Treatment of chitin-producing wastewater by micro-electrolysis-contact oxidization

The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5. The CODcr removal efficiency by biochemical process can be more than 80%. During a half year抯 operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge stan-dards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.

Superior drainage treated by combinational technique of biologic contact oxidation and constructed wetland

The superior drainage was pre-treated by biologic contact oxidation on BOD5 load of 0.72 kg/(m3·d),and then post-treated by constructed wetland. The results about the effect on the constructed wetland post-treatment show that the total nitrogen (TN) is the restrictive index of the combinational technique treatment effect. To meet the reclaimed water quality standard and reuse for waterscape,the peak hydraulic load of constructed wetland is 0.50 m/d in summer (30-36 ℃) and 0.33 m/d in winter (8-12℃),and the load ratio of the peak hydraulic under the two temperature conditions is 3-2. The results are combined of reclaimed water quantity requirements in different seasons of green building. Reasonable scale of the reclaimed water treatment systems can be determined. The treatment efficacy can be well predicted,and both the design and operations can be effectively guided,by which the reclaimed water treatment systems regard superior drainage as the source and are purified by combinational technique of contact oxidation and artificial wetland.

Oxidation Properties of Silver Alloy Powders and Microstructures of Oxidized Powders for Making Electrical Contact Composites

The oxidation properties of silver alloy powders and microstructures of oxidized powders have been investigated by thermo gravity analysis(TGA), scanning electron microscopy(SEM) and wave dispersive X ray spectroscopy(WDEX). Ag Sn RE alloy powders have been oxidized completely at 610 ℃ within 60 min, with an external pure silver scale forming around each oxidized particle. It is useful to produce electrical contact composites. The excellent oxidation properties of Ag Sn RE alloy powders are attributed to the ideal microstructure of the oxidized powders.

Effect of La on arc erosion behaviors and oxidation resistance of Cu alloys

Cu with and without La addition was prepared and the effect of a trace amount of La on the arc erosion behaviors and oxidation resistance of Cu alloys was investigated. The results indicate that CuLa alloy exhibits superior oxidation resistance and arc erosion resistance. The contact resistance and temperature rise were obviously improved. The oxidation resistance of CuLa alloy mainly is due to the interface wrapping of La2O3 particles and CuLa alloy phase on Cu atoms. Thermodynamic calculation indicated that La2O3 could form preferentially in the CuLa alloy, which was beneficial for the protection of the Cu substrate. According to kinetics analysis, the activation energy of CuLa alloy was higher than that of pure Cu, indicating the better oxidation resistance of CuLa alloys.

Oxidized film on C_p/Cu-Cd electrical contact material

Constituents of the oxidized surface film on diamond particles reinforced Cu-Cd alloy matrix composite （Cp/Cu-Cd） were investigated by XPS. The results show that Cu2O is the main constituent when the oxidized film is thin; CuO appears only after the film is rather thick. The originally formed oxidized film on the Cp/Cu-Cd is about 10nm in thickness and is mainly composed of Cu2O and Cu. After oxidized at 120℃ over 30h, CuO is detected in the film.

Oxidative Degradation of o-Chlorophenol with Contact Glow Discharges in Aqueous Solution

Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.

Theoretical Study on the Dark Oxidation Reaction Mechanism of Ethers

The dark oxidation reactions of ethers including aether, isopropyl ether, phenyl isopropyl ether, and benzyl isopropyl ether have been studied by using density functional theory calculations. The structures of initial Contact charge transfer complexes （CCTCs）, transition states and caged radical intermediates have been located at the B3LYP/6-31G （d） level, The bonding nature of ethers with triplet 02 in CCTCs has been analyzed, and the detailed mechanism of dark oxidation reactions of ether is presented clearly.

Improvement of the light output and contact resistance of InGaN-based light-emitting diodes based on tantalum-doped indium tin oxide as p-type electrodes

This paper reports that highly transparent and low resistance tantalum-doped indium tin oxide （Ta-doped ITO） films contacted to p-type GaN have been prepared by the electron-beam evaporation technique. The Ta-doped ITO contacts become Ohmic with a specific contact resistance of $／sim 5.65／times 10^{ - 5}$$／Omega ／cdot$cm$^{2}$ and show the transmittance of $／sim $98% at a wavelength of 440nm when annealed at 500／du. Blue light emitting diodes （LEDs） fabricated with Ta-doped ITO p-type Ohmic contact layers give a forward-bias voltage of 3.21V at an injection current of 20mA. It further shows that the output power of LEDs with Ta-doped ITO contacts is enhanced 62% at 20mA in comparison with that of LEDs with conventional Ni/Au contacts

Contact resistance asymmetry of amorphous indium–gallium–zinc–oxide thin-film transistors by scanning Kelvin probe microscopy

In this work, a method based on scanning Kelvin probe microscopy is proposed to separately extract source/drain（S/D） series resistance in operating amorphous indium–gallium–zinc–oxide（a-IGZO） thin-film transistors. The asymmetry behavior of S/D contact resistance is deduced and the underlying physics is discussed. The present results suggest that the asymmetry of S/D contact resistance is caused by the difference in bias conditions of the Schottky-like junction at the contact interface induced by the parasitic reaction between contact metal and a-IGZO. The overall contact resistance should be determined by both the bulk channel resistance of the contact region and the interface properties of the metalsemiconductor junction.

Influence of Warm Oxide Layer on Wettability and Contact Angle for Heat Transport Devices

Recently, high heat density has become a problem in electronic devices. Therefore, high heat-transfer efficiency is required in copper heat exchangers. Improvement ofwettability is reported to improve the heat-transfer efficiency. In previous studies, copper oxide layer improves the wettability. In this study, we focus on a copper oxide layer produced under warm conditions （from 200 to 300 ℃）, which are suitable oxidation conditions for improving wettability. Experimental results showed that the surface of the specimens was covered by the oxidation layer and took on a black color. Furthermore, the wettability was improved by the warm copper oxide layer. While, the surface roughness was approximately constant to each warm oxidized specimen. Whereat, the warm oxide layer was observed by SEM （sanning electron microscope）. The results from SEM observations showed that the warm copper oxide layer consisted of stacks and combinations of nanoscopic warm oxidation particles. Thus, the warm oxidation layer has nanoscopic surface asperities. It is seemed that these nanoscopic asperities improved the wettability.

A new contact material—Ag/SnO_2-La_2O_3-Bi_2O_3

A super-fine compound powder, Ag/SnO_2+La_2O_3+ Bi_2O_3, has been obtainedusing the chemical coprecipitation method. And a new contact material, Ag/SnO_2+La_2O_3+Bi_2O_3, wasproduced by the powder metallurgy method. Its properties are as follows: the density is 9.75-9.93g/cm^3, the resistivity is 2.31-2.55 μΩ ·cm, the hardness is 880-985 MPa. Its mi-crostructureshows that the fine oxides have a uniform distribution in the silver matrix. The results ofmake-break capacity and temperature rise testing show that the new material has better ability ofanti-arc erosion and lower temperature rise than that of commonly used Ag/CdO.

A New AgMeO Contact Material

A new silver rare earth oxide contact material, Ag/La2O3(12), was produced by powder metallurgy method. Its performances are as follows: the density is 9.71 similar to 9.96 g.cm(-3); the hardness (HB) is 760 similar to 970 MPa and the resistivity is 2.25 similar to 2.38 mu Omega . cm. The microstructure of Ag/La2O3(12) mas analyzed by SEM and EDS. Rare earth oxide La2O3 shows two shapes, which are uniformly distributed in the form of sphere and abnormality in Ag matrix. La2O3 shows fine spherical shape in the melted area of Ag after laser acting which is used to simulate electric are. The results are contributed to the less splash erosion of Ag. Compared with the main physical and mechanical properties of Ag/SnO2(12) and Ag/CdO(12), the properties of three contact materials are similar, and hence Ag/La2O3(12) may become a potential contact material to be used as the substitute of Ag/CdO(12).

Effects of modified graphene oxide(GO) nanofluid on wettability and IFT changes: Experimental study for EOR applications

The application of nanoparticles(NPs) in enhanced oil recovery(EOR) offers a practical approach to resolving some surface-related problems encountered in contemporary technological processes. In this study, graphene oxide nanosheets(GONs) were synthesized by Hummer's method and, then, were subjected to surface modification by hexamethyldisilazane(HMDS) and diazonium sulfonic(DS) compounds. The new combination was known as GO-Su-HMDS. The potential stability of GO-Su-HMDS nanofluids(NFs) was investigated using the zeta(ζ) potential test. A comparative study of the effect of the synthesized NFs on wettability alteration of the reservoir rock was performed using interfacial tension(IFT) and contact angle experiments. According to the results of this study, the contact angle decreased from the initial value of 161.(oil wet) to 35.(water wet). In addition, IFT decreased from18.45 mN/m for deionized(DI) water to 8.8 mN/m for 500 ppm GO-Su-HMDS NF. Moreover, the results of flooding experiments showed that the NPs of a GO-Su-HMDS concentration of 400 and 500 ppm could increase the oil recovery by 20% and 19%, respectively. The experimental results showed that GO-SuHMDS NFs with a concentration of 500 ppm have the best efficiency in terms of altering the wettability of the rock from oil wet to water wet. Thus, it can be said that this nanofluid can reduce the contact angle and IFT and also increase the sweeping efficiency of oil.

Current transport mechanism of Mg/Au ohmic contacts to lightly doped n-type β-Ga_2O_3

The carrier transport mechanism of Mg/Au ohmic contact for lightly doped β-Ga_2O_3 is investigated. An excellent ohmic contact has been achieved when the sample was annealed at 400 °C and the specific contact resistance is 4.3 × 10-4 Ω·cm2. For the annealed sample, the temperature dependence of specific contact resistance is studied in the range from 300 to 375 K. The specific contact resistance is decreased from 4.3 × 10-4 to 1.59 × 10-4 Ω·cm2 with an increase of test temperature. As combination with the judge of E00, the basic mechanism of current transport is dominant by thermionic emission theory. The effective barrier height between Mg/Au and β-Ga_2O_3 is evaluated to be 0.1 eV for annealed sample by fitting experimental data with thermionic emission model.

Processing,Properties and Microstructures of Ag-ZnO Electrical Contact Composites

New powder metallurgy processing routes were designed to manufacture Ag ZnO electrical contact composites. Their physical properties, electrical contact properties and microstructures were investigated. By modelling tests, it is shown that the requirements of commercial use were met. It is proved that Ag ZnO composites could be used to substitute toxic Ag CdO on large load electrical contactors.

The Role of Fe(Ⅱ)in the Contact Glow Discharge Electrolysis

In this paper, we use methyl violet as a model organic substrate in wastewater to study the effect of Fe（Ⅱ） ion on the contact glow discharge electrolysis （CGDE）. The decoloration rate and the COD （Chemical Oxygen Demand） value have been examined. It is found that the presence of Fe（Ⅱ） ion can accelerate obviously the degradation of methyl violet, because it reacts with H2O2 in the CGDE process to yield hydroxyl radical, just acting as a Fenton-like reagent. Moreover, the optimal conditions for decoloring methyl violet were obtained, by means of an orthogonal experiment, to be [Fe^2＋] =1×10^-3 mol/L, applied voltage of 700 V of and pH = 9.0.

Application of Sodium Ion Sensor Based on the SnO_2/ITO Glass in the Detection of Rinsing Solution for Contact Lenses

This paper presents the studying results of the sodium ion sensor device based on the SnO_2/ITO glass structure in the detection of rinsing solution for contact lenses.The selective membrane contains poly (vinyl chloride) (PVC),bis (2-ethylhexyl) sebacate (DOS),(12-crown-4) methylmalonate (B12C4),and sodium tetrakis (4-fluoropbenyl) borate dehydrate (NaTFBD). The final weight ratios are PVC:DOS:B12C4:NaTFBD=33:66:2:2.In this condition,the sensor has performances with linear sensitivity,short response time,good repeatability and selectivity.The sensor was used to measure the rinsing solution for the contact lenses.Because the experimental results show close to the accurate value for four commercial products,this sensor can preliminary be used in detecting the rinsing solution for the contact lenses.Using this structure and sodium-sensing membrane to construct the sodium sensor is proven successfully in this application.

Transparent conducting indium-tin-oxide(ITO) film as full front electrode in Ⅲ–Ⅴ compound solar cell

The application of transparent conducting indium-tin-oxide （ITO） film as full front electrode replacing the conven- tional bus-bar metal electrode in III-V compound GalnP solar cell was proposed. A high-quality, non-rectifying contact between ITO and 10 nm N＋-GaAs contact layer was formed, which is benefiting from a high carrier concentration of the terrilium-doped N＋-GaAs layer, up to 2×10^19 cm^-3. A good device performance of the GalnP solar cell with the ITO electrode was observed. This result indicates a great potential of transparent conducting films in the future fabrication of larger area flexible III-V solar cell.

The Wetting Behavior of Fresh and Aged Soot Studied through Contact Angle Measurements

In this work, contact angle measurements for soot samples collected from a kerosene lantern, wood-burning fireplace, and municipal bus engine exhaust lines are reported. Contact angles for both freshly collected soot and samples treated with various doses of O3 (g), HNO3 (g), and H2SO4 (g) are considered. Use of a literature method has allowed estimation of the enthalpy of immersion (Himm) for the soot samples based on contact angle observed. Contact angles for freshly collected soot were 65 - 110 deg. indicating its hydrophobic nature. Chemical processing of soot usually resulted in smaller contact angles and large increases in immersion enthalpy. However, the dose of ozone, nitric or sulfuric acid vapor required to achieve alteration of the soot surface appeared to be considerably larger than that expected to be experienced by authentic atmospheric samples during the soot particles lifetime. The most significant variability of soot contact angle was observed for the municipal bus exhaust samples, suggesting that combustion chemistry may significantly affect wetting behavior.

Ohmic Hetero-Junction of n-Type Silicon and Tungsten Trioxide for Visible-Light Sensitive Photocatalyst

Visible light-sensitive photocatalyst was developed by combining n-type silicon (n-Si) and tungsten trioxide (WO3, n-Si/WO3), yielding an ohmic contact in between. In this system, the ohmic contact acted as an electron-and-hole mediator for the transfer of electrons and holes in the conduction band (CB) of WO3 and in the valence band (VB) of n-Si, respectively. Utilizing thus- constructed n-Si/WO3, the decomposition of 2-propanolto CO2 via acetone was achieved under visible light irradiation, by the contribution of holes in the VB of WO3 to decompose 2-propanol and the consumption of electrons in the CB of n-Si to reduce O2. The combination of p-type Si (p-Si) and WO3 (p-Si/ WO3), not the ohmic contact but the rectifying contact, was much less effective, compared to n-Si/WO3.