Effect Of Production Method Research Articles

Effect of production methods on tribological characteristics of babbitt coatings

The authors have studied variations in such tribological characteristics as the friction coefficient and wear rate of babbitt coatings obtained by the methods of turbulent casting, gas surfacing, plasma spraying, and activated arc metallization. The results obtained are discussed from the standpoints of microstructural metallographic analysis.

Effects of Production Method and Heat Treatment on the AdhesionStrength and Microstructural Behavior of MCrAlY Coatings

Thermal barrier coatings (TBCs) are widely-used as protective and insulative coatings on hot section components of gas turbines and their applications, like blades and combustion chambers, power generation. TBCs are used to allow higher service temperatures hot section of turbines and thus higher turbine efficiencies. TBCs generally consist of a metallic bond coating (BC) usually MCrAlY, a ceramic top coating (TC) usually ZrO2+Y2O3 and a thin oxide ceramic inter-layer (TGO) that forms under service condition within the bond coat / top coat interface. In this study, CoNiCrAlY powders were deposited on stainless steel substrate. High velocity oxy-fuel (HVOF) and Atmospheric plasma spraying (APS) techniques were used to produce two different types of bond coats. The ceramic top layers on both BC types were produced by APS. TBC specimens were subjected to heat treatment tests. Heat treatment tests was carried out in standard atmosphere at 550 °C, 650 °C and 750 °C for 1 and 2 hours. The microstructure and adhesion strength for top coat / bond coat interface of as sprayed and heat treated samples were investigated. Besides, the mechanical and microstructure behaviors of the produced layers in TBCs with heat treated and without heat treated samples were characterized and evaluated by SEM and optical microscope (OM). The results show the heat treatment of the coatings in different temperatures caused changes in microstructure and increase in adhesion strength properties of the coatings.

Consumer choice of broiler meat: The effects of country of origin and production methods

An increasing interest and concern among consumers in the ways in which food is produced has led to a need for differentiation in production methods in directions valued by consumers. In this study we used a choice experiment to analyse the importance of the production method, such as organic production and methods emphasising animal welfare or consumer health, and country of origin on the selection of broiler meat by Finnish consumers. The results revealed very strong positive perceptions of domestically produced broiler products. The effect of production method was significant but minor. Emphasising animal welfare in production particularly increased the probability of consumer choice. We also tested the effect of providing production information either in labels or verbally, and found that well-established labels have positive impacts whereas non-familiar labels may be counter-productive. Latent class analysis revealed the heterogeneity of consumer preferences, but did not facilitate the profiling of consumer groups based on socioeconomic data.

The effect of production method on properties of Fe–TiC composite

In this work, the properties of in-situ and in-mould produced iron–TiC composites have been investigated. The in-situ method consists of melting and casting the required composite materials, whereas in in-mould method the produced nano-powder TiC crystals via microwave procedure, have been added into the molten matrix with chemical similar to in-situ composite material. XRD method has been used for investigation of the phases. Also, the optical microscope has been used for detailed analysis of microstructures. In addition, wear resistance and hardness testing have been used for determining the materials properties. By comparing these results, it was found that the Fe–TiC composite can be produced using both methods, although the hardness and wear resistance properties are much better in the case of in-mould method in addition to having finer structure with respect to in-situ method.

Effect of Production Method and Gene Amplification on the Glycosylation Pattern of a Secreted Reporter Protein in CHO Cells

We have investigated the independent effects of selective gene amplification (using the dhfr amplifiable selection marker) and culture operating strategy (batch vs repeated fed-batch vs semicontinuous perfusion) on the glycosylation of a recombinant reporter protein (secreted alkaline phosphatase, SEAP) produced in transfected Chinese hamster ovary (CHO) cells. HPLC analyses coupled with susceptibility to various exoglycosidases were used to determine the N-glycosylation profile of SEAP samples. The dhfr amplified cell line yielded an almost 10-fold increase in specific productivity as compared to that of the unamplified cell line. The glycosylation pattern of the reporter protein produced in batch bioreactor cultures of the amplified cell line showed only slight differences as compared to the glycosylation pattern of the protein from batch bioreactor cultures of the unamplified cell line. In contrast, analysis of SEAP glycosylation structures from the protein isolated from semicontinuous perfusion cultures indicated that both relative glycan content and extent of sialylation were increased as compared to samples isolated from repeated fed-batch cultures. These results suggest that the slow growing perfusion cultures produce more completely glycosylated proteins than the faster growing repeated fed-batch cultures.

Effect of Production Methods on the Features of Sodium-Reduced Tantalum Powders

The paper presents a study into production method effect on characteristics of sodium-reduced tantalum powders. The powders were produced by feeding liquid sodium onto the surface of a melt consisting of K2TaF7 and a flux (I) and by feeding solid K2TaF7 onto the surface of a melt consisting of liquid sodium and a diluent salt (II). It is shown that production method renders essential influence to powder morphology and specific surface.

Cobalt nanoparticles formed in polysiloxane copolymer micelles: effect of production methods on magnetic properties

The effect of production method on the chemical and magnetic stability of a range of cobalt nanoparticles formed in polysiloxane copolymer micelles was studied. The nanoparticles were suspended in polydimethylsiloxane (PDMS) carrier fluids and are prototypes for use in biomedical applications. Three families of particles were investigated: cobalt particles in triblock copolymer micelles and silica-coated cobalt particles where the silica coating is formed either in toluene or PDMS carrier fluid. The silica coating effectively protects the cobalt particles from ongoing oxidation, with little change in the saturation magnetization of the particles observed over time and only a small shift in the centre of the field-cooled hysteresis loop observed. Temperature-dependent magnetization measurements show that the silica-coated particles have superparamagnetic blocking temperatures of 100–130 K compared with the non-silica-coated particles, which do not reach their characteristic blocking temperature below the melting point of the frozen fluids. This result is interpreted as a smaller magnetic core size in the silica-coated particles. The zero-field-cooled temperature-dependent magnetization of the silica-coated particles has two apparent superparamagnetic blocking temperatures, with a second, lower blocking temperature of approximately 15 K. This second apparent blocking temperature may be due to unreacted cobalt clusters in the suspensions or, alternatively, due to surface states on the nanoscale cobalt particles. The prototype silica-coated cobalt particles show promise for potential biomedical applications.

The effects of production methods on the microstructures and mechanical properties of an aluminum bronze

The purpose of this study is to investigate the mechanical properties and microstructures of an aluminum bronze subjected to some physical treatments. In particular, the solidification structure, the effects of solution treatment, tempering heat treatment and mold types on the microstructure of the aluminum bronze produced in two different molds are examined. The results showed that the heat treatments have some interesting effects on the mechanical properties, microstructures and phase transformation temperatures of the samples. It was obtained that α+β 1 and α+β 1′ phase transformation were formed depending on both the die casting and the heat treatments, but in contrast α+β phase was formed in the sand-casting specimen.

Carbonization of some fast-growing species in Sudan

Four wood species, indigenous Acacia seyal (talh) and exotic fast-growing Conocarpus lancifolius (damas), Eucalyptus microtheca (kafur) and Prosopis chilensis (mesquite) grown in Sudan, were assessed and compared as raw materials for charcoal making. The effects of production method (traditional earth mound and improved metal kiln) and the physical and chemical properties of the wood and bark on the yield and quality of charcoal produced were assessed. Regression analyses of wood properties and heat value data indicated high negative correlations of the wood heat value with holocellulose and ash, and high positive correlations with wood density, lignin, and alcohol-benzene and hot-water solubles. Carbonization with the Tropical Products Institute metal kiln produced higher yields (33%) than the traditional earth mound (27%), although the difference in energy transformation yields was found to be insignificant both between appliances and species. Charcoal produced by the earth mound had a slightly higher density and was more resistant to shatter, but no significant differences were recorded with respect to the water boiling test or the gross heat value. The exotic species studied gave equal or better charcoal, in terms of yield and quality, compared with the traditionally preferred talh.

Effect of production method on the systemic clearance rate of a human monoclonal antibody in the rat

Pharmacologic studies of human immunoglobulins (IgM) in non-primate animal models, whether directed toward efficacy or toxicity, rely on pharmacokinetic parameters to achieve optimal doses and schedules. In rodents, human IgMs have an effective circulatory half-life of 11 h and a plasma clearance rate of 0.044 ml/min/kg. Studies of a new group of human monoclonal antibodies (hMAb) specific for Gram-negative bacteria and endotoxin revealed an IgM molecule, hMAb-10058, which, when purified from tissue culture medium, exhibited a suprisingly short circulatory lifetime in rodents. Investigations into possible explanations for this short circulatory half-life resulted in the development of a simple and efficient method for producing hMAbs in the immunodeficient NIH-3 mouse (bg x nu x XID). This method of production of hMAb-10058 had dramatic effects on its half-life. Whereas hMAb-10058 produced in serum-free, defined medium had a clearance rate of 14.4 ml/min/kg and an effective half-life of 0.12 h, the same hMAb-10058 raised in mouse ascites had a decreased clearance rate of 0.092 ml/min/kg and an increased effective half-life of 12 h. This 100-fold enhancement of the hMAb's half-life was not affected by the purification process. Some potential molecular structures involved in the circulatory half-life of this hMAb are discussed.

Effect of production method on distribution of fatty acis

It would appear that the best method of the three investigated for preparing a labelled fatty acid to be used in nuclear cardiology is to autoclave an omega-brominated fatty acid in the presence of radioiodine, resuspend the labelled preparation in Tween 80∶D5W: propylene glycol (10∶80∶10) and sonicate it for 30 minutes. Care must be taken when injecting Tween although no adverse effects were noted during the present study.