干法乙炔电石渣中生电石的定量分析

介绍了干法乙炔生产过程产生的电石渣中生电石含量的定量分析方法,指出该方法具有准确度高、简便易行的特点。

干法乙炔装置生产中电石水解率分析

干法乙炔装置作为电石制乙炔行业内的主导装置,电石的充分反应是生产的关键,此次从电石进入乙炔装置储存开始,到电石破碎,再到发生器反应各个环节逐个分析,从电石颗粒大小、水比值的给定、搅拌频率的设置、注水喷头选用和注水管线的布局等多方面考虑如何达到最佳的电石水解率,使反应完成的固相产物中生电石尽可能少,同时,分析电石水解不足可能造成的危害及影响来说明水解率的重要性,最后依据实际反应情况作出最优化的调整。

Petroleum Hydrocarbon Degradation Potential of Soil Bacteria Native to the Yellow River Delta

The bioremediation potential of bacteria indigenous to soils of the Yellow River Delta in China was evaluated as a treatment option for soil remediation. Petroleum hydrocarbon degraders were isolated from contaminated soil samples from the Yellow River Delta. Four microbial communities and eight isolates were obtained. The optimal temperature, salinity, pH, and the ratios of C, N, and P (C:N:P) for the maximum biodegradation of diesel oil, crude oil, n-alkanes, and polyaromatic hydrocarbons by indigenous bacteria were determined, and the kinetics changes in microbial communities were monitored. In general, the mixed microbial consortia demonstrated wider catabolic versatility and faster overall rate of hydrocarbon degradation than individual isolates. Our experimental results demonstrated the feasibility of biodegradation of petroleum hydrocarbon by indigenous bacteria for soil remediation in the Yellow River Delta.

Electrolytic Production of NF3 Using Boron-Doped Diamond Anode in Molten NH4F·2HF

The current efficiency for NF3 formation was independent on the current density in the range of 200 to 1,000 mA·cm^2. The average values of NF3 current efficiencies on the BDD （boron-doped diamond） anode with the boron-concentration of 2,500 ppm were 32.3% at 80℃, 63.3% at 100℃ and 59.7% at 120℃. The best current efficiencies for NF3 formation on the BDD anode with boron-concentrations of 2,500, 5,000 and 7,500 ppm were obtained at 100℃ and those were 63.3%, 73.3% and 56.2%, respectively. Although anode effect occurred on the BDD electrodes covered with a part of the surface of the spiculate structure, which had the boron-concentrations higher than 7,500 ppm, it did not take place on the BDD electrodes covered with the surface of diamond structure, even if the BDD electrode had the boron-concentration of 8,000 ppm.

Promising Graphene Modified Electrode Using Layer-by-Layer Method for Microbial Biofilm Connection

In order to enhance the power output of microbial fuel cell as well as its stability, the development of a new type of anode is essential. The purpose of this work is to modify a stainless steel foam, using the layer-by-layer self-assembly technique, with rGO （reduced grapbene oxide） and PEI （polyethyleneimine）. The efficiency of this kind of modification has been investigated to determine the supply of graphene in term of electricity generation and stability. Under an applied voltage, which is used to form an electroactive biofilm, the modified stainless steel foam （SSF/（PE1/rGO）5） exhibited a current 50 times higher than the blank anode. The roughness of the SSF/（PEI/rGO）5 observed by SEM （scanning electron microscopy） is more favorable to attach more bacteria on it. Also, graphene improved the stability of the electrode as no response where observed for the blank anode after 18 days meanwhile the SSF/（PEI/rGO）5 was still running after 54 days.

Opisthorchiasis-associated biliary stones:Light and scanning electron microscopic study

AIM:Biliary stones are frequently encountered in areas endemic for opisthorchiasis in Thailand.The present study was to describe the prevalence and pathogenesis of these stones. METHODS:Gallstones and/or common bile duct stones and bile specimens from 113 consecutive cholecystectomies were included.Bile samples,including sludge and/or microcalculi,were examined for Opisthorchis viverrinieggs, calcium and bilirubin.The stones were also processed for scanning electron microscopic(SEM)study. RESULTS:Of the 113 cases,82 had pigment stones,while one had cholesterol stones.The other 30 cases had no stones.Most of the stone cases(76%,63/83)had multiple stones,while the remainder had a single stone.Stones were more frequently observed in females.Bile examination was positive for O.viverrini eggs in 50% of the cases studied.Aggregates of calcium bilirubinate precipitates were observed in all cases with sludge.Deposition of calcium bilirubinate on the eggshell was visualized by special staining.A SEM study demonstrated the presence of the parasite eggs in the stones.Numerous crystals, morphologically consistent with calcium derivatives and cholesterol precipitates,were seen. CONCLUSION:Northeast Thailand has a high prevalence of pigment stones,as observed at the cholecystectomy,and liver fluke infestation seems involved in the pathogenesis of stone formation.

Assessment of Electric Power Generation via Water Hyacinths and Agricultural Waste

The importance and the necessary of researches on renewable energy have become a hot topic in recent years due to climate change and global warming. In addition, the fossil fuel reserves is facing rapid depletion on the earth. Currently, most researches have concentrated on producing biogas for heating, lighting, drying, cooking but lack in researching on electricity production because the possibility of producing biogas at households are common at small scale. Studying on alternative energy sources to replace traditional fuel for electric power generation brings new chances and great opportunities for development. This study presents an assessment electric power generation via water hyacinths and agricultural waste. In this paper, the evaluation electric power is generated by operating internal combustion engines which use biogas fuel to replace traditional fuel （diesel, gasoline）. The results of the studies were demonstrated by experiments on the renewable energy production system at Hoa An Biotechnology Research and Experimental Center of Cantho University.

In vitro biodegradability and biocompatibility of porous Mg-Zn scaffolds coated with nano hydroxyapatite via pulse electrodeposition

The biodegradability and biocompatibility of porous Mg-2Zn（mass fraction, %） scaffolds coated with nano hydroxyapatite（HAP） were investigated. The nano HAP coating on Mg-2Zn scaffolds was prepared by the pulse electrodeposition method. The as-deposited scaffolds were then post-treated with alkaline solution to improve the biodegradation behavior and biocompatibility for implant applications. The microstructure and composition of scaffold and nano HAP coating, as well as their degradation and cytotoxicity behavior in simulated body fluid（SBF） were investigated. The post-treated coating is composed of needle-like HAP with the diameter less than 100 nm developed almost perpendicularly to the substrate, which exhibits a similar composition to natural bone. It is found that the products of immersion in SBF are identified to be HAP,（Ca,Mg）3（PO4）2 and Mg（OH）2. The bioactivity, biocompatibility and cell viabilities for the as-coated and post-treated scaffold extracts are higher than those for the uncoated scaffold. MG63 cells are found to adhere and proliferate on the surface of the as-coated and post-treated scaffolds, making it a promising choice for medical application. The results show that the pulse electrodeposition of nano HAP coating and alkaline treatment is a useful approach to improve the biodegradability and bioactivity of porous Mg-Zn scaffolds.

Degradation Characteristics and Community Structure of a Hydrocarbon Degrading Bacterial Consortium

A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.

Carbon Foam Anode Modified by Urea and Its Higher Electrochemical Performance in Marine Benthic Microbial Fuel Cell

Electrode materials have an important effect on the property of microbial fuel cell(MFC). Carbon foam is utilized as an anode and further modified by urea to improve its performance in marine benthic microbial fuel cell(BMFC) with higher voltage and output power. The electrochemical properties of plain carbon foam(PC) and urea-modified carbon foam(UC) are measured respectively. Results show that the UC obtains better wettability after its modification and higher anti-polarization ability than the PC. A novel phenomenon has been found that the electrical potential of the modified UC anode is nearly 100 m V lower than that of the PC, reaching-570 ±10 m V(vs. SCE), and that it also has a much higher electron transfer kinetic activity, reaching 9399.4 m W m-2, which is 566.2-fold higher than that from plain graphite anode(PG). The fuel cell containing the UC anode has the maximum power density(256.0 m W m-2) among the three different BMFCs. Urea would enhance the bacteria biofilm formation with a more diverse microbial community and maintain more electrons, leading to a lower anodic redox potential and higher power output. The paper primarily analyzes why the electrical potential of the modified anode becomes much lower than that of others after urea modification. These results can be utilized to construct a novel BMFC with higher output power and to design the conditioner of voltage booster with a higher conversion ratio. Finally, the carbon foam with a bigger pore size would be a potential anodic material in conventional MFC.

Electron transfer from sulfate-reducing bacteria biofilm promoted by reduced graphene sheets

Reduced graphene sheets (RGSs) mediate electron transfer between sulfate-reducing bacteria (SRB) and solid electrodes, and promote the development of microbial fuel cells (MFC). We have investigated RSG-promoted electron transfer between SRB and a glassy carbon (GC) electrode. The RGSs were produced at high yield by a chemical sequence involving graphite oxidation, ultrasonic exfoliation of nanosheets, and N2H4 reduction. Cyclic voltammetric testing showed that the characteristic anodic peaks (around 0.3 V) might arise from the combination of bacterial membrane surface cytochrome c3 and the metabolic products of SRB. After 6 d, another anodic wave gradually increased to a maximum current peak and a third anodic signal became visible at around 0 V. The enhancements of two characteristic anodic peaks suggest that RSGs mediate electron-transfer kinetics between bacteria and the solid electrode. Manipulation of these recently-discovered electron-transport mechanisms will lead to significant advances in MFC engineering.

Use of Renewable Energy Sources in Saudi Arabia through Smart Grid

Even though Saudi Arabia is the world＇s largest producer and exporter of petroleum and petroleum based products, it is also blessed with high potential of renewable energy sources like solar and wind. Untapped wind and solar energy sources, which are abundant throughout the kingdom, can be connected and optimally integrated into the grid through the use of smart grid technologies and the expansion of transmission facilities. Smart grid is an auto-balancing, self-monitoring power grid that accepts power from any source of fuel like oil, sun or wind and delivers electricity from suppliers to consumers. It helps to control the use of appliances in order to save energy, reduces cost and increase reliability. This paper describes the attributes of a smart grid and how these act as driving force to modernize the electrical power grid. The necessity of conservation of oil in Saudi Arabia is argued. Moreover, the vast availability of renewable energy sources like solar and wind in Saudi Arabia and advantages in utilizing these sources through smart grid technologies are advocated in this paper.

3-Phase Fault Finding in Oil Field MV Distribution Network Using Fuzzy Clustering Techniques

This paper studies an existing 13.8 kilovolt distribution network which, serves an oil production field spread over an area of approximately 60 kilometers square, in order to locate any fault that may occur anywhere in the network using fuzzy c-mean classification techniques. In addition, Sections 5 and 6 introduce two different methods for normalizing data and selecting the optimum number of clusters in order to classify data. Results and conclusions are given to show the feasibility for the suggested fault location method. Suggestion for future related research has been provided in Section 8.

Flow-induced voltage generation in graphene network

We report a voltage generator based on a graphene network （GN）. In response to the movement of a droplet of ionic solution over a GN strip, a voltage of several hundred millivolts is observed under ambient conditions. In the voltage-generation process, the unique structure of GN plays an important role in improving the rate of electron transfer. Given their excellent mechanical properties, GNs may find applications for harvesting vibrational energy in various places such as raincoats, umbrellas, windows, and other surfaces that are exposed to rain.

High-quality graphene grown directly on stainless steel meshes through CVD process for enhanced current collectors of supercapacitors

High-quality graphene coating was directly grown on stainless steel meshes via chemical vapor deposition process,during which the morphology of the stainless steel was transformed rugged.When the graphene-coated stainless steel meshes were applied as current collectors of supercapacitors,the changes of the appearance and the graphene coating improved the contact between stainless steel meshes and the active materials,thus benefiting the performance of the supercapacitors.Furthermore,this simple method can be used to prepare the enhanced current collectors for other energy storage devices.

Wrinkle-free graphene with spatially uniform electrical properties grown on hot-pressed copper

The chemical vapor deposition （CVD） of graphene on Cu substrates enables the fabrication of large-area monolayer graphene on desired substrates. However, during the transfer of the synthesized graphene, topographic defects are unavoidably formed along the Cu grain boundaries, degrading the electrical properties of graphene and increasing the device-to-device variability. Here, we introduce a method of hot-pressing as a surface pre-treatment to improve the thermal stability of Cu thin film for the suppression of grain boundary grooving. The flattened Cu thin film maintains its smooth surface even after the subsequent high temperature CVD process necessary for graphene growth, and the formation of graphene without wrinkles is realized. Graphene field effect transistors （FETs） fabricated using the graphene synthesized on hot-pressed Cu thin film exhibit superior field effect mobility and significantly reduced device-to-device variation.

Graphene-supported platinum catalysts for fuel cells

Increasing concerns with non-renewable energy sources drive research and development of sustainable energy technology. Fuel cells have become a central part in solving challenges associated with energy conversion. This review summarizes recent development of catalysts used for fuel cells over the past 15 years. It is focused on polymer electrolyte membrane fuel cells as an environmentally benign and feasible energy source. Graphene is used as a promising support material for Pt catalysts. It ensures high catalyst loading, good electro- catalysis and stability. Attention has been drawn to structural sensitivity of the catalysts, as well as polymetallic and nanos- tructured catalysts in order to improve the oxygen reduction reaction. Characterization methods including electrochemical, microscopic and spectroscopic techniques are summarized with an overview of the latest technological advances in the field. Future perspective is given in a form of Pt-free catalysts, such as microbial fuel cells for long-term development.

Celestine blue as a new indicator in electrochemical DNA biosensors

Celestine blue(CB)was introduced as a new electroactive indicator in DNA biosensors.The interaction of CB with DNA was investigated by electrochemical and spectroscopic methods.The effect of buffer kind and p H on the electrochemical behavior of CB was studied.The peak currents of CB were linearly related to DNA concentration in the range of 5.0×10^(-9) to 1.0×10^(-7)mol/L.The detection limit of this approach was 4.76×10^(-10) mol/L.Based on spectrometry data a hypochromic effect was observed in UV-Vis spectra of CB with increasing DNA concentration.The results illustrate the possible interaction mode between CB and DNA is electrostatic binding.