Process Time (process + time)

Distribution by Scientific Domains


Selected Abstracts


Thermal processing of prawn ,kuruma' in retortable pouches and aluminium cans

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2008
Chitradurga O. Mohan
Summary Prawn ,kuruma' was prepared from Indian white shrimp (Fenneropenaeus indicus), packed in conventional 301 × 206 and 401 × 411 aluminium cans and in thin profile retort pouches having a three-layer configuration of 12.5 , polyester, 12.5 , aluminium foil and 85 , cast polypropylene of size 16 × 20 cm and 17 × 30 cm. The physico-chemical tests conducted on these containers showed their suitability for thermal processing. Prawn to kuruma ratio of 65:35 was maintained in all the containers and heat processed to equal lethality in an over pressure autoclave with the facility to record the time,temperature data, F0 value and cook value. The process time was calculated by using formula method. The processing in 16 × 20 cm and 17 × 30 cm retortable pouch resulted in 35.67% and 56.56% reduction in process time compared with 301 × 206 and 401 × 411 cans, respectively, with equal pack weight. The amino acid content did not vary considerably in both containers. In the canned samples the reduction of sulfhydryl content was 50.54% more when compared with the pouched product. Products packed in pouches were found to be superior to canned products with regard to sensory and textural attributes such as colour, firmness, hardness, chewiness, and overall acceptability. [source]


The use of sodium formate for the recovery of precious metals from acidic base metal effluents

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2001
Herman G Julsing
Abstract Zinc was used for the reduction of the platinum group metals (PGMs) in acidic effluents. Due to the increasing cost of zinc, sodium formate was investigated as an alternative reductant. In a base metal-containing acidic effluent, called diethylenetriamine barren, sodium formate was used to precipitate the PGMs. This effluent was the filtrate obtained after a precipitation procedure had been used to remove rhodium and iridium. It was found that pH 1.5 was the optimum starting pH for sodium formate reduction. The pH increased to approximately 4.5 after the addition of sodium formate. The optimum concentration of sodium formate was found to be 30,g,dm,3 at a temperature of 100,°C where the process time was 6,h. Platinum and palladium were the most effectively reduced PGMs, both exhibiting an average precipitation efficiency of greater than 99%. Difficulty was experienced with the precipitation of iridium (average precipitation efficiency of 76%). The precipitated PGMs readily dissolved in hydrochloric acid (6,M) and sodium chlorate (2%). A reduction in costs resulted from the discontinuation of the use of zinc for reduction purposes. An additional advantage was that zinc was no longer introduced into the PGM refinery circuits. © 2001 Society of Chemical Industry [source]


A randomized comparison of plateletpheresis with the same donors using four blood separators at a single blood center,

JOURNAL OF CLINICAL APHERESIS, Issue 4 2002
Grace C. Tenorio
Abstract At one blood center, each of 20 donors underwent plateletpheresis on four blood cell separators in random order. We compared the CS3000+, Amicus V 2.41, MCS Plus, and Spectra LRS V 7 Turbo regarding platelet (PLT) yield, pre- and post-procedure PLT counts, percent fall in donor PLT count, process time, efficiency, PLT product and donor PLT volume (MPV). Using , 150 × 109 PLTs/L pre-donation counts, a goal was set of 4.5 × 1011 PLTs unit in up to 100 minutes processing time. Results were (mean values) PLT yields of Amicus, Spectra, CS3000+, and MCS Plus: 4.3, 4.6, 4.3, 4.0 × 1011 PLTS, respectively; percent donor PLT fall: 24, 32, 30, 29%, respectively; processing times: 50, 74, 87, 101 minutes, respectively; relative efficiency (RE): 2.2, 1.6, 1.2,1.0, respectively (based on the MCS Plus performance with RE of 1 = 4 × 109 PLTS/min); PLT product MPV: 6.7, 7.4, 6.8,7.1 fL, respectively; pre-procedure donor MPV: 7.7, 7.3, 7.6 and 7.6 fL, respectively; and percent donor MPV change: ,5.2, 0, ,6.6, and ,10%, respectively. Significant changes in the donor MPV were noted (P < 0.05) but could not be related to product MPV. Spectra seemed to collect larger PLTs (higher MPV); the significance remains unknown for both donors and recipients. Importantly, all four separators gave acceptable and comparable PLT yields (P < 0.05) with Spectra trending higher. The short process time and high RE together indicate highly efficient collections particularly by Amicus and Spectra. J. Clin. Apheresis 17:170,176, 2002. © 2002 Wiley-Liss, Inc. [source]


SCALE-UP and FIELD TEST of the VACUUM/STEAM/VACUUM SURFACE INTERVENTION PROCESS FOR POULTRY,

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2003
MICHAEL KOZEMPEL
ABSTRACT The Vacuum/Steam/Vacuum surface intervention pilot plant processor was scaled up to a mobile unit that can be transported to close proximity of chicken processing plants. After several modifications to the mandrel that supports the broiler carcass in the treatment chamber to minimize mechanical damage, the unit was capable of 1.1 log cfu/mL kill of inoculated Listeria innocua and 1.4 log cfu/mL kill of inoculated E. coli K-12. Field tests achieved 1.4 log kill of E. coli and 1.2 log kill of Campylobacter on freshly processed chicken using 3 cycles and 138C saturated steam. But, there was extensive mechanical damage. the mandrel was modified in the Eastern Regional Research Center pilot plant to eliminate the mechanical damage. With mechanical damage eliminated, the bacteria kill was 1.1,1.5 log of inoculated E. coli K-12 with a total process time of 1.1 s. [source]


Quality Evaluation of Pinto Beans and Green Beans Canned in Two Large Reusable Containers

JOURNAL OF FOOD SCIENCE, Issue 6 2003
W.G. McGlynn
ABSTRACT: As an alternative to standard metal cans, 2 large-scale, reusable containers were constructed with volumetric capacities 3.6 to 3.8 times greater and process times 1.36 to 2.05 times longer than a nr 10 can. Effects of increased process time on product quality were measured by conducting objective color and texture evaluations on green beans and pinto beans canned in both containers. Green beans and pinto beans had comparable texture profiles to beans processed conventionally in nr 10 cans. The color of green beans also was comparable; the color of pinto beans was darker, possibly due to contact with the metal container. Color and texture differences were minimal between inner and outer product layers. [source]


Energy Consumption, Density, and Rehydration Rate of Vacuum Microwave- and Hot-Air Convection- Dehydrated Tomatoes

JOURNAL OF FOOD SCIENCE, Issue 6 2002
T.D. Durance
ABSTRACT: Vacuum to lower boiling temperature and microwaves for energy transfer can provide very rapid dehydration at low temperatures. Tomato sections were dehydrated in a batch convection air dryer (AD), a 16 kW vacuum microwave (VM) dryer, or by 1 of 3 combination processes. Drying rate of the 100% VM process was 18 times that of the 100% AD process. Only a slight falling rate effect was noted in VM drying AD and VM in sequence allowed the operator to choose any process time between 0.8 and 14.75 h. In this instance the least energy consumption occurred in the 100% VM process. Lowest energy cost was found for the 70% AD / 30% VM process. These results are expected to be strongly dependent upon the scale and design of dryers. Tomatoes finish-dried by VM exhibited a puffed structure associated with faster rehydration. [source]


Pressureless Rapid Sintering of UO2 Assisted by High-frequency Induction Heating Process

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008
Jae Ho Yang
Heat generation of uranium dioxide (UO2) powder and its pressureless rapid sintering behaviors have been studied using a high-frequency induction heating apparatus. The porous graphite housing has been used to prevent heat loss and to preheat the uranium oxides, simultaneously. At an elevated temperature, UO2 powder generated extra heat by itself. The synergism of individual heat generation between the graphite and UO2 powder could effectively heat the UO2 to the sintering temperature of 1700°C. Using this process, densification behavior of cylindrical and disk-type UO2 green pellets according to the heating rate and grain structure of sintered UO2 pellets were investigated. Rapid sintering caused a large crack around the circumference of the sintered pellet. The formation of cracks could be avoided when the heating rate or sample dimension are properly reduced. A dense and crack-free UO2 pellet with a relative density of up to 96% was produced within 5 min of the process time. The induction heat sintering process can be a potential candidate for the rapid fabrication of ceramics and composites. [source]


An Integrated Atmospheric Microwave Plasma Source

PLASMA PROCESSES AND POLYMERS, Issue S1 2009
Reinhold Kovacs
Abstract Atmospheric plasma processes become more and more popular in recent times. A new integrated atmospheric plasma source is presented which consists of a microwave resonator combined with a solid-state power oscillator. This allows for a very compact and efficient design of a microwave plasma source without external microwave power supply and matching units. Hydrophobic polymers have to be activated to ensure an effective painting or glueing. The performance of this new plasma source has been investigated with respect to surface activation depending on axial and radial distance to the substrate, process time, process gas, and flow velocity. Several polymeric materials have been compared. Polyethylene, polyamide, polystyrene, polypropylene, polycarbonate, and polytetrafluorineethylene show good activation results. This tool can be used especially for bulky goods and/or mass products, when a vacuum process is not possible or too expensive. [source]


Analyses of Thick Lithium Coatings Deposited by Sputter-Evaporation and Exposed to Air

PLASMA PROCESSES AND POLYMERS, Issue S1 2009
C. Rigaux
Abstract Lithium coatings on various substrates have numerous applications: Boron neutron capture therapy, neutron activation analysis, super-conducting tokamak etc. Traditionally these coatings are produced by well-known techniques such as electrochemistry and evaporation. In this work, we investigated a new method based on sputter-evaporation, which enables thick coatings (>10,µm) to be built on various substrates within a short timeframe. In order to minimize the process time, evaporation techniques can be used but the coating quality suffers. Moreover, it is well known that the use of DC magnetron sputtering results in the deposition of good quality coatings (smoothness, density, adhesion); however, the deposition rate is low. The rationale of this work is to combine these two techniques, yielding a sputter-evaporation process that possesses the advantages of each separate technique. Li is placed in a stainless steel crucible (cathode), and heated by the plasma generated by a magnetron discharge. The Li temperature is measured by a thermocouple welded onto the cathode and measured at different plasma power densities. The deposition rate of lithium is measured using a quartz balance and by profilometry, at several temperatures (from 0 to 580,°C). Li samples were depth-profiled with the resonant nuclear reaction 7Li(p,,)7. In addition to the concentration, certain characteristics like the density and the chemical reactivity of layers, are also important. Thus we have studied the evolution of the density with time, estimated by weight and profilometry measurements, and the change in morphology, by cross-sectional scanning electron microscopy (SEM), of samples exposed to air at room temperature. The evolution of the film compounds have also been determined by X-ray powder diffraction. These physical properties have been investigated for various bias substrates during deposition. [source]


Machining of plastics: A new approach for modeling

POLYMER ENGINEERING & SCIENCE, Issue 3 2008
F. Quadrini
A theoretical model was defined to predict cutting forces in drilling of polyamide. This model was not built in analogy to metal cutting but starting from the viscoelastic behavior of the workpiece material. The drilling thrust and torque were assumed to be a logarithmic function of the ratio between a characteristic time of the material and a process time. Drilling tests were carried out to experimentally evaluate the thrust and torque in dependence of drilling speed and feed rate. The experimental data are in good agreement with the predicted logarithmic trend, except at high feed rates at which a plateau is observed. The chip formation mechanism was recognized to affect the thrust and torque dependence on feed rate so that the theoretical model was opportunely corrected. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers [source]


Improvement of charge minority-carrier lifetime in p(boron)-type Czochralski silicon by rapid thermal annealing

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 6 2001
Ji Youn Lee
In p -type Czochralski-grown (Cz) silicon a light-induced degradation of the minority-carrier lifetime is well known in the literature. Reducing the extent of this degradation would significantly improve the stable effective lifetime and thus the related performance of solar cells. In this work, the reduction of the density of the metastable defect underlying the degradation is performed by rapid thermal annealing (RTA). For a proper analysis it is extremely important to avoid contamination by the RTA furnace. Both, SiNx and SiO2 were examined as a barrier layer. A 60 nm SiNx layer was proven to act as the most effective barrier layer, allowing maintenance of a very high lifetime of 700,,s on 1.25 ,,cm p -type FZ material. A design-of-experiments (DOE) study was used to analyze the effect of five process parameters on the stable effective lifetime. Especially, the plateau temperature shows a strong correlation with ,d, the stable effective lifetime after light-induced degradation. The effect of plateau temperature on ,d of Cz- and FZ-Si wafers is examined in the temperature range of 700,1050°C for plateau time 120 s. It was found that the stable effective lifetime of all RTA-treated Cz-wafers is increased compared with the initial stable effective lifetime before processing. The highest increase of stable effective lifetime (by a factor of around 2) is obtained at 900°C with a process time of 120 s. This increase in lifetime is reflected in a reduced concentration of the metastable defect. Copyright © 2001 John Wiley & Sons, Ltd. [source]


New milliliter-scale stirred tank bioreactors for the cultivation of mycelium forming microorganisms

BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010
Ralf Hortsch
Abstract A novel milliliter-scale stirred tank bioreactor was developed for the cultivation of mycelium forming microorganisms on a 10 milliliter-scale. A newly designed one-sided paddle impeller is driven magnetically and rotates freely on an axis in an unbaffled reaction vessel made of polystyrene. A rotating lamella is formed which spreads out along the reactor wall. Thus an enhanced surface-to-volume ratio of the liquid phase is generated where oxygen is introduced via surface aeration. Volumetric oxygen transfer coefficients (kLa),>,0.15,s,1 were measured. The fast moving liquid lamella efficiently prevents wall growth and foaming. Mean power consumption and maximum local energy dissipation were measured as function of operating conditions in the milliliter-scale stirred tank bioreactor (V,=,10,mL) and compared to a standard laboratory-scale stirred tank bioreactor with six-bladed Rushton turbines (V,=,2,000,mL). Mean power consumption increases with increasing impeller speed and shows the same characteristics and values on both scales. The maximum local energy dissipation of the milliliter-scale stirred tank bioreactor was reduced compared to the laboratory-scale at the same mean volumetric power input. Hence the milliliter impeller distributes power more uniformly in the reaction medium. Based on these data a reliable and robust scale-up of fermentation processes is possible. This was demonstrated with the cultivation of the actinomycete Streptomyces tendae on both scales. It was shown that the process performances were equivalent with regard to biomass concentration, mannitol consumption and production of the pharmaceutical relevant fungicide nikkomycin Z up to a process time of 120,h. A high parallel reproducibility was observed on the milliliter-scale (standard deviation,<,8%) with up to 48 stirred tank bioreactors operated in a magnetic inductive drive. Rheological behavior of the culture broth was measured and showed a highly viscous shear-thinning non-Newtonian behavior. The newly developed one-sided paddle impellers operated in unbaffled reactors on a 10 milliliter-scale with a magnetic inductive drive for up to 48 parallel bioreactors allows for the first time the parallel bioprocess development with mycelium forming microorganisms. This is especially important since these kinds of cultivations normally exhibit process times of 100,h and more. Thus the operation of parallel stirred tank reactors will have the potential to reduce process development times drastically. Biotechnol. Bioeng. 2010; 106: 443,451. © 2010 Wiley Periodicals, Inc. [source]


Application of immobilized bovine enterokinase in repetitive fusion protein cleavage for the production of mucin 1

BIOTECHNOLOGY JOURNAL, Issue 11 2009
Tina Kubitzki
Abstract Bovine enterokinase is a serine protease that catalyzes the hydrolysis of peptide bonds and plays a key role in mammalian metabolism. Because of its high specificity towards the amino acid sequence (Asp)4 -Lys, enterokinase is a potential tool for the cleavage of fusion proteins, which are gaining more importance in biopharmaceutical production. A candidate for adaptive cancer immunotherapy is mucin 1, which is produced recombinantly as a fusion protein in CHO cells. Here, we present the first repetitive application of immobilized enterokinase for the cleavage of the mucin fusion protein. The immobilization enables a facile biocatalytic process due to simplified separation of the biocatalyst and the target protein. Immobilized enterokinase was applied in a maximum of 18 repetitive reactions. The enzyme utilization (total turnover number) was increased significantly 419-fold compared to unbound enzyme by both immobilization and optimization of process conditions. Slight enzyme inactivation throughout the reaction cycles was observed, but was compensated by adjusting the process time accordingly. Thus, complete fusion protein cleavage was achieved. Furthermore, we obtained isolated mucin 1 with a purity of more than 90% by applying a simple and efficient purification process. The presented results demonstrate enterokinase to be an attractive tool for fusion protein cleavage. [source]


Emergency Department Patient Volume and Troponin Laboratory Turnaround Time

ACADEMIC EMERGENCY MEDICINE, Issue 5 2010
Ula Hwang MD
Abstract Objectives:, Increases in emergency department (ED) visits may place a substantial burden on both the ED and hospital-based laboratories. Studies have identified laboratory turnaround time (TAT) as a barrier to patient process times and lengths of stay. Prolonged laboratory study results may also result in delayed recognition of critically ill patients and initiation of appropriate therapies. The objective of this study was to determine how ED patient volume itself is associated with laboratory TAT. Methods:, This was a retrospective cohort review of patients at five academic, tertiary care EDs in the United States. Data were collected on all adult patients seen in each ED with troponin laboratory testing during the months of January, April, July, and October 2007. Primary predictor variables were two ED patient volume measures at the time the troponin test was ordered: 1) number of all patients in the ED/number of beds (occupancy) and 2) number of admitted patients waiting for beds/beds (boarder occupancy). The outcome variable was troponin turnaround time (TTAT). Adjusted covariates included patient characteristics, triage severity, season (month of the laboratory test), and site. Multivariable adjusted quantile regression was carried out to assess the association of ED volume measures with TTAT. Results:, At total of 9,492 troponin tests were reviewed. Median TTAT for this cohort was 107 minutes (interquartile range [IQR] = 73,148 minutes). Median occupancy for this cohort was 1.05 patients (IQR = 0.78,1.38 patients) and median boarder occupancy was 0.21 (IQR = 0.11,0.32). Adjusted quantile regression demonstrated a significant association between increased ED patient volume and longer times to TTAT. For every 100% increase in census, or number of boarders over the number of ED beds, respectively, there was a 12 (95% confidence interval [CI] = 9 to 14) or 33 (95% CI = 24 to 42)-minute increase in TTAT. Conclusions:, Increased ED patient volume is associated with longer hospital laboratory processing times. Prolonged laboratory TAT may delay recognition of conditions in the acutely ill, potentially affecting clinician decision-making and the initiation of timely treatment. Use of laboratory TAT as a patient throughput measure and the study of factors associated with its prolonging should be further investigated. ACADEMIC EMERGENCY MEDICINE 2010; 17:501,507 © 2010 by the Society for Academic Emergency Medicine [source]


Quality Evaluation of Pinto Beans and Green Beans Canned in Two Large Reusable Containers

JOURNAL OF FOOD SCIENCE, Issue 6 2003
W.G. McGlynn
ABSTRACT: As an alternative to standard metal cans, 2 large-scale, reusable containers were constructed with volumetric capacities 3.6 to 3.8 times greater and process times 1.36 to 2.05 times longer than a nr 10 can. Effects of increased process time on product quality were measured by conducting objective color and texture evaluations on green beans and pinto beans canned in both containers. Green beans and pinto beans had comparable texture profiles to beans processed conventionally in nr 10 cans. The color of green beans also was comparable; the color of pinto beans was darker, possibly due to contact with the metal container. Color and texture differences were minimal between inner and outer product layers. [source]


IMPROVING JOB SHOP PERFORMANCE THROUGH PROCESS QUEUE MANAGEMENT UNDER TRANSFER BATCHING

PRODUCTION AND OPERATIONS MANAGEMENT, Issue 4 2000
JOEL LITCHFIELD
This research investigated the value of protecting the continuity of release batchs in a transfer batching environment, by modifying the SPT rule. A simulation model of a job shop was used to test the modified SPT rule. The performance measures evaluated were mean flow time, flow time variance, and mean lateness. Conditions under which the SPT modification improved results were as follows: large number of transfer batches, small setup time to process time ratio, and large variation in process times from station to station. The results suggest that shop loading is not a significant factor affecting performance of the modified SPT rule. [source]


New milliliter-scale stirred tank bioreactors for the cultivation of mycelium forming microorganisms

BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010
Ralf Hortsch
Abstract A novel milliliter-scale stirred tank bioreactor was developed for the cultivation of mycelium forming microorganisms on a 10 milliliter-scale. A newly designed one-sided paddle impeller is driven magnetically and rotates freely on an axis in an unbaffled reaction vessel made of polystyrene. A rotating lamella is formed which spreads out along the reactor wall. Thus an enhanced surface-to-volume ratio of the liquid phase is generated where oxygen is introduced via surface aeration. Volumetric oxygen transfer coefficients (kLa),>,0.15,s,1 were measured. The fast moving liquid lamella efficiently prevents wall growth and foaming. Mean power consumption and maximum local energy dissipation were measured as function of operating conditions in the milliliter-scale stirred tank bioreactor (V,=,10,mL) and compared to a standard laboratory-scale stirred tank bioreactor with six-bladed Rushton turbines (V,=,2,000,mL). Mean power consumption increases with increasing impeller speed and shows the same characteristics and values on both scales. The maximum local energy dissipation of the milliliter-scale stirred tank bioreactor was reduced compared to the laboratory-scale at the same mean volumetric power input. Hence the milliliter impeller distributes power more uniformly in the reaction medium. Based on these data a reliable and robust scale-up of fermentation processes is possible. This was demonstrated with the cultivation of the actinomycete Streptomyces tendae on both scales. It was shown that the process performances were equivalent with regard to biomass concentration, mannitol consumption and production of the pharmaceutical relevant fungicide nikkomycin Z up to a process time of 120,h. A high parallel reproducibility was observed on the milliliter-scale (standard deviation,<,8%) with up to 48 stirred tank bioreactors operated in a magnetic inductive drive. Rheological behavior of the culture broth was measured and showed a highly viscous shear-thinning non-Newtonian behavior. The newly developed one-sided paddle impellers operated in unbaffled reactors on a 10 milliliter-scale with a magnetic inductive drive for up to 48 parallel bioreactors allows for the first time the parallel bioprocess development with mycelium forming microorganisms. This is especially important since these kinds of cultivations normally exhibit process times of 100,h and more. Thus the operation of parallel stirred tank reactors will have the potential to reduce process development times drastically. Biotechnol. Bioeng. 2010; 106: 443,451. © 2010 Wiley Periodicals, Inc. [source]