Effect of a synthesized anionic fluorinated surfactant on wettability alteration for chemical treatment of near-wellbore zone in carbonate gas condensate reservoirs

The pressure drop during production in the near-wellbore zone of gas condensate reservoirs causes condensate formation in this area.Condensate blockage in this area causes an additional pressure drop that weakens the effective parameters of production,such as permeability.Reservoir rock wettability alteration to gas-wet through chemical treatment is one of the solutions to produce these condensates and eliminate condensate blockage in the area.In this study,an anionic fluorinated surfactant was synthesized and used for chemical treatment and carbonate rock wettability alteration.The synthesized surfactant was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.Then,using surface tension tests,its critical micelle concentration(CMC)was determined.Contact angle experiments on chemically treated sections with surfactant solutions and spontaneous imbibition were performed to investigate the wettability alteration.Surfactant adsorption on porous media was calculated using flooding.Finally,the surfactant foamability was investigated using a Ross-Miles foam generator.According to the results,the synthesized surfactant has suitable thermal stability for use in gas condensate reservoirs.A CMC of 3500 ppm was obtained for the surfactant based on the surface tension experiments.Contact angle experiments show the ability of the surfactant to chemical treatment and wettability alteration of carbonate rocks to gas-wet so that at the constant concentration of CMC and at 373 K,the contact angles at treatment times of 30,60,120 and 240 min were obtained 87.94°,93.50°,99.79°and 106.03°,respectively.However,this ability varies at different surfactant concentrations and temperatures.The foamability test also shows the suitable stability of the foam generated by the surfactant,and a foam half-life time of 13 min was obtained for the surfactant at CMC.

Structural Change of Wood Molecules and Chemorheological Behaviors during Chemical Treatment

It is very important to clarify the relationship of changes of molecular combinations in wood cell walls and the chemical rheological behavior during various chemical reagent treatments, for it would be helpful to develop new wood modification technologies and to enrich the theory of chemical rheology of wood. Based on previous investigations on the chemorheological properties of wood by chemical treatments and the applied methods in chemical rheology of wool fibers, this paper proposes the study of various additional reagents to wood saturated in water for long periods of time in order to investigate the chemical rheology of wood, which can provide information about the character of combinations between wood molecules and the structural changes of molecules and further put forward the idea of modifying wood in a decrystallized state.

Atomic Force Microscopy Studies on the Chemical Treatment of Nanocrystalline Porous TiO_2 Films

AFM has been utilized to study the surface topography and the local conductivity of nanocrystalline TiO2 films. Improving the local conductivity by Ti(iso-C3H7O)4 treatment is characterized by quantitative analysis of the simultaneous current image. The mechanism of Ti(iso C3H7O)4 treatment is discussed.

Chemical Treatment of Carbon Nanotubes as Electrodes in Electrochemical Double-Layer Capacitors

Multi-walled carbon nanombes with homogeneous diameters （40 - 60 nm）, produced by chemical vapor deposition of hydrocarbon gas, are purified by nitric acids. Infrared and Raman studies indicate that oxygen containing surface groups, which are predominately carboxylic, phenolic and lactonic groups, are introduced into purified carbon nanotubes. Then three kinds of block-form porous tablets of carbon nanotubes are fabricated as electrodes in electrochemical double-layer capacitors. Using mounded mixture comprising carbon nanotubes and binder powders provides these tablets. Comparison of the effect of different processing on the structural performance of the capacitors is specifically investigated. Using chemically treated electrodes, electrochemical double-layer capacitors with a specific capacitance of about 33 F/g are obtained with 38 wt % H2SO4 as the electrolyte.

Time-resolved Microwave Conductivity Studies on the Chemical Treatment of the Nanocrystalline Porous TiO2 Films

Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.

Effects of O_2 Plasma Treatment on the Chemical and Electric Properties of Low-k SiOF Films

With the progress of ULSI technology, materials with low dielectric constant are required to replace SiO2 film as the interlayer to scale down the interconnection delay. Fluorinated Si oxide thin films (SiOF) are a promising material for the low dielectric constant and the process compatibility in existing technology. However, SiOF films are liable to absorb moisture when exposed to air. By treating the SiOF films with O-2 plasma, it was found that the moisture resistibility of SiOF films was remarkably improved. The mechanism of the improvement in stability of dielectric constant was investigated. The results show that: 1) F atoms dissociated from the films and the bond angle of Si-O-Si decreased. 2) The plasma treatment enhanced the strength of Si-F bonds by removing unstable =SiF2 structures in the films. Resistibility of SiOF films in moisture was improved.

Spring Wheat Disease and Yield Responses to Nitrogen Fertilization and Chemical Treatments

P. tritici-repentis, B. graminb and C. sativus are important diseases of spring wheat in Estonia. Field trials were carried out during 2006 and 2008 in JiSgeva PBI. Two kinds of treatments were used： Tl consisted of four different rates of basic fertilizer： NO = NOPOK0; N1 = N60P13K23, N2 = N 100P22K39; N3 = N140P31K54 kg ha^-1. T2 treatment consisted of same rates of basic fertilizers and in addition growth regulator, fungicides and leaf fertilizers. Seeds of the varieties ＂Monsun＂ and ＂Vinjett＂ were untreated. Results of the effects of fertilizers on the infections of fungal diseases on spring wheat monoculture revealed that test years had the biggest influence on infection intensity of B. graminis （REy = 50.7-59.2） in T1 and T2 and P. tritici-repentis in T2 （REy = 31.6）, whereas infection of C. sativus was more dependent on year in Tl （R2y = 37.3）. Yield correlated highly with a fertilizer rate and year. In the treatment T2, the yield depended more on weather conditions （REy = 40.7） and in T1, the yield was more dependent on fertilization rate （REF = 60.2）. We found TI to be more economic as the optimum N rate varied from N60 to N100 kg hat and the benefit in monetary terms raised from 297ε hal （＂Monsun＂ 2007） to 9056 hal （＂Vinjett＂ 2008）. In T2, N rate 60 kg ha^-1 raised the monetary benefit from 806 ha^-1 （＂Monsun＂ 2007） to 731ε ha^-1 （＂Vinjett＂ 2008）. The highest economic profit was gained by using low rates of fertilizer for ＂Monsun＂ and the highest rates of fertilizer for ＂Vinjett＂.

Influence of Chemical Precleaning on the Plasma Treatment Efficiency of Aluminum by RF Plasma Pencil

This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.the surface morphology and chemical groups）of plasma modified aluminum significantly depends on the chemical precleaning.Commonly used chemicals（isopropanol,trichlorethane,solution of Na OH in deionized water）were used as precleaning agents.The plasma treatments were done using a radio frequency driven atmospheric pressure plasma pencil developed at Masaryk University,which operates in Ar,Ar/O_2 gas mixtures.The effectiveness of the plasma treatment was estimated by the wettability measurements,showing high wettability improvement already after 0.3 s treatment.The effects of surface cleaning（hydrocarbon removal）,surface oxidation and activation（generation of OH groups）were estimated using infrared spectroscopy.The changes in the surface morphology were measured using scanning electron microscopy.Optical emission spectroscopy measurements in the near-to-surface region with temperature calculations showed that plasma itself depends on the sample precleaning procedure.

Effects of Different Treatment Methods on Germination Rate of Hard Seeds of Wild Lotus corniculatus L

Birdsfoot trefoil （Lotus corniculatus L.） is high in nutritional value and adapted to slightly acidic, droughty, infertile, or wet soils. However, the impermeable seed coat restricts water imbibition and results in poor seed germination and subse- quent stand establishment. The aim of this study was to identify the dormancy mechanism of Birdsfoot trefoil seeds, and investigate the suitable pretreatment to overcome the poor seed germination. Germination behavior was characterized by using the final germination percentage and the mean germination time. The results indicated that coat thickness of dormant seeds was significant larger. The average hard seed rate was up to 92.3%. It was found that mechanical scarification, chemi- cal scarification with concentrated sulfuric acid （98% H_2SO_4）, and gibberellic acid soaking following freezing below zero temperature were effective in reducing hard- seededness and lead to increases of seed germination.

Synthesis of Sodium Beta Alumina Films by Heat Treatment of Sodium Aluminum Oxides

Sodium beta alumina（Na-β-alumina） films were synthesized by heat treatment of NaAl6O（9.5）and γ-NaA1O2 films at temperatures of 1 373-1 573 K.Single-phase γ-NaA1O2 and NaAl6O（9.5） films were prepared by laser chemical vapor deposition at the deposition temperatures of 976 and 1 100 K,respectively.Subsequent heat treatment of the films resulted in the formation of Na-β-alumina with α-Al2O3 at temperatures above 1 373 K for NaAl6O（9.5） and 1 473 K for γ-NaA1O2.On heat treatment at temperatures of 1 473-1 573 K,the faceted morphology with terraces of the as-deposited（110）-oriented γ-NaAlO2 films transformed to a porous morphology with platelet grains comprising Na-β-alumina and α-Al2O3.On heat treatment at temperatures of1 373-1 473 K,the pyramidal,faceted grains of as-deposited NaAl6O（9.5） films transformed to planer,shapeanisotropic morphology in the film of mixed Na-β-alumina and α-Al2O3.A dense morphology was observed in both the as-deposited and heat-treated NaAl6O（9.5） films.

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

Experiments were carried out to study the removal of heavy metals from municipal sewage sludge by proper method for land application. The sequential extractions for metal fractionation showed that the non digested sludge from Guangzhou contained Cu and Zn principally bound to carbonate and oxides and the metal sulfides were low. Among H 2SO 4, EDTA and NH 4HCO 3 extractant agents, H 2SO 4 was the most efficient and economic in removing the heavy metals, especially with the addition of the concentrated acid. Plant experiment in pots with Chinese cabbage ( Brassica Chinensis ) showed that the acidified sludges neutralized with alkaline amendments such as phosphate rock could increase significantly the plant yield and decreased the soil and plant contamination by heavy metals originated from sewage sludge.

Effects of Periodic Temperature Changes on Stress Relaxation of Chemically Treated Wood

In order to clarify the relationship between the microstructural changes and the rheological behaviors of four chemically treated woods (delignified wood, hemicellulose-removed wood, DMSO swollen and decrystallization treated wood), the stress relaxation of wood with three different moisture contents was determined during periodic temperature changes. The experi- mental results show that after wood relaxation for 4 h at 25 °C, the stress decays sharply when the temperature increases and 2 h later the stress recovers again when the temperature drops back to the original point. The additional stress relaxation, produced after tem- perature begins to increase, is mainly caused by the thermal swelling, molecular thermal movement and the break of a part of residual hydrogen bonds. The number of hydrogen bonds and the size and amount of cavities in various treated woods greatly affect the magnitude of the additional relaxed stress and the recovery stress.

Particle size distribution and removal by a chemical-biological flocculation process

The particle characterization from the influent and effluent of a chemical-biological flocculation （CBF） process was studied with a laser diffraction device. Water samples from a chemically enhanced primary treatment （CEPT） process and a primary sediment tank process were also analyzed for comparison. The results showed that CBF process was not only effective for both the big size particles and small size particles removal, but also the best particle removal process in the three processes. The results also indicated that CBF process was superior to CEPT process in the heavy metals removal. The high and non-selective removal for heavy metals might be closely related to its strong ability to eliminate small particles. Samples from different locations in CBF reactors showed that small particles were easier to aggregate into big ones and those disrupted flocs could properly flocculate again along CBF reactor because of the biological flocculation.

Improvement of Bonding Strength of AZ31B Magnesium Alloy by Anodizing and Chromium-free Conversion Treatments

The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversion treatment and anodizing can increase the bonding strength. The anodizing treatment gives higher bonding strength and better corrosion resistance than chemical conversion treatment. The increase of bonding strength by the treatmetlts may be attributed to the uneven surface structures with micro-pores, resulting in increased bonding areas and the embedding effect.

Stress Relaxation of Chemically Treated Wood during Processes of Temperature Elevation and Decline

In order to clarify the effect of drying on structural changes of DMSO swell treated and DEA-SO2-DMSO decrystallization treated Chinese fir （Cunninghamia lanceolate） wood, the stress relaxation of treated oven-dry specimens during the processes of temperature elevation and reduction and that of treated wet specimens at constant temperature were determined. A stress decrease process and a stress increase process were observed in all stress ratio curves of wood during the processes of decreasing temperature. Untreated wood, during the process of temperature reduction under higher initial temperature conditions and during the process of temperature elevation, has a larger stress decrease than treated woods. In a wet state this trend is reversed. It indicated that the drying set made treated woods have a smaller increase in fluidity of wood constituents with increasing temperature. Some bonding between decrystallization reagents and wood molecules may occur.

APPLICATION OF RARE EARTH IN SURFACE HEAT TREATMENT OF HOT-WORKING DIE STEELS

This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused layer. XRD and SEM energy spectrum prove that trace RE element actually penetrates into the surface layer of steels. The result shows that RE can reduce the gradient of change of hardness in diffused layer, improve the morphology and distribution of compounds , and reduce the degree of surface alligator crack for thermal fatigue. The behavior of thermal fatigue of hot-working die steels is raised by 70% or so after the application of RE. The effect of RE is analysed according to the theory.

Properties of Different Chemically Treated Woven Hemp Fabric Reinforced Bio-Composites

The objective of this work is to carry out the chemical treatment for the hemp fabrics in a closed vacuum system and to prepare bio-based composites using treated hemp fabrics.The change in surface tension of the treated fabrics was measured using contact angle measurement and the wetting behavior using a tensiometer.Bio-based composites were fabricated using bio-based epoxy resin and different chemically treated fabrics.The flexural strength and dynamic water absorption behavior of the composites were characterized.The acetylated fabrics showed very good wetting behavior,and the contact angle values were marginally low compared to other treatment techniques.The bio-based composites fabricated using maleic anhydride treated fabrics achieved the flexural strength of 148 MPa and the dynamic water absorption values were less than 6%.The acetylated and maleic anhydride treatment methods were effective chemical treatments for the hemp fabrics and they enhanced both the wettability and fiber-matrix interaction.The chemical treatment methods that are carried out in the sealed environment can be utilized for all other natural fabrics that help overcome the moisture absorption behavior.

Development of Physical and Chemical Processes to Increase the Efficiency of Concentration of Vinasse＇s Solids

Each year, ethanol production is increasing in Brazil, consequently, the generation of byproducts as well. Among these, the vinasse stands out. With polluting power a hundred times greater than domestic sewage and high concentration of minerals, vinasse is generated in large volumes. Because of these characteristics, it is widely used in fertirrigation. However, it is composed of about 97% water, inflating the cost of the transport from the plant to the field. For these reasons, removing water from the vinasse and the consequent concentration of solids is an alternative management and application of this by-product. This project aimed to analyze the efficiency of various physical and chemical processes in the removal of water from the vinasse.

Influence of Heat Treatment Temperature on Microstructure and Bonding of TiO2 Film Coated on Diamond Particles Surface

TiO_2 films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO2 films were investigated through SEM, TEM, X-ray diffraction analysis, Raman spectroscopy, FTIR, and XPS. The results showed that when being heat-treated at 600 ℃, the amorphous TiO_2 film transfered to the anatase film which bonded well with diamond substrate. Meanwhile, the Ti-O-C bond formed between TiO2 film and diamond substrate. When being heat-treated at 800 ℃, TiO2 film was still anatase, and partial diamond began to graphitize. The graphitizated carbon could also form the Ti-O-C bond with TiO_2 film, although TiO_2 film would tend to crack in this case.

A Report on Identification, Segregation, Disposal and Reduction of Chemical Wastes

The accumulation of generated chemical wastes posed a serious problem for the UP College of Pharmacy. The faculty from the Department of Pharmaceutical Chemistry devised a scheme for the identification and segregation of the chemical wastes and created a system for proper disposal of future chemical wastes. There were a total of 1,142 of accumulated chemical waste bottles, 804 of which were subjected to identification and segregation procedures. The wastes were preliminarily tested for its solubility/miscibility in water and acidity or basicity. The identification was done by qualitative tests for cyanide, sulfide, halogenated, non-halogenated, oxidizing, nitro, and heavy metal compounds. The final segregation was based on the presence of the most hazardous component or on pH and water-miscibility. The Department then developed and implemented a scheme for the proper disposal of the chemical wastes generated in laboratory experiments done in the College. Laboratory experiments were also modified to use less toxic and less amounts of chemicals.