Thermal behaviour of CpCuPEt3 in gas phase and Cu thin films processing

Decomposition of CpCuPEt3 (Cp=NNN(η5-C5H5)) and MOCVD of Cu films from CpCuPEt3 have been investigated in the frame of an ongoing project on the processing of Cu-containing coatings. The behaviour of CpCuPEt3 vapours under heating conditions was studied by in situ mass spectrometry. It was established that this compound is monomeric in gas phase. Its decomposition mechanism on hot surface was proposed. From mass spectroscopy experiments, it was established that decomposition in vacuum begins at 150 °C with evolution of PEt3. Beyond 270 °C, formation of cyclopentadiene is observed, indicating that a change in decomposition mechanism occurs. The saturating vapour pressure of CpCuPEt3 was estimated through static method, in order to optimize transport conditions and to control the molar fraction of the precursor in the gas phase. Finally, growth rate and microstructure of MOCVD processed Cu films from CpCuPEt3 have been investigated

MOCVD-Fabricated TiO2 Thin Films: Influence of Growth Conditions on Fibroblast Cells Culture

TiO2 thin films with various morphologies were grown on Ti substrates by the LP-MOCVD technique (Low Pressure Chemical Vapour Deposition from Metal-Organic precursor), with titanium tetra-iso-propoxide as a precursor. All the films were prepared in the same conditions except the deposition time. They were characterized by X-ray diffraction, scanning electron microscopy, optical 15 interferometry, water contact angle measurements. MOCVD-fabricated TiO2 thin films are known to be adapted to cell culture for implant requirements. Human gingival fibroblasts were cultured on the various TiO2 deposits. Differences in cell viability (MTT tests) and cell spreading (qualitative assessment) were observed and related to film roughness, wettability and allotropic composition

Chemical vapor deposition of iron, iron carbides, and iron nitride films from amidinate precursors

Iron bis(N,N-diisopropylacetamidinate) [Fe2(µ-iPr-MeAMD)2(2-iPr-MeAMD)2] and iron bis(N,N-di-tert-butylacetamidinate) [Fe(tBu-MeAMD)2] were used as precursors for the metallorganic chemical vapor deposition (MOCVD) of iron-containing compounds including pure iron, iron carbides, Fe3C and Fe4C, and iron nitrides Fe4C. Their decomposition mechanism involves hydrogen migration followed by dissociation of the Fe–N bond and the release of free hydrogenated ligand (HL) and radicals. Surface intermediates are either released or decomposed on the surface providing Fe–N or Fe–C bonds. MOCVD experiments were run at 10 Torr, in the temperature ranges of 350–450°C with Fe2(µ−iPr-MeAMD)2(2-iPr-MeAMD)2 and 280–350°C with Fe(tBu-MeAMD)2. Films prepared from Fe2(µ−iPr-MeAMD)2(2-iPr-MeAMD)2 contain Fe, Fe3C, and Fe4C. Those prepared from Fe(tBu-MeAMD)2 contain Fe, Fe3C, and also Fe4C or Fe4N, depending on the temperature and hydrogen to precursor ratio (H/P) in the input gas. The room-temperature coercive field of films processed from Fe(tBu-MeAMD)2 is 3 times higher than that of the high temperature processed Fe4N films

Non-equilibrium plasma properties of electric arc discharge in air between copper electrodes

Spectroscopy investigations of plasma of free burning electric arc discharge as well as discharge in air flow of 6.45 slpm at currents 3.5, 30, 50 and 100 A were carried out. Plasma state deviation from thermodynamic equilibrium was found at arc current 100 A. Two-temperatures model was used to estimate plasma composition at arc current 100 A.Выполнены спектроскопические исследования плазмы свободно горящего электродугового разряда, а также разряда в потоке воздуха 6,45 л/мин при силах тока 3,5, 30, 50 и 100 А. Установлено отклонение состояния плазмы от термодинамического равновесия при силе тока 100 А. Использована двухтемпературная модель для оценки состава плазмы при силе тока 100 А.Виконані спектроскопічні дослідження плазми вільно існуючого електродугового розряду, а також, розряду в потоці повітря 6,45 л/хв при силах струму 3,5, 30, 50 и 100 А. Встановлено відхилення стану плазми від термодинамічної рівноваги при силі струму 100 А. Використано двотемпературну модель для оцінки складу плазми при силі струму 100 А

The Value of Suction Drainage Fluid Culture during Aseptic and Septic Orthopedic Surgery: A Prospective Study of 901 Patients

There are no guidelines on the value of suction drainage fluid culture (SDC), and it is difficult to determine whether the organisms cultured from suction drainage fluid samples are pathogenic or simply contaminants. We performed 2989 cultures of suction drainage fluid samples obtained, during a 1-year period, from 901 patients who underwent aseptic or septic orthopedic surgery (946 operations). The culture results were analyzed to evaluate their ability to detect postoperative infection after aseptic operations or to detect either a persistent or new episode of sepsis in patients known to have infection. For aseptic operations, the sensitivity of SDC was 25%, the specificity was 99%, the positive predictive value was 25%, and the negative predictive value was 99%. For septic operations, the sensitivity of SDC was 81%, the specificity was 96%, the positive predictive value was 87%, and the negative predictive value was 94%. We conclude that, for aseptic orthopedic surgery, SDC is not useful in detecting postoperative infection. However, for septic orthopedic surgery, it is of clinical importanc

Iron amidinates as precursors for the MOCVD of iron-containing thin films

Iron amidinates as precursors for the MOCVD of iron-containing thin film

Collisional kinetics of non-uniform electric field, low-pressure, direct-current discharges in H2_{2}

A model of the collisional kinetics of energetic hydrogen atoms, molecules, and ions in pure H$_2$ discharges is used to predict H$_\alpha$ emission profiles and spatial distributions of emission from the cathode regions of low-pressure, weakly-ionized discharges for comparison with a wide variety of experiments. Positive and negative ion energy distributions are also predicted. The model developed for spatially uniform electric fields and current densities less than $10^{-3}$ A/m$^2$ is extended to non-uniform electric fields, current densities of $10^{3}$ A/m$^2$, and electric field to gas density ratios $E/N = 1.3$ MTd at 0.002 to 5 Torr pressure. (1 Td = $10^{-21}$ V m$^2$ and 1 Torr = 133 Pa) The observed far-wing Doppler broadening and spatial distribution of the H$_\alpha$ emission is consistent with reactions among H$^+$, H$_2^+$, H$_3^+$, and H$^-H$ ions, fast H atoms, and fast H$_2$ molecules, and with reflection, excitation, and attachment to fast H atoms at surfaces. The H$_\alpha$ excitation and H$^-$ formation occur principally by collisions of fast H, fast H$_2$, and H$^+$ with H$_2$. Simplifications include using a one-dimensional geometry, a multi-beam transport model, and the average cathode-fall electric field. The H$_\alpha$ emission is linear with current density over eight orders of magnitude. The calculated ion energy distributions agree satisfactorily with experiment for H$_2^+$ and H$_3^+$, but are only in qualitative agreement for H$^+$ and H$^-$. The experiments successfully modeled range from short-gap, parallel-plane glow discharges to beam-like, electrostatic-confinement discharges.Comment: Submitted to Plasmas Sources Science and Technology 8/18/201

Thermal plasma of electric arc discharge in air between composite Cu-C electrodes

The complex technique of plasma property studies is suggested. As the first step the radial profiles of temperature and electron density in plasma of free burning electric arc discharge in air between Cu-C composite and brass electrodes, as well as copper electrodes in air flow, were measured by optical emission spectroscopy techniques. As the next step the radial profiles of electric conductivity of plasma mixture were calculated by solution of energy balance equation. The electron density is obtained from electric conductivity by calculation in assumption of local thermodynamical equilibrium in plasma.Предложена комплексная методика исследования плазмы. На первом этапе методами оптической эмиссионной спектроскопии проводились измерения радиальных распределений температуры и электронной концентрации в плазме электродугового разряда в воздухе между композитными Cu-C и латунными электродами, а также медными электродами в потоке воздуха. На следующем этапе рассчитывались радиальные распределения электропроводности плазменной смеси путем решения уравнения энергетического баланса. Распределение электронной концентрации получено из электропроводности плазмы в допущении локального термодинамического равновесия.Запропонована комплексна методика дослідження плазми. На першому етапі методами оптичної емісійної спектроскопії проводились дослідження радіальних розподілів температури та електронної концентрації в плазмі електродугового розряду в повітрі між композитними Cu-C та латунними електродами, а також мідними електродами в потоці повітря. Наступним кроком розраховувались радіальні розподіли електро-провідності плазмової суміші шляхом розв’язку рівняння енергетичного балансу. Розподіл електронної концентрації отримали з електропровідності плазми в припущенні локальної термодинамічної рівноваги

Analytical Bethe Ansatz for closed and open gl(n)-spin chains in any representation

We present an "algebraic treatment" of the analytical Bethe Ansatz. For this purpose, we introduce abstract monodromy and transfer matrices which provide an algebraic framework for the analytical Bethe Ansatz. It allows us to deal with a generic gl(n)-spin chain possessing on each site an arbitrary gl(n)-representation. For open spin chains, we use the classification of the reflection matrices to treat all the diagonal boundary cases. As a result, we obtain the Bethe equations in their full generality for closed and open spin chains. The classifications of finite dimensional irreducible representations for the Yangian (closed spin chains) and for the reflection algebras (open spin chains) are directly linked to the calculation of the transfer matrix eigenvalues. As examples, we recover the usual closed and open spin chains, we treat the alternating spin chains and the closed spin chain with impurity