Min Processing Time Research Articles

Synthesis and thermoelectric properties of Sb0.20CoSb2.80 skutterudite

Polycrystalline samples of cobalt antimonide (CoSb2.79) were submitted to different conditions of pressure, temperature and processing time, in a high-pressure toroidal-type chamber, aiming to maximize the production of the high pressure phase previously observed in experiments with a diamond anvil cell. Rietveld refinements of X-ray powder diffraction data were performed to determine the phase composition and structural parameters. The maximum yield, 89(2)wt.% of SbxCoSb3−x phase, was obtained at 7.7GPa, 550°C and (at least) 5min of processing time. The mechanism behind the formation of SbxCoSb3−x at high pressure and high temperature is actually not the same as that previously inferred from experiments at higher pressures (20GPa) and room temperature with the diamond anvil cell. Indeed, evidences suggest that, at high pressure and high temperature, SbxCoSb3−x is formed by insertion of Sb resulting from decomposition of cobalt antimonide. Thermal conductivity, Seebeck coefficient and electrical conductivity were estimated for CoSb2.79 and Sb0.20CoSb2.80. The thermoelectric figure of merit at room temperature for Sb0.20CoSb2.80 resulted 33% greater than that for CoSb2.79.

Study on the Degumming Process of Abelmoschus Manihot (L.) Medik by Microwave-Assisted Treatment

In this study, aiming at the characteristics of Abelmoschus manihot (L.) bast lignin content is high and degumming difficulty, it introduces a new type of degumming methods. Microwave-assisted treatment was used in the degumming process of Abelmoschus manihot (L.) Medik. The effect of NaOH concentration, microwave-assisted treatment time and temperature on the residual gum content in Abelmoschus manihot (L.) Medik fibers were investigated. The result showed that the optimal conditions by microwave-assisted treatment were 50min of processing time,10g/L of NaOH concentration and 95°C of temperature when the residual gum content could reach to 0.96%. Compared with the traditional process, this method significantly shortened the time from 90-240min to 50min. Developed a highly efficient, low energy consumption degumming process, and the Abelmoschus manihot (L.) fiber after the degumming process was be applied to the development and utilization of textile products.

Interfacial reactions and strength properties of diffusion bonded joints of Ti64 alloy and 17-4PH stainless steel using nickel alloy interlayer

Interfacial reactions and strength properties of diffusion bonded joints between Ti64 alloy (Ti64) and 17-4 precipitation hardening stainless steel (PHSS) using a nickel alloy (NiA) as an interlayer was carried out in the temperature range of 800–900°C in steps of 25°C for 45min and at 900°C for 5, 10, 15, 30 and 45min in vacuum. The effects of bonding temperature and time on interface reactions of the bonded joint were characterized by scanning electron microscopy and electron probe microanalyser. The interfaces indicate that Ni–Ti base reaction products are formed at the NiA–Ti64 interface and the PHSS–NiA interface is free from intermetallics up to 875°C for 45min processing temperature and at 900°C up to 15min processing time. The bright regions of Fe5Cr35Ni40Ti15 have been observed within the Ni3Ti intermetallic layer. Fe–Ti and Fe–Cr–Ti bases reaction products have been observed beyond 15min processing time at 900°C temperature. Joint tensile was measured; a high tensile strength of ∼517.6MPa along with ∼6.1% elongation was obtained for bonded joint when processed at 875°C for 45min. The bonded samples were fractured through the NiTi2 intermetallic compounds at NiA–Ti64 interface up to 875°C for 45min and up to 15min at 900°C. However, higher processing temperature, the fracture of the joints took place through the phase mixture of NiTi2+Fe2Ti and β-Ti.

Optimization of a fluorine-free metal-organic deposition to fabricate BaZrO3-doped YBa2Cu3O7−δ film on RABiTS substrates

In this study, we used a systematic route to optimize the fluorine-free MOD process to achieve a high critical current density (Jc) in BaZrO3 (BZO)-doped YBCO films on RABiTS substrates. The BZO content is given by 1 YBCO+x BZO films, where x is moles of BZO per 1 mole of YBCO. We found x = 0.10 to be the optimal BZO content and ∼795–805 °C to be the optimal growth temperature window with 60–90 min processing time. TEM studies show the BZO nanoparticles are ∼20 nm in size and spaced ∼50–100 nm apart. The in-field Jc and the peak pinning force (Fp) of the film grown at the optimal conditions were greatly increased at 77 K relative to pure YBCO films, achieving ∼6.7 GN m−3 at 77 K, H ‖ c in a ∼800 nm thick x = 0.10 film. The angular dependence of in-field Jc measurements also shows greatly reduced angular anisotropy at 1 and 4 T at 77 K due to isotropic pinning by BZO nanoparticles.

Metal type and natural organic matter source for direct filtration electrocoagulation of drinking water

Electrocoagulation (EC) was combined with immediate microfiltration as direct filtration electrocoagulation (DFEC) for dissolved organic carbon (DOC) removal in drinking water from synthetic and natural highly natural organic matter (NOM) impacted waters from three different sources: Suwannee River (Georgia, USA DOC0=13.79mg/L), Nordic Reservoir (Vallsjøen, Norway DOC0=9.03mg/L), and a natural source (Lost Lagoon, Vancouver, Canada DOC0=13.31mg/L). Three anode materials were investigated: iron, aluminum, and zinc, in a batch EC process without rapid mixing, flocculation, or settling. Fifteen seconds of process time with the iron electrode (36mg Fe/L) led to DOC removal of 44%. After 1min of process time, DOC reduction was 65% (zinc)–73 (iron)%, with ∼ 85% reduction (all metals) in UV-abs-254 (UV-abs-254 final=0.06cm−1) for Suwannee NOM. Specific UV absorbance (SUVA—L/mgm) values decreased from 3.1 to 4.2 to under 2.0, indicating removal of high MW fractions of NOM. High performance size exclusion chromatography (HPSEC) fractionation supported SUVA results, showing reductions from 76% of DOC>1450Da to approximately 40% after EC for all metals and Suwannee NOM. EC performed equally well for two different initial DOC concentrations of 13.79 and 21.59mg/L DOC, showing 75% DOC and 89% UV-abs-254 reductions.

Microwave torrefaction of rice straw and pennisetum

Microwave torrefaction of rice straw and pennisetum was researched in this article. Higher microwave power levels contributed to higher heating rate and reaction temperature, and thus produced the torrefied biomass with higher heating value and lower H/C and O/C ratios. Kinetic parameters were determined with good coefficients of determination, so the microwave torrefaction of biomass might be very close to first-order reaction. Only 150W microwave power levels and 10min processing time were needed to meet about 70% mass yield and 80% energy yield for torrefied biomass. The energy density of torrefied biomass was about 14% higher than that of raw biomass. The byproducts (liquid and gas) possessed about 30% mass and 20% energy of raw biomass, and they can be seen as energy sources for heat or electricity. Microwave torrefaction of biomass could be a competitive technology to employ the least energy and to retain the most bioenergy.

The effect of γ‐Irradiation and reactive extrusion on the structure and properties of polycarbonate and starch blends: A work oriented to the recycling of thermoplastic wastes

AbstractPolymer materials with improved properties can be obtained through polymer blends. As a polymer mixture is generally immiscible and incompatible, it is necessary to develop new methods to improve the interfacial adhesion. In this study, polycarbonate‐based extruded thermoplastic were developed by blending polycarbonate with thermoplastic starch using extensive process engineering based on structure–property correlations. Starch was destructurized and plasticized followed by melt‐blending with polycarbonate. The optimal conditions for processing of the thermoplastics blends were found to be 230°C, 2 min of processing time, and 3–6 wt % of glycerol. The effect of γ‐irradiation on the fabrication of the blend was studied. Changes in structure, morphology, and properties resulting from γ‐exposure in the range 0–150 kGy were investigated. Electron spin resonance results revealed that numerous radicals remained trapped in the materials after irradiation even after a long time enabling reactions between starch and polycarbonate. Results obtained from tensile test, differential scanning calorimetry, and dynamic mechanical analysis revealed the relatively good affinity between the two components after blending in a micro‐extruder. Irradiated blends are thermally more stable than those non‐irradiated. Mechanical tests also showed that the efficiency of the irradiation depended greatly on the dose applied to the initial materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Fluidized-bed drying as a feasible method for dehydration of Enterococcus faecium M74

The suitability of fluidized-bed technology for the dehydration of probiotic Enterococcus faecium M74 was evaluated. Fluidized-bed drying was processed by layering the microorganisms on spherical pellets. The impact on cell viability of atomizing air pressure, processing temperature and time was investigated. Using 1.5bar atomizing air pressure, 37°C processing temperature, and 15min processing time provided optimal dehydration condition. Changing these values resulted in excessive stress on the cells and affected the cell viability. Next, we compared the impact on cell viability of fluidized-bed drying with that of freeze-drying. Fluidized-bed drying caused more substantial losses of cell viability. However, viability of cells pre-treated with membrane protective agents such as sucrose or skim milk was less affected by fluidized-bed drying than by freeze-drying, resulted in a minor degree of membrane damage after 2months storage. Comparison of the flow characteristics of freeze-dried cells and fluidized-bed dried cells layered on spherical pellets showed the superior flowability of the latter.Thus, fluidized-bed technology might represent a feasible alternative for the dehydration of probiotics maintaining adequate viability and providing improved flowability for their processing into solid formulations.

Enhancement of Lipid Extraction from Marine Microalga,ScenedesmusAssociated with High-Pressure Homogenization Process

Marine microalga, Scenedesmus sp., which is known to be suitable for biodiesel production because of its high lipid content, was subjected to the conventional Folch method of lipid extraction combined with high-pressure homogenization pretreatment process at 1200 psi and 35°C. Algal lipid yield was about 24.9% through this process, whereas only 19.8% lipid can be obtained by following a conventional lipid extraction procedure using the solvent, chloroform : methanol (2 : 1, v/v). Present approach requires 30 min process time and a moderate working temperature of 35°C as compared to the conventional extraction method which usually requires >5 hrs and 65°C temperature. It was found that this combined extraction process followed second-order reaction kinetics, which means most of the cellular lipids were extracted during initial periods of extraction, mostly within 30 min. In contrast, during the conventional extraction process, the cellular lipids were slowly and continuously extracted for >5 hrs by following first-order kinetics. Confocal and scanning electron microscopy revealed altered texture of algal biomass pretreated with high-pressure homogenization. These results clearly demonstrate that the Folch method coupled with high-pressure homogenization pretreatment can easily destruct the rigid cell walls of microalgae and release the intact lipids, with minimized extraction time and temperature, both of which are essential for maintaining good quality of the lipids for biodiesel production.

Optimization of various extraction methods for quercetin from onion skin using response surface methodology

Quercertin and typical flavonoids present in onion skin draw interest due to bioactive properties. For utilizing quercetin from onion skin, conventional solvent extraction (CSE), microwave assisted extraction (MAE), and ultrasound assisted extraction (UAE) were employed. Statistic models of each method were proposed to estimate the best possible yield of quercertin employing response surface methodology (RSM). The effects of several independent variables including concentration of ethanol, provided power or the temperature, and reaction time were investigated. From 1 g sample of dried onion skin, the highest yield of each method could be achieved at 16.5 min of process time under 59.2°C for CSE with 59.3% ethanol, 117 s for MAE with 69.7% ethanol, and 21.7 min for UAE using power of 606.4 W with 43.8% ethanol. The most productive method was MAE, whose maximum yield was 20.3 and 30.8% higher than UAE and CSE, respectively.

Inactivation kinetics of peroxidase in zucchini (Cucurbita pepo L.) by heat and UV-C radiation

The effect of traditional thermal water blanching, or its combination with a UV-C radiation pre-treatment (11 J/m 2 ), on the inactivation kinetics of peroxidase in zucchini ( Cucurbita pepo L.) was carried out in the temperature range of 80 to 98 °C, and up to 3 min of processing time. Peroxidase inactivation started being noticed only at temperatures around 85 °C. For both treatments, the inactivation kinetics followed a first order reaction with the Arrhenius model describing the temperature dependence of the reaction rate. The obtained kinetic parameters ( k Heat 89.6 °C = 7.37 × 10 − 7 ± 3.47 × 10 − 7 min − 1 and E a Heat = 925 ± 69 kJ mol − 1 ; k Heat 89.6 °C + UV-C = 2.42 × 10 − 5 ± 6.58 × 10 − 6 min − 1 and E a Heat + UV-C = 596 ± 48.8 kJ mol − 1 ) showed that UV-C radiation had a significant contribution to increase the peroxidase degradation rate. These results will help to design new pre-processing conditions for the production of frozen zucchini, using less severe thermal treatments and attempt to minimize quality losses. The use of UV-C radiation in processing creates novel methodologies, which can be complementary to classical techniques, providing reduced processing times and increased efficiency. Having been proved to be particularly useful in sterilization of liquids and surfaces, inhibition of microbial population and in decrease of protein synthesis, its application in combination with the traditional blanching may be in favor of less severe heating treatments. The evaluation of the kinetics of zucchini ( Cucurbita pepo L . ) peroxidase inactivation with the traditional blanching method and combined with ultraviolet radiation suggests that short UV-C treatments may be a useful non-chemical pre-freezing method, allowing the application of shorter blanching times, leading to a product with eventual higher quality retention which is highly relevant to industry. ► Heat blanching + UV-C above 85 °C promoted a synergistic effect on enzyme inactivation. ► Peroxidase heat + UV-C radiation inactivation in zucchini follows first-order kinetics. ► Addition of UV-C radiation to heat blanching favors a less severe blanching treatment. ► A UV-C radiation chamber was conceived by University of Algarve, Portugal.

Synthesis of mullite from sillimanite dissociation through transferred arc plasma torch

The transferred arc plasma process is characterized by extremely high temperatures, low environmental impact and short processing time. By virtue of high temperature and power density it paves the way for a high production rate. Hence an experiment was undertaken to synthesize mullite from the dissociation of sillimanite through thermal plasma processing. For this purpose, a transferred arc plasma (TAP) torch was specially designed on laboratory scale level and the operating parameters were optimized in order to achieve a maximum percentage of mullite with time and cost effectiveness. The phase and microstructure formation of the processed samples were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) images. The obtained results clearly show that the torch input power and processing time strongly influence the mullite microstructure and phase formation. The present TAP torch processing gives maximum percentage of mullite (95%) through sillimanite dissociation at 15 kW power level with 4 min of processing time.

Fast crystallization of lactose and milk powder in fluidized bed dryer/crystallizer

The rationale of this study has been to produce stabilized dairy powders for longer-term ambient storage by partial crystallization of the sticky amorphous lactose component in vibrated fluidized beds. Various combinations of temperatures, humidities, and processing times were used to crystallize lactose and milk powder in a fluidized bed dryer/crystallizer to achieve different degrees of amorphicity of powder. Under these conditions, lactose crystallinity and the crystallinity of the lactose portion in milk powder were found to increase significantly compared with the amorphous powders that were produced by conventional spray dryers. Different analytical techniques were used to investigate the degree of amorphicity and the improvement in powder crystallinity, such as modulated differential scanning calorimetry, water-induced crystallization, and Raman spectroscopy. The resulting powders were not sticky and were produced by different experimental conditions of processing temperature as 50–70 °C and 40% relative humidity in 30–60 min processing time. This technique is able to crystallize amorphous lactose and lactose-containing powder after spray drying in a reasonable processing time.

Microwave enhanced stabilization of copper in artificially contaminated soil

Microwave processing was used to stabilize copper ions in soil samples. Its effects on the stabilization efficiency were studied as a function of additive, microwave power, process time, and reaction atmosphere. The stabilization efficiency of the microwave process was evaluated based on the results of the toxicity characteristic leaching procedure (TCLP) test. The results showed that the optimal experimental condition contained a 700W microwave power, 20 min process time and 3 iron wires as the additive, and that the highest stabilization efficiency level was more than 70%. In addition, the different reaction atmospheres showed no apparent effect on the stabilization efficiency of copper in the artificially contaminated soil. According to the result of the Tessier sequential extraction, the partial species of copper in the contaminated soil was deduced to transform from unstable species to stable states after the microwave process.

Sesame cake protein hydrolysis by alcalase: Effects of process parameters on hydrolysis, solubilisation, and enzyme inactivation

We investigated the effects of process parameters (substrate concentration, enzyme concentration, temperature and pH) on the hydrolysis and solubilization of sesame cake protein as well as enzyme stability. The sesame cake protein was hydrolyzed by Alcalase enzyme (a bacterial protease produced by a selected strain of Bacillus Licheniformis) that was chosen among five commercial enzymes examined. The optimum process conditions for hydrolysis and solubilization were obtained as 15 g L−1 substrate concentration, 3 ml L−1 enzyme concentration, 50 °C and pH 8.5. Under these conditions, the values of degree of hydrolysis and solubilization were found as 26.3% and 82.1%, respectively, and enzyme lost its activity by approx. 56% at the end of 120 min processing time. Modeling studies were performed to determine the kinetics of hydrolysis, solubilization and enzyme inactivation. The relationship between hydrolysis and solubilization was found linear for all experimental conditions examined. The inactivation energy of Alcalase at the temperature range of 45–55 °C was determined to be 25544 J mol−1.

고로쇠 수피 초고압 추출물의 항암활성 증진

본 연구에서는 초고압 공정을 통하여 기존의 일반 열수추출공정과 비교함으로써 초고압 공정에 의한 항산화 활성 증진 및 항암활성 증진 효과를 확인하였다. 기존의 추출공정과 비교하여 높은 압력 하에서 추출수율이 증가한 것은 시료의 세포막이 비가역적으로 분해되어 막 투과성이 증가되어 물질 이동이 용이하게 되어 용매가 세포 안으로 들어가 보다 많은 성분이 세포 밖으로 쉽게 용출되어 나오는 결과라고 추정된다. DPPH radical 소거활성을 측정한 결과, 네 가지의 추출물 중 15분간 초고압 처리한 추출물의 활성이 1.0㎎/mL의 농도에서 94.56%로 가장 높은 활성을 보였고, 또한 BHA의 93.24%보다 높은 활성을 보였다. SOD 유사활성 결과를 살펴보면 15분간 초고압 처리를 한 추출물의 활성이 모든 농도에서 대조군으로 비교한 BHA의 활성보다 높았고, 열수추출의 활성보다 높은 결과를 나타내었다. 인간의 정상폐 세포인 HEL299를 이용한 세포 독성은 초음파 공정을 15분간 처리한 추출물 1.0 ㎎/mL의 농도에서 20.12%로, 일반 열수 추출물의 24.53%보다 낮은 세포독성을 나타내어 초고압 공정을 통한 세포독성 저감 효과를 확인할 수 있었다. 또한 인간 정상 신장 세포인 HEK293을 이용한 세포 독성실험에서도 1.0 ㎎/mL의 농도에서 초고압 처리를 15분 동안 한 추출물이 23.54%를 나타내어 일반 열수 추출물보다 약 3% 낮은 독성을 보였다. 암세포 억제활성 측정은 AGS, A549, MCF-7, Hep3B, Caco-2의 세포를 이용하여 실험을 하였다. 위의 4가지 암세포에서 1.0 ㎎/mL의 농도에서 70% 이상의 높은 암세포 억제 활성을 보였고, 암세포의 생육활성에 대한 정상 세포의 세포독성의 비로 나타낸 선택적사멸도는 1.0 ㎎/mL의 농도에서 4 정도로 나타났으며, 초고압 공정에 의한 추출물의 사멸도가 높게 나타났다. 본 실험 결과를 통하여 기존의 일반 열수 추출에 비해 초고압 공정을 통한 추출물의 수율향상 및 세포독성 저감 효과를 확인할 수 있었는데, 이는 초고압에 의한 고로쇠 수피 표면조직의 파괴와 성분 변화로 인한 유용물질 및 신물질의 대량 용출과 함께 독성물질이 파괴되거나 변성되어 나타난 결과라고 생각된다. 또한 항산화 활성 및 항암활성 증진효과를 확인할 수 있었는데 이를 통해 고로쇠나무의 항산화제 및 항암 신소재로의 가능성을 확인할 수 있었다. 더 나아가 초고압 공정에 의해 용출된 성분의 분리 및 성분 분석에 관한 연구가 더 필요할 것으로 사료된다.

Rapid detection of anti-chromatin autoantibodies in human serum using a portable electrochemical biosensor

The current system employed electrochemical sensor technology for the measurement of autoantibodies in human sera. Anti-chromatin antibodies are an early and sensitive indicator of systemic lupus erythematosus (SLE) and are typically quantified using enzyme-linked immunosorbent assays (ELISA). Electrochemical detection compared favorably with ELISA using a sample of 30 SLE sera (r=0.9), and non-specific binding by normal serum immunoglobulin was undetectable. The electrochemical sensor assay required <20min processing time and utilized a hand-held apparatus with a disposable electrode. These results demonstrate the applicability of this technology to the rapid measurement of a clinically relevant analyte with an apparatus of potential simplicity and low cost.

Automatic body feature extraction from a marker-less scanned human body

In this paper, we propose a novel method of body feature extraction from a marker-less scanned body. The descriptions of human body features mostly defined in ASTM (1999) and ISO (1989) are interpreted into logical mathematical definitions. Using these significant definitions, we employ image processing and computational geometry techniques to identify, automatically, body features from the torso cloud points. We have currently extracted 21 feature points and 35 feature lines on the human torso; this number may be extended if necessary. Moreover, less than 2 min processing time is taken for body feature extraction starting from the raw point cloud. This algorithm is successfully tested on several Asian female adults who are aged from 18 to 60.

XPS studies on aluminum ions modified polyimide with the PIII technique

Polyimide samples modified by aluminum (Al) ions produced by filtered cathodic vacuum arc (FCVA) with plasma immersion ion implantation (PIII) technique, under ambient argon and oxygen gases (flow rate Ar:O2=2:1) were investigated by x-ray photoelectron spectroscopy (XPS). The working pressure was about 8×10−4 Torr and the plasma density was estimated to be 109 ions∕cm3. The applied bias voltages were varied from 5 to 12.5 kV but with fixed frequency at 900 Hz and duty time of 15μs. For 1 min process time, C 1s and O 1s spectra for modified samples clearly indicated that the carbonyl group (C=O) was largely destroyed by incident Al ions while Al 2p spectra suggested Al atoms remain inside polyimide matrices in the form of C-O-Al complexes. For a 5 min process time, when the ion fluence became large, both C 1s and O 1s spectra suggested a structure of “aluminum oxide-mixed layer-polyimide” and Al 2p spectra confirmed that most Al atoms were bonded to oxygen atoms on the top surface. These XPS results revealed the chemical bonds between implanted and deposited Al ions and polyimide matrix by using the PIII technique. The structural information can also be suggested. Furthermore in this paper, some discussions with the theoretical [the stopping and range of ions in matter (SRIM)] simulation were also mentioned in order to explore the effectiveness of Al ions irradiation on polyimide.

Decontamination of food products with superheated steam

Food products can often be contaminated with mycotoxins and spores, many of which are resistant to heat. To ensure the safety of our food supply they must be reduced or eliminated from the final product through processing procedures. The effects of superheated steam (SS) as a processing medium on grains contaminated with the Fusarium mycotoxin deoxynivalenol (DON) and with Geobacillus stearothermophilus spores are presented here. The processing temperature was between 110 and 185 °C with three steam velocities of 0.65, 1.3 and 1.5 m/s for DON contaminated wheat and between 105 and 175 °C at one steam velocity of 0.35 m/s for mixture of sand and spores. Reductions in DON concentration of up to 52% were achieved at 185 °C and 6 min processing time. This was due only to thermal degradation and not to solubilization and extraction. The effect of processing with SS on heat resistant spores was conducted for processing times of 0.5–480 min. The thermal resistance constant for G. stearothermophilus was determined to be 28.4 °C for the SS processing temperature of 130–175 °C. The first 5 min of SS processing were most effective in the reduction of spores. The use of SS has proven itself to be beneficial by reducing the contamination in foods in addition to any drying that may occur.