adherence.

    Science.gov (United States)

    Assawasuwannakit, P; Braund, R; Duffull, S B

    2015-03-01

    The circumstance of how sensitive therapeutic success is under imperfect adherence is driven by the property known as forgiveness. To date, no studies have considered variability in the pharmacokinetic-pharmacodynamic process in conjunction with imperfect adherence patterns in order to develop a comparative criterion to determine the forgiveness of a drug. In this study, we have proposed a criterion to quantify forgiveness; illustrated the criterion for a theoretical example and evaluated the forgiveness of a motivating example, namely warfarin. A forgiveness criterion, relative forgiveness, is defined as the number of times more likely that a target is successfully attained under perfect adherence compared to imperfect adherence; or when comparing two drugs under a standard setting of imperfect adherence. The relative forgiveness criterion may have important implications for both drug development and clinical practice since the choice of drug can account for the likely influence of its forgiveness.

  5. Forgiveness of non-adherence to HIV-1 antiretroviral therapy.

    Science.gov (United States)

    Shuter, Jonathan

    2008-04-01

    Superior adherence to HIV-1 antiretroviral therapy is a mainstay of successful HIV management. Studies performed in the early era of highly active antiretroviral therapy demonstrated the need for > or =95% adherence in order to achieve and sustain viral suppression. High rates of viral suppression have been observed at more moderate levels of adherence with newer antiretroviral regimens. The term 'forgiveness' is being used to describe the ability of a regimen to achieve and sustain viral suppression, despite suboptimal adherence. A variety of pharmacological, viral and host properties determine the level of forgiveness of any specific regimen. As the choice of treatment options continues to expand, forgiveness of non-adherence is likely to emerge as an increasingly important factor in therapeutic decision-making.

  6. Improved adhesion of photoresist to III-V substrates using PECVD carbon films

    Science.gov (United States)

    Mancini, David P.; Smith, Steven M.; Hooper, Andrew F.; Talin, A.; Chang, Daniel; Resnick, Douglas J.; Voight, Steven A.

    2002-07-01

    Amorphous PECVD carbon films have been investigated as a means to prepare III-V compound semiconductor substrates for improved photoresist adhesion. Results show that significant improvements in adhesive durability of patterned photoresist occurred for carbon primed GaAs and InGaAs wafers used in conjunction with both i-line and DUV lithography processes. These carbon layers, were 50-100 Angstrom in thickness, and varied in composition and morphology from a nitrogen-doped, diamond-like material (DLC), to a more hydrogen rich, polymer-like material (PLC). Adhesion durability tests performed in baths of ammonium hydroxide (NH4OH) and hydrochloric acid (HCl) in general showed superior performance compared to non-primed substrates. The sole exception was a failure of PLC priming on GaAs wafers used with a DUV anti-reflective coating. This same system, however, was shown to work extremely well when a DLC coating was substituted. Characterization of PLC and DLC films included use of AES, XPS, FTIR, AFM, and contact angle analysis. Results indicate that carbon films passivate III-V oxides, creating a stable, hydrophobic surface. This factor is proposed as a key reason for the improved resistance to aggressive aqueous environments. AFM results show that carbon films are extremely smooth and actually decrease surface roughness, indicating that mechanical adhesion is unlikely.

  7. Dual ion beam deposition of carbon films with diamondlike properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1984-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamondlike films generated by sputtering a graphite target.

  8. Unravelling adherence to prophylaxis in haemophilia: a patients' perspective.

    Science.gov (United States)

    Schrijvers, L H; Kars, M C; Beijlevelt-van der Zande, M; Peters, M; Schuurmans, M J; Fischer, K

    2015-09-01

    Given the lifelong therapy in haemophilia patients, insight in non-adherence behaviour from a patient perspective is important to understand patients' difficulties with the following treatment recommendations. The aim of this study was to clarify the process underlying adherence (behaviour) to prophylactic treatment, from a patients' perspective. To develop a grounded theory, a qualitative study using individual in-depth interviews was performed to understand experiences, perceptions and beliefs concerning adherence to prophylaxis. From two Dutch treatment centres, 21 adults with haemophilia using prophylaxis were interviewed. Patients were asked how they experience their task to administer prophylaxis and how they adhere to this. The interviews were transcribed, coded and analysed in an iterative process, leading to the development of the grounded theory. Adherence was determined by the position of prophylaxis in life. The position of prophylaxis was determined by the perception of prophylaxis and the ability to exert prophylaxis. Patients' perception was influenced by two main factors: acceptance of haemophilia and feeling/fearing symptoms. The ability to exert prophylaxis was influenced by understanding haemophilia and prophylaxis and planning/infusion skills. The combination of different perceptions and skills led to four main positions of prophylaxis in life: (i) prophylaxis integrated in life, (ii) prophylaxis according to doctors' advice, struggling with irregular situations, (iii) prophylaxis is too much to handle, (iv) prophylaxis is a confrontation with illness. The adherence level gradually decreased from position 1 to 4. This information can be used to design tailored interventions to promote adherence.

  9. Factors affecting adherence to a raw vegan diet.

    Science.gov (United States)

    Link, Lilli B; Jacobson, Judith S

    2008-02-01

    The purpose of this study was to evaluate adherence and identify predictors of adherence to a raw vegan diet (i.e., uncooked plant foods) following a stay at a raw vegan institute. In this cohort study of guests at a raw vegan institute, subjects completed written questionnaires upon arrival and 12 weeks later. Of 107 eligible guests, 84 participated. Mean age was 54 years, 23 were male, and 73 white. Fifty-one completed the 12-week follow-up. Eight (16%) reported their diet to be 80% raw vegan at baseline and 14 (28%) at follow-up. Based on a raw vegan dietary adherence score (range 0-42) created for this study, mean adherence (SD) increased from 15.1 (5.4) to 17.0 (5.8) over 12 weeks (p=0.03). Baseline predictors of adherence included: education (beta=0.95), severity of disease (beta=0.98), and self-efficacy to adhere (beta=0.72). Future interventions that evaluate this diet should address self-efficacy, an important, potentially remediable predictor of adherence.

  10. Spillover adherence effects of fixed-dose combination HIV therapy

    Directory of Open Access Journals (Sweden)

    Kauf TL

    2012-02-01

    Full Text Available Teresa L Kauf1, Keith L Davis2, Stephanie R Earnshaw2, E Anne Davis31Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida, Gainesville, FL, 2RTI Health Solutions, Research Triangle Park, NC, 3Independent consultant, Pittsboro, NC, USAAbstract: The impact of fixed-dose combination (FDC products on adherence to other, non-fixed regimen components has not been examined. We compared adherence to a third antiretroviral (ART component among patients receiving a nucleoside reverse transcriptase inhibitor (NRTI backbone consisting of the FDC Epzicom®, GlaxoSmithKline Inc, Research Triangle Park, NC (abacavir sulfate 600 mg + lamivudine 300 mg; FDC group versus NRTI combinations taken as two separate pills (NRTI Combo group using data from a national sample of 30 health plans covering approximately 38 million lives from 1997 to 2005. Adherence was measured as the medication possession ratio (MPR. Multivariate logistic regression compared treatment groups based on the likelihood of achieving ≥95% adherence, with sensitivity analyses using alternative thresholds. MPR was assessed as a continuous variable using multivariate linear regression. Covariates included age, gender, insurance payer type, year of study drug initiation, presence of mental health and substance abuse disorders, and third agent class. The study sample consisted of 650 FDC and 1947 NRTI Combo patients. Unadjusted mean adherence to the third agent was higher in the FDC group than the NRTI Combo group (0.92 vs 0.85; P < 0.0001. In regression analyses, FDC patients were 48% and 39% more likely to achieve 95% and 90% third agent adherence, respectively (P ≤ 0.03. None of the other MPR specifications achieved comparable results. Among managed care patients, use of an FDC appears to substantially improve adherence to a third regimen component and thus the likelihood of achieving the accepted standard for adherence to HIV therapy of 95%.Keywords

  11. Adherence to diabetes regimens: empirical status and clinical applications.

    Science.gov (United States)

    Kurtz, S M

    1990-01-01

    Adherence to diabetes treatment regimens has proved to be a conceptual and empirical enigma. Consequently, reliable and valid applications to the clinical practice of diabetes care and education have been wanting. Rates of nonadherence are staggeringly high, regardless of the methodology employed, and verification of self-reports is complicated by social desirability to appear compliant. Low intertask correlations further complicate our understanding of adherence-metabolic control relationships. Studies relating to the Health Belief Model, social learning theory, and the psychology of interpersonal relationships that have sought to identify determinants of adherence behaviors have specific relevance to the clinical practice of diabetes education.

  12. Primary non-adherence to prescribed medication in general practice

    DEFF Research Database (Denmark)

    Linnet, Kristján; Halldórsson, Matthías; Thengilsdóttir, Gudrún

    2013-01-01

    prescriptions issued electronically by 140 physicians at 16 primary health care centres in the Reykjavik capital area during two periods before and after increases in copayment were matched with those dispensed in pharmacies, the difference constituting primary non-adherence (population: 200&emsp14......;000; patients: 21 571; prescriptions: 22 991). Eight drug classes were selected to reflect symptom relief and degree of copayment. Two-tailed chi-square test and odds ratios for non-adherence by patient copayment groups were calculated. RESULTS: The rate of primary non-adherence was 6...

  13. An assessment of adherence to basic ecological principles by payments for ecosystem service projects.

    Science.gov (United States)

    Prager, C M; Varga, A; Olmsted, P; Ingram, J C; Cattau, M; Freund, C; Wynn-Grant, R; Naeem, S

    2016-08-01

    Programs and projects employing payments for ecosystem service (PES) interventions achieve their objectives by linking buyers and sellers of ecosystem services. Although PES projects are popular conservation and development interventions, little is known about their adherence to basic ecological principles. We conducted a quantitative assessment of the degree to which a global set of PES projects adhered to four ecological principles that are basic scientific considerations for any project focused on ecosystem management: collection of baseline data, identification of threats to an ecosystem service, monitoring, and attention to ecosystem dynamics or the formation of an adaptive management plan. We evaluated 118 PES projects in three markets-biodiversity, carbon, and water-compiled using websites of major conservation organizations; ecology, economic, and climate-change databases; and three scholarly databases (ISI Web of Knowledge, Web of Science, and Google Scholar). To assess adherence to ecological principles, we constructed two scientific indices (one additive [ASI] and one multiplicative [MSI]) based on our four ecological criteria and analyzed index scores by relevant project characteristics (e.g., sector, buyer, seller). Carbon-sector projects had higher ASI values (P principles. Projects financed by public-private partnerships had significantly higher ASI values than projects financed by governments (P principles based on the inclusion of cobenefits, the spatial extent of a project, or the size of a project's budget. These findings suggest, at this critical phase in the rapid growth of PES projects, that fundamental ecological principles should be considered more carefully in PES project design and implementation in an effort to ensure PES project viability and sustainability.

  14. Fewer Bacteria Adhere to Softer Hydrogels.

    Science.gov (United States)

    Kolewe, Kristopher W; Peyton, Shelly R; Schiffman, Jessica D

    2015-09-01

    Clinically, biofilm-associated infections commonly form on intravascular catheters and other hydrogel surfaces. The overuse of antibiotics to treat these infections has led to the spread of antibiotic resistance and underscores the importance of developing alternative strategies that delay the onset of biofilm formation. Previously, it has been reported that during surface contact, bacteria can detect surfaces through subtle changes in the function of their motors. However, how the stiffness of a polymer hydrogel influences the initial attachment of bacteria is unknown. Systematically, we investigated poly(ethylene glycol) dimethacrylate (PEGDMA) and agar hydrogels that were 20 times thicker than the cumulative size of bacterial cell appendages, as a function of Young's moduli. Soft (44.05-308.5 kPa), intermediate (1495-2877 kPa), and stiff (5152-6489 kPa) hydrogels were synthesized. Escherichia coli and Staphylococcus aureus attachment onto the hydrogels was analyzed using confocal microscopy after 2 and 24 h incubation periods. Independent of hydrogel chemistry and incubation time, E. coli and S. aureus attachment correlated positively to increasing hydrogel stiffness. For example, after a 24 h incubation period, there were 52 and 82% fewer E. coli adhered to soft PEGDMA hydrogels than to the intermediate and stiff PEGDMA hydrogels, respectively. A 62 and 79% reduction in the area coverage by the Gram-positive microbe S. aureus occurred after 24 h incubation on the soft versus intermediate and stiff PEGDMA hydrogels. We suggest that hydrogel stiffness is an easily tunable variable that could potentially be used synergistically with traditional antimicrobial strategies to reduce early bacterial adhesion and therefore the occurrence of biofilm-associated infections.

  15. Fewer Bacteria Adhere to Softer Hydrogels

    Science.gov (United States)

    Kolewe, Kristopher W.; Peyton, Shelly R.; Schiffman, Jessica D.

    2015-01-01

    Clinically, biofilm-associated infections commonly form on intravascular catheters and other hydrogel surfaces. The overuse of antibiotics to treat these infections has led to the spread of antibiotic resistance and underscores the importance of developing alternative strategies that delay the onset of biofilm formation. Previously, it has been reported that during surface contact, bacteria can detect surfaces through subtle changes in the function of their motors. However, how the stiffness of a polymer hydrogel influences the initial attachment of bacteria is unknown. Systematically, we investigated poly(ethylene glycol) dimethacrylate (PEGDMA) and agar hydrogels that were twenty times thicker than the cumulative size of bacterial cell appendages, as a function of Young’s moduli. Soft (44.05 – 308.5 kPa), intermediate (1495 – 2877 kPa), and stiff (5152 – 6489 kPa) hydrogels were synthesized. Escherichia coli and Staphylococcus aureus attachment onto the hydrogels was analyzed using confocal microscopy after 2 and 24 hr incubation periods. Independent of hydrogel chemistry and incubation time, E. coli and S. aureus attachment correlated positively to increasing hydrogel stiffness. For example, after a 24 hr incubation period, there were 52% and 82% less E. coli adhered to soft PEGDMA hydrogels, than to the intermediate and stiff PEGDMA hydrogels, respectively. A 62% and 79% reduction in the area coverage by the Gram-positive microbe S. aureus occurred after 24 hr incubation on the soft versus intermediate and stiff PEGDMA hydrogels. We suggest that hydrogel stiffness is an easily tunable variable that, potentially, could be used synergistically with traditional antimicrobial strategies to reduce early bacterial adhesion, and therefore the occurrence of biofilm-associated infections. PMID:26291308

  16. Bipolar disorder and medication: adherence, patients' knowledge and serum monitoring of lithium carbonate Trastorno bipolar y medicamentos: adhesión, conocimiento de los pacientes y monitorización sérica del carbonato de litio Transtorno bipolar e medicamentos: adesão, conhecimento dos pacientes e monitorização sérica do carbonato de lítio

    Directory of Open Access Journals (Sweden)

    Camila de Souza

    2013-04-01

    Full Text Available OBJECTIVES: this study featured patients with affective bipolar disorder who were making use of lithium and received care at an outpatient care center located in a country town in the state of Sao Paulo in 2009; it assessed the adherence and knowledge of these patients in relation to the medication prescribed to them and verified the proportion of blood tests performed per year in the service, for each individual, to measure lithium levels in the blood. METHOD: descriptive study with quantitative approach, involving 36 participants. Structured interviews and review of medical records were used for data collection and descriptive statistics for data analysis. RESULTS: difficulties in reporting the dosage of the medication prescribed and a high rate of non-adherence were identified among the participants. None of the participants in the study was submitted to two tests a year to measure lithium levels in the blood, which is the minimum proportion of tests recommended by the literature for maintenance treatment using lithium carbonate. CONCLUSION: this study highlights the critical factors for the promotion of patients' safety in monitoring lithium drug therapy. OBJETIVOS: este estudio caracterizó pacientes con trastorno afectivo bipolar, tratadas con litio, atendidos en el año de 2009 en un servicio de ambulatorio del interior del estado de Sao Paulo, en Brasil; evaluó la adhesión y conocimiento de los mismos sobre medicamentos prescritos y verificó la proporción de litemias/año realizadas, en el servicio, para cada individuo. MÉTODO: se trata de estudio descriptivo, con abordaje cuantitativo, del cual participaron 36 personas. Fueron utilizadas entrevistas estructuradas y revisión de fichas para recolección de datos y estadística descriptiva para análisis de los mismos. RESULTADOS: entre los participantes, fueron identificadas dificultades en relatar la dosis de los fármacos prescritos y una alta tasa de no adhesión. En ning

  17. Older Adults' Uptake and Adherence to Exercise Classes: Instructors' Perspectives.

    Science.gov (United States)

    Hawley-Hague, Helen; Horne, Maria; Skelton, Dawn A; Todd, Chris

    2016-01-01

    Exercise classes provide a range of benefits for older adults, but adherence levels are poor. We know little of instructors' experiences of delivering exercise classes to older adults. Semistructured interviews, informed by the Theory of Planned Behavior (TPB), were conducted with instructors (n = 19) delivering multicomponent exercise classes to establish their perspectives on older adults' uptake and adherence to exercise classes. Analysis revealed 'barriers' to uptake related to identity, choice/control, cost, and venue, and 'solutions' included providing choice/control, relating exercise to identity, a personal touch, and social support. Barriers to adherence included unrealistic expectations and social influences, and solutions identified were encouraging commitment, creating social cohesion, and an emphasis on achieving outcomes. Older adults' attitudes were an underlying theme, which related to all barriers and solutions. The instructor plays an important, but not isolated, role in older adults' uptake and adherence to classes. Instructors' perspectives help us to further understand how we can design successful exercise classes.

  18. Method of detaching adherent cells for flow cytometry

    KAUST Repository

    Kaur, Mandeep

    2015-12-24

    In one aspect, a method for detaching adherent cells can include adding a cell lifting solution to the media including a sample of adherent cells and incubating the sample of adherent cells with the cell lifting solution. No scraping or pipetting is needed to facilitate cell detachment. The method do not require inactivation of cell lifting solution and no washing of detaching cells is required to remove cell lifting solution. Detached cells can be stained with dye in the presence of cell lifting solution and are further analyzed using flow cytometer. The method has been tested using 6 different cell lines, 4 different assays, two different plate formats (96 and 384 well plates) and two different flow cytometry instruments. The method is simple to perform, less time consuming, with no cell loss and makes high throughput flow cytometry on adherent cells a reality.

  19. In vitro adherence of Moraxella bovis to intact corneal epithelium.

    Science.gov (United States)

    Jackman, S H; Rosenbusch, R F

    1984-09-01

    An in vitro assay is described using radiolabeled Moraxella bovis for studying adherence to intact bovine corneal epithelial surfaces. The assay was optimized for time (45 min) and for the ratio of epithelial cells to bacteria (1:1000) that demonstrated a significant difference in adherence between M. bovis strain 118F, a piliated organism and a nonpiliated variant, strain 118F/4-2. Adherence of these organisms correlated with previous pathogenicity studies involving experimental infection of calves. Scanning electron microscopy of tissues treated in the assay revealed a predilection of M. bovis for dark epithelial cells and for association with depressions in the tissue surface. This assay technique is discussed in comparison with other in vitro adherence assay methods.

  20. Predictors of duloxetine adherence and persistence in patients with fibromyalgia

    Directory of Open Access Journals (Sweden)

    Cui Z

    2012-06-01

    Full Text Available Zhanglin Cui, Yang Zhao, Diego Novick, Douglas FariesEli Lilly and Company, Indianapolis, IN, USAObjectives: Adherence to medication for the treatment of fibromyalgia (FM is predictive of lower overall health-care costs, and thus a lower burden on both patients and providers. The objectives of this study were to examine the predictors of adherence to and persistence with duloxetine therapy among commercially insured FM patients, and to identify subgroups of patients with high duloxetine persistence and adherence.Study design: This cross-sectional, retrospective study analyzed medical and pharmacy records over 1 year for patients in the US aged 18–64 years with FM who initiated (no prior 90-day use duloxetine treatment in 2008.Methods: Adherence to duloxetine was measured by medication possession ratio (MPR, with high adherence defined as MPR ≥ 0.8. Persistence was defined as the duration of therapy from the index date to the earliest of: the ending date of the last prescription, the date of the first gap of >15 days between prescriptions, or the end of the study period (12 months. Demographic and clinical predictors of adherence were examined via multiple logistic regression (MLR, and subgroups of duloxetine-persistent and -adherent patients were identified using classification and regression trees (CART.Results: Among 4660 duloxetine patients, 33% achieved high adherence. Factors associated with high adherence from MLR included older age, North Central and Northeast regions, prior venlafaxine, pregabalin, selective serotonin reuptake inhibitor (SSRI, or other antidepressant use, or comorbid dyslipidemia or osteoarthritis (all P < 0.05. CART analysis revealed that patients with prior antidepressant use, aged ≥46, or prior osteoarthritis had higher MPR (all P < 0.05, and patients aged ≥45 with a history of SSRI, venlafaxine, or anticonvulsant use had longer duration of therapy (all P < 0.05.Conclusions: Patients with high adherence to and

  1. Non-adherence to topical treatments for actinic keratosis

    Directory of Open Access Journals (Sweden)

    Shergill B

    2013-12-01

    Full Text Available Bav Shergill,1 Simon Zokaie,2 Alison J Carr3 1Department of Dermatology, Brighton and Sussex University Hospitals, Elm Grove, Brighton, UK; 2Leo Pharma, Princes Risborough, 3Hamell, London, UK Background: There is limited information on the patterns of use, adherence rates, and factors that impact adherence with topical treatments for actinic keratosis (AK. Objectives: To establish patterns of use and adherence with topical treatments for AK and to identify treatment-related factors that impact on adherence. Methods: A community-based, cross-sectional study was performed using a standardized questionnaire completed online or via telephone interview. Patients were stratified according to the presence of AK lesions on the scalp and/or other extremities; and presence of scarring resulting from treatment. Results: This study included 305 patients with AK who were currently using a patient-applied topical therapy for AK or had used one within the previous 12 months. In total, 88% (n = 268/305 of patients were either non-adherent, non-persistent or both non-adherent and non-persistent to topical therapy. Duration of treatment was associated with increasing rates of non-adherence (adjusted odds ratio [OR]; for treatment durations greater than 4 weeks, 2.2, P < 0.01: 52% of patients were non-adherent with 3–4 week treatment duration; 69% of patients with 4–8 week treatment duration; and 71% of patients with 6–12 week treatment duration. There were similar increases in non-persistence with increasing treatment duration (adjusted OR; for treatment durations greater than 4 weeks, 2.1, P < 0.05. Conclusion: This study found high rates of non-adherence and non-persistence in patients with AK. Duration of treatment was a significant factor contributing to non-adherence and non-persistence to topical treatments. Patient-applied topical therapies that require less frequent application and have shorter treatment duration may be associated with improved

  2. Older adults' uptake and adherence to exercise classes: Instructors' perspectives.

    OpenAIRE

    Hawley-Hague, Helen; Horne, Maria; Skelton, Dawn A; Todd, Chris

    2016-01-01

    Exercise classes provide a range of benefits for older adults, but adherence levels are poor. We know little of instructors' experiences of delivering exercise classes to older adults. Semistructured interviews, informed by the Theory of Planned Behavior (TPB), were conducted with instructors (n = 19) delivering multicomponent exercise classes to establish their perspectives on older adults' uptake and adherence to exercise classes. Analysis revealed 'barriers' to uptake related to identity, ...

  3. Elderly adherence to hypertension treatment and nursing interventions

    OpenAIRE

    Jênifa Cavalcante dos Santos; Raquel Sampaio Florêncio; Célida Juliana de Oliveira; Thereza Maria Magalhães Moreira

    2016-01-01

    Adherence to the treatment of arterial hypertension is a challenge to health professionals. Thus, this study aimed at verifying adherence to treatment of hypertension of elderly patients followed in a group and describe the possible nursing interventions on the clientele. The descriptive research was developed in two phases: between December/2008 and January/2009, we used data collection instrument to assess compliance to treatment; from February to April/2009, we used the technique Focus Gro...

  4. Engineering adherent bacteria by creating a single synthetic curli operon.

    Science.gov (United States)

    Drogue, Benoît; Thomas, Philippe; Balvay, Laurent; Prigent-Combaret, Claire; Dorel, Corinne

    2012-11-16

    The method described here consists in redesigning E. coli adherence properties by assembling the minimum number of curli genes under the control of a strong and metal-overinducible promoter, and in visualizing and quantifying the resulting gain of bacterial adherence. This method applies appropriate engineering principles of abstraction and standardization of synthetic biology, and results in the BBa_K540000 Biobrick (Best new Biobrick device, engineered, iGEM 2011). The first step consists in the design of the synthetic operon devoted to curli overproduction in response to metal, and therefore in increasing the adherence abilities of the wild type strain. The original curli operon was modified in silico in order to optimize transcriptional and translational signals and escape the "natural" regulation of curli. This approach allowed to test with success our current understanding of curli production. Moreover, simplifying the curli regulation by switching the endogenous complex promoter (more than 10 transcriptional regulators identified) to a simple metal-regulated promoter makes adherence much easier to control. The second step includes qualitative and quantitative assessment of adherence abilities by implementation of simple methods. These methods are applicable to a large range of adherent bacteria regardless of biological structures involved in biofilm formation. Adherence test in 24-well polystyrene plates provides a quick preliminary visualization of the bacterial biofilm after crystal violet staining. This qualitative test can be sharpened by the quantification of the percentage of adherence. Such a method is very simple but more accurate than only crystal violet staining as described previously with both a good repeatability and reproducibility. Visualization of GFP-tagged bacteria on glass slides by fluorescence or laser confocal microscopy allows to strengthen the results obtained with the 24-well plate test by direct observation of the phenomenon.

  5. Medication adherence: the critical step towards better patient outcome

    Directory of Open Access Journals (Sweden)

    Anish Desai

    2014-10-01

    Full Text Available Medication adherence is defined as patient's adherence to take their medications as prescribed and continue to take the prescribed medication for stipulated time frame. Medication non-adherence is a growing concern to physicians, healthcare systems, and other stakeholders (e.g., payers and there is an increasing evidence of its prevalence and is associated with adverse clinical outcomes eventually resulting into higher costs of care. The cost of non-adherence has been estimated at $100 billion to $300 billion annually, including costs from avoidable hospitalizations, nursing home admissions, and premature deaths. Improving adherence to medication is critical to improve the quality of health care, to encourage better chronic care management, and promote better health outcomes. Reasons for non-adherence are multiple and complex. Studies have reported that poor adherence to drug dosage is due to patient perception that the disease is non-significant, adverse drug effects, lack of treatment effectiveness, and the patient's poor or incomplete knowledge of the disease and (cost. A multifactorial approach is required to tackle this complex problem as a single approach will be ineffective for all patients. The most effective intervention is to use a combination of approaches and address literacy, behavior, and organizational issues. There are challenges as well as opportunities in addressing the public health issue of medication adherence. Changing healthcare reforms, advances in digital health media, social media and modern technologies can now provide alternatives to tackle this issue. [Int J Basic Clin Pharmacol 2014; 3(5.000: 748-754

  6. Adherence of human basophils to cultured umbilical vein endothelial cells.

    OpenAIRE

    1988-01-01

    The mechanism by which circulating human basophils adhere to vascular endothelium and migrate to sites of allergic reactions is unknown. Agents have been identified which stimulate the adherence of purified basophils to cultured human umbilical vein vascular endothelial cells (HuVEC). Treatment of HuVEC with interleukin 1, tumor necrosis factor (TNF), bacterial endotoxin, and 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in time and dose-dependent increases of adhesiveness for basophils...

  7. Treatment non-adherence in pseudo-refractory epilepsy.

    Science.gov (United States)

    Brodtkorb, Eylert; Samsonsen, Christian; Sund, Janne Kutschera; Bråthen, Geir; Helde, Grethe; Reimers, Arne

    2016-05-01

    Non-adherence to antiepileptic drug treatment strongly affects the outcome of epilepsy and is frequently clinically unrecognized. This review addresses current knowledge on medication-taking behavior in people with epilepsy, as well as the importance of tailoring interventions to the individual patterns of non-adherence. Non-adherence can be categorized as non-initiation, poor execution (accidental or intentional) or non-persistence and are related to clinical characteristics and health care barriers. All available methods to assess adherence are hampered by shortcomings. Self-reports are indirect and subjective. Pill-counts, electronic bottle-tops and pharmacy records are objective, but indirect measures of drug ingestion. Therapeutic drug monitoring is both direct and objective, but pharmacokinetic and diurnal variability must be taken into account. Young adults with generalized epilepsy may be particularly vulnerable to non-adherence. The drug burden in the form of polytherapy, multiple dosing and side effects are obvious obstacles. Poor understanding of the principles of prophylactic treatment as well as drug costs may be important in people with low socioeconomic status. Depression is also associated with low adherence. In people with multihandicaps, failed oral intake may be due to behavioral or physical problems, as well as insufficient education of the caregivers. Non-adherence often results in seizure breakthrough and hospital admissions, but the consequences may be more dramatic. It is the leading cause of status epilepticus in people with epilepsy, and the association with sudden death (SUDEP) is clear. The management of poor drug-taking behavior should be based on the identification of the specific causes in each individual and corresponding multiprofessional interventions. Non-adherence to antiepileptic drugs needs more clinical and scientific attention.

  8. MONETARY EXPECTATIONS OF THE ROMANIAN EXECUTIVES REGARDING THE ADHERATION

    Directory of Open Access Journals (Sweden)

    Ramona DUMITRIU

    2006-01-01

    Full Text Available This paper explores the monetary expectations induced to the managers of Romanian firms by adheration. It is based on an investigation among twenty Romanian executives regarding the impact on adheration over monetary aspects: inflation, exchange rates and adoption of euro. We conclude that the results of the monetary policy in the last years made the executives confident that the Romanian authorities could maintain the monetary stability after theadheration.

  9. LARGE AREA FILTERED ARC DEPOSITION OF CARBON AND BORON BASED HARD COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Rabi S.

    2003-12-05

    This document is a final report covering work performed under Contract No. DE-FG02-99ER82911 from the Department of Energy under a SBIR Phase II Program. Wear resistant, hard coatings can play a vital role in many engineering applications. The primary goal of this project was to develop coatings containing boron and carbon with hardness greater than 30 GPa and evaluate these coatings for machining applications. UES has developed a number of carbon and boron containing coatings with hardness in the range of 34 to 65 GPa using a combination of filtered cathodic arc and magnetron sputtering. The boron containing coatings were based on TiB2, TiBN, and TiBCN, while the carbon containing coatings ere TiC+C and hydrogen free diamond-like-carbon. Machining tests were performed with single and multilayer coated tools. The turning and milling tests were run at TechSolve Inc., under a subcontract at Ohio State University. Significant increases in tool lives were realized in end milling of H-13 die steel (8X) and titanium alloy (80%) using the TiBN coating. A multilayer TiBN/TiN performed the best in end-milling of highly abrasive Al-Si alloys. A 40% increase in life over the TiAlN benchmark coating was found. Further evaluations of these coatings with commercialization partners are currently in progress.

  10. Nanoindentation and AFM studies of PECVD DLC and reactively sputtered Ti containing carbon films

    Indian Academy of Sciences (India)

    A Pauschitz; J Schalko; T Koch; C Eisenmenger-Sittner; S Kvasnica; Manish Roy

    2003-10-01

    Amorphous carbon film, also known as DLC film, is a promising material for tribological application. It is noted that properties relevant to tribological application change significantly depending on the method of preparation of these films. These properties are also altered by the composition of the films. In view of this, the objective of the present work is to compare the nanoindentation and atomic force microscopy (AFM) study of diamond like carbon (DLC) film obtained by plasma enhanced chemical vapour deposition (PECVD) with the Ti containing amorphous carbon (Ti/-C : H) film obtained by unbalanced magnetron sputter deposition (UMSD). Towards that purpose, DLC and Ti/-C : H films are deposited on silicon substrate by PECVD and UMSD processes, respectively. The microstructural features and the mechanical properties of these films are evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nanoindentation and by AFM. The results show that the PECVD DLC film has a higher elastic modulus, hardness and roughness than the UMSD Ti/-C : H film. It also has a lower pull off force than Ti containing amorphous carbon film.

  11. Nanotribological Behavior of Carbon Based Thin Films: Friction and Lubricity Mechanisms at the Nanoscale

    Directory of Open Access Journals (Sweden)

    Costas A. Charitidis

    2013-04-01

    Full Text Available The use of materials with very attractive friction and wear properties has raised much attention in research and industrial sectors. A wide range of tribological applications, including rolling and sliding bearings, machining, mechanical seals, biomedical implants and microelectromechanical systems (MEMS, require thin films with high mechanical strength, chemical inertness, broad optical transparency, high refractive index, wide bandgap excellent thermal conductivity and extremely low thermal expansion. Carbon based thin films like diamond, diamond-like carbon, carbon nitride and cubic boron nitride known as “super-hard” material have been studied thoroughly as the ideal candidate for tribological applications. In this study, the results of experimental and simulation works on the nanotribological behavior of carbon films and fundamental mechanisms of friction and lubricity at the nano-scale are reviewed. The study is focused on the nanomechanical properties and analysis of the nanoscratching processes at low loads to obtain quantitative analysis, the comparison obtain quantitative analysis, the comparison of their elastic/plastic deformation response, and nanotribological behavior of the a-C, ta-C, a-C:H, CNx, and a-C:M films. For ta-C and a-C:M films new data are presented and discussed.

  12. Common mental health problems and antiretroviral therapy adherence.

    Science.gov (United States)

    Nel, Adriaan; Kagee, Ashraf

    2011-11-01

    This paper reviews the literature on various mental health problems and their impact on adherence to antiretroviral therapy (ART). Depression, anxiety disorders, and disorders related to substance abuse were identified as key role-players influencing adherence. The severity of symptoms related to these disorders was found to be inversely related to ART adherence, with the possible exception of post-traumatic stress disorder (PTSD). PTSD was found to have both positive and negative implications for adherence, with severity of symptoms ranging from health-protective concern to disabling distress. Possible solutions aimed at addressing the adverse effects of mental health problems on adherence are discussed. Routine screening in ART settings is suggested in settings where follow-up of positive screen scores are possible, along with the necessary interventions to resolve the disorder of concern. Suggested interventions include utilising psychotherapeutic treatment, both in isolation and in conjunction with medication, to address mental health problems. Furthermore, finding effective ways of marshalling social support is recommended for ensuring optimal adherence, and possibly mitigating the adverse effects of mental health problems. Further research is needed to find feasible ways of identifying, assessing and treating patients with mental health problems in resource-constrained settings where HIV prevalence is highest.

  13. Comparison of adherent and non-adherent staphylococci in the induction of polymorphonuclear leukocyte activation in vitro

    DEFF Research Database (Denmark)

    Riber, U; Espersen, F; Kharazmi, A

    1995-01-01

    The ability to consume complement and activate neutrophils was investigated for staphylococci adherent to silicone surfaces and non-adherent staphylococci. Staphylococcus epidermidis strain ATCC 14990 and Staphylococcus aureus strain E 2371 were used in this study. The bacteria were allowed...... at 37 degrees C. The bacteria consumed complement to approximately the same extent when adherent to the catheter segments, but more slowly in comparison with planktonic bacteria. When planktonic bacteria were compared, complement was consumed more quickly by S. epidermidis than by S. aureus. Measuring...... the induction of chemiluminescence by planktonic bacteria, S. epidermidis induced a lower response than S. aureus, while when adherent to the catheter segments the bacteria induced similar responses. These responses were only 15 to 20% of those induced by planktonic bacteria and only slightly higher than...

  14. Alcohol use, antiretroviral therapy adherence, and preferences regarding an alcohol-focused adherence intervention in patients with human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Kekwaletswe CT

    2014-03-01

    Full Text Available Connie T Kekwaletswe,1 Neo K Morojele1,21Alcohol and Drug Abuse Research Unit, Medical Research Council, Pretoria, 2School of Public Health, University of the Witwatersrand, Johannesburg, South AfricaBackground: The primary objectives of this study were to determine the association between alcohol and antiretroviral therapy (ART adherence and the perceived appropriateness and acceptability of elements of an adherence counseling program with a focus on alcohol-related ART nonadherence among a sample of ART recipients in human immunodeficiency virus (HIV clinics in Tshwane, South Africa.Methods: We conducted a cross-sectional study with purposive sampling. The sample comprised 304 male and female ART recipients at two President's Emergency Plan For AIDS Relief-supported HIV clinics. Using an interview schedule, we assessed patients' alcohol use (Alcohol Use Disorders Identification Test, other drug use, level of adherence to ART, and reasons for missing ART doses (AIDS Clinical Trials Group adherence instrument. Additionally, patients’ views were solicited on: the likely effectiveness of potential facilitators; the preferred quantity, duration, format, and setting of the sessions; the usefulness of having family members/friends attend sessions along with the patient; and potential skill sets to be imparted.Results: About half of the male drinkers’ and three quarters of the female drinkers’ Alcohol Use Disorders Identification Test scores were suggestive of hazardous or harmful drinking. Average self-reported ART adherence was 89.7%. There was a significant association between level of alcohol use and degree of ART adherence. Overall, participants perceived two clinic-based sessions, each of one hour’s duration, in a group format, and facilitated by a peer or adherence counselor, as most appropriate and acceptable. Participants also had a favorable attitude towards family and friends accompanying them to the sessions. They also favored an

  15. Treatment adherence and quality of life in patients on antihypertensive medications in a Middle Eastern population: adherence

    Directory of Open Access Journals (Sweden)

    Alhaddad IA

    2016-10-01

    Full Text Available Imad A Alhaddad,1 Omar Hamoui,2 Ayman Hammoudeh,3 Samir Mallat4 1Cardiovascular Department, Jordan Hospital, Amman, Jordan; 2Cardiology Department, Clemenceau Medical Center, Beirut, Lebanon; 3Cardiology Department, Istishari Hospital, Amman, Jordan; 4Department of Internal Medicine, Nephrology Division, American University of Beirut Medical Center, Beirut, Lebanon Background: Poor adherence to antihypertensive treatment remains a clinical challenge worldwide. The objectives of this study were to assess the adherence level to antihypertensive treatment and to identify its associated factors in a sample of hypertensive patients in Lebanon and Jordan. Methods: We conducted an observational study between May 2011 and September 2012. A total of 1,470 eligible hypertensive patients were enrolled in our study and followed up for a period of 6 months. Data were collected regarding sociodemographic, health behavior, and hypertension-related characteristics. The adherence to treatment and the quality of life were self-reported using the Morisky, Green & Levine Scale and the Hypertension Quality of Life Questionnaire. Results: Our results revealed that 55.9 % of the patients were adherent to their antihypertensive medication. Older age was associated with better adherence, whereas being divorced or widowed, having a poorer quality of life, and being classified as having stage 1 or 2 hypertension at the end of the study were all associated with poorer adherence. Conclusion: Efforts should be exerted on all levels in order to increase the adherence to antihypertensive treatment through the implementation of educational campaigns. Keywords: adherence, NC 7 guidelines, Morisky, Green & Levine Scale, Hypertension Quality of Life Questionnaire, Lebanon, Jordan

  16. Evaluating adherence to ocular hypotensives using the Travatan dosing aid

    Directory of Open Access Journals (Sweden)

    O'Dell L

    2012-01-01

    Full Text Available Leslie O'Dell1, Amy L Hennessy2,3, Alan L Robin2–41May Eye Care Center, Hanover, PA, USA; 2Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; 3Glaucoma Specialists, Baltimore, MD, USA; 4Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USAPurpose: The Travatan™ Dosing Aid (TDA is the first commercially available device designed to aid in patients' adherence to their glaucoma therapies and to record patients' eyedrop administration, so that doctors can better assess adherence. No prior studies have objectively evaluated adherence to glaucoma medications and its relationship to the severity of glaucoma or the use of multiple systemic medications.Methods: We enrolled 100 consecutive subjects from a private glaucoma practice, all currently using topical travoprost 0.004%. Each subject was issued a TDA to record the time and date of each drop instilled. Informed consents were signed and the subjects were aware that their medication use was being monitored. Patients returned for follow-up 30–60 days after their initial exam.Results: 89 subjects completed the study: 44 were male, with a mean age of 67 years, and 69.7% were Caucasian. Overall, patient adherence was 74.8% (range 22%–100% improving to 85.4% on the day prior to follow-up. The mean number of missed doses per month was 6.24 ± 5.9. Only 7.9% of the study population never missed a dose and 23.6% ± 4.3% missed more than ten drops per month. No marked association was observed between the severity of glaucoma, race, or the number of systemic medications and adherence. A marked improvement in adherence was noted in patients using travoprost 0.004% as monocular therapy rather than binocular therapy, 84.0% ± 17.1% vs 67.4% ± 23.5% (P < 0.005.Conclusion: Patient adherence to glaucoma medical therapy is a major barrier in the management and treatment of glaucoma patients given the chronic nature and asymptomatic course of the disease. Until recently

  17. Protective Sliding Carbon-Based Nanolayers Prepared by Argon or Nitrogen Ion-Beam Assisted Deposition on Ti6Al4V Alloy

    Directory of Open Access Journals (Sweden)

    Petr Vlcak

    2016-01-01

    Full Text Available The microstructure and the surface properties of samples coated by carbon-based nanolayer were investigated in an effort to increase the surface hardness and reduce the coefficient of friction of the Ti6Al4V alloy. Protective carbon-based nanolayers were fabricated by argon or nitrogen ion-beam assisted deposition at ion energy of 700 eV on Ti6Al4V substrates. The Raman spectra indicated that nanolayers had a diamond-like carbon character with sp2 rich bonds. The TiC and TiN compounds formed in the surface area were detected by X-ray diffraction. Nanoscratch tests showed increased adhesion of a carbon-based nanolayer deposited with ion assistance in comparison with a carbon nanolayer deposited without ion assistance. The results showed that argon ion assistance leads to greater nanohardness than a sample coated by a carbon-based nanolayer with nitrogen ion assistance. A more than twofold increase in nanohardness and a more than fivefold decrease in the coefficient of friction were obtained for samples coated by a carbon-based nanolayer with ion assistance, in comparison with the reference sample.

  18. An exploration of factors influencing ambulance and emergency nurses protocol adherence in the Netherlands

    NARCIS (Netherlands)

    Ebben, Remco; Vloet, Lilian; Mintjes, Joke; Achterberg, Theo van

    2012-01-01

    Adherence to ambulance and ED protocols is often suboptimal. Insight into factors influencing adherence is a requisite for improvement of adherence. This study aims to gain an in-depth understanding of factors that influence ambulance and emergency nurses’ adherence to protocols.

  19. Factors influencing long-term adherence to two previously implemented hospital guidelines

    NARCIS (Netherlands)

    A.M. Knops; M.N. Storm-Versloot; A.P.M. Mank; D.T. Ubbink; H. Vermeulen; P.M.M. Bossuyt; A. Goossens

    2010-01-01

    After successful implementation, adherence to hospital guidelines should be sustained. Long-term adherence to two hospital guidelines was audited. The overall aim was to explore factors accounting for their long-term adherence or non-adherence. A fluid balance guideline (FBG) and body temperature gu

  20. The relationship between clinical outcomes and medication adherence in difficult-to-control asthma.

    Science.gov (United States)

    Murphy, Anna C; Proeschal, Amandine; Brightling, Christopher E; Wardlaw, Andrew J; Pavord, Ian; Bradding, Peter; Green, Ruth H

    2012-08-01

    Medication non-adherence and the clinical implications in difficult-to-control asthma were audited. Prescription issue data from 115 patients identified sub-optimal adherence (asthma (p=0.008). The majority of patients with difficult-to-control asthma are non-adherent with their asthma medication. Non-adherence is correlated with poor clinical outcomes.

  1. 76 FR 12969 - Campaign To Improve Poor Medication Adherence (U18)

    Science.gov (United States)

    2011-03-09

    ... HUMAN SERVICES Food and Drug Administration Campaign To Improve Poor Medication Adherence (U18) AGENCY... ] importance of good medication adherence, a vital first step toward improved adherence behavior and better...' awareness of the importance of good medication adherence and provide tools to prescribers to help...

  2. Impact of an exercise program on adherence and fitness indicators.

    Science.gov (United States)

    Carpenter, Roger; Gilleland, Diana

    2016-05-01

    Adherence to exercise is one of the most problematic health behaviors. This pilot study describes the impact of an exercise program on adherence to exercise and fitness indicators for overweight and obese adults enrolled in an insurance reimbursed exercise plan. Chart reviews were conducted retrospectively in a convenience sample of 77 subjects from a human performance lab (HPL) at a large southern university. Charts from 2004 to 2009 were reviewed for health history, fitness indicators (fitness level, weight, BMI, hip/waist ratio, % body fat, BP, HR, cholesterol), and adherence (number of exercise sessions/month). Exercise supervision was operationalized in two phases over 12 months: Phase I (3 months supervised exercise) and Phase II (9 months unsupervised exercise). Fifty-eight participants completed Phase I, and 8 completed Phase II. Six-nine percent of those completing Phase I visited the gym at least 8 times/month with significant (α=.05) improvement in all fitness indicators. Those visiting body fat. Twenty-four subjects continued into Phase II, with only eight completing Phase II. Of those eight, only one subject visited the HPL at least 8 times/month. Health history data including co-morbidities, symptoms, habits, perceived tension, job stress, and fitness level were not associated with adherence. Symptoms of swollen, stiff, painful joints, and swollen ankles and legs were associated with decreased adherence to exercise. Supervised exercise was positively related to adherence and improved fitness indicators. Adults with joint symptoms may require more support. Based on these pilot data, designing a study with a larger sample and the inclusion of barriers and facilitators for adherence to self-directed exercise would allow additional analysis. Innovative interventions are needed that mimic the supervised environment, shifting responsibility for the exercise plan from the supervisor to those exercising.

  3. Perceived barriers to guideline adherence: A survey among general practitioners

    Directory of Open Access Journals (Sweden)

    Besters Casper F

    2011-09-01

    Full Text Available Abstract Background Despite considerable efforts to promote and support guideline use, adherence is often suboptimal. Barriers to adherence vary not only across guidelines but also across recommendations within guidelines. The aim of this study was to assess the perceived barriers to guideline adherence among GPs by focusing on key recommendations within guidelines. Methods We conducted a cross-sectional electronic survey among 703 GPs in the Netherlands. Sixteen key recommendations were derived from four national guidelines. Six statements were included to address the attitudes towards guidelines in general. In addition, GPs were asked to rate their perceived adherence (one statement and the perceived barriers (fourteen statements for each of the key recommendations, based on an existing framework. Results 264 GPs (38% completed the questionnaire. Although 35% of the GPs reported difficulties in changing routines and habits to follow guidelines, 89% believed that following guidelines leads to improved patient care. Perceived adherence varied between 52 and 95% across recommendations (mean: 77%. The most perceived barriers were related to external factors, in particular patient ability and behaviour (mean: 30% and patient preferences (mean: 23%. Lack of applicability of recommendations in general (mean: 22% and more specifically to individual patients (mean: 25% were also frequently perceived as barriers. The scores on perceived barriers differed largely between recommendations [minimum range 14%; maximum range 67%]. Conclusions Dutch GPs have a positive attitude towards the NHG guidelines, report high adherence rates and low levels of perceived barriers. However, the perceived adherence and perceived barriers varied largely across recommendations. The most perceived barriers across recommendations are patient related, suggesting that current guidelines do not always adequately incorporate patient preferences, needs and abilities. It may be

  4. Adherence to the Mediterranean dietary pattern among Balearic Islands adolescents.

    Science.gov (United States)

    Martínez, Elisa; Llull, Rosa; Del Mar Bibiloni, Maria; Pons, Antoni; Tur, Josep A

    2010-06-01

    The aim of the present work was to assess the prevalence of the Mediterranean dietary pattern (MDP) in Balearic Islands adolescents, and socio-demographic and lifestyle factors that might determine adherence to the MDP. A cross-sectional nutritional survey was carried out in the Balearic Islands between 2007 and 2008. A random sample (n 1231) of the adolescent population (12-17 years old) was interviewed. Dietary questionnaires and a general questionnaire incorporating questions related to socio-economic status, parental education level and lifestyle factors were used. Dietary habits were assessed by means of two 24 h recalls and a quantitative FFQ. Adherence to the MDP was defined according to a score constructed considering the consumption of nine MDP characteristic components: high MUFA:SFA ratio, moderate ethanol consumption, high legumes, cereals and roots, fruits, vegetables and fish consumption, and low consumption of meat and milk. Then, socio-demographic, lifestyle and health status variables that could determine a higher or ower adherence were assessed. The mean adherence was 57.9 (sd 8.9) % and the median adherence was 57.3 %. Half of the Balearic Islands adolescents (50.5 %) showed an adherence to the MDP comprised between 52.7 and 62.8 %. By multivariate analyses, a high maternal level of education, increased physical activity, reduced alcohol intake and abstinence from smoking were independent associations of better adherence to the MDP. The promotion of not only the MDP but also the Mediterranean lifestyle, including greater physical activity, should be reinforced among the Balearic younger generations.

  5. Factors associated with suboptimal adherence to antiretroviral therapy in Asia

    Directory of Open Access Journals (Sweden)

    Awachana Jiamsakul

    2014-05-01

    Full Text Available Introduction: Adherence to antiretroviral therapy (ART plays an important role in treatment outcomes. It is crucial to identify factors influencing adherence in order to optimize treatment responses. The aim of this study was to assess the rates of, and factors associated with, suboptimal adherence (SubAdh in the first 24 months of ART in an Asian HIV cohort. Methods: As part of a prospective resistance monitoring study, the TREAT Asia Studies to Evaluate Resistance Monitoring Study (TASER-M collected patients’ adherence based on the World Health Organization-validated Adherence Visual Analogue Scale. SubAdh was defined in two ways: (i 14 days. Time was divided into four intervals: 0–6, 6–12, 12–18 and 18–24 months. Factors associated with SubAdh were analysed using generalized estimating equations. Results: Out of 1316 patients, 32% ever reported 2 assessments per patient per year had an odds ratio (OR=0.7 (95% confidence interval (CI (0.55 to 0.90, p=0.006, compared to sites with ≤2 assessments per patient per year. Compared to heterosexual exposure, SubAdh was higher in injecting drug users (IDUs (OR=1.92, 95% CI (1.23 to 3.00, p=0.004 and lower in homosexual exposure (OR=0.52, 95% CI (0.38 to 0.71, p<0.001. Patients taking a nucleoside transcriptase inhibitor and protease inhibitor (NRTI+PI combination were less likely to report adherence <100% (OR=0.36, 95% CI (0.20 to 0.67, p=0.001 compared to patients taking an NRTI and non-nucleoside transcriptase inhibitor (NRTI+NNRTI combination. SubAdh decreased with increasing time on ART (all p<0.001. Similar associations were found with adherence <95% as the outcome. Conclusions: We found that SubAdh, defined as either <100% and <95%, was associated with mode of HIV exposure, ART regimen, time on ART and frequency of adherence measurement. The more frequently sites assessed patients, the lower the SubAdh, possibly reflecting site resourcing for patient counselling. Although social

  6. Approaches to improve adherence to pharmacotherapy in patients with schizophrenia

    Directory of Open Access Journals (Sweden)

    Shuler KM

    2014-05-01

    Full Text Available Kimberly M Shuler Shuler Counseling and Consulting, Fayetteville, AR, USA Purpose: In patients with schizophrenia, nonadherence to prescribed medications increases the risk of patient relapse and hospitalization, key contributors to the costs associated with treatment. The objectives of this review were to evaluate the impact of nonadherence to pharmacotherapy in patients with schizophrenia as it relates to health care professionals, particularly social workers, and to identify effective team approaches to supporting patients based on studies assessing implementation of assertive community treatment teams. Materials and methods: A systematic review of the medical literature was conducted by searching the Scopus database to identify articles associated with treatment adherence in patients with schizophrenia. Articles included were published from January 1, 2003, through July 15, 2013, were written in English, and reported findings concerning any and all aspects of nonadherence to prescribed treatment in patients with schizophrenia. Results: Of 92 unique articles identified and formally screened, 47 met the inclusion criteria for the systematic review. The burden of nonadherence in schizophrenia is significant. Factors with the potential to affect adherence include antipsychotic drug class and formulation, patient-specific factors, and family/social support system. There is inconclusive evidence suggesting superior adherence with an atypical versus typical antipsychotic or with a long-acting injectable versus an oral formulation. Patient-specific factors that contribute to adherence include awareness/denial of illness, cognitive issues, stigma associated with taking medication, substance abuse, access to health care, employment/poverty, and insurance status. Lack of social or family support may adversely affect adherence, necessitating the assistance of health care professionals, such as social workers. Evidence supports the concept that an

  7. Fatigue resistant carbon coatings for rolling/sliding contacts

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Harpal; Ramirez, Giovanni; Eryilmaz, Osman; Greco, Aaron; Doll, Gary; Erdemir, Ali

    2016-06-01

    The growing demands for renewable energy production have recently resulted in a significant increase in wind plant installation. Field data from these plants show that wind turbines suffer from costly repair, maintenance and high failure rates. Often times the reliability issues are linked with tribological components used in wind turbine drivetrains. The primary failure modes in bearings and gears are associated with micropitting, wear, brinelling, scuffing, smearing and macropitting all of which occur at or near the surface. Accordingly, a variety of surface engineering approaches are currently being considered to alter the near surface properties of such bearings and gears to prevent these tribological failures. In the present work, we have evaluated the tribological performance of compliant highly hydrogenated diamond like carbon coating developed at Argonne National Laboratory, under mixed rolling/sliding contact conditions for wind turbine drivetrain components. The coating was deposited on AISI 52100 steel specimens using a magnetron sputter deposition system. The experiments were performed on a PCS Micro-Pitting-Rig (MPR) with four material pairs at 1.79 GPa contact stress, 40% slide to roll ratio and in polyalphaolefin (PAO4) basestock oil (to ensure extreme boundary conditions). The post-test analysis was performed using optical microscopy, surface profilometry, and Raman spectroscopy. The results obtained show a potential for these coatings in sliding/rolling contact applications as no failures were observed with coated specimens even after 100 million cycles compared to uncoated pair in which they failed after 32 million cycles, under the given test conditions.

  8. Value-based insurance design yields near- and long-term improvements in medication adherence.

    Science.gov (United States)

    Collado, Megan

    2013-03-01

    Key findings. (1) Value-based insurance design (VBID) improves medication adherence by 1 to 3 percent in the first year after implementation; (2) Improvements in adherence were sustained and amplified in the second year post-implementation, ranging from 2 to 5 percent; (3) Adherence improvements varied ac­cording to VBID participants' baseline adherence, with greatest improve­ments evident in those with poorer baseline adherence

  9. Adherence with tobramycin inhaled solution and health care utilization

    Directory of Open Access Journals (Sweden)

    Sacco Patricia

    2011-01-01

    Full Text Available Abstract Background Adherence with tobramycin inhalation solution (TIS during routine cystic fibrosis (CF care may differ from recommended guidelines and affect health care utilization. Methods We analyzed 2001-2006 healthcare claims data from 45 large employers. Study subjects had diagnoses of CF and at least 1 prescription for TIS. We measured adherence as the number of TIS therapy cycles completed during the year and categorized overall adherence as: low ≤ 2 cycles, medium >2 to Results Among 804 individuals identified with CF and a prescription for TIS, only 7% (n = 54 received ≥ 4 cycles of TIS per year. High adherence with TIS was associated with a decreased risk of hospitalization when compared to individuals receiving ≤ 2 cycles (adjusted odds ratio 0.40; 95% confidence interval 0.19-0.84. High adherence with TIS was also associated with lower outpatient service costs (IQR: $2,159-$8444 vs. $2,410-$14,423 and higher outpatient prescription drug costs (IQR: $35,125-$60,969 vs. $10,353-$46,768. Conclusions Use of TIS did not reflect recommended guidelines and may impact other health care utilization.

  10. Determinants of CPAP Adherence in Hispanics with Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Montserrat Diaz-Abad

    2014-01-01

    Full Text Available Purpose. We hypothesized that socioeconomic factors and a language barrier would impact adherence with continuous positive airway pressure (CPAP among Hispanics with obstructive sleep apnea (OSA. Methods. Patients with OSA who were prescribed CPAP for at least 1 year and completed a questionnaire evaluating demographic data, socioeconomic status, and CPAP knowledge and adherence participated in the study. Results. Seventy-nine patients (26 males; 53±11 yrs; body mass index (BMI=45±9 kg/m2 with apnea-hypopnea index (AHI 33±30 events/hr completed the study. Included were 25 Hispanics, 39 African Americans, and 15 Caucasians, with no difference in age, AHI, CPAP use, or BMI between the groups. While there was a difference in educational level (P=0.006, income level (P<0.001, and employment status (P=0.03 between the groups, these did not influence CPAP adherence. Instead, overall improvement in quality of life and health status and perceived benefit from CPAP influenced adherence, both for the group as a whole (P=0.03, P=0.004, and P=0.001, resp., as well as in Hispanics (P=0.02, P=0.02, P=0.03, resp.. Conclusion. In Hispanic patients with OSA, perceived benefit with therapy, rather than socioeconomic status or a language barrier, appears to be the most important factor in determining CPAP adherence.

  11. Bacterial adherence to SiO2-based multifunctional bioceramics.

    Science.gov (United States)

    Kinnari, Teemu J; Esteban, Jaime; Gomez-Barrena, Enrique; Zamora, Nieves; Fernandez-Roblas, Ricardo; Nieto, Alejandra; Doadrio, Juan C; López-Noriega, Adolfo; Ruiz-Hernández, Eduardo; Arcos, Daniel; Vallet-Regí, María

    2009-04-01

    The bacterial adherence onto different multifunctional silica-based bioceramics has been evaluated. Staphylococcus aureus and Staphylococcus epidermidis were chosen, as they cause the majority of the implant-related infections in this field. Two SiO2 mesoporous materials (MCM-41, SBA-15), an ordered SiO2-CaO-P2O5 mesoporous glass (OMG), and a biphasic magnetic bioceramic (BMB), were incubated with S. aureus and S. epidermidis for 90 min, and subsequently sonicated to quantify the number of adhered bacteria on each material. It was found that S. aureus and S. epidermidis (10(8) CFU/mL) adhered significantly less to BMB samples when compared to MCM-41, SBA-15, or OMG. However, when the material pores accessible for bacteria in each material were taken into account, the lowest bacterial adherence was found in MCM-41, and the highest in SBA-15. The results show that bacterial adherence is higher on mesoporous bioceramics, although this higher microbial attachment is mainly due to the intergranular porosity and grain size morphology rather than to the mesoporous structure.

  12. Improving patient outcomes in psoriasis: strategies to ensure treatment adherence

    Directory of Open Access Journals (Sweden)

    Yélamos O

    2015-07-01

    Full Text Available Oriol Yélamos, Sandra Ros, Lluís Puig Department of Dermatology, Hospital de la Santa Creu i Sant Pau – Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain Abstract: Psoriasis is a frequent inflammatory disease with a chronic and relapsing course. Therefore, patients with psoriasis are likely to undergo different treatments for long periods of time. Traditionally, therapies used in psoriasis have been associated with poor levels of adherence due to the complexity of the regimens and the poor results obtained with the topical therapies. These poor outcomes are associated with high levels of frustration and anxiety, which decrease adherence and worsen the disease. With the recent introduction of highly efficacious biologic therapies, patients can achieve very good and prolonged responses. However, most patients with psoriasis have mild disease and may be treated with skin-directed therapies. Therefore, it is important to develop strategies to improve adherence in order to achieve better outcomes, and to improve the overall quality of life. Hence, acknowledging the causes of nonadherence is crucial for implementing these strategies. In this summary, we review the causes of nonadherence, and we provide behavioral strategies in order to improve adherence and, ultimately, the outcome of patients with psoriasis. Keywords: psoriasis, adherence, outcome, drug therapy, psychotherapy

  13. The therapeutic relationship and adherence to antipsychotic medication in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Rosemarie McCabe

    Full Text Available OBJECTIVE: Previous research has shown that a better therapeutic relationship (TR predicts more positive attitudes towards antipsychotic medication, but did not address whether it is also linked with actual adherence. This study investigated whether the TR is associated with adherence to antipsychotics in patients with schizophrenia. METHODS: 134 clinicians and 507 of their patients with schizophrenia or a related psychotic disorder participated in a European multi-centre study. A logistic regression model examined how the TR as rated by patients and by clinicians is associated with medication adherence, adjusting for clinician clustering and symptom severity. RESULTS: Patient and clinician ratings of the TR were weakly inter-correlated (r(s = 0.13, p = 0.004, but each was independently linked with better adherence. After adjusting for patient rated TR and symptom severity, each unit increase in clinician rated TR was associated with an increase of the odds ratio of good compliance by 65.9% (95% CI: 34.6% to 104.5%. After adjusting for clinician rated TR and symptom severity, for each unit increase in patient rated TR the odds ratio of good compliance was increased by 20.8% (95% CI: 4.4% to 39.8%. CONCLUSIONS: A better TR is associated with better adherence to medication among patients with schizophrenia. Patients' and clinicians' perspectives of the TR are both important, but may reflect distinct aspects.

  14. Theoretical study of carbon-based tips for scanning tunnelling microscopy.

    Science.gov (United States)

    González, C; Abad, E; Dappe, Y J; Cuevas, J C

    2016-03-11

    Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy.

  15. Theoretical study of carbon-based tips for scanning tunnelling microscopy

    Science.gov (United States)

    González, C.; Abad, E.; Dappe, Y. J.; Cuevas, J. C.

    2016-03-01

    Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy.

  16. Growth kinetics of nanometric dendrites in metal-carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, C., E-mail: corbella@ub.edu [FEMAN Research Group, Institute of Nanoscience and Nanotechnology of the Universitat de Barcelona, c/Marti i Franques 1, E-08028 Barcelona (Spain); Echebarria, B.; Ramirez-Piscina, L. [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, Av. Doctor Maranon 44, E-08028 Barcelona (Spain); Pascual, E.; Andujar, J.L.; Bertran, E. [FEMAN Research Group, Institute of Nanoscience and Nanotechnology of the Universitat de Barcelona, c/Marti i Franques 1, E-08028 Barcelona (Spain)

    2009-10-15

    Tungsten-carbon films deposited by pulsed-DC reactive magnetron sputtering show the formation of a dendritic structure at the nanometric scale. The structure is formed by a combination of a polycrystalline {beta}-W phase together with a non-stoichiometric WC{sub 1-x} phase. The nanodendrites coincide with W-rich zones, whereas C-rich regions are located at the interstices. The characteristics of this nanostructure have been modulated by varying the metal concentration of the films. The composition, structure and morphology were characterized by X-ray photoelectron spectroscopy, electron probe microanalysis, transmission electron microscopy, X-ray diffraction and atomic force microscopy, and the mechanical and tribological properties were evaluated by profilometry, nanoindentation and microscratch. The observed growth pattern is interpreted as the result of nucleation and growth of a W phase into a W-C amorphous matrix, whose growth is controlled by diffusion of carbon. A simulation model based on phase field modelling and presenting similar morphologies is formulated. This special structure combines properties of W and diamond-like carbon films, which enlarges the scope of applications towards self-lubricating hard and low-friction coatings with improved stability.

  17. Tribochemistry of Carbon Films in Oxygen and Humid Environments: Oxidative Wear and Galvanic Corrosion.

    Science.gov (United States)

    Alazizi, Ala; Draskovics, Andrew; Ramirez, Giovanni; Erdemir, Ali; Kim, Seong H

    2016-03-01

    The effects of oxidation on wear of carbon/steel tribological interfaces were studied. When mechanical wear was small, the oxidation behavior of hydrogenated diamond-like carbon (H-DLC) and stainless steel (SS) sliding interface varied depending on the nature of the oxidizing environment. In dry air or oxygen, both H-DLC and SS wore readily. The wear debris of SS did not form iron oxide in dry air and oxygen. In humid nitrogen, however, the wear of H-DLC diminished with increasing humidity, and the SS surface showed mild wear and iron oxide debris accumulated around the sliding contact region. These results revealed that different tribochemical reactions occur in dry oxygen and humid environments. In the absence of water, oxygen oxidizes the H-DLC surface, making it susceptible to wear, creating debris, and inducing wear on both H-DLC and SS. In contrast, adsorbed water molecules at less than 40% RH act as a molecular lubricant of the oxidized DLC surface, while multiwater layers adsorbed at near-saturation act as electrolyte inducing electrochemical galvanic corrosion reactions on the SS surface. When hydrogen-free amorphous carbon (a-C) was used in tribo-tests, severe wear of the SS surface occurs, in addition to the tribochemical wear observed for H-DLC, due to the high hardness of the a-C film.

  18. Sonoporation of adherent cells under regulated ultrasound cavitation conditions.

    Science.gov (United States)

    Muleki Seya, Pauline; Fouqueray, Manuela; Ngo, Jacqueline; Poizat, Adrien; Inserra, Claude; Béra, Jean-Christophe

    2015-04-01

    A sonoporation device dedicated to the adherent cell monolayer has been implemented with a regulation process allowing the real-time monitoring and control of inertial cavitation activity. Use of the cavitation-regulated device revealed first that adherent cell sonoporation efficiency is related to inertial cavitation activity, without inducing additional cell mortality. Reproducibility is enhanced for the highest sonoporation rates (up to 17%); sonoporation efficiency can reach 26% when advantage is taken of the standing wave acoustic configuration by applying a frequency sweep with ultrasound frequency tuned to the modal acoustic modes of the cavity. This device allows sonoporation of adherent and suspended cells, and the use of regulation allows some environmental parameters such as the temperature of the medium to be overcome, resulting in the possibility of cell sonoporation even at ambient temperature.

  19. Decisional capacity and medication adherence among youth with HIV.

    Science.gov (United States)

    Chenneville, Tiffany; Clutter, Michiko Otsuki; Hintz, Stephanie; Walsh, Audra; Emmanuel, Patricia; Lujan-Zilberman, Jorge; Rodriguez, Carina

    2015-01-01

    This exploratory study examined the degree to which decisional capacity (DC) is associated with measures of self-reported medication adherence. We hypothesized that youth with higher levels of DC would report greater levels of antiretroviral medication adherence. Seventy-two (72) youth with HIV aged 13-24 participated in this study. Data collection included administration of the MacArthur Competence Tool for Treatment and measures of adherence (i.e., seven-day self-report interview, visual analog scale, and biological indicators). Data were analyzed using descriptive statistics, intercorrelations, and multiple and Poisson regression analyses. Youth with HIV who exhibited greater understanding of their disease were more likely to report fewer missed doses in the last seven days. Findings build upon literature in the areas of DC and health literacy and highlight the potential utility of enhancing HIV disease understanding among youth with HIV.

  20. Bridging the gap between antiretroviral access and adherence in Mexico.

    Science.gov (United States)

    Campero, Lourdes; Herrera, Cristina; Kendall, Tamil; Caballero, Marta

    2007-05-01

    The goal in this article is to examine social problems associated with highly active antiretroviral therapy (HAART) adherence in Mexico and the related challenges for Mexican persons living with HIV/AIDS (PLWHAs). The study was conducted from the perspective of infected and affected individuals. The authors completed 64 in-depth interviews with heterosexual male and female PLWHAs, as well as with some key individuals from their social network. Following the principles of grounded theory, they carried out inductive analysis to create codes and organize central themes. The authors identified problems related to accessing HAART and found that conditions for implementing recommendations made in the international literature to improve adherence are poor. The findings highlight the importance of social factors, such as health care system irregularities, ineffective physician-patient communication, and availability of family and other sources of social support such as self-help groups for PLWHAs' access and adherence to antiretroviral therapy in Mexico.

  1. Stick to your gums: mechanisms of oral microbial adherence.

    Science.gov (United States)

    Nobbs, A H; Jenkinson, H F; Jakubovics, N S

    2011-11-01

    Studies on the adherence properties of oral bacteria have been a major focus in microbiology research for several decades. The ability of bacteria to adhere to the variety of surfaces present in the oral cavity, and to become integrated within the resident microbial communities, confers growth and survival properties. Molecular analyses have revealed several families of Gram-positive bacterial surface proteins, including serine-rich repeat, antigen I/II, and pilus families, that mediate adherence to a variety of salivary and oral bacterial receptors. In Gram-negative bacteria, pili, auto-transporters, and extracellular matrix-binding proteins provide components for host tissue recognition and building of complex microbial communities. Future studies will reveal in greater detail the binding pockets for these adhesin families and their receptors. This information will be crucial for the development of new inhibitors or vaccines that target the functional regions of bacterial proteins that are involved in colonization and pathogenesis.

  2. Association of Continuity of Primary Care and Statin Adherence.

    Directory of Open Access Journals (Sweden)

    James R Warren

    Full Text Available Deficiencies in medication adherence are a major barrier to effectiveness of chronic condition management. Continuity of primary care may promote adherence. We assessed the association of continuity of primary care with adherence to long-term medication as exemplified by statins.We linked data from a prospective study of 267,091 Australians aged 45 years and over to national data sets on prescription reimbursements, general practice claims, hospitalisations and deaths. For participants having a statin dispense within 90 days of study entry, we computed medication possession ratio (MPR and usual provider continuity index (UPI for the subsequent two years. We used multivariate Poisson regression to calculate the relative risk (RR and 95% confidence interval (CI for the association between tertiles of UPI and MPR adjusted for socio-demographic and health-related patient factors, including age, gender, remoteness of residence, smoking, alcohol intake, fruit and vegetable intake, physical activity, prior heart disease and speaking a language other than English at home. We performed a comparison approach using propensity score matching on a subset of the sample.36,144 participants were eligible and included in the analysis among whom 58% had UPI greater than 75%. UPI was significantly associated with 5% increased MPR for statin adherence (95% CI 1.04-1.06 for highest versus lowest tertile. Dichotomised analysis using a cut-off of UPI at 75% showed a similar effect size. The association between UPI and statin adherence was independent of socio-demographic and health-related factors. Stratification analyses further showed a stronger association among those who were new to statins (RR 1.33, 95% CI 1.15-1.54.Greater continuity of care has a positive association with medication adherence for statins which is independent of socio-demographic and health-related factors.

  3. Characteristics of HIV antiretroviral regimen and treatment adherence

    Directory of Open Access Journals (Sweden)

    Vera Lúcia da Silveira

    2003-06-01

    Full Text Available The relationship between characteristics of HIV antiretroviral regimens and treatment adherence was studied in adolescent and adult patients who underwent antiretroviral therapy from January 1998 to September 2000, at the Service for Specialized Assistance in Pelotas. The patients were interviewed on two occasions, and the use of antiretrovirals during the previous 48 hours was investigated by a self-report. Adherence was defined as use of 95% or more of the prescribed medication. Social-demographic variables were collected through direct questionnaires. The antiretroviral regimen and clinical data were copied from the patients' records. Associations between the independent variables and adherence were analyzed by means of logistic regression. The multivariate analysis included characteristics of the antiretroviral regimens, social-demographic variables, as well as perception of negative effects, negative physiological states, and adverse effects of the treatment. Among the 224 selected patients, 194 participated in our study. Their ages varied from 17 to 67 years; most patients were men, with few years of schooling and a low family income. Only 49% adhered to the treatment. Adherence to treatment regimens was reduced when more daily doses were indicated: three to four doses (odds ratio of adherence to treatment (OR=0.47, 95% confidence interval (CI 0.22-1.01 and five to six (OR=0.24, 95% CI 0.09-0.62; two or more doses taken in a fasting state (OR=0.59, 95% CI 0.11-0.68, and for patients who reported adverse effects to the treatment (OR=0.39, 95% CI 0.19-0.77. Most of the regimens with more than two daily doses of medication included at least one dose apart from mealtimes. The results suggest that, if possible, regimens with a reduced number of doses should be chosen, with no compulsory fasting, and with few adverse effects. Strategies to minimize these effects should be discussed with the patients.

  4. Effects of high dietary fluorine on erythrocytes and erythrocyte immune adherence function in broiler chickens.

    Science.gov (United States)

    Deng, Yubing; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Luo, Qin

    2013-11-01

    Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C3b receptor rosette rate (E-C3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn-soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.

  5. Adherence and neurocognitive screening in Romanian HIV patients

    Directory of Open Access Journals (Sweden)

    M Arbune

    2012-11-01

    Full Text Available Background: Adherence is critical for the effectiveness of antiretroviral HIV therapy (ART, accordingly decreasing the opportunistic diseases and increasing the quality of life. Neurocognitive disorders (NCD are still frequent in ART era and could impair the adherence, but how ethical is to refer ART in patients with NCD? Objective: To assess the relation between NCD and adherence in HIV Romanian patients. Material and methods: Cross-sectional screening study on 151 patients under ART, no drug users, from HIV Clinic - Galati, assessed by HIV-Associated Dementia Scale (HDS, Hospital Anxiety and Depression Scale (HADS [1], ART CNS-effectiveness Letendre scores [2] and adherence assessment questionnaire CNLAS- Romania. Normal values: HDS >10; anxiety/ depression <8. Statistical analysis performed: Chi-square test and Mann-Whitney test, with 5% significance level. Results: Characteristics of the patients: median age 22 [20; 56] years old; sex ratio F/M 1.17; median educational level 8 [0; >12] years; HBV co-infection 27.8%; AIDS stage 85.3%; current median CD4 526/mm3 [8; 1605] and 65% undetectable HIV-RNA levels. 49.6% (75/151 patients attain HDS scores <10 and imply probable NCD. Scores below 8 for anxiety are more frequent than for depression: 24% vs 13%. The median ART CNS penetration score is 8 [5; 12]. Adherence is considered for 66% patients and is correlating with CD4 number (p=0.001, educational level >4 years (p=0.001; OR=4.2, HDS >10 (p=0.01; OR=2.4 and ART-CNS penetration score >7 (p=0.023; OR=2.4. Low HDS are influenced by old age (p=0.003, depression (p=0.02 and ART-CNS penetration scores <7 (p=0.01. Anxiety is related neither with adherence nor with NCD by HDS, but females are obvious anxious than males (p<0.001. Conclusions: Basic educational level is sufficient for developing ART adherence. High scores of HDS screening should be predictors for ART adherence. Referring ART as well to patients with low HDS scores is rational and

  6. Treating depression in HIV-positive patients affects adherence

    Directory of Open Access Journals (Sweden)

    M Y H Moosa

    2012-09-01

    Full Text Available Aim. To determine changes in adherence to antiretroviral therapy (ART in HIV-positive patients with depression, following treatment with an antidepressant or psychotherapy. Methods. The study was prospective, randomised and controlled. Consenting volunteers aged ≥18 years and stable on ART for ≥6 months were included in the study. Sociodemographic data were obtained, and a clinical diagnostic evaluation and the Hamilton Depression rating scale (HAMD were performed on all subjects at entry to and at the end of the study. Participants found to be depressed were randomly assigned antidepressant treatment (20 mg citalopram or interpersonal psychotherapy (IPT (5 sessions. Medication was dispensed at each visit and patients were asked to return all unused medication to determine ART adherence. The study was approved by the University of the Witwatersrand. Results. Sixty-two HIV-positive persons receiving ART participated; 30 were not depressed (control group and 32 were depressed (patient group. No significant differences in demographic characteristics existed between the control and patient groups. Mean ART adherence at the start of the study was 99.5% (standard error (SE ±0.46 and 92.1% (SE ±1.69 in the control and patients groups, respectively. Mean ART adherence at the end of the study changed marginally in the control group (99.7%; SE ±0.46 and increased significantly in the patient group (99.5%; SE± 0.13 (p>0.05. The mean ART adherence rate of patients who received pharmacotherapy increased from 92.8% to 99.5%, and of those who received psychotherapy increased from 91.1% to 99.6% (p>0.05. There was no significant association between the increased adherence in the patient group and baseline demographic and clinical characteristics, irrespective of antidepressant therapy or IPT (p>0.05. Conclusion. Successful treatment of depression with an antidepressant or psychotherapy was associated with improved ART adherence, independent of the type

  7. Promoting adherence to nebulized therapy in cystic fibrosis: poster development and a qualitative exploration of adherence

    Directory of Open Access Journals (Sweden)

    Jones S

    2015-08-01

    Full Text Available Stephen Jones,1 Nathan Babiker,2 Emma Gardner,2,3 Jane Royle,2 Rachael Curley,3,4 Zhe Hui Hoo,3,4 Martin J Wildman3,4 1Psychology Department, University of Sheffield, 2Psychological Services, Sheffield Teaching Hospitals NHS Foundation Trust, 3Adult Cystic Fibrosis Unit, Northern General Hospital, 4School of Health and Related Research (ScHARR, University of Sheffield, Sheffield, UK Background: Cystic fibrosis (CF health care professionals recognize the need to motivate people with CF to adhere to nebulizer treatments, yet little is known about how best to achieve this. We aimed to produce motivational posters to support nebulizer adherence by using social marketing involving people with CF in the development of those posters. Methods: The Sheffield CF multidisciplinary team produced preliminary ideas that were elaborated upon with semi-structured interviews among people with CF to explore barriers and facilitators to the use of nebulized therapy. Initial themes and poster designs were refined using an online focus group to finalize the poster designs. Results: People with CF preferred aspirational posters describing what could be achieved through adherence in contrast to posters that highlighted the adverse consequences of nonadherence. A total of 14 posters were produced through this process. Conclusion: People with CF can be engaged to develop promotional material to support adherence, providing a unique perspective differing from that of the CF multidisciplinary team. Further research is needed to evaluate the effectiveness of these posters to support nebulizer adherence. Keywords: behavior change, social marketing, patient participation, nebulizers, medication adherence

  8. Influence of adhesion to activated carbon particles on the viability of waterborne pathogenic bacteria under flow

    NARCIS (Netherlands)

    van der Mei, Henny C.; Atema-Smit, Jelly; Jager, Debbie; Langworthy, Don E.; Collias, Dimitris I.; Mitchell, Michael D.; Busscher, Henk J.

    2008-01-01

    In rural areas around the world, people often rely on water filtration plants using activated carbon particles for safe water supply. Depending on the carbon surface, adhering microorganisms die or grow to form a biofilm. Assays to assess the efficacy of activated carbons in bacterial removal do not

  9. A systematic review of medication non-adherence in persons with dementia or cognitive impairment

    Science.gov (United States)

    Weller, Carolina; Kennedy, Briohny; Winbolt, Margaret; Young, Carmel

    2017-01-01

    Background Adherence to medication is vital for disease management while simultaneously reducing healthcare expenditure. Older persons with cognitive impairment (CI) are at risk for non-adherence as cognitive processes are needed to manage medications. This systematic review focuses on the relationship between medication non-adherence and specific cognitive domains in persons with CI, and explores determinants of medication non-adherence. When available, relationships and factors are compared with cognitively intact populations. Methods A seven database systematic search of studies published between 1 January 1949–31 December 2015 examining medication non-adherence in community dwelling persons with CI or dementia was conducted. Articles reporting medication non-adherence in people with CI or dementia in the community, with or without caregiver supports were eligible for inclusion. Papers reporting adherence to treatments in cognitively intact populations, populations from hospital or institutional settings, for non-prescribed medication or those describing dementia as a factor predicting medication non-adherence were excluded. Data on study and population characteristics, research design, data sources and analysis, specific cognitive domains, non-adherence prevalence, measurement of adherence, salient findings, factors associated with adherence and strategies to improve medication adherence were extracted. Study limitations included inconsistencies between data sources and definitions, resulting in a loss of fidelity in the value and comprehensiveness of data, as well as exclusion of non-pharmacological treatments and regimens. Findings Fifteen studies met inclusion criteria. Adherence among CI subjects ranged from 10.7%-38% with better rates of adherence in non-CI individuals. Medication non-adherence definitions varied considerably. New-learning, memory and executive functioning were associated with improved adherence and formed the focus of most studies

  10. Medication adherence in schizophrenia: Exploring patients', carers' and professionals' views

    NARCIS (Netherlands)

    M.J. Kikkert; A.H. Schene; M.W.J. Koeter; D. Robson; A. Born; H. Helm; M. Nose; C. Goss; G. Thornicroft; R.J. Gray

    2006-01-01

    One of the major clinical problems in the treatment of people with schizophrenia is suboptimal medication adherence. Most research focusing on determinants of nonadherence use quantitative research methods. These studies have some important limitations in exploring the decision-making process of pat

  11. Novel Aggregative Adherence Fimbria Variant of Enteroaggregative Escherichia coli

    DEFF Research Database (Denmark)

    Jønsson, Rie; Struve, Carsten; Boisen, Nadia

    2015-01-01

    Enteroaggregative Escherichia coli (EAEC) organisms belong to a diarrheagenic pathotype known to cause diarrhea and can be characterized by distinct aggregative adherence (AA) in a stacked-brick pattern to cultured epithelial cells. In this study, we investigated 118 EAEC strains isolated from...

  12. Adherence of paclitaxel drug in magnetite chitosan nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Escobar Zapata, Edna V.; Martinez Perez, Carlos A.; Rodriguez Gonzalez, Claudia A.; Castro Carmona, Javier S. [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Ciudad Juarez, Ave. Del Charro 610 norte, Col. Partido Romero, C.P. 32320, Cd. Juarez Chihuahua (Mexico); Quevedo Lopez, Manuel A. [Departamento de Polimeros y Materiales, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora (Mexico); Garcia-Casillas, Perla E., E-mail: pegarcia@uacj.mx [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Ciudad Juarez, Ave. Del Charro 610 norte, Col. Partido Romero, C.P. 32320, Cd. Juarez Chihuahua (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Chitosan silica magnetite adsorbs antineoplastic drug. Black-Right-Pointing-Pointer Silica coating improve the drug adherence. - Abstract: Cancer treatment is a big challenge in medicine where chemotherapies and radiotherapies are aggressive and poorly effective having side effects as delirium, fatigue, insomnia, nausea and vomiting which are common problems for cancer patients. For this reason, during the last two decades, many researchers have developed several techniques to improve the current therapies; one of them is the functionalization of magnetic nanoparticles for drug delivery. In this work, magnetic nanoparticles with an average crystallite size 21.8 nm were covered in a core/shell type; magnetite/silica, magnetite/chitosan, and a double shell magnetite/silica/chitosan were developed for attaching an antineoplastic drug. The mechanism for the functionalization of the nanoparticles with a single and double shell was studied with Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The adherence of an antineoplastic drug, paclitaxel, onto functionalized nanoparticles was analyzed with a UV-Visible spectroscopy at a wavelength of 253 nm. It was found that the adherence of the drug is improved up to 18% when magnetite nanoparticles are coated with a single chitosan shell, and when the nanoparticles are coated with a silica/chitosan shell the adherence increases up to 29%.

  13. Factors influencing adherence to an emergency department national protocol.

    NARCIS (Netherlands)

    Ebben, R.H.A.; Vloet, L.C.M.; Groot, J.M. de; Achterberg, T. van

    2012-01-01

    The objective of this study was to identify factors that influence emergency nurses' adherence to an emergency department national protocol (EDNP). A survey of emergency nurses (n=200) and physicians with medical end responsibility on an emergency department (n=103) was carried out. Emergency nurses

  14. Adherence to preventive statin therapy according to socioeconomic position

    DEFF Research Database (Denmark)

    Wallach-Kildemoes, Helle; Andersen, Morten; Diderichsen, Finn;

    2013-01-01

    AIM: To explore whether long-term adherence to preventive statin therapy depends on socioeconomic position (SEP). METHODS: A cohort of individuals without established cardiovascular disease (CVD) or diabetes initiating preventive statin therapy during 2002-2005 was followed in the individual...

  15. Telephone interventions for adherence to colpocytological examination 1

    Science.gov (United States)

    Lima, Thais Marques; Nicolau, Ana Izabel Oliveira; Carvalho, Francisco Herlânio Costa; Vasconcelos, Camila Teixeira Moreira; Aquino, Priscila de Souza; Pinheiro, Ana Karina Bezerra

    2017-01-01

    ABSTRACT Objective: to test the effects of behavioral and educational intervention by telephone on adherence of women with inappropriate periodicity to colpocytological examination. Method: quasi-experimental study with a sample of 524 women, selected with the following inclusion criteria: be aged between 25 and 64 years, have initiated sexual activity, have inappropriate periodicity of examination and have mobile or landline phone. The women were divided into two groups for application of behavioral and educational intervention by telephone. It was used an intervention script according to the principles of Motivational Interviewing. Results: on comparing the results before and after the behavioral and educational interventions, it was found that there was a statistically significant change (p = 0.0283) with increase of knowledge of women who participated in the educational intervention. There was no change in the attitude of women of any of the groups and there was an increase of adherence to colpocytological examination in both groups (p < 0.0001), with greater adherence of women participating in the behavioral group (66.8%). Conclusion: the behavioral and educational interventions by phone were effective in the adherence of women to colpocytological examination, representing important strategies for permanent health education and promotion of care for the prevention of cervical cancer. PMID:28177055

  16. Interaction of adhered metallic dust with transient plasma heat loads

    NARCIS (Netherlands)

    Ratynskaia, S.; Tolias, P.; I. Bykov,; Rudakov, D.; de Angeli, M.; Vignitchouk, L.; Ripamonti, D.; Riva, G.; Bardin, S.; van der Meiden, H.; Vernimmen, J.; Bystrov, K.; De Temmerman, G.

    2016-01-01

    The first study of the interaction of metallic dust (tungsten, aluminum) adhered on tungsten substrates with transient plasma heat loads is presented. Experiments were carried out in the Pilot-PSI linear device with transient heat fluxes up to 550 MW m −2 and in the DIII-D divertor tokamak. The cent

  17. Generic substitution of antihypertensive drugs : does it affect adherence?

    NARCIS (Netherlands)

    Van Wijk, Boris L G; Klungel, Olaf H; Heerdink, Eibert R; de Boer, Anthonius

    2006-01-01

    BACKGROUND: Generic substitution is an important opportunity to reduce the costs of pharmaceutical care. However, pharmacists and physicians often find that patients and brand-name manufacturers have doubt about the equivalence of the substituted drug. This may be reflected by decreased adherence to

  18. Adherence Process Research on Developmental Interventions: Filling in the Middle.

    Science.gov (United States)

    Hogue, Aaron

    2002-01-01

    Presents a framework and some practical examples for using rigorous implementation research to inform program outcomes and foster program development for developmental interventions. Focuses on: (1) role of process research, specifically developing developmental interventions; (2) characteristics of adherence process research; and (3)…

  19. Intervention Adherence for Research and Practice: Necessity or Triage Outcome?

    Science.gov (United States)

    Barnett, David; Hawkins, Renee; Lentz, F. Edward, Jr.

    2011-01-01

    Intervention integrity or adherence describes qualities of carrying out an intervention plan and in research is fundamentally linked to experimental validity questions addressed by measurement of independent and dependent variables. Integrity has been well described in conceptual writing but has been a continuing thorny subject in research and…

  20. Adherence with Universal Precautions after Immediate, Personalized Performance Feedback

    Science.gov (United States)

    Luke, Molli M.; Alavosius, Mark

    2011-01-01

    We evaluated the effects of immediate, personalized performance feedback on adherence with hand hygiene by health-care staff in the context of a multiple baseline design across participants. Target behaviors reached mastery levels and were maintained near 100% throughout 2 months of maintenance probes. (Contains 1 table and 1 figure.)