共查询到20条相似文献,搜索用时 0 毫秒
1.
Youl-Moon Sung 《Thin solid films》2007,515(12):4996-4999
Sputter deposition followed by surface treatment was studied using reactive RF plasma as a method for preparing titanium oxide (TiO2) films on indium tin oxide (ITO) coated glass substrate for dye-sensitized solar cells (DSCs). Anatase structure TiO2 films deposited by reactive RF magnetron sputtering under the conditions of Ar/O2(5%) mixtures, RF power of 600 W and substrate temperature of 400 °C were surface-treated by inductive coupled plasma (ICP) with Ar/O2 mixtures at substrate temperature of 400 °C, and thus the films were applied to the DSCs. The TiO2 films made on these experimental bases exhibited the BET specific surface area of 95 m2/g, the pore volume of 0.3 cm2/g and the TEM particle size of ∼ 25 nm. The DSCs made of this TiO2 material exhibited an energy conversion efficiency of about 2.25% at 100 mW/cm2 light intensity. 相似文献
2.
Water absorption is one of key parameters in quality assessment of wood-plastic composites. The influence of surface treatment of lignocellulosic particles on water absorption of composites made from poly(vinyl chloride) (PVC) and moso bamboo (Phyllostachys pubescens) particles was studied. The effect of modification with three kinds of chemical treatment agent (alkali, silica and oxidant) on particle surface was examined. The concentration and pH values of the agent aqueous solutions were analyzed and their relationships with water absorption, porosity ratio, thermal property, micro-structure and hemicelluloses content were evaluated. Results showed that pH values of aqueous solutions had little impact on water absorption of the composites while the types of treatment agents did. Alkali treatment lowered the content of hemicelluloses in moso bamboo particles and thus reduced corresponding water absorption. Water resistance improvements of silicate or oxidant treated particles reinforced composites were due to changes of porosity ratio. In general, surface treatment improved water resistance of moso bamboo particles reinforced PVC composites. Compared with the other two agents, sodium bisulfite enhanced the compatibility between cellulose particles and granulated PVC. 相似文献
3.
A 2.8 kJ plasma focus device with a nitrogen gas filling and a copper anode capsulated by aluminum was used to modify the surface of AISI304 steel substrate, in order to improve its properties. The treatment was carried out using a various number of nitrogen plasma focus shots at a pressure of 0.5 mbar and at two steel sample distances (20 and 40 mm) from the anode. The plasma diagnostics was made using the voltage and current curves recorded by a voltage divider, Rogowskii coil, accompanied with calculations using a five phase radiative Lee model (RADPF5.15a) to determine the temperature and plasma density.The surface hardness of AISI304 steel was increased by ∼175% after plasma treatment and the thickness of the treated layers was about 1-2 μm. Results show that the surface hardness is increased with increasing shot number and decreased with increasing distance from the anode. Changes in surface morphology and the elemental composition were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). 相似文献
4.
Woo Seok Kang 《Thin solid films》2010,518(22):6578-6582
Atomic oxygen (AO) generation is experimentally and numerically investigated for in-situ plasma and post-plasma produced by dielectric barrier discharges (DBDs) for surface treatment. The AO generation in in-situ plasma inside a DBD reactor is closely related to the plasma characteristics depending on the applied voltage and O2 additive concentration, while the AO density distribution along the post-plasma ejected outside the reactor exit is influenced by the AO generation in the in-situ plasma, gas flow rate, and effluent distance. Contact angle measurements show that the metal surface characteristics, which are treated by in-situ plasma and post-plasma, respectively, are distinctive from each other depending on the AO densities. 相似文献
5.
Tae Yoon Kang 《Thin solid films》2009,517(14):3919-3922
In this paper, reactive ion etching of Au is performed with CF4/Ar gases, and process optimization method is suggested using a statistically established process model. The I-optimal design was employed to set up the etching experiment with operating parameters, namely, gas composition, RF power and chamber pressure. Its analysis was performed on individual parameters of the etch rate, selectivity, and profile. In addition, process optimization, including all three responses of interest, is provided simultaneously. We confirmed that a nonvolatile by-product AuFx was re-deposited on the surface, but controlling the amount of carbon fluoride provided a good etch rate with a satisfactory sidewall profile by reducing by-products. Although RF power is closely related with etch rate, increased power gives poor selectivity due to increased physical etching. Pressure and gas flows strongly interact with each other, affecting sidewall characteristics. Suggested optimization simultaneously considers three responses of interests, which is crucial in process development and optimization for quickly ramping up high volume manufacturing. 相似文献
6.
Mario S.G. Chiodo 《Engineering Fracture Mechanics》2010,77(3):415-436
This work provides an estimation procedure to determine the J-integral and CTOD for pipes with circumferential surface cracks subjected to bending load for a wide range of crack geometries and material (hardening) based upon fully-plastic solutions. A summary of the methodology upon which J and CTOD are derived sets the necessary framework to determine nondimensional functions h1 and h2 applicable to a wide range of crack geometries and material properties characteristic of structural, pressure vessel and pipeline steels. The extensive nonlinear, 3-D numerical analyses provide a definite full set of solutions for J and CTOD which enters directly into fitness-for-service (FFS) analyses and defect assessment procedures of cracked pipes and cylinders subjected to bending load. 相似文献
7.
The relative densities of SiCln (n=0-2) in SiCl4 radio frequency (rf) glow discharge plasma are measured by mass spectrometry. The effects of discharge parameters, including rf power, discharge pressure, substrate temperature and SiCl4 flow rate on the relative densities of SiCln (n=0-2) are investigated in detail. The experimental results demonstrate that the relative densities of SiCln (n=0-2) in SiCl4 plasma are dependent strongly on these discharge parameters. An optimum configuration of discharge parameters (low rf power, high discharge pressure, low substrate temperature and low flow rate), which enhanced the formation of SiCln (n=0-2) radicals, was searched. Further, researching of SiCln (n=0-2) spatial distribution for seeking a suitable deposition condition is beneficial for understanding the deposition mechanism of thin films. 相似文献
8.
By using a sputter-assisted chemical vapor deposition (CVD) of supermagnetron plasma, amorphous CNx:H films were deposited on the lower part of two parallel electrodes. By applying rf power to the upper electrode (UPRF) at 5 W to 800 W, polymer-like a-CNx:H films were deposited on substrates placed on the lower electrode with an rf power (LORF) of 10 W. The deposition rate increased as UPRF increased. The hardness was as low as about 6.5 GPa, which is less than that of glass (13.1 GPa). The refractive index changed only slightly as UPRF changed from 1.6 to 1.75. The FT-IR spectrum showed strong absorption bands of NH and CH bonds at high and low UPRFs, respectively. The optical band gap was as large as 2.1 to 2.5, and it decreased as UPRF increased. These a-CNx:H films showed white photoluminescence (PL) with broadband. With the increase of UPRF from 5 W to 800 W, the PL peak energy shifted down from 2.3 eV to 1.9 eV. 相似文献
9.
Vimal Chandra Pandey P.C. Abhilash Raj Narayan Upadhyay D.D. Tewari 《Journal of hazardous materials》2009
The present study was undertaken to examine the influence of the application of fly ash (FA) into garden soil for Cajanus cajan L. cultivation and on accumulation and translocation of hazardous metals from FA to edible part. Numerous studies have been reported on the growth and yield of agricultural crops under FA stress; however, there is a dearth of studies recommending the safe utilization of fly ash for crop production. Pot experiments were conducted on C. cajan L., a widely cultivating legume in India for its highly nutritious seeds. C. cajan L. were grown in garden soil and amended with varying concentrations of FA in a weight/weight ratio (0%, 25%, 50% and 100%; w/w). Incorporation of fly ash from 25% to 100% in garden soil increases the levels of pH, particle density, porosity and water holding capacity from 3.47% to 26.39%, 3.98% to 26.14%, 37.50% to 147.92% and 163.16% to 318.42%, respectively, than the control while bulk density decrease respectively from 8.94% to 48.89%. Pot experiment found that accumulation and translocation of heavy metals in tested plant depends on the concentration of FA. Addition of FA at lower concentration (25%) had shown positive results in most of the studied parameters of growth and yield (14.23% than control). The experimental results confirmed that lower concentration of FA (25%) is safe for C. cajan cultivation, which not only enhanced the yield of C. cajan L. significantly but also ensured the translocation of heavy metals to edible parts within the critical limits. 相似文献
10.
Yun-Jae KimDo-Jun Shim Jae-Boong ChoiYoung-Jin Kim 《Engineering Fracture Mechanics》2002,69(13):1447-1463
This paper provides a simplified engineering J estimation method for semi-elliptical surface cracked plates in tension, based on the reference stress approach. Note that the essential element of the reference stress approach is the plastic limit load in the definition of the reference stress. However, for surface cracks, the definition of the limit load is ambiguous (“local” or “global” limit load), and thus the most relevant limit load (and thus reference stress) for the J estimation should be determined. In the present work, such limit load solution is found by comparing reference stress based J results with those from extensive 3-D finite element (FE) analyses. Based on the present FE results, the global limit load solution proposed by Goodall for surface cracked plates in combined bending and tension was modified, in the case of tension loading only, to account for a weak dependence on w/c and was defined as the reference normalizing load. Validation of the proposed equation against FE J results based on actual experimental tensile data of a 304 stainless steel shows excellent agreements not only for the J values at the deepest point but also for those at an arbitrary point along the crack front, including at the surface point. Thus the present results provide a good engineering tool for elastic-plastic fracture analyses of surface cracked plates in tension. 相似文献
11.
For the compact tension (CT) specimen with a mismatched weld in creep properties, an equivalent homogeneity model is presented based on the limit load analysis. In use of the proposed equivalent material model and existing limit load solutions, the modified experimental C∗ integral estimation equations for the CT specimens with weld centre crack, fusion line crack and asymmetric crack were derived. Finite element (FE) analysis for C∗ integral of CT specimens with a mismatched weld was performed by using the ABAQUS software. Results show that, compared with the ηo factor for homogeneous CT specimens, a soft under-mismatched weld will increase the non-dimensional factor ηw while a hard over-mismatched weld will decrease the ηw value. It indicates that the current C∗ estimation equation in ASTM E1457 may underestimate C∗ for creep soft weld but overestimate it for creep-hard weld. The discrepancies between the C∗ from ASTM E1457 and FE analysis are sensitive to the crack location in weld, to the mismatch ratio and to the weld width. Whether for under-mismatched weld (M < 1) or for over-mismatched weld considered herein, the predicted C∗ parameters from the presented formulae are very close to FE results and thus can be used to interpret the creep crack growth behaviour of welded specimens. 相似文献
12.
Oualid BaghricheAbed Zertal Arutiun P. EhiasarianR. Sanjines Cesar Pulgarin Ewelina Kusiak-Nejman Antoni W. MorawskiJohn Kiwi 《Thin solid films》2012,520(9):3567-3573
This study addresses the DC-magnetron sputtering (DCMS) of Ag-films on polyester and compares the results found for the E. coli inactivation with the inactivation obtained when applying highly ionized pulse plasma power magnetron sputtering (HIPIMS). The amounts of Ag needed to inactivate E. coli by HIPIMS sputtering were an order of magnitude lower than with DCMS indicating a significant saving of noble metal and concomitantly a faster E. coli inactivation was observed compared to samples sputtered with DCMS. Higher current densities applied with DCMS led to shorter E. coli inactivation times and this trend was observed also for HIPIMS sputtered samples. By DCMS the thicker layers needed to inactivate E. coli comprised slightly larger Ag-aggregates compared to the thinner Ag-layers sputtered by HIPIMS to inactivate E. coli within short times. Longer sputtering times by DCMS and HIPIMS lead to optically darker Ag-deposits reaching the absorption edge of silver absorption of ~ 1000 nm. Mass spectroscopic analyses indicated that HIPIMS produced a much higher amount of Ag1+ and Ag2+ compared to DCMS due to the higher peak discharge current employed in the former case. 相似文献
13.
Hyungjun Park Jeoungin Lee J. Yi Semyoung Oh Donggeun Jung Heeyeop Chae 《Thin solid films》2008,516(7):1370-1373
Admittance spectroscopic analysis was used to examine the effect of a CFX plasma surface treatment on indium tin oxide (ITO) anodes using CF4 gas and model the equivalent circuit for organic light emitting diodes (OLEDs) with the of ITO anode surface treated with CFX plasma. This device with the ITO/N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-diphenyl-4,4′-diamine/tris-(8-hydroxyquinoline) aluminum/lithium fluoride/Al structure was modeled as a simple combination of two resistors and a capacitor. The ITO anode surface treated with the CFX plasma showed a shift in the vacuum level of the ITO, which resulted in a decrease in the barrier height for hole injection at the ITO/organic interface. Admittance spectroscopy measurements of the devices with the CFX plasma treatment on the surface of the ITO anodes showed a change in the contact resistance, bulk resistance and bulk capacitance. 相似文献
14.
Creep crack growth behavior is very sensitive to the materials’ micro-structures such as the heat affected zone of a weld joint. This is a main issue to be clarified for 9%Cr ferritic heat resistant steel for their application in structural components. In this paper, high temperature creep crack growth tests were conducted on CT specimens with cracks in the heat affected zone of weld joints of W added 9%Cr ferritic heat resistant steel, ASME grade P92. The creep crack growth behavior in the heat affected zone of welded joint was investigated using the Q∗ concept following which the algorithm of predicting the life of creep crack growth has been proposed. Furthermore, three-dimensional elastic-plastic creep FEM analyses were conducted and the effect of stress multiaxiality of welded joint on creep crack growth rate was discussed as compared with that of base metal. 相似文献
15.
A pot experiment was carried out to assess the effect of different amendments of industrial sludge on the growth of Canna indica L. as well as the translocation potential of heavy metals of this plant. The accumulation of metals (Cr, Fe, Cd, Cu, Ni, Zn, Mn and Pb) in different parts of C. indica L. grown on industrial sludge-amended soil increased with time and increasing doses of sludge amendments. Sequential extraction method was followed to estimate the different fractions of heavy metals in sludge-amended soils collected from different periods of this study. The results showed that Mn, Zn, Cd, Cr and Pb were mostly associated with Fe–Mn oxide fraction in all amendments, whereas, Ni was mostly found in residual (RES) fraction. Cu and Fe were found to be higher in organically bounded form (OM) and RES fraction. The metal concentration in C. indica L. after 90 days of experiment started, was in the order of Fe > Cr > Mn > Zn > Ni > Cu > Cd > Pb and the metal translocation was found lesser in shoot. With the increasing percentage of sludge amendments in soil the metal concentrations increased in different parts of plants. Overall, the plant C. indica L. was found to be well adapted in industrial sludge amendments and it may be recommended that this plant was found suitable for phytoremediation of most of the studied metals. 相似文献
16.
Equilibrium and kinetic studies for the biosorption system of copper(II) ion from aqueous solution using Tectona grandis L.f. leaves powder 总被引:1,自引:0,他引:1
The biosorption of copper(II) ions from aqueous solution by Tectona grandis L.f. was studied in a batch adsorption system as a function of pH, metal ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of copper(II) ions onto T. grandis L.f. were evaluated. The Langmuir, Freundlich, Redlich-Peterson and Temkin adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model with maximum adsorption capacity of 15.43 mg/g of copper(II) ion on T. grandis L.f. leaves powder. The kinetic experimental data properly correlated with the second-order kinetic model. Various thermodynamic parameters such as deltaG(o), deltaH(o), and deltaS(o) were calculated indicating that this system was a spontaneous and exothermic process. 相似文献
17.
The plasma polymer thin films were deposited on Si(100) substrate by PECVD (plasma enhanced chemical vapor deposition) method. Liquid cyclohexene was used as single organic precursor. It was heated up to 60 °C and bubbled up by hydrogen gas, which flow rate was 50 sccm (standard cubic centimeters per min). Deposition temperature was room temperature. Plasma was ignited by a radio frequency (RF; 13.56 MHz) of 10 W.As-deposited plasma polymer thin films were treated by e-beam of 300 keV with various adsorption radiation doses. The plasma polymer films, which were treated by high energy e-beam (HEEB), were investigated by FT-IR (Fourier Transform Infrared), XPS (X-ray Photoelectron Spectroscopy), AFM (Atomic Force Microscopy), and the water contact angles.From IR spectra, the intensity of OH functional group is increased by increasing electron dose rate. XPS results also show that the intensity of O1s peak is increased by increasing electron dose rate. C1s peak shows that oxygen bonded at carbon site. The water contact angles are decreased by increasing electron dose rate. From the AFM analysis, we observed the formation of λ-DNA (deoxyribonucleic acid) array on plasma polymer film, which was treated by HEEB with 14 kGy of adsorption radiation dose. 相似文献
18.
In this paper, we report the utilization of the DC pulse discharge plasma jet technique as a means for the preparation of titanium oxide (TiO2) films on fluorine dope tin oxide (FTO) coated glass substrates used for dye-sensitized solar cells (DSCs). The TiO2 film made on these experimental bases exhibited the BET specific surface area of 95 m2/g, the pore volume of 0.3 cm2/g and the TEM particle size of ∼25 nm. The DSCs made by the TiO2 film exhibited an energy conversion efficiency of 5.7% at 100 mW/cm2 light intensity. Consequently, we believe that the optimization between the specific surface area and photocurrent density of TiO2 film was achieved by the plasma surface treatment which also contributed to the improvement of energy conversion efficiency of DSCs. 相似文献
19.
In situ TiB whisker reinforced Ti6Al4V (TiBw/Ti64) composites with a network architecture were extruded and heat treated in order to further improve their mechanical properties. The microstructure results show that the equiaxed network architecture was extruded to column network architecture and TiB whisker to alignment distribution. The transformed β phase is formed and the residual stress generated during extrusion obviously decreases after water quenching and aging processes. The tensile test results show that the strength, elastic modulus and ductility of the composites can be significantly improved by the subsequent extrusion, and then, the strength can be further improved by water quenching and aging processes after hot extrusion deformation. The elastic modulus of the as-sintered composites with a novel network microstructure follows the upper bound of Hashin-Shtrikman (H-S) theory before extrusion, while that of the as-extruded composites with a column network microstructure agrees well with the prediction from Halpin-Tsai equation. 相似文献
20.
Lucas Máximo Alves 《Engineering Fracture Mechanics》2010,77(13):2451-2466
In this paper, fractal geometry is used to modify the Griffith-Irwin-Orowan classical energy balance. Crack fractal geometry is introduced in the elastic-plastic fracture mechanics by means of the Eshelby-Rice J-integral and the influence of the ruggedness of the crack surface on the quasistatic crack growth is evaluated. It is shown that the rising of the J-R curve correlates to the topological ruggedness dimension of the crack surface. Results from fracture experiments are shown to be very well fitted with the proposed model, which is shown to be a unifying approach for fractal models currently used in fracture mechanics. 相似文献