Effect Of Technological Parameters Research Articles

Effect of the technological parameters on the properties of granular porous crystal glass material based on zeolite-bearing rock

The effect of various technological parameters in the production of light porous granular crystal glass material based on zeolite-bearing rock is studied. To produce light porous crystal glass material at temperatures corresponding to the foam-glass production technology (800–900°C), the mix must be presintered at 700°C. It is found that increasing the fineness of the milling of the fritted mix to particles sizes smaller than 0.08 mm decreases the bulk density of the granular zeolite foam.

Impact of materials science and stereology on the design of experiments in concrete technology

Experimentation in concrete technology relies heavily on correct fulfilment of the various sampling principles from stereology and materials science. Random sampling is uneconomical and technically difficult, hence in this paper it is replaced by orthogonal tripod (orthrip) sampling. It is indicated how the efforts can be minimised. The cases of dispersed fibres and cracks are elaborated, making use of projections and sections. Size sampling is a major issue in the paper, requiring introduction of the materials science principles of stochastic heterogeneity and structural sensitivity. Samples are generally of subrepresentative size in concrete technology, so that the estimated characteristics of material structure or properties that are to some degree dependent on configuration (instead of solely on composition) will be biased. Yet comparison of the effects of technological parameters can be achieved in an unbiased way when sample size and sensitivity of observations are fixed proportions of the respective representative elements. This is illustrated with two examples.

Macro- and microdispersion of carbon black in liquid silicone rubbers

A correlation between the online during mixing measured conductance of carbon black (CB) filled silicone rubber and macrodispersion of CB determined by optical microscopy and microdispersion analysed by AFM has been established. The online conductance is a suitable tool to characterise the effect of technological parameters (e.g. rotor type, speed, mixing temperature) and material parameters (matrix viscosity, CB type and content) on the macro- and microdispersion directly during the mixing process. Thus, a modified method of the online conductance measurement can be used as the in-process method for monitoring the production process of electrical conductive polymer materials with low viscosity, e.g. liquid silicone rubbers.

Technological developments in making polypropylene surgical monofilaments

Special technology has been developed for the production of polypropylene surgical monofilaments to meet medical needs for a suture material meeting tight specifications for physical and mechanical properties. To produce polypropylene monofilaments having improved elastic properties and strength, studies have been made on the effects of technological parameters (temperatures of liquid and of cooling bath, molding rate, thermal drawing ratios and temperatures, the thermal stabilization temperature, and temperature of additional thermal treatment of existing monofilaments with or without shrinkage) as regards the strength, elongation, the strength and elongation in knots, and bending rigidity. Conditions are given for making surgical monofilaments of various diameters with improved manipulation and strength.

Effect of dynamics on the process of formation of holes during honing

A model of the process of honing holes with a specified initial error of the surface shape is developed. The process of improvement of the error of the shape of holes during the treatment is numerically analyzed. The tool shaft is schematized as a rotating rod transmitting rotation to a hone holder with cutting bars and guide bars elastically mounted on it. Cutting forces are modeled as friction forces that depend on a normal pressure on a contact surface, and removal of allowance during passage of the surface by cutting bars is modeled according to Preston’s hypothesis. The effect of technological parameters on integral criteria of treatment quality is analyzed.

Whey Starter for Grana Padano Cheese: Effect of Technological Parameters on Viability and Composition of the Microbial Community

This work aimed to investigate the effects of thermal treatments and yeast extract addition on the composition of the microbial community of natural whey starters for Grana Padano cheese. Different natural whey starter samples were held at 4°C for 24h (cooling treatment), or at −20°C for 24h (freezing treatment) to evaluate the possibility of conservation, or at 54°C for 1h (heat treatment) to evaluate the effect of the temperature commonly used during curd cooking. Separately, another set of samples was enriched with 0.3, 0.5, and 1.0% (wt/vol) of yeast extract to study its effect on the growth of lactic acid bacteria (LAB) in the starter. The new approach in this study is the use of 2 culture-independent methods: length heterogeneity (LH)-reverse transcription (RT)-PCR and fluorescence microscopy. These techniques allowed us to easily, quickly, and reproducibly assess metabolically active LAB in the control and treated samples. The LH-RT-PCR technique distinguished microorganisms based on natural variations in the length of 16S rRNA amplified by RT-PCR, as analyzed by using an automatic gene sequencer. Fluorescence microscopy counts were performed by using a Live/Dead BacLight bacterial viability kit. The repeatability of LH-RT-PCR showed that this technique has great potential to reveal changes in the microbial community of natural whey starters for Grana Padano cheese. All species showed low sensitivity to cold (4°C). However, after the freezing (−20°C) and heating (54°C) treatments, different behaviors of the species were reported, with significant changes in their viability and relative composition. Heating treatment during curd cooking profoundly affected the viability and composition of the community that remained in the cheese and that consequently modified the microbial population. At the same time, this treatment produced the selection of LAB in whey and could be considered as the first step in natural whey starter production. Addition of yeast extract stimulated the growth of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. lactis to the detriment of Lactobacillus helveticus species. Because the yeast extract altered the microflora balance, whey starter conservation at −20°C and yeast extract addition cannot be suggested as technological innovations.

Preparation and Performance of Ceramic Coatings Formed by Micro Arc Oxidation on Titanium Alloy

The effect of technological parameters on MAO ceramic coating were investigated through the technique of micro-arc oxidation (MAO) on TC4 titanium alloy and. Microstructure and morphology of coatings were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result shows that electric parameters and compositions of the electrolyte have notable effects on the growth of MAO ceramic coatings. The cathodic and anodic voltage rise gradually with the oxidation time increasing. The growth rate of ceramic coating is fast at the beginning, and then turns slowly. The ceramic coatings can be divided into three layers from interior to exterior, such as the transition layer, the dense layer and the porous layer. The coating is mainly composed of rutile and anatase and combined with the substrate firmly. The ceramic coating’s composition in inner and outer layers appears quite different. The ceramic coating on titanium alloy is of excellent performance on anti-attrition and anti-corrosion.

Effect of technological parameters on the properties of Cuo-TiO2 sol-gel films

The effect of technological parameters on the properties of 2-and 42-day film-forming solutions of the system CuO-TiO2 is analyzed. It is found that the initial components have a strong effect on the maturing of film-forming colloidal solutions (FCS) and the properties of coatings. The properties of coatings obtained from solutions of different age are associated with changes in their microstructure. The index of refraction and the thickness of the films from 42-day FCS are essentially independent of the calcination regime; the variation of the refractive coefficient and chemical stability is inconsistent.

Characterization of the porous structure of carbon materials by means of density functional theory

Nitrogen adsorption isotherms were analyzed using density functional theory (DFT) to characterize active carbons. It is shown how the effect of technological parameters on the structure of active carbons can be revealed with the help of DFT. DFT is used to analyze the pore-size distribution and to determine the pore surface area for active carbons of different types.

Study on the Mechanism about the Effect of Technological Parameters on Performance of Fiber Coupler

To find out the effect mechanism of technological parameters on the performance of fiber coupler, the relationship between the technological parameters and the optical performance is investigated by using a six-axes optical fiber coupler machine as experimental setup. It is discovered that the technological parameters such as drawing speed and fused temperature have a great effect on optical performance of fibre coupler. The fused region and taper region of fiber coupler are tested with scanning electron microscope (SEM). It is discovered that there are crystalline grains in the fused region. And the crystalline grains decrease while drawing speed increase. In the taper region, there are micro cracks. And the cracks are more obvious while drawing speed increases. When the fused temperature is above some point (here is 1350), the micro cracks in the taper region disappear and the optical performance of fiber coupler is the highest at this time.

Effects of technological parameters on the microstructure of laser remelted hydroxyapatite (HA) coatings

In this paper, the influence of different laser power and scanning speed on the microstructure of laser remelted as-sprayed hydroxyapatite (HA) coatings was studied and the optimum technological parameters were obtained. The morphologies, elements and phase analysis of both sprayed and remelted coatings were examined by means of electron probe microanalysis, x-ray diffraction and so on. The results show that the plasma sprayed coatings could be improved by laser remelting and the optimum technological parameters are that the laser power is 600 W and the scanning speed is 11.2 mm s−1. In the technological condition, the remelted coating which has compact columnar and cellular dendritic crystal consists of HA, α-TCP, CaO and TiO2 phases, and the Ca/P ratio of the coating is the most approximate to that of HA. When increasing the laser power and slowing the scanning speed, the structure of the coating will become much coarser and the Ca/P ratio will deviate more from that of HA. On the contrary, if the laser power is reduced and the scanning speed is accelerated, the influence of technological parameters of laser remelting on the sprayed coating will be weakened.

Effect of technological parameters of the diffusion bonding of VT alloy on the quality of welded joints

Effect of technological parameters of the diffusion bonding of VT alloy on the quality of welded joints

Mechanical properties and modelling of a hydrophilic composite used as a biomaterial

Artificial ligaments were fabricated by reinforcing a hydrophilic thermoplastic polyurethane matrix with poly-ethyleneterephtalate (PET) fibres, using the filament winding technology. The specimens were then tested in simple tension to measure the mechanical properties of the artificial ligaments. In order to investigate on the effect of technological parameters, three types of windings were manufactured, each type being identified by the winding angle and the fibre volume fraction that were used. Moreover, a certain amount of the PET fibres was plasma-treated before winding, so composite ligaments reinforced with plasma-treated fibres were obtained. All of the artificial ligaments displayed the typical J-shaped stress–strain curve of natural ligaments, the plasma-treated ones mainly exhibiting a smaller toe region. A mathematical model is proposed to predict the mechanical behaviour of the artificial ligaments. The model is able to reproduce the behaviour of the artificial ligaments, especially the ones reinforced with plasma-treated fibres, and can be further used to simulate the behaviour of artificial ligaments subject to a more physiological deformation history, such as the combination of tension and torsion.

Preparation and properties of 4.25Cu-0.75Ni/NiFe2O4 cermet

4.25Cu-0.75Ni/NiFe2O4 cermets were prepared by doping NiFe2O4 ceramic matrix with the mixed powders of Cu and Ni or Cu-Ni alloy powder as the electrical conducting metallic elements. The effects of technological parameters, such as the adding modes of metallic elements, the ball milling time, the sintering time and the sintering temperature, on the relative density and resistivity of the cermets were studied. The results show that the resistivity of 4.25Cu-0.75Ni/NiFe2O4 cermets decreases with increasing temperature, and has a turning point at 590 °C, which is similar to that of NiFe2O4 ceramic. The sintering temperature and adding modes of metallic elements have a great influence on the properties of 4.25Cu-0.75Ni/NiFe2O4 cermets. When the sintering temperature increases from 1200 °C to 1300 °C, the relative density increases from 89.86% to 95.33%, and the resistivity at 960 °C decreases from 0.11 Ω · cm to 0.03 Ω · cm, respectively. When the metallic elements are added with the mixed powders of Cu and Ni, the cermets of finely and uniformly dispersed metallic phase, high density and electric conductivity are obtained. The relative density and resistivity at 960 °C are 90.23% and 0.04 Ω · cm respectively for the cermet samples sintered at 1200 °C for 2 h, which are both better than those of the cermets prepared under the same technique conditions but with the metallic elements added as 85Cu-15Ni alloy powders.

Technology and interface structure for diffusion bonding of Fe3Al/18-8 dissimilar materials

The effects of technological parameters on the interface morphology and shear strength of Fe3Al/18-8 diffusion bonded joints have been researched by means of a JXA-80 scanning electron microscope (SEM) and a digital tensile press test machine. Microstructural characteristics and fracture morphology near the Fe3Al/18-8 diffusion interface, obtained under conditions of various technological parameters, have been analysed using the SEM. The test results indicate that a diffusion bonded joint with higher shear strength (στ = 226 MPa) may be obtained with a heating temperature T = 1020 – 1040°C, holding time t = 45 – 60 min and pressure P = 12 – 15 MPa.

Drain disturb during CHISEL programming of NOR flash EEPROMs-physical mechanisms and impact of technological parameters

The origin of drain disturb in NOR Flash EEPROM cells under channel initiated secondary electron (CHISEL) programming operation is identified. A comparative study of drain disturb under channel hot electron (CHE) and CHISEL operation is performed as a function of drain bias and temperature on bitcells having different floating gate length and junction depth. The disturb mechanism is shown to originate from band-to-band tunneling under CHISEL operation, unlike that under CHE operation that originates from source-drain leakage. The effect of technological parameters (channel doping and drain junction depth) on CHISEL drain disturb is studied for both the charge gain (erased cell) and charge loss (programmed cell) disturb modes. Fullband Monte Carlo device simulations are used to explain the experimental results. It is shown that methods for improving CHISEL programming performance (higher channel doping and/or lower drain junction depth or halo) increase drain disturb, which has to be carefully considered for efficient design of scaled cells.

Modeling and simulation of 3D thermal stress in solidification process of large-sized castings

When heavy machines and receiving system of communication arc manufactured, it always needs to produce large-sized steel castings, aluminum castings and etc. Some defects of hot cracking by thermal stress often appear during solidification processes as these castings arc produced, which results in failure of castings. Therefore predicting the effects of technological parameters for production of castings on the thermal stress during solidification processes becomes an important means. In this paper the mathematical models have been established, and numerical calculation of temperature fields by using finite difference method (FDM) and then thermal stress fields by using finite element method (FEM) during solidification processes of castings were carried out. The technological parameters of production were optimized by results of calculation and the defects of hot cracking were eliminated. Modeling and simulation of 3D thermal stress during solidification processes of large-sized castings provided a scientific basis, which promoted further development of advanced manufacturing technique.

Effects of Technological Parameters and Fishing Ground on Quality Attributes of Thawed, Chilled Cod Fillets Stored in Modified Atmosphere Packaging

Effects were studied of various technological parameters and fishing ground on quality attributes of thawed, chilled cod fillets stored in modified atmosphere packaging (MAP). Frozen fillets of Baltic Sea and Barents Sea cod, representing two commercial fishing grounds, were used as raw material. The parameters investigated were: (1) packaging in modified atmosphere during frozen storage, (2) frozen storage period and temperature, (3) fishing ground and chill storage temperature, together with (4) the addition of trimethylamine oxide (TMAO) and sodium chloride (NaCl) to cod fillets before freezing or after freezing and thawing. Application of MAP during frozen storage resulted in a significant increase in the drip loss of thawed, chilled MAP cod fillets but none of the other quality attributes studied were influenced by this treatment. This implies that packaging cod fillets without MAP during frozen storage is more appropriate for manufacturing of thawed chilled MAP cod fillets. During chill storage of thawed MAP Barents Sea fillets previously kept at −30°C for 15 weeks, significant growth of Photobacterium phosphoreum and production of trimethylamine were observed. On the contrary, P. phosphoreum growth and trimethylamine production in thawed and chill-stored MAP Baltic Sea cod fillets were strongly inhibited after as little as 4 weeks of frozen storage at 30°C. Contents of trimethylamine oxide and NaCl were substantially higher in fillets of Barents Sea cod compared to fillets of Baltic Sea cod. Therefore, addition of trimethylamine oxide and NaCl to Baltic Sea cod fillets was evaluated and shown to protect P. phosphoreum against frozen storage inactivation and this explained the observed differences in growth of the spoilage bacteria and trimethylamine production between thawed and chill stored MAP fillets from the two fishing grounds. Despite modest production of trimethylamine in Baltic Sea fillets, this cod raw material was less suitable for production of thawed MAP products due to high drip losses during chill storage.

Effect of technological parameters on the characteristics of kasseri cheese made from raw or pasteurized ewes’ milk

Two groups of kasseri cheese (pasta filata type) were manufactured from raw or pasteurized ewes’ milk, without starter cultures. Cheeses of each group were divided into two subgroups: the first was ripened and stored at 4°C and packaged in plastic film; the second ripened and stored at 15°C and coated with paraffin wax. Milk pasteurization and technological parameters had a significant effect on the pH ( P < 0.05), while only technological parameters had an effect on the total solids content. At day 120, the range of mean cfu/g counts for the mesophilic aerobic flora was 9.5 × 107−1.4 × 108; for the thermophilic streptococci, the range was 2.6 × 107−7.6 × 107; and for the thermophilic bacilli, 9.8 × 106−1.7 × 107. Changes in the N fractions became significant after 30 days of ripening. For mature 120‐day‐old cheeses, the percentage of total N soluble at pH 4.6 was 22.7%–22.9% in raw milk cheeses and 19.0%–21.7% in pasteurized milk cheeses. The percentage of total N soluble at 12% TCA was 10.1%–12.2% in raw milk cheeses and 7.3%–11.5% in pasteurized milk cheeses; the percentages of total N soluble at 5% PTA were 3.1%–4.0% and 2.6%–3.6%, respectively. The residual αs‐casein percentages at day 120 ranged between 63% and 78% of the respective area at day 1; the residual β‐casein ranged between 67% and 75%. There were some characteristic differences in the reverse phase‐HPLC peptide profiles of the four cheeses. In general, the effect of the different ripening conditions was more pronounced in cheeses made from pasteurized milk.

Effect of some technological parameters on Fowler–Nordheim injection through tunnel oxides for non-volatile memories

In this work the effects of various technological parameters on Fowler–Nordheim injection through thin (around 7.2 nm) silicon dioxide films in metal-oxide-semiconductor capacitors have been studied. Attention has been paid to the effect of gate geometry (round or strip gate) and area, substrate doping type (boron or phosphorus one), polycrystalline silicon gate structure (simple polysilicon or polysilicon-oxide-nitride-oxide-polysilicon structure) and tunnel oxide type (standard or nitrided silicon dioxide). The effect of all these parameters on Fowler–Nordheim tunneling injection and on the potential barrier height at both oxide injecting interfaces are usually neglected in literature and moreover the tunnel coefficients obtained from a simple capacitor are used in the simulation of programmable operations of electrically erasable programmable read only memories. Quasi-static capacitance (voltage) and current (voltage) measurements have been performed and the latter have been simulated by using a constant effective barrier height at the injecting interface. We have found that Fowler–Nordheim tunneling parameters and potential barrier height at both oxide injecting interfaces are affected by the substrate doping type, oxide type, gate geometry and gate structure but they are not affected by the gate area. Moreover in all structures, a difference between the barrier heights at the two injecting interfaces has been observed. The variation induced by the studied technological parameters on the potential barrier height are comparable to the variation induced by considering a constant (classical theory) or electrical field dependent (quantum theory) barrier height as reported in literature.