Influence Of Processing Temperature Research Articles

Influence of process temperature on ethanol content in kombucha products obtained by fermentation of flotated must effluent

The aim of this paper was ethanol content determination in kombucha products obtained by fermentation of effluent from white wine production. Used substrate contained 5% of total sugars and production process was conducted at 20, 25 and 30?C. Ethanol was determined by volumetric method common for ethanol determination in refreshing non-alcoholic beverages. Winery effluent was successfully applied in kombucha fermentation process. Results indicated that the produced kombucha beverages are suitable for human consumption as non-alcoholic beverages. Only products obtained at 30?C (the sixth day) and at 20?C (the sixth and the ninth day) do not belong to the group of non-alcoholic beverages. Certain process parameters were established in order to produce suitable kombucha product.

Effect of Temperature on Grain Size in AA6063 Aluminum Alloy Subjected to Repetitive Corrugation and Straightening

The influence of processing temperature on grain size reduction in AA 6063 aluminum alloy subjected to repetitive corrugation and straightening (RCS) is investigated in this work. The aluminum alloy was processed by RCS at different temperatures (room temperature, 100 °C, 200 °C and 300 °C) till the maximum number of passes possible before failure and the mechanical properties such as tensile strength and hardness were measured. The grain size and their misorientation of grains of the processed samples were analyzed using the electron backscattered diffraction. The results indicated that the transformation of low-angle grain boundaries to high-angle grain boundaries and dislocation tangles were highly dependent on the strain imparted, which could be controlled by selecting the proper processing temperature. As a result, the mechanical properties are affected. In particular, the room temperature tensile strength and hardness values of the processed material decrease with increasing processing temperature.

The initiation stage of Food Court Waste during air versus steam gasification processes

Using different gasification agents: air and steam, two types of gasification process were performed into a batch reactor at temperature of 750°C and 850°C and atmospheric pressure. The only difference between of the two compared experimental configurations was represented by the gasification agent used in the process. The amount of oxygen introduced into the reactor for air gasification at an ER of 0.3 was computed. Therefore, in the steam gasification process, the same amount of oxygen was introduced, so establishing an unordinary steam to biomass ratio. In this way, the two processes, air vs. steam gasification, were compared, the rest of the process parameters being kept constant. This paper approaches the transitory regimes (initiation stage) of gasification process in order to observe the influence of process temperature and gasification agent on the process run. According to the experimental results, better gas quality is obtained if steam is used as a gasifying agent, yet the conversion and energy efficiencies decreases. By optimizing time residence in steam gasification, process efficiencies may be increased.

Processing temperature dependent chemiresistive performance of spin-coated cerium oxide films

Abstract An influence of processing temperature on structural, morphological, and chemiresistive properties of cerium oxide (CeO2) films, deposited on glass substrate by a spin-coating method and composed of nanocrystallites (NCs), has been systematically investigated and reported. As-deposited CeO2 films demonstrate the cubic polycrystalline crystal structure and mixed-agglomerated type of surface morphology with several crevices, elevating easy and deep percolation to gas molecules for enhanced adsorption-desorption process. Chemiresistive gas sensing performance of CeO2 films studied to various target gases and operating temperatures; demonstrates excellent selectivity, rapid response/recovery time signatures, and consistent operation repeatability to nitrogen dioxide (NO2) gas @200 °C, over other target gases, along with superior response repeatability. The response signature of sensor increases from 6% to 45% when NO2 gas ppm level is increased from 5 to 100. Chemiresistive change in the CeO2 film sensor in presence of NO2 gas has been studied thoroughly and explored using band model and impedance spectroscopy analysis.

Influence of processing temperature on the reaction product and strength gain in alkali-activated fly ash

The roles of temperature and curing periods on product formation and strength gain in alkali activation of low-calcium siliceous fly ash are evaluated. Higher temperature favors the kinetics of amorphous reaction product formation and inclusion of Si in the reaction product, which accompanies the densification of the microstructure. Following initial curing at 60 °C, the reaction product continues to form in the activated system on decreasing the temperature to 25 °C. Initial curing at 25 °C does not lead to formation of reaction product. Reaction product forms in the system for initial curing temperature of 40 °C and higher. The rate of the solid-based reaction, after hardening, is increased by temperature. The total amorphous reaction product content formed in the system depends on the water to solids ratio of the activated mix. The amorphous product composition, however, varies with temperature. With time there is an increase in the Si/Al ratio in the reaction product formed 40 °C and higher. For initial curing at 60 °C, there is no increase in the Si/Al ratio in the reaction product when the temperature is decreased to 25 °C. Reaction product with a higher Si/Al atomic ratio achieves a higher ultimate compressive strength. On increasing the Si/Al ratio in the reaction product from 2.5 to 3.3, the ultimate compressive strength achieved increased from 60 MPa to 74 MPa. Early curing, immediately after mixing, at a higher temperature is critical in achieving a higher Si/Al atomic ratio in the reaction product. Optimum initial curing time at high temperature is based on achieving a high Si/Al atomic ratio in the reaction product.

Numerical modelling of thermoplastic resin behaviour for thermoforming of laminates composed of non-crimp fabrics

Although composite materials have been used for many years in aeronautic and defense industries, the interest in the automotive industry has grown only recently. However, since they are expensive, aeronautic materials cannot be directly used for automotive and new woven fiber composites are being developed such as Non-Crimp Fabrics (NCF) with thermoplastic resin. Woven fiber composite material properties depend on many parameters such as non-linearity of tensile stiffness in yarn direction, shearing effect between fibers, temperature and strain rate dependency. Numerical simulation becomes a helpful tool which can be used to estimate the risk of defects after forming. A reliable characterization of resin behavior with respect to the process temperature and speed will allow users to optimize the process and reduce development cycles.In this study, we investigate a method to model a NCF thermoplastic composite taking into account both thermal and strain rate dependency using the non-linear finite element solver RADIOSS®. A new multi-layer property is used to model the NCF resin and fabric components. Fibers are modeled with a hyper-elastic anisotropic fabric material model available in RADIOSS, and the resin is modelled as an elastoplastic thermal and strain-rate dependent material. The laminate behavior is characterized using data from Bias tests in two different directions and validated process simulation. A numerical study is used to show the influence of process temperature and speed on the final shape and presence of defects. The first section in your paper

Effect of Thermal Treatment on Selected Fire Safety Features of Tropical Wood

The subject matter of the article is thermally modified tropical wood (Meranti and Merbau) and its reaction on fire. Thermal treatment of wood (thermal wood) is a new technology of wood treatment improving its physical and biological properties and increasing its resistance to biological wood destroying processes and atmospheric effects. The fire and technical properties of thermal wood, especially its reaction to fire, have not been studied sufficiently. The latter is the subject matter of this article. A comparison is made to describe the influence of process temperatures of the thermal modification of selected tropical woody plants. Experimental equipment was non-standardized laboratory equipment using a flame source of higher intensity (flame burner - propane-butane) affecting the test sample in an open environment. This is a simulation of an actual fire. The performance of the thermally treated wood (20 °C, 160 °C, 180 °C) is evaluated by measuring the weight loss and the burning rate. The results are presented in tables and diagrams and are statistically evaluated. This study investigated the effects of the thermal treatment of Merbau and Meranti wood on selected burning characteristics. The results obtained from raw (untreated) wood test specimens were compared to results obtained from the test specimens subjected to thermal treatment at 160 °C, 180 °C and 210 °C. The monitored characteristics were weight loss and the burn rate. The results showed that the thermal treatment of Merbau and Meranti wood significantly increased its flammability and accelerated its combustion. In addition, its burn rate was higher than in untreated wood, reflecting that it is necessary to add fire retardants to thermally treated Merbau and Meranti wood.

PRODUCTION OF CASTOR OIL MALEATE USING DI-TERT-BUTYL PEROXIDE AS FREE RADICAL CATALYST

Abstract Castor oil maleate is used in healthcare products, synthetic lubricants, drying oils, water-soluble paints and as a monomer in several polymers. This compound is formed by direct reaction between castor oil and maleic anhydride, which can be accelerated using free radical catalysts. In this work, the influence of processing temperature and the concentration of di-tert-butyl peroxide (DTBP) in the production of castor oil maleate was studied applying response surface methodology. The results showed that the use of the radical initiator increased the rate of reaction, leading to a shorter reaction time and higher productivity. The optimal operating condition was found at 120oC, 1 mol of maleic anhydride/mol of castor oil and 0.005 mol of DTBP/mol of castor oil, yielding 90.2% of castor oil maleate in 90 min.

A comparison of the torrefaction behavior of wood, miscanthus and palm kernel shells: Measurements on single particles with geometries of technical relevance

A torrefaction test rig was designed to investigate large single biomass particles up to characteristic sizes of 25 mm, typical for industrial reactors. Time-resolved mass loss for such particles is measured with a magnetic suspension balance at well-defined torrefaction conditions (temperature, residence time, gas atmosphere). This paper comprises the results of woody and non-woody biomass: pine, a coniferous, and beech, a deciduous, wood, palm kernel shells and miscanthus. Influence of process temperature (240 to 320 °C), residence time (up to 1 h) and type of solid biomass on time-resolved mass loss is presented. Additional tests with oxygen in the process gas (0–15 vol%), typical for industrial torrefaction systems, are carried out for selected samples of beech wood. The differences in torrefaction behaviour of bark, sap- and heartwood of pine are evaluated. Finally, it is shown that the torrefaction reactor developed allows to derive kinetic parameters for mass loss. At temperatures up to 300 °C the mass loss for palm kern shells is highest followed by miscanthus, and pine. By examining pine, as an example, it is shown that heartwood is significantly more reactive than sapwood and bark. Finally, it is demonstrated, that for the particle sizes considered here heat and mass transfer limitations can be neglected for the determination of torrefaction kinetics. Kinetic data agree well with data from literature.

Polymer Analyses for an Adapted Process Design of the Pipe-Extrusion of Polyetherimide

Over the last years, the use of high performance thermoplastic materials increased significantly especially in aviation applications. Thus, the processing of these high temperature polymers became more and more interesting. Especially, the groups of polymers like polyphenylene sulfide (PPS), polyether ether ketone (PEEK) or polyetherimide (PEI) are in the focus of recent developments and investigations. These materials show excellent thermal, mechanical and chemical properties while processing remains still challenging. Especially the influence of processing temperatures, temperature depending viscosities, the specific heat capacities and the thermal expansion show a high impact to the quality of the produced parts, e.g. degradation and dimensionally stability. Thus, this paper shows experimental characterizations in regard to the processing of PEI by pipe extrusion processes. In this context, a suitable methodology for the determination of appropriate process parameters is shown, which includes the comprehensive determination of temperature dependent thermal, thermomechanical and degradation properties of specific PEI extrusion materials.

Influence of processing temperature on flux decline during skim milk ultrafiltration

The flux decline behaviour during skim milk ultrafiltration (UF) was investigated at 10 °C, 30 °C and 50 °C. Despite higher fluxes, UF processing at higher temperatures resulted in higher magnitudes and rates of irreversible fouling. Fouling in this temperature range was primarily proteinaceous, consisting of mainly peptides and alpha-lactalbumin (α-LA), with minor amounts of beta-lactoglobulin (β-LG) present only at 50 °C. The increase in fouling resistance with processing temperature was concluded to be mainly due to increased pore fouling by α-LA deposition, and in part to β-LG deposition at 50 °C. These are attributed respectively to the thermal expansion of membrane pores and reversible conformational changes of β-LG.

Influence of processing temperature and precursor composition on phase region of solution processed methylammonium lead iodide perovskite

Solution processed organic–inorganic metal halide perovskite and its derivatives are promising in the development of efficient thin film photovoltaic devices. In the context of increasing the efficiency and sustainability of perovskite solar cells (PSC) devices, we have attempted to experimentally develop phase diagram for solution processed methyl ammonium lead iodide (CH3NH3PbI3 (MAPbI3)) perovskite. The phase diagram emphasized the role of processing parameters (precursor composition and crystallization temperature) on the crystallographic functionality and optical band gap of perovskite. The phase dynamics of low dimensional perovskite, which has emerged as a potential candidate for absorber layer in perovskite solar cells (PSC) with higher stability in ambient conditions is also discussed. We observed that crystallization via non-equilibrium annealing introduced lattice strain in perovskite which affected the crystallographic properties of perovskite. A highly crystalline perovskite, with large grain size was obtained by optimizing the crystallization parameters and precursor composition together with nucleation of perovskite crystal and its growth dynamics.

Inductively and capacitively coupled plasmas at interface: A comparative study towards highly efficient amorphous-crystalline Si solar cells

A comparative study on the application of two quite different plasma-based techniques to the preparation of amorphous/crystalline silicon (a-Si:H/c-Si) interfaces for solar cells is presented. The interfaces were fabricated and processed by hydrogen plasma treatment using the conventional plasma-enhanced chemical vacuum deposition (PECVD) and inductively coupled plasma chemical vapour deposition (ICP-CVD) methods The influence of processing temperature, radio-frequency power, treatment duration and other parameters on interface properties and degree of surface passivation were studied. It was found that passivation could be improved by post-deposition treatment using both ICP-CVD and PECVD, but PECVD treatment is more efficient for the improvement on passivation quality, whereas the minority carrier lifetime increased from 1.65×10−4 to 2.25×10−4 and 3.35×10−4s after the hydrogen plasma treatment by ICP-CVD and PECVD, respectively. In addition to the improvement of carrier lifetimes at low temperatures, low RF powers and short processing times, both techniques are efficient in band gap adjustment at sophisticated interfaces.

Tunable electron affinity with electronic band alignment of solution processed dielectric

We report the tunability of the electronic band structure, especially the electron affinity, of an all-inorganic precursor processed sol-gel aluminium oxide phosphate dielectric by the influence of processing temperature. The dielectric offers tunable electron affinity ranging from 1.42 eV to 0.72 eV with the change in processing temperature from as-prepared to 1000 °C, respectively. The remarkable change in electron affinity is ascribed to the variation in the bulk oxygen concentration in solution processed oxide. As a result, the leakage current of the dielectric is affected significantly by a factor of ∼103.

The Effects of Nb and Mo Addition on Microstructure and Mechanical Behaviour of Ti-6Al-4V Alloy

The effects of Nb and Mo addition, with different contents, on the microstructure and some mechanical properties of Ti-6Al-4V alloy were investigated. Treatments were performed at various high temperatures about 1200 and 1300 °C for 3h using vacuum furnace as first treatment and using an argon atmosphere as second treatment. The samples were characterized by X-ray diffraction and the influence of processing temperature on microstructure was studied, the microstructural evolution was evaluated by optical microscopy and SEM. The results revealed that the Nb and Mo elements added to the titanium alloy stabilized the β phase and changed the lattice parameters of α phase. Microstructural observations, phase analysis shown that Ti-6Al-4V alloy contain single phase and increasing Nb and Mo contents the equiaxed grain is refined, and reduction in the prior β grain size. Moreover, Nb/Mo addition up to 10 wt.% increases the volume fraction of β phase in the microstructure. Some mechanical properties such as hardness, Young's modulus and fracture toughness were achieved and tensile test was performed at room temperature. Experimental results revealed good mechanical properties including a low Young's modulus and high deformability, the hardness values of the alloy is about 350-570 HV and the fracture toughness values K<sub>IC</sub> are ranging from 16.8 MPa m<sup>1/2</sup> to 28.5 MPa m<sup>1/2</sup> depending on Nb/Mo contents.

Studying the Influence of Temperatures, Used for Processing ABS, PA 6.6 and POM, on Certain Electrical Properties, when Injection Moulding Items for the Automotive Industry, by Methods Employed for Determining Relative Permittivity and the Dielectric Dissipation Factor

This paper analyses the influence of processing temperatures of acrylonitrile butadiene styrene (ABS), polyamide 6.6 (PA 6.6) and polyoxymethylene (POM) on some electrical properties when injecting items used in the automotive industry. The ABS specimens were made at the following injection temperatures: 220, 230, 240 and 250�C. The PA 6.6 specimens were made at the following injection temperatures: 280, 290, 300, 310 and 320�C. The POM specimens were made at the following injection temperatures: 180, 190, 200, and 210�C. The determination of electrical properties were carried out using the methods for determining the relative permittivity and the dielectric dissipation factor using zero method with Schering bridge. It was found in the three polymers analysed that the temperature rise processing by injection leads to insignificant changes in relative permittivity (er) and dielectric dissipation factor (tgd).

Structure–Property Correlation of Al–SiC–Al2O3 Composites: Influence of Processing Temperatures

This paper deals with the change in the mechanical behaviour of aluminium alloy 6061 with different weight percentage of Silicon Carbide (SiC) and Alumina (Al2O3) ceramic powders and change in processing temperature. The crucial properties of this aluminium alloy are relatively light in weight, better corrosion resistance, wear resistance and have low production cost. These properties make them pleasant for different applications such as aerospace, defense, automotive sectors. The purpose of designing Metal Matrix Composite is to figure the desired qualities of metals and ceramics. The fabrication of the MMC was done by stir casting process. The tensile test, hardness test and impact test were performed on these composite samples to study the mechanical behaviour. The result shows that there is a significant increase in tensile strength for the samples that are processed at the temperature of 750 °C with a higher weight fraction of SiC. Also, the samples made at 850 °C exhibit better hardness and impact strength with increased content of alumina. The internal microstructure of the composites was analyzed by scanning electron microscope.

Effect of supercritical carbon dioxide treatment on structure and mechanical properties of β-nucleated polypropylene processed at different temperatures

Polypropylene (PP) was compounded with β-nucleating agent and injection-molded at 180 °C or 220 °C. The samples were subsequently treated by supercritical carbon dioxide (scCO2) at different temperatures. Results show that processing temperature and scCO2 treatment could strongly influence the tensile and impact properties of β-nucleated PP. In particular, the sample processed at 220 °C and treated at 120 °C exhibit much enhanced impact strength (4.8 times that of its untreated counterpart). FTIR, WAXD, SEM and DMA were performed to explore the effects of processing temperature and scCO2 treatment on structure of the samples. Deformation-induced plastic flow and micro-voids were also evaluated to construct structure-property relations. It was found that the influence of processing temperature on mechanical properties is mainly associated with the β-form content and β-crystalline morphology, while the structural changes in the crystalline lamellar scale may be responsible for the toughening effect of scCO2 treatment.

Influence of process temperature and salting methods on starter and NSLAB growth and enzymatic activity during the ripening of cheeses produced with Streptococcus thermophilus and Lactobacillus helveticus

The effect of varying cook temperature (40 or 50 °C) and salting method (dry or brine salting) on bacterial viability, enzymatic activity and chemical composition in cheeses made using Streptococcus thermophilus and Lactobacillus helveticus were investigated. Dry salting resulted in decreased cell viability of L. helveticus, increased lactate dehydrogenase activity and increased free amino acid levels, compared with brine salted cheeses, irrespective of cook temperature. A cook temperature of 50 °C resulted in reduced primary proteolysis and increased pH in comparison with that in cheeses cooked to 40 °C. Salting method influenced moisture content with higher levels in brine salted cheeses; cook temperature was also influential with higher cook temperature resulting in lower moisture within each salting method. Variations in manufacture procedure can allow for the development of cheese varieties with novel flavour and texture profiles using existing Cheddar or Swiss-style manufacturing facilities.

Influence of Sintering Temperature on the Microstructure and Mechanical Properties of In Situ Reinforced Titanium Composites by Inductive Hot Pressing.

This research is focused on the influence of processing temperature on titanium matrix composites reinforced through Ti, Al, and B4C reactions. In order to investigate the effect of Ti-Al based intermetallic compounds on the properties of the composites, aluminum powder was incorporated into the starting materials. In this way, in situ TixAly were expected to form as well as TiB and TiC. The specimens were fabricated by the powder metallurgy technique known as inductive hot pressing (iHP), using a temperature range between 900 °C and 1400 °C, at 40 MPa for 5 min. Raising the inductive hot pressing temperature may affect the microstructure and properties of the composites. Consequently, the variations of the reinforcing phases were investigated. X-ray diffraction, microstructural analysis, and mechanical properties (Young’s modulus and hardness) of the specimens were carried out to evaluate and determine the significant influence of the processing temperature on the behavior of the composites.